loop: add initiator string to user agent

client_test.go

@@ -34,6 +34,7 @@ var (
 		MaxPrepayAmount:     100,
 		MaxPrepayRoutingFee: 75000,
 		MaxSwapRoutingFee:   70000,
+		Initiator:           "test",
 	}
 
 	swapInvoiceDesc   = "swap"

interface.go

@@ -81,6 +81,11 @@ type OutRequest struct {
 
 	// Label contains an optional label for the swap.
 	Label string
+
+	// Initiator is an optional string that identifies what software
+	// initiated the swap (loop CLI, autolooper, LiT UI and so on) and is
+	// appended to the user agent string.
+	Initiator string
 }
 
 // Out contains the full details of a loop out request. This includes things
@@ -196,6 +201,11 @@ type LoopInRequest struct {
 
 	// Label contains an optional label for the swap.
 	Label string
+
+	// Initiator is an optional string that identifies what software
+	// initiated the swap (loop CLI, autolooper, LiT UI and so on) and is
+	// appended to the user agent string.
+	Initiator string
 }
 
 // LoopInTerms are the server terms on which it executes loop in swaps.

loopin.go

@@ -166,7 +166,7 @@ func newLoopInSwap(globalCtx context.Context, cfg *swapConfig,
 	log.Infof("Initiating swap request at height %v", currentHeight)
 	swapResp, err := cfg.server.NewLoopInSwap(globalCtx, swapHash,
 		request.Amount, senderKey, swapInvoice, probeInvoice,
-		request.LastHop,
+		request.LastHop, request.Initiator,
 	)
 	probeWaitCancel()
 	if err != nil {

loopin_test.go

@@ -21,6 +21,7 @@ var (
 		Amount:         btcutil.Amount(50000),
 		MaxSwapFee:     btcutil.Amount(1000),
 		HtlcConfTarget: 2,
+		Initiator:      "test",
 	}
 )
 

loopout.go

@@ -114,7 +114,7 @@ func newLoopOutSwap(globalCtx context.Context, cfg *swapConfig,
 	// latest swap publication time.
 	swapResp, err := cfg.server.NewLoopOutSwap(
 		globalCtx, swapHash, request.Amount, request.Expiry,
-		receiverKey, request.SwapPublicationDeadline,
+		receiverKey, request.SwapPublicationDeadline, request.Initiator,
 	)
 	if err != nil {
 		return nil, fmt.Errorf("cannot initiate swap: %v", err)

server_mock_test.go

@@ -64,10 +64,9 @@ func newServerMock(lnd *test.LndMockServices) *serverMock {
 	}
 }
 
-func (s *serverMock) NewLoopOutSwap(ctx context.Context,
-	swapHash lntypes.Hash, amount btcutil.Amount, expiry int32,
-	receiverKey [33]byte, _ time.Time) (
-	*newLoopOutResponse, error) {
+func (s *serverMock) NewLoopOutSwap(_ context.Context, swapHash lntypes.Hash,
+	amount btcutil.Amount, _ int32, _ [33]byte, _ time.Time,
+	_ string) (*newLoopOutResponse, error) {
 
 	_, senderKey := test.CreateKey(100)
 
@@ -138,10 +137,9 @@ func getInvoice(hash lntypes.Hash, amt btcutil.Amount, memo string) (string, err
 	return reqString, nil
 }
 
-func (s *serverMock) NewLoopInSwap(ctx context.Context,
-	swapHash lntypes.Hash, amount btcutil.Amount,
-	senderKey [33]byte, swapInvoice, probeInvoice string,
-	lastHop *route.Vertex) (*newLoopInResponse, error) {
+func (s *serverMock) NewLoopInSwap(_ context.Context, swapHash lntypes.Hash,
+	amount btcutil.Amount, _ [33]byte, swapInvoice, _ string,
+	_ *route.Vertex, _ string) (*newLoopInResponse, error) {
 
 	_, receiverKey := test.CreateKey(101)
 

swap_server_client.go

@@ -55,9 +55,8 @@ type swapServerClient interface {
 
 	NewLoopOutSwap(ctx context.Context,
 		swapHash lntypes.Hash, amount btcutil.Amount, expiry int32,
-		receiverKey [33]byte,
-		swapPublicationDeadline time.Time) (
-		*newLoopOutResponse, error)
+		receiverKey [33]byte, swapPublicationDeadline time.Time,
+		initiator string) (*newLoopOutResponse, error)
 
 	PushLoopOutPreimage(ctx context.Context,
 		preimage lntypes.Preimage) error
@@ -65,7 +64,8 @@ type swapServerClient interface {
 	NewLoopInSwap(ctx context.Context,
 		swapHash lntypes.Hash, amount btcutil.Amount,
 		senderKey [33]byte, swapInvoice, probeInvoice string,
-		lastHop *route.Vertex) (*newLoopInResponse, error)
+		lastHop *route.Vertex, initiator string) (*newLoopInResponse,
+		error)
 
 	// SubscribeLoopOutUpdates subscribes to loop out server state.
 	SubscribeLoopOutUpdates(ctx context.Context,
@@ -220,8 +220,8 @@ func (s *grpcSwapServerClient) GetLoopInQuote(ctx context.Context,
 
 func (s *grpcSwapServerClient) NewLoopOutSwap(ctx context.Context,
 	swapHash lntypes.Hash, amount btcutil.Amount, expiry int32,
-	receiverKey [33]byte, swapPublicationDeadline time.Time) (
-	*newLoopOutResponse, error) {
+	receiverKey [33]byte, swapPublicationDeadline time.Time,
+	initiator string) (*newLoopOutResponse, error) {
 
 	rpcCtx, rpcCancel := context.WithTimeout(ctx, globalCallTimeout)
 	defer rpcCancel()
@@ -233,7 +233,7 @@ func (s *grpcSwapServerClient) NewLoopOutSwap(ctx context.Context,
 			SwapPublicationDeadline: swapPublicationDeadline.Unix(),
 			ProtocolVersion:         loopdb.CurrentRPCProtocolVersion,
 			Expiry:                  expiry,
-			UserAgent:               UserAgent(),
+			UserAgent:               UserAgent(initiator),
 		},
 	)
 	if err != nil {
@@ -276,7 +276,8 @@ func (s *grpcSwapServerClient) PushLoopOutPreimage(ctx context.Context,
 
 func (s *grpcSwapServerClient) NewLoopInSwap(ctx context.Context,
 	swapHash lntypes.Hash, amount btcutil.Amount, senderKey [33]byte,
-	swapInvoice, probeInvoice string, lastHop *route.Vertex) (*newLoopInResponse, error) {
+	swapInvoice, probeInvoice string, lastHop *route.Vertex,
+	initiator string) (*newLoopInResponse, error) {
 
 	rpcCtx, rpcCancel := context.WithTimeout(ctx, globalCallTimeout)
 	defer rpcCancel()
@@ -288,7 +289,7 @@ func (s *grpcSwapServerClient) NewLoopInSwap(ctx context.Context,
 		SwapInvoice:     swapInvoice,
 		ProtocolVersion: loopdb.CurrentRPCProtocolVersion,
 		ProbeInvoice:    probeInvoice,
-		UserAgent:       UserAgent(),
+		UserAgent:       UserAgent(initiator),
 	}
 	if lastHop != nil {
 		req.LastHop = lastHop[:]

version.go

@@ -53,10 +53,21 @@ func Version() string {
 
 // UserAgent returns the full user agent string that identifies the software
 // that is submitting swaps to the loop server.
-func UserAgent() string {
+func UserAgent(initiator string) string {
+	// We'll only allow "safe" characters in the initiator portion of the
+	// user agent string and spaces only if surrounded by other characters.
+	initiatorAlphabet := semanticAlphabet + ". "
+	cleanInitiator := normalizeVerString(
+		strings.TrimSpace(initiator), initiatorAlphabet,
+	)
+	if len(cleanInitiator) > 0 {
+		cleanInitiator = fmt.Sprintf(",initiator=%s", cleanInitiator)
+	}
+
 	// Assemble full string, including the commit hash of current build.
 	return fmt.Sprintf(
-		"%s/v%s/commit=%s", AgentName, semanticVersion(), Commit,
+		"%s/v%s/commit=%s%s", AgentName, semanticVersion(), Commit,
+		cleanInitiator,
 	)
 }