/*
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_bw.c

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

#include "quakedef.h"
#include "dosisms.h"


// this section is general Unix stuff that we need

#define EIO       5 /* I/O error */
#define EBADS     9
#define EWOULDBLOCK   35  /* function would block */
#define EMSGSIZE    40  /* message to big for buffers */
#define EPROTONOSUPPORT 43  /* Protocol not supported */
#define ESOCKTNOSUPPORT 44  /* Socket type not supported */
#define EPFNOSUPPORT  46  /* Protocol family not supported */
#define EAFNOSUPPORT  47  /* Address family not supported */
#define ECONNABORTED  53  /* User requested hangup */
#define ENOBUFS     55  /* No buffers available */
#define EISCONN     56  /* Socket has closed */
#define ENOTCONN    57  /* Socket is not connected */
#define ESHUTDOWN   58  /* Socket is closed */
#define ETOOMANYREFS  59  /* Too many sockets open */
#define ETIMEDOUT   60  /* Connection timed out */
#define ECONNREFUSED  61  /* Connection refused */

#define AF_INET     2 /* internet */

#define PF_INET     AF_INET

#define SOCK_STREAM   1   /* stream */
#define SOCK_DGRAM    2   /* datagram */

#define IPPROTO_TCP   6
#define IPPROTO_UDP   17

#define INADDR_ANY    0

#define SIOCDONE    0x7300
#define FIONREAD    0x667f
#define FIONBIO     0x667e
#define FIONWIN     0x1000
#define FIONTIN     0x2000

#define BRDINIT     0
#define BRDADDR     10

#define MAXHOSTNAMELEN  256

#define SOL_SOCKET    0xffff    /* options for socket level */

/*
 * Option flags per-socket.
 */
#define SO_DEBUG    0x0001    /* turn on debugging info recording */
#define SO_ACCEPTCONN 0x0002    /* socket has had listen() */
#define SO_REUSEADDR  0x0004    /* allow local address reuse */
#define SO_KEEPALIVE  0x0008    /* keep connections alive */
#define SO_DONTROUTE  0x0010    /* just use interface addresses */
#define SO_BROADCAST  0x0020    /* permit sending of broadcast msgs */
#define SO_USELOOPBACK  0x0040    /* bypass hardware when possible */
#define SO_LINGER   0x0080    /* linger on close if data present */
#define SO_OOBINLINE  0x0100    /* leave received OOB data in line */
#define SO_USEPRIV    0x4000    /* allocate from privileged port area */
#define SO_CANTSIG    0x8000    /* prevent SIGPIPE on SS_CANTSENDMORE */

/*
 * Additional options, not kept in so_options.
 */
#define SO_SNDBUF   0x1001    /* send buffer size */
#define SO_RCVBUF   0x1002    /* receive buffer size */
#define SO_SNDLOWAT   0x1003    /* send low-water mark */
#define SO_RCVLOWAT   0x1004    /* receive low-water mark */
#define SO_SNDTIMEO   0x1005    /* send timeout */
#define SO_RCVTIMEO   0x1006    /* receive timeout */
#define SO_ERROR    0x1007    /* get error status and clear */
#define SO_TYPE     0x1008    /* get socket type */


struct in_addr
{
  union
  {
    struct { unsigned char s_b1,s_b2,s_b3,s_b4; } S_un_b;
    struct { unsigned short s_w1,s_w2; } S_un_w;
    unsigned long S_addr;
  } S_un;
};
#define s_addr  S_un.S_addr /* can be used for most tcp & ip code */
#define s_host  S_un.S_un_b.s_b2  /* host on imp */
#define s_net S_un.S_un_b.s_b1  /* network */
#define s_imp S_un.S_un_w.s_w2  /* imp */
#define s_impno S_un.S_un_b.s_b4  /* imp # */
#define s_lh  S_un.S_un_b.s_b3  /* logical host */

struct sockaddr_in
{
    short     sin_family;
    unsigned short  sin_port;
  struct in_addr  sin_addr;
    char      sin_zero[8];
};

struct  hostent {
  char  *h_name;  /* official name of host */
  char  **h_aliases;  /* alias list */
  int h_addrtype; /* host address type */
  int h_length; /* length of address */
  char  **h_addr_list;  /* list of addresses from name server */
#define h_addr  h_addr_list[0]  /* address, for backward compatiblity */
};

char *inet_ntoa(struct in_addr in);


// this section is B&W specific constants & structures

#define BW_IOCTL_BIND     0
#define BW_IOCTL_CLEAROPTIONS 5
#define BW_IOCTL_SETOPTIONS   6
#define BW_IOCTL_PEEK     7
#define BW_IOCTL_SETWINMASK   8

#define BW_OPTION_BLOCKING    0x01
#define BW_OPTION_REUSEBUFFERS  0x80

#define BW_ERR_USR_HANGUP   50
#define BW_ERR_HANGUP     51
#define BW_ERR_NET_ERR      52
#define BW_ERR_IS_CLOSED    53
#define BW_ERR_TIME_OUT     54
#define BW_ERR_RESET      55
#define BW_ERR_FULL       56
#define BW_ERR_BLOCK      57
#define BW_ERR_SHUTDOWN     58

#pragma pack(1)

typedef struct
{
  char      state;      // always 1
  short     localPort;
  struct in_addr  localAddr;
  char      reason;     // always 0
  char      options;
  short     dataAvailable;
} BW_UDPinfo_t;

typedef struct
{
  char      reserved1 [6];
  unsigned short  info2Offset;
  char      reserved2 [18];
  struct in_addr  remoteAddr;
} BW_UDPreadInfo1_t;

typedef struct
{
  short     remotePort;
  char      reserved1 [2];
  unsigned short  dataLenPlus8;
  char      reserved2 [2];
  char      data[1];      // actual size is <dataLenPlus8> - 8    
} BW_UDPreadInfo2_t;

typedef struct
{
  char      reserved1 [2];
  short     remotePort;
  unsigned short  dataLen;
  struct in_addr  remoteAddr;
  char      reserved2 [42];
  char      data[1];      // actual size is <datalen>
} BW_writeInfo_t;

typedef struct
{
  short ioport;
  byte  dma;
  byte  vector;
  byte  irq;
  short bufferSize;
  short maxWindow;
  short timeZone;
  byte  myType;
  int   inetAddr;
  short value;
  byte  subnetMask;
  short etherPointer;
  short logserverPointer;
  short nameserverPointer;
  short printserverPointer;
  short timeserverPointer;
  short gatewayPointer;
  short driverSegment;
  byte  transferSize;
  char  cardName [9];
} BW_ethdevinfo_t;

#pragma pack()

#define LOWMEM_SIZE 4096

static unsigned char *lowmem_buffer;
static int lowmem_bufseg;
static int lowmem_bufoff;
static BW_ethdevinfo_t ethdevinfo;
static int netmask;
static struct in_addr bcastaddr;

extern regs_t regs;

static int net_acceptsocket = -1;   // socket for fielding new connections
static int net_controlsocket = 0;

#include "net_bw.h"

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

static int BW_ioctl(int s, char *msg, int msglen)
{
  Q_memcpy(lowmem_buffer, msg, msglen);

  regs.x.ax = 0x4403;
  regs.x.bx = s;
  regs.x.cx = msglen;
  regs.x.dx = lowmem_bufoff;
  regs.x.ds = lowmem_bufseg;
  if (dos_int86(0x21))
    return regs.x.ax;
  return 0;
}

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

static int BW_TranslateError(int error)
{
  switch(error)
  {
    case BW_ERR_USR_HANGUP: return ECONNABORTED;
    case BW_ERR_HANGUP:   return EISCONN;
    case BW_ERR_NET_ERR:  return ENOTCONN;
    case BW_ERR_IS_CLOSED:  return ENOTCONN;
    case BW_ERR_TIME_OUT: return ETIMEDOUT;
    case BW_ERR_RESET:    return ECONNREFUSED;
    case BW_ERR_FULL:   return ETOOMANYREFS;
    case BW_ERR_BLOCK:    return EWOULDBLOCK;
    case BW_ERR_SHUTDOWN: return ESHUTDOWN;
  }
  return EIO;
}

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

static int GetEthdevinfo(void)
{
  int fd;

  Q_strcpy((char *)lowmem_buffer, "ETHDEV27");
  regs.x.ax = 0x3d42;
  regs.x.ds = lowmem_bufseg;
  regs.x.dx = lowmem_bufoff;
  if (dos_int86(0x21))
    return -1;
  fd = regs.x.ax;

  regs.x.ax = 0x4401;
  regs.x.bx = fd;
  regs.x.dx = 0x60;
  dos_int86(0x21);

  regs.h.ah = 0x3f;
  regs.x.cx = sizeof(ethdevinfo);
  regs.x.es = regs.x.ds = lowmem_bufseg;
  regs.x.dx = lowmem_bufoff;
  regs.x.bx = fd;
  if (dos_int86(0x21))
    return -1;
  Q_memcpy(&ethdevinfo, lowmem_buffer, regs.x.ax);

  regs.h.ah = 0x3e;
  regs.x.bx = fd;
  dos_int86(0x21);

  return 0;
}

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

int BW_Init(void)
{
  struct qsockaddr addr;
  char *colon;

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

  lowmem_buffer = dos_getmemory(LOWMEM_SIZE);
  if (!lowmem_buffer)
    Sys_Error("not enough low memory\n");
  lowmem_bufoff = ptr2real(lowmem_buffer) & 0xf;
  lowmem_bufseg = ptr2real(lowmem_buffer) >> 4;

  if (GetEthdevinfo())
  {
    Con_DPrintf("Beame & Whiteside TCP/IP not detected\n");
    dos_freememory(lowmem_buffer);
    return -1;
  }
  netmask = 0xffffffff >> (32 - ethdevinfo.subnetMask);
  bcastaddr.s_addr = (ethdevinfo.inetAddr & netmask) | (~netmask);

  if ((net_controlsocket = BW_OpenSocket (0)) == -1)
  {
    dos_freememory(lowmem_buffer);
    Con_DPrintf ("BW_Init unable to open control socket; disabled\n");
    return -1;
  }

  BW_GetSocketAddr (net_controlsocket, &addr);
  Q_strcpy(my_tcpip_address,  BW_AddrToString (&addr));
  colon = Q_strrchr (my_tcpip_address, ':');
  if (colon)
    *colon = 0;

  Con_Printf("BW_Init: UDP initialized\n");
  tcpipAvailable = true;

  return net_controlsocket;
}

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

void BW_Shutdown(void)
{
  BW_Listen (false);
  BW_CloseSocket (net_controlsocket);
  dos_freememory(lowmem_buffer);
}

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

void BW_Listen (qboolean state)
{
  // enable listening
  if (state)
  {
    if (net_acceptsocket != -1)
      return;
    if ((net_acceptsocket = BW_OpenSocket (net_hostport)) == -1)
      Sys_Error ("BW_Listen: Unable to open accept socket\n");
    return;
  }

  // disable listening
  if (net_acceptsocket == -1)
    return;
  BW_CloseSocket (net_acceptsocket);
  net_acceptsocket = -1;
}


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

/*
OpenSocket returns a handle to a network socket that has been opened,
set to nonblocking, and bound to <port>.  Additional socket options
should be set here if they are needed.  -1 is returned on failure.
*/

int BW_OpenSocket(int port)
{
  int s;
  int ret;
  int deadman = 3 * 1024;
  static int dynamic = 1024;
  static char reuse_msg[2] = {BW_IOCTL_SETOPTIONS, BW_OPTION_REUSEBUFFERS};
  static char bind_msg[3] = {BW_IOCTL_BIND, 0, 0};
  static char nonblock_msg[2] = {BW_IOCTL_CLEAROPTIONS, BW_OPTION_BLOCKING};

  // allocate a UDP socket
  Q_strcpy((char *)lowmem_buffer, "UDP-IP10");
  regs.x.ax = 0x3d42;
  regs.x.ds = lowmem_bufseg;
  regs.x.dx = lowmem_bufoff;
  if (dos_int86(0x21))
  {
    Con_Printf("BW_OpenSocket failed: %u\n", BW_TranslateError(regs.x.ax));
    return -1;
  }
  s = regs.x.ax;

  // set file descriptor to raw mode
  regs.x.ax = 0x4401;
  regs.x.bx = s;
  regs.x.dx = 0x60;
  dos_int86(0x21);

  if (BW_ioctl(s, reuse_msg, 2))
  {
    Con_Printf("BW_OpenSocket ioctl(reuse) failed\n");
    return -1;
  }

  if (BW_ioctl(s, nonblock_msg, 2))
  {
    Con_Printf("BW_OpenSocket ioctl(nonblocking) failed\n");
    return -1;
  }

  // if a socket was specified, bind to it and return
  if (port)
  {
    *(short *)&bind_msg[1] = port;
    if (BW_ioctl(s, bind_msg, 3))
    {
      BW_CloseSocket(s);
      return -1;
    }
    return s;
  }

  // B&W does NOT do dynamic allocation, so if port == 0 we must fake it
  do
  {
    port = dynamic++;
    if (dynamic == 4096)
      dynamic = 1024;
    deadman--;
    *(short *)&bind_msg[1] = port;
    ret = BW_ioctl(s, bind_msg, 3);
  }
  while (ret && deadman);
  if (ret)
    return -1;
  return s;
}

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

int BW_CloseSocket(int socket)
{
  regs.h.ah = 0x3e;
  regs.x.bx = socket;
  if(dos_int86(0x21))
    {
      Con_Printf("BW_CloseSocket %u failed: %u\n", socket, BW_TranslateError(regs.x.ax));
      return -1;
    }
  return 0;
}

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

int BW_Connect (int socket, struct qsockaddr *hostaddr)
{
  return 0;
}

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

int BW_CheckNewConnections(void)
{
  if (net_acceptsocket == 0)
    return -1;

  // see if there's anything waiting
  regs.x.ax = 0x4406;
  regs.x.bx = net_acceptsocket;
  dos_int86(0x21);
  if (regs.x.ax == 0)
    return -1;
  return net_acceptsocket;
}

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

int BW_Read(int s, byte *buf, int len, struct qsockaddr *from)
{
  BW_UDPreadInfo1_t *info1;
  BW_UDPreadInfo2_t *info2;

  // ask if there's anything waiting
  regs.x.ax = 0x4406;
  regs.x.bx = s;
  dos_int86(0x21);
  if (regs.x.ax == 0)
    return 0;

  // there was, so let's get it
  regs.h.ah = 0x3f;
  regs.x.cx = /* len + 53 */ LOWMEM_SIZE;
  regs.x.es = regs.x.ds = lowmem_bufseg;
  regs.x.dx = lowmem_bufoff;
  regs.x.bx = s;
  if (dos_int86(0x21))
  {
    Con_Printf("BW UDP read error: %u\n", BW_TranslateError(regs.x.ax));
    return -1;
  }

  info1 = (BW_UDPreadInfo1_t *)lowmem_buffer;
  info2 = (BW_UDPreadInfo2_t *)(lowmem_buffer + info1->info2Offset);

  if (from)
  {
    from->sa_family = AF_INET;
    ((struct sockaddr_in *)from)->sin_addr = info1->remoteAddr;
    ((struct sockaddr_in *)from)->sin_port = htons(info2->remotePort);
  }

  len = info2->dataLenPlus8 - 8;
  if (len > NET_DATAGRAMSIZE)
  {
    Con_Printf("BW UDP read packet too large: %u\n", len);
    return -1;
  }
  Q_memcpy(buf, info2->data, len);

  return len;
}

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

int BW_Broadcast(int s, byte *msg, int len)
{
  BW_writeInfo_t *writeInfo;

  // ask if we're clear to send
  regs.x.ax = 0x4407;
  regs.x.bx = s;
  dos_int86(0x21);
  if (regs.x.ax == 0)
    return 0;

  // yes, let's do it
  writeInfo = (BW_writeInfo_t *)lowmem_buffer;
  writeInfo->remoteAddr = bcastaddr;
  writeInfo->remotePort = net_hostport;
  writeInfo->dataLen = len;
  if (len > NET_DATAGRAMSIZE)
    Sys_Error("BW UDP write packet too large: %u\n", len);
  Q_memcpy(writeInfo->data, msg, len);
  writeInfo->data[len] = 0;
  regs.h.ah = 0x40;
  regs.x.bx = s;
  regs.x.cx = len + sizeof(BW_writeInfo_t);
  regs.x.es = regs.x.ds = lowmem_bufseg;
  regs.x.dx = lowmem_bufoff;
  if (dos_int86(0x21))
  {
    Con_Printf("BW_Broadcast failed: %u\n", BW_TranslateError(regs.x.ax));
    return -1;
  }

  return len;
}

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

int BW_Write(int s, byte *msg, int len, struct qsockaddr *to)
{
  BW_writeInfo_t *writeInfo;

  // ask if we're clear to send
  regs.x.ax = 0x4407;
  regs.x.bx = s;
  dos_int86(0x21);
  if (regs.x.ax == 0)
    return 0;

  // yes, let's do it
  writeInfo = (BW_writeInfo_t *)lowmem_buffer;
  writeInfo->remoteAddr = ((struct sockaddr_in *)to)->sin_addr;
  writeInfo->remotePort = ntohs(((struct sockaddr_in *)to)->sin_port);
  writeInfo->dataLen = len;
  if (len > NET_DATAGRAMSIZE)
    Sys_Error("BW UDP write packet too large: %u\n", len);
  Q_memcpy(writeInfo->data, msg, len);
  writeInfo->data[len] = 0;
  regs.h.ah = 0x40;
  regs.x.bx = s;
  regs.x.cx = len + sizeof(BW_writeInfo_t);
  regs.x.es = regs.x.ds = lowmem_bufseg;
  regs.x.dx = lowmem_bufoff;
  if (dos_int86(0x21))
  {
    Con_Printf("BW_Write failed: %u\n", BW_TranslateError(regs.x.ax));
    return -1;
  }

  return len;
}

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


char *BW_AddrToString (struct qsockaddr *addr)
{
  static char buffer[22];

  sprintf(buffer, "%d.%d.%d.%d:%d",
    ((struct sockaddr_in *)addr)->sin_addr.s_net,
    ((struct sockaddr_in *)addr)->sin_addr.s_host,
    ((struct sockaddr_in *)addr)->sin_addr.s_lh,
    ((struct sockaddr_in *)addr)->sin_addr.s_impno,
    ntohs(((struct sockaddr_in *)addr)->sin_port)
    );
  return buffer;
}

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

int BW_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->sa_family = AF_INET;
  ((struct sockaddr_in *)addr)->sin_addr.s_addr = htonl(ipaddr);
  ((struct sockaddr_in *)addr)->sin_port = htons((short)hp);
  return 0;
}

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

int BW_GetSocketAddr (int socket, struct qsockaddr *addr)
{
  regs.x.ax = 0x4402;
  regs.x.bx = socket;
  regs.x.cx = sizeof(BW_UDPinfo_t);
  regs.x.dx = lowmem_bufoff;
  regs.x.ds = lowmem_bufseg;
  dos_int86(0x21);

  addr->sa_family = AF_INET;
  ((struct sockaddr_in *)addr)->sin_addr.s_addr = ((BW_UDPinfo_t *)lowmem_buffer)->localAddr.s_addr;
  ((struct sockaddr_in *)addr)->sin_port = htons(((BW_UDPinfo_t *)lowmem_buffer)->localPort);

  return 0;
}

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

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

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

int BW_GetAddrFromName (char *name, struct qsockaddr *hostaddr)
{
  char buff[MAXHOSTNAMELEN];
  char *b;
  int addr;
  int num;
  int mask;
  int run;
  int port;

  if (name[0] < '0' || name[0] > '9')
    return -1;

  buff[0] = '.';
  b = buff;
  Q_strcpy(buff+1, name);
  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;
  }
  addr = htonl(addr);
  mask = htonl(mask);

  if (*b++ == ':')
    port = Q_atoi(b);
  else
    port = net_hostport;

  hostaddr->sa_family = AF_INET;
  ((struct sockaddr_in *)hostaddr)->sin_port = htons((short)port);  
  ((struct sockaddr_in *)hostaddr)->sin_addr.s_addr =
  ((ethdevinfo.inetAddr & mask) | addr);

  return 0;
}

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

int BW_AddrCompare (struct qsockaddr *addr1, struct qsockaddr *addr2)
{
  if (addr1->sa_family != addr2->sa_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 BW_GetSocketPort (struct qsockaddr *addr)
{
  return ntohs(((struct sockaddr_in *)addr)->sin_port);
}


int BW_SetSocketPort (struct qsockaddr *addr, int port)
{
  ((struct sockaddr_in *)addr)->sin_port = htons(port);
  return 0;
}

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