/*
 * Written: 10/29/93 by Tim Bird (original code)
 * All modifications in this file to the original code are
 * (C) Copyright 1992, ..., 2007 the "DOSEMU-Development-Team".
 *
 * for details see file COPYING.DOSEMU in the DOSEMU distribution
 */

/***********************************************
 * File: LREDIR.C
 *  Program for Linux DOSEMU disk redirector functions
 * Fixes: 1/7/95 by Tim Josling TEJ: check correct # args
 *      :                            display read/write status correctly
 * Changes: 3/19/95 by Kang-Jin Lee
 *  Removed unused variables
 *  Changes to eliminate warnings
 *  Display read/write status when redirecting drive
 *  Usage information is more verbose
 *
 * Changes: 11/27/97 Hans Lermen
 *  new detection stuff,
 *  rewrote to use plain C and intr(), instead of asm and fiddling with
 *  (maybe used) machine registers.
 *
 * Changes: 990703 Hans Lermen
 *  Checking for DosC and exiting with error, if not redirector capable.
 *  Printing DOS errors in clear text.
 *
 * Changes: 010211 Bart Oldeman
 *   Make it possible to "reredirect": LREDIR drive filepath
 *   can overwrite the direction for the drive.
 *
 * NOTES:
 *  LREDIR supports the following commands:
 *  LREDIR drive filepath
 *    redirects the indicated drive to the specified linux filepath
 *    drive = the drive letter followed by a colon (ex. 'E:')
 *    filepath has linux, fs and a file path (ex. 'LINUX\FS\USR\SRC')
 *  LREDIR DEL drive
 *    cancels redirection of the indicated drive
 *  LREDIR
 *    shows drives that are currently redirected (mapped)
 *  LREDIR HELP or LREDIR ?
 *    show usage information for LREDIR
 ***********************************************/


#include <ctype.h>    /* toupper */
#include <dos.h>      /* geninterrupt and MK_FP */
#include <stdio.h>    /* printf  */
#include <stdlib.h>   /* exit    */
#include <string.h>
#include "detect.h"

typedef unsigned char uint8;
typedef unsigned int uint16;

#define CARRY_FLAG    1 /* carry bit in flags register */
#define CC_SUCCESS    0

#define DOS_GET_LIST_OF_LISTS  0x5200
#define DOS_GET_SDA_POINTER    0x5D06
#define DOS_GET_REDIRECTION    0x5F02
#define DOS_REDIRECT_DEVICE    0x5F03
#define DOS_CANCEL_REDIRECTION 0x5F04

#define MAX_RESOURCE_STRING_LENGTH  36  /* 16 + 16 + 3 for slashes + 1 for NULL */
#define MAX_RESOURCE_PATH_LENGTH   128  /* added to support Linux paths */
#define MAX_DEVICE_STRING_LENGTH     5  /* enough for printer strings */

#define REDIR_PRINTER_TYPE    3
#define REDIR_DISK_TYPE       4

#define READ_ONLY_DRIVE_ATTRIBUTE 1  /* same as NetWare Lite */

#define KEYWORD_DEL   "DELETE"
#define KEYWORD_DEL_COMPARE_LENGTH  3

#define DEFAULT_REDIR_PARAM   0

#define DOS_HELPER_INT          0xE6

#define MAX_DOSERROR		0x5A
static char *DOSerrcodes[MAX_DOSERROR+1] = {
  /* the below error list is shamelessly stolen from Ralph Brown's */
  /* 0x00 */  "no error",
#if 0
  /* 0x01 */  "function number invalid",
#else
  /* 0x01 */  "invalid argument",
#endif
  /* 0x02 */  "file not found",
  /* 0x03 */  "path not found",
  /* 0x04 */  "too many open files",
  /* 0x05 */  "access denied",
  /* 0x06 */  "invalid handle",
  /* 0x07 */  "memory control block destroyed",
  /* 0x08 */  "insufficient memory",
  /* 0x09 */  "memory block address invalid",
  /* 0x0A */  "environment invalid",
  /* 0x0B */  "format invalid",
  /* 0x0C */  "access code invalid",
  /* 0x0D */  "data invalid",
  /* 0x0E */  0,
  /* 0x0F */  "invalid drive",
  /* 0x10 */  "attempted to remove current directory",
  /* 0x11 */  "not same device",
  /* 0x12 */  "no more files",
  /* 0x13 */  "disk write-protected",
  /* 0x14 */  "unknown unit",
  /* 0x15 */  "drive not ready",
  /* 0x16 */  "unknown command",
  /* 0x17 */  "data error (CRC)",
  /* 0x18 */  "bad request structure length",
  /* 0x19 */  "seek error",
  /* 0x1A */  "unknown media type",
  /* 0x1B */  "sector not found",
  /* 0x1C */  "printer out of paper",
  /* 0x1D */  "write fault",
  /* 0x1E */  "read fault",
  /* 0x1F */  "general failure",
  /* 0x20 */  "sharing violation",
  /* 0x21 */  "lock violation",
  /* 0x22 */  "disk change invalid",
  /* 0x23 */  "FCB unavailable",
  /* 0x24 */  "sharing buffer overflow",
  /* 0x25 */  "code page mismatch",
  /* 0x26 */  "cannot complete file operation (out of input)",
  /* 0x27 */  "insufficient disk space",
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  /* 0x32 */  "network request not supported",
  /* 0x33 */  "remote computer not listening",
  /* 0x34 */  "duplicate name on network",
  /* 0x35 */  "network name not found",
  /* 0x36 */  "network busy",
  /* 0x37 */  "network device no longer exists",
  /* 0x38 */  "network BIOS command limit exceeded",
  /* 0x39 */  "network adapter hardware error",
  /* 0x3A */  "incorrect response from network",
  /* 0x3B */  "unexpected network error",
  /* 0x3C */  "incompatible remote adapter",
  /* 0x3D */  "print queue full",
  /* 0x3E */  "queue not full",
  /* 0x3F */  "not enough space to print file",
  /* 0x40 */  "network name was deleted",
  /* 0x41 */  "network: Access denied",
  /* 0x42 */  "network device type incorrect",
  /* 0x43 */  "network name not found",
  /* 0x44 */  "network name limit exceeded",
  /* 0x45 */  "network BIOS session limit exceeded",
  /* 0x46 */  "temporarily paused",
  /* 0x47 */  "network request not accepted",
  /* 0x48 */  "network print/disk redirection paused",
  /* 0x49 */  "network software not installed",
  /* 0x4A */  "unexpected adapter close",
  /* 0x4B */  "password expired",
  /* 0x4C */  "login attempt invalid at this time",
  /* 0x4D */  "disk limit exceeded on network node",
  /* 0x4E */  "not logged in to network node",
  /* 0x4F */  0,
  /* 0x50 */  "file exists",
  /* 0x51 */  0,
  /* 0x52 */  "cannot make directory",
  /* 0x53 */  "fail on INT 24h",
  /* 0x54 */  "too many redirections",
  /* 0x55 */  "duplicate redirection",
  /* 0x56 */  "invalid password",
  /* 0x57 */  "invalid parameter",
  /* 0x58 */  "network write fault",
  /* 0x59 */  "function not supported on network",
  /* 0x5A */  "required system component not installed"

#if 0 /* the below won't happen here */
   0, 0, 0, 0, 0, 0, 0, 0, 0,
  /* 0x64 */  "(MSCDEX) unknown error",
  /* 0x65 */  "(MSCDEX) not ready",
  /* 0x66 */  "(MSCDEX) EMS memory no longer valid",
  /* 0x67 */  "(MSCDEX) not High Sierra or ISO-9660 format",
  /* 0x68 */  "(MSCDEX) door open",
#endif
};

static char * decode_DOS_error(uint16 errcode)
{
    static char *unknown = "unknown error";
    if (errcode > MAX_DOSERROR) return unknown;
    if (!DOSerrcodes[errcode]) return unknown;
    return DOSerrcodes[errcode];
}

char far *
GetListOfLists(void)
{
    char far *LOL;
    struct REGPACK preg;

    preg.r_ax = DOS_GET_LIST_OF_LISTS;
    intr(0x21, &preg);
    LOL = MK_FP(preg.r_es, preg.r_bx);
    return (LOL);
}

char far *
GetSDAPointer(void)
{
    char far *SDA;
    struct REGPACK preg;

    preg.r_ax = DOS_GET_SDA_POINTER;
    intr(0x21, &preg);
    SDA = MK_FP(preg.r_ds, preg.r_si);

    return (SDA);
}

/********************************************
 * InitMFS - call Emulator to initialize MFS
 ********************************************/
/* tej - changed return type to void as nothing returned */
void InitMFS(void)
{
    char far *LOL;
    char far *SDA;
    struct REGPACK preg;

    LOL = GetListOfLists();
    SDA = GetSDAPointer();

    /* get DOS version into CX */
    preg.r_cx = _osmajor | (_osminor <<8);

    preg.r_dx = FP_OFF(LOL);
    preg.r_es = FP_SEG(LOL);
    preg.r_si = FP_OFF(SDA);
    preg.r_ds = FP_SEG(SDA);
    preg.r_bx = 0x500;
    preg.r_ax = 0x20;
    intr(DOS_HELPER_INT, &preg);
}

/********************************************
 * RedirectDevice - redirect a device to a remote resource
 * ON ENTRY:
 *  deviceStr has a string with the device name:
 *    either disk or printer (ex. 'D:' or 'LPT1')
 *  resourceStr has a string with the server and name of resource
 *    (ex. 'TIM\TOOLS')
 *  deviceType indicates the type of device being redirected
 *    3 = printer, 4 = disk
 *  deviceParameter is a value to be saved with this redirection
 *  which will be returned on GetRedirectionList
 * ON EXIT:
 *  returns CC_SUCCESS if the operation was successful,
 *  otherwise returns the DOS error code
 * NOTES:
 *  deviceParameter is used in DOSEMU to return the drive attribute
 *  It is not actually saved and returned as specified by the redirector
 *  specification.  This type of usage is common among commercial redirectors.
 ********************************************/
uint16 RedirectDevice(char *deviceStr, char *resourceStr, uint8 deviceType,
                      uint16 deviceParameter)
{
    char slashedResourceStr[MAX_RESOURCE_PATH_LENGTH];
    struct REGPACK preg;

    /* prepend the resource string with slashes */
    strcpy(slashedResourceStr, "\\\\");
    strcat(slashedResourceStr, resourceStr);

    /* should verify strings before sending them down ??? */
    preg.r_ds = FP_SEG(deviceStr);
    preg.r_si = FP_OFF(deviceStr);
    preg.r_es = FP_SEG(slashedResourceStr);
    preg.r_di = FP_OFF(slashedResourceStr);
    preg.r_cx = deviceParameter;
    preg.r_bx = deviceType;
    preg.r_ax = DOS_REDIRECT_DEVICE;
    intr(0x21, &preg);

    if (preg.r_flags & CARRY_FLAG) {
      return (preg.r_ax);
    }
    else {
      return (CC_SUCCESS);
    }
}

/********************************************
 * GetRedirection - get next entry from list of redirected devices
 * ON ENTRY:
 *  redirIndex has the index of the next device to return
 *    this should start at 0, and be incremented between calls
 *    to retrieve all elements of the redirection list
 * ON EXIT:
 *  returns CC_SUCCESS if the operation was successful, and
 *  deviceStr has a string with the device name:
 *    either disk or printer (ex. 'D:' or 'LPT1')
 *  resourceStr has a string with the server and name of resource
 *    (ex. 'TIM\TOOLS')
 *  deviceType indicates the type of device which was redirected
 *    3 = printer, 4 = disk
 *  deviceParameter has my rights to this resource
 * NOTES:
 *
 ********************************************/
uint16 GetRedirection(uint16 redirIndex, char *deviceStr, char *resourceStr,
                      uint8 * deviceType, uint16 * deviceParameter)
{
    uint16 ccode;
    uint8 deviceTypeTemp;
    char slashedResourceStr[MAX_RESOURCE_PATH_LENGTH];
    struct REGPACK preg;

    preg.r_ds = FP_SEG(deviceStr);
    preg.r_si = FP_OFF(deviceStr);
    preg.r_es = FP_SEG(slashedResourceStr);
    preg.r_di = FP_OFF(slashedResourceStr);
    preg.r_bx = redirIndex;
    preg.r_ax = DOS_GET_REDIRECTION;
    intr(0x21, &preg);

    ccode = preg.r_ax;
    deviceTypeTemp = preg.r_bx & 0xff;       /* save device type before C ruins it */
    *deviceType = deviceTypeTemp;
    *deviceParameter = preg.r_cx;

    /* copy back unslashed portion of resource string */
    if (preg.r_flags & CARRY_FLAG) {
      return (ccode);
    }
    else {
      /* eat the leading slashes */
      strcpy(resourceStr, slashedResourceStr + 2);
      return (CC_SUCCESS);
    }
}

/********************************************
 * CancelRedirection - delete a device mapped to a remote resource
 * ON ENTRY:
 *  deviceStr has a string with the device name:
 *    either disk or printer (ex. 'D:' or 'LPT1')
 * ON EXIT:
 *  returns CC_SUCCESS if the operation was successful,
 *  otherwise returns the DOS error code
 * NOTES:
 *
 ********************************************/
uint16 CancelRedirection(char *deviceStr)
{
    struct REGPACK preg;

    preg.r_ds = FP_SEG(deviceStr);
    preg.r_si = FP_OFF(deviceStr);
    preg.r_ax = DOS_CANCEL_REDIRECTION;
    intr(0x21, &preg);

    if (preg.r_flags & CARRY_FLAG) {
      return (preg.r_ax);
    }
    else {
      return (CC_SUCCESS);
    }
}

/*************************************
 * ShowMyRedirections
 *  show my current drive redirections
 * NOTES:
 *  I show the read-only attribute for each drive
 *    which is returned in deviceParam.
 *************************************/
void
ShowMyRedirections(void)
{
    int driveCount;
    uint16 redirIndex, deviceParam, ccode;
    uint8 deviceType;

    char deviceStr[MAX_DEVICE_STRING_LENGTH];
    char resourceStr[MAX_RESOURCE_PATH_LENGTH];

    redirIndex = 0;
    driveCount = 0;

    ccode = GetRedirection(redirIndex, deviceStr, resourceStr,
                           &deviceType, &deviceParam);

    while (ccode == CC_SUCCESS) {
      /* only print disk redirections here */
      if (deviceType == REDIR_DISK_TYPE) {
        if (driveCount == 0) {
          printf("Current Drive Redirections:\n");
        }
        driveCount++;
        printf("%-2s = %-20s ", deviceStr, resourceStr);

        /* read attribute is returned in the device parameter */
        if (deviceParam & 0x80) {
          switch (deviceParam & 0x7f) { /* tej 1/7/95 */
            case READ_ONLY_DRIVE_ATTRIBUTE:
              printf("attrib = READ ONLY\n");
              break;
            default:
              printf("attrib = READ/WRITE\n");
              break;
          }
        }
      }

      redirIndex++;
      ccode = GetRedirection(redirIndex, deviceStr, resourceStr,
                             &deviceType, &deviceParam);
    }

    if (driveCount == 0) {
      printf("No drives are currently redirected to Linux.\n");
    }
}

void
DeleteDriveRedirection(char *deviceStr)
{
    uint16 ccode;

    /* convert device string to upper case */
    strupr(deviceStr);
    ccode = CancelRedirection(deviceStr);
    if (ccode) {
      printf("Error %x (%s)\ncanceling redirection on drive %s\n",
             ccode, decode_DOS_error(ccode), deviceStr);
      }
    else {
      printf("Redirection for drive %s was deleted.\n", deviceStr);
    }
}

/********************************************
 * Check wether we are running DosC (FreeDos)
 * and check wether this version can cope with redirection
 * ON ENTRY:
 *  nothing
 * ON EXIT:
 *  returns 0 if not running DosC
 *  otherwise returns the DosC 'build' number
 *
 ********************************************/
uint16 CheckForDosc(void)
{
    struct REGPACK preg;

    preg.r_ax = 0xdddc;
    intr(0xe6, &preg);

    if (preg.r_ax == 0xdddc) {
      return 0;
    }
    else {
      return (preg.r_bx);
    }
}

main(int argc, char **argv)
{
    uint16 ccode;
    uint16 deviceParam;
    unsigned long dversion;

    char deviceStr[MAX_DEVICE_STRING_LENGTH];
    char resourceStr[MAX_RESOURCE_PATH_LENGTH];

    if ((dversion = is_dosemu()) == 0) {
      printf("This program requires DOSEMU to run, aborting\n");
      exit(1);
    }

#define D98min	((98UL << 16) | (7 << 8) | 1)
#define D99min  ((99UL << 16) | (12 << 8) | 1)

    if (((dversion >= D98min) && (dversion < (99UL << 16)))
                                        || (dversion >= D99min)) {
      if ((ccode = CheckForDosc()) != 0) {
        if (ccode <= 1937) {
          printf("You are running the FreeDos kernel.\n"
                 "This has no support for lredir, aborting\n");
          exit(1);
        }
      }
    }

    /* initialize the MFS, just in case the user didn't run EMUFS.SYS */
    InitMFS();

    /* need to parse the command line */
    /* if no parameters, then just show current mappings */
    if (argc == 1) {
      ShowMyRedirections();
      exit(0);
    }

    /* tej one parm is either error or HELP/-help etc */
    if (argc == 2) {
      printf("Usage: LREDIR [drive: LINUX\\FS\\path [R] | HELP]\n");
      printf("Redirect a drive to the Linux file system.\n\n");
      printf("LREDIR X: LINUX\\FS\\tmp\n");
      printf("  Redirect drive X: to /tmp of Linux file system for read/write\n");
      printf("  If R is specified, the drive will be read-only\n");
      printf("  ${home} represents user's home directory\n\n");
      printf("LREDIR DEL drive:\n");
      printf("  delete a drive redirection\n\n");
      printf("LREDIR\n");
      printf("  show current drive redirections\n\n");
      printf("LREDIR HELP\n");
      printf("  show this help screen\n");
      exit(0);
    }

    if (strncmpi(argv[1], KEYWORD_DEL, KEYWORD_DEL_COMPARE_LENGTH) == 0) {
      DeleteDriveRedirection(argv[2]);
      exit(0);
    }

    /* assume the command is to redirect a drive */
    /* read the drive letter and resource string */
    strcpy(deviceStr, argv[1]);
    strcpy(resourceStr, argv[2]);
    deviceParam = DEFAULT_REDIR_PARAM;

    if (argc > 3) {
      if (toupper(argv[3][0]) == 'R') {
        deviceParam = 1;
      }
    }

    /* upper-case both strings */
    strupr(deviceStr);
    strupr(resourceStr);

    /* now actually redirect the drive */
    ccode = RedirectDevice(deviceStr, resourceStr, REDIR_DISK_TYPE,
                           deviceParam);

    /* duplicate redirection: try to reredirect */
    if (ccode == 0x55) {
      DeleteDriveRedirection(deviceStr);     
      ccode = RedirectDevice(deviceStr, resourceStr, REDIR_DISK_TYPE,
                             deviceParam);
    }

    if (ccode) {
      printf("Error %x (%s)\nwhile redirecting drive %s to %s\n",
             ccode, decode_DOS_error(ccode), deviceStr, resourceStr);
      goto MainExit;
    }

    printf("%s = %s  attrib = ", deviceStr, resourceStr);
    switch (deviceParam) {
      case READ_ONLY_DRIVE_ATTRIBUTE:
        printf("READ ONLY\n");
        break;
      default:
        printf("READ/WRITE\n");
        break;
    }

MainExit:
    return (ccode);
}
