ndn_Error
ndn_decodeTlvNameComponent
(struct ndn_NameComponent *component, struct ndn_TlvDecoder *decoder)
{
ndn_Error error;
uint64_t type;
size_t saveOffset;
saveOffset = decoder->offset;
if ((error = ndn_TlvDecoder_readVarNumber(decoder, &type)))
return error;
// Restore the position.
ndn_TlvDecoder_seek(decoder, saveOffset);
if ((error = ndn_TlvDecoder_readBlobTlv(decoder, type, &component->value)))
return error;
if (type == ndn_Tlv_ImplicitSha256DigestComponent)
component->type = ndn_NameComponentType_IMPLICIT_SHA256_DIGEST;
else if (type == ndn_Tlv_ParametersSha256DigestComponent)
component->type = ndn_NameComponentType_PARAMETERS_SHA256_DIGEST;
else if (type == ndn_Tlv_NameComponent)
component->type = ndn_NameComponentType_GENERIC;
else {
// Unrecognized type code.
component->type = ndn_NameComponentType_OTHER_CODE;
component->otherTypeCode = (int)type;
}
return NDN_ERROR_success;
}
ndn_Error
ndn_decodeTlvInterest
(struct ndn_Interest *interest, size_t *signedPortionBeginOffset,
size_t *signedPortionEndOffset, struct ndn_TlvDecoder *decoder)
{
ndn_Error errorV03;
size_t saveOffset;
saveOffset = decoder->offset;
errorV03 = ndn_decodeTlvInterestV02
(interest, signedPortionBeginOffset, signedPortionEndOffset, decoder);
if (errorV03 == NDN_ERROR_success)
return NDN_ERROR_success;
// Failed to decode as format v0.2. Restore offset and try to decode as v0.3.
ndn_TlvDecoder_seek(decoder, saveOffset);
if (ndn_decodeTlvInterestV03
(interest, signedPortionBeginOffset, signedPortionEndOffset, decoder)
== NDN_ERROR_success)
return NDN_ERROR_success;
// Ignore the exception decoding as format v0.3 and throw the exception
// from trying to decode as format as format v0.2.
return errorV03;
}
ndn_Error
ndn_decodeTlvNameComponent
(struct ndn_NameComponent *component, struct ndn_TlvDecoder *decoder)
{
ndn_Error error;
uint64_t type;
size_t saveOffset;
saveOffset = decoder->offset;
if ((error = ndn_TlvDecoder_readVarNumber(decoder, &type)))
return error;
// Restore the position.
ndn_TlvDecoder_seek(decoder, saveOffset);
if ((error = ndn_TlvDecoder_readBlobTlv(decoder, type, &component->value)))
return error;
if (type == ndn_Tlv_ImplicitSha256DigestComponent)
component->type = ndn_NameComponentType_IMPLICIT_SHA256_DIGEST;
else
component->type = ndn_NameComponentType_GENERIC;
return NDN_ERROR_success;
}
ndn_Error
ndn_decodeTlvLpPacket
(struct ndn_LpPacket *lpPacket, struct ndn_TlvDecoder *decoder)
{
ndn_Error error;
size_t endOffset;
ndn_LpPacket_clear(lpPacket);
if ((error = ndn_TlvDecoder_readNestedTlvsStart
(decoder, ndn_Tlv_LpPacket_LpPacket, &endOffset)))
return error;
while (decoder->offset < endOffset) {
// Imitate ndn_TlvDecoder_readTypeAndLength.
uint64_t fieldTypeVarNumber;
int fieldType;
uint64_t fieldLength;
size_t fieldEndOffset;
if ((error = ndn_TlvDecoder_readVarNumber(decoder, &fieldTypeVarNumber)))
return error;
fieldType = (int)fieldTypeVarNumber;
if ((error = ndn_TlvDecoder_readVarNumber(decoder, &fieldLength)))
return error;
fieldEndOffset = decoder->offset + (size_t)fieldLength;
if (fieldEndOffset > decoder->inputLength)
return NDN_ERROR_TLV_length_exceeds_buffer_length;
if (fieldType == ndn_Tlv_LpPacket_Fragment) {
// Set the fragment to the bytes of the TLV value.
if ((error = ndn_TlvDecoder_getSlice
(decoder, decoder->offset, fieldEndOffset,
&lpPacket->fragmentWireEncoding)))
return error;
ndn_TlvDecoder_seek(decoder, fieldEndOffset);
// The fragment is supposed to be the last field.
break;
}
else if (fieldType == ndn_Tlv_LpPacket_Nack) {
struct ndn_NetworkNack *networkNack;
int code;
if ((error = ndn_NetworkNack_add(lpPacket, &networkNack)))
return error;
if ((error = ndn_TlvDecoder_readOptionalNonNegativeIntegerTlv
(decoder, ndn_Tlv_LpPacket_NackReason, fieldEndOffset, &code)))
return error;
// The enum numeric values are the same as this wire format, so use as is.
if (code < 0 || code == ndn_NetworkNackReason_NONE)
// This includes an omitted NackReason.
networkNack->reason = ndn_NetworkNackReason_NONE;
else if (code == ndn_NetworkNackReason_CONGESTION ||
code == ndn_NetworkNackReason_DUPLICATE ||
code == ndn_NetworkNackReason_NO_ROUTE)
networkNack->reason = code;
else {
// Unrecognized reason.
networkNack->reason = ndn_NetworkNackReason_OTHER_CODE;
networkNack->otherReasonCode = code;
}
}
else if (fieldType == ndn_Tlv_LpPacket_IncomingFaceId) {
struct ndn_IncomingFaceId *incomingFaceId;
if ((error = ndn_IncomingFaceId_add(lpPacket, &incomingFaceId)))
return error;
if ((error = ndn_TlvDecoder_readNonNegativeInteger
(decoder, fieldLength, &incomingFaceId->faceId)))
return error;
}
else {
// Unrecognized field type. The conditions for ignoring are here:
// http://redmine.named-data.net/projects/nfd/wiki/NDNLPv2
int canIgnore =
(fieldType >= ndn_Tlv_LpPacket_IGNORE_MIN &&
fieldType <= ndn_Tlv_LpPacket_IGNORE_MAX &&
(fieldType & 0x01) == 1);
if (!canIgnore)
return NDN_ERROR_did_not_get_the_expected_TLV_type;
// Ignore.
ndn_TlvDecoder_seek(decoder, fieldEndOffset);
}
if ((error = ndn_TlvDecoder_finishNestedTlvs(decoder, fieldEndOffset)))
return error;
}
if ((error = ndn_TlvDecoder_finishNestedTlvs(decoder, endOffset)))
return error;
return NDN_ERROR_success;
}
static ndn_Error
ndn_decodeTlvInterestV02
(struct ndn_Interest *interest, size_t *signedPortionBeginOffset,
size_t *signedPortionEndOffset, struct ndn_TlvDecoder *decoder)
{
ndn_Error error;
size_t endOffset;
int gotExpectedType;
if ((error = ndn_TlvDecoder_readNestedTlvsStart(decoder, ndn_Tlv_Interest, &endOffset)))
return error;
if ((error = ndn_decodeTlvName
(&interest->name, signedPortionBeginOffset, signedPortionEndOffset,
decoder)))
return error;
if ((error = ndn_TlvDecoder_peekType(decoder, ndn_Tlv_Selectors, endOffset, &gotExpectedType)))
return error;
if (gotExpectedType) {
if ((error = decodeSelectors(interest, decoder)))
return error;
}
else {
// Set selectors to none.
interest->minSuffixComponents = -1;
interest->maxSuffixComponents = -1;
ndn_KeyLocator_initialize
(&interest->keyLocator, interest->keyLocator.keyName.components,
interest->keyLocator.keyName.maxComponents);
interest->exclude.nEntries = 0;
interest->childSelector = -1;
interest->mustBeFresh = 0;
}
// Require a Nonce, but don't force it to be 4 bytes.
if ((error = ndn_TlvDecoder_readBlobTlv(decoder, ndn_Tlv_Nonce, &interest->nonce)))
return error;
if ((error = ndn_TlvDecoder_readOptionalNonNegativeIntegerTlvAsDouble
(decoder, ndn_Tlv_InterestLifetime, endOffset, &interest->interestLifetimeMilliseconds)))
return error;
// Get the encoded sequence of delegations as is.
if ((error = ndn_TlvDecoder_readOptionalBlobTlv
(decoder, ndn_Tlv_ForwardingHint, endOffset,
&interest->forwardingHintWireEncoding)))
return error;
if ((error = ndn_TlvDecoder_peekType(decoder, ndn_Tlv_Data, endOffset, &gotExpectedType)))
return error;
if (gotExpectedType) {
// Get the bytes of the Link TLV.
size_t linkBeginOffset = decoder->offset;
size_t linkEndOffset;
if ((error = ndn_TlvDecoder_readNestedTlvsStart
(decoder, ndn_Tlv_Data, &linkEndOffset)))
return error;
ndn_TlvDecoder_seek(decoder, linkEndOffset);
if ((error = ndn_TlvDecoder_getSlice
(decoder, linkBeginOffset, linkEndOffset, &interest->linkWireEncoding)))
return error;
}
else
ndn_Blob_initialize(&interest->linkWireEncoding, 0, 0);
if ((error = ndn_TlvDecoder_readOptionalNonNegativeIntegerTlv
(decoder, ndn_Tlv_SelectedDelegation, endOffset,
&interest->selectedDelegationIndex)))
return error;
if (interest->selectedDelegationIndex >= 0 && !interest->linkWireEncoding.value)
return NDN_ERROR_Interest_has_a_selected_delegation_but_no_link_object;
if ((error = ndn_TlvDecoder_finishNestedTlvs(decoder, endOffset)))
return error;
return NDN_ERROR_success;
}
