Add price oracle proxy

config.go

@@ -15,6 +15,7 @@ import (
 	"github.com/lightninglabs/taproot-assets/tapdb"
 	"github.com/lightninglabs/taproot-assets/tapfreighter"
 	"github.com/lightninglabs/taproot-assets/tapgarden"
+	"github.com/lightninglabs/taproot-assets/taprpc/priceoraclerpc"
 	"github.com/lightninglabs/taproot-assets/universe"
 	"github.com/lightningnetwork/lnd"
 	"github.com/lightningnetwork/lnd/build"
@@ -52,6 +53,8 @@ type RPCConfig struct {
 
 	AllowPublicStats bool
 
+	AllowPublicPriceOracle bool
+
 	LetsEncryptDir string
 
 	LetsEncryptListen string
@@ -197,6 +200,10 @@ type Config struct {
 
 	PriceOracle rfq.PriceOracle
 
+	// ProxyPriceOracle is an optional price oracle that can be used to
+	// proxy price requests to another price oracle.
+	ProxyPriceOracle priceoraclerpc.PriceOracleClient
+
 	UniverseStats universe.Telemetry
 
 	AuxLeafSigner *tapchannel.AuxLeafSigner

itest/integration_test.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/lightninglabs/taproot-assets/taprpc"
+	"github.com/lightninglabs/taproot-assets/taprpc/priceoraclerpc"
 	"github.com/lightningnetwork/lnd/lntest"
 	"github.com/stretchr/testify/require"
 )
@@ -129,3 +130,23 @@ func testGetInfo(t *harnessTest) {
 	// Ensure the response matches the expected response.
 	require.Equal(t.t, resp, respCli)
 }
+
+// testPriceOracleProxy tests the price oracle proxy.
+func testPriceOracleProxy(t *harnessTest) {
+	ctxb := context.Background()
+	ctxt, cancel := context.WithTimeout(ctxb, defaultWaitTimeout)
+	defer cancel()
+
+	resp, err := t.tapd.PriceOracleClient.QueryAssetRates(
+		ctxt, &priceoraclerpc.QueryAssetRatesRequest{},
+	)
+	require.NoError(t.t, err)
+
+	okResp := resp.GetOk()
+	require.NotNil(t.t, okResp)
+
+	require.Equal(
+		t.t, fmt.Sprintf("%v", mockPriceOracleCoef),
+		okResp.AssetRates.SubjectAssetRate.Coefficient,
+	)
+}

itest/tapd_harness.go

@@ -23,6 +23,7 @@ import (
 	"github.com/lightninglabs/taproot-assets/taprpc"
 	"github.com/lightninglabs/taproot-assets/taprpc/assetwalletrpc"
 	"github.com/lightninglabs/taproot-assets/taprpc/mintrpc"
+	"github.com/lightninglabs/taproot-assets/taprpc/priceoraclerpc"
 	"github.com/lightninglabs/taproot-assets/taprpc/rfqrpc"
 	tchrpc "github.com/lightninglabs/taproot-assets/taprpc/tapchannelrpc"
 	"github.com/lightninglabs/taproot-assets/taprpc/tapdevrpc"
@@ -83,6 +84,10 @@ const (
 	// timeout we'll use for waiting for a receiver to acknowledge a proof
 	// transfer.
 	defaultProofTransferReceiverAckTimeout = 500 * time.Millisecond
+
+	// mockPriceOracleCoef is the coefficient used in the mock price oracle
+	// to calculate the asset rate.
+	mockPriceOracleCoef = 5_820_600
 )
 
 // tapdHarness is a test harness that holds everything that is needed to
@@ -102,6 +107,7 @@ type tapdHarness struct {
 	tchrpc.TaprootAssetChannelsClient
 	universerpc.UniverseClient
 	tapdevrpc.TapDevClient
+	priceoraclerpc.PriceOracleClient
 }
 
 // tapdConfig holds all configuration items that are required to start a tapd
@@ -223,7 +229,7 @@ func newTapdHarness(t *testing.T, ht *harnessTest, cfg tapdConfig,
 		Rfq: rfq.CliConfig{
 			//nolint:lll
 			PriceOracleAddress:     rfq.MockPriceOracleServiceAddress,
-			MockOracleAssetsPerBTC: 5_820_600,
+			MockOracleAssetsPerBTC: mockPriceOracleCoef,
 		},
 	}
 
@@ -425,6 +431,7 @@ func (hs *tapdHarness) start(expectErrExit bool) error {
 	)
 	hs.UniverseClient = universerpc.NewUniverseClient(rpcConn)
 	hs.TapDevClient = tapdevrpc.NewTapDevClient(rpcConn)
+	hs.PriceOracleClient = priceoraclerpc.NewPriceOracleClient(rpcConn)
 
 	return nil
 }

itest/test_list_on_test.go

@@ -336,6 +336,10 @@ var testCases = []*testCase{
 		name: "asset signing after lnd restore from seed",
 		test: testRestoreLndFromSeed,
 	},
+	{
+		name: "price oracle proxy",
+		test: testPriceOracleProxy,
+	},
 }
 
 var optionalTestCases = []*testCase{

perms/perms.go

@@ -311,6 +311,10 @@ var (
 			Entity: "assets",
 			Action: "write",
 		}},
+		"/priceoraclerpc.PriceOracle/QueryAssetRates": {{
+			Entity: "priceoracle",
+			Action: "read",
+		}},
 	}
 
 	// defaultMacaroonWhitelist defines a default set of RPC endpoints that
@@ -332,7 +336,8 @@ var (
 // macaroon authentication.
 func MacaroonWhitelist(allowUniPublicAccessRead bool,
 	allowUniPublicAccessWrite bool, allowPublicUniProofCourier bool,
-	allowPublicStats bool) map[string]struct{} {
+	allowPublicStats bool, allowPublicPriceOracle bool,
+) map[string]struct{} {
 
 	// Make a copy of the default whitelist.
 	whitelist := make(map[string]struct{})
@@ -357,5 +362,10 @@ func MacaroonWhitelist(allowUniPublicAccessRead bool,
 		whitelist["/universerpc.Universe/QueryEvents"] = struct{}{}
 	}
 
+	// Conditionally add public price oracle RPC endpoints to the whitelist.
+	if allowPublicPriceOracle {
+		whitelist["/priceoraclerpc.PriceOracle/QueryAssetRates"] = struct{}{} // nolint: lll
+	}
+
 	return whitelist
 }

rfq/mock.go

@@ -9,8 +9,11 @@ import (
 	"github.com/lightninglabs/taproot-assets/fn"
 	"github.com/lightninglabs/taproot-assets/rfqmath"
 	"github.com/lightninglabs/taproot-assets/rfqmsg"
+	"github.com/lightninglabs/taproot-assets/taprpc/priceoraclerpc"
+	oraclerpc "github.com/lightninglabs/taproot-assets/taprpc/priceoraclerpc"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/stretchr/testify/mock"
+	"google.golang.org/grpc"
 )
 
 // MockPriceOracle is a mock implementation of the PriceOracle interface.
@@ -113,6 +116,34 @@ func (m *MockPriceOracle) QueryBidPrice(ctx context.Context,
 	return resp, args.Error(1)
 }
 
+// QueryAssetRates is a mock implementation of the QueryAssetRates method.
+func (m *MockPriceOracle) QueryAssetRates(ctx context.Context,
+	in *priceoraclerpc.QueryAssetRatesRequest, opts ...grpc.CallOption,
+) (*priceoraclerpc.QueryAssetRatesResponse, error) {
+
+	// Unmarshal the subject asset to BTC rate.
+	rpcRate := &priceoraclerpc.FixedPoint{
+		Coefficient: m.assetToBtcRate.Coefficient.String(),
+		Scale:       uint32(m.assetToBtcRate.Scale),
+	}
+
+	return &priceoraclerpc.QueryAssetRatesResponse{
+		Result: &priceoraclerpc.QueryAssetRatesResponse_Ok{
+			Ok: &priceoraclerpc.QueryAssetRatesOkResponse{
+				AssetRates: &priceoraclerpc.AssetRates{
+					SubjectAssetRate: rpcRate,
+				},
+			},
+		},
+	}, nil
+}
+
+// Client returns a client that can be used to interact with the mock price
+// oracle.
+func (m *MockPriceOracle) Client() oraclerpc.PriceOracleClient {
+	return m
+}
+
 // Ensure that MockPriceOracle implements the PriceOracle interface.
 var _ PriceOracle = (*MockPriceOracle)(nil)
 

rfq/oracle.go

@@ -107,6 +107,9 @@ type PriceOracle interface {
 		paymentMaxAmt fn.Option[lnwire.MilliSatoshi],
 		assetRateHint fn.Option[rfqmsg.AssetRate]) (
 		*OracleResponse, error)
+
+	// RawClient returns the underlying RPC client.
+	Client() oraclerpc.PriceOracleClient
 }
 
 // RpcPriceOracle is a price oracle that uses an external RPC server to get
@@ -404,5 +407,10 @@ func (r *RpcPriceOracle) QueryBidPrice(ctx context.Context,
 	}
 }
 
+// Client returns the underlying RPC client.
+func (r *RpcPriceOracle) Client() oraclerpc.PriceOracleClient {
+	return r.client
+}
+
 // Ensure that RpcPriceOracle implements the PriceOracle interface.
 var _ PriceOracle = (*RpcPriceOracle)(nil)

rpcserver.go

@@ -46,6 +46,7 @@ import (
 	"github.com/lightninglabs/taproot-assets/taprpc"
 	wrpc "github.com/lightninglabs/taproot-assets/taprpc/assetwalletrpc"
 	"github.com/lightninglabs/taproot-assets/taprpc/mintrpc"
+	"github.com/lightninglabs/taproot-assets/taprpc/priceoraclerpc"
 	"github.com/lightninglabs/taproot-assets/taprpc/rfqrpc"
 	tchrpc "github.com/lightninglabs/taproot-assets/taprpc/tapchannelrpc"
 	"github.com/lightninglabs/taproot-assets/taprpc/tapdevrpc"
@@ -70,6 +71,8 @@ import (
 	"golang.org/x/exp/maps"
 	"golang.org/x/time/rate"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 )
 
 var (
@@ -84,6 +87,11 @@ var (
 	// P2TRChangeType is the type of change address that should be used for
 	// funding PSBTs, as we'll always want to use P2TR change addresses.
 	P2TRChangeType = walletrpc.ChangeAddressType_CHANGE_ADDRESS_TYPE_P2TR
+
+	// ErrPriceOracleUnimplemented is the error returned when the price
+	// oracle service is unimplemented.
+	ErrPriceOracleUnimplemented = status.Error(
+		codes.Unimplemented, "price oracle service is unimplemented")
 )
 
 const (
@@ -161,6 +169,7 @@ type rpcServer struct {
 	tchrpc.UnimplementedTaprootAssetChannelsServer
 	tapdevrpc.UnimplementedTapDevServer
 	unirpc.UnimplementedUniverseServer
+	priceoraclerpc.UnimplementedPriceOracleServer
 
 	interceptor signal.Interceptor
 
@@ -230,6 +239,8 @@ func (r *rpcServer) RegisterWithGrpcServer(grpcServer *grpc.Server) error {
 	tchrpc.RegisterTaprootAssetChannelsServer(grpcServer, r)
 	unirpc.RegisterUniverseServer(grpcServer, r)
 	tapdevrpc.RegisterGrpcServer(grpcServer, r)
+	priceoraclerpc.RegisterPriceOracleServer(grpcServer, r)
+
 	return nil
 }
 
@@ -8259,3 +8270,18 @@ func (r *rpcServer) RegisterTransfer(ctx context.Context,
 		RegisteredAsset: rpcAsset,
 	}, nil
 }
+
+// QueryAssetRates retrieves the exchange rate between a tap asset and BTC for
+// a specified transaction type, subject asset, and payment asset. The asset
+// rate represents the number of tap asset units per BTC.
+// NOTE: This call is proxied to the underlying price oracle.
+func (r *rpcServer) QueryAssetRates(ctx context.Context,
+	req *priceoraclerpc.QueryAssetRatesRequest) (
+	*priceoraclerpc.QueryAssetRatesResponse, error) {
+
+	if r.cfg.ProxyPriceOracle == nil {
+		return nil, ErrPriceOracleUnimplemented
+	}
+
+	return r.cfg.ProxyPriceOracle.QueryAssetRates(ctx, req)
+}

sample-tapd.conf

@@ -128,6 +128,9 @@
 ; Disable macaroon authentication for stats RPC endpoints
 ; allow-public-stats=false
 
+; Disble macaroon authentication for price oracle proxy RPC endpoints
+; allow-public-price-oracle=false
+
 ; Add an ip:port/hostname to allow cross origin access from
 ; To allow all origins, set as "*"
 ; restcors=

server.go

@@ -315,6 +315,7 @@ func (s *Server) RunUntilShutdown(mainErrChan <-chan error) error {
 		s.cfg.UniversePublicAccess.IsWriteAccessGranted(),
 		s.cfg.RPCConfig.AllowPublicUniProofCourier,
 		s.cfg.RPCConfig.AllowPublicStats,
+		s.cfg.RPCConfig.AllowPublicPriceOracle,
 	)
 
 	// Create a new RPC interceptor that we'll add to the GRPC server. This

tapcfg/config.go

@@ -238,6 +238,7 @@ type RpcConfig struct {
 
 	AllowPublicUniProofCourier bool `long:"allow-public-uni-proof-courier" description:"Disable macaroon authentication for universe proof courier RPC endpoints."`
 	AllowPublicStats           bool `long:"allow-public-stats" description:"Disable macaroon authentication for stats RPC endpoints."`
+	AllowPublicPriceOracle     bool `long:"allow-public-price-oracle" description:"Disable macaroon authentication for price oracle RPC endpoints."`
 
 	RestCORS []string `long:"restcors" description:"Add an ip:port/hostname to allow cross origin access from. To allow all origins, set as \"*\"."`
 

tapcfg/server.go

@@ -20,6 +20,7 @@ import (
 	"github.com/lightninglabs/taproot-assets/tapdb/sqlc"
 	"github.com/lightninglabs/taproot-assets/tapfreighter"
 	"github.com/lightninglabs/taproot-assets/tapgarden"
+	"github.com/lightninglabs/taproot-assets/taprpc/priceoraclerpc"
 	"github.com/lightninglabs/taproot-assets/tapscript"
 	"github.com/lightninglabs/taproot-assets/universe"
 	"github.com/lightningnetwork/lnd"
@@ -366,6 +367,7 @@ func genServerConfig(cfg *Config, cfgLogger btclog.Logger,
 	// Determine whether we should use the mock price oracle service or a
 	// real price oracle service.
 	var priceOracle rfq.PriceOracle
+	var rpcPriceOracleClient priceoraclerpc.PriceOracleClient
 
 	rfqCfg := cfg.Experimental.Rfq
 	switch rfqCfg.PriceOracleAddress {
@@ -381,6 +383,7 @@ func genServerConfig(cfg *Config, cfgLogger btclog.Logger,
 				3600, rfqCfg.MockOracleSatsPerAsset,
 			)
 		}
+		rpcPriceOracleClient = priceOracle.Client()
 
 	case "":
 		// Leave the price oracle as nil, which will cause the RFQ
@@ -395,6 +398,7 @@ func genServerConfig(cfg *Config, cfgLogger btclog.Logger,
 			return nil, fmt.Errorf("unable to create price "+
 				"oracle: %w", err)
 		}
+		rpcPriceOracleClient = priceOracle.Client()
 	}
 
 	// Construct the RFQ manager.
@@ -590,6 +594,7 @@ func genServerConfig(cfg *Config, cfgLogger btclog.Logger,
 		UniverseQueriesBurst:     cfg.Universe.UniverseQueriesBurst,
 		RfqManager:               rfqManager,
 		PriceOracle:              priceOracle,
+		ProxyPriceOracle:         rpcPriceOracleClient,
 		AuxLeafSigner:            auxLeafSigner,
 		AuxFundingController:     auxFundingController,
 		AuxChanCloser:            auxChanCloser,