a603ac4938
In this commit, we create a new `ExtraOpaqueData` based on the field with the same name that's present in all the announcement related messages. In later commits, we'll embed this new type in each message, so we'll have a generic way to add/parse TLV extensions from messages.
85 lines
2.3 KiB
Go
85 lines
2.3 KiB
Go
package lnwire
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import (
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"bytes"
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"io"
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"io/ioutil"
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"github.com/lightningnetwork/lnd/tlv"
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)
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// ExtraOpaqueData is the set of data that was appended to this message, some
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// of which we may not actually know how to iterate or parse. By holding onto
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// this data, we ensure that we're able to properly validate the set of
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// signatures that cover these new fields, and ensure we're able to make
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// upgrades to the network in a forwards compatible manner.
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type ExtraOpaqueData []byte
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// Encode attempts to encode the raw extra bytes into the passed io.Writer.
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func (e *ExtraOpaqueData) Encode(w io.Writer) error {
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eBytes := []byte((*e)[:])
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if err := WriteElements(w, eBytes); err != nil {
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return err
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}
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return nil
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}
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// Decode attempts to unpack the raw bytes encoded in the passed io.Reader as a
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// set of extra opaque data.
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func (e *ExtraOpaqueData) Decode(r io.Reader) error {
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// First, we'll attempt to read a set of bytes contained within the
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// passed io.Reader (if any exist).
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rawBytes, err := ioutil.ReadAll(r)
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if err != nil {
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return err
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}
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// If we _do_ have some bytes, then we'll swap out our backing pointer.
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// This ensures that any struct that embeds this type will properly
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// store the bytes once this method exits.
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if len(rawBytes) > 0 {
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*e = ExtraOpaqueData(rawBytes)
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} else {
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*e = make([]byte, 0)
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}
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return nil
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}
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// PackRecords attempts to encode the set of tlv records into the target
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// ExtraOpaqueData instance. The records will be encoded as a raw TLV stream
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// and stored within the backing slice pointer.
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func (e *ExtraOpaqueData) PackRecords(records ...tlv.Record) error {
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tlvStream, err := tlv.NewStream(records...)
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if err != nil {
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return err
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}
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var extraBytesWriter bytes.Buffer
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if err := tlvStream.Encode(&extraBytesWriter); err != nil {
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return err
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}
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*e = ExtraOpaqueData(extraBytesWriter.Bytes())
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return nil
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}
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// ExtractRecords attempts to decode any types in the internal raw bytes as if
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// it were a tlv stream. The set of raw parsed types is returned, and any
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// passed records (if found in the stream) will be parsed into the proper
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// tlv.Record.
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func (e *ExtraOpaqueData) ExtractRecords(records ...tlv.Record) (
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tlv.TypeMap, error) {
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extraBytesReader := bytes.NewReader(*e)
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tlvStream, err := tlv.NewStream(records...)
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if err != nil {
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return nil, err
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}
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return tlvStream.DecodeWithParsedTypes(extraBytesReader)
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}
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