(Hopefully) fix the problem Kai reported with

net ads leave and IPv6. Ensure all DC lookups
prefer IPv4.
Jeremy.

4 files changed, 60 insertions, 8 deletions

diff --git a/source3/include/proto.h b/source3/include/proto.h
index fc009145f0..697051ceea 100644
--- a/source3/include/proto.h
+++ b/source3/include/proto.h
@@ -1333,6 +1333,9 @@ bool is_broadcast_addr(const struct sockaddr *pss);
 bool interpret_string_addr(struct sockaddr_storage *pss,
 		const char *str,
 		int flags);
+bool interpret_string_addr_prefer_ipv4(struct sockaddr_storage *pss,
+		const char *str,
+		int flags);
 bool is_loopback_ip_v4(struct in_addr ip);
 bool is_loopback_addr(const struct sockaddr *pss);
 bool is_zero_addr(const struct sockaddr *pss);
diff --git a/source3/lib/util_sock.c b/source3/lib/util_sock.c
index af64f370ba..ec88b6046a 100644
--- a/source3/lib/util_sock.c
+++ b/source3/lib/util_sock.c
@@ -23,12 +23,14 @@
 
 /*******************************************************************
  Map a text hostname or IP address (IPv4 or IPv6) into a
- struct sockaddr_storage.
+ struct sockaddr_storage. Takes a flag which allows it to
+ prefer an IPv4 address (needed for DC's).
 ******************************************************************/
 
-bool interpret_string_addr(struct sockaddr_storage *pss,
+static bool interpret_string_addr_pref(struct sockaddr_storage *pss,
 		const char *str,
-		int flags)
+		int flags,
+		bool prefer_ipv4)
 {
 	struct addrinfo *res = NULL;
 #if defined(HAVE_IPV6)
@@ -60,8 +62,24 @@ bool interpret_string_addr(struct sockaddr_storage *pss,
 	if (!res) {
 		return false;
 	}
-	/* Copy the first sockaddr. */
-	memcpy(pss, res->ai_addr, res->ai_addrlen);
+
+	if (prefer_ipv4) {
+		struct addrinfo *p;
+
+		for (p = res; p; p = p->ai_next) {
+			if (p->ai_family == AF_INET) {
+				memcpy(pss, p->ai_addr, p->ai_addrlen);
+				break;
+			}
+		}
+		if (p == NULL) {
+			/* Copy the first sockaddr. */
+			memcpy(pss, res->ai_addr, res->ai_addrlen);
+		}
+	} else {
+		/* Copy the first sockaddr. */
+		memcpy(pss, res->ai_addr, res->ai_addrlen);
+	}
 
 #if defined(HAVE_IPV6)
 	if (pss->ss_family == AF_INET6 && scope_id) {
@@ -78,6 +96,36 @@ bool interpret_string_addr(struct sockaddr_storage *pss,
 }
 
 /*******************************************************************
+ Map a text hostname or IP address (IPv4 or IPv6) into a
+ struct sockaddr_storage. Address agnostic version.
+******************************************************************/
+
+bool interpret_string_addr(struct sockaddr_storage *pss,
+		const char *str,
+		int flags)
+{
+	return interpret_string_addr_pref(pss,
+					str,
+					flags,
+					false);
+}
+
+/*******************************************************************
+ Map a text hostname or IP address (IPv4 or IPv6) into a
+ struct sockaddr_storage. Version that prefers IPv4.
+******************************************************************/
+
+bool interpret_string_addr_prefer_ipv4(struct sockaddr_storage *pss,
+		const char *str,
+		int flags)
+{
+	return interpret_string_addr_pref(pss,
+					str,
+					flags,
+					true);
+}
+
+/*******************************************************************
  Set an address to INADDR_ANY.
 ******************************************************************/
 
diff --git a/source3/libads/cldap.c b/source3/libads/cldap.c
index 523020797b..5cefd6ccc1 100644
--- a/source3/libads/cldap.c
+++ b/source3/libads/cldap.c
@@ -44,7 +44,7 @@ bool ads_cldap_netlogon(TALLOC_CTX *mem_ctx,
 	int ret;
 	struct tsocket_address *dest_addr;
 
-	if (!interpret_string_addr(&ss, server, 0)) {
+	if (!interpret_string_addr_prefer_ipv4(&ss, server, 0)) {
 		DEBUG(2,("Failed to resolve[%s] into an address for cldap\n",
 			server));
 		return false;
diff --git a/source3/libsmb/dsgetdcname.c b/source3/libsmb/dsgetdcname.c
index 3e0f4977aa..de020d4791 100644
--- a/source3/libsmb/dsgetdcname.c
+++ b/source3/libsmb/dsgetdcname.c
@@ -613,7 +613,8 @@ static NTSTATUS discover_dc_dns(TALLOC_CTX *mem_ctx,
 		/* If we don't have an IP list for a name, lookup it up */
 
 		if (!dcs[i].ss_s) {
-			interpret_string_addr(&r->ss, dcs[i].hostname, 0);
+			interpret_string_addr_prefer_ipv4(&r->ss,
+						dcs[i].hostname, 0);
 			i++;
 			j = 0;
 		} else {
@@ -973,7 +974,7 @@ static NTSTATUS process_dc_netbios(TALLOC_CTX *mem_ctx,
 		ip_list.ss = dclist[i].ss;
 		ip_list.port = 0;
 
-		if (!interpret_string_addr(&ss, dclist[i].hostname, AI_NUMERICHOST)) {
+		if (!interpret_string_addr_prefer_ipv4(&ss, dclist[i].hostname, AI_NUMERICHOST)) {
 			return NT_STATUS_UNSUCCESSFUL;
 		}