/src/ffmpeg/libavutil/bprint.c

Source
/*
 * Copyright (c) 2012 Nicolas George
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <limits.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include "avstring.h"
#include "bprint.h"
#include "compat/va_copy.h"
#include "error.h"
#include "macros.h"
#include "mem.h"

#define av_bprint_room(buf) ((buf)->size - FFMIN((buf)->len, (buf)->size))
#define av_bprint_is_allocated(buf) ((buf)->str != (buf)->reserved_internal_buffer)

static int av_bprint_alloc(AVBPrint *buf, unsigned room)
{
    char *old_str, *new_str;
    unsigned min_size, new_size;

    if (buf->size == buf->size_max)
        return AVERROR(EIO);
    if (!av_bprint_is_complete(buf))
        return AVERROR_INVALIDDATA; /* it is already truncated anyway */
    min_size = buf->len + 1 + FFMIN(UINT_MAX - buf->len - 1, room);
    new_size = buf->size > buf->size_max / 2 ? buf->size_max : buf->size * 2;
    if (new_size < min_size)
        new_size = FFMIN(buf->size_max, min_size);
    old_str = av_bprint_is_allocated(buf) ? buf->str : NULL;
    new_str = av_realloc(old_str, new_size);
    if (!new_str)
        return AVERROR(ENOMEM);
    if (!old_str)
        memcpy(new_str, buf->str, buf->len + 1);
    buf->str  = new_str;
    buf->size = new_size;
    return 0;
}

static void av_bprint_grow(AVBPrint *buf, unsigned extra_len)
{
    /* arbitrary margin to avoid small overflows */
    extra_len = FFMIN(extra_len, UINT_MAX - 5 - buf->len);
    buf->len += extra_len;
    if (buf->size)
        buf->str[FFMIN(buf->len, buf->size - 1)] = 0;
}

void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
{
    unsigned size_auto = (char *)buf + sizeof(*buf) -
                         buf->reserved_internal_buffer;

    if (size_max == AV_BPRINT_SIZE_AUTOMATIC)
        size_max = size_auto;
    buf->str      = buf->reserved_internal_buffer;
    buf->len      = 0;
    buf->size     = FFMIN(size_auto, size_max);
    buf->size_max = size_max;
    *buf->str = 0;
    if (size_init > buf->size)
        av_bprint_alloc(buf, size_init - 1);
}

void av_bprint_init_for_buffer(AVBPrint *buf, char *buffer, unsigned size)
{
    if (size == 0) {
        av_bprint_init(buf, 0, AV_BPRINT_SIZE_COUNT_ONLY);
        return;
    }

    buf->str      = buffer;
    buf->len      = 0;
    buf->size     = size;
    buf->size_max = size;
    *buf->str = 0;
}

void av_vbprintf(AVBPrint *buf, const char *fmt, va_list vl_arg)
{
    unsigned room;
    char *dst;
    int extra_len;
    va_list vl;

    while (1) {
        room = av_bprint_room(buf);
        dst = room ? buf->str + buf->len : NULL;
        va_copy(vl, vl_arg);
        extra_len = vsnprintf(dst, room, fmt, vl);
        va_end(vl);
        if (extra_len <= 0)
            return;
        if (extra_len < room)
            break;
        if (av_bprint_alloc(buf, extra_len))
            break;
    }
    av_bprint_grow(buf, extra_len);
}

void av_bprintf(AVBPrint *buf, const char *fmt, ...)
{
    va_list vl;
    va_start(vl, fmt);
    av_vbprintf(buf, fmt, vl);
    va_end(vl);
}

void av_bprint_chars(AVBPrint *buf, char c, unsigned n)
{
    unsigned room, real_n;

    while (1) {
        room = av_bprint_room(buf);
        if (n < room)
            break;
        if (av_bprint_alloc(buf, n))
            break;
    }
    if (room) {
        real_n = FFMIN(n, room - 1);
        memset(buf->str + buf->len, c, real_n);
    }
    av_bprint_grow(buf, n);
}

void av_bprint_append_data(AVBPrint *buf, const char *data, unsigned size)
{
    unsigned room, real_n;

    while (1) {
        room = av_bprint_room(buf);
        if (size < room)
            break;
        if (av_bprint_alloc(buf, size))
            break;
    }
    if (room) {
        real_n = FFMIN(size, room - 1);
        memcpy(buf->str + buf->len, data, real_n);
    }
    av_bprint_grow(buf, size);
}

void av_bprint_strftime(AVBPrint *buf, const char *fmt, const struct tm *tm)
{
    unsigned room;
    size_t l;
    size_t fmt_len = strlen(fmt);

    if (!*fmt)
        return;
    while (1) {
        room = av_bprint_room(buf);
        if (room && (l = strftime(buf->str + buf->len, room, fmt, tm)))
            break;

        /* Due to the limitations of strftime() it is not possible to know if
         * the output buffer is too small or the output is empty.
         * However, a 256x output space requirement compared to the format
         * string length is so unlikely we can safely assume empty output. This
         * allows supporting possibly empty format strings like "%p". */
        if (room >> 8 > fmt_len)
            break;

        /* strftime does not tell us how much room it would need: let us
           retry with twice as much until the buffer is large enough */
        room = !room ? fmt_len + 1 :
               room <= INT_MAX / 2 ? room * 2 : INT_MAX;
        if (av_bprint_alloc(buf, room)) {
            /* impossible to grow, try to manage something useful anyway */
            room = av_bprint_room(buf);
            if (room < 1024) {
                /* if strftime fails because the buffer has (almost) reached
                   its maximum size, let us try in a local buffer; 1k should
                   be enough to format any real date+time string */
                char buf2[1024];
                if ((l = strftime(buf2, sizeof(buf2), fmt, tm))) {
                    av_bprintf(buf, "%s", buf2);
                    return;
                }
            }
            if (room) {
                /* if anything else failed and the buffer is not already
                   truncated, let us add a stock string and force truncation */
                static const char txt[] = "[truncated strftime output]";
                memset(buf->str + buf->len, '!', room);
                memcpy(buf->str + buf->len, txt, FFMIN(sizeof(txt) - 1, room));
                av_bprint_grow(buf, room); /* force truncation */
            }
            return;
        }
    }
    av_bprint_grow(buf, l);
}

void av_bprint_get_buffer(AVBPrint *buf, unsigned size,
                          unsigned char **mem, unsigned *actual_size)
{
    if (size > av_bprint_room(buf))
        av_bprint_alloc(buf, size);
    *actual_size = av_bprint_room(buf);
    *mem = *actual_size ? buf->str + buf->len : NULL;
}

void av_bprint_clear(AVBPrint *buf)
{
    if (buf->len) {
        *buf->str = 0;
        buf->len  = 0;
    }
}

int av_bprint_finalize(AVBPrint *buf, char **ret_str)
{
    unsigned real_size = FFMIN(buf->len + 1, buf->size);
    char *str;
    int ret = 0;

    if (ret_str) {
        if (av_bprint_is_allocated(buf)) {
            str = av_realloc(buf->str, real_size);
            if (!str)
                str = buf->str;
            buf->str = NULL;
        } else {
            str = av_memdup(buf->str, real_size);
            if (!str)
                ret = AVERROR(ENOMEM);
        }
        *ret_str = str;
    } else {
        if (av_bprint_is_allocated(buf))
            av_freep(&buf->str);
    }
    buf->size = real_size;
    return ret;
}

#define WHITESPACES " \n\t\r"

void av_bprint_escape(AVBPrint *dstbuf, const char *src, const char *special_chars,
                      enum AVEscapeMode mode, int flags)
{
    const char *src0 = src;

    if (mode == AV_ESCAPE_MODE_AUTO)
        mode = AV_ESCAPE_MODE_BACKSLASH; /* TODO: implement a heuristic */

    switch (mode) {
    case AV_ESCAPE_MODE_QUOTE:
        /* enclose the string between '' */
        av_bprint_chars(dstbuf, '\'', 1);
        for (; *src; src++) {
            if (*src == '\'')
                av_bprintf(dstbuf, "'\\''");
            else
                av_bprint_chars(dstbuf, *src, 1);
        }
        av_bprint_chars(dstbuf, '\'', 1);
        break;

    case AV_ESCAPE_MODE_XML:
        /* escape XML non-markup character data as per 2.4 by default: */
        /*  [^<&]* - ([^<&]* ']]>' [^<&]*) */

        /* additionally, given one of the AV_ESCAPE_FLAG_XML_* flags, */
        /* escape those specific characters as required. */
        for (; *src; src++) {
            switch (*src) {
            case '&' : av_bprintf(dstbuf, "%s", "&amp;");  break;
            case '<' : av_bprintf(dstbuf, "%s", "&lt;");   break;
            case '>' : av_bprintf(dstbuf, "%s", "&gt;");   break;
            case '\'':
                if (!(flags & AV_ESCAPE_FLAG_XML_SINGLE_QUOTES))
                    goto XML_DEFAULT_HANDLING;

                av_bprintf(dstbuf, "%s", "&apos;");
                break;
            case '"' :
                if (!(flags & AV_ESCAPE_FLAG_XML_DOUBLE_QUOTES))
                    goto XML_DEFAULT_HANDLING;

                av_bprintf(dstbuf, "%s", "&quot;");
                break;
XML_DEFAULT_HANDLING:
            default: av_bprint_chars(dstbuf, *src, 1);
            }
        }
        break;

    /* case AV_ESCAPE_MODE_BACKSLASH or unknown mode */
    default:
        /* \-escape characters */
        for (; *src; src++) {
            int is_first_last       = src == src0 || !*(src+1);
            int is_ws               = !!strchr(WHITESPACES, *src);
            int is_strictly_special = special_chars && strchr(special_chars, *src);
            int is_special          =
                is_strictly_special || strchr("'\\", *src) ||
                (is_ws && (flags & AV_ESCAPE_FLAG_WHITESPACE));

            if (is_strictly_special ||
                (!(flags & AV_ESCAPE_FLAG_STRICT) &&
                 (is_special || (is_ws && is_first_last))))
                av_bprint_chars(dstbuf, '\\', 1);
            av_bprint_chars(dstbuf, *src, 1);
        }
        break;
    }
}

Coverage Report

Created: 2026-01-25 07:18

Line	Count	Source
1		/*
2		* Copyright (c) 2012 Nicolas George
3		*
4		* This file is part of FFmpeg.
5		*
6		* FFmpeg is free software; you can redistribute it and/or
7		* modify it under the terms of the GNU Lesser General Public
8		* License as published by the Free Software Foundation; either
9		* version 2.1 of the License, or (at your option) any later version.
10		*
11		* FFmpeg is distributed in the hope that it will be useful,
12		* but WITHOUT ANY WARRANTY; without even the implied warranty of
13		* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14		* Lesser General Public License for more details.
15		*
16		* You should have received a copy of the GNU Lesser General Public
17		* License along with FFmpeg; if not, write to the Free Software
18		* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19		*/
20
21		#include <limits.h>
22		#include <stdarg.h>
23		#include <stdio.h>
24		#include <string.h>
25		#include <time.h>
26		#include "avstring.h"
27		#include "bprint.h"
28		#include "compat/va_copy.h"
29		#include "error.h"
30		#include "macros.h"
31		#include "mem.h"
32
33	0	#define av_bprint_room(buf) ((buf)->size - FFMIN((buf)->len, (buf)->size))
34	0	#define av_bprint_is_allocated(buf) ((buf)->str != (buf)->reserved_internal_buffer)
35
36		static int av_bprint_alloc(AVBPrint *buf, unsigned room)
37	0	{
38	0	char old_str, new_str;
39	0	unsigned min_size, new_size;
40
41	0	if (buf->size == buf->size_max)
42	0	return AVERROR(EIO);
43	0	if (!av_bprint_is_complete(buf))
44	0	return AVERROR_INVALIDDATA; /* it is already truncated anyway */
45	0	min_size = buf->len + 1 + FFMIN(UINT_MAX - buf->len - 1, room);
46	0	new_size = buf->size > buf->size_max / 2 ? buf->size_max : buf->size * 2;
47	0	if (new_size < min_size)
48	0	new_size = FFMIN(buf->size_max, min_size);
49	0	old_str = av_bprint_is_allocated(buf) ? buf->str : NULL;
50	0	new_str = av_realloc(old_str, new_size);
51	0	if (!new_str)
52	0	return AVERROR(ENOMEM);
53	0	if (!old_str)
54	0	memcpy(new_str, buf->str, buf->len + 1);
55	0	buf->str = new_str;
56	0	buf->size = new_size;
57	0	return 0;
58	0	}
59
60		static void av_bprint_grow(AVBPrint *buf, unsigned extra_len)
61	0	{
62		/* arbitrary margin to avoid small overflows */
63	0	extra_len = FFMIN(extra_len, UINT_MAX - 5 - buf->len);
64	0	buf->len += extra_len;
65	0	if (buf->size)
66	0	buf->str[FFMIN(buf->len, buf->size - 1)] = 0;
67	0	}
68
69		void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
70	0	{
71	0	unsigned size_auto = (char )buf + sizeof(buf) -
72	0	buf->reserved_internal_buffer;
73
74	0	if (size_max == AV_BPRINT_SIZE_AUTOMATIC)
75	0	size_max = size_auto;
76	0	buf->str = buf->reserved_internal_buffer;
77	0	buf->len = 0;
78	0	buf->size = FFMIN(size_auto, size_max);
79	0	buf->size_max = size_max;
80	0	*buf->str = 0;
81	0	if (size_init > buf->size)
82	0	av_bprint_alloc(buf, size_init - 1);
83	0	}
84
85		void av_bprint_init_for_buffer(AVBPrint buf, char buffer, unsigned size)
86	0	{
87	0	if (size == 0) {
88	0	av_bprint_init(buf, 0, AV_BPRINT_SIZE_COUNT_ONLY);
89	0	return;
90	0	}
91
92	0	buf->str = buffer;
93	0	buf->len = 0;
94	0	buf->size = size;
95	0	buf->size_max = size;
96	0	*buf->str = 0;
97	0	}
98
99		void av_vbprintf(AVBPrint buf, const char fmt, va_list vl_arg)
100	0	{
101	0	unsigned room;
102	0	char *dst;
103	0	int extra_len;
104	0	va_list vl;
105
106	0	while (1) {
107	0	room = av_bprint_room(buf);
108	0	dst = room ? buf->str + buf->len : NULL;
109	0	va_copy(vl, vl_arg);
110	0	extra_len = vsnprintf(dst, room, fmt, vl);
111	0	va_end(vl);
112	0	if (extra_len <= 0)
113	0	return;
114	0	if (extra_len < room)
115	0	break;
116	0	if (av_bprint_alloc(buf, extra_len))
117	0	break;
118	0	}
119	0	av_bprint_grow(buf, extra_len);
120	0	}
121
122		void av_bprintf(AVBPrint buf, const char fmt, ...)
123	0	{
124	0	va_list vl;
125	0	va_start(vl, fmt);
126	0	av_vbprintf(buf, fmt, vl);
127	0	va_end(vl);
128	0	}
129
130		void av_bprint_chars(AVBPrint *buf, char c, unsigned n)
131	0	{
132	0	unsigned room, real_n;
133
134	0	while (1) {
135	0	room = av_bprint_room(buf);
136	0	if (n < room)
137	0	break;
138	0	if (av_bprint_alloc(buf, n))
139	0	break;
140	0	}
141	0	if (room) {
142	0	real_n = FFMIN(n, room - 1);
143	0	memset(buf->str + buf->len, c, real_n);
144	0	}
145	0	av_bprint_grow(buf, n);
146	0	}
147
148		void av_bprint_append_data(AVBPrint buf, const char data, unsigned size)
149	0	{
150	0	unsigned room, real_n;
151
152	0	while (1) {
153	0	room = av_bprint_room(buf);
154	0	if (size < room)
155	0	break;
156	0	if (av_bprint_alloc(buf, size))
157	0	break;
158	0	}
159	0	if (room) {
160	0	real_n = FFMIN(size, room - 1);
161	0	memcpy(buf->str + buf->len, data, real_n);
162	0	}
163	0	av_bprint_grow(buf, size);
164	0	}
165
166		void av_bprint_strftime(AVBPrint buf, const char fmt, const struct tm *tm)
167	0	{
168	0	unsigned room;
169	0	size_t l;
170	0	size_t fmt_len = strlen(fmt);
171
172	0	if (!*fmt)
173	0	return;
174	0	while (1) {
175	0	room = av_bprint_room(buf);
176	0	if (room && (l = strftime(buf->str + buf->len, room, fmt, tm)))
177	0	break;
178
179		/* Due to the limitations of strftime() it is not possible to know if
180		* the output buffer is too small or the output is empty.
181		* However, a 256x output space requirement compared to the format
182		* string length is so unlikely we can safely assume empty output. This
183		* allows supporting possibly empty format strings like "%p". */
184	0	if (room >> 8 > fmt_len)
185	0	break;
186
187		/* strftime does not tell us how much room it would need: let us
188		retry with twice as much until the buffer is large enough */
189	0	room = !room ? fmt_len + 1 :
190	0	room <= INT_MAX / 2 ? room * 2 : INT_MAX;
191	0	if (av_bprint_alloc(buf, room)) {
192		/* impossible to grow, try to manage something useful anyway */
193	0	room = av_bprint_room(buf);
194	0	if (room < 1024) {
195		/* if strftime fails because the buffer has (almost) reached
196		its maximum size, let us try in a local buffer; 1k should
197		be enough to format any real date+time string */
198	0	char buf2[1024];
199	0	if ((l = strftime(buf2, sizeof(buf2), fmt, tm))) {
200	0	av_bprintf(buf, "%s", buf2);
201	0	return;
202	0	}
203	0	}
204	0	if (room) {
205		/* if anything else failed and the buffer is not already
206		truncated, let us add a stock string and force truncation */
207	0	static const char txt[] = "[truncated strftime output]";
208	0	memset(buf->str + buf->len, '!', room);
209	0	memcpy(buf->str + buf->len, txt, FFMIN(sizeof(txt) - 1, room));
210	0	av_bprint_grow(buf, room); /* force truncation */
211	0	}
212	0	return;
213	0	}
214	0	}
215	0	av_bprint_grow(buf, l);
216	0	}
217
218		void av_bprint_get_buffer(AVBPrint *buf, unsigned size,
219		unsigned char *mem, unsigned actual_size)
220	0	{
221	0	if (size > av_bprint_room(buf))
222	0	av_bprint_alloc(buf, size);
223	0	*actual_size = av_bprint_room(buf);
224	0	mem = actual_size ? buf->str + buf->len : NULL;
225	0	}
226
227		void av_bprint_clear(AVBPrint *buf)
228	0	{
229	0	if (buf->len) {
230	0	*buf->str = 0;
231	0	buf->len = 0;
232	0	}
233	0	}
234
235		int av_bprint_finalize(AVBPrint buf, char *ret_str)
236	0	{
237	0	unsigned real_size = FFMIN(buf->len + 1, buf->size);
238	0	char *str;
239	0	int ret = 0;
240
241	0	if (ret_str) {
242	0	if (av_bprint_is_allocated(buf)) {
243	0	str = av_realloc(buf->str, real_size);
244	0	if (!str)
245	0	str = buf->str;
246	0	buf->str = NULL;
247	0	} else {
248	0	str = av_memdup(buf->str, real_size);
249	0	if (!str)
250	0	ret = AVERROR(ENOMEM);
251	0	}
252	0	*ret_str = str;
253	0	} else {
254	0	if (av_bprint_is_allocated(buf))
255	0	av_freep(&buf->str);
256	0	}
257	0	buf->size = real_size;
258	0	return ret;
259	0	}
260
261	0	#define WHITESPACES " \n\t\r"
262
263		void av_bprint_escape(AVBPrint dstbuf, const char src, const char *special_chars,
264		enum AVEscapeMode mode, int flags)
265	0	{
266	0	const char *src0 = src;
267
268	0	if (mode == AV_ESCAPE_MODE_AUTO)
269	0	mode = AV_ESCAPE_MODE_BACKSLASH; /* TODO: implement a heuristic */
270
271	0	switch (mode) {
272	0	case AV_ESCAPE_MODE_QUOTE:
273		/* enclose the string between '' */
274	0	av_bprint_chars(dstbuf, '\'', 1);
275	0	for (; *src; src++) {
276	0	if (*src == '\'')
277	0	av_bprintf(dstbuf, "'\\''");
278	0	else
279	0	av_bprint_chars(dstbuf, *src, 1);
280	0	}
281	0	av_bprint_chars(dstbuf, '\'', 1);
282	0	break;
283
284	0	case AV_ESCAPE_MODE_XML:
285		/* escape XML non-markup character data as per 2.4 by default: */
286		/* [^<&]* - ([^<&]* ']]>' [^<&]) /
287
288		/* additionally, given one of the AV_ESCAPE_FLAG_XML_* flags, */
289		/* escape those specific characters as required. */
290	0	for (; *src; src++) {
291	0	switch (*src) {
292	0	case '&' : av_bprintf(dstbuf, "%s", "&"); break;
293	0	case '<' : av_bprintf(dstbuf, "%s", "<"); break;
294	0	case '>' : av_bprintf(dstbuf, "%s", ">"); break;
295	0	case '\'':
296	0	if (!(flags & AV_ESCAPE_FLAG_XML_SINGLE_QUOTES))
297	0	goto XML_DEFAULT_HANDLING;
298
299	0	av_bprintf(dstbuf, "%s", "'");
300	0	break;
301	0	case '"' :
302	0	if (!(flags & AV_ESCAPE_FLAG_XML_DOUBLE_QUOTES))
303	0	goto XML_DEFAULT_HANDLING;
304
305	0	av_bprintf(dstbuf, "%s", """);
306	0	break;
307	0	XML_DEFAULT_HANDLING:
308	0	default: av_bprint_chars(dstbuf, *src, 1);
309	0	}
310	0	}
311	0	break;
312
313		/* case AV_ESCAPE_MODE_BACKSLASH or unknown mode */
314	0	default:
315		/* \-escape characters */
316	0	for (; *src; src++) {
317	0	int is_first_last = src == src0 \|\| !*(src+1);
318	0	int is_ws = !!strchr(WHITESPACES, *src);
319	0	int is_strictly_special = special_chars && strchr(special_chars, *src);
320	0	int is_special =
321	0	is_strictly_special \|\| strchr("'\\", *src) \|\|
322	0	(is_ws && (flags & AV_ESCAPE_FLAG_WHITESPACE));
323
324	0	if (is_strictly_special \|\|
325	0	(!(flags & AV_ESCAPE_FLAG_STRICT) &&
326	0	(is_special \|\| (is_ws && is_first_last))))
327	0	av_bprint_chars(dstbuf, '\\', 1);
328	0	av_bprint_chars(dstbuf, *src, 1);
329	0	}
330	0	break;
331	0	}
332	0	}