reactos/dll/win32/msports/comdb.c

   1 /*
   2  * PROJECT:     Ports installer library
   3  * LICENSE:     GPL - See COPYING in the top level directory
   4  * FILE:        dll\win32\msports\comdb.c
   5  * PURPOSE:     COM port database
   6  * COPYRIGHT:   Copyright 2011 Eric Kohl
   7  */
   8
   9 #include <windows.h>
  10 #include <msports.h>
  11
  12 #include <wine/debug.h>
  13
  14 WINE_DEFAULT_DEBUG_CHANNEL(msports);
  15
  16 #define BITS_PER_BYTE 8
  17
  18 typedef struct _COMDB
  19 {
  20     HKEY hKey;
  21     DWORD dwSize;
  22     PBYTE pBitmap;
  23     PBYTE pData;
  24 } COMDB, *PCOMDB;
  25
  26
  27 LONG
  28 WINAPI
  29 ComDBClaimPort(IN HCOMDB hComDB,
  30                IN DWORD ComNumber,
  31                IN BOOL ForceClaim,
  32                OUT PBOOL Forced)
  33 {
  34     PCOMDB pComDB;
  35     PBYTE pByte;
  36     BYTE cMask;
  37     DWORD dwBitIndex;
  38     DWORD dwType;
  39     DWORD dwSize;
  40     LONG lError;
  41
  42     if (hComDB == INVALID_HANDLE_VALUE ||
  43         hComDB == NULL ||
  44         ComNumber == 0 ||
  45         ComNumber > COMDB_MAX_PORTS_ARBITRATED)
  46         return ERROR_INVALID_PARAMETER;
  47
  48     pComDB = (PCOMDB)hComDB;
  49
  50     /* Update the bitmap */
  51     dwSize = pComDB->dwSize;
  52     lError = RegQueryValueExW(pComDB->hKey,
  53                               L"ComDB",
  54                               NULL,
  55                               &dwType,
  56                               pComDB->pBitmap,
  57                               &dwSize);
  58     if (lError != ERROR_SUCCESS)
  59         return lError;
  60
  61     /* Get the bit index */
  62     dwBitIndex = ComNumber - 1;
  63
  64     /* Check if the bit to set fits into the bitmap */
  65     if (dwBitIndex >= (pComDB->dwSize * BITS_PER_BYTE))
  66     {
  67         /* FIXME: Resize the bitmap */
  68         return ERROR_INVALID_PARAMETER;
  69     }
  70
  71     /* Get a pointer to the affected byte and calculate a mask for the affected bit */
  72     pByte = &(pComDB->pBitmap[dwBitIndex / BITS_PER_BYTE]);
  73     cMask = 1 << (dwBitIndex % BITS_PER_BYTE);
  74
  75     /* Check if the bit is not set */
  76     if ((*pByte & cMask) == 0)
  77     {
  78         /* Set the bit */
  79         *pByte |= cMask;
  80         lError = ERROR_SUCCESS;
  81     }
  82     else
  83     {
  84         /* The bit is already set */
  85         lError = ERROR_SHARING_VIOLATION;
  86     }
  87
  88     /* Save the bitmap if it was modified */
  89     if (lError == ERROR_SUCCESS)
  90     {
  91         lError = RegSetValueExW(pComDB->hKey,
  92                                 L"ComDB",
  93                                 0,
  94                                 REG_BINARY,
  95                                 pComDB->pData,
  96                                 pComDB->dwSize);
  97     }
  98
  99     return lError;
 100 }
 101
 102
 103 LONG
 104 WINAPI
 105 ComDBClose(IN HCOMDB hComDB)
 106 {
 107     PCOMDB pComDB;
 108
 109     if (hComDB == HCOMDB_INVALID_HANDLE_VALUE || hComDB == NULL)
 110         return ERROR_INVALID_PARAMETER;
 111
 112     pComDB = (PCOMDB)hComDB;
 113
 114     /* Close the registry key */
 115     if (pComDB->hKey != NULL)
 116         RegCloseKey(pComDB->hKey);
 117
 118     /* Release the bitmap */
 119     if (pComDB->pBitmap != NULL)
 120         HeapFree(GetProcessHeap(), 0, pComDB->pBitmap);
 121
 122     /* Release the database */
 123     HeapFree(GetProcessHeap(), 0, pComDB);
 124
 125     return ERROR_SUCCESS;
 126 }
 127
 128
 129 LONG
 130 WINAPI
 131 ComDBOpen(OUT HCOMDB *phComDB)
 132 {
 133     PCOMDB pComDB;
 134     DWORD dwDisposition;
 135     DWORD dwType;
 136     LONG lError;
 137
 138     TRACE("ComDBOpen(%p)\n", phComDB);
 139
 140     /* Allocate a new database */
 141     pComDB = HeapAlloc(GetProcessHeap(),
 142                        HEAP_ZERO_MEMORY,
 143                        sizeof(COMDB));
 144     if (pComDB == NULL)
 145     {
 146         ERR("Failed to allocaete the database!\n");
 147         return ERROR_ACCESS_DENIED;
 148     }
 149
 150     /* Create or open the database key */
 151     lError = RegCreateKeyExW(HKEY_LOCAL_MACHINE,
 152                              L"System\\CurrentControlSet\\Control\\COM Name Arbiter",
 153                              0,
 154                              NULL,
 155                              0,
 156                              KEY_ALL_ACCESS,
 157                              NULL,
 158                              &pComDB->hKey,
 159                              &dwDisposition);
 160     if (lError != ERROR_SUCCESS)
 161         goto done;
 162
 163     /* Get the required bitmap size */
 164     lError = RegQueryValueExW(pComDB->hKey,
 165                               L"ComDB",
 166                               NULL,
 167                               &dwType,
 168                               NULL,
 169                               &pComDB->dwSize);
 170     if (lError == ERROR_FILE_NOT_FOUND)
 171     {
 172         /* Allocate a new bitmap */
 173         pComDB->dwSize = COMDB_MIN_PORTS_ARBITRATED / BITS_PER_BYTE;
 174         pComDB->pData = HeapAlloc(GetProcessHeap(),
 175                                   HEAP_ZERO_MEMORY,
 176                                   pComDB->dwSize);
 177         if (pComDB->pData == NULL)
 178         {
 179             ERR("Failed to allocaete the bitmap!\n");
 180             lError = ERROR_ACCESS_DENIED;
 181             goto done;
 182         }
 183
 184         /* Read the bitmap from the registry */
 185         lError = RegSetValueExW(pComDB->hKey,
 186                                 L"ComDB",
 187                                 0,
 188                                 REG_BINARY,
 189                                 pComDB->pData,
 190                                 pComDB->dwSize);
 191     }
 192
 193 done:;
 194     if (lError != ERROR_SUCCESS)
 195     {
 196         /* Clean up in case of failure */
 197         if (pComDB->hKey != NULL)
 198             RegCloseKey(pComDB->hKey);
 199
 200         if (pComDB->pData != NULL)
 201             HeapFree(GetProcessHeap(), 0, pComDB->pData);
 202
 203         HeapFree(GetProcessHeap(), 0, pComDB);
 204
 205         *phComDB = HCOMDB_INVALID_HANDLE_VALUE;
 206     }
 207     else
 208     {
 209         /* Return the database handle */
 210         *phComDB = (HCOMDB)pComDB;
 211     }
 212
 213     TRACE("done (Error %lu)\n", lError);
 214
 215     return lError;
 216 }
 217
 218 /* EOF */