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; }