lnd.xprv/lnwire/commit_sig.go
2020-12-04 23:07:53 +08:00

96 lines
3.2 KiB
Go

package lnwire
import (
"io"
)
// CommitSig is sent by either side to stage any pending HTLC's in the
// receiver's pending set into a new commitment state. Implicitly, the new
// commitment transaction constructed which has been signed by CommitSig
// includes all HTLC's in the remote node's pending set. A CommitSig message
// may be sent after a series of UpdateAddHTLC/UpdateFulfillHTLC messages in
// order to batch add several HTLC's with a single signature covering all
// implicitly accepted HTLC's.
type CommitSig struct {
// ChanID uniquely identifies to which currently active channel this
// CommitSig applies to.
ChanID ChannelID
// CommitSig is Alice's signature for Bob's new commitment transaction.
// Alice is able to send this signature without requesting any
// additional data due to the piggybacking of Bob's next revocation
// hash in his prior RevokeAndAck message, as well as the canonical
// ordering used for all inputs/outputs within commitment transactions.
// If initiating a new commitment state, this signature should ONLY
// cover all of the sending party's pending log updates, and the log
// updates of the remote party that have been ACK'd.
CommitSig Sig
// HtlcSigs is a signature for each relevant HTLC output within the
// created commitment. The order of the signatures is expected to be
// identical to the placement of the HTLC's within the BIP 69 sorted
// commitment transaction. For each outgoing HTLC (from the PoV of the
// sender of this message), a signature for an HTLC timeout transaction
// should be signed, for each incoming HTLC the HTLC timeout
// transaction should be signed.
HtlcSigs []Sig
}
// NewCommitSig creates a new empty CommitSig message.
func NewCommitSig() *CommitSig {
return &CommitSig{}
}
// A compile time check to ensure CommitSig implements the lnwire.Message
// interface.
var _ Message = (*CommitSig)(nil)
// Decode deserializes a serialized CommitSig message stored in the
// passed io.Reader observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *CommitSig) Decode(r io.Reader, pver uint32) error {
return ReadElements(r,
&c.ChanID,
&c.CommitSig,
&c.HtlcSigs,
)
}
// Encode serializes the target CommitSig into the passed io.Writer
// observing the protocol version specified.
//
// This is part of the lnwire.Message interface.
func (c *CommitSig) Encode(w io.Writer, pver uint32) error {
return WriteElements(w,
c.ChanID,
c.CommitSig,
c.HtlcSigs,
)
}
// MsgType returns the integer uniquely identifying this message type on the
// wire.
//
// This is part of the lnwire.Message interface.
func (c *CommitSig) MsgType() MessageType {
return MsgCommitSig
}
// MaxPayloadLength returns the maximum allowed payload size for a
// CommitSig complete message observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *CommitSig) MaxPayloadLength(uint32) uint32 {
// 32 + 64 + 2 + max_allowed_htlcs
return MaxMessagePayload
}
// TargetChanID returns the channel id of the link for which this message is
// intended.
//
// NOTE: Part of peer.LinkUpdater interface.
func (c *CommitSig) TargetChanID() ChannelID {
return c.ChanID
}