lnd.xprv/lnwire/commit_revocation.go
Olaoluwa Osuntokun 6c7880ef76
lnwire: channels are now identified by outpoint
This commit modifies most of the wire messages to uniquely identify any
*active* channels by their funding output. This allows the wire
protocol to support funding transactions which open several channels in
parallel.

Any pending channels created by partial completion of the funding
workflow are to be identified by a uint64 initialized by both sides as
follows: the initiator of the connection starts from 0, while the
listening node starts from (1 << 63). These pending channel identifiers
are expected to be monotonically increasing with each new funding
workflow between two nodes. This identifier is volatile w.r.t to each
connection initiation.
2016-06-21 13:13:07 -07:00

117 lines
3.5 KiB
Go

package lnwire
import (
"fmt"
"io"
"github.com/roasbeef/btcd/wire"
)
// CommitRevocation is sent by either side once a CommitSignature message has
// been received, and validated. This message serves to revoke the prior
// commitment transaction, which was the most up to date version until a
// CommitSignature message referencing the specified ChannelPoint was received.
// Additionally, this message also piggyback's the next revocation hash that
// Alice should use when constructing the Bob's version of the next commitment
// transaction (which would be done before sending a CommitSignature message).
// This piggybacking allows Alice to send the next CommitSignature message
// modifying Bob's commitment transaction without first asking for a revocation
// hash initially.
type CommitRevocation struct {
// ChannelPoint uniquely identifies to which currently active channel this
// CommitRevocation applies to.
ChannelPoint *wire.OutPoint
// Revocation is the pre-image to the revocation hash of the now prior
// commitment transaction.
Revocation [20]byte
// NextRevocationHash is the next revocation hash to use to create the
// next commitment transaction which is to be created upon receipt of a
// CommitSignature message.
NextRevocationHash [20]byte
}
// NewCommitRevocation creates a new CommitRevocation message.
func NewCommitRevocation() *CommitRevocation {
return &CommitRevocation{}
}
// A compile time check to ensure CommitRevocation implements the lnwire.Message
// interface.
var _ Message = (*CommitRevocation)(nil)
// Decode deserializes a serialized CommitRevocation message stored in the
// passed io.Reader observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *CommitRevocation) Decode(r io.Reader, pver uint32) error {
// ChannelPoint (8)
// NextRevocationHash (20)
// Revocation (20)
err := readElements(r,
&c.ChannelPoint,
&c.NextRevocationHash,
&c.Revocation,
)
if err != nil {
return err
}
return nil
}
// Encode serializes the target CommitRevocation into the passed io.Writer
// observing the protocol version specified.
//
// This is part of the lnwire.Message interface.
func (c *CommitRevocation) Encode(w io.Writer, pver uint32) error {
err := writeElements(w,
c.ChannelPoint,
c.NextRevocationHash,
c.Revocation,
)
if err != nil {
return err
}
return nil
}
// Command returns the integer uniquely identifying this message type on the
// wire.
//
// This is part of the lnwire.Message interface.
func (c *CommitRevocation) Command() uint32 {
return CmdCommitRevocation
}
// MaxPayloadLength returns the maximum allowed payload size for a
// CommitRevocation complete message observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *CommitRevocation) MaxPayloadLength(uint32) uint32 {
// 36 + 20 + 20
return 76
}
// Validate performs any necessary sanity checks to ensure all fields present
// on the CommitRevocation are valid.
//
// This is part of the lnwire.Message interface.
func (c *CommitRevocation) Validate() error {
// We're good!
return nil
}
// String returns the string representation of the target CommitRevocation.
//
// This is part of the lnwire.Message interface.
func (c *CommitRevocation) String() string {
return fmt.Sprintf("\n--- Begin CommitRevocation ---\n") +
fmt.Sprintf("ChannelPoint:\t%d\n", c.ChannelPoint) +
fmt.Sprintf("NextRevocationHash:\t%x\n", c.NextRevocationHash) +
fmt.Sprintf("Revocation:\t%x\n", c.Revocation) +
fmt.Sprintf("--- End CommitRevocation ---\n")
}