/
lnd_services.go
462 lines (388 loc) · 13.8 KB
/
lnd_services.go
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package lndclient
import (
"context"
"errors"
"fmt"
"net"
"path/filepath"
"time"
"github.com/btcsuite/btcd/chaincfg"
"github.com/btcsuite/btcutil"
"github.com/lightningnetwork/lnd/lncfg"
"github.com/lightningnetwork/lnd/lnrpc/verrpc"
"google.golang.org/grpc"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/credentials"
"google.golang.org/grpc/status"
)
var (
rpcTimeout = 30 * time.Second
// minimalCompatibleVersion is the minimum version and build tags
// required in lnd to get all functionality implemented in lndclient.
// Users can provide their own, specific version if needed. If only a
// subset of the lndclient functionality is needed, the required build
// tags can be adjusted accordingly. This default will be used as a fall
// back version if none is specified in the configuration.
minimalCompatibleVersion = &verrpc.Version{
AppMajor: 0,
AppMinor: 10,
AppPatch: 1,
BuildTags: []string{
"signrpc", "walletrpc", "chainrpc", "invoicesrpc",
},
}
// ErrVersionCheckNotImplemented is the error that is returned if the
// version RPC is not implemented in lnd. This means the version of lnd
// is lower than v0.10.0-beta.
ErrVersionCheckNotImplemented = errors.New("version check not " +
"implemented, need minimum lnd version of v0.10.0-beta")
// ErrVersionIncompatible is the error that is returned if the connected
// lnd instance is not supported.
ErrVersionIncompatible = errors.New("version incompatible")
// ErrBuildTagsMissing is the error that is returned if the
// connected lnd instance does not have all built tags activated that
// are required.
ErrBuildTagsMissing = errors.New("build tags missing")
)
// LndServicesConfig holds all configuration settings that are needed to connect
// to an lnd node.
type LndServicesConfig struct {
// LndAddress is the network address (host:port) of the lnd node to
// connect to.
LndAddress string
// Network is the bitcoin network we expect the lnd node to operate on.
Network Network
// MacaroonDir is the directory where all lnd macaroons can be found.
MacaroonDir string
// TLSPath is the path to lnd's TLS certificate file.
TLSPath string
// CheckVersion is the minimum version the connected lnd node needs to
// be in order to be compatible. The node will be checked against this
// when connecting. If no version is supplied, the default minimum
// version will be used.
CheckVersion *verrpc.Version
// Dialer is an optional dial function that can be passed in if the
// default lncfg.ClientAddressDialer should not be used.
Dialer DialerFunc
}
// DialerFunc is a function that is used as grpc.WithContextDialer().
type DialerFunc func(context.Context, string) (net.Conn, error)
// LndServices constitutes a set of required services.
type LndServices struct {
Client LightningClient
WalletKit WalletKitClient
ChainNotifier ChainNotifierClient
Signer SignerClient
Invoices InvoicesClient
Router RouterClient
Versioner VersionerClient
ChainParams *chaincfg.Params
NodeAlias string
NodePubkey [33]byte
Version *verrpc.Version
macaroons *macaroonPouch
}
// GrpcLndServices constitutes a set of required RPC services.
type GrpcLndServices struct {
LndServices
cleanup func()
}
// NewLndServices creates creates a connection to the given lnd instance and
// creates a set of required RPC services.
func NewLndServices(cfg *LndServicesConfig) (*GrpcLndServices, error) {
// We need to use a custom dialer so we can also connect to unix
// sockets and not just TCP addresses.
if cfg.Dialer == nil {
cfg.Dialer = lncfg.ClientAddressDialer(defaultRPCPort)
}
// Fall back to minimal compatible version if none if specified.
if cfg.CheckVersion == nil {
cfg.CheckVersion = minimalCompatibleVersion
}
// Based on the network, if the macaroon directory isn't set, then
// we'll use the expected default locations.
macaroonDir := cfg.MacaroonDir
if macaroonDir == "" {
switch cfg.Network {
case NetworkTestnet:
macaroonDir = filepath.Join(
defaultLndDir, defaultDataDir,
defaultChainSubDir, "bitcoin", "testnet",
)
case NetworkMainnet:
macaroonDir = filepath.Join(
defaultLndDir, defaultDataDir,
defaultChainSubDir, "bitcoin", "mainnet",
)
case NetworkSimnet:
macaroonDir = filepath.Join(
defaultLndDir, defaultDataDir,
defaultChainSubDir, "bitcoin", "simnet",
)
case NetworkRegtest:
macaroonDir = filepath.Join(
defaultLndDir, defaultDataDir,
defaultChainSubDir, "bitcoin", "regtest",
)
default:
return nil, fmt.Errorf("unsupported network: %v",
cfg.Network)
}
}
// Setup connection with lnd
log.Infof("Creating lnd connection to %v", cfg.LndAddress)
conn, err := getClientConn(cfg)
if err != nil {
return nil, err
}
log.Infof("Connected to lnd")
chainParams, err := cfg.Network.ChainParams()
if err != nil {
return nil, err
}
// We are going to check that the connected lnd is on the same network
// and is a compatible version with all the required subservers enabled.
// For this, we make two calls, both of which only need the readonly
// macaroon. We don't use the pouch yet because if not all subservers
// are enabled, then not all macaroons might be there and the user would
// get a more cryptic error message.
readonlyMac, err := newSerializedMacaroon(
filepath.Join(macaroonDir, defaultReadonlyFilename),
)
if err != nil {
return nil, err
}
nodeAlias, nodeKey, version, err := checkLndCompatibility(
conn, chainParams, readonlyMac, cfg.Network, cfg.CheckVersion,
)
if err != nil {
return nil, err
}
// Now that we've ensured our macaroon directory is set properly, we
// can retrieve our full macaroon pouch from the directory.
macaroons, err := newMacaroonPouch(macaroonDir)
if err != nil {
return nil, fmt.Errorf("unable to obtain macaroons: %v", err)
}
// With the macaroons loaded and the version checked, we can now create
// the real lightning client which uses the admin macaroon.
lightningClient := newLightningClient(
conn, chainParams, macaroons.adminMac,
)
// With the network check passed, we'll now initialize the rest of the
// sub-server connections, giving each of them their specific macaroon.
notifierClient := newChainNotifierClient(conn, macaroons.chainMac)
signerClient := newSignerClient(conn, macaroons.signerMac)
walletKitClient := newWalletKitClient(conn, macaroons.walletKitMac)
invoicesClient := newInvoicesClient(conn, macaroons.invoiceMac)
routerClient := newRouterClient(conn, macaroons.routerMac)
versionerClient := newVersionerClient(conn, macaroons.readonlyMac)
cleanup := func() {
log.Debugf("Closing lnd connection")
err := conn.Close()
if err != nil {
log.Errorf("Error closing client connection: %v", err)
}
log.Debugf("Wait for client to finish")
lightningClient.WaitForFinished()
log.Debugf("Wait for chain notifier to finish")
notifierClient.WaitForFinished()
log.Debugf("Wait for invoices to finish")
invoicesClient.WaitForFinished()
log.Debugf("Lnd services finished")
}
services := &GrpcLndServices{
LndServices: LndServices{
Client: lightningClient,
WalletKit: walletKitClient,
ChainNotifier: notifierClient,
Signer: signerClient,
Invoices: invoicesClient,
Router: routerClient,
Versioner: versionerClient,
ChainParams: chainParams,
NodeAlias: nodeAlias,
NodePubkey: nodeKey,
Version: version,
macaroons: macaroons,
},
cleanup: cleanup,
}
log.Infof("Using network %v", cfg.Network)
return services, nil
}
// Close closes the lnd connection and waits for all sub server clients to
// finish their goroutines.
func (s *GrpcLndServices) Close() {
s.cleanup()
log.Debugf("Lnd services finished")
}
// checkLndCompatibility makes sure the connected lnd instance is running on the
// correct network, has the version RPC implemented, is the correct minimal
// version and supports all required build tags/subservers.
func checkLndCompatibility(conn *grpc.ClientConn, chainParams *chaincfg.Params,
readonlyMac serializedMacaroon, network Network,
minVersion *verrpc.Version) (string, [33]byte, *verrpc.Version, error) {
// onErr is a closure that simplifies returning multiple values in the
// error case.
onErr := func(err error) (string, [33]byte, *verrpc.Version, error) {
closeErr := conn.Close()
if closeErr != nil {
log.Errorf("Error closing lnd connection: %v", closeErr)
}
// Make static error messages a bit less cryptic by adding the
// version or build tag that we expect.
newErr := fmt.Errorf("lnd compatibility check failed: %v", err)
if err == ErrVersionIncompatible || err == ErrBuildTagsMissing {
newErr = fmt.Errorf("error checking connected lnd "+
"version. at least version \"%s\" is "+
"required", VersionString(minVersion))
}
return "", [33]byte{}, nil, newErr
}
// We use our own clients with a readonly macaroon here, because we know
// that's all we need for the checks.
lightningClient := newLightningClient(conn, chainParams, readonlyMac)
versionerClient := newVersionerClient(conn, readonlyMac)
// With our readonly macaroon obtained, we'll ensure that the network
// for lnd matches our expected network.
info, err := lightningClient.GetInfo(context.Background())
if err != nil {
err := fmt.Errorf("unable to get info for lnd node: %v", err)
return onErr(err)
}
if string(network) != info.Network {
err := fmt.Errorf("network mismatch with connected lnd node, "+
"wanted '%s', got '%s'", network, info.Network)
return onErr(err)
}
// Now let's also check the version of the connected lnd node.
version, err := checkVersionCompatibility(versionerClient, minVersion)
if err != nil {
return onErr(err)
}
// Return the static part of the info we just queried from the node so
// it can be cached for later use.
return info.Alias, info.IdentityPubkey, version, nil
}
// checkVersionCompatibility makes sure the connected lnd node has the correct
// version and required build tags enabled.
//
// NOTE: This check will **never** return a non-nil error for a version of
// lnd < 0.10.0 because any version previous to 0.10.0 doesn't have the version
// endpoint implemented!
func checkVersionCompatibility(client VersionerClient,
expected *verrpc.Version) (*verrpc.Version, error) {
// First, test that the version RPC is even implemented.
version, err := client.GetVersion(context.Background())
if err != nil {
// The version service has only been added in lnd v0.10.0. If
// we get an unimplemented error, it means the lnd version is
// definitely older than that.
s, ok := status.FromError(err)
if ok && s.Code() == codes.Unimplemented {
return nil, ErrVersionCheckNotImplemented
}
return nil, fmt.Errorf("GetVersion error: %v", err)
}
log.Infof("lnd version: %v", VersionString(version))
// Now check the version and make sure all required build tags are set.
err = assertVersionCompatible(version, expected)
if err != nil {
return nil, err
}
err = assertBuildTagsEnabled(version, expected.BuildTags)
if err != nil {
return nil, err
}
// All check positive, version is fully compatible.
return version, nil
}
// assertVersionCompatible makes sure the detected lnd version is compatible
// with our current version requirements.
func assertVersionCompatible(actual *verrpc.Version,
expected *verrpc.Version) error {
// We need to check the versions parts sequentially as they are
// hierarchical.
if actual.AppMajor != expected.AppMajor {
if actual.AppMajor > expected.AppMajor {
return nil
}
return ErrVersionIncompatible
}
if actual.AppMinor != expected.AppMinor {
if actual.AppMinor > expected.AppMinor {
return nil
}
return ErrVersionIncompatible
}
if actual.AppPatch != expected.AppPatch {
if actual.AppPatch > expected.AppPatch {
return nil
}
return ErrVersionIncompatible
}
// The actual version and expected version are identical.
return nil
}
// assertBuildTagsEnabled makes sure all required build tags are set.
func assertBuildTagsEnabled(actual *verrpc.Version,
requiredTags []string) error {
tagMap := make(map[string]struct{})
for _, tag := range actual.BuildTags {
tagMap[tag] = struct{}{}
}
for _, required := range requiredTags {
if _, ok := tagMap[required]; !ok {
return ErrBuildTagsMissing
}
}
// All tags found.
return nil
}
var (
defaultRPCPort = "10009"
defaultLndDir = btcutil.AppDataDir("lnd", false)
defaultTLSCertFilename = "tls.cert"
defaultTLSCertPath = filepath.Join(
defaultLndDir, defaultTLSCertFilename,
)
defaultDataDir = "data"
defaultChainSubDir = "chain"
defaultAdminMacaroonFilename = "admin.macaroon"
defaultInvoiceMacaroonFilename = "invoices.macaroon"
defaultChainMacaroonFilename = "chainnotifier.macaroon"
defaultWalletKitMacaroonFilename = "walletkit.macaroon"
defaultRouterMacaroonFilename = "router.macaroon"
defaultSignerFilename = "signer.macaroon"
defaultReadonlyFilename = "readonly.macaroon"
// maxMsgRecvSize is the largest gRPC message our client will receive.
// We set this to 200MiB.
maxMsgRecvSize = grpc.MaxCallRecvMsgSize(1 * 1024 * 1024 * 200)
)
func getClientConn(cfg *LndServicesConfig) (*grpc.ClientConn, error) {
// Load the specified TLS certificate and build transport credentials
// with it.
tlsPath := cfg.TLSPath
if tlsPath == "" {
tlsPath = defaultTLSCertPath
}
creds, err := credentials.NewClientTLSFromFile(tlsPath, "")
if err != nil {
return nil, err
}
// Create a dial options array.
opts := []grpc.DialOption{
grpc.WithTransportCredentials(creds),
// Use a custom dialer, to allow connections to unix sockets,
// in-memory listeners etc, and not just TCP addresses.
grpc.WithContextDialer(cfg.Dialer),
grpc.WithDefaultCallOptions(maxMsgRecvSize),
}
conn, err := grpc.Dial(cfg.LndAddress, opts...)
if err != nil {
return nil, fmt.Errorf("unable to connect to RPC server: %v",
err)
}
return conn, nil
}