/// <summary>
/// Decode input as an NDN-TLV LpPacket and set the fields of the lpPacket object.
/// </summary>
///
/// <param name="lpPacket">The LpPacket object whose fields are updated.</param>
/// <param name="input"></param>
/// <param name="copy">unchanged while the Blob values are used.</param>
/// <exception cref="EncodingException">For invalid encoding.</exception>
public override void decodeLpPacket(LpPacket lpPacket, ByteBuffer input, bool copy)
{
lpPacket.clear();
TlvDecoder decoder = new TlvDecoder(input);
int endOffset = decoder.readNestedTlvsStart(net.named_data.jndn.encoding.tlv.Tlv.LpPacket_LpPacket);
while (decoder.getOffset() < endOffset) {
// Imitate TlvDecoder.readTypeAndLength.
int fieldType = decoder.readVarNumber();
int fieldLength = decoder.readVarNumber();
int fieldEndOffset = decoder.getOffset() + fieldLength;
if (fieldEndOffset > input.limit())
throw new EncodingException(
"TLV length exceeds the buffer length");
if (fieldType == net.named_data.jndn.encoding.tlv.Tlv.LpPacket_Fragment) {
// Set the fragment to the bytes of the TLV value.
lpPacket.setFragmentWireEncoding(new Blob(decoder.getSlice(
decoder.getOffset(), fieldEndOffset), copy));
decoder.seek(fieldEndOffset);
// The fragment is supposed to be the last field.
break;
} else if (fieldType == net.named_data.jndn.encoding.tlv.Tlv.LpPacket_Nack) {
NetworkNack networkNack = new NetworkNack();
int code = (int) decoder.readOptionalNonNegativeIntegerTlv(
net.named_data.jndn.encoding.tlv.Tlv.LpPacket_NackReason, fieldEndOffset);
// The enum numeric values are the same as this wire format, so use as is.
if (code < 0
|| code == net.named_data.jndn.NetworkNack.Reason.NONE.getNumericType())
// This includes an omitted NackReason.
networkNack.setReason(net.named_data.jndn.NetworkNack.Reason.NONE);
else if (code == net.named_data.jndn.NetworkNack.Reason.CONGESTION.getNumericType())
networkNack.setReason(net.named_data.jndn.NetworkNack.Reason.CONGESTION);
else if (code == net.named_data.jndn.NetworkNack.Reason.DUPLICATE.getNumericType())
networkNack.setReason(net.named_data.jndn.NetworkNack.Reason.DUPLICATE);
else if (code == net.named_data.jndn.NetworkNack.Reason.NO_ROUTE.getNumericType())
networkNack.setReason(net.named_data.jndn.NetworkNack.Reason.NO_ROUTE);
else {
// Unrecognized reason.
networkNack.setReason(net.named_data.jndn.NetworkNack.Reason.OTHER_CODE);
networkNack.setOtherReasonCode(code);
}
lpPacket.addHeaderField(networkNack);
} else if (fieldType == net.named_data.jndn.encoding.tlv.Tlv.LpPacket_IncomingFaceId) {
IncomingFaceId incomingFaceId = new IncomingFaceId();
incomingFaceId.setFaceId(decoder
.readNonNegativeInteger(fieldLength));
lpPacket.addHeaderField(incomingFaceId);
} else {
// Unrecognized field type. The conditions for ignoring are here:
// http://redmine.named-data.net/projects/nfd/wiki/NDNLPv2
bool canIgnore = (fieldType >= net.named_data.jndn.encoding.tlv.Tlv.LpPacket_IGNORE_MIN
&& fieldType <= net.named_data.jndn.encoding.tlv.Tlv.LpPacket_IGNORE_MAX && (fieldType & 0x01) == 1);
if (!canIgnore)
throw new EncodingException(
"Did not get the expected TLV type");
// Ignore.
decoder.seek(fieldEndOffset);
}
decoder.finishNestedTlvs(fieldEndOffset);
}
decoder.finishNestedTlvs(endOffset);
}
private static void decodeSignatureInfo(SignatureHolder signatureHolder,
TlvDecoder decoder, bool copy)
{
int beginOffset = decoder.getOffset();
int endOffset = decoder.readNestedTlvsStart(net.named_data.jndn.encoding.tlv.Tlv.SignatureInfo);
int signatureType = (int) decoder
.readNonNegativeIntegerTlv(net.named_data.jndn.encoding.tlv.Tlv.SignatureType);
if (signatureType == net.named_data.jndn.encoding.tlv.Tlv.SignatureType_SignatureSha256WithRsa) {
signatureHolder.setSignature(new Sha256WithRsaSignature());
// Modify the holder's signature object because if we create an object
// and set it, then the holder will have to copy all the fields.
Sha256WithRsaSignature signatureInfo = (Sha256WithRsaSignature) signatureHolder
.getSignature();
decodeKeyLocator(net.named_data.jndn.encoding.tlv.Tlv.KeyLocator, signatureInfo.getKeyLocator(),
decoder, copy);
if (decoder.peekType(net.named_data.jndn.encoding.tlv.Tlv.ValidityPeriod_ValidityPeriod, endOffset))
decodeValidityPeriod(signatureInfo.getValidityPeriod(), decoder);
} else if (signatureType == net.named_data.jndn.encoding.tlv.Tlv.SignatureType_SignatureSha256WithEcdsa) {
signatureHolder.setSignature(new Sha256WithEcdsaSignature());
Sha256WithEcdsaSignature signatureInfo_0 = (Sha256WithEcdsaSignature) signatureHolder
.getSignature();
decodeKeyLocator(net.named_data.jndn.encoding.tlv.Tlv.KeyLocator, signatureInfo_0.getKeyLocator(),
decoder, copy);
if (decoder.peekType(net.named_data.jndn.encoding.tlv.Tlv.ValidityPeriod_ValidityPeriod, endOffset))
decodeValidityPeriod(signatureInfo_0.getValidityPeriod(), decoder);
} else if (signatureType == net.named_data.jndn.encoding.tlv.Tlv.SignatureType_SignatureHmacWithSha256) {
signatureHolder.setSignature(new HmacWithSha256Signature());
HmacWithSha256Signature signatureInfo_1 = (HmacWithSha256Signature) signatureHolder
.getSignature();
decodeKeyLocator(net.named_data.jndn.encoding.tlv.Tlv.KeyLocator, signatureInfo_1.getKeyLocator(),
decoder, copy);
} else if (signatureType == net.named_data.jndn.encoding.tlv.Tlv.SignatureType_DigestSha256)
signatureHolder.setSignature(new DigestSha256Signature());
else {
signatureHolder.setSignature(new GenericSignature());
GenericSignature signatureInfo_2 = (GenericSignature) signatureHolder
.getSignature();
// Get the bytes of the SignatureInfo TLV.
signatureInfo_2.setSignatureInfoEncoding(
new Blob(decoder.getSlice(beginOffset, endOffset), copy),
signatureType);
}
decoder.finishNestedTlvs(endOffset);
}
/// <summary>
/// Decode input as an interest in NDN-TLV and set the fields of the interest
/// object.
/// </summary>
///
/// <param name="interest">The Interest object whose fields are updated.</param>
/// <param name="input"></param>
/// <param name="signedPortionBeginOffset">name component and ends just before the final name component (which is assumed to be a signature for a signed interest).</param>
/// <param name="signedPortionEndOffset">name component and ends just before the final name component (which is assumed to be a signature for a signed interest).</param>
/// <param name="copy">unchanged while the Blob values are used.</param>
/// <exception cref="EncodingException">For invalid encoding.</exception>
public override void decodeInterest(Interest interest, ByteBuffer input,
int[] signedPortionBeginOffset, int[] signedPortionEndOffset,
bool copy)
{
TlvDecoder decoder = new TlvDecoder(input);
int endOffset = decoder.readNestedTlvsStart(net.named_data.jndn.encoding.tlv.Tlv.Interest);
decodeName(interest.getName(), signedPortionBeginOffset,
signedPortionEndOffset, decoder, copy);
if (decoder.peekType(net.named_data.jndn.encoding.tlv.Tlv.Selectors, endOffset))
decodeSelectors(interest, decoder, copy);
// Require a Nonce, but don't force it to be 4 bytes.
ByteBuffer nonce = decoder.readBlobTlv(net.named_data.jndn.encoding.tlv.Tlv.Nonce);
interest.setInterestLifetimeMilliseconds(decoder
.readOptionalNonNegativeIntegerTlv(net.named_data.jndn.encoding.tlv.Tlv.InterestLifetime,
endOffset));
if (decoder.peekType(net.named_data.jndn.encoding.tlv.Tlv.Data, endOffset)) {
// Get the bytes of the Link TLV.
int linkBeginOffset = decoder.getOffset();
int linkEndOffset = decoder.readNestedTlvsStart(net.named_data.jndn.encoding.tlv.Tlv.Data);
decoder.seek(linkEndOffset);
interest.setLinkWireEncoding(
new Blob(decoder.getSlice(linkBeginOffset, linkEndOffset),
copy), this);
} else
interest.unsetLink();
interest.setSelectedDelegationIndex((int) decoder
.readOptionalNonNegativeIntegerTlv(net.named_data.jndn.encoding.tlv.Tlv.SelectedDelegation,
endOffset));
if (interest.getSelectedDelegationIndex() >= 0 && !interest.hasLink())
throw new EncodingException(
"Interest has a selected delegation, but no link object");
// Set the nonce last because setting other interest fields clears it.
interest.setNonce(new Blob(nonce, copy));
decoder.finishNestedTlvs(endOffset);
}