/src/file/src/readelf.c

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/*
 * Copyright (c) Christos Zoulas 2003.
 * All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice immediately at the beginning of the file, without modification,
 *    this list of conditions, and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#include "file.h"

#ifndef lint
FILE_RCSID("@(#)$File: readelf.c,v 1.190 2023/07/27 19:39:06 christos Exp $")
#endif

#ifdef BUILTIN_ELF
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#include "readelf.h"
#include "magic.h"

#ifdef  ELFCORE
file_private int dophn_core(struct magic_set *, int, int, int, off_t, int,
    size_t, off_t, int *, uint16_t *);
#endif
file_private int dophn_exec(struct magic_set *, int, int, int, off_t, int,
    size_t, off_t, int, int *, uint16_t *);
file_private int doshn(struct magic_set *, int, int, int, off_t, int, size_t,
    off_t, int, int, int *, uint16_t *);
file_private size_t donote(struct magic_set *, void *, size_t, size_t, int,
    int, size_t, int *, uint16_t *, int, off_t, int, off_t);

#define ELF_ALIGN(a)  ((((a) + align - 1) / align) * align)

#define isquote(c) (strchr("'\"`", (c)) != NULL)

file_private uint16_t getu16(int, uint16_t);
file_private uint32_t getu32(int, uint32_t);
file_private uint64_t getu64(int, uint64_t);

#define SIZE_UNKNOWN  CAST(off_t, -1)

file_private int
toomany(struct magic_set *ms, const char *name, uint16_t num)
{
  if (ms->flags & MAGIC_MIME)
    return 1;
  if (file_printf(ms, ", too many %s (%u)", name, num) == -1)
    return -1;
  return 1;
}

file_private uint16_t
getu16(int swap, uint16_t value)
{
  union {
    uint16_t ui;
    char c[2];
  } retval, tmpval;

  if (swap) {
    tmpval.ui = value;

    retval.c[0] = tmpval.c[1];
    retval.c[1] = tmpval.c[0];

    return retval.ui;
  } else
    return value;
}

file_private uint32_t
getu32(int swap, uint32_t value)
{
  union {
    uint32_t ui;
    char c[4];
  } retval, tmpval;

  if (swap) {
    tmpval.ui = value;

    retval.c[0] = tmpval.c[3];
    retval.c[1] = tmpval.c[2];
    retval.c[2] = tmpval.c[1];
    retval.c[3] = tmpval.c[0];

    return retval.ui;
  } else
    return value;
}

file_private uint64_t
getu64(int swap, uint64_t value)
{
  union {
    uint64_t ui;
    char c[8];
  } retval, tmpval;

  if (swap) {
    tmpval.ui = value;

    retval.c[0] = tmpval.c[7];
    retval.c[1] = tmpval.c[6];
    retval.c[2] = tmpval.c[5];
    retval.c[3] = tmpval.c[4];
    retval.c[4] = tmpval.c[3];
    retval.c[5] = tmpval.c[2];
    retval.c[6] = tmpval.c[1];
    retval.c[7] = tmpval.c[0];

    return retval.ui;
  } else
    return value;
}

#define elf_getu16(swap, value) getu16(swap, value)
#define elf_getu32(swap, value) getu32(swap, value)
#define elf_getu64(swap, value) getu64(swap, value)

#define xsh_addr  (clazz == ELFCLASS32      \
       ? CAST(void *, &sh32)     \
       : CAST(void *, &sh64))
#define xsh_sizeof  (clazz == ELFCLASS32      \
       ? sizeof(sh32)        \
       : sizeof(sh64))
#define xsh_size  CAST(size_t, (clazz == ELFCLASS32 \
       ? elf_getu32(swap, sh32.sh_size) \
       : elf_getu64(swap, sh64.sh_size)))
#define xsh_offset  CAST(off_t, (clazz == ELFCLASS32  \
       ? elf_getu32(swap, sh32.sh_offset) \
       : elf_getu64(swap, sh64.sh_offset)))
#define xsh_type  (clazz == ELFCLASS32      \
       ? elf_getu32(swap, sh32.sh_type)  \
       : elf_getu32(swap, sh64.sh_type))
#define xsh_name      (clazz == ELFCLASS32      \
       ? elf_getu32(swap, sh32.sh_name)  \
       : elf_getu32(swap, sh64.sh_name))

#define xph_addr  (clazz == ELFCLASS32      \
       ? CAST(void *, &ph32)     \
       : CAST(void *, &ph64))
#define xph_sizeof  (clazz == ELFCLASS32      \
       ? sizeof(ph32)        \
       : sizeof(ph64))
#define xph_type  (clazz == ELFCLASS32      \
       ? elf_getu32(swap, ph32.p_type) \
       : elf_getu32(swap, ph64.p_type))
#define xph_offset  CAST(off_t, (clazz == ELFCLASS32  \
       ? elf_getu32(swap, ph32.p_offset)  \
       : elf_getu64(swap, ph64.p_offset)))
#define xph_align CAST(size_t, (clazz == ELFCLASS32 \
       ? CAST(off_t, (ph32.p_align ?    \
          elf_getu32(swap, ph32.p_align) : 4))\
       : CAST(off_t, (ph64.p_align ?    \
          elf_getu64(swap, ph64.p_align) : 4))))
#define xph_vaddr CAST(size_t, (clazz == ELFCLASS32 \
       ? CAST(off_t, (ph32.p_vaddr ?    \
          elf_getu32(swap, ph32.p_vaddr) : 4))\
       : CAST(off_t, (ph64.p_vaddr ?    \
          elf_getu64(swap, ph64.p_vaddr) : 4))))
#define xph_filesz  CAST(size_t, (clazz == ELFCLASS32 \
       ? elf_getu32(swap, ph32.p_filesz)  \
       : elf_getu64(swap, ph64.p_filesz)))
#define xph_memsz CAST(size_t, ((clazz == ELFCLASS32  \
       ? elf_getu32(swap, ph32.p_memsz) \
       : elf_getu64(swap, ph64.p_memsz))))
#define xnh_addr  (clazz == ELFCLASS32      \
       ? CAST(void *, &nh32)     \
       : CAST(void *, &nh64))
#define xnh_sizeof  (clazz == ELFCLASS32      \
       ? sizeof(nh32)        \
       : sizeof(nh64))
#define xnh_type  (clazz == ELFCLASS32      \
       ? elf_getu32(swap, nh32.n_type) \
       : elf_getu32(swap, nh64.n_type))
#define xnh_namesz  (clazz == ELFCLASS32      \
       ? elf_getu32(swap, nh32.n_namesz) \
       : elf_getu32(swap, nh64.n_namesz))
#define xnh_descsz  (clazz == ELFCLASS32      \
       ? elf_getu32(swap, nh32.n_descsz) \
       : elf_getu32(swap, nh64.n_descsz))

#define xdh_addr  (clazz == ELFCLASS32      \
       ? CAST(void *, &dh32)     \
       : CAST(void *, &dh64))
#define xdh_sizeof  (clazz == ELFCLASS32      \
       ? sizeof(dh32)        \
       : sizeof(dh64))
#define xdh_tag   (clazz == ELFCLASS32      \
       ? elf_getu32(swap, dh32.d_tag)    \
       : elf_getu64(swap, dh64.d_tag))
#define xdh_val   (clazz == ELFCLASS32      \
       ? elf_getu32(swap, dh32.d_un.d_val) \
       : elf_getu64(swap, dh64.d_un.d_val))

#define xcap_addr (clazz == ELFCLASS32      \
       ? CAST(void *, &cap32)      \
       : CAST(void *, &cap64))
#define xcap_sizeof (clazz == ELFCLASS32      \
       ? sizeof(cap32)      \
       : sizeof(cap64))
#define xcap_tag  (clazz == ELFCLASS32      \
       ? elf_getu32(swap, cap32.c_tag) \
       : elf_getu64(swap, cap64.c_tag))
#define xcap_val  (clazz == ELFCLASS32      \
       ? elf_getu32(swap, cap32.c_un.c_val)  \
       : elf_getu64(swap, cap64.c_un.c_val))

#define xauxv_addr  (clazz == ELFCLASS32      \
       ? CAST(void *, &auxv32)   \
       : CAST(void *, &auxv64))
#define xauxv_sizeof  (clazz == ELFCLASS32      \
       ? sizeof(auxv32)      \
       : sizeof(auxv64))
#define xauxv_type  (clazz == ELFCLASS32      \
       ? elf_getu32(swap, auxv32.a_type) \
       : elf_getu64(swap, auxv64.a_type))
#define xauxv_val (clazz == ELFCLASS32      \
       ? elf_getu32(swap, auxv32.a_v)    \
       : elf_getu64(swap, auxv64.a_v))

#define prpsoffsets(i)  (clazz == ELFCLASS32      \
       ? prpsoffsets32[i]      \
       : prpsoffsets64[i])

#ifdef ELFCORE
/*
 * Try larger offsets first to avoid false matches
 * from earlier data that happen to look like strings.
 */
static const size_t prpsoffsets32[] = {
#ifdef USE_NT_PSINFO
  104,    /* SunOS 5.x (command line) */
  88,   /* SunOS 5.x (short name) */
#endif /* USE_NT_PSINFO */

  100,    /* SunOS 5.x (command line) */
  84,   /* SunOS 5.x (short name) */

  44,   /* Linux (command line) */
  28,   /* Linux (short name) */

  48,   /* Linux PowerPC (command line) */
  32,   /* Linux PowerPC (short name) */

  8,    /* FreeBSD */
};

static const size_t prpsoffsets64[] = {
#ifdef USE_NT_PSINFO
  152,    /* SunOS 5.x (command line) */
  136,    /* SunOS 5.x (short name) */
#endif /* USE_NT_PSINFO */

  136,    /* SunOS 5.x, 64-bit (command line) */
  120,    /* SunOS 5.x, 64-bit (short name) */

  56,   /* Linux (command line) */
  40,             /* Linux (tested on core from 2.4.x, short name) */

  16,   /* FreeBSD, 64-bit */
};

#define NOFFSETS32  __arraycount(prpsoffsets32)
#define NOFFSETS64  __arraycount(prpsoffsets64)

#define NOFFSETS  (clazz == ELFCLASS32 ? NOFFSETS32 : NOFFSETS64)

/*
 * Look through the program headers of an executable image, searching
 * for a PT_NOTE section of type NT_PRPSINFO, with a name "CORE" or
 * "FreeBSD"; if one is found, try looking in various places in its
 * contents for a 16-character string containing only printable
 * characters - if found, that string should be the name of the program
 * that dropped core.  Note: right after that 16-character string is,
 * at least in SunOS 5.x (and possibly other SVR4-flavored systems) and
 * Linux, a longer string (80 characters, in 5.x, probably other
 * SVR4-flavored systems, and Linux) containing the start of the
 * command line for that program.
 *
 * SunOS 5.x core files contain two PT_NOTE sections, with the types
 * NT_PRPSINFO (old) and NT_PSINFO (new).  These structs contain the
 * same info about the command name and command line, so it probably
 * isn't worthwhile to look for NT_PSINFO, but the offsets are provided
 * above (see USE_NT_PSINFO), in case we ever decide to do so.  The
 * NT_PRPSINFO and NT_PSINFO sections are always in order and adjacent;
 * the SunOS 5.x file command relies on this (and prefers the latter).
 *
 * The signal number probably appears in a section of type NT_PRSTATUS,
 * but that's also rather OS-dependent, in ways that are harder to
 * dissect with heuristics, so I'm not bothering with the signal number.
 * (I suppose the signal number could be of interest in situations where
 * you don't have the binary of the program that dropped core; if you
 * *do* have that binary, the debugger will probably tell you what
 * signal it was.)
 */

#define OS_STYLE_SVR4   0
#define OS_STYLE_FREEBSD  1
#define OS_STYLE_NETBSD   2

file_private const char os_style_names[][8] = {
  "SVR4",
  "FreeBSD",
  "NetBSD",
};

#define FLAGS_CORE_STYLE    0x0003

#define FLAGS_DID_CORE      0x0004
#define FLAGS_DID_OS_NOTE   0x0008
#define FLAGS_DID_BUILD_ID    0x0010
#define FLAGS_DID_CORE_STYLE    0x0020
#define FLAGS_DID_NETBSD_PAX    0x0040
#define FLAGS_DID_NETBSD_MARCH    0x0080
#define FLAGS_DID_NETBSD_CMODEL   0x0100
#define FLAGS_DID_NETBSD_EMULATION  0x0200
#define FLAGS_DID_NETBSD_UNKNOWN  0x0400
#define FLAGS_IS_CORE     0x0800
#define FLAGS_DID_AUXV      0x1000

file_private int
dophn_core(struct magic_set *ms, int clazz, int swap, int fd, off_t off,
    int num, size_t size, off_t fsize, int *flags, uint16_t *notecount)
{
  Elf32_Phdr ph32;
  Elf64_Phdr ph64;
  size_t offset, len;
  unsigned char nbuf[BUFSIZ];
  ssize_t bufsize;
  off_t ph_off = off, offs;
  int ph_num = num;

  if (ms->flags & MAGIC_MIME)
    return 0;

  if (num == 0) {
    if (file_printf(ms, ", no program header") == -1)
      return -1;
    return 0;
  }
  if (size != xph_sizeof) {
    if (file_printf(ms, ", corrupted program header size") == -1)
      return -1;
    return 0;
  }

  /*
   * Loop through all the program headers.
   */
  for ( ; num; num--) {
    if (pread(fd, xph_addr, xph_sizeof, off) <
        CAST(ssize_t, xph_sizeof)) {
      if (file_printf(ms, 
          ", can't read elf program headers at %jd",
          (intmax_t)off) == -1)
        return -1;
      return 0;
    }
    off += size;

    if (fsize != SIZE_UNKNOWN && xph_offset > fsize) {
      /* Perhaps warn here */
      continue;
    }

    if (xph_type != PT_NOTE)
      continue;

    /*
     * This is a PT_NOTE section; loop through all the notes
     * in the section.
     */
    len = xph_filesz < sizeof(nbuf) ? xph_filesz : sizeof(nbuf);
    offs = xph_offset;
    if ((bufsize = pread(fd, nbuf, len, offs)) == -1) {
      if (file_printf(ms, " can't read note section at %jd",
          (intmax_t)offs) == -1)
        return -1;
      return 0;
    }
    offset = 0;
    for (;;) {
      if (offset >= CAST(size_t, bufsize))
        break;
      offset = donote(ms, nbuf, offset, CAST(size_t, bufsize),
          clazz, swap, 4, flags, notecount, fd, ph_off,
          ph_num, fsize);
      if (offset == 0)
        break;

    }
  }
  return 0;
}
#endif

static int
do_note_netbsd_version(struct magic_set *ms, int swap, void *v)
{
  uint32_t desc;
  memcpy(&desc, v, sizeof(desc));
  desc = elf_getu32(swap, desc);

  if (file_printf(ms, ", for NetBSD") == -1)
    return -1;
  /*
   * The version number used to be stuck as 199905, and was thus
   * basically content-free.  Newer versions of NetBSD have fixed
   * this and now use the encoding of __NetBSD_Version__:
   *
   *  MMmmrrpp00
   *
   * M = major version
   * m = minor version
   * r = release ["",A-Z,Z[A-Z] but numeric]
   * p = patchlevel
   */
  if (desc > 100000000U) {
    uint32_t ver_patch = (desc / 100) % 100;
    uint32_t ver_rel = (desc / 10000) % 100;
    uint32_t ver_min = (desc / 1000000) % 100;
    uint32_t ver_maj = desc / 100000000;

    if (file_printf(ms, " %u.%u", ver_maj, ver_min) == -1)
      return -1;
    if (ver_maj >= 9) {
      ver_patch += 100 * ver_rel;
      ver_rel = 0;
    }
    if (ver_rel == 0 && ver_patch != 0) {
      if (file_printf(ms, ".%u", ver_patch) == -1)
        return -1;
    } else if (ver_rel != 0) {
      while (ver_rel > 26) {
        if (file_printf(ms, "Z") == -1)
          return -1;
        ver_rel -= 26;
      }
      if (file_printf(ms, "%c", 'A' + ver_rel - 1) == -1)
        return -1;
    }
  }
  return 0;
}

static int
do_note_freebsd_version(struct magic_set *ms, int swap, void *v)
{
  uint32_t desc;

  memcpy(&desc, v, sizeof(desc));
  desc = elf_getu32(swap, desc);
  if (file_printf(ms, ", for FreeBSD") == -1)
    return -1;

  /*
   * Contents is __FreeBSD_version, whose relation to OS
   * versions is defined by a huge table in the Porter's
   * Handbook.  This is the general scheme:
   *
   * Releases:
   *  Mmp000 (before 4.10)
   *  Mmi0p0 (before 5.0)
   *  Mmm0p0
   *
   * Development branches:
   *  Mmpxxx (before 4.6)
   *  Mmp1xx (before 4.10)
   *  Mmi1xx (before 5.0)
   *  M000xx (pre-M.0)
   *  Mmm1xx
   *
   * M = major version
   * m = minor version
   * i = minor version increment (491000 -> 4.10)
   * p = patchlevel
   * x = revision
   *
   * The first release of FreeBSD to use ELF by default
   * was version 3.0.
   */
  if (desc == 460002) {
    if (file_printf(ms, " 4.6.2") == -1)
      return -1;
  } else if (desc < 460100) {
    if (file_printf(ms, " %d.%d", desc / 100000,
        desc / 10000 % 10) == -1)
      return -1;
    if (desc / 1000 % 10 > 0)
      if (file_printf(ms, ".%d", desc / 1000 % 10) == -1)
        return -1;
    if ((desc % 1000 > 0) || (desc % 100000 == 0))
      if (file_printf(ms, " (%d)", desc) == -1)
        return -1;
  } else if (desc < 500000) {
    if (file_printf(ms, " %d.%d", desc / 100000,
        desc / 10000 % 10 + desc / 1000 % 10) == -1)
      return -1;
    if (desc / 100 % 10 > 0) {
      if (file_printf(ms, " (%d)", desc) == -1)
        return -1;
    } else if (desc / 10 % 10 > 0) {
      if (file_printf(ms, ".%d", desc / 10 % 10) == -1)
        return -1;
    }
  } else {
    if (file_printf(ms, " %d.%d", desc / 100000,
        desc / 1000 % 100) == -1)
      return -1;
    if ((desc / 100 % 10 > 0) ||
        (desc % 100000 / 100 == 0)) {
      if (file_printf(ms, " (%d)", desc) == -1)
        return -1;
    } else if (desc / 10 % 10 > 0) {
      if (file_printf(ms, ".%d", desc / 10 % 10) == -1)
        return -1;
    }
  }
  return 0;
}

file_private int
/*ARGSUSED*/
do_bid_note(struct magic_set *ms, unsigned char *nbuf, uint32_t type,
    int swap __attribute__((__unused__)), uint32_t namesz, uint32_t descsz,
    size_t noff, size_t doff, int *flags)
{
  if (namesz == 4 && strcmp(RCAST(char *, &nbuf[noff]), "GNU") == 0 &&
      type == NT_GNU_BUILD_ID && (descsz >= 4 && descsz <= 20)) {
    uint8_t desc[20];
    const char *btype;
    uint32_t i;
    *flags |= FLAGS_DID_BUILD_ID;
    switch (descsz) {
    case 8:
        btype = "xxHash";
        break;
    case 16:
        btype = "md5/uuid";
        break;
    case 20:
        btype = "sha1";
        break;
    default:
        btype = "unknown";
        break;
    }
    if (file_printf(ms, ", BuildID[%s]=", btype) == -1)
      return -1;
    memcpy(desc, &nbuf[doff], descsz);
    for (i = 0; i < descsz; i++)
        if (file_printf(ms, "%02x", desc[i]) == -1)
      return -1;
    return 1;
  }
  if (namesz == 4 && strcmp(RCAST(char *, &nbuf[noff]), "Go") == 0 &&
      type == NT_GO_BUILD_ID && descsz < 128) {
    char buf[256];
    if (file_printf(ms, ", Go BuildID=%s",
        file_copystr(buf, sizeof(buf), descsz,
        RCAST(const char *, &nbuf[doff]))) == -1)
      return -1;
    return 1;
  }
  return 0;
}

file_private int
do_os_note(struct magic_set *ms, unsigned char *nbuf, uint32_t type,
    int swap, uint32_t namesz, uint32_t descsz,
    size_t noff, size_t doff, int *flags)
{
  const char *name = RCAST(const char *, &nbuf[noff]);

  if (namesz == 5 && strcmp(name, "SuSE") == 0 &&
    type == NT_GNU_VERSION && descsz == 2) {
    *flags |= FLAGS_DID_OS_NOTE;
    if (file_printf(ms, ", for SuSE %d.%d", nbuf[doff],
        nbuf[doff + 1]) == -1)
        return -1;
      return 1;
  }

  if (namesz == 4 && strcmp(name, "GNU") == 0 &&
      type == NT_GNU_VERSION && descsz == 16) {
    uint32_t desc[4];
    memcpy(desc, &nbuf[doff], sizeof(desc));

    *flags |= FLAGS_DID_OS_NOTE;
    if (file_printf(ms, ", for GNU/") == -1)
      return -1;
    switch (elf_getu32(swap, desc[0])) {
    case GNU_OS_LINUX:
      if (file_printf(ms, "Linux") == -1)
        return -1;
      break;
    case GNU_OS_HURD:
      if (file_printf(ms, "Hurd") == -1)
        return -1;
      break;
    case GNU_OS_SOLARIS:
      if (file_printf(ms, "Solaris") == -1)
        return -1;
      break;
    case GNU_OS_KFREEBSD:
      if (file_printf(ms, "kFreeBSD") == -1)
        return -1;
      break;
    case GNU_OS_KNETBSD:
      if (file_printf(ms, "kNetBSD") == -1)
        return -1;
      break;
    default:
      if (file_printf(ms, "<unknown>") == -1)
        return -1;
    }
    if (file_printf(ms, " %d.%d.%d", elf_getu32(swap, desc[1]),
        elf_getu32(swap, desc[2]), elf_getu32(swap, desc[3])) == -1)
      return -1;
    return 1;
  }

  if (namesz == 7 && strcmp(name, "NetBSD") == 0) {
        if (type == NT_NETBSD_VERSION && descsz == 4) {
      *flags |= FLAGS_DID_OS_NOTE;
      if (do_note_netbsd_version(ms, swap, &nbuf[doff]) == -1)
        return -1;
      return 1;
    }
  }

  if (namesz == 8 && strcmp(name, "FreeBSD") == 0) {
        if (type == NT_FREEBSD_VERSION && descsz == 4) {
      *flags |= FLAGS_DID_OS_NOTE;
      if (do_note_freebsd_version(ms, swap, &nbuf[doff])
          == -1)
        return -1;
      return 1;
    }
  }

  if (namesz == 8 && strcmp(name, "OpenBSD") == 0 &&
      type == NT_OPENBSD_VERSION && descsz == 4) {
    *flags |= FLAGS_DID_OS_NOTE;
    if (file_printf(ms, ", for OpenBSD") == -1)
      return -1;
    /* Content of note is always 0 */
    return 1;
  }

  if (namesz == 10 && strcmp(name, "DragonFly") == 0 &&
      type == NT_DRAGONFLY_VERSION && descsz == 4) {
    uint32_t desc;
    *flags |= FLAGS_DID_OS_NOTE;
    if (file_printf(ms, ", for DragonFly") == -1)
      return -1;
    memcpy(&desc, &nbuf[doff], sizeof(desc));
    desc = elf_getu32(swap, desc);
    if (file_printf(ms, " %d.%d.%d", desc / 100000,
        desc / 10000 % 10, desc % 10000) == -1)
      return -1;
    return 1;
  }
  return 0;
}

file_private int
do_pax_note(struct magic_set *ms, unsigned char *nbuf, uint32_t type,
    int swap, uint32_t namesz, uint32_t descsz,
    size_t noff, size_t doff, int *flags)
{
  const char *name = RCAST(const char *, &nbuf[noff]);

  if (namesz == 4 && strcmp(name, "PaX") == 0 &&
      type == NT_NETBSD_PAX && descsz == 4) {
    static const char *pax[] = {
        "+mprotect",
        "-mprotect",
        "+segvguard",
        "-segvguard",
        "+ASLR",
        "-ASLR",
    };
    uint32_t desc;
    size_t i;
    int did = 0;

    *flags |= FLAGS_DID_NETBSD_PAX;
    memcpy(&desc, &nbuf[doff], sizeof(desc));
    desc = elf_getu32(swap, desc);

    if (desc && file_printf(ms, ", PaX: ") == -1)
      return -1;

    for (i = 0; i < __arraycount(pax); i++) {
      if (((1 << CAST(int, i)) & desc) == 0)
        continue;
      if (file_printf(ms, "%s%s", did++ ? "," : "",
          pax[i]) == -1)
        return -1;
    }
    return 1;
  }
  return 0;
}

file_private int
do_core_note(struct magic_set *ms, unsigned char *nbuf, uint32_t type,
    int swap, uint32_t namesz, uint32_t descsz,
    size_t noff, size_t doff, int *flags, size_t size, int clazz)
{
#ifdef ELFCORE
  char buf[256];
  const char *name = RCAST(const char *, &nbuf[noff]);

  int os_style = -1;
  /*
   * Sigh.  The 2.0.36 kernel in Debian 2.1, at
   * least, doesn't correctly implement name
   * sections, in core dumps, as specified by
   * the "Program Linking" section of "UNIX(R) System
   * V Release 4 Programmer's Guide: ANSI C and
   * Programming Support Tools", because my copy
   * clearly says "The first 'namesz' bytes in 'name'
   * contain a *null-terminated* [emphasis mine]
   * character representation of the entry's owner
   * or originator", but the 2.0.36 kernel code
   * doesn't include the terminating null in the
   * name....
   */
  if ((namesz == 4 && strncmp(name, "CORE", 4) == 0) ||
      (namesz == 5 && strcmp(name, "CORE") == 0)) {
    os_style = OS_STYLE_SVR4;
  }

  if ((namesz == 8 && strcmp(name, "FreeBSD") == 0)) {
    os_style = OS_STYLE_FREEBSD;
  }

  if ((namesz >= 11 && strncmp(name, "NetBSD-CORE", 11)
      == 0)) {
    os_style = OS_STYLE_NETBSD;
  }

  if (os_style != -1 && (*flags & FLAGS_DID_CORE_STYLE) == 0) {
    if (file_printf(ms, ", %s-style", os_style_names[os_style])
        == -1)
      return -1;
    *flags |= FLAGS_DID_CORE_STYLE;
    *flags |= os_style;
  }

  switch (os_style) {
  case OS_STYLE_NETBSD:
    if (type == NT_NETBSD_CORE_PROCINFO) {
      char sbuf[512];
      struct NetBSD_elfcore_procinfo pi;
      memset(&pi, 0, sizeof(pi));
      memcpy(&pi, nbuf + doff, MIN(descsz, sizeof(pi)));

      if (file_printf(ms, ", from '%.31s', pid=%u, uid=%u, "
          "gid=%u, nlwps=%u, lwp=%u (signal %u/code %u)",
          file_printable(ms, sbuf, sizeof(sbuf),
          RCAST(char *, pi.cpi_name), sizeof(pi.cpi_name)),
          elf_getu32(swap, CAST(uint32_t, pi.cpi_pid)),
          elf_getu32(swap, pi.cpi_euid),
          elf_getu32(swap, pi.cpi_egid),
          elf_getu32(swap, pi.cpi_nlwps),
          elf_getu32(swap, CAST(uint32_t, pi.cpi_siglwp)),
          elf_getu32(swap, pi.cpi_signo),
          elf_getu32(swap, pi.cpi_sigcode)) == -1)
        return -1;

      *flags |= FLAGS_DID_CORE;
      return 1;
    }
    break;

  case OS_STYLE_FREEBSD:
    if (type == NT_PRPSINFO && *flags & FLAGS_IS_CORE) {
      size_t argoff, pidoff;

      if (clazz == ELFCLASS32)
        argoff = 4 + 4 + 17;
      else
        argoff = 4 + 4 + 8 + 17;
      if (file_printf(ms, ", from '%.80s'", nbuf + doff +
          argoff) == -1)
        return -1;
      pidoff = argoff + 81 + 2;
      if (doff + pidoff + 4 <= size) {
        if (file_printf(ms, ", pid=%u",
            elf_getu32(swap, *RCAST(uint32_t *, (nbuf +
            doff + pidoff)))) == -1)
          return -1;
      }
      *flags |= FLAGS_DID_CORE;
    }          
    break;

  default:
    if (type == NT_PRPSINFO && *flags & FLAGS_IS_CORE) {
      size_t i, j;
      unsigned char c;
      /*
       * Extract the program name.  We assume
       * it to be 16 characters (that's what it
       * is in SunOS 5.x and Linux).
       *
       * Unfortunately, it's at a different offset
       * in various OSes, so try multiple offsets.
       * If the characters aren't all printable,
       * reject it.
       */
      for (i = 0; i < NOFFSETS; i++) {
        unsigned char *cname, *cp;
        size_t reloffset = prpsoffsets(i);
        size_t noffset = doff + reloffset;
        size_t k;
        for (j = 0; j < 16; j++, noffset++,
            reloffset++) {
          /*
           * Make sure we're not past
           * the end of the buffer; if
           * we are, just give up.
           */
          if (noffset >= size)
            goto tryanother;

          /*
           * Make sure we're not past
           * the end of the contents;
           * if we are, this obviously
           * isn't the right offset.
           */
          if (reloffset >= descsz)
            goto tryanother;

          c = nbuf[noffset];
          if (c == '\0') {
            /*
             * A '\0' at the
             * beginning is
             * obviously wrong.
             * Any other '\0'
             * means we're done.
             */
            if (j == 0)
              goto tryanother;
            else
              break;
          } else {
            /*
             * A nonprintable
             * character is also
             * wrong.
             */
            if (!isprint(c) || isquote(c))
              goto tryanother;
          }
        }
        /*
         * Well, that worked.
         */

        /*
         * Try next offsets, in case this match is
         * in the middle of a string.
         */
        for (k = i + 1 ; k < NOFFSETS; k++) {
          size_t no;
          int adjust = 1;
          if (prpsoffsets(k) >= prpsoffsets(i))
            continue;
          /*
           * pr_fname == pr_psargs - 16 &&
           * non-nul-terminated fname (qemu)
           */
          if (prpsoffsets(k) ==
              prpsoffsets(i) - 16 && j == 16)
            continue;
          for (no = doff + prpsoffsets(k);
               no < doff + prpsoffsets(i); no++)
            adjust = adjust
                     && isprint(nbuf[no]);
          if (adjust)
            i = k;
        }

        cname = CAST(unsigned char *,
            &nbuf[doff + prpsoffsets(i)]);
        for (cp = cname; cp < nbuf + size && *cp
            && isprint(*cp); cp++)
          continue;
        /*
         * Linux apparently appends a space at the end
         * of the command line: remove it.
         */
        while (cp > cname && isspace(cp[-1]))
          cp--;
        if (file_printf(ms, ", from '%s'",
            file_copystr(buf, sizeof(buf),
            CAST(size_t, cp - cname),
            RCAST(char *, cname))) == -1)
          return -1;
        *flags |= FLAGS_DID_CORE;
        return 1;

      tryanother:
        ;
      }
    }
    break;
  }
#endif
  return 0;
}

file_private off_t
get_offset_from_virtaddr(struct magic_set *ms, int swap, int clazz, int fd,
    off_t off, int num, off_t fsize, uint64_t virtaddr)
{
  Elf32_Phdr ph32;
  Elf64_Phdr ph64;

  /*
   * Loop through all the program headers and find the header with
   * virtual address in which the "virtaddr" belongs to.
   */
  for ( ; num; num--) {
    if (pread(fd, xph_addr, xph_sizeof, off) <
        CAST(ssize_t, xph_sizeof)) {
      if (file_printf(ms,
          ", can't read elf program header at %jd",
          (intmax_t)off) == -1)
        return -1;
      return 0;

    }
    off += xph_sizeof;

    if (fsize != SIZE_UNKNOWN && xph_offset > fsize) {
      /* Perhaps warn here */
      continue;
    }

    if (virtaddr >= xph_vaddr && virtaddr < xph_vaddr + xph_filesz)
      return xph_offset + (virtaddr - xph_vaddr);
  }
  return 0;
}

file_private size_t
get_string_on_virtaddr(struct magic_set *ms,
    int swap, int clazz, int fd, off_t ph_off, int ph_num,
    off_t fsize, uint64_t virtaddr, char *buf, ssize_t buflen)
{
  char *bptr;
  off_t offset;

  if (buflen == 0)
    return 0;

  offset = get_offset_from_virtaddr(ms, swap, clazz, fd, ph_off, ph_num,
      fsize, virtaddr);
  if (offset < 0 ||
      (buflen = pread(fd, buf, CAST(size_t, buflen), offset)) <= 0) {
    (void)file_printf(ms, ", can't read elf string at %jd",
        (intmax_t)offset);
    return 0;
  }

  buf[buflen - 1] = '\0';

  /* We expect only printable characters, so return if buffer contains
   * non-printable character before the '\0' or just '\0'. */
  for (bptr = buf; *bptr && isprint(CAST(unsigned char, *bptr)); bptr++)
    continue;
  if (*bptr != '\0')
    return 0;

  return bptr - buf;
}


/*ARGSUSED*/
file_private int
do_auxv_note(struct magic_set *ms, unsigned char *nbuf, uint32_t type,
    int swap, uint32_t namesz __attribute__((__unused__)),
    uint32_t descsz __attribute__((__unused__)),
    size_t noff __attribute__((__unused__)), size_t doff,
    int *flags, size_t size __attribute__((__unused__)), int clazz,
    int fd, off_t ph_off, int ph_num, off_t fsize)
{
#ifdef ELFCORE
  Aux32Info auxv32;
  Aux64Info auxv64;
  size_t elsize = xauxv_sizeof;
  const char *tag;
  int is_string;
  size_t nval, off;

  if ((*flags & (FLAGS_IS_CORE|FLAGS_DID_CORE_STYLE)) !=
      (FLAGS_IS_CORE|FLAGS_DID_CORE_STYLE))
    return 0;

  switch (*flags & FLAGS_CORE_STYLE) {
  case OS_STYLE_SVR4:
    if (type != NT_AUXV)
      return 0;
    break;
#ifdef notyet
  case OS_STYLE_NETBSD:
    if (type != NT_NETBSD_CORE_AUXV)
      return 0;
    break;
  case OS_STYLE_FREEBSD:
    if (type != NT_FREEBSD_PROCSTAT_AUXV)
      return 0;
    break;
#endif
  default:
    return 0;
  }

  *flags |= FLAGS_DID_AUXV;

  nval = 0;
  for (off = 0; off + elsize <= descsz; off += elsize) {
    memcpy(xauxv_addr, &nbuf[doff + off], xauxv_sizeof);
    /* Limit processing to 50 vector entries to prevent DoS */
    if (nval++ >= 50) {
      file_error(ms, 0, "Too many ELF Auxv elements");
      return 1;
    }

    switch(xauxv_type) {
    case AT_LINUX_EXECFN:
      is_string = 1;
      tag = "execfn";
      break;
    case AT_LINUX_PLATFORM:
      is_string = 1;
      tag = "platform";
      break;
    case AT_LINUX_UID:
      is_string = 0;
      tag = "real uid";
      break;
    case AT_LINUX_GID:
      is_string = 0;
      tag = "real gid";
      break;
    case AT_LINUX_EUID:
      is_string = 0;
      tag = "effective uid";
      break;
    case AT_LINUX_EGID:
      is_string = 0;
      tag = "effective gid";
      break;
    default:
      is_string = 0;
      tag = NULL;
      break;
    }

    if (tag == NULL)
      continue;

    if (is_string) {
      char buf[256];
      ssize_t buflen;
      buflen = get_string_on_virtaddr(ms, swap, clazz, fd,
          ph_off, ph_num, fsize, xauxv_val, buf, sizeof(buf));

      if (buflen == 0)
        continue;

      if (file_printf(ms, ", %s: '%s'", tag, buf) == -1)
        return -1;
    } else {
      if (file_printf(ms, ", %s: %d", tag,
          CAST(int, xauxv_val)) == -1)
        return -1;
    }
  }
  return 1;
#else
  return 0;
#endif
}

file_private size_t
dodynamic(struct magic_set *ms, void *vbuf, size_t offset, size_t size,
    int clazz, int swap, int *pie, size_t *need)
{
  Elf32_Dyn dh32;
  Elf64_Dyn dh64;
  unsigned char *dbuf = CAST(unsigned char *, vbuf);

  if (xdh_sizeof + offset > size) {
    /*
     * We're out of note headers.
     */
    return xdh_sizeof + offset;
  }

  memcpy(xdh_addr, &dbuf[offset], xdh_sizeof);
  offset += xdh_sizeof;

  switch (xdh_tag) {
  case DT_FLAGS_1:
    *pie = 1;
    if (xdh_val & DF_1_PIE)
      ms->mode |= 0111;
    else
      ms->mode &= ~0111;
    break;
  case DT_NEEDED:
    (*need)++;
    break;
  default:
    break;
  }
  return offset;
}


file_private size_t
donote(struct magic_set *ms, void *vbuf, size_t offset, size_t size,
    int clazz, int swap, size_t align, int *flags, uint16_t *notecount,
    int fd, off_t ph_off, int ph_num, off_t fsize)
{
  Elf32_Nhdr nh32;
  Elf64_Nhdr nh64;
  size_t noff, doff;
  uint32_t namesz, descsz;
  char buf[256];
  unsigned char *nbuf = CAST(unsigned char *, vbuf);

  if (*notecount == 0)
    return 0;
  --*notecount;

  if (xnh_sizeof + offset > size) {
    /*
     * We're out of note headers.
     */
    return xnh_sizeof + offset;
  }
  /*XXX: GCC */
  memset(&nh32, 0, sizeof(nh32));
  memset(&nh64, 0, sizeof(nh64));

  memcpy(xnh_addr, &nbuf[offset], xnh_sizeof);
  offset += xnh_sizeof;

  namesz = xnh_namesz;
  descsz = xnh_descsz;

  if ((namesz == 0) && (descsz == 0)) {
    /*
     * We're out of note headers.
     */
    return (offset >= size) ? offset : size;
  }

  if (namesz & 0x80000000) {
      (void)file_printf(ms, ", bad note name size %#lx",
    CAST(unsigned long, namesz));
      return 0;
  }

  if (descsz & 0x80000000) {
    (void)file_printf(ms, ", bad note description size %#lx",
        CAST(unsigned long, descsz));
    return 0;
  }

  noff = offset;
  doff = ELF_ALIGN(offset + namesz);

  if (offset + namesz > size) {
    /*
     * We're past the end of the buffer.
     */
    return doff;
  }

  offset = ELF_ALIGN(doff + descsz);
  if (doff + descsz > size) {
    /*
     * We're past the end of the buffer.
     */
    return (offset >= size) ? offset : size;
  }


  if ((*flags & FLAGS_DID_OS_NOTE) == 0) {
    if (do_os_note(ms, nbuf, xnh_type, swap,
        namesz, descsz, noff, doff, flags))
      return offset;
  }

  if ((*flags & FLAGS_DID_BUILD_ID) == 0) {
    if (do_bid_note(ms, nbuf, xnh_type, swap,
        namesz, descsz, noff, doff, flags))
      return offset;
  }

  if ((*flags & FLAGS_DID_NETBSD_PAX) == 0) {
    if (do_pax_note(ms, nbuf, xnh_type, swap,
        namesz, descsz, noff, doff, flags))
      return offset;
  }

  if ((*flags & FLAGS_DID_CORE) == 0) {
    if (do_core_note(ms, nbuf, xnh_type, swap,
        namesz, descsz, noff, doff, flags, size, clazz))
      return offset;
  }

  if ((*flags & FLAGS_DID_AUXV) == 0) {
    if (do_auxv_note(ms, nbuf, xnh_type, swap,
      namesz, descsz, noff, doff, flags, size, clazz,
      fd, ph_off, ph_num, fsize))
      return offset;
  }

  if (namesz == 7 && strcmp(RCAST(char *, &nbuf[noff]), "NetBSD") == 0) {
    int descw, flag;
    const char *str, *tag;
    if (descsz > 100)
      descsz = 100;
    switch (xnh_type) {
        case NT_NETBSD_VERSION:
      return offset;
    case NT_NETBSD_MARCH:
      flag = FLAGS_DID_NETBSD_MARCH;
      tag = "compiled for";
      break;
    case NT_NETBSD_CMODEL:
      flag = FLAGS_DID_NETBSD_CMODEL;
      tag = "compiler model";
      break;
    case NT_NETBSD_EMULATION:
      flag = FLAGS_DID_NETBSD_EMULATION;
      tag = "emulation:";
      break;
    default:
      if (*flags & FLAGS_DID_NETBSD_UNKNOWN)
        return offset;
      *flags |= FLAGS_DID_NETBSD_UNKNOWN;
      if (file_printf(ms, ", note=%u", xnh_type) == -1)
        return offset;
      return offset;
    }

    if (*flags & flag)
      return offset;
    str = RCAST(const char *, &nbuf[doff]);
    descw = CAST(int, descsz);
    *flags |= flag;
    file_printf(ms, ", %s: %s", tag,
        file_copystr(buf, sizeof(buf), descw, str));
    return offset;
  }

  return offset;
}

/* SunOS 5.x hardware capability descriptions */
typedef struct cap_desc {
  uint64_t cd_mask;
  const char *cd_name;
} cap_desc_t;

static const cap_desc_t cap_desc_sparc[] = {
  { AV_SPARC_MUL32,   "MUL32" },
  { AV_SPARC_DIV32,   "DIV32" },
  { AV_SPARC_FSMULD,    "FSMULD" },
  { AV_SPARC_V8PLUS,    "V8PLUS" },
  { AV_SPARC_POPC,    "POPC" },
  { AV_SPARC_VIS,     "VIS" },
  { AV_SPARC_VIS2,    "VIS2" },
  { AV_SPARC_ASI_BLK_INIT,  "ASI_BLK_INIT" },
  { AV_SPARC_FMAF,    "FMAF" },
  { AV_SPARC_FJFMAU,    "FJFMAU" },
  { AV_SPARC_IMA,     "IMA" },
  { 0, NULL }
};

static const cap_desc_t cap_desc_386[] = {
  { AV_386_FPU,     "FPU" },
  { AV_386_TSC,     "TSC" },
  { AV_386_CX8,     "CX8" },
  { AV_386_SEP,     "SEP" },
  { AV_386_AMD_SYSC,    "AMD_SYSC" },
  { AV_386_CMOV,      "CMOV" },
  { AV_386_MMX,     "MMX" },
  { AV_386_AMD_MMX,   "AMD_MMX" },
  { AV_386_AMD_3DNow,   "AMD_3DNow" },
  { AV_386_AMD_3DNowx,    "AMD_3DNowx" },
  { AV_386_FXSR,      "FXSR" },
  { AV_386_SSE,     "SSE" },
  { AV_386_SSE2,      "SSE2" },
  { AV_386_PAUSE,     "PAUSE" },
  { AV_386_SSE3,      "SSE3" },
  { AV_386_MON,     "MON" },
  { AV_386_CX16,      "CX16" },
  { AV_386_AHF,     "AHF" },
  { AV_386_TSCP,      "TSCP" },
  { AV_386_AMD_SSE4A,   "AMD_SSE4A" },
  { AV_386_POPCNT,    "POPCNT" },
  { AV_386_AMD_LZCNT,   "AMD_LZCNT" },
  { AV_386_SSSE3,     "SSSE3" },
  { AV_386_SSE4_1,    "SSE4.1" },
  { AV_386_SSE4_2,    "SSE4.2" },
  { 0, NULL }
};

file_private int
doshn(struct magic_set *ms, int clazz, int swap, int fd, off_t off, int num,
    size_t size, off_t fsize, int mach, int strtab, int *flags,
    uint16_t *notecount)
{
  Elf32_Shdr sh32;
  Elf64_Shdr sh64;
  int stripped = 1, has_debug_info = 0;
  size_t nbadcap = 0;
  void *nbuf;
  off_t noff, coff, name_off, offs;
  uint64_t cap_hw1 = 0; /* SunOS 5.x hardware capabilities */
  uint64_t cap_sf1 = 0; /* SunOS 5.x software capabilities */
  char name[50];
  ssize_t namesize;

  if (ms->flags & MAGIC_MIME)
    return 0;

  if (num == 0) {
    if (file_printf(ms, ", no section header") == -1)
      return -1;
    return 0;
  }
  if (size != xsh_sizeof) {
    if (file_printf(ms, ", corrupted section header size") == -1)
      return -1;
    return 0;
  }

  /* Read offset of name section to be able to read section names later */
  offs = CAST(off_t, (off + size * strtab));
  if (pread(fd, xsh_addr, xsh_sizeof, offs) < CAST(ssize_t, xsh_sizeof)) {
    if (file_printf(ms, ", missing section headers at %jd",
        (intmax_t)offs) == -1)
      return -1;
    return 0;
  }
  name_off = xsh_offset;

  if (fsize != SIZE_UNKNOWN && fsize < name_off) {
    if (file_printf(ms, ", too large section header offset %jd",
        (intmax_t)name_off) == -1)
      return -1;
    return 0;
  }

  for ( ; num; num--) {
    /* Read the name of this section. */
    offs = name_off + xsh_name;
    if ((namesize = pread(fd, name, sizeof(name) - 1, offs))
        == -1) {
      if (file_printf(ms, 
          ", can't read name of elf section at %jd",
          (intmax_t)offs) == -1)
        return -1;
      return 0;
    }
    name[namesize] = '\0';
    if (strcmp(name, ".debug_info") == 0) {
      has_debug_info = 1;
      stripped = 0;
    }

    if (pread(fd, xsh_addr, xsh_sizeof, off) <
        CAST(ssize_t, xsh_sizeof)) {
      if (file_printf(ms, ", can't read elf section at %jd",
          (intmax_t)off) == -1)
        return -1;
      return 0;
    }
    off += size;

    /* Things we can determine before we seek */
    switch (xsh_type) {
    case SHT_SYMTAB:
#if 0
    case SHT_DYNSYM:
#endif
      stripped = 0;
      break;
    default:
      if (fsize != SIZE_UNKNOWN && xsh_offset > fsize) {
        /* Perhaps warn here */
        continue;
      }
      break;
    }


    /* Things we can determine when we seek */
    switch (xsh_type) {
    case SHT_NOTE:
      if (CAST(uintmax_t, (xsh_size + xsh_offset)) >
          CAST(uintmax_t, fsize)) {
        if (file_printf(ms,
            ", note offset/size %#" INTMAX_T_FORMAT
            "x+%#" INTMAX_T_FORMAT "x exceeds"
            " file size %#" INTMAX_T_FORMAT "x",
            CAST(uintmax_t, xsh_offset),
            CAST(uintmax_t, xsh_size),
            CAST(uintmax_t, fsize)) == -1)
          return -1;
        return 0;
      }
      if (xsh_size > ms->elf_shsize_max) {
        file_error(ms, errno, "Note section size too "
            "big (%ju > %zu)", (uintmax_t)xsh_size,
            ms->elf_shsize_max);
        return -1;
      }
      if ((nbuf = malloc(xsh_size)) == NULL) {
        file_error(ms, errno, "Cannot allocate memory"
            " for note");
        return -1;
      }
      offs = xsh_offset;
      if (pread(fd, nbuf, xsh_size, offs) <
          CAST(ssize_t, xsh_size)) {
        free(nbuf);
        if (file_printf(ms,
            ", can't read elf note at %jd",
            (intmax_t)offs) == -1)
          return -1;
        return 0;
      }

      noff = 0;
      for (;;) {
        if (noff >= CAST(off_t, xsh_size))
          break;
        noff = donote(ms, nbuf, CAST(size_t, noff),
            xsh_size, clazz, swap, 4, flags, notecount,
            fd, 0, 0, 0);
        if (noff == 0)
          break;
      }
      free(nbuf);
      break;
    case SHT_SUNW_cap:
      switch (mach) {
      case EM_SPARC:
      case EM_SPARCV9:
      case EM_IA_64:
      case EM_386:
      case EM_AMD64:
        break;
      default:
        goto skip;
      }

      if (nbadcap > 5)
        break;
      if (lseek(fd, xsh_offset, SEEK_SET)
          == CAST(off_t, -1)) {
        file_badseek(ms);
        return -1;
      }
      coff = 0;
      for (;;) {
        Elf32_Cap cap32;
        Elf64_Cap cap64;
        char cbuf[/*CONSTCOND*/
            MAX(sizeof(cap32), sizeof(cap64))];
        if ((coff += xcap_sizeof) >
            CAST(off_t, xsh_size))
          break;
        if (read(fd, cbuf, CAST(size_t, xcap_sizeof)) !=
            CAST(ssize_t, xcap_sizeof)) {
          file_badread(ms);
          return -1;
        }
        if (cbuf[0] == 'A') {
#ifdef notyet
          char *p = cbuf + 1;
          uint32_t len, tag;
          memcpy(&len, p, sizeof(len));
          p += 4;
          len = getu32(swap, len);
          if (memcmp("gnu", p, 3) != 0) {
              if (file_printf(ms,
            ", unknown capability %.3s", p)
            == -1)
            return -1;
              break;
          }
          p += strlen(p) + 1;
          tag = *p++;
          memcpy(&len, p, sizeof(len));
          p += 4;
          len = getu32(swap, len);
          if (tag != 1) {
              if (file_printf(ms, ", unknown gnu"
            " capability tag %d", tag)
            == -1)
            return -1;
              break;
          }
          // gnu attributes
#endif
          break;
        }
        memcpy(xcap_addr, cbuf, xcap_sizeof);
        switch (xcap_tag) {
        case CA_SUNW_NULL:
          break;
        case CA_SUNW_HW_1:
          cap_hw1 |= xcap_val;
          break;
        case CA_SUNW_SF_1:
          cap_sf1 |= xcap_val;
          break;
        default:
          if (file_printf(ms,
              ", with unknown capability "
              "%#" INT64_T_FORMAT "x = %#"
              INT64_T_FORMAT "x",
              CAST(unsigned long long, xcap_tag),
              CAST(unsigned long long, xcap_val))
              == -1)
            return -1;
          if (nbadcap++ > 2)
            coff = xsh_size;
          break;
        }
      }
      /*FALLTHROUGH*/
    skip:
    default:
      break;
    }
  }

  if (has_debug_info) {
    if (file_printf(ms, ", with debug_info") == -1)
      return -1;
  }
  if (file_printf(ms, ", %sstripped", stripped ? "" : "not ") == -1)
    return -1;
  if (cap_hw1) {
    const cap_desc_t *cdp;
    switch (mach) {
    case EM_SPARC:
    case EM_SPARC32PLUS:
    case EM_SPARCV9:
      cdp = cap_desc_sparc;
      break;
    case EM_386:
    case EM_IA_64:
    case EM_AMD64:
      cdp = cap_desc_386;
      break;
    default:
      cdp = NULL;
      break;
    }
    if (file_printf(ms, ", uses") == -1)
      return -1;
    if (cdp) {
      while (cdp->cd_name) {
        if (cap_hw1 & cdp->cd_mask) {
          if (file_printf(ms,
              " %s", cdp->cd_name) == -1)
            return -1;
          cap_hw1 &= ~cdp->cd_mask;
        }
        ++cdp;
      }
      if (cap_hw1)
        if (file_printf(ms,
            " unknown hardware capability %#"
            INT64_T_FORMAT "x",
            CAST(unsigned long long, cap_hw1)) == -1)
          return -1;
    } else {
      if (file_printf(ms,
          " hardware capability %#" INT64_T_FORMAT "x",
          CAST(unsigned long long, cap_hw1)) == -1)
        return -1;
    }
  }
  if (cap_sf1) {
    if (cap_sf1 & SF1_SUNW_FPUSED) {
      if (file_printf(ms,
          (cap_sf1 & SF1_SUNW_FPKNWN)
          ? ", uses frame pointer"
          : ", not known to use frame pointer") == -1)
        return -1;
    }
    cap_sf1 &= ~SF1_SUNW_MASK;
    if (cap_sf1)
      if (file_printf(ms,
          ", with unknown software capability %#"
          INT64_T_FORMAT "x",
          CAST(unsigned long long, cap_sf1)) == -1)
        return -1;
  }
  return 0;
}

/*
 * Look through the program headers of an executable image, to determine
 * if it is statically or dynamically linked. If it has a dynamic section,
 * it is pie, and does not have an interpreter or needed libraries, we
 * call it static pie.
 */
file_private int
dophn_exec(struct magic_set *ms, int clazz, int swap, int fd, off_t off,
    int num, size_t size, off_t fsize, int sh_num, int *flags,
    uint16_t *notecount)
{
  Elf32_Phdr ph32;
  Elf64_Phdr ph64;
  const char *linking_style;
  unsigned char nbuf[BUFSIZ];
  char ibuf[BUFSIZ];
  char interp[BUFSIZ];
  ssize_t bufsize;
  size_t offset, align, need = 0;
  int pie = 0, dynamic = 0;

  if (num == 0) {
    if (file_printf(ms, ", no program header") == -1)
      return -1;
    return 0;
  }
  if (size != xph_sizeof) {
    if (file_printf(ms, ", corrupted program header size") == -1)
      return -1;
    return 0;
  }

  interp[0] = '\0';
    for ( ; num; num--) {
    int doread;
    if (pread(fd, xph_addr, xph_sizeof, off) <
        CAST(ssize_t, xph_sizeof)) {
      if (file_printf(ms,
          ", can't read elf program headers at %jd",
          (intmax_t)off) == -1)
        return -1;
      return 0;
    }

    off += size;
    bufsize = 0;
    align = 4;

    /* Things we can determine before we seek */
    switch (xph_type) {
    case PT_DYNAMIC:
      doread = 1;
      break;
    case PT_NOTE:
      if (sh_num)  /* Did this through section headers */
        continue;
      if (((align = xph_align) & 0x80000000UL) != 0 ||
          align < 4) {
        if (file_printf(ms,
            ", invalid note alignment %#lx",
            CAST(unsigned long, align)) == -1)
          return -1;
        align = 4;
      }
      /*FALLTHROUGH*/
    case PT_INTERP:
      doread = 1;
      break;
    default:
      doread = 0;
      if (fsize != SIZE_UNKNOWN && xph_offset > fsize) {
        /* Maybe warn here? */
        continue;
      }
      break;
    }

    if (doread) {
      size_t len = xph_filesz < sizeof(nbuf) ? xph_filesz
          : sizeof(nbuf);
      off_t offs = xph_offset;
      bufsize = pread(fd, nbuf, len, offs);
      if (bufsize == -1) {
        if (file_printf(ms,
            ", can't read section at %jd",
            (intmax_t)offs) == -1)
          return -1;
        return 0;
      }
    }

    /* Things we can determine when we seek */
    switch (xph_type) {
    case PT_DYNAMIC:
      dynamic = 1;
      offset = 0;
      // Let DF_1 determine if we are PIE or not.
      ms->mode &= ~0111;
      for (;;) {
        if (offset >= CAST(size_t, bufsize))
          break;
        offset = dodynamic(ms, nbuf, offset,
            CAST(size_t, bufsize), clazz, swap,
            &pie, &need);
        if (offset == 0)
          break;
      }
      if (ms->flags & MAGIC_MIME)
        continue;
      break;

    case PT_INTERP:
      need++;
      if (ms->flags & MAGIC_MIME)
        continue;
      if (bufsize && nbuf[0]) {
        nbuf[bufsize - 1] = '\0';
        memcpy(interp, nbuf, CAST(size_t, bufsize));
      } else
        strlcpy(interp, "*empty*", sizeof(interp));
      break;
    case PT_NOTE:
      if (ms->flags & MAGIC_MIME)
        return 0;
      /*
       * This is a PT_NOTE section; loop through all the notes
       * in the section.
       */
      offset = 0;
      for (;;) {
        if (offset >= CAST(size_t, bufsize))
          break;
        offset = donote(ms, nbuf, offset,
            CAST(size_t, bufsize), clazz, swap, align,
            flags, notecount, fd, 0, 0, 0);
        if (offset == 0)
          break;
      }
      break;
    default:
      if (ms->flags & MAGIC_MIME)
        continue;
      break;
    }
  }
  if (ms->flags & MAGIC_MIME)
    return 0;
  if (dynamic) {
    if (pie && need == 0)
      linking_style = "static-pie";
    else
      linking_style = "dynamically";
  } else {
    linking_style = "statically";
  }
  if (file_printf(ms, ", %s linked", linking_style) == -1)
    return -1;
  if (interp[0])
    if (file_printf(ms, ", interpreter %s", file_printable(ms,
        ibuf, sizeof(ibuf), interp, sizeof(interp))) == -1)
      return -1;
  return 0;
}


file_protected int
file_tryelf(struct magic_set *ms, const struct buffer *b)
{
  int fd = b->fd;
  const unsigned char *buf = CAST(const unsigned char *, b->fbuf);
  size_t nbytes = b->flen;
  union {
    int32_t l;
    char c[sizeof(int32_t)];
  } u;
  int clazz;
  int swap;
  struct stat st;
  const struct stat *stp;
  off_t fsize;
  int flags = 0;
  Elf32_Ehdr elf32hdr;
  Elf64_Ehdr elf64hdr;
  uint16_t type, phnum, shnum, notecount;

  if (ms->flags & (MAGIC_APPLE|MAGIC_EXTENSION))
    return 0;
  /*
   * ELF executables have multiple section headers in arbitrary
   * file locations and thus file(1) cannot determine it from easily.
   * Instead we traverse thru all section headers until a symbol table
   * one is found or else the binary is stripped.
   * Return immediately if it's not ELF (so we avoid pipe2file unless
   * needed).
   */
  if (buf[EI_MAG0] != ELFMAG0
      || (buf[EI_MAG1] != ELFMAG1 && buf[EI_MAG1] != OLFMAG1)
      || buf[EI_MAG2] != ELFMAG2 || buf[EI_MAG3] != ELFMAG3)
    return 0;

  /*
   * If we cannot seek, it must be a pipe, socket or fifo.
   */
  if((lseek(fd, CAST(off_t, 0), SEEK_SET) == CAST(off_t, -1))
      && (errno == ESPIPE))
    fd = file_pipe2file(ms, fd, buf, nbytes);

  if (fd == -1) {
    file_badread(ms);
    return -1;
  }

  stp = &b->st;
  /*
   * b->st.st_size != 0 if previous fstat() succeeded,
   * which is likely, we can avoid extra stat() call.
   */
  if (b->st.st_size == 0) {
    stp = &st;
    if (fstat(fd, &st) == -1) {
      file_badread(ms);
      return -1;
    }
  }
  if (S_ISREG(stp->st_mode) || stp->st_size != 0)
    fsize = stp->st_size;
  else
    fsize = SIZE_UNKNOWN;

  clazz = buf[EI_CLASS];

  switch (clazz) {
  case ELFCLASS32:
#undef elf_getu
#define elf_getu(a, b)  elf_getu32(a, b)
#undef elfhdr
#define elfhdr elf32hdr
#include "elfclass.h"
  case ELFCLASS64:
#undef elf_getu
#define elf_getu(a, b)  elf_getu64(a, b)
#undef elfhdr
#define elfhdr elf64hdr
#include "elfclass.h"
  default:
      if (file_printf(ms, ", unknown class %d", clazz) == -1)
        return -1;
      break;
  }
  return 0;
}
#endif

Coverage Report

Created: 2023-09-25 06:40