net_udp.c

/*
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_udp.c

#include "quakedef.h"
#include "unixquake.h"

#include "net_udp.h"

// socket for fielding new connections
static sys_socket_t net_acceptsocket = INVALID_SOCKET;
static sys_socket_t net_controlsocket;
static sys_socket_t net_broadcastsocket = 0;
static struct sockaddr_in broadcastaddr;

/*
There are three addresses that we may use in different ways:
	myAddr	- This is the "default" address returned by the OS
	localAddr	- This is an address to advertise in CCREP_SERVER_INFO
		 and CCREP_ACCEPT response packets, rather than the
		 default address (sometimes the default address is not
		 suitable for LAN clients; i.e. loopback address). Set
		 on the command line using the "-localip" option.
	bindAddr	- The address to which we bind our network socket. The
		 default is INADDR_ANY, but in some cases we may want
		 to only listen on a particular address. Set on the
		 command line using the "-ip" option.
*/

static struct in_addr myAddr;
static struct in_addr localAddr;
static struct in_addr bindAddr;
static char ifname[IFNAMSIZ];

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

static int udp_scan_iface(sys_socket_t net_socket)
{
	struct ifconf ifc;
	struct ifreq *ifr;
	char buf[8192];
	int i, n;
	struct sockaddr_in *iaddr;
	struct in_addr addr;

	if (COM_CheckParm("-noifscan"))
		return -1;

	ifc.ifc_len = sizeof (buf);
	ifc.ifc_buf = buf;

	if (ioctl(net_socket, SIOCGIFCONF, &ifc) == -1)
	{
		Con_Printf("udp_scan_iface: SIOCGIFCONF failed\n");
		return -1;
	}

	ifr = ifc.ifc_req;
	n = ifc.ifc_len / sizeof(struct ifreq);

	for (i = 0; i < n; i++) 
	{
		if (ioctl(net_socket, SIOCGIFADDR, &ifr[i]) == -1)
			continue;

		iaddr = (struct sockaddr_in *)&ifr[i].ifr_addr;
		Con_DPrintf("%s: %s\n", ifr[i].ifr_name, inet_ntoa(iaddr->sin_addr));
		addr.s_addr = iaddr->sin_addr.s_addr;
		
		if (addr.s_addr != htonl(INADDR_LOOPBACK)) 
		{
			myAddr.s_addr = addr.s_addr;
			strcpy(ifname, ifr[i].ifr_name);
			return 0;
		}
	}

	return -1;
}


sys_socket_t UDP_Init (void)
{
	int i, err;
	struct hostent *local;
	char buff[MAXHOSTNAMELEN];
	struct qsockaddr addr;
	char *colon;

	if (COM_CheckParm ("-noudp"))
		return INVALID_SOCKET;

	// determine my name & address
	myAddr.s_addr = htonl(INADDR_LOOPBACK);
	err = gethostname(buff, MAXHOSTNAMELEN);
	if (err) 
	{
		Con_SafePrintf("UDP_Init: gethostname failed (errno: %i)\n", errno);
	}
	else
	{

		buff[MAXHOSTNAMELEN - 1] = 0;
		local = gethostbyname(buff);
		if (!local)
		{
			Con_Warning("UDP_Init: gethostbyname failed (errno: %i)\n", errno);
		}
		else if (local->h_addrtype != AF_INET)
		{
			Con_Printf("UDP_Init: address from gethostbyname not IPv4\n");
		}
		else
		{
			myAddr = *(struct in_addr *)local->h_addr_list[0];
		}
	}

	i = COM_CheckParm("-ip");
	if (i && i < com_argc - 1) 
	{
		bindAddr.s_addr = inet_addr(com_argv[i + 1]);

		if (bindAddr.s_addr == htonl(INADDR_NONE))
			Sys_Error("UDP_Init: %s is not a valid IP address", com_argv[i + 1]);

		Con_Printf("Binding to IP Interface Address of %s\n", com_argv[i + 1]);
	} 
	else 
	{
		bindAddr.s_addr = htonl(INADDR_NONE);
	}

	i = COM_CheckParm("-localip");
	if (i && i < com_argc - 1) 
	{
		localAddr.s_addr = inet_addr(com_argv[i + 1]);

		if (localAddr.s_addr == htonl(INADDR_NONE))
			Sys_Error("UDP_Init: %s is not a valid IP address", com_argv[i + 1]);

		Con_Printf("Advertising %s as the local IP in response packets\n", com_argv[i + 1]);
	} 
	else 
	{
		localAddr.s_addr = htonl(INADDR_NONE);
	}

	net_controlsocket = UDP_OpenSocket(0);
	if (net_controlsocket == INVALID_SOCKET) 
	{
		Con_Printf("UDP_Init: Unable to open control socket, UDP disabled\n");
		return INVALID_SOCKET;
	}

	// myAddr may resolve to 127.0.0.1, see if we can do any better
	memset (ifname, 0, sizeof(ifname));
	if (myAddr.s_addr == htonl(INADDR_LOOPBACK)) 
	{
		if (udp_scan_iface(net_controlsocket) == 0)
			Con_Printf ("UDP, Local address: %s (%s)\n", inet_ntoa(myAddr), ifname);
	}
	if (ifname[0] == 0) 
	{
		Con_Printf ("UDP, Local address: %s\n", inet_ntoa(myAddr));
	}

	broadcastaddr.sin_family = AF_INET;
	broadcastaddr.sin_addr.s_addr = htonl(INADDR_BROADCAST);
	broadcastaddr.sin_port = htons((unsigned short)net_hostport);

	UDP_GetSocketAddr (net_controlsocket, &addr);
	strcpy(my_tcpip_address,  UDP_AddrToString (&addr));
	colon = strrchr (my_tcpip_address, ':');
	if (colon)
		*colon = 0;

	Con_Printf("UDP initialized (%s)\n", my_tcpip_address);
	tcpipAvailable = true;

	return net_controlsocket;
}

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

void UDP_Shutdown (void)
{
	UDP_Listen (false);
	UDP_CloseSocket (net_controlsocket);
}

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

void UDP_Listen (qboolean state)
{
	// enable listening
	if (state)
	{
		if (net_acceptsocket != INVALID_SOCKET)
			return;
		if ((net_acceptsocket = UDP_OpenSocket (net_hostport)) == INVALID_SOCKET)
			Sys_Error ("UDP_Listen: Unable to open accept socket");
		return;
	}

	// disable listening
	if (net_acceptsocket == INVALID_SOCKET)
		return;

	UDP_CloseSocket (net_acceptsocket);
	net_acceptsocket = INVALID_SOCKET;
}

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

sys_socket_t UDP_OpenSocket (int port)
{
	sys_socket_t newsocket;
	struct sockaddr_in address;
	unsigned long _true = 1; // was int

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

	if (ioctl(newsocket, FIONBIO, &_true) == SOCKET_ERROR)
		goto ErrorReturn;

	address.sin_family = AF_INET;
	if (bindAddr.s_addr != htonl(INADDR_NONE))
		address.sin_addr.s_addr = bindAddr.s_addr;
	else
		address.sin_addr.s_addr = htonl(INADDR_ANY);
	address.sin_port = htons((unsigned short)port);

	if (bind(newsocket, (struct sockaddr *)&address, sizeof(address)) == -1)
		goto ErrorReturn;
	else
		return newsocket;

ErrorReturn:
	if (tcpipAvailable)
		Sys_Error("UDP_OpenSocket: Unable to bind to %s", UDP_AddrToString((struct qsockaddr *)&address));
	else // we are still in init phase, no need to error
		Con_Printf("UDP_OpenSocket: Unable to bind to %s\n", UDP_AddrToString((struct qsockaddr *)&address));

	UDP_CloseSocket (newsocket);
	return INVALID_SOCKET;
}

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

int UDP_CloseSocket (sys_socket_t net_socket)
{
	if (net_socket == net_broadcastsocket)
		net_broadcastsocket = 0;

	return close(net_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 = atoi(b);
	else
		port = net_hostport;

	hostaddr->qsa_family = AF_INET;
	((struct sockaddr_in *)hostaddr)->sin_port = htons((unsigned short)port);
	((struct sockaddr_in *)hostaddr)->sin_addr.s_addr = (myAddr.s_addr & htonl(mask)) | htonl(addr);

	return 0;
}

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

sys_socket_t UDP_CheckNewConnections (void)
{
	char buf[4096];
	int ret;

	if (net_acceptsocket == INVALID_SOCKET)
		return INVALID_SOCKET;

	// ProQuake fix
	ret = (int)recvfrom(net_acceptsocket, buf, sizeof(buf), MSG_PEEK, NULL, NULL);
	if (ret != SOCKET_ERROR)
		return net_acceptsocket;

	return INVALID_SOCKET;
}

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

int UDP_Read (sys_socket_t net_socket, byte *buf, int len, struct qsockaddr *addr)
{
	socklen_t addrlen = sizeof(struct qsockaddr);
	int ret;

	ret = (int)recvfrom(net_socket, (char *)buf, len, 0, (struct sockaddr *)addr, &addrlen);
	if (ret == SOCKET_ERROR)
	{
		if (errno == EWOULDBLOCK || errno == ECONNREFUSED)
			return 0;
	}

	return ret;
}

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

int UDP_MakeSocketBroadcastCapable (sys_socket_t net_socket)
{
	int	i = 1;

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

	net_broadcastsocket = net_socket;

	return 0;
}

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

int UDP_Broadcast (sys_socket_t net_socket, byte *buf, int len)
{
	int ret;

	if (net_socket != net_broadcastsocket)
	{
		if (net_broadcastsocket != 0)
			Sys_Error("UDP_Broadcast: Attempted to use multiple broadcasts sockets");

		ret = UDP_MakeSocketBroadcastCapable (net_socket);
		if (ret == -1)
		{
			Con_Printf("Unable to make socket broadcast capable\n");
			return ret;
		}
	}

	return UDP_Write (net_socket, buf, len, (struct qsockaddr *)&broadcastaddr);
}

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

int UDP_Write (sys_socket_t net_socket, byte *buf, int len, struct qsockaddr *addr)
{
	int ret;

	ret = (int)sendto(net_socket, (char *)buf, len, 0, (struct sockaddr *)addr, sizeof(struct qsockaddr));
	if (ret == SOCKET_ERROR)
		if (errno == EWOULDBLOCK)
			return 0;

	return ret;
}

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

char *UDP_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 UDP_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->qsa_family = AF_INET;
	((struct sockaddr_in *)addr)->sin_addr.s_addr = htonl(ipaddr);
	((struct sockaddr_in *)addr)->sin_port = htons((unsigned short)hp);

	return 0;
}

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

int UDP_GetSocketAddr (sys_socket_t net_socket, struct qsockaddr *addr)
{
	struct sockaddr_in *address = (struct sockaddr_in *)addr;
	socklen_t addrlen = sizeof(struct qsockaddr);
	struct in_addr a;

	memset(addr, 0, sizeof(struct qsockaddr));
	getsockname(net_socket, (struct sockaddr *)addr, &addrlen);

/*
	The returned IP is embedded in our response to a broadcast request for
	server info from clients. The server admin may wish to advertise a
	specific IP for various reasons, so allow the "default" address
	returned by the OS to be overridden.
*/
	if (localAddr.s_addr != htonl(INADDR_NONE))
		address->sin_addr.s_addr = localAddr.s_addr;
	else 
	{
		a = address->sin_addr;
		if (!a.s_addr || a.s_addr == htonl(INADDR_LOOPBACK))
			address->sin_addr.s_addr = myAddr.s_addr;
	}

	return 0;
}

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

int UDP_GetNameFromAddr (struct qsockaddr *addr, char *name)
{
/*	ProQuake connect speedup fix (verified for w95 -> XP) */
/*	// pq comment out this block
	struct hostent *hostentry;

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

	return 0;
}

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

int UDP_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->qsa_family = AF_INET;
	((struct sockaddr_in *)addr)->sin_port = htons((unsigned short)net_hostport);
	((struct sockaddr_in *)addr)->sin_addr.s_addr = *(in_addr_t *)hostentry->h_addr_list[0];

	return 0;
}

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

int UDP_AddrCompare (struct qsockaddr *addr1, struct qsockaddr *addr2)
{
	if (addr1->qsa_family != addr2->qsa_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 UDP_GetSocketPort (struct qsockaddr *addr)
{
	return ntohs(((struct sockaddr_in *)addr)->sin_port);
}


int UDP_SetSocketPort (struct qsockaddr *addr, int port)
{
	((struct sockaddr_in *)addr)->sin_port = htons((unsigned short)port);

	return 0;
}

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

int UDP_GetDefaultMTU (void)
{
    return (sv.protocol == PROTOCOL_NETQUAKE) ? DATAGRAM_MTU_NQ : DATAGRAM_MTU;
}