2 files changed, 16 insertions, 10 deletions

diff --git a/conf.c b/conf.c
index ed25e35..37f25d6 100644
--- a/conf.c
+++ b/conf.c
@@ -395,6 +395,9 @@ static void add_dns4(struct ctx *c, struct in_addr *addr, struct in_addr **conf)
 		if (!c->no_map_gw) {
 			**conf = c->ip4.gw;
 			(*conf)++;
+
+			if (IN4_IS_ADDR_UNSPECIFIED(&c->ip4.dns_match))
+				c->ip4.dns_match = c->ip4.gw;
 		}
 	} else {
 		**conf = *addr;
@@ -419,6 +422,9 @@ static void add_dns6(struct ctx *c,
 		if (!c->no_map_gw) {
 			memcpy(*conf, &c->ip6.gw, sizeof(**conf));
 			(*conf)++;
+
+			if (IN6_IS_ADDR_UNSPECIFIED(&c->ip6.dns_match))
+				memcpy(&c->ip6.dns_match, addr, sizeof(*addr));
 		}
 	} else {
 		memcpy(*conf, addr, sizeof(**conf));
diff --git a/udp.c b/udp.c
index 1d65559..20a9ea0 100644
--- a/udp.c
+++ b/udp.c
@@ -857,17 +857,16 @@ int udp_tap_handler(struct ctx *c, int af, const void *addr,
 
 		udp_tap_map[V4][src].ts = now->tv_sec;
 
-		if (IN4_ARE_ADDR_EQUAL(&s_in.sin_addr, &c->ip4.gw) &&
-		    !c->no_map_gw) {
+		if (IN4_ARE_ADDR_EQUAL(&s_in.sin_addr, &c->ip4.dns_match) &&
+		    ntohs(s_in.sin_port) == 53) {
+			s_in.sin_addr = c->ip4.dns_host;
+		} else if (IN4_ARE_ADDR_EQUAL(&s_in.sin_addr, &c->ip4.gw) &&
+			   !c->no_map_gw) {
 			if (!(udp_tap_map[V4][dst].flags & PORT_LOCAL) ||
 			    (udp_tap_map[V4][dst].flags & PORT_LOOPBACK))
 				s_in.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
 			else
 				s_in.sin_addr = c->ip4.addr_seen;
-		} else if (IN4_ARE_ADDR_EQUAL(&s_in.sin_addr,
-					      &c->ip4.dns_match) &&
-			   ntohs(s_in.sin_port) == 53) {
-			s_in.sin_addr = c->ip4.dns_host;
 		}
 	} else {
 		s_in6 = (struct sockaddr_in6) {
@@ -880,7 +879,11 @@ int udp_tap_handler(struct ctx *c, int af, const void *addr,
 		sa = (struct sockaddr *)&s_in6;
 		sl = sizeof(s_in6);
 
-		if (IN6_ARE_ADDR_EQUAL(addr, &c->ip6.gw) && !c->no_map_gw) {
+		if (IN6_ARE_ADDR_EQUAL(addr, &c->ip6.dns_match) &&
+		    ntohs(s_in6.sin6_port) == 53) {
+			s_in6.sin6_addr = c->ip6.dns_host;
+		} else if (IN6_ARE_ADDR_EQUAL(addr, &c->ip6.gw) &&
+			   !c->no_map_gw) {
 			if (!(udp_tap_map[V6][dst].flags & PORT_LOCAL) ||
 			    (udp_tap_map[V6][dst].flags & PORT_LOOPBACK))
 				s_in6.sin6_addr = in6addr_loopback;
@@ -888,9 +891,6 @@ int udp_tap_handler(struct ctx *c, int af, const void *addr,
 				s_in6.sin6_addr = c->ip6.addr;
 			else
 				s_in6.sin6_addr = c->ip6.addr_seen;
-		} else if (IN6_ARE_ADDR_EQUAL(addr, &c->ip6.dns_match) &&
-			   ntohs(s_in6.sin6_port) == 53) {
-			s_in6.sin6_addr = c->ip6.dns_host;
 		} else if (IN6_IS_ADDR_LINKLOCAL(&s_in6.sin6_addr)) {
 			bind_addr = &c->ip6.addr_ll;
 		}