reactos/ntoskrnl/ke/config.c

   1 /*
   2  * PROJECT:         ReactOS Kernel
   3  * LICENSE:         GPL - See COPYING in the top level directory
   4  * FILE:            ntoskrnl/ke/config.c
   5  * PURPOSE:         Configuration Tree Routines
   6  * PROGRAMMERS:     Alex Ionescu (alex.ionescu@reactos.org)
   7  */
   8
   9 /* INCLUDES ******************************************************************/
  10
  11 #include <ntoskrnl.h>
  12 #define NDEBUG
  13 #include <internal/debug.h>
  14
  15 /* FUNCTIONS *****************************************************************/
  16
  17 /*
  18  * @implemented
  19  */
  20 PCONFIGURATION_COMPONENT_DATA
  21 NTAPI
  22 INIT_FUNCTION
  23 KeFindConfigurationEntry(IN PCONFIGURATION_COMPONENT_DATA Child,
  24                          IN CONFIGURATION_CLASS Class,
  25                          IN CONFIGURATION_TYPE Type,
  26                          IN PULONG ComponentKey OPTIONAL)
  27 {
  28     /* Start Search at Root */
  29     return KeFindConfigurationNextEntry(Child,
  30                                         Class,
  31                                         Type,
  32                                         ComponentKey,
  33                                         NULL);
  34 }
  35
  36 /*
  37  * @implemented
  38  */
  39 PCONFIGURATION_COMPONENT_DATA
  40 NTAPI
  41 INIT_FUNCTION
  42 KeFindConfigurationNextEntry(IN PCONFIGURATION_COMPONENT_DATA Child,
  43                              IN CONFIGURATION_CLASS Class,
  44                              IN CONFIGURATION_TYPE Type,
  45                              IN PULONG ComponentKey OPTIONAL,
  46                              IN PCONFIGURATION_COMPONENT_DATA *NextLink)
  47 {
  48     ULONG Key = 0;
  49     ULONG Mask = 0;
  50     PCONFIGURATION_COMPONENT_DATA Sibling;
  51     PCONFIGURATION_COMPONENT_DATA ReturnEntry;
  52
  53     /* If we did get a key, then use it instead */
  54     if (ComponentKey)
  55     {
  56         Key = *ComponentKey;
  57         Mask = -1;
  58     }
  59
  60     /* Loop the Components until we find a a match */
  61     while (Child)
  62     {
  63         /* Check if we are starting somewhere already */
  64         if (*NextLink)
  65         {
  66             /* If we've found the place where we started, clear and continue */
  67             if (Child == *NextLink) *NextLink = NULL;
  68         }
  69         else
  70         {
  71             /* Try to get a match */
  72             if ((Child->ComponentEntry.Class) == Class &&
  73                 (Child->ComponentEntry.Type) == Type &&
  74                 (Child->ComponentEntry.Key & Mask) == Key)
  75             {
  76                 /* Match found */
  77                 return Child;
  78             }
  79         }
  80
  81         /* Now we've also got to lookup the siblings */
  82         Sibling = Child->Sibling;
  83         while (Sibling)
  84         {
  85             /* Check if we are starting somewhere already */
  86             if (*NextLink)
  87             {
  88                 /* If we've found the place where we started, clear and continue */
  89                 if (Sibling == *NextLink) *NextLink = NULL;
  90             }
  91             else
  92             {
  93                 /* Try to get a match */
  94                 if ((Sibling->ComponentEntry.Class == Class) &&
  95                     (Sibling->ComponentEntry.Type == Type) &&
  96                     (Sibling->ComponentEntry.Key & Mask) == Key)
  97                 {
  98                     /* Match found */
  99                     return Sibling;
 100                 }
 101             }
 102
 103             /* We've got to check if the Sibling has a Child as well */
 104             if (Sibling->Child)
 105             {
 106                 /* We're just going to call ourselves again */
 107                 ReturnEntry = KeFindConfigurationNextEntry(Sibling->Child,
 108                                                            Class,
 109                                                            Type,
 110                                                            ComponentKey,
 111                                                            NextLink);
 112                 if (ReturnEntry) return ReturnEntry;
 113             }
 114
 115             /* Next Sibling */
 116             Sibling = Sibling->Sibling;
 117         }
 118
 119         /* Next Child */
 120         Child = Child->Child;
 121     }
 122
 123     /* If we got here, nothign was found */
 124     return NULL;
 125 }
 126