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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  int follow;
76 #if HAVE_DIRENT_H
77  DIR *dir;
78 #endif
79 } FileContext;
80 
81 static const AVOption file_options[] = {
82  { "truncate", "truncate existing files on write", offsetof(FileContext, trunc), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, AV_OPT_FLAG_ENCODING_PARAM },
83  { "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 },
84  { "follow", "Follow a file as it is being written", offsetof(FileContext, follow), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AV_OPT_FLAG_DECODING_PARAM },
85  { NULL }
86 };
87 
88 static const AVOption pipe_options[] = {
89  { "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 },
90  { NULL }
91 };
92 
93 static const AVClass file_class = {
94  .class_name = "file",
95  .item_name = av_default_item_name,
96  .option = file_options,
97  .version = LIBAVUTIL_VERSION_INT,
98 };
99 
100 static const AVClass pipe_class = {
101  .class_name = "pipe",
102  .item_name = av_default_item_name,
103  .option = pipe_options,
104  .version = LIBAVUTIL_VERSION_INT,
105 };
106 
107 static int file_read(URLContext *h, unsigned char *buf, int size)
108 {
109  FileContext *c = h->priv_data;
110  int ret;
111  size = FFMIN(size, c->blocksize);
112  ret = read(c->fd, buf, size);
113  if (ret == 0 && c->follow)
114  return AVERROR(EAGAIN);
115  return (ret == -1) ? AVERROR(errno) : ret;
116 }
117 
118 static int file_write(URLContext *h, const unsigned char *buf, int size)
119 {
120  FileContext *c = h->priv_data;
121  int ret;
122  size = FFMIN(size, c->blocksize);
123  ret = write(c->fd, buf, size);
124  return (ret == -1) ? AVERROR(errno) : ret;
125 }
126 
128 {
129  FileContext *c = h->priv_data;
130  return c->fd;
131 }
132 
133 static int file_check(URLContext *h, int mask)
134 {
135  int ret = 0;
136  const char *filename = h->filename;
137  av_strstart(filename, "file:", &filename);
138 
139  {
140 #if HAVE_ACCESS && defined(R_OK)
141  if (access(filename, F_OK) < 0)
142  return AVERROR(errno);
143  if (mask&AVIO_FLAG_READ)
144  if (access(filename, R_OK) >= 0)
145  ret |= AVIO_FLAG_READ;
146  if (mask&AVIO_FLAG_WRITE)
147  if (access(filename, W_OK) >= 0)
148  ret |= AVIO_FLAG_WRITE;
149 #else
150  struct stat st;
151 # ifndef _WIN32
152  ret = stat(filename, &st);
153 # else
154  ret = win32_stat(filename, &st);
155 # endif
156  if (ret < 0)
157  return AVERROR(errno);
158 
159  ret |= st.st_mode&S_IRUSR ? mask&AVIO_FLAG_READ : 0;
160  ret |= st.st_mode&S_IWUSR ? mask&AVIO_FLAG_WRITE : 0;
161 #endif
162  }
163  return ret;
164 }
165 
167 {
168 #if HAVE_UNISTD_H
169  int ret;
170  const char *filename = h->filename;
171  av_strstart(filename, "file:", &filename);
172 
173  ret = rmdir(filename);
174  if (ret < 0 && errno == ENOTDIR)
175  ret = unlink(filename);
176  if (ret < 0)
177  return AVERROR(errno);
178 
179  return ret;
180 #else
181  return AVERROR(ENOSYS);
182 #endif /* HAVE_UNISTD_H */
183 }
184 
185 static int file_move(URLContext *h_src, URLContext *h_dst)
186 {
187  const char *filename_src = h_src->filename;
188  const char *filename_dst = h_dst->filename;
189  av_strstart(filename_src, "file:", &filename_src);
190  av_strstart(filename_dst, "file:", &filename_dst);
191 
192  if (rename(filename_src, filename_dst) < 0)
193  return AVERROR(errno);
194 
195  return 0;
196 }
197 
198 #if CONFIG_FILE_PROTOCOL
199 
200 static int file_open(URLContext *h, const char *filename, int flags)
201 {
202  FileContext *c = h->priv_data;
203  int access;
204  int fd;
205  struct stat st;
206 
207  av_strstart(filename, "file:", &filename);
208 
209  if (flags & AVIO_FLAG_WRITE && flags & AVIO_FLAG_READ) {
210  access = O_CREAT | O_RDWR;
211  if (c->trunc)
212  access |= O_TRUNC;
213  } else if (flags & AVIO_FLAG_WRITE) {
214  access = O_CREAT | O_WRONLY;
215  if (c->trunc)
216  access |= O_TRUNC;
217  } else {
218  access = O_RDONLY;
219  }
220 #ifdef O_BINARY
221  access |= O_BINARY;
222 #endif
223  fd = avpriv_open(filename, access, 0666);
224  if (fd == -1)
225  return AVERROR(errno);
226  c->fd = fd;
227 
228  h->is_streamed = !fstat(fd, &st) && S_ISFIFO(st.st_mode);
229 
230  return 0;
231 }
232 
233 /* XXX: use llseek */
234 static int64_t file_seek(URLContext *h, int64_t pos, int whence)
235 {
236  FileContext *c = h->priv_data;
237  int64_t ret;
238 
239  if (whence == AVSEEK_SIZE) {
240  struct stat st;
241  ret = fstat(c->fd, &st);
242  return ret < 0 ? AVERROR(errno) : (S_ISFIFO(st.st_mode) ? 0 : st.st_size);
243  }
244 
245  ret = lseek(c->fd, pos, whence);
246 
247  return ret < 0 ? AVERROR(errno) : ret;
248 }
249 
250 static int file_close(URLContext *h)
251 {
252  FileContext *c = h->priv_data;
253  return close(c->fd);
254 }
255 
256 static int file_open_dir(URLContext *h)
257 {
258 #if HAVE_LSTAT
259  FileContext *c = h->priv_data;
260 
261  c->dir = opendir(h->filename);
262  if (!c->dir)
263  return AVERROR(errno);
264 
265  return 0;
266 #else
267  return AVERROR(ENOSYS);
268 #endif /* HAVE_LSTAT */
269 }
270 
271 static int file_read_dir(URLContext *h, AVIODirEntry **next)
272 {
273 #if HAVE_LSTAT
274  FileContext *c = h->priv_data;
275  struct dirent *dir;
276  char *fullpath = NULL;
277 
278  *next = ff_alloc_dir_entry();
279  if (!*next)
280  return AVERROR(ENOMEM);
281  do {
282  errno = 0;
283  dir = readdir(c->dir);
284  if (!dir) {
285  av_freep(next);
286  return AVERROR(errno);
287  }
288  } while (!strcmp(dir->d_name, ".") || !strcmp(dir->d_name, ".."));
289 
290  fullpath = av_append_path_component(h->filename, dir->d_name);
291  if (fullpath) {
292  struct stat st;
293  if (!lstat(fullpath, &st)) {
294  if (S_ISDIR(st.st_mode))
295  (*next)->type = AVIO_ENTRY_DIRECTORY;
296  else if (S_ISFIFO(st.st_mode))
297  (*next)->type = AVIO_ENTRY_NAMED_PIPE;
298  else if (S_ISCHR(st.st_mode))
299  (*next)->type = AVIO_ENTRY_CHARACTER_DEVICE;
300  else if (S_ISBLK(st.st_mode))
301  (*next)->type = AVIO_ENTRY_BLOCK_DEVICE;
302  else if (S_ISLNK(st.st_mode))
303  (*next)->type = AVIO_ENTRY_SYMBOLIC_LINK;
304  else if (S_ISSOCK(st.st_mode))
305  (*next)->type = AVIO_ENTRY_SOCKET;
306  else if (S_ISREG(st.st_mode))
307  (*next)->type = AVIO_ENTRY_FILE;
308  else
309  (*next)->type = AVIO_ENTRY_UNKNOWN;
310 
311  (*next)->group_id = st.st_gid;
312  (*next)->user_id = st.st_uid;
313  (*next)->size = st.st_size;
314  (*next)->filemode = st.st_mode & 0777;
315  (*next)->modification_timestamp = INT64_C(1000000) * st.st_mtime;
316  (*next)->access_timestamp = INT64_C(1000000) * st.st_atime;
317  (*next)->status_change_timestamp = INT64_C(1000000) * st.st_ctime;
318  }
319  av_free(fullpath);
320  }
321 
322  (*next)->name = av_strdup(dir->d_name);
323  return 0;
324 #else
325  return AVERROR(ENOSYS);
326 #endif /* HAVE_LSTAT */
327 }
328 
329 static int file_close_dir(URLContext *h)
330 {
331 #if HAVE_LSTAT
332  FileContext *c = h->priv_data;
333  closedir(c->dir);
334  return 0;
335 #else
336  return AVERROR(ENOSYS);
337 #endif /* HAVE_LSTAT */
338 }
339 
341  .name = "file",
342  .url_open = file_open,
343  .url_read = file_read,
344  .url_write = file_write,
345  .url_seek = file_seek,
346  .url_close = file_close,
347  .url_get_file_handle = file_get_handle,
348  .url_check = file_check,
349  .url_delete = file_delete,
350  .url_move = file_move,
351  .priv_data_size = sizeof(FileContext),
352  .priv_data_class = &file_class,
353  .url_open_dir = file_open_dir,
354  .url_read_dir = file_read_dir,
355  .url_close_dir = file_close_dir,
356  .default_whitelist = "file,crypto"
357 };
358 
359 #endif /* CONFIG_FILE_PROTOCOL */
360 
361 #if CONFIG_PIPE_PROTOCOL
362 
363 static int pipe_open(URLContext *h, const char *filename, int flags)
364 {
365  FileContext *c = h->priv_data;
366  int fd;
367  char *final;
368  av_strstart(filename, "pipe:", &filename);
369 
370  fd = strtol(filename, &final, 10);
371  if((filename == final) || *final ) {/* No digits found, or something like 10ab */
372  if (flags & AVIO_FLAG_WRITE) {
373  fd = 1;
374  } else {
375  fd = 0;
376  }
377  }
378 #if HAVE_SETMODE
379  setmode(fd, O_BINARY);
380 #endif
381  c->fd = fd;
382  h->is_streamed = 1;
383  return 0;
384 }
385 
387  .name = "pipe",
388  .url_open = pipe_open,
389  .url_read = file_read,
390  .url_write = file_write,
391  .url_get_file_handle = file_get_handle,
392  .url_check = file_check,
393  .priv_data_size = sizeof(FileContext),
394  .priv_data_class = &pipe_class,
395  .default_whitelist = "crypto"
396 };
397 
398 #endif /* CONFIG_PIPE_PROTOCOL */
#define NULL
Definition: coverity.c:32
static int file_read(URLContext *h, unsigned char *buf, int size)
Definition: file.c:107
AVOption.
Definition: opt.h:245
#define LIBAVUTIL_VERSION_INT
Definition: version.h:70
static const AVOption pipe_options[]
Definition: file.c:88
#define O_BINARY
int is_streamed
true if streamed (no seek possible), default = false
Definition: url.h:45
Describes single entry of the directory.
Definition: avio.h:78
#define AVIO_FLAG_READ
read-only
Definition: avio.h:606
#define AVIO_FLAG_WRITE
write-only
Definition: avio.h:607
int follow
Definition: file.c:75
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:133
#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:166
#define S_ISFIFO(m)
Definition: file.c:46
const URLProtocol ff_pipe_protocol
const URLProtocol ff_file_protocol
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
static int file_move(URLContext *h_src, URLContext *h_dst)
Definition: file.c:185
char * av_strdup(const char *s)
Duplicate the string s.
Definition: mem.c:267
void * buf
Definition: avisynth_c.h:553
Definition: url.h:38
Describe the class of an AVClass context structure.
Definition: log.h:67
void * priv_data
Definition: url.h:41
#define AV_OPT_FLAG_DECODING_PARAM
a generic parameter which can be set by the user for demuxing or decoding
Definition: opt.h:276
static const AVClass file_class
Definition: file.c:93
static const AVOption file_options[]
Definition: file.c:81
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:127
static const AVClass pipe_class
Definition: file.c:100
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:42
#define AVSEEK_SIZE
ORing this as the "whence" parameter to a seek function causes it to return the filesize without seek...
Definition: avio.h:485
#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:118