? dhcpd
? ktrace.out
Index: dhcp.c
===================================================================
RCS file: /cvs/src/usr.sbin/dhcpd/dhcp.c,v
retrieving revision 1.43
diff -u -p -r1.43 dhcp.c
--- dhcp.c	20 Aug 2015 22:39:29 -0000	1.43
+++ dhcp.c	26 Oct 2015 00:41:08 -0000
@@ -513,17 +513,9 @@ dhcpinform(struct packet *packet)
 	 * not all clients are standards compliant.
 	 */
 	cip.len = 4;
-	if (packet->raw->ciaddr.s_addr) {
-		if (memcmp(&packet->raw->ciaddr.s_addr,
-		    packet->client_addr.iabuf, 4) != 0) {
-			note("DHCPINFORM from %s but ciaddr %s is not "
-			    "consistent with actual address",
-			    piaddr(packet->client_addr),
-			    inet_ntoa(packet->raw->ciaddr));
-			return;
-		}
+	if (packet->raw->ciaddr.s_addr)
 		memcpy(cip.iabuf, &packet->raw->ciaddr.s_addr, 4);
-	} else
+	else
 		memcpy(cip.iabuf, &packet->client_addr.iabuf, 4);
 
 	note("DHCPINFORM from %s", piaddr(cip));
Index: options.c
===================================================================
RCS file: /cvs/src/usr.sbin/dhcpd/options.c,v
retrieving revision 1.29
diff -u -p -r1.29 options.c
--- options.c	27 Jun 2015 14:29:39 -0000	1.29
+++ options.c	26 Oct 2015 00:41:08 -0000
@@ -536,7 +536,7 @@ do_packet(struct interface_info *interfa
 	    tp.options[DHO_DHCP_MESSAGE_TYPE].data)
 		tp.packet_type = tp.options[DHO_DHCP_MESSAGE_TYPE].data[0];
 
-	if (interface->is_udpsock) {
+	if (0 && interface->is_udpsock) {
 		if (tp.packet_type != DHCPINFORM) {
 			note("Unable to handle a DHCP message type=%d on UDP "
 			    "socket", tp.packet_type);
Index: udpsock.c
===================================================================
RCS file: /cvs/src/usr.sbin/dhcpd/udpsock.c,v
retrieving revision 1.2
diff -u -p -r1.2 udpsock.c
--- udpsock.c	16 Jan 2015 06:40:16 -0000	1.2
+++ udpsock.c	26 Oct 2015 00:41:08 -0000
@@ -34,6 +34,7 @@ ssize_t	 udpsock_send_packet(struct inte
     size_t, struct in_addr, struct sockaddr_in *, struct hardware *);
 
 struct udpsock {
+	struct in_addr addr;
 	int	 sock;
 };
 
@@ -64,11 +65,12 @@ udpsock_startup(struct in_addr bindaddr)
 	if (bind(sock, (struct sockaddr *)&sin4, sizeof(sin4)) != 0)
 		error("bind failed for udp: %s", strerror(errno));
 
+	udpsock->addr = bindaddr;
+	udpsock->sock = sock;
+
 	add_protocol("udp", sock, udpsock_handler, (void *)(intptr_t)udpsock);
 	note("Listening on %s:%d/udp.", inet_ntoa(sin4.sin_addr),
 	    ntohs(server_port));
-
-	udpsock->sock = sock;
 }
 
 void
@@ -152,7 +154,10 @@ udpsock_handler(struct protocol *protoco
 	strlcpy(iface.name, ifname, sizeof(iface.name));
 
 	addr.len = 4;
-	memcpy(&addr.iabuf, &iface.primary_address, addr.len);
+	if (udpsock->addr.s_addr == htonl(INADDR_BROADCAST))
+		memcpy(&addr.iabuf, &iface.primary_address, addr.len);
+	else
+		memcpy(&addr.iabuf, &sin4->sin_addr, addr.len);
 
 	if ((subnet = find_subnet(addr)) == NULL)
 		return;