sock: osmo_sock_init2_multiaddr: decouple addr resolution from socket creation

Address resolution is done first and once we have the information, it
proceeds to create the socket. This separation in steps will help when
adding support for IPv6+IPv4 sets, where AF_UNSPEC is passed and created
socket needs to be AF_INET6 in order to handle addr of both versions.

Change-Id: I03147e3033a0c1fd04c9ac61d2ffbd78a1bb784a

1 files changed, 43 insertions, 46 deletions

diff --git a/src/socket.c b/src/socket.c
index 9c608218..9c421daa 100644
--- a/src/socket.c
+++ b/src/socket.c
@@ -483,7 +483,7 @@ int osmo_sock_init2_multiaddr(uint16_t family, uint16_t type, uint8_t proto,
 		   unsigned int flags)
 
 {
-	struct addrinfo *result[OSMO_SOCK_MAX_ADDRS];
+	struct addrinfo *res_loc[OSMO_SOCK_MAX_ADDRS], *res_rem[OSMO_SOCK_MAX_ADDRS];
 	int sfd = -1, rc, on = 1;
 	int i;
 	struct sockaddr_in addrs4[OSMO_SOCK_MAX_ADDRS];
@@ -519,21 +519,31 @@ int osmo_sock_init2_multiaddr(uint16_t family, uint16_t type, uint8_t proto,
 
 	/* figure out local side of socket */
 	if (flags & OSMO_SOCK_F_BIND) {
-		rc = addrinfo_helper_multi(result, family, type, proto, local_hosts,
-					       local_hosts_cnt, local_port, true);
+		rc = addrinfo_helper_multi(res_loc, family, type, proto, local_hosts,
+					   local_hosts_cnt, local_port, true);
 		if (rc < 0)
 			return -EINVAL;
+	}
+	/* figure out remote side of socket */
+	if (flags & OSMO_SOCK_F_CONNECT) {
+		rc = addrinfo_helper_multi(res_rem, family, type, proto, remote_hosts,
+					   remote_hosts_cnt, remote_port, false);
+		if (rc < 0)
+			return -EINVAL;
+	}
+
+	/* figure out local side of socket */
+	if (flags & OSMO_SOCK_F_BIND) {
 
 		/* Since addrinfo_helper sets ai_family, socktype and
 		   ai_protocol in hints, we know all results will use same
 		   values, so simply pick the first one and pass it to create
 		   the socket:
 		*/
-		sfd = socket_helper(result[0], flags);
+		sfd = socket_helper(res_loc[0], flags);
 		if (sfd < 0) {
-			for (i = 0; i < local_hosts_cnt; i++)
-				freeaddrinfo(result[i]);
-			return sfd;
+			rc = sfd;
+			goto ret_freeaddrinfo;
 		}
 
 		/* Since so far we only allow IPPROTO_SCTP in this function,
@@ -547,22 +557,17 @@ int osmo_sock_init2_multiaddr(uint16_t family, uint16_t type, uint8_t proto,
 			     " %s:%u: %s\n",
 			     strbuf, local_port,
 			     strerror(errno));
-			for (i = 0; i < local_hosts_cnt; i++)
-				freeaddrinfo(result[i]);
-			close(sfd);
-			return rc;
+			goto ret_close;
 		}
 
 		/* Build array of addresses taking first of same family for each host.
 		   TODO: Ideally we should use backtracking storing last used
 		   indexes and trying next combination if connect() fails .*/
-		rc = addrinfo_to_sockaddr(family, (const struct addrinfo **)result,
+		rc = addrinfo_to_sockaddr(family, (const struct addrinfo **)res_loc,
 					  local_hosts, local_hosts_cnt, addrs4, addrs6);
 		if (rc < 0) {
-			for (i = 0; i < local_hosts_cnt; i++)
-				freeaddrinfo(result[i]);
-			close(sfd);
-			return -ENODEV;
+			rc = -ENODEV;
+			goto ret_close;
 		}
 
 		if (family == AF_INET)
@@ -573,13 +578,9 @@ int osmo_sock_init2_multiaddr(uint16_t family, uint16_t type, uint8_t proto,
 			multiaddr_snprintf(strbuf, sizeof(strbuf), local_hosts, local_hosts_cnt);
 			LOGP(DLGLOBAL, LOGL_NOTICE, "unable to bind socket: %s:%u: %s\n",
 			     strbuf, local_port, strerror(errno));
-			for (i = 0; i < local_hosts_cnt; i++)
-			     freeaddrinfo(result[i]);
-			close(sfd);
-			return -ENODEV;
+			rc = -ENODEV;
+			goto ret_close;
 		}
-		for (i = 0; i < local_hosts_cnt; i++)
-			freeaddrinfo(result[i]);
 	}
 
 	/* Reached this point, if OSMO_SOCK_F_BIND then sfd is valid (>=0) or it
@@ -588,38 +589,27 @@ int osmo_sock_init2_multiaddr(uint16_t family, uint16_t type, uint8_t proto,
 
 	/* figure out remote side of socket */
 	if (flags & OSMO_SOCK_F_CONNECT) {
-		rc = addrinfo_helper_multi(result, family, type, proto, remote_hosts,
-					       remote_hosts_cnt, remote_port, false);
-		if (rc < 0) {
-			if (sfd >= 0)
-				close(sfd);
-			return -EINVAL;
-		}
-
 		if (sfd < 0) {
 			/* Since addrinfo_helper sets ai_family, socktype and
 			   ai_protocol in hints, we know all results will use same
 			   values, so simply pick the first one and pass it to create
 			   the socket:
 			*/
-			sfd = socket_helper(result[0], flags);
+			sfd = socket_helper(res_rem[0], flags);
 			if (sfd < 0) {
-				for (i = 0; i < remote_hosts_cnt; i++)
-					freeaddrinfo(result[i]);
-				return sfd;
+				rc = sfd;
+				goto ret_freeaddrinfo;
 			}
 		}
 
 		/* Build array of addresses taking first of same family for each host.
 		   TODO: Ideally we should use backtracking storing last used
 		   indexes and trying next combination if connect() fails .*/
-		rc = addrinfo_to_sockaddr(family, (const struct addrinfo **)result,
+		rc = addrinfo_to_sockaddr(family, (const struct addrinfo **)res_rem,
 					  remote_hosts, remote_hosts_cnt, addrs4, addrs6);
 		if (rc < 0) {
-			for (i = 0; i < remote_hosts_cnt; i++)
-				freeaddrinfo(result[i]);
-			close(sfd);
-			return -ENODEV;
+			rc = -ENODEV;
+			goto ret_close;
 		}
 
 		if (family == AF_INET)
@@ -631,13 +621,9 @@ int osmo_sock_init2_multiaddr(uint16_t family, uint16_t type, uint8_t proto,
 			multiaddr_snprintf(strbuf, sizeof(strbuf), remote_hosts, remote_hosts_cnt);
 			LOGP(DLGLOBAL, LOGL_ERROR, "unable to connect socket: %s:%u: %s\n",
 				strbuf, remote_port, strerror(errno));
-			for (i = 0; i < remote_hosts_cnt; i++)
-				freeaddrinfo(result[i]);
-			close(sfd);
-			return -ENODEV;
+			rc = -ENODEV;
+			goto ret_close;
 		}
-		for (i = 0; i < remote_hosts_cnt; i++)
-			freeaddrinfo(result[i]);
 	}
 
 	rc = osmo_sock_init_tail(sfd, type, flags);
@@ -646,7 +632,18 @@ int osmo_sock_init2_multiaddr(uint16_t family, uint16_t type, uint8_t proto,
 		sfd = -1;
 	}
 
-	return sfd;
+	rc = sfd;
+	goto ret_freeaddrinfo;
+
+ret_close:
+	if (sfd >= 0)
+		close(sfd);
+ret_freeaddrinfo:
+	for (i = 0; i < local_hosts_cnt; i++)
+		freeaddrinfo(res_loc[i]);
+	for (i = 0; i < remote_hosts_cnt; i++)
+		freeaddrinfo(res_rem[i]);
+	return rc;
 }
 #endif /* HAVE_LIBSCTP */