/*
===========================================================================
Copyright (C) 1999-2005 Id Software, Inc.
Copyright (C) 2000-2006 Tim Angus

This file is part of Tremulous.

Tremulous 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.

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

#include "../qcommon/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

#ifdef __sun
#include <sys/filio.h>
#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;
	socklen_t	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;
	}

	// 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;

	// the checks below are bogus, aren't they? -- ln

	// 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
		if( adr.ip[0] == 192 && localIP[i][0] == 192 && adr.ip[1] == 168 && localIP[i][1] == 168 ) {
			return qtrue;
		}
	}
	return qfalse;
}

/*
==================
Sys_ShowIP
==================
*/
void Sys_ShowIP(void) {
	int i;

	for (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] );
	}
}

/*
=====================
NET_GetLocalAddress
=====================
*/
#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

void NET_GetLocalAddress( void ) {
        struct ifreq requestBuffer[MAX_IPS], *linkInterface, *inetInterface;
        struct ifconf ifc;
        struct ifreq ifr;
        struct sockaddr_dl *sdl;
        int interfaceSocket;
        int family;
        
        Com_Printf("NET_GetLocalAddress: Querying for network interfaces\n");
        
        // 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);
        }
        Com_Printf("NET_GetLocalAddress: DONE querying for network interfaces\n");

        close(interfaceSocket);
}

#else
void NET_GetLocalAddress( void ) {
	char				hostname[256];
	struct hostent		*hostInfo;
	// int					error; // bk001204 - unused
	char				*p;
	int					ip;
	int					n;

	if ( gethostname( hostname, 256 ) == -1 ) {
		return;
	}

	hostInfo = gethostbyname( hostname );
	if ( !hostInfo ) {
		return;
	}

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

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

	numIP = 0;
	while( ( p = hostInfo->h_addr_list[numIP++] ) != NULL && numIP < MAX_IPS ) {
		ip = ntohl( *(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 );
	}
}
#endif

/*
====================
NET_OpenIP
====================
*/
// bk001204 - prototype needed
int NET_IPSocket (char *net_interface, int port);
void NET_OpenIP (void)
{
	cvar_t	*ip;
	int		port;
	int		i;

	ip = Cvar_Get ("net_ip", "localhost", 0);

	port = Cvar_Get("net_port", va("%i", PORT_SERVER), 0)->value;

	for ( i = 0 ; i < 10 ; i++ ) {
		ip_socket = NET_IPSocket (ip->string, port + i);
		if ( ip_socket ) {
			Cvar_SetValue( "net_port", port + i );
			NET_GetLocalAddress();
			return;
		}
	}
	Com_Error (ERR_FATAL, "Couldn't allocate IP port");
}


/*
====================
NET_Init
====================
*/
void NET_Init (void)
{
	noudp = Cvar_Get ("net_noudp", "0", 0);
	// open sockets
	if (! noudp->value) {
		NET_OpenIP ();
	}
}


/*
====================
NET_IPSocket
====================
*/
int NET_IPSocket (char *net_interface, int port)
{
	int newsocket;
	struct sockaddr_in address;
	qboolean _qtrue = qtrue;
	int	i = 1;

	if ( net_interface ) {
		Com_Printf("Opening IP socket: %s:%i\n", net_interface, port );
	} else {
		Com_Printf("Opening IP socket: localhost:%i\n", port );
	}

	if ((newsocket = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1)
	{
		Com_Printf ("ERROR: UDP_OpenSocket: socket: %s", NET_ErrorString());
		return 0;
	}

	// make it non-blocking
	if (ioctl (newsocket, FIONBIO, &_qtrue) == -1)
	{
		Com_Printf ("ERROR: UDP_OpenSocket: ioctl FIONBIO:%s\n", NET_ErrorString());
		return 0;
	}

	// make it broadcast capable
	if (setsockopt(newsocket, SOL_SOCKET, SO_BROADCAST, (char *)&i, sizeof(i)) == -1)
	{
		Com_Printf ("ERROR: UDP_OpenSocket: setsockopt SO_BROADCAST:%s\n", NET_ErrorString());
		return 0;
	}

	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);

	if (port == PORT_ANY)
		address.sin_port = 0;
	else
		address.sin_port = htons((short)port);

	address.sin_family = AF_INET;

	if( bind (newsocket, (void *)&address, sizeof(address)) == -1)
	{
		Com_Printf ("ERROR: UDP_OpenSocket: bind: %s\n", NET_ErrorString());
		close (newsocket);
		return 0;
	}

	return newsocket;
}

/*
====================
NET_Shutdown
====================
*/
void	NET_Shutdown (void)
{
	if (ip_socket) {
		close(ip_socket);
		ip_socket = 0;
	}
}


/*
====================
NET_ErrorString
====================
*/
char *NET_ErrorString (void)
{
	int		code;

	code = errno;
	return strerror (code);
}

// sleeps msec or until net socket is ready
void NET_Sleep(int msec)
{
    struct timeval timeout;
	fd_set	fdset;
	extern qboolean stdin_active;

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

	FD_ZERO(&fdset);
	if (stdin_active)
		FD_SET(0, &fdset); // stdin is processed too
	FD_SET(ip_socket, &fdset); // network socket
	timeout.tv_sec = msec/1000;
	timeout.tv_usec = (msec%1000)*1000;
	select(ip_socket+1, &fdset, NULL, NULL, &timeout);
}