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1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 // SPDX-License-Identifier: GPL-2.0-only /* * lib/bitmap.c * Helper functions for bitmap.h. */ #include <linux/export.h> #include <linux/thread_info.h> #include <linux/ctype.h> #include <linux/errno.h> #include <linux/bitmap.h> #include <linux/bitops.h> #include <linux/bug.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/uaccess.h> #include <asm/page.h> #include "kstrtox.h" /** * DOC: bitmap introduction * * bitmaps provide an array of bits, implemented using an an * array of unsigned longs. The number of valid bits in a * given bitmap does _not_ need to be an exact multiple of * BITS_PER_LONG. * * The possible unused bits in the last, partially used word * of a bitmap are 'don't care'. The implementation makes * no particular effort to keep them zero. It ensures that * their value will not affect the results of any operation. * The bitmap operations that return Boolean (bitmap_empty, * for example) or scalar (bitmap_weight, for example) results * carefully filter out these unused bits from impacting their * results. * * The byte ordering of bitmaps is more natural on little * endian architectures. See the big-endian headers * include/asm-ppc64/bitops.h and include/asm-s390/bitops.h * for the best explanations of this ordering. */ int __bitmap_equal(const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int bits) { unsigned int k, lim = bits/BITS_PER_LONG; for (k = 0; k < lim; ++k) if (bitmap1[k] != bitmap2[k]) return 0; if (bits % BITS_PER_LONG) if ((bitmap1[k] ^ bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) return 0; return 1; } EXPORT_SYMBOL(__bitmap_equal); bool __bitmap_or_equal(const unsigned long *bitmap1, const unsigned long *bitmap2, const unsigned long *bitmap3, unsigned int bits) { unsigned int k, lim = bits / BITS_PER_LONG; unsigned long tmp; for (k = 0; k < lim; ++k) { if ((bitmap1[k] | bitmap2[k]) != bitmap3[k]) return false; } if (!(bits % BITS_PER_LONG)) return true; tmp = (bitmap1[k] | bitmap2[k]) ^ bitmap3[k]; return (tmp & BITMAP_LAST_WORD_MASK(bits)) == 0; } void __bitmap_complement(unsigned long *dst, const unsigned long *src, unsigned int bits) { unsigned int k, lim = BITS_TO_LONGS(bits); for (k = 0; k < lim; ++k) dst[k] = ~src[k]; } EXPORT_SYMBOL(__bitmap_complement); /** * __bitmap_shift_right - logical right shift of the bits in a bitmap * @dst : destination bitmap * @src : source bitmap * @shift : shift by this many bits * @nbits : bitmap size, in bits * * Shifting right (dividing) means moving bits in the MS -> LS bit * direction. Zeros are fed into the vacated MS positions and the * LS bits shifted off the bottom are lost. */ void __bitmap_shift_right(unsigned long *dst, const unsigned long *src, unsigned shift, unsigned nbits) { unsigned k, lim = BITS_TO_LONGS(nbits); unsigned off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; unsigned long mask = BITMAP_LAST_WORD_MASK(nbits); for (k = 0; off + k < lim; ++k) { unsigned long upper, lower; /* * If shift is not word aligned, take lower rem bits of * word above and make them the top rem bits of result. */ if (!rem || off + k + 1 >= lim) upper = 0; else { upper = src[off + k + 1]; if (off + k + 1 == lim - 1) upper &= mask; upper <<= (BITS_PER_LONG - rem); } lower = src[off + k]; if (off + k == lim - 1) lower &= mask; lower >>= rem; dst[k] = lower | upper; } if (off) memset(&dst[lim - off], 0, off*sizeof(unsigned long)); } EXPORT_SYMBOL(__bitmap_shift_right); /** * __bitmap_shift_left - logical left shift of the bits in a bitmap * @dst : destination bitmap * @src : source bitmap * @shift : shift by this many bits * @nbits : bitmap size, in bits * * Shifting left (multiplying) means moving bits in the LS -> MS * direction. Zeros are fed into the vacated LS bit positions * and those MS bits shifted off the top are lost. */ void __bitmap_shift_left(unsigned long *dst, const unsigned long *src, unsigned int shift, unsigned int nbits) { int k; unsigned int lim = BITS_TO_LONGS(nbits); unsigned int off = shift/BITS_PER_LONG, rem = shift % BITS_PER_LONG; for (k = lim - off - 1; k >= 0; --k) { unsigned long upper, lower; /* * If shift is not word aligned, take upper rem bits of * word below and make them the bottom rem bits of result. */ if (rem && k > 0) lower = src[k - 1] >> (BITS_PER_LONG - rem); else lower = 0; upper = src[k] << rem; dst[k + off] = lower | upper; } if (off) memset(dst, 0, off*sizeof(unsigned long)); } EXPORT_SYMBOL(__bitmap_shift_left); int __bitmap_and(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int bits) { unsigned int k; unsigned int lim = bits/BITS_PER_LONG; unsigned long result = 0; for (k = 0; k < lim; k++) result |= (dst[k] = bitmap1[k] & bitmap2[k]); if (bits % BITS_PER_LONG) result |= (dst[k] = bitmap1[k] & bitmap2[k] & BITMAP_LAST_WORD_MASK(bits)); return result != 0; } EXPORT_SYMBOL(__bitmap_and); void __bitmap_or(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int bits) { unsigned int k; unsigned int nr = BITS_TO_LONGS(bits); for (k = 0; k < nr; k++) dst[k] = bitmap1[k] | bitmap2[k]; } EXPORT_SYMBOL(__bitmap_or); void __bitmap_xor(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int bits) { unsigned int k; unsigned int nr = BITS_TO_LONGS(bits); for (k = 0; k < nr; k++) dst[k] = bitmap1[k] ^ bitmap2[k]; } EXPORT_SYMBOL(__bitmap_xor); int __bitmap_andnot(unsigned long *dst, const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int bits) { unsigned int k; unsigned int lim = bits/BITS_PER_LONG; unsigned long result = 0; for (k = 0; k < lim; k++) result |= (dst[k] = bitmap1[k] & ~bitmap2[k]); if (bits % BITS_PER_LONG) result |= (dst[k] = bitmap1[k] & ~bitmap2[k] & BITMAP_LAST_WORD_MASK(bits)); return result != 0; } EXPORT_SYMBOL(__bitmap_andnot); int __bitmap_intersects(const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int bits) { unsigned int k, lim = bits/BITS_PER_LONG; for (k = 0; k < lim; ++k) if (bitmap1[k] & bitmap2[k]) return 1; if (bits % BITS_PER_LONG) if ((bitmap1[k] & bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) return 1; return 0; } EXPORT_SYMBOL(__bitmap_intersects); int __bitmap_subset(const unsigned long *bitmap1, const unsigned long *bitmap2, unsigned int bits) { unsigned int k, lim = bits/BITS_PER_LONG; for (k = 0; k < lim; ++k) if (bitmap1[k] & ~bitmap2[k]) return 0; if (bits % BITS_PER_LONG) if ((bitmap1[k] & ~bitmap2[k]) & BITMAP_LAST_WORD_MASK(bits)) return 0; return 1; } EXPORT_SYMBOL(__bitmap_subset); int __bitmap_weight(const unsigned long *bitmap, unsigned int bits) { unsigned int k, lim = bits/BITS_PER_LONG; int w = 0; for (k = 0; k < lim; k++) w += hweight_long(bitmap[k]); if (bits % BITS_PER_LONG) w += hweight_long(bitmap[k] & BITMAP_LAST_WORD_MASK(bits)); return w; } EXPORT_SYMBOL(__bitmap_weight); void __bitmap_set(unsigned long *map, unsigned int start, int len) { unsigned long *p = map + BIT_WORD(start); const unsigned int size = start + len; int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); while (len - bits_to_set >= 0) { *p |= mask_to_set; len -= bits_to_set; bits_to_set = BITS_PER_LONG; mask_to_set = ~0UL; p++; } if (len) { mask_to_set &= BITMAP_LAST_WORD_MASK(size); *p |= mask_to_set; } } EXPORT_SYMBOL(__bitmap_set); void __bitmap_clear(unsigned long *map, unsigned int start, int len) { unsigned long *p = map + BIT_WORD(start); const unsigned int size = start + len; int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); while (len - bits_to_clear >= 0) { *p &= ~mask_to_clear; len -= bits_to_clear; bits_to_clear = BITS_PER_LONG; mask_to_clear = ~0UL; p++; } if (len) { mask_to_clear &= BITMAP_LAST_WORD_MASK(size); *p &= ~mask_to_clear; } } EXPORT_SYMBOL(__bitmap_clear); /** * bitmap_find_next_zero_area_off - find a contiguous aligned zero area * @map: The address to base the search on * @size: The bitmap size in bits * @start: The bitnumber to start searching at * @nr: The number of zeroed bits we're looking for * @align_mask: Alignment mask for zero area * @align_offset: Alignment offset for zero area. * * The @align_mask should be one less than a power of 2; the effect is that * the bit offset of all zero areas this function finds plus @align_offset * is multiple of that power of 2. */ unsigned long bitmap_find_next_zero_area_off(unsigned long *map, unsigned long size, unsigned long start, unsigned int nr, unsigned long align_mask, unsigned long align_offset) { unsigned long index, end, i; again: index = find_next_zero_bit(map, size, start); /* Align allocation */ index = __ALIGN_MASK(index + align_offset, align_mask) - align_offset; end = index + nr; if (end > size) return end; i = find_next_bit(map, end, index); if (i < end) { start = i + 1; goto again; } return index; } EXPORT_SYMBOL(bitmap_find_next_zero_area_off); /* * Bitmap printing & parsing functions: first version by Nadia Yvette Chambers, * second version by Paul Jackson, third by Joe Korty. */ #define CHUNKSZ 32 #define nbits_to_hold_value(val) fls(val) #define BASEDEC 10 /* fancier cpuset lists input in decimal */ /** * __bitmap_parse - convert an ASCII hex string into a bitmap. * @buf: pointer to buffer containing string. * @buflen: buffer size in bytes. If string is smaller than this * then it must be terminated with a \0. * @is_user: location of buffer, 0 indicates kernel space * @maskp: pointer to bitmap array that will contain result. * @nmaskbits: size of bitmap, in bits. * * Commas group hex digits into chunks. Each chunk defines exactly 32 * bits of the resultant bitmask. No chunk may specify a value larger * than 32 bits (%-EOVERFLOW), and if a chunk specifies a smaller value * then leading 0-bits are prepended. %-EINVAL is returned for illegal * characters and for grouping errors such as "1,,5", ",44", "," and "". * Leading and trailing whitespace accepted, but not embedded whitespace. */ int __bitmap_parse(const char *buf, unsigned int buflen, int is_user, unsigned long *maskp, int nmaskbits) { int c, old_c, totaldigits, ndigits, nchunks, nbits; u32 chunk; const char __user __force *ubuf = (const char __user __force *)buf; bitmap_zero(maskp, nmaskbits); nchunks = nbits = totaldigits = c = 0; do { chunk = 0; ndigits = totaldigits; /* Get the next chunk of the bitmap */ while (buflen) { old_c = c; if (is_user) { if (__get_user(c, ubuf++)) return -EFAULT; } else c = *buf++; buflen--; if (isspace(c)) continue; /* * If the last character was a space and the current * character isn't '\0', we've got embedded whitespace. * This is a no-no, so throw an error. */ if (totaldigits && c && isspace(old_c)) return -EINVAL; /* A '\0' or a ',' signal the end of the chunk */ if (c == '\0' || c == ',') break; if (!isxdigit(c)) return -EINVAL; /* * Make sure there are at least 4 free bits in 'chunk'. * If not, this hexdigit will overflow 'chunk', so * throw an error. */ if (chunk & ~((1UL << (CHUNKSZ - 4)) - 1)) return -EOVERFLOW; chunk = (chunk << 4) | hex_to_bin(c); totaldigits++; } if (ndigits == totaldigits) return -EINVAL; if (nchunks == 0 && chunk == 0) continue; __bitmap_shift_left(maskp, maskp, CHUNKSZ, nmaskbits); *maskp |= chunk; nchunks++; nbits += (nchunks == 1) ? nbits_to_hold_value(chunk) : CHUNKSZ; if (nbits > nmaskbits) return -EOVERFLOW; } while (buflen && c == ','); return 0; } EXPORT_SYMBOL(__bitmap_parse); /** * bitmap_parse_user - convert an ASCII hex string in a user buffer into a bitmap * * @ubuf: pointer to user buffer containing string. * @ulen: buffer size in bytes. If string is smaller than this * then it must be terminated with a \0. * @maskp: pointer to bitmap array that will contain result. * @nmaskbits: size of bitmap, in bits. * * Wrapper for __bitmap_parse(), providing it with user buffer. * * We cannot have this as an inline function in bitmap.h because it needs * linux/uaccess.h to get the access_ok() declaration and this causes * cyclic dependencies. */ int bitmap_parse_user(const char __user *ubuf, unsigned int ulen, unsigned long *maskp, int nmaskbits) { if (!access_ok(ubuf, ulen)) return -EFAULT; return __bitmap_parse((const char __force *)ubuf, ulen, 1, maskp, nmaskbits); } EXPORT_SYMBOL(bitmap_parse_user); /** * bitmap_print_to_pagebuf - convert bitmap to list or hex format ASCII string * @list: indicates whether the bitmap must be list * @buf: page aligned buffer into which string is placed * @maskp: pointer to bitmap to convert * @nmaskbits: size of bitmap, in bits * * Output format is a comma-separated list of decimal numbers and * ranges if list is specified or hex digits grouped into comma-separated * sets of 8 digits/set. Returns the number of characters written to buf. * * It is assumed that @buf is a pointer into a PAGE_SIZE, page-aligned * area and that sufficient storage remains at @buf to accommodate the * bitmap_print_to_pagebuf() output. Returns the number of characters * actually printed to @buf, excluding terminating '\0'. */ int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, int nmaskbits) { ptrdiff_t len = PAGE_SIZE - offset_in_page(buf); return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); } EXPORT_SYMBOL(bitmap_print_to_pagebuf); /* * Region 9-38:4/10 describes the following bitmap structure: * 0 9 12 18 38 * .........****......****......****...... * ^ ^ ^ ^ * start off group_len end */ struct region { unsigned int start; unsigned int off; unsigned int group_len; unsigned int end; }; static int bitmap_set_region(const struct region *r, unsigned long *bitmap, int nbits) { unsigned int start; if (r->end >= nbits) return -ERANGE; for (start = r->start; start <= r->end; start += r->group_len) bitmap_set(bitmap, start, min(r->end - start + 1, r->off)); return 0; } static int bitmap_check_region(const struct region *r) { if (r->start > r->end || r->group_len == 0 || r->off > r->group_len) return -EINVAL; return 0; } static const char *bitmap_getnum(const char *str, unsigned int *num) { unsigned long long n; unsigned int len; len = _parse_integer(str, 10, &n); if (!len) return ERR_PTR(-EINVAL); if (len & KSTRTOX_OVERFLOW || n != (unsigned int)n) return ERR_PTR(-EOVERFLOW); *num = n; return str + len; } static inline bool end_of_str(char c) { return c == '\0' || c == '\n'; } static inline bool __end_of_region(char c) { return isspace(c) || c == ','; } static inline bool end_of_region(char c) { return __end_of_region(c) || end_of_str(c); } /* * The format allows commas and whitespases at the beginning * of the region. */ static const char *bitmap_find_region(const char *str) { while (__end_of_region(*str)) str++; return end_of_str(*str) ? NULL : str; } static const char *bitmap_parse_region(const char *str, struct region *r) { str = bitmap_getnum(str, &r->start); if (IS_ERR(str)) return str; if (end_of_region(*str)) goto no_end; if (*str != '-') return ERR_PTR(-EINVAL); str = bitmap_getnum(str + 1, &r->end); if (IS_ERR(str)) return str; if (end_of_region(*str)) goto no_pattern; if (*str != ':') return ERR_PTR(-EINVAL); str = bitmap_getnum(str + 1, &r->off); if (IS_ERR(str)) return str; if (*str != '/') return ERR_PTR(-EINVAL); return bitmap_getnum(str + 1, &r->group_len); no_end: r->end = r->start; no_pattern: r->off = r->end + 1; r->group_len = r->end + 1; return end_of_str(*str) ? NULL : str; } /** * bitmap_parselist - convert list format ASCII string to bitmap * @buf: read user string from this buffer; must be terminated * with a \0 or \n. * @maskp: write resulting mask here * @nmaskbits: number of bits in mask to be written * * Input format is a comma-separated list of decimal numbers and * ranges. Consecutively set bits are shown as two hyphen-separated * decimal numbers, the smallest and largest bit numbers set in * the range. * Optionally each range can be postfixed to denote that only parts of it * should be set. The range will divided to groups of specific size. * From each group will be used only defined amount of bits. * Syntax: range:used_size/group_size * Example: 0-1023:2/256 ==> 0,1,256,257,512,513,768,769 * * Returns: 0 on success, -errno on invalid input strings. Error values: * * - ``-EINVAL``: wrong region format * - ``-EINVAL``: invalid character in string * - ``-ERANGE``: bit number specified too large for mask * - ``-EOVERFLOW``: integer overflow in the input parameters */ int bitmap_parselist(const char *buf, unsigned long *maskp, int nmaskbits) { struct region r; long ret; bitmap_zero(maskp, nmaskbits); while (buf) { buf = bitmap_find_region(buf); if (buf == NULL) return 0; buf = bitmap_parse_region(buf, &r); if (IS_ERR(buf)) return PTR_ERR(buf); ret = bitmap_check_region(&r); if (ret) return ret; ret = bitmap_set_region(&r, maskp, nmaskbits); if (ret) return ret; } return 0; } EXPORT_SYMBOL(bitmap_parselist); /** * bitmap_parselist_user() * * @ubuf: pointer to user buffer containing string. * @ulen: buffer size in bytes. If string is smaller than this * then it must be terminated with a \0. * @maskp: pointer to bitmap array that will contain result. * @nmaskbits: size of bitmap, in bits. * * Wrapper for bitmap_parselist(), providing it with user buffer. */ int bitmap_parselist_user(const char __user *ubuf, unsigned int ulen, unsigned long *maskp, int nmaskbits) { char *buf; int ret; buf = memdup_user_nul(ubuf, ulen); if (IS_ERR(buf)) return PTR_ERR(buf); ret = bitmap_parselist(buf, maskp, nmaskbits); kfree(buf); return ret; } EXPORT_SYMBOL(bitmap_parselist_user); #ifdef CONFIG_NUMA /** * bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap * @buf: pointer to a bitmap * @pos: a bit position in @buf (0 <= @pos < @nbits) * @nbits: number of valid bit positions in @buf * * Map the bit at position @pos in @buf (of length @nbits) to the * ordinal of which set bit it is. If it is not set or if @pos * is not a valid bit position, map to -1. * * If for example, just bits 4 through 7 are set in @buf, then @pos * values 4 through 7 will get mapped to 0 through 3, respectively, * and other @pos values will get mapped to -1. When @pos value 7 * gets mapped to (returns) @ord value 3 in this example, that means * that bit 7 is the 3rd (starting with 0th) set bit in @buf. * * The bit positions 0 through @bits are valid positions in @buf. */ static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits) { if (pos >= nbits || !test_bit(pos, buf)) return -1; return __bitmap_weight(buf, pos); } /** * bitmap_ord_to_pos - find position of n-th set bit in bitmap * @buf: pointer to bitmap * @ord: ordinal bit position (n-th set bit, n >= 0) * @nbits: number of valid bit positions in @buf * * Map the ordinal offset of bit @ord in @buf to its position in @buf. * Value of @ord should be in range 0 <= @ord < weight(buf). If @ord * >= weight(buf), returns @nbits. * * If for example, just bits 4 through 7 are set in @buf, then @ord * values 0 through 3 will get mapped to 4 through 7, respectively, * and all other @ord values returns @nbits. When @ord value 3 * gets mapped to (returns) @pos value 7 in this example, that means * that the 3rd set bit (starting with 0th) is at position 7 in @buf. * * The bit positions 0 through @nbits-1 are valid positions in @buf. */ unsigned int bitmap_ord_to_pos(const unsigned long *buf, unsigned int ord, unsigned int nbits) { unsigned int pos; for (pos = find_first_bit(buf, nbits); pos < nbits && ord; pos = find_next_bit(buf, nbits, pos + 1)) ord--; return pos; } /** * bitmap_remap - Apply map defined by a pair of bitmaps to another bitmap * @dst: remapped result * @src: subset to be remapped * @old: defines domain of map * @new: defines range of map * @nbits: number of bits in each of these bitmaps * * Let @old and @new define a mapping of bit positions, such that * whatever position is held by the n-th set bit in @old is mapped * to the n-th set bit in @new. In the more general case, allowing * for the possibility that the weight 'w' of @new is less than the * weight of @old, map the position of the n-th set bit in @old to * the position of the m-th set bit in @new, where m == n % w. * * If either of the @old and @new bitmaps are empty, or if @src and * @dst point to the same location, then this routine copies @src * to @dst. * * The positions of unset bits in @old are mapped to themselves * (the identify map). * * Apply the above specified mapping to @src, placing the result in * @dst, clearing any bits previously set in @dst. * * For example, lets say that @old has bits 4 through 7 set, and * @new has bits 12 through 15 set. This defines the mapping of bit * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other * bit positions unchanged. So if say @src comes into this routine * with bits 1, 5 and 7 set, then @dst should leave with bits 1, * 13 and 15 set. */ void bitmap_remap(unsigned long *dst, const unsigned long *src, const unsigned long *old, const unsigned long *new, unsigned int nbits) { unsigned int oldbit, w; if (dst == src) /* following doesn't handle inplace remaps */ return; bitmap_zero(dst, nbits); w = bitmap_weight(new, nbits); for_each_set_bit(oldbit, src, nbits) { int n = bitmap_pos_to_ord(old, oldbit, nbits); if (n < 0 || w == 0) set_bit(oldbit, dst); /* identity map */ else set_bit(bitmap_ord_to_pos(new, n % w, nbits), dst); } } /** * bitmap_bitremap - Apply map defined by a pair of bitmaps to a single bit * @oldbit: bit position to be mapped * @old: defines domain of map * @new: defines range of map * @bits: number of bits in each of these bitmaps * * Let @old and @new define a mapping of bit positions, such that * whatever position is held by the n-th set bit in @old is mapped * to the n-th set bit in @new. In the more general case, allowing * for the possibility that the weight 'w' of @new is less than the * weight of @old, map the position of the n-th set bit in @old to * the position of the m-th set bit in @new, where m == n % w. * * The positions of unset bits in @old are mapped to themselves * (the identify map). * * Apply the above specified mapping to bit position @oldbit, returning * the new bit position. * * For example, lets say that @old has bits 4 through 7 set, and * @new has bits 12 through 15 set. This defines the mapping of bit * position 4 to 12, 5 to 13, 6 to 14 and 7 to 15, and of all other * bit positions unchanged. So if say @oldbit is 5, then this routine * returns 13. */ int bitmap_bitremap(int oldbit, const unsigned long *old, const unsigned long *new, int bits) { int w = bitmap_weight(new, bits); int n = bitmap_pos_to_ord(old, oldbit, bits); if (n < 0 || w == 0) return oldbit; else return bitmap_ord_to_pos(new, n % w, bits); } /** * bitmap_onto - translate one bitmap relative to another * @dst: resulting translated bitmap * @orig: original untranslated bitmap * @relmap: bitmap relative to which translated * @bits: number of bits in each of these bitmaps * * Set the n-th bit of @dst iff there exists some m such that the * n-th bit of @relmap is set, the m-th bit of @orig is set, and * the n-th bit of @relmap is also the m-th _set_ bit of @relmap. * (If you understood the previous sentence the first time your * read it, you're overqualified for your current job.) * * In other words, @orig is mapped onto (surjectively) @dst, * using the map { <n, m> | the n-th bit of @relmap is the * m-th set bit of @relmap }. * * Any set bits in @orig above bit number W, where W is the * weight of (number of set bits in) @relmap are mapped nowhere. * In particular, if for all bits m set in @orig, m >= W, then * @dst will end up empty. In situations where the possibility * of such an empty result is not desired, one way to avoid it is * to use the bitmap_fold() operator, below, to first fold the * @orig bitmap over itself so that all its set bits x are in the * range 0 <= x < W. The bitmap_fold() operator does this by * setting the bit (m % W) in @dst, for each bit (m) set in @orig. * * Example [1] for bitmap_onto(): * Let's say @relmap has bits 30-39 set, and @orig has bits * 1, 3, 5, 7, 9 and 11 set. Then on return from this routine, * @dst will have bits 31, 33, 35, 37 and 39 set. * * When bit 0 is set in @orig, it means turn on the bit in * @dst corresponding to whatever is the first bit (if any) * that is turned on in @relmap. Since bit 0 was off in the * above example, we leave off that bit (bit 30) in @dst. * * When bit 1 is set in @orig (as in the above example), it * means turn on the bit in @dst corresponding to whatever * is the second bit that is turned on in @relmap. The second * bit in @relmap that was turned on in the above example was * bit 31, so we turned on bit 31 in @dst. * * Similarly, we turned on bits 33, 35, 37 and 39 in @dst, * because they were the 4th, 6th, 8th and 10th set bits * set in @relmap, and the 4th, 6th, 8th and 10th bits of * @orig (i.e. bits 3, 5, 7 and 9) were also set. * * When bit 11 is set in @orig, it means turn on the bit in * @dst corresponding to whatever is the twelfth bit that is * turned on in @relmap. In the above example, there were * only ten bits turned on in @relmap (30..39), so that bit * 11 was set in @orig had no affect on @dst. * * Example [2] for bitmap_fold() + bitmap_onto(): * Let's say @relmap has these ten bits set:: * * 40 41 42 43 45 48 53 61 74 95 * * (for the curious, that's 40 plus the first ten terms of the * Fibonacci sequence.) * * Further lets say we use the following code, invoking * bitmap_fold() then bitmap_onto, as suggested above to * avoid the possibility of an empty @dst result:: * * unsigned long *tmp; // a temporary bitmap's bits * * bitmap_fold(tmp, orig, bitmap_weight(relmap, bits), bits); * bitmap_onto(dst, tmp, relmap, bits); * * Then this table shows what various values of @dst would be, for * various @orig's. I list the zero-based positions of each set bit. * The tmp column shows the intermediate result, as computed by * using bitmap_fold() to fold the @orig bitmap modulo ten * (the weight of @relmap): * * =============== ============== ================= * @orig tmp @dst * 0 0 40 * 1 1 41 * 9 9 95 * 10 0 40 [#f1]_ * 1 3 5 7 1 3 5 7 41 43 48 61 * 0 1 2 3 4 0 1 2 3 4 40 41 42 43 45 * 0 9 18 27 0 9 8 7 40 61 74 95 * 0 10 20 30 0 40 * 0 11 22 33 0 1 2 3 40 41 42 43 * 0 12 24 36 0 2 4 6 40 42 45 53 * 78 102 211 1 2 8 41 42 74 [#f1]_ * =============== ============== ================= * * .. [#f1] * * For these marked lines, if we hadn't first done bitmap_fold() * into tmp, then the @dst result would have been empty. * * If either of @orig or @relmap is empty (no set bits), then @dst * will be returned empty. * * If (as explained above) the only set bits in @orig are in positions * m where m >= W, (where W is the weight of @relmap) then @dst will * once again be returned empty. * * All bits in @dst not set by the above rule are cleared. */ void bitmap_onto(unsigned long *dst, const unsigned long *orig, const unsigned long *relmap, unsigned int bits) { unsigned int n, m; /* same meaning as in above comment */ if (dst == orig) /* following doesn't handle inplace mappings */ return; bitmap_zero(dst, bits); /* * The following code is a more efficient, but less * obvious, equivalent to the loop: * for (m = 0; m < bitmap_weight(relmap, bits); m++) { * n = bitmap_ord_to_pos(orig, m, bits); * if (test_bit(m, orig)) * set_bit(n, dst); * } */ m = 0; for_each_set_bit(n, relmap, bits) { /* m == bitmap_pos_to_ord(relmap, n, bits) */ if (test_bit(m, orig)) set_bit(n, dst); m++; } } /** * bitmap_fold - fold larger bitmap into smaller, modulo specified size * @dst: resulting smaller bitmap * @orig: original larger bitmap * @sz: specified size * @nbits: number of bits in each of these bitmaps * * For each bit oldbit in @orig, set bit oldbit mod @sz in @dst. * Clear all other bits in @dst. See further the comment and * Example [2] for bitmap_onto() for why and how to use this. */ void bitmap_fold(unsigned long *dst, const unsigned long *orig, unsigned int sz, unsigned int nbits) { unsigned int oldbit; if (dst == orig) /* following doesn't handle inplace mappings */ return; bitmap_zero(dst, nbits); for_each_set_bit(oldbit, orig, nbits) set_bit(oldbit % sz, dst); } #endif /* CONFIG_NUMA */ /* * Common code for bitmap_*_region() routines. * bitmap: array of unsigned longs corresponding to the bitmap * pos: the beginning of the region * order: region size (log base 2 of number of bits) * reg_op: operation(s) to perform on that region of bitmap * * Can set, verify and/or release a region of bits in a bitmap, * depending on which combination of REG_OP_* flag bits is set. * * A region of a bitmap is a sequence of bits in the bitmap, of * some size '1 << order' (a power of two), aligned to that same * '1 << order' power of two. * * Returns 1 if REG_OP_ISFREE succeeds (region is all zero bits). * Returns 0 in all other cases and reg_ops. */ enum { REG_OP_ISFREE, /* true if region is all zero bits */ REG_OP_ALLOC, /* set all bits in region */ REG_OP_RELEASE, /* clear all bits in region */ }; static int __reg_op(unsigned long *bitmap, unsigned int pos, int order, int reg_op) { int nbits_reg; /* number of bits in region */ int index; /* index first long of region in bitmap */ int offset; /* bit offset region in bitmap[index] */ int nlongs_reg; /* num longs spanned by region in bitmap */ int nbitsinlong; /* num bits of region in each spanned long */ unsigned long mask; /* bitmask for one long of region */ int i; /* scans bitmap by longs */ int ret = 0; /* return value */ /* * Either nlongs_reg == 1 (for small orders that fit in one long) * or (offset == 0 && mask == ~0UL) (for larger multiword orders.) */ nbits_reg = 1 << order; index = pos / BITS_PER_LONG; offset = pos - (index * BITS_PER_LONG); nlongs_reg = BITS_TO_LONGS(nbits_reg); nbitsinlong = min(nbits_reg, BITS_PER_LONG); /* * Can't do "mask = (1UL << nbitsinlong) - 1", as that * overflows if nbitsinlong == BITS_PER_LONG. */ mask = (1UL << (nbitsinlong - 1)); mask += mask - 1; mask <<= offset; switch (reg_op) { case REG_OP_ISFREE: for (i = 0; i < nlongs_reg; i++) { if (bitmap[index + i] & mask) goto done; } ret = 1; /* all bits in region free (zero) */ break; case REG_OP_ALLOC: for (i = 0; i < nlongs_reg; i++) bitmap[index + i] |= mask; break; case REG_OP_RELEASE: for (i = 0; i < nlongs_reg; i++) bitmap[index + i] &= ~mask; break; } done: return ret; } /** * bitmap_find_free_region - find a contiguous aligned mem region * @bitmap: array of unsigned longs corresponding to the bitmap * @bits: number of bits in the bitmap * @order: region size (log base 2 of number of bits) to find * * Find a region of free (zero) bits in a @bitmap of @bits bits and * allocate them (set them to one). Only consider regions of length * a power (@order) of two, aligned to that power of two, which * makes the search algorithm much faster. * * Return the bit offset in bitmap of the allocated region, * or -errno on failure. */ int bitmap_find_free_region(unsigned long *bitmap, unsigned int bits, int order) { unsigned int pos, end; /* scans bitmap by regions of size order */ for (pos = 0 ; (end = pos + (1U << order)) <= bits; pos = end) { if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) continue; __reg_op(bitmap, pos, order, REG_OP_ALLOC); return pos; } return -ENOMEM; } EXPORT_SYMBOL(bitmap_find_free_region); /** * bitmap_release_region - release allocated bitmap region * @bitmap: array of unsigned longs corresponding to the bitmap * @pos: beginning of bit region to release * @order: region size (log base 2 of number of bits) to release * * This is the complement to __bitmap_find_free_region() and releases * the found region (by clearing it in the bitmap). * * No return value. */ void bitmap_release_region(unsigned long *bitmap, unsigned int pos, int order) { __reg_op(bitmap, pos, order, REG_OP_RELEASE); } EXPORT_SYMBOL(bitmap_release_region); /** * bitmap_allocate_region - allocate bitmap region * @bitmap: array of unsigned longs corresponding to the bitmap * @pos: beginning of bit region to allocate * @order: region size (log base 2 of number of bits) to allocate * * Allocate (set bits in) a specified region of a bitmap. * * Return 0 on success, or %-EBUSY if specified region wasn't * free (not all bits were zero). */ int bitmap_allocate_region(unsigned long *bitmap, unsigned int pos, int order) { if (!__reg_op(bitmap, pos, order, REG_OP_ISFREE)) return -EBUSY; return __reg_op(bitmap, pos, order, REG_OP_ALLOC); } EXPORT_SYMBOL(bitmap_allocate_region); /** * bitmap_copy_le - copy a bitmap, putting the bits into little-endian order. * @dst: destination buffer * @src: bitmap to copy * @nbits: number of bits in the bitmap * * Require nbits % BITS_PER_LONG == 0. */ #ifdef __BIG_ENDIAN void bitmap_copy_le(unsigned long *dst, const unsigned long *src, unsigned int nbits) { unsigned int i; for (i = 0; i < nbits/BITS_PER_LONG; i++) { if (BITS_PER_LONG == 64) dst[i] = cpu_to_le64(src[i]); else dst[i] = cpu_to_le32(src[i]); } } EXPORT_SYMBOL(bitmap_copy_le); #endif unsigned long *bitmap_alloc(unsigned int nbits, gfp_t flags) { return kmalloc_array(BITS_TO_LONGS(nbits), sizeof(unsigned long), flags); } EXPORT_SYMBOL(bitmap_alloc); unsigned long *bitmap_zalloc(unsigned int nbits, gfp_t flags) { return bitmap_alloc(nbits, flags | __GFP_ZERO); } EXPORT_SYMBOL(bitmap_zalloc); void bitmap_free(const unsigned long *bitmap) { kfree(bitmap); } EXPORT_SYMBOL(bitmap_free); #if BITS_PER_LONG == 64 /** * bitmap_from_arr32 - copy the contents of u32 array of bits to bitmap * @bitmap: array of unsigned longs, the destination bitmap * @buf: array of u32 (in host byte order), the source bitmap * @nbits: number of bits in @bitmap */ void bitmap_from_arr32(unsigned long *bitmap, const u32 *buf, unsigned int nbits) { unsigned int i, halfwords; halfwords = DIV_ROUND_UP(nbits, 32); for (i = 0; i < halfwords; i++) { bitmap[i/2] = (unsigned long) buf[i]; if (++i < halfwords) bitmap[i/2] |= ((unsigned long) buf[i]) << 32; } /* Clear tail bits in last word beyond nbits. */ if (nbits % BITS_PER_LONG) bitmap[(halfwords - 1) / 2] &= BITMAP_LAST_WORD_MASK(nbits); } EXPORT_SYMBOL(bitmap_from_arr32); /** * bitmap_to_arr32 - copy the contents of bitmap to a u32 array of bits * @buf: array of u32 (in host byte order), the dest bitmap * @bitmap: array of unsigned longs, the source bitmap * @nbits: number of bits in @bitmap */ void bitmap_to_arr32(u32 *buf, const unsigned long *bitmap, unsigned int nbits) { unsigned int i, halfwords; halfwords = DIV_ROUND_UP(nbits, 32); for (i = 0; i < halfwords; i++) { buf[i] = (u32) (bitmap[i/2] & UINT_MAX); if (++i < halfwords) buf[i] = (u32) (bitmap[i/2] >> 32); } /* Clear tail bits in last element of array beyond nbits. */ if (nbits % BITS_PER_LONG) buf[halfwords - 1] &= (u32) (UINT_MAX >> ((-nbits) & 31)); } EXPORT_SYMBOL(bitmap_to_arr32); #endif
458 458 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 /* Netfilter messages via netlink socket. Allows for user space * protocol helpers and general trouble making from userspace. * * (C) 2001 by Jay Schulist <jschlst@samba.org>, * (C) 2002-2005 by Harald Welte <laforge@gnumonks.org> * (C) 2005-2017 by Pablo Neira Ayuso <pablo@netfilter.org> * * Initial netfilter messages via netlink development funded and * generally made possible by Network Robots, Inc. (www.networkrobots.com) * * Further development of this code funded by Astaro AG (http://www.astaro.com) * * This software may be used and distributed according to the terms * of the GNU General Public License, incorporated herein by reference. */ #include <linux/module.h> #include <linux/types.h> #include <linux/socket.h> #include <linux/kernel.h> #include <linux/string.h> #include <linux/sockios.h> #include <linux/net.h> #include <linux/skbuff.h> #include <linux/uaccess.h> #include <net/sock.h> #include <linux/init.h> #include <linux/sched/signal.h> #include <net/netlink.h> #include <linux/netfilter/nfnetlink.h> MODULE_LICENSE("GPL"); MODULE_AUTHOR("Harald Welte <laforge@netfilter.org>"); MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_NETFILTER); #define nfnl_dereference_protected(id) \ rcu_dereference_protected(table[(id)].subsys, \ lockdep_nfnl_is_held((id))) #define NFNL_MAX_ATTR_COUNT 32 static struct { struct mutex mutex; const struct nfnetlink_subsystem __rcu *subsys; } table[NFNL_SUBSYS_COUNT]; static const int nfnl_group2type[NFNLGRP_MAX+1] = { [NFNLGRP_CONNTRACK_NEW] = NFNL_SUBSYS_CTNETLINK, [NFNLGRP_CONNTRACK_UPDATE] = NFNL_SUBSYS_CTNETLINK, [NFNLGRP_CONNTRACK_DESTROY] = NFNL_SUBSYS_CTNETLINK, [NFNLGRP_CONNTRACK_EXP_NEW] = NFNL_SUBSYS_CTNETLINK_EXP, [NFNLGRP_CONNTRACK_EXP_UPDATE] = NFNL_SUBSYS_CTNETLINK_EXP, [NFNLGRP_CONNTRACK_EXP_DESTROY] = NFNL_SUBSYS_CTNETLINK_EXP, [NFNLGRP_NFTABLES] = NFNL_SUBSYS_NFTABLES, [NFNLGRP_ACCT_QUOTA] = NFNL_SUBSYS_ACCT, [NFNLGRP_NFTRACE] = NFNL_SUBSYS_NFTABLES, }; void nfnl_lock(__u8 subsys_id) { mutex_lock(&table[subsys_id].mutex); } EXPORT_SYMBOL_GPL(nfnl_lock); void nfnl_unlock(__u8 subsys_id) { mutex_unlock(&table[subsys_id].mutex); } EXPORT_SYMBOL_GPL(nfnl_unlock); #ifdef CONFIG_PROVE_LOCKING bool lockdep_nfnl_is_held(u8 subsys_id) { return lockdep_is_held(&table[subsys_id].mutex); } EXPORT_SYMBOL_GPL(lockdep_nfnl_is_held); #endif int nfnetlink_subsys_register(const struct nfnetlink_subsystem *n) { u8 cb_id; /* Sanity-check attr_count size to avoid stack buffer overflow. */ for (cb_id = 0; cb_id < n->cb_count; cb_id++) if (WARN_ON(n->cb[cb_id].attr_count > NFNL_MAX_ATTR_COUNT)) return -EINVAL; nfnl_lock(n->subsys_id); if (table[n->subsys_id].subsys) { nfnl_unlock(n->subsys_id); return -EBUSY; } rcu_assign_pointer(table[n->subsys_id].subsys, n); nfnl_unlock(n->subsys_id); return 0; } EXPORT_SYMBOL_GPL(nfnetlink_subsys_register); int nfnetlink_subsys_unregister(const struct nfnetlink_subsystem *n) { nfnl_lock(n->subsys_id); table[n->subsys_id].subsys = NULL; nfnl_unlock(n->subsys_id); synchronize_rcu(); return 0; } EXPORT_SYMBOL_GPL(nfnetlink_subsys_unregister); static inline const struct nfnetlink_subsystem *nfnetlink_get_subsys(u16 type) { u8 subsys_id = NFNL_SUBSYS_ID(type); if (subsys_id >= NFNL_SUBSYS_COUNT) return NULL; return rcu_dereference(table[subsys_id].subsys); } static inline const struct nfnl_callback * nfnetlink_find_client(u16 type, const struct nfnetlink_subsystem *ss) { u8 cb_id = NFNL_MSG_TYPE(type); if (cb_id >= ss->cb_count) return NULL; return &ss->cb[cb_id]; } int nfnetlink_has_listeners(struct net *net, unsigned int group) { return netlink_has_listeners(net->nfnl, group); } EXPORT_SYMBOL_GPL(nfnetlink_has_listeners); int nfnetlink_send(struct sk_buff *skb, struct net *net, u32 portid, unsigned int group, int echo, gfp_t flags) { return nlmsg_notify(net->nfnl, skb, portid, group, echo, flags); } EXPORT_SYMBOL_GPL(nfnetlink_send); int nfnetlink_set_err(struct net *net, u32 portid, u32 group, int error) { return netlink_set_err(net->nfnl, portid, group, error); } EXPORT_SYMBOL_GPL(nfnetlink_set_err); int nfnetlink_unicast(struct sk_buff *skb, struct net *net, u32 portid) { int err; err = nlmsg_unicast(net->nfnl, skb, portid); if (err == -EAGAIN) err = -ENOBUFS; return err; } EXPORT_SYMBOL_GPL(nfnetlink_unicast); /* Process one complete nfnetlink message. */ static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { struct net *net = sock_net(skb->sk); const struct nfnl_callback *nc; const struct nfnetlink_subsystem *ss; int type, err; /* All the messages must at least contain nfgenmsg */ if (nlmsg_len(nlh) < sizeof(struct nfgenmsg)) return 0; type = nlh->nlmsg_type; replay: rcu_read_lock(); ss = nfnetlink_get_subsys(type); if (!ss) { #ifdef CONFIG_MODULES rcu_read_unlock(); request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type)); rcu_read_lock(); ss = nfnetlink_get_subsys(type); if (!ss) #endif { rcu_read_unlock(); return -EINVAL; } } nc = nfnetlink_find_client(type, ss); if (!nc) { rcu_read_unlock(); return -EINVAL; } { int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); u8 cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); struct nlattr *cda[NFNL_MAX_ATTR_COUNT + 1]; struct nlattr *attr = (void *)nlh + min_len; int attrlen = nlh->nlmsg_len - min_len; __u8 subsys_id = NFNL_SUBSYS_ID(type); /* Sanity-check NFNL_MAX_ATTR_COUNT */ if (ss->cb[cb_id].attr_count > NFNL_MAX_ATTR_COUNT) { rcu_read_unlock(); return -ENOMEM; } err = nla_parse_deprecated(cda, ss->cb[cb_id].attr_count, attr, attrlen, ss->cb[cb_id].policy, extack); if (err < 0) { rcu_read_unlock(); return err; } if (nc->call_rcu) { err = nc->call_rcu(net, net->nfnl, skb, nlh, (const struct nlattr **)cda, extack); rcu_read_unlock(); } else { rcu_read_unlock(); nfnl_lock(subsys_id); if (nfnl_dereference_protected(subsys_id) != ss || nfnetlink_find_client(type, ss) != nc) err = -EAGAIN; else if (nc->call) err = nc->call(net, net->nfnl, skb, nlh, (const struct nlattr **)cda, extack); else err = -EINVAL; nfnl_unlock(subsys_id); } if (err == -EAGAIN) goto replay; return err; } } struct nfnl_err { struct list_head head; struct nlmsghdr *nlh; int err; struct netlink_ext_ack extack; }; static int nfnl_err_add(struct list_head *list, struct nlmsghdr *nlh, int err, const struct netlink_ext_ack *extack) { struct nfnl_err *nfnl_err; nfnl_err = kmalloc(sizeof(struct nfnl_err), GFP_KERNEL); if (nfnl_err == NULL) return -ENOMEM; nfnl_err->nlh = nlh; nfnl_err->err = err; nfnl_err->extack = *extack; list_add_tail(&nfnl_err->head, list); return 0; } static void nfnl_err_del(struct nfnl_err *nfnl_err) { list_del(&nfnl_err->head); kfree(nfnl_err); } static void nfnl_err_reset(struct list_head *err_list) { struct nfnl_err *nfnl_err, *next; list_for_each_entry_safe(nfnl_err, next, err_list, head) nfnl_err_del(nfnl_err); } static void nfnl_err_deliver(struct list_head *err_list, struct sk_buff *skb) { struct nfnl_err *nfnl_err, *next; list_for_each_entry_safe(nfnl_err, next, err_list, head) { netlink_ack(skb, nfnl_err->nlh, nfnl_err->err, &nfnl_err->extack); nfnl_err_del(nfnl_err); } } enum { NFNL_BATCH_FAILURE = (1 << 0), NFNL_BATCH_DONE = (1 << 1), NFNL_BATCH_REPLAY = (1 << 2), }; static void nfnetlink_rcv_batch(struct sk_buff *skb, struct nlmsghdr *nlh, u16 subsys_id, u32 genid) { struct sk_buff *oskb = skb; struct net *net = sock_net(skb->sk); const struct nfnetlink_subsystem *ss; const struct nfnl_callback *nc; struct netlink_ext_ack extack; LIST_HEAD(err_list); u32 status; int err; if (subsys_id >= NFNL_SUBSYS_COUNT) return netlink_ack(skb, nlh, -EINVAL, NULL); replay: status = 0; replay_abort: skb = netlink_skb_clone(oskb, GFP_KERNEL); if (!skb) return netlink_ack(oskb, nlh, -ENOMEM, NULL); nfnl_lock(subsys_id); ss = nfnl_dereference_protected(subsys_id); if (!ss) { #ifdef CONFIG_MODULES nfnl_unlock(subsys_id); request_module("nfnetlink-subsys-%d", subsys_id); nfnl_lock(subsys_id); ss = nfnl_dereference_protected(subsys_id); if (!ss) #endif { nfnl_unlock(subsys_id); netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL); return kfree_skb(skb); } } if (!ss->valid_genid || !ss->commit || !ss->abort) { nfnl_unlock(subsys_id); netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL); return kfree_skb(skb); } if (!try_module_get(ss->owner)) { nfnl_unlock(subsys_id); netlink_ack(oskb, nlh, -EOPNOTSUPP, NULL); return kfree_skb(skb); } if (!ss->valid_genid(net, genid)) { module_put(ss->owner); nfnl_unlock(subsys_id); netlink_ack(oskb, nlh, -ERESTART, NULL); return kfree_skb(skb); } nfnl_unlock(subsys_id); while (skb->len >= nlmsg_total_size(0)) { int msglen, type; if (fatal_signal_pending(current)) { nfnl_err_reset(&err_list); err = -EINTR; status = NFNL_BATCH_FAILURE; goto done; } memset(&extack, 0, sizeof(extack)); nlh = nlmsg_hdr(skb); err = 0; if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len || nlmsg_len(nlh) < sizeof(struct nfgenmsg)) { nfnl_err_reset(&err_list); status |= NFNL_BATCH_FAILURE; goto done; } /* Only requests are handled by the kernel */ if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) { err = -EINVAL; goto ack; } type = nlh->nlmsg_type; if (type == NFNL_MSG_BATCH_BEGIN) { /* Malformed: Batch begin twice */ nfnl_err_reset(&err_list); status |= NFNL_BATCH_FAILURE; goto done; } else if (type == NFNL_MSG_BATCH_END) { status |= NFNL_BATCH_DONE; goto done; } else if (type < NLMSG_MIN_TYPE) { err = -EINVAL; goto ack; } /* We only accept a batch with messages for the same * subsystem. */ if (NFNL_SUBSYS_ID(type) != subsys_id) { err = -EINVAL; goto ack; } nc = nfnetlink_find_client(type, ss); if (!nc) { err = -EINVAL; goto ack; } { int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); u8 cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type); struct nlattr *cda[NFNL_MAX_ATTR_COUNT + 1]; struct nlattr *attr = (void *)nlh + min_len; int attrlen = nlh->nlmsg_len - min_len; /* Sanity-check NFTA_MAX_ATTR */ if (ss->cb[cb_id].attr_count > NFNL_MAX_ATTR_COUNT) { err = -ENOMEM; goto ack; } err = nla_parse_deprecated(cda, ss->cb[cb_id].attr_count, attr, attrlen, ss->cb[cb_id].policy, NULL); if (err < 0) goto ack; if (nc->call_batch) { err = nc->call_batch(net, net->nfnl, skb, nlh, (const struct nlattr **)cda, &extack); } /* The lock was released to autoload some module, we * have to abort and start from scratch using the * original skb. */ if (err == -EAGAIN) { status |= NFNL_BATCH_REPLAY; goto done; } } ack: if (nlh->nlmsg_flags & NLM_F_ACK || err) { /* Errors are delivered once the full batch has been * processed, this avoids that the same error is * reported several times when replaying the batch. */ if (nfnl_err_add(&err_list, nlh, err, &extack) < 0) { /* We failed to enqueue an error, reset the * list of errors and send OOM to userspace * pointing to the batch header. */ nfnl_err_reset(&err_list); netlink_ack(oskb, nlmsg_hdr(oskb), -ENOMEM, NULL); status |= NFNL_BATCH_FAILURE; goto done; } /* We don't stop processing the batch on errors, thus, * userspace gets all the errors that the batch * triggers. */ if (err) status |= NFNL_BATCH_FAILURE; } msglen = NLMSG_ALIGN(nlh->nlmsg_len); if (msglen > skb->len) msglen = skb->len; skb_pull(skb, msglen); } done: if (status & NFNL_BATCH_REPLAY) { ss->abort(net, oskb, NFNL_ABORT_AUTOLOAD); nfnl_err_reset(&err_list); kfree_skb(skb); module_put(ss->owner); goto replay; } else if (status == NFNL_BATCH_DONE) { err = ss->commit(net, oskb); if (err == -EAGAIN) { status |= NFNL_BATCH_REPLAY; goto done; } else if (err) { ss->abort(net, oskb, NFNL_ABORT_NONE); netlink_ack(oskb, nlmsg_hdr(oskb), err, NULL); } } else { enum nfnl_abort_action abort_action; if (status & NFNL_BATCH_FAILURE) abort_action = NFNL_ABORT_NONE; else abort_action = NFNL_ABORT_VALIDATE; err = ss->abort(net, oskb, abort_action); if (err == -EAGAIN) { nfnl_err_reset(&err_list); kfree_skb(skb); module_put(ss->owner); status |= NFNL_BATCH_FAILURE; goto replay_abort; } } if (ss->cleanup) ss->cleanup(net); nfnl_err_deliver(&err_list, oskb); kfree_skb(skb); module_put(ss->owner); } static const struct nla_policy nfnl_batch_policy[NFNL_BATCH_MAX + 1] = { [NFNL_BATCH_GENID] = { .type = NLA_U32 }, }; static void nfnetlink_rcv_skb_batch(struct sk_buff *skb, struct nlmsghdr *nlh) { int min_len = nlmsg_total_size(sizeof(struct nfgenmsg)); struct nlattr *attr = (void *)nlh + min_len; struct nlattr *cda[NFNL_BATCH_MAX + 1]; int attrlen = nlh->nlmsg_len - min_len; struct nfgenmsg *nfgenmsg; int msglen, err; u32 gen_id = 0; u16 res_id; msglen = NLMSG_ALIGN(nlh->nlmsg_len); if (msglen > skb->len) msglen = skb->len; if (skb->len < NLMSG_HDRLEN + sizeof(struct nfgenmsg)) return; err = nla_parse_deprecated(cda, NFNL_BATCH_MAX, attr, attrlen, nfnl_batch_policy, NULL); if (err < 0) { netlink_ack(skb, nlh, err, NULL); return; } if (cda[NFNL_BATCH_GENID]) gen_id = ntohl(nla_get_be32(cda[NFNL_BATCH_GENID])); nfgenmsg = nlmsg_data(nlh); skb_pull(skb, msglen); /* Work around old nft using host byte order */ if (nfgenmsg->res_id == NFNL_SUBSYS_NFTABLES) res_id = NFNL_SUBSYS_NFTABLES; else res_id = ntohs(nfgenmsg->res_id); nfnetlink_rcv_batch(skb, nlh, res_id, gen_id); } static void nfnetlink_rcv(struct sk_buff *skb) { struct nlmsghdr *nlh = nlmsg_hdr(skb); if (skb->len < NLMSG_HDRLEN || nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) return; if (!netlink_net_capable(skb, CAP_NET_ADMIN)) { netlink_ack(skb, nlh, -EPERM, NULL); return; } if (nlh->nlmsg_type == NFNL_MSG_BATCH_BEGIN) nfnetlink_rcv_skb_batch(skb, nlh); else netlink_rcv_skb(skb, nfnetlink_rcv_msg); } #ifdef CONFIG_MODULES static int nfnetlink_bind(struct net *net, int group) { const struct nfnetlink_subsystem *ss; int type; if (group <= NFNLGRP_NONE || group > NFNLGRP_MAX) return 0; type = nfnl_group2type[group]; rcu_read_lock(); ss = nfnetlink_get_subsys(type << 8); rcu_read_unlock(); if (!ss) request_module_nowait("nfnetlink-subsys-%d", type); return 0; } #endif static int __net_init nfnetlink_net_init(struct net *net) { struct sock *nfnl; struct netlink_kernel_cfg cfg = { .groups = NFNLGRP_MAX, .input = nfnetlink_rcv, #ifdef CONFIG_MODULES .bind = nfnetlink_bind, #endif }; nfnl = netlink_kernel_create(net, NETLINK_NETFILTER, &cfg); if (!nfnl) return -ENOMEM; net->nfnl_stash = nfnl; rcu_assign_pointer(net->nfnl, nfnl); return 0; } static void __net_exit nfnetlink_net_exit_batch(struct list_head *net_exit_list) { struct net *net; list_for_each_entry(net, net_exit_list, exit_list) RCU_INIT_POINTER(net->nfnl, NULL); synchronize_net(); list_for_each_entry(net, net_exit_list, exit_list) netlink_kernel_release(net->nfnl_stash); } static struct pernet_operations nfnetlink_net_ops = { .init = nfnetlink_net_init, .exit_batch = nfnetlink_net_exit_batch, }; static int __init nfnetlink_init(void) { int i; for (i = NFNLGRP_NONE + 1; i <= NFNLGRP_MAX; i++) BUG_ON(nfnl_group2type[i] == NFNL_SUBSYS_NONE); for (i=0; i<NFNL_SUBSYS_COUNT; i++) mutex_init(&table[i].mutex); return register_pernet_subsys(&nfnetlink_net_ops); } static void __exit nfnetlink_exit(void) { unregister_pernet_subsys(&nfnetlink_net_ops); } module_init(nfnetlink_init); module_exit(nfnetlink_exit);
299 415 112 676 674 47 675 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 /* SPDX-License-Identifier: GPL-2.0 */ /* * Copyright 2019 Google LLC */ #ifndef __LINUX_BLK_CRYPTO_INTERNAL_H #define __LINUX_BLK_CRYPTO_INTERNAL_H #include <linux/bio.h> #include <linux/blkdev.h> /* Represents a crypto mode supported by blk-crypto */ struct blk_crypto_mode { const char *cipher_str; /* crypto API name (for fallback case) */ unsigned int keysize; /* key size in bytes */ unsigned int ivsize; /* iv size in bytes */ }; extern const struct blk_crypto_mode blk_crypto_modes[]; #ifdef CONFIG_BLK_INLINE_ENCRYPTION void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE], unsigned int inc); bool bio_crypt_rq_ctx_compatible(struct request *rq, struct bio *bio); bool bio_crypt_ctx_mergeable(struct bio_crypt_ctx *bc1, unsigned int bc1_bytes, struct bio_crypt_ctx *bc2); static inline bool bio_crypt_ctx_back_mergeable(struct request *req, struct bio *bio) { return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req), bio->bi_crypt_context); } static inline bool bio_crypt_ctx_front_mergeable(struct request *req, struct bio *bio) { return bio_crypt_ctx_mergeable(bio->bi_crypt_context, bio->bi_iter.bi_size, req->crypt_ctx); } static inline bool bio_crypt_ctx_merge_rq(struct request *req, struct request *next) { return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req), next->crypt_ctx); } static inline void blk_crypto_rq_set_defaults(struct request *rq) { rq->crypt_ctx = NULL; rq->crypt_keyslot = NULL; } static inline bool blk_crypto_rq_is_encrypted(struct request *rq) { return rq->crypt_ctx; } #else /* CONFIG_BLK_INLINE_ENCRYPTION */ static inline bool bio_crypt_rq_ctx_compatible(struct request *rq, struct bio *bio) { return true; } static inline bool bio_crypt_ctx_front_mergeable(struct request *req, struct bio *bio) { return true; } static inline bool bio_crypt_ctx_back_mergeable(struct request *req, struct bio *bio) { return true; } static inline bool bio_crypt_ctx_merge_rq(struct request *req, struct request *next) { return true; } static inline void blk_crypto_rq_set_defaults(struct request *rq) { } static inline bool blk_crypto_rq_is_encrypted(struct request *rq) { return false; } #endif /* CONFIG_BLK_INLINE_ENCRYPTION */ void __bio_crypt_advance(struct bio *bio, unsigned int bytes); static inline void bio_crypt_advance(struct bio *bio, unsigned int bytes) { if (bio_has_crypt_ctx(bio)) __bio_crypt_advance(bio, bytes); } void __bio_crypt_free_ctx(struct bio *bio); static inline void bio_crypt_free_ctx(struct bio *bio) { if (bio_has_crypt_ctx(bio)) __bio_crypt_free_ctx(bio); } static inline void bio_crypt_do_front_merge(struct request *rq, struct bio *bio) { #ifdef CONFIG_BLK_INLINE_ENCRYPTION if (bio_has_crypt_ctx(bio)) memcpy(rq->crypt_ctx->bc_dun, bio->bi_crypt_context->bc_dun, sizeof(rq->crypt_ctx->bc_dun)); #endif } bool __blk_crypto_bio_prep(struct bio **bio_ptr); static inline bool blk_crypto_bio_prep(struct bio **bio_ptr) { if (bio_has_crypt_ctx(*bio_ptr)) return __blk_crypto_bio_prep(bio_ptr); return true; } blk_status_t __blk_crypto_init_request(struct request *rq); static inline blk_status_t blk_crypto_init_request(struct request *rq) { if (blk_crypto_rq_is_encrypted(rq)) return __blk_crypto_init_request(rq); return BLK_STS_OK; } void __blk_crypto_free_request(struct request *rq); static inline void blk_crypto_free_request(struct request *rq) { if (blk_crypto_rq_is_encrypted(rq)) __blk_crypto_free_request(rq); } int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, gfp_t gfp_mask); /** * blk_crypto_rq_bio_prep - Prepare a request's crypt_ctx when its first bio * is inserted * @rq: The request to prepare * @bio: The first bio being inserted into the request * @gfp_mask: Memory allocation flags * * Return: 0 on success, -ENOMEM if out of memory. -ENOMEM is only possible if * @gfp_mask doesn't include %__GFP_DIRECT_RECLAIM. */ static inline int blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio, gfp_t gfp_mask) { if (bio_has_crypt_ctx(bio)) return __blk_crypto_rq_bio_prep(rq, bio, gfp_mask); return 0; } /** * blk_crypto_insert_cloned_request - Prepare a cloned request to be inserted * into a request queue. * @rq: the request being queued * * Return: BLK_STS_OK on success, nonzero on error. */ static inline blk_status_t blk_crypto_insert_cloned_request(struct request *rq) { if (blk_crypto_rq_is_encrypted(rq)) return blk_crypto_init_request(rq); return BLK_STS_OK; } #ifdef CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num); bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr); int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key); #else /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */ static inline int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num) { pr_warn_once("crypto API fallback is disabled\n"); return -ENOPKG; } static inline bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr) { pr_warn_once("crypto API fallback disabled; failing request.\n"); (*bio_ptr)->bi_status = BLK_STS_NOTSUPP; return false; } static inline int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key) { return 0; } #endif /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */ #endif /* __LINUX_BLK_CRYPTO_INTERNAL_H */
648 648 648 648 648 648 648 136 719 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 // SPDX-License-Identifier: GPL-2.0-only /* * Link physical devices with ACPI devices support * * Copyright (c) 2005 David Shaohua Li <shaohua.li@intel.com> * Copyright (c) 2005 Intel Corp. */ #include <linux/acpi_iort.h> #include <linux/export.h> #include <linux/init.h> #include <linux/list.h> #include <linux/device.h> #include <linux/slab.h> #include <linux/rwsem.h> #include <linux/acpi.h> #include <linux/dma-mapping.h> #include <linux/platform_device.h> #include "internal.h" #define ACPI_GLUE_DEBUG 0 #if ACPI_GLUE_DEBUG #define DBG(fmt, ...) \ printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__) #else #define DBG(fmt, ...) \ do { \ if (0) \ printk(KERN_DEBUG PREFIX fmt, ##__VA_ARGS__); \ } while (0) #endif static LIST_HEAD(bus_type_list); static DECLARE_RWSEM(bus_type_sem); #define PHYSICAL_NODE_STRING "physical_node" #define PHYSICAL_NODE_NAME_SIZE (sizeof(PHYSICAL_NODE_STRING) + 10) int register_acpi_bus_type(struct acpi_bus_type *type) { if (acpi_disabled) return -ENODEV; if (type && type->match && type->find_companion) { down_write(&bus_type_sem); list_add_tail(&type->list, &bus_type_list); up_write(&bus_type_sem); printk(KERN_INFO PREFIX "bus type %s registered\n", type->name); return 0; } return -ENODEV; } EXPORT_SYMBOL_GPL(register_acpi_bus_type); int unregister_acpi_bus_type(struct acpi_bus_type *type) { if (acpi_disabled) return 0; if (type) { down_write(&bus_type_sem); list_del_init(&type->list); up_write(&bus_type_sem); printk(KERN_INFO PREFIX "bus type %s unregistered\n", type->name); return 0; } return -ENODEV; } EXPORT_SYMBOL_GPL(unregister_acpi_bus_type); static struct acpi_bus_type *acpi_get_bus_type(struct device *dev) { struct acpi_bus_type *tmp, *ret = NULL; down_read(&bus_type_sem); list_for_each_entry(tmp, &bus_type_list, list) { if (tmp->match(dev)) { ret = tmp; break; } } up_read(&bus_type_sem); return ret; } #define FIND_CHILD_MIN_SCORE 1 #define FIND_CHILD_MAX_SCORE 2 static int find_child_checks(struct acpi_device *adev, bool check_children) { bool sta_present = true; unsigned long long sta; acpi_status status; status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta); if (status == AE_NOT_FOUND) sta_present = false; else if (ACPI_FAILURE(status) || !(sta & ACPI_STA_DEVICE_ENABLED)) return -ENODEV; if (check_children && list_empty(&adev->children)) return -ENODEV; /* * If the device has a _HID returning a valid ACPI/PNP device ID, it is * better to make it look less attractive here, so that the other device * with the same _ADR value (that may not have a valid device ID) can be * matched going forward. [This means a second spec violation in a row, * so whatever we do here is best effort anyway.] */ return sta_present && !adev->pnp.type.platform_id ? FIND_CHILD_MAX_SCORE : FIND_CHILD_MIN_SCORE; } struct acpi_device *acpi_find_child_device(struct acpi_device *parent, u64 address, bool check_children) { struct acpi_device *adev, *ret = NULL; int ret_score = 0; if (!parent) return NULL; list_for_each_entry(adev, &parent->children, node) { unsigned long long addr; acpi_status status; int score; status = acpi_evaluate_integer(adev->handle, METHOD_NAME__ADR, NULL, &addr); if (ACPI_FAILURE(status) || addr != address) continue; if (!ret) { /* This is the first matching object. Save it. */ ret = adev; continue; } /* * There is more than one matching device object with the same * _ADR value. That really is unexpected, so we are kind of * beyond the scope of the spec here. We have to choose which * one to return, though. * * First, check if the previously found object is good enough * and return it if so. Second, do the same for the object that * we've just found. */ if (!ret_score) { ret_score = find_child_checks(ret, check_children); if (ret_score == FIND_CHILD_MAX_SCORE) return ret; } score = find_child_checks(adev, check_children); if (score == FIND_CHILD_MAX_SCORE) { return adev; } else if (score > ret_score) { ret = adev; ret_score = score; } } return ret; } EXPORT_SYMBOL_GPL(acpi_find_child_device); static void acpi_physnode_link_name(char *buf, unsigned int node_id) { if (node_id > 0) snprintf(buf, PHYSICAL_NODE_NAME_SIZE, PHYSICAL_NODE_STRING "%u", node_id); else strcpy(buf, PHYSICAL_NODE_STRING); } int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev) { struct acpi_device_physical_node *physical_node, *pn; char physical_node_name[PHYSICAL_NODE_NAME_SIZE]; struct list_head *physnode_list; unsigned int node_id; int retval = -EINVAL; if (has_acpi_companion(dev)) { if (acpi_dev) { dev_warn(dev, "ACPI companion already set\n"); return -EINVAL; } else { acpi_dev = ACPI_COMPANION(dev); } } if (!acpi_dev) return -EINVAL; get_device(&acpi_dev->dev); get_device(dev); physical_node = kzalloc(sizeof(*physical_node), GFP_KERNEL); if (!physical_node) { retval = -ENOMEM; goto err; } mutex_lock(&acpi_dev->physical_node_lock); /* * Keep the list sorted by node_id so that the IDs of removed nodes can * be recycled easily. */ physnode_list = &acpi_dev->physical_node_list; node_id = 0; list_for_each_entry(pn, &acpi_dev->physical_node_list, node) { /* Sanity check. */ if (pn->dev == dev) { mutex_unlock(&acpi_dev->physical_node_lock); dev_warn(dev, "Already associated with ACPI node\n"); kfree(physical_node); if (ACPI_COMPANION(dev) != acpi_dev) goto err; put_device(dev); put_device(&acpi_dev->dev); return 0; } if (pn->node_id == node_id) { physnode_list = &pn->node; node_id++; } } physical_node->node_id = node_id; physical_node->dev = dev; list_add(&physical_node->node, physnode_list); acpi_dev->physical_node_count++; if (!has_acpi_companion(dev)) ACPI_COMPANION_SET(dev, acpi_dev); acpi_physnode_link_name(physical_node_name, node_id); retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj, physical_node_name); if (retval) dev_err(&acpi_dev->dev, "Failed to create link %s (%d)\n", physical_node_name, retval); retval = sysfs_create_link(&dev->kobj, &acpi_dev->dev.kobj, "firmware_node"); if (retval) dev_err(dev, "Failed to create link firmware_node (%d)\n", retval); mutex_unlock(&acpi_dev->physical_node_lock); if (acpi_dev->wakeup.flags.valid) device_set_wakeup_capable(dev, true); return 0; err: ACPI_COMPANION_SET(dev, NULL); put_device(dev); put_device(&acpi_dev->dev); return retval; } EXPORT_SYMBOL_GPL(acpi_bind_one); int acpi_unbind_one(struct device *dev) { struct acpi_device *acpi_dev = ACPI_COMPANION(dev); struct acpi_device_physical_node *entry; if (!acpi_dev) return 0; mutex_lock(&acpi_dev->physical_node_lock); list_for_each_entry(entry, &acpi_dev->physical_node_list, node) if (entry->dev == dev) { char physnode_name[PHYSICAL_NODE_NAME_SIZE]; list_del(&entry->node); acpi_dev->physical_node_count--; acpi_physnode_link_name(physnode_name, entry->node_id); sysfs_remove_link(&acpi_dev->dev.kobj, physnode_name); sysfs_remove_link(&dev->kobj, "firmware_node"); ACPI_COMPANION_SET(dev, NULL); /* Drop references taken by acpi_bind_one(). */ put_device(dev); put_device(&acpi_dev->dev); kfree(entry); break; } mutex_unlock(&acpi_dev->physical_node_lock); return 0; } EXPORT_SYMBOL_GPL(acpi_unbind_one); static int acpi_device_notify(struct device *dev) { struct acpi_bus_type *type = acpi_get_bus_type(dev); struct acpi_device *adev; int ret; ret = acpi_bind_one(dev, NULL); if (ret && type) { struct acpi_device *adev; adev = type->find_companion(dev); if (!adev) { DBG("Unable to get handle for %s\n", dev_name(dev)); ret = -ENODEV; goto out; } ret = acpi_bind_one(dev, adev); if (ret) goto out; } adev = ACPI_COMPANION(dev); if (!adev) goto out; if (dev_is_platform(dev)) acpi_configure_pmsi_domain(dev); if (type && type->setup) type->setup(dev); else if (adev->handler && adev->handler->bind) adev->handler->bind(dev); out: #if ACPI_GLUE_DEBUG if (!ret) { struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; acpi_get_name(ACPI_HANDLE(dev), ACPI_FULL_PATHNAME, &buffer); DBG("Device %s -> %s\n", dev_name(dev), (char *)buffer.pointer); kfree(buffer.pointer); } else DBG("Device %s -> No ACPI support\n", dev_name(dev)); #endif return ret; } static int acpi_device_notify_remove(struct device *dev) { struct acpi_device *adev = ACPI_COMPANION(dev); struct acpi_bus_type *type; if (!adev) return 0; type = acpi_get_bus_type(dev); if (type && type->cleanup) type->cleanup(dev); else if (adev->handler && adev->handler->unbind) adev->handler->unbind(dev); acpi_unbind_one(dev); return 0; } int acpi_platform_notify(struct device *dev, enum kobject_action action) { switch (action) { case KOBJ_ADD: acpi_device_notify(dev); break; case KOBJ_REMOVE: acpi_device_notify_remove(dev); break; default: break; } return 0; }
653 653 653 653 136 136 137 9 9 9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 // SPDX-License-Identifier: GPL-2.0 /* * fs/sysfs/symlink.c - sysfs symlink implementation * * Copyright (c) 2001-3 Patrick Mochel * Copyright (c) 2007 SUSE Linux Products GmbH * Copyright (c) 2007 Tejun Heo <teheo@suse.de> * * Please see Documentation/filesystems/sysfs.txt for more information. */ #include <linux/fs.h> #include <linux/module.h> #include <linux/kobject.h> #include <linux/mutex.h> #include <linux/security.h> #include "sysfs.h" static int sysfs_do_create_link_sd(struct kernfs_node *parent, struct kobject *target_kobj, const char *name, int warn) { struct kernfs_node *kn, *target = NULL; if (WARN_ON(!name || !parent)) return -EINVAL; /* * We don't own @target_kobj and it may be removed at any time. * Synchronize using sysfs_symlink_target_lock. See * sysfs_remove_dir() for details. */ spin_lock(&sysfs_symlink_target_lock); if (target_kobj->sd) { target = target_kobj->sd; kernfs_get(target); } spin_unlock(&sysfs_symlink_target_lock); if (!target) return -ENOENT; kn = kernfs_create_link(parent, name, target); kernfs_put(target); if (!IS_ERR(kn)) return 0; if (warn && PTR_ERR(kn) == -EEXIST) sysfs_warn_dup(parent, name); return PTR_ERR(kn); } /** * sysfs_create_link_sd - create symlink to a given object. * @kn: directory we're creating the link in. * @target: object we're pointing to. * @name: name of the symlink. */ int sysfs_create_link_sd(struct kernfs_node *kn, struct kobject *target, const char *name) { return sysfs_do_create_link_sd(kn, target, name, 1); } static int sysfs_do_create_link(struct kobject *kobj, struct kobject *target, const char *name, int warn) { struct kernfs_node *parent = NULL; if (!kobj) parent = sysfs_root_kn; else parent = kobj->sd; if (!parent) return -EFAULT; return sysfs_do_create_link_sd(parent, target, name, warn); } /** * sysfs_create_link - create symlink between two objects. * @kobj: object whose directory we're creating the link in. * @target: object we're pointing to. * @name: name of the symlink. */ int sysfs_create_link(struct kobject *kobj, struct kobject *target, const char *name) { return sysfs_do_create_link(kobj, target, name, 1); } EXPORT_SYMBOL_GPL(sysfs_create_link); /** * sysfs_create_link_nowarn - create symlink between two objects. * @kobj: object whose directory we're creating the link in. * @target: object we're pointing to. * @name: name of the symlink. * * This function does the same as sysfs_create_link(), but it * doesn't warn if the link already exists. */ int sysfs_create_link_nowarn(struct kobject *kobj, struct kobject *target, const char *name) { return sysfs_do_create_link(kobj, target, name, 0); } EXPORT_SYMBOL_GPL(sysfs_create_link_nowarn); /** * sysfs_delete_link - remove symlink in object's directory. * @kobj: object we're acting for. * @targ: object we're pointing to. * @name: name of the symlink to remove. * * Unlike sysfs_remove_link sysfs_delete_link has enough information * to successfully delete symlinks in tagged directories. */ void sysfs_delete_link(struct kobject *kobj, struct kobject *targ, const char *name) { const void *ns = NULL; /* * We don't own @target and it may be removed at any time. * Synchronize using sysfs_symlink_target_lock. See * sysfs_remove_dir() for details. */ spin_lock(&sysfs_symlink_target_lock); if (targ->sd && kernfs_ns_enabled(kobj->sd)) ns = targ->sd->ns; spin_unlock(&sysfs_symlink_target_lock); kernfs_remove_by_name_ns(kobj->sd, name, ns); } /** * sysfs_remove_link - remove symlink in object's directory. * @kobj: object we're acting for. * @name: name of the symlink to remove. */ void sysfs_remove_link(struct kobject *kobj, const char *name) { struct kernfs_node *parent = NULL; if (!kobj) parent = sysfs_root_kn; else parent = kobj->sd; kernfs_remove_by_name(parent, name); } EXPORT_SYMBOL_GPL(sysfs_remove_link); /** * sysfs_rename_link_ns - rename symlink in object's directory. * @kobj: object we're acting for. * @targ: object we're pointing to. * @old: previous name of the symlink. * @new: new name of the symlink. * @new_ns: new namespace of the symlink. * * A helper function for the common rename symlink idiom. */ int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *targ, const char *old, const char *new, const void *new_ns) { struct kernfs_node *parent, *kn = NULL; const void *old_ns = NULL; int result; if (!kobj) parent = sysfs_root_kn; else parent = kobj->sd; if (targ->sd) old_ns = targ->sd->ns; result = -ENOENT; kn = kernfs_find_and_get_ns(parent, old, old_ns); if (!kn) goto out; result = -EINVAL; if (kernfs_type(kn) != KERNFS_LINK) goto out; if (kn->symlink.target_kn->priv != targ) goto out; result = kernfs_rename_ns(kn, parent, new, new_ns); out: kernfs_put(kn); return result; } EXPORT_SYMBOL_GPL(sysfs_rename_link_ns);
4 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_LOCAL_H #define _ASM_X86_LOCAL_H #include <linux/percpu.h> #include <linux/atomic.h> #include <asm/asm.h> typedef struct { atomic_long_t a; } local_t; #define LOCAL_INIT(i) { ATOMIC_LONG_INIT(i) } #define local_read(l) atomic_long_read(&(l)->a) #define local_set(l, i) atomic_long_set(&(l)->a, (i)) static inline void local_inc(local_t *l) { asm volatile(_ASM_INC "%0" : "+m" (l->a.counter)); } static inline void local_dec(local_t *l) { asm volatile(_ASM_DEC "%0" : "+m" (l->a.counter)); } static inline void local_add(long i, local_t *l) { asm volatile(_ASM_ADD "%1,%0" : "+m" (l->a.counter) : "ir" (i)); } static inline void local_sub(long i, local_t *l) { asm volatile(_ASM_SUB "%1,%0" : "+m" (l->a.counter) : "ir" (i)); } /** * local_sub_and_test - subtract value from variable and test result * @i: integer value to subtract * @l: pointer to type local_t * * Atomically subtracts @i from @l and returns * true if the result is zero, or false for all * other cases. */ static inline bool local_sub_and_test(long i, local_t *l) { return GEN_BINARY_RMWcc(_ASM_SUB, l->a.counter, e, "er", i); } /** * local_dec_and_test - decrement and test * @l: pointer to type local_t * * Atomically decrements @l by 1 and * returns true if the result is 0, or false for all other * cases. */ static inline bool local_dec_and_test(local_t *l) { return GEN_UNARY_RMWcc(_ASM_DEC, l->a.counter, e); } /** * local_inc_and_test - increment and test * @l: pointer to type local_t * * Atomically increments @l by 1 * and returns true if the result is zero, or false for all * other cases. */ static inline bool local_inc_and_test(local_t *l) { return GEN_UNARY_RMWcc(_ASM_INC, l->a.counter, e); } /** * local_add_negative - add and test if negative * @i: integer value to add * @l: pointer to type local_t * * Atomically adds @i to @l and returns true * if the result is negative, or false when * result is greater than or equal to zero. */ static inline bool local_add_negative(long i, local_t *l) { return GEN_BINARY_RMWcc(_ASM_ADD, l->a.counter, s, "er", i); } /** * local_add_return - add and return * @i: integer value to add * @l: pointer to type local_t * * Atomically adds @i to @l and returns @i + @l */ static inline long local_add_return(long i, local_t *l) { long __i = i; asm volatile(_ASM_XADD "%0, %1;" : "+r" (i), "+m" (l->a.counter) : : "memory"); return i + __i; } static inline long local_sub_return(long i, local_t *l) { return local_add_return(-i, l); } #define local_inc_return(l) (local_add_return(1, l)) #define local_dec_return(l) (local_sub_return(1, l)) #define local_cmpxchg(l, o, n) \ (cmpxchg_local(&((l)->a.counter), (o), (n))) /* Always has a lock prefix */ #define local_xchg(l, n) (xchg(&((l)->a.counter), (n))) /** * local_add_unless - add unless the number is a given value * @l: pointer of type local_t * @a: the amount to add to l... * @u: ...unless l is equal to u. * * Atomically adds @a to @l, so long as it was not @u. * Returns non-zero if @l was not @u, and zero otherwise. */ #define local_add_unless(l, a, u) \ ({ \ long c, old; \ c = local_read((l)); \ for (;;) { \ if (unlikely(c == (u))) \ break; \ old = local_cmpxchg((l), c, c + (a)); \ if (likely(old == c)) \ break; \ c = old; \ } \ c != (u); \ }) #define local_inc_not_zero(l) local_add_unless((l), 1, 0) /* On x86_32, these are no better than the atomic variants. * On x86-64 these are better than the atomic variants on SMP kernels * because they dont use a lock prefix. */ #define __local_inc(l) local_inc(l) #define __local_dec(l) local_dec(l) #define __local_add(i, l) local_add((i), (l)) #define __local_sub(i, l) local_sub((i), (l)) #endif /* _ASM_X86_LOCAL_H */
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2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 // SPDX-License-Identifier: GPL-2.0-or-later /* * NETLINK Kernel-user communication protocol. * * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk> * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> * Patrick McHardy <kaber@trash.net> * * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith * added netlink_proto_exit * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br> * use nlk_sk, as sk->protinfo is on a diet 8) * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org> * - inc module use count of module that owns * the kernel socket in case userspace opens * socket of same protocol * - remove all module support, since netlink is * mandatory if CONFIG_NET=y these days */ #include <linux/module.h> #include <linux/capability.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/signal.h> #include <linux/sched.h> #include <linux/errno.h> #include <linux/string.h> #include <linux/stat.h> #include <linux/socket.h> #include <linux/un.h> #include <linux/fcntl.h> #include <linux/termios.h> #include <linux/sockios.h> #include <linux/net.h> #include <linux/fs.h> #include <linux/slab.h> #include <linux/uaccess.h> #include <linux/skbuff.h> #include <linux/netdevice.h> #include <linux/rtnetlink.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/notifier.h> #include <linux/security.h> #include <linux/jhash.h> #include <linux/jiffies.h> #include <linux/random.h> #include <linux/bitops.h> #include <linux/mm.h> #include <linux/types.h> #include <linux/audit.h> #include <linux/mutex.h> #include <linux/vmalloc.h> #include <linux/if_arp.h> #include <linux/rhashtable.h> #include <asm/cacheflush.h> #include <linux/hash.h> #include <linux/genetlink.h> #include <linux/net_namespace.h> #include <linux/nospec.h> #include <net/net_namespace.h> #include <net/netns/generic.h> #include <net/sock.h> #include <net/scm.h> #include <net/netlink.h> #include "af_netlink.h" struct listeners { struct rcu_head rcu; unsigned long masks[0]; }; /* state bits */ #define NETLINK_S_CONGESTED 0x0 static inline int netlink_is_kernel(struct sock *sk) { return nlk_sk(sk)->flags & NETLINK_F_KERNEL_SOCKET; } struct netlink_table *nl_table __read_mostly; EXPORT_SYMBOL_GPL(nl_table); static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait); static struct lock_class_key nlk_cb_mutex_keys[MAX_LINKS]; static const char *const nlk_cb_mutex_key_strings[MAX_LINKS + 1] = { "nlk_cb_mutex-ROUTE", "nlk_cb_mutex-1", "nlk_cb_mutex-USERSOCK", "nlk_cb_mutex-FIREWALL", "nlk_cb_mutex-SOCK_DIAG", "nlk_cb_mutex-NFLOG", "nlk_cb_mutex-XFRM", "nlk_cb_mutex-SELINUX", "nlk_cb_mutex-ISCSI", "nlk_cb_mutex-AUDIT", "nlk_cb_mutex-FIB_LOOKUP", "nlk_cb_mutex-CONNECTOR", "nlk_cb_mutex-NETFILTER", "nlk_cb_mutex-IP6_FW", "nlk_cb_mutex-DNRTMSG", "nlk_cb_mutex-KOBJECT_UEVENT", "nlk_cb_mutex-GENERIC", "nlk_cb_mutex-17", "nlk_cb_mutex-SCSITRANSPORT", "nlk_cb_mutex-ECRYPTFS", "nlk_cb_mutex-RDMA", "nlk_cb_mutex-CRYPTO", "nlk_cb_mutex-SMC", "nlk_cb_mutex-23", "nlk_cb_mutex-24", "nlk_cb_mutex-25", "nlk_cb_mutex-26", "nlk_cb_mutex-27", "nlk_cb_mutex-28", "nlk_cb_mutex-29", "nlk_cb_mutex-30", "nlk_cb_mutex-31", "nlk_cb_mutex-MAX_LINKS" }; static int netlink_dump(struct sock *sk); /* nl_table locking explained: * Lookup and traversal are protected with an RCU read-side lock. Insertion * and removal are protected with per bucket lock while using RCU list * modification primitives and may run in parallel to RCU protected lookups. * Destruction of the Netlink socket may only occur *after* nl_table_lock has * been acquired * either during or after the socket has been removed from * the list and after an RCU grace period. */ DEFINE_RWLOCK(nl_table_lock); EXPORT_SYMBOL_GPL(nl_table_lock); static atomic_t nl_table_users = ATOMIC_INIT(0); #define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock)); static BLOCKING_NOTIFIER_HEAD(netlink_chain); static const struct rhashtable_params netlink_rhashtable_params; static inline u32 netlink_group_mask(u32 group) { if (group > 32) return 0; return group ? 1 << (group - 1) : 0; } static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb, gfp_t gfp_mask) { unsigned int len = skb_end_offset(skb); struct sk_buff *new; new = alloc_skb(len, gfp_mask); if (new == NULL) return NULL; NETLINK_CB(new).portid = NETLINK_CB(skb).portid; NETLINK_CB(new).dst_group = NETLINK_CB(skb).dst_group; NETLINK_CB(new).creds = NETLINK_CB(skb).creds; skb_put_data(new, skb->data, len); return new; } static unsigned int netlink_tap_net_id; struct netlink_tap_net { struct list_head netlink_tap_all; struct mutex netlink_tap_lock; }; int netlink_add_tap(struct netlink_tap *nt) { struct net *net = dev_net(nt->dev); struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); if (unlikely(nt->dev->type != ARPHRD_NETLINK)) return -EINVAL; mutex_lock(&nn->netlink_tap_lock); list_add_rcu(&nt->list, &nn->netlink_tap_all); mutex_unlock(&nn->netlink_tap_lock); __module_get(nt->module); return 0; } EXPORT_SYMBOL_GPL(netlink_add_tap); static int __netlink_remove_tap(struct netlink_tap *nt) { struct net *net = dev_net(nt->dev); struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); bool found = false; struct netlink_tap *tmp; mutex_lock(&nn->netlink_tap_lock); list_for_each_entry(tmp, &nn->netlink_tap_all, list) { if (nt == tmp) { list_del_rcu(&nt->list); found = true; goto out; } } pr_warn("__netlink_remove_tap: %p not found\n", nt); out: mutex_unlock(&nn->netlink_tap_lock); if (found) module_put(nt->module); return found ? 0 : -ENODEV; } int netlink_remove_tap(struct netlink_tap *nt) { int ret; ret = __netlink_remove_tap(nt); synchronize_net(); return ret; } EXPORT_SYMBOL_GPL(netlink_remove_tap); static __net_init int netlink_tap_init_net(struct net *net) { struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); INIT_LIST_HEAD(&nn->netlink_tap_all); mutex_init(&nn->netlink_tap_lock); return 0; } static struct pernet_operations netlink_tap_net_ops = { .init = netlink_tap_init_net, .id = &netlink_tap_net_id, .size = sizeof(struct netlink_tap_net), }; static bool netlink_filter_tap(const struct sk_buff *skb) { struct sock *sk = skb->sk; /* We take the more conservative approach and * whitelist socket protocols that may pass. */ switch (sk->sk_protocol) { case NETLINK_ROUTE: case NETLINK_USERSOCK: case NETLINK_SOCK_DIAG: case NETLINK_NFLOG: case NETLINK_XFRM: case NETLINK_FIB_LOOKUP: case NETLINK_NETFILTER: case NETLINK_GENERIC: return true; } return false; } static int __netlink_deliver_tap_skb(struct sk_buff *skb, struct net_device *dev) { struct sk_buff *nskb; struct sock *sk = skb->sk; int ret = -ENOMEM; if (!net_eq(dev_net(dev), sock_net(sk))) return 0; dev_hold(dev); if (is_vmalloc_addr(skb->head)) nskb = netlink_to_full_skb(skb, GFP_ATOMIC); else nskb = skb_clone(skb, GFP_ATOMIC); if (nskb) { nskb->dev = dev; nskb->protocol = htons((u16) sk->sk_protocol); nskb->pkt_type = netlink_is_kernel(sk) ? PACKET_KERNEL : PACKET_USER; skb_reset_network_header(nskb); ret = dev_queue_xmit(nskb); if (unlikely(ret > 0)) ret = net_xmit_errno(ret); } dev_put(dev); return ret; } static void __netlink_deliver_tap(struct sk_buff *skb, struct netlink_tap_net *nn) { int ret; struct netlink_tap *tmp; if (!netlink_filter_tap(skb)) return; list_for_each_entry_rcu(tmp, &nn->netlink_tap_all, list) { ret = __netlink_deliver_tap_skb(skb, tmp->dev); if (unlikely(ret)) break; } } static void netlink_deliver_tap(struct net *net, struct sk_buff *skb) { struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id); rcu_read_lock(); if (unlikely(!list_empty(&nn->netlink_tap_all))) __netlink_deliver_tap(skb, nn); rcu_read_unlock(); } static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src, struct sk_buff *skb) { if (!(netlink_is_kernel(dst) && netlink_is_kernel(src))) netlink_deliver_tap(sock_net(dst), skb); } static void netlink_overrun(struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); if (!(nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)) { if (!test_and_set_bit(NETLINK_S_CONGESTED, &nlk_sk(sk)->state)) { sk->sk_err = ENOBUFS; sk->sk_error_report(sk); } } atomic_inc(&sk->sk_drops); } static void netlink_rcv_wake(struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); if (skb_queue_empty(&sk->sk_receive_queue)) clear_bit(NETLINK_S_CONGESTED, &nlk->state); if (!test_bit(NETLINK_S_CONGESTED, &nlk->state)) wake_up_interruptible(&nlk->wait); } static void netlink_skb_destructor(struct sk_buff *skb) { if (is_vmalloc_addr(skb->head)) { if (!skb->cloned || !atomic_dec_return(&(skb_shinfo(skb)->dataref))) vfree(skb->head); skb->head = NULL; } if (skb->sk != NULL) sock_rfree(skb); } static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk) { WARN_ON(skb->sk != NULL); skb->sk = sk; skb->destructor = netlink_skb_destructor; atomic_add(skb->truesize, &sk->sk_rmem_alloc); sk_mem_charge(sk, skb->truesize); } static void netlink_sock_destruct(struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); if (nlk->cb_running) { if (nlk->cb.done) nlk->cb.done(&nlk->cb); module_put(nlk->cb.module); kfree_skb(nlk->cb.skb); } skb_queue_purge(&sk->sk_receive_queue); if (!sock_flag(sk, SOCK_DEAD)) { printk(KERN_ERR "Freeing alive netlink socket %p\n", sk); return; } WARN_ON(atomic_read(&sk->sk_rmem_alloc)); WARN_ON(refcount_read(&sk->sk_wmem_alloc)); WARN_ON(nlk_sk(sk)->groups); } static void netlink_sock_destruct_work(struct work_struct *work) { struct netlink_sock *nlk = container_of(work, struct netlink_sock, work); sk_free(&nlk->sk); } /* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on * SMP. Look, when several writers sleep and reader wakes them up, all but one * immediately hit write lock and grab all the cpus. Exclusive sleep solves * this, _but_ remember, it adds useless work on UP machines. */ void netlink_table_grab(void) __acquires(nl_table_lock) { might_sleep(); write_lock_irq(&nl_table_lock); if (atomic_read(&nl_table_users)) { DECLARE_WAITQUEUE(wait, current); add_wait_queue_exclusive(&nl_table_wait, &wait); for (;;) { set_current_state(TASK_UNINTERRUPTIBLE); if (atomic_read(&nl_table_users) == 0) break; write_unlock_irq(&nl_table_lock); schedule(); write_lock_irq(&nl_table_lock); } __set_current_state(TASK_RUNNING); remove_wait_queue(&nl_table_wait, &wait); } } void netlink_table_ungrab(void) __releases(nl_table_lock) { write_unlock_irq(&nl_table_lock); wake_up(&nl_table_wait); } static inline void netlink_lock_table(void) { unsigned long flags; /* read_lock() synchronizes us to netlink_table_grab */ read_lock_irqsave(&nl_table_lock, flags); atomic_inc(&nl_table_users); read_unlock_irqrestore(&nl_table_lock, flags); } static inline void netlink_unlock_table(void) { if (atomic_dec_and_test(&nl_table_users)) wake_up(&nl_table_wait); } struct netlink_compare_arg { possible_net_t pnet; u32 portid; }; /* Doing sizeof directly may yield 4 extra bytes on 64-bit. */ #define netlink_compare_arg_len \ (offsetof(struct netlink_compare_arg, portid) + sizeof(u32)) static inline int netlink_compare(struct rhashtable_compare_arg *arg, const void *ptr) { const struct netlink_compare_arg *x = arg->key; const struct netlink_sock *nlk = ptr; return nlk->portid != x->portid || !net_eq(sock_net(&nlk->sk), read_pnet(&x->pnet)); } static void netlink_compare_arg_init(struct netlink_compare_arg *arg, struct net *net, u32 portid) { memset(arg, 0, sizeof(*arg)); write_pnet(&arg->pnet, net); arg->portid = portid; } static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid, struct net *net) { struct netlink_compare_arg arg; netlink_compare_arg_init(&arg, net, portid); return rhashtable_lookup_fast(&table->hash, &arg, netlink_rhashtable_params); } static int __netlink_insert(struct netlink_table *table, struct sock *sk) { struct netlink_compare_arg arg; netlink_compare_arg_init(&arg, sock_net(sk), nlk_sk(sk)->portid); return rhashtable_lookup_insert_key(&table->hash, &arg, &nlk_sk(sk)->node, netlink_rhashtable_params); } static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid) { struct netlink_table *table = &nl_table[protocol]; struct sock *sk; rcu_read_lock(); sk = __netlink_lookup(table, portid, net); if (sk) sock_hold(sk); rcu_read_unlock(); return sk; } static const struct proto_ops netlink_ops; static void netlink_update_listeners(struct sock *sk) { struct netlink_table *tbl = &nl_table[sk->sk_protocol]; unsigned long mask; unsigned int i; struct listeners *listeners; listeners = nl_deref_protected(tbl->listeners); if (!listeners) return; for (i = 0; i < NLGRPLONGS(tbl->groups); i++) { mask = 0; sk_for_each_bound(sk, &tbl->mc_list) { if (i < NLGRPLONGS(nlk_sk(sk)->ngroups)) mask |= nlk_sk(sk)->groups[i]; } listeners->masks[i] = mask; } /* this function is only called with the netlink table "grabbed", which * makes sure updates are visible before bind or setsockopt return. */ } static int netlink_insert(struct sock *sk, u32 portid) { struct netlink_table *table = &nl_table[sk->sk_protocol]; int err; lock_sock(sk); err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY; if (nlk_sk(sk)->bound) goto err; nlk_sk(sk)->portid = portid; sock_hold(sk); err = __netlink_insert(table, sk); if (err) { /* In case the hashtable backend returns with -EBUSY * from here, it must not escape to the caller. */ if (unlikely(err == -EBUSY)) err = -EOVERFLOW; if (err == -EEXIST) err = -EADDRINUSE; sock_put(sk); goto err; } /* We need to ensure that the socket is hashed and visible. */ smp_wmb(); /* Paired with lockless reads from netlink_bind(), * netlink_connect() and netlink_sendmsg(). */ WRITE_ONCE(nlk_sk(sk)->bound, portid); err: release_sock(sk); return err; } static void netlink_remove(struct sock *sk) { struct netlink_table *table; table = &nl_table[sk->sk_protocol]; if (!rhashtable_remove_fast(&table->hash, &nlk_sk(sk)->node, netlink_rhashtable_params)) { WARN_ON(refcount_read(&sk->sk_refcnt) == 1); __sock_put(sk); } netlink_table_grab(); if (nlk_sk(sk)->subscriptions) { __sk_del_bind_node(sk); netlink_update_listeners(sk); } if (sk->sk_protocol == NETLINK_GENERIC) atomic_inc(&genl_sk_destructing_cnt); netlink_table_ungrab(); } static struct proto netlink_proto = { .name = "NETLINK", .owner = THIS_MODULE, .obj_size = sizeof(struct netlink_sock), }; static int __netlink_create(struct net *net, struct socket *sock, struct mutex *cb_mutex, int protocol, int kern) { struct sock *sk; struct netlink_sock *nlk; sock->ops = &netlink_ops; sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, kern); if (!sk) return -ENOMEM; sock_init_data(sock, sk); nlk = nlk_sk(sk); if (cb_mutex) { nlk->cb_mutex = cb_mutex; } else { nlk->cb_mutex = &nlk->cb_def_mutex; mutex_init(nlk->cb_mutex); lockdep_set_class_and_name(nlk->cb_mutex, nlk_cb_mutex_keys + protocol, nlk_cb_mutex_key_strings[protocol]); } init_waitqueue_head(&nlk->wait); sk->sk_destruct = netlink_sock_destruct; sk->sk_protocol = protocol; return 0; } static int netlink_create(struct net *net, struct socket *sock, int protocol, int kern) { struct module *module = NULL; struct mutex *cb_mutex; struct netlink_sock *nlk; int (*bind)(struct net *net, int group); void (*unbind)(struct net *net, int group); int err = 0; sock->state = SS_UNCONNECTED; if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM) return -ESOCKTNOSUPPORT; if (protocol < 0 || protocol >= MAX_LINKS) return -EPROTONOSUPPORT; protocol = array_index_nospec(protocol, MAX_LINKS); netlink_lock_table(); #ifdef CONFIG_MODULES if (!nl_table[protocol].registered) { netlink_unlock_table(); request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol); netlink_lock_table(); } #endif if (nl_table[protocol].registered && try_module_get(nl_table[protocol].module)) module = nl_table[protocol].module; else err = -EPROTONOSUPPORT; cb_mutex = nl_table[protocol].cb_mutex; bind = nl_table[protocol].bind; unbind = nl_table[protocol].unbind; netlink_unlock_table(); if (err < 0) goto out; err = __netlink_create(net, sock, cb_mutex, protocol, kern); if (err < 0) goto out_module; local_bh_disable(); sock_prot_inuse_add(net, &netlink_proto, 1); local_bh_enable(); nlk = nlk_sk(sock->sk); nlk->module = module; nlk->netlink_bind = bind; nlk->netlink_unbind = unbind; out: return err; out_module: module_put(module); goto out; } static void deferred_put_nlk_sk(struct rcu_head *head) { struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu); struct sock *sk = &nlk->sk; kfree(nlk->groups); nlk->groups = NULL; if (!refcount_dec_and_test(&sk->sk_refcnt)) return; if (nlk->cb_running && nlk->cb.done) { INIT_WORK(&nlk->work, netlink_sock_destruct_work); schedule_work(&nlk->work); return; } sk_free(sk); } static int netlink_release(struct socket *sock) { struct sock *sk = sock->sk; struct netlink_sock *nlk; if (!sk) return 0; netlink_remove(sk); sock_orphan(sk); nlk = nlk_sk(sk); /* * OK. Socket is unlinked, any packets that arrive now * will be purged. */ /* must not acquire netlink_table_lock in any way again before unbind * and notifying genetlink is done as otherwise it might deadlock */ if (nlk->netlink_unbind) { int i; for (i = 0; i < nlk->ngroups; i++) if (test_bit(i, nlk->groups)) nlk->netlink_unbind(sock_net(sk), i + 1); } if (sk->sk_protocol == NETLINK_GENERIC && atomic_dec_return(&genl_sk_destructing_cnt) == 0) wake_up(&genl_sk_destructing_waitq); sock->sk = NULL; wake_up_interruptible_all(&nlk->wait); skb_queue_purge(&sk->sk_write_queue); if (nlk->portid && nlk->bound) { struct netlink_notify n = { .net = sock_net(sk), .protocol = sk->sk_protocol, .portid = nlk->portid, }; blocking_notifier_call_chain(&netlink_chain, NETLINK_URELEASE, &n); } module_put(nlk->module); if (netlink_is_kernel(sk)) { netlink_table_grab(); BUG_ON(nl_table[sk->sk_protocol].registered == 0); if (--nl_table[sk->sk_protocol].registered == 0) { struct listeners *old; old = nl_deref_protected(nl_table[sk->sk_protocol].listeners); RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL); kfree_rcu(old, rcu); nl_table[sk->sk_protocol].module = NULL; nl_table[sk->sk_protocol].bind = NULL; nl_table[sk->sk_protocol].unbind = NULL; nl_table[sk->sk_protocol].flags = 0; nl_table[sk->sk_protocol].registered = 0; } netlink_table_ungrab(); } local_bh_disable(); sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1); local_bh_enable(); call_rcu(&nlk->rcu, deferred_put_nlk_sk); return 0; } static int netlink_autobind(struct socket *sock) { struct sock *sk = sock->sk; struct net *net = sock_net(sk); struct netlink_table *table = &nl_table[sk->sk_protocol]; s32 portid = task_tgid_vnr(current); int err; s32 rover = -4096; bool ok; retry: cond_resched(); rcu_read_lock(); ok = !__netlink_lookup(table, portid, net); rcu_read_unlock(); if (!ok) { /* Bind collision, search negative portid values. */ if (rover == -4096) /* rover will be in range [S32_MIN, -4097] */ rover = S32_MIN + prandom_u32_max(-4096 - S32_MIN); else if (rover >= -4096) rover = -4097; portid = rover--; goto retry; } err = netlink_insert(sk, portid); if (err == -EADDRINUSE) goto retry; /* If 2 threads race to autobind, that is fine. */ if (err == -EBUSY) err = 0; return err; } /** * __netlink_ns_capable - General netlink message capability test * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace. * @user_ns: The user namespace of the capability to use * @cap: The capability to use * * Test to see if the opener of the socket we received the message * from had when the netlink socket was created and the sender of the * message has has the capability @cap in the user namespace @user_ns. */ bool __netlink_ns_capable(const struct netlink_skb_parms *nsp, struct user_namespace *user_ns, int cap) { return ((nsp->flags & NETLINK_SKB_DST) || file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) && ns_capable(user_ns, cap); } EXPORT_SYMBOL(__netlink_ns_capable); /** * netlink_ns_capable - General netlink message capability test * @skb: socket buffer holding a netlink command from userspace * @user_ns: The user namespace of the capability to use * @cap: The capability to use * * Test to see if the opener of the socket we received the message * from had when the netlink socket was created and the sender of the * message has has the capability @cap in the user namespace @user_ns. */ bool netlink_ns_capable(const struct sk_buff *skb, struct user_namespace *user_ns, int cap) { return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap); } EXPORT_SYMBOL(netlink_ns_capable); /** * netlink_capable - Netlink global message capability test * @skb: socket buffer holding a netlink command from userspace * @cap: The capability to use * * Test to see if the opener of the socket we received the message * from had when the netlink socket was created and the sender of the * message has has the capability @cap in all user namespaces. */ bool netlink_capable(const struct sk_buff *skb, int cap) { return netlink_ns_capable(skb, &init_user_ns, cap); } EXPORT_SYMBOL(netlink_capable); /** * netlink_net_capable - Netlink network namespace message capability test * @skb: socket buffer holding a netlink command from userspace * @cap: The capability to use * * Test to see if the opener of the socket we received the message * from had when the netlink socket was created and the sender of the * message has has the capability @cap over the network namespace of * the socket we received the message from. */ bool netlink_net_capable(const struct sk_buff *skb, int cap) { return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap); } EXPORT_SYMBOL(netlink_net_capable); static inline int netlink_allowed(const struct socket *sock, unsigned int flag) { return (nl_table[sock->sk->sk_protocol].flags & flag) || ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN); } static void netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions) { struct netlink_sock *nlk = nlk_sk(sk); if (nlk->subscriptions && !subscriptions) __sk_del_bind_node(sk); else if (!nlk->subscriptions && subscriptions) sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list); nlk->subscriptions = subscriptions; } static int netlink_realloc_groups(struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); unsigned int groups; unsigned long *new_groups; int err = 0; netlink_table_grab(); groups = nl_table[sk->sk_protocol].groups; if (!nl_table[sk->sk_protocol].registered) { err = -ENOENT; goto out_unlock; } if (nlk->ngroups >= groups) goto out_unlock; new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC); if (new_groups == NULL) { err = -ENOMEM; goto out_unlock; } memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0, NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups)); nlk->groups = new_groups; nlk->ngroups = groups; out_unlock: netlink_table_ungrab(); return err; } static void netlink_undo_bind(int group, long unsigned int groups, struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); int undo; if (!nlk->netlink_unbind) return; for (undo = 0; undo < group; undo++) if (test_bit(undo, &groups)) nlk->netlink_unbind(sock_net(sk), undo + 1); } static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len) { struct sock *sk = sock->sk; struct net *net = sock_net(sk); struct netlink_sock *nlk = nlk_sk(sk); struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; int err = 0; unsigned long groups; bool bound; if (addr_len < sizeof(struct sockaddr_nl)) return -EINVAL; if (nladdr->nl_family != AF_NETLINK) return -EINVAL; groups = nladdr->nl_groups; /* Only superuser is allowed to listen multicasts */ if (groups) { if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) return -EPERM; err = netlink_realloc_groups(sk); if (err) return err; } if (nlk->ngroups < BITS_PER_LONG) groups &= (1UL << nlk->ngroups) - 1; /* Paired with WRITE_ONCE() in netlink_insert() */ bound = READ_ONCE(nlk->bound); if (bound) { /* Ensure nlk->portid is up-to-date. */ smp_rmb(); if (nladdr->nl_pid != nlk->portid) return -EINVAL; } netlink_lock_table(); if (nlk->netlink_bind && groups) { int group; /* nl_groups is a u32, so cap the maximum groups we can bind */ for (group = 0; group < BITS_PER_TYPE(u32); group++) { if (!test_bit(group, &groups)) continue; err = nlk->netlink_bind(net, group + 1); if (!err) continue; netlink_undo_bind(group, groups, sk); goto unlock; } } /* No need for barriers here as we return to user-space without * using any of the bound attributes. */ if (!bound) { err = nladdr->nl_pid ? netlink_insert(sk, nladdr->nl_pid) : netlink_autobind(sock); if (err) { netlink_undo_bind(BITS_PER_TYPE(u32), groups, sk); goto unlock; } } if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0])) goto unlock; netlink_unlock_table(); netlink_table_grab(); netlink_update_subscriptions(sk, nlk->subscriptions + hweight32(groups) - hweight32(nlk->groups[0])); nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups; netlink_update_listeners(sk); netlink_table_ungrab(); return 0; unlock: netlink_unlock_table(); return err; } static int netlink_connect(struct socket *sock, struct sockaddr *addr, int alen, int flags) { int err = 0; struct sock *sk = sock->sk; struct netlink_sock *nlk = nlk_sk(sk); struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr; if (alen < sizeof(addr->sa_family)) return -EINVAL; if (addr->sa_family == AF_UNSPEC) { sk->sk_state = NETLINK_UNCONNECTED; nlk->dst_portid = 0; nlk->dst_group = 0; return 0; } if (addr->sa_family != AF_NETLINK) return -EINVAL; if (alen < sizeof(struct sockaddr_nl)) return -EINVAL; if ((nladdr->nl_groups || nladdr->nl_pid) && !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) return -EPERM; /* No need for barriers here as we return to user-space without * using any of the bound attributes. * Paired with WRITE_ONCE() in netlink_insert(). */ if (!READ_ONCE(nlk->bound)) err = netlink_autobind(sock); if (err == 0) { sk->sk_state = NETLINK_CONNECTED; nlk->dst_portid = nladdr->nl_pid; nlk->dst_group = ffs(nladdr->nl_groups); } return err; } static int netlink_getname(struct socket *sock, struct sockaddr *addr, int peer) { struct sock *sk = sock->sk; struct netlink_sock *nlk = nlk_sk(sk); DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr); nladdr->nl_family = AF_NETLINK; nladdr->nl_pad = 0; if (peer) { nladdr->nl_pid = nlk->dst_portid; nladdr->nl_groups = netlink_group_mask(nlk->dst_group); } else { nladdr->nl_pid = nlk->portid; netlink_lock_table(); nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0; netlink_unlock_table(); } return sizeof(*nladdr); } static int netlink_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) { /* try to hand this ioctl down to the NIC drivers. */ return -ENOIOCTLCMD; } static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid) { struct sock *sock; struct netlink_sock *nlk; sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid); if (!sock) return ERR_PTR(-ECONNREFUSED); /* Don't bother queuing skb if kernel socket has no input function */ nlk = nlk_sk(sock); if (sock->sk_state == NETLINK_CONNECTED && nlk->dst_portid != nlk_sk(ssk)->portid) { sock_put(sock); return ERR_PTR(-ECONNREFUSED); } return sock; } struct sock *netlink_getsockbyfilp(struct file *filp) { struct inode *inode = file_inode(filp); struct sock *sock; if (!S_ISSOCK(inode->i_mode)) return ERR_PTR(-ENOTSOCK); sock = SOCKET_I(inode)->sk; if (sock->sk_family != AF_NETLINK) return ERR_PTR(-EINVAL); sock_hold(sock); return sock; } static struct sk_buff *netlink_alloc_large_skb(unsigned int size, int broadcast) { struct sk_buff *skb; void *data; if (size <= NLMSG_GOODSIZE || broadcast) return alloc_skb(size, GFP_KERNEL); size = SKB_DATA_ALIGN(size) + SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); data = vmalloc(size); if (data == NULL) return NULL; skb = __build_skb(data, size); if (skb == NULL) vfree(data); else skb->destructor = netlink_skb_destructor; return skb; } /* * Attach a skb to a netlink socket. * The caller must hold a reference to the destination socket. On error, the * reference is dropped. The skb is not send to the destination, just all * all error checks are performed and memory in the queue is reserved. * Return values: * < 0: error. skb freed, reference to sock dropped. * 0: continue * 1: repeat lookup - reference dropped while waiting for socket memory. */ int netlink_attachskb(struct sock *sk, struct sk_buff *skb, long *timeo, struct sock *ssk) { struct netlink_sock *nlk; nlk = nlk_sk(sk); if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || test_bit(NETLINK_S_CONGESTED, &nlk->state))) { DECLARE_WAITQUEUE(wait, current); if (!*timeo) { if (!ssk || netlink_is_kernel(ssk)) netlink_overrun(sk); sock_put(sk); kfree_skb(skb); return -EAGAIN; } __set_current_state(TASK_INTERRUPTIBLE); add_wait_queue(&nlk->wait, &wait); if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf || test_bit(NETLINK_S_CONGESTED, &nlk->state)) && !sock_flag(sk, SOCK_DEAD)) *timeo = schedule_timeout(*timeo); __set_current_state(TASK_RUNNING); remove_wait_queue(&nlk->wait, &wait); sock_put(sk); if (signal_pending(current)) { kfree_skb(skb); return sock_intr_errno(*timeo); } return 1; } netlink_skb_set_owner_r(skb, sk); return 0; } static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb) { int len = skb->len; netlink_deliver_tap(sock_net(sk), skb); skb_queue_tail(&sk->sk_receive_queue, skb); sk->sk_data_ready(sk); return len; } int netlink_sendskb(struct sock *sk, struct sk_buff *skb) { int len = __netlink_sendskb(sk, skb); sock_put(sk); return len; } void netlink_detachskb(struct sock *sk, struct sk_buff *skb) { kfree_skb(skb); sock_put(sk); } static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation) { int delta; WARN_ON(skb->sk != NULL); delta = skb->end - skb->tail; if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize) return skb; if (skb_shared(skb)) { struct sk_buff *nskb = skb_clone(skb, allocation); if (!nskb) return skb; consume_skb(skb); skb = nskb; } pskb_expand_head(skb, 0, -delta, (allocation & ~__GFP_DIRECT_RECLAIM) | __GFP_NOWARN | __GFP_NORETRY); return skb; } static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb, struct sock *ssk) { int ret; struct netlink_sock *nlk = nlk_sk(sk); ret = -ECONNREFUSED; if (nlk->netlink_rcv != NULL) { ret = skb->len; netlink_skb_set_owner_r(skb, sk); NETLINK_CB(skb).sk = ssk; netlink_deliver_tap_kernel(sk, ssk, skb); nlk->netlink_rcv(skb); consume_skb(skb); } else { kfree_skb(skb); } sock_put(sk); return ret; } int netlink_unicast(struct sock *ssk, struct sk_buff *skb, u32 portid, int nonblock) { struct sock *sk; int err; long timeo; skb = netlink_trim(skb, gfp_any()); timeo = sock_sndtimeo(ssk, nonblock); retry: sk = netlink_getsockbyportid(ssk, portid); if (IS_ERR(sk)) { kfree_skb(skb); return PTR_ERR(sk); } if (netlink_is_kernel(sk)) return netlink_unicast_kernel(sk, skb, ssk); if (sk_filter(sk, skb)) { err = skb->len; kfree_skb(skb); sock_put(sk); return err; } err = netlink_attachskb(sk, skb, &timeo, ssk); if (err == 1) goto retry; if (err) return err; return netlink_sendskb(sk, skb); } EXPORT_SYMBOL(netlink_unicast); int netlink_has_listeners(struct sock *sk, unsigned int group) { int res = 0; struct listeners *listeners; BUG_ON(!netlink_is_kernel(sk)); rcu_read_lock(); listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners); if (listeners && group - 1 < nl_table[sk->sk_protocol].groups) res = test_bit(group - 1, listeners->masks); rcu_read_unlock(); return res; } EXPORT_SYMBOL_GPL(netlink_has_listeners); bool netlink_strict_get_check(struct sk_buff *skb) { const struct netlink_sock *nlk = nlk_sk(NETLINK_CB(skb).sk); return nlk->flags & NETLINK_F_STRICT_CHK; } EXPORT_SYMBOL_GPL(netlink_strict_get_check); static int netlink_broadcast_deliver(struct sock *sk, struct sk_buff *skb) { struct netlink_sock *nlk = nlk_sk(sk); if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf && !test_bit(NETLINK_S_CONGESTED, &nlk->state)) { netlink_skb_set_owner_r(skb, sk); __netlink_sendskb(sk, skb); return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1); } return -1; } struct netlink_broadcast_data { struct sock *exclude_sk; struct net *net; u32 portid; u32 group; int failure; int delivery_failure; int congested; int delivered; gfp_t allocation; struct sk_buff *skb, *skb2; int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data); void *tx_data; }; static void do_one_broadcast(struct sock *sk, struct netlink_broadcast_data *p) { struct netlink_sock *nlk = nlk_sk(sk); int val; if (p->exclude_sk == sk) return; if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || !test_bit(p->group - 1, nlk->groups)) return; if (!net_eq(sock_net(sk), p->net)) { if (!(nlk->flags & NETLINK_F_LISTEN_ALL_NSID)) return; if (!peernet_has_id(sock_net(sk), p->net)) return; if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns, CAP_NET_BROADCAST)) return; } if (p->failure) { netlink_overrun(sk); return; } sock_hold(sk); if (p->skb2 == NULL) { if (skb_shared(p->skb)) { p->skb2 = skb_clone(p->skb, p->allocation); } else { p->skb2 = skb_get(p->skb); /* * skb ownership may have been set when * delivered to a previous socket. */ skb_orphan(p->skb2); } } if (p->skb2 == NULL) { netlink_overrun(sk); /* Clone failed. Notify ALL listeners. */ p->failure = 1; if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR) p->delivery_failure = 1; goto out; } if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) { kfree_skb(p->skb2); p->skb2 = NULL; goto out; } if (sk_filter(sk, p->skb2)) { kfree_skb(p->skb2); p->skb2 = NULL; goto out; } NETLINK_CB(p->skb2).nsid = peernet2id(sock_net(sk), p->net); if (NETLINK_CB(p->skb2).nsid != NETNSA_NSID_NOT_ASSIGNED) NETLINK_CB(p->skb2).nsid_is_set = true; val = netlink_broadcast_deliver(sk, p->skb2); if (val < 0) { netlink_overrun(sk); if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR) p->delivery_failure = 1; } else { p->congested |= val; p->delivered = 1; p->skb2 = NULL; } out: sock_put(sk); } int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid, u32 group, gfp_t allocation, int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data), void *filter_data) { struct net *net = sock_net(ssk); struct netlink_broadcast_data info; struct sock *sk; skb = netlink_trim(skb, allocation); info.exclude_sk = ssk; info.net = net; info.portid = portid; info.group = group; info.failure = 0; info.delivery_failure = 0; info.congested = 0; info.delivered = 0; info.allocation = allocation; info.skb = skb; info.skb2 = NULL; info.tx_filter = filter; info.tx_data = filter_data; /* While we sleep in clone, do not allow to change socket list */ netlink_lock_table(); sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) do_one_broadcast(sk, &info); consume_skb(skb); netlink_unlock_table(); if (info.delivery_failure) { kfree_skb(info.skb2); return -ENOBUFS; } consume_skb(info.skb2); if (info.delivered) { if (info.congested && gfpflags_allow_blocking(allocation)) yield(); return 0; } return -ESRCH; } EXPORT_SYMBOL(netlink_broadcast_filtered); int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid, u32 group, gfp_t allocation) { return netlink_broadcast_filtered(ssk, skb, portid, group, allocation, NULL, NULL); } EXPORT_SYMBOL(netlink_broadcast); struct netlink_set_err_data { struct sock *exclude_sk; u32 portid; u32 group; int code; }; static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p) { struct netlink_sock *nlk = nlk_sk(sk); int ret = 0; if (sk == p->exclude_sk) goto out; if (!net_eq(sock_net(sk), sock_net(p->exclude_sk))) goto out; if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups || !test_bit(p->group - 1, nlk->groups)) goto out; if (p->code == ENOBUFS && nlk->flags & NETLINK_F_RECV_NO_ENOBUFS) { ret = 1; goto out; } sk->sk_err = p->code; sk->sk_error_report(sk); out: return ret; } /** * netlink_set_err - report error to broadcast listeners * @ssk: the kernel netlink socket, as returned by netlink_kernel_create() * @portid: the PORTID of a process that we want to skip (if any) * @group: the broadcast group that will notice the error * @code: error code, must be negative (as usual in kernelspace) * * This function returns the number of broadcast listeners that have set the * NETLINK_NO_ENOBUFS socket option. */ int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code) { struct netlink_set_err_data info; struct sock *sk; int ret = 0; info.exclude_sk = ssk; info.portid = portid; info.group = group; /* sk->sk_err wants a positive error value */ info.code = -code; read_lock(&nl_table_lock); sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list) ret += do_one_set_err(sk, &info); read_unlock(&nl_table_lock); return ret; } EXPORT_SYMBOL(netlink_set_err); /* must be called with netlink table grabbed */ static void netlink_update_socket_mc(struct netlink_sock *nlk, unsigned int group, int is_new) { int old, new = !!is_new, subscriptions; old = test_bit(group - 1, nlk->groups); subscriptions = nlk->subscriptions - old + new; if (new) __set_bit(group - 1, nlk->groups); else __clear_bit(group - 1, nlk->groups); netlink_update_subscriptions(&nlk->sk, subscriptions); netlink_update_listeners(&nlk->sk); } static int netlink_setsockopt(struct socket *sock, int level, int optname, char __user *optval, unsigned int optlen) { struct sock *sk = sock->sk; struct netlink_sock *nlk = nlk_sk(sk); unsigned int val = 0; int err; if (level != SOL_NETLINK) return -ENOPROTOOPT; if (optlen >= sizeof(int) && get_user(val, (unsigned int __user *)optval)) return -EFAULT; switch (optname) { case NETLINK_PKTINFO: if (val) nlk->flags |= NETLINK_F_RECV_PKTINFO; else nlk->flags &= ~NETLINK_F_RECV_PKTINFO; err = 0; break; case NETLINK_ADD_MEMBERSHIP: case NETLINK_DROP_MEMBERSHIP: { if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV)) return -EPERM; err = netlink_realloc_groups(sk); if (err) return err; if (!val || val - 1 >= nlk->ngroups) return -EINVAL; if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) { err = nlk->netlink_bind(sock_net(sk), val); if (err) return err; } netlink_table_grab(); netlink_update_socket_mc(nlk, val, optname == NETLINK_ADD_MEMBERSHIP); netlink_table_ungrab(); if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind) nlk->netlink_unbind(sock_net(sk), val); err = 0; break; } case NETLINK_BROADCAST_ERROR: if (val) nlk->flags |= NETLINK_F_BROADCAST_SEND_ERROR; else nlk->flags &= ~NETLINK_F_BROADCAST_SEND_ERROR; err = 0; break; case NETLINK_NO_ENOBUFS: if (val) { nlk->flags |= NETLINK_F_RECV_NO_ENOBUFS; clear_bit(NETLINK_S_CONGESTED, &nlk->state); wake_up_interruptible(&nlk->wait); } else { nlk->flags &= ~NETLINK_F_RECV_NO_ENOBUFS; } err = 0; break; case NETLINK_LISTEN_ALL_NSID: if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_BROADCAST)) return -EPERM; if (val) nlk->flags |= NETLINK_F_LISTEN_ALL_NSID; else nlk->flags &= ~NETLINK_F_LISTEN_ALL_NSID; err = 0; break; case NETLINK_CAP_ACK: if (val) nlk->flags |= NETLINK_F_CAP_ACK; else nlk->flags &= ~NETLINK_F_CAP_ACK; err = 0; break; case NETLINK_EXT_ACK: if (val) nlk->flags |= NETLINK_F_EXT_ACK; else nlk->flags &= ~NETLINK_F_EXT_ACK; err = 0; break; case NETLINK_GET_STRICT_CHK: if (val) nlk->flags |= NETLINK_F_STRICT_CHK; else nlk->flags &= ~NETLINK_F_STRICT_CHK; err = 0; break; default: err = -ENOPROTOOPT; } return err; } static int netlink_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen) { struct sock *sk = sock->sk; struct netlink_sock *nlk = nlk_sk(sk); int len, val, err; if (level != SOL_NETLINK) return -ENOPROTOOPT; if (get_user(len, optlen)) return -EFAULT; if (len < 0) return -EINVAL; switch (optname) { case NETLINK_PKTINFO: if (len < sizeof(int)) return -EINVAL; len = sizeof(int); val = nlk->flags & NETLINK_F_RECV_PKTINFO ? 1 : 0; if (put_user(len, optlen) || put_user(val, optval)) return -EFAULT; err = 0; break; case NETLINK_BROADCAST_ERROR: if (len < sizeof(int)) return -EINVAL; len = sizeof(int); val = nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR ? 1 : 0; if (put_user(len, optlen) || put_user(val, optval)) return -EFAULT; err = 0; break; case NETLINK_NO_ENOBUFS: if (len < sizeof(int)) return -EINVAL; len = sizeof(int); val = nlk->flags & NETLINK_F_RECV_NO_ENOBUFS ? 1 : 0; if (put_user(len, optlen) || put_user(val, optval)) return -EFAULT; err = 0; break; case NETLINK_LIST_MEMBERSHIPS: { int pos, idx, shift; err = 0; netlink_lock_table(); for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) { if (len - pos < sizeof(u32)) break; idx = pos / sizeof(unsigned long); shift = (pos % sizeof(unsigned long)) * 8; if (put_user((u32)(nlk->groups[idx] >> shift), (u32 __user *)(optval + pos))) { err = -EFAULT; break; } } if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen)) err = -EFAULT; netlink_unlock_table(); break; } case NETLINK_CAP_ACK: if (len < sizeof(int)) return -EINVAL; len = sizeof(int); val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0; if (put_user(len, optlen) || put_user(val, optval)) return -EFAULT; err = 0; break; case NETLINK_EXT_ACK: if (len < sizeof(int)) return -EINVAL; len = sizeof(int); val = nlk->flags & NETLINK_F_EXT_ACK ? 1 : 0; if (put_user(len, optlen) || put_user(val, optval)) return -EFAULT; err = 0; break; case NETLINK_GET_STRICT_CHK: if (len < sizeof(int)) return -EINVAL; len = sizeof(int); val = nlk->flags & NETLINK_F_STRICT_CHK ? 1 : 0; if (put_user(len, optlen) || put_user(val, optval)) return -EFAULT; err = 0; break; default: err = -ENOPROTOOPT; } return err; } static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb) { struct nl_pktinfo info; info.group = NETLINK_CB(skb).dst_group; put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info); } static void netlink_cmsg_listen_all_nsid(struct sock *sk, struct msghdr *msg, struct sk_buff *skb) { if (!NETLINK_CB(skb).nsid_is_set) return; put_cmsg(msg, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, sizeof(int), &NETLINK_CB(skb).nsid); } static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) { struct sock *sk = sock->sk; struct netlink_sock *nlk = nlk_sk(sk); DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); u32 dst_portid; u32 dst_group; struct sk_buff *skb; int err; struct scm_cookie scm; u32 netlink_skb_flags = 0; if (msg->msg_flags&MSG_OOB) return -EOPNOTSUPP; if (len == 0) { pr_warn_once("Zero length message leads to an empty skb\n"); return -ENODATA; } err = scm_send(sock, msg, &scm, true); if (err < 0) return err; if (msg->msg_namelen) { err = -EINVAL; if (msg->msg_namelen < sizeof(struct sockaddr_nl)) goto out; if (addr->nl_family != AF_NETLINK) goto out; dst_portid = addr->nl_pid; dst_group = ffs(addr->nl_groups); err = -EPERM; if ((dst_group || dst_portid) && !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND)) goto out; netlink_skb_flags |= NETLINK_SKB_DST; } else { dst_portid = nlk->dst_portid; dst_group = nlk->dst_group; } /* Paired with WRITE_ONCE() in netlink_insert() */ if (!READ_ONCE(nlk->bound)) { err = netlink_autobind(sock); if (err) goto out; } else { /* Ensure nlk is hashed and visible. */ smp_rmb(); } err = -EMSGSIZE; if (len > sk->sk_sndbuf - 32) goto out; err = -ENOBUFS; skb = netlink_alloc_large_skb(len, dst_group); if (skb == NULL) goto out; NETLINK_CB(skb).portid = nlk->portid; NETLINK_CB(skb).dst_group = dst_group; NETLINK_CB(skb).creds = scm.creds; NETLINK_CB(skb).flags = netlink_skb_flags; err = -EFAULT; if (memcpy_from_msg(skb_put(skb, len), msg, len)) { kfree_skb(skb); goto out; } err = security_netlink_send(sk, skb); if (err) { kfree_skb(skb); goto out; } if (dst_group) { refcount_inc(&skb->users); netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL); } err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT); out: scm_destroy(&scm); return err; } static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, int flags) { struct scm_cookie scm; struct sock *sk = sock->sk; struct netlink_sock *nlk = nlk_sk(sk); int noblock = flags&MSG_DONTWAIT; size_t copied; struct sk_buff *skb, *data_skb; int err, ret; if (flags&MSG_OOB) return -EOPNOTSUPP; copied = 0; skb = skb_recv_datagram(sk, flags, noblock, &err); if (skb == NULL) goto out; data_skb = skb; #ifdef CONFIG_COMPAT_NETLINK_MESSAGES if (unlikely(skb_shinfo(skb)->frag_list)) { /* * If this skb has a frag_list, then here that means that we * will have to use the frag_list skb's data for compat tasks * and the regular skb's data for normal (non-compat) tasks. * * If we need to send the compat skb, assign it to the * 'data_skb' variable so that it will be used below for data * copying. We keep 'skb' for everything else, including * freeing both later. */ if (flags & MSG_CMSG_COMPAT) data_skb = skb_shinfo(skb)->frag_list; } #endif /* Record the max length of recvmsg() calls for future allocations */ nlk->max_recvmsg_len = max(nlk->max_recvmsg_len, len); nlk->max_recvmsg_len = min_t(size_t, nlk->max_recvmsg_len, SKB_WITH_OVERHEAD(32768)); copied = data_skb->len; if (len < copied) { msg->msg_flags |= MSG_TRUNC; copied = len; } err = skb_copy_datagram_msg(data_skb, 0, msg, copied); if (msg->msg_name) { DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name); addr->nl_family = AF_NETLINK; addr->nl_pad = 0; addr->nl_pid = NETLINK_CB(skb).portid; addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group); msg->msg_namelen = sizeof(*addr); } if (nlk->flags & NETLINK_F_RECV_PKTINFO) netlink_cmsg_recv_pktinfo(msg, skb); if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID) netlink_cmsg_listen_all_nsid(sk, msg, skb); memset(&scm, 0, sizeof(scm)); scm.creds = *NETLINK_CREDS(skb); if (flags & MSG_TRUNC) copied = data_skb->len; skb_free_datagram(sk, skb); if (nlk->cb_running && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) { ret = netlink_dump(sk); if (ret) { sk->sk_err = -ret; sk->sk_error_report(sk); } } scm_recv(sock, msg, &scm, flags); out: netlink_rcv_wake(sk); return err ? : copied; } static void netlink_data_ready(struct sock *sk) { BUG(); } /* * We export these functions to other modules. They provide a * complete set of kernel non-blocking support for message * queueing. */ struct sock * __netlink_kernel_create(struct net *net, int unit, struct module *module, struct netlink_kernel_cfg *cfg) { struct socket *sock; struct sock *sk; struct netlink_sock *nlk; struct listeners *listeners = NULL; struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL; unsigned int groups; BUG_ON(!nl_table); if (unit < 0 || unit >= MAX_LINKS) return NULL; if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock)) return NULL; if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0) goto out_sock_release_nosk; sk = sock->sk; if (!cfg || cfg->groups < 32) groups = 32; else groups = cfg->groups; listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); if (!listeners) goto out_sock_release; sk->sk_data_ready = netlink_data_ready; if (cfg && cfg->input) nlk_sk(sk)->netlink_rcv = cfg->input; if (netlink_insert(sk, 0)) goto out_sock_release; nlk = nlk_sk(sk); nlk->flags |= NETLINK_F_KERNEL_SOCKET; netlink_table_grab(); if (!nl_table[unit].registered) { nl_table[unit].groups = groups; rcu_assign_pointer(nl_table[unit].listeners, listeners); nl_table[unit].cb_mutex = cb_mutex; nl_table[unit].module = module; if (cfg) { nl_table[unit].bind = cfg->bind; nl_table[unit].unbind = cfg->unbind; nl_table[unit].flags = cfg->flags; if (cfg->compare) nl_table[unit].compare = cfg->compare; } nl_table[unit].registered = 1; } else { kfree(listeners); nl_table[unit].registered++; } netlink_table_ungrab(); return sk; out_sock_release: kfree(listeners); netlink_kernel_release(sk); return NULL; out_sock_release_nosk: sock_release(sock); return NULL; } EXPORT_SYMBOL(__netlink_kernel_create); void netlink_kernel_release(struct sock *sk) { if (sk == NULL || sk->sk_socket == NULL) return; sock_release(sk->sk_socket); } EXPORT_SYMBOL(netlink_kernel_release); int __netlink_change_ngroups(struct sock *sk, unsigned int groups) { struct listeners *new, *old; struct netlink_table *tbl = &nl_table[sk->sk_protocol]; if (groups < 32) groups = 32; if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) { new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC); if (!new) return -ENOMEM; old = nl_deref_protected(tbl->listeners); memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups)); rcu_assign_pointer(tbl->listeners, new); kfree_rcu(old, rcu); } tbl->groups = groups; return 0; } /** * netlink_change_ngroups - change number of multicast groups * * This changes the number of multicast groups that are available * on a certain netlink family. Note that it is not possible to * change the number of groups to below 32. Also note that it does * not implicitly call netlink_clear_multicast_users() when the * number of groups is reduced. * * @sk: The kernel netlink socket, as returned by netlink_kernel_create(). * @groups: The new number of groups. */ int netlink_change_ngroups(struct sock *sk, unsigned int groups) { int err; netlink_table_grab(); err = __netlink_change_ngroups(sk, groups); netlink_table_ungrab(); return err; } void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group) { struct sock *sk; struct netlink_table *tbl = &nl_table[ksk->sk_protocol]; sk_for_each_bound(sk, &tbl->mc_list) netlink_update_socket_mc(nlk_sk(sk), group, 0); } struct nlmsghdr * __nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags) { struct nlmsghdr *nlh; int size = nlmsg_msg_size(len); nlh = skb_put(skb, NLMSG_ALIGN(size)); nlh->nlmsg_type = type; nlh->nlmsg_len = size; nlh->nlmsg_flags = flags; nlh->nlmsg_pid = portid; nlh->nlmsg_seq = seq; if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0) memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size); return nlh; } EXPORT_SYMBOL(__nlmsg_put); /* * It looks a bit ugly. * It would be better to create kernel thread. */ static int netlink_dump(struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); struct netlink_ext_ack extack = {}; struct netlink_callback *cb; struct sk_buff *skb = NULL; struct nlmsghdr *nlh; struct module *module; int err = -ENOBUFS; int alloc_min_size; int alloc_size; mutex_lock(nlk->cb_mutex); if (!nlk->cb_running) { err = -EINVAL; goto errout_skb; } if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) goto errout_skb; /* NLMSG_GOODSIZE is small to avoid high order allocations being * required, but it makes sense to _attempt_ a 16K bytes allocation * to reduce number of system calls on dump operations, if user * ever provided a big enough buffer. */ cb = &nlk->cb; alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); if (alloc_min_size < nlk->max_recvmsg_len) { alloc_size = nlk->max_recvmsg_len; skb = alloc_skb(alloc_size, (GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) | __GFP_NOWARN | __GFP_NORETRY); } if (!skb) { alloc_size = alloc_min_size; skb = alloc_skb(alloc_size, GFP_KERNEL); } if (!skb) goto errout_skb; /* Trim skb to allocated size. User is expected to provide buffer as * large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at * netlink_recvmsg())). dump will pack as many smaller messages as * could fit within the allocated skb. skb is typically allocated * with larger space than required (could be as much as near 2x the * requested size with align to next power of 2 approach). Allowing * dump to use the excess space makes it difficult for a user to have a * reasonable static buffer based on the expected largest dump of a * single netdev. The outcome is MSG_TRUNC error. */ skb_reserve(skb, skb_tailroom(skb) - alloc_size); /* Make sure malicious BPF programs can not read unitialized memory * from skb->head -> skb->data */ skb_reset_network_header(skb); skb_reset_mac_header(skb); netlink_skb_set_owner_r(skb, sk); if (nlk->dump_done_errno > 0) { cb->extack = &extack; nlk->dump_done_errno = cb->dump(skb, cb); cb->extack = NULL; } if (nlk->dump_done_errno > 0 || skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) { mutex_unlock(nlk->cb_mutex); if (sk_filter(sk, skb)) kfree_skb(skb); else __netlink_sendskb(sk, skb); return 0; } nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(nlk->dump_done_errno), NLM_F_MULTI | cb->answer_flags); if (WARN_ON(!nlh)) goto errout_skb; nl_dump_check_consistent(cb, nlh); memcpy(nlmsg_data(nlh), &nlk->dump_done_errno, sizeof(nlk->dump_done_errno)); if (extack._msg && nlk->flags & NETLINK_F_EXT_ACK) { nlh->nlmsg_flags |= NLM_F_ACK_TLVS; if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack._msg)) nlmsg_end(skb, nlh); } if (sk_filter(sk, skb)) kfree_skb(skb); else __netlink_sendskb(sk, skb); if (cb->done) cb->done(cb); nlk->cb_running = false; module = cb->module; skb = cb->skb; mutex_unlock(nlk->cb_mutex); module_put(module); consume_skb(skb); return 0; errout_skb: mutex_unlock(nlk->cb_mutex); kfree_skb(skb); return err; } int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, const struct nlmsghdr *nlh, struct netlink_dump_control *control) { struct netlink_sock *nlk, *nlk2; struct netlink_callback *cb; struct sock *sk; int ret; refcount_inc(&skb->users); sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid); if (sk == NULL) { ret = -ECONNREFUSED; goto error_free; } nlk = nlk_sk(sk); mutex_lock(nlk->cb_mutex); /* A dump is in progress... */ if (nlk->cb_running) { ret = -EBUSY; goto error_unlock; } /* add reference of module which cb->dump belongs to */ if (!try_module_get(control->module)) { ret = -EPROTONOSUPPORT; goto error_unlock; } cb = &nlk->cb; memset(cb, 0, sizeof(*cb)); cb->dump = control->dump; cb->done = control->done; cb->nlh = nlh; cb->data = control->data; cb->module = control->module; cb->min_dump_alloc = control->min_dump_alloc; cb->skb = skb; nlk2 = nlk_sk(NETLINK_CB(skb).sk); cb->strict_check = !!(nlk2->flags & NETLINK_F_STRICT_CHK); if (control->start) { ret = control->start(cb); if (ret) goto error_put; } nlk->cb_running = true; nlk->dump_done_errno = INT_MAX; mutex_unlock(nlk->cb_mutex); ret = netlink_dump(sk); sock_put(sk); if (ret) return ret; /* We successfully started a dump, by returning -EINTR we * signal not to send ACK even if it was requested. */ return -EINTR; error_put: module_put(control->module); error_unlock: sock_put(sk); mutex_unlock(nlk->cb_mutex); error_free: kfree_skb(skb); return ret; } EXPORT_SYMBOL(__netlink_dump_start); void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err, const struct netlink_ext_ack *extack) { struct sk_buff *skb; struct nlmsghdr *rep; struct nlmsgerr *errmsg; size_t payload = sizeof(*errmsg); size_t tlvlen = 0; struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk); unsigned int flags = 0; bool nlk_has_extack = nlk->flags & NETLINK_F_EXT_ACK; /* Error messages get the original request appened, unless the user * requests to cap the error message, and get extra error data if * requested. */ if (nlk_has_extack && extack && extack->_msg) tlvlen += nla_total_size(strlen(extack->_msg) + 1); if (err) { if (!(nlk->flags & NETLINK_F_CAP_ACK)) payload += nlmsg_len(nlh); else flags |= NLM_F_CAPPED; if (nlk_has_extack && extack && extack->bad_attr) tlvlen += nla_total_size(sizeof(u32)); } else { flags |= NLM_F_CAPPED; if (nlk_has_extack && extack && extack->cookie_len) tlvlen += nla_total_size(extack->cookie_len); } if (tlvlen) flags |= NLM_F_ACK_TLVS; skb = nlmsg_new(payload + tlvlen, GFP_KERNEL); if (!skb) { NETLINK_CB(in_skb).sk->sk_err = ENOBUFS; NETLINK_CB(in_skb).sk->sk_error_report(NETLINK_CB(in_skb).sk); return; } rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, NLMSG_ERROR, payload, flags); errmsg = nlmsg_data(rep); errmsg->error = err; memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh)); if (nlk_has_extack && extack) { if (extack->_msg) { WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG, extack->_msg)); } if (err) { if (extack->bad_attr && !WARN_ON((u8 *)extack->bad_attr < in_skb->data || (u8 *)extack->bad_attr >= in_skb->data + in_skb->len)) WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS, (u8 *)extack->bad_attr - (u8 *)nlh)); } else { if (extack->cookie_len) WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE, extack->cookie_len, extack->cookie)); } } nlmsg_end(skb, rep); netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT); } EXPORT_SYMBOL(netlink_ack); int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *, struct nlmsghdr *, struct netlink_ext_ack *)) { struct netlink_ext_ack extack; struct nlmsghdr *nlh; int err; while (skb->len >= nlmsg_total_size(0)) { int msglen; memset(&extack, 0, sizeof(extack)); nlh = nlmsg_hdr(skb); err = 0; if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) return 0; /* Only requests are handled by the kernel */ if (!(nlh->nlmsg_flags & NLM_F_REQUEST)) goto ack; /* Skip control messages */ if (nlh->nlmsg_type < NLMSG_MIN_TYPE) goto ack; err = cb(skb, nlh, &extack); if (err == -EINTR) goto skip; ack: if (nlh->nlmsg_flags & NLM_F_ACK || err) netlink_ack(skb, nlh, err, &extack); skip: msglen = NLMSG_ALIGN(nlh->nlmsg_len); if (msglen > skb->len) msglen = skb->len; skb_pull(skb, msglen); } return 0; } EXPORT_SYMBOL(netlink_rcv_skb); /** * nlmsg_notify - send a notification netlink message * @sk: netlink socket to use * @skb: notification message * @portid: destination netlink portid for reports or 0 * @group: destination multicast group or 0 * @report: 1 to report back, 0 to disable * @flags: allocation flags */ int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 portid, unsigned int group, int report, gfp_t flags) { int err = 0; if (group) { int exclude_portid = 0; if (report) { refcount_inc(&skb->users); exclude_portid = portid; } /* errors reported via destination sk->sk_err, but propagate * delivery errors if NETLINK_BROADCAST_ERROR flag is set */ err = nlmsg_multicast(sk, skb, exclude_portid, group, flags); if (err == -ESRCH) err = 0; } if (report) { int err2; err2 = nlmsg_unicast(sk, skb, portid); if (!err) err = err2; } return err; } EXPORT_SYMBOL(nlmsg_notify); #ifdef CONFIG_PROC_FS struct nl_seq_iter { struct seq_net_private p; struct rhashtable_iter hti; int link; }; static void netlink_walk_start(struct nl_seq_iter *iter) { rhashtable_walk_enter(&nl_table[iter->link].hash, &iter->hti); rhashtable_walk_start(&iter->hti); } static void netlink_walk_stop(struct nl_seq_iter *iter) { rhashtable_walk_stop(&iter->hti); rhashtable_walk_exit(&iter->hti); } static void *__netlink_seq_next(struct seq_file *seq) { struct nl_seq_iter *iter = seq->private; struct netlink_sock *nlk; do { for (;;) { nlk = rhashtable_walk_next(&iter->hti); if (IS_ERR(nlk)) { if (PTR_ERR(nlk) == -EAGAIN) continue; return nlk; } if (nlk) break; netlink_walk_stop(iter); if (++iter->link >= MAX_LINKS) return NULL; netlink_walk_start(iter); } } while (sock_net(&nlk->sk) != seq_file_net(seq)); return nlk; } static void *netlink_seq_start(struct seq_file *seq, loff_t *posp) { struct nl_seq_iter *iter = seq->private; void *obj = SEQ_START_TOKEN; loff_t pos; iter->link = 0; netlink_walk_start(iter); for (pos = *posp; pos && obj && !IS_ERR(obj); pos--) obj = __netlink_seq_next(seq); return obj; } static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos) { ++*pos; return __netlink_seq_next(seq); } static void netlink_seq_stop(struct seq_file *seq, void *v) { struct nl_seq_iter *iter = seq->private; if (iter->link >= MAX_LINKS) return; netlink_walk_stop(iter); } static int netlink_seq_show(struct seq_file *seq, void *v) { if (v == SEQ_START_TOKEN) { seq_puts(seq, "sk Eth Pid Groups " "Rmem Wmem Dump Locks Drops Inode\n"); } else { struct sock *s = v; struct netlink_sock *nlk = nlk_sk(s); seq_printf(seq, "%pK %-3d %-10u %08x %-8d %-8d %-5d %-8d %-8u %-8lu\n", s, s->sk_protocol, nlk->portid, nlk->groups ? (u32)nlk->groups[0] : 0, sk_rmem_alloc_get(s), sk_wmem_alloc_get(s), nlk->cb_running, refcount_read(&s->sk_refcnt), atomic_read(&s->sk_drops), sock_i_ino(s) ); } return 0; } static const struct seq_operations netlink_seq_ops = { .start = netlink_seq_start, .next = netlink_seq_next, .stop = netlink_seq_stop, .show = netlink_seq_show, }; #endif int netlink_register_notifier(struct notifier_block *nb) { return blocking_notifier_chain_register(&netlink_chain, nb); } EXPORT_SYMBOL(netlink_register_notifier); int netlink_unregister_notifier(struct notifier_block *nb) { return blocking_notifier_chain_unregister(&netlink_chain, nb); } EXPORT_SYMBOL(netlink_unregister_notifier); static const struct proto_ops netlink_ops = { .family = PF_NETLINK, .owner = THIS_MODULE, .release = netlink_release, .bind = netlink_bind, .connect = netlink_connect, .socketpair = sock_no_socketpair, .accept = sock_no_accept, .getname = netlink_getname, .poll = datagram_poll, .ioctl = netlink_ioctl, .listen = sock_no_listen, .shutdown = sock_no_shutdown, .setsockopt = netlink_setsockopt, .getsockopt = netlink_getsockopt, .sendmsg = netlink_sendmsg, .recvmsg = netlink_recvmsg, .mmap = sock_no_mmap, .sendpage = sock_no_sendpage, }; static const struct net_proto_family netlink_family_ops = { .family = PF_NETLINK, .create = netlink_create, .owner = THIS_MODULE, /* for consistency 8) */ }; static int __net_init netlink_net_init(struct net *net) { #ifdef CONFIG_PROC_FS if (!proc_create_net("netlink", 0, net->proc_net, &netlink_seq_ops, sizeof(struct nl_seq_iter))) return -ENOMEM; #endif return 0; } static void __net_exit netlink_net_exit(struct net *net) { #ifdef CONFIG_PROC_FS remove_proc_entry("netlink", net->proc_net); #endif } static void __init netlink_add_usersock_entry(void) { struct listeners *listeners; int groups = 32; listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL); if (!listeners) panic("netlink_add_usersock_entry: Cannot allocate listeners\n"); netlink_table_grab(); nl_table[NETLINK_USERSOCK].groups = groups; rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners); nl_table[NETLINK_USERSOCK].module = THIS_MODULE; nl_table[NETLINK_USERSOCK].registered = 1; nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND; netlink_table_ungrab(); } static struct pernet_operations __net_initdata netlink_net_ops = { .init = netlink_net_init, .exit = netlink_net_exit, }; static inline u32 netlink_hash(const void *data, u32 len, u32 seed) { const struct netlink_sock *nlk = data; struct netlink_compare_arg arg; netlink_compare_arg_init(&arg, sock_net(&nlk->sk), nlk->portid); return jhash2((u32 *)&arg, netlink_compare_arg_len / sizeof(u32), seed); } static const struct rhashtable_params netlink_rhashtable_params = { .head_offset = offsetof(struct netlink_sock, node), .key_len = netlink_compare_arg_len, .obj_hashfn = netlink_hash, .obj_cmpfn = netlink_compare, .automatic_shrinking = true, }; static int __init netlink_proto_init(void) { int i; int err = proto_register(&netlink_proto, 0); if (err != 0) goto out; BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb)); nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL); if (!nl_table) goto panic; for (i = 0; i < MAX_LINKS; i++) { if (rhashtable_init(&nl_table[i].hash, &netlink_rhashtable_params) < 0) { while (--i > 0) rhashtable_destroy(&nl_table[i].hash); kfree(nl_table); goto panic; } } netlink_add_usersock_entry(); sock_register(&netlink_family_ops); register_pernet_subsys(&netlink_net_ops); register_pernet_subsys(&netlink_tap_net_ops); /* The netlink device handler may be needed early. */ rtnetlink_init(); out: return err; panic: panic("netlink_init: Cannot allocate nl_table\n"); } core_initcall(netlink_proto_init);
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1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 // SPDX-License-Identifier: GPL-2.0-only /* * net/core/fib_rules.c Generic Routing Rules * * Authors: Thomas Graf <tgraf@suug.ch> */ #include <linux/types.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/list.h> #include <linux/module.h> #include <net/net_namespace.h> #include <net/sock.h> #include <net/fib_rules.h> #include <net/ip_tunnels.h> static const struct fib_kuid_range fib_kuid_range_unset = { KUIDT_INIT(0), KUIDT_INIT(~0), }; bool fib_rule_matchall(const struct fib_rule *rule) { if (rule->iifindex || rule->oifindex || rule->mark || rule->tun_id || rule->flags) return false; if (rule->suppress_ifgroup != -1 || rule->suppress_prefixlen != -1) return false; if (!uid_eq(rule->uid_range.start, fib_kuid_range_unset.start) || !uid_eq(rule->uid_range.end, fib_kuid_range_unset.end)) return false; if (fib_rule_port_range_set(&rule->sport_range)) return false; if (fib_rule_port_range_set(&rule->dport_range)) return false; return true; } EXPORT_SYMBOL_GPL(fib_rule_matchall); int fib_default_rule_add(struct fib_rules_ops *ops, u32 pref, u32 table, u32 flags) { struct fib_rule *r; r = kzalloc(ops->rule_size, GFP_KERNEL); if (r == NULL) return -ENOMEM; refcount_set(&r->refcnt, 1); r->action = FR_ACT_TO_TBL; r->pref = pref; r->table = table; r->flags = flags; r->proto = RTPROT_KERNEL; r->fr_net = ops->fro_net; r->uid_range = fib_kuid_range_unset; r->suppress_prefixlen = -1; r->suppress_ifgroup = -1; /* The lock is not required here, the list in unreacheable * at the moment this function is called */ list_add_tail(&r->list, &ops->rules_list); return 0; } EXPORT_SYMBOL(fib_default_rule_add); static u32 fib_default_rule_pref(struct fib_rules_ops *ops) { struct list_head *pos; struct fib_rule *rule; if (!list_empty(&ops->rules_list)) { pos = ops->rules_list.next; if (pos->next != &ops->rules_list) { rule = list_entry(pos->next, struct fib_rule, list); if (rule->pref) return rule->pref - 1; } } return 0; } static void notify_rule_change(int event, struct fib_rule *rule, struct fib_rules_ops *ops, struct nlmsghdr *nlh, u32 pid); static struct fib_rules_ops *lookup_rules_ops(struct net *net, int family) { struct fib_rules_ops *ops; rcu_read_lock(); list_for_each_entry_rcu(ops, &net->rules_ops, list) { if (ops->family == family) { if (!try_module_get(ops->owner)) ops = NULL; rcu_read_unlock(); return ops; } } rcu_read_unlock(); return NULL; } static void rules_ops_put(struct fib_rules_ops *ops) { if (ops) module_put(ops->owner); } static void flush_route_cache(struct fib_rules_ops *ops) { if (ops->flush_cache) ops->flush_cache(ops); } static int __fib_rules_register(struct fib_rules_ops *ops) { int err = -EEXIST; struct fib_rules_ops *o; struct net *net; net = ops->fro_net; if (ops->rule_size < sizeof(struct fib_rule)) return -EINVAL; if (ops->match == NULL || ops->configure == NULL || ops->compare == NULL || ops->fill == NULL || ops->action == NULL) return -EINVAL; spin_lock(&net->rules_mod_lock); list_for_each_entry(o, &net->rules_ops, list) if (ops->family == o->family) goto errout; list_add_tail_rcu(&ops->list, &net->rules_ops); err = 0; errout: spin_unlock(&net->rules_mod_lock); return err; } struct fib_rules_ops * fib_rules_register(const struct fib_rules_ops *tmpl, struct net *net) { struct fib_rules_ops *ops; int err; ops = kmemdup(tmpl, sizeof(*ops), GFP_KERNEL); if (ops == NULL) return ERR_PTR(-ENOMEM); INIT_LIST_HEAD(&ops->rules_list); ops->fro_net = net; err = __fib_rules_register(ops); if (err) { kfree(ops); ops = ERR_PTR(err); } return ops; } EXPORT_SYMBOL_GPL(fib_rules_register); static void fib_rules_cleanup_ops(struct fib_rules_ops *ops) { struct fib_rule *rule, *tmp; list_for_each_entry_safe(rule, tmp, &ops->rules_list, list) { list_del_rcu(&rule->list); if (ops->delete) ops->delete(rule); fib_rule_put(rule); } } void fib_rules_unregister(struct fib_rules_ops *ops) { struct net *net = ops->fro_net; spin_lock(&net->rules_mod_lock); list_del_rcu(&ops->list); spin_unlock(&net->rules_mod_lock); fib_rules_cleanup_ops(ops); kfree_rcu(ops, rcu); } EXPORT_SYMBOL_GPL(fib_rules_unregister); static int uid_range_set(struct fib_kuid_range *range) { return uid_valid(range->start) && uid_valid(range->end); } static struct fib_kuid_range nla_get_kuid_range(struct nlattr **tb) { struct fib_rule_uid_range *in; struct fib_kuid_range out; in = (struct fib_rule_uid_range *)nla_data(tb[FRA_UID_RANGE]); out.start = make_kuid(current_user_ns(), in->start); out.end = make_kuid(current_user_ns(), in->end); return out; } static int nla_put_uid_range(struct sk_buff *skb, struct fib_kuid_range *range) { struct fib_rule_uid_range out = { from_kuid_munged(current_user_ns(), range->start), from_kuid_munged(current_user_ns(), range->end) }; return nla_put(skb, FRA_UID_RANGE, sizeof(out), &out); } static int nla_get_port_range(struct nlattr *pattr, struct fib_rule_port_range *port_range) { const struct fib_rule_port_range *pr = nla_data(pattr); if (!fib_rule_port_range_valid(pr)) return -EINVAL; port_range->start = pr->start; port_range->end = pr->end; return 0; } static int nla_put_port_range(struct sk_buff *skb, int attrtype, struct fib_rule_port_range *range) { return nla_put(skb, attrtype, sizeof(*range), range); } static int fib_rule_match(struct fib_rule *rule, struct fib_rules_ops *ops, struct flowi *fl, int flags, struct fib_lookup_arg *arg) { int ret = 0; if (rule->iifindex && (rule->iifindex != fl->flowi_iif)) goto out; if (rule->oifindex && (rule->oifindex != fl->flowi_oif)) goto out; if ((rule->mark ^ fl->flowi_mark) & rule->mark_mask) goto out; if (rule->tun_id && (rule->tun_id != fl->flowi_tun_key.tun_id)) goto out; if (rule->l3mdev && !l3mdev_fib_rule_match(rule->fr_net, fl, arg)) goto out; if (uid_lt(fl->flowi_uid, rule->uid_range.start) || uid_gt(fl->flowi_uid, rule->uid_range.end)) goto out; ret = ops->match(rule, fl, flags); out: return (rule->flags & FIB_RULE_INVERT) ? !ret : ret; } int fib_rules_lookup(struct fib_rules_ops *ops, struct flowi *fl, int flags, struct fib_lookup_arg *arg) { struct fib_rule *rule; int err; rcu_read_lock(); list_for_each_entry_rcu(rule, &ops->rules_list, list) { jumped: if (!fib_rule_match(rule, ops, fl, flags, arg)) continue; if (rule->action == FR_ACT_GOTO) { struct fib_rule *target; target = rcu_dereference(rule->ctarget); if (target == NULL) { continue; } else { rule = target; goto jumped; } } else if (rule->action == FR_ACT_NOP) continue; else err = ops->action(rule, fl, flags, arg); if (!err && ops->suppress && ops->suppress(rule, flags, arg)) continue; if (err != -EAGAIN) { if ((arg->flags & FIB_LOOKUP_NOREF) || likely(refcount_inc_not_zero(&rule->refcnt))) { arg->rule = rule; goto out; } break; } } err = -ESRCH; out: rcu_read_unlock(); return err; } EXPORT_SYMBOL_GPL(fib_rules_lookup); static int call_fib_rule_notifier(struct notifier_block *nb, struct net *net, enum fib_event_type event_type, struct fib_rule *rule, int family) { struct fib_rule_notifier_info info = { .info.family = family, .rule = rule, }; return call_fib_notifier(nb, net, event_type, &info.info); } static int call_fib_rule_notifiers(struct net *net, enum fib_event_type event_type, struct fib_rule *rule, struct fib_rules_ops *ops, struct netlink_ext_ack *extack) { struct fib_rule_notifier_info info = { .info.family = ops->family, .info.extack = extack, .rule = rule, }; ops->fib_rules_seq++; return call_fib_notifiers(net, event_type, &info.info); } /* Called with rcu_read_lock() */ int fib_rules_dump(struct net *net, struct notifier_block *nb, int family) { struct fib_rules_ops *ops; struct fib_rule *rule; ops = lookup_rules_ops(net, family); if (!ops) return -EAFNOSUPPORT; list_for_each_entry_rcu(rule, &ops->rules_list, list) call_fib_rule_notifier(nb, net, FIB_EVENT_RULE_ADD, rule, family); rules_ops_put(ops); return 0; } EXPORT_SYMBOL_GPL(fib_rules_dump); unsigned int fib_rules_seq_read(struct net *net, int family) { unsigned int fib_rules_seq; struct fib_rules_ops *ops; ASSERT_RTNL(); ops = lookup_rules_ops(net, family); if (!ops) return 0; fib_rules_seq = ops->fib_rules_seq; rules_ops_put(ops); return fib_rules_seq; } EXPORT_SYMBOL_GPL(fib_rules_seq_read); static struct fib_rule *rule_find(struct fib_rules_ops *ops, struct fib_rule_hdr *frh, struct nlattr **tb, struct fib_rule *rule, bool user_priority) { struct fib_rule *r; list_for_each_entry(r, &ops->rules_list, list) { if (rule->action && r->action != rule->action) continue; if (rule->table && r->table != rule->table) continue; if (user_priority && r->pref != rule->pref) continue; if (rule->iifname[0] && memcmp(r->iifname, rule->iifname, IFNAMSIZ)) continue; if (rule->oifname[0] && memcmp(r->oifname, rule->oifname, IFNAMSIZ)) continue; if (rule->mark && r->mark != rule->mark) continue; if (rule->suppress_ifgroup != -1 && r->suppress_ifgroup != rule->suppress_ifgroup) continue; if (rule->suppress_prefixlen != -1 && r->suppress_prefixlen != rule->suppress_prefixlen) continue; if (rule->mark_mask && r->mark_mask != rule->mark_mask) continue; if (rule->tun_id && r->tun_id != rule->tun_id) continue; if (r->fr_net != rule->fr_net) continue; if (rule->l3mdev && r->l3mdev != rule->l3mdev) continue; if (uid_range_set(&rule->uid_range) && (!uid_eq(r->uid_range.start, rule->uid_range.start) || !uid_eq(r->uid_range.end, rule->uid_range.end))) continue; if (rule->ip_proto && r->ip_proto != rule->ip_proto) continue; if (rule->proto && r->proto != rule->proto) continue; if (fib_rule_port_range_set(&rule->sport_range) && !fib_rule_port_range_compare(&r->sport_range, &rule->sport_range)) continue; if (fib_rule_port_range_set(&rule->dport_range) && !fib_rule_port_range_compare(&r->dport_range, &rule->dport_range)) continue; if (!ops->compare(r, frh, tb)) continue; return r; } return NULL; } #ifdef CONFIG_NET_L3_MASTER_DEV static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule, struct netlink_ext_ack *extack) { nlrule->l3mdev = nla_get_u8(nla); if (nlrule->l3mdev != 1) { NL_SET_ERR_MSG(extack, "Invalid l3mdev attribute"); return -1; } return 0; } #else static int fib_nl2rule_l3mdev(struct nlattr *nla, struct fib_rule *nlrule, struct netlink_ext_ack *extack) { NL_SET_ERR_MSG(extack, "l3mdev support is not enabled in kernel"); return -1; } #endif static int fib_nl2rule(struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack, struct fib_rules_ops *ops, struct nlattr *tb[], struct fib_rule **rule, bool *user_priority) { struct net *net = sock_net(skb->sk); struct fib_rule_hdr *frh = nlmsg_data(nlh); struct fib_rule *nlrule = NULL; int err = -EINVAL; if (frh->src_len) if (!tb[FRA_SRC] || frh->src_len > (ops->addr_size * 8) || nla_len(tb[FRA_SRC]) != ops->addr_size) { NL_SET_ERR_MSG(extack, "Invalid source address"); goto errout; } if (frh->dst_len) if (!tb[FRA_DST] || frh->dst_len > (ops->addr_size * 8) || nla_len(tb[FRA_DST]) != ops->addr_size) { NL_SET_ERR_MSG(extack, "Invalid dst address"); goto errout; } nlrule = kzalloc(ops->rule_size, GFP_KERNEL); if (!nlrule) { err = -ENOMEM; goto errout; } refcount_set(&nlrule->refcnt, 1); nlrule->fr_net = net; if (tb[FRA_PRIORITY]) { nlrule->pref = nla_get_u32(tb[FRA_PRIORITY]); *user_priority = true; } else { nlrule->pref = fib_default_rule_pref(ops); } nlrule->proto = tb[FRA_PROTOCOL] ? nla_get_u8(tb[FRA_PROTOCOL]) : RTPROT_UNSPEC; if (tb[FRA_IIFNAME]) { struct net_device *dev; nlrule->iifindex = -1; nla_strlcpy(nlrule->iifname, tb[FRA_IIFNAME], IFNAMSIZ); dev = __dev_get_by_name(net, nlrule->iifname); if (dev) nlrule->iifindex = dev->ifindex; } if (tb[FRA_OIFNAME]) { struct net_device *dev; nlrule->oifindex = -1; nla_strlcpy(nlrule->oifname, tb[FRA_OIFNAME], IFNAMSIZ); dev = __dev_get_by_name(net, nlrule->oifname); if (dev) nlrule->oifindex = dev->ifindex; } if (tb[FRA_FWMARK]) { nlrule->mark = nla_get_u32(tb[FRA_FWMARK]); if (nlrule->mark) /* compatibility: if the mark value is non-zero all bits * are compared unless a mask is explicitly specified. */ nlrule->mark_mask = 0xFFFFFFFF; } if (tb[FRA_FWMASK]) nlrule->mark_mask = nla_get_u32(tb[FRA_FWMASK]); if (tb[FRA_TUN_ID]) nlrule->tun_id = nla_get_be64(tb[FRA_TUN_ID]); err = -EINVAL; if (tb[FRA_L3MDEV] && fib_nl2rule_l3mdev(tb[FRA_L3MDEV], nlrule, extack) < 0) goto errout_free; nlrule->action = frh->action; nlrule->flags = frh->flags; nlrule->table = frh_get_table(frh, tb); if (tb[FRA_SUPPRESS_PREFIXLEN]) nlrule->suppress_prefixlen = nla_get_u32(tb[FRA_SUPPRESS_PREFIXLEN]); else nlrule->suppress_prefixlen = -1; if (tb[FRA_SUPPRESS_IFGROUP]) nlrule->suppress_ifgroup = nla_get_u32(tb[FRA_SUPPRESS_IFGROUP]); else nlrule->suppress_ifgroup = -1; if (tb[FRA_GOTO]) { if (nlrule->action != FR_ACT_GOTO) { NL_SET_ERR_MSG(extack, "Unexpected goto"); goto errout_free; } nlrule->target = nla_get_u32(tb[FRA_GOTO]); /* Backward jumps are prohibited to avoid endless loops */ if (nlrule->target <= nlrule->pref) { NL_SET_ERR_MSG(extack, "Backward goto not supported"); goto errout_free; } } else if (nlrule->action == FR_ACT_GOTO) { NL_SET_ERR_MSG(extack, "Missing goto target for action goto"); goto errout_free; } if (nlrule->l3mdev && nlrule->table) { NL_SET_ERR_MSG(extack, "l3mdev and table are mutually exclusive"); goto errout_free; } if (tb[FRA_UID_RANGE]) { if (current_user_ns() != net->user_ns) { err = -EPERM; NL_SET_ERR_MSG(extack, "No permission to set uid"); goto errout_free; } nlrule->uid_range = nla_get_kuid_range(tb); if (!uid_range_set(&nlrule->uid_range) || !uid_lte(nlrule->uid_range.start, nlrule->uid_range.end)) { NL_SET_ERR_MSG(extack, "Invalid uid range"); goto errout_free; } } else { nlrule->uid_range = fib_kuid_range_unset; } if (tb[FRA_IP_PROTO]) nlrule->ip_proto = nla_get_u8(tb[FRA_IP_PROTO]); if (tb[FRA_SPORT_RANGE]) { err = nla_get_port_range(tb[FRA_SPORT_RANGE], &nlrule->sport_range); if (err) { NL_SET_ERR_MSG(extack, "Invalid sport range"); goto errout_free; } } if (tb[FRA_DPORT_RANGE]) { err = nla_get_port_range(tb[FRA_DPORT_RANGE], &nlrule->dport_range); if (err) { NL_SET_ERR_MSG(extack, "Invalid dport range"); goto errout_free; } } *rule = nlrule; return 0; errout_free: kfree(nlrule); errout: return err; } static int rule_exists(struct fib_rules_ops *ops, struct fib_rule_hdr *frh, struct nlattr **tb, struct fib_rule *rule) { struct fib_rule *r; list_for_each_entry(r, &ops->rules_list, list) { if (r->action != rule->action) continue; if (r->table != rule->table) continue; if (r->pref != rule->pref) continue; if (memcmp(r->iifname, rule->iifname, IFNAMSIZ)) continue; if (memcmp(r->oifname, rule->oifname, IFNAMSIZ)) continue; if (r->mark != rule->mark) continue; if (r->suppress_ifgroup != rule->suppress_ifgroup) continue; if (r->suppress_prefixlen != rule->suppress_prefixlen) continue; if (r->mark_mask != rule->mark_mask) continue; if (r->tun_id != rule->tun_id) continue; if (r->fr_net != rule->fr_net) continue; if (r->l3mdev != rule->l3mdev) continue; if (!uid_eq(r->uid_range.start, rule->uid_range.start) || !uid_eq(r->uid_range.end, rule->uid_range.end)) continue; if (r->ip_proto != rule->ip_proto) continue; if (r->proto != rule->proto) continue; if (!fib_rule_port_range_compare(&r->sport_range, &rule->sport_range)) continue; if (!fib_rule_port_range_compare(&r->dport_range, &rule->dport_range)) continue; if (!ops->compare(r, frh, tb)) continue; return 1; } return 0; } int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { struct net *net = sock_net(skb->sk); struct fib_rule_hdr *frh = nlmsg_data(nlh); struct fib_rules_ops *ops = NULL; struct fib_rule *rule = NULL, *r, *last = NULL; struct nlattr *tb[FRA_MAX + 1]; int err = -EINVAL, unresolved = 0; bool user_priority = false; if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { NL_SET_ERR_MSG(extack, "Invalid msg length"); goto errout; } ops = lookup_rules_ops(net, frh->family); if (!ops) { err = -EAFNOSUPPORT; NL_SET_ERR_MSG(extack, "Rule family not supported"); goto errout; } err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack); if (err < 0) { NL_SET_ERR_MSG(extack, "Error parsing msg"); goto errout; } err = fib_nl2rule(skb, nlh, extack, ops, tb, &rule, &user_priority); if (err) goto errout; if ((nlh->nlmsg_flags & NLM_F_EXCL) && rule_exists(ops, frh, tb, rule)) { err = -EEXIST; goto errout_free; } err = ops->configure(rule, skb, frh, tb, extack); if (err < 0) goto errout_free; err = call_fib_rule_notifiers(net, FIB_EVENT_RULE_ADD, rule, ops, extack); if (err < 0) goto errout_free; list_for_each_entry(r, &ops->rules_list, list) { if (r->pref == rule->target) { RCU_INIT_POINTER(rule->ctarget, r); break; } } if (rcu_dereference_protected(rule->ctarget, 1) == NULL) unresolved = 1; list_for_each_entry(r, &ops->rules_list, list) { if (r->pref > rule->pref) break; last = r; } if (last) list_add_rcu(&rule->list, &last->list); else list_add_rcu(&rule->list, &ops->rules_list); if (ops->unresolved_rules) { /* * There are unresolved goto rules in the list, check if * any of them are pointing to this new rule. */ list_for_each_entry(r, &ops->rules_list, list) { if (r->action == FR_ACT_GOTO && r->target == rule->pref && rtnl_dereference(r->ctarget) == NULL) { rcu_assign_pointer(r->ctarget, rule); if (--ops->unresolved_rules == 0) break; } } } if (rule->action == FR_ACT_GOTO) ops->nr_goto_rules++; if (unresolved) ops->unresolved_rules++; if (rule->tun_id) ip_tunnel_need_metadata(); notify_rule_change(RTM_NEWRULE, rule, ops, nlh, NETLINK_CB(skb).portid); flush_route_cache(ops); rules_ops_put(ops); return 0; errout_free: kfree(rule); errout: rules_ops_put(ops); return err; } EXPORT_SYMBOL_GPL(fib_nl_newrule); int fib_nl_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { struct net *net = sock_net(skb->sk); struct fib_rule_hdr *frh = nlmsg_data(nlh); struct fib_rules_ops *ops = NULL; struct fib_rule *rule = NULL, *r, *nlrule = NULL; struct nlattr *tb[FRA_MAX+1]; int err = -EINVAL; bool user_priority = false; if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { NL_SET_ERR_MSG(extack, "Invalid msg length"); goto errout; } ops = lookup_rules_ops(net, frh->family); if (ops == NULL) { err = -EAFNOSUPPORT; NL_SET_ERR_MSG(extack, "Rule family not supported"); goto errout; } err = nlmsg_parse_deprecated(nlh, sizeof(*frh), tb, FRA_MAX, ops->policy, extack); if (err < 0) { NL_SET_ERR_MSG(extack, "Error parsing msg"); goto errout; } err = fib_nl2rule(skb, nlh, extack, ops, tb, &nlrule, &user_priority); if (err) goto errout; rule = rule_find(ops, frh, tb, nlrule, user_priority); if (!rule) { err = -ENOENT; goto errout; } if (rule->flags & FIB_RULE_PERMANENT) { err = -EPERM; goto errout; } if (ops->delete) { err = ops->delete(rule); if (err) goto errout; } if (rule->tun_id) ip_tunnel_unneed_metadata(); list_del_rcu(&rule->list); if (rule->action == FR_ACT_GOTO) { ops->nr_goto_rules--; if (rtnl_dereference(rule->ctarget) == NULL) ops->unresolved_rules--; } /* * Check if this rule is a target to any of them. If so, * adjust to the next one with the same preference or * disable them. As this operation is eventually very * expensive, it is only performed if goto rules, except * current if it is goto rule, have actually been added. */ if (ops->nr_goto_rules > 0) { struct fib_rule *n; n = list_next_entry(rule, list); if (&n->list == &ops->rules_list || n->pref != rule->pref) n = NULL; list_for_each_entry(r, &ops->rules_list, list) { if (rtnl_dereference(r->ctarget) != rule) continue; rcu_assign_pointer(r->ctarget, n); if (!n) ops->unresolved_rules++; } } call_fib_rule_notifiers(net, FIB_EVENT_RULE_DEL, rule, ops, NULL); notify_rule_change(RTM_DELRULE, rule, ops, nlh, NETLINK_CB(skb).portid); fib_rule_put(rule); flush_route_cache(ops); rules_ops_put(ops); kfree(nlrule); return 0; errout: kfree(nlrule); rules_ops_put(ops); return err; } EXPORT_SYMBOL_GPL(fib_nl_delrule); static inline size_t fib_rule_nlmsg_size(struct fib_rules_ops *ops, struct fib_rule *rule) { size_t payload = NLMSG_ALIGN(sizeof(struct fib_rule_hdr)) + nla_total_size(IFNAMSIZ) /* FRA_IIFNAME */ + nla_total_size(IFNAMSIZ) /* FRA_OIFNAME */ + nla_total_size(4) /* FRA_PRIORITY */ + nla_total_size(4) /* FRA_TABLE */ + nla_total_size(4) /* FRA_SUPPRESS_PREFIXLEN */ + nla_total_size(4) /* FRA_SUPPRESS_IFGROUP */ + nla_total_size(4) /* FRA_FWMARK */ + nla_total_size(4) /* FRA_FWMASK */ + nla_total_size_64bit(8) /* FRA_TUN_ID */ + nla_total_size(sizeof(struct fib_kuid_range)) + nla_total_size(1) /* FRA_PROTOCOL */ + nla_total_size(1) /* FRA_IP_PROTO */ + nla_total_size(sizeof(struct fib_rule_port_range)) /* FRA_SPORT_RANGE */ + nla_total_size(sizeof(struct fib_rule_port_range)); /* FRA_DPORT_RANGE */ if (ops->nlmsg_payload) payload += ops->nlmsg_payload(rule); return payload; } static int fib_nl_fill_rule(struct sk_buff *skb, struct fib_rule *rule, u32 pid, u32 seq, int type, int flags, struct fib_rules_ops *ops) { struct nlmsghdr *nlh; struct fib_rule_hdr *frh; nlh = nlmsg_put(skb, pid, seq, type, sizeof(*frh), flags); if (nlh == NULL) return -EMSGSIZE; frh = nlmsg_data(nlh); frh->family = ops->family; frh->table = rule->table < 256 ? rule->table : RT_TABLE_COMPAT; if (nla_put_u32(skb, FRA_TABLE, rule->table)) goto nla_put_failure; if (nla_put_u32(skb, FRA_SUPPRESS_PREFIXLEN, rule->suppress_prefixlen)) goto nla_put_failure; frh->res1 = 0; frh->res2 = 0; frh->action = rule->action; frh->flags = rule->flags; if (nla_put_u8(skb, FRA_PROTOCOL, rule->proto)) goto nla_put_failure; if (rule->action == FR_ACT_GOTO && rcu_access_pointer(rule->ctarget) == NULL) frh->flags |= FIB_RULE_UNRESOLVED; if (rule->iifname[0]) { if (nla_put_string(skb, FRA_IIFNAME, rule->iifname)) goto nla_put_failure; if (rule->iifindex == -1) frh->flags |= FIB_RULE_IIF_DETACHED; } if (rule->oifname[0]) { if (nla_put_string(skb, FRA_OIFNAME, rule->oifname)) goto nla_put_failure; if (rule->oifindex == -1) frh->flags |= FIB_RULE_OIF_DETACHED; } if ((rule->pref && nla_put_u32(skb, FRA_PRIORITY, rule->pref)) || (rule->mark && nla_put_u32(skb, FRA_FWMARK, rule->mark)) || ((rule->mark_mask || rule->mark) && nla_put_u32(skb, FRA_FWMASK, rule->mark_mask)) || (rule->target && nla_put_u32(skb, FRA_GOTO, rule->target)) || (rule->tun_id && nla_put_be64(skb, FRA_TUN_ID, rule->tun_id, FRA_PAD)) || (rule->l3mdev && nla_put_u8(skb, FRA_L3MDEV, rule->l3mdev)) || (uid_range_set(&rule->uid_range) && nla_put_uid_range(skb, &rule->uid_range)) || (fib_rule_port_range_set(&rule->sport_range) && nla_put_port_range(skb, FRA_SPORT_RANGE, &rule->sport_range)) || (fib_rule_port_range_set(&rule->dport_range) && nla_put_port_range(skb, FRA_DPORT_RANGE, &rule->dport_range)) || (rule->ip_proto && nla_put_u8(skb, FRA_IP_PROTO, rule->ip_proto))) goto nla_put_failure; if (rule->suppress_ifgroup != -1) { if (nla_put_u32(skb, FRA_SUPPRESS_IFGROUP, rule->suppress_ifgroup)) goto nla_put_failure; } if (ops->fill(rule, skb, frh) < 0) goto nla_put_failure; nlmsg_end(skb, nlh); return 0; nla_put_failure: nlmsg_cancel(skb, nlh); return -EMSGSIZE; } static int dump_rules(struct sk_buff *skb, struct netlink_callback *cb, struct fib_rules_ops *ops) { int idx = 0; struct fib_rule *rule; int err = 0; rcu_read_lock(); list_for_each_entry_rcu(rule, &ops->rules_list, list) { if (idx < cb->args[1]) goto skip; err = fib_nl_fill_rule(skb, rule, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, RTM_NEWRULE, NLM_F_MULTI, ops); if (err) break; skip: idx++; } rcu_read_unlock(); cb->args[1] = idx; rules_ops_put(ops); return err; } static int fib_valid_dumprule_req(const struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { struct fib_rule_hdr *frh; if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*frh))) { NL_SET_ERR_MSG(extack, "Invalid header for fib rule dump request"); return -EINVAL; } frh = nlmsg_data(nlh); if (frh->dst_len || frh->src_len || frh->tos || frh->table || frh->res1 || frh->res2 || frh->action || frh->flags) { NL_SET_ERR_MSG(extack, "Invalid values in header for fib rule dump request"); return -EINVAL; } if (nlmsg_attrlen(nlh, sizeof(*frh))) { NL_SET_ERR_MSG(extack, "Invalid data after header in fib rule dump request"); return -EINVAL; } return 0; } static int fib_nl_dumprule(struct sk_buff *skb, struct netlink_callback *cb) { const struct nlmsghdr *nlh = cb->nlh; struct net *net = sock_net(skb->sk); struct fib_rules_ops *ops; int idx = 0, family; if (cb->strict_check) { int err = fib_valid_dumprule_req(nlh, cb->extack); if (err < 0) return err; } family = rtnl_msg_family(nlh); if (family != AF_UNSPEC) { /* Protocol specific dump request */ ops = lookup_rules_ops(net, family); if (ops == NULL) return -EAFNOSUPPORT; dump_rules(skb, cb, ops); return skb->len; } rcu_read_lock(); list_for_each_entry_rcu(ops, &net->rules_ops, list) { if (idx < cb->args[0] || !try_module_get(ops->owner)) goto skip; if (dump_rules(skb, cb, ops) < 0) break; cb->args[1] = 0; skip: idx++; } rcu_read_unlock(); cb->args[0] = idx; return skb->len; } static void notify_rule_change(int event, struct fib_rule *rule, struct fib_rules_ops *ops, struct nlmsghdr *nlh, u32 pid) { struct net *net; struct sk_buff *skb; int err = -ENOMEM; net = ops->fro_net; skb = nlmsg_new(fib_rule_nlmsg_size(ops, rule), GFP_KERNEL); if (skb == NULL) goto errout; err = fib_nl_fill_rule(skb, rule, pid, nlh->nlmsg_seq, event, 0, ops); if (err < 0) { /* -EMSGSIZE implies BUG in fib_rule_nlmsg_size() */ WARN_ON(err == -EMSGSIZE); kfree_skb(skb); goto errout; } rtnl_notify(skb, net, pid, ops->nlgroup, nlh, GFP_KERNEL); return; errout: if (err < 0) rtnl_set_sk_err(net, ops->nlgroup, err); } static void attach_rules(struct list_head *rules, struct net_device *dev) { struct fib_rule *rule; list_for_each_entry(rule, rules, list) { if (rule->iifindex == -1 && strcmp(dev->name, rule->iifname) == 0) rule->iifindex = dev->ifindex; if (rule->oifindex == -1 && strcmp(dev->name, rule->oifname) == 0) rule->oifindex = dev->ifindex; } } static void detach_rules(struct list_head *rules, struct net_device *dev) { struct fib_rule *rule; list_for_each_entry(rule, rules, list) { if (rule->iifindex == dev->ifindex) rule->iifindex = -1; if (rule->oifindex == dev->ifindex) rule->oifindex = -1; } } static int fib_rules_event(struct notifier_block *this, unsigned long event, void *ptr) { struct net_device *dev = netdev_notifier_info_to_dev(ptr); struct net *net = dev_net(dev); struct fib_rules_ops *ops; ASSERT_RTNL(); switch (event) { case NETDEV_REGISTER: list_for_each_entry(ops, &net->rules_ops, list) attach_rules(&ops->rules_list, dev); break; case NETDEV_CHANGENAME: list_for_each_entry(ops, &net->rules_ops, list) { detach_rules(&ops->rules_list, dev); attach_rules(&ops->rules_list, dev); } break; case NETDEV_UNREGISTER: list_for_each_entry(ops, &net->rules_ops, list) detach_rules(&ops->rules_list, dev); break; } return NOTIFY_DONE; } static struct notifier_block fib_rules_notifier = { .notifier_call = fib_rules_event, }; static int __net_init fib_rules_net_init(struct net *net) { INIT_LIST_HEAD(&net->rules_ops); spin_lock_init(&net->rules_mod_lock); return 0; } static void __net_exit fib_rules_net_exit(struct net *net) { WARN_ON_ONCE(!list_empty(&net->rules_ops)); } static struct pernet_operations fib_rules_net_ops = { .init = fib_rules_net_init, .exit = fib_rules_net_exit, }; static int __init fib_rules_init(void) { int err; rtnl_register(PF_UNSPEC, RTM_NEWRULE, fib_nl_newrule, NULL, 0); rtnl_register(PF_UNSPEC, RTM_DELRULE, fib_nl_delrule, NULL, 0); rtnl_register(PF_UNSPEC, RTM_GETRULE, NULL, fib_nl_dumprule, 0); err = register_pernet_subsys(&fib_rules_net_ops); if (err < 0) goto fail; err = register_netdevice_notifier(&fib_rules_notifier); if (err < 0) goto fail_unregister; return 0; fail_unregister: unregister_pernet_subsys(&fib_rules_net_ops); fail: rtnl_unregister(PF_UNSPEC, RTM_NEWRULE); rtnl_unregister(PF_UNSPEC, RTM_DELRULE); rtnl_unregister(PF_UNSPEC, RTM_GETRULE); return err; } subsys_initcall(fib_rules_init);
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3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 /* SPDX-License-Identifier: GPL-2.0 */ /* Copyright (c) 2018 Facebook */ #include <uapi/linux/btf.h> #include <uapi/linux/types.h> #include <linux/seq_file.h> #include <linux/compiler.h> #include <linux/ctype.h> #include <linux/errno.h> #include <linux/slab.h> #include <linux/anon_inodes.h> #include <linux/file.h> #include <linux/uaccess.h> #include <linux/kernel.h> #include <linux/idr.h> #include <linux/sort.h> #include <linux/bpf_verifier.h> #include <linux/btf.h> /* BTF (BPF Type Format) is the meta data format which describes * the data types of BPF program/map. Hence, it basically focus * on the C programming language which the modern BPF is primary * using. * * ELF Section: * ~~~~~~~~~~~ * The BTF data is stored under the ".BTF" ELF section * * struct btf_type: * ~~~~~~~~~~~~~~~ * Each 'struct btf_type' object describes a C data type. * Depending on the type it is describing, a 'struct btf_type' * object may be followed by more data. F.e. * To describe an array, 'struct btf_type' is followed by * 'struct btf_array'. * * 'struct btf_type' and any extra data following it are * 4 bytes aligned. * * Type section: * ~~~~~~~~~~~~~ * The BTF type section contains a list of 'struct btf_type' objects. * Each one describes a C type. Recall from the above section * that a 'struct btf_type' object could be immediately followed by extra * data in order to desribe some particular C types. * * type_id: * ~~~~~~~ * Each btf_type object is identified by a type_id. The type_id * is implicitly implied by the location of the btf_type object in * the BTF type section. The first one has type_id 1. The second * one has type_id 2...etc. Hence, an earlier btf_type has * a smaller type_id. * * A btf_type object may refer to another btf_type object by using * type_id (i.e. the "type" in the "struct btf_type"). * * NOTE that we cannot assume any reference-order. * A btf_type object can refer to an earlier btf_type object * but it can also refer to a later btf_type object. * * For example, to describe "const void *". A btf_type * object describing "const" may refer to another btf_type * object describing "void *". This type-reference is done * by specifying type_id: * * [1] CONST (anon) type_id=2 * [2] PTR (anon) type_id=0 * * The above is the btf_verifier debug log: * - Each line started with "[?]" is a btf_type object * - [?] is the type_id of the btf_type object. * - CONST/PTR is the BTF_KIND_XXX * - "(anon)" is the name of the type. It just * happens that CONST and PTR has no name. * - type_id=XXX is the 'u32 type' in btf_type * * NOTE: "void" has type_id 0 * * String section: * ~~~~~~~~~~~~~~ * The BTF string section contains the names used by the type section. * Each string is referred by an "offset" from the beginning of the * string section. * * Each string is '\0' terminated. * * The first character in the string section must be '\0' * which is used to mean 'anonymous'. Some btf_type may not * have a name. */ /* BTF verification: * * To verify BTF data, two passes are needed. * * Pass #1 * ~~~~~~~ * The first pass is to collect all btf_type objects to * an array: "btf->types". * * Depending on the C type that a btf_type is describing, * a btf_type may be followed by extra data. We don't know * how many btf_type is there, and more importantly we don't * know where each btf_type is located in the type section. * * Without knowing the location of each type_id, most verifications * cannot be done. e.g. an earlier btf_type may refer to a later * btf_type (recall the "const void *" above), so we cannot * check this type-reference in the first pass. * * In the first pass, it still does some verifications (e.g. * checking the name is a valid offset to the string section). * * Pass #2 * ~~~~~~~ * The main focus is to resolve a btf_type that is referring * to another type. * * We have to ensure the referring type: * 1) does exist in the BTF (i.e. in btf->types[]) * 2) does not cause a loop: * struct A { * struct B b; * }; * * struct B { * struct A a; * }; * * btf_type_needs_resolve() decides if a btf_type needs * to be resolved. * * The needs_resolve type implements the "resolve()" ops which * essentially does a DFS and detects backedge. * * During resolve (or DFS), different C types have different * "RESOLVED" conditions. * * When resolving a BTF_KIND_STRUCT, we need to resolve all its * members because a member is always referring to another * type. A struct's member can be treated as "RESOLVED" if * it is referring to a BTF_KIND_PTR. Otherwise, the * following valid C struct would be rejected: * * struct A { * int m; * struct A *a; * }; * * When resolving a BTF_KIND_PTR, it needs to keep resolving if * it is referring to another BTF_KIND_PTR. Otherwise, we cannot * detect a pointer loop, e.g.: * BTF_KIND_CONST -> BTF_KIND_PTR -> BTF_KIND_CONST -> BTF_KIND_PTR + * ^ | * +-----------------------------------------+ * */ #define BITS_PER_U128 (sizeof(u64) * BITS_PER_BYTE * 2) #define BITS_PER_BYTE_MASK (BITS_PER_BYTE - 1) #define BITS_PER_BYTE_MASKED(bits) ((bits) & BITS_PER_BYTE_MASK) #define BITS_ROUNDDOWN_BYTES(bits) ((bits) >> 3) #define BITS_ROUNDUP_BYTES(bits) \ (BITS_ROUNDDOWN_BYTES(bits) + !!BITS_PER_BYTE_MASKED(bits)) #define BTF_INFO_MASK 0x8f00ffff #define BTF_INT_MASK 0x0fffffff #define BTF_TYPE_ID_VALID(type_id) ((type_id) <= BTF_MAX_TYPE) #define BTF_STR_OFFSET_VALID(name_off) ((name_off) <= BTF_MAX_NAME_OFFSET) /* 16MB for 64k structs and each has 16 members and * a few MB spaces for the string section. * The hard limit is S32_MAX. */ #define BTF_MAX_SIZE (16 * 1024 * 1024) #define for_each_member(i, struct_type, member) \ for (i = 0, member = btf_type_member(struct_type); \ i < btf_type_vlen(struct_type); \ i++, member++) #define for_each_member_from(i, from, struct_type, member) \ for (i = from, member = btf_type_member(struct_type) + from; \ i < btf_type_vlen(struct_type); \ i++, member++) #define for_each_vsi(i, struct_type, member) \ for (i = 0, member = btf_type_var_secinfo(struct_type); \ i < btf_type_vlen(struct_type); \ i++, member++) #define for_each_vsi_from(i, from, struct_type, member) \ for (i = from, member = btf_type_var_secinfo(struct_type) + from; \ i < btf_type_vlen(struct_type); \ i++, member++) DEFINE_IDR(btf_idr); DEFINE_SPINLOCK(btf_idr_lock); struct btf { void *data; struct btf_type **types; u32 *resolved_ids; u32 *resolved_sizes; const char *strings; void *nohdr_data; struct btf_header hdr; u32 nr_types; u32 types_size; u32 data_size; refcount_t refcnt; u32 id; struct rcu_head rcu; }; enum verifier_phase { CHECK_META, CHECK_TYPE, }; struct resolve_vertex { const struct btf_type *t; u32 type_id; u16 next_member; }; enum visit_state { NOT_VISITED, VISITED, RESOLVED, }; enum resolve_mode { RESOLVE_TBD, /* To Be Determined */ RESOLVE_PTR, /* Resolving for Pointer */ RESOLVE_STRUCT_OR_ARRAY, /* Resolving for struct/union * or array */ }; #define MAX_RESOLVE_DEPTH 32 struct btf_sec_info { u32 off; u32 len; }; struct btf_verifier_env { struct btf *btf; u8 *visit_states; struct resolve_vertex stack[MAX_RESOLVE_DEPTH]; struct bpf_verifier_log log; u32 log_type_id; u32 top_stack; enum verifier_phase phase; enum resolve_mode resolve_mode; }; static const char * const btf_kind_str[NR_BTF_KINDS] = { [BTF_KIND_UNKN] = "UNKNOWN", [BTF_KIND_INT] = "INT", [BTF_KIND_PTR] = "PTR", [BTF_KIND_ARRAY] = "ARRAY", [BTF_KIND_STRUCT] = "STRUCT", [BTF_KIND_UNION] = "UNION", [BTF_KIND_ENUM] = "ENUM", [BTF_KIND_FWD] = "FWD", [BTF_KIND_TYPEDEF] = "TYPEDEF", [BTF_KIND_VOLATILE] = "VOLATILE", [BTF_KIND_CONST] = "CONST", [BTF_KIND_RESTRICT] = "RESTRICT", [BTF_KIND_FUNC] = "FUNC", [BTF_KIND_FUNC_PROTO] = "FUNC_PROTO", [BTF_KIND_VAR] = "VAR", [BTF_KIND_DATASEC] = "DATASEC", }; struct btf_kind_operations { s32 (*check_meta)(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left); int (*resolve)(struct btf_verifier_env *env, const struct resolve_vertex *v); int (*check_member)(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type); int (*check_kflag_member)(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type); void (*log_details)(struct btf_verifier_env *env, const struct btf_type *t); void (*seq_show)(const struct btf *btf, const struct btf_type *t, u32 type_id, void *data, u8 bits_offsets, struct seq_file *m); }; static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS]; static struct btf_type btf_void; static int btf_resolve(struct btf_verifier_env *env, const struct btf_type *t, u32 type_id); static bool btf_type_is_modifier(const struct btf_type *t) { /* Some of them is not strictly a C modifier * but they are grouped into the same bucket * for BTF concern: * A type (t) that refers to another * type through t->type AND its size cannot * be determined without following the t->type. * * ptr does not fall into this bucket * because its size is always sizeof(void *). */ switch (BTF_INFO_KIND(t->info)) { case BTF_KIND_TYPEDEF: case BTF_KIND_VOLATILE: case BTF_KIND_CONST: case BTF_KIND_RESTRICT: return true; } return false; } bool btf_type_is_void(const struct btf_type *t) { return t == &btf_void; } static bool btf_type_is_fwd(const struct btf_type *t) { return BTF_INFO_KIND(t->info) == BTF_KIND_FWD; } static bool btf_type_is_func(const struct btf_type *t) { return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC; } static bool btf_type_is_func_proto(const struct btf_type *t) { return BTF_INFO_KIND(t->info) == BTF_KIND_FUNC_PROTO; } static bool btf_type_nosize(const struct btf_type *t) { return btf_type_is_void(t) || btf_type_is_fwd(t) || btf_type_is_func(t) || btf_type_is_func_proto(t); } static bool btf_type_nosize_or_null(const struct btf_type *t) { return !t || btf_type_nosize(t); } /* union is only a special case of struct: * all its offsetof(member) == 0 */ static bool btf_type_is_struct(const struct btf_type *t) { u8 kind = BTF_INFO_KIND(t->info); return kind == BTF_KIND_STRUCT || kind == BTF_KIND_UNION; } static bool __btf_type_is_struct(const struct btf_type *t) { return BTF_INFO_KIND(t->info) == BTF_KIND_STRUCT; } static bool btf_type_is_array(const struct btf_type *t) { return BTF_INFO_KIND(t->info) == BTF_KIND_ARRAY; } static bool btf_type_is_ptr(const struct btf_type *t) { return BTF_INFO_KIND(t->info) == BTF_KIND_PTR; } static bool btf_type_is_int(const struct btf_type *t) { return BTF_INFO_KIND(t->info) == BTF_KIND_INT; } static bool btf_type_is_var(const struct btf_type *t) { return BTF_INFO_KIND(t->info) == BTF_KIND_VAR; } static bool btf_type_is_datasec(const struct btf_type *t) { return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC; } /* Types that act only as a source, not sink or intermediate * type when resolving. */ static bool btf_type_is_resolve_source_only(const struct btf_type *t) { return btf_type_is_var(t) || btf_type_is_datasec(t); } /* What types need to be resolved? * * btf_type_is_modifier() is an obvious one. * * btf_type_is_struct() because its member refers to * another type (through member->type). * * btf_type_is_var() because the variable refers to * another type. btf_type_is_datasec() holds multiple * btf_type_is_var() types that need resolving. * * btf_type_is_array() because its element (array->type) * refers to another type. Array can be thought of a * special case of struct while array just has the same * member-type repeated by array->nelems of times. */ static bool btf_type_needs_resolve(const struct btf_type *t) { return btf_type_is_modifier(t) || btf_type_is_ptr(t) || btf_type_is_struct(t) || btf_type_is_array(t) || btf_type_is_var(t) || btf_type_is_datasec(t); } /* t->size can be used */ static bool btf_type_has_size(const struct btf_type *t) { switch (BTF_INFO_KIND(t->info)) { case BTF_KIND_INT: case BTF_KIND_STRUCT: case BTF_KIND_UNION: case BTF_KIND_ENUM: case BTF_KIND_DATASEC: return true; } return false; } static const char *btf_int_encoding_str(u8 encoding) { if (encoding == 0) return "(none)"; else if (encoding == BTF_INT_SIGNED) return "SIGNED"; else if (encoding == BTF_INT_CHAR) return "CHAR"; else if (encoding == BTF_INT_BOOL) return "BOOL"; else return "UNKN"; } static u16 btf_type_vlen(const struct btf_type *t) { return BTF_INFO_VLEN(t->info); } static bool btf_type_kflag(const struct btf_type *t) { return BTF_INFO_KFLAG(t->info); } static u32 btf_member_bit_offset(const struct btf_type *struct_type, const struct btf_member *member) { return btf_type_kflag(struct_type) ? BTF_MEMBER_BIT_OFFSET(member->offset) : member->offset; } static u32 btf_member_bitfield_size(const struct btf_type *struct_type, const struct btf_member *member) { return btf_type_kflag(struct_type) ? BTF_MEMBER_BITFIELD_SIZE(member->offset) : 0; } static u32 btf_type_int(const struct btf_type *t) { return *(u32 *)(t + 1); } static const struct btf_array *btf_type_array(const struct btf_type *t) { return (const struct btf_array *)(t + 1); } static const struct btf_member *btf_type_member(const struct btf_type *t) { return (const struct btf_member *)(t + 1); } static const struct btf_enum *btf_type_enum(const struct btf_type *t) { return (const struct btf_enum *)(t + 1); } static const struct btf_var *btf_type_var(const struct btf_type *t) { return (const struct btf_var *)(t + 1); } static const struct btf_var_secinfo *btf_type_var_secinfo(const struct btf_type *t) { return (const struct btf_var_secinfo *)(t + 1); } static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t) { return kind_ops[BTF_INFO_KIND(t->info)]; } static bool btf_name_offset_valid(const struct btf *btf, u32 offset) { return BTF_STR_OFFSET_VALID(offset) && offset < btf->hdr.str_len; } static bool __btf_name_char_ok(char c, bool first, bool dot_ok) { if ((first ? !isalpha(c) : !isalnum(c)) && c != '_' && ((c == '.' && !dot_ok) || c != '.')) return false; return true; } static bool __btf_name_valid(const struct btf *btf, u32 offset, bool dot_ok) { /* offset must be valid */ const char *src = &btf->strings[offset]; const char *src_limit; if (!__btf_name_char_ok(*src, true, dot_ok)) return false; /* set a limit on identifier length */ src_limit = src + KSYM_NAME_LEN; src++; while (*src && src < src_limit) { if (!__btf_name_char_ok(*src, false, dot_ok)) return false; src++; } return !*src; } /* Only C-style identifier is permitted. This can be relaxed if * necessary. */ static bool btf_name_valid_identifier(const struct btf *btf, u32 offset) { return __btf_name_valid(btf, offset, false); } static bool btf_name_valid_section(const struct btf *btf, u32 offset) { return __btf_name_valid(btf, offset, true); } static const char *__btf_name_by_offset(const struct btf *btf, u32 offset) { if (!offset) return "(anon)"; else if (offset < btf->hdr.str_len) return &btf->strings[offset]; else return "(invalid-name-offset)"; } const char *btf_name_by_offset(const struct btf *btf, u32 offset) { if (offset < btf->hdr.str_len) return &btf->strings[offset]; return NULL; } const struct btf_type *btf_type_by_id(const struct btf *btf, u32 type_id) { if (type_id > btf->nr_types) return NULL; return btf->types[type_id]; } /* * Regular int is not a bit field and it must be either * u8/u16/u32/u64 or __int128. */ static bool btf_type_int_is_regular(const struct btf_type *t) { u8 nr_bits, nr_bytes; u32 int_data; int_data = btf_type_int(t); nr_bits = BTF_INT_BITS(int_data); nr_bytes = BITS_ROUNDUP_BYTES(nr_bits); if (BITS_PER_BYTE_MASKED(nr_bits) || BTF_INT_OFFSET(int_data) || (nr_bytes != sizeof(u8) && nr_bytes != sizeof(u16) && nr_bytes != sizeof(u32) && nr_bytes != sizeof(u64) && nr_bytes != (2 * sizeof(u64)))) { return false; } return true; } /* * Check that given struct member is a regular int with expected * offset and size. */ bool btf_member_is_reg_int(const struct btf *btf, const struct btf_type *s, const struct btf_member *m, u32 expected_offset, u32 expected_size) { const struct btf_type *t; u32 id, int_data; u8 nr_bits; id = m->type; t = btf_type_id_size(btf, &id, NULL); if (!t || !btf_type_is_int(t)) return false; int_data = btf_type_int(t); nr_bits = BTF_INT_BITS(int_data); if (btf_type_kflag(s)) { u32 bitfield_size = BTF_MEMBER_BITFIELD_SIZE(m->offset); u32 bit_offset = BTF_MEMBER_BIT_OFFSET(m->offset); /* if kflag set, int should be a regular int and * bit offset should be at byte boundary. */ return !bitfield_size && BITS_ROUNDUP_BYTES(bit_offset) == expected_offset && BITS_ROUNDUP_BYTES(nr_bits) == expected_size; } if (BTF_INT_OFFSET(int_data) || BITS_PER_BYTE_MASKED(m->offset) || BITS_ROUNDUP_BYTES(m->offset) != expected_offset || BITS_PER_BYTE_MASKED(nr_bits) || BITS_ROUNDUP_BYTES(nr_bits) != expected_size) return false; return true; } __printf(2, 3) static void __btf_verifier_log(struct bpf_verifier_log *log, const char *fmt, ...) { va_list args; va_start(args, fmt); bpf_verifier_vlog(log, fmt, args); va_end(args); } __printf(2, 3) static void btf_verifier_log(struct btf_verifier_env *env, const char *fmt, ...) { struct bpf_verifier_log *log = &env->log; va_list args; if (!bpf_verifier_log_needed(log)) return; va_start(args, fmt); bpf_verifier_vlog(log, fmt, args); va_end(args); } __printf(4, 5) static void __btf_verifier_log_type(struct btf_verifier_env *env, const struct btf_type *t, bool log_details, const char *fmt, ...) { struct bpf_verifier_log *log = &env->log; u8 kind = BTF_INFO_KIND(t->info); struct btf *btf = env->btf; va_list args; if (!bpf_verifier_log_needed(log)) return; __btf_verifier_log(log, "[%u] %s %s%s", env->log_type_id, btf_kind_str[kind], __btf_name_by_offset(btf, t->name_off), log_details ? " " : ""); if (log_details) btf_type_ops(t)->log_details(env, t); if (fmt && *fmt) { __btf_verifier_log(log, " "); va_start(args, fmt); bpf_verifier_vlog(log, fmt, args); va_end(args); } __btf_verifier_log(log, "\n"); } #define btf_verifier_log_type(env, t, ...) \ __btf_verifier_log_type((env), (t), true, __VA_ARGS__) #define btf_verifier_log_basic(env, t, ...) \ __btf_verifier_log_type((env), (t), false, __VA_ARGS__) __printf(4, 5) static void btf_verifier_log_member(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const char *fmt, ...) { struct bpf_verifier_log *log = &env->log; struct btf *btf = env->btf; va_list args; if (!bpf_verifier_log_needed(log)) return; /* The CHECK_META phase already did a btf dump. * * If member is logged again, it must hit an error in * parsing this member. It is useful to print out which * struct this member belongs to. */ if (env->phase != CHECK_META) btf_verifier_log_type(env, struct_type, NULL); if (btf_type_kflag(struct_type)) __btf_verifier_log(log, "\t%s type_id=%u bitfield_size=%u bits_offset=%u", __btf_name_by_offset(btf, member->name_off), member->type, BTF_MEMBER_BITFIELD_SIZE(member->offset), BTF_MEMBER_BIT_OFFSET(member->offset)); else __btf_verifier_log(log, "\t%s type_id=%u bits_offset=%u", __btf_name_by_offset(btf, member->name_off), member->type, member->offset); if (fmt && *fmt) { __btf_verifier_log(log, " "); va_start(args, fmt); bpf_verifier_vlog(log, fmt, args); va_end(args); } __btf_verifier_log(log, "\n"); } __printf(4, 5) static void btf_verifier_log_vsi(struct btf_verifier_env *env, const struct btf_type *datasec_type, const struct btf_var_secinfo *vsi, const char *fmt, ...) { struct bpf_verifier_log *log = &env->log; va_list args; if (!bpf_verifier_log_needed(log)) return; if (env->phase != CHECK_META) btf_verifier_log_type(env, datasec_type, NULL); __btf_verifier_log(log, "\t type_id=%u offset=%u size=%u", vsi->type, vsi->offset, vsi->size); if (fmt && *fmt) { __btf_verifier_log(log, " "); va_start(args, fmt); bpf_verifier_vlog(log, fmt, args); va_end(args); } __btf_verifier_log(log, "\n"); } static void btf_verifier_log_hdr(struct btf_verifier_env *env, u32 btf_data_size) { struct bpf_verifier_log *log = &env->log; const struct btf *btf = env->btf; const struct btf_header *hdr; if (!bpf_verifier_log_needed(log)) return; hdr = &btf->hdr; __btf_verifier_log(log, "magic: 0x%x\n", hdr->magic); __btf_verifier_log(log, "version: %u\n", hdr->version); __btf_verifier_log(log, "flags: 0x%x\n", hdr->flags); __btf_verifier_log(log, "hdr_len: %u\n", hdr->hdr_len); __btf_verifier_log(log, "type_off: %u\n", hdr->type_off); __btf_verifier_log(log, "type_len: %u\n", hdr->type_len); __btf_verifier_log(log, "str_off: %u\n", hdr->str_off); __btf_verifier_log(log, "str_len: %u\n", hdr->str_len); __btf_verifier_log(log, "btf_total_size: %u\n", btf_data_size); } static int btf_add_type(struct btf_verifier_env *env, struct btf_type *t) { struct btf *btf = env->btf; /* < 2 because +1 for btf_void which is always in btf->types[0]. * btf_void is not accounted in btf->nr_types because btf_void * does not come from the BTF file. */ if (btf->types_size - btf->nr_types < 2) { /* Expand 'types' array */ struct btf_type **new_types; u32 expand_by, new_size; if (btf->types_size == BTF_MAX_TYPE) { btf_verifier_log(env, "Exceeded max num of types"); return -E2BIG; } expand_by = max_t(u32, btf->types_size >> 2, 16); new_size = min_t(u32, BTF_MAX_TYPE, btf->types_size + expand_by); new_types = kvcalloc(new_size, sizeof(*new_types), GFP_KERNEL | __GFP_NOWARN); if (!new_types) return -ENOMEM; if (btf->nr_types == 0) new_types[0] = &btf_void; else memcpy(new_types, btf->types, sizeof(*btf->types) * (btf->nr_types + 1)); kvfree(btf->types); btf->types = new_types; btf->types_size = new_size; } btf->types[++(btf->nr_types)] = t; return 0; } static int btf_alloc_id(struct btf *btf) { int id; idr_preload(GFP_KERNEL); spin_lock_bh(&btf_idr_lock); id = idr_alloc_cyclic(&btf_idr, btf, 1, INT_MAX, GFP_ATOMIC); if (id > 0) btf->id = id; spin_unlock_bh(&btf_idr_lock); idr_preload_end(); if (WARN_ON_ONCE(!id)) return -ENOSPC; return id > 0 ? 0 : id; } static void btf_free_id(struct btf *btf) { unsigned long flags; /* * In map-in-map, calling map_delete_elem() on outer * map will call bpf_map_put on the inner map. * It will then eventually call btf_free_id() * on the inner map. Some of the map_delete_elem() * implementation may have irq disabled, so * we need to use the _irqsave() version instead * of the _bh() version. */ spin_lock_irqsave(&btf_idr_lock, flags); idr_remove(&btf_idr, btf->id); spin_unlock_irqrestore(&btf_idr_lock, flags); } static void btf_free(struct btf *btf) { kvfree(btf->types); kvfree(btf->resolved_sizes); kvfree(btf->resolved_ids); kvfree(btf->data); kfree(btf); } static void btf_free_rcu(struct rcu_head *rcu) { struct btf *btf = container_of(rcu, struct btf, rcu); btf_free(btf); } void btf_put(struct btf *btf) { if (btf && refcount_dec_and_test(&btf->refcnt)) { btf_free_id(btf); call_rcu(&btf->rcu, btf_free_rcu); } } static int env_resolve_init(struct btf_verifier_env *env) { struct btf *btf = env->btf; u32 nr_types = btf->nr_types; u32 *resolved_sizes = NULL; u32 *resolved_ids = NULL; u8 *visit_states = NULL; /* +1 for btf_void */ resolved_sizes = kvcalloc(nr_types + 1, sizeof(*resolved_sizes), GFP_KERNEL | __GFP_NOWARN); if (!resolved_sizes) goto nomem; resolved_ids = kvcalloc(nr_types + 1, sizeof(*resolved_ids), GFP_KERNEL | __GFP_NOWARN); if (!resolved_ids) goto nomem; visit_states = kvcalloc(nr_types + 1, sizeof(*visit_states), GFP_KERNEL | __GFP_NOWARN); if (!visit_states) goto nomem; btf->resolved_sizes = resolved_sizes; btf->resolved_ids = resolved_ids; env->visit_states = visit_states; return 0; nomem: kvfree(resolved_sizes); kvfree(resolved_ids); kvfree(visit_states); return -ENOMEM; } static void btf_verifier_env_free(struct btf_verifier_env *env) { kvfree(env->visit_states); kfree(env); } static bool env_type_is_resolve_sink(const struct btf_verifier_env *env, const struct btf_type *next_type) { switch (env->resolve_mode) { case RESOLVE_TBD: /* int, enum or void is a sink */ return !btf_type_needs_resolve(next_type); case RESOLVE_PTR: /* int, enum, void, struct, array, func or func_proto is a sink * for ptr */ return !btf_type_is_modifier(next_type) && !btf_type_is_ptr(next_type); case RESOLVE_STRUCT_OR_ARRAY: /* int, enum, void, ptr, func or func_proto is a sink * for struct and array */ return !btf_type_is_modifier(next_type) && !btf_type_is_array(next_type) && !btf_type_is_struct(next_type); default: BUG(); } } static bool env_type_is_resolved(const struct btf_verifier_env *env, u32 type_id) { return env->visit_states[type_id] == RESOLVED; } static int env_stack_push(struct btf_verifier_env *env, const struct btf_type *t, u32 type_id) { struct resolve_vertex *v; if (env->top_stack == MAX_RESOLVE_DEPTH) return -E2BIG; if (env->visit_states[type_id] != NOT_VISITED) return -EEXIST; env->visit_states[type_id] = VISITED; v = &env->stack[env->top_stack++]; v->t = t; v->type_id = type_id; v->next_member = 0; if (env->resolve_mode == RESOLVE_TBD) { if (btf_type_is_ptr(t)) env->resolve_mode = RESOLVE_PTR; else if (btf_type_is_struct(t) || btf_type_is_array(t)) env->resolve_mode = RESOLVE_STRUCT_OR_ARRAY; } return 0; } static void env_stack_set_next_member(struct btf_verifier_env *env, u16 next_member) { env->stack[env->top_stack - 1].next_member = next_member; } static void env_stack_pop_resolved(struct btf_verifier_env *env, u32 resolved_type_id, u32 resolved_size) { u32 type_id = env->stack[--(env->top_stack)].type_id; struct btf *btf = env->btf; btf->resolved_sizes[type_id] = resolved_size; btf->resolved_ids[type_id] = resolved_type_id; env->visit_states[type_id] = RESOLVED; } static const struct resolve_vertex *env_stack_peak(struct btf_verifier_env *env) { return env->top_stack ? &env->stack[env->top_stack - 1] : NULL; } /* The input param "type_id" must point to a needs_resolve type */ static const struct btf_type *btf_type_id_resolve(const struct btf *btf, u32 *type_id) { *type_id = btf->resolved_ids[*type_id]; return btf_type_by_id(btf, *type_id); } const struct btf_type *btf_type_id_size(const struct btf *btf, u32 *type_id, u32 *ret_size) { const struct btf_type *size_type; u32 size_type_id = *type_id; u32 size = 0; size_type = btf_type_by_id(btf, size_type_id); if (btf_type_nosize_or_null(size_type)) return NULL; if (btf_type_has_size(size_type)) { size = size_type->size; } else if (btf_type_is_array(size_type)) { size = btf->resolved_sizes[size_type_id]; } else if (btf_type_is_ptr(size_type)) { size = sizeof(void *); } else { if (WARN_ON_ONCE(!btf_type_is_modifier(size_type) && !btf_type_is_var(size_type))) return NULL; size_type_id = btf->resolved_ids[size_type_id]; size_type = btf_type_by_id(btf, size_type_id); if (btf_type_nosize_or_null(size_type)) return NULL; else if (btf_type_has_size(size_type)) size = size_type->size; else if (btf_type_is_array(size_type)) size = btf->resolved_sizes[size_type_id]; else if (btf_type_is_ptr(size_type)) size = sizeof(void *); else return NULL; } *type_id = size_type_id; if (ret_size) *ret_size = size; return size_type; } static int btf_df_check_member(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type) { btf_verifier_log_basic(env, struct_type, "Unsupported check_member"); return -EINVAL; } static int btf_df_check_kflag_member(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type) { btf_verifier_log_basic(env, struct_type, "Unsupported check_kflag_member"); return -EINVAL; } /* Used for ptr, array and struct/union type members. * int, enum and modifier types have their specific callback functions. */ static int btf_generic_check_kflag_member(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type) { if (BTF_MEMBER_BITFIELD_SIZE(member->offset)) { btf_verifier_log_member(env, struct_type, member, "Invalid member bitfield_size"); return -EINVAL; } /* bitfield size is 0, so member->offset represents bit offset only. * It is safe to call non kflag check_member variants. */ return btf_type_ops(member_type)->check_member(env, struct_type, member, member_type); } static int btf_df_resolve(struct btf_verifier_env *env, const struct resolve_vertex *v) { btf_verifier_log_basic(env, v->t, "Unsupported resolve"); return -EINVAL; } static void btf_df_seq_show(const struct btf *btf, const struct btf_type *t, u32 type_id, void *data, u8 bits_offsets, struct seq_file *m) { seq_printf(m, "<unsupported kind:%u>", BTF_INFO_KIND(t->info)); } static int btf_int_check_member(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type) { u32 int_data = btf_type_int(member_type); u32 struct_bits_off = member->offset; u32 struct_size = struct_type->size; u32 nr_copy_bits; u32 bytes_offset; if (U32_MAX - struct_bits_off < BTF_INT_OFFSET(int_data)) { btf_verifier_log_member(env, struct_type, member, "bits_offset exceeds U32_MAX"); return -EINVAL; } struct_bits_off += BTF_INT_OFFSET(int_data); bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); nr_copy_bits = BTF_INT_BITS(int_data) + BITS_PER_BYTE_MASKED(struct_bits_off); if (nr_copy_bits > BITS_PER_U128) { btf_verifier_log_member(env, struct_type, member, "nr_copy_bits exceeds 128"); return -EINVAL; } if (struct_size < bytes_offset || struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { btf_verifier_log_member(env, struct_type, member, "Member exceeds struct_size"); return -EINVAL; } return 0; } static int btf_int_check_kflag_member(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type) { u32 struct_bits_off, nr_bits, nr_int_data_bits, bytes_offset; u32 int_data = btf_type_int(member_type); u32 struct_size = struct_type->size; u32 nr_copy_bits; /* a regular int type is required for the kflag int member */ if (!btf_type_int_is_regular(member_type)) { btf_verifier_log_member(env, struct_type, member, "Invalid member base type"); return -EINVAL; } /* check sanity of bitfield size */ nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); nr_int_data_bits = BTF_INT_BITS(int_data); if (!nr_bits) { /* Not a bitfield member, member offset must be at byte * boundary. */ if (BITS_PER_BYTE_MASKED(struct_bits_off)) { btf_verifier_log_member(env, struct_type, member, "Invalid member offset"); return -EINVAL; } nr_bits = nr_int_data_bits; } else if (nr_bits > nr_int_data_bits) { btf_verifier_log_member(env, struct_type, member, "Invalid member bitfield_size"); return -EINVAL; } bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); nr_copy_bits = nr_bits + BITS_PER_BYTE_MASKED(struct_bits_off); if (nr_copy_bits > BITS_PER_U128) { btf_verifier_log_member(env, struct_type, member, "nr_copy_bits exceeds 128"); return -EINVAL; } if (struct_size < bytes_offset || struct_size - bytes_offset < BITS_ROUNDUP_BYTES(nr_copy_bits)) { btf_verifier_log_member(env, struct_type, member, "Member exceeds struct_size"); return -EINVAL; } return 0; } static s32 btf_int_check_meta(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left) { u32 int_data, nr_bits, meta_needed = sizeof(int_data); u16 encoding; if (meta_left < meta_needed) { btf_verifier_log_basic(env, t, "meta_left:%u meta_needed:%u", meta_left, meta_needed); return -EINVAL; } if (btf_type_vlen(t)) { btf_verifier_log_type(env, t, "vlen != 0"); return -EINVAL; } if (btf_type_kflag(t)) { btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); return -EINVAL; } int_data = btf_type_int(t); if (int_data & ~BTF_INT_MASK) { btf_verifier_log_basic(env, t, "Invalid int_data:%x", int_data); return -EINVAL; } nr_bits = BTF_INT_BITS(int_data) + BTF_INT_OFFSET(int_data); if (nr_bits > BITS_PER_U128) { btf_verifier_log_type(env, t, "nr_bits exceeds %zu", BITS_PER_U128); return -EINVAL; } if (BITS_ROUNDUP_BYTES(nr_bits) > t->size) { btf_verifier_log_type(env, t, "nr_bits exceeds type_size"); return -EINVAL; } /* * Only one of the encoding bits is allowed and it * should be sufficient for the pretty print purpose (i.e. decoding). * Multiple bits can be allowed later if it is found * to be insufficient. */ encoding = BTF_INT_ENCODING(int_data); if (encoding && encoding != BTF_INT_SIGNED && encoding != BTF_INT_CHAR && encoding != BTF_INT_BOOL) { btf_verifier_log_type(env, t, "Unsupported encoding"); return -ENOTSUPP; } btf_verifier_log_type(env, t, NULL); return meta_needed; } static void btf_int_log(struct btf_verifier_env *env, const struct btf_type *t) { int int_data = btf_type_int(t); btf_verifier_log(env, "size=%u bits_offset=%u nr_bits=%u encoding=%s", t->size, BTF_INT_OFFSET(int_data), BTF_INT_BITS(int_data), btf_int_encoding_str(BTF_INT_ENCODING(int_data))); } static void btf_int128_print(struct seq_file *m, void *data) { /* data points to a __int128 number. * Suppose * int128_num = *(__int128 *)data; * The below formulas shows what upper_num and lower_num represents: * upper_num = int128_num >> 64; * lower_num = int128_num & 0xffffffffFFFFFFFFULL; */ u64 upper_num, lower_num; #ifdef __BIG_ENDIAN_BITFIELD upper_num = *(u64 *)data; lower_num = *(u64 *)(data + 8); #else upper_num = *(u64 *)(data + 8); lower_num = *(u64 *)data; #endif if (upper_num == 0) seq_printf(m, "0x%llx", lower_num); else seq_printf(m, "0x%llx%016llx", upper_num, lower_num); } static void btf_int128_shift(u64 *print_num, u16 left_shift_bits, u16 right_shift_bits) { u64 upper_num, lower_num; #ifdef __BIG_ENDIAN_BITFIELD upper_num = print_num[0]; lower_num = print_num[1]; #else upper_num = print_num[1]; lower_num = print_num[0]; #endif /* shake out un-needed bits by shift/or operations */ if (left_shift_bits >= 64) { upper_num = lower_num << (left_shift_bits - 64); lower_num = 0; } else { upper_num = (upper_num << left_shift_bits) | (lower_num >> (64 - left_shift_bits)); lower_num = lower_num << left_shift_bits; } if (right_shift_bits >= 64) { lower_num = upper_num >> (right_shift_bits - 64); upper_num = 0; } else { lower_num = (lower_num >> right_shift_bits) | (upper_num << (64 - right_shift_bits)); upper_num = upper_num >> right_shift_bits; } #ifdef __BIG_ENDIAN_BITFIELD print_num[0] = upper_num; print_num[1] = lower_num; #else print_num[0] = lower_num; print_num[1] = upper_num; #endif } static void btf_bitfield_seq_show(void *data, u8 bits_offset, u8 nr_bits, struct seq_file *m) { u16 left_shift_bits, right_shift_bits; u8 nr_copy_bytes; u8 nr_copy_bits; u64 print_num[2] = {}; nr_copy_bits = nr_bits + bits_offset; nr_copy_bytes = BITS_ROUNDUP_BYTES(nr_copy_bits); memcpy(print_num, data, nr_copy_bytes); #ifdef __BIG_ENDIAN_BITFIELD left_shift_bits = bits_offset; #else left_shift_bits = BITS_PER_U128 - nr_copy_bits; #endif right_shift_bits = BITS_PER_U128 - nr_bits; btf_int128_shift(print_num, left_shift_bits, right_shift_bits); btf_int128_print(m, print_num); } static void btf_int_bits_seq_show(const struct btf *btf, const struct btf_type *t, void *data, u8 bits_offset, struct seq_file *m) { u32 int_data = btf_type_int(t); u8 nr_bits = BTF_INT_BITS(int_data); u8 total_bits_offset; /* * bits_offset is at most 7. * BTF_INT_OFFSET() cannot exceed 128 bits. */ total_bits_offset = bits_offset + BTF_INT_OFFSET(int_data); data += BITS_ROUNDDOWN_BYTES(total_bits_offset); bits_offset = BITS_PER_BYTE_MASKED(total_bits_offset); btf_bitfield_seq_show(data, bits_offset, nr_bits, m); } static void btf_int_seq_show(const struct btf *btf, const struct btf_type *t, u32 type_id, void *data, u8 bits_offset, struct seq_file *m) { u32 int_data = btf_type_int(t); u8 encoding = BTF_INT_ENCODING(int_data); bool sign = encoding & BTF_INT_SIGNED; u8 nr_bits = BTF_INT_BITS(int_data); if (bits_offset || BTF_INT_OFFSET(int_data) || BITS_PER_BYTE_MASKED(nr_bits)) { btf_int_bits_seq_show(btf, t, data, bits_offset, m); return; } switch (nr_bits) { case 128: btf_int128_print(m, data); break; case 64: if (sign) seq_printf(m, "%lld", *(s64 *)data); else seq_printf(m, "%llu", *(u64 *)data); break; case 32: if (sign) seq_printf(m, "%d", *(s32 *)data); else seq_printf(m, "%u", *(u32 *)data); break; case 16: if (sign) seq_printf(m, "%d", *(s16 *)data); else seq_printf(m, "%u", *(u16 *)data); break; case 8: if (sign) seq_printf(m, "%d", *(s8 *)data); else seq_printf(m, "%u", *(u8 *)data); break; default: btf_int_bits_seq_show(btf, t, data, bits_offset, m); } } static const struct btf_kind_operations int_ops = { .check_meta = btf_int_check_meta, .resolve = btf_df_resolve, .check_member = btf_int_check_member, .check_kflag_member = btf_int_check_kflag_member, .log_details = btf_int_log, .seq_show = btf_int_seq_show, }; static int btf_modifier_check_member(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type) { const struct btf_type *resolved_type; u32 resolved_type_id = member->type; struct btf_member resolved_member; struct btf *btf = env->btf; resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); if (!resolved_type) { btf_verifier_log_member(env, struct_type, member, "Invalid member"); return -EINVAL; } resolved_member = *member; resolved_member.type = resolved_type_id; return btf_type_ops(resolved_type)->check_member(env, struct_type, &resolved_member, resolved_type); } static int btf_modifier_check_kflag_member(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type) { const struct btf_type *resolved_type; u32 resolved_type_id = member->type; struct btf_member resolved_member; struct btf *btf = env->btf; resolved_type = btf_type_id_size(btf, &resolved_type_id, NULL); if (!resolved_type) { btf_verifier_log_member(env, struct_type, member, "Invalid member"); return -EINVAL; } resolved_member = *member; resolved_member.type = resolved_type_id; return btf_type_ops(resolved_type)->check_kflag_member(env, struct_type, &resolved_member, resolved_type); } static int btf_ptr_check_member(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type) { u32 struct_size, struct_bits_off, bytes_offset; struct_size = struct_type->size; struct_bits_off = member->offset; bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); if (BITS_PER_BYTE_MASKED(struct_bits_off)) { btf_verifier_log_member(env, struct_type, member, "Member is not byte aligned"); return -EINVAL; } if (struct_size - bytes_offset < sizeof(void *)) { btf_verifier_log_member(env, struct_type, member, "Member exceeds struct_size"); return -EINVAL; } return 0; } static int btf_ref_type_check_meta(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left) { if (btf_type_vlen(t)) { btf_verifier_log_type(env, t, "vlen != 0"); return -EINVAL; } if (btf_type_kflag(t)) { btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); return -EINVAL; } if (!BTF_TYPE_ID_VALID(t->type)) { btf_verifier_log_type(env, t, "Invalid type_id"); return -EINVAL; } /* typedef type must have a valid name, and other ref types, * volatile, const, restrict, should have a null name. */ if (BTF_INFO_KIND(t->info) == BTF_KIND_TYPEDEF) { if (!t->name_off || !btf_name_valid_identifier(env->btf, t->name_off)) { btf_verifier_log_type(env, t, "Invalid name"); return -EINVAL; } } else { if (t->name_off) { btf_verifier_log_type(env, t, "Invalid name"); return -EINVAL; } } btf_verifier_log_type(env, t, NULL); return 0; } static int btf_modifier_resolve(struct btf_verifier_env *env, const struct resolve_vertex *v) { const struct btf_type *t = v->t; const struct btf_type *next_type; u32 next_type_id = t->type; struct btf *btf = env->btf; next_type = btf_type_by_id(btf, next_type_id); if (!next_type || btf_type_is_resolve_source_only(next_type)) { btf_verifier_log_type(env, v->t, "Invalid type_id"); return -EINVAL; } if (!env_type_is_resolve_sink(env, next_type) && !env_type_is_resolved(env, next_type_id)) return env_stack_push(env, next_type, next_type_id); /* Figure out the resolved next_type_id with size. * They will be stored in the current modifier's * resolved_ids and resolved_sizes such that it can * save us a few type-following when we use it later (e.g. in * pretty print). */ if (!btf_type_id_size(btf, &next_type_id, NULL)) { if (env_type_is_resolved(env, next_type_id)) next_type = btf_type_id_resolve(btf, &next_type_id); /* "typedef void new_void", "const void"...etc */ if (!btf_type_is_void(next_type) && !btf_type_is_fwd(next_type) && !btf_type_is_func_proto(next_type)) { btf_verifier_log_type(env, v->t, "Invalid type_id"); return -EINVAL; } } env_stack_pop_resolved(env, next_type_id, 0); return 0; } static int btf_var_resolve(struct btf_verifier_env *env, const struct resolve_vertex *v) { const struct btf_type *next_type; const struct btf_type *t = v->t; u32 next_type_id = t->type; struct btf *btf = env->btf; next_type = btf_type_by_id(btf, next_type_id); if (!next_type || btf_type_is_resolve_source_only(next_type)) { btf_verifier_log_type(env, v->t, "Invalid type_id"); return -EINVAL; } if (!env_type_is_resolve_sink(env, next_type) && !env_type_is_resolved(env, next_type_id)) return env_stack_push(env, next_type, next_type_id); if (btf_type_is_modifier(next_type)) { const struct btf_type *resolved_type; u32 resolved_type_id; resolved_type_id = next_type_id; resolved_type = btf_type_id_resolve(btf, &resolved_type_id); if (btf_type_is_ptr(resolved_type) && !env_type_is_resolve_sink(env, resolved_type) && !env_type_is_resolved(env, resolved_type_id)) return env_stack_push(env, resolved_type, resolved_type_id); } /* We must resolve to something concrete at this point, no * forward types or similar that would resolve to size of * zero is allowed. */ if (!btf_type_id_size(btf, &next_type_id, NULL)) { btf_verifier_log_type(env, v->t, "Invalid type_id"); return -EINVAL; } env_stack_pop_resolved(env, next_type_id, 0); return 0; } static int btf_ptr_resolve(struct btf_verifier_env *env, const struct resolve_vertex *v) { const struct btf_type *next_type; const struct btf_type *t = v->t; u32 next_type_id = t->type; struct btf *btf = env->btf; next_type = btf_type_by_id(btf, next_type_id); if (!next_type || btf_type_is_resolve_source_only(next_type)) { btf_verifier_log_type(env, v->t, "Invalid type_id"); return -EINVAL; } if (!env_type_is_resolve_sink(env, next_type) && !env_type_is_resolved(env, next_type_id)) return env_stack_push(env, next_type, next_type_id); /* If the modifier was RESOLVED during RESOLVE_STRUCT_OR_ARRAY, * the modifier may have stopped resolving when it was resolved * to a ptr (last-resolved-ptr). * * We now need to continue from the last-resolved-ptr to * ensure the last-resolved-ptr will not referring back to * the currenct ptr (t). */ if (btf_type_is_modifier(next_type)) { const struct btf_type *resolved_type; u32 resolved_type_id; resolved_type_id = next_type_id; resolved_type = btf_type_id_resolve(btf, &resolved_type_id); if (btf_type_is_ptr(resolved_type) && !env_type_is_resolve_sink(env, resolved_type) && !env_type_is_resolved(env, resolved_type_id)) return env_stack_push(env, resolved_type, resolved_type_id); } if (!btf_type_id_size(btf, &next_type_id, NULL)) { if (env_type_is_resolved(env, next_type_id)) next_type = btf_type_id_resolve(btf, &next_type_id); if (!btf_type_is_void(next_type) && !btf_type_is_fwd(next_type) && !btf_type_is_func_proto(next_type)) { btf_verifier_log_type(env, v->t, "Invalid type_id"); return -EINVAL; } } env_stack_pop_resolved(env, next_type_id, 0); return 0; } static void btf_modifier_seq_show(const struct btf *btf, const struct btf_type *t, u32 type_id, void *data, u8 bits_offset, struct seq_file *m) { t = btf_type_id_resolve(btf, &type_id); btf_type_ops(t)->seq_show(btf, t, type_id, data, bits_offset, m); } static void btf_var_seq_show(const struct btf *btf, const struct btf_type *t, u32 type_id, void *data, u8 bits_offset, struct seq_file *m) { t = btf_type_id_resolve(btf, &type_id); btf_type_ops(t)->seq_show(btf, t, type_id, data, bits_offset, m); } static void btf_ptr_seq_show(const struct btf *btf, const struct btf_type *t, u32 type_id, void *data, u8 bits_offset, struct seq_file *m) { /* It is a hashed value */ seq_printf(m, "%p", *(void **)data); } static void btf_ref_type_log(struct btf_verifier_env *env, const struct btf_type *t) { btf_verifier_log(env, "type_id=%u", t->type); } static struct btf_kind_operations modifier_ops = { .check_meta = btf_ref_type_check_meta, .resolve = btf_modifier_resolve, .check_member = btf_modifier_check_member, .check_kflag_member = btf_modifier_check_kflag_member, .log_details = btf_ref_type_log, .seq_show = btf_modifier_seq_show, }; static struct btf_kind_operations ptr_ops = { .check_meta = btf_ref_type_check_meta, .resolve = btf_ptr_resolve, .check_member = btf_ptr_check_member, .check_kflag_member = btf_generic_check_kflag_member, .log_details = btf_ref_type_log, .seq_show = btf_ptr_seq_show, }; static s32 btf_fwd_check_meta(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left) { if (btf_type_vlen(t)) { btf_verifier_log_type(env, t, "vlen != 0"); return -EINVAL; } if (t->type) { btf_verifier_log_type(env, t, "type != 0"); return -EINVAL; } /* fwd type must have a valid name */ if (!t->name_off || !btf_name_valid_identifier(env->btf, t->name_off)) { btf_verifier_log_type(env, t, "Invalid name"); return -EINVAL; } btf_verifier_log_type(env, t, NULL); return 0; } static void btf_fwd_type_log(struct btf_verifier_env *env, const struct btf_type *t) { btf_verifier_log(env, "%s", btf_type_kflag(t) ? "union" : "struct"); } static struct btf_kind_operations fwd_ops = { .check_meta = btf_fwd_check_meta, .resolve = btf_df_resolve, .check_member = btf_df_check_member, .check_kflag_member = btf_df_check_kflag_member, .log_details = btf_fwd_type_log, .seq_show = btf_df_seq_show, }; static int btf_array_check_member(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type) { u32 struct_bits_off = member->offset; u32 struct_size, bytes_offset; u32 array_type_id, array_size; struct btf *btf = env->btf; if (BITS_PER_BYTE_MASKED(struct_bits_off)) { btf_verifier_log_member(env, struct_type, member, "Member is not byte aligned"); return -EINVAL; } array_type_id = member->type; btf_type_id_size(btf, &array_type_id, &array_size); struct_size = struct_type->size; bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); if (struct_size - bytes_offset < array_size) { btf_verifier_log_member(env, struct_type, member, "Member exceeds struct_size"); return -EINVAL; } return 0; } static s32 btf_array_check_meta(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left) { const struct btf_array *array = btf_type_array(t); u32 meta_needed = sizeof(*array); if (meta_left < meta_needed) { btf_verifier_log_basic(env, t, "meta_left:%u meta_needed:%u", meta_left, meta_needed); return -EINVAL; } /* array type should not have a name */ if (t->name_off) { btf_verifier_log_type(env, t, "Invalid name"); return -EINVAL; } if (btf_type_vlen(t)) { btf_verifier_log_type(env, t, "vlen != 0"); return -EINVAL; } if (btf_type_kflag(t)) { btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); return -EINVAL; } if (t->size) { btf_verifier_log_type(env, t, "size != 0"); return -EINVAL; } /* Array elem type and index type cannot be in type void, * so !array->type and !array->index_type are not allowed. */ if (!array->type || !BTF_TYPE_ID_VALID(array->type)) { btf_verifier_log_type(env, t, "Invalid elem"); return -EINVAL; } if (!array->index_type || !BTF_TYPE_ID_VALID(array->index_type)) { btf_verifier_log_type(env, t, "Invalid index"); return -EINVAL; } btf_verifier_log_type(env, t, NULL); return meta_needed; } static int btf_array_resolve(struct btf_verifier_env *env, const struct resolve_vertex *v) { const struct btf_array *array = btf_type_array(v->t); const struct btf_type *elem_type, *index_type; u32 elem_type_id, index_type_id; struct btf *btf = env->btf; u32 elem_size; /* Check array->index_type */ index_type_id = array->index_type; index_type = btf_type_by_id(btf, index_type_id); if (btf_type_nosize_or_null(index_type) || btf_type_is_resolve_source_only(index_type)) { btf_verifier_log_type(env, v->t, "Invalid index"); return -EINVAL; } if (!env_type_is_resolve_sink(env, index_type) && !env_type_is_resolved(env, index_type_id)) return env_stack_push(env, index_type, index_type_id); index_type = btf_type_id_size(btf, &index_type_id, NULL); if (!index_type || !btf_type_is_int(index_type) || !btf_type_int_is_regular(index_type)) { btf_verifier_log_type(env, v->t, "Invalid index"); return -EINVAL; } /* Check array->type */ elem_type_id = array->type; elem_type = btf_type_by_id(btf, elem_type_id); if (btf_type_nosize_or_null(elem_type) || btf_type_is_resolve_source_only(elem_type)) { btf_verifier_log_type(env, v->t, "Invalid elem"); return -EINVAL; } if (!env_type_is_resolve_sink(env, elem_type) && !env_type_is_resolved(env, elem_type_id)) return env_stack_push(env, elem_type, elem_type_id); elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); if (!elem_type) { btf_verifier_log_type(env, v->t, "Invalid elem"); return -EINVAL; } if (btf_type_is_int(elem_type) && !btf_type_int_is_regular(elem_type)) { btf_verifier_log_type(env, v->t, "Invalid array of int"); return -EINVAL; } if (array->nelems && elem_size > U32_MAX / array->nelems) { btf_verifier_log_type(env, v->t, "Array size overflows U32_MAX"); return -EINVAL; } env_stack_pop_resolved(env, elem_type_id, elem_size * array->nelems); return 0; } static void btf_array_log(struct btf_verifier_env *env, const struct btf_type *t) { const struct btf_array *array = btf_type_array(t); btf_verifier_log(env, "type_id=%u index_type_id=%u nr_elems=%u", array->type, array->index_type, array->nelems); } static void btf_array_seq_show(const struct btf *btf, const struct btf_type *t, u32 type_id, void *data, u8 bits_offset, struct seq_file *m) { const struct btf_array *array = btf_type_array(t); const struct btf_kind_operations *elem_ops; const struct btf_type *elem_type; u32 i, elem_size, elem_type_id; elem_type_id = array->type; elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); elem_ops = btf_type_ops(elem_type); seq_puts(m, "["); for (i = 0; i < array->nelems; i++) { if (i) seq_puts(m, ","); elem_ops->seq_show(btf, elem_type, elem_type_id, data, bits_offset, m); data += elem_size; } seq_puts(m, "]"); } static struct btf_kind_operations array_ops = { .check_meta = btf_array_check_meta, .resolve = btf_array_resolve, .check_member = btf_array_check_member, .check_kflag_member = btf_generic_check_kflag_member, .log_details = btf_array_log, .seq_show = btf_array_seq_show, }; static int btf_struct_check_member(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type) { u32 struct_bits_off = member->offset; u32 struct_size, bytes_offset; if (BITS_PER_BYTE_MASKED(struct_bits_off)) { btf_verifier_log_member(env, struct_type, member, "Member is not byte aligned"); return -EINVAL; } struct_size = struct_type->size; bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); if (struct_size - bytes_offset < member_type->size) { btf_verifier_log_member(env, struct_type, member, "Member exceeds struct_size"); return -EINVAL; } return 0; } static s32 btf_struct_check_meta(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left) { bool is_union = BTF_INFO_KIND(t->info) == BTF_KIND_UNION; const struct btf_member *member; u32 meta_needed, last_offset; struct btf *btf = env->btf; u32 struct_size = t->size; u32 offset; u16 i; meta_needed = btf_type_vlen(t) * sizeof(*member); if (meta_left < meta_needed) { btf_verifier_log_basic(env, t, "meta_left:%u meta_needed:%u", meta_left, meta_needed); return -EINVAL; } /* struct type either no name or a valid one */ if (t->name_off && !btf_name_valid_identifier(env->btf, t->name_off)) { btf_verifier_log_type(env, t, "Invalid name"); return -EINVAL; } btf_verifier_log_type(env, t, NULL); last_offset = 0; for_each_member(i, t, member) { if (!btf_name_offset_valid(btf, member->name_off)) { btf_verifier_log_member(env, t, member, "Invalid member name_offset:%u", member->name_off); return -EINVAL; } /* struct member either no name or a valid one */ if (member->name_off && !btf_name_valid_identifier(btf, member->name_off)) { btf_verifier_log_member(env, t, member, "Invalid name"); return -EINVAL; } /* A member cannot be in type void */ if (!member->type || !BTF_TYPE_ID_VALID(member->type)) { btf_verifier_log_member(env, t, member, "Invalid type_id"); return -EINVAL; } offset = btf_member_bit_offset(t, member); if (is_union && offset) { btf_verifier_log_member(env, t, member, "Invalid member bits_offset"); return -EINVAL; } /* * ">" instead of ">=" because the last member could be * "char a[0];" */ if (last_offset > offset) { btf_verifier_log_member(env, t, member, "Invalid member bits_offset"); return -EINVAL; } if (BITS_ROUNDUP_BYTES(offset) > struct_size) { btf_verifier_log_member(env, t, member, "Member bits_offset exceeds its struct size"); return -EINVAL; } btf_verifier_log_member(env, t, member, NULL); last_offset = offset; } return meta_needed; } static int btf_struct_resolve(struct btf_verifier_env *env, const struct resolve_vertex *v) { const struct btf_member *member; int err; u16 i; /* Before continue resolving the next_member, * ensure the last member is indeed resolved to a * type with size info. */ if (v->next_member) { const struct btf_type *last_member_type; const struct btf_member *last_member; u32 last_member_type_id; last_member = btf_type_member(v->t) + v->next_member - 1; last_member_type_id = last_member->type; if (WARN_ON_ONCE(!env_type_is_resolved(env, last_member_type_id))) return -EINVAL; last_member_type = btf_type_by_id(env->btf, last_member_type_id); if (btf_type_kflag(v->t)) err = btf_type_ops(last_member_type)->check_kflag_member(env, v->t, last_member, last_member_type); else err = btf_type_ops(last_member_type)->check_member(env, v->t, last_member, last_member_type); if (err) return err; } for_each_member_from(i, v->next_member, v->t, member) { u32 member_type_id = member->type; const struct btf_type *member_type = btf_type_by_id(env->btf, member_type_id); if (btf_type_nosize_or_null(member_type) || btf_type_is_resolve_source_only(member_type)) { btf_verifier_log_member(env, v->t, member, "Invalid member"); return -EINVAL; } if (!env_type_is_resolve_sink(env, member_type) && !env_type_is_resolved(env, member_type_id)) { env_stack_set_next_member(env, i + 1); return env_stack_push(env, member_type, member_type_id); } if (btf_type_kflag(v->t)) err = btf_type_ops(member_type)->check_kflag_member(env, v->t, member, member_type); else err = btf_type_ops(member_type)->check_member(env, v->t, member, member_type); if (err) return err; } env_stack_pop_resolved(env, 0, 0); return 0; } static void btf_struct_log(struct btf_verifier_env *env, const struct btf_type *t) { btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); } /* find 'struct bpf_spin_lock' in map value. * return >= 0 offset if found * and < 0 in case of error */ int btf_find_spin_lock(const struct btf *btf, const struct btf_type *t) { const struct btf_member *member; u32 i, off = -ENOENT; if (!__btf_type_is_struct(t)) return -EINVAL; for_each_member(i, t, member) { const struct btf_type *member_type = btf_type_by_id(btf, member->type); if (!__btf_type_is_struct(member_type)) continue; if (member_type->size != sizeof(struct bpf_spin_lock)) continue; if (strcmp(__btf_name_by_offset(btf, member_type->name_off), "bpf_spin_lock")) continue; if (off != -ENOENT) /* only one 'struct bpf_spin_lock' is allowed */ return -E2BIG; off = btf_member_bit_offset(t, member); if (off % 8) /* valid C code cannot generate such BTF */ return -EINVAL; off /= 8; if (off % __alignof__(struct bpf_spin_lock)) /* valid struct bpf_spin_lock will be 4 byte aligned */ return -EINVAL; } return off; } static void btf_struct_seq_show(const struct btf *btf, const struct btf_type *t, u32 type_id, void *data, u8 bits_offset, struct seq_file *m) { const char *seq = BTF_INFO_KIND(t->info) == BTF_KIND_UNION ? "|" : ","; const struct btf_member *member; u32 i; seq_puts(m, "{"); for_each_member(i, t, member) { const struct btf_type *member_type = btf_type_by_id(btf, member->type); const struct btf_kind_operations *ops; u32 member_offset, bitfield_size; u32 bytes_offset; u8 bits8_offset; if (i) seq_puts(m, seq); member_offset = btf_member_bit_offset(t, member); bitfield_size = btf_member_bitfield_size(t, member); bytes_offset = BITS_ROUNDDOWN_BYTES(member_offset); bits8_offset = BITS_PER_BYTE_MASKED(member_offset); if (bitfield_size) { btf_bitfield_seq_show(data + bytes_offset, bits8_offset, bitfield_size, m); } else { ops = btf_type_ops(member_type); ops->seq_show(btf, member_type, member->type, data + bytes_offset, bits8_offset, m); } } seq_puts(m, "}"); } static struct btf_kind_operations struct_ops = { .check_meta = btf_struct_check_meta, .resolve = btf_struct_resolve, .check_member = btf_struct_check_member, .check_kflag_member = btf_generic_check_kflag_member, .log_details = btf_struct_log, .seq_show = btf_struct_seq_show, }; static int btf_enum_check_member(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type) { u32 struct_bits_off = member->offset; u32 struct_size, bytes_offset; if (BITS_PER_BYTE_MASKED(struct_bits_off)) { btf_verifier_log_member(env, struct_type, member, "Member is not byte aligned"); return -EINVAL; } struct_size = struct_type->size; bytes_offset = BITS_ROUNDDOWN_BYTES(struct_bits_off); if (struct_size - bytes_offset < member_type->size) { btf_verifier_log_member(env, struct_type, member, "Member exceeds struct_size"); return -EINVAL; } return 0; } static int btf_enum_check_kflag_member(struct btf_verifier_env *env, const struct btf_type *struct_type, const struct btf_member *member, const struct btf_type *member_type) { u32 struct_bits_off, nr_bits, bytes_end, struct_size; u32 int_bitsize = sizeof(int) * BITS_PER_BYTE; struct_bits_off = BTF_MEMBER_BIT_OFFSET(member->offset); nr_bits = BTF_MEMBER_BITFIELD_SIZE(member->offset); if (!nr_bits) { if (BITS_PER_BYTE_MASKED(struct_bits_off)) { btf_verifier_log_member(env, struct_type, member, "Member is not byte aligned"); return -EINVAL; } nr_bits = int_bitsize; } else if (nr_bits > int_bitsize) { btf_verifier_log_member(env, struct_type, member, "Invalid member bitfield_size"); return -EINVAL; } struct_size = struct_type->size; bytes_end = BITS_ROUNDUP_BYTES(struct_bits_off + nr_bits); if (struct_size < bytes_end) { btf_verifier_log_member(env, struct_type, member, "Member exceeds struct_size"); return -EINVAL; } return 0; } static s32 btf_enum_check_meta(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left) { const struct btf_enum *enums = btf_type_enum(t); struct btf *btf = env->btf; u16 i, nr_enums; u32 meta_needed; nr_enums = btf_type_vlen(t); meta_needed = nr_enums * sizeof(*enums); if (meta_left < meta_needed) { btf_verifier_log_basic(env, t, "meta_left:%u meta_needed:%u", meta_left, meta_needed); return -EINVAL; } if (btf_type_kflag(t)) { btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); return -EINVAL; } if (t->size > 8 || !is_power_of_2(t->size)) { btf_verifier_log_type(env, t, "Unexpected size"); return -EINVAL; } /* enum type either no name or a valid one */ if (t->name_off && !btf_name_valid_identifier(env->btf, t->name_off)) { btf_verifier_log_type(env, t, "Invalid name"); return -EINVAL; } btf_verifier_log_type(env, t, NULL); for (i = 0; i < nr_enums; i++) { if (!btf_name_offset_valid(btf, enums[i].name_off)) { btf_verifier_log(env, "\tInvalid name_offset:%u", enums[i].name_off); return -EINVAL; } /* enum member must have a valid name */ if (!enums[i].name_off || !btf_name_valid_identifier(btf, enums[i].name_off)) { btf_verifier_log_type(env, t, "Invalid name"); return -EINVAL; } btf_verifier_log(env, "\t%s val=%d\n", __btf_name_by_offset(btf, enums[i].name_off), enums[i].val); } return meta_needed; } static void btf_enum_log(struct btf_verifier_env *env, const struct btf_type *t) { btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); } static void btf_enum_seq_show(const struct btf *btf, const struct btf_type *t, u32 type_id, void *data, u8 bits_offset, struct seq_file *m) { const struct btf_enum *enums = btf_type_enum(t); u32 i, nr_enums = btf_type_vlen(t); int v = *(int *)data; for (i = 0; i < nr_enums; i++) { if (v == enums[i].val) { seq_printf(m, "%s", __btf_name_by_offset(btf, enums[i].name_off)); return; } } seq_printf(m, "%d", v); } static struct btf_kind_operations enum_ops = { .check_meta = btf_enum_check_meta, .resolve = btf_df_resolve, .check_member = btf_enum_check_member, .check_kflag_member = btf_enum_check_kflag_member, .log_details = btf_enum_log, .seq_show = btf_enum_seq_show, }; static s32 btf_func_proto_check_meta(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left) { u32 meta_needed = btf_type_vlen(t) * sizeof(struct btf_param); if (meta_left < meta_needed) { btf_verifier_log_basic(env, t, "meta_left:%u meta_needed:%u", meta_left, meta_needed); return -EINVAL; } if (t->name_off) { btf_verifier_log_type(env, t, "Invalid name"); return -EINVAL; } if (btf_type_kflag(t)) { btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); return -EINVAL; } btf_verifier_log_type(env, t, NULL); return meta_needed; } static void btf_func_proto_log(struct btf_verifier_env *env, const struct btf_type *t) { const struct btf_param *args = (const struct btf_param *)(t + 1); u16 nr_args = btf_type_vlen(t), i; btf_verifier_log(env, "return=%u args=(", t->type); if (!nr_args) { btf_verifier_log(env, "void"); goto done; } if (nr_args == 1 && !args[0].type) { /* Only one vararg */ btf_verifier_log(env, "vararg"); goto done; } btf_verifier_log(env, "%u %s", args[0].type, __btf_name_by_offset(env->btf, args[0].name_off)); for (i = 1; i < nr_args - 1; i++) btf_verifier_log(env, ", %u %s", args[i].type, __btf_name_by_offset(env->btf, args[i].name_off)); if (nr_args > 1) { const struct btf_param *last_arg = &args[nr_args - 1]; if (last_arg->type) btf_verifier_log(env, ", %u %s", last_arg->type, __btf_name_by_offset(env->btf, last_arg->name_off)); else btf_verifier_log(env, ", vararg"); } done: btf_verifier_log(env, ")"); } static struct btf_kind_operations func_proto_ops = { .check_meta = btf_func_proto_check_meta, .resolve = btf_df_resolve, /* * BTF_KIND_FUNC_PROTO cannot be directly referred by * a struct's member. * * It should be a funciton pointer instead. * (i.e. struct's member -> BTF_KIND_PTR -> BTF_KIND_FUNC_PROTO) * * Hence, there is no btf_func_check_member(). */ .check_member = btf_df_check_member, .check_kflag_member = btf_df_check_kflag_member, .log_details = btf_func_proto_log, .seq_show = btf_df_seq_show, }; static s32 btf_func_check_meta(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left) { if (!t->name_off || !btf_name_valid_identifier(env->btf, t->name_off)) { btf_verifier_log_type(env, t, "Invalid name"); return -EINVAL; } if (btf_type_vlen(t)) { btf_verifier_log_type(env, t, "vlen != 0"); return -EINVAL; } if (btf_type_kflag(t)) { btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); return -EINVAL; } btf_verifier_log_type(env, t, NULL); return 0; } static struct btf_kind_operations func_ops = { .check_meta = btf_func_check_meta, .resolve = btf_df_resolve, .check_member = btf_df_check_member, .check_kflag_member = btf_df_check_kflag_member, .log_details = btf_ref_type_log, .seq_show = btf_df_seq_show, }; static s32 btf_var_check_meta(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left) { const struct btf_var *var; u32 meta_needed = sizeof(*var); if (meta_left < meta_needed) { btf_verifier_log_basic(env, t, "meta_left:%u meta_needed:%u", meta_left, meta_needed); return -EINVAL; } if (btf_type_vlen(t)) { btf_verifier_log_type(env, t, "vlen != 0"); return -EINVAL; } if (btf_type_kflag(t)) { btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); return -EINVAL; } if (!t->name_off || !__btf_name_valid(env->btf, t->name_off, true)) { btf_verifier_log_type(env, t, "Invalid name"); return -EINVAL; } /* A var cannot be in type void */ if (!t->type || !BTF_TYPE_ID_VALID(t->type)) { btf_verifier_log_type(env, t, "Invalid type_id"); return -EINVAL; } var = btf_type_var(t); if (var->linkage != BTF_VAR_STATIC && var->linkage != BTF_VAR_GLOBAL_ALLOCATED) { btf_verifier_log_type(env, t, "Linkage not supported"); return -EINVAL; } btf_verifier_log_type(env, t, NULL); return meta_needed; } static void btf_var_log(struct btf_verifier_env *env, const struct btf_type *t) { const struct btf_var *var = btf_type_var(t); btf_verifier_log(env, "type_id=%u linkage=%u", t->type, var->linkage); } static const struct btf_kind_operations var_ops = { .check_meta = btf_var_check_meta, .resolve = btf_var_resolve, .check_member = btf_df_check_member, .check_kflag_member = btf_df_check_kflag_member, .log_details = btf_var_log, .seq_show = btf_var_seq_show, }; static s32 btf_datasec_check_meta(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left) { const struct btf_var_secinfo *vsi; u64 last_vsi_end_off = 0, sum = 0; u32 i, meta_needed; meta_needed = btf_type_vlen(t) * sizeof(*vsi); if (meta_left < meta_needed) { btf_verifier_log_basic(env, t, "meta_left:%u meta_needed:%u", meta_left, meta_needed); return -EINVAL; } if (!btf_type_vlen(t)) { btf_verifier_log_type(env, t, "vlen == 0"); return -EINVAL; } if (!t->size) { btf_verifier_log_type(env, t, "size == 0"); return -EINVAL; } if (btf_type_kflag(t)) { btf_verifier_log_type(env, t, "Invalid btf_info kind_flag"); return -EINVAL; } if (!t->name_off || !btf_name_valid_section(env->btf, t->name_off)) { btf_verifier_log_type(env, t, "Invalid name"); return -EINVAL; } btf_verifier_log_type(env, t, NULL); for_each_vsi(i, t, vsi) { /* A var cannot be in type void */ if (!vsi->type || !BTF_TYPE_ID_VALID(vsi->type)) { btf_verifier_log_vsi(env, t, vsi, "Invalid type_id"); return -EINVAL; } if (vsi->offset < last_vsi_end_off || vsi->offset >= t->size) { btf_verifier_log_vsi(env, t, vsi, "Invalid offset"); return -EINVAL; } if (!vsi->size || vsi->size > t->size) { btf_verifier_log_vsi(env, t, vsi, "Invalid size"); return -EINVAL; } last_vsi_end_off = vsi->offset + vsi->size; if (last_vsi_end_off > t->size) { btf_verifier_log_vsi(env, t, vsi, "Invalid offset+size"); return -EINVAL; } btf_verifier_log_vsi(env, t, vsi, NULL); sum += vsi->size; } if (t->size < sum) { btf_verifier_log_type(env, t, "Invalid btf_info size"); return -EINVAL; } return meta_needed; } static int btf_datasec_resolve(struct btf_verifier_env *env, const struct resolve_vertex *v) { const struct btf_var_secinfo *vsi; struct btf *btf = env->btf; u16 i; for_each_vsi_from(i, v->next_member, v->t, vsi) { u32 var_type_id = vsi->type, type_id, type_size = 0; const struct btf_type *var_type = btf_type_by_id(env->btf, var_type_id); if (!var_type || !btf_type_is_var(var_type)) { btf_verifier_log_vsi(env, v->t, vsi, "Not a VAR kind member"); return -EINVAL; } if (!env_type_is_resolve_sink(env, var_type) && !env_type_is_resolved(env, var_type_id)) { env_stack_set_next_member(env, i + 1); return env_stack_push(env, var_type, var_type_id); } type_id = var_type->type; if (!btf_type_id_size(btf, &type_id, &type_size)) { btf_verifier_log_vsi(env, v->t, vsi, "Invalid type"); return -EINVAL; } if (vsi->size < type_size) { btf_verifier_log_vsi(env, v->t, vsi, "Invalid size"); return -EINVAL; } } env_stack_pop_resolved(env, 0, 0); return 0; } static void btf_datasec_log(struct btf_verifier_env *env, const struct btf_type *t) { btf_verifier_log(env, "size=%u vlen=%u", t->size, btf_type_vlen(t)); } static void btf_datasec_seq_show(const struct btf *btf, const struct btf_type *t, u32 type_id, void *data, u8 bits_offset, struct seq_file *m) { const struct btf_var_secinfo *vsi; const struct btf_type *var; u32 i; seq_printf(m, "section (\"%s\") = {", __btf_name_by_offset(btf, t->name_off)); for_each_vsi(i, t, vsi) { var = btf_type_by_id(btf, vsi->type); if (i) seq_puts(m, ","); btf_type_ops(var)->seq_show(btf, var, vsi->type, data + vsi->offset, bits_offset, m); } seq_puts(m, "}"); } static const struct btf_kind_operations datasec_ops = { .check_meta = btf_datasec_check_meta, .resolve = btf_datasec_resolve, .check_member = btf_df_check_member, .check_kflag_member = btf_df_check_kflag_member, .log_details = btf_datasec_log, .seq_show = btf_datasec_seq_show, }; static int btf_func_proto_check(struct btf_verifier_env *env, const struct btf_type *t) { const struct btf_type *ret_type; const struct btf_param *args; const struct btf *btf; u16 nr_args, i; int err; btf = env->btf; args = (const struct btf_param *)(t + 1); nr_args = btf_type_vlen(t); /* Check func return type which could be "void" (t->type == 0) */ if (t->type) { u32 ret_type_id = t->type; ret_type = btf_type_by_id(btf, ret_type_id); if (!ret_type) { btf_verifier_log_type(env, t, "Invalid return type"); return -EINVAL; } if (btf_type_needs_resolve(ret_type) && !env_type_is_resolved(env, ret_type_id)) { err = btf_resolve(env, ret_type, ret_type_id); if (err) return err; } /* Ensure the return type is a type that has a size */ if (!btf_type_id_size(btf, &ret_type_id, NULL)) { btf_verifier_log_type(env, t, "Invalid return type"); return -EINVAL; } } if (!nr_args) return 0; /* Last func arg type_id could be 0 if it is a vararg */ if (!args[nr_args - 1].type) { if (args[nr_args - 1].name_off) { btf_verifier_log_type(env, t, "Invalid arg#%u", nr_args); return -EINVAL; } nr_args--; } err = 0; for (i = 0; i < nr_args; i++) { const struct btf_type *arg_type; u32 arg_type_id; arg_type_id = args[i].type; arg_type = btf_type_by_id(btf, arg_type_id); if (!arg_type) { btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); err = -EINVAL; break; } if (args[i].name_off && (!btf_name_offset_valid(btf, args[i].name_off) || !btf_name_valid_identifier(btf, args[i].name_off))) { btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); err = -EINVAL; break; } if (btf_type_needs_resolve(arg_type) && !env_type_is_resolved(env, arg_type_id)) { err = btf_resolve(env, arg_type, arg_type_id); if (err) break; } if (!btf_type_id_size(btf, &arg_type_id, NULL)) { btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); err = -EINVAL; break; } } return err; } static int btf_func_check(struct btf_verifier_env *env, const struct btf_type *t) { const struct btf_type *proto_type; const struct btf_param *args; const struct btf *btf; u16 nr_args, i; btf = env->btf; proto_type = btf_type_by_id(btf, t->type); if (!proto_type || !btf_type_is_func_proto(proto_type)) { btf_verifier_log_type(env, t, "Invalid type_id"); return -EINVAL; } args = (const struct btf_param *)(proto_type + 1); nr_args = btf_type_vlen(proto_type); for (i = 0; i < nr_args; i++) { if (!args[i].name_off && args[i].type) { btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1); return -EINVAL; } } return 0; } static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = { [BTF_KIND_INT] = &int_ops, [BTF_KIND_PTR] = &ptr_ops, [BTF_KIND_ARRAY] = &array_ops, [BTF_KIND_STRUCT] = &struct_ops, [BTF_KIND_UNION] = &struct_ops, [BTF_KIND_ENUM] = &enum_ops, [BTF_KIND_FWD] = &fwd_ops, [BTF_KIND_TYPEDEF] = &modifier_ops, [BTF_KIND_VOLATILE] = &modifier_ops, [BTF_KIND_CONST] = &modifier_ops, [BTF_KIND_RESTRICT] = &modifier_ops, [BTF_KIND_FUNC] = &func_ops, [BTF_KIND_FUNC_PROTO] = &func_proto_ops, [BTF_KIND_VAR] = &var_ops, [BTF_KIND_DATASEC] = &datasec_ops, }; static s32 btf_check_meta(struct btf_verifier_env *env, const struct btf_type *t, u32 meta_left) { u32 saved_meta_left = meta_left; s32 var_meta_size; if (meta_left < sizeof(*t)) { btf_verifier_log(env, "[%u] meta_left:%u meta_needed:%zu", env->log_type_id, meta_left, sizeof(*t)); return -EINVAL; } meta_left -= sizeof(*t); if (t->info & ~BTF_INFO_MASK) { btf_verifier_log(env, "[%u] Invalid btf_info:%x", env->log_type_id, t->info); return -EINVAL; } if (BTF_INFO_KIND(t->info) > BTF_KIND_MAX || BTF_INFO_KIND(t->info) == BTF_KIND_UNKN) { btf_verifier_log(env, "[%u] Invalid kind:%u", env->log_type_id, BTF_INFO_KIND(t->info)); return -EINVAL; } if (!btf_name_offset_valid(env->btf, t->name_off)) { btf_verifier_log(env, "[%u] Invalid name_offset:%u", env->log_type_id, t->name_off); return -EINVAL; } var_meta_size = btf_type_ops(t)->check_meta(env, t, meta_left); if (var_meta_size < 0) return var_meta_size; meta_left -= var_meta_size; return saved_meta_left - meta_left; } static int btf_check_all_metas(struct btf_verifier_env *env) { struct btf *btf = env->btf; struct btf_header *hdr; void *cur, *end; hdr = &btf->hdr; cur = btf->nohdr_data + hdr->type_off; end = cur + hdr->type_len; env->log_type_id = 1; while (cur < end) { struct btf_type *t = cur; s32 meta_size; meta_size = btf_check_meta(env, t, end - cur); if (meta_size < 0) return meta_size; btf_add_type(env, t); cur += meta_size; env->log_type_id++; } return 0; } static bool btf_resolve_valid(struct btf_verifier_env *env, const struct btf_type *t, u32 type_id) { struct btf *btf = env->btf; if (!env_type_is_resolved(env, type_id)) return false; if (btf_type_is_struct(t) || btf_type_is_datasec(t)) return !btf->resolved_ids[type_id] && !btf->resolved_sizes[type_id]; if (btf_type_is_modifier(t) || btf_type_is_ptr(t) || btf_type_is_var(t)) { t = btf_type_id_resolve(btf, &type_id); return t && !btf_type_is_modifier(t) && !btf_type_is_var(t) && !btf_type_is_datasec(t); } if (btf_type_is_array(t)) { const struct btf_array *array = btf_type_array(t); const struct btf_type *elem_type; u32 elem_type_id = array->type; u32 elem_size; elem_type = btf_type_id_size(btf, &elem_type_id, &elem_size); return elem_type && !btf_type_is_modifier(elem_type) && (array->nelems * elem_size == btf->resolved_sizes[type_id]); } return false; } static int btf_resolve(struct btf_verifier_env *env, const struct btf_type *t, u32 type_id) { u32 save_log_type_id = env->log_type_id; const struct resolve_vertex *v; int err = 0; env->resolve_mode = RESOLVE_TBD; env_stack_push(env, t, type_id); while (!err && (v = env_stack_peak(env))) { env->log_type_id = v->type_id; err = btf_type_ops(v->t)->resolve(env, v); } env->log_type_id = type_id; if (err == -E2BIG) { btf_verifier_log_type(env, t, "Exceeded max resolving depth:%u", MAX_RESOLVE_DEPTH); } else if (err == -EEXIST) { btf_verifier_log_type(env, t, "Loop detected"); } /* Final sanity check */ if (!err && !btf_resolve_valid(env, t, type_id)) { btf_verifier_log_type(env, t, "Invalid resolve state"); err = -EINVAL; } env->log_type_id = save_log_type_id; return err; } static int btf_check_all_types(struct btf_verifier_env *env) { struct btf *btf = env->btf; u32 type_id; int err; err = env_resolve_init(env); if (err) return err; env->phase++; for (type_id = 1; type_id <= btf->nr_types; type_id++) { const struct btf_type *t = btf_type_by_id(btf, type_id); env->log_type_id = type_id; if (btf_type_needs_resolve(t) && !env_type_is_resolved(env, type_id)) { err = btf_resolve(env, t, type_id); if (err) return err; } if (btf_type_is_func_proto(t)) { err = btf_func_proto_check(env, t); if (err) return err; } if (btf_type_is_func(t)) { err = btf_func_check(env, t); if (err) return err; } } return 0; } static int btf_parse_type_sec(struct btf_verifier_env *env) { const struct btf_header *hdr = &env->btf->hdr; int err; /* Type section must align to 4 bytes */ if (hdr->type_off & (sizeof(u32) - 1)) { btf_verifier_log(env, "Unaligned type_off"); return -EINVAL; } if (!hdr->type_len) { btf_verifier_log(env, "No type found"); return -EINVAL; } err = btf_check_all_metas(env); if (err) return err; return btf_check_all_types(env); } static int btf_parse_str_sec(struct btf_verifier_env *env) { const struct btf_header *hdr; struct btf *btf = env->btf; const char *start, *end; hdr = &btf->hdr; start = btf->nohdr_data + hdr->str_off; end = start + hdr->str_len; if (end != btf->data + btf->data_size) { btf_verifier_log(env, "String section is not at the end"); return -EINVAL; } if (!hdr->str_len || hdr->str_len - 1 > BTF_MAX_NAME_OFFSET || start[0] || end[-1]) { btf_verifier_log(env, "Invalid string section"); return -EINVAL; } btf->strings = start; return 0; } static const size_t btf_sec_info_offset[] = { offsetof(struct btf_header, type_off), offsetof(struct btf_header, str_off), }; static int btf_sec_info_cmp(const void *a, const void *b) { const struct btf_sec_info *x = a; const struct btf_sec_info *y = b; return (int)(x->off - y->off) ? : (int)(x->len - y->len); } static int btf_check_sec_info(struct btf_verifier_env *env, u32 btf_data_size) { struct btf_sec_info secs[ARRAY_SIZE(btf_sec_info_offset)]; u32 total, expected_total, i; const struct btf_header *hdr; const struct btf *btf; btf = env->btf; hdr = &btf->hdr; /* Populate the secs from hdr */ for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) secs[i] = *(struct btf_sec_info *)((void *)hdr + btf_sec_info_offset[i]); sort(secs, ARRAY_SIZE(btf_sec_info_offset), sizeof(struct btf_sec_info), btf_sec_info_cmp, NULL); /* Check for gaps and overlap among sections */ total = 0; expected_total = btf_data_size - hdr->hdr_len; for (i = 0; i < ARRAY_SIZE(btf_sec_info_offset); i++) { if (expected_total < secs[i].off) { btf_verifier_log(env, "Invalid section offset"); return -EINVAL; } if (total < secs[i].off) { /* gap */ btf_verifier_log(env, "Unsupported section found"); return -EINVAL; } if (total > secs[i].off) { btf_verifier_log(env, "Section overlap found"); return -EINVAL; } if (expected_total - total < secs[i].len) { btf_verifier_log(env, "Total section length too long"); return -EINVAL; } total += secs[i].len; } /* There is data other than hdr and known sections */ if (expected_total != total) { btf_verifier_log(env, "Unsupported section found"); return -EINVAL; } return 0; } static int btf_parse_hdr(struct btf_verifier_env *env) { u32 hdr_len, hdr_copy, btf_data_size; const struct btf_header *hdr; struct btf *btf; int err; btf = env->btf; btf_data_size = btf->data_size; if (btf_data_size < offsetof(struct btf_header, hdr_len) + sizeof(hdr->hdr_len)) { btf_verifier_log(env, "hdr_len not found"); return -EINVAL; } hdr = btf->data; hdr_len = hdr->hdr_len; if (btf_data_size < hdr_len) { btf_verifier_log(env, "btf_header not found"); return -EINVAL; } /* Ensure the unsupported header fields are zero */ if (hdr_len > sizeof(btf->hdr)) { u8 *expected_zero = btf->data + sizeof(btf->hdr); u8 *end = btf->data + hdr_len; for (; expected_zero < end; expected_zero++) { if (*expected_zero) { btf_verifier_log(env, "Unsupported btf_header"); return -E2BIG; } } } hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr)); memcpy(&btf->hdr, btf->data, hdr_copy); hdr = &btf->hdr; btf_verifier_log_hdr(env, btf_data_size); if (hdr->magic != BTF_MAGIC) { btf_verifier_log(env, "Invalid magic"); return -EINVAL; } if (hdr->version != BTF_VERSION) { btf_verifier_log(env, "Unsupported version"); return -ENOTSUPP; } if (hdr->flags) { btf_verifier_log(env, "Unsupported flags"); return -ENOTSUPP; } if (btf_data_size == hdr->hdr_len) { btf_verifier_log(env, "No data"); return -EINVAL; } err = btf_check_sec_info(env, btf_data_size); if (err) return err; return 0; } static struct btf *btf_parse(void __user *btf_data, u32 btf_data_size, u32 log_level, char __user *log_ubuf, u32 log_size) { struct btf_verifier_env *env = NULL; struct bpf_verifier_log *log; struct btf *btf = NULL; u8 *data; int err; if (btf_data_size > BTF_MAX_SIZE) return ERR_PTR(-E2BIG); env = kzalloc(sizeof(*env), GFP_KERNEL | __GFP_NOWARN); if (!env) return ERR_PTR(-ENOMEM); log = &env->log; if (log_level || log_ubuf || log_size) { /* user requested verbose verifier output * and supplied buffer to store the verification trace */ log->level = log_level; log->ubuf = log_ubuf; log->len_total = log_size; /* log attributes have to be sane */ if (log->len_total < 128 || log->len_total > UINT_MAX >> 8 || !log->level || !log->ubuf) { err = -EINVAL; goto errout; } } btf = kzalloc(sizeof(*btf), GFP_KERNEL | __GFP_NOWARN); if (!btf) { err = -ENOMEM; goto errout; } env->btf = btf; data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN); if (!data) { err = -ENOMEM; goto errout; } btf->data = data; btf->data_size = btf_data_size; if (copy_from_user(data, btf_data, btf_data_size)) { err = -EFAULT; goto errout; } err = btf_parse_hdr(env); if (err) goto errout; btf->nohdr_data = btf->data + btf->hdr.hdr_len; err = btf_parse_str_sec(env); if (err) goto errout; err = btf_parse_type_sec(env); if (err) goto errout; if (log->level && bpf_verifier_log_full(log)) { err = -ENOSPC; goto errout; } btf_verifier_env_free(env); refcount_set(&btf->refcnt, 1); return btf; errout: btf_verifier_env_free(env); if (btf) btf_free(btf); return ERR_PTR(err); } void btf_type_seq_show(const struct btf *btf, u32 type_id, void *obj, struct seq_file *m) { const struct btf_type *t = btf_type_by_id(btf, type_id); btf_type_ops(t)->seq_show(btf, t, type_id, obj, 0, m); } #ifdef CONFIG_PROC_FS static void bpf_btf_show_fdinfo(struct seq_file *m, struct file *filp) { const struct btf *btf = filp->private_data; seq_printf(m, "btf_id:\t%u\n", btf->id); } #endif static int btf_release(struct inode *inode, struct file *filp) { btf_put(filp->private_data); return 0; } const struct file_operations btf_fops = { #ifdef CONFIG_PROC_FS .show_fdinfo = bpf_btf_show_fdinfo, #endif .release = btf_release, }; static int __btf_new_fd(struct btf *btf) { return anon_inode_getfd("btf", &btf_fops, btf, O_RDONLY | O_CLOEXEC); } int btf_new_fd(const union bpf_attr *attr) { struct btf *btf; int ret; btf = btf_parse(u64_to_user_ptr(attr->btf), attr->btf_size, attr->btf_log_level, u64_to_user_ptr(attr->btf_log_buf), attr->btf_log_size); if (IS_ERR(btf)) return PTR_ERR(btf); ret = btf_alloc_id(btf); if (ret) { btf_free(btf); return ret; } /* * The BTF ID is published to the userspace. * All BTF free must go through call_rcu() from * now on (i.e. free by calling btf_put()). */ ret = __btf_new_fd(btf); if (ret < 0) btf_put(btf); return ret; } struct btf *btf_get_by_fd(int fd) { struct btf *btf; struct fd f; f = fdget(fd); if (!f.file) return ERR_PTR(-EBADF); if (f.file->f_op != &btf_fops) { fdput(f); return ERR_PTR(-EINVAL); } btf = f.file->private_data; refcount_inc(&btf->refcnt); fdput(f); return btf; } int btf_get_info_by_fd(const struct btf *btf, const union bpf_attr *attr, union bpf_attr __user *uattr) { struct bpf_btf_info __user *uinfo; struct bpf_btf_info info; u32 info_copy, btf_copy; void __user *ubtf; u32 uinfo_len; uinfo = u64_to_user_ptr(attr->info.info); uinfo_len = attr->info.info_len; info_copy = min_t(u32, uinfo_len, sizeof(info)); memset(&info, 0, sizeof(info)); if (copy_from_user(&info, uinfo, info_copy)) return -EFAULT; info.id = btf->id; ubtf = u64_to_user_ptr(info.btf); btf_copy = min_t(u32, btf->data_size, info.btf_size); if (copy_to_user(ubtf, btf->data, btf_copy)) return -EFAULT; info.btf_size = btf->data_size; if (copy_to_user(uinfo, &info, info_copy) || put_user(info_copy, &uattr->info.info_len)) return -EFAULT; return 0; } int btf_get_fd_by_id(u32 id) { struct btf *btf; int fd; rcu_read_lock(); btf = idr_find(&btf_idr, id); if (!btf || !refcount_inc_not_zero(&btf->refcnt)) btf = ERR_PTR(-ENOENT); rcu_read_unlock(); if (IS_ERR(btf)) return PTR_ERR(btf); fd = __btf_new_fd(btf); if (fd < 0) btf_put(btf); return fd; } u32 btf_id(const struct btf *btf) { return btf->id; }
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1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 // SPDX-License-Identifier: GPL-2.0 /* * linux/fs/ext4/indirect.c * * from * * linux/fs/ext4/inode.c * * Copyright (C) 1992, 1993, 1994, 1995 * Remy Card (card@masi.ibp.fr) * Laboratoire MASI - Institut Blaise Pascal * Universite Pierre et Marie Curie (Paris VI) * * from * * linux/fs/minix/inode.c * * Copyright (C) 1991, 1992 Linus Torvalds * * Goal-directed block allocation by Stephen Tweedie * (sct@redhat.com), 1993, 1998 */ #include "ext4_jbd2.h" #include "truncate.h" #include <linux/dax.h> #include <linux/uio.h> #include <trace/events/ext4.h> typedef struct { __le32 *p; __le32 key; struct buffer_head *bh; } Indirect; static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) { p->key = *(p->p = v); p->bh = bh; } /** * ext4_block_to_path - parse the block number into array of offsets * @inode: inode in question (we are only interested in its superblock) * @i_block: block number to be parsed * @offsets: array to store the offsets in * @boundary: set this non-zero if the referred-to block is likely to be * followed (on disk) by an indirect block. * * To store the locations of file's data ext4 uses a data structure common * for UNIX filesystems - tree of pointers anchored in the inode, with * data blocks at leaves and indirect blocks in intermediate nodes. * This function translates the block number into path in that tree - * return value is the path length and @offsets[n] is the offset of * pointer to (n+1)th node in the nth one. If @block is out of range * (negative or too large) warning is printed and zero returned. * * Note: function doesn't find node addresses, so no IO is needed. All * we need to know is the capacity of indirect blocks (taken from the * inode->i_sb). */ /* * Portability note: the last comparison (check that we fit into triple * indirect block) is spelled differently, because otherwise on an * architecture with 32-bit longs and 8Kb pages we might get into trouble * if our filesystem had 8Kb blocks. We might use long long, but that would * kill us on x86. Oh, well, at least the sign propagation does not matter - * i_block would have to be negative in the very beginning, so we would not * get there at all. */ static int ext4_block_to_path(struct inode *inode, ext4_lblk_t i_block, ext4_lblk_t offsets[4], int *boundary) { int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb); int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb); const long direct_blocks = EXT4_NDIR_BLOCKS, indirect_blocks = ptrs, double_blocks = (1 << (ptrs_bits * 2)); int n = 0; int final = 0; if (i_block < direct_blocks) { offsets[n++] = i_block; final = direct_blocks; } else if ((i_block -= direct_blocks) < indirect_blocks) { offsets[n++] = EXT4_IND_BLOCK; offsets[n++] = i_block; final = ptrs; } else if ((i_block -= indirect_blocks) < double_blocks) { offsets[n++] = EXT4_DIND_BLOCK; offsets[n++] = i_block >> ptrs_bits; offsets[n++] = i_block & (ptrs - 1); final = ptrs; } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { offsets[n++] = EXT4_TIND_BLOCK; offsets[n++] = i_block >> (ptrs_bits * 2); offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); offsets[n++] = i_block & (ptrs - 1); final = ptrs; } else { ext4_warning(inode->i_sb, "block %lu > max in inode %lu", i_block + direct_blocks + indirect_blocks + double_blocks, inode->i_ino); } if (boundary) *boundary = final - 1 - (i_block & (ptrs - 1)); return n; } /** * ext4_get_branch - read the chain of indirect blocks leading to data * @inode: inode in question * @depth: depth of the chain (1 - direct pointer, etc.) * @offsets: offsets of pointers in inode/indirect blocks * @chain: place to store the result * @err: here we store the error value * * Function fills the array of triples <key, p, bh> and returns %NULL * if everything went OK or the pointer to the last filled triple * (incomplete one) otherwise. Upon the return chain[i].key contains * the number of (i+1)-th block in the chain (as it is stored in memory, * i.e. little-endian 32-bit), chain[i].p contains the address of that * number (it points into struct inode for i==0 and into the bh->b_data * for i>0) and chain[i].bh points to the buffer_head of i-th indirect * block for i>0 and NULL for i==0. In other words, it holds the block * numbers of the chain, addresses they were taken from (and where we can * verify that chain did not change) and buffer_heads hosting these * numbers. * * Function stops when it stumbles upon zero pointer (absent block) * (pointer to last triple returned, *@err == 0) * or when it gets an IO error reading an indirect block * (ditto, *@err == -EIO) * or when it reads all @depth-1 indirect blocks successfully and finds * the whole chain, all way to the data (returns %NULL, *err == 0). * * Need to be called with * down_read(&EXT4_I(inode)->i_data_sem) */ static Indirect *ext4_get_branch(struct inode *inode, int depth, ext4_lblk_t *offsets, Indirect chain[4], int *err) { struct super_block *sb = inode->i_sb; Indirect *p = chain; struct buffer_head *bh; int ret = -EIO; *err = 0; /* i_data is not going away, no lock needed */ add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets); if (!p->key) goto no_block; while (--depth) { bh = sb_getblk(sb, le32_to_cpu(p->key)); if (unlikely(!bh)) { ret = -ENOMEM; goto failure; } if (!bh_uptodate_or_lock(bh)) { if (bh_submit_read(bh) < 0) { put_bh(bh); goto failure; } /* validate block references */ if (ext4_check_indirect_blockref(inode, bh)) { put_bh(bh); goto failure; } } add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets); /* Reader: end */ if (!p->key) goto no_block; } return NULL; failure: *err = ret; no_block: