FFmpeg
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file.c
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1 /*
2  * buffered file I/O
3  * Copyright (c) 2001 Fabrice Bellard
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavutil/avstring.h"
23 #include "libavutil/internal.h"
24 #include "libavutil/opt.h"
25 #include "avformat.h"
26 #if HAVE_DIRENT_H
27 #include <dirent.h>
28 #endif
29 #include <fcntl.h>
30 #if HAVE_IO_H
31 #include <io.h>
32 #endif
33 #if HAVE_UNISTD_H
34 #include <unistd.h>
35 #endif
36 #include <sys/stat.h>
37 #include <stdlib.h>
38 #include "os_support.h"
39 #include "url.h"
40 
41 /* Some systems may not have S_ISFIFO */
42 #ifndef S_ISFIFO
43 # ifdef S_IFIFO
44 # define S_ISFIFO(m) (((m) & S_IFMT) == S_IFIFO)
45 # else
46 # define S_ISFIFO(m) 0
47 # endif
48 #endif
49 
50 /* Not available in POSIX.1-1996 */
51 #ifndef S_ISLNK
52 # ifdef S_IFLNK
53 # define S_ISLNK(m) (((m) & S_IFLNK) == S_IFLNK)
54 # else
55 # define S_ISLNK(m) 0
56 # endif
57 #endif
58 
59 /* Not available in POSIX.1-1996 */
60 #ifndef S_ISSOCK
61 # ifdef S_IFSOCK
62 # define S_ISSOCK(m) (((m) & S_IFMT) == S_IFSOCK)
63 # else
64 # define S_ISSOCK(m) 0
65 # endif
66 #endif
67 
68 /* standard file protocol */
69 
70 typedef struct FileContext {
71  const AVClass *class;
72  int fd;
73  int trunc;
74  int blocksize;
75 #if HAVE_DIRENT_H
76  DIR *dir;
77 #endif
78 } FileContext;
79 
80 static const AVOption file_options[] = {
81  { "truncate", "truncate existing files on write", offsetof(FileContext, trunc), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, AV_OPT_FLAG_ENCODING_PARAM },
82  { "blocksize", "set I/O operation maximum block size", offsetof(FileContext, blocksize), AV_OPT_TYPE_INT, { .i64 = INT_MAX }, 1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
83  { NULL }
84 };
85 
86 static const AVOption pipe_options[] = {
87  { "blocksize", "set I/O operation maximum block size", offsetof(FileContext, blocksize), AV_OPT_TYPE_INT, { .i64 = INT_MAX }, 1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
88  { NULL }
89 };
90 
91 static const AVClass file_class = {
92  .class_name = "file",
93  .item_name = av_default_item_name,
94  .option = file_options,
95  .version = LIBAVUTIL_VERSION_INT,
96 };
97 
98 static const AVClass pipe_class = {
99  .class_name = "pipe",
100  .item_name = av_default_item_name,
101  .option = pipe_options,
102  .version = LIBAVUTIL_VERSION_INT,
103 };
104 
105 static int file_read(URLContext *h, unsigned char *buf, int size)
106 {
107  FileContext *c = h->priv_data;
108  int ret;
109  size = FFMIN(size, c->blocksize);
110  ret = read(c->fd, buf, size);
111  return (ret == -1) ? AVERROR(errno) : ret;
112 }
113 
114 static int file_write(URLContext *h, const unsigned char *buf, int size)
115 {
116  FileContext *c = h->priv_data;
117  int ret;
118  size = FFMIN(size, c->blocksize);
119  ret = write(c->fd, buf, size);
120  return (ret == -1) ? AVERROR(errno) : ret;
121 }
122 
124 {
125  FileContext *c = h->priv_data;
126  return c->fd;
127 }
128 
129 static int file_check(URLContext *h, int mask)
130 {
131  int ret = 0;
132  const char *filename = h->filename;
133  av_strstart(filename, "file:", &filename);
134 
135  {
136 #if HAVE_ACCESS && defined(R_OK)
137  if (access(filename, F_OK) < 0)
138  return AVERROR(errno);
139  if (mask&AVIO_FLAG_READ)
140  if (access(filename, R_OK) >= 0)
141  ret |= AVIO_FLAG_READ;
142  if (mask&AVIO_FLAG_WRITE)
143  if (access(filename, W_OK) >= 0)
144  ret |= AVIO_FLAG_WRITE;
145 #else
146  struct stat st;
147  ret = stat(filename, &st);
148  if (ret < 0)
149  return AVERROR(errno);
150 
151  ret |= st.st_mode&S_IRUSR ? mask&AVIO_FLAG_READ : 0;
152  ret |= st.st_mode&S_IWUSR ? mask&AVIO_FLAG_WRITE : 0;
153 #endif
154  }
155  return ret;
156 }
157 
159 {
160 #if HAVE_UNISTD_H
161  int ret;
162  const char *filename = h->filename;
163  av_strstart(filename, "file:", &filename);
164 
165  ret = rmdir(filename);
166  if (ret < 0 && errno == ENOTDIR)
167  ret = unlink(filename);
168  if (ret < 0)
169  return AVERROR(errno);
170 
171  return ret;
172 #else
173  return AVERROR(ENOSYS);
174 #endif /* HAVE_UNISTD_H */
175 }
176 
177 static int file_move(URLContext *h_src, URLContext *h_dst)
178 {
179 #if HAVE_UNISTD_H
180  const char *filename_src = h_src->filename;
181  const char *filename_dst = h_dst->filename;
182  av_strstart(filename_src, "file:", &filename_src);
183  av_strstart(filename_dst, "file:", &filename_dst);
184 
185  if (rename(filename_src, filename_dst) < 0)
186  return AVERROR(errno);
187 
188  return 0;
189 #else
190  return AVERROR(ENOSYS);
191 #endif /* HAVE_UNISTD_H */
192 }
193 
194 #if CONFIG_FILE_PROTOCOL
195 
196 static int file_open(URLContext *h, const char *filename, int flags)
197 {
198  FileContext *c = h->priv_data;
199  int access;
200  int fd;
201  struct stat st;
202 
203  av_strstart(filename, "file:", &filename);
204 
205  if (flags & AVIO_FLAG_WRITE && flags & AVIO_FLAG_READ) {
206  access = O_CREAT | O_RDWR;
207  if (c->trunc)
208  access |= O_TRUNC;
209  } else if (flags & AVIO_FLAG_WRITE) {
210  access = O_CREAT | O_WRONLY;
211  if (c->trunc)
212  access |= O_TRUNC;
213  } else {
214  access = O_RDONLY;
215  }
216 #ifdef O_BINARY
217  access |= O_BINARY;
218 #endif
219  fd = avpriv_open(filename, access, 0666);
220  if (fd == -1)
221  return AVERROR(errno);
222  c->fd = fd;
223 
224  h->is_streamed = !fstat(fd, &st) && S_ISFIFO(st.st_mode);
225 
226  return 0;
227 }
228 
229 /* XXX: use llseek */
230 static int64_t file_seek(URLContext *h, int64_t pos, int whence)
231 {
232  FileContext *c = h->priv_data;
233  int64_t ret;
234 
235  if (whence == AVSEEK_SIZE) {
236  struct stat st;
237  ret = fstat(c->fd, &st);
238  return ret < 0 ? AVERROR(errno) : (S_ISFIFO(st.st_mode) ? 0 : st.st_size);
239  }
240 
241  ret = lseek(c->fd, pos, whence);
242 
243  return ret < 0 ? AVERROR(errno) : ret;
244 }
245 
246 static int file_close(URLContext *h)
247 {
248  FileContext *c = h->priv_data;
249  return close(c->fd);
250 }
251 
252 static int file_open_dir(URLContext *h)
253 {
254 #if HAVE_LSTAT
255  FileContext *c = h->priv_data;
256 
257  c->dir = opendir(h->filename);
258  if (!c->dir)
259  return AVERROR(errno);
260 
261  return 0;
262 #else
263  return AVERROR(ENOSYS);
264 #endif /* HAVE_LSTAT */
265 }
266 
267 static int file_read_dir(URLContext *h, AVIODirEntry **next)
268 {
269 #if HAVE_LSTAT
270  FileContext *c = h->priv_data;
271  struct dirent *dir;
272  char *fullpath = NULL;
273 
274  *next = ff_alloc_dir_entry();
275  if (!*next)
276  return AVERROR(ENOMEM);
277  do {
278  errno = 0;
279  dir = readdir(c->dir);
280  if (!dir) {
281  av_freep(next);
282  return AVERROR(errno);
283  }
284  } while (!strcmp(dir->d_name, ".") || !strcmp(dir->d_name, ".."));
285 
286  fullpath = av_append_path_component(h->filename, dir->d_name);
287  if (fullpath) {
288  struct stat st;
289  if (!lstat(fullpath, &st)) {
290  if (S_ISDIR(st.st_mode))
291  (*next)->type = AVIO_ENTRY_DIRECTORY;
292  else if (S_ISFIFO(st.st_mode))
293  (*next)->type = AVIO_ENTRY_NAMED_PIPE;
294  else if (S_ISCHR(st.st_mode))
295  (*next)->type = AVIO_ENTRY_CHARACTER_DEVICE;
296  else if (S_ISBLK(st.st_mode))
297  (*next)->type = AVIO_ENTRY_BLOCK_DEVICE;
298  else if (S_ISLNK(st.st_mode))
299  (*next)->type = AVIO_ENTRY_SYMBOLIC_LINK;
300  else if (S_ISSOCK(st.st_mode))
301  (*next)->type = AVIO_ENTRY_SOCKET;
302  else if (S_ISREG(st.st_mode))
303  (*next)->type = AVIO_ENTRY_FILE;
304  else
305  (*next)->type = AVIO_ENTRY_UNKNOWN;
306 
307  (*next)->group_id = st.st_gid;
308  (*next)->user_id = st.st_uid;
309  (*next)->size = st.st_size;
310  (*next)->filemode = st.st_mode & 0777;
311  (*next)->modification_timestamp = INT64_C(1000000) * st.st_mtime;
312  (*next)->access_timestamp = INT64_C(1000000) * st.st_atime;
313  (*next)->status_change_timestamp = INT64_C(1000000) * st.st_ctime;
314  }
315  av_free(fullpath);
316  }
317 
318  (*next)->name = av_strdup(dir->d_name);
319  return 0;
320 #else
321  return AVERROR(ENOSYS);
322 #endif /* HAVE_LSTAT */
323 }
324 
325 static int file_close_dir(URLContext *h)
326 {
327 #if HAVE_LSTAT
328  FileContext *c = h->priv_data;
329  closedir(c->dir);
330  return 0;
331 #else
332  return AVERROR(ENOSYS);
333 #endif /* HAVE_LSTAT */
334 }
335 
336 URLProtocol ff_file_protocol = {
337  .name = "file",
338  .url_open = file_open,
339  .url_read = file_read,
340  .url_write = file_write,
341  .url_seek = file_seek,
342  .url_close = file_close,
343  .url_get_file_handle = file_get_handle,
344  .url_check = file_check,
345  .url_delete = file_delete,
346  .url_move = file_move,
347  .priv_data_size = sizeof(FileContext),
348  .priv_data_class = &file_class,
349  .url_open_dir = file_open_dir,
350  .url_read_dir = file_read_dir,
351  .url_close_dir = file_close_dir,
352  .default_whitelist = "file"
353 };
354 
355 #endif /* CONFIG_FILE_PROTOCOL */
356 
357 #if CONFIG_PIPE_PROTOCOL
358 
359 static int pipe_open(URLContext *h, const char *filename, int flags)
360 {
361  FileContext *c = h->priv_data;
362  int fd;
363  char *final;
364  av_strstart(filename, "pipe:", &filename);
365 
366  fd = strtol(filename, &final, 10);
367  if((filename == final) || *final ) {/* No digits found, or something like 10ab */
368  if (flags & AVIO_FLAG_WRITE) {
369  fd = 1;
370  } else {
371  fd = 0;
372  }
373  }
374 #if HAVE_SETMODE
375  setmode(fd, O_BINARY);
376 #endif
377  c->fd = fd;
378  h->is_streamed = 1;
379  return 0;
380 }
381 
382 URLProtocol ff_pipe_protocol = {
383  .name = "pipe",
384  .url_open = pipe_open,
385  .url_read = file_read,
386  .url_write = file_write,
387  .url_get_file_handle = file_get_handle,
388  .url_check = file_check,
389  .priv_data_size = sizeof(FileContext),
390  .priv_data_class = &pipe_class,
391  .default_whitelist = "none"
392 };
393 
394 #endif /* CONFIG_PIPE_PROTOCOL */
#define NULL
Definition: coverity.c:32
static int file_read(URLContext *h, unsigned char *buf, int size)
Definition: file.c:105
AVOption.
Definition: opt.h:245
#define LIBAVUTIL_VERSION_INT
Definition: version.h:70
static const AVOption pipe_options[]
Definition: file.c:86
int is_streamed
true if streamed (no seek possible), default = false
Definition: url.h:46
Describes single entry of the directory.
Definition: avio.h:78
#define AVIO_FLAG_READ
read-only
Definition: avio.h:537
#define AVIO_FLAG_WRITE
write-only
Definition: avio.h:538
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
AVOptions.
miscellaneous OS support macros and functions.
int blocksize
Definition: file.c:74
int avpriv_open(const char *filename, int flags,...)
A wrapper for open() setting O_CLOEXEC.
Definition: file_open.c:66
ptrdiff_t size
Definition: opengl_enc.c:101
static int file_check(URLContext *h, int mask)
Definition: file.c:129
#define AV_OPT_FLAG_ENCODING_PARAM
a generic parameter which can be set by the user for muxing or encoding
Definition: opt.h:275
int trunc
Definition: file.c:73
static const uint16_t mask[17]
Definition: lzw.c:38
av_default_item_name
#define AVERROR(e)
Definition: error.h:43
static int file_delete(URLContext *h)
Definition: file.c:158
#define S_ISFIFO(m)
Definition: file.c:46
common internal API header
#define FFMIN(a, b)
Definition: common.h:96
static av_always_inline av_const double trunc(double x)
Definition: libm.h:458
#define O_BINARY
static int file_move(URLContext *h_src, URLContext *h_dst)
Definition: file.c:177
char * av_strdup(const char *s)
Duplicate the string s.
Definition: mem.c:267
void * buf
Definition: avisynth_c.h:553
Definition: url.h:39
Describe the class of an AVClass context structure.
Definition: log.h:67
void * priv_data
Definition: url.h:42
static const AVClass file_class
Definition: file.c:91
static const AVOption file_options[]
Definition: file.c:80
const char * name
Definition: url.h:54
int fd
Definition: file.c:72
static int flags
Definition: cpu.c:47
#define S_ISLNK(m)
Definition: file.c:55
int av_strstart(const char *str, const char *pfx, const char **ptr)
Return non-zero if pfx is a prefix of str.
Definition: avstring.c:34
Main libavformat public API header.
char * av_append_path_component(const char *path, const char *component)
Append path component to the existing path.
Definition: avstring.c:272
#define S_ISSOCK(m)
Definition: file.c:64
static int file_get_handle(URLContext *h)
Definition: file.c:123
static const AVClass pipe_class
Definition: file.c:98
static double c[64]
AVIODirEntry * ff_alloc_dir_entry(void)
Allocate directory entry with default values.
Definition: url.c:149
char * filename
specified URL
Definition: url.h:43
#define AVSEEK_SIZE
Passing this as the "whence" parameter to a seek function causes it to return the filesize without se...
Definition: avio.h:416
#define av_free(p)
#define av_freep(p)
unbuffered private I/O API
static int file_write(URLContext *h, const unsigned char *buf, int size)
Definition: file.c:114