lnd.xprv/lnwire/node_announcement.go
Olaoluwa Osuntokun 29af6e6932
lnwire: shift fields in NodeAnnouncment to match recent BOLT-0007 changes
This commit modifies the NodeAnnouncement message to ensure that it
matches the current spec ordering. The spec was recently modified to
place the feature vector first to allow for future changes to the
fields to be forwards compatible.
2017-08-22 00:51:59 -07:00

155 lines
3.8 KiB
Go

package lnwire
import (
"bytes"
"fmt"
"io"
"net"
"unicode/utf8"
"github.com/roasbeef/btcd/btcec"
)
var (
startPort uint16 = 1024
endPort uint16 = 49151
)
// RGB is used to represent the "color" of a particular node encoded as a 24
// bit value.
type RGB struct {
red uint8
green uint8
blue uint8
}
// NodeAlias a hex encoded UTF-8 string that may be displayed as an alternative
// to the node's ID. Notice that aliases are not unique and may be freely
// chosen by the node operators.
type NodeAlias [32]byte
// NewNodeAlias creates a new instance of a NodeAlias. Verification is
// performed on the passed string to ensure it meets the alias requirements.
func NewNodeAlias(s string) (NodeAlias, error) {
var n NodeAlias
if len(s) > 32 {
return n, fmt.Errorf("alias too large: max is %v, got %v", 32, len(s))
}
if !utf8.ValidString(s) {
return n, fmt.Errorf("invalid utf8 string")
}
copy(n[:], []byte(s))
return n, nil
}
// String returns a utf8 string representation of the alias bytes.
func (n NodeAlias) String() string {
return string(n[:])
}
// NodeAnnouncement message is used to announce the presence of a Lightning
// node and also to signal that the node is accepting incoming connections.
// Each NodeAnnouncement authenticating the advertised information within the
// announcement via a signature using the advertised node pubkey.
type NodeAnnouncement struct {
// Signature is used to prove the ownership of node id.
Signature *btcec.Signature
// Features is the list of protocol features this node supports.
Features *FeatureVector
// Timestamp allows ordering in the case of multiple announcements.
Timestamp uint32
// NodeID is a public key which is used as node identification.
NodeID *btcec.PublicKey
// RGBColor is used to customize their node's appearance in maps and
// graphs
RGBColor RGB
// Alias is used to customize their node's appearance in maps and
// graphs
Alias NodeAlias
// Address includes two specification fields: 'ipv6' and 'port' on
// which the node is accepting incoming connections.
Addresses []net.Addr
}
// A compile time check to ensure NodeAnnouncement implements the
// lnwire.Message interface.
var _ Message = (*NodeAnnouncement)(nil)
// Decode deserializes a serialized NodeAnnouncement stored in the passed
// io.Reader observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (a *NodeAnnouncement) Decode(r io.Reader, pver uint32) error {
return readElements(r,
&a.Signature,
&a.Features,
&a.Timestamp,
&a.NodeID,
&a.RGBColor,
a.Alias[:],
&a.Addresses,
)
}
// Encode serializes the target NodeAnnouncement into the passed io.Writer
// observing the protocol version specified.
//
func (a *NodeAnnouncement) Encode(w io.Writer, pver uint32) error {
return writeElements(w,
a.Signature,
a.Features,
a.Timestamp,
a.NodeID,
a.RGBColor,
a.Alias[:],
a.Addresses,
)
}
// MsgType returns the integer uniquely identifying this message type on the
// wire.
//
// This is part of the lnwire.Message interface.
func (a *NodeAnnouncement) MsgType() MessageType {
return MsgNodeAnnouncement
}
// MaxPayloadLength returns the maximum allowed payload size for this message
// observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (a *NodeAnnouncement) MaxPayloadLength(pver uint32) uint32 {
return 65533
}
// DataToSign returns the part of the message that should be signed.
func (a *NodeAnnouncement) DataToSign() ([]byte, error) {
// We should not include the signatures itself.
var w bytes.Buffer
err := writeElements(&w,
a.Features,
a.Timestamp,
a.NodeID,
a.RGBColor,
a.Alias[:],
a.Addresses,
)
if err != nil {
return nil, err
}
// TODO(roasbeef): also capture the excess bytes in msg padded out?
return w.Bytes(), nil
}