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 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     PCONFIGURATION_COMPONENT_DATA NextLink = NULL;
  29
  30     /* Start Search at Root */
  31     return KeFindConfigurationNextEntry(Child,
  32                                         Class,
  33                                         Type,
  34                                         ComponentKey,
  35                                         &NextLink);
  36 }
  37
  38 /*
  39  * @implemented
  40  */
  41 PCONFIGURATION_COMPONENT_DATA
  42 NTAPI
  43 INIT_FUNCTION
  44 KeFindConfigurationNextEntry(IN PCONFIGURATION_COMPONENT_DATA Child,
  45                              IN CONFIGURATION_CLASS Class,
  46                              IN CONFIGURATION_TYPE Type,
  47                              IN PULONG ComponentKey OPTIONAL,
  48                              IN PCONFIGURATION_COMPONENT_DATA *NextLink)
  49 {
  50     ULONG Key = 0;
  51     ULONG Mask = 0;
  52     PCONFIGURATION_COMPONENT_DATA Sibling;
  53     PCONFIGURATION_COMPONENT_DATA ReturnEntry;
  54
  55     /* If we did get a key, then use it instead */
  56     if (ComponentKey)
  57     {
  58         Key = *ComponentKey;
  59         Mask = -1;
  60     }
  61
  62     /* Loop the Components until we find a a match */
  63     while (Child)
  64     {
  65         /* Check if we are starting somewhere already */
  66         if (*NextLink)
  67         {
  68             /* If we've found the place where we started, clear and continue */
  69             if (Child == *NextLink) *NextLink = NULL;
  70         }
  71         else
  72         {
  73             /* Try to get a match */
  74             if ((Child->ComponentEntry.Class) == Class &&
  75                 (Child->ComponentEntry.Type) == Type &&
  76                 (Child->ComponentEntry.Key & Mask) == Key)
  77             {
  78                 /* Match found */
  79                 return Child;
  80             }
  81         }
  82
  83         /* Now we've also got to lookup the siblings */
  84         Sibling = Child->Sibling;
  85         while (Sibling)
  86         {
  87             /* Check if we are starting somewhere already */
  88             if (*NextLink)
  89             {
  90                 /* If we've found the place where we started, clear and continue */
  91                 if (Sibling == *NextLink) *NextLink = NULL;
  92             }
  93             else
  94             {
  95                 /* Try to get a match */
  96                 if ((Sibling->ComponentEntry.Class == Class) &&
  97                     (Sibling->ComponentEntry.Type == Type) &&
  98                     (Sibling->ComponentEntry.Key & Mask) == Key)
  99                 {
 100                     /* Match found */
 101                     return Sibling;
 102                 }
 103             }
 104
 105             /* We've got to check if the Sibling has a Child as well */
 106             if (Sibling->Child)
 107             {
 108                 /* We're just going to call ourselves again */
 109                 ReturnEntry = KeFindConfigurationNextEntry(Sibling->Child,
 110                                                            Class,
 111                                                            Type,
 112                                                            ComponentKey,
 113                                                            NextLink);
 114                 if (ReturnEntry) return ReturnEntry;
 115             }
 116
 117             /* Next Sibling */
 118             Sibling = Sibling->Sibling;
 119         }
 120
 121         /* Next Child */
 122         Child = Child->Child;
 123     }
 124
 125     /* If we got here, nothign was found */
 126     return NULL;
 127 }