Date: Sun, 12 May 1996 10:47:21 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
To: djgpp-workers AT delorie DOT com
Subject: Patches to mntent.c
Message-Id: <Pine.SUN.3.91.960512104452.25890A-100000@is>
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII

The following patches fix 2 bugs, add support for Jam disk comression 
software, and augment the `mntent' docs.

*** compat/mntent/mntent.c~1	Sun Feb  4 19:36:02 1996
--- compat/mntent/mntent.c	Fri May 10 18:21:04 1996
*************** static          char dev_opts[] = "r ,de
*** 72,77 ****
--- 72,78 ----
  
  static char NAME_dblsp[] = "dblsp";
  static char NAME_stac[] = "stac";
+ static char NAME_jam[] = "jam";
  static char NAME_ram[] = "ram";
  static char NAME_cdrom[] = "cdrom";
  static char NAME_net[] = "net";
*************** static char NAME_fd[] = "fd";
*** 79,84 ****
--- 80,86 ----
  static char NAME_hd[] = "hd";
  static char NAME_subst[] = "subst";
  static char NAME_join[] = "join";
+ static char NAME_unknown[] = "???";
  
  int _is_remote_drive(int);
  
*************** get_stacker_info(int drive_num)
*** 179,184 ****
--- 181,187 ----
  {
    __dpmi_regs r;
    unsigned long stac_driver_ptr;
+   unsigned char seq, host;
  
    /* Put a known DWORD into the Transfer Buffer.  If this drive
       isn't compressed with Stacker, it will remain unchanged.  */
*************** get_stacker_info(int drive_num)
*** 201,228 ****
  
    /* Sanity check: real-mode addresses are only 20 bit-long, so we can
       safely reject anything that's larger than FFFFFh, lest we get an
!      illegal address abort when we try to peek at the signature below.  */
!   if (stac_driver_ptr > 0xfffff)
      return 0;
  
    /* Stacker Anywhere returns pointer to 1 byte before the A55Ah
       signature (which is at offset 1Ah), while all other versions
       of Stacker point to the signature itself.  */
!   if (_farpeekw(dos_mem_base,   stac_driver_ptr) == 0xa55a ||
!       _farpeekw(dos_mem_base, ++stac_driver_ptr) == 0xa55a)
!     {
!       /* We have indeed Stacker device driver.  Get the volume
!          number (at offset 58h) and host drive (from the 26-byte
!          table beginning at offset 70h).  */
!       unsigned char seq  = _farpeekb(dos_mem_base, stac_driver_ptr + 0x3e);
!       unsigned char host = _farpeekb(dos_mem_base,
!                                      stac_driver_ptr + 0x55 + drive_num);
  
!       sprintf(mnt_fsname, "%c:\\STACVOL.%03u", 'A' + host, seq);
!       mnt_type = NAME_stac;
!       return 1;
!     }
!   return 0;
  }
  
  /*
--- 204,289 ----
  
    /* Sanity check: real-mode addresses are only 20 bit-long, so we can
       safely reject anything that's larger than FFFFFh, lest we get an
!      illegal address abort when we try to peek at the signature below.
!      Actually, it's enough to test for (FFFFFh - 55h - drive), because
!      we need to get the host drive number at that offset. */
!   if (stac_driver_ptr > 0x0000fffaa - drive_num)
      return 0;
  
    /* Stacker Anywhere returns pointer to 1 byte before the A55Ah
       signature (which is at offset 1Ah), while all other versions
       of Stacker point to the signature itself.  */
!   if (_farpeekw(dos_mem_base,   stac_driver_ptr) != 0xa55a &&
!       _farpeekw(dos_mem_base, ++stac_driver_ptr) != 0xa55a)
!     return 0;
!   stac_driver_ptr -= 0x1a; /* start of the device driver */
  
!   /* Check for the "SWAP" signature.  */                /*  P A W S  */
!   if (_farpeekl(dos_mem_base, stac_driver_ptr + 0x6c) != 0x50415753)
!     return 0;
! 
!   /* We have indeed Stacker device driver.  Get the volume
!      number (at offset 58h) and host drive (from the 26-byte
!      table beginning at offset 70h).  */
!   seq  = _farpeekb(dos_mem_base, stac_driver_ptr + 0x58);
!   host = _farpeekb(dos_mem_base, stac_driver_ptr + 0x70 + drive_num - 1);
!   sprintf(mnt_fsname, "%c:\\STACVOL.%03u", 'A' + host, seq);
!   mnt_type = NAME_stac;
!   return 1;
! }
! 
! /*
!  * For a drive compressed with Jam, get the full file name of
!  * the compressed archive file, fill MNT_FSNAME[] with its
!  * name and return non-zero.  If this drive isn't controlled by
!  * Jam, return 0.
!  *
!  * (JAM is a shareware disk compressor software.)
!  *
!  * Contributed by Markus F.X.J. Oberhumer <markus DOT oberhumer AT jk DOT uni-linz DOT ac DOT at>
!  */
! static int
! get_jam_info(int drive_num)
! {
!   __dpmi_regs r;
!   unsigned jam_version, offset;
! 
!   r.x.ax = 0x5200;              /* Jam Get Version */
!   __dpmi_int(0x2f, &r);
!   if (r.h.ah != 0x80)           /* JAM.SYS is not installed */
!     return 0;
!   jam_version = r.x.bx;         /* v1.25 == 0x125 */
!   if (jam_version < 0x110)      /* version sanity check */
!     return 0;
!   /* Sanity check of the size of the JAMINFO structure.  */
!   if (r.x.cx < 0x115 || r.x.cx > _go32_info_block.size_of_transfer_buffer)
!     return 0;
!   if (jam_version >= 0x120 && r.x.cx < 0x124)
!     return 0;
! 
!   r.x.ax = 0x5201;              /* Jam Get Compressed Drive Information */
!   r.h.dl = drive_num;
!   r.x.ds = __tb >> 4;
!   r.x.bx = __tb & 15;
!   __dpmi_int(0x2f, &r);
!   if (r.h.ah != 0)              /* drive is not a Jam drive */
!     return 0;
! 
!   /* Check that the drive is mounted (attached).  */
!   r.h.ah = 0x32;                /* Get Device Parameter Block function */
!   r.h.dl = drive_num;
!   __dpmi_int(0x21, &r);
!   if (r.h.al != 0)              /* drive is not mounted (or other error) */
!     return 0;
!        
!   /* Copy the full name of the Jam archive file.  */
!   offset = (jam_version >= 0x120) ? 0x38 : 0x2a;
!   movedata(dos_mem_base, __tb + offset,
!            our_mem_base, (unsigned) mnt_fsname, 127);
!   mnt_fsname[127] = 0;
! 
!   mnt_type = NAME_jam;
!   return 1;
  }
  
  /*
*************** cdrom_drive_ready(int drive_num)
*** 318,324 ****
  
    /* Int 2Fh/AX=1505h (Read Volume Table Of Contents) will return
       with error for empty drives or if the disk is an AUDIO disk.  */
!   r.x.es = __tb;
    r.x.bx = __tb & 15;
    r.x.cx = drive_num - 1;   /* 0 = A: */
    r.x.dx = 0;   /* get the 1st descriptor (usually, the only one) */
--- 379,385 ----
  
    /* Int 2Fh/AX=1505h (Read Volume Table Of Contents) will return
       with error for empty drives or if the disk is an AUDIO disk.  */
!   r.x.es = __tb >> 4;
    r.x.bx = __tb & 15;
    r.x.cx = drive_num - 1;   /* 0 = A: */
    r.x.dx = 0;   /* get the 1st descriptor (usually, the only one) */
*************** is_ram_drive(int drive_num)
*** 354,362 ****
  
    if (r.h.al == 0)
      {
!       /* The pointer to DPB is in DS:DX.  The number of FAT copies is at
           offset 8 in the DPB.  */
!       char fat_copies = _farpeekb(dos_mem_base, MK_FOFF(r.x.ds, r.x.dx) + 8);
  
        return fat_copies == 1;
      }
--- 415,423 ----
  
    if (r.h.al == 0)
      {
!       /* The pointer to DPB is in DS:BX.  The number of FAT copies is at
           offset 8 in the DPB.  */
!       char fat_copies = _farpeekb(dos_mem_base, MK_FOFF(r.x.ds, r.x.bx) + 8);
  
        return fat_copies == 1;
      }
*************** setmntent(char *filename, char *type)
*** 438,444 ****
    return (FILE *) 1;
  }
  
- static char NAME_unknown[] = "???";
  struct mntent *
  getmntent(FILE *filep)
  {
--- 499,504 ----
*************** getmntent(FILE *filep)
*** 459,465 ****
    cds_drives = setdisk(0xffff);
  
    /* There may be a maximum of 32 block devices.  Novell Netware indeed
!      allows for 32 disks (A-Z plus 6 more characters from [ to ' */
    while (drive_number < 32)
      {
        unsigned char *p, *q;
--- 519,525 ----
    cds_drives = setdisk(0xffff);
  
    /* There may be a maximum of 32 block devices.  Novell Netware indeed
!      allows for 32 disks (A-Z plus 6 more characters from '[' to '\'') */
    while (drive_number < 32)
      {
        unsigned char *p, *q;
*************** getmntent(FILE *filep)
*** 524,532 ****
  
        /* For the ``File System Name'' we use one of the following:
  
!          * X:\DBLSPACE.NNN or X:\STACVOL.NNN for compressed drives,
!            where X: is the host drive of the compressed volume and NNN
!            is the volume sequence number;
           * What _truename() returns for the root directory, in case
             it isn't the usual ``X:\'';
           * The name of the volume label;
--- 584,594 ----
  
        /* For the ``File System Name'' we use one of the following:
  
!          * X:\DBLSPACE.NNN or X:\STACVOL.NNN for drives compressed with
! 	   DblSpace or Stacker, where X: is the host drive of the
! 	   compressed volume and NNN is the volume sequence number;
!          * The full filename of the compressed volume file for 
!            a drive that is compressed with Jam;
           * What _truename() returns for the root directory, in case
             it isn't the usual ``X:\'';
           * The name of the volume label;
*************** getmntent(FILE *filep)
*** 555,560 ****
--- 617,623 ----
               hd     for hard disks
               dblsp  for disks compressed with DoubleSpace
               stac   for disks compressed with Stacker
+              jam    for disks compressed with Jam
               cdrom  for CD-ROM drives
               ram    for RAM disks
               subst  for SUBSTed directories
*************** getmntent(FILE *filep)
*** 604,612 ****
              }
            else
              {
!               /* Check for DoubleSpace- or Stacker- compressed drive.  */
!               if ((got_fsname = get_doublespace_info(drive_number)) == 0)
!                 got_fsname = get_stacker_info(drive_number);
              }
          }
        /* JOINed drives fail _truename().  I don't know how to check
--- 667,677 ----
              }
            else
              {
!               /* Check for compressed drives (DoubleSpace, Stacker,
! 		 or Jam).  */
!               got_fsname = get_doublespace_info(drive_number)
! 			   || get_stacker_info(drive_number)
! 			   || get_jam_info(drive_number);
              }
          }
        /* JOINed drives fail _truename().  I don't know how to check
*************** endmntent(FILE *filep)
*** 750,758 ****
  
  #ifdef  TEST
  
  int main()
  {
!   FILE *mp = setmntent("", "r");
    struct mntent *me;
    int i = 0;
  
--- 815,831 ----
  
  #ifdef  TEST
  
+ #if defined(MNT_MNTTAB)
+ #define MNTTAB_FILE MNT_MNTTAB
+ #elif defined(MNTTABNAME)
+ #define MNTTAB_FILE MNTTABNAME
+ #else
+ #define MNTTAB_FILE "/etc/mnttab"
+ #endif
+ 
  int main()
  {
!   FILE *mp = setmntent(MNTTAB_FILE, "r");
    struct mntent *me;
    int i = 0;
  
*************** int main()
*** 763,770 ****
      }
  
    while ((me = getmntent(mp)) != NULL)
!     printf("%d:  %s\t\t%s\t%s\t%s\n", i++,
             me->mnt_fsname, me->mnt_type, me->mnt_opts, me->mnt_dir);
    return 0;
  }
  
--- 836,844 ----
      }
  
    while ((me = getmntent(mp)) != NULL)
!     printf("%d:  %-35s %s\t%s\t%s\n", i++,
             me->mnt_fsname, me->mnt_type, me->mnt_opts, me->mnt_dir);
+ 
    return 0;
  }
  
*** compat/mntent/mntent.t~0	Wed Aug 23 07:51:58 1995
--- compat/mntent/mntent.txh	Sat May  4 13:42:46 1996
***************
*** 4,22 ****
  @example
  #include <mntent.h>
  
! FILE *setmntent(char *filename, char *type);
  @end example
  
  @subheading Description
  
  This function returns an open FILE* pointer which can be used by
! getmntent (@pxref{getmntent}).
  
  @subheading Return Value
  
  The FILE* pointer is returned.  For MS-DOS, this FILE* is not a real
  pointer and may only be used by @code{getmntent}.
  
  @c ----------------------------------------------------------------------
  @node getmntent, unix
  @subheading Syntax
--- 4,43 ----
  @example
  #include <mntent.h>
  
! FILE *setmntent(char *filename, char *mode);
  @end example
  
  @subheading Description
  
  This function returns an open FILE* pointer which can be used by
! getmntent (@pxref{getmntent}).  The arguments @var{filename} and
! @var{mode} are always ignored under MS-DOS, but for portability should
! be set, accordingly, to the name of the file which describes the mounted
! filesystems and the open mode of that file (like the @var{mode} argument
! to @code{fopen}, @xref{fopen}).  (There is no single standard for the
! name of the file that keeps the mounted filesystems, but it is usually,
! although not always, listed in the header @code{<mntent.h>}.)
  
  @subheading Return Value
  
  The FILE* pointer is returned.  For MS-DOS, this FILE* is not a real
  pointer and may only be used by @code{getmntent}.
  
+ @subheading Example
+ 
+ @example
+ #include <mntent.h>
+ #if defined(MNT_MNTTAB)
+ #define MNTTAB_FILE MNT_MNTTAB
+ #elif defined(MNTTABNAME)
+ #define MNTTAB_FILE MNTTABNAME
+ #else
+ #define MNTTAB_FILE "/etc/mnttab"
+ #endif
+ 
+   FILE *mnt_fp = setmntent (MNTTAB_FILE, "r");
+ @end example
+ 
  @c ----------------------------------------------------------------------
  @node getmntent, unix
  @subheading Syntax
*************** sequence number of the Compressed Volume
*** 71,76 ****
--- 92,100 ----
  For drives compressed with Stacker, the string "X:\STACVOL.NNN", where
  ``X'' and ``NNN'' are as for DoubleSpace drives.
  
+ For drives compressed with Jam (a shareware disk compression software),
+ the full name of the Jam archive file.
+ 
  For SUBSTed drives, the actual directory name that that was SUBSTed to
  emulate a drive.
  
*************** depending on which drive letter was last
*** 97,102 ****
--- 121,127 ----
   "hd"     for hard disks
   "dblsp"  for disks compressed with DoubleSpace
   "stac"   for disks compressed with Stacker
+  "jam"    for disks compressed with Jam
   "cdrom"  for CD-ROM drives
   "ram"    for RAM disks
   "subst"  for SUBSTed directories
*************** NULL if there are no more drives to repo
*** 126,132 ****
  @example
  struct mntent *m;
  FILE *f;
! f = setmntent("", "");
  while ((m = getmntent(f)))
    printf("Drive %s, name %s\n", m->mnt_dir, m->mnt_fsname);
  endmntent(f);
--- 151,157 ----
  @example
  struct mntent *m;
  FILE *f;
! f = setmntent("/etc/mnttab", "r");
  while ((m = getmntent(f)))
    printf("Drive %s, name %s\n", m->mnt_dir, m->mnt_fsname);
  endmntent(f);