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libavformat/udp.c

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00001 /*
00002  * UDP prototype streaming system
00003  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00027 #define _BSD_SOURCE     /* Needed for using struct ip_mreq with recent glibc */
00028 #include "avformat.h"
00029 #include <unistd.h>
00030 #include "internal.h"
00031 #include "network.h"
00032 #include "os_support.h"
00033 #if HAVE_SYS_SELECT_H
00034 #include <sys/select.h>
00035 #endif
00036 #include <sys/time.h>
00037 
00038 #ifndef IPV6_ADD_MEMBERSHIP
00039 #define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
00040 #define IPV6_DROP_MEMBERSHIP IPV6_LEAVE_GROUP
00041 #endif
00042 #ifndef IN_MULTICAST
00043 #define IN_MULTICAST(a) ((((uint32_t)(a)) & 0xf0000000) == 0xe0000000)
00044 #endif
00045 #ifndef IN6_IS_ADDR_MULTICAST
00046 #define IN6_IS_ADDR_MULTICAST(a) (((uint8_t *) (a))[0] == 0xff)
00047 #endif
00048 
00049 typedef struct {
00050     int udp_fd;
00051     int ttl;
00052     int buffer_size;
00053     int is_multicast;
00054     int local_port;
00055     int reuse_socket;
00056     struct sockaddr_storage dest_addr;
00057     int dest_addr_len;
00058 } UDPContext;
00059 
00060 #define UDP_TX_BUF_SIZE 32768
00061 #define UDP_MAX_PKT_SIZE 65536
00062 
00063 static int udp_set_multicast_ttl(int sockfd, int mcastTTL,
00064                                  struct sockaddr *addr)
00065 {
00066 #ifdef IP_MULTICAST_TTL
00067     if (addr->sa_family == AF_INET) {
00068         if (setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL, &mcastTTL, sizeof(mcastTTL)) < 0) {
00069             av_log(NULL, AV_LOG_ERROR, "setsockopt(IP_MULTICAST_TTL): %s\n", strerror(errno));
00070             return -1;
00071         }
00072     }
00073 #endif
00074 #if defined(IPPROTO_IPV6) && defined(IPV6_MULTICAST_HOPS)
00075     if (addr->sa_family == AF_INET6) {
00076         if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &mcastTTL, sizeof(mcastTTL)) < 0) {
00077             av_log(NULL, AV_LOG_ERROR, "setsockopt(IPV6_MULTICAST_HOPS): %s\n", strerror(errno));
00078             return -1;
00079         }
00080     }
00081 #endif
00082     return 0;
00083 }
00084 
00085 static int udp_join_multicast_group(int sockfd, struct sockaddr *addr)
00086 {
00087 #ifdef IP_ADD_MEMBERSHIP
00088     if (addr->sa_family == AF_INET) {
00089         struct ip_mreq mreq;
00090 
00091         mreq.imr_multiaddr.s_addr = ((struct sockaddr_in *)addr)->sin_addr.s_addr;
00092         mreq.imr_interface.s_addr= INADDR_ANY;
00093         if (setsockopt(sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, (const void *)&mreq, sizeof(mreq)) < 0) {
00094             av_log(NULL, AV_LOG_ERROR, "setsockopt(IP_ADD_MEMBERSHIP): %s\n", strerror(errno));
00095             return -1;
00096         }
00097     }
00098 #endif
00099 #if HAVE_STRUCT_IPV6_MREQ
00100     if (addr->sa_family == AF_INET6) {
00101         struct ipv6_mreq mreq6;
00102 
00103         memcpy(&mreq6.ipv6mr_multiaddr, &(((struct sockaddr_in6 *)addr)->sin6_addr), sizeof(struct in6_addr));
00104         mreq6.ipv6mr_interface= 0;
00105         if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
00106             av_log(NULL, AV_LOG_ERROR, "setsockopt(IPV6_ADD_MEMBERSHIP): %s\n", strerror(errno));
00107             return -1;
00108         }
00109     }
00110 #endif
00111     return 0;
00112 }
00113 
00114 static int udp_leave_multicast_group(int sockfd, struct sockaddr *addr)
00115 {
00116 #ifdef IP_DROP_MEMBERSHIP
00117     if (addr->sa_family == AF_INET) {
00118         struct ip_mreq mreq;
00119 
00120         mreq.imr_multiaddr.s_addr = ((struct sockaddr_in *)addr)->sin_addr.s_addr;
00121         mreq.imr_interface.s_addr= INADDR_ANY;
00122         if (setsockopt(sockfd, IPPROTO_IP, IP_DROP_MEMBERSHIP, (const void *)&mreq, sizeof(mreq)) < 0) {
00123             av_log(NULL, AV_LOG_ERROR, "setsockopt(IP_DROP_MEMBERSHIP): %s\n", strerror(errno));
00124             return -1;
00125         }
00126     }
00127 #endif
00128 #if HAVE_STRUCT_IPV6_MREQ
00129     if (addr->sa_family == AF_INET6) {
00130         struct ipv6_mreq mreq6;
00131 
00132         memcpy(&mreq6.ipv6mr_multiaddr, &(((struct sockaddr_in6 *)addr)->sin6_addr), sizeof(struct in6_addr));
00133         mreq6.ipv6mr_interface= 0;
00134         if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
00135             av_log(NULL, AV_LOG_ERROR, "setsockopt(IPV6_DROP_MEMBERSHIP): %s\n", strerror(errno));
00136             return -1;
00137         }
00138     }
00139 #endif
00140     return 0;
00141 }
00142 
00143 static struct addrinfo* udp_resolve_host(const char *hostname, int port,
00144                                          int type, int family, int flags)
00145 {
00146     struct addrinfo hints, *res = 0;
00147     int error;
00148     char sport[16];
00149     const char *node = 0, *service = "0";
00150 
00151     if (port > 0) {
00152         snprintf(sport, sizeof(sport), "%d", port);
00153         service = sport;
00154     }
00155     if ((hostname) && (hostname[0] != '\0') && (hostname[0] != '?')) {
00156         node = hostname;
00157     }
00158     memset(&hints, 0, sizeof(hints));
00159     hints.ai_socktype = type;
00160     hints.ai_family   = family;
00161     hints.ai_flags = flags;
00162     if ((error = getaddrinfo(node, service, &hints, &res))) {
00163         res = NULL;
00164         av_log(NULL, AV_LOG_ERROR, "udp_resolve_host: %s\n", gai_strerror(error));
00165     }
00166 
00167     return res;
00168 }
00169 
00170 static int udp_set_url(struct sockaddr_storage *addr,
00171                        const char *hostname, int port)
00172 {
00173     struct addrinfo *res0;
00174     int addr_len;
00175 
00176     res0 = udp_resolve_host(hostname, port, SOCK_DGRAM, AF_UNSPEC, 0);
00177     if (res0 == 0) return AVERROR(EIO);
00178     memcpy(addr, res0->ai_addr, res0->ai_addrlen);
00179     addr_len = res0->ai_addrlen;
00180     freeaddrinfo(res0);
00181 
00182     return addr_len;
00183 }
00184 
00185 static int is_multicast_address(struct sockaddr_storage *addr)
00186 {
00187     if (addr->ss_family == AF_INET) {
00188         return IN_MULTICAST(ntohl(((struct sockaddr_in *)addr)->sin_addr.s_addr));
00189     }
00190 #if HAVE_STRUCT_SOCKADDR_IN6
00191     if (addr->ss_family == AF_INET6) {
00192         return IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)addr)->sin6_addr);
00193     }
00194 #endif
00195 
00196     return 0;
00197 }
00198 
00199 static int udp_socket_create(UDPContext *s,
00200                              struct sockaddr_storage *addr, int *addr_len)
00201 {
00202     int udp_fd = -1;
00203     struct addrinfo *res0 = NULL, *res = NULL;
00204     int family = AF_UNSPEC;
00205 
00206     if (((struct sockaddr *) &s->dest_addr)->sa_family)
00207         family = ((struct sockaddr *) &s->dest_addr)->sa_family;
00208     res0 = udp_resolve_host(0, s->local_port, SOCK_DGRAM, family, AI_PASSIVE);
00209     if (res0 == 0)
00210         goto fail;
00211     for (res = res0; res; res=res->ai_next) {
00212         udp_fd = socket(res->ai_family, SOCK_DGRAM, 0);
00213         if (udp_fd > 0) break;
00214         av_log(NULL, AV_LOG_ERROR, "socket: %s\n", strerror(errno));
00215     }
00216 
00217     if (udp_fd < 0)
00218         goto fail;
00219 
00220     memcpy(addr, res->ai_addr, res->ai_addrlen);
00221     *addr_len = res->ai_addrlen;
00222 
00223     freeaddrinfo(res0);
00224 
00225     return udp_fd;
00226 
00227  fail:
00228     if (udp_fd >= 0)
00229         closesocket(udp_fd);
00230     if(res0)
00231         freeaddrinfo(res0);
00232     return -1;
00233 }
00234 
00235 static int udp_port(struct sockaddr_storage *addr, int addr_len)
00236 {
00237     char sbuf[sizeof(int)*3+1];
00238 
00239     if (getnameinfo((struct sockaddr *)addr, addr_len, NULL, 0,  sbuf, sizeof(sbuf), NI_NUMERICSERV) != 0) {
00240         av_log(NULL, AV_LOG_ERROR, "getnameinfo: %s\n", strerror(errno));
00241         return -1;
00242     }
00243 
00244     return strtol(sbuf, NULL, 10);
00245 }
00246 
00247 
00263 int udp_set_remote_url(URLContext *h, const char *uri)
00264 {
00265     UDPContext *s = h->priv_data;
00266     char hostname[256];
00267     int port;
00268 
00269     ff_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port, NULL, 0, uri);
00270 
00271     /* set the destination address */
00272     s->dest_addr_len = udp_set_url(&s->dest_addr, hostname, port);
00273     if (s->dest_addr_len < 0) {
00274         return AVERROR(EIO);
00275     }
00276     s->is_multicast = is_multicast_address(&s->dest_addr);
00277 
00278     return 0;
00279 }
00280 
00286 int udp_get_local_port(URLContext *h)
00287 {
00288     UDPContext *s = h->priv_data;
00289     return s->local_port;
00290 }
00291 
00297 #if (LIBAVFORMAT_VERSION_MAJOR >= 53)
00298 static
00299 #endif
00300 int udp_get_file_handle(URLContext *h)
00301 {
00302     UDPContext *s = h->priv_data;
00303     return s->udp_fd;
00304 }
00305 
00306 /* put it in UDP context */
00307 /* return non zero if error */
00308 static int udp_open(URLContext *h, const char *uri, int flags)
00309 {
00310     char hostname[1024];
00311     int port, udp_fd = -1, tmp, bind_ret = -1;
00312     UDPContext *s = NULL;
00313     int is_output;
00314     const char *p;
00315     char buf[256];
00316     struct sockaddr_storage my_addr;
00317     int len;
00318 
00319     h->is_streamed = 1;
00320     h->max_packet_size = 1472;
00321 
00322     is_output = (flags & URL_WRONLY);
00323 
00324     s = av_mallocz(sizeof(UDPContext));
00325     if (!s)
00326         return AVERROR(ENOMEM);
00327 
00328     h->priv_data = s;
00329     s->ttl = 16;
00330     s->buffer_size = is_output ? UDP_TX_BUF_SIZE : UDP_MAX_PKT_SIZE;
00331 
00332     p = strchr(uri, '?');
00333     if (p) {
00334         s->reuse_socket = find_info_tag(buf, sizeof(buf), "reuse", p);
00335         if (find_info_tag(buf, sizeof(buf), "ttl", p)) {
00336             s->ttl = strtol(buf, NULL, 10);
00337         }
00338         if (find_info_tag(buf, sizeof(buf), "localport", p)) {
00339             s->local_port = strtol(buf, NULL, 10);
00340         }
00341         if (find_info_tag(buf, sizeof(buf), "pkt_size", p)) {
00342             h->max_packet_size = strtol(buf, NULL, 10);
00343         }
00344         if (find_info_tag(buf, sizeof(buf), "buffer_size", p)) {
00345             s->buffer_size = strtol(buf, NULL, 10);
00346         }
00347     }
00348 
00349     /* fill the dest addr */
00350     ff_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port, NULL, 0, uri);
00351 
00352     /* XXX: fix ff_url_split */
00353     if (hostname[0] == '\0' || hostname[0] == '?') {
00354         /* only accepts null hostname if input */
00355         if (flags & URL_WRONLY)
00356             goto fail;
00357     } else {
00358         udp_set_remote_url(h, uri);
00359     }
00360 
00361     if (s->is_multicast && !(h->flags & URL_WRONLY))
00362         s->local_port = port;
00363     udp_fd = udp_socket_create(s, &my_addr, &len);
00364     if (udp_fd < 0)
00365         goto fail;
00366 
00367     if (s->reuse_socket)
00368         if (setsockopt (udp_fd, SOL_SOCKET, SO_REUSEADDR, &(s->reuse_socket), sizeof(s->reuse_socket)) != 0)
00369             goto fail;
00370 
00371     /* the bind is needed to give a port to the socket now */
00372     /* if multicast, try the multicast address bind first */
00373     if (s->is_multicast && !(h->flags & URL_WRONLY)) {
00374         bind_ret = bind(udp_fd,(struct sockaddr *)&s->dest_addr, len);
00375     }
00376     /* bind to the local address if not multicast or if the multicast
00377      * bind failed */
00378     if (bind_ret < 0 && bind(udp_fd,(struct sockaddr *)&my_addr, len) < 0)
00379         goto fail;
00380 
00381     len = sizeof(my_addr);
00382     getsockname(udp_fd, (struct sockaddr *)&my_addr, &len);
00383     s->local_port = udp_port(&my_addr, len);
00384 
00385     if (s->is_multicast) {
00386         if (h->flags & URL_WRONLY) {
00387             /* output */
00388             if (udp_set_multicast_ttl(udp_fd, s->ttl, (struct sockaddr *)&s->dest_addr) < 0)
00389                 goto fail;
00390         } else {
00391             /* input */
00392             if (udp_join_multicast_group(udp_fd, (struct sockaddr *)&s->dest_addr) < 0)
00393                 goto fail;
00394         }
00395     }
00396 
00397     if (is_output) {
00398         /* limit the tx buf size to limit latency */
00399         tmp = s->buffer_size;
00400         if (setsockopt(udp_fd, SOL_SOCKET, SO_SNDBUF, &tmp, sizeof(tmp)) < 0) {
00401             av_log(NULL, AV_LOG_ERROR, "setsockopt(SO_SNDBUF): %s\n", strerror(errno));
00402             goto fail;
00403         }
00404     } else {
00405         /* set udp recv buffer size to the largest possible udp packet size to
00406          * avoid losing data on OSes that set this too low by default. */
00407         tmp = s->buffer_size;
00408         if (setsockopt(udp_fd, SOL_SOCKET, SO_RCVBUF, &tmp, sizeof(tmp)) < 0) {
00409             av_log(NULL, AV_LOG_WARNING, "setsockopt(SO_RECVBUF): %s\n", strerror(errno));
00410         }
00411         /* make the socket non-blocking */
00412         ff_socket_nonblock(udp_fd, 1);
00413     }
00414 
00415     s->udp_fd = udp_fd;
00416     return 0;
00417  fail:
00418     if (udp_fd >= 0)
00419         closesocket(udp_fd);
00420     av_free(s);
00421     return AVERROR(EIO);
00422 }
00423 
00424 static int udp_read(URLContext *h, uint8_t *buf, int size)
00425 {
00426     UDPContext *s = h->priv_data;
00427     int len;
00428     fd_set rfds;
00429     int ret;
00430     struct timeval tv;
00431 
00432     for(;;) {
00433         if (url_interrupt_cb())
00434             return AVERROR(EINTR);
00435         FD_ZERO(&rfds);
00436         FD_SET(s->udp_fd, &rfds);
00437         tv.tv_sec = 0;
00438         tv.tv_usec = 100 * 1000;
00439         ret = select(s->udp_fd + 1, &rfds, NULL, NULL, &tv);
00440         if (ret < 0) {
00441             if (ff_neterrno() == FF_NETERROR(EINTR))
00442                 continue;
00443             return AVERROR(EIO);
00444         }
00445         if (!(ret > 0 && FD_ISSET(s->udp_fd, &rfds)))
00446             continue;
00447         len = recv(s->udp_fd, buf, size, 0);
00448         if (len < 0) {
00449             if (ff_neterrno() != FF_NETERROR(EAGAIN) &&
00450                 ff_neterrno() != FF_NETERROR(EINTR))
00451                 return AVERROR(EIO);
00452         } else {
00453             break;
00454         }
00455     }
00456     return len;
00457 }
00458 
00459 static int udp_write(URLContext *h, uint8_t *buf, int size)
00460 {
00461     UDPContext *s = h->priv_data;
00462     int ret;
00463 
00464     for(;;) {
00465         ret = sendto (s->udp_fd, buf, size, 0,
00466                       (struct sockaddr *) &s->dest_addr,
00467                       s->dest_addr_len);
00468         if (ret < 0) {
00469             if (ff_neterrno() != FF_NETERROR(EINTR) &&
00470                 ff_neterrno() != FF_NETERROR(EAGAIN))
00471                 return AVERROR(EIO);
00472         } else {
00473             break;
00474         }
00475     }
00476     return size;
00477 }
00478 
00479 static int udp_close(URLContext *h)
00480 {
00481     UDPContext *s = h->priv_data;
00482 
00483     if (s->is_multicast && !(h->flags & URL_WRONLY))
00484         udp_leave_multicast_group(s->udp_fd, (struct sockaddr *)&s->dest_addr);
00485     closesocket(s->udp_fd);
00486     av_free(s);
00487     return 0;
00488 }
00489 
00490 URLProtocol udp_protocol = {
00491     "udp",
00492     udp_open,
00493     udp_read,
00494     udp_write,
00495     NULL, /* seek */
00496     udp_close,
00497     .url_get_file_handle = udp_get_file_handle,
00498 };

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