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7203dbde39
ffmpeg/libavformat/rtpproto.c
Ed Torbett 7203dbde39 avformat/rt*p: Joining a SSM multicast group using an SDP (Issue #2171) 
Passes Source-Specific Multicast parameters read from an sdp file through to the UDP socket code,
allowing source-specific multicast streams to be correctly received. As an integral part of this
change, additional checking (currently only enabled in the case of SSM streams, but probably
useful in similar scenarios) has been added to the RTP protocol handler to distinguish UDP packets
arriving from multiple sources to the same port and process only the expected packets
(those transmitted from the expected UDP source address). This resolves an issue identified
when multiple instances of FFmpeg subscribe to different Source-Specific Multicast streams
but with each sharing the same destination port.

Signed-off-by: Edward Torbett <ed.torbett@simulation-systems.co.uk>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
2013-07-18 18:01:31 +02:00

425 lines
14 KiB
C
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/*
* RTP network protocol
* Copyright (c) 2002 Fabrice Bellard
*
* This file is part of FFmpeg.
*
* FFmpeg 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.
*
* FFmpeg 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 FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* RTP protocol
*/
#include "libavutil/parseutils.h"
#include "libavutil/avstring.h"
#include "avformat.h"
#include "avio_internal.h"
#include "rtpdec.h"
#include "url.h"
#include <stdarg.h>
#include "internal.h"
#include "network.h"
#include "os_support.h"
#include <fcntl.h>
#if HAVE_POLL_H
#include <sys/poll.h>
#endif
typedef struct RTPContext {
URLContext *rtp_hd, *rtcp_hd;
int rtp_fd, rtcp_fd, ssm;
struct sockaddr_storage ssm_addr;
} RTPContext;
/**
* 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.
*
* @param h media file context
* @param uri of the remote server
* @return zero if no error.
*/
int ff_rtp_set_remote_url(URLContext *h, const char *uri)
{
RTPContext *s = h->priv_data;
char hostname[256];
int port;
char buf[1024];
char path[1024];
av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port,
path, sizeof(path), uri);
ff_url_join(buf, sizeof(buf), "udp", NULL, hostname, port, "%s", path);
ff_udp_set_remote_url(s->rtp_hd, buf);
ff_url_join(buf, sizeof(buf), "udp", NULL, hostname, port + 1, "%s", path);
ff_udp_set_remote_url(s->rtcp_hd, buf);
return 0;
}
static struct addrinfo* rtp_resolve_host(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(NULL, AV_LOG_ERROR, "rtp_resolve_host: %s\n", gai_strerror(error));
}
return res;
}
/**
* add option to url of the form:
* "http://host:port/path?option1=val1&option2=val2...
*/
static av_printf_format(3, 4) void url_add_option(char *buf, int buf_size, const char *fmt, ...)
{
char buf1[1024];
va_list ap;
va_start(ap, fmt);
if (strchr(buf, '?'))
av_strlcat(buf, "&", buf_size);
else
av_strlcat(buf, "?", buf_size);
vsnprintf(buf1, sizeof(buf1), fmt, ap);
av_strlcat(buf, buf1, buf_size);
va_end(ap);
}
static void build_udp_url(char *buf, int buf_size,
const char *hostname, int port,
int ssm, const char* source_addr,
int local_port, int ttl,
int max_packet_size, int connect)
{
ff_url_join(buf, buf_size, "udp", NULL, hostname, port, NULL);
if (local_port >= 0)
url_add_option(buf, buf_size, "localport=%d", local_port);
if (ttl >= 0)
url_add_option(buf, buf_size, "ttl=%d", ttl);
if (max_packet_size >=0)
url_add_option(buf, buf_size, "pkt_size=%d", max_packet_size);
if (ssm)
url_add_option(buf, buf_size, "sources=%s", source_addr);
if (connect)
url_add_option(buf, buf_size, "connect=1");
url_add_option(buf, buf_size, "fifo_size=0");
}
/**
* url syntax: rtp://host:port[?option=val...]
* option: 'ttl=n' : set the ttl value (for multicast only)
* 'rtcpport=n' : set the remote rtcp port to n
* 'localrtpport=n' : set the local rtp port to n
* 'localrtcpport=n' : set the local rtcp port to n
* 'pkt_size=n' : set max packet size
* 'connect=0/1' : do a connect() on the UDP socket
* deprecated option:
* 'localport=n' : set the local port to n
* 'ssm=ip' : use ip as source-specific multicast address
*
* if rtcpport isn't set the rtcp port will be the rtp port + 1
* if local rtp port isn't set any available port will be used for the local
* rtp and rtcp ports
* if the local rtcp port is not set it will be the local rtp port + 1
*/
static int rtp_open(URLContext *h, const char *uri, int flags)
{
RTPContext *s = h->priv_data;
int rtp_port, rtcp_port,
ttl, connect,
local_rtp_port, local_rtcp_port, max_packet_size;
char hostname[256],source_ip[50];
char buf[1024];
char path[1024];
const char *p;
struct addrinfo *sourceaddr;
av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &rtp_port,
path, sizeof(path), uri);
/* extract parameters */
ttl = -1;
rtcp_port = rtp_port+1;
local_rtp_port = -1;
local_rtcp_port = -1;
max_packet_size = -1;
s->ssm = 0;
connect = 0;
p = strchr(uri, '?');
if (p) {
if (av_find_info_tag(buf, sizeof(buf), "ttl", p)) {
ttl = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "rtcpport", p)) {
rtcp_port = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "localport", p)) {
local_rtp_port = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "localrtpport", p)) {
local_rtp_port = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "localrtcpport", p)) {
local_rtcp_port = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "pkt_size", p)) {
max_packet_size = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "connect", p)) {
connect = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "ssm", p)) {
s->ssm = 1;
snprintf(source_ip, sizeof(source_ip), "%s", buf);
sourceaddr = rtp_resolve_host(source_ip, 0,
SOCK_DGRAM, AF_UNSPEC,
AI_NUMERICHOST);
memcpy(&s->ssm_addr, sourceaddr->ai_addr, sourceaddr->ai_addrlen);
freeaddrinfo(sourceaddr);
}
}
build_udp_url(buf, sizeof(buf),
hostname, rtp_port, s->ssm, source_ip, local_rtp_port, ttl, max_packet_size,
connect);
if (ffurl_open(&s->rtp_hd, buf, flags, &h->interrupt_callback, NULL) < 0)
goto fail;
if (local_rtp_port>=0 && local_rtcp_port<0)
local_rtcp_port = ff_udp_get_local_port(s->rtp_hd) + 1;
build_udp_url(buf, sizeof(buf),
hostname, rtcp_port, s->ssm, source_ip, local_rtcp_port, ttl, max_packet_size,
connect);
if (ffurl_open(&s->rtcp_hd, buf, flags, &h->interrupt_callback, NULL) < 0)
goto fail;
/* just to ease handle access. XXX: need to suppress direct handle
access */
s->rtp_fd = ffurl_get_file_handle(s->rtp_hd);
s->rtcp_fd = ffurl_get_file_handle(s->rtcp_hd);
h->max_packet_size = s->rtp_hd->max_packet_size;
h->is_streamed = 1;
return 0;
fail:
if (s->rtp_hd)
ffurl_close(s->rtp_hd);
if (s->rtcp_hd)
ffurl_close(s->rtcp_hd);
return AVERROR(EIO);
}
static int rtp_read(URLContext *h, uint8_t *buf, int size)
{
RTPContext *s = h->priv_data;
struct sockaddr_storage from;
socklen_t from_len;
int len, n;
struct pollfd p[2] = {{s->rtp_fd, POLLIN, 0}, {s->rtcp_fd, POLLIN, 0}};
for(;;) {
if (ff_check_interrupt(&h->interrupt_callback))
return AVERROR_EXIT;
/* build fdset to listen to RTP and RTCP packets */
n = poll(p, 2, 100);
if (n > 0) {
/* first try RTCP */
if (p[1].revents & POLLIN) {
from_len = sizeof(from);
len = recvfrom (s->rtcp_fd, buf, size, 0,
(struct sockaddr *)&from, &from_len);
if (len < 0) {
if (ff_neterrno() == AVERROR(EAGAIN) ||
ff_neterrno() == AVERROR(EINTR))
continue;
return AVERROR(EIO);
}
if (s->ssm) {
if (from.ss_family == AF_INET && s->ssm_addr.ss_family == AF_INET) {
uint32_t intended_source = ((struct sockaddr_in *)&s->ssm_addr)->sin_addr.s_addr;
uint32_t actual_source = ((struct sockaddr_in *)&from)->sin_addr.s_addr;
if (intended_source != actual_source) {
// discard the packet without any processing
continue;
}
}
#if defined(IPPROTO_IPV6)
if (from.ss_family == AF_INET6 && s->ssm_addr.ss_family == AF_INET6) {
unsigned char* intended_source = ((struct sockaddr_in6 *)&s->ssm_addr)->sin6_addr.s6_addr;
unsigned char* actual_source = ((struct sockaddr_in6 *)&from)->sin6_addr.s6_addr;
if (memcmp(intended_source, actual_source, 16) != 0) {
// discard the packet without any processing
continue;
}
}
#endif
}
break;
}
/* then RTP */
if (p[0].revents & POLLIN) {
from_len = sizeof(from);
len = recvfrom (s->rtp_fd, buf, size, 0,
(struct sockaddr *)&from, &from_len);
if (len < 0) {
if (ff_neterrno() == AVERROR(EAGAIN) ||
ff_neterrno() == AVERROR(EINTR))
continue;
return AVERROR(EIO);
}
if (s->ssm) {
if (from.ss_family == AF_INET && s->ssm_addr.ss_family == AF_INET) {
uint32_t intended_source = ((struct sockaddr_in *)&s->ssm_addr)->sin_addr.s_addr;
uint32_t actual_source = ((struct sockaddr_in *)&from)->sin_addr.s_addr;
if (intended_source != actual_source) {
// discard the packet without any processing
continue;
}
}
#if defined(IPPROTO_IPV6)
if (from.ss_family == AF_INET6 && s->ssm_addr.ss_family == AF_INET6) {
unsigned char* intended_source = ((struct sockaddr_in6 *)&s->ssm_addr)->sin6_addr.s6_addr;
unsigned char* actual_source = ((struct sockaddr_in6 *)&from)->sin6_addr.s6_addr;
if (memcmp(intended_source, actual_source, 16) != 0) {
// discard the packet without any processing
continue;
}
}
#endif
}
break;
}
} else if (n < 0) {
if (ff_neterrno() == AVERROR(EINTR))
continue;
return AVERROR(EIO);
}
}
return len;
}
static int rtp_write(URLContext *h, const uint8_t *buf, int size)
{
RTPContext *s = h->priv_data;
int ret;
URLContext *hd;
if (RTP_PT_IS_RTCP(buf[1])) {
/* RTCP payload type */
hd = s->rtcp_hd;
} else {
/* RTP payload type */
hd = s->rtp_hd;
}
ret = ffurl_write(hd, buf, size);
return ret;
}
static int rtp_close(URLContext *h)
{
RTPContext *s = h->priv_data;
ffurl_close(s->rtp_hd);
ffurl_close(s->rtcp_hd);
return 0;
}
/**
* Return the local rtp port used by the RTP connection
* @param h media file context
* @return the local port number
*/
int ff_rtp_get_local_rtp_port(URLContext *h)
{
RTPContext *s = h->priv_data;
return ff_udp_get_local_port(s->rtp_hd);
}
/**
* Return the local rtcp port used by the RTP connection
* @param h media file context
* @return the local port number
*/
int ff_rtp_get_local_rtcp_port(URLContext *h)
{
RTPContext *s = h->priv_data;
return ff_udp_get_local_port(s->rtcp_hd);
}
static int rtp_get_file_handle(URLContext *h)
{
RTPContext *s = h->priv_data;
return s->rtp_fd;
}
static int rtp_get_multi_file_handle(URLContext *h, int **handles,
int *numhandles)
{
RTPContext *s = h->priv_data;
int *hs = *handles = av_malloc(sizeof(**handles) * 2);
if (!hs)
return AVERROR(ENOMEM);
hs[0] = s->rtp_fd;
hs[1] = s->rtcp_fd;
*numhandles = 2;
return 0;
}
URLProtocol ff_rtp_protocol = {
.name = "rtp",
.url_open = rtp_open,
.url_read = rtp_read,
.url_write = rtp_write,
.url_close = rtp_close,
.url_get_file_handle = rtp_get_file_handle,
.url_get_multi_file_handle = rtp_get_multi_file_handle,
.priv_data_size = sizeof(RTPContext),
.flags = URL_PROTOCOL_FLAG_NETWORK,
};
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