cnq3/code/qcommon/net_ip.cpp

/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.

This file is part of Quake III Arena source code.

Quake III Arena source code is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of the License,
or (at your option) any later version.

Quake III Arena source code is distributed in the hope that it will be
useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Quake III Arena source code; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/

#include "../qcommon/q_shared.h"
#include "../qcommon/qcommon.h"

#ifdef _WIN32
#include <winsock.h>

typedef int socklen_t;
#define EAGAIN			WSAEWOULDBLOCK
#define EADDRNOTAVAIL	WSAEADDRNOTAVAIL
#define EAFNOSUPPORT	WSAEAFNOSUPPORT
#define ECONNRESET		WSAECONNRESET
#define socketError		WSAGetLastError()

static WSADATA	winsockdata;

#else

#if MAC_OS_X_VERSION_MIN_REQUIRED == 1020
#define _BSD_SOCKLEN_T_ // needed for socklen_t on OSX 10.2
#endif

#include <arpa/inet.h>
#include <errno.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>

#ifdef MACOS_X
#include <sys/sockio.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/if_dl.h>         // for 'struct sockaddr_dl'
#endif

#ifdef __sun
#include <sys/filio.h>
#endif

typedef int SOCKET;
static const SOCKET INVALID_SOCKET = -1;
#define SOCKET_ERROR		-1
#define closesocket			close
#define ioctlsocket			ioctl
#define socketError			errno

#endif

static qboolean usingSocks = qfalse;
static qboolean networkingEnabled = qfalse;

static cvar_t* net_noudp;
static cvar_t* net_socksEnabled;
static cvar_t* net_socksServer;
static cvar_t* net_socksPort;
static cvar_t* net_socksUsername;
static cvar_t* net_socksPassword;
static struct sockaddr socksRelayAddr;

static SOCKET ip_socket = INVALID_SOCKET;
static SOCKET socks_socket = INVALID_SOCKET;

#define MAX_IPS 16
static int numIP;
static byte localIP[MAX_IPS][4];


///////////////////////////////////////////////////////////////


static const char* NET_ErrorString()
{
#ifdef _WIN32
	//FIXME: replace with FormatMessage?
#define WSA_ERR2STR(x) case x: return #x;
	switch ( socketError ) {
		WSA_ERR2STR( WSAEINTR );
		WSA_ERR2STR( WSAEBADF );
		WSA_ERR2STR( WSAEACCES );
		WSA_ERR2STR( WSAEDISCON );
		WSA_ERR2STR( WSAEFAULT );
		WSA_ERR2STR( WSAEINVAL );
		WSA_ERR2STR( WSAEMFILE );
		WSA_ERR2STR( WSAEWOULDBLOCK );
		WSA_ERR2STR( WSAEINPROGRESS );
		WSA_ERR2STR( WSAEALREADY );
		WSA_ERR2STR( WSAENOTSOCK );
		WSA_ERR2STR( WSAEDESTADDRREQ );
		WSA_ERR2STR( WSAEMSGSIZE );
		WSA_ERR2STR( WSAEPROTOTYPE );
		WSA_ERR2STR( WSAENOPROTOOPT );
		WSA_ERR2STR( WSAEPROTONOSUPPORT );
		WSA_ERR2STR( WSAESOCKTNOSUPPORT );
		WSA_ERR2STR( WSAEOPNOTSUPP );
		WSA_ERR2STR( WSAEPFNOSUPPORT );
		WSA_ERR2STR( WSAEAFNOSUPPORT );
		WSA_ERR2STR( WSAEADDRINUSE );
		WSA_ERR2STR( WSAEADDRNOTAVAIL );
		WSA_ERR2STR( WSAENETDOWN );
		WSA_ERR2STR( WSAENETUNREACH );
		WSA_ERR2STR( WSAENETRESET );
		WSA_ERR2STR( WSAECONNABORTED );
		WSA_ERR2STR( WSAECONNRESET );
		WSA_ERR2STR( WSAENOBUFS );
		WSA_ERR2STR( WSAEISCONN );
		WSA_ERR2STR( WSAENOTCONN );
		WSA_ERR2STR( WSAESHUTDOWN );
		WSA_ERR2STR( WSAETOOMANYREFS );
		WSA_ERR2STR( WSAETIMEDOUT );
		WSA_ERR2STR( WSAECONNREFUSED );
		WSA_ERR2STR( WSAELOOP );
		WSA_ERR2STR( WSAENAMETOOLONG );
		WSA_ERR2STR( WSAEHOSTDOWN );
		WSA_ERR2STR( WSASYSNOTREADY );
		WSA_ERR2STR( WSAVERNOTSUPPORTED );
		WSA_ERR2STR( WSANOTINITIALISED );
		WSA_ERR2STR( WSAHOST_NOT_FOUND );
		WSA_ERR2STR( WSATRY_AGAIN );
		WSA_ERR2STR( WSANO_RECOVERY );
		WSA_ERR2STR( WSANO_DATA );
		default: return "UNKNOWN ERROR";
	}
#undef WSA_ERR2STR
#else
	return strerror( errno );
#endif
}


static void NetadrToSockadr( const netadr_t* a, struct sockaddr* s )
{
	memset( s, 0, sizeof(*s) );

	if( a->type == NA_BROADCAST ) {
		((struct sockaddr_in *)s)->sin_family = AF_INET;
		((struct sockaddr_in *)s)->sin_port = a->port;
		((struct sockaddr_in *)s)->sin_addr.s_addr = INADDR_BROADCAST;
	}
	else if( a->type == NA_IP ) {
		((struct sockaddr_in *)s)->sin_family = AF_INET;
		((struct sockaddr_in *)s)->sin_addr.s_addr = *(int *)&a->ip;
		((struct sockaddr_in *)s)->sin_port = a->port;
	}
}


static void SockadrToNetadr( const struct sockaddr* s, netadr_t* a )
{
	if (s->sa_family == AF_INET) {
		a->type = NA_IP;
		*(int *)&a->ip = ((struct sockaddr_in *)s)->sin_addr.s_addr;
		a->port = ((struct sockaddr_in *)s)->sin_port;
	}
}


static qbool Sys_StringToSockaddr( const char *s, struct sockaddr *sadr )
{
	memset( sadr, 0, sizeof( *sadr ) );

	((struct sockaddr_in *)sadr)->sin_family = AF_INET;
	((struct sockaddr_in *)sadr)->sin_port = 0;

	if( s[0] >= '0' && s[0] <= '9' ) {
		*(int *)&((struct sockaddr_in *)sadr)->sin_addr = inet_addr(s);
	} else {
		struct hostent* h;
		if( ( h = gethostbyname( s ) ) == 0 ) {
			return 0;
		}
		*(int *)&((struct sockaddr_in *)sadr)->sin_addr = *(int *)h->h_addr_list[0];
	}

	return qtrue;
}


qbool Sys_StringToAdr( const char *s, netadr_t *a )
{
	struct sockaddr sadr;

	if ( !Sys_StringToSockaddr( s, &sadr ) ) {
		return qfalse;
	}

	SockadrToNetadr( &sadr, a );
	return qtrue;
}


///////////////////////////////////////////////////////////////


// never called by the game logic, just the system event queing

#ifdef _DEBUG
static int recvfromCount;
#endif

qbool Sys_GetPacket( netadr_t* net_from, msg_t* net_message )
{
	if (ip_socket == INVALID_SOCKET)
		return qfalse;

#ifdef _DEBUG
	++recvfromCount;
#endif

	struct sockaddr from;
	socklen_t fromlen = sizeof(from);
	int ret = recvfrom( ip_socket, (char*)net_message->data, net_message->maxsize, 0, (struct sockaddr *)&from, &fromlen );
	if (ret == SOCKET_ERROR) {
		int err = socketError;
		if (err == EAGAIN || err == ECONNRESET)
			return qfalse;
		Com_Printf( "NET_GetPacket: %s\n", NET_ErrorString() );
		return qfalse;
	}

	memset( ((struct sockaddr_in *)&from)->sin_zero, 0, 8 );

	if ( usingSocks && memcmp( &from, &socksRelayAddr, fromlen ) == 0 ) {
		if ( ret < 10 || net_message->data[0] != 0 || net_message->data[1] != 0 || net_message->data[2] != 0 || net_message->data[3] != 1 ) {
			return qfalse;
		}
		net_from->type = NA_IP;
		net_from->ip[0] = net_message->data[4];
		net_from->ip[1] = net_message->data[5];
		net_from->ip[2] = net_message->data[6];
		net_from->ip[3] = net_message->data[7];
		net_from->port = *(short *)&net_message->data[8];
		net_message->readcount = 10;
	}
	else {
		SockadrToNetadr( &from, net_from );
		net_message->readcount = 0;
	}

	if( ret == net_message->maxsize ) {
		Com_Printf( "Oversize packet from %s\n", NET_AdrToString (*net_from) );
		return qfalse;
	}

	net_message->cursize = ret;
	return qtrue;
}


void Sys_SendPacket( int length, const void* data, netadr_t to )
{
	static char socksBuf[4096];
	int ret;

	if( to.type != NA_BROADCAST && to.type != NA_IP ) {
		Com_Error( ERR_FATAL, "Sys_SendPacket: bad address type" );
		return;
	}

	if (ip_socket == INVALID_SOCKET)
		return;

	struct sockaddr addr;
	NetadrToSockadr( &to, &addr );

	if( usingSocks && to.type == NA_IP ) {
		socksBuf[0] = 0;	// reserved
		socksBuf[1] = 0;
		socksBuf[2] = 0;	// fragment (not fragmented)
		socksBuf[3] = 1;	// address type: IPV4
		*(int *)&socksBuf[4] = ((struct sockaddr_in *)&addr)->sin_addr.s_addr;
		*(short *)&socksBuf[8] = ((struct sockaddr_in *)&addr)->sin_port;
		memcpy( &socksBuf[10], data, length );
		ret = sendto( ip_socket, socksBuf, length+10, 0, &socksRelayAddr, sizeof(socksRelayAddr) );
	}
	else {
		ret = sendto( ip_socket, (const char*)data, length, 0, &addr, sizeof(addr) );
	}

	if (ret == SOCKET_ERROR) {
		int err = socketError;

		// wouldblock is silent
		if( err == EAGAIN ) {
			return;
		}

		// some PPP links do not allow broadcasts and return an error
		if( ( err == EADDRNOTAVAIL ) && ( ( to.type == NA_BROADCAST ) ) ) {
			return;
		}

		Com_Printf( "NET_SendPacket: %s\n", NET_ErrorString() );
	}
}


///////////////////////////////////////////////////////////////


// LAN clients will have their rate var ignored

qbool Sys_IsLANAddress( const netadr_t& adr )
{
	int i;

	if (adr.type == NA_LOOPBACK)
		return qtrue;

	if (adr.type != NA_IP)
		return qfalse;

	// RFC1918:
	// 10.0.0.0        -   10.255.255.255  (10/8 prefix)
	// 172.16.0.0      -   172.31.255.255  (172.16/12 prefix)
	// 192.168.0.0     -   192.168.255.255 (192.168/16 prefix)
	if(adr.ip[0] == 10)
		return qtrue;
	if(adr.ip[0] == 172 && (adr.ip[1]&0xf0) == 16)
		return qtrue;
	if(adr.ip[0] == 192 && adr.ip[1] == 168)
		return qtrue;

	// choose which comparison to use based on the class of the address being tested
	// any local adresses of a different class than the address being tested will fail based on the first byte
	// FIXME tma 28/08/07 Try and make this work for arbitrary subnet masks somehow

	if( adr.ip[0] == 127 && adr.ip[1] == 0 && adr.ip[2] == 0 && adr.ip[3] == 1 ) {
		return qtrue;
	}

	// Class A
	if( (adr.ip[0] & 0x80) == 0x00 ) {
		for ( i = 0 ; i < numIP ; i++ ) {
			if( adr.ip[0] == localIP[i][0] ) {
				return qtrue;
			}
		}
		return qfalse;
	}

	// Class B
	if( (adr.ip[0] & 0xc0) == 0x80 ) {
		for ( i = 0 ; i < numIP ; i++ ) {
			if( adr.ip[0] == localIP[i][0] && adr.ip[1] == localIP[i][1] ) {
				return qtrue;
			}
		}
		return qfalse;
	}

	// Class C
	for ( i = 0 ; i < numIP ; i++ ) {
		if( adr.ip[0] == localIP[i][0] && adr.ip[1] == localIP[i][1] && adr.ip[2] == localIP[i][2] ) {
			return qtrue;
		}
	}

	return qfalse;
}


void Sys_ShowIP()
{
	for (int i = 0; i < numIP; ++i) {
		Com_Printf( "IP: %i.%i.%i.%i\n", localIP[i][0], localIP[i][1], localIP[i][2], localIP[i][3] );
	}
}


///////////////////////////////////////////////////////////////


static SOCKET NET_IPSocket( const char* net_interface, int port )
{
	SOCKET newsocket;
	struct sockaddr_in address;

	Com_Printf( "Opening IP socket: %s:%i\n", net_interface ? net_interface : "localhost", port );

	if( ( newsocket = socket( AF_INET, SOCK_DGRAM, IPPROTO_UDP ) ) == INVALID_SOCKET ) {
		int err = socketError;
		if (err != EAFNOSUPPORT) {
			Com_Printf( "WARNING: NET_IPSocket: socket: %s\n", NET_ErrorString() );
		}
		return INVALID_SOCKET;
	}

	// make it non-blocking
	qboolean uglyapi = qtrue;
	if( ioctlsocket( newsocket, FIONBIO, (u_long*)&uglyapi ) == SOCKET_ERROR ) {
		Com_Printf( "WARNING: NET_IPSocket: ioctl FIONBIO: %s\n", NET_ErrorString() );
		return INVALID_SOCKET;
	}

	// make it broadcast capable (note: winsock has the wrong prototype for the
	if( setsockopt( newsocket, SOL_SOCKET, SO_BROADCAST, (const char*)&uglyapi, sizeof(uglyapi) ) == SOCKET_ERROR ) {
		Com_Printf( "WARNING: NET_IPSocket: setsockopt SO_BROADCAST: %s\n", NET_ErrorString() );
		return INVALID_SOCKET;
	}

	if( !net_interface || !net_interface[0] || !Q_stricmp(net_interface, "localhost") ) {
		address.sin_addr.s_addr = INADDR_ANY;
	}
	else {
		Sys_StringToSockaddr( net_interface, (struct sockaddr *)&address );
	}

	address.sin_port = (port == PORT_ANY) ? 0 : htons( (unsigned short)port );
	address.sin_family = AF_INET;

	if( bind( newsocket, (const sockaddr*)&address, sizeof(address) ) == SOCKET_ERROR ) {
		Com_Printf( "WARNING: NET_IPSocket: bind: %s\n", NET_ErrorString() );
		closesocket( newsocket );
		return INVALID_SOCKET;
	}

	return newsocket;
}


static void NET_OpenSocks( int port )
{
	const int SOCKS_VERSION = 5;
	struct sockaddr_in	address;
	int					err;
	struct hostent		*h;
	int					len;
	unsigned char		buf[64];

	usingSocks = qfalse;

	Com_Printf( "Opening connection to SOCKS server.\n" );

	if ( ( socks_socket = socket( AF_INET, SOCK_STREAM, IPPROTO_TCP ) ) == INVALID_SOCKET ) {
		err = socketError;
		Com_Printf( "WARNING: NET_OpenSocks: socket: %s\n", NET_ErrorString() );
		return;
	}

	h = gethostbyname( net_socksServer->string );
	if ( h == NULL ) {
		err = socketError;
		Com_Printf( "WARNING: NET_OpenSocks: gethostbyname: %s\n", NET_ErrorString() );
		return;
	}
	if ( h->h_addrtype != AF_INET ) {
		Com_Printf( "WARNING: NET_OpenSocks: gethostbyname: address type was not AF_INET\n" );
		return;
	}
	address.sin_family = AF_INET;
	address.sin_addr.s_addr = *(int *)h->h_addr_list[0];
	address.sin_port = htons( (short)net_socksPort->integer );

	if ( connect( socks_socket, (struct sockaddr *)&address, sizeof( address ) ) == SOCKET_ERROR ) {
		err = socketError;
		Com_Printf( "NET_OpenSocks: connect: %s\n", NET_ErrorString() );
		return;
	}

	// send socks authentication handshake
	qbool rfc1929 = (*net_socksUsername->string || *net_socksPassword->string);

	buf[0] = SOCKS_VERSION;
	// method count
	if ( rfc1929 ) {
		buf[1] = 2;
		len = 4;
	}
	else {
		buf[1] = 1;
		len = 3;
	}
	buf[2] = 0;		// method #1 - method id #00: no authentication
	if ( rfc1929 ) {
		buf[2] = 2;		// method #2 - method id #02: username/password
	}
	if ( send( socks_socket, (const char*)buf, len, 0 ) == SOCKET_ERROR ) {
		err = socketError;
		Com_Printf( "NET_OpenSocks: send: %s\n", NET_ErrorString() );
		return;
	}

	// get the response
	len = recv( socks_socket, (char*)buf, 64, 0 );
	if ( len == SOCKET_ERROR ) {
		err = socketError;
		Com_Printf( "NET_OpenSocks: recv: %s\n", NET_ErrorString() );
		return;
	}
	if ( len != 2 || buf[0] != SOCKS_VERSION ) {
		Com_Printf( "NET_OpenSocks: bad response\n" );
		return;
	}
	switch( buf[1] ) {
	case 0: // no authentication
		break;
	case 2: // username/password authentication
		break;
	default:
		Com_Printf( "NET_OpenSocks: request denied\n" );
		return;
	}

	// do username/password authentication if needed
	if ( buf[1] == 2 ) {
		// build the request
		int ulen = strlen( net_socksUsername->string );
		int plen = strlen( net_socksPassword->string );

		buf[0] = 1;		// username/password authentication version
		buf[1] = ulen;
		if ( ulen ) {
			memcpy( &buf[2], net_socksUsername->string, ulen );
		}
		buf[2 + ulen] = plen;
		if ( plen ) {
			memcpy( &buf[3 + ulen], net_socksPassword->string, plen );
		}

		// send it
		if ( send( socks_socket, (const char*)buf, 3 + ulen + plen, 0 ) == SOCKET_ERROR ) {
			err = socketError;
			Com_Printf( "NET_OpenSocks: send: %s\n", NET_ErrorString() );
			return;
		}

		// get the response
		len = recv( socks_socket, (char*)buf, 64, 0 );
		if ( len == SOCKET_ERROR ) {
			err = socketError;
			Com_Printf( "NET_OpenSocks: recv: %s\n", NET_ErrorString() );
			return;
		}
		if ( len != 2 || buf[0] != 1 ) {
			Com_Printf( "NET_OpenSocks: bad response\n" );
			return;
		}
		if ( buf[1] != 0 ) {
			Com_Printf( "NET_OpenSocks: authentication failed\n" );
			return;
		}
	}

	// send the UDP associate request
	buf[0] = SOCKS_VERSION;
	buf[1] = 3;		// command: UDP associate
	buf[2] = 0;		// reserved
	buf[3] = 1;		// address type: IPV4
	*(int *)&buf[4] = INADDR_ANY;
	*(short *)&buf[8] = htons( (short)port );		// port
	if ( send( socks_socket, (const char*)buf, 10, 0 ) == SOCKET_ERROR ) {
		err = socketError;
		Com_Printf( "NET_OpenSocks: send: %s\n", NET_ErrorString() );
		return;
	}

	// get the response
	len = recv( socks_socket, (char*)buf, 64, 0 );
	if( len == SOCKET_ERROR ) {
		err = socketError;
		Com_Printf( "NET_OpenSocks: recv: %s\n", NET_ErrorString() );
		return;
	}
	if( len < 2 || buf[0] != SOCKS_VERSION ) {
		Com_Printf( "NET_OpenSocks: bad response\n" );
		return;
	}
	// check completion code
	if( buf[1] != 0 ) {
		Com_Printf( "NET_OpenSocks: request denied: %i\n", buf[1] );
		return;
	}
	if( buf[3] != 1 ) {
		Com_Printf( "NET_OpenSocks: relay address is not IPV4: %i\n", buf[3] );
		return;
	}
	((struct sockaddr_in *)&socksRelayAddr)->sin_family = AF_INET;
	((struct sockaddr_in *)&socksRelayAddr)->sin_addr.s_addr = *(int *)&buf[4];
	((struct sockaddr_in *)&socksRelayAddr)->sin_port = *(short *)&buf[8];
	memset( ((struct sockaddr_in *)&socksRelayAddr)->sin_zero, 0, 8 );

	usingSocks = qtrue;
}


#ifdef MACOS_X
// Don't do a forward mapping from the hostname of the machine to the IP.
// The reason is that we might have obtained an IP address from DHCP and
// there might not be any name registered for the machine.  On Mac OS X,
// the machine name defaults to 'localhost' and NetInfo has 127.0.0.1
// listed for this name.  Instead, we want to get a list of all the IP
// network interfaces on the machine. This code adapted from OmniNetworking.

#ifdef _SIZEOF_ADDR_IFREQ
	// tjw: OSX 10.4 does not have sa_len
	#define IFR_NEXT(ifr)	\
	((struct ifreq *) ((char *) ifr + _SIZEOF_ADDR_IFREQ(*ifr)))
#else
	// tjw: assume that once upon a time some version did have sa_len
	#define IFR_NEXT(ifr)	\
	((struct ifreq *) ((char *) (ifr) + sizeof(*(ifr)) + \
	MAX(0, (int) (ifr)->ifr_addr.sa_len - (int) sizeof((ifr)->ifr_addr))))
#endif

static void NET_GetLocalAddress()
{
	struct ifreq requestBuffer[MAX_IPS], *linkInterface, *inetInterface;
	struct ifconf ifc;
	struct ifreq ifr;
	struct sockaddr_dl *sdl;
	int interfaceSocket;
	int family;

	// Set this early so we can just return if there is an error
	numIP = 0;

	ifc.ifc_len = sizeof(requestBuffer);
	ifc.ifc_buf = (caddr_t)requestBuffer;

	// Since we get at this info via an ioctl, we need a temporary little socket.
	// This will only get AF_INET interfaces, but we probably don't care about
	// anything else.  If we do end up caring later, we should add a
	// ONAddressFamily and at a -interfaces method to it.
	family = AF_INET;
	if ((interfaceSocket = socket(family, SOCK_DGRAM, 0)) < 0) {
		Com_Printf("NET_GetLocalAddress: Unable to create temporary socket, errno = %d\n", errno);
		return;
	}

	if (ioctl(interfaceSocket, SIOCGIFCONF, &ifc) != 0) {
		Com_Printf("NET_GetLocalAddress: Unable to get list of network interfaces, errno = %d\n", errno);
		return;
	}

	linkInterface = (struct ifreq *) ifc.ifc_buf;
	while ((char *) linkInterface < &ifc.ifc_buf[ifc.ifc_len]) {
		unsigned int nameLength;

		// The ioctl returns both the entries having the address (AF_INET)
		// and the link layer entries (AF_LINK).  The AF_LINK entry has the
		// link layer address which contains the interface type.  This is the
		// only way I can see to get this information.  We cannot assume that
		// we will get bot an AF_LINK and AF_INET entry since the interface
		// may not be configured.  For example, if you have a 10Mb port on
		// the motherboard and a 100Mb card, you may not configure the
		// motherboard port.

		// For each AF_LINK entry...
		if (linkInterface->ifr_addr.sa_family == AF_LINK) {
			// if there is a matching AF_INET entry
			inetInterface = (struct ifreq *) ifc.ifc_buf;
			while ((char *) inetInterface < &ifc.ifc_buf[ifc.ifc_len]) {
				if (inetInterface->ifr_addr.sa_family == AF_INET &&
						!strncmp(inetInterface->ifr_name, linkInterface->ifr_name,
							sizeof(linkInterface->ifr_name))) {

					for (nameLength = 0; nameLength < IFNAMSIZ; nameLength++)
						if (!linkInterface->ifr_name[nameLength])
							break;

					sdl = (struct sockaddr_dl *)&linkInterface->ifr_addr;
					// Skip loopback interfaces
					if (sdl->sdl_type != IFT_LOOP) {
						// Get the local interface address
						strncpy(ifr.ifr_name, inetInterface->ifr_name, sizeof(ifr.ifr_name));
						if (ioctl(interfaceSocket, OSIOCGIFADDR, (caddr_t)&ifr) < 0) {
							Com_Printf("NET_GetLocalAddress: Unable to get local address "
									"for interface '%s', errno = %d\n", inetInterface->ifr_name, errno);
						} else {
							struct sockaddr_in *sin;
							int ip;

							sin = (struct sockaddr_in *)&ifr.ifr_addr;

							ip = ntohl(sin->sin_addr.s_addr);
							localIP[ numIP ][0] = (ip >> 24) & 0xff;
							localIP[ numIP ][1] = (ip >> 16) & 0xff;
							localIP[ numIP ][2] = (ip >>  8) & 0xff;
							localIP[ numIP ][3] = (ip >>  0) & 0xff;
							Com_Printf( "IP: %i.%i.%i.%i (%s)\n",
									localIP[ numIP ][0], localIP[ numIP ][1],
									localIP[ numIP ][2], localIP[ numIP ][3],
									inetInterface->ifr_name);
							numIP++;
						}
					}

					// We will assume that there is only one AF_INET entry per AF_LINK entry.
					// What happens when we have an interface that has multiple IP addresses, or
					// can that even happen?
					// break;
				}
				inetInterface = IFR_NEXT(inetInterface);
			}
		}
		linkInterface = IFR_NEXT(linkInterface);
	}

	close(interfaceSocket);
}

#else

static void NET_GetLocalAddress()
{
	int error;
	const char* p;

	char hostname[256];
	if (gethostname( hostname, 256 ) == SOCKET_ERROR) {
		error = socketError;
		return;
	}

	const struct hostent* hostInfo = gethostbyname( hostname );
	if (!hostInfo) {
		error = socketError;
		return;
	}

	Com_Printf( "Hostname: %s\n", hostInfo->h_name );
	for (int n = 0; (p = hostInfo->h_aliases[n]); ++n) {
		Com_Printf( "Alias: %s\n", p );
	}

	if (hostInfo->h_addrtype != AF_INET)
		return;

	numIP = 0;
	while ((p = hostInfo->h_addr_list[numIP]) && (numIP < MAX_IPS)) {
		int ip = ntohl( *(const int*)p );
		localIP[ numIP ][0] = p[0];
		localIP[ numIP ][1] = p[1];
		localIP[ numIP ][2] = p[2];
		localIP[ numIP ][3] = p[3];
		Com_Printf( "IP: %i.%i.%i.%i\n", ( ip >> 24 ) & 0xff, ( ip >> 16 ) & 0xff, ( ip >> 8 ) & 0xff, ip & 0xff );
		++numIP;
	}
}

#endif


static void NET_OpenIP()
{
	const cvar_t* ip = Cvar_Get( "net_ip", "localhost", CVAR_LATCH );
	int port = Cvar_Get( "net_port", va( "%i", PORT_SERVER ), CVAR_LATCH )->integer;

	// automatically scan for a valid port, so multiple
	// dedicated servers can be started without requiring
	// a different net_port for each one
	for (int i = 0; i < 10; ++i) {
		ip_socket = NET_IPSocket( ip->string, port + i );
		if (ip_socket != INVALID_SOCKET) {
			Cvar_SetValue( "net_port", port + i );
			if ( net_socksEnabled->integer ) {
				NET_OpenSocks( port + i );
			}
			NET_GetLocalAddress();
			return;
		}
	}

	Com_Printf( "WARNING: Couldn't allocate IP port\n");
}


///////////////////////////////////////////////////////////////


static qboolean NET_GetCvars()
{
	qboolean modified = qfalse;

	if (net_noudp && net_noudp->modified)
		modified = qtrue;
	net_noudp = Cvar_Get( "net_noudp", "0", CVAR_LATCH | CVAR_ARCHIVE );

	if (net_socksEnabled && net_socksEnabled->modified)
		modified = qtrue;
	net_socksEnabled = Cvar_Get( "net_socksEnabled", "0", CVAR_LATCH | CVAR_ARCHIVE );

	if (net_socksEnabled->integer) {
		if (net_socksServer && net_socksServer->modified)
			modified = qtrue;
		net_socksServer = Cvar_Get( "net_socksServer", "", CVAR_LATCH | CVAR_ARCHIVE );

		if (net_socksPort && net_socksPort->modified)
			modified = qtrue;
		net_socksPort = Cvar_Get( "net_socksPort", "1080", CVAR_LATCH | CVAR_ARCHIVE );

		if (net_socksUsername && net_socksUsername->modified)
			modified = qtrue;
		net_socksUsername = Cvar_Get( "net_socksUsername", "", CVAR_LATCH | CVAR_ARCHIVE );

		if (net_socksPassword && net_socksPassword->modified)
			modified = qtrue;
		net_socksPassword = Cvar_Get( "net_socksPassword", "", CVAR_LATCH | CVAR_ARCHIVE );
	}

	return modified;
}


static void NET_Config( qboolean enableNetworking )
{
	// get any latched changes to cvars
	qboolean modified = NET_GetCvars();

	if (net_noudp->integer)
		enableNetworking = qfalse;

	// if enable state is the same and no cvars were modified, we have nothing to do
	if ((enableNetworking == networkingEnabled) && !modified)
		return;

	qboolean stop;
	if (enableNetworking == networkingEnabled) {
		stop = enableNetworking;
	}
	else {
		stop = !enableNetworking;
		networkingEnabled = enableNetworking;
	}

	if (stop) {
		if (ip_socket != INVALID_SOCKET) {
			closesocket( ip_socket );
			ip_socket = INVALID_SOCKET;
		}

		if (socks_socket != INVALID_SOCKET) {
			closesocket( socks_socket );
			socks_socket = INVALID_SOCKET;
		}
	}

	if (enableNetworking && !net_noudp->integer) {
		NET_OpenIP();
	}
}


void NET_Init()
{
	QSUBSYSTEM_INIT_START( "Networking" );

#ifdef _WIN32
	int r = WSAStartup( MAKEWORD( 1, 1 ), &winsockdata );
	if (r) {
		Com_Printf( "WARNING: Winsock initialization failed, returned %d\n", r );
		return;
	}
	Com_Printf( "Winsock Initialized\n" );
#endif

	// this is really just to get the cvars registered
	NET_GetCvars();

	NET_Config( qtrue );

	QSUBSYSTEM_INIT_DONE( "Networking" );
}


void NET_Shutdown()
{
	if (!networkingEnabled)
		return;

	NET_Config( qfalse );

#ifdef _WIN32
	WSACleanup();
#endif
}


// sleeps msec or until something happens on the network

void NET_Sleep( int msec )
{
	struct timeval timeout;
	fd_set fdset;

	if (!com_dedicated->integer)
		return; // we're not a server, just run full speed

	if (ip_socket == INVALID_SOCKET)
		return;

	if (msec < 0)
		return;

	FD_ZERO(&fdset);
	FD_SET(ip_socket, &fdset);
	timeout.tv_sec = msec/1000;
	timeout.tv_usec = (msec%1000)*1000;
	select(ip_socket+1, &fdset, NULL, NULL, &timeout);
}


void NET_Restart()
{
	NET_Config( networkingEnabled );
}