bsd/hfs/hfscommon/Misc/BTreeWrapper.c

   1 /*
   2  * Copyright (c) 2000, 2002, 2005-2008 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #include "../headers/BTreesPrivate.h"
  30 #include <sys/kernel.h>
  31 #include <sys/malloc.h>
  32 #include <libkern/libkern.h>
  33
  34
  35 // local routines
  36 static OSErr    CheckBTreeKey(const BTreeKey *key, const BTreeControlBlock *btcb);
  37 static Boolean  ValidHFSRecord(const void *record, const BTreeControlBlock *btcb, u_int16_t recordSize);
  38
  39
  40 OSErr ReplaceBTreeRecord(FileReference refNum, const void* key, u_int32_t hint, void *newData, u_int16_t dataSize, u_int32_t *newHint)
  41 {
  42         FSBufferDescriptor      btRecord;
  43         struct BTreeIterator *iterator = NULL;
  44         FCB                                     *fcb;
  45         BTreeControlBlock       *btcb;
  46         OSStatus                        result;
  47
  48         MALLOC (iterator, struct BTreeIterator *, sizeof (struct BTreeIterator), M_TEMP, M_WAITOK);
  49         if (iterator == NULL) {
  50                 return memFullErr;  //translates to ENOMEM
  51         }
  52         bzero (iterator, sizeof (*iterator));
  53
  54         fcb = GetFileControlBlock(refNum);
  55         btcb = (BTreeControlBlock*) fcb->fcbBTCBPtr;
  56
  57         btRecord.bufferAddress = newData;
  58         btRecord.itemSize = dataSize;
  59         btRecord.itemCount = 1;
  60
  61         iterator->hint.nodeNum = hint;
  62
  63         result = CheckBTreeKey((const BTreeKey *) key, btcb);
  64         if (result) {
  65                 goto ErrorExit;
  66         }
  67
  68         BlockMoveData(key, &iterator->key, CalcKeySize(btcb, (const BTreeKey *) key));          //\80\80 should we range check against maxkeylen?
  69
  70         if ( DEBUG_BUILD && !ValidHFSRecord(newData, btcb, dataSize) )
  71                 DebugStr("ReplaceBTreeRecord: bad record?");
  72
  73         result = BTReplaceRecord( fcb, iterator, &btRecord, dataSize );
  74
  75         *newHint = iterator->hint.nodeNum;
  76
  77 ErrorExit:
  78
  79         FREE (iterator, M_TEMP);
  80         return result;
  81 }
  82
  83
  84
  85 static OSErr CheckBTreeKey(const BTreeKey *key, const BTreeControlBlock *btcb)
  86 {
  87         u_int16_t       keyLen;
  88
  89         if ( btcb->attributes & kBTBigKeysMask )
  90                 keyLen = key->length16;
  91         else
  92                 keyLen = key->length8;
  93
  94         if ( (keyLen < 6) || (keyLen > btcb->maxKeyLength) )
  95         {
  96                 if ( DEBUG_BUILD )
  97                         DebugStr("CheckBTreeKey: bad key length!");
  98                 return fsBTInvalidKeyLengthErr;
  99         }
 100
 101         return noErr;
 102 }
 103
 104
 105 static Boolean ValidHFSRecord(const void *record, const BTreeControlBlock *btcb, u_int16_t recordSize)
 106 {
 107         u_int32_t                       cNodeID;
 108
 109         if ( btcb->maxKeyLength == kHFSExtentKeyMaximumLength )
 110         {
 111                 return ( recordSize == sizeof(HFSExtentRecord) );
 112         }
 113         else if (btcb->maxKeyLength == kHFSPlusExtentKeyMaximumLength )
 114         {
 115                 return ( recordSize == sizeof(HFSPlusExtentRecord) );
 116         }
 117         else // Catalog record
 118         {
 119                 const CatalogRecord *catalogRecord = (const CatalogRecord*) record;
 120
 121                 switch(catalogRecord->recordType)
 122                 {
 123                         case kHFSFolderRecord:
 124                         {
 125                                 if ( recordSize != sizeof(HFSCatalogFolder) )
 126                                         return false;
 127                                 if ( catalogRecord->hfsFolder.flags != 0 )
 128                                         return false;
 129                                 if ( catalogRecord->hfsFolder.valence > 0x7FFF )
 130                                         return false;
 131
 132                                 cNodeID = catalogRecord->hfsFolder.folderID;
 133
 134                                 if ( (cNodeID == 0) || (cNodeID < 16 && cNodeID > 2) )
 135                                         return false;
 136                         }
 137                         break;
 138
 139                         case kHFSPlusFolderRecord:
 140                         {
 141                                 if ( recordSize != sizeof(HFSPlusCatalogFolder) )
 142                                         return false;
 143                                 if ( catalogRecord->hfsPlusFolder.flags != 0 )
 144                                         return false;
 145                                 if ( catalogRecord->hfsPlusFolder.valence > 0x7FFF )
 146                                         return false;
 147
 148                                 cNodeID = catalogRecord->hfsPlusFolder.folderID;
 149
 150                                 if ( (cNodeID == 0) || (cNodeID < 16 && cNodeID > 2) )
 151                                         return false;
 152                         }
 153                         break;
 154
 155                         case kHFSFileRecord:
 156                         {
 157 //                              u_int16_t                                       i;
 158                                 HFSExtentDescriptor     *dataExtent;
 159                                 HFSExtentDescriptor     *rsrcExtent;
 160
 161                                 if ( recordSize != sizeof(HFSCatalogFile) )
 162                                         return false;
 163                                 if ( (catalogRecord->hfsFile.flags & ~(0x83)) != 0 )
 164                                         return false;
 165
 166                                 cNodeID = catalogRecord->hfsFile.fileID;
 167
 168                                 if ( cNodeID < 16 )
 169                                         return false;
 170
 171                                 // make sure 0 ¾ LEOF ¾ PEOF for both forks
 172
 173                                 if ( catalogRecord->hfsFile.dataLogicalSize < 0 )
 174                                         return false;
 175                                 if ( catalogRecord->hfsFile.dataPhysicalSize < catalogRecord->hfsFile.dataLogicalSize )
 176                                         return false;
 177                                 if ( catalogRecord->hfsFile.rsrcLogicalSize < 0 )
 178                                         return false;
 179                                 if ( catalogRecord->hfsFile.rsrcPhysicalSize < catalogRecord->hfsFile.rsrcLogicalSize )
 180                                         return false;
 181
 182                                 dataExtent = (HFSExtentDescriptor*) &catalogRecord->hfsFile.dataExtents;
 183                                 rsrcExtent = (HFSExtentDescriptor*) &catalogRecord->hfsFile.rsrcExtents;
 184
 185 #if 0
 186                                 for (i = 0; i < kHFSExtentDensity; ++i)
 187                                 {
 188                                         if ( (dataExtent[i].blockCount > 0) && (dataExtent[i].startBlock == 0) )
 189                                                 return false;
 190                                         if ( (rsrcExtent[i].blockCount > 0) && (rsrcExtent[i].startBlock == 0) )
 191                                                 return false;
 192                                 }
 193 #endif
 194                         }
 195                         break;
 196
 197                         case kHFSPlusFileRecord:
 198                         {
 199 //                              u_int16_t                                       i;
 200                                 HFSPlusExtentDescriptor *dataExtent;
 201                                 HFSPlusExtentDescriptor *rsrcExtent;
 202
 203                                 if ( recordSize != sizeof(HFSPlusCatalogFile) )
 204                                         return false;
 205                                 if ( (catalogRecord->hfsPlusFile.flags & ~(0x83)) != 0 )
 206                                         return false;
 207
 208                                 cNodeID = catalogRecord->hfsPlusFile.fileID;
 209
 210                                 if ( cNodeID < 16 )
 211                                         return false;
 212
 213                                 // make sure 0 ¾ LEOF ¾ PEOF for both forks
 214
 215                                 dataExtent = (HFSPlusExtentDescriptor*) &catalogRecord->hfsPlusFile.dataFork.extents;
 216                                 rsrcExtent = (HFSPlusExtentDescriptor*) &catalogRecord->hfsPlusFile.resourceFork.extents;
 217
 218 #if 0
 219                                 for (i = 0; i < kHFSPlusExtentDensity; ++i)
 220                                 {
 221                                         if ( (dataExtent[i].blockCount > 0) && (dataExtent[i].startBlock == 0) )
 222                                                 return false;
 223                                         if ( (rsrcExtent[i].blockCount > 0) && (rsrcExtent[i].startBlock == 0) )
 224                                                 return false;
 225                                 }
 226 #endif
 227                         }
 228                         break;
 229
 230                         case kHFSFolderThreadRecord:
 231                         case kHFSFileThreadRecord:
 232                         {
 233                                 if ( recordSize != sizeof(HFSCatalogThread) )
 234                                         return false;
 235
 236                                 cNodeID = catalogRecord->hfsThread.parentID;
 237                                 if ( (cNodeID == 0) || (cNodeID < 16 && cNodeID > 2) )
 238                                         return false;
 239
 240                                 if ( (catalogRecord->hfsThread.nodeName[0] == 0) ||
 241                                          (catalogRecord->hfsThread.nodeName[0] > 31) )
 242                                         return false;
 243                         }
 244                         break;
 245
 246                         case kHFSPlusFolderThreadRecord:
 247                         case kHFSPlusFileThreadRecord:
 248                         {
 249                                 if ( recordSize > sizeof(HFSPlusCatalogThread) || recordSize < (sizeof(HFSPlusCatalogThread) - sizeof(HFSUniStr255)))
 250                                         return false;
 251
 252                                 cNodeID = catalogRecord->hfsPlusThread.parentID;
 253                                 if ( (cNodeID == 0) || (cNodeID < 16 && cNodeID > 2) )
 254                                         return false;
 255
 256                                 if ( (catalogRecord->hfsPlusThread.nodeName.length == 0) ||
 257                                          (catalogRecord->hfsPlusThread.nodeName.length > 255) )
 258                                         return false;
 259                         }
 260                         break;
 261
 262                         default:
 263                                 return false;
 264                 }
 265         }
 266
 267         return true;    // record appears to be OK
 268 }