1/*
2 * UDP prototype streaming system
3 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; 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 * UDP protocol
25 */
26
27#define _BSD_SOURCE     /* Needed for using struct ip_mreq with recent glibc */
28
29#include "avformat.h"
30#include "avio_internal.h"
31#include "libavutil/parseutils.h"
32#include "libavutil/avstring.h"
33#include <unistd.h>
34#include "internal.h"
35#include "network.h"
36#include "os_support.h"
37#include "url.h"
38#include <sys/time.h>
39
40#ifndef IPV6_ADD_MEMBERSHIP
41#define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
42#define IPV6_DROP_MEMBERSHIP IPV6_LEAVE_GROUP
43#endif
44
45typedef struct {
46    int udp_fd;
47    int ttl;
48    int buffer_size;
49    int is_multicast;
50    int local_port;
51    int reuse_socket;
52    struct sockaddr_storage dest_addr;
53    int dest_addr_len;
54    int is_connected;
55} UDPContext;
56
57#define UDP_TX_BUF_SIZE 32768
58#define UDP_MAX_PKT_SIZE 65536
59
60static int udp_set_multicast_ttl(int sockfd, int mcastTTL,
61                                 struct sockaddr *addr)
62{
63#ifdef IP_MULTICAST_TTL
64    if (addr->sa_family == AF_INET) {
65        if (setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL, &mcastTTL, sizeof(mcastTTL)) < 0) {
66            av_log(NULL, AV_LOG_ERROR, "setsockopt(IP_MULTICAST_TTL): %s\n", strerror(errno));
67            return -1;
68        }
69    }
70#endif
71#if defined(IPPROTO_IPV6) && defined(IPV6_MULTICAST_HOPS)
72    if (addr->sa_family == AF_INET6) {
73        if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &mcastTTL, sizeof(mcastTTL)) < 0) {
74            av_log(NULL, AV_LOG_ERROR, "setsockopt(IPV6_MULTICAST_HOPS): %s\n", strerror(errno));
75            return -1;
76        }
77    }
78#endif
79    return 0;
80}
81
82static int udp_join_multicast_group(int sockfd, struct sockaddr *addr)
83{
84#ifdef IP_ADD_MEMBERSHIP
85    if (addr->sa_family == AF_INET) {
86        struct ip_mreq mreq;
87
88        mreq.imr_multiaddr.s_addr = ((struct sockaddr_in *)addr)->sin_addr.s_addr;
89        mreq.imr_interface.s_addr= INADDR_ANY;
90        if (setsockopt(sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, (const void *)&mreq, sizeof(mreq)) < 0) {
91            av_log(NULL, AV_LOG_ERROR, "setsockopt(IP_ADD_MEMBERSHIP): %s\n", strerror(errno));
92            return -1;
93        }
94    }
95#endif
96#if HAVE_STRUCT_IPV6_MREQ && defined(IPPROTO_IPV6)
97    if (addr->sa_family == AF_INET6) {
98        struct ipv6_mreq mreq6;
99
100        memcpy(&mreq6.ipv6mr_multiaddr, &(((struct sockaddr_in6 *)addr)->sin6_addr), sizeof(struct in6_addr));
101        mreq6.ipv6mr_interface= 0;
102        if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
103            av_log(NULL, AV_LOG_ERROR, "setsockopt(IPV6_ADD_MEMBERSHIP): %s\n", strerror(errno));
104            return -1;
105        }
106    }
107#endif
108    return 0;
109}
110
111static int udp_leave_multicast_group(int sockfd, struct sockaddr *addr)
112{
113#ifdef IP_DROP_MEMBERSHIP
114    if (addr->sa_family == AF_INET) {
115        struct ip_mreq mreq;
116
117        mreq.imr_multiaddr.s_addr = ((struct sockaddr_in *)addr)->sin_addr.s_addr;
118        mreq.imr_interface.s_addr= INADDR_ANY;
119        if (setsockopt(sockfd, IPPROTO_IP, IP_DROP_MEMBERSHIP, (const void *)&mreq, sizeof(mreq)) < 0) {
120            av_log(NULL, AV_LOG_ERROR, "setsockopt(IP_DROP_MEMBERSHIP): %s\n", strerror(errno));
121            return -1;
122        }
123    }
124#endif
125#if HAVE_STRUCT_IPV6_MREQ && defined(IPPROTO_IPV6)
126    if (addr->sa_family == AF_INET6) {
127        struct ipv6_mreq mreq6;
128
129        memcpy(&mreq6.ipv6mr_multiaddr, &(((struct sockaddr_in6 *)addr)->sin6_addr), sizeof(struct in6_addr));
130        mreq6.ipv6mr_interface= 0;
131        if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
132            av_log(NULL, AV_LOG_ERROR, "setsockopt(IPV6_DROP_MEMBERSHIP): %s\n", strerror(errno));
133            return -1;
134        }
135    }
136#endif
137    return 0;
138}
139
140static struct addrinfo* udp_resolve_host(const char *hostname, int port,
141                                         int type, int family, int flags)
142{
143    struct addrinfo hints, *res = 0;
144    int error;
145    char sport[16];
146    const char *node = 0, *service = "0";
147
148    if (port > 0) {
149        snprintf(sport, sizeof(sport), "%d", port);
150        service = sport;
151    }
152    if ((hostname) && (hostname[0] != '\0') && (hostname[0] != '?')) {
153        node = hostname;
154    }
155    memset(&hints, 0, sizeof(hints));
156    hints.ai_socktype = type;
157    hints.ai_family   = family;
158    hints.ai_flags = flags;
159    if ((error = getaddrinfo(node, service, &hints, &res))) {
160        res = NULL;
161        av_log(NULL, AV_LOG_ERROR, "udp_resolve_host: %s\n", gai_strerror(error));
162    }
163
164    return res;
165}
166
167static int udp_set_url(struct sockaddr_storage *addr,
168                       const char *hostname, int port)
169{
170    struct addrinfo *res0;
171    int addr_len;
172
173    res0 = udp_resolve_host(hostname, port, SOCK_DGRAM, AF_UNSPEC, 0);
174    if (res0 == 0) return AVERROR(EIO);
175    memcpy(addr, res0->ai_addr, res0->ai_addrlen);
176    addr_len = res0->ai_addrlen;
177    freeaddrinfo(res0);
178
179    return addr_len;
180}
181
182static int udp_socket_create(UDPContext *s, struct sockaddr_storage *addr,
183                             int *addr_len, const char *localaddr)
184{
185    int udp_fd = -1;
186    struct addrinfo *res0 = NULL, *res = NULL;
187    int family = AF_UNSPEC;
188
189    if (((struct sockaddr *) &s->dest_addr)->sa_family)
190        family = ((struct sockaddr *) &s->dest_addr)->sa_family;
191    res0 = udp_resolve_host(localaddr[0] ? localaddr : NULL, s->local_port,
192                            SOCK_DGRAM, family, AI_PASSIVE);
193    if (res0 == 0)
194        goto fail;
195    for (res = res0; res; res=res->ai_next) {
196        udp_fd = socket(res->ai_family, SOCK_DGRAM, 0);
197        if (udp_fd > 0) break;
198        av_log(NULL, AV_LOG_ERROR, "socket: %s\n", strerror(errno));
199    }
200
201    if (udp_fd < 0)
202        goto fail;
203
204    memcpy(addr, res->ai_addr, res->ai_addrlen);
205    *addr_len = res->ai_addrlen;
206
207    freeaddrinfo(res0);
208
209    return udp_fd;
210
211 fail:
212    if (udp_fd >= 0)
213        closesocket(udp_fd);
214    if(res0)
215        freeaddrinfo(res0);
216    return -1;
217}
218
219static int udp_port(struct sockaddr_storage *addr, int addr_len)
220{
221    char sbuf[sizeof(int)*3+1];
222
223    if (getnameinfo((struct sockaddr *)addr, addr_len, NULL, 0,  sbuf, sizeof(sbuf), NI_NUMERICSERV) != 0) {
224        av_log(NULL, AV_LOG_ERROR, "getnameinfo: %s\n", strerror(errno));
225        return -1;
226    }
227
228    return strtol(sbuf, NULL, 10);
229}
230
231
232/**
233 * If no filename is given to av_open_input_file because you want to
234 * get the local port first, then you must call this function to set
235 * the remote server address.
236 *
237 * url syntax: udp://host:port[?option=val...]
238 * option: 'ttl=n'       : set the ttl value (for multicast only)
239 *         'localport=n' : set the local port
240 *         'pkt_size=n'  : set max packet size
241 *         'reuse=1'     : enable reusing the socket
242 *
243 * @param h media file context
244 * @param uri of the remote server
245 * @return zero if no error.
246 */
247int ff_udp_set_remote_url(URLContext *h, const char *uri)
248{
249    UDPContext *s = h->priv_data;
250    char hostname[256], buf[10];
251    int port;
252    const char *p;
253
254    av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port, NULL, 0, uri);
255
256    /* set the destination address */
257    s->dest_addr_len = udp_set_url(&s->dest_addr, hostname, port);
258    if (s->dest_addr_len < 0) {
259        return AVERROR(EIO);
260    }
261    s->is_multicast = ff_is_multicast_address((struct sockaddr*) &s->dest_addr);
262    p = strchr(uri, '?');
263    if (p) {
264        if (av_find_info_tag(buf, sizeof(buf), "connect", p)) {
265            int was_connected = s->is_connected;
266            s->is_connected = strtol(buf, NULL, 10);
267            if (s->is_connected && !was_connected) {
268                if (connect(s->udp_fd, (struct sockaddr *) &s->dest_addr,
269                            s->dest_addr_len)) {
270                    s->is_connected = 0;
271                    av_log(h, AV_LOG_ERROR, "connect: %s\n", strerror(errno));
272                    return AVERROR(EIO);
273                }
274            }
275        }
276    }
277
278    return 0;
279}
280
281/**
282 * Return the local port used by the UDP connection
283 * @param h media file context
284 * @return the local port number
285 */
286int ff_udp_get_local_port(URLContext *h)
287{
288    UDPContext *s = h->priv_data;
289    return s->local_port;
290}
291
292/**
293 * Return the udp file handle for select() usage to wait for several RTP
294 * streams at the same time.
295 * @param h media file context
296 */
297static int udp_get_file_handle(URLContext *h)
298{
299    UDPContext *s = h->priv_data;
300    return s->udp_fd;
301}
302
303/* put it in UDP context */
304/* return non zero if error */
305static int udp_open(URLContext *h, const char *uri, int flags)
306{
307    char hostname[1024], localaddr[1024] = "";
308    int port, udp_fd = -1, tmp, bind_ret = -1;
309    UDPContext *s = h->priv_data;
310    int is_output;
311    const char *p;
312    char buf[256];
313    struct sockaddr_storage my_addr;
314    int len;
315    int reuse_specified = 0;
316
317    h->is_streamed = 1;
318    h->max_packet_size = 1472;
319
320    is_output = !(flags & AVIO_FLAG_READ);
321
322    s->ttl = 16;
323    s->buffer_size = is_output ? UDP_TX_BUF_SIZE : UDP_MAX_PKT_SIZE;
324
325    p = strchr(uri, '?');
326    if (p) {
327        if (av_find_info_tag(buf, sizeof(buf), "reuse", p)) {
328            char *endptr = NULL;
329            s->reuse_socket = strtol(buf, &endptr, 10);
330            /* assume if no digits were found it is a request to enable it */
331            if (buf == endptr)
332                s->reuse_socket = 1;
333            reuse_specified = 1;
334        }
335        if (av_find_info_tag(buf, sizeof(buf), "ttl", p)) {
336            s->ttl = strtol(buf, NULL, 10);
337        }
338        if (av_find_info_tag(buf, sizeof(buf), "localport", p)) {
339            s->local_port = strtol(buf, NULL, 10);
340        }
341        if (av_find_info_tag(buf, sizeof(buf), "pkt_size", p)) {
342            h->max_packet_size = strtol(buf, NULL, 10);
343        }
344        if (av_find_info_tag(buf, sizeof(buf), "buffer_size", p)) {
345            s->buffer_size = strtol(buf, NULL, 10);
346        }
347        if (av_find_info_tag(buf, sizeof(buf), "connect", p)) {
348            s->is_connected = strtol(buf, NULL, 10);
349        }
350        if (av_find_info_tag(buf, sizeof(buf), "localaddr", p)) {
351            av_strlcpy(localaddr, buf, sizeof(localaddr));
352        }
353    }
354
355    /* fill the dest addr */
356    av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port, NULL, 0, uri);
357
358    /* XXX: fix av_url_split */
359    if (hostname[0] == '\0' || hostname[0] == '?') {
360        /* only accepts null hostname if input */
361        if (!(flags & AVIO_FLAG_READ))
362            goto fail;
363    } else {
364        if (ff_udp_set_remote_url(h, uri) < 0)
365            goto fail;
366    }
367
368    if ((s->is_multicast || !s->local_port) && (h->flags & AVIO_FLAG_READ))
369        s->local_port = port;
370    udp_fd = udp_socket_create(s, &my_addr, &len, localaddr);
371    if (udp_fd < 0)
372        goto fail;
373
374    /* Follow the requested reuse option, unless it's multicast in which
375     * case enable reuse unless explicitly disabled.
376     */
377    if (s->reuse_socket || (s->is_multicast && !reuse_specified)) {
378        s->reuse_socket = 1;
379        if (setsockopt (udp_fd, SOL_SOCKET, SO_REUSEADDR, &(s->reuse_socket), sizeof(s->reuse_socket)) != 0)
380            goto fail;
381    }
382
383    /* the bind is needed to give a port to the socket now */
384    /* if multicast, try the multicast address bind first */
385    if (s->is_multicast && (h->flags & AVIO_FLAG_READ)) {
386        bind_ret = bind(udp_fd,(struct sockaddr *)&s->dest_addr, len);
387    }
388    /* bind to the local address if not multicast or if the multicast
389     * bind failed */
390    if (bind_ret < 0 && bind(udp_fd,(struct sockaddr *)&my_addr, len) < 0)
391        goto fail;
392
393    len = sizeof(my_addr);
394    getsockname(udp_fd, (struct sockaddr *)&my_addr, &len);
395    s->local_port = udp_port(&my_addr, len);
396
397    if (s->is_multicast) {
398        if (!(h->flags & AVIO_FLAG_READ)) {
399            /* output */
400            if (udp_set_multicast_ttl(udp_fd, s->ttl, (struct sockaddr *)&s->dest_addr) < 0)
401                goto fail;
402        } else {
403            /* input */
404            if (udp_join_multicast_group(udp_fd, (struct sockaddr *)&s->dest_addr) < 0)
405                goto fail;
406        }
407    }
408
409    if (is_output) {
410        /* limit the tx buf size to limit latency */
411        tmp = s->buffer_size;
412        if (setsockopt(udp_fd, SOL_SOCKET, SO_SNDBUF, &tmp, sizeof(tmp)) < 0) {
413            av_log(h, AV_LOG_ERROR, "setsockopt(SO_SNDBUF): %s\n", strerror(errno));
414            goto fail;
415        }
416    } else {
417        /* set udp recv buffer size to the largest possible udp packet size to
418         * avoid losing data on OSes that set this too low by default. */
419        tmp = s->buffer_size;
420        if (setsockopt(udp_fd, SOL_SOCKET, SO_RCVBUF, &tmp, sizeof(tmp)) < 0) {
421            av_log(h, AV_LOG_WARNING, "setsockopt(SO_RECVBUF): %s\n", strerror(errno));
422        }
423        /* make the socket non-blocking */
424        ff_socket_nonblock(udp_fd, 1);
425    }
426    if (s->is_connected) {
427        if (connect(udp_fd, (struct sockaddr *) &s->dest_addr, s->dest_addr_len)) {
428            av_log(h, AV_LOG_ERROR, "connect: %s\n", strerror(errno));
429            goto fail;
430        }
431    }
432
433    s->udp_fd = udp_fd;
434    return 0;
435 fail:
436    if (udp_fd >= 0)
437        closesocket(udp_fd);
438    return AVERROR(EIO);
439}
440
441static int udp_read(URLContext *h, uint8_t *buf, int size)
442{
443    UDPContext *s = h->priv_data;
444    int ret;
445
446    if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
447        ret = ff_network_wait_fd(s->udp_fd, 0);
448        if (ret < 0)
449            return ret;
450    }
451    ret = recv(s->udp_fd, buf, size, 0);
452    return ret < 0 ? ff_neterrno() : ret;
453}
454
455static int udp_write(URLContext *h, const uint8_t *buf, int size)
456{
457    UDPContext *s = h->priv_data;
458    int ret;
459
460    if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
461        ret = ff_network_wait_fd(s->udp_fd, 1);
462        if (ret < 0)
463            return ret;
464    }
465
466    if (!s->is_connected) {
467        ret = sendto (s->udp_fd, buf, size, 0,
468                      (struct sockaddr *) &s->dest_addr,
469                      s->dest_addr_len);
470    } else
471        ret = send(s->udp_fd, buf, size, 0);
472
473    return ret < 0 ? ff_neterrno() : ret;
474}
475
476static int udp_close(URLContext *h)
477{
478    UDPContext *s = h->priv_data;
479
480    if (s->is_multicast && (h->flags & AVIO_FLAG_READ))
481        udp_leave_multicast_group(s->udp_fd, (struct sockaddr *)&s->dest_addr);
482    closesocket(s->udp_fd);
483    return 0;
484}
485
486URLProtocol ff_udp_protocol = {
487    .name                = "udp",
488    .url_open            = udp_open,
489    .url_read            = udp_read,
490    .url_write           = udp_write,
491    .url_close           = udp_close,
492    .url_get_file_handle = udp_get_file_handle,
493    .priv_data_size      = sizeof(UDPContext),
494    .flags               = URL_PROTOCOL_FLAG_NETWORK,
495};
496