BUG: proto_tcp: don't try to bind to a foreign address if sin_family is unknown

This is 1.5-specific. It causes issues with transparent source binding involving
hdr_ip. We must not try to bind() to a foreign address when the family is not set,
and we must set the family when an address is set.
diff --git a/src/backend.c b/src/backend.c
index 248bf1e..6a12cf4 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -881,6 +881,7 @@
 		case SRV_TPROXY_DYN:
 			if (srv->bind_hdr_occ) {
 				/* bind to the IP in a header */
+				((struct sockaddr_in *)&s->req->cons->addr.from)->sin_family = AF_INET;
 				((struct sockaddr_in *)&s->req->cons->addr.from)->sin_port = 0;
 				((struct sockaddr_in *)&s->req->cons->addr.from)->sin_addr.s_addr =
 					htonl(get_ip_from_hdr2(&s->txn.req,
@@ -907,6 +908,7 @@
 		case PR_O_TPXY_DYN:
 			if (s->be->bind_hdr_occ) {
 				/* bind to the IP in a header */
+				((struct sockaddr_in *)&s->req->cons->addr.from)->sin_family = AF_INET;
 				((struct sockaddr_in *)&s->req->cons->addr.from)->sin_port = 0;
 				((struct sockaddr_in *)&s->req->cons->addr.from)->sin_addr.s_addr =
 					htonl(get_ip_from_hdr2(&s->txn.req,
diff --git a/src/proto_tcp.c b/src/proto_tcp.c
index ecef63f..caeb539 100644
--- a/src/proto_tcp.c
+++ b/src/proto_tcp.c
@@ -146,6 +146,9 @@
 			if (flags & 2)
 				((struct sockaddr_in6 *)&bind_addr)->sin6_port = ((struct sockaddr_in6 *)remote)->sin6_port;
 			break;
+		default:
+			/* we don't want to try to bind to an unknown address family */
+			foreign_ok = 0;
 		}
 	}