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avio.c
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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 
33 static URLProtocol *first_protocol = NULL;
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) return h->prot->name;
46  else return "NULL";
47 }
48 
49 static void *urlcontext_child_next(void *obj, void *prev)
50 {
51  URLContext *h = obj;
52  if (!prev && h->priv_data && h->prot->priv_data_class)
53  return h->priv_data;
54  return NULL;
55 }
56 
57 static const AVClass *urlcontext_child_class_next(const AVClass *prev)
58 {
59  URLProtocol *p = NULL;
60 
61  /* find the protocol that corresponds to prev */
62  while (prev && (p = ffurl_protocol_next(p)))
63  if (p->priv_data_class == prev)
64  break;
65 
66  /* find next protocol with priv options */
67  while (p = ffurl_protocol_next(p))
68  if (p->priv_data_class)
69  return p->priv_data_class;
70  return NULL;
71 
72 }
73 
74 static const AVOption options[] = {{NULL}};
76  .class_name = "URLContext",
77  .item_name = urlcontext_to_name,
78  .option = options,
79  .version = LIBAVUTIL_VERSION_INT,
80  .child_next = urlcontext_child_next,
81  .child_class_next = urlcontext_child_class_next,
82 };
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)) return NULL;
91  if ((output && p->url_write) || (!output && p->url_read))
92  return p->name;
93  return avio_enum_protocols(opaque, output);
94 }
95 
97 {
98  URLProtocol **p;
99  if (size < sizeof(URLProtocol)) {
101  memcpy(temp, protocol, size);
102  protocol = temp;
103  }
104  p = &first_protocol;
105  while (*p != NULL) p = &(*p)->next;
106  *p = protocol;
107  protocol->next = NULL;
108  return 0;
109 }
110 
111 static int url_alloc_for_protocol (URLContext **puc, struct URLProtocol *up,
112  const char *filename, int flags,
113  const AVIOInterruptCB *int_cb)
114 {
115  URLContext *uc;
116  int err;
117 
118 #if CONFIG_NETWORK
120  return AVERROR(EIO);
121 #endif
122  if ((flags & AVIO_FLAG_READ) && !up->url_read) {
123  av_log(NULL, AV_LOG_ERROR,
124  "Impossible to open the '%s' protocol for reading\n", up->name);
125  return AVERROR(EIO);
126  }
127  if ((flags & AVIO_FLAG_WRITE) && !up->url_write) {
128  av_log(NULL, AV_LOG_ERROR,
129  "Impossible to open the '%s' protocol for writing\n", up->name);
130  return AVERROR(EIO);
131  }
132  uc = av_mallocz(sizeof(URLContext) + strlen(filename) + 1);
133  if (!uc) {
134  err = AVERROR(ENOMEM);
135  goto fail;
136  }
138  uc->filename = (char *) &uc[1];
139  strcpy(uc->filename, filename);
140  uc->prot = up;
141  uc->flags = flags;
142  uc->is_streamed = 0; /* default = not streamed */
143  uc->max_packet_size = 0; /* default: stream file */
144  if (up->priv_data_size) {
146  if (!uc->priv_data) {
147  err = AVERROR(ENOMEM);
148  goto fail;
149  }
150  if (up->priv_data_class) {
151  int proto_len= strlen(up->name);
152  char *start = strchr(uc->filename, ',');
153  *(const AVClass**)uc->priv_data = up->priv_data_class;
155  if(!strncmp(up->name, uc->filename, proto_len) && uc->filename + proto_len == start){
156  int ret= 0;
157  char *p= start;
158  char sep= *++p;
159  char *key, *val;
160  p++;
161  while(ret >= 0 && (key= strchr(p, sep)) && p<key && (val = strchr(key+1, sep))){
162  *val= *key= 0;
163  ret= av_opt_set(uc->priv_data, p, key+1, 0);
164  if (ret == AVERROR_OPTION_NOT_FOUND)
165  av_log(uc, AV_LOG_ERROR, "Key '%s' not found.\n", p);
166  *val= *key= sep;
167  p= val+1;
168  }
169  if(ret<0 || p!=key){
170  av_log(uc, AV_LOG_ERROR, "Error parsing options string %s\n", start);
171  av_freep(&uc->priv_data);
172  av_freep(&uc);
173  err = AVERROR(EINVAL);
174  goto fail;
175  }
176  memmove(start, key+1, strlen(key));
177  }
178  }
179  }
180  if (int_cb)
181  uc->interrupt_callback = *int_cb;
182 
183  *puc = uc;
184  return 0;
185  fail:
186  *puc = NULL;
187  if (uc)
188  av_freep(&uc->priv_data);
189  av_freep(&uc);
190 #if CONFIG_NETWORK
193 #endif
194  return err;
195 }
196 
198 {
199  int err =
200  uc->prot->url_open2 ? uc->prot->url_open2(uc, uc->filename, uc->flags, 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, for example for http
206  if( (uc->flags & AVIO_FLAG_WRITE)
207  || !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 int ffurl_alloc(URLContext **puc, const char *filename, int flags,
219  const AVIOInterruptCB *int_cb)
220 {
221  URLProtocol *up = NULL;
222  char proto_str[128], proto_nested[128], *ptr;
223  size_t proto_len = strspn(filename, URL_SCHEME_CHARS);
224 
225  if (!first_protocol) {
226  av_log(NULL, AV_LOG_WARNING, "No URL Protocols are registered. "
227  "Missing call to av_register_all()?\n");
228  }
229 
230  if (filename[proto_len] != ':' &&
231  (filename[proto_len] != ',' || !strchr(filename + proto_len + 1, ':')) ||
232  is_dos_path(filename))
233  strcpy(proto_str, "file");
234  else
235  av_strlcpy(proto_str, filename, FFMIN(proto_len+1, sizeof(proto_str)));
236 
237  if ((ptr = strchr(proto_str, ',')))
238  *ptr = '\0';
239  av_strlcpy(proto_nested, proto_str, sizeof(proto_nested));
240  if ((ptr = strchr(proto_nested, '+')))
241  *ptr = '\0';
242 
243  while (up = ffurl_protocol_next(up)) {
244  if (!strcmp(proto_str, up->name))
245  return url_alloc_for_protocol (puc, up, filename, flags, int_cb);
247  !strcmp(proto_nested, up->name))
248  return url_alloc_for_protocol (puc, up, filename, flags, int_cb);
249  }
250  *puc = NULL;
251  if (!strcmp("https", proto_str))
252  av_log(NULL, AV_LOG_WARNING, "https protocol not found, recompile with openssl or gnutls enabled.\n");
254 }
255 
256 int ffurl_open(URLContext **puc, const char *filename, int flags,
257  const AVIOInterruptCB *int_cb, AVDictionary **options)
258 {
259  int ret = ffurl_alloc(puc, filename, flags, int_cb);
260  if (ret)
261  return ret;
262  if (options && (*puc)->prot->priv_data_class &&
263  (ret = av_opt_set_dict((*puc)->priv_data, options)) < 0)
264  goto fail;
265  ret = ffurl_connect(*puc, options);
266  if (!ret)
267  return 0;
268 fail:
269  ffurl_close(*puc);
270  *puc = NULL;
271  return ret;
272 }
273 
274 static inline int retry_transfer_wrapper(URLContext *h, unsigned char *buf, int size, int size_min,
275  int (*transfer_func)(URLContext *h, unsigned char *buf, int size))
276 {
277  int ret, len;
278  int fast_retries = 5;
279  int64_t wait_since = 0;
280 
281  len = 0;
282  while (len < size_min) {
284  return AVERROR_EXIT;
285  ret = transfer_func(h, buf+len, size-len);
286  if (ret == AVERROR(EINTR))
287  continue;
288  if (h->flags & AVIO_FLAG_NONBLOCK)
289  return ret;
290  if (ret == AVERROR(EAGAIN)) {
291  ret = 0;
292  if (fast_retries) {
293  fast_retries--;
294  } else {
295  if (h->rw_timeout) {
296  if (!wait_since)
297  wait_since = av_gettime();
298  else if (av_gettime() > wait_since + h->rw_timeout)
299  return AVERROR(EIO);
300  }
301  av_usleep(1000);
302  }
303  } else if (ret < 1)
304  return (ret < 0 && ret != AVERROR_EOF) ? ret : len;
305  if (ret)
306  fast_retries = FFMAX(fast_retries, 2);
307  len += ret;
308  }
309  return len;
310 }
311 
312 int ffurl_read(URLContext *h, unsigned char *buf, int size)
313 {
314  if (!(h->flags & AVIO_FLAG_READ))
315  return AVERROR(EIO);
316  return retry_transfer_wrapper(h, buf, size, 1, h->prot->url_read);
317 }
318 
319 int ffurl_read_complete(URLContext *h, unsigned char *buf, int size)
320 {
321  if (!(h->flags & AVIO_FLAG_READ))
322  return AVERROR(EIO);
323  return retry_transfer_wrapper(h, buf, size, size, h->prot->url_read);
324 }
325 
326 int ffurl_write(URLContext *h, const unsigned char *buf, int size)
327 {
328  if (!(h->flags & AVIO_FLAG_WRITE))
329  return AVERROR(EIO);
330  /* avoid sending too big packets */
331  if (h->max_packet_size && size > h->max_packet_size)
332  return AVERROR(EIO);
333 
334  return retry_transfer_wrapper(h, (unsigned char *)buf, size, size, (void*)h->prot->url_write);
335 }
336 
337 int64_t ffurl_seek(URLContext *h, int64_t pos, int whence)
338 {
339  int64_t ret;
340 
341  if (!h->prot->url_seek)
342  return AVERROR(ENOSYS);
343  ret = h->prot->url_seek(h, pos, whence & ~AVSEEK_FORCE);
344  return ret;
345 }
346 
348 {
349  URLContext *h= *hh;
350  int ret = 0;
351  if (!h) return 0; /* can happen when ffurl_open fails */
352 
353  if (h->is_connected && h->prot->url_close)
354  ret = h->prot->url_close(h);
355 #if CONFIG_NETWORK
358 #endif
359  if (h->prot->priv_data_size) {
360  if (h->prot->priv_data_class)
362  av_freep(&h->priv_data);
363  }
364  av_freep(hh);
365  return ret;
366 }
367 
369 {
370  return ffurl_closep(&h);
371 }
372 
373 
374 int avio_check(const char *url, int flags)
375 {
376  URLContext *h;
377  int ret = ffurl_alloc(&h, url, flags, NULL);
378  if (ret)
379  return ret;
380 
381  if (h->prot->url_check) {
382  ret = h->prot->url_check(h, flags);
383  } else {
384  ret = ffurl_connect(h, NULL);
385  if (ret >= 0)
386  ret = flags;
387  }
388 
389  ffurl_close(h);
390  return ret;
391 }
392 
394 {
395  int64_t pos, size;
396 
397  size= ffurl_seek(h, 0, AVSEEK_SIZE);
398  if(size<0){
399  pos = ffurl_seek(h, 0, SEEK_CUR);
400  if ((size = ffurl_seek(h, -1, SEEK_END)) < 0)
401  return size;
402  size++;
403  ffurl_seek(h, pos, SEEK_SET);
404  }
405  return size;
406 }
407 
409 {
410  if (!h->prot->url_get_file_handle)
411  return -1;
412  return h->prot->url_get_file_handle(h);
413 }
414 
415 int ffurl_get_multi_file_handle(URLContext *h, int **handles, int *numhandles)
416 {
417  if (!h->prot->url_get_multi_file_handle) {
418  if (!h->prot->url_get_file_handle)
419  return AVERROR(ENOSYS);
420  *handles = av_malloc(sizeof(**handles));
421  if (!*handles)
422  return AVERROR(ENOMEM);
423  *numhandles = 1;
424  *handles[0] = h->prot->url_get_file_handle(h);
425  return 0;
426  }
427  return h->prot->url_get_multi_file_handle(h, handles, numhandles);
428 }
429 
431 {
432  if (!h->prot->url_shutdown)
433  return AVERROR(EINVAL);
434  return h->prot->url_shutdown(h, flags);
435 }
436 
438 {
439  int ret;
440  if (cb && cb->callback && (ret = cb->callback(cb->opaque)))
441  return ret;
442  return 0;
443 }