Merge branch '187-libirs-handle-scoped-ipv6-addresses-in-etc-resolv.conf' into 'master'

libirs: handle scoped IPv6 addresses in /etc/resolv.conf

Closes #187

See merge request isc-projects/bind9!854

CHANGES

@@ -1,3 +1,7 @@
+5050.	[bug]		The libirs version of getaddrinfo() was unable to parse
+			scoped IPv6 addresses present in /etc/resolv.conf.
+			[GL #187]
+
 5049.	[cleanup]	Qname minimization has been deeply refactored. [GL #16]
 
 5048.	[feature]	Add configure option to enabled and enforce FIPS mode

lib/irs/getaddrinfo.c

@@ -181,6 +181,47 @@ static void _freeaddrinfo(struct addrinfo *ai);
 #define FOUND_IPV6	0x2
 #define FOUND_MAX	2
 
+/*%
+ * Try converting the scope identifier in 'src' to a network interface index.
+ * Upon success, return true and store the resulting index in 'dst'.  Upon
+ * failure, return false.
+ */
+static bool
+parse_scopeid(const char *src, uint32_t *dst) {
+	uint32_t scopeid = 0;
+
+	REQUIRE(src != NULL);
+	REQUIRE(dst != NULL);
+
+#ifdef HAVE_IF_NAMETOINDEX
+	/*
+	 * Try using if_nametoindex() first if it is available.  As it does not
+	 * handle numeric scopes, we do not simply return if it fails.
+	 */
+	scopeid = (uint32_t)if_nametoindex(src);
+#endif
+
+	/*
+	 * Fall back to numeric scope processing if if_nametoindex() either
+	 * fails or is unavailable.
+	 */
+	if (scopeid == 0) {
+		char *endptr = NULL;
+		scopeid = (uint32_t)strtoul(src, &endptr, 10);
+		/*
+		 * The scope identifier must not be empty and no trailing
+		 * characters are allowed after it.
+		 */
+		if (src == endptr || endptr == NULL || *endptr != '\0') {
+			return (false);
+		}
+	}
+
+	*dst = scopeid;
+
+	return (true);
+}
+
 #define ISC_AI_MASK (AI_PASSIVE|AI_CANONNAME|AI_NUMERICHOST)
 /*%
  * Get a list of IP addresses and port numbers for host hostname and
@@ -365,39 +406,24 @@ getaddrinfo(const char *hostname, const char *servname,
 		char abuf[sizeof(struct in6_addr)];
 		char nbuf[NI_MAXHOST];
 		int addrsize, addroff;
-#ifdef IRS_HAVE_SIN6_SCOPE_ID
-		char *p, *ep;
 		char ntmp[NI_MAXHOST];
-		uint32_t scopeid;
-#endif
+		uint32_t scopeid = 0;
 
-#ifdef IRS_HAVE_SIN6_SCOPE_ID
 		/*
 		 * Scope identifier portion.
 		 */
 		ntmp[0] = '\0';
 		if (strchr(hostname, '%') != NULL) {
+			char *p;
 			strlcpy(ntmp, hostname, sizeof(ntmp));
 			p = strchr(ntmp, '%');
-			ep = NULL;
 
-			/*
-			 * Vendors may want to support non-numeric
-			 * scopeid around here.
-			 */
-
-			if (p != NULL)
-				scopeid = (uint32_t)strtoul(p + 1,
-								&ep, 10);
-			if (p != NULL && ep != NULL && ep[0] == '\0')
+			if (p != NULL && parse_scopeid(p + 1, &scopeid)) {
 				*p = '\0';
-			else {
+			} else {
 				ntmp[0] = '\0';
-				scopeid = 0;
 			}
-		} else
-			scopeid = 0;
-#endif
+		}
 
 		if (inet_pton(AF_INET, hostname, (struct in_addr *)abuf)
 		    == 1) {
@@ -415,7 +441,6 @@ getaddrinfo(const char *hostname, const char *servname,
 			addroff = offsetof(struct sockaddr_in, sin_addr);
 			family = AF_INET;
 			goto common;
-#ifdef IRS_HAVE_SIN6_SCOPE_ID
 		} else if (ntmp[0] != '\0' &&
 			   inet_pton(AF_INET6, ntmp, abuf) == 1) {
 			if (family && family != AF_INET6)
@@ -424,7 +449,6 @@ getaddrinfo(const char *hostname, const char *servname,
 			addroff = offsetof(struct sockaddr_in6, sin6_addr);
 			family = AF_INET6;
 			goto common;
-#endif
 		} else if (inet_pton(AF_INET6, hostname, abuf) == 1) {
 			if (family != 0 && family != AF_INET6)
 				return (EAI_NONAME);
@@ -444,12 +468,10 @@ getaddrinfo(const char *hostname, const char *servname,
 			ai->ai_socktype = socktype;
 			SIN(ai->ai_addr)->sin_port = port;
 			memmove((char *)ai->ai_addr + addroff, abuf, addrsize);
+			if (ai->ai_family == AF_INET6) {
+				SIN6(ai->ai_addr)->sin6_scope_id = scopeid;
+			}
 			if ((flags & AI_CANONNAME) != 0) {
-#ifdef IRS_HAVE_SIN6_SCOPE_ID
-				if (ai->ai_family == AF_INET6)
-					SIN6(ai->ai_addr)->sin6_scope_id =
-						scopeid;
-#endif
 				if (getnameinfo(ai->ai_addr,
 						(socklen_t)ai->ai_addrlen,
 						nbuf, sizeof(nbuf), NULL, 0,

lib/irs/tests/resconf_test.c

@@ -64,6 +64,9 @@ ATF_TC_BODY(irs_resconf_load, tc) {
 		}, {
 			"testdata/nameserver-v6.conf", ISC_R_SUCCESS,
 			NULL, ISC_R_SUCCESS
+		}, {
+			"testdata/nameserver-v6-scoped.conf", ISC_R_SUCCESS,
+			NULL, ISC_R_SUCCESS
 		}, {
 			"testdata/options-debug.conf", ISC_R_SUCCESS,
 			NULL, ISC_R_SUCCESS

lib/irs/tests/testdata/nameserver-v6-scoped.conf

@@ -0,0 +1,10 @@
+# Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+#
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# See the COPYRIGHT file distributed with this work for additional
+# information regarding copyright ownership.
+
+nameserver fe80::1%1

util/copyrights

@@ -3298,6 +3298,7 @@
 ./lib/irs/tests/resconf_test.c			C	2016,2018
 ./lib/irs/tests/testdata/domain.conf		CONF-SH	2016,2018
 ./lib/irs/tests/testdata/nameserver-v4.conf	CONF-SH	2016,2018
+./lib/irs/tests/testdata/nameserver-v6-scoped.conf	CONF-SH	2018
 ./lib/irs/tests/testdata/nameserver-v6.conf	CONF-SH	2016,2018
 ./lib/irs/tests/testdata/options-bad-ndots.conf	CONF-SH	2018
 ./lib/irs/tests/testdata/options-debug.conf	CONF-SH	2016,2018