bool
ccnxCodecSchemaV1PacketDecoder_Decode(CCNxCodecTlvDecoder *packetDecoder, CCNxTlvDictionary *packetDictionary)
{
bool decodeSuccess = false;
_CCNxCodecSchemaV1Data data;
// we temporarily store this reference, but we do not destroy it. This
// is just to pass the reference down the decode chain, it is not
// stored beyond the immediate scope. Therefore, no reference acquired.
data.packetDictionary = packetDictionary;
data.decoder = packetDecoder;
if (ccnxCodecSchemaV1FixedHeaderDecoder_Decode(data.decoder, data.packetDictionary)) {
if (_decodeOptionalHeaders(&data)) {
// Record the position we'd start the signature verification at
size_t signatureStartPosition = ccnxCodecTlvDecoder_Position(data.decoder);
// Mark the beginning of the ContentObject hash region.
CCNxWireFormatFacadeV1_Implementation.setContentObjectHashRegionStart(data.packetDictionary, signatureStartPosition);
if (_decodeMessage(&data)) {
// If there's anything else left, it must be the validation alg and payload
if (!ccnxCodecTlvDecoder_IsEmpty(data.decoder)) {
if (_decodeValidationAlg(&data)) {
// at this point, we've advanced to the end of the validation algorithm,
// that's where we would end signature verification
size_t signatureStopPosition = ccnxCodecTlvDecoder_Position(data.decoder);
CCNxWireFormatFacadeV1_Implementation.setProtectedRegionStart(data.packetDictionary, signatureStartPosition);
CCNxWireFormatFacadeV1_Implementation.setProtectedRegionLength(data.packetDictionary, signatureStopPosition - signatureStartPosition);
if (_decodeValidationPayload(&data)) {
decodeSuccess = true;
}
}
} else {
// nothing after the message, so that's a successful decode
decodeSuccess = true;
}
// Mark the length of the ContentObject hash region (to the end of the packet).
size_t contentObjectHashRegionLength = ccnxCodecTlvDecoder_Position(data.decoder) - signatureStartPosition;
CCNxWireFormatFacadeV1_Implementation.setContentObjectHashRegionLength(data.packetDictionary, contentObjectHashRegionLength);
}
}
}
return decodeSuccess;
}
LONGBOW_TEST_CASE(Global, ccnxTlvCodecName_Decode_WrongType)
{
uint8_t decodeBytes[] = { 0x10, 0x20, 0x00, 0x0E, 0x00, CCNxNameLabelType_NAME, 0x00, 0x0A, 'b', 'r', 'a', 'n', 'd', 'y', 'w', 'i', 'n', 'e' };
PARCBuffer *decodeBuffer = parcBuffer_Wrap(decodeBytes, sizeof(decodeBytes), 0, sizeof(decodeBytes));
CCNxCodecTlvDecoder *decoder = ccnxCodecTlvDecoder_Create(decodeBuffer);
CCNxName *test = ccnxCodecSchemaV1NameCodec_Decode(decoder, 0xFFFF);
assertNull(test, "Name should have returned NULL because the name type does not match");
assertTrue(ccnxCodecTlvDecoder_Position(decoder) == 0, "Position should not have moved, expected 0, got %zu", ccnxCodecTlvDecoder_Position(decoder));
ccnxCodecTlvDecoder_Destroy(&decoder);
parcBuffer_Release(&decodeBuffer);
}
bool
ccnxCodecSchemaV1FixedHeaderDecoder_Decode(CCNxCodecTlvDecoder *decoder, CCNxTlvDictionary *packetDictionary)
{
if (ccnxCodecTlvDecoder_EnsureRemaining(decoder, _fixedHeaderBytes)) {
PARCBuffer *buffer = ccnxCodecTlvDecoder_GetValue(decoder, _fixedHeaderBytes);
bool success = ccnxTlvDictionary_PutBuffer(packetDictionary, CCNxCodecSchemaV1TlvDictionary_HeadersFastArray_FixedHeader, buffer);
// validation
parcBuffer_SetPosition(buffer, _fixedHeader_VersionOffset);
uint8_t version = parcBuffer_GetUint8(buffer);
parcBuffer_SetPosition(buffer, _fixedHeader_PacketLengthOffset);
uint16_t packetLength = parcBuffer_GetUint16(buffer);
parcBuffer_SetPosition(buffer, _fixedHeader_HopLimitOffset);
uint8_t hopLimit = parcBuffer_GetUint8(buffer);
parcBuffer_SetPosition(buffer, _fixedHeader_HeaderLengthOffset);
uint8_t headerLength = parcBuffer_GetUint8(buffer);
if (version != 1) {
CCNxCodecError *error = ccnxCodecError_Create(TLV_ERR_VERSION, __func__, __LINE__, _fixedHeader_VersionOffset);
ccnxCodecTlvDecoder_SetError(decoder, error);
ccnxCodecError_Release(&error);
success = false;
} else if (packetLength < _fixedHeaderBytes) {
CCNxCodecError *error = ccnxCodecError_Create(TLV_ERR_PACKETLENGTH_TOO_SHORT, __func__, __LINE__, _fixedHeader_PacketTypeOffset);
ccnxCodecTlvDecoder_SetError(decoder, error);
ccnxCodecError_Release(&error);
success = false;
} else if (headerLength < _fixedHeaderBytes) {
CCNxCodecError *error = ccnxCodecError_Create(TLV_ERR_HEADERLENGTH_TOO_SHORT, __func__, __LINE__, _fixedHeader_HeaderLengthOffset);
ccnxCodecTlvDecoder_SetError(decoder, error);
ccnxCodecError_Release(&error);
success = false;
} else if (packetLength < headerLength) {
CCNxCodecError *error = ccnxCodecError_Create(TLV_ERR_PACKETLENGTHSHORTER, __func__, __LINE__, _fixedHeader_PacketTypeOffset);
ccnxCodecTlvDecoder_SetError(decoder, error);
ccnxCodecError_Release(&error);
success = false;
}
// decoder now points to just past the fixed header
parcBuffer_Release(&buffer);
// Set the hoplimit in the dictionary.
ccnxTlvDictionary_PutInteger(packetDictionary, CCNxCodecSchemaV1TlvDictionary_MessageFastArray_HOPLIMIT, hopLimit);
return success;
} else {
CCNxCodecError *error = ccnxCodecError_Create(TLV_ERR_DECODE, __func__, __LINE__, ccnxCodecTlvDecoder_Position(decoder));
ccnxCodecTlvDecoder_SetError(decoder, error);
ccnxCodecError_Release(&error);
return false;
}
}
static bool
_decodeValidationAlg(_CCNxCodecSchemaV1Data *data)
{
bool success = false;
if (ccnxCodecTlvDecoder_EnsureRemaining(data->decoder, 4)) {
// what kind of message are we looking at?
// Note that this is based on the TLV container, not the fixed head PacketType
uint16_t tlv_type = ccnxCodecTlvDecoder_GetType(data->decoder);
uint16_t tlv_length = ccnxCodecTlvDecoder_GetLength(data->decoder);
if (tlv_type == CCNxCodecSchemaV1Types_MessageType_ValidationAlg &&
ccnxCodecTlvDecoder_EnsureRemaining(data->decoder, tlv_length)) {
CCNxCodecTlvDecoder *decoder = ccnxCodecTlvDecoder_GetContainer(data->decoder, tlv_length);
success = ccnxCodecSchemaV1ValidationDecoder_DecodeAlg(decoder, data->packetDictionary);
ccnxCodecTlvDecoder_Destroy(&decoder);
} else {
// raise and error
if (!ccnxCodecTlvDecoder_EnsureRemaining(data->decoder, tlv_length)) {
// tlv_length goes beyond the decoder
CCNxCodecError *error = ccnxCodecError_Create(TLV_ERR_TOO_LONG, __func__, __LINE__, ccnxCodecTlvDecoder_Position(data->decoder));
ccnxCodecTlvDecoder_SetError(data->decoder, error);
ccnxCodecError_Release(&error);
} else {
// not CCNxCodecSchemaV1Types_MessageType_ValidationAlg
CCNxCodecError *error = ccnxCodecError_Create(TLV_ERR_DECODE, __func__, __LINE__, ccnxCodecTlvDecoder_Position(data->decoder));
ccnxCodecTlvDecoder_SetError(data->decoder, error);
ccnxCodecError_Release(&error);
}
}
}
return success;
}
/**
* Decodes the CCNx message inside a TLV packet
*
* Creates an inner decoder that slices the decode buffer then passes that and our
* message dictionary to the appropriate inner decoder.
*
* @param [in] data The packet decoder state
*
* @return true successful decode
* @return false A decoding error
*
* Example:
* @code
* <#example#>
* @endcode
*/
static bool
_decodeMessage(_CCNxCodecSchemaV1Data *data)
{
bool success = false;
if (ccnxCodecTlvDecoder_EnsureRemaining(data->decoder, 4)) {
// what kind of message are we looking at?
// Note that this is based on the TLV container, not the fixed head PacketType
uint16_t tlv_type = ccnxCodecTlvDecoder_GetType(data->decoder);
uint16_t tlv_length = ccnxCodecTlvDecoder_GetLength(data->decoder);
// ensure its a proper tlv type
switch (tlv_type) {
case CCNxCodecSchemaV1Types_MessageType_Interest: // fallthrough
case CCNxCodecSchemaV1Types_MessageType_ContentObject: // fallthrough
case CCNxCodecSchemaV1Types_MessageType_Control: // fallthrough
break;
default:
return false;
}
// cross check with the fixed header value
// ccnxCodecSchemaV1FixedHeaderDecoder_Decode ensures that PacketLength is not less than HeaderLength
size_t messageLength = ccnxCodecSchemaV1FixedHeaderDecoder_GetPacketLength(data->packetDictionary) - ccnxCodecSchemaV1FixedHeaderDecoder_GetHeaderLength(data->packetDictionary);
if (tlv_length <= messageLength && ccnxCodecTlvDecoder_EnsureRemaining(data->decoder, tlv_length)) {
// This decode is for the "value" of the message, it does not include the wrapper
CCNxCodecTlvDecoder *messageDecoder = ccnxCodecTlvDecoder_GetContainer(data->decoder, tlv_length);
if (tlv_type == CCNxCodecSchemaV1Types_MessageType_Control) {
// the CPI messages are not a proper "message" in that there's no inner TLV, its just data
success = _decodeCPI(messageDecoder, data->packetDictionary);
} else {
success = ccnxCodecSchemaV1MessageDecoder_Decode(messageDecoder, data->packetDictionary);
}
ccnxCodecTlvDecoder_Destroy(&messageDecoder);
} else {
// raise an error
CCNxCodecError *error = ccnxCodecError_Create(TLV_ERR_TOO_LONG, __func__, __LINE__, ccnxCodecTlvDecoder_Position(data->decoder));
ccnxCodecTlvDecoder_SetError(data->decoder, error);
ccnxCodecError_Release(&error);
}
}
return success;
}
static bool
_decodeType(CCNxCodecTlvDecoder *decoder, CCNxTlvDictionary *packetDictionary, uint16_t type, uint16_t length)
{
bool success = false;
switch (type) {
case CCNxCodecSchemaV1Types_OptionalHeaders_InterestFragment:
success = ccnxCodecTlvUtilities_PutAsBuffer(decoder, packetDictionary, type, length, CCNxCodecSchemaV1TlvDictionary_HeadersFastArray_INTFRAG);
break;
case CCNxCodecSchemaV1Types_OptionalHeaders_ContentObjectFragment:
success = ccnxCodecTlvUtilities_PutAsBuffer(decoder, packetDictionary, type, length, CCNxCodecSchemaV1TlvDictionary_HeadersFastArray_OBJFRAG);
break;
case CCNxCodecSchemaV1Types_OptionalHeaders_InterestLifetime:
// its a time, so use an Integer
success = ccnxCodecTlvUtilities_PutAsInteger(decoder, packetDictionary, type, length, CCNxCodecSchemaV1TlvDictionary_HeadersFastArray_InterestLifetime);
break;
case CCNxCodecSchemaV1Types_OptionalHeaders_RecommendedCacheTime:
// its a time, so use an Integer
success = ccnxCodecTlvUtilities_PutAsInteger(decoder, packetDictionary, type, length, CCNxCodecSchemaV1TlvDictionary_HeadersFastArray_RecommendedCacheTime);
break;
default: {
// if we do not know the TLV type, put it in this container's unknown list
success = ccnxCodecTlvUtilities_PutAsListBuffer(decoder, packetDictionary, type, length, CCNxCodecSchemaV1TlvDictionary_Lists_HEADERS);
}
break;
}
if (!success) {
CCNxCodecError *error = ccnxCodecError_Create(TLV_ERR_DECODE, __func__, __LINE__, ccnxCodecTlvDecoder_Position(decoder));
ccnxCodecTlvDecoder_SetError(decoder, error);
ccnxCodecError_Release(&error);
}
return success;
}
