3 * Copyright (c) 2012 Luca Barbato
5 * This file is part of Libav.
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.
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.
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
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]
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.
40 #include <netinet/in.h>
41 #include <netinet/sctp.h>
51 #include "libavutil/intreadwrite.h"
52 #include "libavutil/parseutils.h"
56 #include "os_support.h"
60 * The sctp_recvmsg and sctp_sendmsg functions are part of the user
61 * library that offers support
62 * for the SCTP kernel Implementation. The main purpose of this
63 * code is to provide the SCTP Socket API mappings for user
64 * application to interface with the SCTP in kernel.
66 * This implementation is based on the Socket API Extensions for SCTP
67 * defined in <draft-ietf-tsvwg-sctpsocket-10.txt>
69 * Copyright (c) 2003 International Business Machines, Corp.
71 * Written or modified by:
72 * Ryan Layer <rmlayer@us.ibm.com>
75 static int ff_sctp_recvmsg(int s, void *msg, size_t len, struct sockaddr *from,
76 socklen_t *fromlen, struct sctp_sndrcvinfo *sinfo,
81 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
82 struct msghdr inmsg = { 0 };
83 struct cmsghdr *cmsg = NULL;
88 inmsg.msg_name = from;
89 inmsg.msg_namelen = fromlen ? *fromlen : 0;
92 inmsg.msg_control = incmsg;
93 inmsg.msg_controllen = sizeof(incmsg);
95 if ((recvb = recvmsg(s, &inmsg, msg_flags ? *msg_flags : 0)) < 0)
99 *fromlen = inmsg.msg_namelen;
101 *msg_flags = inmsg.msg_flags;
103 for (cmsg = CMSG_FIRSTHDR(&inmsg); cmsg != NULL;
104 cmsg = CMSG_NXTHDR(&inmsg, cmsg)) {
105 if ((IPPROTO_SCTP == cmsg->cmsg_level) &&
106 (SCTP_SNDRCV == cmsg->cmsg_type))
112 memcpy(sinfo, CMSG_DATA(cmsg), sizeof(struct sctp_sndrcvinfo));
117 static int ff_sctp_send(int s, const void *msg, size_t len,
118 const struct sctp_sndrcvinfo *sinfo, int flags)
120 struct msghdr outmsg;
123 outmsg.msg_name = NULL;
124 outmsg.msg_namelen = 0;
125 outmsg.msg_iov = &iov;
128 outmsg.msg_iovlen = 1;
129 outmsg.msg_controllen = 0;
132 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
133 struct cmsghdr *cmsg;
135 outmsg.msg_control = outcmsg;
136 outmsg.msg_controllen = sizeof(outcmsg);
137 outmsg.msg_flags = 0;
139 cmsg = CMSG_FIRSTHDR(&outmsg);
140 cmsg->cmsg_level = IPPROTO_SCTP;
141 cmsg->cmsg_type = SCTP_SNDRCV;
142 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
144 outmsg.msg_controllen = cmsg->cmsg_len;
145 memcpy(CMSG_DATA(cmsg), sinfo, sizeof(struct sctp_sndrcvinfo));
148 return sendmsg(s, &outmsg, flags);
151 typedef struct SCTPContext {
154 struct sockaddr_storage dest_addr;
155 socklen_t dest_addr_len;
158 static int sctp_open(URLContext *h, const char *uri, int flags)
160 struct addrinfo *ai, *cur_ai;
161 struct addrinfo hints = { 0 };
162 struct sctp_event_subscribe event = { 0 };
163 struct sctp_initmsg initparams = { 0 };
166 SCTPContext *s = h->priv_data;
169 int ret, listen_socket = 0;
170 char hostname[1024], proto[1024], path[1024];
173 av_url_split(proto, sizeof(proto), NULL, 0, hostname, sizeof(hostname),
174 &port, path, sizeof(path), uri);
175 if (strcmp(proto,"sctp") || port <= 0 || port >= 65536)
176 return AVERROR(EINVAL);
179 p = strchr(uri, '?');
181 if (av_find_info_tag(buf, sizeof(buf), "listen", p))
183 if (av_find_info_tag(buf, sizeof(buf), "max_streams", p))
184 s->max_streams = strtol(buf, NULL, 10);
187 hints.ai_family = AF_UNSPEC;
188 hints.ai_socktype = SOCK_STREAM;
189 snprintf(portstr, sizeof(portstr), "%d", port);
190 ret = getaddrinfo(hostname, portstr, &hints, &ai);
192 av_log(h, AV_LOG_ERROR, "Failed to resolve hostname %s: %s\n",
193 hostname, gai_strerror(ret));
199 fd = socket(cur_ai->ai_family, SOCK_STREAM, IPPROTO_SCTP);
203 s->dest_addr_len = sizeof(s->dest_addr);
207 ret = bind(fd, cur_ai->ai_addr, cur_ai->ai_addrlen);
209 fd1 = accept(fd, NULL, NULL);
213 ret = connect(fd, cur_ai->ai_addr, cur_ai->ai_addrlen);
215 ff_socket_nonblock(fd, 1);
217 event.sctp_data_io_event = 1;
218 /* TODO: Subscribe to more event types and handle them */
220 if (setsockopt(fd, IPPROTO_SCTP, SCTP_EVENTS, &event,
221 sizeof(event)) != 0) {
222 av_log(h, AV_LOG_ERROR,
223 "SCTP ERROR: Unable to subscribe to events\n");
227 if (s->max_streams) {
228 initparams.sinit_max_instreams = s->max_streams;
229 initparams.sinit_num_ostreams = s->max_streams;
230 if (setsockopt(fd, IPPROTO_SCTP, SCTP_INITMSG, &initparams,
231 sizeof(initparams)) < 0)
232 av_log(h, AV_LOG_ERROR,
233 "SCTP ERROR: Unable to initialize socket max streams %d\n",
249 static int sctp_wait_fd(int fd, int write)
251 int ev = write ? POLLOUT : POLLIN;
252 struct pollfd p = { .fd = fd, .events = ev, .revents = 0 };
255 ret = poll(&p, 1, 100);
256 return ret < 0 ? ff_neterrno() : p.revents & ev ? 0 : AVERROR(EAGAIN);
259 static int sctp_read(URLContext *h, uint8_t *buf, int size)
261 SCTPContext *s = h->priv_data;
264 if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
265 ret = sctp_wait_fd(s->fd, 0);
270 if (s->max_streams) {
271 /*StreamId is introduced as a 2byte code into the stream*/
272 struct sctp_sndrcvinfo info = { 0 };
273 ret = ff_sctp_recvmsg(s->fd, buf + 2, size - 2, NULL, 0, &info, 0);
274 AV_WB16(buf, info.sinfo_stream);
275 ret = ret < 0 ? ret : ret + 2;
277 ret = recv(s->fd, buf, size, 0);
279 return ret < 0 ? ff_neterrno() : ret;
282 static int sctp_write(URLContext *h, const uint8_t *buf, int size)
284 SCTPContext *s = h->priv_data;
287 if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
288 ret = sctp_wait_fd(s->fd, 1);
293 if (s->max_streams) {
294 /*StreamId is introduced as a 2byte code into the stream*/
295 struct sctp_sndrcvinfo info = { 0 };
296 info.sinfo_stream = AV_RB16(buf);
297 if (info.sinfo_stream > s->max_streams)
299 ret = ff_sctp_send(s->fd, buf + 2, size - 2, &info, MSG_EOR);
301 ret = send(s->fd, buf, size, 0);
303 return ret < 0 ? ff_neterrno() : ret;
306 static int sctp_close(URLContext *h)
308 SCTPContext *s = h->priv_data;
313 static int sctp_get_file_handle(URLContext *h)
315 SCTPContext *s = h->priv_data;
319 URLProtocol ff_sctp_protocol = {
321 .url_open = sctp_open,
322 .url_read = sctp_read,
323 .url_write = sctp_write,
324 .url_close = sctp_close,
325 .url_get_file_handle = sctp_get_file_handle,
326 .priv_data_size = sizeof(SCTPContext),
327 .flags = URL_PROTOCOL_FLAG_NETWORK,