Blame SOURCES/dhcp-hop-limit.patch

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From accb28721d061f2e06e927bdb1337317db3aa706 Mon Sep 17 00:00:00 2001
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From: Thomas Markwalder <tmark@isc.org>
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Date: Mon, 19 Jan 2015 13:40:25 -0500
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Subject: [PATCH] [v4_2] Fixed inconsistencies in setting hop count limit in
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 dhcrelay
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diff --git a/common/socket.c b/common/socket.c
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index c170448..5467a35 100644
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--- a/common/socket.c
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+++ b/common/socket.c
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@@ -300,18 +300,24 @@ if_register_socket(struct interface_info *info, int family,
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 #endif
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 	}
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-	if ((family == AF_INET6) &&
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-	    ((info->flags & INTERFACE_UPSTREAM) != 0)) {
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-		int hop_limit = 32;
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-		if (setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
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-			       &hop_limit, sizeof(int)) < 0) {
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-			log_fatal("setsockopt: IPV6_MULTICAST_HOPS: %m");
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-		}
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-	}
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 #endif /* DHCPv6 */
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 	return sock;
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 }
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+
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+#ifdef DHCPv6
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+void set_multicast_hop_limit(struct interface_info* info, int hop_limit) {
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+	if (setsockopt(info->wfdesc, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
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+		       &hop_limit, sizeof(int)) < 0) {
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+		log_fatal("setMulticaseHopLimit: IPV6_MULTICAST_HOPS: %m");
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+	}
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+
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+	log_debug("Setting hop count limit to %d for interface %s",
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+		  hop_limit, info->name);
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+
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+}
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+#endif /* DHCPv6 */
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+
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 #endif /* USE_SOCKET_SEND || USE_SOCKET_RECEIVE || USE_SOCKET_FALLBACK */
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 #if defined (USE_SOCKET_SEND) || defined (USE_SOCKET_FALLBACK)
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diff --git a/includes/dhcpd.h b/includes/dhcpd.h
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index 2b15430..bd11b48 100644
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--- a/includes/dhcpd.h
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+++ b/includes/dhcpd.h
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@@ -2386,6 +2386,8 @@ void get_hw_addr(const char *name, struct hardware *hw);
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 #if defined (USE_SOCKET_SEND) || defined (USE_SOCKET_RECEIVE) \
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 	|| defined (USE_SOCKET_FALLBACK)
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 int if_register_socket(struct interface_info *, int, int *, struct in6_addr *);
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+
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+void set_multicast_hop_limit(struct interface_info* info, int hop_limit);
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 #endif
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 #if defined (USE_SOCKET_FALLBACK) && !defined (USE_SOCKET_SEND)
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diff --git a/relay/dhcrelay.c b/relay/dhcrelay.c
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index 927e404..ad76d3e 100644
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--- a/relay/dhcrelay.c
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+++ b/relay/dhcrelay.c
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@@ -1173,8 +1173,8 @@ parse_downstream(char *arg) {
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 	/* Share with up side? */
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 	for (up = upstreams; up; up = up->next) {
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 		if (strcmp(ifname, up->ifp->name) == 0) {
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-			log_info("Interface '%s' is both down and up.",
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-				 ifname);
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+			log_info("parse_downstream: Interface '%s' is "
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+				 "both down and up.", ifname);
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 			ifp = up->ifp;
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 			break;
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 		}
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@@ -1192,8 +1192,8 @@ parse_downstream(char *arg) {
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 			interface_dereference(&interfaces, MDL);
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 		}
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 		interface_reference(&interfaces, ifp, MDL);
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-		ifp->flags |= INTERFACE_REQUESTED | INTERFACE_DOWNSTREAM;
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 	}
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+	ifp->flags |= INTERFACE_REQUESTED | INTERFACE_DOWNSTREAM;
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 	/* New downstream. */
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 	dp = (struct stream_list *) dmalloc(sizeof(*dp), MDL);
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@@ -1244,6 +1244,8 @@ parse_upstream(char *arg) {
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 	}
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 	for (dp = downstreams; dp; dp = dp->next) {
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 		if (strcmp(ifname, dp->ifp->name) == 0) {
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+			log_info("parse_upstream: Interface '%s' is "
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+				 "both down and up.", ifname);
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 			ifp = dp->ifp;
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 			break;
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 		}
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@@ -1261,8 +1263,8 @@ parse_upstream(char *arg) {
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 			interface_dereference(&interfaces, MDL);
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 		}
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 		interface_reference(&interfaces, ifp, MDL);
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-		ifp->flags |= INTERFACE_REQUESTED | INTERFACE_UPSTREAM;
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 	}
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+	ifp->flags |= INTERFACE_REQUESTED | INTERFACE_UPSTREAM;
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 	/* New upstream. */
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 	up = (struct stream_list *) dmalloc(sizeof(*up), MDL);
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@@ -1330,6 +1332,13 @@ setup_streams(void) {
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 		if (up->ifp->v6address_count == 0)
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 			log_fatal("Interface '%s' has no IPv6 addresses.",
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 				  up->ifp->name);
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+
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+		/* RFC 3315 Sec 20 - "If the relay agent relays messages to
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+		 * the All_DHCP_Servers address or other multicast addresses,
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+		 * it sets the Hop Limit field to 32." */
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+		if (IN6_IS_ADDR_MULTICAST(&up->link.sin6_addr)) {
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+			set_multicast_hop_limit(up->ifp, HOP_COUNT_LIMIT);
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+		}
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 	}
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 }
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-- 
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2.1.0
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