[Tc2-checkins] [CSET 1.20] udp: allow selection of interface for multicast

[<mr...@mr...>]

# This is a BitKeeper generated diff -Nru style patch.
#
# ChangeSet
#   2004/08/25 14:46:01+02:00 mr...@fo... =

#   udp: allow selection of interface for multicast
# =

# src/multicast/mc.c
#   2004/08/25 14:46:00+02:00 mr...@fo... +30 -2
#   select interface for multicast using ?if=3Daddr syntax
# =

diff -Nru a/src/multicast/mc.c b/src/multicast/mc.c
--- a/src/multicast/mc.c	2004-08-25 14:46:16 +02:00
+++ b/src/multicast/mc.c	2004-08-25 14:46:16 +02:00
@@ -103,6 +103,7 @@
     mc_stream_t *mcs;
     uint32_t addr;
     url_t *u;
+    char *iface =3D NULL;
     char *pp;
     int port;
     int sock;
@@ -122,7 +123,21 @@
 	return NULL;
 =

     *pp++ =3D 0;
-    port =3D strtol(pp, NULL, 0);
+    port =3D strtol(pp, &pp, 0);
+
+    if(*pp++ =3D=3D '?'){
+	while(pp && *pp){
+	    char *np =3D strchr(pp, '&');
+	    char *v =3D strchr(pp, '=3D');
+	    if(np)
+		*np++ =3D 0;
+	    if(v)
+		*v++ =3D 0;
+	    if(!strcmp(pp, "if"))
+		iface =3D v;
+	    pp =3D np;
+	}
+    }
 =

     if(!(hn =3D gethostbyname(url)))
 	return NULL;
@@ -139,8 +154,21 @@
     addr =3D *(uint32_t *) hn->h_addr;
     if(IN_MULTICAST(ntohl(addr))){
 	struct ip_mreq mrq;
+	uint32_t ifaddr =3D htonl(INADDR_ANY);
+
+	if(iface){
+	    hn =3D gethostbyname(iface);
+	    if(hn){
+		ifaddr =3D *(uint32_t *) hn->h_addr;
+		tc2_print("UDP", TC2_PRINT_DEBUG, "using interface %s\n",
+			  iface);
+	    } else {
+		tc2_print("UDP", TC2_PRINT_WARNING, "bad interface address\n");
+	    }
+	}
+
 	mrq.imr_multiaddr.s_addr =3D addr;
-	mrq.imr_interface.s_addr =3D htonl(INADDR_ANY);
+	mrq.imr_interface.s_addr =3D ifaddr;
 	if(setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mrq,
 		      sizeof(mrq)) < 0)
 	    return NULL;