removed generator

go.mod

@@ -3,13 +3,13 @@ module github.com/dapperlabs/protoc-gen-go-grpc-scopes
 go 1.20
 
 require (
-	github.com/golang/protobuf v1.5.3
 	github.com/stretchr/testify v1.8.4
 	google.golang.org/grpc v1.56.1
 )
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

proto/scopes.proto

@@ -11,6 +11,6 @@ message RequiredScopesOption {
   repeated string scopes = 1;
 }
 
-extend google.protobuf.MessageOptions {
-  RequiredScopesOption required_req_scopes = 50000; // 50000 is an example, replace it with your desired field number
+extend google.protobuf.MethodOptions {
+  RequiredScopesOption required_method_scopes = 70000;
 }

scopes/grpc.go

@@ -2,20 +2,78 @@ package scopes
 
 import (
 	"context"
+	"fmt"
+	"strings"
 
+	"github.com/dapperlabs/protoc-gen-go-grpc-scopes/scopesproto"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/reflect/protoregistry"
+	"google.golang.org/protobuf/types/descriptorpb"
 )
 
 type ScopeValidator func(ctx context.Context, scopes []string) error
 
+func getMethodDescriptor(info *grpc.UnaryServerInfo) (protoreflect.MethodDescriptor, error) {
+	// /package.Service/Method
+	fullMethodSplit := strings.Split(info.FullMethod, "/")
+
+	if len(fullMethodSplit) != 3 {
+		return nil, fmt.Errorf("invalid full method: %s", info.FullMethod)
+	}
+
+	svcFullName := protoreflect.FullName(fullMethodSplit[1])
+
+	descriptorByService, err := protoregistry.GlobalFiles.FindDescriptorByName(svcFullName)
+	if err != nil {
+		return nil, fmt.Errorf("failed to find service descriptor: %s", err)
+	}
+
+	svc, ok := descriptorByService.(protoreflect.ServiceDescriptor)
+	if !ok {
+		return nil, fmt.Errorf("descriptor is not of a service: %s", descriptorByService.FullName())
+	}
+
+	serviceMethod := protoreflect.FullName(info.FullMethod).Name()
+
+	// Service/Method
+	serviceMethodSplit := strings.Split(string(serviceMethod), "/")
+	if len(serviceMethodSplit) != 2 {
+		return nil, fmt.Errorf("invalid service method: %s", serviceMethod)
+	}
+
+	methodName := protoreflect.Name(serviceMethodSplit[1])
+
+	method := svc.Methods().ByName(methodName)
+	if method == nil {
+		return nil, fmt.Errorf("method not found: %s", methodName)
+	}
+
+	return method, nil
+}
+
 // ScopeValidationInterceptor validates that the request has the required scopes
 func ScopeValidationInterceptor(v ScopeValidator) grpc.UnaryServerInterceptor {
 	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
-		if scopeFetcher, ok := req.(HasScopeRequirements); ok {
-			if err := v(ctx, scopeFetcher.RequiredScopes()); err != nil {
+		method, err := getMethodDescriptor(info)
+		if err != nil {
+			return nil, status.Errorf(codes.Internal, "failed to get method descriptor: %s", err)
+		}
+
+		methodOptionsPB := method.Options().(*descriptorpb.MethodOptions)
+
+		methodExt := proto.GetExtension(methodOptionsPB, scopesproto.E_RequiredMethodScopes)
+		if methodExt != nil {
+			scopesExt := methodExt.(*scopesproto.RequiredScopesOption)
+
+			if err := v(ctx, scopesExt.GetScopes()); err != nil {
 				return nil, err
 			}
 		}
+
 		return handler(ctx, req)
 	}
 }

scopes/grpc_test.go

@@ -18,6 +18,9 @@ import (
 func TestScopeValidationInterceptor(t *testing.T) {
 	server := grpc.NewServer(
 		grpc.UnaryInterceptor(scopes.ScopeValidationInterceptor(func(ctx context.Context, scopes []string) error {
+			if len(scopes) == 0 {
+				return nil
+			}
 			md, ok := metadata.FromIncomingContext(ctx)
 			if !ok {
 				return status.Error(codes.Unauthenticated, "missing metadata")
@@ -53,7 +56,7 @@ func TestScopeValidationInterceptor(t *testing.T) {
 	ctx := metadata.NewOutgoingContext(context.Background(), header)
 
 	res, err := client.Ping(ctx, &testgen.PingRequest{})
-	assert.NoError(t, err)
+	require.NoError(t, err)
 	assert.Equal(t, "pong", res.GetPong())
 
 	res, err = client.Ping(context.Background(), &testgen.PingRequest{})
@@ -63,11 +66,19 @@ func TestScopeValidationInterceptor(t *testing.T) {
 	ctx = metadata.NewOutgoingContext(context.Background(), header)
 	res, err = client.Ping(ctx, &testgen.PingRequest{})
 	assert.Equal(t, codes.PermissionDenied, status.Code(err))
+
+	res, err = client.FreePing(ctx, &testgen.PingRequest{})
+	require.NoError(t, err)
+	assert.Equal(t, "free pong", res.GetPong())
 }
 
 type ScopeValidatorServer struct {
 }
 
+func (s ScopeValidatorServer) FreePing(ctx context.Context, request *testgen.PingRequest) (*testgen.PingResponse, error) {
+	return &testgen.PingResponse{Pong: "free pong"}, nil
+}
+
 func (s ScopeValidatorServer) Ping(ctx context.Context, request *testgen.PingRequest) (*testgen.PingResponse, error) {
 	return &testgen.PingResponse{Pong: "pong"}, nil
 }

test/buf.gen.yaml

@@ -9,8 +9,4 @@ plugins:
     out: ./testgen
     opt:
       - paths=source_relative
-      - require_unimplemented_servers=false
-  - name: go-grpc-scopes
-    out: ./testgen
-    opt:
-      - paths=source_relative
+      - require_unimplemented_servers=false

test/buf.lock

@@ -8,4 +8,4 @@ deps:
   - remote: buf.build
     owner: rrrkren
     repository: protoc-gen-go-grpc-scopes
-    commit: 1ca8d5541c154b60afd6d65d7f63acee
+    commit: 65b5b0c776414d3c8f89b8310b77ec1c

test/test.proto

@@ -4,14 +4,7 @@ package testscopes;
 
 option go_package = "github.com/dapperlabs/protoc-gen-go-grpc-scopes/test/testgen";
 
-import "scopes.proto";
-service PingPong {
-  rpc Ping (PingRequest) returns (PingResponse);
-}
-
 message PingRequest {
-  option (scopes.required_req_scopes).scopes = "scope1";
-  option (scopes.required_req_scopes).scopes = "scope2";
   string ping = 1;
 }