Always call res_init() before getaddrinfo().

Unfortunately, glibc assumes that /etc/resolv.conf is a static file that
never changes. Even on servers, /etc/resolv.conf might be a dynamically
generated file, and we never know when it changes. So just call
res_init() every time, so glibc uses up-to-date nameserver information.

Conflicts:
	src/have.h
	src/net.c
	src/net_setup.c

src/net_packet.c

@@ -64,7 +64,7 @@ static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999
 
 static void send_udppacket(node_t *, vpn_packet_t *);
 
-unsigned replaywin = 16;
+unsigned replaywin = 32;
 bool localdiscovery = true;
 bool udp_discovery = true;
 int udp_discovery_keepalive_interval = 10;

src/net_setup.c

@@ -857,14 +857,14 @@ static bool setup_myself(void) {
 	}
 
 	if(get_config_int(lookup_config(config_tree, "UDPRcvBuf"), &udp_rcvbuf)) {
-		if(udp_rcvbuf <= 0) {
+		if(udp_rcvbuf < 0) {
 			logger(DEBUG_ALWAYS, LOG_ERR, "UDPRcvBuf cannot be negative!");
 			return false;
 		}
 	}
 
 	if(get_config_int(lookup_config(config_tree, "UDPSndBuf"), &udp_sndbuf)) {
-		if(udp_sndbuf <= 0) {
+		if(udp_sndbuf < 0) {
 			logger(DEBUG_ALWAYS, LOG_ERR, "UDPSndBuf cannot be negative!");
 			return false;
 		}

src/net_socket.c

@@ -43,8 +43,8 @@
 int addressfamily = AF_UNSPEC;
 int maxtimeout = 900;
 int seconds_till_retry = 5;
-int udp_rcvbuf = 0;
-int udp_sndbuf = 0;
+int udp_rcvbuf = 1024 * 1024;
+int udp_sndbuf = 1024 * 1024;
 int max_connection_burst = 100;
 
 listen_socket_t listen_socket[MAXSOCKETS];