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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 "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; | |
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 = (void*)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 | av_log(h, AV_LOG_ERROR, "bad input data\n"); | |
f6fa7814 | 301 | return AVERROR_BUG; |
2ba45a60 DM |
302 | } |
303 | ret = ff_sctp_send(s->fd, buf + 2, size - 2, &info, MSG_EOR); | |
304 | } else | |
305 | ret = send(s->fd, buf, size, MSG_NOSIGNAL); | |
306 | ||
307 | return ret < 0 ? ff_neterrno() : ret; | |
308 | } | |
309 | ||
310 | static int sctp_close(URLContext *h) | |
311 | { | |
312 | SCTPContext *s = h->priv_data; | |
313 | closesocket(s->fd); | |
314 | return 0; | |
315 | } | |
316 | ||
317 | static int sctp_get_file_handle(URLContext *h) | |
318 | { | |
319 | SCTPContext *s = h->priv_data; | |
320 | return s->fd; | |
321 | } | |
322 | ||
323 | URLProtocol ff_sctp_protocol = { | |
324 | .name = "sctp", | |
325 | .url_open = sctp_open, | |
326 | .url_read = sctp_read, | |
327 | .url_write = sctp_write, | |
328 | .url_close = sctp_close, | |
329 | .url_get_file_handle = sctp_get_file_handle, | |
330 | .priv_data_size = sizeof(SCTPContext), | |
331 | .flags = URL_PROTOCOL_FLAG_NETWORK, | |
332 | }; |