3ab25e4574
This reverts commit 6cc12353a88dfb21c4c5a38e6c83280483b0ec88. Conflicts: libavformat/version.h Allowing to automatically select the concat demuxer raises security concerns, as it allows a possibly hostile file to access any file on the system. Guessing the format based on the file name extension does not allow to enable the safe mode designed to avoid it.
293 lines
8.7 KiB
C
293 lines
8.7 KiB
C
/*
|
|
* 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 "libavutil/avstring.h"
|
|
#include "libavutil/opt.h"
|
|
#include "libavutil/parseutils.h"
|
|
#include "avformat.h"
|
|
#include "internal.h"
|
|
|
|
typedef struct {
|
|
char *url;
|
|
int64_t start_time;
|
|
int64_t duration;
|
|
} ConcatFile;
|
|
|
|
typedef struct {
|
|
AVClass *class;
|
|
ConcatFile *files;
|
|
ConcatFile *cur_file;
|
|
unsigned nb_files;
|
|
AVFormatContext *avf;
|
|
int safe;
|
|
} ConcatContext;
|
|
|
|
static int concat_probe(AVProbeData *probe)
|
|
{
|
|
return memcmp(probe->buf, "ffconcat version 1.0", 20) ?
|
|
0 : AVPROBE_SCORE_MAX;
|
|
}
|
|
|
|
static char *get_keyword(uint8_t **cursor)
|
|
{
|
|
char *ret = *cursor += strspn(*cursor, SPACE_CHARS);
|
|
*cursor += strcspn(*cursor, SPACE_CHARS);
|
|
if (**cursor) {
|
|
*((*cursor)++) = 0;
|
|
*cursor += strspn(*cursor, SPACE_CHARS);
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int safe_filename(const char *f)
|
|
{
|
|
const char *start = f;
|
|
|
|
for (; *f; f++) {
|
|
/* A-Za-z0-9_- */
|
|
if (!((unsigned)((*f | 32) - 'a') < 26 ||
|
|
(unsigned)(*f - '0') < 10 || *f == '_' || *f == '-')) {
|
|
if (f == start)
|
|
return 0;
|
|
else if (*f == '/')
|
|
start = f + 1;
|
|
else if (*f != '.')
|
|
return 0;
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
#define FAIL(retcode) do { ret = (retcode); goto fail; } while(0)
|
|
|
|
static int add_file(AVFormatContext *avf, char *filename, ConcatFile **rfile,
|
|
unsigned *nb_files_alloc)
|
|
{
|
|
ConcatContext *cat = avf->priv_data;
|
|
ConcatFile *file;
|
|
char *url;
|
|
size_t url_len;
|
|
|
|
if (cat->safe > 0 && !safe_filename(filename)) {
|
|
av_log(avf, AV_LOG_ERROR, "Unsafe file name '%s'\n", filename);
|
|
return AVERROR(EPERM);
|
|
}
|
|
url_len = strlen(avf->filename) + strlen(filename) + 16;
|
|
if (!(url = av_malloc(url_len)))
|
|
return AVERROR(ENOMEM);
|
|
ff_make_absolute_url(url, url_len, avf->filename, filename);
|
|
av_free(filename);
|
|
|
|
if (cat->nb_files >= *nb_files_alloc) {
|
|
size_t n = FFMAX(*nb_files_alloc * 2, 16);
|
|
ConcatFile *new_files;
|
|
if (n <= cat->nb_files || n > SIZE_MAX / sizeof(*cat->files) ||
|
|
!(new_files = av_realloc(cat->files, n * sizeof(*cat->files))))
|
|
return AVERROR(ENOMEM);
|
|
cat->files = new_files;
|
|
*nb_files_alloc = n;
|
|
}
|
|
|
|
file = &cat->files[cat->nb_files++];
|
|
memset(file, 0, sizeof(*file));
|
|
*rfile = file;
|
|
|
|
file->url = url;
|
|
file->start_time = AV_NOPTS_VALUE;
|
|
file->duration = AV_NOPTS_VALUE;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int open_file(AVFormatContext *avf, unsigned fileno)
|
|
{
|
|
ConcatContext *cat = avf->priv_data;
|
|
ConcatFile *file = &cat->files[fileno];
|
|
int ret;
|
|
|
|
if ((ret = avformat_open_input(&cat->avf, file->url, NULL, NULL)) < 0 ||
|
|
(ret = avformat_find_stream_info(cat->avf, NULL)) < 0) {
|
|
av_log(avf, AV_LOG_ERROR, "Impossible to open '%s'\n", file->url);
|
|
return ret;
|
|
}
|
|
cat->cur_file = file;
|
|
if (file->start_time == AV_NOPTS_VALUE)
|
|
file->start_time = !fileno ? 0 :
|
|
cat->files[fileno - 1].start_time +
|
|
cat->files[fileno - 1].duration;
|
|
return 0;
|
|
}
|
|
|
|
static int concat_read_close(AVFormatContext *avf)
|
|
{
|
|
ConcatContext *cat = avf->priv_data;
|
|
unsigned i;
|
|
|
|
if (cat->avf)
|
|
avformat_close_input(&cat->avf);
|
|
for (i = 0; i < cat->nb_files; i++)
|
|
av_freep(&cat->files[i].url);
|
|
av_freep(&cat->files);
|
|
return 0;
|
|
}
|
|
|
|
static int concat_read_header(AVFormatContext *avf)
|
|
{
|
|
ConcatContext *cat = avf->priv_data;
|
|
uint8_t buf[4096];
|
|
uint8_t *cursor, *keyword;
|
|
int ret, line = 0, i;
|
|
unsigned nb_files_alloc = 0;
|
|
ConcatFile *file = NULL;
|
|
AVStream *st, *source_st;
|
|
|
|
while (1) {
|
|
if ((ret = ff_get_line(avf->pb, buf, sizeof(buf))) <= 0)
|
|
break;
|
|
line++;
|
|
cursor = buf;
|
|
keyword = get_keyword(&cursor);
|
|
if (!*keyword || *keyword == '#')
|
|
continue;
|
|
|
|
if (!strcmp(keyword, "file")) {
|
|
char *filename = av_get_token((const char **)&cursor, SPACE_CHARS);
|
|
if (!filename) {
|
|
av_log(avf, AV_LOG_ERROR, "Line %d: filename required\n", line);
|
|
FAIL(AVERROR_INVALIDDATA);
|
|
}
|
|
if ((ret = add_file(avf, filename, &file, &nb_files_alloc)) < 0)
|
|
FAIL(ret);
|
|
} else if (!strcmp(keyword, "duration")) {
|
|
char *dur_str = get_keyword(&cursor);
|
|
int64_t dur;
|
|
if (!file) {
|
|
av_log(avf, AV_LOG_ERROR, "Line %d: duration without file\n",
|
|
line);
|
|
FAIL(AVERROR_INVALIDDATA);
|
|
}
|
|
if ((ret = av_parse_time(&dur, dur_str, 1)) < 0) {
|
|
av_log(avf, AV_LOG_ERROR, "Line %d: invalid duration '%s'\n",
|
|
line, dur_str);
|
|
FAIL(ret);
|
|
}
|
|
file->duration = dur;
|
|
} else if (!strcmp(keyword, "ffconcat")) {
|
|
char *ver_kw = get_keyword(&cursor);
|
|
char *ver_val = get_keyword(&cursor);
|
|
if (strcmp(ver_kw, "version") || strcmp(ver_val, "1.0")) {
|
|
av_log(avf, AV_LOG_ERROR, "Line %d: invalid version\n", line);
|
|
FAIL(AVERROR_INVALIDDATA);
|
|
}
|
|
if (cat->safe < 0)
|
|
cat->safe = 1;
|
|
} else {
|
|
av_log(avf, AV_LOG_ERROR, "Line %d: unknown keyword '%s'\n",
|
|
line, keyword);
|
|
FAIL(AVERROR_INVALIDDATA);
|
|
}
|
|
}
|
|
if (ret < 0)
|
|
FAIL(ret);
|
|
|
|
if ((ret = open_file(avf, 0)) < 0)
|
|
FAIL(ret);
|
|
for (i = 0; i < cat->avf->nb_streams; i++) {
|
|
if (!(st = avformat_new_stream(avf, NULL)))
|
|
FAIL(AVERROR(ENOMEM));
|
|
source_st = cat->avf->streams[i];
|
|
if ((ret = avcodec_copy_context(st->codec, source_st->codec)) < 0)
|
|
FAIL(ret);
|
|
st->r_frame_rate = source_st->r_frame_rate;
|
|
st->avg_frame_rate = source_st->avg_frame_rate;
|
|
st->time_base = source_st->time_base;
|
|
st->sample_aspect_ratio = source_st->sample_aspect_ratio;
|
|
}
|
|
|
|
return 0;
|
|
|
|
fail:
|
|
concat_read_close(avf);
|
|
return ret;
|
|
}
|
|
|
|
static int open_next_file(AVFormatContext *avf)
|
|
{
|
|
ConcatContext *cat = avf->priv_data;
|
|
unsigned fileno = cat->cur_file - cat->files;
|
|
|
|
if (cat->cur_file->duration == AV_NOPTS_VALUE)
|
|
cat->cur_file->duration = cat->avf->duration;
|
|
|
|
if (++fileno >= cat->nb_files)
|
|
return AVERROR_EOF;
|
|
avformat_close_input(&cat->avf);
|
|
return open_file(avf, fileno);
|
|
}
|
|
|
|
static int concat_read_packet(AVFormatContext *avf, AVPacket *pkt)
|
|
{
|
|
ConcatContext *cat = avf->priv_data;
|
|
int ret;
|
|
int64_t delta;
|
|
|
|
while (1) {
|
|
if ((ret = av_read_frame(cat->avf, pkt)) != AVERROR_EOF ||
|
|
(ret = open_next_file(avf)) < 0)
|
|
break;
|
|
}
|
|
delta = av_rescale_q(cat->cur_file->start_time - cat->avf->start_time,
|
|
AV_TIME_BASE_Q,
|
|
cat->avf->streams[pkt->stream_index]->time_base);
|
|
if (pkt->pts != AV_NOPTS_VALUE)
|
|
pkt->pts += delta;
|
|
if (pkt->dts != AV_NOPTS_VALUE)
|
|
pkt->dts += delta;
|
|
return ret;
|
|
}
|
|
|
|
#define OFFSET(x) offsetof(ConcatContext, x)
|
|
#define DEC AV_OPT_FLAG_DECODING_PARAM
|
|
|
|
static const AVOption options[] = {
|
|
{ "safe", "enable safe mode",
|
|
OFFSET(safe), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 1, DEC },
|
|
{ NULL }
|
|
};
|
|
|
|
static const AVClass concat_class = {
|
|
.class_name = "concat demuxer",
|
|
.item_name = av_default_item_name,
|
|
.option = options,
|
|
.version = LIBAVUTIL_VERSION_INT,
|
|
};
|
|
|
|
|
|
AVInputFormat ff_concat_demuxer = {
|
|
.name = "concat",
|
|
.long_name = NULL_IF_CONFIG_SMALL("Virtual concatenation script"),
|
|
.priv_data_size = sizeof(ConcatContext),
|
|
.read_probe = concat_probe,
|
|
.read_header = concat_read_header,
|
|
.read_packet = concat_read_packet,
|
|
.read_close = concat_read_close,
|
|
.priv_class = &concat_class,
|
|
};
|