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

doc/tinc.conf.5.in

@@ -464,10 +464,10 @@ and
 .Ev REMOTEPORT
 are available.
 .El
-.It Va ReplayWindow Li = Ar bytes Pq 16
+.It Va ReplayWindow Li = Ar bytes Pq 32
 This is the size of the replay tracking window for each remote node, in bytes.
 The window is a bitfield which tracks 1 packet per bit, so for example
-the default setting of 16 will track up to 128 packets in the window. In high
+the default setting of 32 will track up to 256 packets in the window. In high
 bandwidth scenarios, setting this to a higher value can reduce packet loss from
 the interaction of replay tracking with underlying real packet loss and/or
 reordering. Setting this to zero will disable replay tracking completely and
@@ -502,12 +502,14 @@ If tinc doesn't receive any UDP ping replies over the specified interval,
 it will assume UDP communication is broken and will fall back to TCP.
 .It Va UDPInfoInterval Li = Ar seconds Pq 5
 The minimum amount of time between sending periodic updates about UDP addresses, which are mostly useful for UDP hole punching.
-.It Va UDPRcvBuf Li = Ar bytes Pq OS default
+.It Va UDPRcvBuf Li = Ar bytes Pq 1048576
 Sets the socket receive buffer size for the UDP socket, in bytes.
-If unset, the default buffer size will be used by the operating system.
-.It Va UDPSndBuf Li = Ar bytes Pq OS default
+If set to zero, the default buffer size will be used by the operating system.
+Note: this setting can have a significant impact on performance, especially raw throughput.
+.It Va UDPSndBuf Li = Ar bytes Pq 1048576
 Sets the socket send buffer size for the UDP socket, in bytes.
-If unset, the default buffer size will be used by the operating system.
+If set to zero, the default buffer size will be used by the operating system.
+Note: this setting can have a significant impact on performance, especially raw throughput.
 .El
 .Sh HOST CONFIGURATION FILES
 The host configuration files contain all information needed

doc/tinc.texi

@@ -1207,10 +1207,10 @@ The environment variables @env{NAME}, @env{NODE}, @env{REMOTEADDRES} and @env{RE
 @end table
 
 @cindex ReplayWindow
-@item ReplayWindow = <bytes> (16)
+@item ReplayWindow = <bytes> (32)
 This is the size of the replay tracking window for each remote node, in bytes.
 The window is a bitfield which tracks 1 packet per bit, so for example
-the default setting of 16 will track up to 128 packets in the window. In high
+the default setting of 32 will track up to 256 packets in the window. In high
 bandwidth scenarios, setting this to a higher value can reduce packet loss from
 the interaction of replay tracking with underlying real packet loss and/or
 reordering. Setting this to zero will disable replay tracking completely and
@@ -1258,14 +1258,16 @@ it will assume UDP communication is broken and will fall back to TCP.
 The minimum amount of time between sending periodic updates about UDP addresses, which are mostly useful for UDP hole punching.
 
 @cindex UDPRcvBuf
-@item UDPRcvBuf = <bytes> (OS default)
+@item UDPRcvBuf = <bytes> (1048576)
 Sets the socket receive buffer size for the UDP socket, in bytes.
-If unset, the default buffer size will be used by the operating system.
+If set to zero, the default buffer size will be used by the operating system.
+Note: this setting can have a significant impact on performance, especially raw throughput.
 
 @cindex UDPSndBuf
-@item UDPSndBuf = <bytes> Pq OS default
+@item UDPSndBuf = <bytes> (1048576)
 Sets the socket send buffer size for the UDP socket, in bytes.
-If unset, the default buffer size will be used by the operating system.
+If set to zero, the default buffer size will be used by the operating system.
+Note: this setting can have a significant impact on performance, especially raw throughput.
 
 @end table
 

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];