http.c
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1 /*
2  * HTTP protocol for avconv client
3  * Copyright (c) 2000, 2001 Fabrice Bellard
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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 "avformat.h"
24 #include <unistd.h>
25 #include "internal.h"
26 #include "network.h"
27 #include "http.h"
28 #include "os_support.h"
29 #include "httpauth.h"
30 #include "url.h"
31 #include "libavutil/opt.h"
32 
33 /* XXX: POST protocol is not completely implemented because avconv uses
34  only a subset of it. */
35 
36 /* used for protocol handling */
37 #define BUFFER_SIZE 1024
38 #define MAX_REDIRECTS 8
39 
40 typedef struct {
41  const AVClass *class;
43  unsigned char buffer[BUFFER_SIZE], *buf_ptr, *buf_end;
45  int http_code;
46  int64_t chunksize;
47  int64_t off, filesize;
48  char location[MAX_URL_SIZE];
51  char *headers;
52  int willclose;
54 } HTTPContext;
55 
56 #define OFFSET(x) offsetof(HTTPContext, x)
57 #define D AV_OPT_FLAG_DECODING_PARAM
58 #define E AV_OPT_FLAG_ENCODING_PARAM
59 static const AVOption options[] = {
60 {"chunked_post", "use chunked transfer-encoding for posts", OFFSET(chunked_post), AV_OPT_TYPE_INT, {.dbl = 1}, 0, 1, E },
61 {"headers", "custom HTTP headers, can override built in default headers", OFFSET(headers), AV_OPT_TYPE_STRING, { 0 }, 0, 0, D|E },
62 {NULL}
63 };
64 #define HTTP_CLASS(flavor)\
65 static const AVClass flavor ## _context_class = {\
66  .class_name = #flavor,\
67  .item_name = av_default_item_name,\
68  .option = options,\
69  .version = LIBAVUTIL_VERSION_INT,\
70 }
71 
72 HTTP_CLASS(http);
73 HTTP_CLASS(https);
74 
75 static int http_connect(URLContext *h, const char *path, const char *local_path,
76  const char *hoststr, const char *auth,
77  const char *proxyauth, int *new_location);
78 
80 {
81  memcpy(&((HTTPContext*)dest->priv_data)->auth_state,
82  &((HTTPContext*)src->priv_data)->auth_state, sizeof(HTTPAuthState));
83  memcpy(&((HTTPContext*)dest->priv_data)->proxy_auth_state,
84  &((HTTPContext*)src->priv_data)->proxy_auth_state,
85  sizeof(HTTPAuthState));
86 }
87 
88 /* return non zero if error */
89 static int http_open_cnx(URLContext *h)
90 {
91  const char *path, *proxy_path, *lower_proto = "tcp", *local_path;
92  char hostname[1024], hoststr[1024], proto[10];
93  char auth[1024], proxyauth[1024] = "";
94  char path1[1024];
95  char buf[1024], urlbuf[1024];
96  int port, use_proxy, err, location_changed = 0, redirects = 0;
97  HTTPAuthType cur_auth_type, cur_proxy_auth_type;
98  HTTPContext *s = h->priv_data;
99  URLContext *hd = NULL;
100 
101  proxy_path = getenv("http_proxy");
102  use_proxy = (proxy_path != NULL) && !getenv("no_proxy") &&
103  av_strstart(proxy_path, "http://", NULL);
104 
105  /* fill the dest addr */
106  redo:
107  /* needed in any case to build the host string */
108  av_url_split(proto, sizeof(proto), auth, sizeof(auth),
109  hostname, sizeof(hostname), &port,
110  path1, sizeof(path1), s->location);
111  ff_url_join(hoststr, sizeof(hoststr), NULL, NULL, hostname, port, NULL);
112 
113  if (!strcmp(proto, "https")) {
114  lower_proto = "tls";
115  use_proxy = 0;
116  if (port < 0)
117  port = 443;
118  }
119  if (port < 0)
120  port = 80;
121 
122  if (path1[0] == '\0')
123  path = "/";
124  else
125  path = path1;
126  local_path = path;
127  if (use_proxy) {
128  /* Reassemble the request URL without auth string - we don't
129  * want to leak the auth to the proxy. */
130  ff_url_join(urlbuf, sizeof(urlbuf), proto, NULL, hostname, port, "%s",
131  path1);
132  path = urlbuf;
133  av_url_split(NULL, 0, proxyauth, sizeof(proxyauth),
134  hostname, sizeof(hostname), &port, NULL, 0, proxy_path);
135  }
136 
137  ff_url_join(buf, sizeof(buf), lower_proto, NULL, hostname, port, NULL);
138  err = ffurl_open(&hd, buf, AVIO_FLAG_READ_WRITE,
139  &h->interrupt_callback, NULL);
140  if (err < 0)
141  goto fail;
142 
143  s->hd = hd;
144  cur_auth_type = s->auth_state.auth_type;
145  cur_proxy_auth_type = s->auth_state.auth_type;
146  if (http_connect(h, path, local_path, hoststr, auth, proxyauth, &location_changed) < 0)
147  goto fail;
148  if (s->http_code == 401) {
149  if (cur_auth_type == HTTP_AUTH_NONE && s->auth_state.auth_type != HTTP_AUTH_NONE) {
150  ffurl_close(hd);
151  goto redo;
152  } else
153  goto fail;
154  }
155  if (s->http_code == 407) {
156  if (cur_proxy_auth_type == HTTP_AUTH_NONE &&
158  ffurl_close(hd);
159  goto redo;
160  } else
161  goto fail;
162  }
163  if ((s->http_code == 301 || s->http_code == 302 || s->http_code == 303 || s->http_code == 307)
164  && location_changed == 1) {
165  /* url moved, get next */
166  ffurl_close(hd);
167  if (redirects++ >= MAX_REDIRECTS)
168  return AVERROR(EIO);
169  location_changed = 0;
170  goto redo;
171  }
172  return 0;
173  fail:
174  if (hd)
175  ffurl_close(hd);
176  s->hd = NULL;
177  return AVERROR(EIO);
178 }
179 
180 static int http_open(URLContext *h, const char *uri, int flags)
181 {
182  HTTPContext *s = h->priv_data;
183 
184  h->is_streamed = 1;
185 
186  s->filesize = -1;
187  av_strlcpy(s->location, uri, sizeof(s->location));
188 
189  if (s->headers) {
190  int len = strlen(s->headers);
191  if (len < 2 || strcmp("\r\n", s->headers + len - 2))
192  av_log(h, AV_LOG_WARNING, "No trailing CRLF found in HTTP header.\n");
193  }
194 
195  return http_open_cnx(h);
196 }
197 static int http_getc(HTTPContext *s)
198 {
199  int len;
200  if (s->buf_ptr >= s->buf_end) {
201  len = ffurl_read(s->hd, s->buffer, BUFFER_SIZE);
202  if (len < 0) {
203  return AVERROR(EIO);
204  } else if (len == 0) {
205  return -1;
206  } else {
207  s->buf_ptr = s->buffer;
208  s->buf_end = s->buffer + len;
209  }
210  }
211  return *s->buf_ptr++;
212 }
213 
214 static int http_get_line(HTTPContext *s, char *line, int line_size)
215 {
216  int ch;
217  char *q;
218 
219  q = line;
220  for(;;) {
221  ch = http_getc(s);
222  if (ch < 0)
223  return AVERROR(EIO);
224  if (ch == '\n') {
225  /* process line */
226  if (q > line && q[-1] == '\r')
227  q--;
228  *q = '\0';
229 
230  return 0;
231  } else {
232  if ((q - line) < line_size - 1)
233  *q++ = ch;
234  }
235  }
236 }
237 
238 static int process_line(URLContext *h, char *line, int line_count,
239  int *new_location)
240 {
241  HTTPContext *s = h->priv_data;
242  char *tag, *p, *end;
243 
244  /* end of header */
245  if (line[0] == '\0')
246  return 0;
247 
248  p = line;
249  if (line_count == 0) {
250  while (!isspace(*p) && *p != '\0')
251  p++;
252  while (isspace(*p))
253  p++;
254  s->http_code = strtol(p, &end, 10);
255 
256  av_dlog(NULL, "http_code=%d\n", s->http_code);
257 
258  /* error codes are 4xx and 5xx, but regard 401 as a success, so we
259  * don't abort until all headers have been parsed. */
260  if (s->http_code >= 400 && s->http_code < 600 && (s->http_code != 401
261  || s->auth_state.auth_type != HTTP_AUTH_NONE) &&
262  (s->http_code != 407 || s->proxy_auth_state.auth_type != HTTP_AUTH_NONE)) {
263  end += strspn(end, SPACE_CHARS);
264  av_log(h, AV_LOG_WARNING, "HTTP error %d %s\n",
265  s->http_code, end);
266  return -1;
267  }
268  } else {
269  while (*p != '\0' && *p != ':')
270  p++;
271  if (*p != ':')
272  return 1;
273 
274  *p = '\0';
275  tag = line;
276  p++;
277  while (isspace(*p))
278  p++;
279  if (!av_strcasecmp(tag, "Location")) {
280  strcpy(s->location, p);
281  *new_location = 1;
282  } else if (!av_strcasecmp (tag, "Content-Length") && s->filesize == -1) {
283  s->filesize = atoll(p);
284  } else if (!av_strcasecmp (tag, "Content-Range")) {
285  /* "bytes $from-$to/$document_size" */
286  const char *slash;
287  if (!strncmp (p, "bytes ", 6)) {
288  p += 6;
289  s->off = atoll(p);
290  if ((slash = strchr(p, '/')) && strlen(slash) > 0)
291  s->filesize = atoll(slash+1);
292  }
293  h->is_streamed = 0; /* we _can_ in fact seek */
294  } else if (!av_strcasecmp(tag, "Accept-Ranges") && !strncmp(p, "bytes", 5)) {
295  h->is_streamed = 0;
296  } else if (!av_strcasecmp (tag, "Transfer-Encoding") && !av_strncasecmp(p, "chunked", 7)) {
297  s->filesize = -1;
298  s->chunksize = 0;
299  } else if (!av_strcasecmp (tag, "WWW-Authenticate")) {
301  } else if (!av_strcasecmp (tag, "Authentication-Info")) {
303  } else if (!av_strcasecmp (tag, "Proxy-Authenticate")) {
305  } else if (!av_strcasecmp (tag, "Connection")) {
306  if (!strcmp(p, "close"))
307  s->willclose = 1;
308  }
309  }
310  return 1;
311 }
312 
313 static inline int has_header(const char *str, const char *header)
314 {
315  /* header + 2 to skip over CRLF prefix. (make sure you have one!) */
316  if (!str)
317  return 0;
318  return av_stristart(str, header + 2, NULL) || av_stristr(str, header);
319 }
320 
321 static int http_connect(URLContext *h, const char *path, const char *local_path,
322  const char *hoststr, const char *auth,
323  const char *proxyauth, int *new_location)
324 {
325  HTTPContext *s = h->priv_data;
326  int post, err;
327  char line[1024];
328  char headers[1024] = "";
329  char *authstr = NULL, *proxyauthstr = NULL;
330  int64_t off = s->off;
331  int len = 0;
332  const char *method;
333 
334 
335  /* send http header */
336  post = h->flags & AVIO_FLAG_WRITE;
337  method = post ? "POST" : "GET";
338  authstr = ff_http_auth_create_response(&s->auth_state, auth, local_path,
339  method);
340  proxyauthstr = ff_http_auth_create_response(&s->proxy_auth_state, proxyauth,
341  local_path, method);
342 
343  /* set default headers if needed */
344  if (!has_header(s->headers, "\r\nUser-Agent: "))
345  len += av_strlcatf(headers + len, sizeof(headers) - len,
346  "User-Agent: %s\r\n", LIBAVFORMAT_IDENT);
347  if (!has_header(s->headers, "\r\nAccept: "))
348  len += av_strlcpy(headers + len, "Accept: */*\r\n",
349  sizeof(headers) - len);
350  if (!has_header(s->headers, "\r\nRange: ") && !post)
351  len += av_strlcatf(headers + len, sizeof(headers) - len,
352  "Range: bytes=%"PRId64"-\r\n", s->off);
353  if (!has_header(s->headers, "\r\nConnection: "))
354  len += av_strlcpy(headers + len, "Connection: close\r\n",
355  sizeof(headers)-len);
356  if (!has_header(s->headers, "\r\nHost: "))
357  len += av_strlcatf(headers + len, sizeof(headers) - len,
358  "Host: %s\r\n", hoststr);
359 
360  /* now add in custom headers */
361  if (s->headers)
362  av_strlcpy(headers + len, s->headers, sizeof(headers) - len);
363 
364  snprintf(s->buffer, sizeof(s->buffer),
365  "%s %s HTTP/1.1\r\n"
366  "%s"
367  "%s"
368  "%s"
369  "%s%s"
370  "\r\n",
371  method,
372  path,
373  post && s->chunked_post ? "Transfer-Encoding: chunked\r\n" : "",
374  headers,
375  authstr ? authstr : "",
376  proxyauthstr ? "Proxy-" : "", proxyauthstr ? proxyauthstr : "");
377 
378  av_freep(&authstr);
379  av_freep(&proxyauthstr);
380  if (ffurl_write(s->hd, s->buffer, strlen(s->buffer)) < 0)
381  return AVERROR(EIO);
382 
383  /* init input buffer */
384  s->buf_ptr = s->buffer;
385  s->buf_end = s->buffer;
386  s->line_count = 0;
387  s->off = 0;
388  s->filesize = -1;
389  s->willclose = 0;
390  if (post) {
391  /* Pretend that it did work. We didn't read any header yet, since
392  * we've still to send the POST data, but the code calling this
393  * function will check http_code after we return. */
394  s->http_code = 200;
395  return 0;
396  }
397  s->chunksize = -1;
398 
399  /* wait for header */
400  for(;;) {
401  if (http_get_line(s, line, sizeof(line)) < 0)
402  return AVERROR(EIO);
403 
404  av_dlog(NULL, "header='%s'\n", line);
405 
406  err = process_line(h, line, s->line_count, new_location);
407  if (err < 0)
408  return err;
409  if (err == 0)
410  break;
411  s->line_count++;
412  }
413 
414  return (off == s->off) ? 0 : -1;
415 }
416 
417 
418 static int http_buf_read(URLContext *h, uint8_t *buf, int size)
419 {
420  HTTPContext *s = h->priv_data;
421  int len;
422  /* read bytes from input buffer first */
423  len = s->buf_end - s->buf_ptr;
424  if (len > 0) {
425  if (len > size)
426  len = size;
427  memcpy(buf, s->buf_ptr, len);
428  s->buf_ptr += len;
429  } else {
430  if (!s->willclose && s->filesize >= 0 && s->off >= s->filesize)
431  return AVERROR_EOF;
432  len = ffurl_read(s->hd, buf, size);
433  }
434  if (len > 0) {
435  s->off += len;
436  if (s->chunksize > 0)
437  s->chunksize -= len;
438  }
439  return len;
440 }
441 
442 static int http_read(URLContext *h, uint8_t *buf, int size)
443 {
444  HTTPContext *s = h->priv_data;
445 
446  if (s->chunksize >= 0) {
447  if (!s->chunksize) {
448  char line[32];
449 
450  for(;;) {
451  do {
452  if (http_get_line(s, line, sizeof(line)) < 0)
453  return AVERROR(EIO);
454  } while (!*line); /* skip CR LF from last chunk */
455 
456  s->chunksize = strtoll(line, NULL, 16);
457 
458  av_dlog(NULL, "Chunked encoding data size: %"PRId64"'\n", s->chunksize);
459 
460  if (!s->chunksize)
461  return 0;
462  break;
463  }
464  }
465  size = FFMIN(size, s->chunksize);
466  }
467  return http_buf_read(h, buf, size);
468 }
469 
470 /* used only when posting data */
471 static int http_write(URLContext *h, const uint8_t *buf, int size)
472 {
473  char temp[11] = ""; /* 32-bit hex + CRLF + nul */
474  int ret;
475  char crlf[] = "\r\n";
476  HTTPContext *s = h->priv_data;
477 
478  if (!s->chunked_post) {
479  /* non-chunked data is sent without any special encoding */
480  return ffurl_write(s->hd, buf, size);
481  }
482 
483  /* silently ignore zero-size data since chunk encoding that would
484  * signal EOF */
485  if (size > 0) {
486  /* upload data using chunked encoding */
487  snprintf(temp, sizeof(temp), "%x\r\n", size);
488 
489  if ((ret = ffurl_write(s->hd, temp, strlen(temp))) < 0 ||
490  (ret = ffurl_write(s->hd, buf, size)) < 0 ||
491  (ret = ffurl_write(s->hd, crlf, sizeof(crlf) - 1)) < 0)
492  return ret;
493  }
494  return size;
495 }
496 
497 static int http_close(URLContext *h)
498 {
499  int ret = 0;
500  char footer[] = "0\r\n\r\n";
501  HTTPContext *s = h->priv_data;
502 
503  /* signal end of chunked encoding if used */
504  if ((h->flags & AVIO_FLAG_WRITE) && s->chunked_post) {
505  ret = ffurl_write(s->hd, footer, sizeof(footer) - 1);
506  ret = ret > 0 ? 0 : ret;
507  }
508 
509  if (s->hd)
510  ffurl_close(s->hd);
511  return ret;
512 }
513 
514 static int64_t http_seek(URLContext *h, int64_t off, int whence)
515 {
516  HTTPContext *s = h->priv_data;
517  URLContext *old_hd = s->hd;
518  int64_t old_off = s->off;
519  uint8_t old_buf[BUFFER_SIZE];
520  int old_buf_size;
521 
522  if (whence == AVSEEK_SIZE)
523  return s->filesize;
524  else if ((s->filesize == -1 && whence == SEEK_END) || h->is_streamed)
525  return -1;
526 
527  /* we save the old context in case the seek fails */
528  old_buf_size = s->buf_end - s->buf_ptr;
529  memcpy(old_buf, s->buf_ptr, old_buf_size);
530  s->hd = NULL;
531  if (whence == SEEK_CUR)
532  off += s->off;
533  else if (whence == SEEK_END)
534  off += s->filesize;
535  s->off = off;
536 
537  /* if it fails, continue on old connection */
538  if (http_open_cnx(h) < 0) {
539  memcpy(s->buffer, old_buf, old_buf_size);
540  s->buf_ptr = s->buffer;
541  s->buf_end = s->buffer + old_buf_size;
542  s->hd = old_hd;
543  s->off = old_off;
544  return -1;
545  }
546  ffurl_close(old_hd);
547  return off;
548 }
549 
550 static int
552 {
553  HTTPContext *s = h->priv_data;
554  return ffurl_get_file_handle(s->hd);
555 }
556 
557 #if CONFIG_HTTP_PROTOCOL
558 URLProtocol ff_http_protocol = {
559  .name = "http",
560  .url_open = http_open,
561  .url_read = http_read,
562  .url_write = http_write,
563  .url_seek = http_seek,
564  .url_close = http_close,
565  .url_get_file_handle = http_get_file_handle,
566  .priv_data_size = sizeof(HTTPContext),
567  .priv_data_class = &http_context_class,
569 };
570 #endif
571 #if CONFIG_HTTPS_PROTOCOL
572 URLProtocol ff_https_protocol = {
573  .name = "https",
574  .url_open = http_open,
575  .url_read = http_read,
576  .url_write = http_write,
577  .url_seek = http_seek,
578  .url_close = http_close,
579  .url_get_file_handle = http_get_file_handle,
580  .priv_data_size = sizeof(HTTPContext),
581  .priv_data_class = &https_context_class,
583 };
584 #endif
585 
586 #if CONFIG_HTTPPROXY_PROTOCOL
587 static int http_proxy_close(URLContext *h)
588 {
589  HTTPContext *s = h->priv_data;
590  if (s->hd)
591  ffurl_close(s->hd);
592  return 0;
593 }
594 
595 static int http_proxy_open(URLContext *h, const char *uri, int flags)
596 {
597  HTTPContext *s = h->priv_data;
598  char hostname[1024], hoststr[1024];
599  char auth[1024], pathbuf[1024], *path;
600  char line[1024], lower_url[100];
601  int port, ret = 0;
602  HTTPAuthType cur_auth_type;
603  char *authstr;
604 
605  h->is_streamed = 1;
606 
607  av_url_split(NULL, 0, auth, sizeof(auth), hostname, sizeof(hostname), &port,
608  pathbuf, sizeof(pathbuf), uri);
609  ff_url_join(hoststr, sizeof(hoststr), NULL, NULL, hostname, port, NULL);
610  path = pathbuf;
611  if (*path == '/')
612  path++;
613 
614  ff_url_join(lower_url, sizeof(lower_url), "tcp", NULL, hostname, port,
615  NULL);
616 redo:
617  ret = ffurl_open(&s->hd, lower_url, AVIO_FLAG_READ_WRITE,
618  &h->interrupt_callback, NULL);
619  if (ret < 0)
620  return ret;
621 
623  path, "CONNECT");
624  snprintf(s->buffer, sizeof(s->buffer),
625  "CONNECT %s HTTP/1.1\r\n"
626  "Host: %s\r\n"
627  "Connection: close\r\n"
628  "%s%s"
629  "\r\n",
630  path,
631  hoststr,
632  authstr ? "Proxy-" : "", authstr ? authstr : "");
633  av_freep(&authstr);
634 
635  if ((ret = ffurl_write(s->hd, s->buffer, strlen(s->buffer))) < 0)
636  goto fail;
637 
638  s->buf_ptr = s->buffer;
639  s->buf_end = s->buffer;
640  s->line_count = 0;
641  s->filesize = -1;
642  cur_auth_type = s->proxy_auth_state.auth_type;
643 
644  for (;;) {
645  int new_loc;
646  // Note: This uses buffering, potentially reading more than the
647  // HTTP header. If tunneling a protocol where the server starts
648  // the conversation, we might buffer part of that here, too.
649  // Reading that requires using the proper ffurl_read() function
650  // on this URLContext, not using the fd directly (as the tls
651  // protocol does). This shouldn't be an issue for tls though,
652  // since the client starts the conversation there, so there
653  // is no extra data that we might buffer up here.
654  if (http_get_line(s, line, sizeof(line)) < 0) {
655  ret = AVERROR(EIO);
656  goto fail;
657  }
658 
659  av_dlog(h, "header='%s'\n", line);
660 
661  ret = process_line(h, line, s->line_count, &new_loc);
662  if (ret < 0)
663  goto fail;
664  if (ret == 0)
665  break;
666  s->line_count++;
667  }
668  if (s->http_code == 407 && cur_auth_type == HTTP_AUTH_NONE &&
670  ffurl_close(s->hd);
671  s->hd = NULL;
672  goto redo;
673  }
674 
675  if (s->http_code < 400)
676  return 0;
677  ret = AVERROR(EIO);
678 
679 fail:
680  http_proxy_close(h);
681  return ret;
682 }
683 
684 static int http_proxy_write(URLContext *h, const uint8_t *buf, int size)
685 {
686  HTTPContext *s = h->priv_data;
687  return ffurl_write(s->hd, buf, size);
688 }
689 
690 URLProtocol ff_httpproxy_protocol = {
691  .name = "httpproxy",
692  .url_open = http_proxy_open,
693  .url_read = http_buf_read,
694  .url_write = http_proxy_write,
695  .url_close = http_proxy_close,
696  .url_get_file_handle = http_get_file_handle,
697  .priv_data_size = sizeof(HTTPContext),
698  .flags = URL_PROTOCOL_FLAG_NETWORK,
699 };
700 #endif