/* make send-socket (dsockfd) buffer size no less
* than that of read-socket (ssockfd)
*/
static int
sync_dsockbuf_len( int ssockfd, int dsockfd )
{
size_t curr_sendbuf_len = 0, curr_rcvbuf_len = 0;
int rc = 0;
if ( 0 != g_uopt.nosync_dbuf ) {
TRACE( (void)tmfprintf( g_flog,
"Must not adjust buffer size "
"for send socket [%d]\n", dsockfd) );
return 0;
}
assert( ssockfd && dsockfd );
rc = get_sendbuf( dsockfd, &curr_sendbuf_len );
if (0 != rc) return rc;
rc = get_rcvbuf( ssockfd, &curr_rcvbuf_len );
if (0 != rc) return rc;
if ( curr_rcvbuf_len > curr_sendbuf_len ) {
rc = set_sendbuf( dsockfd, curr_rcvbuf_len );
if (0 != rc) return rc;
}
return rc;
}
/* set up the socket to receive multicast data
*
*/
int
setup_mcast_listener( struct sockaddr_in* sa,
const struct ip_mreq* mreq,
int* mcastfd,
int sockbuflen )
{
int sockfd, rc;
int ON = 1;
int buflen = sockbuflen;
size_t rcvbuf_len = 0;
assert( sa && mreq && mcastfd && (sockbuflen >= 0) );
TRACE( (void)tmfprintf( g_flog, "Setting up multicast listener\n") );
rc = ERR_INTERNAL;
do {
sockfd = socket( AF_INET, SOCK_DGRAM, 0 );
if( -1 == sockfd ) {
mperror(g_flog, errno, "%s: socket", __func__);
break;
}
if (buflen != 0) {
rc = get_rcvbuf( sockfd, &rcvbuf_len );
if (0 != rc) break;
if ((size_t)buflen > rcvbuf_len) {
rc = set_rcvbuf( sockfd, buflen );
if (0 != rc) break;
}
}
else {
TRACE( (void)tmfprintf( g_flog, "Must not adjust buffer size "
"for mcast socket [%d]\n", sockfd ) );
}
rc = setsockopt( sockfd, SOL_SOCKET, SO_REUSEADDR,
&ON, sizeof(ON) );
if( 0 != rc ) {
mperror(g_flog, errno, "%s: setsockopt SO_REUSEADDR",
__func__);
break;
}
#ifdef SO_REUSEPORT
/* On some systems (such as FreeBSD) SO_REUSEADDR
just isn't enough to subscribe to N same channels for different clients.
*/
rc = setsockopt( sockfd, SOL_SOCKET, SO_REUSEPORT,
&ON, sizeof(ON) );
if( 0 != rc ) {
mperror(g_flog, errno, "%s: setsockopt SO_REUSEPORT",
__func__);
break;
}
#endif /* SO_REUSEPORT */
rc = bind( sockfd, (struct sockaddr*)sa, sizeof(*sa) );
if( 0 != rc ) {
mperror(g_flog, errno, "%s: bind", __func__);
break;
}
rc = set_multicast( sockfd, mreq, IP_ADD_MEMBERSHIP );
if( 0 != rc )
break;
} while(0);
if( 0 == rc ) {
*mcastfd = sockfd;
TRACE( (void)tmfprintf( g_flog, "Mcast listener socket=[%d] set up\n",
sockfd) );
}
else {
(void)close(sockfd);
}
return rc;
}
