Merge pull request #3348 from wpaulino/max-cltv-expiry-config

htlcswitch: make max cltv expiry configurable and lower default
This commit is contained in:
Olaoluwa Osuntokun 2019-08-02 14:00:17 -07:00 committed by GitHub
commit 9eb7237a2e
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5 changed files with 32 additions and 16 deletions

@ -26,6 +26,7 @@ import (
"github.com/lightningnetwork/lnd/chanbackup"
"github.com/lightningnetwork/lnd/channeldb"
"github.com/lightningnetwork/lnd/discovery"
"github.com/lightningnetwork/lnd/htlcswitch"
"github.com/lightningnetwork/lnd/htlcswitch/hodl"
"github.com/lightningnetwork/lnd/lncfg"
"github.com/lightningnetwork/lnd/lnrpc/routerrpc"
@ -311,6 +312,8 @@ type config struct {
StaggerInitialReconnect bool `long:"stagger-initial-reconnect" description:"If true, will apply a randomized staggering between 0s and 30s when reconnecting to persistent peers on startup. The first 10 reconnections will be attempted instantly, regardless of the flag's value"`
MaxOutgoingCltvExpiry uint32 `long:"max-cltv-expiry" description:"The maximum number of blocks funds could be locked up for when forwarding payments."`
net tor.Net
Routing *routing.Conf `group:"routing" namespace:"routing"`
@ -424,6 +427,7 @@ func loadConfig() (*config, error) {
Watchtower: &lncfg.Watchtower{
TowerDir: defaultTowerDir,
},
MaxOutgoingCltvExpiry: htlcswitch.DefaultMaxOutgoingCltvExpiry,
}
// Pre-parse the command line options to pick up an alternative config

@ -30,16 +30,18 @@ func init() {
}
const (
// maxCltvExpiry is the maximum outgoing time lock that the node accepts
// for forwarded payments. The value is relative to the current block
// height. The reason to have a maximum is to prevent funds getting
// locked up unreasonably long. Otherwise, an attacker willing to lock
// its own funds too, could force the funds of this node to be locked up
// for an indefinite (max int32) number of blocks.
// DefaultMaxOutgoingCltvExpiry is the maximum outgoing time lock that
// the node accepts for forwarded payments. The value is relative to the
// current block height. The reason to have a maximum is to prevent
// funds getting locked up unreasonably long. Otherwise, an attacker
// willing to lock its own funds too, could force the funds of this node
// to be locked up for an indefinite (max int32) number of blocks.
//
// The value 5000 is based on the maximum number of hops (20), the
// default cltv delta (144) and some extra margin.
maxCltvExpiry = 5000
// The value 1008 corresponds to on average one week worth of blocks and
// is based on the maximum number of hops (20), the default cltv delta
// (40) and some extra margin to account for the other lightning
// implementations.
DefaultMaxOutgoingCltvExpiry = 1008
// DefaultMinLinkFeeUpdateTimeout represents the minimum interval in
// which a link should propose to update its commitment fee rate.
@ -249,6 +251,11 @@ type ChannelLinkConfig struct {
// encrypting, and uploading of justice transactions to the daemon's
// configured set of watchtowers.
TowerClient TowerClient
// MaxCltvExpiry is the maximum outgoing timelock that the link should
// accept for a forwarded HTLC. The value is relative to the current
// block height.
MaxOutgoingCltvExpiry uint32
}
// channelLink is the service which drives a channel's commitment update
@ -2337,10 +2344,10 @@ func (l *channelLink) htlcSatifiesPolicyOutgoing(policy ForwardingPolicy,
}
// Check absolute max delta.
if timeout > maxCltvExpiry+heightNow {
if timeout > l.cfg.MaxOutgoingCltvExpiry+heightNow {
l.errorf("outgoing htlc(%x) has a time lock too far in the "+
"future: got %v, but maximum is %v", payHash[:],
timeout-heightNow, maxCltvExpiry)
timeout-heightNow, l.cfg.MaxOutgoingCltvExpiry)
return &lnwire.FailExpiryTooFar{}
}

@ -1689,9 +1689,10 @@ func newSingleLinkTestHarness(chanAmt, chanReserve btcutil.Amount) (
FwdPkgGCTicker: ticker.NewForce(15 * time.Second),
// Make the BatchSize and Min/MaxFeeUpdateTimeout large enough
// to not trigger commit updates automatically during tests.
BatchSize: 10000,
MinFeeUpdateTimeout: 30 * time.Minute,
MaxFeeUpdateTimeout: 40 * time.Minute,
BatchSize: 10000,
MinFeeUpdateTimeout: 30 * time.Minute,
MaxFeeUpdateTimeout: 40 * time.Minute,
MaxOutgoingCltvExpiry: DefaultMaxOutgoingCltvExpiry,
}
const startingHeight = 100
@ -4238,8 +4239,9 @@ func (h *persistentLinkHarness) restartLink(
MinFeeUpdateTimeout: 30 * time.Minute,
MaxFeeUpdateTimeout: 40 * time.Minute,
// Set any hodl flags requested for the new link.
HodlMask: hodl.MaskFromFlags(hodlFlags...),
DebugHTLC: len(hodlFlags) > 0,
HodlMask: hodl.MaskFromFlags(hodlFlags...),
DebugHTLC: len(hodlFlags) > 0,
MaxOutgoingCltvExpiry: DefaultMaxOutgoingCltvExpiry,
}
const startingHeight = 100
@ -5559,6 +5561,7 @@ func TestHtlcSatisfyPolicy(t *testing.T) {
BaseFee: 10,
},
FetchLastChannelUpdate: fetchLastChannelUpdate,
MaxOutgoingCltvExpiry: DefaultMaxOutgoingCltvExpiry,
},
}

@ -1115,6 +1115,7 @@ func (h *hopNetwork) createChannelLink(server, peer *mockServer,
MaxFeeUpdateTimeout: maxFeeUpdateTimeout,
OnChannelFailure: func(lnwire.ChannelID, lnwire.ShortChannelID, LinkFailureError) {},
OutgoingCltvRejectDelta: 3,
MaxOutgoingCltvExpiry: DefaultMaxOutgoingCltvExpiry,
},
channel,
)

@ -585,6 +585,7 @@ func (p *peer) addLink(chanPoint *wire.OutPoint,
MaxFeeUpdateTimeout: htlcswitch.DefaultMaxLinkFeeUpdateTimeout,
OutgoingCltvRejectDelta: p.outgoingCltvRejectDelta,
TowerClient: p.server.towerClient,
MaxOutgoingCltvExpiry: cfg.MaxOutgoingCltvExpiry,
}
link := htlcswitch.NewChannelLink(linkCfg, lnChan)