libavformat/file.c

   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     int seekable;
  77 #if HAVE_DIRENT_H
  78     DIR *dir;
  79 #endif
  80 } FileContext;
  81
  82 static const AVOption file_options[] = {
  83     { "truncate", "truncate existing files on write", offsetof(FileContext, trunc), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, AV_OPT_FLAG_ENCODING_PARAM },
  84     { "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 },
  85     { "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 },
  86     { "seekable", "Sets if the file is seekable", offsetof(FileContext, seekable), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 0, AV_OPT_FLAG_DECODING_PARAM | AV_OPT_FLAG_ENCODING_PARAM },
  87     { NULL }
  88 };
  89
  90 static const AVOption pipe_options[] = {
  91     { "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 },
  92     { NULL }
  93 };
  94
  95 static const AVClass file_class = {
  96     .class_name = "file",
  97     .item_name  = av_default_item_name,
  98     .option     = file_options,
  99     .version    = LIBAVUTIL_VERSION_INT,
 100 };
 101
 102 static const AVClass pipe_class = {
 103     .class_name = "pipe",
 104     .item_name  = av_default_item_name,
 105     .option     = pipe_options,
 106     .version    = LIBAVUTIL_VERSION_INT,
 107 };
 108
 109 static int file_read(URLContext *h, unsigned char *buf, int size)
 110 {
 111     FileContext *c = h->priv_data;
 112     int ret;
 113     size = FFMIN(size, c->blocksize);
 114     ret = read(c->fd, buf, size);
 115     if (ret == 0 && c->follow)
 116         return AVERROR(EAGAIN);
 117     if (ret == 0)
 118         return AVERROR_EOF;
 119     return (ret == -1) ? AVERROR(errno) : ret;
 120 }
 121
 122 static int file_write(URLContext *h, const unsigned char *buf, int size)
 123 {
 124     FileContext *c = h->priv_data;
 125     int ret;
 126     size = FFMIN(size, c->blocksize);
 127     ret = write(c->fd, buf, size);
 128     return (ret == -1) ? AVERROR(errno) : ret;
 129 }
 130
 131 static int file_get_handle(URLContext *h)
 132 {
 133     FileContext *c = h->priv_data;
 134     return c->fd;
 135 }
 136
 137 static int file_check(URLContext *h, int mask)
 138 {
 139     int ret = 0;
 140     const char *filename = h->filename;
 141     av_strstart(filename, "file:", &filename);
 142
 143     {
 144 #if HAVE_ACCESS && defined(R_OK)
 145     if (access(filename, F_OK) < 0)
 146         return AVERROR(errno);
 147     if (mask&AVIO_FLAG_READ)
 148         if (access(filename, R_OK) >= 0)
 149             ret |= AVIO_FLAG_READ;
 150     if (mask&AVIO_FLAG_WRITE)
 151         if (access(filename, W_OK) >= 0)
 152             ret |= AVIO_FLAG_WRITE;
 153 #else
 154     struct stat st;
 155 #   ifndef _WIN32
 156     ret = stat(filename, &st);
 157 #   else
 158     ret = win32_stat(filename, &st);
 159 #   endif
 160     if (ret < 0)
 161         return AVERROR(errno);
 162
 163     ret |= st.st_mode&S_IRUSR ? mask&AVIO_FLAG_READ  : 0;
 164     ret |= st.st_mode&S_IWUSR ? mask&AVIO_FLAG_WRITE : 0;
 165 #endif
 166     }
 167     return ret;
 168 }
 169
 170 static int file_delete(URLContext *h)
 171 {
 172 #if HAVE_UNISTD_H
 173     int ret;
 174     const char *filename = h->filename;
 175     av_strstart(filename, "file:", &filename);
 176
 177     ret = rmdir(filename);
 178     if (ret < 0 && (errno == ENOTDIR
 179 #   ifdef _WIN32
 180         || errno == EINVAL
 181 #   endif
 182         ))
 183         ret = unlink(filename);
 184     if (ret < 0)
 185         return AVERROR(errno);
 186
 187     return ret;
 188 #else
 189     return AVERROR(ENOSYS);
 190 #endif /* HAVE_UNISTD_H */
 191 }
 192
 193 static int file_move(URLContext *h_src, URLContext *h_dst)
 194 {
 195     const char *filename_src = h_src->filename;
 196     const char *filename_dst = h_dst->filename;
 197     av_strstart(filename_src, "file:", &filename_src);
 198     av_strstart(filename_dst, "file:", &filename_dst);
 199
 200     if (rename(filename_src, filename_dst) < 0)
 201         return AVERROR(errno);
 202
 203     return 0;
 204 }
 205
 206 #if CONFIG_FILE_PROTOCOL
 207
 208 static int file_open(URLContext *h, const char *filename, int flags)
 209 {
 210     FileContext *c = h->priv_data;
 211     int access;
 212     int fd;
 213     struct stat st;
 214
 215     av_strstart(filename, "file:", &filename);
 216
 217     if (flags & AVIO_FLAG_WRITE && flags & AVIO_FLAG_READ) {
 218         access = O_CREAT | O_RDWR;
 219         if (c->trunc)
 220             access |= O_TRUNC;
 221     } else if (flags & AVIO_FLAG_WRITE) {
 222         access = O_CREAT | O_WRONLY;
 223         if (c->trunc)
 224             access |= O_TRUNC;
 225     } else {
 226         access = O_RDONLY;
 227     }
 228 #ifdef O_BINARY
 229     access |= O_BINARY;
 230 #endif
 231     fd = avpriv_open(filename, access, 0666);
 232     if (fd == -1)
 233         return AVERROR(errno);
 234     c->fd = fd;
 235
 236     h->is_streamed = !fstat(fd, &st) && S_ISFIFO(st.st_mode);
 237
 238     /* Buffer writes more than the default 32k to improve throughput especially
 239      * with networked file systems */
 240     if (!h->is_streamed && flags & AVIO_FLAG_WRITE)
 241         h->min_packet_size = h->max_packet_size = 262144;
 242
 243     if (c->seekable >= 0)
 244         h->is_streamed = !c->seekable;
 245
 246     return 0;
 247 }
 248
 249 /* XXX: use llseek */
 250 static int64_t file_seek(URLContext *h, int64_t pos, int whence)
 251 {
 252     FileContext *c = h->priv_data;
 253     int64_t ret;
 254
 255     if (whence == AVSEEK_SIZE) {
 256         struct stat st;
 257         ret = fstat(c->fd, &st);
 258         return ret < 0 ? AVERROR(errno) : (S_ISFIFO(st.st_mode) ? 0 : st.st_size);
 259     }
 260
 261     ret = lseek(c->fd, pos, whence);
 262
 263     return ret < 0 ? AVERROR(errno) : ret;
 264 }
 265
 266 static int file_close(URLContext *h)
 267 {
 268     FileContext *c = h->priv_data;
 269     return close(c->fd);
 270 }
 271
 272 static int file_open_dir(URLContext *h)
 273 {
 274 #if HAVE_LSTAT
 275     FileContext *c = h->priv_data;
 276
 277     c->dir = opendir(h->filename);
 278     if (!c->dir)
 279         return AVERROR(errno);
 280
 281     return 0;
 282 #else
 283     return AVERROR(ENOSYS);
 284 #endif /* HAVE_LSTAT */
 285 }
 286
 287 static int file_read_dir(URLContext *h, AVIODirEntry **next)
 288 {
 289 #if HAVE_LSTAT
 290     FileContext *c = h->priv_data;
 291     struct dirent *dir;
 292     char *fullpath = NULL;
 293
 294     *next = ff_alloc_dir_entry();
 295     if (!*next)
 296         return AVERROR(ENOMEM);
 297     do {
 298         errno = 0;
 299         dir = readdir(c->dir);
 300         if (!dir) {
 301             av_freep(next);
 302             return AVERROR(errno);
 303         }
 304     } while (!strcmp(dir->d_name, ".") || !strcmp(dir->d_name, ".."));
 305
 306     fullpath = av_append_path_component(h->filename, dir->d_name);
 307     if (fullpath) {
 308         struct stat st;
 309         if (!lstat(fullpath, &st)) {
 310             if (S_ISDIR(st.st_mode))
 311                 (*next)->type = AVIO_ENTRY_DIRECTORY;
 312             else if (S_ISFIFO(st.st_mode))
 313                 (*next)->type = AVIO_ENTRY_NAMED_PIPE;
 314             else if (S_ISCHR(st.st_mode))
 315                 (*next)->type = AVIO_ENTRY_CHARACTER_DEVICE;
 316             else if (S_ISBLK(st.st_mode))
 317                 (*next)->type = AVIO_ENTRY_BLOCK_DEVICE;
 318             else if (S_ISLNK(st.st_mode))
 319                 (*next)->type = AVIO_ENTRY_SYMBOLIC_LINK;
 320             else if (S_ISSOCK(st.st_mode))
 321                 (*next)->type = AVIO_ENTRY_SOCKET;
 322             else if (S_ISREG(st.st_mode))
 323                 (*next)->type = AVIO_ENTRY_FILE;
 324             else
 325                 (*next)->type = AVIO_ENTRY_UNKNOWN;
 326
 327             (*next)->group_id = st.st_gid;
 328             (*next)->user_id = st.st_uid;
 329             (*next)->size = st.st_size;
 330             (*next)->filemode = st.st_mode & 0777;
 331             (*next)->modification_timestamp = INT64_C(1000000) * st.st_mtime;
 332             (*next)->access_timestamp =  INT64_C(1000000) * st.st_atime;
 333             (*next)->status_change_timestamp = INT64_C(1000000) * st.st_ctime;
 334         }
 335         av_free(fullpath);
 336     }
 337
 338     (*next)->name = av_strdup(dir->d_name);
 339     return 0;
 340 #else
 341     return AVERROR(ENOSYS);
 342 #endif /* HAVE_LSTAT */
 343 }
 344
 345 static int file_close_dir(URLContext *h)
 346 {
 347 #if HAVE_LSTAT
 348     FileContext *c = h->priv_data;
 349     closedir(c->dir);
 350     return 0;
 351 #else
 352     return AVERROR(ENOSYS);
 353 #endif /* HAVE_LSTAT */
 354 }
 355
 356 const URLProtocol ff_file_protocol = {
 357     .name                = "file",
 358     .url_open            = file_open,
 359     .url_read            = file_read,
 360     .url_write           = file_write,
 361     .url_seek            = file_seek,
 362     .url_close           = file_close,
 363     .url_get_file_handle = file_get_handle,
 364     .url_check           = file_check,
 365     .url_delete          = file_delete,
 366     .url_move            = file_move,
 367     .priv_data_size      = sizeof(FileContext),
 368     .priv_data_class     = &file_class,
 369     .url_open_dir        = file_open_dir,
 370     .url_read_dir        = file_read_dir,
 371     .url_close_dir       = file_close_dir,
 372     .default_whitelist   = "file,crypto,data"
 373 };
 374
 375 #endif /* CONFIG_FILE_PROTOCOL */
 376
 377 #if CONFIG_PIPE_PROTOCOL
 378
 379 static int pipe_open(URLContext *h, const char *filename, int flags)
 380 {
 381     FileContext *c = h->priv_data;
 382     int fd;
 383     char *final;
 384     av_strstart(filename, "pipe:", &filename);
 385
 386     fd = strtol(filename, &final, 10);
 387     if((filename == final) || *final ) {/* No digits found, or something like 10ab */
 388         if (flags & AVIO_FLAG_WRITE) {
 389             fd = 1;
 390         } else {
 391             fd = 0;
 392         }
 393     }
 394 #if HAVE_SETMODE
 395     setmode(fd, O_BINARY);
 396 #endif
 397     c->fd = fd;
 398     h->is_streamed = 1;
 399     return 0;
 400 }
 401
 402 const URLProtocol ff_pipe_protocol = {
 403     .name                = "pipe",
 404     .url_open            = pipe_open,
 405     .url_read            = file_read,
 406     .url_write           = file_write,
 407     .url_get_file_handle = file_get_handle,
 408     .url_check           = file_check,
 409     .priv_data_size      = sizeof(FileContext),
 410     .priv_data_class     = &pipe_class,
 411     .default_whitelist   = "crypto,data"
 412 };
 413
 414 #endif /* CONFIG_PIPE_PROTOCOL */