lnd.xprv/lnwire/onion_error.go
Olaoluwa Osuntokun 31e92c4ff2
lnwire: add new compatibility parsing more for onion error chan updates
In this commit, we add a compatibility mode for older version of
clightning to ensure that we're able to properly parse all their channel
updates. An older version of c-lightning would send out encapsulated
onion error message with an additional type byte. This would throw off
our parsing as we didn't expect the type byte, and so we always 2 bytes
off. In order to ensure that we're able to parse these messages and make
adjustments to our path finding, we'll first check to see if the type
byte is there, if so, then we'll snip off two bytes from the front and
continue with parsing. if the bytes aren't found, then we can proceed as
normal and parse the request.
2018-08-31 17:24:26 -07:00

1206 lines
35 KiB
Go

package lnwire
import (
"bufio"
"crypto/sha256"
"encoding/binary"
"fmt"
"io"
"bytes"
"github.com/davecgh/go-spew/spew"
"github.com/go-errors/errors"
)
// FailureMessage represents the onion failure object identified by its unique
// failure code.
type FailureMessage interface {
// Code returns a failure code describing the exact nature of the
// error.
Code() FailCode
// Error returns a human readable string describing the error. With
// this method, the FailureMessage interface meets the built-in error
// interface.
Error() string
}
// failureMessageLength is the size of the failure message plus the size of
// padding. The FailureMessage message should always be EXACTLY this size.
const failureMessageLength = 256
const (
// FlagBadOnion error flag describes an unparsable, encrypted by
// previous node.
FlagBadOnion FailCode = 0x8000
// FlagPerm error flag indicates a permanent failure.
FlagPerm FailCode = 0x4000
// FlagNode error flag indicates anode failure.
FlagNode FailCode = 0x2000
// FlagUpdate error flag indicates a new channel update is enclosed
// within the error.
FlagUpdate FailCode = 0x1000
)
// FailCode specifies the precise reason that an upstream HTLC was cancelled.
// Each UpdateFailHTLC message carries a FailCode which is to be passed
// backwards, encrypted at each step back to the source of the HTLC within the
// route.
type FailCode uint16
// The currently defined onion failure types within this current version of the
// Lightning protocol.
const (
CodeNone FailCode = 0
CodeInvalidRealm = FlagBadOnion | 1
CodeTemporaryNodeFailure = FlagNode | 2
CodePermanentNodeFailure = FlagPerm | FlagNode | 2
CodeRequiredNodeFeatureMissing = FlagPerm | FlagNode | 3
CodeInvalidOnionVersion = FlagBadOnion | FlagPerm | 4
CodeInvalidOnionHmac = FlagBadOnion | FlagPerm | 5
CodeInvalidOnionKey = FlagBadOnion | FlagPerm | 6
CodeTemporaryChannelFailure = FlagUpdate | 7
CodePermanentChannelFailure = FlagPerm | 8
CodeRequiredChannelFeatureMissing = FlagPerm | 9
CodeUnknownNextPeer = FlagPerm | 10
CodeAmountBelowMinimum = FlagUpdate | 11
CodeFeeInsufficient = FlagUpdate | 12
CodeIncorrectCltvExpiry = FlagUpdate | 13
CodeExpiryTooSoon = FlagUpdate | 14
CodeChannelDisabled = FlagUpdate | 20
CodeUnknownPaymentHash = FlagPerm | 15
CodeIncorrectPaymentAmount = FlagPerm | 16
CodeFinalExpiryTooSoon FailCode = 17
CodeFinalIncorrectCltvExpiry FailCode = 18
CodeFinalIncorrectHtlcAmount FailCode = 19
)
// String returns the string representation of the failure code.
func (c FailCode) String() string {
switch c {
case CodeInvalidRealm:
return "InvalidRealm"
case CodeTemporaryNodeFailure:
return "TemporaryNodeFailure"
case CodePermanentNodeFailure:
return "PermanentNodeFailure"
case CodeRequiredNodeFeatureMissing:
return "RequiredNodeFeatureMissing"
case CodeInvalidOnionVersion:
return "InvalidOnionVersion"
case CodeInvalidOnionHmac:
return "InvalidOnionHmac"
case CodeInvalidOnionKey:
return "InvalidOnionKey"
case CodeTemporaryChannelFailure:
return "TemporaryChannelFailure"
case CodePermanentChannelFailure:
return "PermanentChannelFailure"
case CodeRequiredChannelFeatureMissing:
return "RequiredChannelFeatureMissing"
case CodeUnknownNextPeer:
return "UnknownNextPeer"
case CodeAmountBelowMinimum:
return "AmountBelowMinimum"
case CodeFeeInsufficient:
return "FeeInsufficient"
case CodeIncorrectCltvExpiry:
return "IncorrectCltvExpiry"
case CodeExpiryTooSoon:
return "ExpiryTooSoon"
case CodeChannelDisabled:
return "ChannelDisabled"
case CodeUnknownPaymentHash:
return "UnknownPaymentHash"
case CodeIncorrectPaymentAmount:
return "IncorrectPaymentAmount"
case CodeFinalExpiryTooSoon:
return "FinalExpiryTooSoon"
case CodeFinalIncorrectCltvExpiry:
return "FinalIncorrectCltvExpiry"
case CodeFinalIncorrectHtlcAmount:
return "FinalIncorrectHtlcAmount"
default:
return "<unknown>"
}
}
// FailInvalidRealm is returned if the realm byte is unknown.
//
// NOTE: May be returned by any node in the payment route.
type FailInvalidRealm struct{}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailInvalidRealm) Error() string {
return f.Code().String()
}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f FailInvalidRealm) Code() FailCode {
return CodeInvalidRealm
}
// FailTemporaryNodeFailure is returned if an otherwise unspecified transient
// error occurs for the entire node.
//
// NOTE: May be returned by any node in the payment route.
type FailTemporaryNodeFailure struct{}
// Code returns the failure unique code.
// NOTE: Part of the FailureMessage interface.
func (f FailTemporaryNodeFailure) Code() FailCode {
return CodeTemporaryNodeFailure
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailTemporaryNodeFailure) Error() string {
return f.Code().String()
}
// FailPermanentNodeFailure is returned if an otherwise unspecified permanent
// error occurs for the entire node.
//
// NOTE: May be returned by any node in the payment route.
type FailPermanentNodeFailure struct{}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f FailPermanentNodeFailure) Code() FailCode {
return CodePermanentNodeFailure
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailPermanentNodeFailure) Error() string {
return f.Code().String()
}
// FailRequiredNodeFeatureMissing is returned if a node has requirement
// advertised in its node_announcement features which were not present in the
// onion.
//
// NOTE: May be returned by any node in the payment route.
type FailRequiredNodeFeatureMissing struct{}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f FailRequiredNodeFeatureMissing) Code() FailCode {
return CodeRequiredNodeFeatureMissing
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailRequiredNodeFeatureMissing) Error() string {
return f.Code().String()
}
// FailPermanentChannelFailure is return if an otherwise unspecified permanent
// error occurs for the outgoing channel (eg. channel (recently).
//
// NOTE: May be returned by any node in the payment route.
type FailPermanentChannelFailure struct{}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f FailPermanentChannelFailure) Code() FailCode {
return CodePermanentChannelFailure
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailPermanentChannelFailure) Error() string {
return f.Code().String()
}
// FailRequiredChannelFeatureMissing is returned if the outgoing channel has a
// requirement advertised in its channel announcement features which were not
// present in the onion.
//
// NOTE: May only be returned by intermediate nodes.
type FailRequiredChannelFeatureMissing struct{}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f FailRequiredChannelFeatureMissing) Code() FailCode {
return CodeRequiredChannelFeatureMissing
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailRequiredChannelFeatureMissing) Error() string {
return f.Code().String()
}
// FailUnknownNextPeer is returned if the next peer specified by the onion is
// not known.
//
// NOTE: May only be returned by intermediate nodes.
type FailUnknownNextPeer struct{}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f FailUnknownNextPeer) Code() FailCode {
return CodeUnknownNextPeer
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailUnknownNextPeer) Error() string {
return f.Code().String()
}
// FailUnknownPaymentHash is returned If the payment hash has already been
// paid, the final node MAY treat the payment hash as unknown, or may succeed
// in accepting the HTLC. If the payment hash is unknown, the final node MUST
// fail the HTLC.
//
// NOTE: May only be returned by the final node in the path.
type FailUnknownPaymentHash struct{}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f FailUnknownPaymentHash) Code() FailCode {
return CodeUnknownPaymentHash
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailUnknownPaymentHash) Error() string {
return f.Code().String()
}
// FailIncorrectPaymentAmount is returned if the amount paid is less than the
// amount expected, the final node MUST fail the HTLC. If the amount paid is
// more than twice the amount expected, the final node SHOULD fail the HTLC.
// This allows the sender to reduce information leakage by altering the amount,
// without allowing accidental gross overpayment.
//
// NOTE: May only be returned by the final node in the path.
type FailIncorrectPaymentAmount struct{}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f FailIncorrectPaymentAmount) Code() FailCode {
return CodeIncorrectPaymentAmount
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailIncorrectPaymentAmount) Error() string {
return f.Code().String()
}
// FailFinalExpiryTooSoon is returned if the cltv_expiry is too low, the final
// node MUST fail the HTLC.
//
// NOTE: May only be returned by the final node in the path.
type FailFinalExpiryTooSoon struct{}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f FailFinalExpiryTooSoon) Code() FailCode {
return CodeFinalExpiryTooSoon
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailFinalExpiryTooSoon) Error() string {
return f.Code().String()
}
// FailInvalidOnionVersion is returned if the onion version byte is unknown.
//
// NOTE: May be returned only by intermediate nodes.
type FailInvalidOnionVersion struct {
// OnionSHA256 hash of the onion blob which haven't been proceeded.
OnionSHA256 [sha256.Size]byte
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailInvalidOnionVersion) Error() string {
return fmt.Sprintf("InvalidOnionVersion(onion_sha=%x)", f.OnionSHA256[:])
}
// NewInvalidOnionVersion creates new instance of the FailInvalidOnionVersion.
func NewInvalidOnionVersion(onion []byte) *FailInvalidOnionVersion {
return &FailInvalidOnionVersion{OnionSHA256: sha256.Sum256(onion)}
}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f *FailInvalidOnionVersion) Code() FailCode {
return CodeInvalidOnionVersion
}
// Decode decodes the failure from bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailInvalidOnionVersion) Decode(r io.Reader, pver uint32) error {
return readElement(r, f.OnionSHA256[:])
}
// Encode writes the failure in bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailInvalidOnionVersion) Encode(w io.Writer, pver uint32) error {
return writeElement(w, f.OnionSHA256[:])
}
// FailInvalidOnionHmac is return if the onion HMAC is incorrect.
//
// NOTE: May only be returned by intermediate nodes.
type FailInvalidOnionHmac struct {
// OnionSHA256 hash of the onion blob which haven't been proceeded.
OnionSHA256 [sha256.Size]byte
}
// NewInvalidOnionHmac creates new instance of the FailInvalidOnionHmac.
func NewInvalidOnionHmac(onion []byte) *FailInvalidOnionHmac {
return &FailInvalidOnionHmac{OnionSHA256: sha256.Sum256(onion)}
}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f *FailInvalidOnionHmac) Code() FailCode {
return CodeInvalidOnionHmac
}
// Decode decodes the failure from bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailInvalidOnionHmac) Decode(r io.Reader, pver uint32) error {
return readElement(r, f.OnionSHA256[:])
}
// Encode writes the failure in bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailInvalidOnionHmac) Encode(w io.Writer, pver uint32) error {
return writeElement(w, f.OnionSHA256[:])
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailInvalidOnionHmac) Error() string {
return fmt.Sprintf("InvalidOnionHMAC(onion_sha=%x)", f.OnionSHA256[:])
}
// FailInvalidOnionKey is return if the ephemeral key in the onion is
// unparsable.
//
// NOTE: May only be returned by intermediate nodes.
type FailInvalidOnionKey struct {
// OnionSHA256 hash of the onion blob which haven't been proceeded.
OnionSHA256 [sha256.Size]byte
}
// NewInvalidOnionKey creates new instance of the FailInvalidOnionKey.
func NewInvalidOnionKey(onion []byte) *FailInvalidOnionKey {
return &FailInvalidOnionKey{OnionSHA256: sha256.Sum256(onion)}
}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f *FailInvalidOnionKey) Code() FailCode {
return CodeInvalidOnionKey
}
// Decode decodes the failure from bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailInvalidOnionKey) Decode(r io.Reader, pver uint32) error {
return readElement(r, f.OnionSHA256[:])
}
// Encode writes the failure in bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailInvalidOnionKey) Encode(w io.Writer, pver uint32) error {
return writeElement(w, f.OnionSHA256[:])
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailInvalidOnionKey) Error() string {
return fmt.Sprintf("InvalidOnionKey(onion_sha=%x)", f.OnionSHA256[:])
}
// parseChannelUpdateCompatabilityMode will attempt to parse a channel updated
// encoded into an onion error payload in two ways. First, we'll try the
// compatibility oriented version wherein we'll _skip_ the length prefixing on
// the channel update message. Older versions of c-lighting do this so we'll
// attempt to parse these messages in order to retain compatibility. If we're
// unable to pull out a fully valid version, then we'll fall back to the
// regular parsing mechanism which includes the length prefix an NO type byte.
func parseChannelUpdateCompatabilityMode(r *bufio.Reader,
chanUpdate *ChannelUpdate, pver uint32) error {
// We'll peek out two bytes from the buffer without advancing the
// buffer so we can decide how to parse the remainder of it.
maybeTypeBytes, err := r.Peek(2)
if err != nil {
return err
}
// Some nodes well prefix an additional set of bytes in front of their
// channel updates. These bytes will _almost_ always be 258 or the type
// of the ChannelUpdate message.
typeInt := binary.BigEndian.Uint16(maybeTypeBytes)
if typeInt == MsgChannelUpdate {
// At this point it's likely the case that this is a channel
// update message with its type prefixed, so we'll snip off the
// first two bytes and parse it as normal.
var throwAwayTypeBytes [2]byte
_, err := r.Read(throwAwayTypeBytes[:])
if err != nil {
return err
}
}
// At this pint, we've either decided to keep the entire thing, or snip
// off the first two bytes. In either case, we can just read it as
// normal.
return chanUpdate.Decode(r, pver)
}
// FailTemporaryChannelFailure is if an otherwise unspecified transient error
// occurs for the outgoing channel (eg. channel capacity reached, too many
// in-flight htlcs)
//
// NOTE: May only be returned by intermediate nodes.
type FailTemporaryChannelFailure struct {
// Update is used to update information about state of the channel
// which caused the failure.
//
// NOTE: This field is optional.
Update *ChannelUpdate
}
// NewTemporaryChannelFailure creates new instance of the FailTemporaryChannelFailure.
func NewTemporaryChannelFailure(update *ChannelUpdate) *FailTemporaryChannelFailure {
return &FailTemporaryChannelFailure{Update: update}
}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f *FailTemporaryChannelFailure) Code() FailCode {
return CodeTemporaryChannelFailure
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailTemporaryChannelFailure) Error() string {
if f.Update == nil {
return f.Code().String()
}
return fmt.Sprintf("TemporaryChannelFailure(update=%v)",
spew.Sdump(f.Update))
}
// Decode decodes the failure from bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailTemporaryChannelFailure) Decode(r io.Reader, pver uint32) error {
var length uint16
err := readElement(r, &length)
if err != nil {
return err
}
if length != 0 {
f.Update = &ChannelUpdate{}
return parseChannelUpdateCompatabilityMode(
bufio.NewReader(r), f.Update, pver,
)
}
return nil
}
// Encode writes the failure in bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailTemporaryChannelFailure) Encode(w io.Writer, pver uint32) error {
var payload []byte
if f.Update != nil {
var bw bytes.Buffer
if err := f.Update.Encode(&bw, pver); err != nil {
return err
}
payload = bw.Bytes()
}
if err := writeElement(w, uint16(len(payload))); err != nil {
return err
}
_, err := w.Write(payload)
return err
}
// FailAmountBelowMinimum is returned if the HTLC does not reach the current
// minimum amount, we tell them the amount of the incoming HTLC and the current
// channel setting for the outgoing channel.
//
// NOTE: May only be returned by the intermediate nodes in the path.
type FailAmountBelowMinimum struct {
// HtlcMsat is the wrong amount of the incoming HTLC.
HtlcMsat MilliSatoshi
// Update is used to update information about state of the channel
// which caused the failure.
Update ChannelUpdate
}
// NewAmountBelowMinimum creates new instance of the FailAmountBelowMinimum.
func NewAmountBelowMinimum(htlcMsat MilliSatoshi,
update ChannelUpdate) *FailAmountBelowMinimum {
return &FailAmountBelowMinimum{
HtlcMsat: htlcMsat,
Update: update,
}
}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f *FailAmountBelowMinimum) Code() FailCode {
return CodeAmountBelowMinimum
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailAmountBelowMinimum) Error() string {
return fmt.Sprintf("AmountBelowMinimum(amt=%v, update=%v", f.HtlcMsat,
spew.Sdump(f.Update))
}
// Decode decodes the failure from bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailAmountBelowMinimum) Decode(r io.Reader, pver uint32) error {
if err := readElement(r, &f.HtlcMsat); err != nil {
return err
}
var length uint16
if err := readElement(r, &length); err != nil {
return err
}
f.Update = ChannelUpdate{}
return parseChannelUpdateCompatabilityMode(
bufio.NewReader(r), &f.Update, pver,
)
}
// Encode writes the failure in bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailAmountBelowMinimum) Encode(w io.Writer, pver uint32) error {
if err := writeElement(w, f.HtlcMsat); err != nil {
return err
}
err := writeElement(w, uint16(f.Update.MaxPayloadLength(pver)))
if err != nil {
return err
}
return f.Update.Encode(w, pver)
}
// FailFeeInsufficient is returned if the HTLC does not pay sufficient fee, we
// tell them the amount of the incoming HTLC and the current channel setting
// for the outgoing channel.
//
// NOTE: May only be returned by intermediate nodes.
type FailFeeInsufficient struct {
// HtlcMsat is the wrong amount of the incoming HTLC.
HtlcMsat MilliSatoshi
// Update is used to update information about state of the channel
// which caused the failure.
Update ChannelUpdate
}
// NewFeeInsufficient creates new instance of the FailFeeInsufficient.
func NewFeeInsufficient(htlcMsat MilliSatoshi,
update ChannelUpdate) *FailFeeInsufficient {
return &FailFeeInsufficient{
HtlcMsat: htlcMsat,
Update: update,
}
}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f *FailFeeInsufficient) Code() FailCode {
return CodeFeeInsufficient
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailFeeInsufficient) Error() string {
return fmt.Sprintf("FeeInsufficient(htlc_amt==%v, update=%v", f.HtlcMsat,
spew.Sdump(f.Update))
}
// Decode decodes the failure from bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailFeeInsufficient) Decode(r io.Reader, pver uint32) error {
if err := readElement(r, &f.HtlcMsat); err != nil {
return err
}
var length uint16
if err := readElement(r, &length); err != nil {
return err
}
f.Update = ChannelUpdate{}
return parseChannelUpdateCompatabilityMode(
bufio.NewReader(r), &f.Update, pver,
)
}
// Encode writes the failure in bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailFeeInsufficient) Encode(w io.Writer, pver uint32) error {
if err := writeElement(w, f.HtlcMsat); err != nil {
return err
}
err := writeElement(w, uint16(f.Update.MaxPayloadLength(pver)))
if err != nil {
return err
}
return f.Update.Encode(w, pver)
}
// FailIncorrectCltvExpiry is returned if outgoing cltv value does not match
// the update add htlc's cltv expiry minus cltv expiry delta for the outgoing
// channel, we tell them the cltv expiry and the current channel setting for
// the outgoing channel.
//
// NOTE: May only be returned by intermediate nodes.
type FailIncorrectCltvExpiry struct {
// CltvExpiry is the wrong absolute timeout in blocks, after which
// outgoing HTLC expires.
CltvExpiry uint32
// Update is used to update information about state of the channel
// which caused the failure.
Update ChannelUpdate
}
// NewIncorrectCltvExpiry creates new instance of the FailIncorrectCltvExpiry.
func NewIncorrectCltvExpiry(cltvExpiry uint32,
update ChannelUpdate) *FailIncorrectCltvExpiry {
return &FailIncorrectCltvExpiry{
CltvExpiry: cltvExpiry,
Update: update,
}
}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f *FailIncorrectCltvExpiry) Code() FailCode {
return CodeIncorrectCltvExpiry
}
func (f *FailIncorrectCltvExpiry) Error() string {
return fmt.Sprintf("IncorrectCltvExpiry(expiry=%v, update=%v",
f.CltvExpiry, spew.Sdump(f.Update))
}
// Decode decodes the failure from bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailIncorrectCltvExpiry) Decode(r io.Reader, pver uint32) error {
if err := readElement(r, &f.CltvExpiry); err != nil {
return err
}
var length uint16
if err := readElement(r, &length); err != nil {
return err
}
f.Update = ChannelUpdate{}
return parseChannelUpdateCompatabilityMode(
bufio.NewReader(r), &f.Update, pver,
)
}
// Encode writes the failure in bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailIncorrectCltvExpiry) Encode(w io.Writer, pver uint32) error {
if err := writeElement(w, f.CltvExpiry); err != nil {
return err
}
err := writeElement(w, uint16(f.Update.MaxPayloadLength(pver)))
if err != nil {
return err
}
return f.Update.Encode(w, pver)
}
// FailExpiryTooSoon is returned if the ctlv-expiry is too near, we tell them
// the current channel setting for the outgoing channel.
//
// NOTE: May only be returned by intermediate nodes.
type FailExpiryTooSoon struct {
// Update is used to update information about state of the channel
// which caused the failure.
Update ChannelUpdate
}
// NewExpiryTooSoon creates new instance of the FailExpiryTooSoon.
func NewExpiryTooSoon(update ChannelUpdate) *FailExpiryTooSoon {
return &FailExpiryTooSoon{
Update: update,
}
}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f *FailExpiryTooSoon) Code() FailCode {
return CodeExpiryTooSoon
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f *FailExpiryTooSoon) Error() string {
return fmt.Sprintf("ExpiryTooSoon(update=%v", spew.Sdump(f.Update))
}
// Decode decodes the failure from l stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailExpiryTooSoon) Decode(r io.Reader, pver uint32) error {
var length uint16
if err := readElement(r, &length); err != nil {
return err
}
f.Update = ChannelUpdate{}
return parseChannelUpdateCompatabilityMode(
bufio.NewReader(r), &f.Update, pver,
)
}
// Encode writes the failure in bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailExpiryTooSoon) Encode(w io.Writer, pver uint32) error {
err := writeElement(w, uint16(f.Update.MaxPayloadLength(pver)))
if err != nil {
return err
}
return f.Update.Encode(w, pver)
}
// FailChannelDisabled is returned if the channel is disabled, we tell them the
// current channel setting for the outgoing channel.
//
// NOTE: May only be returned by intermediate nodes.
type FailChannelDisabled struct {
// Flags least-significant bit must be set to 0 if the creating node
// corresponds to the first node in the previously sent channel
// announcement and 1 otherwise.
Flags uint16
// Update is used to update information about state of the channel
// which caused the failure.
Update ChannelUpdate
}
// NewChannelDisabled creates new instance of the FailChannelDisabled.
func NewChannelDisabled(flags uint16, update ChannelUpdate) *FailChannelDisabled {
return &FailChannelDisabled{
Flags: flags,
Update: update,
}
}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f *FailChannelDisabled) Code() FailCode {
return CodeChannelDisabled
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailChannelDisabled) Error() string {
return fmt.Sprintf("ChannelDisabled(flags=%v, update=%v", f.Flags,
spew.Sdump(f.Update))
}
// Decode decodes the failure from bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailChannelDisabled) Decode(r io.Reader, pver uint32) error {
if err := readElement(r, &f.Flags); err != nil {
return err
}
var length uint16
if err := readElement(r, &length); err != nil {
return err
}
f.Update = ChannelUpdate{}
return parseChannelUpdateCompatabilityMode(
bufio.NewReader(r), &f.Update, pver,
)
}
// Encode writes the failure in bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailChannelDisabled) Encode(w io.Writer, pver uint32) error {
if err := writeElement(w, f.Flags); err != nil {
return err
}
err := writeElement(w, uint16(f.Update.MaxPayloadLength(pver)))
if err != nil {
return err
}
return f.Update.Encode(w, pver)
}
// FailFinalIncorrectCltvExpiry is returned if the outgoing_cltv_value does not
// match the ctlv_expiry of the HTLC at the final hop.
//
// NOTE: might be returned by final node only.
type FailFinalIncorrectCltvExpiry struct {
// CltvExpiry is the wrong absolute timeout in blocks, after which
// outgoing HTLC expires.
CltvExpiry uint32
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailFinalIncorrectCltvExpiry) Error() string {
return fmt.Sprintf("FinalIncorrectCltvExpiry(expiry=%v)", f.CltvExpiry)
}
// NewFinalIncorrectCltvExpiry creates new instance of the
// FailFinalIncorrectCltvExpiry.
func NewFinalIncorrectCltvExpiry(cltvExpiry uint32) *FailFinalIncorrectCltvExpiry {
return &FailFinalIncorrectCltvExpiry{
CltvExpiry: cltvExpiry,
}
}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f *FailFinalIncorrectCltvExpiry) Code() FailCode {
return CodeFinalIncorrectCltvExpiry
}
// Decode decodes the failure from bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailFinalIncorrectCltvExpiry) Decode(r io.Reader, pver uint32) error {
return readElement(r, &f.CltvExpiry)
}
// Encode writes the failure in bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailFinalIncorrectCltvExpiry) Encode(w io.Writer, pver uint32) error {
return writeElement(w, f.CltvExpiry)
}
// FailFinalIncorrectHtlcAmount is returned if the amt_to_forward is higher
// than incoming_htlc_amt of the HTLC at the final hop.
//
// NOTE: May only be returned by the final node.
type FailFinalIncorrectHtlcAmount struct {
// IncomingHTLCAmount is the wrong forwarded htlc amount.
IncomingHTLCAmount MilliSatoshi
}
// Returns a human readable string describing the target FailureMessage.
//
// NOTE: Implements the error interface.
func (f FailFinalIncorrectHtlcAmount) Error() string {
return fmt.Sprintf("FinalIncorrectHtlcAmount(amt=%v)",
f.IncomingHTLCAmount)
}
// NewFinalIncorrectHtlcAmount creates new instance of the
// FailFinalIncorrectHtlcAmount.
func NewFinalIncorrectHtlcAmount(amount MilliSatoshi) *FailFinalIncorrectHtlcAmount {
return &FailFinalIncorrectHtlcAmount{
IncomingHTLCAmount: amount,
}
}
// Code returns the failure unique code.
//
// NOTE: Part of the FailureMessage interface.
func (f *FailFinalIncorrectHtlcAmount) Code() FailCode {
return CodeFinalIncorrectHtlcAmount
}
// Decode decodes the failure from bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailFinalIncorrectHtlcAmount) Decode(r io.Reader, pver uint32) error {
return readElement(r, &f.IncomingHTLCAmount)
}
// Encode writes the failure in bytes stream.
//
// NOTE: Part of the Serializable interface.
func (f *FailFinalIncorrectHtlcAmount) Encode(w io.Writer, pver uint32) error {
return writeElement(w, f.IncomingHTLCAmount)
}
// DecodeFailure decodes, validates, and parses the lnwire onion failure, for
// the provided protocol version.
func DecodeFailure(r io.Reader, pver uint32) (FailureMessage, error) {
// First, we'll parse out the encapsulated failure message itself. This
// is a 2 byte length followed by the payload itself.
var failureLength uint16
if err := readElement(r, &failureLength); err != nil {
return nil, fmt.Errorf("unable to read error len: %v", err)
}
if failureLength > failureMessageLength {
return nil, fmt.Errorf("failure message is too "+
"long: %v", failureLength)
}
failureData := make([]byte, failureLength)
if _, err := io.ReadFull(r, failureData); err != nil {
return nil, fmt.Errorf("unable to full read payload of "+
"%v: %v", failureLength, err)
}
dataReader := bytes.NewReader(failureData)
// Once we have the failure data, we can obtain the failure code from
// the first two bytes of the buffer.
var codeBytes [2]byte
if _, err := io.ReadFull(dataReader, codeBytes[:]); err != nil {
return nil, fmt.Errorf("unable to read failure code: %v", err)
}
failCode := FailCode(binary.BigEndian.Uint16(codeBytes[:]))
// Create the empty failure by given code and populate the failure with
// additional data if needed.
failure, err := makeEmptyOnionError(failCode)
if err != nil {
return nil, fmt.Errorf("unable to make empty error: %v", err)
}
// Finally, if this failure has a payload, then we'll read that now as
// well.
switch f := failure.(type) {
case Serializable:
if err := f.Decode(dataReader, pver); err != nil {
return nil, fmt.Errorf("unable to decode error "+
"update (type=%T, len_bytes=%v, bytes=%x): %v",
failure, failureLength, failureData[:], err)
}
}
return failure, nil
}
// EncodeFailure encodes, including the necessary onion failure header
// information.
func EncodeFailure(w io.Writer, failure FailureMessage, pver uint32) error {
var failureMessageBuffer bytes.Buffer
// First, we'll write out the error code itself into the failure
// buffer.
var codeBytes [2]byte
code := uint16(failure.Code())
binary.BigEndian.PutUint16(codeBytes[:], code)
_, err := failureMessageBuffer.Write(codeBytes[:])
if err != nil {
return err
}
// Next, some message have an additional message payload, if this is
// one of those types, then we'll also encode the error payload as
// well.
switch failure := failure.(type) {
case Serializable:
if err := failure.Encode(&failureMessageBuffer, pver); err != nil {
return err
}
}
// The combined size of this message must be below the max allowed
// failure message length.
failureMessage := failureMessageBuffer.Bytes()
if len(failureMessage) > failureMessageLength {
return fmt.Errorf("failure message exceed max "+
"available size: %v", len(failureMessage))
}
// Finally, we'll add some padding in order to ensure that all failure
// messages are fixed size.
pad := make([]byte, failureMessageLength-len(failureMessage))
return writeElements(w,
uint16(len(failureMessage)),
failureMessage,
uint16(len(pad)),
pad,
)
}
// makeEmptyOnionError creates a new empty onion error of the proper concrete
// type based on the passed failure code.
func makeEmptyOnionError(code FailCode) (FailureMessage, error) {
switch code {
case CodeInvalidRealm:
return &FailInvalidRealm{}, nil
case CodeTemporaryNodeFailure:
return &FailTemporaryNodeFailure{}, nil
case CodePermanentNodeFailure:
return &FailPermanentNodeFailure{}, nil
case CodeRequiredNodeFeatureMissing:
return &FailRequiredNodeFeatureMissing{}, nil
case CodePermanentChannelFailure:
return &FailPermanentChannelFailure{}, nil
case CodeRequiredChannelFeatureMissing:
return &FailRequiredChannelFeatureMissing{}, nil
case CodeUnknownNextPeer:
return &FailUnknownNextPeer{}, nil
case CodeUnknownPaymentHash:
return &FailUnknownPaymentHash{}, nil
case CodeIncorrectPaymentAmount:
return &FailIncorrectPaymentAmount{}, nil
case CodeFinalExpiryTooSoon:
return &FailFinalExpiryTooSoon{}, nil
case CodeInvalidOnionVersion:
return &FailInvalidOnionVersion{}, nil
case CodeInvalidOnionHmac:
return &FailInvalidOnionHmac{}, nil
case CodeInvalidOnionKey:
return &FailInvalidOnionKey{}, nil
case CodeTemporaryChannelFailure:
return &FailTemporaryChannelFailure{}, nil
case CodeAmountBelowMinimum:
return &FailAmountBelowMinimum{}, nil
case CodeFeeInsufficient:
return &FailFeeInsufficient{}, nil
case CodeIncorrectCltvExpiry:
return &FailIncorrectCltvExpiry{}, nil
case CodeExpiryTooSoon:
return &FailExpiryTooSoon{}, nil
case CodeChannelDisabled:
return &FailChannelDisabled{}, nil
case CodeFinalIncorrectCltvExpiry:
return &FailFinalIncorrectCltvExpiry{}, nil
case CodeFinalIncorrectHtlcAmount:
return &FailFinalIncorrectHtlcAmount{}, nil
default:
return nil, errors.Errorf("unknown error code: %v", code)
}
}