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