15325172502

Committed 29 May 2025 01:38PM UTC coverage: 58.328% (+0.001%) from 58.327%

Build # 15325172502

Build Type

Pull #9876

github

Committed by

web-flow

Commit Message

Merge fb5563b27 into bff2f2440

Pull Request Pull Request #9876: accessman: remove restrictions on protected/temporary peers

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71.81

/accessman.go

package lnd

import (
        "context"
        "fmt"
        "maps"
        "sync"

        "github.com/btcsuite/btcd/btcec/v2"
        "github.com/btcsuite/btclog/v2"
        "github.com/lightningnetwork/lnd/channeldb"
        "github.com/lightningnetwork/lnd/lnutils"
)

// accessMan is responsible for managing the server's access permissions.
type accessMan struct {
        cfg *accessManConfig

        // banScoreMtx is used for the server's ban tracking. If the server
        // mutex is also going to be locked, ensure that this is locked after
        // the server mutex.
        banScoreMtx sync.RWMutex

        // peerCounts is a mapping from remote public key to {bool, uint64}
        // where the bool indicates that we have an open/closed channel with
        // the peer and where the uint64 indicates the number of pending-open
        // channels we currently have with them. This mapping will be used to
        // determine access permissions for the peer. The map key is the
        // string-version of the serialized public key.
        //
        // NOTE: This MUST be accessed with the banScoreMtx held.
        peerCounts map[string]channeldb.ChanCount

        // peerScores stores each connected peer's access status. The map key
        // is the string-version of the serialized public key.
        //
        // NOTE: This MUST be accessed with the banScoreMtx held.
        peerScores map[string]peerSlotStatus

        // numRestricted tracks the number of peers with restricted access in
        // peerScores. This MUST be accessed with the banScoreMtx held.
        numRestricted int64
}

type accessManConfig struct {
        // initAccessPerms checks the channeldb for initial access permissions
        // and then populates the peerCounts and peerScores maps.
        initAccessPerms func() (map[string]channeldb.ChanCount, error)

        // shouldDisconnect determines whether we should disconnect a peer or
        // not.
        shouldDisconnect func(*btcec.PublicKey) (bool, error)

        // maxRestrictedSlots is the number of restricted slots we'll allocate.
        maxRestrictedSlots int64
}

func newAccessMan(cfg *accessManConfig) (*accessMan, error) {
        a := &accessMan{
                cfg:        cfg,
                peerCounts: make(map[string]channeldb.ChanCount),
                peerScores: make(map[string]peerSlotStatus),
        }

        counts, err := a.cfg.initAccessPerms()
        if err != nil {
                return nil, err
        }

        // We'll populate the server's peerCounts map with the counts fetched
        // via initAccessPerms. Also note that we haven't yet connected to the
        // peers.
        maps.Copy(a.peerCounts, counts)

        acsmLog.Info("Access Manager initialized")

        return a, nil
}

// assignPeerPerms assigns a new peer its permissions. This does not track the
// access in the maps. This is intentional.
func (a *accessMan) assignPeerPerms(remotePub *btcec.PublicKey) (
        peerAccessStatus, error) {

        ctx := btclog.WithCtx(
                context.TODO(), lnutils.LogPubKey("peer", remotePub),
        )

        peerMapKey := string(remotePub.SerializeCompressed())

        acsmLog.DebugS(ctx, "Assigning permissions")

        // Default is restricted unless the below filters say otherwise.
        access := peerStatusRestricted

        // Lock banScoreMtx for reading so that we can update the banning maps
        // below.
        a.banScoreMtx.RLock()
        if count, found := a.peerCounts[peerMapKey]; found {
                if count.HasOpenOrClosedChan {
                        acsmLog.DebugS(ctx, "Peer has open/closed channel, "+
                                "assigning protected access")

                        access = peerStatusProtected
                } else if count.PendingOpenCount != 0 {
                        acsmLog.DebugS(ctx, "Peer has pending channel(s), "+
                                "assigning temporary access")

                        access = peerStatusTemporary
                }
        }
        a.banScoreMtx.RUnlock()

        // Exit early if the peer status is no longer restricted.
        if access != peerStatusRestricted {
                return access, nil
        }

        // Check whether this peer is banned.
        shouldDisconnect, err := a.cfg.shouldDisconnect(remotePub)
        if err != nil {
                acsmLog.ErrorS(ctx, "Error checking disconnect status", err)

                // Access is restricted here.
                return access, err
        }

        if shouldDisconnect {
                acsmLog.WarnS(ctx, "Peer is banned, assigning restricted access",
                        ErrGossiperBan)

                // Access is restricted here.
                return access, ErrGossiperBan
        }

        // If we've reached this point and access hasn't changed from
        // restricted, then we need to check if we even have a slot for this
        // peer.
        acsmLog.DebugS(ctx, "Peer has no channels, assigning restricted access")

        if a.numRestricted >= a.cfg.maxRestrictedSlots {
                acsmLog.WarnS(ctx, "No more restricted slots available, "+
                        "denying peer", ErrNoMoreRestrictedAccessSlots,
                        "num_restricted", a.numRestricted, "max_restricted",
                        a.cfg.maxRestrictedSlots)

                return access, ErrNoMoreRestrictedAccessSlots
        }

        return access, nil
}

// newPendingOpenChan is called after the pending-open channel has been
// committed to the database. This may transition a restricted-access peer to a
// temporary-access peer.
func (a *accessMan) newPendingOpenChan(remotePub *btcec.PublicKey) error {
        a.banScoreMtx.Lock()
        defer a.banScoreMtx.Unlock()

        ctx := btclog.WithCtx(
                context.TODO(), lnutils.LogPubKey("peer", remotePub),
        )

        acsmLog.DebugS(ctx, "Processing new pending open channel")

        peerMapKey := string(remotePub.SerializeCompressed())

        // Fetch the peer's access status from peerScores.
        status, found := a.peerScores[peerMapKey]
        if !found {
                acsmLog.ErrorS(ctx, "Peer score not found", ErrNoPeerScore)

                // If we didn't find the peer, we'll return an error.
                return ErrNoPeerScore
        }

        switch status.state {
        case peerStatusProtected:
                acsmLog.DebugS(ctx, "Peer already protected, no change")

                // If this peer's access status is protected, we don't need to
                // do anything.
                return nil

        case peerStatusTemporary:
                // If this peer's access status is temporary, we'll need to
                // update the peerCounts map. The peer's access status will stay
                // temporary.
                peerCount, found := a.peerCounts[peerMapKey]
                if !found {
                        // Error if we did not find any info in peerCounts.
                        acsmLog.ErrorS(ctx, "Pending peer info not found",
                                ErrNoPendingPeerInfo)

                        return ErrNoPendingPeerInfo
                }

                // Increment the pending channel amount.
                peerCount.PendingOpenCount += 1
                a.peerCounts[peerMapKey] = peerCount

                acsmLog.DebugS(ctx, "Peer is temporary, incremented "+
                        "pending count",
                        "pending_count", peerCount.PendingOpenCount)

        case peerStatusRestricted:
                // If the peer's access status is restricted, then we can
                // transition it to a temporary-access peer. We'll need to
                // update numRestricted and also peerScores. We'll also need to
                // update peerCounts.
                peerCount := channeldb.ChanCount{
                        HasOpenOrClosedChan: false,
                        PendingOpenCount:    1,
                }

                a.peerCounts[peerMapKey] = peerCount

                // A restricted-access slot has opened up.
                oldRestricted := a.numRestricted
                a.numRestricted -= 1

                a.peerScores[peerMapKey] = peerSlotStatus{
                        state: peerStatusTemporary,
                }

                acsmLog.InfoS(ctx, "Peer transitioned restricted -> "+
                        "temporary (pending open)",
                        "old_restricted", oldRestricted,
                        "new_restricted", a.numRestricted)

        default:
                // This should not be possible.
                err := fmt.Errorf("invalid peer access status %v for %x",
                        status.state, peerMapKey)
                acsmLog.ErrorS(ctx, "Invalid peer access status", err)

                return err
        }

        return nil
}

// newPendingCloseChan is called when a pending-open channel prematurely closes
// before the funding transaction has confirmed. This potentially demotes a
// temporary-access peer to a restricted-access peer. If no restricted-access
// slots are available, the peer will be disconnected.
func (a *accessMan) newPendingCloseChan(remotePub *btcec.PublicKey) error {
        a.banScoreMtx.Lock()
        defer a.banScoreMtx.Unlock()

        ctx := btclog.WithCtx(
                context.TODO(), lnutils.LogPubKey("peer", remotePub),
        )

        acsmLog.DebugS(ctx, "Processing pending channel close")

        peerMapKey := string(remotePub.SerializeCompressed())

        // Fetch the peer's access status from peerScores.
        status, found := a.peerScores[peerMapKey]
        if !found {
                acsmLog.ErrorS(ctx, "Peer score not found", ErrNoPeerScore)

                return ErrNoPeerScore
        }

        switch status.state {
        case peerStatusProtected:
                // If this peer is protected, we don't do anything.
                acsmLog.DebugS(ctx, "Peer is protected, no change")

                return nil

        case peerStatusTemporary:
                // If this peer is temporary, we need to check if it will
                // revert to a restricted-access peer.
                peerCount, found := a.peerCounts[peerMapKey]
                if !found {
                        acsmLog.ErrorS(ctx, "Pending peer info not found",
                                ErrNoPendingPeerInfo)

                        // Error if we did not find any info in peerCounts.
                        return ErrNoPendingPeerInfo
                }

                currentNumPending := peerCount.PendingOpenCount - 1

                acsmLog.DebugS(ctx, "Peer is temporary, decrementing "+
                        "pending count",
                        "pending_count", currentNumPending)

                if currentNumPending == 0 {
                        // Remove the entry from peerCounts.
                        delete(a.peerCounts, peerMapKey)

                        // If this is the only pending-open channel for this
                        // peer and it's getting removed, attempt to demote
                        // this peer to a restricted peer.
                        if a.numRestricted == a.cfg.maxRestrictedSlots {
                                // There are no available restricted slots, so
                                // we need to disconnect this peer. We leave
                                // this up to the caller.
                                acsmLog.WarnS(ctx, "Peer last pending "+
                                        "channel closed: ",
                                        ErrNoMoreRestrictedAccessSlots,
                                        "num_restricted", a.numRestricted,
                                        "max_restricted", a.cfg.maxRestrictedSlots)

                                return ErrNoMoreRestrictedAccessSlots
                        }

                        // Otherwise, there is an available restricted-access
                        // slot, so we can demote this peer.
                        a.peerScores[peerMapKey] = peerSlotStatus{
                                state: peerStatusRestricted,
                        }

                        // Update numRestricted.
                        oldRestricted := a.numRestricted
                        a.numRestricted++

                        acsmLog.InfoS(ctx, "Peer transitioned "+
                                "temporary -> restricted "+
                                "(last pending closed)",
                                "old_restricted", oldRestricted,
                                "new_restricted", a.numRestricted)

                        return nil
                }

                // Else, we don't need to demote this peer since it has other
                // pending-open channels with us.
                peerCount.PendingOpenCount = currentNumPending
                a.peerCounts[peerMapKey] = peerCount

                acsmLog.DebugS(ctx, "Peer still has other pending channels",
                        "pending_count", currentNumPending)

                return nil

        case peerStatusRestricted:
                // This should not be possible. This indicates an error.
                err := fmt.Errorf("invalid peer access state transition: "+
                        "pending close for restricted peer %x", peerMapKey)
                acsmLog.ErrorS(ctx, "Invalid peer access state transition", err)

                return err

        default:
                // This should not be possible.
                err := fmt.Errorf("invalid peer access status %v for %x",
                        status.state, peerMapKey)
                acsmLog.ErrorS(ctx, "Invalid peer access status", err)

                return err
        }
}

// newOpenChan is called when a pending-open channel becomes an open channel
// (i.e. the funding transaction has confirmed). If the remote peer is a
// temporary-access peer, it will be promoted to a protected-access peer.
func (a *accessMan) newOpenChan(remotePub *btcec.PublicKey) error {
        a.banScoreMtx.Lock()
        defer a.banScoreMtx.Unlock()

        ctx := btclog.WithCtx(
                context.TODO(), lnutils.LogPubKey("peer", remotePub),
        )

        acsmLog.DebugS(ctx, "Processing new open channel")

        peerMapKey := string(remotePub.SerializeCompressed())

        // Fetch the peer's access status from peerScores.
        status, found := a.peerScores[peerMapKey]
        if !found {
                // If we didn't find the peer, we'll return an error.
                acsmLog.ErrorS(ctx, "Peer score not found", ErrNoPeerScore)

                return ErrNoPeerScore
        }

        switch status.state {
        case peerStatusProtected:
                acsmLog.DebugS(ctx, "Peer already protected, no change")

                // If the peer's state is already protected, we don't need to do
                // anything more.
                return nil

        case peerStatusTemporary:
                // If the peer's state is temporary, we'll upgrade the peer to
                // a protected peer.
                peerCount, found := a.peerCounts[peerMapKey]
                if !found {
                        // Error if we did not find any info in peerCounts.
                        acsmLog.ErrorS(ctx, "Pending peer info not found",
                                ErrNoPendingPeerInfo)

                        return ErrNoPendingPeerInfo
                }

                peerCount.HasOpenOrClosedChan = true
                a.peerCounts[peerMapKey] = peerCount

                newStatus := peerSlotStatus{
                        state: peerStatusProtected,
                }
                a.peerScores[peerMapKey] = newStatus

                acsmLog.InfoS(ctx, "Peer transitioned temporary -> "+
                        "protected (channel opened)")

                return nil

        case peerStatusRestricted:
                // This should not be possible. For the server to receive a
                // state-transition event via NewOpenChan, the server must have
                // previously granted this peer "temporary" access. This
                // temporary access would not have been revoked or downgraded
                // without `CloseChannel` being called with the pending
                // argument set to true. This means that an open-channel state
                // transition would be impossible. Therefore, we can return an
                // error.
                err := fmt.Errorf("invalid peer access status: new open "+
                        "channel for restricted peer %x", peerMapKey)

                acsmLog.ErrorS(ctx, "Invalid peer access status", err)

                return err

        default:
                // This should not be possible.
                err := fmt.Errorf("invalid peer access status %v for %x",
                        status.state, peerMapKey)

                acsmLog.ErrorS(ctx, "Invalid peer access status", err)

                return err
        }
}

// checkIncomingConnBanScore checks whether, given the remote's public hex-
// encoded key, we should not accept this incoming connection or immediately
// disconnect. This does not assign to the server's peerScores maps. This is
// just an inbound filter that the brontide listeners use.
func (a *accessMan) checkIncomingConnBanScore(remotePub *btcec.PublicKey) (
        bool, error) {

        ctx := btclog.WithCtx(
                context.TODO(), lnutils.LogPubKey("peer", remotePub),
        )

        peerMapKey := string(remotePub.SerializeCompressed())

        acsmLog.TraceS(ctx, "Checking incoming connection ban score")

        a.banScoreMtx.RLock()
        defer a.banScoreMtx.RUnlock()

        if _, found := a.peerCounts[peerMapKey]; !found {
                acsmLog.DebugS(ctx, "Peer not found in counts, "+
                        "checking restricted slots")

                // Check numRestricted to see if there is an available slot. In
                // the future, it's possible to add better heuristics.
                if a.numRestricted < a.cfg.maxRestrictedSlots {
                        // There is an available slot.
                        acsmLog.DebugS(ctx, "Restricted slot available, "+
                                "accepting",
                                "num_restricted", a.numRestricted,
                                "max_restricted", a.cfg.maxRestrictedSlots)

                        return true, nil
                }

                // If there are no slots left, then we reject this connection.
                acsmLog.WarnS(ctx, "No restricted slots available, "+
                        "rejecting",
                        ErrNoMoreRestrictedAccessSlots,
                        "num_restricted", a.numRestricted,
                        "max_restricted", a.cfg.maxRestrictedSlots)

                return false, ErrNoMoreRestrictedAccessSlots
        }

        // Else, the peer is either protected or temporary.
        acsmLog.DebugS(ctx, "Peer found (protected/temporary), accepting")

        return true, nil
}

// addPeerAccess tracks a peer's access in the maps. This should be called when
// the peer has fully connected.
func (a *accessMan) addPeerAccess(remotePub *btcec.PublicKey,
        access peerAccessStatus) {

        ctx := btclog.WithCtx(
                context.TODO(), lnutils.LogPubKey("peer", remotePub),
        )

        acsmLog.DebugS(ctx, "Adding peer access", "access", access)

        // Add the remote public key to peerScores.
        a.banScoreMtx.Lock()
        defer a.banScoreMtx.Unlock()

        peerMapKey := string(remotePub.SerializeCompressed())

        a.peerScores[peerMapKey] = peerSlotStatus{state: access}

        // Increment numRestricted.
        if access == peerStatusRestricted {
                oldRestricted := a.numRestricted
                a.numRestricted++

                acsmLog.DebugS(ctx, "Incremented restricted slots",
                        "old_restricted", oldRestricted,
                        "new_restricted", a.numRestricted)
        }
}

// removePeerAccess removes the peer's access from the maps. This should be
// called when the peer has been disconnected.
func (a *accessMan) removePeerAccess(remotePub *btcec.PublicKey) {
        a.banScoreMtx.Lock()
        defer a.banScoreMtx.Unlock()

        ctx := btclog.WithCtx(
                context.TODO(), lnutils.LogPubKey("peer", remotePub),
        )

        acsmLog.DebugS(ctx, "Removing peer access")

        peerMapKey := string(remotePub.SerializeCompressed())

        status, found := a.peerScores[peerMapKey]
        if !found {
                acsmLog.InfoS(ctx, "Peer score not found during removal")
                return
        }

        if status.state == peerStatusRestricted {
                // If the status is restricted, then we decrement from
                // numRestrictedSlots.
                oldRestricted := a.numRestricted
                a.numRestricted--

                acsmLog.DebugS(ctx, "Decremented restricted slots",
                        "old_restricted", oldRestricted,
                        "new_restricted", a.numRestricted)
        }

        acsmLog.TraceS(ctx, "Deleting peer from peerScores")

        delete(a.peerScores, peerMapKey)
}

1	package lnd
2
3	import (
4	"context"
5	"fmt"
6	"maps"
7	"sync"
8
9	"github.com/btcsuite/btcd/btcec/v2"
10	"github.com/btcsuite/btclog/v2"
11	"github.com/lightningnetwork/lnd/channeldb"
12	"github.com/lightningnetwork/lnd/lnutils"
13	)
14
15	// accessMan is responsible for managing the server's access permissions.
16	type accessMan struct {
17	cfg *accessManConfig
18
19	// banScoreMtx is used for the server's ban tracking. If the server
20	// mutex is also going to be locked, ensure that this is locked after
21	// the server mutex.
22	banScoreMtx sync.RWMutex
23
24	// peerCounts is a mapping from remote public key to {bool, uint64}
25	// where the bool indicates that we have an open/closed channel with
26	// the peer and where the uint64 indicates the number of pending-open
27	// channels we currently have with them. This mapping will be used to
28	// determine access permissions for the peer. The map key is the
29	// string-version of the serialized public key.
30	//
31	// NOTE: This MUST be accessed with the banScoreMtx held.
32	peerCounts map[string]channeldb.ChanCount
33
34	// peerScores stores each connected peer's access status. The map key
35	// is the string-version of the serialized public key.
36	//
37	// NOTE: This MUST be accessed with the banScoreMtx held.
38	peerScores map[string]peerSlotStatus
39
40	// numRestricted tracks the number of peers with restricted access in
41	// peerScores. This MUST be accessed with the banScoreMtx held.
42	numRestricted int64
43	}
44
45	type accessManConfig struct {
46	// initAccessPerms checks the channeldb for initial access permissions
47	// and then populates the peerCounts and peerScores maps.
48	initAccessPerms func() (map[string]channeldb.ChanCount, error)
49
50	// shouldDisconnect determines whether we should disconnect a peer or
51	// not.
52	shouldDisconnect func(*btcec.PublicKey) (bool, error)
53
54	// maxRestrictedSlots is the number of restricted slots we'll allocate.
55	maxRestrictedSlots int64
56	}
57
58	func newAccessMan(cfg accessManConfig) (accessMan, error) {	3✔
59	a := &accessMan{	3✔
60	cfg: cfg,	3✔
61	peerCounts: make(map[string]channeldb.ChanCount),	3✔
62	peerScores: make(map[string]peerSlotStatus),	3✔
63	}	3✔
64		3✔
65	counts, err := a.cfg.initAccessPerms()	3✔
66	if err != nil {	3✔
67	return nil, err	×
68	}	×
69
70	// We'll populate the server's peerCounts map with the counts fetched
71	// via initAccessPerms. Also note that we haven't yet connected to the
72	// peers.
73	maps.Copy(a.peerCounts, counts)	3✔
74		3✔
75	acsmLog.Info("Access Manager initialized")	3✔
76		3✔
77	return a, nil	3✔
78	}
79
80	// assignPeerPerms assigns a new peer its permissions. This does not track the
81	// access in the maps. This is intentional.
82	func (a accessMan) assignPeerPerms(remotePub btcec.PublicKey) (
83	peerAccessStatus, error) {	3✔
84		3✔
85	ctx := btclog.WithCtx(	3✔
86	context.TODO(), lnutils.LogPubKey("peer", remotePub),	3✔
87	)	3✔
88		3✔
89	peerMapKey := string(remotePub.SerializeCompressed())	3✔
90		3✔
91	acsmLog.DebugS(ctx, "Assigning permissions")	3✔
92		3✔
93	// Default is restricted unless the below filters say otherwise.	3✔
94	access := peerStatusRestricted	3✔
95		3✔
96	// Lock banScoreMtx for reading so that we can update the banning maps	3✔
97	// below.	3✔
98	a.banScoreMtx.RLock()	3✔
99	if count, found := a.peerCounts[peerMapKey]; found {	6✔
100	if count.HasOpenOrClosedChan {	6✔
101	acsmLog.DebugS(ctx, "Peer has open/closed channel, "+	3✔
102	"assigning protected access")	3✔
103		3✔
104	access = peerStatusProtected	3✔
105	} else if count.PendingOpenCount != 0 {	9✔
106	acsmLog.DebugS(ctx, "Peer has pending channel(s), "+	3✔
107	"assigning temporary access")	3✔
108		3✔
109	access = peerStatusTemporary	3✔
110	}	3✔
111	}
112	a.banScoreMtx.RUnlock()	3✔
113		3✔
114	// Exit early if the peer status is no longer restricted.	3✔
115	if access != peerStatusRestricted {	6✔
116	return access, nil	3✔
117	}	3✔
118
119	// Check whether this peer is banned.
120	shouldDisconnect, err := a.cfg.shouldDisconnect(remotePub)	3✔
121	if err != nil {	3✔
NEW 122	acsmLog.ErrorS(ctx, "Error checking disconnect status", err)	×
NEW 123		×
NEW 124	// Access is restricted here.	×
NEW 125	return access, err	×
NEW 126	}	×
127
128	if shouldDisconnect {	3✔
NEW 129	acsmLog.WarnS(ctx, "Peer is banned, assigning restricted access",	×
NEW 130	ErrGossiperBan)	×
NEW 131		×
NEW 132	// Access is restricted here.	×
NEW 133	return access, ErrGossiperBan	×
NEW 134	}	×
135
136	// If we've reached this point and access hasn't changed from
137	// restricted, then we need to check if we even have a slot for this
138	// peer.
139	acsmLog.DebugS(ctx, "Peer has no channels, assigning restricted access")	3✔
140		3✔
141	if a.numRestricted >= a.cfg.maxRestrictedSlots {	3✔
NEW 142	acsmLog.WarnS(ctx, "No more restricted slots available, "+	×
NEW 143	"denying peer", ErrNoMoreRestrictedAccessSlots,	×
NEW 144	"num_restricted", a.numRestricted, "max_restricted",	×
NEW 145	a.cfg.maxRestrictedSlots)	×
146		×
NEW 147	return access, ErrNoMoreRestrictedAccessSlots	×
148	}	×
149
150	return access, nil	3✔
151	}
152
153	// newPendingOpenChan is called after the pending-open channel has been
154	// committed to the database. This may transition a restricted-access peer to a
155	// temporary-access peer.
156	func (a accessMan) newPendingOpenChan(remotePub btcec.PublicKey) error {	3✔
157	a.banScoreMtx.Lock()	3✔
158	defer a.banScoreMtx.Unlock()	3✔
159		3✔
160	ctx := btclog.WithCtx(	3✔
161	context.TODO(), lnutils.LogPubKey("peer", remotePub),	3✔
162	)	3✔
163		3✔
164	acsmLog.DebugS(ctx, "Processing new pending open channel")	3✔
165		3✔
166	peerMapKey := string(remotePub.SerializeCompressed())	3✔
167		3✔
168	// Fetch the peer's access status from peerScores.	3✔
169	status, found := a.peerScores[peerMapKey]	3✔
170	if !found {	3✔
171	acsmLog.ErrorS(ctx, "Peer score not found", ErrNoPeerScore)	×
172		×
173	// If we didn't find the peer, we'll return an error.	×
174	return ErrNoPeerScore	×
175	}	×
176
177	switch status.state {	3✔
178	case peerStatusProtected:	3✔
179	acsmLog.DebugS(ctx, "Peer already protected, no change")	3✔
180		3✔
181	// If this peer's access status is protected, we don't need to	3✔
182	// do anything.	3✔
183	return nil	3✔
184
185	case peerStatusTemporary:	3✔
186	// If this peer's access status is temporary, we'll need to	3✔
187	// update the peerCounts map. The peer's access status will stay	3✔
188	// temporary.	3✔
189	peerCount, found := a.peerCounts[peerMapKey]	3✔
190	if !found {	3✔
191	// Error if we did not find any info in peerCounts.	×
192	acsmLog.ErrorS(ctx, "Pending peer info not found",	×
193	ErrNoPendingPeerInfo)	×
194		×
195	return ErrNoPendingPeerInfo	×
196	}	×
197
198	// Increment the pending channel amount.
199	peerCount.PendingOpenCount += 1	3✔
200	a.peerCounts[peerMapKey] = peerCount	3✔
201		3✔
202	acsmLog.DebugS(ctx, "Peer is temporary, incremented "+	3✔
203	"pending count",	3✔
204	"pending_count", peerCount.PendingOpenCount)	3✔
205
206	case peerStatusRestricted:	3✔
207	// If the peer's access status is restricted, then we can	3✔
208	// transition it to a temporary-access peer. We'll need to	3✔
209	// update numRestricted and also peerScores. We'll also need to	3✔
210	// update peerCounts.	3✔
211	peerCount := channeldb.ChanCount{	3✔
212	HasOpenOrClosedChan: false,	3✔
213	PendingOpenCount: 1,	3✔
214	}	3✔
215		3✔
216	a.peerCounts[peerMapKey] = peerCount	3✔
217		3✔
218	// A restricted-access slot has opened up.	3✔
219	oldRestricted := a.numRestricted	3✔
220	a.numRestricted -= 1	3✔
221		3✔
222	a.peerScores[peerMapKey] = peerSlotStatus{	3✔
223	state: peerStatusTemporary,	3✔
224	}	3✔
225		3✔
226	acsmLog.InfoS(ctx, "Peer transitioned restricted -> "+	3✔
227	"temporary (pending open)",	3✔
228	"old_restricted", oldRestricted,	3✔
229	"new_restricted", a.numRestricted)	3✔
230
231	default:	×
232	// This should not be possible.	×
233	err := fmt.Errorf("invalid peer access status %v for %x",	×
234	status.state, peerMapKey)	×
235	acsmLog.ErrorS(ctx, "Invalid peer access status", err)	×
236		×
237	return err	×
238	}
239
240	return nil	3✔
241	}
242
243	// newPendingCloseChan is called when a pending-open channel prematurely closes
244	// before the funding transaction has confirmed. This potentially demotes a
245	// temporary-access peer to a restricted-access peer. If no restricted-access
246	// slots are available, the peer will be disconnected.
247	func (a accessMan) newPendingCloseChan(remotePub btcec.PublicKey) error {	3✔
248	a.banScoreMtx.Lock()	3✔
249	defer a.banScoreMtx.Unlock()	3✔
250		3✔
251	ctx := btclog.WithCtx(	3✔
252	context.TODO(), lnutils.LogPubKey("peer", remotePub),	3✔
253	)	3✔
254		3✔
255	acsmLog.DebugS(ctx, "Processing pending channel close")	3✔
256		3✔
257	peerMapKey := string(remotePub.SerializeCompressed())	3✔
258		3✔
259	// Fetch the peer's access status from peerScores.	3✔
260	status, found := a.peerScores[peerMapKey]	3✔
261	if !found {	3✔
262	acsmLog.ErrorS(ctx, "Peer score not found", ErrNoPeerScore)	×
263		×
264	return ErrNoPeerScore	×
265	}	×
266
267	switch status.state {	3✔
268	case peerStatusProtected:	×
269	// If this peer is protected, we don't do anything.	×
270	acsmLog.DebugS(ctx, "Peer is protected, no change")	×
271		×
272	return nil	×
273
274	case peerStatusTemporary:	3✔
275	// If this peer is temporary, we need to check if it will	3✔
276	// revert to a restricted-access peer.	3✔
277	peerCount, found := a.peerCounts[peerMapKey]	3✔
278	if !found {	3✔
279	acsmLog.ErrorS(ctx, "Pending peer info not found",	×
280	ErrNoPendingPeerInfo)	×
281		×
282	// Error if we did not find any info in peerCounts.	×
283	return ErrNoPendingPeerInfo	×
284	}	×
285
286	currentNumPending := peerCount.PendingOpenCount - 1	3✔
287		3✔
288	acsmLog.DebugS(ctx, "Peer is temporary, decrementing "+	3✔
289	"pending count",	3✔
290	"pending_count", currentNumPending)	3✔
291		3✔
292	if currentNumPending == 0 {	6✔
293	// Remove the entry from peerCounts.	3✔
294	delete(a.peerCounts, peerMapKey)	3✔
295		3✔
296	// If this is the only pending-open channel for this	3✔
297	// peer and it's getting removed, attempt to demote	3✔
298	// this peer to a restricted peer.	3✔
299	if a.numRestricted == a.cfg.maxRestrictedSlots {	3✔
300	// There are no available restricted slots, so	×
301	// we need to disconnect this peer. We leave	×
302	// this up to the caller.	×
303	acsmLog.WarnS(ctx, "Peer last pending "+	×
304	"channel closed: ",	×
305	ErrNoMoreRestrictedAccessSlots,	×
306	"num_restricted", a.numRestricted,	×
307	"max_restricted", a.cfg.maxRestrictedSlots)	×
308		×
309	return ErrNoMoreRestrictedAccessSlots	×
310	}	×
311
312	// Otherwise, there is an available restricted-access
313	// slot, so we can demote this peer.
314	a.peerScores[peerMapKey] = peerSlotStatus{	3✔
315	state: peerStatusRestricted,	3✔
316	}	3✔
317		3✔
318	// Update numRestricted.	3✔
319	oldRestricted := a.numRestricted	3✔
320	a.numRestricted++	3✔
321		3✔
322	acsmLog.InfoS(ctx, "Peer transitioned "+	3✔
323	"temporary -> restricted "+	3✔
324	"(last pending closed)",	3✔
325	"old_restricted", oldRestricted,	3✔
326	"new_restricted", a.numRestricted)	3✔
327		3✔
328	return nil	3✔
329	}
330
331	// Else, we don't need to demote this peer since it has other
332	// pending-open channels with us.
333	peerCount.PendingOpenCount = currentNumPending	×
334	a.peerCounts[peerMapKey] = peerCount	×
335		×
336	acsmLog.DebugS(ctx, "Peer still has other pending channels",	×
337	"pending_count", currentNumPending)	×
338		×
339	return nil	×
340
341	case peerStatusRestricted:	×
342	// This should not be possible. This indicates an error.	×
343	err := fmt.Errorf("invalid peer access state transition: "+	×
344	"pending close for restricted peer %x", peerMapKey)	×
345	acsmLog.ErrorS(ctx, "Invalid peer access state transition", err)	×
346		×
347	return err	×
348
349	default:	×
350	// This should not be possible.	×
351	err := fmt.Errorf("invalid peer access status %v for %x",	×
352	status.state, peerMapKey)	×
353	acsmLog.ErrorS(ctx, "Invalid peer access status", err)	×
354		×
355	return err	×
356	}
357	}
358
359	// newOpenChan is called when a pending-open channel becomes an open channel
360	// (i.e. the funding transaction has confirmed). If the remote peer is a
361	// temporary-access peer, it will be promoted to a protected-access peer.
362	func (a accessMan) newOpenChan(remotePub btcec.PublicKey) error {	3✔
363	a.banScoreMtx.Lock()	3✔
364	defer a.banScoreMtx.Unlock()	3✔
365		3✔
366	ctx := btclog.WithCtx(	3✔
367	context.TODO(), lnutils.LogPubKey("peer", remotePub),	3✔
368	)	3✔
369		3✔
370	acsmLog.DebugS(ctx, "Processing new open channel")	3✔
371		3✔
372	peerMapKey := string(remotePub.SerializeCompressed())	3✔
373		3✔
374	// Fetch the peer's access status from peerScores.	3✔
375	status, found := a.peerScores[peerMapKey]	3✔
376	if !found {	6✔
377	// If we didn't find the peer, we'll return an error.	3✔
378	acsmLog.ErrorS(ctx, "Peer score not found", ErrNoPeerScore)	3✔
379		3✔
380	return ErrNoPeerScore	3✔
381	}	3✔
382
383	switch status.state {	3✔
384	case peerStatusProtected:	3✔
385	acsmLog.DebugS(ctx, "Peer already protected, no change")	3✔
386		3✔
387	// If the peer's state is already protected, we don't need to do	3✔
388	// anything more.	3✔
389	return nil	3✔
390
391	case peerStatusTemporary:	3✔
392	// If the peer's state is temporary, we'll upgrade the peer to	3✔
393	// a protected peer.	3✔
394	peerCount, found := a.peerCounts[peerMapKey]	3✔
395	if !found {	3✔
396	// Error if we did not find any info in peerCounts.	×
397	acsmLog.ErrorS(ctx, "Pending peer info not found",	×
398	ErrNoPendingPeerInfo)	×
399		×
400	return ErrNoPendingPeerInfo	×
401	}	×
402
403	peerCount.HasOpenOrClosedChan = true	3✔
404	a.peerCounts[peerMapKey] = peerCount	3✔
405		3✔
406	newStatus := peerSlotStatus{	3✔
407	state: peerStatusProtected,	3✔
408	}	3✔
409	a.peerScores[peerMapKey] = newStatus	3✔
410		3✔
411	acsmLog.InfoS(ctx, "Peer transitioned temporary -> "+	3✔
412	"protected (channel opened)")	3✔
413		3✔
414	return nil	3✔
415
416	case peerStatusRestricted:	×
417	// This should not be possible. For the server to receive a	×
418	// state-transition event via NewOpenChan, the server must have	×
419	// previously granted this peer "temporary" access. This	×
420	// temporary access would not have been revoked or downgraded	×
421	// without `CloseChannel` being called with the pending	×
422	// argument set to true. This means that an open-channel state	×
423	// transition would be impossible. Therefore, we can return an	×
424	// error.	×
425	err := fmt.Errorf("invalid peer access status: new open "+	×
426	"channel for restricted peer %x", peerMapKey)	×
427		×
428	acsmLog.ErrorS(ctx, "Invalid peer access status", err)	×
429		×
430	return err	×
431
432	default:	×
433	// This should not be possible.	×
434	err := fmt.Errorf("invalid peer access status %v for %x",	×
435	status.state, peerMapKey)	×
436		×
437	acsmLog.ErrorS(ctx, "Invalid peer access status", err)	×
438		×
439	return err	×
440	}
441	}
442
443	// checkIncomingConnBanScore checks whether, given the remote's public hex-
444	// encoded key, we should not accept this incoming connection or immediately
445	// disconnect. This does not assign to the server's peerScores maps. This is
446	// just an inbound filter that the brontide listeners use.
447	func (a accessMan) checkIncomingConnBanScore(remotePub btcec.PublicKey) (
448	bool, error) {	3✔
449		3✔
450	ctx := btclog.WithCtx(	3✔
451	context.TODO(), lnutils.LogPubKey("peer", remotePub),	3✔
452	)	3✔
453		3✔
454	peerMapKey := string(remotePub.SerializeCompressed())	3✔
455		3✔
456	acsmLog.TraceS(ctx, "Checking incoming connection ban score")	3✔
457		3✔
458	a.banScoreMtx.RLock()	3✔
459	defer a.banScoreMtx.RUnlock()	3✔
460		3✔
461	if _, found := a.peerCounts[peerMapKey]; !found {	6✔
462	acsmLog.DebugS(ctx, "Peer not found in counts, "+	3✔
463	"checking restricted slots")	3✔
464		3✔
465	// Check numRestricted to see if there is an available slot. In	3✔
466	// the future, it's possible to add better heuristics.	3✔
467	if a.numRestricted < a.cfg.maxRestrictedSlots {	6✔
468	// There is an available slot.	3✔
469	acsmLog.DebugS(ctx, "Restricted slot available, "+	3✔
470	"accepting",	3✔
471	"num_restricted", a.numRestricted,	3✔
472	"max_restricted", a.cfg.maxRestrictedSlots)	3✔
473		3✔
474	return true, nil	3✔
475	}	3✔
476
477	// If there are no slots left, then we reject this connection.
478	acsmLog.WarnS(ctx, "No restricted slots available, "+	3✔
479	"rejecting",	3✔
480	ErrNoMoreRestrictedAccessSlots,	3✔
481	"num_restricted", a.numRestricted,	3✔
482	"max_restricted", a.cfg.maxRestrictedSlots)	3✔
483		3✔
484	return false, ErrNoMoreRestrictedAccessSlots	3✔
485	}
486
487	// Else, the peer is either protected or temporary.
488	acsmLog.DebugS(ctx, "Peer found (protected/temporary), accepting")	3✔
489		3✔
490	return true, nil	3✔
491	}
492
493	// addPeerAccess tracks a peer's access in the maps. This should be called when
494	// the peer has fully connected.
495	func (a accessMan) addPeerAccess(remotePub btcec.PublicKey,
496	access peerAccessStatus) {	3✔
497		3✔
498	ctx := btclog.WithCtx(	3✔
499	context.TODO(), lnutils.LogPubKey("peer", remotePub),	3✔
500	)	3✔
501		3✔
502	acsmLog.DebugS(ctx, "Adding peer access", "access", access)	3✔
503		3✔
504	// Add the remote public key to peerScores.	3✔
505	a.banScoreMtx.Lock()	3✔
506	defer a.banScoreMtx.Unlock()	3✔
507		3✔
508	peerMapKey := string(remotePub.SerializeCompressed())	3✔
509		3✔
510	a.peerScores[peerMapKey] = peerSlotStatus{state: access}	3✔
511		3✔
512	// Increment numRestricted.	3✔
513	if access == peerStatusRestricted {	6✔
514	oldRestricted := a.numRestricted	3✔
515	a.numRestricted++	3✔
516		3✔
517	acsmLog.DebugS(ctx, "Incremented restricted slots",	3✔
518	"old_restricted", oldRestricted,	3✔
519	"new_restricted", a.numRestricted)	3✔
520	}	3✔
521	}
522
523	// removePeerAccess removes the peer's access from the maps. This should be
524	// called when the peer has been disconnected.
525	func (a accessMan) removePeerAccess(remotePub btcec.PublicKey) {	3✔
526	a.banScoreMtx.Lock()	3✔
527	defer a.banScoreMtx.Unlock()	3✔
528		3✔
529	ctx := btclog.WithCtx(	3✔
530	context.TODO(), lnutils.LogPubKey("peer", remotePub),	3✔
531	)	3✔
532		3✔
533	acsmLog.DebugS(ctx, "Removing peer access")	3✔
534		3✔
535	peerMapKey := string(remotePub.SerializeCompressed())	3✔
536		3✔
537	status, found := a.peerScores[peerMapKey]	3✔
538	if !found {	3✔
539	acsmLog.InfoS(ctx, "Peer score not found during removal")	×
540	return	×
541	}	×
542
543	if status.state == peerStatusRestricted {	6✔
544	// If the status is restricted, then we decrement from	3✔
545	// numRestrictedSlots.	3✔
546	oldRestricted := a.numRestricted	3✔
547	a.numRestricted--	3✔
548		3✔
549	acsmLog.DebugS(ctx, "Decremented restricted slots",	3✔
550	"old_restricted", oldRestricted,	3✔
551	"new_restricted", a.numRestricted)	3✔
552	}	3✔
553
554	acsmLog.TraceS(ctx, "Deleting peer from peerScores")	3✔
555		3✔
556	delete(a.peerScores, peerMapKey)	3✔
557	}

lightningnetwork / lnd / 15325172502

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