wsockdos.c

Libnet is a cross-platform library aimed at game developers. It has an abstract high level API, whic

/*----------------------------------------------------------------
 * wsock.c - Winsock in DOS driver for libnet
 *----------------------------------------------------------------
 *  libnet is (c) Copyright Chad Catlett and George Foot 1997-1998
 *
 *  Please look in `docs' for details, documentation and
 *  distribution conditions.
 */

#include "platdefs.h"

/* If we can use the Winsock from DOS, do so.  Otherwise, dummy driver...
 */
#ifdef __USE_REAL_WSOCK_DOS__

#include <assert.h>
#include <ctype.h>
#include <dpmi.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/farptr.h>
#include <sys/segments.h>
#include <time.h>
#include <netinet/in.h>

#include "wsockdos.h"

extern int __libnet_internal_wsockdos__dns_lookup (const char *, int, void *);

/*------------------------------------------------ VxD interface code */

#define VxdLdr_DeviceID 0x0027
#define VxdLdr_LoadDevice 1
#define VxdLdr_UnLoadDevice 2

static int VxdLdrEntry [2] = {0, 0};  /* VxD loader/unloader 16 bit PM entry */

static void VxdGetEntry (int *Entry, int ID)
{
	int dummy;
	asm ("\
		pushl   %%es            \n\
		movw    %%di, %%es      \n\
		int     $0x2f           \n\
		movl    $0, %%ecx       \n\
		movw    %%es, %%cx      \n\
		popl    %%es            "
	:
		"=a" (dummy),
		"=c" (Entry [1]),
		"=D" (Entry [0])
	:
		"a" (0x1684),
		"b" (ID),
		"D" (0)
	:
		"%edx"
	);
}

static void VxdLdrInit (void)
{
	VxdGetEntry (VxdLdrEntry, VxdLdr_DeviceID);
}

static int VxdLdrLoadDevice (char Device [])
{
	int Error;
	__dpmi_meminfo _dev;
	int dev;

	if (VxdLdrEntry [1] == 0) VxdLdrInit ();
	if (VxdLdrEntry [1] == 0) return -1;

	_dev.handle = 0;
	_dev.size = strlen (Device) + 1;
	_dev.address = 0;

	__dpmi_allocate_memory (&_dev);
	dev = __dpmi_allocate_ldt_descriptors (1);
	__dpmi_set_segment_base_address (dev, _dev.address);
	__dpmi_set_segment_limit (dev, _dev.size);

	_farpokex (dev, 0, Device, _dev.size);

	asm ("\
		pushl   %%ds               \n\
		movw    %%cx, %%ds         \n\
		lcall  *%%cs:_VxdLdrEntry  \n\
		setc    %%al               \n\
		movzbl  %%al, %%eax        \n\
		popl    %%ds"
	:
		"=a" (Error)
	:
		"a" (VxdLdr_LoadDevice),
		"c" (dev),
		"d" (0)
	);

	__dpmi_free_ldt_descriptor (dev);
	__dpmi_free_memory (_dev.handle);

	return Error;
}

static int VxdLdrUnLoadDevice (char Device [])
{
	int Error;
	__dpmi_meminfo _dev;
	int dev;

	if (VxdLdrEntry [1] == 0) VxdLdrInit ();
	if (VxdLdrEntry [1] == 0) return -1;

	_dev.handle = 0;
	_dev.size = strlen (Device) + 1;
	_dev.address = 0;

	__dpmi_allocate_memory (&_dev);
	dev = __dpmi_allocate_ldt_descriptors (1);
	__dpmi_set_segment_base_address (dev, _dev.address);
	__dpmi_set_segment_limit (dev, _dev.size);

	_farpokex (dev, 0, Device, _dev.size);

	asm ("\
		pushl   %%ds               \n\
		movw    %%cx, %%ds         \n\
		lcall  *%%cs:_VxdLdrEntry  \n\
		setc    %%al               \n\
		movzbl  %%al, %%eax        \n\
		popl    %%ds"
	:
		"=a" (Error)
	:
		"a" (VxdLdr_UnLoadDevice),
		"c" (dev),
		"d" (0)
	);

	__dpmi_free_ldt_descriptor (dev);
	__dpmi_free_memory (_dev.handle);

	return Error;
}


/*------------------------------------------------ Interface to WSOCK.VXD */

static __dpmi_meminfo _SocketP;         /* 64k selector for parameters */
static int SocketP;
static __dpmi_meminfo _SocketD;         /* 64k selector for data */
static int SocketD;
static int last_error = 0;              /* last error code from VxD function */
static int WSockEntry  [2] = {0, 0};    /* wsock.vxd 16 bit PM entry */


static int call_vxd(int func)
{
	int error;

	asm ("\
		pushl   %%es                    \n\
		pushl   %%ecx                   \n\
		popl    %%es                    \n\
		lcall  *_WSockEntry             \n\
		andl    $0x0000ffff, %%eax      \n\
		popl    %%es"
	:
		"=a" (error)
	:
		"a" (func),
		"b" (0),
		"c" (SocketP)
	);

	return error;
}

static int handle_error(int error)
{
	if (error && (error != 65535)) {
		last_error = error;
		return SOCKET_ERROR;
	} else
		return 0;
}


/* Semi-standard socket functions (some winsock-style rather than Berkeley) */

static SOCKET accept (SOCKET s, struct sockaddr *addr, int *addrlen)
{
	int error;
	int AddressLength,AddressPointer;
	SOCKET t;

	if (addrlen)
		AddressLength = *addrlen;
	else
		AddressLength = 0;

	if (addr)
		AddressPointer = (SocketP << 16) + (7 * 4);
	else
		AddressPointer = 0;

	_farpokel (SocketP, 0 * 4, AddressPointer);             /* Address */
	_farpokel (SocketP, 1 * 4, s);                          /* Listening Socket */
	_farpokel (SocketP, 2 * 4, 0);                          /* Connected Socket */
	_farpokel (SocketP, 3 * 4, AddressLength);              /* Address Length */
	_farpokel (SocketP, 4 * 4, 0);                          /* Connected Socket Handle */
	_farpokel (SocketP, 5 * 4, 0);                          /* Apc Routing */
	_farpokel (SocketP, 6 * 4, 0);                          /* Apc Context */

	error = call_vxd(WSOCK_ACCEPT_CMD);

	if (addr&&addrlen)
		_farpeekx (SocketP, 7 * 4, addr, *addrlen);            // should also update *addrlen

	t = _farpeekl (SocketP, 2 * 4);

	if (!error)
		return t;
	else {
		handle_error(error);
		return INVALID_SOCKET;
	}
}

static int bind (SOCKET s, const struct sockaddr *name, int namelen)
{
	int error;

	_farpokel (SocketP, 0 * 4, (SocketP << 16) + (5 * 4));      /* Address */
	_farpokel (SocketP, 1 * 4, s);                              /* Socket */
	_farpokel (SocketP, 2 * 4, namelen);                        /* Address Length */
	_farpokel (SocketP, 3 * 4, 0);                              /* Apc Routine */
	_farpokel (SocketP, 4 * 4, 0);                              /* Apc Context */

	_farpokex (SocketP, 5 * 4, name, namelen);

	error = call_vxd(WSOCK_BIND_CMD);

	return handle_error(error);
}

static int closesocket (SOCKET s)
{
	int error;

	_farpokel (SocketP, 0 * 4, s);
	error = call_vxd(WSOCK_CLOSESOCKET_CMD);

	return handle_error(error);
}

static int connect (SOCKET s, const struct sockaddr *name, int namelen)
{
	int error;

	_farpokel (SocketP, 0 * 4, (SocketP << 16) + (5 * 4));      // Address
	_farpokel (SocketP, 1 * 4, s);                              // Socket
	_farpokel (SocketP, 2 * 4, namelen);                        // Address Length
	_farpokel (SocketP, 3 * 4, 0);                              // Apc Routine
	_farpokel (SocketP, 4 * 4, 0);                              // Apc Context

	_farpokex (SocketP, 5 * 4, name, namelen);

	error = call_vxd(WSOCK_CONNECT_CMD);

	return handle_error(error);
}

static int getpeername (SOCKET s, struct sockaddr *name, int *namelen)
{
	int error;

	_farpokel (SocketP, 0 * 4, (SocketP << 16) + (3 * 4));      /* Address */
	_farpokel (SocketP, 1 * 4, s);                              /* Socket */
	_farpokel (SocketP, 2 * 4, *namelen);                       /* Address Length */

	error = call_vxd(WSOCK_GETPEERNAME_CMD);

	_farpeekx (SocketP, 3 * 4, name, *namelen);

	return handle_error(error);
}

static int getsockname (SOCKET s, struct sockaddr *name, int *namelen)
{
	int error;

	_farpokel (SocketP, 0 * 4, (SocketP << 16) + (3 * 4));      /* Address */
	_farpokel (SocketP, 1 * 4, s);                              /* Socket */
	_farpokel (SocketP, 2 * 4, *namelen);                       /* Address Length */

	error = call_vxd(WSOCK_GETSOCKNAME_CMD);

	_farpeekx (SocketP, 3 * 4, name, *namelen);

	return handle_error(error);
}

static int getsockopt (SOCKET s, int level, int optname, char *optval, int *optlen)
{
	int error;

	_farpokel (SocketP, 0 * 4, (SocketP << 16) + (6 * 4));      /* Value */
	_farpokel (SocketP, 1 * 4, s);                              /* Socket */
	_farpokel (SocketP, 2 * 4, level);                          /* Option Level */
	_farpokel (SocketP, 3 * 4, optname);                        /* Option Name */
	_farpokel (SocketP, 4 * 4, *optlen);                        /* Value Length */
	_farpokel (SocketP, 5 * 4, 0);                              /* Int Value */

	error = call_vxd (WSOCK_GETSOCKOPT_CMD);

	if (*optlen == 4)
		*((int *) optval) = _farpeekl (SocketP, 5 * 4);
	else
		_farpeekx (SocketP, 6 * 4, optval, *optlen);

	return handle_error(error);
}

static unsigned long inet_addr (const char *cp) {
	unsigned int a[4] = { 0 };
	int i = 0, error = 0;
	const char *s = cp;

	do {
		if (!isdigit (*s))
			error = 1;
		else {
			do {
				a[i] = a[i] * 10 + (*s - '0');
				s++;
			} while (isdigit (*s));
			if (*s == '.') {
				if ((i == 3) || (a[i] > 255)) error = 1;
				s++;
				i++;
			}
		}
	} while ((*s) && (!error));

	if (error) return INADDR_NONE;

	switch (i) {
		case 0:
			return a[0];
			break;
		case 1:
			if (a[1] >= (1<<24)) return INADDR_NONE;
			return (a[0] << 24) + a[1];
			break;
		case 2:
			if (a[2] >= (1<<16)) return INADDR_NONE;
			return (a[0] << 24) + (a[1] << 16) + a[2];
			break;
		case 3:
			if (a[3] >= (1<<8)) return INADDR_NONE;
			return (a[0] << 24) + (a[1] << 16) + (a[2] << 8) + a[3];
			break;
	}
	return INADDR_NONE;
}

static char inet_ntoa_buffer[32] = { 0 };

static void write_number (unsigned int num, char **where) {
	if (num >= 10) write_number (num/10, where);
	*((*where)++) = '0' + (num % 10);
}

static char *inet_ntoa (struct in_addr in) {
	char *chp = inet_ntoa_buffer;
	unsigned char *v = (unsigned char *)&in.s_addr;
	write_number (v[3], &chp);
	*chp++ = '.';
	write_number (v[2], &chp);
	*chp++ = '.';
	write_number (v[1], &chp);
	*chp++ = '.';
	write_number (v[0], &chp);
	*chp++ = 0;
	return inet_ntoa_buffer;
}

static int ioctlsocket (SOCKET s, long cmd, u_long *argp)
{
	int error;
	int size;

	_farpokel (SocketP, 0 * 4, s);                        /* Socket */
	_farpokel (SocketP, 1 * 4, cmd);                      /* Command */
	_farpokel (SocketP, 2 * 4, *argp);                    /* Parameter */

	error = call_vxd (WSOCK_IOCTLSOCKET_CMD);

	switch (cmd) {
		case FIONBIO:
		case FIONREAD:
			size=4;
			break;
		case SIOCATMARK:
			size=1;
			break;
		default:
			size=0;
	}

	_farpeekx (SocketP, 2 * 4, argp, size);

	return handle_error(error);
}

static int listen(SOCKET s, int backlog)
{
	_farpokel (SocketP, 0 * 4, s);                      /* Socket */
	_farpokel (SocketP, 1 * 4, backlog);                /* Backlog */

	return handle_error(call_vxd(WSOCK_LISTEN_CMD));
}

static int recvfrom (SOCKET s, char *buf, int len, int flags, struct sockaddr *from, int *fromlen)
{
	int error;
	int AddressPointer, AddressLength;

	if (from) {
		if (fromlen)
			AddressLength=*fromlen;
		else
			AddressLength=0;
		AddressPointer = (SocketP << 16) + (10 * 4);
	} else {
		AddressPointer = 0;
		AddressLength  = 0;
	}

	_farpokel (SocketP, 0 * 4, SocketD << 16);              /* Buffer */
	_farpokel (SocketP, 1 * 4, AddressPointer);             /* Address */
	_farpokel (SocketP, 2 * 4, s);                          /* Socket */
	_farpokel (SocketP, 3 * 4, len);                        /* Buffer Length */
	_farpokel (SocketP, 4 * 4, flags);                      /* Flags */
	_farpokel (SocketP, 5 * 4, AddressLength);              /* Address Length */
	_farpokel (SocketP, 6 * 4, 0);                          /* Bytes Received */
	_farpokel (SocketP, 7 * 4, 0);                          /* Apc Routine */
	_farpokel (SocketP, 8 * 4, 0);                          /* Apc Context */
	_farpokel (SocketP, 9 * 4, 0);                          /* Timeout */

	error = call_vxd (WSOCK_RECV_CMD);

	if (from) _farpeekx (SocketP, 10 * 4, from, AddressLength);

	_farpeekx (SocketD, 0, buf, len);

	if (error==0)
		return _farpeekl (SocketP, 6 * 4);
	else
		return handle_error(error);
}

static int recv (SOCKET s, char *buf, int len, int flags)
{
	return recvfrom(s,buf,len,flags,0,0);
}

static int sendto (SOCKET s, const char *buf, int len, int flags, const struct sockaddr *to, int tolen)
{
	int error;
	int AddressPointer, AddressLength;

	if (to) {
		AddressPointer = (SocketP << 16) + (10 * 4);
		AddressLength  = tolen;
	} else {
		AddressPointer = 0;
		AddressLength  = 0;
	}

	_farpokel (SocketP, 0 * 4, SocketD << 16);                  /* Buffer */
	_farpokel (SocketP, 1 * 4, AddressPointer);                 /* Address */
	_farpokel (SocketP, 2 * 4, s);                              /* Socket */
	_farpokel (SocketP, 3 * 4, len);                            /* Buffer Length */
	_farpokel (SocketP, 4 * 4, flags);                          /* Flags */
	_farpokel (SocketP, 5 * 4, AddressLength);                  /* Address Length */
	_farpokel (SocketP, 6 * 4, 0);                              /* Bytes Sent */
	_farpokel (SocketP, 7 * 4, 0);                              /* Apc Routine */
	_farpokel (SocketP, 8 * 4, 0);                              /* Apc Context */
	_farpokel (SocketP, 9 * 4, 0);                              /* Timeout */

	if (to) _farpokex (SocketP, 10 * 4, to, tolen);

	_farpokex (SocketD, 0, buf, len);

	error = call_vxd (WSOCK_SEND_CMD);

	if (error==0)
		return _farpeekl (SocketP, 6 * 4);
	else
		return handle_error(error);
}

static int send (SOCKET s, const char *buf, int len, int flags)
{
	return sendto(s,buf,len,flags,0,0);
}

static int setsockopt (SOCKET s, int level, int optname, const char *optval, int optlen)
{
	int error;

	_farpokel (SocketP, 0 * 4, (SocketP << 16) + (6 * 4));      /* Value */
	_farpokel (SocketP, 1 * 4, s);                              /* Socket */
	_farpokel (SocketP, 2 * 4, level);                          /* Option Level */
	_farpokel (SocketP, 3 * 4, optname);                        /* Option Name */
	_farpokel (SocketP, 4 * 4, optlen);                         /* Value Length */
	_farpokel (SocketP, 5 * 4, *((int *) optval));              /* Int Value */

	_farpokex (SocketP, 6 * 4, optval, optlen);

	error = call_vxd (WSOCK_SETSOCKOPT_CMD);

	return handle_error(error);
}

static int shutdown (SOCKET s, int how)
{
	_farpokel (SocketP, 0 * 4, s);                              /* Socket */
	_farpokel (SocketP, 1 * 4, how);                            /* How */

	return handle_error(call_vxd(WSOCK_SHUTDOWN_CMD));
}

static SOCKET socket (int af, int type, int protocol)
{
	SOCKET s;
	int error;

	_farpokel (SocketP, 0 * 4, af);                             /* Address Family */
	_farpokel (SocketP, 1 * 4, type);                           /* Socket Type */
	_farpokel (SocketP, 2 * 4, protocol);                       /* Protocol */
	_farpokel (SocketP, 3 * 4, 0);                              /* New Socket */
	_farpokel (SocketP, 4 * 4, 0);                              /* New Socket Handle */

	error = call_vxd (WSOCK_SOCKET_CMD);