From 0 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Fri, 7 Dec 2018 21:11:06 +0300
Subject: [PATCH 37] dhcrelay: fix relaying of return packets


diff --git a/dhcp/common/discover.c b/dhcp/common/discover.c
index defaced..defaced 100644
--- a/dhcp/common/discover.c
+++ b/dhcp/common/discover.c
@@ -768,9 +768,9 @@ discover_interfaces(int state) {
 					  INTERFACE_REQUESTED);
 
 #ifdef DHCPv6
-		if (!(tmp->flags & INTERFACE_REQUESTED)) {
+		if (!(tmp->flags & INTERFACE_REQUESTED) && state != DISCOVER_RELAY) {
 #else
-		if (!tmp -> ifp || !(tmp -> flags & INTERFACE_REQUESTED)) {
+		if (!tmp -> ifp || (!(tmp -> flags & INTERFACE_REQUESTED) && state != DISCOVER_RELAY)) {
 #endif /* DHCPv6 */
 			if ((tmp -> flags & INTERFACE_REQUESTED) != ir)
 				log_fatal ("%s: not found", tmp -> name);
diff --git a/dhcp/relay/dhcrelay.c b/dhcp/relay/dhcrelay.c
index defaced..defaced 100644
--- a/dhcp/relay/dhcrelay.c
+++ b/dhcp/relay/dhcrelay.c
@@ -993,6 +993,11 @@ do_relay4(struct interface_info *ip, struct dhcp_packet *packet,
 		return;
 	}
 
+       /* If this is not a BOOTREPLY, and it is not on a requested interface,
+	 * drop it. */
+	if (!(ip->flags & INTERFACE_REQUESTED))
+		return;
+
 	/* Add relay agent options if indicated.   If something goes wrong,
 	 * drop the packet.  Note this may set packet->giaddr if RFC3527
 	 * is enabled. */