13725358077

Committed 07 Mar 2025 04:51PM UTC coverage: 58.224% (-10.4%) from 68.615%

Build # 13725358077

Build Type

Pull #9458

github

Committed by

web-flow

Commit Message

Merge bf4c6625f into ab2dc09eb

Pull Request Pull Request #9458: multi+server.go: add initial permissions for some peers

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77.43

/routing/unified_edges.go

package routing

import (
        "math"

        "github.com/btcsuite/btcd/btcutil"
        graphdb "github.com/lightningnetwork/lnd/graph/db"
        "github.com/lightningnetwork/lnd/graph/db/models"
        "github.com/lightningnetwork/lnd/lnwire"
        "github.com/lightningnetwork/lnd/routing/route"
)

// nodeEdgeUnifier holds all edge unifiers for connections towards a node.
type nodeEdgeUnifier struct {
        // edgeUnifiers contains an edge unifier for every from node.
        edgeUnifiers map[route.Vertex]*edgeUnifier

        // sourceNode is the sender of a payment. The rules to pick the final
        // policy are different for local channels.
        sourceNode route.Vertex

        // toNode is the node for which the edge unifiers are instantiated.
        toNode route.Vertex

        // useInboundFees indicates whether to take inbound fees into account.
        useInboundFees bool

        // outChanRestr is an optional outgoing channel restriction for the
        // local channel to use.
        outChanRestr map[uint64]struct{}
}

// newNodeEdgeUnifier instantiates a new nodeEdgeUnifier object. Channel
// policies can be added to this object.
func newNodeEdgeUnifier(sourceNode, toNode route.Vertex, useInboundFees bool,
        outChanRestr map[uint64]struct{}) *nodeEdgeUnifier {

        return &nodeEdgeUnifier{
                edgeUnifiers:   make(map[route.Vertex]*edgeUnifier),
                toNode:         toNode,
                useInboundFees: useInboundFees,
                sourceNode:     sourceNode,
                outChanRestr:   outChanRestr,
        }
}

// addPolicy adds a single channel policy. Capacity may be zero if unknown
// (light clients). We expect a non-nil payload size function and will request a
// graceful shutdown if it is not provided as this indicates that edges are
// incorrectly specified.
func (u *nodeEdgeUnifier) addPolicy(fromNode route.Vertex,
        edge *models.CachedEdgePolicy, inboundFee models.InboundFee,
        capacity btcutil.Amount, hopPayloadSizeFn PayloadSizeFunc,
        blindedPayment *BlindedPayment) {

        localChan := fromNode == u.sourceNode

        // Skip channels if there is an outgoing channel restriction.
        if localChan && u.outChanRestr != nil {
                if _, ok := u.outChanRestr[edge.ChannelID]; !ok {
                        log.Debugf("Skipped adding policy for restricted edge "+
                                "%v", edge.ChannelID)

                        return
                }
        }

        // Update the edgeUnifiers map.
        unifier, ok := u.edgeUnifiers[fromNode]
        if !ok {
                unifier = &edgeUnifier{
                        localChan: localChan,
                }
                u.edgeUnifiers[fromNode] = unifier
        }

        // In case no payload size function was provided a graceful shutdown
        // is requested, because this function is not used as intended.
        if hopPayloadSizeFn == nil {
                log.Criticalf("No payloadsize function was provided for the "+
                        "edge (chanid=%v) when adding it to the edge unifier "+
                        "of node: %v", edge.ChannelID, fromNode)

                return
        }

        // Zero inbound fee for exit hops.
        if !u.useInboundFees {
                inboundFee = models.InboundFee{}
        }

        unifier.edges = append(unifier.edges, newUnifiedEdge(
                edge, capacity, inboundFee, hopPayloadSizeFn, blindedPayment,
        ))
}

// addGraphPolicies adds all policies that are known for the toNode in the
// graph.
func (u *nodeEdgeUnifier) addGraphPolicies(g Graph) error {
        cb := func(channel *graphdb.DirectedChannel) error {
                // If there is no edge policy for this candidate node, skip.
                // Note that we are searching backwards so this node would have
                // come prior to the pivot node in the route.
                if channel.InPolicy == nil {
                        log.Debugf("Skipped adding edge %v due to nil policy",
                                channel.ChannelID)

                        return nil
                }

                // Add this policy to the corresponding edgeUnifier. We default
                // to the clear hop payload size function because
                // `addGraphPolicies` is only used for cleartext intermediate
                // hops in a route.
                inboundFee := models.NewInboundFeeFromWire(
                        channel.InboundFee,
                )

                u.addPolicy(
                        channel.OtherNode, channel.InPolicy, inboundFee,
                        channel.Capacity, defaultHopPayloadSize, nil,
                )

                return nil
        }

        // Iterate over all channels of the to node.
        return g.ForEachNodeDirectedChannel(u.toNode, cb)
}

// unifiedEdge is the individual channel data that is kept inside an edgeUnifier
// object.
type unifiedEdge struct {
        policy      *models.CachedEdgePolicy
        capacity    btcutil.Amount
        inboundFees models.InboundFee

        // hopPayloadSize supplies an edge with the ability to calculate the
        // exact payload size if this edge would be included in a route. This
        // is needed because hops of a blinded path differ in their payload
        // structure compared to cleartext hops.
        hopPayloadSizeFn PayloadSizeFunc

        // blindedPayment if set, is the BlindedPayment that this edge was
        // derived from originally.
        blindedPayment *BlindedPayment
}

// newUnifiedEdge constructs a new unifiedEdge.
func newUnifiedEdge(policy *models.CachedEdgePolicy, capacity btcutil.Amount,
        inboundFees models.InboundFee, hopPayloadSizeFn PayloadSizeFunc,
        blindedPayment *BlindedPayment) *unifiedEdge {

        return &unifiedEdge{
                policy:           policy,
                capacity:         capacity,
                inboundFees:      inboundFees,
                hopPayloadSizeFn: hopPayloadSizeFn,
                blindedPayment:   blindedPayment,
        }
}

// amtInRange checks whether an amount falls within the valid range for a
// channel.
func (u *unifiedEdge) amtInRange(amt lnwire.MilliSatoshi) bool {
        // If the capacity is available (non-light clients), skip channels that
        // are too small.
        if u.capacity > 0 &&
                amt > lnwire.NewMSatFromSatoshis(u.capacity) {

                log.Tracef("Not enough capacity: amt=%v, capacity=%v",
                        amt, u.capacity)
                return false
        }

        // Skip channels for which this htlc is too large.
        if u.policy.MessageFlags.HasMaxHtlc() &&
                amt > u.policy.MaxHTLC {

                log.Tracef("Exceeds policy's MaxHTLC: amt=%v, MaxHTLC=%v",
                        amt, u.policy.MaxHTLC)
                return false
        }

        // Skip channels for which this htlc is too small.
        if amt < u.policy.MinHTLC {
                log.Tracef("below policy's MinHTLC: amt=%v, MinHTLC=%v",
                        amt, u.policy.MinHTLC)
                return false
        }

        return true
}

// edgeUnifier is an object that covers all channels between a pair of nodes.
type edgeUnifier struct {
        edges     []*unifiedEdge
        localChan bool
}

// getEdge returns the optimal unified edge to use for this connection given a
// specific amount to send. It differentiates between local and network
// channels.
func (u *edgeUnifier) getEdge(netAmtReceived lnwire.MilliSatoshi,
        bandwidthHints bandwidthHints,
        nextOutFee lnwire.MilliSatoshi) *unifiedEdge {

        if u.localChan {
                return u.getEdgeLocal(
                        netAmtReceived, bandwidthHints, nextOutFee,
                )
        }

        return u.getEdgeNetwork(netAmtReceived, nextOutFee)
}

// calcCappedInboundFee calculates the inbound fee for a channel, taking into
// account the total node fee for the "to" node.
func calcCappedInboundFee(edge *unifiedEdge, amt lnwire.MilliSatoshi,
        nextOutFee lnwire.MilliSatoshi) int64 {

        // Calculate the inbound fee charged for the amount that passes over the
        // channel.
        inboundFee := edge.inboundFees.CalcFee(amt)

        // Take into account that the total node fee cannot be negative.
        if inboundFee < -int64(nextOutFee) {
                inboundFee = -int64(nextOutFee)
        }

        return inboundFee
}

// getEdgeLocal returns the optimal unified edge to use for this local
// connection given a specific amount to send.
func (u *edgeUnifier) getEdgeLocal(netAmtReceived lnwire.MilliSatoshi,
        bandwidthHints bandwidthHints,
        nextOutFee lnwire.MilliSatoshi) *unifiedEdge {

        var (
                bestEdge     *unifiedEdge
                maxBandwidth lnwire.MilliSatoshi
        )

        for _, edge := range u.edges {
                // Calculate the inbound fee charged at the receiving node.
                inboundFee := calcCappedInboundFee(
                        edge, netAmtReceived, nextOutFee,
                )

                // Add inbound fee to get to the amount that is sent over the
                // local channel.
                amt := netAmtReceived + lnwire.MilliSatoshi(inboundFee)

                // Check valid amount range for the channel. We skip this test
                // for payments with custom HTLC data, as the amount sent on
                // the BTC layer may differ from the amount that is actually
                // forwarded in custom channels.
                if bandwidthHints.firstHopCustomBlob().IsNone() &&
                        !edge.amtInRange(amt) {

                        log.Debugf("Amount %v not in range for edge %v",
                                netAmtReceived, edge.policy.ChannelID)

                        continue
                }

                // For local channels, there is no fee to pay or an extra time
                // lock. We only consider the currently available bandwidth for
                // channel selection. The disabled flag is ignored for local
                // channels.

                // Retrieve bandwidth for this local channel. If not
                // available, assume this channel has enough bandwidth.
                //
                // TODO(joostjager): Possibly change to skipping this
                // channel. The bandwidth hint is expected to be
                // available.
                bandwidth, ok := bandwidthHints.availableChanBandwidth(
                        edge.policy.ChannelID, amt,
                )
                if !ok {
                        log.Debugf("Cannot get bandwidth for edge %v, use max "+
                                "instead", edge.policy.ChannelID)
                        bandwidth = lnwire.MaxMilliSatoshi
                }

                // TODO(yy): if the above `!ok` is chosen, we'd have
                // `bandwidth` to be the max value, which will end up having
                // the `maxBandwidth` to be have the largest value and this
                // edge will be the chosen one. This is wrong in two ways,
                // 1. we need to understand why `availableChanBandwidth` cannot
                // find bandwidth for this edge as something is wrong with this
                // channel, and,
                // 2. this edge is likely NOT the local channel with the
                // highest available bandwidth.
                //
                // Skip channels that can't carry the payment.
                if amt > bandwidth {
                        log.Debugf("Skipped edge %v: not enough bandwidth, "+
                                "bandwidth=%v, amt=%v", edge.policy.ChannelID,
                                bandwidth, amt)

                        continue
                }

                // We pick the local channel with the highest available
                // bandwidth, to maximize the success probability. It can be
                // that the channel state changes between querying the bandwidth
                // hints and sending out the htlc.
                if bandwidth < maxBandwidth {
                        log.Debugf("Skipped edge %v: not max bandwidth, "+
                                "bandwidth=%v, maxBandwidth=%v",
                                edge.policy.ChannelID, bandwidth, maxBandwidth)

                        continue
                }
                maxBandwidth = bandwidth

                // Update best edge.
                bestEdge = newUnifiedEdge(
                        edge.policy, edge.capacity, edge.inboundFees,
                        edge.hopPayloadSizeFn, edge.blindedPayment,
                )
        }

        return bestEdge
}

// getEdgeNetwork returns the optimal unified edge to use for this connection
// given a specific amount to send. The goal is to return a unified edge with a
// policy that maximizes the probability of a successful forward in a non-strict
// forwarding context.
func (u *edgeUnifier) getEdgeNetwork(netAmtReceived lnwire.MilliSatoshi,
        nextOutFee lnwire.MilliSatoshi) *unifiedEdge {

        var (
                bestPolicy       *unifiedEdge
                maxFee           int64 = math.MinInt64
                maxTimelock      uint16
                maxCapMsat       lnwire.MilliSatoshi
                hopPayloadSizeFn PayloadSizeFunc
        )

        for _, edge := range u.edges {
                // Calculate the inbound fee charged at the receiving node.
                inboundFee := calcCappedInboundFee(
                        edge, netAmtReceived, nextOutFee,
                )

                // Add inbound fee to get to the amount that is sent over the
                // channel.
                amt := netAmtReceived + lnwire.MilliSatoshi(inboundFee)

                // Check valid amount range for the channel.
                if !edge.amtInRange(amt) {
                        log.Debugf("Amount %v not in range for edge %v",
                                amt, edge.policy.ChannelID)
                        continue
                }

                // For network channels, skip the disabled ones.
                edgeFlags := edge.policy.ChannelFlags
                isDisabled := edgeFlags&lnwire.ChanUpdateDisabled != 0
                if isDisabled {
                        log.Debugf("Skipped edge %v due to it being disabled",
                                edge.policy.ChannelID)
                        continue
                }

                // Track the maximal capacity for usable channels. If we don't
                // know the capacity, we fall back to MaxHTLC.
                capMsat := lnwire.NewMSatFromSatoshis(edge.capacity)
                if capMsat == 0 && edge.policy.MessageFlags.HasMaxHtlc() {
                        log.Tracef("No capacity available for channel %v, "+
                                "using MaxHtlcMsat (%v) as a fallback.",
                                edge.policy.ChannelID, edge.policy.MaxHTLC)

                        capMsat = edge.policy.MaxHTLC
                }
                maxCapMsat = max(capMsat, maxCapMsat)

                // Track the maximum time lock of all channels that are
                // candidate for non-strict forwarding at the routing node.
                maxTimelock = max(maxTimelock, edge.policy.TimeLockDelta)

                outboundFee := int64(edge.policy.ComputeFee(amt))
                fee := outboundFee + inboundFee

                // Use the policy that results in the highest fee for this
                // specific amount.
                if fee < maxFee {
                        log.Debugf("Skipped edge %v due to it produces less "+
                                "fee: fee=%v, maxFee=%v",
                                edge.policy.ChannelID, fee, maxFee)

                        continue
                }
                maxFee = fee

                bestPolicy = newUnifiedEdge(
                        edge.policy, 0, edge.inboundFees, nil,
                        edge.blindedPayment,
                )

                // The payload size function for edges to a connected peer is
                // always the same hence there is not need to find the maximum.
                // This also counts for blinded edges where we only have one
                // edge to a blinded peer.
                hopPayloadSizeFn = edge.hopPayloadSizeFn
        }

        // Return early if no channel matches.
        if bestPolicy == nil {
                return nil
        }

        // We have already picked the highest fee that could be required for
        // non-strict forwarding. To also cover the case where a lower fee
        // channel requires a longer time lock, we modify the policy by setting
        // the maximum encountered time lock. Note that this results in a
        // synthetic policy that is not actually present on the routing node.
        //
        // The reason we do this, is that we try to maximize the chance that we
        // get forwarded. Because we penalize pair-wise, there won't be a second
        // chance for this node pair. But this is all only needed for nodes that
        // have distinct policies for channels to the same peer.
        policyCopy := *bestPolicy.policy
        policyCopy.TimeLockDelta = maxTimelock
        modifiedEdge := newUnifiedEdge(
                &policyCopy, maxCapMsat.ToSatoshis(), bestPolicy.inboundFees,
                hopPayloadSizeFn, bestPolicy.blindedPayment,
        )

        return modifiedEdge
}

// minAmt returns the minimum amount that can be forwarded on this connection.
func (u *edgeUnifier) minAmt() lnwire.MilliSatoshi {
        minAmount := lnwire.MaxMilliSatoshi
        for _, edge := range u.edges {
                minAmount = min(minAmount, edge.policy.MinHTLC)
        }

        return minAmount
}

1	package routing
2
3	import (
4	"math"
5
6	"github.com/btcsuite/btcd/btcutil"
7	graphdb "github.com/lightningnetwork/lnd/graph/db"
8	"github.com/lightningnetwork/lnd/graph/db/models"
9	"github.com/lightningnetwork/lnd/lnwire"
10	"github.com/lightningnetwork/lnd/routing/route"
11	)
12
13	// nodeEdgeUnifier holds all edge unifiers for connections towards a node.
14	type nodeEdgeUnifier struct {
15	// edgeUnifiers contains an edge unifier for every from node.
16	edgeUnifiers map[route.Vertex]*edgeUnifier
17
18	// sourceNode is the sender of a payment. The rules to pick the final
19	// policy are different for local channels.
20	sourceNode route.Vertex
21
22	// toNode is the node for which the edge unifiers are instantiated.
23	toNode route.Vertex
24
25	// useInboundFees indicates whether to take inbound fees into account.
26	useInboundFees bool
27
28	// outChanRestr is an optional outgoing channel restriction for the
29	// local channel to use.
30	outChanRestr map[uint64]struct{}
31	}
32
33	// newNodeEdgeUnifier instantiates a new nodeEdgeUnifier object. Channel
34	// policies can be added to this object.
35	func newNodeEdgeUnifier(sourceNode, toNode route.Vertex, useInboundFees bool,
36	outChanRestr map[uint64]struct{}) *nodeEdgeUnifier {	3✔
37		3✔
38	return &nodeEdgeUnifier{	3✔
39	edgeUnifiers: make(map[route.Vertex]*edgeUnifier),	3✔
40	toNode: toNode,	3✔
41	useInboundFees: useInboundFees,	3✔
42	sourceNode: sourceNode,	3✔
43	outChanRestr: outChanRestr,	3✔
44	}	3✔
45	}	3✔
46
47	// addPolicy adds a single channel policy. Capacity may be zero if unknown
48	// (light clients). We expect a non-nil payload size function and will request a
49	// graceful shutdown if it is not provided as this indicates that edges are
50	// incorrectly specified.
51	func (u *nodeEdgeUnifier) addPolicy(fromNode route.Vertex,
52	edge *models.CachedEdgePolicy, inboundFee models.InboundFee,
53	capacity btcutil.Amount, hopPayloadSizeFn PayloadSizeFunc,
54	blindedPayment *BlindedPayment) {	3✔
55		3✔
56	localChan := fromNode == u.sourceNode	3✔
57		3✔
58	// Skip channels if there is an outgoing channel restriction.	3✔
59	if localChan && u.outChanRestr != nil {	3✔
UNCOV 60	if _, ok := u.outChanRestr[edge.ChannelID]; !ok {	×
UNCOV 61	log.Debugf("Skipped adding policy for restricted edge "+	×
UNCOV 62	"%v", edge.ChannelID)	×
UNCOV 63		×
UNCOV 64	return	×
UNCOV 65	}	×
66	}
67
68	// Update the edgeUnifiers map.
69	unifier, ok := u.edgeUnifiers[fromNode]	3✔
70	if !ok {	6✔
71	unifier = &edgeUnifier{	3✔
72	localChan: localChan,	3✔
73	}	3✔
74	u.edgeUnifiers[fromNode] = unifier	3✔
75	}	3✔
76
77	// In case no payload size function was provided a graceful shutdown
78	// is requested, because this function is not used as intended.
79	if hopPayloadSizeFn == nil {	3✔
80	log.Criticalf("No payloadsize function was provided for the "+	×
81	"edge (chanid=%v) when adding it to the edge unifier "+	×
82	"of node: %v", edge.ChannelID, fromNode)	×
83		×
84	return	×
85	}	×
86
87	// Zero inbound fee for exit hops.
88	if !u.useInboundFees {	6✔
89	inboundFee = models.InboundFee{}	3✔
90	}	3✔
91
92	unifier.edges = append(unifier.edges, newUnifiedEdge(	3✔
93	edge, capacity, inboundFee, hopPayloadSizeFn, blindedPayment,	3✔
94	))	3✔
95	}
96
97	// addGraphPolicies adds all policies that are known for the toNode in the
98	// graph.
99	func (u *nodeEdgeUnifier) addGraphPolicies(g Graph) error {	3✔
100	cb := func(channel *graphdb.DirectedChannel) error {	6✔
101	// If there is no edge policy for this candidate node, skip.	3✔
102	// Note that we are searching backwards so this node would have	3✔
103	// come prior to the pivot node in the route.	3✔
104	if channel.InPolicy == nil {	3✔
105	log.Debugf("Skipped adding edge %v due to nil policy",	×
106	channel.ChannelID)	×
107		×
108	return nil	×
109	}	×
110
111	// Add this policy to the corresponding edgeUnifier. We default
112	// to the clear hop payload size function because
113	// `addGraphPolicies` is only used for cleartext intermediate
114	// hops in a route.
115	inboundFee := models.NewInboundFeeFromWire(	3✔
116	channel.InboundFee,	3✔
117	)	3✔
118		3✔
119	u.addPolicy(	3✔
120	channel.OtherNode, channel.InPolicy, inboundFee,	3✔
121	channel.Capacity, defaultHopPayloadSize, nil,	3✔
122	)	3✔
123		3✔
124	return nil	3✔
125	}
126
127	// Iterate over all channels of the to node.
128	return g.ForEachNodeDirectedChannel(u.toNode, cb)	3✔
129	}
130
131	// unifiedEdge is the individual channel data that is kept inside an edgeUnifier
132	// object.
133	type unifiedEdge struct {
134	policy *models.CachedEdgePolicy
135	capacity btcutil.Amount
136	inboundFees models.InboundFee
137
138	// hopPayloadSize supplies an edge with the ability to calculate the
139	// exact payload size if this edge would be included in a route. This
140	// is needed because hops of a blinded path differ in their payload
141	// structure compared to cleartext hops.
142	hopPayloadSizeFn PayloadSizeFunc
143
144	// blindedPayment if set, is the BlindedPayment that this edge was
145	// derived from originally.
146	blindedPayment *BlindedPayment
147	}
148
149	// newUnifiedEdge constructs a new unifiedEdge.
150	func newUnifiedEdge(policy *models.CachedEdgePolicy, capacity btcutil.Amount,
151	inboundFees models.InboundFee, hopPayloadSizeFn PayloadSizeFunc,
152	blindedPayment BlindedPayment) unifiedEdge {	3✔
153		3✔
154	return &unifiedEdge{	3✔
155	policy: policy,	3✔
156	capacity: capacity,	3✔
157	inboundFees: inboundFees,	3✔
158	hopPayloadSizeFn: hopPayloadSizeFn,	3✔
159	blindedPayment: blindedPayment,	3✔
160	}	3✔
161	}	3✔
162
163	// amtInRange checks whether an amount falls within the valid range for a
164	// channel.
165	func (u *unifiedEdge) amtInRange(amt lnwire.MilliSatoshi) bool {	3✔
166	// If the capacity is available (non-light clients), skip channels that	3✔
167	// are too small.	3✔
168	if u.capacity > 0 &&	3✔
169	amt > lnwire.NewMSatFromSatoshis(u.capacity) {	3✔
UNCOV 170		×
UNCOV 171	log.Tracef("Not enough capacity: amt=%v, capacity=%v",	×
UNCOV 172	amt, u.capacity)	×
UNCOV 173	return false	×
UNCOV 174	}	×
175
176	// Skip channels for which this htlc is too large.
177	if u.policy.MessageFlags.HasMaxHtlc() &&	3✔
178	amt > u.policy.MaxHTLC {	6✔
179		3✔
180	log.Tracef("Exceeds policy's MaxHTLC: amt=%v, MaxHTLC=%v",	3✔
181	amt, u.policy.MaxHTLC)	3✔
182	return false	3✔
183	}	3✔
184
185	// Skip channels for which this htlc is too small.
186	if amt < u.policy.MinHTLC {	6✔
187	log.Tracef("below policy's MinHTLC: amt=%v, MinHTLC=%v",	3✔
188	amt, u.policy.MinHTLC)	3✔
189	return false	3✔
190	}	3✔
191
192	return true	3✔
193	}
194
195	// edgeUnifier is an object that covers all channels between a pair of nodes.
196	type edgeUnifier struct {
197	edges []*unifiedEdge
198	localChan bool
199	}
200
201	// getEdge returns the optimal unified edge to use for this connection given a
202	// specific amount to send. It differentiates between local and network
203	// channels.
204	func (u *edgeUnifier) getEdge(netAmtReceived lnwire.MilliSatoshi,
205	bandwidthHints bandwidthHints,
206	nextOutFee lnwire.MilliSatoshi) *unifiedEdge {	3✔
207		3✔
208	if u.localChan {	6✔
209	return u.getEdgeLocal(	3✔
210	netAmtReceived, bandwidthHints, nextOutFee,	3✔
211	)	3✔
212	}	3✔
213
214	return u.getEdgeNetwork(netAmtReceived, nextOutFee)	3✔
215	}
216
217	// calcCappedInboundFee calculates the inbound fee for a channel, taking into
218	// account the total node fee for the "to" node.
219	func calcCappedInboundFee(edge *unifiedEdge, amt lnwire.MilliSatoshi,
220	nextOutFee lnwire.MilliSatoshi) int64 {	3✔
221		3✔
222	// Calculate the inbound fee charged for the amount that passes over the	3✔
223	// channel.	3✔
224	inboundFee := edge.inboundFees.CalcFee(amt)	3✔
225		3✔
226	// Take into account that the total node fee cannot be negative.	3✔
227	if inboundFee < -int64(nextOutFee) {	3✔
UNCOV 228	inboundFee = -int64(nextOutFee)	×
UNCOV 229	}	×
230
231	return inboundFee	3✔
232	}
233
234	// getEdgeLocal returns the optimal unified edge to use for this local
235	// connection given a specific amount to send.
236	func (u *edgeUnifier) getEdgeLocal(netAmtReceived lnwire.MilliSatoshi,
237	bandwidthHints bandwidthHints,
238	nextOutFee lnwire.MilliSatoshi) *unifiedEdge {	3✔
239		3✔
240	var (	3✔
241	bestEdge *unifiedEdge	3✔
242	maxBandwidth lnwire.MilliSatoshi	3✔
243	)	3✔
244		3✔
245	for _, edge := range u.edges {	6✔
246	// Calculate the inbound fee charged at the receiving node.	3✔
247	inboundFee := calcCappedInboundFee(	3✔
248	edge, netAmtReceived, nextOutFee,	3✔
249	)	3✔
250		3✔
251	// Add inbound fee to get to the amount that is sent over the	3✔
252	// local channel.	3✔
253	amt := netAmtReceived + lnwire.MilliSatoshi(inboundFee)	3✔
254		3✔
255	// Check valid amount range for the channel. We skip this test	3✔
256	// for payments with custom HTLC data, as the amount sent on	3✔
257	// the BTC layer may differ from the amount that is actually	3✔
258	// forwarded in custom channels.	3✔
259	if bandwidthHints.firstHopCustomBlob().IsNone() &&	3✔
260	!edge.amtInRange(amt) {	3✔
UNCOV 261		×
UNCOV 262	log.Debugf("Amount %v not in range for edge %v",	×
UNCOV 263	netAmtReceived, edge.policy.ChannelID)	×
UNCOV 264		×
UNCOV 265	continue	×
266	}
267
268	// For local channels, there is no fee to pay or an extra time
269	// lock. We only consider the currently available bandwidth for
270	// channel selection. The disabled flag is ignored for local
271	// channels.
272
273	// Retrieve bandwidth for this local channel. If not
274	// available, assume this channel has enough bandwidth.
275	//
276	// TODO(joostjager): Possibly change to skipping this
277	// channel. The bandwidth hint is expected to be
278	// available.
279	bandwidth, ok := bandwidthHints.availableChanBandwidth(	3✔
280	edge.policy.ChannelID, amt,	3✔
281	)	3✔
282	if !ok {	3✔
UNCOV 283	log.Debugf("Cannot get bandwidth for edge %v, use max "+	×
UNCOV 284	"instead", edge.policy.ChannelID)	×
UNCOV 285	bandwidth = lnwire.MaxMilliSatoshi	×
UNCOV 286	}	×
287
288	// TODO(yy): if the above `!ok` is chosen, we'd have
289	// `bandwidth` to be the max value, which will end up having
290	// the `maxBandwidth` to be have the largest value and this
291	// edge will be the chosen one. This is wrong in two ways,
292	// 1. we need to understand why `availableChanBandwidth` cannot
293	// find bandwidth for this edge as something is wrong with this
294	// channel, and,
295	// 2. this edge is likely NOT the local channel with the
296	// highest available bandwidth.
297	//
298	// Skip channels that can't carry the payment.
299	if amt > bandwidth {	6✔
300	log.Debugf("Skipped edge %v: not enough bandwidth, "+	3✔
301	"bandwidth=%v, amt=%v", edge.policy.ChannelID,	3✔
302	bandwidth, amt)	3✔
303		3✔
304	continue	3✔
305	}
306
307	// We pick the local channel with the highest available
308	// bandwidth, to maximize the success probability. It can be
309	// that the channel state changes between querying the bandwidth
310	// hints and sending out the htlc.
311	if bandwidth < maxBandwidth {	3✔
UNCOV 312	log.Debugf("Skipped edge %v: not max bandwidth, "+	×
UNCOV 313	"bandwidth=%v, maxBandwidth=%v",	×
UNCOV 314	edge.policy.ChannelID, bandwidth, maxBandwidth)	×
UNCOV 315		×
UNCOV 316	continue	×
317	}
318	maxBandwidth = bandwidth	3✔
319		3✔
320	// Update best edge.	3✔
321	bestEdge = newUnifiedEdge(	3✔
322	edge.policy, edge.capacity, edge.inboundFees,	3✔
323	edge.hopPayloadSizeFn, edge.blindedPayment,	3✔
324	)	3✔
325	}
326
327	return bestEdge	3✔
328	}
329
330	// getEdgeNetwork returns the optimal unified edge to use for this connection
331	// given a specific amount to send. The goal is to return a unified edge with a
332	// policy that maximizes the probability of a successful forward in a non-strict
333	// forwarding context.
334	func (u *edgeUnifier) getEdgeNetwork(netAmtReceived lnwire.MilliSatoshi,
335	nextOutFee lnwire.MilliSatoshi) *unifiedEdge {	3✔
336		3✔
337	var (	3✔
338	bestPolicy *unifiedEdge	3✔
339	maxFee int64 = math.MinInt64	3✔
340	maxTimelock uint16	3✔
341	maxCapMsat lnwire.MilliSatoshi	3✔
342	hopPayloadSizeFn PayloadSizeFunc	3✔
343	)	3✔
344		3✔
345	for _, edge := range u.edges {	6✔
346	// Calculate the inbound fee charged at the receiving node.	3✔
347	inboundFee := calcCappedInboundFee(	3✔
348	edge, netAmtReceived, nextOutFee,	3✔
349	)	3✔
350		3✔
351	// Add inbound fee to get to the amount that is sent over the	3✔
352	// channel.	3✔
353	amt := netAmtReceived + lnwire.MilliSatoshi(inboundFee)	3✔
354		3✔
355	// Check valid amount range for the channel.	3✔
356	if !edge.amtInRange(amt) {	6✔
357	log.Debugf("Amount %v not in range for edge %v",	3✔
358	amt, edge.policy.ChannelID)	3✔
359	continue	3✔
360	}
361
362	// For network channels, skip the disabled ones.
363	edgeFlags := edge.policy.ChannelFlags	3✔
364	isDisabled := edgeFlags&lnwire.ChanUpdateDisabled != 0	3✔
365	if isDisabled {	3✔
UNCOV 366	log.Debugf("Skipped edge %v due to it being disabled",	×
UNCOV 367	edge.policy.ChannelID)	×
UNCOV 368	continue	×
369	}
370
371	// Track the maximal capacity for usable channels. If we don't
372	// know the capacity, we fall back to MaxHTLC.
373	capMsat := lnwire.NewMSatFromSatoshis(edge.capacity)	3✔
374	if capMsat == 0 && edge.policy.MessageFlags.HasMaxHtlc() {	3✔
UNCOV 375	log.Tracef("No capacity available for channel %v, "+	×
UNCOV 376	"using MaxHtlcMsat (%v) as a fallback.",	×
UNCOV 377	edge.policy.ChannelID, edge.policy.MaxHTLC)	×
UNCOV 378		×
UNCOV 379	capMsat = edge.policy.MaxHTLC	×
UNCOV 380	}	×
381	maxCapMsat = max(capMsat, maxCapMsat)	3✔
382		3✔
383	// Track the maximum time lock of all channels that are	3✔
384	// candidate for non-strict forwarding at the routing node.	3✔
385	maxTimelock = max(maxTimelock, edge.policy.TimeLockDelta)	3✔
386		3✔
387	outboundFee := int64(edge.policy.ComputeFee(amt))	3✔
388	fee := outboundFee + inboundFee	3✔
389		3✔
390	// Use the policy that results in the highest fee for this	3✔
391	// specific amount.	3✔
392	if fee < maxFee {	3✔
UNCOV 393	log.Debugf("Skipped edge %v due to it produces less "+	×
UNCOV 394	"fee: fee=%v, maxFee=%v",	×
UNCOV 395	edge.policy.ChannelID, fee, maxFee)	×
UNCOV 396		×
UNCOV 397	continue	×
398	}
399	maxFee = fee	3✔
400		3✔
401	bestPolicy = newUnifiedEdge(	3✔
402	edge.policy, 0, edge.inboundFees, nil,	3✔
403	edge.blindedPayment,	3✔
404	)	3✔
405		3✔
406	// The payload size function for edges to a connected peer is	3✔
407	// always the same hence there is not need to find the maximum.	3✔
408	// This also counts for blinded edges where we only have one	3✔
409	// edge to a blinded peer.	3✔
410	hopPayloadSizeFn = edge.hopPayloadSizeFn	3✔
411	}
412
413	// Return early if no channel matches.
414	if bestPolicy == nil {	6✔
415	return nil	3✔
416	}	3✔
417
418	// We have already picked the highest fee that could be required for
419	// non-strict forwarding. To also cover the case where a lower fee
420	// channel requires a longer time lock, we modify the policy by setting
421	// the maximum encountered time lock. Note that this results in a
422	// synthetic policy that is not actually present on the routing node.
423	//
424	// The reason we do this, is that we try to maximize the chance that we
425	// get forwarded. Because we penalize pair-wise, there won't be a second
426	// chance for this node pair. But this is all only needed for nodes that
427	// have distinct policies for channels to the same peer.
428	policyCopy := *bestPolicy.policy	3✔
429	policyCopy.TimeLockDelta = maxTimelock	3✔
430	modifiedEdge := newUnifiedEdge(	3✔
431	&policyCopy, maxCapMsat.ToSatoshis(), bestPolicy.inboundFees,	3✔
432	hopPayloadSizeFn, bestPolicy.blindedPayment,	3✔
433	)	3✔
434		3✔
435	return modifiedEdge	3✔
436	}
437
438	// minAmt returns the minimum amount that can be forwarded on this connection.
UNCOV 439	func (u *edgeUnifier) minAmt() lnwire.MilliSatoshi {	×
UNCOV 440	minAmount := lnwire.MaxMilliSatoshi	×
UNCOV 441	for _, edge := range u.edges {	×
UNCOV 442	minAmount = min(minAmount, edge.policy.MinHTLC)	×
UNCOV 443	}	×
444
UNCOV 445	return minAmount	×
446	}

lightningnetwork / lnd / 13725358077

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