ffmpeg/libav/udp.c

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/*
* UDP prototype streaming system
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard.
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "avformat.h"
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
typedef struct {
int udp_fd;
int ttl;
int is_multicast;
int local_port;
struct ip_mreq mreq;
struct sockaddr_in dest_addr;
} UDPContext;
#define UDP_TX_BUF_SIZE 32768
/**
* 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: 'multicast=1' : enable multicast
* 'ttl=n' : set the ttl value (for multicast only)
* 'localport=n' : set the local port
*
* @param s1 media file context
* @param uri of the remote server
* @return zero if no error.
*/
int udp_set_remote_url(URLContext *h, const char *uri)
{
UDPContext *s = h->priv_data;
char hostname[256];
int port;
url_split(NULL, 0, hostname, sizeof(hostname), &port, NULL, 0, uri);
/* set the destination address */
if (resolve_host(&s->dest_addr.sin_addr, hostname) < 0)
return -EIO;
s->dest_addr.sin_family = AF_INET;
s->dest_addr.sin_port = htons(port);
return 0;
}
/**
* Return the local port used by the UDP connexion
* @param s1 media file context
* @return the local port number
*/
int 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
*/
int udp_get_file_handle(URLContext *h)
{
UDPContext *s = h->priv_data;
return s->udp_fd;
}
/* put it in UDP context */
/* return non zero if error */
static int udp_open(URLContext *h, const char *uri, int flags)
{
struct sockaddr_in my_addr, my_addr1;
char hostname[1024];
int port, udp_fd = -1, tmp;
UDPContext *s = NULL;
int is_output, len;
const char *p;
char buf[256];
h->is_streamed = 1;
is_output = (flags & URL_WRONLY);
s = av_malloc(sizeof(UDPContext));
if (!s)
return -ENOMEM;
h->priv_data = s;
s->ttl = 16;
s->is_multicast = 0;
p = strchr(uri, '?');
if (p) {
s->is_multicast = find_info_tag(buf, sizeof(buf), "multicast", p);
if (find_info_tag(buf, sizeof(buf), "ttl", p)) {
s->ttl = strtol(buf, NULL, 10);
}
if (find_info_tag(buf, sizeof(buf), "localport", p)) {
s->local_port = strtol(buf, NULL, 10);
}
}
/* fill the dest addr */
url_split(NULL, 0, hostname, sizeof(hostname), &port, NULL, 0, uri);
/* XXX: fix url_split */
if (hostname[0] == '\0' || hostname[0] == '?') {
/* only accepts null hostname if input */
if (s->is_multicast || (flags & URL_WRONLY))
goto fail;
} else {
udp_set_remote_url(h, uri);
}
udp_fd = socket(PF_INET, SOCK_DGRAM, 0);
if (udp_fd < 0)
goto fail;
if (s->is_multicast && !(h->flags & URL_WRONLY)) {
/* special case: the bind must be done on the multicast address */
my_addr = s->dest_addr;
} else {
my_addr.sin_family = AF_INET;
my_addr.sin_port = htons(s->local_port);
my_addr.sin_addr.s_addr = htonl (INADDR_ANY);
}
/* the bind is needed to give a port to the socket now */
if (bind(udp_fd,(struct sockaddr *)&my_addr, sizeof(my_addr)) < 0)
goto fail;
len = sizeof(my_addr1);
getsockname(udp_fd, (struct sockaddr *)&my_addr1, &len);
s->local_port = ntohs(my_addr1.sin_port);
if (s->is_multicast) {
if (h->flags & URL_WRONLY) {
/* output */
if (setsockopt(udp_fd, IPPROTO_IP, IP_MULTICAST_TTL,
&s->ttl, sizeof(s->ttl)) < 0) {
perror("IP_MULTICAST_TTL");
goto fail;
}
} else {
/* input */
memset(&s->mreq, 0, sizeof(s->mreq));
s->mreq.imr_multiaddr = s->dest_addr.sin_addr;
s->mreq.imr_interface.s_addr = htonl (INADDR_ANY);
if (setsockopt(udp_fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
&s->mreq, sizeof(s->mreq)) < 0) {
perror("rtp: IP_ADD_MEMBERSHIP");
goto fail;
}
}
}
if (is_output) {
/* limit the tx buf size to limit latency */
tmp = UDP_TX_BUF_SIZE;
if (setsockopt(udp_fd, SOL_SOCKET, SO_SNDBUF, &tmp, sizeof(tmp)) < 0) {
perror("setsockopt sndbuf");
goto fail;
}
}
s->udp_fd = udp_fd;
h->max_packet_size = 1472; /* XXX: probe it ? */
return 0;
fail:
if (udp_fd >= 0)
close(udp_fd);
av_free(s);
return -EIO;
}
static int udp_read(URLContext *h, UINT8 *buf, int size)
{
UDPContext *s = h->priv_data;
struct sockaddr_in from;
int from_len, len;
for(;;) {
from_len = sizeof(from);
len = recvfrom (s->udp_fd, buf, size, 0,
(struct sockaddr *)&from, &from_len);
if (len < 0) {
if (errno != EAGAIN && errno != EINTR)
return -EIO;
} else {
break;
}
}
return len;
}
static int udp_write(URLContext *h, UINT8 *buf, int size)
{
UDPContext *s = h->priv_data;
int ret;
for(;;) {
ret = sendto (s->udp_fd, buf, size, 0,
(struct sockaddr *) &s->dest_addr,
sizeof (s->dest_addr));
if (ret < 0) {
if (errno != EINTR && errno != EAGAIN)
return -EIO;
} else {
break;
}
}
return size;
}
static int udp_close(URLContext *h)
{
UDPContext *s = h->priv_data;
if (s->is_multicast && !(h->flags & URL_WRONLY)) {
if (setsockopt(s->udp_fd, IPPROTO_IP, IP_DROP_MEMBERSHIP,
&s->mreq, sizeof(s->mreq)) < 0) {
perror("IP_DROP_MEMBERSHIP");
}
}
close(s->udp_fd);
av_free(s);
return 0;
}
URLProtocol udp_protocol = {
"udp",
udp_open,
udp_read,
udp_write,
NULL, /* seek */
udp_close,
};