otError Frame::ValidatePsdu(void) const
{
otError error = OT_ERROR_NONE;
uint8_t offset = FindPayloadIndex();
VerifyOrExit(offset != kInvalidIndex, error = OT_ERROR_PARSE);
VerifyOrExit((offset + GetFooterLength()) <= GetPsduLength(), error = OT_ERROR_PARSE);
exit:
return error;
}
ThreadError Frame::ValidatePsdu(void)
{
ThreadError error = kThreadError_Parse;
uint8_t offset = 0;
uint16_t fcf;
uint8_t footerLength = kFcsSize;
VerifyOrExit((offset += kFcfSize + kDsnSize) <= GetPsduLength(),);
fcf = static_cast<uint16_t>((GetPsdu()[1] << 8) | GetPsdu()[0]);
// Destinatinon PAN + Address
switch (fcf & Frame::kFcfDstAddrMask)
{
case Frame::kFcfDstAddrNone:
break;
case Frame::kFcfDstAddrShort:
offset += sizeof(PanId) + sizeof(ShortAddress);
break;
case Frame::kFcfDstAddrExt:
offset += sizeof(PanId) + sizeof(ExtAddress);
break;
default:
goto exit;
}
// Source PAN + Address
switch (fcf & Frame::kFcfSrcAddrMask)
{
case Frame::kFcfSrcAddrNone:
break;
case Frame::kFcfSrcAddrShort:
if ((fcf & Frame::kFcfPanidCompression) == 0)
{
offset += sizeof(PanId);
}
offset += sizeof(ShortAddress);
break;
case Frame::kFcfSrcAddrExt:
if ((fcf & Frame::kFcfPanidCompression) == 0)
{
offset += sizeof(PanId);
}
offset += sizeof(ExtAddress);
break;
default:
goto exit;
}
// Security Header
if (fcf & Frame::kFcfSecurityEnabled)
{
VerifyOrExit(offset <= GetPsduLength(),);
uint8_t secControl = GetPsdu()[offset];
switch (secControl & kKeyIdModeMask)
{
case kKeyIdMode0:
offset += kKeySourceSizeMode0;
break;
case kKeyIdMode1:
offset += kKeySourceSizeMode1 + kKeyIndexSize;
break;
case kKeyIdMode2:
offset += kKeySourceSizeMode2 + kKeyIndexSize;
break;
case kKeyIdMode3:
offset += kKeySourceSizeMode3 + kKeyIndexSize;
break;
}
switch (secControl & kSecLevelMask)
{
case kSecNone:
case kSecEnc:
footerLength += kMic0Size;
break;
case kSecMic32:
case kSecEncMic32:
footerLength += kMic32Size;
break;
case kSecMic64:
case kSecEncMic64:
footerLength += kMic64Size;
break;
case kSecMic128:
case kSecEncMic128:
footerLength += kMic128Size;
break;
}
}
const uint8_t *Frame::GetFooter(void) const
{
return GetPsdu() + GetPsduLength() - GetFooterLength();
}
uint8_t Frame::FindPayloadIndex(void) const
{
uint8_t index = 0;
uint16_t fcf;
// Frame Control
index += kFcfSize;
// Sequence Number
index += kDsnSize;
VerifyOrExit((index + kFcsSize) <= GetPsduLength(), index = kInvalidIndex);
fcf = GetFrameControlField();
// Destination PAN + Address
switch (fcf & kFcfDstAddrMask)
{
case kFcfDstAddrNone:
break;
case kFcfDstAddrShort:
index += sizeof(PanId) + sizeof(ShortAddress);
break;
case kFcfDstAddrExt:
index += sizeof(PanId) + sizeof(ExtAddress);
break;
default:
ExitNow(index = kInvalidIndex);
}
// Source PAN + Address
switch (fcf & kFcfSrcAddrMask)
{
case kFcfSrcAddrNone:
break;
case kFcfSrcAddrShort:
if ((fcf & kFcfPanidCompression) == 0)
{
index += sizeof(PanId);
}
index += sizeof(ShortAddress);
break;
case kFcfSrcAddrExt:
if ((fcf & kFcfPanidCompression) == 0)
{
index += sizeof(PanId);
}
index += sizeof(ExtAddress);
break;
default:
ExitNow(index = kInvalidIndex);
}
VerifyOrExit((index + kFcsSize) <= GetPsduLength(), index = kInvalidIndex);
// Security Control + Frame Counter + Key Identifier
if ((fcf & kFcfSecurityEnabled) != 0)
{
uint8_t securityControl = *(GetPsdu() + index);
index += kSecurityControlSize + kFrameCounterSize;
switch (securityControl & kKeyIdModeMask)
{
case kKeyIdMode0:
index += kKeySourceSizeMode0;
break;
case kKeyIdMode1:
index += kKeySourceSizeMode1 + kKeyIndexSize;
break;
case kKeyIdMode2:
index += kKeySourceSizeMode2 + kKeyIndexSize;
break;
case kKeyIdMode3:
index += kKeySourceSizeMode3 + kKeyIndexSize;
break;
}
}
// Command ID
if ((fcf & kFcfFrameTypeMask) == kFcfFrameMacCmd)
{
index += kCommandIdSize;
}
exit:
return index;
}
uint8_t Frame::GetPayloadLength(void) const
{
return GetPsduLength() - (GetHeaderLength() + GetFooterLength());
}