/*
	net_ipx.c

	@description@

	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:

		Free Software Foundation, Inc.
		59 Temple Place - Suite 330
		Boston, MA  02111-1307, USA

*/
static const char rcsid[] = 
	"$Id$";

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <stdio.h>
#include <stdlib.h>
#include <dpmi.h>

#include "dosisms.h"
#include "net_ipx.h"

#define	EIO		 		5				/* I/O error */

#define AF_NETWARE 		64

#define IPX_OPEN					0
#define IPX_CLOSE					1
#define IPX_GETROUTE				2
#define IPX_SEND					3
#define IPX_LISTEN					4
#define IPX_SCHEDULEEVENT			5
#define IPX_CANCEL					6
#define IPX_SCHEDULESPECIALEVENT	7
#define IPX_GETINTERVALMARKER		8
#define IPX_GETADDRESS				9
#define IPX_RELINQUISH				10

#define PTYPE_UNKNOWN				0
#define PTYPE_RIP					1
#define PTYPE_ECHO					2
#define PTYPE_ERROR					3
#define PTYPE_IPX					4
#define PTYPE_SPX					5

#pragma pack(1)

typedef struct {
	byte        network[4];
	byte        node[6];
	short       socket;
} IPXaddr;

struct sockaddr_ipx {
	short       sipx_family;
	IPXaddr     sipx_addr;
	char        sipx_zero[2];
};

#define sipx_port sipx_addr.socket

typedef struct {
	short       checkSum;
	short       length;
	byte        transportControl;
	byte        type;
	IPXaddr     destination;
	IPXaddr     source;
} IPXheader;

typedef struct ECBStructure {
	struct ECBStructure *link;
	unsigned short ESR_off;
	unsigned short ESR_seg;
	byte        inUse;
	byte        completionCode;
	short       socket;
	byte        IPXWorkspace[4];
	byte        driverWorkspace[12];
	byte        immediateAddress[6];
	short       fragCount;
	short       fragOff;
	short       fragSeg;
	short       fragSize;
} ECB;

#pragma pack()

typedef struct {
	ECB         ecb;
	IPXheader   header;
	int         sequence;
	char        data[NET_DATAGRAMSIZE];
} ipx_lowmem_buffer_t;

#define LOWMEMSIZE		(100 * 1024)
#define LOWMEMSAVE		256
#define IPXBUFFERS		((LOWMEMSIZE - LOWMEMSAVE)/ sizeof(ipx_lowmem_buffer_t))
#define IPXSOCKBUFFERS	5
#define IPXSOCKETS		(IPXBUFFERS / IPXSOCKBUFFERS)

// each socket's socketbuffer 0 is used for sending, the others for listening

typedef struct {
	char        reserved[LOWMEMSAVE];
	ipx_lowmem_buffer_t socketbuffer[IPXSOCKETS][IPXSOCKBUFFERS];
} ipx_lowmem_area_t;


static int  ipxsocket[IPXSOCKETS];
static ECB *readlist[IPXSOCKETS];
static int  sequence[IPXSOCKETS];
static int  handlesInUse;
static ipx_lowmem_area_t *lma;
static char *lowmem_buffer;
static int  lowmem_bufseg;
static int  lowmem_bufoff;
static unsigned short ipx_cs;
static unsigned short ipx_ip;
static int  net_acceptsocket = -1;
static int  net_controlsocket;

static void IPX_PollProcedure (void);
static PollProcedure pollProcedure = { NULL, 0.0, IPX_PollProcedure };

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

static void
IPX_GetLocalAddress (IPXaddr * addr)
{
	regs.x.cs = ipx_cs;
	regs.x.ip = ipx_ip;
	regs.x.bx = IPX_GETADDRESS;
	regs.x.es = lowmem_bufseg;
	regs.x.si = lowmem_bufoff;
	__dpmi_simulate_real_mode_procedure_retf ((__dpmi_regs *) & regs);
	Q_memcpy (addr, lowmem_buffer, 10);
}

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

static int
IPX_GetLocalTarget (IPXaddr * addr, byte * localTarget)
{
	regs.x.cs = ipx_cs;
	regs.x.ip = ipx_ip;
	regs.x.bx = IPX_GETROUTE;
	regs.x.es = lowmem_bufseg;
	regs.x.si = lowmem_bufoff;
	regs.x.di = lowmem_bufoff + sizeof (IPXaddr);
	Q_memcpy (lowmem_buffer, addr, sizeof (IPXaddr));
	__dpmi_simulate_real_mode_procedure_retf ((__dpmi_regs *) & regs);
	if (regs.h.al)
		return -1;
	Q_memcpy (localTarget, lowmem_buffer + sizeof (IPXaddr), 6);
	return 0;
}

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

static void
IPX_ListenForPacket (ECB * ecb)
{
	regs.x.cs = ipx_cs;
	regs.x.ip = ipx_ip;
	regs.x.bx = IPX_LISTEN;
	regs.x.es = ptr2real (ecb) >> 4;
	regs.x.si = ptr2real (ecb) & 0xf;
	__dpmi_simulate_real_mode_procedure_retf ((__dpmi_regs *) & regs);
}

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

static void
IPX_RelinquishControl (void)
{
	regs.x.cs = ipx_cs;
	regs.x.ip = ipx_ip;
	regs.x.bx = IPX_RELINQUISH;
	__dpmi_simulate_real_mode_procedure_retf ((__dpmi_regs *) & regs);
}


void
IPX_PollProcedure (void)
{
	IPX_RelinquishControl ();
	SchedulePollProcedure (&pollProcedure, 0.01);
}

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

static void
ProcessReadyList (int s)
{
	int         n;
	ECB        *ecb;
	ECB        *prev;

	for (n = 1; n < IPXSOCKBUFFERS; n++) {
		if (lma->socketbuffer[s][n].ecb.inUse == 0) {
			for (ecb = readlist[s], prev = NULL; ecb; ecb = ecb->link) {
				if (lma->socketbuffer[s][n].sequence <
					((ipx_lowmem_buffer_t *) ecb)->sequence)
					break;
				prev = ecb;
			}
			if (ecb)
				lma->socketbuffer[s][n].ecb.link = ecb;
			else
				lma->socketbuffer[s][n].ecb.link = NULL;
			if (prev)
				prev->link = &lma->socketbuffer[s][n].ecb;
			else
				readlist[s] = &lma->socketbuffer[s][n].ecb;
			lma->socketbuffer[s][n].ecb.inUse = 0xff;
		}
	}
}

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

int
IPX_Init (void)
{
	int         s;
	int         n;
	struct qsockaddr addr;
	char       *colon;

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

	// find the IPX far call entry point
	regs.x.ax = 0x7a00;
	__dpmi_simulate_real_mode_interrupt (0x2f, (__dpmi_regs *) & regs);
	if (regs.h.al != 0xff) {
		Con_Printf ("IPX not detected\n");
		return -1;
	}
	ipx_cs = regs.x.es;
	ipx_ip = regs.x.di;

	// grab a chunk of memory down in DOS land
	lowmem_buffer = dos_getmemory (LOWMEMSIZE);
	if (!lowmem_buffer) {
		Con_Printf ("IPX_Init: Not enough low memory\n");
		return -1;
	}
	lowmem_bufoff = ptr2real (lowmem_buffer) & 0xf;
	lowmem_bufseg = ptr2real (lowmem_buffer) >> 4;

	// init socket handles & buffers
	handlesInUse = 0;
	lma = (ipx_lowmem_area_t *) lowmem_buffer;
	for (s = 0; s < IPXSOCKETS; s++) {
		ipxsocket[s] = 0;
		for (n = 0; n < IPXSOCKBUFFERS; n++) {
			lma->socketbuffer[s][n].ecb.link = NULL;
			lma->socketbuffer[s][n].ecb.ESR_off = 0;
			lma->socketbuffer[s][n].ecb.ESR_seg = 0;
			lma->socketbuffer[s][n].ecb.socket = 0;
			lma->socketbuffer[s][n].ecb.inUse = 0xff;
			lma->socketbuffer[s][n].ecb.completionCode = 0;
			lma->socketbuffer[s][n].ecb.fragCount = 1;
			lma->socketbuffer[s][n].ecb.fragOff =
				ptr2real (&lma->socketbuffer[s][n].header) & 0xf;
			lma->socketbuffer[s][n].ecb.fragSeg =
				ptr2real (&lma->socketbuffer[s][n].header) >> 4;
			lma->socketbuffer[s][n].ecb.fragSize =
				sizeof (IPXheader) + sizeof (int) + NET_DATAGRAMSIZE;
		}
	}

	if ((net_controlsocket = IPX_OpenSocket (0)) == -1) {
		dos_freememory (lowmem_buffer);
		Con_DPrintf ("IPX_Init: Unable to open control socket\n");
		return -1;
	}

	SchedulePollProcedure (&pollProcedure, 0.01);

	IPX_GetSocketAddr (net_controlsocket, &addr);
	Q_strcpy (my_ipx_address, IPX_AddrToString (&addr));
	colon = Q_strrchr (my_ipx_address, ':');
	if (colon)
		*colon = 0;

	Con_Printf ("IPX initialized\n");
	ipxAvailable = true;
	return net_controlsocket;
}

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

void
IPX_Shutdown (void)
{
	IPX_Listen (false);
	IPX_CloseSocket (net_controlsocket);
	dos_freememory (lowmem_buffer);
}

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

void
IPX_Listen (qboolean state)
{
	// enable listening
	if (state) {
		if (net_acceptsocket != -1)
			return;
		if ((net_acceptsocket = IPX_OpenSocket (net_hostport)) == -1)
			Sys_Error ("IPX_Listen: Unable to open accept socket");
		return;
	}
	// disable listening
	if (net_acceptsocket == -1)
		return;
	IPX_CloseSocket (net_acceptsocket);
	net_acceptsocket = -1;
}

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

int
IPX_OpenSocket (int port)
{
	int         handle;
	int         n;
	unsigned short socket;

	if (handlesInUse == IPXSOCKETS)
		return -1;

	// open the IPX socket
	regs.x.cs = ipx_cs;
	regs.x.ip = ipx_ip;
	regs.x.bx = IPX_OPEN;
	regs.h.al = 0;
	regs.x.dx = htons (port);
	__dpmi_simulate_real_mode_procedure_retf ((__dpmi_regs *) & regs);
	if (regs.h.al == 0xfe) {
		Con_DPrintf ("IPX_OpenSocket: all sockets in use\n");
		return -1;
	}
	if (regs.h.al == 0xff) {
		Con_DPrintf ("IPX_OpenSocket: socket already open\n");
		return -1;
	}
	if (regs.h.al != 0) {
		Con_DPrintf ("IPX_OpenSocket: error %02x\n", regs.h.al);
		return -1;
	}
	socket = regs.x.dx;

// grab a handle; fill in the ECBs, and get them listening
	for (handle = 0; handle < IPXSOCKETS; handle++) {
		if (ipxsocket[handle] == 0) {
			ipxsocket[handle] = socket;
			readlist[handle] = NULL;
			sequence[handle] = 0;
			for (n = 0; n < IPXSOCKBUFFERS; n++) {
				lma->socketbuffer[handle][n].ecb.socket = socket;
				lma->socketbuffer[handle][n].ecb.inUse = 0;
				if (n)
					IPX_ListenForPacket (&lma->socketbuffer[handle][n].ecb);
			}
			handlesInUse++;
			return handle;
		}
	}

	// "this will NEVER happen"
	Sys_Error ("IPX_OpenSocket: handle allocation failed");
	return -1;
}

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

int
IPX_CloseSocket (int handle)
{
	// if there's a send in progress, give it one last chance
	if (lma->socketbuffer[handle][0].ecb.inUse != 0)
		IPX_RelinquishControl ();

	// close the socket (all pending sends/received are cancelled)
	regs.x.cs = ipx_cs;
	regs.x.ip = ipx_ip;
	regs.x.bx = IPX_CLOSE;
	regs.x.dx = ipxsocket[handle];
	__dpmi_simulate_real_mode_procedure_retf ((__dpmi_regs *) & regs);

	ipxsocket[handle] = 0;
	handlesInUse--;

	return 0;
}

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

int
IPX_Connect (int handle, struct qsockaddr *addr)
{
	IPXaddr     ipxaddr;

	Q_memcpy (&ipxaddr, &((struct sockaddr_ipx *) addr)->sipx_addr,
			  sizeof (IPXaddr));
	if (IPX_GetLocalTarget
		(&ipxaddr, lma->socketbuffer[handle][0].ecb.immediateAddress) != 0) {
		Con_Printf ("Get Local Target failed\n");
		return -1;
	}

	return 0;
}

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

int
IPX_CheckNewConnections (void)
{
	int         n;

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

	for (n = 1; n < IPXSOCKBUFFERS; n++)
		if (lma->socketbuffer[net_acceptsocket][n].ecb.inUse == 0)
			return net_acceptsocket;
	return -1;
}

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

int
IPX_Read (int handle, byte * buf, int len, struct qsockaddr *addr)
{
	ECB        *ecb;
	ipx_lowmem_buffer_t *rcvbuf;
	int         copylen;

	ProcessReadyList (handle);
  tryagain:
	if (readlist[handle] == NULL)
		return 0;
	ecb = readlist[handle];
	readlist[handle] = ecb->link;

	if (ecb->completionCode != 0) {
		Con_Printf ("Warning: IPX_Read error %02x\n", ecb->completionCode);
		ecb->fragSize = sizeof (IPXheader) + sizeof (int) + NET_DATAGRAMSIZE;

		IPX_ListenForPacket (ecb);
		goto tryagain;
	}

	rcvbuf = (ipx_lowmem_buffer_t *) ecb;

	// copy the data up to the buffer
	copylen =

		ntohs (rcvbuf->header.length) - (sizeof (int) + sizeof (IPXheader));
	if (len < copylen)
		Sys_Error ("IPX_Read: buffer too small (%d vs %d)", len, copylen);
	Q_memcpy (buf, rcvbuf->data, copylen);

	// fill in the addr if they want it
	if (addr) {
		((struct sockaddr_ipx *) addr)->sipx_family = AF_NETWARE;
		Q_memcpy (&((struct sockaddr_ipx *) addr)->sipx_addr,
				  rcvbuf->header.source.network, sizeof (IPXaddr));
		((struct sockaddr_ipx *) addr)->sipx_zero[0] = 0;
		((struct sockaddr_ipx *) addr)->sipx_zero[1] = 0;
	}
	// update the send ecb's immediate address
	Q_memcpy (lma->socketbuffer[handle][0].ecb.immediateAddress,
			  rcvbuf->ecb.immediateAddress, 6);

	// get this ecb listening again
	rcvbuf->ecb.fragSize = sizeof (IPXheader) + sizeof (int) + NET_DATAGRAMSIZE;

	IPX_ListenForPacket (&rcvbuf->ecb);
	return copylen;
}

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

int
IPX_Broadcast (int handle, byte * buf, int len)
{
	struct sockaddr_ipx addr;
	int         ret;

	Q_memset (addr.sipx_addr.network, 0x00, 4);
	Q_memset (addr.sipx_addr.node, 0xff, 6);
	addr.sipx_port = htons (net_hostport);
	Q_memset (lma->socketbuffer[handle][0].ecb.immediateAddress, 0xff, 6);
	ret = IPX_Write (handle, buf, len, (struct qsockaddr *) &addr);
	return ret;
}

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

int
IPX_Write (int handle, byte * buf, int len, struct qsockaddr *addr)
{
	// has the previous send completed?
	while (lma->socketbuffer[handle][0].ecb.inUse != 0)
		IPX_RelinquishControl ();

	switch (lma->socketbuffer[handle][0].ecb.completionCode) {
		case 0x00:						// success
		case 0xfc:						// request cancelled
		break;

		case 0xfd:						// malformed packet
		default:
		Con_Printf ("IPX driver send failure: %02x\n",
					lma->socketbuffer[handle][0].ecb.completionCode);
		break;

		case 0xfe:						// packet undeliverable
		case 0xff:						// unable to send packet
		Con_Printf ("IPX lost route, trying to re-establish\n");

		// look for a new route
		if (IPX_GetLocalTarget
			(&lma->socketbuffer[handle][0].header.destination,
			 lma->socketbuffer[handle][0].ecb.immediateAddress) != 0)
			return -1;

		// re-send the one that failed
		regs.x.cs = ipx_cs;
		regs.x.ip = ipx_ip;
		regs.x.bx = IPX_SEND;
		regs.x.es = ptr2real (&lma->socketbuffer[handle][0].ecb) >> 4;
		regs.x.si = ptr2real (&lma->socketbuffer[handle][0].ecb) & 0xf;
		__dpmi_simulate_real_mode_procedure_retf ((__dpmi_regs *) & regs);

		// report that we did not send the current one
		return 0;
	}

	// ecb : length
	lma->socketbuffer[handle][0].ecb.fragSize =
		sizeof (IPXheader) + sizeof (int) + len;

	// ipx header : type
	lma->socketbuffer[handle][0].header.type = PTYPE_IPX;

	// ipx header : destination
	Q_memcpy (&lma->socketbuffer[handle][0].header.destination,
			  &((struct sockaddr_ipx *) addr)->sipx_addr, sizeof (IPXaddr));

	// sequence number
	lma->socketbuffer[handle][0].sequence = sequence[handle];
	sequence[handle]++;

	// copy down the data
	Q_memcpy (lma->socketbuffer[handle][0].data, buf, len);

	regs.x.cs = ipx_cs;
	regs.x.ip = ipx_ip;
	regs.x.bx = IPX_SEND;
	regs.x.es = ptr2real (&lma->socketbuffer[handle][0].ecb) >> 4;
	regs.x.si = ptr2real (&lma->socketbuffer[handle][0].ecb) & 0xf;
	__dpmi_simulate_real_mode_procedure_retf ((__dpmi_regs *) & regs);

	return len;
}

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

char       *
IPX_AddrToString (struct qsockaddr *addr)
{
	static char buf[28];

	snprintf (buf, sizeof (buf), "%02x%02x%02x%02x:%02x%02x%02x%02x%02x%02x:%u",
			  ((struct sockaddr_ipx *) addr)->sipx_addr.network[0],
			  ((struct sockaddr_ipx *) addr)->sipx_addr.network[1],
			  ((struct sockaddr_ipx *) addr)->sipx_addr.network[2],
			  ((struct sockaddr_ipx *) addr)->sipx_addr.network[3],
			  ((struct sockaddr_ipx *) addr)->sipx_addr.node[0],
			  ((struct sockaddr_ipx *) addr)->sipx_addr.node[1],
			  ((struct sockaddr_ipx *) addr)->sipx_addr.node[2],
			  ((struct sockaddr_ipx *) addr)->sipx_addr.node[3],
			  ((struct sockaddr_ipx *) addr)->sipx_addr.node[4],
			  ((struct sockaddr_ipx *) addr)->sipx_addr.node[5],
			  ntohs (((struct sockaddr_ipx *) addr)->sipx_port)
		);
	return buf;
}

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

int
IPX_StringToAddr (char *string, struct qsockaddr *addr)
{
	int         val;
	char        buf[3];

	buf[2] = 0;
	Q_memset (addr, 0, sizeof (struct qsockaddr));

	addr->sa_family = AF_NETWARE;

#define DO(src,dest)	\
	buf[0] = string[src];	\
	buf[1] = string[src + 1];	\
	if (sscanf (buf, "%x", &val) != 1)	\
		return -1;	\
	((struct sockaddr_ipx *)addr)->sipx_addr.dest = val

	DO (0, network[0]);
	DO (2, network[1]);
	DO (4, network[2]);
	DO (6, network[3]);
	DO (9, node[0]);
	DO (11, node[1]);
	DO (13, node[2]);
	DO (15, node[3]);
	DO (17, node[4]);
	DO (19, node[5]);
#undef DO

	sscanf (&string[22], "%u", &val);
	((struct sockaddr_ipx *) addr)->sipx_port = htons (val);

	return 0;
}

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

int
IPX_GetSocketAddr (int handle, struct qsockaddr *addr)
{
	Q_memset (addr, 0, sizeof (struct qsockaddr));

	addr->sa_family = AF_NETWARE;
	IPX_GetLocalAddress (&((struct sockaddr_ipx *) addr)->sipx_addr);
	((struct sockaddr_ipx *) addr)->sipx_port = ipxsocket[handle];
	return 0;
}

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

int
IPX_GetNameFromAddr (struct qsockaddr *addr, char *name)
{
	Q_strcpy (name, IPX_AddrToString (addr));
	return 0;
}

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

int
IPX_GetAddrFromName (char *name, struct qsockaddr *addr)
{
	int         n;
	char        buf[32];

	n = Q_strlen (name);

	if (n == 12) {
		snprintf (buf, sizeof (buf), "00000000:%s:%u", name, net_hostport);
		return IPX_StringToAddr (buf, addr);
	}
	if (n == 21) {
		snprintf (buf, sizeof (buf), "%s:%u", name, net_hostport);
		return IPX_StringToAddr (buf, addr);
	}
	if (n > 21 && n <= 27)
		return IPX_StringToAddr (name, addr);

	return -1;
}

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

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

	if (Q_memcmp
		(&((struct sockaddr_ipx *) addr1)->sipx_addr,
		 &((struct sockaddr_ipx *) addr2)->sipx_addr, 10))
		return -1;

	if (((struct sockaddr_ipx *) addr1)->sipx_port !=
		((struct sockaddr_ipx *) addr2)->sipx_port)
		return 1;

	return 0;
}

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

int
IPX_GetSocketPort (struct qsockaddr *addr)
{
	return ntohs (((struct sockaddr_ipx *) addr)->sipx_port);
}


int
IPX_SetSocketPort (struct qsockaddr *addr, int port)
{
	((struct sockaddr_ipx *) addr)->sipx_port = htons (port);
	return 0;
}

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