siproxd/src/rtpproxy_relay.c
Thomas Ries c88a45dd20 - use even port numbers for RTP traffic
- some minor fixes
2003-12-15 17:31:59 +00:00

546 lines
16 KiB
C

/*
Copyright (C) 2003 Thomas Ries <tries@gmx.net>
This file is part of Siproxd.
Siproxd is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
Siproxd 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with Siproxd; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "config.h"
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <signal.h>
#include <osipparser2/osip_parser.h>
#include "siproxd.h"
#include "rtpproxy.h"
#include "log.h"
static char const ident[]="$Id: " __FILE__ ": " PACKAGE "-" VERSION "-"\
BUILDSTR " $";
/* configuration storage */
extern struct siproxd_config configuration;
/*
* table to remember all active rtp proxy streams
*/
rtp_proxytable_t rtp_proxytable[RTPPROXY_SIZE];
/* use a 'fast' mutex for synchronizing - as these are portable... */
pthread_mutex_t rtp_proxytable_mutex = PTHREAD_MUTEX_INITIALIZER;
/* thread id of RTP proxy */
pthread_t rtpproxy_tid=0;
/* master fd_set */
static fd_set master_fdset;
static int master_fd_max;
/* forward declarations */
static void *rtpproxy_main(void *i);
static int rtp_recreate_fdset(void);
void rtpproxy_kill( void );
static void sighdl_alm(int sig) {/* just wake up from select() */};
/*
* initialize and create rtp_relay proxy thread
*
* RETURNS
* STS_SUCCESS on success
*/
int rtp_relay_init( void ) {
int sts;
int arg=0;
struct sigaction sigact;
atexit(rtpproxy_kill); /* cancel RTP thread at exit */
/* clean proxy table */
memset (rtp_proxytable, 0, sizeof(rtp_proxytable));
/* initialize fd set for RTP proxy thread */
FD_ZERO(&master_fdset); /* start with an empty fdset */
master_fd_max=-1;
/* install signal handler for SIGALRM - used to wake up
the rtpproxy thread from select() hibernation */
sigact.sa_handler = sighdl_alm;
sigemptyset(&sigact.sa_mask);
sigact.sa_flags=0;
sigaction(SIGALRM, &sigact, NULL);
DEBUGC(DBCLASS_RTP,"create thread");
sts=pthread_create(&rtpproxy_tid, NULL, rtpproxy_main, (void *)&arg);
DEBUGC(DBCLASS_RTP,"created, sts=%i", sts);
return STS_SUCCESS;
}
/*
* main() of rtpproxy
*/
static void *rtpproxy_main(void *arg) {
struct timeval tv;
fd_set fdset;
int fd_max;
time_t t, last_t=0;
int i, sts;
int num_fd;
osip_call_id_t callid;
static int rtp_socket=0;
static char rtp_buff[RTP_BUFFER_SIZE];
int count;
memcpy(&fdset, &master_fdset, sizeof(fdset));
fd_max=master_fd_max;
/* loop forever... */
for (;;) {
tv.tv_sec = 5;
tv.tv_usec = 0;
num_fd=select(fd_max+1, &fdset, NULL, NULL, &tv);
pthread_testcancel();
if ((num_fd<0) && (errno==EINTR)) {
/*
* wakeup due to a change in the proxy table:
* lock mutex copy master FD set and unlock
*/
pthread_mutex_lock(&rtp_proxytable_mutex);
memcpy(&fdset, &master_fdset, sizeof(fdset));
fd_max=master_fd_max;
pthread_mutex_unlock(&rtp_proxytable_mutex);
continue;
}
#ifdef MOREDEBUG /*&&&&*/
if (num_fd<0) {
int i;
WARN("select() returned error [%s]",strerror(errno));
for (i=0;i<RTPPROXY_SIZE;i++) {
DEBUGC(DBCLASS_RTP,"maxfd=%i",master_fd_max);
if (rtp_proxytable[i].sock != 0) {
DEBUGC(DBCLASS_RTP,"[%i] -> socket=%i",i, rtp_proxytable[i].sock);
}
} /* for i */
}
#endif
time(&t);
/*
* LOCK the MUTEX
*/
pthread_mutex_lock(&rtp_proxytable_mutex);
/* check for data available and send to destination */
for (i=0;(i<RTPPROXY_SIZE) && (num_fd>0);i++) {
if ( (rtp_proxytable[i].sock != 0) &&
FD_ISSET(rtp_proxytable[i].sock, &fdset) ) {
/* yup, have some data to send */
/* read from sock rtp_proxytable[i].sock*/
count=read(rtp_proxytable[i].sock, rtp_buff, RTP_BUFFER_SIZE);
#ifdef MOREDEBUG /*&&&&*/
if (count<0) {WARN("read() returned error [%s]",strerror(errno));}
#endif
/* write to dest via socket rtp_inbound*/
sts = sipsock_send_udp(&rtp_socket,
rtp_proxytable[i].inbound_client_ipaddr,
rtp_proxytable[i].inbound_client_port,
rtp_buff, count, 0); /* don't dump it */
#ifdef MOREDEBUG /*&&&&*/
if (sts != STS_SUCCESS) {WARN("sipsock_send_udp() returned error");}
#endif
/* update timestamp of last usage */
rtp_proxytable[i].timestamp=t;
num_fd--;
}
} /* for i */
/*
* age and clean rtp_proxytable (check every 10 seconds)
*/
if (t > (last_t+10) ) {
last_t = t;
for (i=0;i<RTPPROXY_SIZE; i++) {
if ( (rtp_proxytable[i].sock != 0) &&
((rtp_proxytable[i].timestamp+configuration.rtp_timeout)<t)) {
/* this one has expired, clean it up */
callid.number=rtp_proxytable[i].callid_number;
callid.host=rtp_proxytable[i].callid_host;
DEBUGC(DBCLASS_RTP,"RTP stream sock=%i %s@%s (idx=%i) "
"has expired", rtp_proxytable[i].sock,
callid.number, callid.host, i);
rtp_relay_stop_fwd(&callid, 1); /* don't lock the mutex, as we own
the lock already here */
}
}
} /* if (t>...) */
/* copy master FD set */
memcpy(&fdset, &master_fdset, sizeof(fdset));
fd_max=master_fd_max;
/*
* UNLOCK the MUTEX
*/
pthread_mutex_unlock(&rtp_proxytable_mutex);
} /* for(;;) */
return NULL;
}
/*
* start an rtp stream on the proxy
*
* RETURNS
* STS_SUCCESS on success
* STS_FAILURE on error
*/
int rtp_relay_start_fwd (osip_call_id_t *callid, int media_stream_no,
struct in_addr outbound_ipaddr, int *outboundport,
struct in_addr lcl_client_ipaddr, int lcl_clientport) {
int i, j;
int sock, port;
int freeidx;
int sts=STS_SUCCESS;
osip_call_id_t cid;
if (callid == NULL) {
ERROR("rtp_relay_start_fwd: callid is NULL!");
return STS_FAILURE;
}
/*
* life insurance: check size of received call_id strings
* I don't know what the maximum allowed size within SIP is,
* so if this test fails maybe it's just necessary to increase
* the constants CALLIDNUM_SIZE and/or CALLIDHOST_SIZE.
*/
if (callid->number && strlen(callid->number) > CALLIDNUM_SIZE) {
ERROR("rtp_relay_start_fwd: received callid number "
"has too many characters (%i, max=%i)",
strlen(callid->number),CALLIDNUM_SIZE);
return STS_FAILURE;
}
if (callid->host && strlen(callid->host) > CALLIDHOST_SIZE) {
ERROR("rtp_relay_start_fwd: received callid host "
"has too many characters (%i, max=%i)",
strlen(callid->host),CALLIDHOST_SIZE);
return STS_FAILURE;
}
DEBUGC(DBCLASS_RTP,"starting RTP proxy stream for: %s@%s #=%i",
callid->number, callid->host, media_stream_no);
/* lock mutex */
#define return is_forbidden_in_this_code_section
pthread_mutex_lock(&rtp_proxytable_mutex);
/*
* !! We now have a locked MUTEX! It is forbidden to return() from
* !! here up to the end of this funtion where the MUTEX is
* !! unlocked again.
* !! Per design, a mutex is locked (for one purpose) at *exactly one*
* !! place in the code and unlocked also at *exactly one* place.
* !! this minimizes the risk of deadlocks.
*/
/*
* figure out, if this is an request to start an RTP proxy stream
* that is already existing (identified by SIP Call-ID and
* media_stream_no). This can be due to UDP repetitions of the
* INVITE request...
*/
for (i=0; i<RTPPROXY_SIZE; i++) {
cid.number = rtp_proxytable[i].callid_number;
cid.host = rtp_proxytable[i].callid_host;
if (rtp_proxytable[i].sock &&
(compare_callid(callid, &cid) == STS_SUCCESS) &&
(rtp_proxytable[i].media_stream_no == media_stream_no) ) {
/* return the already known port number */
DEBUGC(DBCLASS_RTP,"RTP stream already active (port=%i, "
"id=%s, #=%i)", rtp_proxytable[i].outboundport,
rtp_proxytable[i].callid_number,
rtp_proxytable[i].media_stream_no);
*outboundport=rtp_proxytable[i].outboundport;
sts = STS_SUCCESS;
goto unlock_and_exit;
}
}
/*
* find first free slot in rtp_proxytable
*/
freeidx=-1;
for (j=0; j<RTPPROXY_SIZE; j++) {
if (rtp_proxytable[j].sock==0) {
freeidx=j;
break;
}
}
/* rtp_proxytable port pool full? */
if (freeidx == -1) {
ERROR("rtp_relay_start_fwd: rtp_proxytable is full!");
sts = STS_FAILURE;
goto unlock_and_exit;
}
/* TODO: randomize the port allocation - start at a random offset to
search in the allowed port range (so some modulo stuff w/
random start offset
- for i=x to (p1-p0)+x; p=p0+mod(x,p1-p0) */
/* find a local outbound port number to use and bind to it*/
sock=0;
port=0;
for (i=configuration.rtp_port_low; i<=configuration.rtp_port_high; i+=2) {
for (j=0; j<RTPPROXY_SIZE; j++) {
/* outbound port already in use */
if ((memcmp(&rtp_proxytable[j].outbound_ipaddr,
&outbound_ipaddr, sizeof(struct in_addr))== 0) &&
(rtp_proxytable[j].outboundport == i) ) break;
}
/* port is available, try to allocate */
if (j == RTPPROXY_SIZE) {
port=i;
sock=sockbind(outbound_ipaddr, port, 0);
/* if success break, else try further on */
if (sock) break;
}
} /* for i */
DEBUGC(DBCLASS_RTP,"rtp_relay_start_fwd: port=%i, sock=%i freeidx=%i",
port, sock, freeidx);
/* found an unused port? No -> RTP port pool fully allocated */
if ((port == 0) || (sock == 0)) {
ERROR("rtp_relay_start_fwd: no RTP port available or bind() failed");
sts = STS_FAILURE;
goto unlock_and_exit;
}
/* write entry into rtp_proxytable slot (freeidx) */
rtp_proxytable[freeidx].sock=sock;
if (callid->number) {
strcpy(rtp_proxytable[freeidx].callid_number, callid->number);
} else {
rtp_proxytable[freeidx].callid_number[0]='\0';
}
if (callid->host) {
strcpy(rtp_proxytable[freeidx].callid_host, callid->host);
} else {
rtp_proxytable[freeidx].callid_host[0]='\0';
}
rtp_proxytable[freeidx].media_stream_no = media_stream_no;
memcpy(&rtp_proxytable[freeidx].outbound_ipaddr,
&outbound_ipaddr, sizeof(struct in_addr));
rtp_proxytable[freeidx].outboundport=port;
memcpy(&rtp_proxytable[freeidx].inbound_client_ipaddr,
&lcl_client_ipaddr, sizeof(struct in_addr));
rtp_proxytable[freeidx].inbound_client_port=lcl_clientport;
time(&rtp_proxytable[freeidx].timestamp);
*outboundport=port;
/* prepare FD set for next select operation */
rtp_recreate_fdset();
/* wakeup/signal rtp_proxythread from select() hibernation */
if (!pthread_equal(rtpproxy_tid, pthread_self()))
pthread_kill(rtpproxy_tid, SIGALRM);
unlock_and_exit:
/* unlock mutex */
pthread_mutex_unlock(&rtp_proxytable_mutex);
#undef return
return sts;
}
/*
* stop a rtp stream on the proxy
*
* RETURNS
* STS_SUCCESS on success
* STS_FAILURE on error
*/
int rtp_relay_stop_fwd (osip_call_id_t *callid, int nolock) {
int i, sts;
int retsts=STS_SUCCESS;
int got_match=0;
osip_call_id_t cid;
if (callid == NULL) {
ERROR("rtp_relay_stop_fwd: callid is NULL!");
return STS_FAILURE;
}
DEBUGC(DBCLASS_RTP,"stopping RTP proxy stream for: %s@%s",
callid->number, callid->host);
/*
* lock mutex - only if not requested to skip the lock.
* this is needed as we are also called from within
* the RTP thread itself - and there we already own the lock.
*/
#define return is_forbidden_in_this_code_section
if (nolock == 0) {
pthread_mutex_lock(&rtp_proxytable_mutex);
/*
* !! We now have a locked MUTEX! It is forbidden to return() from
* !! here up to the end of this funtion where the MUTEX is
* !! unlocked again.
* !! Per design, a mutex is locked (for one purpose) at *exactly one*
* !! place in the code and unlocked also at *exactly one* place.
* !! this minimizes the risk of deadlocks.
*/
}
/*
* wakeup/signal rtp_proxythread from select() hibernation.
* This must be done here before we close the socket, otherwise
* we may get an select() error later from the proxy thread that
* is still hibernating in select() now.
*/
if (!pthread_equal(rtpproxy_tid, pthread_self()))
pthread_kill(rtpproxy_tid, SIGALRM);
/*
* find the proper entry in rtp_proxytable
* we need to loop the whole table, as there might be multiple
* media strema active for the same callid (audio + video stream)
*/
for (i=0; i<RTPPROXY_SIZE; i++) {
cid.number = rtp_proxytable[i].callid_number;
cid.host = rtp_proxytable[i].callid_host;
if (rtp_proxytable[i].sock &&
(compare_callid(callid, &cid) == STS_SUCCESS)) {
sts = close(rtp_proxytable[i].sock);
DEBUGC(DBCLASS_RTP,"closed socket %i for RTP stream "
"%s:%s == %s:%s (idx=%i) sts=%i",
rtp_proxytable[i].sock,
rtp_proxytable[i].callid_number,
rtp_proxytable[i].callid_host,
callid->number, callid->host, i, sts);
if (sts < 0) {
ERROR("Error in close(%i): %s nolock=%i %s:%s\n",
rtp_proxytable[i].sock,
strerror(errno), nolock,
callid->number, callid->host);
}
memset(&rtp_proxytable[i], 0, sizeof(rtp_proxytable[0]));
got_match=1;
}
}
/* did not find an active stream... */
if (!got_match) {
DEBUGC(DBCLASS_RTP,"rtp_relay_stop_fwd: can't find active stream for %s@%s",
callid->number, callid->host);
retsts = STS_FAILURE;
goto unlock_and_exit;
}
/* prepare FD set for next select operation */
rtp_recreate_fdset();
unlock_and_exit:
/*
* unlock mutex - only if not requested to skip the lock.
* this is needed as we are also called from within
* the RTP thread itself - and there we already own the lock.
*/
if (nolock == 0) {
pthread_mutex_unlock(&rtp_proxytable_mutex);
}
#undef return
return retsts;
}
/*
* some sockets have been newly created or removed -
* recreate the FD set for next select operation
*
* RETURNS
* STS_SUCCESS on success (always)
*/
static int rtp_recreate_fdset(void) {
int i;
FD_ZERO(&master_fdset);
master_fd_max=-1;
for (i=0;i<RTPPROXY_SIZE;i++) {
if (rtp_proxytable[i].sock != 0) {
FD_SET(rtp_proxytable[i].sock, &master_fdset);
if (rtp_proxytable[i].sock > master_fd_max) {
master_fd_max=rtp_proxytable[i].sock;
}
}
} /* for i */
return STS_SUCCESS;
}
/*
* kills the rtp_proxy thread
*
* RETURNS
* -
*/
void rtpproxy_kill( void ) {
void *thread_status;
if (rtpproxy_tid) {
pthread_cancel(rtpproxy_tid);
pthread_kill(rtpproxy_tid, SIGALRM);
pthread_join(rtpproxy_tid, &thread_status);
}
DEBUGC(DBCLASS_RTP,"killed RTP proxy thread");
return;
}