FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
avio.c
Go to the documentation of this file.
1 /*
2  * unbuffered 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/dict.h"
24 #include "libavutil/opt.h"
25 #include "libavutil/time.h"
26 #include "os_support.h"
27 #include "avformat.h"
28 #if CONFIG_NETWORK
29 #include "network.h"
30 #endif
31 #include "url.h"
32 
34 
36 {
37  return prev ? prev->next : first_protocol;
38 }
39 
40 /** @name Logging context. */
41 /*@{*/
42 static const char *urlcontext_to_name(void *ptr)
43 {
44  URLContext *h = (URLContext *)ptr;
45  if (h->prot)
46  return h->prot->name;
47  else
48  return "NULL";
49 }
50 
51 static void *urlcontext_child_next(void *obj, void *prev)
52 {
53  URLContext *h = obj;
54  if (!prev && h->priv_data && h->prot->priv_data_class)
55  return h->priv_data;
56  return NULL;
57 }
58 
59 static const AVClass *urlcontext_child_class_next(const AVClass *prev)
60 {
61  URLProtocol *p = NULL;
62 
63  /* find the protocol that corresponds to prev */
64  while (prev && (p = ffurl_protocol_next(p)))
65  if (p->priv_data_class == prev)
66  break;
67 
68  /* find next protocol with priv options */
69  while (p = ffurl_protocol_next(p))
70  if (p->priv_data_class)
71  return p->priv_data_class;
72  return NULL;
73 }
74 
75 static const AVOption options[] = { { NULL } };
77  .class_name = "URLContext",
78  .item_name = urlcontext_to_name,
79  .option = options,
80  .version = LIBAVUTIL_VERSION_INT,
81  .child_next = urlcontext_child_next,
82  .child_class_next = urlcontext_child_class_next,
83 };
84 /*@}*/
85 
86 const char *avio_enum_protocols(void **opaque, int output)
87 {
88  URLProtocol *p;
89  *opaque = ffurl_protocol_next(*opaque);
90  if (!(p = *opaque))
91  return NULL;
92  if ((output && p->url_write) || (!output && p->url_read))
93  return p->name;
94  return avio_enum_protocols(opaque, output);
95 }
96 
98 {
99  URLProtocol **p;
100  p = &first_protocol;
101  while (*p)
102  p = &(*p)->next;
103  *p = protocol;
104  protocol->next = NULL;
105  return 0;
106 }
107 
108 static int url_alloc_for_protocol(URLContext **puc, struct URLProtocol *up,
109  const char *filename, int flags,
110  const AVIOInterruptCB *int_cb)
111 {
112  URLContext *uc;
113  int err;
114 
115 #if CONFIG_NETWORK
117  return AVERROR(EIO);
118 #endif
119  if ((flags & AVIO_FLAG_READ) && !up->url_read) {
121  "Impossible to open the '%s' protocol for reading\n", up->name);
122  return AVERROR(EIO);
123  }
124  if ((flags & AVIO_FLAG_WRITE) && !up->url_write) {
126  "Impossible to open the '%s' protocol for writing\n", up->name);
127  return AVERROR(EIO);
128  }
129  uc = av_mallocz(sizeof(URLContext) + strlen(filename) + 1);
130  if (!uc) {
131  err = AVERROR(ENOMEM);
132  goto fail;
133  }
135  uc->filename = (char *)&uc[1];
136  strcpy(uc->filename, filename);
137  uc->prot = up;
138  uc->flags = flags;
139  uc->is_streamed = 0; /* default = not streamed */
140  uc->max_packet_size = 0; /* default: stream file */
141  if (up->priv_data_size) {
143  if (!uc->priv_data) {
144  err = AVERROR(ENOMEM);
145  goto fail;
146  }
147  if (up->priv_data_class) {
148  int proto_len= strlen(up->name);
149  char *start = strchr(uc->filename, ',');
150  *(const AVClass **)uc->priv_data = up->priv_data_class;
152  if(!strncmp(up->name, uc->filename, proto_len) && uc->filename + proto_len == start){
153  int ret= 0;
154  char *p= start;
155  char sep= *++p;
156  char *key, *val;
157  p++;
158  while(ret >= 0 && (key= strchr(p, sep)) && p<key && (val = strchr(key+1, sep))){
159  *val= *key= 0;
160  ret= av_opt_set(uc->priv_data, p, key+1, 0);
161  if (ret == AVERROR_OPTION_NOT_FOUND)
162  av_log(uc, AV_LOG_ERROR, "Key '%s' not found.\n", p);
163  *val= *key= sep;
164  p= val+1;
165  }
166  if(ret<0 || p!=key){
167  av_log(uc, AV_LOG_ERROR, "Error parsing options string %s\n", start);
168  av_freep(&uc->priv_data);
169  av_freep(&uc);
170  err = AVERROR(EINVAL);
171  goto fail;
172  }
173  memmove(start, key+1, strlen(key));
174  }
175  }
176  }
177  if (int_cb)
178  uc->interrupt_callback = *int_cb;
179 
180  *puc = uc;
181  return 0;
182 fail:
183  *puc = NULL;
184  if (uc)
185  av_freep(&uc->priv_data);
186  av_freep(&uc);
187 #if CONFIG_NETWORK
190 #endif
191  return err;
192 }
193 
195 {
196  int err =
197  uc->prot->url_open2 ? uc->prot->url_open2(uc,
198  uc->filename,
199  uc->flags,
200  options) :
201  uc->prot->url_open(uc, uc->filename, uc->flags);
202  if (err)
203  return err;
204  uc->is_connected = 1;
205  /* We must be careful here as ffurl_seek() could be slow,
206  * for example for http */
207  if ((uc->flags & AVIO_FLAG_WRITE) || !strcmp(uc->prot->name, "file"))
208  if (!uc->is_streamed && ffurl_seek(uc, 0, SEEK_SET) < 0)
209  uc->is_streamed = 1;
210  return 0;
211 }
212 
213 #define URL_SCHEME_CHARS \
214  "abcdefghijklmnopqrstuvwxyz" \
215  "ABCDEFGHIJKLMNOPQRSTUVWXYZ" \
216  "0123456789+-."
217 
218 static struct URLProtocol *url_find_protocol(const char *filename)
219 {
220  URLProtocol *up = NULL;
221  char proto_str[128], proto_nested[128], *ptr;
222  size_t proto_len = strspn(filename, URL_SCHEME_CHARS);
223 
224  if (filename[proto_len] != ':' &&
225  (filename[proto_len] != ',' || !strchr(filename + proto_len + 1, ':')) ||
226  is_dos_path(filename))
227  strcpy(proto_str, "file");
228  else
229  av_strlcpy(proto_str, filename,
230  FFMIN(proto_len + 1, sizeof(proto_str)));
231 
232  if ((ptr = strchr(proto_str, ',')))
233  *ptr = '\0';
234  av_strlcpy(proto_nested, proto_str, sizeof(proto_nested));
235  if ((ptr = strchr(proto_nested, '+')))
236  *ptr = '\0';
237 
238  while (up = ffurl_protocol_next(up)) {
239  if (!strcmp(proto_str, up->name))
240  break;
242  !strcmp(proto_nested, up->name))
243  break;
244  }
245 
246  return up;
247 }
248 
249 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
250  const AVIOInterruptCB *int_cb)
251 {
252  URLProtocol *p = NULL;
253 
254  if (!first_protocol) {
255  av_log(NULL, AV_LOG_WARNING, "No URL Protocols are registered. "
256  "Missing call to av_register_all()?\n");
257  }
258 
259  p = url_find_protocol(filename);
260  if (p)
261  return url_alloc_for_protocol(puc, p, filename, flags, int_cb);
262 
263  *puc = NULL;
264  if (av_strstart(filename, "https:", NULL))
265  av_log(NULL, AV_LOG_WARNING, "https protocol not found, recompile with openssl or gnutls enabled.\n");
267 }
268 
269 int ffurl_open(URLContext **puc, const char *filename, int flags,
270  const AVIOInterruptCB *int_cb, AVDictionary **options)
271 {
272  int ret = ffurl_alloc(puc, filename, flags, int_cb);
273  if (ret < 0)
274  return ret;
275  if (options && (*puc)->prot->priv_data_class &&
276  (ret = av_opt_set_dict((*puc)->priv_data, options)) < 0)
277  goto fail;
278  if ((ret = av_opt_set_dict(*puc, options)) < 0)
279  goto fail;
280  ret = ffurl_connect(*puc, options);
281  if (!ret)
282  return 0;
283 fail:
284  ffurl_close(*puc);
285  *puc = NULL;
286  return ret;
287 }
288 
290  int size, int size_min,
291  int (*transfer_func)(URLContext *h,
292  uint8_t *buf,
293  int size))
294 {
295  int ret, len;
296  int fast_retries = 5;
297  int64_t wait_since = 0;
298 
299  len = 0;
300  while (len < size_min) {
302  return AVERROR_EXIT;
303  ret = transfer_func(h, buf + len, size - len);
304  if (ret == AVERROR(EINTR))
305  continue;
306  if (h->flags & AVIO_FLAG_NONBLOCK)
307  return ret;
308  if (ret == AVERROR(EAGAIN)) {
309  ret = 0;
310  if (fast_retries) {
311  fast_retries--;
312  } else {
313  if (h->rw_timeout) {
314  if (!wait_since)
315  wait_since = av_gettime_relative();
316  else if (av_gettime_relative() > wait_since + h->rw_timeout)
317  return AVERROR(EIO);
318  }
319  av_usleep(1000);
320  }
321  } else if (ret < 1)
322  return (ret < 0 && ret != AVERROR_EOF) ? ret : len;
323  if (ret)
324  fast_retries = FFMAX(fast_retries, 2);
325  len += ret;
326  }
327  return len;
328 }
329 
330 int ffurl_read(URLContext *h, unsigned char *buf, int size)
331 {
332  if (!(h->flags & AVIO_FLAG_READ))
333  return AVERROR(EIO);
334  return retry_transfer_wrapper(h, buf, size, 1, h->prot->url_read);
335 }
336 
337 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size)
338 {
339  if (!(h->flags & AVIO_FLAG_READ))
340  return AVERROR(EIO);
341  return retry_transfer_wrapper(h, buf, size, size, h->prot->url_read);
342 }
343 
344 int ffurl_write(URLContext *h, const unsigned char *buf, int size)
345 {
346  if (!(h->flags & AVIO_FLAG_WRITE))
347  return AVERROR(EIO);
348  /* avoid sending too big packets */
349  if (h->max_packet_size && size > h->max_packet_size)
350  return AVERROR(EIO);
351 
352  return retry_transfer_wrapper(h, (unsigned char *)buf, size, size, (void*)h->prot->url_write);
353 }
354 
355 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence)
356 {
357  int64_t ret;
358 
359  if (!h->prot->url_seek)
360  return AVERROR(ENOSYS);
361  ret = h->prot->url_seek(h, pos, whence & ~AVSEEK_FORCE);
362  return ret;
363 }
364 
366 {
367  URLContext *h= *hh;
368  int ret = 0;
369  if (!h)
370  return 0; /* can happen when ffurl_open fails */
371 
372  if (h->is_connected && h->prot->url_close)
373  ret = h->prot->url_close(h);
374 #if CONFIG_NETWORK
377 #endif
378  if (h->prot->priv_data_size) {
379  if (h->prot->priv_data_class)
381  av_freep(&h->priv_data);
382  }
383  av_freep(hh);
384  return ret;
385 }
386 
388 {
389  return ffurl_closep(&h);
390 }
391 
392 
393 const char *avio_find_protocol_name(const char *url)
394 {
395  URLProtocol *p = url_find_protocol(url);
396 
397  return p ? p->name : NULL;
398 }
399 
400 int avio_check(const char *url, int flags)
401 {
402  URLContext *h;
403  int ret = ffurl_alloc(&h, url, flags, NULL);
404  if (ret < 0)
405  return ret;
406 
407  if (h->prot->url_check) {
408  ret = h->prot->url_check(h, flags);
409  } else {
410  ret = ffurl_connect(h, NULL);
411  if (ret >= 0)
412  ret = flags;
413  }
414 
415  ffurl_close(h);
416  return ret;
417 }
418 
420 {
421  int64_t pos, size;
422 
423  size = ffurl_seek(h, 0, AVSEEK_SIZE);
424  if (size < 0) {
425  pos = ffurl_seek(h, 0, SEEK_CUR);
426  if ((size = ffurl_seek(h, -1, SEEK_END)) < 0)
427  return size;
428  size++;
429  ffurl_seek(h, pos, SEEK_SET);
430  }
431  return size;
432 }
433 
435 {
436  if (!h->prot->url_get_file_handle)
437  return -1;
438  return h->prot->url_get_file_handle(h);
439 }
440 
441 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles)
442 {
443  if (!h->prot->url_get_multi_file_handle) {
444  if (!h->prot->url_get_file_handle)
445  return AVERROR(ENOSYS);
446  *handles = av_malloc(sizeof(**handles));
447  if (!*handles)
448  return AVERROR(ENOMEM);
449  *numhandles = 1;
450  *handles[0] = h->prot->url_get_file_handle(h);
451  return 0;
452  }
453  return h->prot->url_get_multi_file_handle(h, handles, numhandles);
454 }
455 
457 {
458  if (!h->prot->url_shutdown)
459  return AVERROR(EINVAL);
460  return h->prot->url_shutdown(h, flags);
461 }
462 
464 {
465  int ret;
466  if (cb && cb->callback && (ret = cb->callback(cb->opaque)))
467  return ret;
468  return 0;
469 }