summaryrefslogtreecommitdiffstats
path: root/libavformat/udp.c
blob: 9d4c130e5bd7060959339aa6a07a760487223e10 (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
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
/*
 * UDP prototype streaming system
 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
 *
 * 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
 * UDP protocol
 */

#define _BSD_SOURCE     /* Needed for using struct ip_mreq with recent glibc */

#include "avformat.h"
#include "avio_internal.h"
#include "libavutil/parseutils.h"
#include "libavutil/avstring.h"
#include "libavutil/opt.h"
#include "internal.h"
#include "network.h"
#include "os_support.h"
#include "url.h"

#ifndef IPV6_ADD_MEMBERSHIP
#define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
#define IPV6_DROP_MEMBERSHIP IPV6_LEAVE_GROUP
#endif

typedef struct UDPContext {
    const AVClass *class;
    int udp_fd;
    int ttl;
    int buffer_size;
    int pkt_size;
    int is_multicast;
    int local_port;
    int reuse_socket;
    struct sockaddr_storage dest_addr;
    int dest_addr_len;
    int is_connected;
    char *localaddr;
    char *sources;
    char *block;
} UDPContext;

#define UDP_TX_BUF_SIZE 32768
#define UDP_MAX_PKT_SIZE 65536

#define OFFSET(x) offsetof(UDPContext, x)
#define D AV_OPT_FLAG_DECODING_PARAM
#define E AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
    { "ttl",            "Time to live (in milliseconds, multicast only)",  OFFSET(ttl),            AV_OPT_TYPE_INT,    { .i64 = 16 },     0, INT_MAX, .flags = D|E },
    { "buffer_size",    "System data size (in bytes)",                     OFFSET(buffer_size),    AV_OPT_TYPE_INT,    { .i64 = -1 },    -1, INT_MAX, .flags = D|E },
    { "local_port",     "Local port",                                      OFFSET(local_port),     AV_OPT_TYPE_INT,    { .i64 = -1 },    -1, INT_MAX, .flags = D|E },
    { "reuse_socket",   "Reuse socket",                                    OFFSET(reuse_socket),   AV_OPT_TYPE_INT,    { .i64 = -1 },    -1, 1,       .flags = D|E },
    { "connect",        "Connect socket",                                  OFFSET(is_connected),   AV_OPT_TYPE_INT,    { .i64 =  0 },     0, 1,       .flags = D|E },
    { "pkt_size",       "Maximum packet size",                             OFFSET(pkt_size),       AV_OPT_TYPE_INT,    { .i64 = -1 },    -1, INT_MAX, .flags = D|E },
    { "localaddr",      "Local address",                                   OFFSET(localaddr),      AV_OPT_TYPE_STRING, { .str = NULL },               .flags = D|E },
    { "sources",        "Source list",                                     OFFSET(sources),        AV_OPT_TYPE_STRING, { .str = NULL },               .flags = D|E },
    { "block",          "Block list",                                      OFFSET(block),          AV_OPT_TYPE_STRING, { .str = NULL },               .flags = D|E },
    { NULL }
};

static const AVClass udp_class = {
    .class_name = "udp",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
};

static void log_net_error(void *ctx, int level, const char* prefix)
{
    char errbuf[100];
    av_strerror(ff_neterrno(), errbuf, sizeof(errbuf));
    av_log(ctx, level, "%s: %s\n", prefix, errbuf);
}

static int udp_set_multicast_ttl(int sockfd, int mcastTTL,
                                 struct sockaddr *addr)
{
#ifdef IP_MULTICAST_TTL
    if (addr->sa_family == AF_INET) {
        if (setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL, &mcastTTL, sizeof(mcastTTL)) < 0) {
            log_net_error(NULL, AV_LOG_ERROR, "setsockopt(IP_MULTICAST_TTL)");
            return -1;
        }
    }
#endif
#if defined(IPPROTO_IPV6) && defined(IPV6_MULTICAST_HOPS)
    if (addr->sa_family == AF_INET6) {
        if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &mcastTTL, sizeof(mcastTTL)) < 0) {
            log_net_error(NULL, AV_LOG_ERROR, "setsockopt(IPV6_MULTICAST_HOPS)");
            return -1;
        }
    }
#endif
    return 0;
}

static int udp_join_multicast_group(int sockfd, struct sockaddr *addr)
{
#ifdef IP_ADD_MEMBERSHIP
    if (addr->sa_family == AF_INET) {
        struct ip_mreq mreq;

        mreq.imr_multiaddr.s_addr = ((struct sockaddr_in *)addr)->sin_addr.s_addr;
        mreq.imr_interface.s_addr= INADDR_ANY;
        if (setsockopt(sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, (const void *)&mreq, sizeof(mreq)) < 0) {
            log_net_error(NULL, AV_LOG_ERROR, "setsockopt(IP_ADD_MEMBERSHIP)");
            return -1;
        }
    }
#endif
#if HAVE_STRUCT_IPV6_MREQ && defined(IPPROTO_IPV6)
    if (addr->sa_family == AF_INET6) {
        struct ipv6_mreq mreq6;

        memcpy(&mreq6.ipv6mr_multiaddr, &(((struct sockaddr_in6 *)addr)->sin6_addr), sizeof(struct in6_addr));
        mreq6.ipv6mr_interface= 0;
        if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
            log_net_error(NULL, AV_LOG_ERROR, "setsockopt(IPV6_ADD_MEMBERSHIP)");
            return -1;
        }
    }
#endif
    return 0;
}

static int udp_leave_multicast_group(int sockfd, struct sockaddr *addr)
{
#ifdef IP_DROP_MEMBERSHIP
    if (addr->sa_family == AF_INET) {
        struct ip_mreq mreq;

        mreq.imr_multiaddr.s_addr = ((struct sockaddr_in *)addr)->sin_addr.s_addr;
        mreq.imr_interface.s_addr= INADDR_ANY;
        if (setsockopt(sockfd, IPPROTO_IP, IP_DROP_MEMBERSHIP, (const void *)&mreq, sizeof(mreq)) < 0) {
            log_net_error(NULL, AV_LOG_ERROR, "setsockopt(IP_DROP_MEMBERSHIP)");
            return -1;
        }
    }
#endif
#if HAVE_STRUCT_IPV6_MREQ && defined(IPPROTO_IPV6)
    if (addr->sa_family == AF_INET6) {
        struct ipv6_mreq mreq6;

        memcpy(&mreq6.ipv6mr_multiaddr, &(((struct sockaddr_in6 *)addr)->sin6_addr), sizeof(struct in6_addr));
        mreq6.ipv6mr_interface= 0;
        if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
            log_net_error(NULL, AV_LOG_ERROR, "setsockopt(IPV6_DROP_MEMBERSHIP)");
            return -1;
        }
    }
#endif
    return 0;
}

static struct addrinfo *udp_resolve_host(URLContext *h,
                                         const char *hostname, int port,
                                         int type, int family, int flags)
{
    struct addrinfo hints = { 0 }, *res = 0;
    int error;
    char sport[16];
    const char *node = 0, *service = "0";

    if (port > 0) {
        snprintf(sport, sizeof(sport), "%d", port);
        service = sport;
    }
    if ((hostname) && (hostname[0] != '\0') && (hostname[0] != '?')) {
        node = hostname;
    }
    hints.ai_socktype = type;
    hints.ai_family   = family;
    hints.ai_flags = flags;
    if ((error = getaddrinfo(node, service, &hints, &res))) {
        res = NULL;
        av_log(h, AV_LOG_ERROR, "getaddrinfo(%s, %s): %s\n",
               node ? node : "unknown",
               service ? service : "unknown",
               gai_strerror(error));
    }

    return res;
}

static int udp_set_multicast_sources(URLContext *h,
                                     int sockfd, struct sockaddr *addr,
                                     int addr_len, char **sources,
                                     int nb_sources, int include)
{
#if HAVE_STRUCT_GROUP_SOURCE_REQ && defined(MCAST_BLOCK_SOURCE) && !defined(_WIN32)
    /* These ones are available in the microsoft SDK, but don't seem to work
     * as on linux, so just prefer the v4-only approach there for now. */
    int i;
    for (i = 0; i < nb_sources; i++) {
        struct group_source_req mreqs;
        int level = addr->sa_family == AF_INET ? IPPROTO_IP : IPPROTO_IPV6;
        struct addrinfo *sourceaddr = udp_resolve_host(h, sources[i], 0,
                                                       SOCK_DGRAM, AF_UNSPEC,
                                                       0);
        if (!sourceaddr)
            return AVERROR(ENOENT);

        mreqs.gsr_interface = 0;
        memcpy(&mreqs.gsr_group, addr, addr_len);
        memcpy(&mreqs.gsr_source, sourceaddr->ai_addr, sourceaddr->ai_addrlen);
        freeaddrinfo(sourceaddr);

        if (setsockopt(sockfd, level,
                       include ? MCAST_JOIN_SOURCE_GROUP : MCAST_BLOCK_SOURCE,
                       (const void *)&mreqs, sizeof(mreqs)) < 0) {
            if (include)
                log_net_error(NULL, AV_LOG_ERROR, "setsockopt(MCAST_JOIN_SOURCE_GROUP)");
            else
                log_net_error(NULL, AV_LOG_ERROR, "setsockopt(MCAST_BLOCK_SOURCE)");
            return ff_neterrno();
        }
    }
#elif HAVE_STRUCT_IP_MREQ_SOURCE && defined(IP_BLOCK_SOURCE)
    int i;
    if (addr->sa_family != AF_INET) {
        av_log(NULL, AV_LOG_ERROR,
               "Setting multicast sources only supported for IPv4\n");
        return AVERROR(EINVAL);
    }
    for (i = 0; i < nb_sources; i++) {
        struct ip_mreq_source mreqs;
        struct addrinfo *sourceaddr = udp_resolve_host(h, sources[i], 0,
                                                       SOCK_DGRAM, AF_UNSPEC,
                                                       0);
        if (!sourceaddr)
            return AVERROR(ENOENT);
        if (sourceaddr->ai_addr->sa_family != AF_INET) {
            freeaddrinfo(sourceaddr);
            av_log(NULL, AV_LOG_ERROR, "%s is of incorrect protocol family\n",
                   sources[i]);
            return AVERROR(EINVAL);
        }

        mreqs.imr_multiaddr.s_addr = ((struct sockaddr_in *)addr)->sin_addr.s_addr;
        mreqs.imr_interface.s_addr = INADDR_ANY;
        mreqs.imr_sourceaddr.s_addr = ((struct sockaddr_in *)sourceaddr->ai_addr)->sin_addr.s_addr;
        freeaddrinfo(sourceaddr);

        if (setsockopt(sockfd, IPPROTO_IP,
                       include ? IP_ADD_SOURCE_MEMBERSHIP : IP_BLOCK_SOURCE,
                       (const void *)&mreqs, sizeof(mreqs)) < 0) {
            if (include)
                log_net_error(NULL, AV_LOG_ERROR, "setsockopt(IP_ADD_SOURCE_MEMBERSHIP)");
            else
                log_net_error(NULL, AV_LOG_ERROR, "setsockopt(IP_BLOCK_SOURCE)");
            return ff_neterrno();
        }
    }
#else
    return AVERROR(ENOSYS);
#endif
    return 0;
}
static int udp_set_url(URLContext *h,
                       struct sockaddr_storage *addr,
                       const char *hostname, int port)
{
    struct addrinfo *res0;
    int addr_len;

    res0 = udp_resolve_host(h, hostname, port, SOCK_DGRAM, AF_UNSPEC, 0);
    if (res0 == 0) return AVERROR(EIO);
    memcpy(addr, res0->ai_addr, res0->ai_addrlen);
    addr_len = res0->ai_addrlen;
    freeaddrinfo(res0);

    return addr_len;
}

static int udp_socket_create(URLContext *h, struct sockaddr_storage *addr,
                             socklen_t *addr_len, const char *localaddr)
{
    UDPContext *s = h->priv_data;
    int udp_fd = -1;
    struct addrinfo *res0 = NULL, *res = NULL;
    int family = AF_UNSPEC;

    if (((struct sockaddr *) &s->dest_addr)->sa_family)
        family = ((struct sockaddr *) &s->dest_addr)->sa_family;
    res0 = udp_resolve_host(h, (localaddr && localaddr[0]) ? localaddr : NULL,
                            s->local_port,
                            SOCK_DGRAM, family, AI_PASSIVE);
    if (res0 == 0)
        goto fail;
    for (res = res0; res; res=res->ai_next) {
        udp_fd = ff_socket(res->ai_family, SOCK_DGRAM, 0);
        if (udp_fd != -1) break;
        log_net_error(NULL, AV_LOG_ERROR, "socket");
    }

    if (udp_fd < 0)
        goto fail;

    memcpy(addr, res->ai_addr, res->ai_addrlen);
    *addr_len = res->ai_addrlen;

    freeaddrinfo(res0);

    return udp_fd;

 fail:
    if (udp_fd >= 0)
        closesocket(udp_fd);
    if(res0)
        freeaddrinfo(res0);
    return -1;
}

static int udp_port(struct sockaddr_storage *addr, int addr_len)
{
    char sbuf[sizeof(int)*3+1];
    int error;

    if ((error = getnameinfo((struct sockaddr *)addr, addr_len, NULL, 0,  sbuf, sizeof(sbuf), NI_NUMERICSERV)) != 0) {
        av_log(NULL, AV_LOG_ERROR, "getnameinfo: %s\n", gai_strerror(error));
        return -1;
    }

    return strtol(sbuf, NULL, 10);
}


/**
 * If no filename is given to av_open_input_file because you want to
 * get the local port first, then you must call this function to set
 * the remote server address.
 *
 * url syntax: udp://host:port[?option=val...]
 * option: 'ttl=n'       : set the ttl value (for multicast only)
 *         'localport=n' : set the local port
 *         'pkt_size=n'  : set max packet size
 *         'reuse=1'     : enable reusing the socket
 *
 * @param h media file context
 * @param uri of the remote server
 * @return zero if no error.
 */
int ff_udp_set_remote_url(URLContext *h, const char *uri)
{
    UDPContext *s = h->priv_data;
    char hostname[256], buf[10];
    int port;
    const char *p;

    av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port, NULL, 0, uri);

    /* set the destination address */
    s->dest_addr_len = udp_set_url(h, &s->dest_addr, hostname, port);
    if (s->dest_addr_len < 0) {
        return AVERROR(EIO);
    }
    s->is_multicast = ff_is_multicast_address((struct sockaddr*) &s->dest_addr);
    p = strchr(uri, '?');
    if (p) {
        if (av_find_info_tag(buf, sizeof(buf), "connect", p)) {
            int was_connected = s->is_connected;
            s->is_connected = strtol(buf, NULL, 10);
            if (s->is_connected && !was_connected) {
                if (connect(s->udp_fd, (struct sockaddr *) &s->dest_addr,
                            s->dest_addr_len)) {
                    s->is_connected = 0;
                    log_net_error(h, AV_LOG_ERROR, "connect");
                    return AVERROR(EIO);
                }
            }
        }
    }

    return 0;
}

/**
 * Return the local port used by the UDP connection
 * @param h media file context
 * @return the local port number
 */
int ff_udp_get_local_port(URLContext *h)
{
    UDPContext *s = h->priv_data;
    return s->local_port;
}

/**
 * Return the udp file handle for select() usage to wait for several RTP
 * streams at the same time.
 * @param h media file context
 */
static int udp_get_file_handle(URLContext *h)
{
    UDPContext *s = h->priv_data;
    return s->udp_fd;
}

static int parse_source_list(char *buf, char **sources, int *num_sources,
                             int max_sources)
{
    char *source_start;

    source_start = buf;
    while (1) {
        char *next = strchr(source_start, ',');
        if (next)
            *next = '\0';
        sources[*num_sources] = av_strdup(source_start);
        if (!sources[*num_sources])
            return AVERROR(ENOMEM);
        source_start = next + 1;
        (*num_sources)++;
        if (*num_sources >= max_sources || !next)
            break;
    }
    return 0;
}

/* put it in UDP context */
/* return non zero if error */
static int udp_open(URLContext *h, const char *uri, int flags)
{
    char hostname[1024], localaddr[1024] = "";
    int port, udp_fd = -1, tmp, bind_ret = -1;
    UDPContext *s = h->priv_data;
    int is_output;
    const char *p;
    char buf[256];
    struct sockaddr_storage my_addr;
    socklen_t len;
    int i, num_include_sources = 0, num_exclude_sources = 0;
    char *include_sources[32], *exclude_sources[32];

    h->is_streamed = 1;
    h->max_packet_size = 1472;

    is_output = !(flags & AVIO_FLAG_READ);

    if (s->buffer_size < 0)
        s->buffer_size = is_output ? UDP_TX_BUF_SIZE : UDP_MAX_PKT_SIZE;

    if (s->sources) {
        if (parse_source_list(s->sources, include_sources,
                              &num_include_sources,
                              FF_ARRAY_ELEMS(include_sources)))
            goto fail;
    }

    if (s->block) {
        if (parse_source_list(s->block, exclude_sources, &num_exclude_sources,
                              FF_ARRAY_ELEMS(exclude_sources)))
            goto fail;
    }

    if (s->pkt_size > 0)
        h->max_packet_size = s->pkt_size;

    p = strchr(uri, '?');
    if (p) {
        if (av_find_info_tag(buf, sizeof(buf), "reuse", p)) {
            char *endptr = NULL;
            s->reuse_socket = strtol(buf, &endptr, 10);
            /* assume if no digits were found it is a request to enable it */
            if (buf == endptr)
                s->reuse_socket = 1;
        }
        if (av_find_info_tag(buf, sizeof(buf), "ttl", p)) {
            s->ttl = strtol(buf, NULL, 10);
        }
        if (av_find_info_tag(buf, sizeof(buf), "localport", p)) {
            s->local_port = strtol(buf, NULL, 10);
        }
        if (av_find_info_tag(buf, sizeof(buf), "pkt_size", p)) {
            h->max_packet_size = strtol(buf, NULL, 10);
        }
        if (av_find_info_tag(buf, sizeof(buf), "buffer_size", p)) {
            s->buffer_size = strtol(buf, NULL, 10);
        }
        if (av_find_info_tag(buf, sizeof(buf), "connect", p)) {
            s->is_connected = strtol(buf, NULL, 10);
        }
        if (av_find_info_tag(buf, sizeof(buf), "localaddr", p)) {
            av_strlcpy(localaddr, buf, sizeof(localaddr));
        }
        if (av_find_info_tag(buf, sizeof(buf), "sources", p)) {
            if (parse_source_list(buf, include_sources, &num_include_sources,
                                  FF_ARRAY_ELEMS(include_sources)))
                goto fail;
        }
        if (av_find_info_tag(buf, sizeof(buf), "block", p)) {
            if (parse_source_list(buf, exclude_sources, &num_exclude_sources,
                                  FF_ARRAY_ELEMS(exclude_sources)))
                goto fail;
        }
    }

    /* fill the dest addr */
    av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port, NULL, 0, uri);

    /* XXX: fix av_url_split */
    if (hostname[0] == '\0' || hostname[0] == '?') {
        /* only accepts null hostname if input */
        if (!(flags & AVIO_FLAG_READ))
            goto fail;
    } else {
        if (ff_udp_set_remote_url(h, uri) < 0)
            goto fail;
    }

    if ((s->is_multicast || s->local_port < 0) && (h->flags & AVIO_FLAG_READ))
        s->local_port = port;

    if (localaddr[0])
        udp_fd = udp_socket_create(h, &my_addr, &len, localaddr);
    else
        udp_fd = udp_socket_create(h, &my_addr, &len, s->localaddr);
    if (udp_fd < 0)
        goto fail;

    /* Follow the requested reuse option, unless it's multicast in which
     * case enable reuse unless explicitly disabled.
     */
    if (s->reuse_socket > 0 || (s->is_multicast && s->reuse_socket < 0)) {
        s->reuse_socket = 1;
        if (setsockopt (udp_fd, SOL_SOCKET, SO_REUSEADDR, &(s->reuse_socket), sizeof(s->reuse_socket)) != 0)
            goto fail;
    }

    /* If multicast, try binding the multicast address first, to avoid
     * receiving UDP packets from other sources aimed at the same UDP
     * port. This fails on windows. This makes sending to the same address
     * using sendto() fail, so only do it if we're opened in read-only mode. */
    if (s->is_multicast && !(h->flags & AVIO_FLAG_WRITE)) {
        bind_ret = bind(udp_fd,(struct sockaddr *)&s->dest_addr, len);
    }
    /* bind to the local address if not multicast or if the multicast
     * bind failed */
    /* the bind is needed to give a port to the socket now */
    if (bind_ret < 0 && bind(udp_fd,(struct sockaddr *)&my_addr, len) < 0) {
        log_net_error(h, AV_LOG_ERROR, "bind failed");
        goto fail;
    }

    len = sizeof(my_addr);
    getsockname(udp_fd, (struct sockaddr *)&my_addr, &len);
    s->local_port = udp_port(&my_addr, len);

    if (s->is_multicast) {
        if (h->flags & AVIO_FLAG_WRITE) {
            /* output */
            if (udp_set_multicast_ttl(udp_fd, s->ttl, (struct sockaddr *)&s->dest_addr) < 0)
                goto fail;
        }
        if (h->flags & AVIO_FLAG_READ) {
            /* input */
            if (num_include_sources && num_exclude_sources) {
                av_log(h, AV_LOG_ERROR, "Simultaneously including and excluding multicast sources is not supported\n");
                goto fail;
            }
            if (num_include_sources) {
                if (udp_set_multicast_sources(h, udp_fd,
                                              (struct sockaddr *)&s->dest_addr,
                                              s->dest_addr_len,
                                              include_sources,
                                              num_include_sources, 1) < 0)
                    goto fail;
            } else {
                if (udp_join_multicast_group(udp_fd, (struct sockaddr *)&s->dest_addr) < 0)
                    goto fail;
            }
            if (num_exclude_sources) {
                if (udp_set_multicast_sources(h, udp_fd,
                                              (struct sockaddr *)&s->dest_addr,
                                              s->dest_addr_len,
                                              exclude_sources,
                                              num_exclude_sources, 0) < 0)
                    goto fail;
            }
        }
    }

    if (is_output) {
        /* limit the tx buf size to limit latency */
        tmp = s->buffer_size;
        if (setsockopt(udp_fd, SOL_SOCKET, SO_SNDBUF, &tmp, sizeof(tmp)) < 0) {
            log_net_error(h, AV_LOG_ERROR, "setsockopt(SO_SNDBUF)");
            goto fail;
        }
    } else {
        /* set udp recv buffer size to the largest possible udp packet size to
         * avoid losing data on OSes that set this too low by default. */
        tmp = s->buffer_size;
        if (setsockopt(udp_fd, SOL_SOCKET, SO_RCVBUF, &tmp, sizeof(tmp)) < 0) {
            log_net_error(h, AV_LOG_WARNING, "setsockopt(SO_RECVBUF)");
        }
        /* make the socket non-blocking */
        ff_socket_nonblock(udp_fd, 1);
    }
    if (s->is_connected) {
        if (connect(udp_fd, (struct sockaddr *) &s->dest_addr, s->dest_addr_len)) {
            log_net_error(h, AV_LOG_ERROR, "connect");
            goto fail;
        }
    }

    for (i = 0; i < num_include_sources; i++)
        av_freep(&include_sources[i]);
    for (i = 0; i < num_exclude_sources; i++)
        av_freep(&exclude_sources[i]);

    s->udp_fd = udp_fd;
    return 0;
 fail:
    if (udp_fd >= 0)
        closesocket(udp_fd);
    for (i = 0; i < num_include_sources; i++)
        av_freep(&include_sources[i]);
    for (i = 0; i < num_exclude_sources; i++)
        av_freep(&exclude_sources[i]);
    return AVERROR(EIO);
}

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

    if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
        ret = ff_network_wait_fd(s->udp_fd, 0);
        if (ret < 0)
            return ret;
    }
    ret = recv(s->udp_fd, buf, size, 0);
    return ret < 0 ? ff_neterrno() : ret;
}

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

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

    if (!s->is_connected) {
        ret = sendto (s->udp_fd, buf, size, 0,
                      (struct sockaddr *) &s->dest_addr,
                      s->dest_addr_len);
    } else
        ret = send(s->udp_fd, buf, size, 0);

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

static int udp_close(URLContext *h)
{
    UDPContext *s = h->priv_data;

    if (s->is_multicast && (h->flags & AVIO_FLAG_READ))
        udp_leave_multicast_group(s->udp_fd, (struct sockaddr *)&s->dest_addr);
    closesocket(s->udp_fd);
    return 0;
}

const URLProtocol ff_udp_protocol = {
    .name                = "udp",
    .url_open            = udp_open,
    .url_read            = udp_read,
    .url_write           = udp_write,
    .url_close           = udp_close,
    .url_get_file_handle = udp_get_file_handle,
    .priv_data_size      = sizeof(UDPContext),
    .flags               = URL_PROTOCOL_FLAG_NETWORK,
    .priv_data_class     = &udp_class,
};
OpenPOWER on IntegriCloud