From accb28721d061f2e06e927bdb1337317db3aa706 Mon Sep 17 00:00:00 2001

From: Thomas Markwalder <tmark@isc.org>

Date: Mon, 19 Jan 2015 13:40:25 -0500

Subject: [PATCH] [v4_2] Fixed inconsistencies in setting hop count limit in

 dhcrelay

diff --git a/common/socket.c b/common/socket.c

index c170448..5467a35 100644

--- a/common/socket.c

+++ b/common/socket.c

@@ -300,18 +300,24 @@ if_register_socket(struct interface_info *info, int family,

 #endif

 	}

-	if ((family == AF_INET6) &&

-	    ((info->flags & INTERFACE_UPSTREAM) != 0)) {

-		int hop_limit = 32;

-		if (setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,

-			       &hop_limit, sizeof(int)) < 0) {

-			log_fatal("setsockopt: IPV6_MULTICAST_HOPS: %m");

-		}

-	}

 #endif /* DHCPv6 */

 	return sock;

 }

+

+#ifdef DHCPv6

+void set_multicast_hop_limit(struct interface_info* info, int hop_limit) {

+	if (setsockopt(info->wfdesc, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,

+		       &hop_limit, sizeof(int)) < 0) {

+		log_fatal("setMulticaseHopLimit: IPV6_MULTICAST_HOPS: %m");

+	}

+

+	log_debug("Setting hop count limit to %d for interface %s",

+		  hop_limit, info->name);

+

+}

+#endif /* DHCPv6 */

+

 #endif /* USE_SOCKET_SEND || USE_SOCKET_RECEIVE || USE_SOCKET_FALLBACK */

 #if defined (USE_SOCKET_SEND) || defined (USE_SOCKET_FALLBACK)

diff --git a/includes/dhcpd.h b/includes/dhcpd.h

index 2b15430..bd11b48 100644

--- a/includes/dhcpd.h

+++ b/includes/dhcpd.h

@@ -2386,6 +2386,8 @@ void get_hw_addr(const char *name, struct hardware *hw);

 #if defined (USE_SOCKET_SEND) || defined (USE_SOCKET_RECEIVE) \

 	|| defined (USE_SOCKET_FALLBACK)

 int if_register_socket(struct interface_info *, int, int *, struct in6_addr *);

+

+void set_multicast_hop_limit(struct interface_info* info, int hop_limit);

 #endif

 #if defined (USE_SOCKET_FALLBACK) && !defined (USE_SOCKET_SEND)

diff --git a/relay/dhcrelay.c b/relay/dhcrelay.c

index 927e404..ad76d3e 100644

--- a/relay/dhcrelay.c

+++ b/relay/dhcrelay.c

@@ -1173,8 +1173,8 @@ parse_downstream(char *arg) {

 	/* Share with up side? */

 	for (up = upstreams; up; up = up->next) {

 		if (strcmp(ifname, up->ifp->name) == 0) {

-			log_info("Interface '%s' is both down and up.",

-				 ifname);

+			log_info("parse_downstream: Interface '%s' is "

+				 "both down and up.", ifname);

 			ifp = up->ifp;

 			break;

 		}

@@ -1192,8 +1192,8 @@ parse_downstream(char *arg) {

 			interface_dereference(&interfaces, MDL);

 		}

 		interface_reference(&interfaces, ifp, MDL);

-		ifp->flags |= INTERFACE_REQUESTED | INTERFACE_DOWNSTREAM;

 	}

+	ifp->flags |= INTERFACE_REQUESTED | INTERFACE_DOWNSTREAM;

 	/* New downstream. */

 	dp = (struct stream_list *) dmalloc(sizeof(*dp), MDL);

@@ -1244,6 +1244,8 @@ parse_upstream(char *arg) {

 	}

 	for (dp = downstreams; dp; dp = dp->next) {

 		if (strcmp(ifname, dp->ifp->name) == 0) {

+			log_info("parse_upstream: Interface '%s' is "

+				 "both down and up.", ifname);

 			ifp = dp->ifp;

 			break;

 		}

@@ -1261,8 +1263,8 @@ parse_upstream(char *arg) {

 			interface_dereference(&interfaces, MDL);

 		}

 		interface_reference(&interfaces, ifp, MDL);

-		ifp->flags |= INTERFACE_REQUESTED | INTERFACE_UPSTREAM;

 	}

+	ifp->flags |= INTERFACE_REQUESTED | INTERFACE_UPSTREAM;

 	/* New upstream. */

 	up = (struct stream_list *) dmalloc(sizeof(*up), MDL);

@@ -1330,6 +1332,13 @@ setup_streams(void) {

 		if (up->ifp->v6address_count == 0)

 			log_fatal("Interface '%s' has no IPv6 addresses.",

 				  up->ifp->name);

+

+		/* RFC 3315 Sec 20 - "If the relay agent relays messages to

+		 * the All_DHCP_Servers address or other multicast addresses,

+		 * it sets the Hop Limit field to 32." */

+		if (IN6_IS_ADDR_MULTICAST(&up->link.sin6_addr)) {

+			set_multicast_hop_limit(up->ifp, HOP_COUNT_LIMIT);

+		}

 	}

 }

-- 

2.1.0