| 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"); |
| 301 | return AVERROR_BUG; |
| 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 | }; |