Merge pull request #278 from lightninglabs/stateless-integrated-mode

Stateless integrated mode

Author: guggero

config.go

@@ -177,6 +177,11 @@ type Config struct {
 	faradayRemote bool
 	loopRemote    bool
 	poolRemote    bool
+
+	// lndAdminMacaroon is the admin macaroon that is given to us by lnd
+	// over an in-memory connection on startup. This is only set in
+	// integrated lnd mode.
+	lndAdminMacaroon []byte
 }
 
 // RemoteConfig holds the configuration parameters that are needed when running
@@ -219,15 +224,16 @@ type RemoteDaemonConfig struct {
 // lndConnectParams returns the connection parameters to connect to the local
 // lnd instance.
 func (c *Config) lndConnectParams() (string, lndclient.Network, string,
-	string) {
+	string, []byte) {
 
 	// In remote lnd mode, we just pass along what was configured in the
 	// remote section of the lnd config.
 	if c.LndMode == ModeRemote {
 		return c.Remote.Lnd.RPCServer,
 			lndclient.Network(c.Network),
 			lncfg.CleanAndExpandPath(c.Remote.Lnd.TLSCertPath),
-			lncfg.CleanAndExpandPath(c.Remote.Lnd.MacaroonPath)
+			lncfg.CleanAndExpandPath(c.Remote.Lnd.MacaroonPath),
+			nil
 	}
 
 	// When we start lnd internally, we take the listen address as
@@ -248,8 +254,8 @@ func (c *Config) lndConnectParams() (string, lndclient.Network, string,
 		)
 	}
 
-	return lndDialAddr, lndclient.Network(c.Network),
-		c.Lnd.TLSCertPath, c.Lnd.AdminMacPath
+	return lndDialAddr, lndclient.Network(c.Network), "", "",
+		c.lndAdminMacaroon
 }
 
 // defaultConfig returns a configuration struct with all default values set.

rpc_proxy.go

@@ -2,10 +2,12 @@ package terminal
 
 import (
 	"context"
+	"crypto/tls"
 	"encoding/base64"
 	"encoding/hex"
 	"fmt"
 	"io/ioutil"
+	"net"
 	"net/http"
 	"strings"
 	"time"
@@ -18,6 +20,7 @@ import (
 	"google.golang.org/grpc/backoff"
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/metadata"
+	"google.golang.org/grpc/test/bufconn"
 	"gopkg.in/macaroon-bakery.v2/bakery"
 	"gopkg.in/macaroon.v2"
 )
@@ -34,7 +37,8 @@ const (
 // or REST request and delegate (and convert if necessary) it to the correct
 // component.
 func newRpcProxy(cfg *Config, validator macaroons.MacaroonValidator,
-	permissionMap map[string][]bakery.Op) *rpcProxy {
+	permissionMap map[string][]bakery.Op,
+	bufListener *bufconn.Listener) *rpcProxy {
 
 	// The gRPC web calls are protected by HTTP basic auth which is defined
 	// by base64(username:password). Because we only have a password, we
@@ -52,6 +56,7 @@ func newRpcProxy(cfg *Config, validator macaroons.MacaroonValidator,
 		cfg:          cfg,
 		basicAuth:    basicAuth,
 		macValidator: validator,
+		bufListener:  bufListener,
 	}
 	p.grpcServer = grpc.NewServer(
 		// From the grpxProxy doc: This codec is *crucial* to the
@@ -125,6 +130,9 @@ type rpcProxy struct {
 	basicAuth string
 
 	macValidator macaroons.MacaroonValidator
+	bufListener  *bufconn.Listener
+
+	superMacaroon string
 
 	lndConn     *grpc.ClientConn
 	faradayConn *grpc.ClientConn
@@ -140,8 +148,14 @@ func (p *rpcProxy) Start() error {
 	var err error
 
 	// Setup the connection to lnd.
-	host, _, tlsPath, _ := p.cfg.lndConnectParams()
-	p.lndConn, err = dialBackend("lnd", host, tlsPath)
+	host, _, tlsPath, _, _ := p.cfg.lndConnectParams()
+
+	// We use a bufconn to connect to lnd in integrated mode.
+	if p.cfg.LndMode == ModeIntegrated {
+		p.lndConn, err = dialBufConnBackend(p.bufListener)
+	} else {
+		p.lndConn, err = dialBackend("lnd", host, tlsPath)
+	}
 	if err != nil {
 		return fmt.Errorf("could not dial lnd: %v", err)
 	}
@@ -390,10 +404,13 @@ func (p *rpcProxy) basicAuthToMacaroon(ctx context.Context,
 		return ctx, nil
 	}
 
-	var macPath string
+	var (
+		macPath string
+		macData []byte
+	)
 	switch {
 	case isLndURI(requestURI):
-		_, _, _, macPath = p.cfg.lndConnectParams()
+		_, _, _, macPath, macData = p.cfg.lndConnectParams()
 
 	case isFaradayURI(requestURI):
 		if p.cfg.faradayRemote {
@@ -421,16 +438,64 @@ func (p *rpcProxy) basicAuthToMacaroon(ctx context.Context,
 			requestURI)
 	}
 
-	// Now that we know which macaroon to load, do it and attach it to the
-	// request context.
-	macBytes, err := readMacaroon(lncfg.CleanAndExpandPath(macPath))
-	if err != nil {
-		return ctx, fmt.Errorf("error reading macaroon: %v", err)
+	switch {
+	// If we have a super macaroon, we can use that one directly since it
+	// will contain all permissions we need.
+	case len(p.superMacaroon) > 0:
+		md.Set(HeaderMacaroon, p.superMacaroon)
+
+	// If we have macaroon data directly, just encode them. This could be
+	// for initial requests to lnd while we don't have the super macaroon
+	// just yet (or are actually calling to bake the super macaroon).
+	case len(macData) > 0:
+		md.Set(HeaderMacaroon, hex.EncodeToString(macData))
+
+	// The fall back is to read the macaroon from a path. This is in remote
+	// mode.
+	case len(macPath) > 0:
+		// Now that we know which macaroon to load, do it and attach it
+		// to the request context.
+		macBytes, err := readMacaroon(lncfg.CleanAndExpandPath(macPath))
+		if err != nil {
+			return ctx, fmt.Errorf("error reading macaroon %s: %v",
+				lncfg.CleanAndExpandPath(macPath), err)
+		}
+
+		md.Set(HeaderMacaroon, hex.EncodeToString(macBytes))
 	}
-	md.Set(HeaderMacaroon, hex.EncodeToString(macBytes))
+
 	return metadata.NewIncomingContext(ctx, md), nil
 }
 
+// dialBufConnBackend dials an in-memory connection to an RPC listener and
+// ignores any TLS certificate mismatches.
+func dialBufConnBackend(listener *bufconn.Listener) (*grpc.ClientConn, error) {
+	tlsConfig := credentials.NewTLS(&tls.Config{
+		InsecureSkipVerify: true,
+	})
+	conn, err := grpc.Dial(
+		"",
+		grpc.WithContextDialer(
+			func(context.Context, string) (net.Conn, error) {
+				return listener.Dial()
+			},
+		),
+		grpc.WithTransportCredentials(tlsConfig),
+
+		// From the grpcProxy doc: This codec is *crucial* to the
+		// functioning of the proxy.
+		grpc.WithCodec(grpcProxy.Codec()), // nolint
+		grpc.WithTransportCredentials(tlsConfig),
+		grpc.WithDefaultCallOptions(maxMsgRecvSize),
+		grpc.WithConnectParams(grpc.ConnectParams{
+			Backoff:           backoff.DefaultConfig,
+			MinConnectTimeout: defaultConnectTimeout,
+		}),
+	)
+
+	return conn, err
+}
+
 // dialBackend connects to a gRPC backend through the given address and uses the
 // given TLS certificate to authenticate the connection.
 func dialBackend(name, dialAddr, tlsCertPath string) (*grpc.ClientConn, error) {
@@ -470,12 +535,12 @@ func readMacaroon(macPath string) ([]byte, error) {
 	// Load the specified macaroon file.
 	macBytes, err := ioutil.ReadFile(macPath)
 	if err != nil {
-		return nil, fmt.Errorf("unable to read macaroon path : %v", err)
+		return nil, fmt.Errorf("unable to read macaroon path: %v", err)
 	}
 
 	// Make sure it actually is a macaroon by parsing it.
 	mac := &macaroon.Macaroon{}
-	if err = mac.UnmarshalBinary(macBytes); err != nil {
+	if err := mac.UnmarshalBinary(macBytes); err != nil {
 		return nil, fmt.Errorf("unable to decode macaroon: %v", err)
 	}
 

subserver_permissions.go

@@ -26,9 +26,9 @@ func getSubserverPermissions() map[string][]bakery.Op {
 	return result
 }
 
-// getAllPermissions returns a merged map of lnd's and all subservers' macaroon
-// permissions.
-func getAllPermissions() map[string][]bakery.Op {
+// getAllMethodPermissions returns a merged map of lnd's and all subservers'
+// method macaroon permissions.
+func getAllMethodPermissions() map[string][]bakery.Op {
 	subserverPermissions := getSubserverPermissions()
 	lndPermissions := lnd.MainRPCServerPermissions()
 	mapSize := len(subserverPermissions) + len(lndPermissions)
@@ -42,6 +42,35 @@ func getAllPermissions() map[string][]bakery.Op {
 	return result
 }
 
+// getAllPermissions retrieves all the permissions needed to bake a super
+// macaroon.
+func getAllPermissions() []bakery.Op {
+	dedupMap := make(map[string]map[string]bool)
+
+	for _, methodPerms := range getAllMethodPermissions() {
+		for _, methodPerm := range methodPerms {
+			if dedupMap[methodPerm.Entity] == nil {
+				dedupMap[methodPerm.Entity] = make(
+					map[string]bool,
+				)
+			}
+			dedupMap[methodPerm.Entity][methodPerm.Action] = true
+		}
+	}
+
+	result := make([]bakery.Op, 0, len(dedupMap))
+	for entity, actions := range dedupMap {
+		for action := range actions {
+			result = append(result, bakery.Op{
+				Entity: entity,
+				Action: action,
+			})
+		}
+	}
+
+	return result
+}
+
 // isLndURI returns true if the given URI belongs to an RPC of lnd.
 func isLndURI(uri string) bool {
 	_, ok := lnd.MainRPCServerPermissions()[uri]