lnwire: add independent writers

This commit breaks the method WriteElement and adds specific writers for each of the data types.
2025-08-30 07:35:07 +02:00 · 2021-06-18 14:40:59 +08:00
parent e381b33b21
commit f04410c546
3 changed files with 1059 additions and 1 deletions
--- a/lnwire/writer.go
+++ b/lnwire/writer.go
@@ -0,0 +1,431 @@
+package lnwire
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"image/color"
+	"math"
+	"net"
+
+	"github.com/btcsuite/btcd/btcec"
+	"github.com/btcsuite/btcd/wire"
+	"github.com/btcsuite/btcutil"
+	"github.com/lightningnetwork/lnd/tor"
+)
+
+var (
+	// ErrNilFeatureVector is returned when the supplied feature is nil.
+	ErrNilFeatureVector = errors.New("cannot write nil feature vector")
+
+	// ErrPkScriptTooLong is returned when the length of the provided
+	// script exceeds 34.
+	ErrPkScriptTooLong = errors.New("'PkScript' too long")
+
+	// ErrNilTCPAddress is returned when the supplied address is nil.
+	ErrNilTCPAddress = errors.New("cannot write nil TCPAddr")
+
+	// ErrNilOnionAddress is returned when the supplied address is nil.
+	ErrNilOnionAddress = errors.New("cannot write nil onion address")
+
+	// ErrNilNetAddress is returned when a nil value is used in []net.Addr.
+	ErrNilNetAddress = errors.New("cannot write nil address")
+
+	// ErrNilPublicKey is returned when a nil pubkey is used.
+	ErrNilPublicKey = errors.New("cannot write nil pubkey")
+
+	// ErrUnknownServiceLength is returned when the onion service length is
+	// unknown.
+	ErrUnknownServiceLength = errors.New("unknown onion service length")
+)
+
+// ErrOutpointIndexTooBig is used when the outpoint index exceeds the max value
+// of uint16.
+func ErrOutpointIndexTooBig(index uint32) error {
+	return fmt.Errorf(
+		"index for outpoint (%v) is greater than "+
+			"max index of %v", index, math.MaxUint16,
+	)
+}
+
+// WriteBytes appends the given bytes to the provided buffer.
+//
+// Note: We intentionally skip the interfacer linter check here because we want
+// to have concrete type (bytes.Buffer) rather than interface type (io.Write)
+// due to performance concern.
+func WriteBytes(buf *bytes.Buffer, b []byte) error { // nolint: interfacer
+	_, err := buf.Write(b)
+	return err
+}
+
+// WriteUint8 appends the uint8 to the provided buffer.
+//
+// Note: We intentionally skip the interfacer linter check here because we want
+// to have concrete type (bytes.Buffer) rather than interface type (io.Write)
+// due to performance concern.
+func WriteUint8(buf *bytes.Buffer, n uint8) error { // nolint: interfacer
+	_, err := buf.Write([]byte{n})
+	return err
+}
+
+// WriteUint16 appends the uint16 to the provided buffer. It encodes the
+// integer using big endian byte order.
+//
+// Note: We intentionally skip the interfacer linter check here because we want
+// to have concrete type (bytes.Buffer) rather than interface type (io.Write)
+// due to performance concern.
+func WriteUint16(buf *bytes.Buffer, n uint16) error { // nolint: interfacer
+	var b [2]byte
+	binary.BigEndian.PutUint16(b[:], n)
+	_, err := buf.Write(b[:])
+	return err
+}
+
+// WriteUint32 appends the uint32 to the provided buffer. It encodes the
+// integer using big endian byte order.
+func WriteUint32(buf *bytes.Buffer, n uint32) error {
+	var b [4]byte
+	binary.BigEndian.PutUint32(b[:], n)
+	_, err := buf.Write(b[:])
+	return err
+}
+
+// WriteUint64 appends the uint64 to the provided buffer. It encodes the
+// integer using big endian byte order.
+//
+// Note: We intentionally skip the interfacer linter check here because we want
+// to have concrete type (bytes.Buffer) rather than interface type (io.Write)
+// due to performance concern.
+func WriteUint64(buf *bytes.Buffer, n uint64) error { // nolint: interfacer
+	var b [8]byte
+	binary.BigEndian.PutUint64(b[:], n)
+	_, err := buf.Write(b[:])
+	return err
+}
+
+// WriteSatoshi appends the Satoshi value to the provided buffer.
+func WriteSatoshi(buf *bytes.Buffer, amount btcutil.Amount) error {
+	return WriteUint64(buf, uint64(amount))
+}
+
+// WriteMilliSatoshi appends the MilliSatoshi value to the provided buffer.
+func WriteMilliSatoshi(buf *bytes.Buffer, amount MilliSatoshi) error {
+	return WriteUint64(buf, uint64(amount))
+}
+
+// WritePublicKey appends the compressed public key to the provided buffer.
+func WritePublicKey(buf *bytes.Buffer, pub *btcec.PublicKey) error {
+	if pub == nil {
+		return ErrNilPublicKey
+	}
+
+	serializedPubkey := pub.SerializeCompressed()
+	return WriteBytes(buf, serializedPubkey)
+
+}
+
+// WriteChannelID appends the ChannelID to the provided buffer.
+func WriteChannelID(buf *bytes.Buffer, channelID ChannelID) error {
+	return WriteBytes(buf, channelID[:])
+}
+
+// WriteNodeAlias appends the alias to the provided buffer.
+func WriteNodeAlias(buf *bytes.Buffer, alias NodeAlias) error {
+	return WriteBytes(buf, alias[:])
+}
+
+// WriteShortChannelID appends the ShortChannelID to the provided buffer. It
+// encodes the BlockHeight and TxIndex each using 3 bytes with big endian byte
+// order, and encodes txPosition using 2 bytes with big endian byte order.
+func WriteShortChannelID(buf *bytes.Buffer, shortChanID ShortChannelID) error {
+	// Check that field fit in 3 bytes and write the blockHeight
+	if shortChanID.BlockHeight > ((1 << 24) - 1) {
+		return errors.New("block height should fit in 3 bytes")
+	}
+
+	var blockHeight [4]byte
+	binary.BigEndian.PutUint32(blockHeight[:], shortChanID.BlockHeight)
+
+	if _, err := buf.Write(blockHeight[1:]); err != nil {
+		return err
+	}
+
+	// Check that field fit in 3 bytes and write the txIndex
+	if shortChanID.TxIndex > ((1 << 24) - 1) {
+		return errors.New("tx index should fit in 3 bytes")
+	}
+
+	var txIndex [4]byte
+	binary.BigEndian.PutUint32(txIndex[:], shortChanID.TxIndex)
+	if _, err := buf.Write(txIndex[1:]); err != nil {
+		return err
+	}
+
+	// Write the TxPosition
+	return WriteUint16(buf, shortChanID.TxPosition)
+}
+
+// WriteSig appends the signature to the provided buffer.
+func WriteSig(buf *bytes.Buffer, sig Sig) error {
+	return WriteBytes(buf, sig[:])
+}
+
+// WriteSigs appends the slice of signatures to the provided buffer with its
+// length.
+func WriteSigs(buf *bytes.Buffer, sigs []Sig) error {
+	// Write the length of the sigs.
+	if err := WriteUint16(buf, uint16(len(sigs))); err != nil {
+		return err
+	}
+
+	for _, sig := range sigs {
+		if err := WriteSig(buf, sig); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// WriteFailCode appends the FailCode to the provided buffer.
+func WriteFailCode(buf *bytes.Buffer, e FailCode) error {
+	return WriteUint16(buf, uint16(e))
+}
+
+// WriteRawFeatureVector encodes the feature using the feature's Encode method
+// and appends the data to the provided buffer. An error will return if the
+// passed feature is nil.
+//
+// Note: We intentionally skip the interfacer linter check here because we want
+// to have concrete type (bytes.Buffer) rather than interface type (io.Write)
+// due to performance concern.
+func WriteRawFeatureVector(buf *bytes.Buffer, // nolint: interfacer
+	feature *RawFeatureVector) error {
+
+	if feature == nil {
+		return ErrNilFeatureVector
+	}
+
+	return feature.Encode(buf)
+}
+
+// WriteColorRGBA appends the RGBA color using three bytes.
+func WriteColorRGBA(buf *bytes.Buffer, e color.RGBA) error {
+	// Write R
+	if err := WriteUint8(buf, e.R); err != nil {
+		return err
+	}
+
+	// Write G
+	if err := WriteUint8(buf, e.G); err != nil {
+		return err
+	}
+
+	// Write B
+	return WriteUint8(buf, e.B)
+}
+
+// WriteShortChanIDEncoding appends the ShortChanIDEncoding to the provided
+// buffer.
+func WriteShortChanIDEncoding(buf *bytes.Buffer, e ShortChanIDEncoding) error {
+	return WriteUint8(buf, uint8(e))
+}
+
+// WriteFundingFlag appends the FundingFlag to the provided buffer.
+func WriteFundingFlag(buf *bytes.Buffer, flag FundingFlag) error {
+	return WriteUint8(buf, uint8(flag))
+}
+
+// WriteChanUpdateMsgFlags appends the update flag to the provided buffer.
+func WriteChanUpdateMsgFlags(buf *bytes.Buffer, f ChanUpdateMsgFlags) error {
+	return WriteUint8(buf, uint8(f))
+}
+
+// WriteChanUpdateChanFlags appends the update flag to the provided buffer.
+func WriteChanUpdateChanFlags(buf *bytes.Buffer, f ChanUpdateChanFlags) error {
+	return WriteUint8(buf, uint8(f))
+}
+
+// WriteDeliveryAddress appends the address to the provided buffer.
+func WriteDeliveryAddress(buf *bytes.Buffer, addr DeliveryAddress) error {
+	return writeDataWithLength(buf, addr)
+}
+
+// WritePingPayload appends the payload to the provided buffer.
+func WritePingPayload(buf *bytes.Buffer, payload PingPayload) error {
+	return writeDataWithLength(buf, payload)
+}
+
+// WritePongPayload appends the payload to the provided buffer.
+func WritePongPayload(buf *bytes.Buffer, payload PongPayload) error {
+	return writeDataWithLength(buf, payload)
+}
+
+// WriteErrorData appends the data to the provided buffer.
+func WriteErrorData(buf *bytes.Buffer, data ErrorData) error {
+	return writeDataWithLength(buf, data)
+}
+
+// WriteOpaqueReason appends the reason to the provided buffer.
+func WriteOpaqueReason(buf *bytes.Buffer, reason OpaqueReason) error {
+	return writeDataWithLength(buf, reason)
+}
+
+// WriteBool appends the boolean to the provided buffer.
+func WriteBool(buf *bytes.Buffer, b bool) error {
+	if b {
+		return WriteBytes(buf, []byte{1})
+	}
+	return WriteBytes(buf, []byte{0})
+}
+
+// WritePkScript appends the script to the provided buffer. Returns an error if
+// the provided script exceeds 34 bytes.
+//
+// Note: We intentionally skip the interfacer linter check here because we want
+// to have concrete type (bytes.Buffer) rather than interface type (io.Write)
+// due to performance concern.
+func WritePkScript(buf *bytes.Buffer, s PkScript) error { // nolint: interfacer
+	// The largest script we'll accept is a p2wsh which is exactly
+	// 34 bytes long.
+	scriptLength := len(s)
+	if scriptLength > 34 {
+		return ErrPkScriptTooLong
+	}
+
+	return wire.WriteVarBytes(buf, 0, s)
+}
+
+// WriteOutPoint appends the outpoint to the provided buffer.
+func WriteOutPoint(buf *bytes.Buffer, p wire.OutPoint) error {
+	// Before we write anything to the buffer, check the Index is sane.
+	if p.Index > math.MaxUint16 {
+		return ErrOutpointIndexTooBig(p.Index)
+	}
+
+	var h [32]byte
+	copy(h[:], p.Hash[:])
+	if _, err := buf.Write(h[:]); err != nil {
+		return err
+	}
+
+	// Write the index using two bytes.
+	return WriteUint16(buf, uint16(p.Index))
+}
+
+// WriteTCPAddr appends the TCP address to the provided buffer, either a IPv4
+// or a IPv6.
+func WriteTCPAddr(buf *bytes.Buffer, addr *net.TCPAddr) error {
+	if addr == nil {
+		return ErrNilTCPAddress
+	}
+
+	// Make a slice of bytes to hold the data of descriptor and ip. At
+	// most, we need 17 bytes - 1 byte for the descriptor, 16 bytes for
+	// IPv6.
+	data := make([]byte, 0, 17)
+
+	if addr.IP.To4() != nil {
+		data = append(data, uint8(tcp4Addr))
+		data = append(data, addr.IP.To4()...)
+	} else {
+		data = append(data, uint8(tcp6Addr))
+		data = append(data, addr.IP.To16()...)
+	}
+
+	if _, err := buf.Write(data); err != nil {
+		return err
+	}
+
+	return WriteUint16(buf, uint16(addr.Port))
+}
+
+// WriteOnionAddr appends the onion address to the provided buffer.
+func WriteOnionAddr(buf *bytes.Buffer, addr *tor.OnionAddr) error {
+	if addr == nil {
+		return ErrNilOnionAddress
+	}
+
+	var (
+		suffixIndex int
+		descriptor  []byte
+	)
+
+	// Decide the suffixIndex and descriptor.
+	switch len(addr.OnionService) {
+	case tor.V2Len:
+		descriptor = []byte{byte(v2OnionAddr)}
+		suffixIndex = tor.V2Len - tor.OnionSuffixLen
+
+	case tor.V3Len:
+		descriptor = []byte{byte(v3OnionAddr)}
+		suffixIndex = tor.V3Len - tor.OnionSuffixLen
+
+	default:
+		return ErrUnknownServiceLength
+	}
+
+	// Decode the address.
+	host, err := tor.Base32Encoding.DecodeString(
+		addr.OnionService[:suffixIndex],
+	)
+	if err != nil {
+		return err
+	}
+
+	// Perform the actual write when the above checks passed.
+	if _, err := buf.Write(descriptor); err != nil {
+		return err
+	}
+	if _, err := buf.Write(host); err != nil {
+		return err
+	}
+
+	return WriteUint16(buf, uint16(addr.Port))
+}
+
+// WriteNetAddrs appends a slice of addresses to the provided buffer with the
+// length info.
+func WriteNetAddrs(buf *bytes.Buffer, addresses []net.Addr) error {
+	// First, we'll encode all the addresses into an intermediate
+	// buffer. We need to do this in order to compute the total
+	// length of the addresses.
+	buffer := make([]byte, 0, MaxMsgBody)
+	addrBuf := bytes.NewBuffer(buffer)
+
+	for _, address := range addresses {
+		switch a := address.(type) {
+		case *net.TCPAddr:
+			if err := WriteTCPAddr(addrBuf, a); err != nil {
+				return err
+			}
+		case *tor.OnionAddr:
+			if err := WriteOnionAddr(addrBuf, a); err != nil {
+				return err
+			}
+		default:
+			return ErrNilNetAddress
+		}
+	}
+
+	// With the addresses fully encoded, we can now write out data.
+	return writeDataWithLength(buf, addrBuf.Bytes())
+}
+
+// writeDataWithLength writes the data and its length to the buffer.
+//
+// Note: We intentionally skip the interfacer linter check here because we want
+// to have concrete type (bytes.Buffer) rather than interface type (io.Write)
+// due to performance concern.
+func writeDataWithLength(buf *bytes.Buffer, // nolint: interfacer
+	data []byte) error {
+
+	var l [2]byte
+	binary.BigEndian.PutUint16(l[:], uint16(len(data)))
+	if _, err := buf.Write(l[:]); err != nil {
+		return err
+	}
+
+	_, err := buf.Write(data)
+	return err
+}