summaryrefslogtreecommitdiffstats
path: root/libavformat/sctp.c
blob: 817b0049a990bfd81b21852863970b017237a889 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
/*
 * SCTP protocol
 * Copyright (c) 2012 Luca Barbato
 *
 * This file is part of Libav.
 *
 * Libav is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * Libav is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 *
 * sctp url_protocol
 *
 * url syntax: sctp://host:port[?option=val...]
 * option: 'listen'        : listen for an incoming connection
 *         'max_streams=n' : set the maximum number of streams
 *         'reuse=1'       : enable reusing the socket [TBD]
 *
 * by setting the maximum number of streams the protocol will use the
 * first two bytes of the incoming/outgoing buffer to store the
 * stream number of the packet being read/written.
 * @see sctp_read
 * @see sctp_write
 */


#include <netinet/in.h>
#include <netinet/sctp.h>
#include <sys/time.h>
#include <unistd.h>

#include "config.h"

#if HAVE_POLL_H
#include <poll.h>
#endif

#include "libavutil/intreadwrite.h"
#include "libavutil/parseutils.h"
#include "avformat.h"
#include "internal.h"
#include "network.h"
#include "os_support.h"
#include "url.h"

/*
 * The sctp_recvmsg and sctp_sendmsg functions are part of the user
 * library that offers support
 * for the SCTP kernel Implementation. The main purpose of this
 * code is to provide the SCTP Socket API mappings for user
 * application to interface with the SCTP in kernel.
 *
 * This implementation is based on the Socket API Extensions for SCTP
 * defined in <draft-ietf-tsvwg-sctpsocket-10.txt>
 *
 * Copyright (c) 2003 International Business Machines, Corp.
 *
 * Written or modified by:
 *  Ryan Layer <rmlayer@us.ibm.com>
 */

static int ff_sctp_recvmsg(int s, void *msg, size_t len, struct sockaddr *from,
                           socklen_t *fromlen, struct sctp_sndrcvinfo *sinfo,
                           int *msg_flags)
{
    int recvb;
    struct iovec iov;
    char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
    struct msghdr inmsg  = { 0 };
    struct cmsghdr *cmsg = NULL;

    iov.iov_base = msg;
    iov.iov_len  = len;

    inmsg.msg_name       = from;
    inmsg.msg_namelen    = fromlen ? *fromlen : 0;
    inmsg.msg_iov        = &iov;
    inmsg.msg_iovlen     = 1;
    inmsg.msg_control    = incmsg;
    inmsg.msg_controllen = sizeof(incmsg);

    if ((recvb = recvmsg(s, &inmsg, msg_flags ? *msg_flags : 0)) < 0)
        return recvb;

    if (fromlen)
        *fromlen   = inmsg.msg_namelen;
    if (msg_flags)
        *msg_flags = inmsg.msg_flags;

    for (cmsg = CMSG_FIRSTHDR(&inmsg); cmsg != NULL;
         cmsg = CMSG_NXTHDR(&inmsg, cmsg)) {
        if ((IPPROTO_SCTP == cmsg->cmsg_level) &&
            (SCTP_SNDRCV  == cmsg->cmsg_type))
            break;
    }

    /* Copy sinfo. */
    if (cmsg)
        memcpy(sinfo, CMSG_DATA(cmsg), sizeof(struct sctp_sndrcvinfo));

    return recvb;
}

static int ff_sctp_send(int s, const void *msg, size_t len,
                        const struct sctp_sndrcvinfo *sinfo, int flags)
{
    struct msghdr outmsg;
    struct iovec iov;

    outmsg.msg_name       = NULL;
    outmsg.msg_namelen    = 0;
    outmsg.msg_iov        = &iov;
    iov.iov_base          = msg;
    iov.iov_len           = len;
    outmsg.msg_iovlen     = 1;
    outmsg.msg_controllen = 0;

    if (sinfo) {
        char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
        struct cmsghdr *cmsg;

        outmsg.msg_control    = outcmsg;
        outmsg.msg_controllen = sizeof(outcmsg);
        outmsg.msg_flags      = 0;

        cmsg             = CMSG_FIRSTHDR(&outmsg);
        cmsg->cmsg_level = IPPROTO_SCTP;
        cmsg->cmsg_type  = SCTP_SNDRCV;
        cmsg->cmsg_len   = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));

        outmsg.msg_controllen = cmsg->cmsg_len;
        memcpy(CMSG_DATA(cmsg), sinfo, sizeof(struct sctp_sndrcvinfo));
    }

    return sendmsg(s, &outmsg, flags);
}

typedef struct SCTPContext {
    int fd;
    int max_streams;
    struct sockaddr_storage dest_addr;
    socklen_t dest_addr_len;
} SCTPContext;

static int sctp_open(URLContext *h, const char *uri, int flags)
{
    struct addrinfo *ai, *cur_ai;
    struct addrinfo hints             = { 0 };
    struct sctp_event_subscribe event = { 0 };
    struct sctp_initmsg initparams    = { 0 };
    int port;
    int fd         = -1;
    SCTPContext *s = h->priv_data;
    const char *p;
    char buf[256];
    int ret, listen_socket = 0;
    char hostname[1024], proto[1024], path[1024];
    char portstr[10];

    av_url_split(proto, sizeof(proto), NULL, 0, hostname, sizeof(hostname),
                 &port, path, sizeof(path), uri);
    if (strcmp(proto,"sctp") || port <= 0 || port >= 65536)
        return AVERROR(EINVAL);

    s->max_streams = 0;
    p = strchr(uri, '?');
    if (p) {
        if (av_find_info_tag(buf, sizeof(buf), "listen", p))
            listen_socket = 1;
        if (av_find_info_tag(buf, sizeof(buf), "max_streams", p))
            s->max_streams = strtol(buf, NULL, 10);
    }

    hints.ai_family   = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    snprintf(portstr, sizeof(portstr), "%d", port);
    ret = getaddrinfo(hostname, portstr, &hints, &ai);
    if (ret) {
        av_log(h, AV_LOG_ERROR, "Failed to resolve hostname %s: %s\n",
               hostname, gai_strerror(ret));
        return AVERROR(EIO);
    }

    cur_ai = ai;

    fd = socket(cur_ai->ai_family, SOCK_STREAM, IPPROTO_SCTP);
    if (fd < 0)
        goto fail;

    s->dest_addr_len = sizeof(s->dest_addr);

    if (listen_socket) {
        int fd1;
        ret = bind(fd, cur_ai->ai_addr, cur_ai->ai_addrlen);
        listen(fd, 100);
        fd1 = accept(fd, NULL, NULL);
        closesocket(fd);
        fd  = fd1;
    } else
        ret = connect(fd, cur_ai->ai_addr, cur_ai->ai_addrlen);

    ff_socket_nonblock(fd, 1);

    event.sctp_data_io_event = 1;
    /* TODO: Subscribe to more event types and handle them */

    if (setsockopt(fd, IPPROTO_SCTP, SCTP_EVENTS, &event,
                   sizeof(event)) != 0) {
        av_log(h, AV_LOG_ERROR,
               "SCTP ERROR: Unable to subscribe to events\n");
        goto fail;
    }

    if (s->max_streams) {
        initparams.sinit_max_instreams = s->max_streams;
        initparams.sinit_num_ostreams  = s->max_streams;
        if (setsockopt(fd, IPPROTO_SCTP, SCTP_INITMSG, &initparams,
                       sizeof(initparams)) < 0)
            av_log(h, AV_LOG_ERROR,
                   "SCTP ERROR: Unable to initialize socket max streams %d\n",
                   s->max_streams);
    }

    h->priv_data   = s;
    h->is_streamed = 1;
    s->fd          = fd;
    freeaddrinfo(ai);
    return 0;

fail:
    ret = AVERROR(EIO);
    freeaddrinfo(ai);
    return ret;
}

static int sctp_wait_fd(int fd, int write)
{
    int ev          = write ? POLLOUT : POLLIN;
    struct pollfd p = { .fd = fd, .events = ev, .revents = 0 };
    int ret;

    ret = poll(&p, 1, 100);
    return ret < 0 ? ff_neterrno() : p.revents & ev ? 0 : AVERROR(EAGAIN);
}

static int sctp_read(URLContext *h, uint8_t *buf, int size)
{
    SCTPContext *s = h->priv_data;
    int ret;

    if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
        ret = sctp_wait_fd(s->fd, 0);
        if (ret < 0)
            return ret;
    }

    if (s->max_streams) {
        /*StreamId is introduced as a 2byte code into the stream*/
        struct sctp_sndrcvinfo info = { 0 };
        ret = ff_sctp_recvmsg(s->fd, buf + 2, size - 2, NULL, 0, &info, 0);
        AV_WB16(buf, info.sinfo_stream);
        ret = ret < 0 ? ret : ret + 2;
    } else
        ret = recv(s->fd, buf, size, 0);

    return ret < 0 ? ff_neterrno() : ret;
}

static int sctp_write(URLContext *h, const uint8_t *buf, int size)
{
    SCTPContext *s = h->priv_data;
    int ret;

    if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
        ret = sctp_wait_fd(s->fd, 1);
        if (ret < 0)
            return ret;
    }

    if (s->max_streams) {
        /*StreamId is introduced as a 2byte code into the stream*/
        struct sctp_sndrcvinfo info = { 0 };
        info.sinfo_stream           = AV_RB16(buf);
        if (info.sinfo_stream > s->max_streams)
            abort();
        ret = ff_sctp_send(s->fd, buf + 2, size - 2, &info, MSG_EOR);
    } else
        ret = send(s->fd, buf, size, 0);

    return ret < 0 ? ff_neterrno() : ret;
}

static int sctp_close(URLContext *h)
{
    SCTPContext *s = h->priv_data;
    closesocket(s->fd);
    return 0;
}

static int sctp_get_file_handle(URLContext *h)
{
    SCTPContext *s = h->priv_data;
    return s->fd;
}

URLProtocol ff_sctp_protocol = {
    .name                = "sctp",
    .url_open            = sctp_open,
    .url_read            = sctp_read,
    .url_write           = sctp_write,
    .url_close           = sctp_close,
    .url_get_file_handle = sctp_get_file_handle,
    .priv_data_size      = sizeof(SCTPContext),
    .flags               = URL_PROTOCOL_FLAG_NETWORK,
};
OpenPOWER on IntegriCloud