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rtmphttp.c
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1 /*
2  * RTMP HTTP network protocol
3  * Copyright (c) 2012 Samuel Pitoiset
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 /**
23  * @file
24  * RTMP HTTP protocol
25  */
26 
27 #include "libavutil/avstring.h"
28 #include "libavutil/intfloat.h"
29 #include "libavutil/opt.h"
30 #include "libavutil/time.h"
31 #include "internal.h"
32 #include "http.h"
33 #include "rtmp.h"
34 
35 #define RTMPT_DEFAULT_PORT 80
36 #define RTMPTS_DEFAULT_PORT RTMPS_DEFAULT_PORT
37 
38 /* protocol handler context */
39 typedef struct RTMP_HTTPContext {
40  const AVClass *class;
41  URLContext *stream; ///< HTTP stream
42  char host[256]; ///< hostname of the server
43  int port; ///< port to connect (default is 80)
44  char client_id[64]; ///< client ID used for all requests except the first one
45  int seq; ///< sequence ID used for all requests
46  uint8_t *out_data; ///< output buffer
47  int out_size; ///< current output buffer size
48  int out_capacity; ///< current output buffer capacity
49  int initialized; ///< flag indicating when the http context is initialized
50  int finishing; ///< flag indicating when the client closes the connection
51  int nb_bytes_read; ///< number of bytes read since the last request
52  int tls; ///< use Transport Security Layer (RTMPTS)
54 
55 static int rtmp_http_send_cmd(URLContext *h, const char *cmd)
56 {
57  RTMP_HTTPContext *rt = h->priv_data;
58  char uri[2048];
59  uint8_t c;
60  int ret;
61 
62  ff_url_join(uri, sizeof(uri), "http", NULL, rt->host, rt->port,
63  "/%s/%s/%d", cmd, rt->client_id, rt->seq++);
64 
65  av_opt_set_bin(rt->stream->priv_data, "post_data", rt->out_data,
66  rt->out_size, 0);
67 
68  /* send a new request to the server */
69  if ((ret = ff_http_do_new_request(rt->stream, uri)) < 0)
70  return ret;
71 
72  /* re-init output buffer */
73  rt->out_size = 0;
74 
75  /* read the first byte which contains the polling interval */
76  if ((ret = ffurl_read(rt->stream, &c, 1)) < 0)
77  return ret;
78 
79  /* re-init the number of bytes read */
80  rt->nb_bytes_read = 0;
81 
82  return ret;
83 }
84 
85 static int rtmp_http_write(URLContext *h, const uint8_t *buf, int size)
86 {
87  RTMP_HTTPContext *rt = h->priv_data;
88  void *ptr;
89 
90  if (rt->out_size + size > rt->out_capacity) {
91  rt->out_capacity = (rt->out_size + size) * 2;
92  ptr = av_realloc(rt->out_data, rt->out_capacity);
93  if (!ptr)
94  return AVERROR(ENOMEM);
95  rt->out_data = ptr;
96  }
97 
98  memcpy(rt->out_data + rt->out_size, buf, size);
99  rt->out_size += size;
100 
101  return size;
102 }
103 
104 static int rtmp_http_read(URLContext *h, uint8_t *buf, int size)
105 {
106  RTMP_HTTPContext *rt = h->priv_data;
107  int ret, off = 0;
108 
109  /* try to read at least 1 byte of data */
110  do {
111  ret = ffurl_read(rt->stream, buf + off, size);
112  if (ret < 0 && ret != AVERROR_EOF)
113  return ret;
114 
115  if (ret == AVERROR_EOF) {
116  if (rt->finishing) {
117  /* Do not send new requests when the client wants to
118  * close the connection. */
119  return AVERROR(EAGAIN);
120  }
121 
122  /* When the client has reached end of file for the last request,
123  * we have to send a new request if we have buffered data.
124  * Otherwise, we have to send an idle POST. */
125  if (rt->out_size > 0) {
126  if ((ret = rtmp_http_send_cmd(h, "send")) < 0)
127  return ret;
128  } else {
129  if (rt->nb_bytes_read == 0) {
130  /* Wait 50ms before retrying to read a server reply in
131  * order to reduce the number of idle requets. */
132  av_usleep(50000);
133  }
134 
135  if ((ret = rtmp_http_write(h, "", 1)) < 0)
136  return ret;
137 
138  if ((ret = rtmp_http_send_cmd(h, "idle")) < 0)
139  return ret;
140  }
141 
142  if (h->flags & AVIO_FLAG_NONBLOCK) {
143  /* no incoming data to handle in nonblocking mode */
144  return AVERROR(EAGAIN);
145  }
146  } else {
147  off += ret;
148  size -= ret;
149  rt->nb_bytes_read += ret;
150  }
151  } while (off <= 0);
152 
153  return off;
154 }
155 
157 {
158  RTMP_HTTPContext *rt = h->priv_data;
159  uint8_t tmp_buf[2048];
160  int ret = 0;
161 
162  if (rt->initialized) {
163  /* client wants to close the connection */
164  rt->finishing = 1;
165 
166  do {
167  ret = rtmp_http_read(h, tmp_buf, sizeof(tmp_buf));
168  } while (ret > 0);
169 
170  /* re-init output buffer before sending the close command */
171  rt->out_size = 0;
172 
173  if ((ret = rtmp_http_write(h, "", 1)) == 1)
174  ret = rtmp_http_send_cmd(h, "close");
175  }
176 
177  av_freep(&rt->out_data);
178  ffurl_close(rt->stream);
179 
180  return ret;
181 }
182 
183 static int rtmp_http_open(URLContext *h, const char *uri, int flags)
184 {
185  RTMP_HTTPContext *rt = h->priv_data;
186  char headers[1024], url[1024];
187  int ret, off = 0;
188 
189  av_url_split(NULL, 0, NULL, 0, rt->host, sizeof(rt->host), &rt->port,
190  NULL, 0, uri);
191 
192  /* This is the first request that is sent to the server in order to
193  * register a client on the server and start a new session. The server
194  * replies with a unique id (usually a number) that is used by the client
195  * for all future requests.
196  * Note: the reply doesn't contain a value for the polling interval.
197  * A successful connect resets the consecutive index that is used
198  * in the URLs. */
199  if (rt->tls) {
200  if (rt->port < 0)
202  ff_url_join(url, sizeof(url), "https", NULL, rt->host, rt->port, "/open/1");
203  } else {
204  if (rt->port < 0)
205  rt->port = RTMPT_DEFAULT_PORT;
206  ff_url_join(url, sizeof(url), "http", NULL, rt->host, rt->port, "/open/1");
207  }
208 
209  /* alloc the http context */
210  if ((ret = ffurl_alloc(&rt->stream, url, AVIO_FLAG_READ_WRITE, NULL)) < 0)
211  goto fail;
212 
213  /* set options */
214  snprintf(headers, sizeof(headers),
215  "Cache-Control: no-cache\r\n"
216  "Content-type: application/x-fcs\r\n"
217  "User-Agent: Shockwave Flash\r\n");
218  av_opt_set(rt->stream->priv_data, "headers", headers, 0);
219  av_opt_set(rt->stream->priv_data, "multiple_requests", "1", 0);
220  av_opt_set_bin(rt->stream->priv_data, "post_data", "", 1, 0);
221 
222  /* open the http context */
223  if ((ret = ffurl_connect(rt->stream, NULL)) < 0)
224  goto fail;
225 
226  /* read the server reply which contains a unique ID */
227  for (;;) {
228  ret = ffurl_read(rt->stream, rt->client_id + off, sizeof(rt->client_id) - off);
229  if (ret == AVERROR_EOF)
230  break;
231  if (ret < 0)
232  goto fail;
233  off += ret;
234  if (off == sizeof(rt->client_id)) {
235  ret = AVERROR(EIO);
236  goto fail;
237  }
238  }
239  while (off > 0 && av_isspace(rt->client_id[off - 1]))
240  off--;
241  rt->client_id[off] = '\0';
242 
243  /* http context is now initialized */
244  rt->initialized = 1;
245  return 0;
246 
247 fail:
248  rtmp_http_close(h);
249  return ret;
250 }
251 
252 #define OFFSET(x) offsetof(RTMP_HTTPContext, x)
253 #define DEC AV_OPT_FLAG_DECODING_PARAM
254 
255 static const AVOption ffrtmphttp_options[] = {
256  {"ffrtmphttp_tls", "Use a HTTPS tunneling connection (RTMPTS).", OFFSET(tls), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC},
257  { NULL },
258 };
259 
260 static const AVClass ffrtmphttp_class = {
261  .class_name = "ffrtmphttp",
262  .item_name = av_default_item_name,
263  .option = ffrtmphttp_options,
264  .version = LIBAVUTIL_VERSION_INT,
265 };
266 
268  .name = "ffrtmphttp",
269  .url_open = rtmp_http_open,
270  .url_read = rtmp_http_read,
271  .url_write = rtmp_http_write,
272  .url_close = rtmp_http_close,
273  .priv_data_size = sizeof(RTMP_HTTPContext),
275  .priv_data_class= &ffrtmphttp_class,
276 };