unix_net.c

quakeIII源码这个不用我多说吧

/*
===========================================================================
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 Foobar; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
===========================================================================
*/
// unix_net.c

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

#include <unistd.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h> // bk001204

#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/uio.h>
#include <errno.h>

#ifdef MACOS_X
#import <sys/sockio.h>
#import <net/if.h>
#import <net/if_types.h>

#import <arpa/inet.h>         // for inet_ntoa()
#import <net/if_dl.h>         // for 'struct sockaddr_dl'
#endif

static cvar_t	*noudp;

netadr_t	net_local_adr;

int			ip_socket;
int			ipx_socket;

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

int NET_Socket (char *net_interface, int port);
char *NET_ErrorString (void);

//=============================================================================

void NetadrToSockadr (netadr_t *a, struct sockaddr_in *s)
{
	memset (s, 0, sizeof(*s));

	if (a->type == NA_BROADCAST)
	{
		s->sin_family = AF_INET;

		s->sin_port = a->port;
		*(int *)&s->sin_addr = -1;
	}
	else if (a->type == NA_IP)
	{
		s->sin_family = AF_INET;

		*(int *)&s->sin_addr = *(int *)&a->ip;
		s->sin_port = a->port;
	}
}

void SockadrToNetadr (struct sockaddr_in *s, netadr_t *a)
{
	*(int *)&a->ip = *(int *)&s->sin_addr;
	a->port = s->sin_port;
	a->type = NA_IP;
}

char	*NET_BaseAdrToString (netadr_t a)
{
	static	char	s[64];
	
	Com_sprintf (s, sizeof(s), "%i.%i.%i.%i", a.ip[0], a.ip[1], a.ip[2], a.ip[3]);

	return s;
}

/*
=============
Sys_StringToAdr

idnewt
192.246.40.70
=============
*/
qboolean	Sys_StringToSockaddr (const char *s, struct sockaddr *sadr)
{
	struct hostent	*h;
	//char	*colon; // bk001204 - unused
	
	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
	{
		if (! (h = gethostbyname(s)) )
			return qfalse;
		*(int *)&((struct sockaddr_in *)sadr)->sin_addr = *(int *)h->h_addr_list[0];
	}
	
	return qtrue;
}

/*
=============
Sys_StringToAdr

localhost
idnewt
idnewt:28000
192.246.40.70
192.246.40.70:28000
=============
*/
qboolean	Sys_StringToAdr (const char *s, netadr_t *a)
{
	struct sockaddr_in sadr;
	
	if (!Sys_StringToSockaddr (s, (struct sockaddr *)&sadr))
		return qfalse;
	
	SockadrToNetadr (&sadr, a);

	return qtrue;
}


//=============================================================================

qboolean	Sys_GetPacket (netadr_t *net_from, msg_t *net_message)
{
	int 	ret;
	struct sockaddr_in	from;
	int		fromlen;
	int		net_socket;
	int		protocol;
	int		err;

	for (protocol = 0 ; protocol < 2 ; protocol++)
	{
		if (protocol == 0)
			net_socket = ip_socket;
		else
			net_socket = ipx_socket;

		if (!net_socket)
			continue;

		fromlen = sizeof(from);
		ret = recvfrom (net_socket, net_message->data, net_message->maxsize
			, 0, (struct sockaddr *)&from, &fromlen);

		SockadrToNetadr (&from, net_from);
		// bk000305: was missing
		net_message->readcount = 0;

		if (ret == -1)
		{
			err = errno;

			if (err == EWOULDBLOCK || err == ECONNREFUSED)
				continue;
			Com_Printf ("NET_GetPacket: %s from %s\n", NET_ErrorString(),
						NET_AdrToString(*net_from));
			continue;
		}

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

		net_message->cursize = ret;
		return qtrue;
	}

	return qfalse;
}

//=============================================================================

void	Sys_SendPacket( int length, const void *data, netadr_t to )
{
	int		ret;
	struct sockaddr_in	addr;
	int		net_socket;

	if (to.type == NA_BROADCAST)
	{
		net_socket = ip_socket;
	}
	else if (to.type == NA_IP)
	{
		net_socket = ip_socket;
	}
	else if (to.type == NA_IPX)
	{
		net_socket = ipx_socket;
	}
	else if (to.type == NA_BROADCAST_IPX)
	{
		net_socket = ipx_socket;
	}
	else {
		Com_Error (ERR_FATAL, "NET_SendPacket: bad address type");
		return;
	}

	if (!net_socket)
		return;

	NetadrToSockadr (&to, &addr);

	ret = sendto (net_socket, data, length, 0, (struct sockaddr *)&addr, sizeof(addr) );
	if (ret == -1)
	{
		Com_Printf ("NET_SendPacket ERROR: %s to %s\n", NET_ErrorString(),
				NET_AdrToString (to));
	}
}


//=============================================================================

/*
==================
Sys_IsLANAddress

LAN clients will have their rate var ignored
==================
*/
qboolean	Sys_IsLANAddress (netadr_t adr) {
	int		i;

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

	if( adr.type == NA_IPX ) {
		return qtrue;
	}

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

	// 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

	// Class A
	if( (adr.ip[0] & 0x80) == 0x00 ) {
		for ( i = 0 ; i < numIP ; i++ ) {
			if( adr.ip[0] == localIP[i][0] ) {
				return qtrue;
			}
		}
		// the RFC1918 class a block will pass the above test
		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;
			}
			// also check against the RFC1918 class b blocks
			if( adr.ip[0] == 172 && localIP[i][0] == 172 && (adr.ip[1] & 0xf0) == 16 && (localIP[i][1] & 0xf0) == 16 ) {
				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;
		}
		// also check against the RFC1918 class c blocks