libavformat/rtmphttp.c

   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/mem.h"
  29 #include "libavutil/opt.h"
  30 #include "libavutil/time.h"
  31 #include "http.h"
  32 #include "rtmp.h"
  33
  34 #define RTMPT_DEFAULT_PORT 80
  35 #define RTMPTS_DEFAULT_PORT RTMPS_DEFAULT_PORT
  36
  37 /* protocol handler context */
  38 typedef struct RTMP_HTTPContext {
  39     const AVClass *class;
  40     URLContext   *stream;           ///< HTTP stream
  41     char         host[256];         ///< hostname of the server
  42     int          port;              ///< port to connect (default is 80)
  43     char         client_id[64];     ///< client ID used for all requests except the first one
  44     int          seq;               ///< sequence ID used for all requests
  45     uint8_t      *out_data;         ///< output buffer
  46     int          out_size;          ///< current output buffer size
  47     int          out_capacity;      ///< current output buffer capacity
  48     int          initialized;       ///< flag indicating when the http context is initialized
  49     int          finishing;         ///< flag indicating when the client closes the connection
  50     int          nb_bytes_read;     ///< number of bytes read since the last request
  51     int          tls;               ///< use Transport Security Layer (RTMPTS)
  52 } RTMP_HTTPContext;
  53
  54 static int rtmp_http_send_cmd(URLContext *h, const char *cmd)
  55 {
  56     RTMP_HTTPContext *rt = h->priv_data;
  57     char uri[2048];
  58     uint8_t c;
  59     int ret;
  60
  61     ff_url_join(uri, sizeof(uri), "http", NULL, rt->host, rt->port,
  62                 "/%s/%s/%d", cmd, rt->client_id, rt->seq++);
  63
  64     av_opt_set_bin(rt->stream->priv_data, "post_data", rt->out_data,
  65                    rt->out_size, 0);
  66
  67     /* send a new request to the server */
  68     if ((ret = ff_http_do_new_request(rt->stream, uri)) < 0)
  69         return ret;
  70
  71     /* re-init output buffer */
  72     rt->out_size = 0;
  73
  74     /* read the first byte which contains the polling interval */
  75     if ((ret = ffurl_read(rt->stream, &c, 1)) < 0)
  76         return ret;
  77
  78     /* re-init the number of bytes read */
  79     rt->nb_bytes_read = 0;
  80
  81     return ret;
  82 }
  83
  84 static int rtmp_http_write(URLContext *h, const uint8_t *buf, int size)
  85 {
  86     RTMP_HTTPContext *rt = h->priv_data;
  87
  88     if (rt->out_size + size > rt->out_capacity) {
  89         int err;
  90         rt->out_capacity = (rt->out_size + size) * 2;
  91         if ((err = av_reallocp(&rt->out_data, rt->out_capacity)) < 0) {
  92             rt->out_size = 0;
  93             rt->out_capacity = 0;
  94             return err;
  95         }
  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 || 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 requests. */
 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
 156 static int rtmp_http_close(URLContext *h)
 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_closep(&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)
 201             rt->port = RTMPTS_DEFAULT_PORT;
 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, &h->interrupt_callback)) < 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     if (!rt->stream->protocol_whitelist && h->protocol_whitelist) {
 223         rt->stream->protocol_whitelist = av_strdup(h->protocol_whitelist);
 224         if (!rt->stream->protocol_whitelist) {
 225             ret = AVERROR(ENOMEM);
 226             goto fail;
 227         }
 228     }
 229
 230     /* open the http context */
 231     if ((ret = ffurl_connect(rt->stream, NULL)) < 0)
 232         goto fail;
 233
 234     /* read the server reply which contains a unique ID */
 235     for (;;) {
 236         ret = ffurl_read(rt->stream, rt->client_id + off, sizeof(rt->client_id) - off);
 237         if (!ret || ret == AVERROR_EOF)
 238             break;
 239         if (ret < 0)
 240             goto fail;
 241         off += ret;
 242         if (off == sizeof(rt->client_id)) {
 243             ret = AVERROR(EIO);
 244             goto fail;
 245         }
 246     }
 247     while (off > 0 && av_isspace(rt->client_id[off - 1]))
 248         off--;
 249     rt->client_id[off] = '\0';
 250
 251     /* http context is now initialized */
 252     rt->initialized = 1;
 253     return 0;
 254
 255 fail:
 256     rtmp_http_close(h);
 257     return ret;
 258 }
 259
 260 #define OFFSET(x) offsetof(RTMP_HTTPContext, x)
 261 #define DEC AV_OPT_FLAG_DECODING_PARAM
 262
 263 static const AVOption ffrtmphttp_options[] = {
 264     {"ffrtmphttp_tls", "Use a HTTPS tunneling connection (RTMPTS).", OFFSET(tls), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC},
 265     { NULL },
 266 };
 267
 268 static const AVClass ffrtmphttp_class = {
 269     .class_name = "ffrtmphttp",
 270     .item_name  = av_default_item_name,
 271     .option     = ffrtmphttp_options,
 272     .version    = LIBAVUTIL_VERSION_INT,
 273 };
 274
 275 const URLProtocol ff_ffrtmphttp_protocol = {
 276     .name           = "ffrtmphttp",
 277     .url_open       = rtmp_http_open,
 278     .url_read       = rtmp_http_read,
 279     .url_write      = rtmp_http_write,
 280     .url_close      = rtmp_http_close,
 281     .priv_data_size = sizeof(RTMP_HTTPContext),
 282     .flags          = URL_PROTOCOL_FLAG_NETWORK,
 283     .priv_data_class= &ffrtmphttp_class,
 284     .default_whitelist = "https,http,tcp,tls",
 285 };