diff -u -r1.586 chan_sip.c
--- channels/chan_sip.c	7 Dec 2004 15:42:00 -0000	1.586
+++ channels/chan_sip.c	8 Dec 2004 21:57:40 -0000
@@ -63,6 +63,9 @@
 #ifndef DEFAULT_USERAGENT
 #define DEFAULT_USERAGENT "Asterisk PBX"
 #endif
+
+#define DSTADDR_SOCKOPT IP_PKTINFO
+#define dstaddr(x) (&(((struct in_pktinfo *)(CMSG_DATA(x)))->ipi_addr))
  
 #define VIDEO_CODEC_MASK        0x1fc0000 /* Video codecs from H.261 thru AST_FORMAT_MAX_VIDEO */
 #ifndef IPTOS_MINCOST
@@ -603,12 +606,52 @@
 {
 	int res;
 	char iabuf[INET_ADDRSTRLEN];
-	if (p->nat & SIP_NAT_ROUTE)
+	if (p->nat & SIP_NAT_ROUTE) {
 	    res=sendto(sipsock, data, len, 0, (struct sockaddr *)&p->recv, sizeof(struct sockaddr_in));
-	else
-	    res=sendto(sipsock, data, len, 0, (struct sockaddr *)&p->sa, sizeof(struct sockaddr_in));
+	} else {
+		struct iovec iov;
+		struct msghdr mesg;
+		struct cmsghdr *cmsg;
+		struct in_pktinfo *pkti;
+		char b[sizeof(struct cmsghdr) + sizeof(struct in_pktinfo)];
+
+		bzero((char *) &mesg, sizeof(mesg));
+
+		/* Our data */
+		iov.iov_base = data;
+		iov.iov_len = len;
+
+		mesg.msg_iov = &iov;
+		mesg.msg_iovlen = 1;
+
+		/* Dst address */
+		mesg.msg_name = &(p->sa);
+		mesg.msg_namelen = sizeof(p->sa);
+
+		/* Control data (source address) */
+
+		mesg.msg_control = b;
+		mesg.msg_controllen = sizeof(b);
+		mesg.msg_flags = 0;
+
+		cmsg = CMSG_FIRSTHDR(&mesg);
+		cmsg->cmsg_len = sizeof(b);
+		cmsg->cmsg_level = SOL_IP;
+		cmsg->cmsg_type = IP_PKTINFO;
+
+		/* Set the actual source address */
+
+		pkti = (struct in_pktinfo *)CMSG_DATA(cmsg);
+		pkti->ipi_ifindex = 0;
+		pkti->ipi_spec_dst = p->ourip;
+		pkti->ipi_addr = p->ourip;
+
+		res = sendmsg(sipsock, &mesg, 0);
+
+	}
 	if (res != len) {
-		ast_log(LOG_WARNING, "sip_xmit of %p (len %d) to %s returned %d: %s\n", data, len, ast_inet_ntoa(iabuf, sizeof(iabuf), p->sa.sin_addr), res, strerror(errno));
+		ast_log(LOG_WARNING, "sip_xmit of %p (len %d) to %s:%d returned %d: %s\n", data, len, 
+			ast_inet_ntoa(iabuf, sizeof(iabuf), p->sa.sin_addr), p->sa.sin_port, res, strerror(errno));
 	}
 	return res;
 }
@@ -2234,7 +2277,7 @@
 }
 
 /*--- sip_alloc: Allocate SIP_PVT structure and set defaults ---*/
-static struct sip_pvt *sip_alloc(char *callid, struct sockaddr_in *sin, int useglobal_nat)
+static struct sip_pvt *sip_alloc(char *callid, struct sockaddr_in *sin, struct sockaddr_in *sout, int useglobal_nat)
 {
 	struct sip_pvt *p;
 	char iabuf[INET_ADDRSTRLEN];
@@ -2255,8 +2298,12 @@
 #endif	
 	if (sin) {
 		memcpy(&p->sa, sin, sizeof(p->sa));
-		if (ast_sip_ouraddrfor(&p->sa.sin_addr,&p->ourip))
-			memcpy(&p->ourip, &__ourip, sizeof(p->ourip));
+		if (sout) {
+			memcpy(&p->ourip, &(sout->sin_addr), sizeof(p->ourip));
+		} else {
+			if (ast_sip_ouraddrfor(&p->sa.sin_addr, &p->ourip))
+				memcpy(&p->ourip, &__ourip, sizeof(p->ourip));
+		}
 	} else {
 		memcpy(&p->ourip, &__ourip, sizeof(p->ourip));
 	}
@@ -2329,7 +2376,7 @@
 
 /*--- find_call: Connect incoming SIP message to current call or create new call structure */
 /*               Called by handle_request ,sipsock_read */
-static struct sip_pvt *find_call(struct sip_request *req, struct sockaddr_in *sin)
+static struct sip_pvt *find_call(struct sip_request *req, struct sockaddr_in *sin, struct sockaddr_in *sout)
 {
 	struct sip_pvt *p;
 	char *callid;
@@ -2385,7 +2432,7 @@
 		p = p->next;
 	}
 	ast_mutex_unlock(&iflock);
-	p = sip_alloc(callid, sin, 1);
+	p = sip_alloc(callid, sin, sout, 1);
 	if (p)
 		ast_mutex_lock(&p->lock);
 	return p;
@@ -4107,7 +4154,7 @@
 			build_callid(r->callid, sizeof(r->callid), __ourip, default_fromdomain);
 			r->callid_valid = 1;
 		}
-		p=sip_alloc( r->callid, NULL, 0);
+		p=sip_alloc( r->callid, NULL, NULL, 0);
 		if (!p) {
 			ast_log(LOG_WARNING, "Unable to allocate registration call\n");
 			return 0;
@@ -7696,17 +7743,47 @@
 static int sipsock_read(int *id, int fd, short events, void *ignore)
 {
 	struct sip_request req;
-	struct sockaddr_in sin = { 0, };
+	struct sockaddr_in sin, sout;
 	struct sip_pvt *p;
 	int res;
 	int len;
 	int nounlock;
 	int recount = 0;
 	int debug;
+	struct iovec vec;
+	struct msghdr msg;
+	struct cmsghdr * cmsgptr;
+	char hdrdata[2048];
 
 	len = sizeof(sin);
 	memset(&req, 0, sizeof(req));
-	res = recvfrom(sipsock, req.data, sizeof(req.data) - 1, 0, (struct sockaddr *)&sin, &len);
+	memset(&sin, 0, sizeof(sin));
+	memset(&sout, 0, sizeof(sout));
+	memset(&msg, 0, sizeof(msg));
+
+	/* Use recvmsg() instead of recvfrom() so we have the dst address -- Theo 02/09/04 */
+
+	vec.iov_base = req.data;
+	vec.iov_len = sizeof(req.data) - 1;
+
+	msg.msg_controllen = sizeof(hdrdata) - sizeof(struct iovec) - sizeof(struct msghdr);
+	msg.msg_control = hdrdata;
+
+	msg.msg_iov = &vec;
+	msg.msg_iovlen = 1;
+
+	msg.msg_name = &sin;
+	msg.msg_namelen = sizeof(struct sockaddr_in);
+
+	res = recvmsg(sipsock, &msg, 0);
+
+	for (cmsgptr = CMSG_FIRSTHDR(&msg); cmsgptr != NULL; cmsgptr = CMSG_NXTHDR(&msg, cmsgptr)) {
+		if (cmsgptr->cmsg_level == IPPROTO_IP && cmsgptr->cmsg_type == DSTADDR_SOCKOPT) {
+			memcpy(&sout.sin_addr, dstaddr(cmsgptr), sizeof(sout.sin_addr));
+			break;
+		}
+	}
+
 	if (res < 0) {
 		if (errno == EAGAIN)
 			ast_log(LOG_NOTICE, "SIP: Received packet with bad UDP checksum\n");
@@ -7731,7 +7808,7 @@
 	/* Process request, with netlock held */
 retrylock:
 	ast_mutex_lock(&netlock);
-	p = find_call(&req, &sin);
+	p = find_call(&req, &sin, &sout);
 	if (p) {
 		/* Go ahead and lock the owner if it has one -- we may need it */
 		if (p->owner && ast_mutex_trylock(&p->owner->lock)) {
@@ -7782,7 +7859,7 @@
 		return 0;
 	}
 	
-	p = sip_alloc(NULL, NULL, 0);
+	p = sip_alloc(NULL, NULL, NULL, 0);
 	if (!p) {
 		ast_log(LOG_WARNING, "Unable to build sip pvt data for MWI\n");
 		ast_mutex_unlock(&peerl.lock);
@@ -8008,7 +8085,7 @@
 		ast_log(LOG_NOTICE, "Still have a call...\n");
 		sip_destroy(peer->call);
 	}
-	p = peer->call = sip_alloc(NULL, NULL, 0);
+	p = peer->call = sip_alloc(NULL, NULL, NULL, 0);
 	if (!peer->call) {
 		ast_log(LOG_WARNING, "Unable to allocate call for poking peer '%s'\n", peer->name);
 		return -1;
@@ -8119,7 +8196,7 @@
 		ast_log(LOG_NOTICE, "Asked to get a channel of unsupported format %s while capability is %s\n", ast_getformatname(oldformat), ast_getformatname(global_capability));
 		return NULL;
 	}
-	p = sip_alloc(NULL, NULL, 0);
+	p = sip_alloc(NULL, NULL, NULL, 0);
 	if (!p) {
 		ast_log(LOG_WARNING, "Unable to build sip pvt data for '%s'\n", (char *)data);
 		return NULL;
@@ -8632,6 +8709,7 @@
 	int format;
 	int oldport = ntohs(bindaddr.sin_port);
 	char iabuf[INET_ADDRSTRLEN];
+	int dstaddr = 1;
 
 	
 	if (gethostname(ourhost, sizeof(ourhost))) {
@@ -8925,6 +9003,10 @@
 			setsockopt(sipsock, SOL_SOCKET, SO_REUSEADDR,
 				   (const char*)&reuseFlag,
 				   sizeof reuseFlag);
+
+			setsockopt(sipsock, SOL_IP, DSTADDR_SOCKOPT,
+				   (const char*)&dstaddr,
+				   sizeof(dstaddr));
 
 			if (bind(sipsock, (struct sockaddr *)&bindaddr, sizeof(bindaddr)) < 0) {
 				ast_log(LOG_WARNING, "Failed to bind to %s:%d: %s\n",