9cfaeccd179d7040432f740c60a0b032477ae454
[libav.git] / libavformat / sctp.c
1 /*
2 * SCTP protocol
3 * Copyright (c) 2012 Luca Barbato
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 /**
23 * @file
24 *
25 * sctp url_protocol
26 *
27 * url syntax: sctp://host:port[?option=val...]
28 * option: 'listen' : listen for an incoming connection
29 * 'max_streams=n' : set the maximum number of streams
30 * 'reuse=1' : enable reusing the socket [TBD]
31 *
32 * by setting the maximum number of streams the protocol will use the
33 * first two bytes of the incoming/outgoing buffer to store the
34 * stream number of the packet being read/written.
35 * @see sctp_read
36 * @see sctp_write
37 */
38
39
40 #include <netinet/in.h>
41 #include <netinet/sctp.h>
42
43 #include "config.h"
44
45 #if HAVE_POLL_H
46 #include <poll.h>
47 #endif
48
49 #include "libavutil/intreadwrite.h"
50 #include "libavutil/parseutils.h"
51 #include "avformat.h"
52 #include "internal.h"
53 #include "network.h"
54 #include "os_support.h"
55 #include "url.h"
56
57 /*
58 * The sctp_recvmsg and sctp_sendmsg functions are part of the user
59 * library that offers support for the SCTP kernel Implementation.
60 * To avoid build-time clashes the functions sport an ff_-prefix here.
61 * The main purpose of this code is to provide the SCTP Socket API
62 * mappings for user applications to interface with SCTP in the kernel.
63 *
64 * This implementation is based on the Socket API Extensions for SCTP
65 * defined in <draft-ietf-tsvwg-sctpsocket-10.txt>
66 *
67 * Copyright (c) 2003 International Business Machines, Corp.
68 *
69 * Written or modified by:
70 * Ryan Layer <rmlayer@us.ibm.com>
71 */
72
73 static int ff_sctp_recvmsg(int s, void *msg, size_t len, struct sockaddr *from,
74 socklen_t *fromlen, struct sctp_sndrcvinfo *sinfo,
75 int *msg_flags)
76 {
77 int recvb;
78 struct iovec iov;
79 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
80 struct msghdr inmsg = { 0 };
81 struct cmsghdr *cmsg = NULL;
82
83 iov.iov_base = msg;
84 iov.iov_len = len;
85
86 inmsg.msg_name = from;
87 inmsg.msg_namelen = fromlen ? *fromlen : 0;
88 inmsg.msg_iov = &iov;
89 inmsg.msg_iovlen = 1;
90 inmsg.msg_control = incmsg;
91 inmsg.msg_controllen = sizeof(incmsg);
92
93 if ((recvb = recvmsg(s, &inmsg, msg_flags ? *msg_flags : 0)) < 0)
94 return recvb;
95
96 if (fromlen)
97 *fromlen = inmsg.msg_namelen;
98 if (msg_flags)
99 *msg_flags = inmsg.msg_flags;
100
101 for (cmsg = CMSG_FIRSTHDR(&inmsg); cmsg != NULL;
102 cmsg = CMSG_NXTHDR(&inmsg, cmsg)) {
103 if ((IPPROTO_SCTP == cmsg->cmsg_level) &&
104 (SCTP_SNDRCV == cmsg->cmsg_type))
105 break;
106 }
107
108 /* Copy sinfo. */
109 if (cmsg)
110 memcpy(sinfo, CMSG_DATA(cmsg), sizeof(struct sctp_sndrcvinfo));
111
112 return recvb;
113 }
114
115 static int ff_sctp_send(int s, const void *msg, size_t len,
116 const struct sctp_sndrcvinfo *sinfo, int flags)
117 {
118 struct msghdr outmsg;
119 struct iovec iov;
120
121 outmsg.msg_name = NULL;
122 outmsg.msg_namelen = 0;
123 outmsg.msg_iov = &iov;
124 iov.iov_base = msg;
125 iov.iov_len = len;
126 outmsg.msg_iovlen = 1;
127 outmsg.msg_controllen = 0;
128
129 if (sinfo) {
130 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
131 struct cmsghdr *cmsg;
132
133 outmsg.msg_control = outcmsg;
134 outmsg.msg_controllen = sizeof(outcmsg);
135 outmsg.msg_flags = 0;
136
137 cmsg = CMSG_FIRSTHDR(&outmsg);
138 cmsg->cmsg_level = IPPROTO_SCTP;
139 cmsg->cmsg_type = SCTP_SNDRCV;
140 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
141
142 outmsg.msg_controllen = cmsg->cmsg_len;
143 memcpy(CMSG_DATA(cmsg), sinfo, sizeof(struct sctp_sndrcvinfo));
144 }
145
146 return sendmsg(s, &outmsg, flags | MSG_NOSIGNAL);
147 }
148
149 typedef struct SCTPContext {
150 int fd;
151 int max_streams;
152 struct sockaddr_storage dest_addr;
153 socklen_t dest_addr_len;
154 } SCTPContext;
155
156 static int sctp_open(URLContext *h, const char *uri, int flags)
157 {
158 struct addrinfo *ai, *cur_ai;
159 struct addrinfo hints = { 0 };
160 struct sctp_event_subscribe event = { 0 };
161 struct sctp_initmsg initparams = { 0 };
162 int port;
163 int fd = -1;
164 SCTPContext *s = h->priv_data;
165 const char *p;
166 char buf[256];
167 int ret, listen_socket = 0;
168 char hostname[1024], proto[1024], path[1024];
169 char portstr[10];
170
171 av_url_split(proto, sizeof(proto), NULL, 0, hostname, sizeof(hostname),
172 &port, path, sizeof(path), uri);
173 if (strcmp(proto, "sctp"))
174 return AVERROR(EINVAL);
175 if (port <= 0 || port >= 65536) {
176 av_log(s, AV_LOG_ERROR, "Port missing in uri\n");
177 return AVERROR(EINVAL);
178 }
179
180 s->max_streams = 0;
181 p = strchr(uri, '?');
182 if (p) {
183 if (av_find_info_tag(buf, sizeof(buf), "listen", p))
184 listen_socket = 1;
185 if (av_find_info_tag(buf, sizeof(buf), "max_streams", p))
186 s->max_streams = strtol(buf, NULL, 10);
187 }
188
189 hints.ai_family = AF_UNSPEC;
190 hints.ai_socktype = SOCK_STREAM;
191 snprintf(portstr, sizeof(portstr), "%d", port);
192 ret = getaddrinfo(hostname, portstr, &hints, &ai);
193 if (ret) {
194 av_log(h, AV_LOG_ERROR, "Failed to resolve hostname %s: %s\n",
195 hostname, gai_strerror(ret));
196 return AVERROR(EIO);
197 }
198
199 cur_ai = ai;
200
201 fd = ff_socket(cur_ai->ai_family, SOCK_STREAM, IPPROTO_SCTP);
202 if (fd < 0)
203 goto fail;
204
205 s->dest_addr_len = sizeof(s->dest_addr);
206
207 if (listen_socket) {
208 int fd1;
209 ret = bind(fd, cur_ai->ai_addr, cur_ai->ai_addrlen);
210 listen(fd, 100);
211 fd1 = accept(fd, NULL, NULL);
212 closesocket(fd);
213 fd = fd1;
214 } else
215 ret = connect(fd, cur_ai->ai_addr, cur_ai->ai_addrlen);
216
217 ff_socket_nonblock(fd, 1);
218
219 event.sctp_data_io_event = 1;
220 /* TODO: Subscribe to more event types and handle them */
221
222 if (setsockopt(fd, IPPROTO_SCTP, SCTP_EVENTS, &event,
223 sizeof(event)) != 0) {
224 av_log(h, AV_LOG_ERROR,
225 "SCTP ERROR: Unable to subscribe to events\n");
226 goto fail;
227 }
228
229 if (s->max_streams) {
230 initparams.sinit_max_instreams = s->max_streams;
231 initparams.sinit_num_ostreams = s->max_streams;
232 if (setsockopt(fd, IPPROTO_SCTP, SCTP_INITMSG, &initparams,
233 sizeof(initparams)) < 0)
234 av_log(h, AV_LOG_ERROR,
235 "SCTP ERROR: Unable to initialize socket max streams %d\n",
236 s->max_streams);
237 }
238
239 h->priv_data = s;
240 h->is_streamed = 1;
241 s->fd = fd;
242 freeaddrinfo(ai);
243 return 0;
244
245 fail:
246 ret = AVERROR(EIO);
247 freeaddrinfo(ai);
248 return ret;
249 }
250
251 static int sctp_wait_fd(int fd, int write)
252 {
253 int ev = write ? POLLOUT : POLLIN;
254 struct pollfd p = { .fd = fd, .events = ev, .revents = 0 };
255 int ret;
256
257 ret = poll(&p, 1, 100);
258 return ret < 0 ? ff_neterrno() : p.revents & ev ? 0 : AVERROR(EAGAIN);
259 }
260
261 static int sctp_read(URLContext *h, uint8_t *buf, int size)
262 {
263 SCTPContext *s = h->priv_data;
264 int ret;
265
266 if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
267 ret = sctp_wait_fd(s->fd, 0);
268 if (ret < 0)
269 return ret;
270 }
271
272 if (s->max_streams) {
273 /*StreamId is introduced as a 2byte code into the stream*/
274 struct sctp_sndrcvinfo info = { 0 };
275 ret = ff_sctp_recvmsg(s->fd, buf + 2, size - 2, NULL, 0, &info, 0);
276 AV_WB16(buf, info.sinfo_stream);
277 ret = ret < 0 ? ret : ret + 2;
278 } else
279 ret = recv(s->fd, buf, size, 0);
280
281 return ret < 0 ? ff_neterrno() : ret;
282 }
283
284 static int sctp_write(URLContext *h, const uint8_t *buf, int size)
285 {
286 SCTPContext *s = h->priv_data;
287 int ret;
288
289 if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
290 ret = sctp_wait_fd(s->fd, 1);
291 if (ret < 0)
292 return ret;
293 }
294
295 if (s->max_streams) {
296 /*StreamId is introduced as a 2byte code into the stream*/
297 struct sctp_sndrcvinfo info = { 0 };
298 info.sinfo_stream = AV_RB16(buf);
299 if (info.sinfo_stream > s->max_streams)
300 return AVERROR_BUG;
301 ret = ff_sctp_send(s->fd, buf + 2, size - 2, &info, MSG_EOR);
302 } else
303 ret = send(s->fd, buf, size, MSG_NOSIGNAL);
304
305 return ret < 0 ? ff_neterrno() : ret;
306 }
307
308 static int sctp_close(URLContext *h)
309 {
310 SCTPContext *s = h->priv_data;
311 closesocket(s->fd);
312 return 0;
313 }
314
315 static int sctp_get_file_handle(URLContext *h)
316 {
317 SCTPContext *s = h->priv_data;
318 return s->fd;
319 }
320
321 URLProtocol ff_sctp_protocol = {
322 .name = "sctp",
323 .url_open = sctp_open,
324 .url_read = sctp_read,
325 .url_write = sctp_write,
326 .url_close = sctp_close,
327 .url_get_file_handle = sctp_get_file_handle,
328 .priv_data_size = sizeof(SCTPContext),
329 .flags = URL_PROTOCOL_FLAG_NETWORK,
330 };