client: monitor wallet peers

client/asset/btc/btc.go

@@ -39,12 +39,6 @@ import (
 const (
 	version = 0
 
-	// Use RawRequest to get the verbose block header for a blockhash.
-	methodGetBlockHeader = "getblockheader"
-	// Use RawRequest to get the verbose block with verbose txs, as the btcd
-	// rpcclient.Client's GetBlockVerboseTx appears to be busted.
-	methodGetNetworkInfo    = "getnetworkinfo"
-	methodGetBlockchainInfo = "getblockchaininfo"
 	// BipID is the BIP-0044 asset ID.
 	BipID = 0
 
@@ -81,6 +75,7 @@ const (
 var (
 	// blockTicker is the delay between calls to check for new blocks.
 	blockTicker                  = time.Second
+	peerCountTicker              = 5 * time.Second
 	walletBlockAllowance         = time.Second * 10
 	conventionalConversionFactor = float64(dexbtc.UnitInfo.Conventional.ConversionFactor)
 	rpcOpts                      = []*asset.ConfigOption{
@@ -513,6 +508,8 @@ type ExchangeWallet struct {
 	log               dex.Logger
 	symbol            string
 	tipChange         func(error)
+	lastPeerCount     uint32
+	peersChange       func(uint32)
 	minNetworkVersion uint64
 	fallbackFeeRate   uint64
 	feeRateLimit      uint64
@@ -727,6 +724,7 @@ func newUnconnectedWallet(cfg *BTCCloneCFG, walletCfg *WalletConfig) (*ExchangeW
 		chainParams:         cfg.ChainParams,
 		log:                 cfg.Logger,
 		tipChange:           cfg.WalletCFG.TipChange,
+		peersChange:         cfg.WalletCFG.PeersChange,
 		fundingCoins:        make(map[outPoint]*utxo),
 		findRedemptionQueue: make(map[outPoint]*findRedemptionReq),
 		minNetworkVersion:   cfg.MinNetworkVersion,
@@ -823,6 +821,11 @@ func (btc *ExchangeWallet) Connect(ctx context.Context) (*sync.WaitGroup, error)
 		btc.watchBlocks(ctx)
 		btc.shutdown()
 	}()
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		btc.monitorPeers(ctx)
+	}()
 	return &wg, nil
 }
 
@@ -865,7 +868,14 @@ func (btc *ExchangeWallet) SyncStatus() (bool, float32, error) {
 		}
 		return false, progress, nil
 	}
-	return true, 1, nil
+
+	// It looks like we are ready based on syncStatus, but that may just be
+	// comparing wallet height to known chain height. Now check peers.
+	numPeers, err := btc.node.peerCount()
+	if err != nil {
+		return false, 0, err
+	}
+	return numPeers > 0, 1, nil
 }
 
 // OwnsAddress indicates if an address belongs to the wallet.
@@ -2692,6 +2702,36 @@ func (btc *ExchangeWallet) RegFeeConfirmations(_ context.Context, id dex.Bytes)
 	return uint32(tx.Confirmations), nil
 }
 
+func (btc *ExchangeWallet) checkPeers() {
+	numPeers, err := btc.node.peerCount()
+	if err != nil {
+		prevPeer := atomic.SwapUint32(&btc.lastPeerCount, 0)
+		if prevPeer != 0 {
+			btc.log.Errorf("Failed to get peer count: %v", err)
+			btc.peersChange(0)
+		}
+		return
+	}
+	prevPeer := atomic.SwapUint32(&btc.lastPeerCount, numPeers)
+	if prevPeer != numPeers {
+		btc.peersChange(numPeers)
+	}
+}
+
+func (btc *ExchangeWallet) monitorPeers(ctx context.Context) {
+	ticker := time.NewTicker(peerCountTicker)
+	defer ticker.Stop()
+	for {
+		btc.checkPeers()
+
+		select {
+		case <-ticker.C:
+		case <-ctx.Done():
+			return
+		}
+	}
+}
+
 // watchBlocks pings for new blocks and runs the tipChange callback function
 // when the block changes.
 func (btc *ExchangeWallet) watchBlocks(ctx context.Context) {

client/asset/btc/btc_test.go

@@ -246,6 +246,10 @@ type tRawRequester struct {
 func (c *tRawRequester) RawRequest(_ context.Context, method string, params []json.RawMessage) (json.RawMessage, error) {
 	switch method {
 	// TODO: handle methodGetBlockHash and add actual tests to cover it.
+	case methodGetNetworkInfo:
+		return json.Marshal(&btcjson.GetNetworkInfoResult{
+			Connections: 1,
+		})
 	case methodEstimateSmartFee:
 		if c.testData.estFeeErr != nil {
 			return nil, c.testData.estFeeErr
@@ -580,6 +584,9 @@ func tNewWallet(segwit bool, walletType string) (*ExchangeWallet, *testData, fun
 			default:
 			}
 		},
+		PeersChange: func(num uint32) {
+			fmt.Println("peer count: ", num)
+		},
 	}
 	walletCtx, shutdown := context.WithCancel(tCtx)
 	cfg := &BTCCloneCFG{

client/asset/btc/livetest/livetest.go

@@ -58,6 +58,9 @@ func tBackend(ctx context.Context, t *testing.T, cfg *Config, node, name string,
 		TipChange: func(err error) {
 			blkFunc(reportName, err)
 		},
+		PeersChange: func(num uint32) {
+			fmt.Println("peer count: ", num)
+		},
 	}
 
 	w, err := cfg.NewWallet(walletCfg, logger, dex.Regtest)

client/asset/btc/rpcclient.go

@@ -47,6 +47,9 @@ const (
 	methodGetBestBlockHash   = "getbestblockhash"
 	methodGetRawMempool      = "getrawmempool"
 	methodGetRawTransaction  = "getrawtransaction"
+	methodGetBlockHeader     = "getblockheader"
+	methodGetNetworkInfo     = "getnetworkinfo"
+	methodGetBlockchainInfo  = "getblockchaininfo"
 )
 
 // RawRequester defines decred's rpcclient RawRequest func where all RPC
@@ -532,6 +535,17 @@ func (wc *rpcClient) getBlockHeight(blockHash *chainhash.Hash) (int32, error) {
 	return int32(hdr.Height), nil
 }
 
+func (wc *rpcClient) peerCount() (uint32, error) {
+	var r struct {
+		Connections uint32 `json:"connections"`
+	}
+	err := wc.call(methodGetNetworkInfo, nil, &r)
+	if err != nil {
+		return 0, err
+	}
+	return r.Connections, nil
+}
+
 // getBlockchainInfo sends the getblockchaininfo request and returns the result.
 func (wc *rpcClient) getBlockchainInfo() (*getBlockchainInfoResult, error) {
 	chainInfo := new(getBlockchainInfoResult)

client/asset/btc/spv.go

@@ -497,6 +497,10 @@ func (w *spvWallet) getChainHeight() (int32, error) {
 	return blk.Height, err
 }
 
+func (w *spvWallet) peerCount() (uint32, error) {
+	return uint32(len(w.cl.Peers())), nil
+}
+
 // syncHeight is the best known sync height among peers.
 func (w *spvWallet) syncHeight() int32 {
 	var maxHeight int32

client/asset/btc/wallet.go

@@ -36,6 +36,7 @@ type Wallet interface {
 	sendToAddress(address string, value, feeRate uint64, subtract bool) (*chainhash.Hash, error)
 	locked() bool
 	syncStatus() (*syncStatus, error)
+	peerCount() (uint32, error)
 	swapConfirmations(txHash *chainhash.Hash, vout uint32, contract []byte, startTime time.Time) (confs uint32, spent bool, err error)
 	getBlockHeader(blockHash *chainhash.Hash) (*blockHeader, error)
 	ownsAddress(addr btcutil.Address) (bool, error)

client/asset/dcr/dcr.go

@@ -17,6 +17,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 
 	"decred.org/dcrdex/client/asset"
@@ -69,6 +70,7 @@ const (
 var (
 	// blockTicker is the delay between calls to check for new blocks.
 	blockTicker                  = time.Second
+	peerCountTicker              = 5 * time.Second
 	conventionalConversionFactor = float64(dexdcr.UnitInfo.Conventional.ConversionFactor)
 	configOpts                   = []*asset.ConfigOption{
 		{
@@ -386,6 +388,8 @@ type ExchangeWallet struct {
 	log              dex.Logger
 	acct             string
 	tipChange        func(error)
+	lastPeerCount    uint32
+	peersChange      func(uint32)
 	fallbackFeeRate  uint64
 	feeRateLimit     uint64
 	redeemConfTarget uint64
@@ -501,6 +505,7 @@ func unconnectedWallet(cfg *asset.WalletConfig, dcrCfg *Config, chainParams *cha
 		chainParams:         chainParams,
 		acct:                dcrCfg.Account,
 		tipChange:           cfg.TipChange,
+		peersChange:         cfg.PeersChange,
 		fundingCoins:        make(map[outPoint]*fundingCoin),
 		findRedemptionQueue: make(map[outPoint]*findRedemptionReq),
 		externalTxCache:     make(map[chainhash.Hash]*externalTx),
@@ -582,6 +587,11 @@ func (dcr *ExchangeWallet) Connect(ctx context.Context) (*sync.WaitGroup, error)
 		}
 		dcr.shutdown()
 	}()
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		dcr.monitorPeers(ctx)
+	}()
 	return &wg, nil
 }
 
@@ -3066,6 +3076,38 @@ func (dcr *ExchangeWallet) getKeys(addr stdaddr.Address) (*secp256k1.PrivateKey,
 	return priv, priv.PubKey(), nil
 }
 
+func (dcr *ExchangeWallet) checkPeers() {
+	ctx, cancel := context.WithTimeout(dcr.ctx, 2*time.Second)
+	defer cancel()
+	numPeers, err := dcr.wallet.PeerCount(ctx)
+	if err != nil { // e.g. dcrd passthrough fail in non-SPV mode
+		prevPeer := atomic.SwapUint32(&dcr.lastPeerCount, 0)
+		if prevPeer != 0 {
+			dcr.log.Errorf("Failed to get peer count: %v", err)
+			dcr.peersChange(0)
+		}
+		return
+	}
+	prevPeer := atomic.SwapUint32(&dcr.lastPeerCount, numPeers)
+	if prevPeer != numPeers {
+		dcr.peersChange(numPeers)
+	}
+}
+
+func (dcr *ExchangeWallet) monitorPeers(ctx context.Context) {
+	ticker := time.NewTicker(peerCountTicker)
+	defer ticker.Stop()
+	for {
+		dcr.checkPeers()
+
+		select {
+		case <-ticker.C:
+		case <-ctx.Done():
+			return
+		}
+	}
+}
+
 // monitorBlocks pings for new blocks and runs the tipChange callback function
 // when the block changes. New blocks are also scanned for potential contract
 // redeems.

client/asset/dcr/dcr_test.go

@@ -152,7 +152,8 @@ func newTxOutResult(script []byte, value uint64, confs int64) *chainjson.GetTxOu
 func tNewWallet() (*ExchangeWallet, *tRPCClient, func(), error) {
 	client := newTRPCClient()
 	walletCfg := &asset.WalletConfig{
-		TipChange: func(error) {},
+		TipChange:   func(error) {},
+		PeersChange: func(uint32) {},
 	}
 	walletCtx, shutdown := context.WithCancel(tCtx)
 	wallet, err := unconnectedWallet(walletCfg, &Config{Account: "default"}, tChainParams, tLogger)
@@ -530,6 +531,12 @@ func (c *tRPCClient) RawRequest(_ context.Context, method string, params []json.
 	}
 
 	switch method {
+	case methodGetPeerInfo:
+		return json.Marshal([]*walletjson.GetPeerInfoResult{
+			{
+				Addr: "127.0.0.1",
+			},
+		})
 	case methodGetCFilterV2:
 		if len(params) != 1 {
 			return nil, fmt.Errorf("getcfilterv2 requires 1 param, got %d", len(params))

client/asset/dcr/rpcwallet.go

@@ -40,6 +40,7 @@ const (
 	methodListLockUnspent    = "listlockunspent"
 	methodSignRawTransaction = "signrawtransaction"
 	methodSyncStatus         = "syncstatus"
+	methodGetPeerInfo        = "getpeerinfo"
 )
 
 // rpcWallet implements Wallet functionality using an rpc client to communicate
@@ -480,6 +481,7 @@ func (w *rpcWallet) GetNewAddressGapPolicy(ctx context.Context, account string,
 // SignRawTransaction signs the provided transaction using rpc RawRequest.
 // Part of the Wallet interface.
 func (w *rpcWallet) SignRawTransaction(ctx context.Context, txHex string) (*walletjson.SignRawTransactionResult, error) {
+	// w.rpcClient.SignRawTransaction exists
 	var res walletjson.SignRawTransactionResult
 	err := w.rpcClientRawRequest(ctx, methodSignRawTransaction, anylist{txHex}, &res)
 	return &res, err
@@ -618,7 +620,24 @@ func (w *rpcWallet) SyncStatus(ctx context.Context) (bool, float32, error) {
 		return false, 0, fmt.Errorf("rawrequest error: %w", err)
 	}
 	ready := syncStatus.Synced && !syncStatus.InitialBlockDownload
-	return ready, syncStatus.HeadersFetchProgress, nil
+	if !ready {
+		return false, syncStatus.HeadersFetchProgress, nil
+	}
+	// It looks like we are ready based on syncstatus, but that may just be
+	// comparing wallet height to known chain height. Now check peers.
+	numPeers, err := w.PeerCount(ctx)
+	if err != nil {
+		return false, 0, err
+	}
+	return numPeers > 0, syncStatus.HeadersFetchProgress, nil
+}
+
+// PeerCount returns the number of network peers to which the wallet or its
+// backing node are connected.
+func (w *rpcWallet) PeerCount(ctx context.Context) (uint32, error) {
+	var peerInfo []*walletjson.GetPeerInfoResult
+	err := w.rpcClientRawRequest(ctx, methodGetPeerInfo, nil, &peerInfo)
+	return uint32(len(peerInfo)), err
 }
 
 // AddressPrivKey fetches the privkey for the specified address.

client/asset/dcr/simnet_test.go

@@ -74,6 +74,9 @@ func tBackend(t *testing.T, name string, blkFunc func(string, error)) (*Exchange
 		TipChange: func(err error) {
 			blkFunc(name, err)
 		},
+		PeersChange: func(num uint32) {
+			t.Log("peer count: ", num)
+		},
 	}
 	var backend asset.Wallet
 	backend, err = NewWallet(walletCfg, tLogger, dex.Simnet)

client/asset/dcr/wallet.go

@@ -135,6 +135,9 @@ type Wallet interface {
 	UnlockAccount(ctx context.Context, account, passphrase string) error
 	// SyncStatus returns the wallet's sync status.
 	SyncStatus(ctx context.Context) (bool, float32, error)
+	// PeerCount returns the number of network peers to which the wallet or its
+	// backing node are connected.
+	PeerCount(ctx context.Context) (uint32, error)
 	// AddressPrivKey fetches the privkey for the specified address.
 	AddressPrivKey(ctx context.Context, address stdaddr.Address) (*dcrutil.WIF, error)
 }