Use a static sockaddr_storage for rpc.udp_dest

There is no need to allocate and deallocate this structue every time
we update the udp destinateion.

For the client side, where we set the destination just once per lifetime
of the context it might not matter too much but once we add udp server support
we will need to update the sockaddr for every rpc we receive.

Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>

include/libnfs-private.h

@@ -117,7 +117,7 @@ struct rpc_context {
 
 	/* special fields for UDP, which can sometimes be BROADCASTed */
 	int is_udp;
-	struct sockaddr *udp_dest;
+	struct sockaddr_storage udp_dest;
 	int is_broadcast;
 
 	/* track the address we connect to so we can auto-reconnect on session failure */

lib/init.c

@@ -336,11 +336,6 @@ void rpc_destroy_context(struct rpc_context *rpc)
 		rpc->error_string = NULL;
 	}
 
-	if (rpc->udp_dest != NULL) {
-		free(rpc->udp_dest);
-		rpc->udp_dest = NULL;
-	}
-
 	rpc->magic = 0;
 	free(rpc);
 }

lib/pdu.c

@@ -186,7 +186,9 @@ int rpc_queue_pdu(struct rpc_context *rpc, struct rpc_pdu *pdu)
 		unsigned int hash;
 
 // XXX add a rpc->udp_dest_sock_size  and get rid of sys/socket.h and netinet/in.h
-		if (sendto(rpc->fd, pdu->zdr.buf, size, MSG_DONTWAIT, rpc->udp_dest, sizeof(struct sockaddr_in)) < 0) {
+		if (sendto(rpc->fd, pdu->zdr.buf, size, MSG_DONTWAIT,
+                           (struct sockaddr *)&rpc->udp_dest,
+                           sizeof(rpc->udp_dest)) < 0) {
 			rpc_set_error(rpc, "Sendto failed with errno %s", strerror(errno));
 			rpc_free_pdu(rpc, pdu);
 			return -1;

lib/socket.c

@@ -765,17 +765,7 @@ int rpc_set_udp_destination(struct rpc_context *rpc, char *addr, int port, int i
 		return -1;
  	}
 
-	if (rpc->udp_dest) {
-		free(rpc->udp_dest);
-		rpc->udp_dest = NULL;
-	}
-	rpc->udp_dest = malloc(ai->ai_addrlen);
-	if (rpc->udp_dest == NULL) {
-		rpc_set_error(rpc, "Out of memory. Failed to allocate sockaddr structure");
-		freeaddrinfo(ai);
-		return -1;
-	}
-	memcpy(rpc->udp_dest, ai->ai_addr, ai->ai_addrlen);
+	memcpy(&rpc->udp_dest, ai->ai_addr, ai->ai_addrlen);
 	freeaddrinfo(ai);
 
 	rpc->is_broadcast = is_broadcast;