udp.c
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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 
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 
45 typedef struct {
46  int udp_fd;
47  int ttl;
52  struct sockaddr_storage dest_addr;
55 } UDPContext;
56 
57 #define UDP_TX_BUF_SIZE 32768
58 #define UDP_MAX_PKT_SIZE 65536
59 
60 static 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 
82 static 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 
111 static 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 
140 static 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 
167 static 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 
182 static 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 
219 static 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 
247 int 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 
287 {
288  UDPContext *s = h->priv_data;
289  return s->local_port;
290 }
291 
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 */
305 static 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 
441 static 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 
455 static 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 
476 static 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 
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),
495 };