lnd.xprv/lnwire/htlc_cancel.go
Olaoluwa Osuntokun 7d0e1576ec
lnwire: remove the HTLC timeout msg in favor of a HTLC cancel msg
This commit removes the previous HTLC timeout in message in favor of a
HTLC cancel message. Within the protocol, a timeout message would never
be sent backwards along the route as in the case of an HTLC timeout
before/after the grace period, the course of action taken would be to
broadcast the current commitment transaction unilaterally on-chain.
2016-09-22 18:51:51 -07:00

101 lines
2.6 KiB
Go

package lnwire
import (
"fmt"
"io"
"github.com/roasbeef/btcd/wire"
)
// CancelHTLC is sent by Alice to Bob in order to remove a previously added
// HTLC. Upon receipt of an CancelHTLC the HTLC should be removed from the next
// commitment transaction, with the CancelHTLC propgated backwards in the route
// to fully un-clear the HTLC.
type CancelHTLC struct {
// ChannelPoint is the particular active channel that this CancelHTLC
// is binded to.
ChannelPoint *wire.OutPoint
// HTLCKey references which HTLC on the remote node's commitment
// transaction has timed out.
HTLCKey HTLCKey
}
// Decode deserializes a serialized CancelHTLC message stored in the passed
// io.Reader observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *CancelHTLC) Decode(r io.Reader, pver uint32) error {
// ChannelPoint(8)
// HTLCKey(8)
err := readElements(r,
&c.ChannelPoint,
&c.HTLCKey,
)
if err != nil {
return err
}
return nil
}
// CancelHTLC creates a new CancelHTLC message.
func NewHTLCTimeoutRequest() *CancelHTLC {
return &CancelHTLC{}
}
// A compile time check to ensure CancelHTLC implements the lnwire.Message
// interface.
var _ Message = (*CancelHTLC)(nil)
// Encode serializes the target CancelHTLC into the passed io.Writer observing
// the protocol version specified.
//
// This is part of the lnwire.Message interface.
func (c *CancelHTLC) Encode(w io.Writer, pver uint32) error {
err := writeElements(w,
c.ChannelPoint,
c.HTLCKey,
)
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 *CancelHTLC) Command() uint32 {
return CmdCancelHTLC
}
// MaxPayloadLength returns the maximum allowed payload size for a CancelHTLC
// complete message observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *CancelHTLC) MaxPayloadLength(uint32) uint32 {
// 36 + 8
return 44
}
// Validate performs any necessary sanity checks to ensure all fields present
// on the CancelHTLC are valid.
//
// This is part of the lnwire.Message interface.
func (c *CancelHTLC) Validate() error {
// We're good!
return nil
}
// String returns the string representation of the target CancelHTLC. This is
// part of the lnwire.Message interface.
func (c *CancelHTLC) String() string {
return fmt.Sprintf("\n--- Begin CancelHTLC ---\n") +
fmt.Sprintf("ChannelPoint:\t%d\n", c.ChannelPoint) +
fmt.Sprintf("HTLCKey:\t%d\n", c.HTLCKey) +
fmt.Sprintf("--- End CancelHTLC ---\n")
}