ffmpeg/libavformat/udp.c
Michael Niedermayer bc900501e0 udp: Replace double select() by select+mutex+cond.
When no data was available both the buffer thread as well as
the main thread would block in select(), when data becomes
available both should move forward and as data is read in the
buffer thread the main thread would block in select() later
the read data was put in the fifo but the main thread still
would be blocked in select() until either the timeout or
another packet would come in.

This is solved in this commit by using a mutex and a condition
variable

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
2011-12-23 01:42:42 +01:00

638 lines
19 KiB
C

/*
* UDP prototype streaming system
* Copyright (c) 2000, 2001, 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
* UDP protocol
*/
#define _BSD_SOURCE /* Needed for using struct ip_mreq with recent glibc */
#include "avformat.h"
#include "avio_internal.h"
#include "libavutil/parseutils.h"
#include "libavutil/fifo.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/avstring.h"
#include <unistd.h>
#include "internal.h"
#include "network.h"
#include "os_support.h"
#include "url.h"
#if HAVE_PTHREADS
#include <pthread.h>
#endif
#include <sys/time.h>
#ifndef IPV6_ADD_MEMBERSHIP
#define IPV6_ADD_MEMBERSHIP IPV6_JOIN_GROUP
#define IPV6_DROP_MEMBERSHIP IPV6_LEAVE_GROUP
#endif
#define UDP_TX_BUF_SIZE 32768
#define UDP_MAX_PKT_SIZE 65536
typedef struct {
int udp_fd;
int ttl;
int buffer_size;
int is_multicast;
int local_port;
int reuse_socket;
struct sockaddr_storage dest_addr;
int dest_addr_len;
int is_connected;
/* Circular Buffer variables for use in UDP receive code */
int circular_buffer_size;
AVFifoBuffer *fifo;
int circular_buffer_error;
#if HAVE_PTHREADS
pthread_t circular_buffer_thread;
pthread_mutex_t mutex;
pthread_cond_t cond;
#endif
uint8_t tmp[UDP_MAX_PKT_SIZE+4];
int remaining_in_dg;
} UDPContext;
static int udp_set_multicast_ttl(int sockfd, int mcastTTL,
struct sockaddr *addr)
{
#ifdef IP_MULTICAST_TTL
if (addr->sa_family == AF_INET) {
if (setsockopt(sockfd, IPPROTO_IP, IP_MULTICAST_TTL, &mcastTTL, sizeof(mcastTTL)) < 0) {
av_log(NULL, AV_LOG_ERROR, "setsockopt(IP_MULTICAST_TTL): %s\n", strerror(errno));
return -1;
}
}
#endif
#if defined(IPPROTO_IPV6) && defined(IPV6_MULTICAST_HOPS)
if (addr->sa_family == AF_INET6) {
if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &mcastTTL, sizeof(mcastTTL)) < 0) {
av_log(NULL, AV_LOG_ERROR, "setsockopt(IPV6_MULTICAST_HOPS): %s\n", strerror(errno));
return -1;
}
}
#endif
return 0;
}
static int udp_join_multicast_group(int sockfd, struct sockaddr *addr)
{
#ifdef IP_ADD_MEMBERSHIP
if (addr->sa_family == AF_INET) {
struct ip_mreq mreq;
mreq.imr_multiaddr.s_addr = ((struct sockaddr_in *)addr)->sin_addr.s_addr;
mreq.imr_interface.s_addr= INADDR_ANY;
if (setsockopt(sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, (const void *)&mreq, sizeof(mreq)) < 0) {
av_log(NULL, AV_LOG_ERROR, "setsockopt(IP_ADD_MEMBERSHIP): %s\n", strerror(errno));
return -1;
}
}
#endif
#if HAVE_STRUCT_IPV6_MREQ && defined(IPPROTO_IPV6)
if (addr->sa_family == AF_INET6) {
struct ipv6_mreq mreq6;
memcpy(&mreq6.ipv6mr_multiaddr, &(((struct sockaddr_in6 *)addr)->sin6_addr), sizeof(struct in6_addr));
mreq6.ipv6mr_interface= 0;
if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
av_log(NULL, AV_LOG_ERROR, "setsockopt(IPV6_ADD_MEMBERSHIP): %s\n", strerror(errno));
return -1;
}
}
#endif
return 0;
}
static int udp_leave_multicast_group(int sockfd, struct sockaddr *addr)
{
#ifdef IP_DROP_MEMBERSHIP
if (addr->sa_family == AF_INET) {
struct ip_mreq mreq;
mreq.imr_multiaddr.s_addr = ((struct sockaddr_in *)addr)->sin_addr.s_addr;
mreq.imr_interface.s_addr= INADDR_ANY;
if (setsockopt(sockfd, IPPROTO_IP, IP_DROP_MEMBERSHIP, (const void *)&mreq, sizeof(mreq)) < 0) {
av_log(NULL, AV_LOG_ERROR, "setsockopt(IP_DROP_MEMBERSHIP): %s\n", strerror(errno));
return -1;
}
}
#endif
#if HAVE_STRUCT_IPV6_MREQ && defined(IPPROTO_IPV6)
if (addr->sa_family == AF_INET6) {
struct ipv6_mreq mreq6;
memcpy(&mreq6.ipv6mr_multiaddr, &(((struct sockaddr_in6 *)addr)->sin6_addr), sizeof(struct in6_addr));
mreq6.ipv6mr_interface= 0;
if (setsockopt(sockfd, IPPROTO_IPV6, IPV6_DROP_MEMBERSHIP, &mreq6, sizeof(mreq6)) < 0) {
av_log(NULL, AV_LOG_ERROR, "setsockopt(IPV6_DROP_MEMBERSHIP): %s\n", strerror(errno));
return -1;
}
}
#endif
return 0;
}
static struct addrinfo* udp_resolve_host(const char *hostname, int port,
int type, int family, int flags)
{
struct addrinfo hints, *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;
}
memset(&hints, 0, sizeof(hints));
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, "udp_resolve_host: %s\n", gai_strerror(error));
}
return res;
}
static int udp_set_url(struct sockaddr_storage *addr,
const char *hostname, int port)
{
struct addrinfo *res0;
int addr_len;
res0 = udp_resolve_host(hostname, port, SOCK_DGRAM, AF_UNSPEC, 0);
if (res0 == 0) return AVERROR(EIO);
memcpy(addr, res0->ai_addr, res0->ai_addrlen);
addr_len = res0->ai_addrlen;
freeaddrinfo(res0);
return addr_len;
}
static int udp_socket_create(UDPContext *s, struct sockaddr_storage *addr,
int *addr_len, const char *localaddr)
{
int udp_fd = -1;
struct addrinfo *res0 = NULL, *res = NULL;
int family = AF_UNSPEC;
if (((struct sockaddr *) &s->dest_addr)->sa_family)
family = ((struct sockaddr *) &s->dest_addr)->sa_family;
res0 = udp_resolve_host(localaddr[0] ? localaddr : NULL, s->local_port,
SOCK_DGRAM, family, AI_PASSIVE);
if (res0 == 0)
goto fail;
for (res = res0; res; res=res->ai_next) {
udp_fd = socket(res->ai_family, SOCK_DGRAM, 0);
if (udp_fd > 0) break;
av_log(NULL, AV_LOG_ERROR, "socket: %s\n", strerror(errno));
}
if (udp_fd < 0)
goto fail;
memcpy(addr, res->ai_addr, res->ai_addrlen);
*addr_len = res->ai_addrlen;
freeaddrinfo(res0);
return udp_fd;
fail:
if (udp_fd >= 0)
closesocket(udp_fd);
if(res0)
freeaddrinfo(res0);
return -1;
}
static int udp_port(struct sockaddr_storage *addr, int addr_len)
{
char sbuf[sizeof(int)*3+1];
if (getnameinfo((struct sockaddr *)addr, addr_len, NULL, 0, sbuf, sizeof(sbuf), NI_NUMERICSERV) != 0) {
av_log(NULL, AV_LOG_ERROR, "getnameinfo: %s\n", strerror(errno));
return -1;
}
return strtol(sbuf, NULL, 10);
}
/**
* 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: 'ttl=n' : set the ttl value (for multicast only)
* 'localport=n' : set the local port
* 'pkt_size=n' : set max packet size
* 'reuse=1' : enable reusing the socket
*
* @param h media file context
* @param uri of the remote server
* @return zero if no error.
*/
int ff_udp_set_remote_url(URLContext *h, const char *uri)
{
UDPContext *s = h->priv_data;
char hostname[256], buf[10];
int port;
const char *p;
av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port, NULL, 0, uri);
/* set the destination address */
s->dest_addr_len = udp_set_url(&s->dest_addr, hostname, port);
if (s->dest_addr_len < 0) {
return AVERROR(EIO);
}
s->is_multicast = ff_is_multicast_address((struct sockaddr*) &s->dest_addr);
p = strchr(uri, '?');
if (p) {
if (av_find_info_tag(buf, sizeof(buf), "connect", p)) {
int was_connected = s->is_connected;
s->is_connected = strtol(buf, NULL, 10);
if (s->is_connected && !was_connected) {
if (connect(s->udp_fd, (struct sockaddr *) &s->dest_addr,
s->dest_addr_len)) {
s->is_connected = 0;
av_log(h, AV_LOG_ERROR, "connect: %s\n", strerror(errno));
return AVERROR(EIO);
}
}
}
}
return 0;
}
/**
* Return the local port used by the UDP connection
* @param h media file context
* @return the local port number
*/
int ff_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
*/
static int udp_get_file_handle(URLContext *h)
{
UDPContext *s = h->priv_data;
return s->udp_fd;
}
#if HAVE_PTHREADS
static void *circular_buffer_task( void *_URLContext)
{
URLContext *h = _URLContext;
UDPContext *s = h->priv_data;
fd_set rfds;
struct timeval tv;
for(;;) {
int left;
int ret;
int len;
if (ff_check_interrupt(&h->interrupt_callback)) {
s->circular_buffer_error = EINTR;
goto end;
}
FD_ZERO(&rfds);
FD_SET(s->udp_fd, &rfds);
tv.tv_sec = 1;
tv.tv_usec = 0;
ret = select(s->udp_fd + 1, &rfds, NULL, NULL, &tv);
if (ret < 0) {
if (ff_neterrno() == AVERROR(EINTR))
continue;
s->circular_buffer_error = EIO;
goto end;
}
if (!(ret > 0 && FD_ISSET(s->udp_fd, &rfds)))
continue;
/* How much do we have left to the end of the buffer */
/* Whats the minimum we can read so that we dont comletely fill the buffer */
left = av_fifo_space(s->fifo);
/* No Space left, error, what do we do now */
if(left < UDP_MAX_PKT_SIZE + 4) {
av_log(h, AV_LOG_ERROR, "circular_buffer: OVERRUN\n");
s->circular_buffer_error = EIO;
goto end;
}
left = FFMIN(left, s->fifo->end - s->fifo->wptr);
len = recv(s->udp_fd, s->tmp+4, sizeof(s->tmp)-4, 0);
if (len < 0) {
if (ff_neterrno() != AVERROR(EAGAIN) && ff_neterrno() != AVERROR(EINTR)) {
s->circular_buffer_error = EIO;
goto end;
}
continue;
}
AV_WL32(s->tmp, len);
pthread_mutex_lock(&s->mutex);
av_fifo_generic_write(s->fifo, s->tmp, len+4, NULL);
pthread_cond_signal(&s->cond);
pthread_mutex_unlock(&s->mutex);
}
end:
pthread_mutex_lock(&s->mutex);
pthread_cond_signal(&s->cond);
pthread_mutex_unlock(&s->mutex);
return NULL;
}
#endif
/* put it in UDP context */
/* return non zero if error */
static int udp_open(URLContext *h, const char *uri, int flags)
{
char hostname[1024], localaddr[1024] = "";
int port, udp_fd = -1, tmp, bind_ret = -1;
UDPContext *s = h->priv_data;
int is_output;
const char *p;
char buf[256];
struct sockaddr_storage my_addr;
int len;
int reuse_specified = 0;
h->is_streamed = 1;
h->max_packet_size = 1472;
is_output = !(flags & AVIO_FLAG_READ);
s->ttl = 16;
s->buffer_size = is_output ? UDP_TX_BUF_SIZE : UDP_MAX_PKT_SIZE;
s->circular_buffer_size = 7*188*4096;
p = strchr(uri, '?');
if (p) {
if (av_find_info_tag(buf, sizeof(buf), "reuse", p)) {
char *endptr = NULL;
s->reuse_socket = strtol(buf, &endptr, 10);
/* assume if no digits were found it is a request to enable it */
if (buf == endptr)
s->reuse_socket = 1;
reuse_specified = 1;
}
if (av_find_info_tag(buf, sizeof(buf), "ttl", p)) {
s->ttl = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "localport", p)) {
s->local_port = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "pkt_size", p)) {
h->max_packet_size = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "buffer_size", p)) {
s->buffer_size = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "connect", p)) {
s->is_connected = strtol(buf, NULL, 10);
}
if (av_find_info_tag(buf, sizeof(buf), "fifo_size", p)) {
s->circular_buffer_size = strtol(buf, NULL, 10)*188;
}
if (av_find_info_tag(buf, sizeof(buf), "localaddr", p)) {
av_strlcpy(localaddr, buf, sizeof(localaddr));
}
}
/* fill the dest addr */
av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port, NULL, 0, uri);
/* XXX: fix av_url_split */
if (hostname[0] == '\0' || hostname[0] == '?') {
/* only accepts null hostname if input */
if (!(flags & AVIO_FLAG_READ))
goto fail;
} else {
if (ff_udp_set_remote_url(h, uri) < 0)
goto fail;
}
if ((s->is_multicast || !s->local_port) && (h->flags & AVIO_FLAG_READ))
s->local_port = port;
udp_fd = udp_socket_create(s, &my_addr, &len, localaddr);
if (udp_fd < 0)
goto fail;
/* Follow the requested reuse option, unless it's multicast in which
* case enable reuse unless explicitly disabled.
*/
if (s->reuse_socket || (s->is_multicast && !reuse_specified)) {
s->reuse_socket = 1;
if (setsockopt (udp_fd, SOL_SOCKET, SO_REUSEADDR, &(s->reuse_socket), sizeof(s->reuse_socket)) != 0)
goto fail;
}
/* the bind is needed to give a port to the socket now */
/* if multicast, try the multicast address bind first */
if (s->is_multicast && (h->flags & AVIO_FLAG_READ)) {
bind_ret = bind(udp_fd,(struct sockaddr *)&s->dest_addr, len);
}
/* bind to the local address if not multicast or if the multicast
* bind failed */
if (bind_ret < 0 && bind(udp_fd,(struct sockaddr *)&my_addr, len) < 0)
goto fail;
len = sizeof(my_addr);
getsockname(udp_fd, (struct sockaddr *)&my_addr, &len);
s->local_port = udp_port(&my_addr, len);
if (s->is_multicast) {
if (!(h->flags & AVIO_FLAG_READ)) {
/* output */
if (udp_set_multicast_ttl(udp_fd, s->ttl, (struct sockaddr *)&s->dest_addr) < 0)
goto fail;
} else {
/* input */
if (udp_join_multicast_group(udp_fd, (struct sockaddr *)&s->dest_addr) < 0)
goto fail;
}
}
if (is_output) {
/* limit the tx buf size to limit latency */
tmp = s->buffer_size;
if (setsockopt(udp_fd, SOL_SOCKET, SO_SNDBUF, &tmp, sizeof(tmp)) < 0) {
av_log(h, AV_LOG_ERROR, "setsockopt(SO_SNDBUF): %s\n", strerror(errno));
goto fail;
}
} else {
/* set udp recv buffer size to the largest possible udp packet size to
* avoid losing data on OSes that set this too low by default. */
tmp = s->buffer_size;
if (setsockopt(udp_fd, SOL_SOCKET, SO_RCVBUF, &tmp, sizeof(tmp)) < 0) {
av_log(h, AV_LOG_WARNING, "setsockopt(SO_RECVBUF): %s\n", strerror(errno));
}
/* make the socket non-blocking */
ff_socket_nonblock(udp_fd, 1);
}
if (s->is_connected) {
if (connect(udp_fd, (struct sockaddr *) &s->dest_addr, s->dest_addr_len)) {
av_log(h, AV_LOG_ERROR, "connect: %s\n", strerror(errno));
goto fail;
}
}
s->udp_fd = udp_fd;
#if HAVE_PTHREADS
if (!is_output && s->circular_buffer_size) {
/* start the task going */
s->fifo = av_fifo_alloc(s->circular_buffer_size);
pthread_mutex_init(&s->mutex, NULL);
pthread_cond_init(&s->cond, NULL);
if (pthread_create(&s->circular_buffer_thread, NULL, circular_buffer_task, h)) {
av_log(h, AV_LOG_ERROR, "pthread_create failed\n");
goto fail;
}
}
#endif
return 0;
fail:
if (udp_fd >= 0)
closesocket(udp_fd);
av_fifo_free(s->fifo);
return AVERROR(EIO);
}
static int udp_read(URLContext *h, uint8_t *buf, int size)
{
UDPContext *s = h->priv_data;
int ret;
int avail;
#if HAVE_PTHREADS
if (s->fifo) {
pthread_mutex_lock(&s->mutex);
do {
avail = av_fifo_size(s->fifo);
if (avail) { // >=size) {
uint8_t tmp[4];
pthread_mutex_unlock(&s->mutex);
av_fifo_generic_read(s->fifo, tmp, 4, NULL);
avail= AV_RL32(tmp);
if(avail > size){
av_log(h, AV_LOG_WARNING, "Part of datagram lost due to insufficient buffer size\n");
avail= size;
}
av_fifo_generic_read(s->fifo, buf, avail, NULL);
av_fifo_drain(s->fifo, AV_RL32(tmp) - avail);
return avail;
} else if(s->circular_buffer_error){
pthread_mutex_unlock(&s->mutex);
return s->circular_buffer_error;
}
else {
pthread_cond_wait(&s->cond, &s->mutex);
}
} while( 1);
}
#endif
if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
ret = ff_network_wait_fd(s->udp_fd, 0);
if (ret < 0)
return ret;
}
ret = recv(s->udp_fd, buf, size, 0);
return ret < 0 ? ff_neterrno() : ret;
}
static int udp_write(URLContext *h, const uint8_t *buf, int size)
{
UDPContext *s = h->priv_data;
int ret;
if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
ret = ff_network_wait_fd(s->udp_fd, 1);
if (ret < 0)
return ret;
}
if (!s->is_connected) {
ret = sendto (s->udp_fd, buf, size, 0,
(struct sockaddr *) &s->dest_addr,
s->dest_addr_len);
} else
ret = send(s->udp_fd, buf, size, 0);
return ret < 0 ? ff_neterrno() : ret;
}
static int udp_close(URLContext *h)
{
UDPContext *s = h->priv_data;
if (s->is_multicast && (h->flags & AVIO_FLAG_READ))
udp_leave_multicast_group(s->udp_fd, (struct sockaddr *)&s->dest_addr);
closesocket(s->udp_fd);
av_fifo_free(s->fifo);
#if HAVE_PTHREADS
pthread_mutex_destroy(&s->mutex);
pthread_cond_destroy(&s->cond);
#endif
return 0;
}
URLProtocol ff_udp_protocol = {
.name = "udp",
.url_open = udp_open,
.url_read = udp_read,
.url_write = udp_write,
.url_close = udp_close,
.url_get_file_handle = udp_get_file_handle,
.priv_data_size = sizeof(UDPContext),
};