[master] fix ECS with family==0

4341.	[bug]		Correct the handling of ECS options with
			address family 0. [RT #41377]

CHANGES

@@ -1,5 +1,8 @@
 	--- 9.11.0a1 released ---
 
+4341.	[bug]		Correct the handling of ECS options with
+			address family 0. [RT #41377]
+
 4340.	[performance]	Implement adaptive read-write locks, reducing the
 			overhead of locks that are only held briefly.
 			[RT #37329]

bin/dig/dighost.c

@@ -2527,14 +2527,14 @@ setup_lookup(dig_lookup_t *lookup) {
 			if (sa->sa_family == AF_INET) {
 				family = 1;
 				sin = (struct sockaddr_in *) sa;
-				memcpy(addr, &sin->sin_addr, 4);
+				memmove(addr, &sin->sin_addr, 4);
 				if ((plen % 8) != 0)
 					addr[addrl-1] &=
 						~0 << (8 - (plen % 8));
 			} else {
 				family = 2;
 				sin6 = (struct sockaddr_in6 *) sa;
-				memcpy(addr, &sin6->sin6_addr, 16);
+				memmove(addr, &sin6->sin6_addr, 16);
 			}
 
 			/* Mask off last address byte */

bin/named/client.c

@@ -1894,7 +1894,6 @@ process_ecs(ns_client_t *client, isc_buffer_t *buf, size_t optlen) {
 	isc_uint16_t family;
 	isc_uint8_t addrlen, addrbytes, scope, *paddr;
 	isc_netaddr_t caddr;
-	int i;
 
 	/*
 	 * If we have already seen a ECS option skip this ECS option.
@@ -1929,21 +1928,51 @@ process_ecs(ns_client_t *client, isc_buffer_t *buf, size_t optlen) {
 		return (DNS_R_OPTERR);
 	}
 
+	if (addrlen == 0 && family != 0) {
+		ns_client_log(client, NS_LOGCATEGORY_CLIENT,
+			      NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2),
+			      "EDNS client-subnet option: "
+			      "source == 0 but family != 0");
+		return (DNS_R_OPTERR);
+	}
+
 	memset(&caddr, 0, sizeof(caddr));
 	switch (family) {
+	case 0:
+		/*
+		 * XXXMUKS: In queries, if FAMILY is set to 0, SOURCE
+		 * PREFIX-LENGTH must be 0 and ADDRESS should not be
+		 * present as the address and prefix lengths don't make
+		 * sense because the family is unknown.
+		 */
+		if (addrlen != 0U) {
+			ns_client_log(client, NS_LOGCATEGORY_CLIENT,
+				      NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2),
+				      "EDNS client-subnet option: invalid "
+				      "address length (%u) for FAMILY=0",
+				      addrlen);
+			return (DNS_R_OPTERR);
+		}
+		caddr.family = AF_UNSPEC;
+		break;
 	case 1:
-		if (addrlen > 32U)
+		if (addrlen > 32U) {
-			goto invalid_length;
+			ns_client_log(client, NS_LOGCATEGORY_CLIENT,
+				      NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2),
+				      "EDNS client-subnet option: invalid "
+				      "address length (%u) for IPv4",
+				      addrlen);
+			return (DNS_R_OPTERR);
+		}
 		caddr.family = AF_INET;
 		break;
 	case 2:
 		if (addrlen > 128U) {
-	invalid_length:
 			ns_client_log(client, NS_LOGCATEGORY_CLIENT,
 				      NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2),
 				      "EDNS client-subnet option: invalid "
-				      "address length (%u) for %s",
+				      "address length (%u) for IPv6",
-				      addrlen, family == 1 ? "IPv4" : "IPv6");
+				      addrlen);
 			return (DNS_R_OPTERR);
 		}
 		caddr.family = AF_INET6;
@@ -1964,17 +1993,18 @@ process_ecs(ns_client_t *client, isc_buffer_t *buf, size_t optlen) {
 	}
 
 	paddr = (isc_uint8_t *) &caddr.type;
-	for (i = 0; i < addrbytes; i++) {
+	if (addrbytes != 0U) {
-		paddr[i] = isc_buffer_getuint8(buf);
+		memmove(paddr, isc_buffer_current(buf), addrbytes);
-		optlen--;
+		isc_buffer_forward(buf, addrbytes);
-	}
+		optlen -= addrbytes;
 
-	if (addrbytes != 0U && (addrlen % 8) != 0) {
+		if ((addrlen % 8) != 0) {
 			isc_uint8_t bits = ~0 << (8 - (addrlen % 8));
 			bits &= paddr[addrbytes - 1];
 			if (bits != paddr[addrbytes - 1])
 				return (DNS_R_OPTERR);
 		}
+	}
 
 	memmove(&client->ecs_addr, &caddr, sizeof(caddr));
 	client->ecs_addrlen = addrlen;

bin/tools/mdig.c

@@ -611,14 +611,14 @@ sendquery(struct query *query, isc_task_t *task)
 			if (sa->sa_family == AF_INET) {
 				family = 1;
 				sin = (struct sockaddr_in *) sa;
-				memcpy(addr, &sin->sin_addr, 4);
+				memmove(addr, &sin->sin_addr, 4);
 				if ((plen % 8) != 0)
 					addr[addrl-1] &=
 						~0 << (8 - (plen % 8));
 			} else {
 				family = 2;
 				sin6 = (struct sockaddr_in6 *) sa;
-				memcpy(addr, &sin6->sin6_addr, 16);
+				memmove(addr, &sin6->sin6_addr, 16);
 			}
 
 			/* Mask off last address byte */

lib/dns/message.c

@@ -3244,6 +3244,9 @@ render_ecs(isc_buffer_t *ecsbuf, isc_buffer_t *target) {
 	addrlen = isc_buffer_getuint8(ecsbuf);
 	scopelen = isc_buffer_getuint8(ecsbuf);
 
+	if (addrlen == 0 && family != 0)
+		return (DNS_R_OPTERR);
+
 	addrbytes = (addrlen + 7) / 8;
 	if (isc_buffer_remaininglength(ecsbuf) < addrbytes)
 		return (DNS_R_OPTERR);
@@ -3256,15 +3259,23 @@ render_ecs(isc_buffer_t *ecsbuf, isc_buffer_t *target) {
 	for (i = 0; i < addrbytes; i ++)
 		addr[i] = isc_buffer_getuint8(ecsbuf);
 
-	if (family == 1) {
+	switch (family) {
+	case 0:
+		if (addrlen != 0U || scopelen != 0U)
+			return (DNS_R_OPTERR);
+		strlcpy(addr_text, "0", sizeof(addr_text));
+		break;
+	case 1:
 		if (addrlen > 32 || scopelen > 32)
 			return (DNS_R_OPTERR);
 		inet_ntop(AF_INET, addr, addr_text, sizeof(addr_text));
-	} else if (family == 2) {
+		break;
+	case 2:
 		if (addrlen > 128 || scopelen > 128)
 			return (DNS_R_OPTERR);
 		inet_ntop(AF_INET6, addr, addr_text, sizeof(addr_text));
-	} else {
+		break;
+	default:
 		snprintf(addr_text, sizeof(addr_text),
 			 "Unsupported family %u", family);
 		ADD_STRING(target, addr_text);

lib/dns/rdata/generic/opt_41.c

@@ -15,8 +15,6 @@
  * PERFORMANCE OF THIS SOFTWARE.
  */
 
-/* $Id$ */
-
 /* Reviewed: Thu Mar 16 14:06:44 PST 2000 by gson */
 
 /* RFC2671 */
@@ -135,7 +133,24 @@ fromwire_opt(ARGS_FROMWIRE) {
 			isc_region_consume(&sregion, 1);
 			scope = uint8_fromregion(&sregion);
 			isc_region_consume(&sregion, 1);
+
+			if (addrlen == 0U && family != 0U)
+				return (DNS_R_OPTERR);
+
 			switch (family) {
+			case 0:
+				/*
+				 * XXXMUKS: In queries and replies, if
+				 * FAMILY is set to 0, SOURCE
+				 * PREFIX-LENGTH and SCOPE PREFIX-LENGTH
+				 * must be 0 and ADDRESS should not be
+				 * present as the address and prefix
+				 * lengths don't make sense because the
+				 * family is unknown.
+				 */
+				if (addrlen != 0U || scope != 0U)
+					return (DNS_R_OPTERR);
+				break;
 			case 1:
 				if (addrlen > 32U || scope > 32U)
 					return (DNS_R_OPTERR);