VxD/hk95c.c

   1 //// HK95c.c
   2 // --------------------------------------------
   3 // Dynamically loadable VxD for DCHOOK
   4 // --------------------------------------------
   5 #define WIN32_LEAN_AND_MEAN // Excludes un-needed parts of windows.h
   6 #include <windows.h>
   7 #include <vmm.h>
   8 #include <vwin32.h>
   9 #include <debug.h>
  10 #include "hk95d.h"
  11
  12 // -------------------------------------
  13 // Externs defined in assembly module
  14 // -------------------------------------
  15 // These defined in assembly for the VMM.INC or VPICD.INC file inclusion
  16 // ------------------------
  17 // PRAGMA for this DATA
  18 // ------------------------
  19 // Establish segment
  20 #pragma data_seg ( "_LDATA","_LCODE")
  21
  22 // ------------------------------------
  23 // Data structures MUST be INITIALIZED
  24 // ------------------------------------
  25 // ------------------------
  26 // PRAGMAS for this CODE
  27 // ------------------------
  28 // Establish segment
  29 #pragma code_seg ( "_LTEXT", "_LCODE" )
  30 //No stack checking for routines in this module
  31 #pragma check_stack(off)
  32
  33 // ---------------------------------------
  34 // Set Good Return code for DIOC requests
  35 // ---------------------------------------
  36 void _declspec(naked)GoodReturnDIOC(void)
  37 {
  38         // Clear eax and carry flag for GOOD return
  39         _asm xor eax,eax
  40         _asm clc
  41         _asm ret;
  42 }
  43
  44 // ---------------------------------------
  45 // Set Bad Return code for DIOC requests
  46 // ---------------------------------------
  47 void _declspec(naked) BadReturnDIOC(void)
  48 {
  49         // NOTE: 50 is a FCN NOT SUPPORTED code -- ok to use
  50         // SET carry flag for BAD return
  51         _asm mov eax,50
  52         _asm stc
  53         _asm ret;
  54 }
  55
  56
  57 // ------------------------------
  58 // Routine for DCHOOK Device UNINIT
  59 // ------------------------------
  60 void CHK95_Device_UNInit()
  61 {
  62         // Set GOOD return code
  63         GoodReturnDIOC();
  64         return;
  65 }
  66 // ------------------------------
  67 // Routine for DCHOOK Device INIT
  68 // ------------------------------
  69
  70 void CHK95_Device_Init()
  71 {
  72     GoodReturnDIOC();
  73 }
  74 DWORD VXDINLINE
  75 PageModPerm( DWORD Page, DWORD nPages, DWORD Flags1, DWORD Flags2 )
  76 {
  77     DWORD    dw;
  78
  79         _asm push [Flags2]
  80         _asm push [Flags1]
  81         _asm push [nPages]
  82         _asm push [Page]
  83     VMMCall( _PageModifyPermissions );
  84         _asm add esp, 10h
  85     _asm mov [dw], eax
  86
  87     return(dw);
  88 }
  89
  90 // --------------------------------
  91 // Routine for DCHOOK Device IO ctrl
  92 // --------------------------------
  93 void CHK95_Device_IOctrl(PDIOCPARAMETERS ptr)
  94 {
  95         int i;
  96         unsigned int addr;
  97         unsigned int page;
  98         int npage;
  99         unsigned char *p;
 100         unsigned char *q;
 101         DWORD oldpermission;
 102         // Field the DEV IO requests from VMM
 103         switch(ptr->dwIoControlCode)
 104                 {
 105                 case DIOC_WRITEABLE_MEMORY:     // The address to be changed must be already committed.
 106                         if ( ptr->lpvInBuffer ){
 107                                 // Does it need a PC_STATIC?
 108
 109                                 long r = 0;
 110
 111                                 // I don't know exact parameters. But it works well, so I don't care about it....
 112
 113                                 r = PageModPerm( *((DWORD*)ptr->lpvInBuffer), 1, 0xFFFFFFFF, PC_WRITEABLE | PC_USER | PC_STATIC );
 114                                 if ( ptr->lpvOutBuffer ){
 115                                         *((DWORD*)ptr->lpvOutBuffer) = r;
 116                                 }
 117                         }
 118                 break;
 119                 case DIOC_NONWRITEABLE_MEMORY:  // The address to be changed must be already committed.
 120                         {
 121                         long r = 0;
 122
 123                         r = PageModPerm( *((DWORD*)ptr->lpvInBuffer), 1, ~PC_WRITEABLE, PC_USER | PC_STATIC );
 124                         if ( ptr->lpvOutBuffer ){
 125                                 *((DWORD*)ptr->lpvOutBuffer) = r;
 126                         }
 127                         }
 128                 break;
 129                 case DIOC_CHANGE_MEMORY:
 130                         addr = (DWORD)ptr->lpvOutBuffer;
 131                         page = addr >> 12;      // 4KB
 132                         npage = ((addr + ptr->cbInBuffer) >> 12) - page + 1;
 133                         oldpermission = PageModPerm( page, npage, 0xFFFFFFFF, PC_WRITEABLE | PC_USER | PC_STATIC );
 134                         _asm pushfd
 135                         _asm cli
 136                         if ( oldpermission == (DWORD)-1 ){
 137                                 _asm popfd
 138                                 BadReturnDIOC();
 139                                 return;
 140                         }
 141                         p = (unsigned char*)addr;
 142                         q = (unsigned char*)ptr->lpvInBuffer;
 143                         for ( i=0;i<ptr->cbInBuffer;i++ ){
 144                                 *p++ = *q++;
 145                         }
 146                         PageModPerm( page, npage, oldpermission, oldpermission );
 147                         _asm popfd
 148                 break;
 149 #if 0
 150                 case DIOC_DEBUG:
 151                         *(DWORD*)ptr->lpvOutBuffer = (DWORD)CHK95_Device_IOctrl;
 152                 break;
 153 #endif
 154                 //The below DIOC_GETVERSION is a part of the dynamic load protocol
 155                 //It MUST return a GOOD code (all codes here use GoodReturnDIOC()
 156 //              case(DIOC_GETVERSION):
 157 //              case(DIOC_CLOSEHANDLE):
 158 //              default:
 159 //              break;
 160         }
 161         GoodReturnDIOC();
 162         return;
 163 }
 164