/*
===========================================================================
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.

#define IFR_NEXT(ifr)	\
    ((struct ifreq *) ((char *) (ifr) + sizeof(*(ifr)) + \
      MAX(0, (int) (ifr)->ifr_addr.sa_len - (int) sizeof((ifr)->ifr_addr))))

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);
        }

        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);
}