workbench/c/Lock.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Lock - Set the write protect status of a device.
   6     Lang: english
   7 */
   8
   9 /**************************************************************************
  10
  11     NAME
  12         Lock
  13
  14     FORMAT
  15         Lock <drive> [ON|OFF] [<passkey>]
  16
  17     SYNOPSIS
  18         DRIVE/A,ON/S,OFF/S,PASSKEY
  19
  20     LOCATION
  21         C:
  22
  23     FUNCTION
  24         Lock will cause the specified device or partition to be made write-
  25         protected or write-enabled. This write protection is a soft write
  26         protection which is handled by the volume filesystem. Hence the
  27         protection will be reset (to writable) on the next system reboot.
  28
  29         It is possible to specify an optional passkey which can be used to
  30         password protect the locking. The same passkey that is used to lock
  31         the volume must be used to unlock the volume. The passkey may be
  32         any number of characters in length.
  33
  34         The volume given MUST be the device or root volume name, not an
  35         assign.
  36
  37     EXAMPLE
  38
  39         1.SYS:> Lock Work:
  40
  41             This will lock the volume called Work: without a passkey.
  42
  43         1.SYS:> Lock Work:
  44         1.SYS:> MakeDir Work:SomeDir
  45         Can't create directory Work:Test
  46         MakeDir: Disk is write-protected
  47
  48             The volume Work: is locked, so it is impossible to create a
  49             directory.
  50
  51         1.SYS:> Lock Work: OFF
  52
  53             This will unlock the volume work.
  54
  55         1.SYS:> Lock Work: MyPassword
  56
  57             This will lock Work: with the passkey "MyPassword"
  58
  59 **************************************************************************/
  60 #define DEBUG 0
  61 #include <aros/debug.h>
  62
  63 #include <exec/types.h>
  64 #include <exec/memory.h>
  65 #include <dos/dosextens.h>
  66 #include <dos/rdargs.h>
  67 #include <proto/exec.h>
  68 #include <proto/dos.h>
  69 #include <utility/tagitem.h>
  70
  71 #define ARG_TEMPLATE    "DRIVE/A,ON/S,OFF/S,PASSKEY"
  72 #define ARG_DRIVE       0
  73 #define ARG_ON          1
  74 #define ARG_OFF         2
  75 #define ARG_PASSKEY     3
  76 #define TOTAL_ARGS      4
  77
  78 const TEXT version[] = "$VER: Lock 41.3 (7.12.2011)";
  79 static const char exthelp[] =
  80     "Lock : Set the write-protect state of a volume\n"
  81     "\tDRIVE/A   The name of the volume to lock\n"
  82     "\tON/S      Turn write protect on\n"
  83     "\tOFF/S     Turn write protect off\n"
  84     "\tPASSKEY   The password string for the lock (optional)\n";
  85
  86 BOOL lockDevice(struct DevProc *dvp, ULONG key)
  87 {
  88     return DoPkt(dvp->dvp_Port, ACTION_WRITE_PROTECT, DOSTRUE, key, 0, 0, 0);
  89 }
  90
  91 BOOL unlockDevice(struct DevProc *dvp, ULONG key)
  92 {
  93     return DoPkt(dvp->dvp_Port, ACTION_WRITE_PROTECT, DOSFALSE, key, 0, 0, 0);
  94 }
  95
  96 /* Perl's hash() algorithm
  97  */
  98 #define HASH_MULTIPLIER 33
  99
 100 ULONG Hash(CONST_STRPTR key)
 101 {
 102     ULONG hash;
 103
 104     if (key == 0 || key[0] == 0)
 105        return 0;
 106
 107     for (hash = 0; *key; key++)
 108         hash = HASH_MULTIPLIER * hash + *key;
 109
 110     /* Improve distribution of low-order bits */
 111     hash += (hash >> 5);
 112
 113     return hash;
 114 }
 115
 116 int __nocommandline;
 117
 118 int main(void)
 119 {
 120     struct RDArgs *rd, *rda = NULL;
 121     IPTR args[TOTAL_ARGS] = { 0, FALSE, FALSE, 0 };
 122     struct DevProc *dp;
 123     int error = 0;
 124
 125     if((rda = AllocDosObject(DOS_RDARGS, NULL)))
 126     {
 127         rda->RDA_ExtHelp = (STRPTR)exthelp;
 128         if((rd = ReadArgs(ARG_TEMPLATE, args, NULL)))
 129         {
 130             /* Firstly, find out the volume */
 131             dp = GetDeviceProc((STRPTR)args[ARG_DRIVE], NULL);
 132
 133             if(    dp == NULL || dp->dvp_DevNode == NULL
 134                 || (   dp->dvp_DevNode->dol_Type != DLT_DEVICE
 135                     && dp->dvp_DevNode->dol_Type != DLT_VOLUME )
 136             )
 137             {
 138                 if( dp != NULL )
 139                     error = ERROR_OBJECT_WRONG_TYPE;
 140                 else
 141                     error = IoErr();
 142             }
 143             else
 144             {
 145                 /* First of find out current state. */
 146                 if (args[ARG_ON] && args[ARG_OFF])
 147                 {
 148                         /* Both are set? */
 149                         error = ERROR_TOO_MANY_ARGS;
 150                 }
 151                 else if (args[ARG_OFF])
 152                 {
 153                     error = unlockDevice(dp, Hash((CONST_STRPTR)args[ARG_PASSKEY])) ? IoErr() : 0;
 154                 }
 155                 else
 156                 {
 157                     error = lockDevice(dp, Hash((CONST_STRPTR)args[ARG_PASSKEY])) ? IoErr() : 0;
 158                 }
 159             }
 160
 161             if( dp )
 162                 FreeDeviceProc(dp);
 163
 164             FreeArgs(rd);
 165         } /* if( ReadArgs() ) */
 166         else
 167             error = IoErr();
 168
 169         FreeDosObject(DOS_RDARGS, rda);
 170     } /* if( AllocDosObject() ) */
 171     else
 172         error = ERROR_NO_FREE_STORE;
 173
 174     if( error != 0 )
 175     {
 176         PrintFault(error, "Lock");
 177         return RETURN_FAIL;
 178     }
 179
 180     SetIoErr(0);
 181     return 0;
 182 }