MEDIUM: socket: always properly use the sock_domain for requested families

Now we make sure to always look up the protocol's domain for an address
family. Previously we would use it as-is, which prevented from properly
using custom addresses (which is when they differ).

This removes some hard-coded tests such as in log.c where UNIX vs UDP
was explicitly checked for example. It requires a bit of care, however,
so as to properly pass value 1 in the 3rd arg of the protocol_lookup()
for DGRAM stuff. Maybe one day we'll change these for defines or enums
to limit mistakes.

src/dns.c

@@ -31,6 +31,7 @@
 #include <haproxy/errors.h>
 #include <haproxy/fd.h>
 #include <haproxy/log.h>
+#include <haproxy/protocol.h>
 #include <haproxy/sc_strm.h>
 #include <haproxy/stconn.h>
 #include <haproxy/stream.h>
@@ -48,6 +49,7 @@ DECLARE_STATIC_POOL(dns_msg_buf, "dns_msg_buf", DNS_TCP_MSG_RING_MAX_SIZE);
 static int dns_connect_nameserver(struct dns_nameserver *ns)
 {
 	struct dgram_conn *dgram = &ns->dgram->conn;
+	const struct protocol *proto;
 	int fd;
 
 	/* Already connected */
@@ -55,7 +57,9 @@ static int dns_connect_nameserver(struct dns_nameserver *ns)
 		return 0;
 
 	/* Create an UDP socket and connect it on the nameserver's IP/Port */
-	if ((fd = socket(dgram->addr.to.ss_family, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
+	proto = protocol_lookup(dgram->addr.to.ss_family, PROTO_TYPE_DGRAM, 1);
+	BUG_ON(!proto);
+	if ((fd = socket(proto->fam->sock_domain, proto->sock_type, proto->sock_prot)) == -1) {
 		send_log(NULL, LOG_WARNING,
 			 "DNS : section '%s': can't create socket for nameserver '%s'.\n",
 			 ns->counters->pid, ns->id);

src/log.c

@@ -38,6 +38,7 @@
 #include <haproxy/lb_map.h>
 #include <haproxy/lb_ss.h>
 #include <haproxy/log.h>
+#include <haproxy/protocol.h>
 #include <haproxy/proxy.h>
 #include <haproxy/sample.h>
 #include <haproxy/sc_strm.h>
@@ -2670,6 +2671,7 @@ static inline void __do_send_log(struct log_target *target, struct log_header hd
 	};
 	static THREAD_LOCAL int logfdunix = -1;	/* syslog to AF_UNIX socket */
 	static THREAD_LOCAL int logfdinet = -1;	/* syslog to AF_INET socket */
+	const struct protocol *proto;
 	int *plogfd;
 	int sent;
 	size_t nbelem;
@@ -2698,8 +2700,13 @@ static inline void __do_send_log(struct log_target *target, struct log_header hd
 
 	if (plogfd && unlikely(*plogfd < 0)) {
 		/* socket not successfully initialized yet */
-		if ((*plogfd = socket(target->addr->ss_family, SOCK_DGRAM,
-		                      (target->addr->ss_family == AF_UNIX) ? 0 : IPPROTO_UDP)) < 0) {
+
+		/* WT: this is not compliant with AF_CUST_* usage but we don't use that
+		 * with DNS at the moment.
+		 */
+		proto = protocol_lookup(target->addr->ss_family, PROTO_TYPE_DGRAM, 1);
+		BUG_ON(!proto);
+		if ((*plogfd = socket(proto->fam->sock_domain, proto->sock_type, proto->sock_prot)) < 0) {
 			static char once;
 
 			if (!once) {

src/resolvers.c

@@ -2633,6 +2633,7 @@ static void resolvers_deinit(void)
  */
 static int resolvers_finalize_config(void)
 {
+	const struct protocol *proto;
 	struct resolvers *resolvers;
 	struct proxy	     *px;
 	int err_code = 0;
@@ -2650,7 +2651,9 @@ static int resolvers_finalize_config(void)
 
 			if (ns->dgram) {
 				/* Check nameserver info */
-				if ((fd = socket(ns->dgram->conn.addr.to.ss_family, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
+				proto = protocol_lookup(ns->dgram->conn.addr.to.ss_family, PROTO_TYPE_DGRAM, 1);
+				BUG_ON(!proto);
+				if ((fd = socket(proto->fam->sock_domain, proto->sock_type, proto->sock_prot)) == -1) {
 					if (!resolvers->conf.implicit) {  /* emit a warning only if it was configured manually */
 						ha_alert("resolvers '%s': can't create socket for nameserver '%s'.\n",
 							 resolvers->id, ns->id);

src/sock.c

@@ -30,7 +30,7 @@
 #include <haproxy/listener.h>
 #include <haproxy/log.h>
 #include <haproxy/namespace.h>
-#include <haproxy/protocol-t.h>
+#include <haproxy/protocol.h>
 #include <haproxy/proto_sockpair.h>
 #include <haproxy/sock.h>
 #include <haproxy/sock_inet.h>
@@ -268,6 +268,7 @@ static int sock_handle_system_err(struct connection *conn, struct proxy *be)
 int sock_create_server_socket(struct connection *conn, struct proxy *be, int *stream_err)
 {
 	const struct netns_entry *ns = NULL;
+	const struct protocol *proto;
 	int sock_fd;
 
 #ifdef USE_NS
@@ -278,7 +279,9 @@ int sock_create_server_socket(struct connection *conn, struct proxy *be, int *st
 			ns = __objt_server(conn->target)->netns;
 	}
 #endif
-	sock_fd = my_socketat(ns, conn->dst->ss_family, SOCK_STREAM, 0);
+	proto = protocol_lookup(conn->dst->ss_family, PROTO_TYPE_STREAM, 0);
+	BUG_ON(!proto);
+	sock_fd = my_socketat(ns, proto->fam->sock_domain, SOCK_STREAM, 0);
 
 	/* at first, handle common to all proto families system limits and permission related errors */
 	if (sock_fd == -1) {

src/tools.c

@@ -1941,6 +1941,7 @@ int addr_is_local(const struct netns_entry *ns,
                   const struct sockaddr_storage *orig)
 {
 	struct sockaddr_storage addr;
+	const struct proto_fam *fam;
 	int result;
 	int fd;
 
@@ -1950,7 +1951,10 @@ int addr_is_local(const struct netns_entry *ns,
 	memcpy(&addr, orig, sizeof(addr));
 	set_host_port(&addr, 0);
 
-	fd = my_socketat(ns, addr.ss_family, SOCK_DGRAM, IPPROTO_UDP);
+	fam = proto_fam_lookup(addr.ss_family);
+	BUG_ON(!fam);
+
+	fd = my_socketat(ns, fam->sock_domain, SOCK_DGRAM, IPPROTO_UDP);
 	if (fd < 0)
 		return -1;