1 /*****************************************************************************
2 * decomp.c : Decompression module for vlc
3 *****************************************************************************
4 * Copyright © 2008 Rémi Denis-Courmont
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU Lesser General Public License as published by
8 * the Free Software Foundation; either version 2.1 of the License, or
9 * (at your option) any later version.
11 * This program 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
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
19 *****************************************************************************/
25 #include <vlc_common.h>
26 #include <vlc_plugin.h>
27 #include <vlc_stream.h>
28 #include <vlc_network.h>
31 # define _POSIX_SPAWN (-1)
36 #include <sys/ioctl.h>
37 #if defined (__linux__) && defined (HAVE_VMSPLICE)
39 # include <sys/mman.h>
44 static int OpenGzip (vlc_object_t *);
45 static int OpenBzip2 (vlc_object_t *);
46 static void Close (vlc_object_t *);
49 set_description (N_("Decompression"))
50 set_category (CAT_INPUT)
51 set_subcategory (SUBCAT_INPUT_STREAM_FILTER)
52 set_capability ("stream_filter", 20)
53 set_callbacks (OpenBzip2, Close)
54 /* TODO: access shortnames for stream_UrlNew() */
57 set_callbacks (OpenGzip, Close)
66 int write_fd, read_fd;
69 static void cloexec (int fd)
71 int flags = fcntl (fd, F_GETFD);
72 fcntl (fd, F_SETFD, FD_CLOEXEC | ((flags != -1) ? flags : 0));
75 extern char **environ;
77 static const size_t bufsize = 65536;
79 static void cleanup_mmap (void *addr)
81 munmap (addr, bufsize);
85 static void *Thread (void *data)
87 stream_t *stream = data;
88 stream_sys_t *p_sys = stream->p_sys;
90 ssize_t page_mask = sysconf (_SC_PAGE_SIZE) - 1;
92 int fd = p_sys->write_fd;
98 int canc = vlc_savecancel ();
100 unsigned char *buf = mmap (NULL, bufsize, PROT_READ|PROT_WRITE,
101 MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
102 vlc_cleanup_push (cleanup_mmap, buf);
104 unsigned char buf[bufsize];
107 len = stream_Read (stream->p_source, buf, bufsize);
108 vlc_restorecancel (canc);
111 for (ssize_t i = 0, j; i < len; i += j)
114 if ((len - i) <= page_mask) /* incomplete last page */
115 j = write (fd, buf + i, len - i);
118 struct iovec iov = { buf + i, (len - i) & ~page_mask, };
119 j = vmsplice (fd, &iov, 1, SPLICE_F_GIFT);
122 j = write (fd, buf + i, len - i);
128 msg_Err (stream, "cannot write data (%m)");
134 vlc_cleanup_run (); /* munmap (buf, bufsize) */
139 msg_Dbg (stream, "compressed stream at EOF");
144 #define MIN_BLOCK (1 << 10)
145 #define MAX_BLOCK (1 << 20)
147 * Reads decompressed from the decompression program
148 * @return -1 for EAGAIN, 0 for EOF, byte count otherwise.
150 static int Read (stream_t *stream, void *buf, unsigned int buflen)
152 stream_sys_t *p_sys = stream->p_sys;
157 if ((peeked = p_sys->peeked) != NULL)
159 bonus = (buflen > peeked->i_buffer) ? peeked->i_buffer : buflen;
160 memcpy (buf, peeked->p_buffer, bonus);
161 peeked->p_buffer += bonus;
162 peeked->i_buffer -= bonus;
163 if (peeked->i_buffer == 0)
165 block_Release (peeked);
166 p_sys->peeked = NULL;
170 length = net_Read (stream, p_sys->read_fd, NULL, buf, buflen, false);
174 p_sys->offset += length;
181 static int Peek (stream_t *stream, const uint8_t **pbuf, unsigned int len)
183 stream_sys_t *p_sys = stream->p_sys;
184 block_t *peeked = p_sys->peeked;
186 int fd = p_sys->read_fd;
189 peeked = block_Alloc (len);
190 else if ((curlen = peeked->i_buffer) < len)
191 peeked = block_Realloc (peeked, 0, len);
193 if ((p_sys->peeked = peeked) == NULL)
198 ssize_t val = net_Read (stream, fd, NULL, peeked->p_buffer + curlen,
203 peeked->i_buffer = curlen;
206 *pbuf = peeked->p_buffer;
213 static int Control (stream_t *stream, int query, va_list args)
215 stream_sys_t *p_sys = stream->p_sys;
219 case STREAM_CAN_SEEK:
220 case STREAM_CAN_FASTSEEK:
221 *(va_arg (args, bool *)) = false;
223 case STREAM_GET_POSITION:
224 *(va_arg (args, int64_t *)) = p_sys->offset;
226 case STREAM_GET_SIZE:
227 *(va_arg (args, int64_t *)) = 0;
230 *(va_arg (args, int *)) = 0;
239 * Pipe data through an external executable.
240 * @param stream the stream filter object.
241 * @param path path to the executable.
243 static int Open (stream_t *stream, const char *path)
245 stream_sys_t *p_sys = stream->p_sys = malloc (sizeof (*p_sys));
249 stream->pf_read = Read;
250 stream->pf_peek = Peek;
251 stream->pf_control = Control;
252 p_sys->peeked = NULL;
256 /* I am not a big fan of the pyramid style, but I cannot think of anything
257 * better here. There are too many failure cases. */
258 int ret = VLC_EGENERIC;
261 /* We use two pipes rather than one stream socket pair, so that we can
262 * use vmsplice() on Linux. */
263 if (pipe (comp) == 0)
266 p_sys->write_fd = comp[1];
269 if (pipe (uncomp) == 0)
272 p_sys->read_fd = uncomp[0];
274 #if (_POSIX_SPAWN >= 0)
275 posix_spawn_file_actions_t actions;
276 if (posix_spawn_file_actions_init (&actions) == 0)
278 char *const argv[] = { (char *)path, NULL };
280 if (!posix_spawn_file_actions_adddup2 (&actions, comp[0], 0)
281 && !posix_spawn_file_actions_addclose (&actions, comp[0])
282 && !posix_spawn_file_actions_adddup2 (&actions, uncomp[1], 1)
283 && !posix_spawn_file_actions_addclose (&actions, uncomp[1])
284 && !posix_spawnp (&p_sys->pid, path, &actions, NULL, argv,
287 if (vlc_clone (&p_sys->thread, Thread, stream,
288 VLC_THREAD_PRIORITY_INPUT) == 0)
293 msg_Err (stream, "Cannot execute %s", path);
296 posix_spawn_file_actions_destroy (&actions);
298 #else /* _POSIX_SPAWN */
299 switch (p_sys->pid = fork ())
302 msg_Err (stream, "Cannot fork (%m)");
309 execlp (path, path, (char *)NULL);
310 exit (1); /* if we get, execlp() failed! */
312 if (vlc_clone (&p_sys->thread, Thread, stream,
313 VLC_THREAD_PRIORITY_INPUT) == 0)
316 #endif /* _POSIX_SPAWN < 0 */
318 if (ret != VLC_SUCCESS)
322 if (ret != VLC_SUCCESS)
325 if (p_sys->pid != -1)
326 while (waitpid (p_sys->pid, &(int){ 0 }, 0) == -1);
334 * Releases allocate resources.
336 static void Close (vlc_object_t *obj)
338 stream_t *stream = (stream_t *)obj;
339 stream_sys_t *p_sys = stream->p_sys;
342 vlc_cancel (p_sys->thread);
343 close (p_sys->read_fd);
344 vlc_join (p_sys->thread, NULL);
345 close (p_sys->write_fd);
347 msg_Dbg (obj, "waiting for PID %u", (unsigned)p_sys->pid);
348 while (waitpid (p_sys->pid, &status, 0) == -1);
349 msg_Dbg (obj, "exit status %d", status);
352 block_Release (p_sys->peeked);
358 * Detects gzip file format
360 static int OpenGzip (vlc_object_t *obj)
362 stream_t *stream = (stream_t *)obj;
365 if (stream_Peek (stream->p_source, &peek, 3) < 3)
368 if (memcmp (peek, "\x1f\x8b\x08", 3))
371 msg_Dbg (obj, "detected gzip compressed stream");
372 return Open (stream, "zcat");
377 * Detects bzip2 file format
379 static int OpenBzip2 (vlc_object_t *obj)
381 stream_t *stream = (stream_t *)obj;
384 /* (Try to) parse the bzip2 header */
385 if (stream_Peek (stream->p_source, &peek, 10) < 10)
388 if (memcmp (peek, "BZh", 3) || (peek[3] < '1') || (peek[3] > '9')
389 || memcmp (peek + 4, "\x31\x41\x59\x26\x53\x59", 6))
392 msg_Dbg (obj, "detected bzip2 compressed stream");
393 return Open (stream, "bzcat");