Source to Quake/net_mp.c


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/*
Copyright (C) 1996-1997 Id Software, Inc.

This program 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.

This program 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 this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/
// net_mpath.c

#include <dpmi.h>
#include "quakedef.h"
#include "mpdosock.h"

short flat_selector;

int WSAGetLastError(void);
void sockets_flush(void);

extern cvar_t hostname;

#define MAXHOSTNAMELEN		256

static int net_acceptsocket = -1;		// socket for fielding new connections
static int net_controlsocket;
static int net_broadcastsocket = 0;
//static qboolean ifbcastinit = false;
static struct qsockaddr broadcastaddr;

static unsigned long myAddr;

#include "net_mp.h"


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

int MPATH_Init (void)
{
	int		i;
	struct hostent *local = NULL;
	char	buff[MAXHOSTNAMELEN];
	struct qsockaddr addr;
	char	*p;

	if (COM_CheckParm ("-mpath") == 0)
		return -1;

   flat_selector = __dpmi_allocate_ldt_descriptors(1);
   if (flat_selector == -1) {
      Con_Printf("MPATH_Init: Can't get flat selector\n");
      return -1;
   }
   if (__dpmi_set_segment_base_address(flat_selector, 0) == -1) {
      Con_Printf("MPATH_Init: Can't seg flat base!\n");
      return -1;
   }
   if (__dpmi_set_segment_limit(flat_selector, 0xffffffff) == -1) {
      Con_Printf("MPATH_Init: Can't set segment limit\n");
      return -1;
   }
	// determine my name & address
	if (gethostname(buff, MAXHOSTNAMELEN) == 0)
		local = gethostbyname(buff);
	if (local)
	{
		myAddr = *(int *)local->h_addr_list[0];

		// if the quake hostname isn't set, set it to the machine name
		if (Q_strcmp(hostname.string, "UNNAMED") == 0)
		{
			// see if it's a text IP address (well, close enough)
			for (p = buff; *p; p++)
				if ((*p < '0' || *p > '9') && *p != '.')
					break;

			// if it is a real name, strip off the domain; we only want the host
			if (*p)
			{
				for (i = 0; i < 15; i++)
					if (buff[i] == '.')
						break;
				buff[i] = 0;
			}
			Cvar_Set ("hostname", buff);
		}
	}

	if ((net_controlsocket = MPATH_OpenSocket (0)) == -1)
		Sys_Error("MPATH_Init: Unable to open control socket\n");

	((struct sockaddr_in *)&broadcastaddr)->sin_family = AF_INET;
	((struct sockaddr_in *)&broadcastaddr)->sin_addr.s_addr = INADDR_BROADCAST;
	((struct sockaddr_in *)&broadcastaddr)->sin_port = htons(net_hostport);

	MPATH_GetSocketAddr (net_controlsocket, &addr);
	Q_strcpy(my_tcpip_address,  MPATH_AddrToString (&addr));
	p = Q_strrchr (my_tcpip_address, ':');
	if (p)
		*p = 0;

	Con_Printf("MPath Initialized\n");
	tcpipAvailable = true;

	return net_controlsocket;
}

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

void MPATH_Shutdown (void)
{
	MPATH_Listen (false);
	MPATH_CloseSocket (net_controlsocket);
}

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

void MPATH_Listen (qboolean state)
{
	// enable listening
	if (state)
	{
		if (net_acceptsocket != -1)
			return;
		if ((net_acceptsocket = MPATH_OpenSocket (net_hostport)) == -1)
			Sys_Error ("MPATH_Listen: Unable to open accept socket\n");
		return;
	}

	// disable listening
	if (net_acceptsocket == -1)
		return;
	MPATH_CloseSocket (net_acceptsocket);
	net_acceptsocket = -1;
}

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

int MPATH_OpenSocket (int port)
{
	int newsocket;
	struct sockaddr_in address;
	u_long _true = 1;

	if ((newsocket = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
		return -1;

	if (ioctlsocket (newsocket, FIONBIO, &_true) == -1)
		goto ErrorReturn;

	address.sin_family = AF_INET;
	address.sin_addr.s_addr = INADDR_ANY;
	address.sin_port = htons(port);
	if( bind (newsocket, (void *)&address, sizeof(address)) == -1)
		goto ErrorReturn;

	return newsocket;

ErrorReturn:
	closesocket (newsocket);
	return -1;
}

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

int MPATH_CloseSocket (int socket)
{
	if (socket == net_broadcastsocket)
		net_broadcastsocket = 0;
	return closesocket (socket);
}


//=============================================================================
/*
============
PartialIPAddress

this lets you type only as much of the net address as required, using
the local network components to fill in the rest
============
*/
static int PartialIPAddress (char *in, struct qsockaddr *hostaddr)
{
	char buff[256];
	char *b;
	int addr;
	int num;
	int mask;
	int run;
	int port;
	
	buff[0] = '.';
	b = buff;
	strcpy(buff+1, in);
	if (buff[1] == '.')
		b++;

	addr = 0;
	mask=-1;
	while (*b == '.')
	{
		b++;
		num = 0;
		run = 0;
		while (!( *b < '0' || *b > '9'))
		{
		  num = num*10 + *b++ - '0';
		  if (++run > 3)
		  	return -1;
		}
		if ((*b < '0' || *b > '9') && *b != '.' && *b != ':' && *b != 0)
			return -1;
		if (num < 0 || num > 255)
			return -1;
		mask<<=8;
		addr = (addr<<8) + num;
	}
	
	if (*b++ == ':')
		port = Q_atoi(b);
	else
		port = net_hostport;

	hostaddr->sa_family = AF_INET;
	((struct sockaddr_in *)hostaddr)->sin_port = htons((short)port);	
	((struct sockaddr_in *)hostaddr)->sin_addr.s_addr = (myAddr & htonl(mask)) | htonl(addr);
	
	return 0;
}
//=============================================================================

int MPATH_Connect (int socket, struct qsockaddr *addr)
{
	return 0;
}

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

int MPATH_CheckNewConnections (void)
{
	char buf[4];

	if (net_acceptsocket == -1)
		return -1;

	if (recvfrom (net_acceptsocket, buf, 4, MSG_PEEK, NULL, NULL) > 0)
		return net_acceptsocket;
	return -1;
}

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

int MPATH_Read (int socket, byte *buf, int len, struct qsockaddr *addr)
{
	int addrlen = sizeof (struct qsockaddr);
	int ret;

	ret = recvfrom (socket, buf, len, 0, (struct sockaddr *)addr, &addrlen);
	if (ret == -1)
	{
		int errno = WSAGetLastError();

		if (errno == WSAEWOULDBLOCK || errno == WSAECONNREFUSED)
			return 0;

	}
	return ret;
}

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

int MPATH_MakeSocketBroadcastCapable (int socket)
{
	int	i = 1;

	// make this socket broadcast capable
	if (setsockopt(socket, SOL_SOCKET, SO_BROADCAST, (char *)&i, sizeof(i)) < 0)
		return -1;
	net_broadcastsocket = socket;

	return 0;
}

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

int MPATH_Broadcast (int socket, byte *buf, int len)
{
	int ret;

	if (socket != net_broadcastsocket)
	{
		if (net_broadcastsocket != 0)
			Sys_Error("Attempted to use multiple broadcasts sockets\n");
		ret = MPATH_MakeSocketBroadcastCapable (socket);
		if (ret == -1)
		{
			Con_Printf("Unable to make socket broadcast capable\n");
			return ret;
		}
	}

	return MPATH_Write (socket, buf, len, &broadcastaddr);
}

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

int MPATH_Write (int socket, byte *buf, int len, struct qsockaddr *addr)
{
	int ret;

	ret = sendto (socket, buf, len, 0, (struct sockaddr *)addr, sizeof(struct qsockaddr));
	if (ret == -1)
		if (WSAGetLastError() == WSAEWOULDBLOCK)
			return 0;

	sockets_flush();

	return ret;
}

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

char *MPATH_AddrToString (struct qsockaddr *addr)
{
	static char buffer[22];
	int haddr;

	haddr = ntohl(((struct sockaddr_in *)addr)->sin_addr.s_addr);
	sprintf(buffer, "%d.%d.%d.%d:%d", (haddr >> 24) & 0xff, (haddr >> 16) & 0xff, (haddr >> 8) & 0xff, haddr & 0xff, ntohs(((struct sockaddr_in *)addr)->sin_port));
	return buffer;
}

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

int MPATH_StringToAddr (char *string, struct qsockaddr *addr)
{
	int ha1, ha2, ha3, ha4, hp;
	int ipaddr;

	sscanf(string, "%d.%d.%d.%d:%d", &ha1, &ha2, &ha3, &ha4, &hp);
	ipaddr = (ha1 << 24) | (ha2 << 16) | (ha3 << 8) | ha4;

	addr->sa_family = AF_INET;
	((struct sockaddr_in *)addr)->sin_addr.s_addr = htonl(ipaddr);
	((struct sockaddr_in *)addr)->sin_port = htons(hp);
	return 0;
}

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

int MPATH_GetSocketAddr (int socket, struct qsockaddr *addr)
{
	int addrlen = sizeof(struct qsockaddr);
	unsigned int a;

	Q_memset(addr, 0, sizeof(struct qsockaddr));
	getsockname(socket, (struct sockaddr *)addr, &addrlen);
	a = ((struct sockaddr_in *)addr)->sin_addr.s_addr;
	if (a == 0 || a == inet_addr("127.0.0.1"))
		((struct sockaddr_in *)addr)->sin_addr.s_addr = myAddr;

	return 0;
}

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

int MPATH_GetNameFromAddr (struct qsockaddr *addr, char *name)
{
	struct hostent *hostentry;

	hostentry = gethostbyaddr ((char *)&((struct sockaddr_in *)addr)->sin_addr, sizeof(struct in_addr), AF_INET);
	if (hostentry)
	{
		Q_strncpy (name, (char *)hostentry->h_name, NET_NAMELEN - 1);
		return 0;
	}

	Q_strcpy (name, MPATH_AddrToString (addr));
	return 0;
}

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

int MPATH_GetAddrFromName(char *name, struct qsockaddr *addr)
{
	struct hostent *hostentry;

	if (name[0] >= '0' && name[0] <= '9')
		return PartialIPAddress (name, addr);
	
	hostentry = gethostbyname (name);
	if (!hostentry)
		return -1;

	addr->sa_family = AF_INET;
	((struct sockaddr_in *)addr)->sin_port = htons(net_hostport);	
	((struct sockaddr_in *)addr)->sin_addr.s_addr = *(int *)hostentry->h_addr_list[0];

	return 0;
}

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

int MPATH_AddrCompare (struct qsockaddr *addr1, struct qsockaddr *addr2)
{
	if (addr1->sa_family != addr2->sa_family)
		return -1;

	if (((struct sockaddr_in *)addr1)->sin_addr.s_addr != ((struct sockaddr_in *)addr2)->sin_addr.s_addr)
		return -1;

	if (((struct sockaddr_in *)addr1)->sin_port != ((struct sockaddr_in *)addr2)->sin_port)
		return 1;

	return 0;
}

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

int MPATH_GetSocketPort (struct qsockaddr *addr)
{
	return ntohs(((struct sockaddr_in *)addr)->sin_port);
}


int MPATH_SetSocketPort (struct qsockaddr *addr, int port)
{
	((struct sockaddr_in *)addr)->sin_port = htons(port);
	return 0;
}

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