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 */
39typedef 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)
53} RTMP_HTTPContext;
54
55static 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
85static int rtmp_http_write(URLContext *h, const uint8_t *buf, int size)
86{
87    RTMP_HTTPContext *rt = h->priv_data;
88
89    if (rt->out_size + size > rt->out_capacity) {
90        int err;
91        rt->out_capacity = (rt->out_size + size) * 2;
92        if ((err = av_reallocp(&rt->out_data, rt->out_capacity)) < 0) {
93            rt->out_size = 0;
94            rt->out_capacity = 0;
95            return err;
96        }
97    }
98
99    memcpy(rt->out_data + rt->out_size, buf, size);
100    rt->out_size += size;
101
102    return size;
103}
104
105static int rtmp_http_read(URLContext *h, uint8_t *buf, int size)
106{
107    RTMP_HTTPContext *rt = h->priv_data;
108    int ret, off = 0;
109
110    /* try to read at least 1 byte of data */
111    do {
112        ret = ffurl_read(rt->stream, buf + off, size);
113        if (ret < 0 && ret != AVERROR_EOF)
114            return ret;
115
116        if (!ret || ret == AVERROR_EOF) {
117            if (rt->finishing) {
118                /* Do not send new requests when the client wants to
119                 * close the connection. */
120                return AVERROR(EAGAIN);
121            }
122
123            /* When the client has reached end of file for the last request,
124             * we have to send a new request if we have buffered data.
125             * Otherwise, we have to send an idle POST. */
126            if (rt->out_size > 0) {
127                if ((ret = rtmp_http_send_cmd(h, "send")) < 0)
128                    return ret;
129            } else {
130                if (rt->nb_bytes_read == 0) {
131                    /* Wait 50ms before retrying to read a server reply in
132                     * order to reduce the number of idle requets. */
133                    av_usleep(50000);
134                }
135
136                if ((ret = rtmp_http_write(h, "", 1)) < 0)
137                    return ret;
138
139                if ((ret = rtmp_http_send_cmd(h, "idle")) < 0)
140                    return ret;
141            }
142
143            if (h->flags & AVIO_FLAG_NONBLOCK) {
144                /* no incoming data to handle in nonblocking mode */
145                return AVERROR(EAGAIN);
146            }
147        } else {
148            off  += ret;
149            size -= ret;
150            rt->nb_bytes_read += ret;
151        }
152    } while (off <= 0);
153
154    return off;
155}
156
157static int rtmp_http_close(URLContext *h)
158{
159    RTMP_HTTPContext *rt = h->priv_data;
160    uint8_t tmp_buf[2048];
161    int ret = 0;
162
163    if (rt->initialized) {
164        /* client wants to close the connection */
165        rt->finishing = 1;
166
167        do {
168            ret = rtmp_http_read(h, tmp_buf, sizeof(tmp_buf));
169        } while (ret > 0);
170
171        /* re-init output buffer before sending the close command */
172        rt->out_size = 0;
173
174        if ((ret = rtmp_http_write(h, "", 1)) == 1)
175            ret = rtmp_http_send_cmd(h, "close");
176    }
177
178    av_freep(&rt->out_data);
179    ffurl_close(rt->stream);
180
181    return ret;
182}
183
184static int rtmp_http_open(URLContext *h, const char *uri, int flags)
185{
186    RTMP_HTTPContext *rt = h->priv_data;
187    char headers[1024], url[1024];
188    int ret, off = 0;
189
190    av_url_split(NULL, 0, NULL, 0, rt->host, sizeof(rt->host), &rt->port,
191                 NULL, 0, uri);
192
193    /* This is the first request that is sent to the server in order to
194     * register a client on the server and start a new session. The server
195     * replies with a unique id (usually a number) that is used by the client
196     * for all future requests.
197     * Note: the reply doesn't contain a value for the polling interval.
198     * A successful connect resets the consecutive index that is used
199     * in the URLs. */
200    if (rt->tls) {
201        if (rt->port < 0)
202            rt->port = RTMPTS_DEFAULT_PORT;
203        ff_url_join(url, sizeof(url), "https", NULL, rt->host, rt->port, "/open/1");
204    } else {
205        if (rt->port < 0)
206            rt->port = RTMPT_DEFAULT_PORT;
207        ff_url_join(url, sizeof(url), "http", NULL, rt->host, rt->port, "/open/1");
208    }
209
210    /* alloc the http context */
211    if ((ret = ffurl_alloc(&rt->stream, url, AVIO_FLAG_READ_WRITE, NULL)) < 0)
212        goto fail;
213
214    /* set options */
215    snprintf(headers, sizeof(headers),
216             "Cache-Control: no-cache\r\n"
217             "Content-type: application/x-fcs\r\n"
218             "User-Agent: Shockwave Flash\r\n");
219    av_opt_set(rt->stream->priv_data, "headers", headers, 0);
220    av_opt_set(rt->stream->priv_data, "multiple_requests", "1", 0);
221    av_opt_set_bin(rt->stream->priv_data, "post_data", "", 1, 0);
222
223    /* open the http context */
224    if ((ret = ffurl_connect(rt->stream, NULL)) < 0)
225        goto fail;
226
227    /* read the server reply which contains a unique ID */
228    for (;;) {
229        ret = ffurl_read(rt->stream, rt->client_id + off, sizeof(rt->client_id) - off);
230        if (!ret || ret == AVERROR_EOF)
231            break;
232        if (ret < 0)
233            goto fail;
234        off += ret;
235        if (off == sizeof(rt->client_id)) {
236            ret = AVERROR(EIO);
237            goto fail;
238        }
239    }
240    while (off > 0 && av_isspace(rt->client_id[off - 1]))
241        off--;
242    rt->client_id[off] = '\0';
243
244    /* http context is now initialized */
245    rt->initialized = 1;
246    return 0;
247
248fail:
249    rtmp_http_close(h);
250    return ret;
251}
252
253#define OFFSET(x) offsetof(RTMP_HTTPContext, x)
254#define DEC AV_OPT_FLAG_DECODING_PARAM
255
256static const AVOption ffrtmphttp_options[] = {
257    {"ffrtmphttp_tls", "Use a HTTPS tunneling connection (RTMPTS).", OFFSET(tls), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, DEC},
258    { NULL },
259};
260
261static const AVClass ffrtmphttp_class = {
262    .class_name = "ffrtmphttp",
263    .item_name  = av_default_item_name,
264    .option     = ffrtmphttp_options,
265    .version    = LIBAVUTIL_VERSION_INT,
266};
267
268URLProtocol ff_ffrtmphttp_protocol = {
269    .name           = "ffrtmphttp",
270    .url_open       = rtmp_http_open,
271    .url_read       = rtmp_http_read,
272    .url_write      = rtmp_http_write,
273    .url_close      = rtmp_http_close,
274    .priv_data_size = sizeof(RTMP_HTTPContext),
275    .flags          = URL_PROTOCOL_FLAG_NETWORK,
276    .priv_data_class= &ffrtmphttp_class,
277};
278