bsdports/net/mpd/files/patch-l2tp-multihomed

Index: src/util.c
===================================================================
--- src/util.c	(revision 2436)
+++ src/util.c	(working copy)
@@ -16,8 +16,9 @@
 #include <netdb.h>
 #include <tcpd.h>
 #include <sys/limits.h>
-#include <sys/wait.h>
+#include <sys/socket.h>
 #include <sys/sysctl.h>
+#include <sys/wait.h>
 #include <net/route.h>
 #include <netinet/if_ether.h>
 #include <net/ethernet.h>
@@ -1545,4 +1546,52 @@ IfaceSetFlag(const char *ifname, int value)
 	}
 	close(s);
 	return (0);
+}
+
+/*
+ * Obtain some data, peer (source) and destination addresses of SOCK_DGRAM IPv4 UDP request.
+ */
+ssize_t GetDataAddrs(int sock, void *dbuf, size_t dbufsize,
+			  struct sockaddr_storage *peer, socklen_t peer_len,
+			  struct u_addr *addr)
+{
+	struct {
+		struct  msghdr msg;
+		struct	iovec iov;
+	} b;
+	union {	/* ensure correct alignment for space */
+		struct cmsghdr cm;
+		char space[CMSG_SPACE(sizeof(struct in_addr))];
+	} buf;
+
+	struct	cmsghdr *p;
+	ssize_t	size;
+
+	/* Sanity check */
+	if (addr->family != AF_INET) {
+		errno = EAFNOSUPPORT;
+		return (-1);
+	}
+
+	b.msg.msg_name = peer;
+	b.msg.msg_namelen = peer_len;
+	b.msg.msg_iov = &b.iov;
+	b.msg.msg_iovlen = 1;
+	b.msg.msg_control = &buf;
+	b.msg.msg_controllen = sizeof(buf);
+	b.msg.msg_flags = 0;
+
+	b.iov.iov_base = dbuf;
+	b.iov.iov_len = dbufsize;
+
+	if ((size = recvmsg(sock, &b.msg, 0)) < 0) {
+		Perror("%s: recvmsg: %s", __FUNCTION__, strerror(errno));
+		return (size);
+	}
+
+	p = CMSG_FIRSTHDR(&b.msg);
+	if (p && p->cmsg_level == IPPROTO_IP && p->cmsg_type == IP_RECVDSTADDR)
+		memcpy(&addr->u.ip4, CMSG_DATA(p), sizeof(addr->u.ip4));
+
+	return (size);
 }
Index: src/util.h
===================================================================
--- src/util.h	(revision 2436)
+++ src/util.h	(working copy)
@@ -101,6 +101,10 @@ extern int GetPeerEther(struct u_addr *addr, struct so
 extern void ppp_util_ascify(char *buf, size_t max, const char *bytes, size_t len);
 extern int IfaceSetFlag(const char *ifname, int value);
 
+ssize_t GetDataAddrs(int sock, void *dbuf, size_t dbufsize,
+			  struct sockaddr_storage *peer, socklen_t peer_len,
+			  struct u_addr *addr);
+
 #ifndef	HAVE_NTOA_R
 extern char *ether_ntoa_r(const struct ether_addr *n, char *a);
 #endif
Index: src/l2tp.c
===================================================================
--- src/l2tp.c	(revision 2436)
+++ src/l2tp.c	(working copy)
@@ -1374,6 +1374,7 @@ L2tpServerEvent(int type, void *arg)
 	struct ngm_mkpeer mkpeer;
 	struct sockaddr_storage peer_sas;
 	struct sockaddr_storage sas;
+	struct u_addr server_addr;
 	const size_t bufsize = 8192;
 	u_int16_t *buf = NULL;
 	char hook[NG_HOOKSIZ];
@@ -1393,9 +1394,18 @@ L2tpServerEvent(int type, void *arg)
 	/* Allocate buffer */
 	buf = Malloc(MB_PHYS, bufsize);
 
+	u_addrcopy(&s->self_addr, &server_addr);
+	
 	/* Read packet */
 	sas_len = sizeof(peer_sas);
-	if ((len = recvfrom(s->sock, buf, bufsize, 0,
+
+	if (u_addrempty(&s->self_addr)) {
+	    if ((len = GetDataAddrs(s->sock, buf, bufsize,
+	    		&peer_sas, sas_len, &server_addr)) == -1) {
+		Perror("L2TP: GetDataAddrs");
+	    	goto fail;
+	    }
+	} else if ((len = recvfrom(s->sock, buf, bufsize, 0,
 	    (struct sockaddr *)&peer_sas, &sas_len)) == -1) {
 		Perror("L2TP: recvfrom");
 		goto fail;
@@ -1415,9 +1425,23 @@ L2tpServerEvent(int type, void *arg)
 	tun->self_port = s->self_port;
 	tun->alive = 1;
 
-	Log(LG_PHYS, ("Incoming L2TP packet from %s %d", 
-		u_addrtoa(&tun->peer_addr, namebuf, sizeof(namebuf)), tun->peer_port));
+	if (u_addrempty(&tun->self_addr))
+		u_addrcopy(&server_addr, &tun->self_addr);
 
+	if (u_addrempty(&tun->self_addr))
+		Log(LG_PHYS, ("Incoming L2TP packet from %s %d",
+		    u_addrtoa(&tun->peer_addr, namebuf, sizeof(namebuf)),
+		    tun->peer_port));
+	else {
+	    char buf3[INET_ADDRSTRLEN];
+
+	    Log(LG_PHYS, ("Incoming L2TP packet from %s %d to %s %d",
+		u_addrtoa(&tun->peer_addr, namebuf, sizeof(namebuf)),
+		tun->peer_port,
+		u_addrtoa(&tun->self_addr, buf3, sizeof(buf3)),
+		tun->self_port));
+	}
+
 	/* Examine all L2TP links to get best possible fit tunnel parameters. */
 	for (k = 0; k < gNumLinks; k++) {
 		Link l2;
@@ -1552,7 +1576,7 @@ L2tpServerEvent(int type, void *arg)
 	}
 
 	/* Bind socket to a new port */
-	u_addrtosockaddr(&s->self_addr,s->self_port,&sas);
+	u_addrtosockaddr(&tun->self_addr,tun->self_port,&sas);
 	if (NgSendMsg(csock, namebuf, NGM_KSOCKET_COOKIE,
 	    NGM_KSOCKET_BIND, &sas, sas.ss_len) == -1) {
 		Perror("L2TP: bind");
@@ -1649,6 +1673,10 @@ L2tpListen(Link l)
 	    SO_REUSEPORT, &one, sizeof(one)) == -1) {
 		Perror("L2TP: setsockopt");
 		goto fail;
+	}
+	if (u_addrempty(&s->self_addr)) {
+		int on = 1;
+		setsockopt(s->sock, IPPROTO_IP, IP_RECVDSTADDR, &on, sizeof(on));
 	}
 	u_addrtosockaddr(&s->self_addr, s->self_port, &sa);
 	if (bind(s->sock, (struct sockaddr *)&sa, sa.ss_len) == -1) {