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1/*
2 * SCTP protocol
3 * Copyright (c) 2012 Luca Barbato
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 *
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 "libavutil/opt.h"
52#include "avformat.h"
53#include "internal.h"
54#include "network.h"
55#include "os_support.h"
56#include "url.h"
57
58/*
59 * The sctp_recvmsg and sctp_sendmsg functions are part of the user
60 * library that offers support for the SCTP kernel Implementation.
61 * To avoid build-time clashes the functions sport an ff_-prefix here.
62 * The main purpose of this code is to provide the SCTP Socket API
63 * mappings for user applications to interface with SCTP in the kernel.
64 *
65 * This implementation is based on the Socket API Extensions for SCTP
66 * defined in <draft-ietf-tsvwg-sctpsocket-10.txt>
67 *
68 * Copyright (c) 2003 International Business Machines, Corp.
69 *
70 * Written or modified by:
71 * Ryan Layer <rmlayer@us.ibm.com>
72 */
73
74static int ff_sctp_recvmsg(int s, void *msg, size_t len, struct sockaddr *from,
75 socklen_t *fromlen, struct sctp_sndrcvinfo *sinfo,
76 int *msg_flags)
77{
78 int recvb;
79 struct iovec iov;
80 char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
81 struct msghdr inmsg = { 0 };
82 struct cmsghdr *cmsg = NULL;
83
84 iov.iov_base = msg;
85 iov.iov_len = len;
86
87 inmsg.msg_name = from;
88 inmsg.msg_namelen = fromlen ? *fromlen : 0;
89 inmsg.msg_iov = &iov;
90 inmsg.msg_iovlen = 1;
91 inmsg.msg_control = incmsg;
92 inmsg.msg_controllen = sizeof(incmsg);
93
94 if ((recvb = recvmsg(s, &inmsg, msg_flags ? *msg_flags : 0)) < 0)
95 return recvb;
96
97 if (fromlen)
98 *fromlen = inmsg.msg_namelen;
99 if (msg_flags)
100 *msg_flags = inmsg.msg_flags;
101
102 for (cmsg = CMSG_FIRSTHDR(&inmsg); cmsg;
103 cmsg = CMSG_NXTHDR(&inmsg, cmsg)) {
104 if ((IPPROTO_SCTP == cmsg->cmsg_level) &&
105 (SCTP_SNDRCV == cmsg->cmsg_type))
106 break;
107 }
108
109 /* Copy sinfo. */
110 if (cmsg)
111 memcpy(sinfo, CMSG_DATA(cmsg), sizeof(struct sctp_sndrcvinfo));
112
113 return recvb;
114}
115
116static int ff_sctp_send(int s, const void *msg, size_t len,
117 const struct sctp_sndrcvinfo *sinfo, int flags)
118{
119 struct msghdr outmsg = { 0 };
120 struct iovec iov;
121
122 outmsg.msg_name = NULL;
123 outmsg.msg_namelen = 0;
124 outmsg.msg_iov = &iov;
125 iov.iov_base = (void*)msg;
126 iov.iov_len = len;
127 outmsg.msg_iovlen = 1;
128 outmsg.msg_controllen = 0;
129
130 if (sinfo) {
131 char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
132 struct cmsghdr *cmsg;
133
134 outmsg.msg_control = outcmsg;
135 outmsg.msg_controllen = sizeof(outcmsg);
136 outmsg.msg_flags = 0;
137
138 cmsg = CMSG_FIRSTHDR(&outmsg);
139 cmsg->cmsg_level = IPPROTO_SCTP;
140 cmsg->cmsg_type = SCTP_SNDRCV;
141 cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
142
143 outmsg.msg_controllen = cmsg->cmsg_len;
144 memcpy(CMSG_DATA(cmsg), sinfo, sizeof(struct sctp_sndrcvinfo));
145 }
146
147 return sendmsg(s, &outmsg, flags | MSG_NOSIGNAL);
148}
149
150typedef struct SCTPContext {
151 const AVClass *class;
152 int fd;
153 int listen;
154 int timeout;
155 int listen_timeout;
156 int max_streams;
157 struct sockaddr_storage dest_addr;
158} SCTPContext;
159
160#define OFFSET(x) offsetof(SCTPContext, x)
161#define D AV_OPT_FLAG_DECODING_PARAM
162#define E AV_OPT_FLAG_ENCODING_PARAM
163static const AVOption options[] = {
164 { "listen", "Listen for incoming connections", OFFSET(listen), AV_OPT_TYPE_BOOL,{ .i64 = 0 }, 0, 1, .flags = D|E },
165 { "timeout", "Connection timeout (in milliseconds)", OFFSET(timeout), AV_OPT_TYPE_INT, { .i64 = 10000 }, INT_MIN, INT_MAX, .flags = D|E },
166 { "listen_timeout", "Bind timeout (in milliseconds)", OFFSET(listen_timeout), AV_OPT_TYPE_INT, { .i64 = -1 }, INT_MIN, INT_MAX, .flags = D|E },
167 { "max_streams", "Max stream to allocate", OFFSET(max_streams), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT16_MAX, .flags = D|E },
168 { NULL }
169};
170
171static const AVClass sctp_class = {
172 .class_name = "sctp",
173 .item_name = av_default_item_name,
174 .option = options,
175 .version = LIBAVUTIL_VERSION_INT,
176};
177
178static int sctp_open(URLContext *h, const char *uri, int flags)
179{
180 struct addrinfo *ai, *cur_ai;
181 struct addrinfo hints = { 0 };
182 struct sctp_event_subscribe event = { 0 };
183 struct sctp_initmsg initparams = { 0 };
184 int port;
185 int fd = -1;
186 SCTPContext *s = h->priv_data;
187 const char *p;
188 char buf[256];
189 int ret;
190 char hostname[1024], proto[1024], path[1024];
191 char portstr[10];
192
193 av_url_split(proto, sizeof(proto), NULL, 0, hostname, sizeof(hostname),
194 &port, path, sizeof(path), uri);
195 if (strcmp(proto, "sctp"))
196 return AVERROR(EINVAL);
197 if (port <= 0 || port >= 65536) {
198 av_log(s, AV_LOG_ERROR, "Port missing in uri\n");
199 return AVERROR(EINVAL);
200 }
201
202 p = strchr(uri, '?');
203 if (p) {
204 if (av_find_info_tag(buf, sizeof(buf), "listen", p))
205 s->listen = 1;
206 if (av_find_info_tag(buf, sizeof(buf), "max_streams", p))
207 s->max_streams = strtol(buf, NULL, 10);
208 }
209
210 hints.ai_family = AF_UNSPEC;
211 hints.ai_socktype = SOCK_STREAM;
212 snprintf(portstr, sizeof(portstr), "%d", port);
213 ret = getaddrinfo(hostname, portstr, &hints, &ai);
214 if (ret) {
215 av_log(h, AV_LOG_ERROR, "Failed to resolve hostname %s: %s\n",
216 hostname, gai_strerror(ret));
217 return AVERROR(EIO);
218 }
219
220 cur_ai = ai;
221
222restart:
223 fd = ff_socket(cur_ai->ai_family, SOCK_STREAM, IPPROTO_SCTP);
224 if (fd < 0) {
225 ret = ff_neterrno();
226 goto fail;
227 }
228
229 if (s->listen) {
230 if ((fd = ff_listen_bind(fd, cur_ai->ai_addr, cur_ai->ai_addrlen,
231 s->listen_timeout, h)) < 0) {
232 ret = fd;
233 goto fail1;
234 }
235 } else {
236 if ((ret = ff_listen_connect(fd, cur_ai->ai_addr, cur_ai->ai_addrlen,
237 s->timeout, h, !!cur_ai->ai_next)) < 0) {
238
239 if (ret == AVERROR_EXIT)
240 goto fail1;
241 else
242 goto fail;
243 }
244 }
245
246 event.sctp_data_io_event = 1;
247 /* TODO: Subscribe to more event types and handle them */
248
249 if (setsockopt(fd, IPPROTO_SCTP, SCTP_EVENTS, &event,
250 sizeof(event)) != 0) {
251 av_log(h, AV_LOG_ERROR,
252 "SCTP ERROR: Unable to subscribe to events\n");
253 goto fail1;
254 }
255
256 if (s->max_streams) {
257 initparams.sinit_max_instreams = s->max_streams;
258 initparams.sinit_num_ostreams = s->max_streams;
259 if (setsockopt(fd, IPPROTO_SCTP, SCTP_INITMSG, &initparams,
260 sizeof(initparams)) < 0) {
261 av_log(h, AV_LOG_ERROR,
262 "SCTP ERROR: Unable to initialize socket max streams %d\n",
263 s->max_streams);
264 ret = ff_neterrno();
265 goto fail1;
266 }
267 }
268
269 h->priv_data = s;
270 h->is_streamed = 1;
271 s->fd = fd;
272 freeaddrinfo(ai);
273 return 0;
274
275fail:
276 if (cur_ai->ai_next) {
277 /* Retry with the next sockaddr */
278 cur_ai = cur_ai->ai_next;
279 if (fd >= 0)
280 closesocket(fd);
281 ret = 0;
282 goto restart;
283 }
284fail1:
285 ret = AVERROR(EIO);
286 freeaddrinfo(ai);
287 return ret;
288}
289
290static int sctp_wait_fd(int fd, int write)
291{
292 int ev = write ? POLLOUT : POLLIN;
293 struct pollfd p = { .fd = fd, .events = ev, .revents = 0 };
294 int ret;
295
296 ret = poll(&p, 1, 100);
297 return ret < 0 ? ff_neterrno() : p.revents & ev ? 0 : AVERROR(EAGAIN);
298}
299
300static int sctp_read(URLContext *h, uint8_t *buf, int size)
301{
302 SCTPContext *s = h->priv_data;
303 int ret;
304
305 if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
306 ret = sctp_wait_fd(s->fd, 0);
307 if (ret < 0)
308 return ret;
309 }
310
311 if (s->max_streams) {
312 /*StreamId is introduced as a 2byte code into the stream*/
313 struct sctp_sndrcvinfo info = { 0 };
314 ret = ff_sctp_recvmsg(s->fd, buf + 2, size - 2, NULL, 0, &info, 0);
315 AV_WB16(buf, info.sinfo_stream);
316 ret = ret < 0 ? ret : ret + 2;
317 } else
318 ret = recv(s->fd, buf, size, 0);
319
320 return ret < 0 ? ff_neterrno() : ret;
321}
322
323static int sctp_write(URLContext *h, const uint8_t *buf, int size)
324{
325 SCTPContext *s = h->priv_data;
326 int ret;
327
328 if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
329 ret = sctp_wait_fd(s->fd, 1);
330 if (ret < 0)
331 return ret;
332 }
333
334 if (s->max_streams) {
335 /*StreamId is introduced as a 2byte code into the stream*/
336 struct sctp_sndrcvinfo info = { 0 };
337 info.sinfo_stream = AV_RB16(buf);
338 if (info.sinfo_stream > s->max_streams) {
339 av_log(h, AV_LOG_ERROR, "bad input data\n");
340 return AVERROR_BUG;
341 }
342 ret = ff_sctp_send(s->fd, buf + 2, size - 2, &info, MSG_EOR);
343 } else
344 ret = send(s->fd, buf, size, MSG_NOSIGNAL);
345
346 return ret < 0 ? ff_neterrno() : ret;
347}
348
349static int sctp_close(URLContext *h)
350{
351 SCTPContext *s = h->priv_data;
352 closesocket(s->fd);
353 return 0;
354}
355
356static int sctp_get_file_handle(URLContext *h)
357{
358 SCTPContext *s = h->priv_data;
359 return s->fd;
360}
361
362const URLProtocol ff_sctp_protocol = {
363 .name = "sctp",
364 .url_open = sctp_open,
365 .url_read = sctp_read,
366 .url_write = sctp_write,
367 .url_close = sctp_close,
368 .url_get_file_handle = sctp_get_file_handle,
369 .priv_data_size = sizeof(SCTPContext),
370 .flags = URL_PROTOCOL_FLAG_NETWORK,
371 .priv_data_class = &sctp_class,
372};
373
generated by cgit at 2024-05-17 05:46:10 (GMT)