12371948523

Committed 17 Dec 2024 11:19AM UTC coverage: 58.595% (-0.04%) from 58.632%

Build # 12371948523

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push

github

Committed by

web-flow

Commit Message

Merge pull request #9303 from yyforyongyu/fix-circuit-closed

htlcswitch+routing: handle nil pointer dereference properly

Run Details

34 of 34 new or added lines in 4 files covered. (100.0%)

136 existing lines in 23 files now uncovered.

134361 of 229306 relevant lines covered (58.59%)

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89.19

/chainntnfs/mempool.go

package chainntnfs

import (
        "sync"
        "sync/atomic"

        "github.com/btcsuite/btcd/btcutil"
        "github.com/btcsuite/btcd/wire"
        "github.com/lightningnetwork/lnd/lnutils"
)

// inputsWithTx is a map of outpoints to the tx that spends them.
type inputsWithTx map[wire.OutPoint]*SpendDetail

// MempoolNotifier defines an internal mempool notifier that's used to notify
// the spending of given inputs. This is mounted to either `BitcoindNotifier`
// or `BtcdNotifier` depending on the chain backend.
type MempoolNotifier struct {
        wg sync.WaitGroup

        // subscribedInputs stores the inputs that we want to watch their
        // spending event for.
        subscribedInputs *lnutils.SyncMap[wire.OutPoint,
                *lnutils.SyncMap[uint64, *MempoolSpendEvent]]

        // sCounter is used to generate unique subscription IDs.
        sCounter atomic.Uint64

        // quit is closed when the notifier is torn down.
        quit chan struct{}
}

// MempoolSpendEvent is returned to the subscriber to watch for the spending
// event for the requested input.
type MempoolSpendEvent struct {
        // Spend is a receive only channel which will be sent upon once the
        // target outpoint has been spent.
        //
        // NOTE: This channel must be buffered.
        Spend <-chan *SpendDetail

        // id is the unique identifier of this subscription.
        id uint64

        // outpoint is the subscribed outpoint.
        outpoint wire.OutPoint

        // event is the channel that will be sent upon once the target outpoint
        // is spent.
        event chan *SpendDetail

        // cancel cancels the subscription.
        cancel chan struct{}
}

// newMempoolSpendEvent returns a new instance of MempoolSpendEvent.
func newMempoolSpendEvent(id uint64, op wire.OutPoint) *MempoolSpendEvent {
        sub := &MempoolSpendEvent{
                id:       id,
                outpoint: op,
                event:    make(chan *SpendDetail, 1),
                cancel:   make(chan struct{}),
        }

        // Mount the receive only channel to the event channel.
        sub.Spend = (<-chan *SpendDetail)(sub.event)

        return sub
}

// NewMempoolNotifier takes a chain connection and returns a new mempool
// notifier.
func NewMempoolNotifier() *MempoolNotifier {
        return &MempoolNotifier{
                subscribedInputs: &lnutils.SyncMap[
                        wire.OutPoint, *lnutils.SyncMap[
                                uint64, *MempoolSpendEvent,
                        ]]{},
                quit: make(chan struct{}),
        }
}

// SubscribeInput takes an outpoint of the input and returns a channel that the
// subscriber can listen to for the spending event.
func (m *MempoolNotifier) SubscribeInput(
        outpoint wire.OutPoint) *MempoolSpendEvent {

        // Get the current subscribers for this input or create a new one.
        clients := &lnutils.SyncMap[uint64, *MempoolSpendEvent]{}
        clients, _ = m.subscribedInputs.LoadOrStore(outpoint, clients)

        // Increment the subscription counter and return the new value.
        subscriptionID := m.sCounter.Add(1)

        // Create a new subscription.
        sub := newMempoolSpendEvent(subscriptionID, outpoint)

        // Add the subscriber with a unique id.
        clients.Store(subscriptionID, sub)

        // Update the subscribed inputs.
        m.subscribedInputs.Store(outpoint, clients)

        Log.Debugf("Subscribed(id=%v) mempool event for input=%s",
                subscriptionID, outpoint)

        return sub
}

// UnsubscribeInput removes all the subscriptions for the given outpoint.
func (m *MempoolNotifier) UnsubscribeInput(outpoint wire.OutPoint) {
        Log.Debugf("Unsubscribing MempoolSpendEvent for input %s", outpoint)
        m.subscribedInputs.Delete(outpoint)
}

// UnsubscribeEvent removes a given subscriber for the given MempoolSpendEvent.
func (m *MempoolNotifier) UnsubscribeEvent(sub *MempoolSpendEvent) {
        Log.Debugf("Unsubscribing(id=%v) MempoolSpendEvent for input=%s",
                sub.id, sub.outpoint)

        // Load all the subscribers for this input.
        clients, loaded := m.subscribedInputs.Load(sub.outpoint)
        if !loaded {
                Log.Debugf("No subscribers for input %s", sub.outpoint)
                return
        }

        // Load the subscriber.
        subscriber, loaded := clients.Load(sub.id)
        if !loaded {
                Log.Debugf("No subscribers for input %s with id %v",
                        sub.outpoint, sub.id)
                return
        }

        // Close the cancel channel in case it's been used in a goroutine.
        close(subscriber.cancel)

        // Remove the subscriber.
        clients.Delete(sub.id)
}

// UnsubsribeConfirmedSpentTx takes a transaction and removes the subscriptions
// identified using its inputs.
func (m *MempoolNotifier) UnsubsribeConfirmedSpentTx(tx *btcutil.Tx) {
        Log.Tracef("Unsubscribe confirmed tx %s", tx.Hash())

        // Get the spent inputs of interest.
        spentInputs, err := m.findRelevantInputs(tx)
        if err != nil {
                Log.Errorf("Unable to find relevant inputs for tx %s: %v",
                        tx.Hash(), err)

                return
        }

        // Unsubscribe the subscribers.
        for outpoint := range spentInputs {
                m.UnsubscribeInput(outpoint)
        }

        Log.Tracef("Finished unsubscribing confirmed tx %s, found %d inputs",
                tx.Hash(), len(spentInputs))
}

// ProcessRelevantSpendTx takes a transaction and checks whether it spends any
// of the subscribed inputs. If so, spend notifications are sent to the
// relevant subscribers.
func (m *MempoolNotifier) ProcessRelevantSpendTx(tx *btcutil.Tx) error {
        Log.Tracef("Processing mempool tx %s", tx.Hash())
        defer Log.Tracef("Finished processing mempool tx %s", tx.Hash())

        // Get the spent inputs of interest.
        spentInputs, err := m.findRelevantInputs(tx)
        if err != nil {
                return err
        }

        // Notify the subscribers.
        m.notifySpent(spentInputs)

        return nil
}

// TearDown stops the notifier and cleans up resources.
func (m *MempoolNotifier) TearDown() {
        Log.Infof("Stopping mempool notifier")
        defer Log.Debug("mempool notifier stopped")

        close(m.quit)
        m.wg.Wait()
}

// findRelevantInputs takes a transaction to find the subscribed inputs and
// returns them.
func (m *MempoolNotifier) findRelevantInputs(tx *btcutil.Tx) (inputsWithTx,
        error) {

        txid := tx.Hash()
        watchedInputs := make(inputsWithTx)

        // NOTE: we may have found multiple targeted inputs in the same tx.
        for i, input := range tx.MsgTx().TxIn {
                op := &input.PreviousOutPoint

                // Check whether this input is subscribed.
                _, loaded := m.subscribedInputs.Load(*op)
                if !loaded {
                        continue
                }

                // If found, save it to watchedInputs to notify the
                // subscriber later.
                Log.Infof("Found input %s, spent in %s", op, txid)

                // Construct the spend details.
                details := &SpendDetail{
                        SpentOutPoint:     op,
                        SpenderTxHash:     txid,
                        SpendingTx:        tx.MsgTx().Copy(),
                        SpenderInputIndex: uint32(i),
                        SpendingHeight:    0,
                }
                watchedInputs[*op] = details

                // Sanity check the witness stack. If it's not empty, continue
                // to next iteration.
                if details.HasSpenderWitness() {
                        continue
                }

                // Return an error if the witness data is not present in the
                // spending transaction.
                Log.Criticalf("Found spending tx for outpoint=%v in mempool, "+
                        "but the transaction %v does not have witness",
                        op, details.SpendingTx.TxHash())

                return nil, ErrEmptyWitnessStack
        }

        return watchedInputs, nil
}

// notifySpent iterates all the spentInputs and notifies the subscribers about
// the spent details.
func (m *MempoolNotifier) notifySpent(spentInputs inputsWithTx) {
        // notifySingle sends a notification to a single subscriber about the
        // spending event.
        //
        // NOTE: must be used inside a goroutine.
        notifySingle := func(id uint64, sub *MempoolSpendEvent,
                op wire.OutPoint, detail *SpendDetail) {

                defer m.wg.Done()

                // Send the spend details to the subscriber.
                select {
                case sub.event <- detail:
                        Log.Debugf("Notified(id=%v) mempool spent for input %s",
                                sub.id, op)

                case <-sub.cancel:
                        Log.Debugf("Subscription(id=%v) canceled, skipped "+
                                "notifying spent for input %s", sub.id, op)

                case <-m.quit:
                        Log.Debugf("Mempool notifier quit, skipped notifying "+
                                "mempool spent for input %s", op)
                }
        }

        // notifyAll is a helper closure that constructs a spend detail and
        // sends it to all the subscribers of that particular input.
        //
        // NOTE: must be used inside a goroutine.
        notifyAll := func(detail *SpendDetail, op wire.OutPoint) {
                defer m.wg.Done()

                txid := detail.SpendingTx.TxHash()
                Log.Debugf("Notifying all clients for the spend of %s in tx %s",
                        op, txid)

                // Load the subscriber.
                subs, loaded := m.subscribedInputs.Load(op)
                if !loaded {
                        Log.Errorf("Sub not found for %s", op)
                        return
                }

                // Iterate all the subscribers for this input and notify them.
                subs.ForEach(func(id uint64, sub *MempoolSpendEvent) error {
                        m.wg.Add(1)
                        go notifySingle(id, sub, op, detail)

                        return nil
                })
        }

        // Iterate the spent inputs to notify the subscribers concurrently.
        for op, tx := range spentInputs {
                op, tx := op, tx

                m.wg.Add(1)
                go notifyAll(tx, op)
        }
}

1	package chainntnfs
2
3	import (
4	"sync"
5	"sync/atomic"
6
7	"github.com/btcsuite/btcd/btcutil"
8	"github.com/btcsuite/btcd/wire"
9	"github.com/lightningnetwork/lnd/lnutils"
10	)
11
12	// inputsWithTx is a map of outpoints to the tx that spends them.
13	type inputsWithTx map[wire.OutPoint]*SpendDetail
14
15	// MempoolNotifier defines an internal mempool notifier that's used to notify
16	// the spending of given inputs. This is mounted to either `BitcoindNotifier`
17	// or `BtcdNotifier` depending on the chain backend.
18	type MempoolNotifier struct {
19	wg sync.WaitGroup
20
21	// subscribedInputs stores the inputs that we want to watch their
22	// spending event for.
23	subscribedInputs *lnutils.SyncMap[wire.OutPoint,
24	lnutils.SyncMap[uint64, MempoolSpendEvent]]
25
26	// sCounter is used to generate unique subscription IDs.
27	sCounter atomic.Uint64
28
29	// quit is closed when the notifier is torn down.
30	quit chan struct{}
31	}
32
33	// MempoolSpendEvent is returned to the subscriber to watch for the spending
34	// event for the requested input.
35	type MempoolSpendEvent struct {
36	// Spend is a receive only channel which will be sent upon once the
37	// target outpoint has been spent.
38	//
39	// NOTE: This channel must be buffered.
40	Spend <-chan *SpendDetail
41
42	// id is the unique identifier of this subscription.
43	id uint64
44
45	// outpoint is the subscribed outpoint.
46	outpoint wire.OutPoint
47
48	// event is the channel that will be sent upon once the target outpoint
49	// is spent.
50	event chan *SpendDetail
51
52	// cancel cancels the subscription.
53	cancel chan struct{}
54	}
55
56	// newMempoolSpendEvent returns a new instance of MempoolSpendEvent.
57	func newMempoolSpendEvent(id uint64, op wire.OutPoint) *MempoolSpendEvent {	18✔
58	sub := &MempoolSpendEvent{	18✔
59	id: id,	18✔
60	outpoint: op,	18✔
61	event: make(chan *SpendDetail, 1),	18✔
62	cancel: make(chan struct{}),	18✔
63	}	18✔
64		18✔
65	// Mount the receive only channel to the event channel.	18✔
66	sub.Spend = (<-chan *SpendDetail)(sub.event)	18✔
67		18✔
68	return sub	18✔
69	}	18✔
70
71	// NewMempoolNotifier takes a chain connection and returns a new mempool
72	// notifier.
73	func NewMempoolNotifier() *MempoolNotifier {	33✔
74	return &MempoolNotifier{	33✔
75	subscribedInputs: &lnutils.SyncMap[	33✔
76	wire.OutPoint, *lnutils.SyncMap[	33✔
77	uint64, *MempoolSpendEvent,	33✔
78	]]{},	33✔
79	quit: make(chan struct{}),	33✔
80	}	33✔
81	}	33✔
82
83	// SubscribeInput takes an outpoint of the input and returns a channel that the
84	// subscriber can listen to for the spending event.
85	func (m *MempoolNotifier) SubscribeInput(
86	outpoint wire.OutPoint) *MempoolSpendEvent {	17✔
87		17✔
88	// Get the current subscribers for this input or create a new one.	17✔
89	clients := &lnutils.SyncMap[uint64, *MempoolSpendEvent]{}	17✔
90	clients, _ = m.subscribedInputs.LoadOrStore(outpoint, clients)	17✔
91		17✔
92	// Increment the subscription counter and return the new value.	17✔
93	subscriptionID := m.sCounter.Add(1)	17✔
94		17✔
95	// Create a new subscription.	17✔
96	sub := newMempoolSpendEvent(subscriptionID, outpoint)	17✔
97		17✔
98	// Add the subscriber with a unique id.	17✔
99	clients.Store(subscriptionID, sub)	17✔
100		17✔
101	// Update the subscribed inputs.	17✔
102	m.subscribedInputs.Store(outpoint, clients)	17✔
103		17✔
104	Log.Debugf("Subscribed(id=%v) mempool event for input=%s",	17✔
105	subscriptionID, outpoint)	17✔
106		17✔
107	return sub	17✔
108	}	17✔
109
110	// UnsubscribeInput removes all the subscriptions for the given outpoint.
111	func (m *MempoolNotifier) UnsubscribeInput(outpoint wire.OutPoint) {	4✔
112	Log.Debugf("Unsubscribing MempoolSpendEvent for input %s", outpoint)	4✔
113	m.subscribedInputs.Delete(outpoint)	4✔
114	}	4✔
115
116	// UnsubscribeEvent removes a given subscriber for the given MempoolSpendEvent.
117	func (m MempoolNotifier) UnsubscribeEvent(sub MempoolSpendEvent) {	4✔
118	Log.Debugf("Unsubscribing(id=%v) MempoolSpendEvent for input=%s",	4✔
119	sub.id, sub.outpoint)	4✔
120		4✔
121	// Load all the subscribers for this input.	4✔
122	clients, loaded := m.subscribedInputs.Load(sub.outpoint)	4✔
123	if !loaded {	6✔
124	Log.Debugf("No subscribers for input %s", sub.outpoint)	2✔
125	return	2✔
126	}	2✔
127
128	// Load the subscriber.
129	subscriber, loaded := clients.Load(sub.id)	4✔
130	if !loaded {	4✔
131	Log.Debugf("No subscribers for input %s with id %v",	×
132	sub.outpoint, sub.id)	×
133	return	×
134	}	×
135
136	// Close the cancel channel in case it's been used in a goroutine.
137	close(subscriber.cancel)	4✔
138		4✔
139	// Remove the subscriber.	4✔
140	clients.Delete(sub.id)	4✔
141	}
142
143	// UnsubsribeConfirmedSpentTx takes a transaction and removes the subscriptions
144	// identified using its inputs.
145	func (m MempoolNotifier) UnsubsribeConfirmedSpentTx(tx btcutil.Tx) {	34✔
146	Log.Tracef("Unsubscribe confirmed tx %s", tx.Hash())	34✔
147		34✔
148	// Get the spent inputs of interest.	34✔
149	spentInputs, err := m.findRelevantInputs(tx)	34✔
150	if err != nil {	34✔
151	Log.Errorf("Unable to find relevant inputs for tx %s: %v",	×
152	tx.Hash(), err)	×
153		×
154	return	×
155	}	×
156
157	// Unsubscribe the subscribers.
158	for outpoint := range spentInputs {	37✔
159	m.UnsubscribeInput(outpoint)	3✔
160	}	3✔
161
162	Log.Tracef("Finished unsubscribing confirmed tx %s, found %d inputs",	34✔
163	tx.Hash(), len(spentInputs))	34✔
164	}
165
166	// ProcessRelevantSpendTx takes a transaction and checks whether it spends any
167	// of the subscribed inputs. If so, spend notifications are sent to the
168	// relevant subscribers.
169	func (m MempoolNotifier) ProcessRelevantSpendTx(tx btcutil.Tx) error {	41✔
170	Log.Tracef("Processing mempool tx %s", tx.Hash())	41✔
171	defer Log.Tracef("Finished processing mempool tx %s", tx.Hash())	41✔
172		41✔
173	// Get the spent inputs of interest.	41✔
174	spentInputs, err := m.findRelevantInputs(tx)	41✔
175	if err != nil {	41✔
176	return err	×
177	}	×
178
179	// Notify the subscribers.
180	m.notifySpent(spentInputs)	41✔
181		41✔
182	return nil	41✔
183	}
184
185	// TearDown stops the notifier and cleans up resources.
186	func (m *MempoolNotifier) TearDown() {	20✔
187	Log.Infof("Stopping mempool notifier")	20✔
188	defer Log.Debug("mempool notifier stopped")	20✔
189		20✔
190	close(m.quit)	20✔
191	m.wg.Wait()	20✔
192	}	20✔
193
194	// findRelevantInputs takes a transaction to find the subscribed inputs and
195	// returns them.
196	func (m MempoolNotifier) findRelevantInputs(tx btcutil.Tx) (inputsWithTx,
197	error) {	75✔
198		75✔
199	txid := tx.Hash()	75✔
200	watchedInputs := make(inputsWithTx)	75✔
201		75✔
202	// NOTE: we may have found multiple targeted inputs in the same tx.	75✔
203	for i, input := range tx.MsgTx().TxIn {	152✔
204	op := &input.PreviousOutPoint	77✔
205		77✔
206	// Check whether this input is subscribed.	77✔
207	_, loaded := m.subscribedInputs.Load(*op)	77✔
208	if !loaded {	151✔
209	continue	74✔
210	}
211
212	// If found, save it to watchedInputs to notify the
213	// subscriber later.
214	Log.Infof("Found input %s, spent in %s", op, txid)	5✔
215		5✔
216	// Construct the spend details.	5✔
217	details := &SpendDetail{	5✔
218	SpentOutPoint: op,	5✔
219	SpenderTxHash: txid,	5✔
220	SpendingTx: tx.MsgTx().Copy(),	5✔
221	SpenderInputIndex: uint32(i),	5✔
222	SpendingHeight: 0,	5✔
223	}	5✔
224	watchedInputs[*op] = details	5✔
225		5✔
226	// Sanity check the witness stack. If it's not empty, continue	5✔
227	// to next iteration.	5✔
228	if details.HasSpenderWitness() {	9✔
229	continue	4✔
230	}
231
232	// Return an error if the witness data is not present in the
233	// spending transaction.
234	Log.Criticalf("Found spending tx for outpoint=%v in mempool, "+	1✔
235	"but the transaction %v does not have witness",	1✔
236	op, details.SpendingTx.TxHash())	1✔
237		1✔
238	return nil, ErrEmptyWitnessStack	1✔
239	}
240
241	return watchedInputs, nil	74✔
242	}
243
244	// notifySpent iterates all the spentInputs and notifies the subscribers about
245	// the spent details.
246	func (m *MempoolNotifier) notifySpent(spentInputs inputsWithTx) {	45✔
247	// notifySingle sends a notification to a single subscriber about the	45✔
248	// spending event.	45✔
249	//	45✔
250	// NOTE: must be used inside a goroutine.	45✔
251	notifySingle := func(id uint64, sub *MempoolSpendEvent,	45✔
252	op wire.OutPoint, detail *SpendDetail) {	53✔
253		8✔
254	defer m.wg.Done()	8✔
255		8✔
256	// Send the spend details to the subscriber.	8✔
257	select {	8✔
258	case sub.event <- detail:	8✔
259	Log.Debugf("Notified(id=%v) mempool spent for input %s",	8✔
260	sub.id, op)	8✔
261
262	case <-sub.cancel:	×
263	Log.Debugf("Subscription(id=%v) canceled, skipped "+	×
264	"notifying spent for input %s", sub.id, op)	×
265
266	case <-m.quit:	×
267	Log.Debugf("Mempool notifier quit, skipped notifying "+	×
268	"mempool spent for input %s", op)	×
269	}
270	}
271
272	// notifyAll is a helper closure that constructs a spend detail and
273	// sends it to all the subscribers of that particular input.
274	//
275	// NOTE: must be used inside a goroutine.
276	notifyAll := func(detail *SpendDetail, op wire.OutPoint) {	52✔
277	defer m.wg.Done()	7✔
278		7✔
279	txid := detail.SpendingTx.TxHash()	7✔
280	Log.Debugf("Notifying all clients for the spend of %s in tx %s",	7✔
281	op, txid)	7✔
282		7✔
283	// Load the subscriber.	7✔
284	subs, loaded := m.subscribedInputs.Load(op)	7✔
285	if !loaded {	7✔
UNCOV 286	Log.Errorf("Sub not found for %s", op)	×
UNCOV 287	return	×
UNCOV 288	}	×
289
290	// Iterate all the subscribers for this input and notify them.
291	subs.ForEach(func(id uint64, sub *MempoolSpendEvent) error {	15✔
292	m.wg.Add(1)	8✔
293	go notifySingle(id, sub, op, detail)	8✔
294		8✔
295	return nil	8✔
296	})	8✔
297	}
298
299	// Iterate the spent inputs to notify the subscribers concurrently.
300	for op, tx := range spentInputs {	52✔
301	op, tx := op, tx	7✔
302		7✔
303	m.wg.Add(1)	7✔
304	go notifyAll(tx, op)	7✔
305	}	7✔
306	}

lightningnetwork / lnd / 12371948523

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