lnd.xprv/lnwire/open_channel.go
Olaoluwa Osuntokun 7f36b70a4a
lnwire: add new single funder messages from specification
This commit adds the new set of single funder messages from the
specification. As a result, after this commit and a follow up, all of
our messages will directly line up with those that are detailed within
the specification.

The new set of funding messages are very similar to our prior ones,
aside from the main difference of the addition of several channel level
constraints that give nodes control over their exposure, throughput,
and other values.
2017-07-30 17:47:37 -07:00

185 lines
6.3 KiB
Go

package lnwire
import (
"io"
"github.com/roasbeef/btcd/btcec"
"github.com/roasbeef/btcd/chaincfg/chainhash"
"github.com/roasbeef/btcutil"
)
// OpenChannel is the message Alice sends to Bob if we should like to create a
// channel with Bob where she's the sole provider of funds to the channel.
// Single funder channels simplify the initial funding workflow, are supported
// by nodes backed by SPV Bitcoin clients, and have a simpler security models
// than dual funded channels.
type OpenChannel struct {
// ChainHash is the target chain that the initiator wishes to open a
// channel within.
ChainHash chainhash.Hash
// PendingChannelID serves to uniquely identify the future channel
// created by the initiated single funder workflow.
PendingChannelID [32]byte
// FundingAmount is the amount of satoshis that the initiator of the
// channel wishes to use as the total capacity of the channel. The
// initial balance of the funding will be this value minus the push
// amount (if set).
FundingAmount btcutil.Amount
// PushAmount is the value that the initiating party wishes to "push"
// to the responding as part of the first commitment state. If the
// responder accepts, then this will be their initial balance.
//
// TODO(roasbeef): is msat
PushAmount btcutil.Amount
// DustLimit is the specific dust limit the sender of this message
// would like enforced on their version of the commitment transaction.
// Any output below this value will be "trimmed" from the commitment
// transaction, with the amount of the HTLC going to dust.
DustLimit btcutil.Amount
// MaxValueInFlight represents the maximum amount of coins that can be
// pending within the channel at any given time. If the amount of funds
// in limbo exceeds this amount, then the channel will be failed.
MaxValueInFlight btcutil.Amount
// ChannelReserve is the amount of BTC that the receiving party MUST
// maintain a balance above at all times. This is a safety mechanism to
// ensure that both sides always have skin in the game during the
// channel's lifetime.
ChannelReserve btcutil.Amount
// HtlcMinimum is the smallest HTLC that the sender of this message
// will accept.
//
// TODO(roasbeef): is msat
HtlcMinimum uint32
// FeePerKiloWeight is the initial fee rate that the initiator suggests
// for both commitment transaction. This value is expressed in sat per
// kilo-weight.
FeePerKiloWeight uint32
// CsvDelay is the number of blocks to use for the relative time lock
// in the pay-to-self output of both commitment transactions.
CsvDelay uint16
// MaxAcceptedHTLCs is the total number of incoming HTLC's that the
// sender of this channel will accept.
MaxAcceptedHTLCs uint16
// FundingKey is the key that should be used on behalf of the sender
// within the 2-of-2 multi-sig output that it contained within the
// funding transaction.
FundingKey *btcec.PublicKey
// RevocationPoint is the base revocation point for the sending party.
// Any commitment transaction belonging to the receiver of this message
// should use this key and their per-commitment point to derive the
// revocation key for the commitment transaction.
RevocationPoint *btcec.PublicKey
// PaymentPoint is the base payment point for the sending party. This
// key should be combined with the per commitment point for a
// particular commitment state in order to create the key that should
// be used in any output that pays directly to the sending party, and
// also within the HTLC covenant transactions.
PaymentPoint *btcec.PublicKey
// DelayedPaymentPoint is the delay point for the sending party. This
// key should be combined with the per commitment point to derive the
// keys that are used in outputs of the sender's commitment transaction
// where they claim funds.
DelayedPaymentPoint *btcec.PublicKey
// FirstCommitmentPoint is the first commitment point for the sending
// party. This value should be combined with the receiver's revocation
// base point in order to derive the revocation keys that are placed
// within the commitment transaction of the sender.
FirstCommitmentPoint *btcec.PublicKey
// ChannelFlags is a bit-field which allows the initiator of the
// channel to specify further behavior surrounding the channel.
// Currently, the least significant bit of this bit field indicates the
// initiator of the channel wishes to advertise this channel publicly.
ChannelFlags byte
}
// A compile time check to ensure OpenChannel implements the lnwire.Message
// interface.
var _ Message = (*OpenChannel)(nil)
// Encode serializes the target OpenChannel into the passed io.Writer
// implementation. Serialization will observe the rules defined by the passed
// protocol version.
//
// This is part of the lnwire.Message interface.
func (o *OpenChannel) Encode(w io.Writer, pver uint32) error {
return writeElements(w,
o.ChainHash[:],
o.PendingChannelID[:],
o.FundingAmount,
o.PushAmount,
o.DustLimit,
o.MaxValueInFlight,
o.ChannelReserve,
o.HtlcMinimum,
o.FeePerKiloWeight,
o.CsvDelay,
o.MaxAcceptedHTLCs,
o.FundingKey,
o.RevocationPoint,
o.PaymentPoint,
o.DelayedPaymentPoint,
o.FirstCommitmentPoint,
o.ChannelFlags,
)
}
// Decode deserializes the serialized OpenChannel stored in the passed
// io.Reader into the target OpenChannel using the deserialization rules
// defined by the passed protocol version.
//
// This is part of the lnwire.Message interface.
func (o *OpenChannel) Decode(r io.Reader, pver uint32) error {
return readElements(r,
o.ChainHash[:],
o.PendingChannelID[:],
&o.FundingAmount,
&o.PushAmount,
&o.DustLimit,
&o.MaxValueInFlight,
&o.ChannelReserve,
&o.HtlcMinimum,
&o.FeePerKiloWeight,
&o.CsvDelay,
&o.MaxAcceptedHTLCs,
&o.FundingKey,
&o.RevocationPoint,
&o.PaymentPoint,
&o.DelayedPaymentPoint,
&o.FirstCommitmentPoint,
&o.ChannelFlags,
)
}
// MsgType returns the MessageType code which uniquely identifies this message
// as a OpenChannel on the wire.
//
// This is part of the lnwire.Message interface.
func (o *OpenChannel) MsgType() MessageType {
return MsgOpenChannel
}
// MaxPayloadLength returns the maximum allowed payload length for a
// OpenChannel message.
//
// This is part of the lnwire.Message interface.
func (o *OpenChannel) MaxPayloadLength(uint32) uint32 {
// (32 * 2) + (8 * 5) + (4 * 2) + (2 * 2) + (33 * 5) + 1
return 282
}