OSX/libsecurity_filedb/lib/ReadWriteSection.cpp

   1 #include "ReadWriteSection.h"
   2
   3 uint32 WriteSection::put(uint32 inOffset, uint32 inValue)
   4 {
   5         uint32 aLength = CheckUInt32Add(inOffset, sizeof(inValue));
   6         if (aLength > mCapacity)
   7                 grow(aLength);
   8
   9         if (mAddress == NULL)
  10                 CssmError::throwMe(CSSMERR_DL_DATABASE_CORRUPT);
  11
  12         *reinterpret_cast<uint32 *>(mAddress + inOffset) = htonl(inValue);
  13         return aLength;
  14 }
  15
  16
  17
  18 uint32 WriteSection::put(uint32 inOffset, uint32 inLength, const uint8 *inData)
  19 {
  20         // if we are being asked to put 0 bytes, just return
  21         if (inLength == 0 || inData == NULL)
  22         {
  23                 return inOffset;
  24         }
  25
  26         uint32 aLength = CheckUInt32Add(inOffset, inLength);
  27
  28         // Round up to nearest multiple of 4 bytes, to pad with zeros
  29         uint32 aNewOffset = align(aLength);
  30         if (aNewOffset > mCapacity)
  31                 grow(aNewOffset);
  32
  33         if (mAddress == NULL)
  34                 CssmError::throwMe(CSSMERR_DL_DATABASE_CORRUPT);
  35
  36         memcpy(mAddress + inOffset, inData, inLength);
  37
  38         for (uint32 anOffset = aLength; anOffset < aNewOffset; anOffset++)
  39                 mAddress[anOffset] = 0;
  40
  41         return aNewOffset;
  42 }
  43
  44
  45
  46 void WriteSection::grow(size_t inNewCapacity)
  47 {
  48         size_t n = CheckUInt32Multiply((uint32)mCapacity, 2);
  49         size_t aNewCapacity = max(n, inNewCapacity);
  50         mAddress = reinterpret_cast<uint8 *>(mAllocator.realloc(mAddress, aNewCapacity));
  51
  52     if (mAddress == NULL)
  53         CssmError::throwMe(CSSMERR_DL_DATABASE_CORRUPT);
  54
  55         memset(mAddress + mCapacity, 0, aNewCapacity - mCapacity);
  56         mCapacity = aNewCapacity;
  57 }