blob: d2696168b10c7f697ddc8a54d7ac28096c8a5b47 [file] [log] [blame]
/*
*
* Copyright 2016 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
/*
Package reflection implements server reflection service.
The service implemented is defined in:
https://github.com/grpc/grpc/blob/master/src/proto/grpc/reflection/v1alpha/reflection.proto.
To register server reflection on a gRPC server:
import "google.golang.org/grpc/reflection"
s := grpc.NewServer()
pb.RegisterYourOwnServer(s, &server{})
// Register reflection service on gRPC server.
reflection.Register(s)
s.Serve(lis)
*/
package reflection // import "google.golang.org/grpc/reflection"
import (
"bytes"
"compress/gzip"
"fmt"
"io"
"io/ioutil"
"reflect"
"sort"
"sync"
"github.com/golang/protobuf/proto"
dpb "github.com/golang/protobuf/protoc-gen-go/descriptor"
"google.golang.org/grpc"
"google.golang.org/grpc/codes"
rpb "google.golang.org/grpc/reflection/grpc_reflection_v1alpha"
"google.golang.org/grpc/status"
)
type serverReflectionServer struct {
rpb.UnimplementedServerReflectionServer
s *grpc.Server
initSymbols sync.Once
serviceNames []string
symbols map[string]*dpb.FileDescriptorProto // map of fully-qualified names to files
}
// Register registers the server reflection service on the given gRPC server.
func Register(s *grpc.Server) {
rpb.RegisterServerReflectionServer(s, &serverReflectionServer{
s: s,
})
}
// protoMessage is used for type assertion on proto messages.
// Generated proto message implements function Descriptor(), but Descriptor()
// is not part of interface proto.Message. This interface is needed to
// call Descriptor().
type protoMessage interface {
Descriptor() ([]byte, []int)
}
func (s *serverReflectionServer) getSymbols() (svcNames []string, symbolIndex map[string]*dpb.FileDescriptorProto) {
s.initSymbols.Do(func() {
serviceInfo := s.s.GetServiceInfo()
s.symbols = map[string]*dpb.FileDescriptorProto{}
s.serviceNames = make([]string, 0, len(serviceInfo))
processed := map[string]struct{}{}
for svc, info := range serviceInfo {
s.serviceNames = append(s.serviceNames, svc)
fdenc, ok := parseMetadata(info.Metadata)
if !ok {
continue
}
fd, err := decodeFileDesc(fdenc)
if err != nil {
continue
}
s.processFile(fd, processed)
}
sort.Strings(s.serviceNames)
})
return s.serviceNames, s.symbols
}
func (s *serverReflectionServer) processFile(fd *dpb.FileDescriptorProto, processed map[string]struct{}) {
filename := fd.GetName()
if _, ok := processed[filename]; ok {
return
}
processed[filename] = struct{}{}
prefix := fd.GetPackage()
for _, msg := range fd.MessageType {
s.processMessage(fd, prefix, msg)
}
for _, en := range fd.EnumType {
s.processEnum(fd, prefix, en)
}
for _, ext := range fd.Extension {
s.processField(fd, prefix, ext)
}
for _, svc := range fd.Service {
svcName := fqn(prefix, svc.GetName())
s.symbols[svcName] = fd
for _, meth := range svc.Method {
name := fqn(svcName, meth.GetName())
s.symbols[name] = fd
}
}
for _, dep := range fd.Dependency {
fdenc := proto.FileDescriptor(dep)
fdDep, err := decodeFileDesc(fdenc)
if err != nil {
continue
}
s.processFile(fdDep, processed)
}
}
func (s *serverReflectionServer) processMessage(fd *dpb.FileDescriptorProto, prefix string, msg *dpb.DescriptorProto) {
msgName := fqn(prefix, msg.GetName())
s.symbols[msgName] = fd
for _, nested := range msg.NestedType {
s.processMessage(fd, msgName, nested)
}
for _, en := range msg.EnumType {
s.processEnum(fd, msgName, en)
}
for _, ext := range msg.Extension {
s.processField(fd, msgName, ext)
}
for _, fld := range msg.Field {
s.processField(fd, msgName, fld)
}
for _, oneof := range msg.OneofDecl {
oneofName := fqn(msgName, oneof.GetName())
s.symbols[oneofName] = fd
}
}
func (s *serverReflectionServer) processEnum(fd *dpb.FileDescriptorProto, prefix string, en *dpb.EnumDescriptorProto) {
enName := fqn(prefix, en.GetName())
s.symbols[enName] = fd
for _, val := range en.Value {
valName := fqn(enName, val.GetName())
s.symbols[valName] = fd
}
}
func (s *serverReflectionServer) processField(fd *dpb.FileDescriptorProto, prefix string, fld *dpb.FieldDescriptorProto) {
fldName := fqn(prefix, fld.GetName())
s.symbols[fldName] = fd
}
func fqn(prefix, name string) string {
if prefix == "" {
return name
}
return prefix + "." + name
}
// fileDescForType gets the file descriptor for the given type.
// The given type should be a proto message.
func (s *serverReflectionServer) fileDescForType(st reflect.Type) (*dpb.FileDescriptorProto, error) {
m, ok := reflect.Zero(reflect.PtrTo(st)).Interface().(protoMessage)
if !ok {
return nil, fmt.Errorf("failed to create message from type: %v", st)
}
enc, _ := m.Descriptor()
return decodeFileDesc(enc)
}
// decodeFileDesc does decompression and unmarshalling on the given
// file descriptor byte slice.
func decodeFileDesc(enc []byte) (*dpb.FileDescriptorProto, error) {
raw, err := decompress(enc)
if err != nil {
return nil, fmt.Errorf("failed to decompress enc: %v", err)
}
fd := new(dpb.FileDescriptorProto)
if err := proto.Unmarshal(raw, fd); err != nil {
return nil, fmt.Errorf("bad descriptor: %v", err)
}
return fd, nil
}
// decompress does gzip decompression.
func decompress(b []byte) ([]byte, error) {
r, err := gzip.NewReader(bytes.NewReader(b))
if err != nil {
return nil, fmt.Errorf("bad gzipped descriptor: %v", err)
}
out, err := ioutil.ReadAll(r)
if err != nil {
return nil, fmt.Errorf("bad gzipped descriptor: %v", err)
}
return out, nil
}
func typeForName(name string) (reflect.Type, error) {
pt := proto.MessageType(name)
if pt == nil {
return nil, fmt.Errorf("unknown type: %q", name)
}
st := pt.Elem()
return st, nil
}
func fileDescContainingExtension(st reflect.Type, ext int32) (*dpb.FileDescriptorProto, error) {
m, ok := reflect.Zero(reflect.PtrTo(st)).Interface().(proto.Message)
if !ok {
return nil, fmt.Errorf("failed to create message from type: %v", st)
}
var extDesc *proto.ExtensionDesc
for id, desc := range proto.RegisteredExtensions(m) {
if id == ext {
extDesc = desc
break
}
}
if extDesc == nil {
return nil, fmt.Errorf("failed to find registered extension for extension number %v", ext)
}
return decodeFileDesc(proto.FileDescriptor(extDesc.Filename))
}
func (s *serverReflectionServer) allExtensionNumbersForType(st reflect.Type) ([]int32, error) {
m, ok := reflect.Zero(reflect.PtrTo(st)).Interface().(proto.Message)
if !ok {
return nil, fmt.Errorf("failed to create message from type: %v", st)
}
exts := proto.RegisteredExtensions(m)
out := make([]int32, 0, len(exts))
for id := range exts {
out = append(out, id)
}
return out, nil
}
// fileDescWithDependencies returns a slice of serialized fileDescriptors in
// wire format ([]byte). The fileDescriptors will include fd and all the
// transitive dependencies of fd with names not in sentFileDescriptors.
func fileDescWithDependencies(fd *dpb.FileDescriptorProto, sentFileDescriptors map[string]bool) ([][]byte, error) {
r := [][]byte{}
queue := []*dpb.FileDescriptorProto{fd}
for len(queue) > 0 {
currentfd := queue[0]
queue = queue[1:]
if sent := sentFileDescriptors[currentfd.GetName()]; len(r) == 0 || !sent {
sentFileDescriptors[currentfd.GetName()] = true
currentfdEncoded, err := proto.Marshal(currentfd)
if err != nil {
return nil, err
}
r = append(r, currentfdEncoded)
}
for _, dep := range currentfd.Dependency {
fdenc := proto.FileDescriptor(dep)
fdDep, err := decodeFileDesc(fdenc)
if err != nil {
continue
}
queue = append(queue, fdDep)
}
}
return r, nil
}
// fileDescEncodingByFilename finds the file descriptor for given filename,
// finds all of its previously unsent transitive dependencies, does marshalling
// on them, and returns the marshalled result.
func (s *serverReflectionServer) fileDescEncodingByFilename(name string, sentFileDescriptors map[string]bool) ([][]byte, error) {
enc := proto.FileDescriptor(name)
if enc == nil {
return nil, fmt.Errorf("unknown file: %v", name)
}
fd, err := decodeFileDesc(enc)
if err != nil {
return nil, err
}
return fileDescWithDependencies(fd, sentFileDescriptors)
}
// parseMetadata finds the file descriptor bytes specified meta.
// For SupportPackageIsVersion4, m is the name of the proto file, we
// call proto.FileDescriptor to get the byte slice.
// For SupportPackageIsVersion3, m is a byte slice itself.
func parseMetadata(meta interface{}) ([]byte, bool) {
// Check if meta is the file name.
if fileNameForMeta, ok := meta.(string); ok {
return proto.FileDescriptor(fileNameForMeta), true
}
// Check if meta is the byte slice.
if enc, ok := meta.([]byte); ok {
return enc, true
}
return nil, false
}
// fileDescEncodingContainingSymbol finds the file descriptor containing the
// given symbol, finds all of its previously unsent transitive dependencies,
// does marshalling on them, and returns the marshalled result. The given symbol
// can be a type, a service or a method.
func (s *serverReflectionServer) fileDescEncodingContainingSymbol(name string, sentFileDescriptors map[string]bool) ([][]byte, error) {
_, symbols := s.getSymbols()
fd := symbols[name]
if fd == nil {
// Check if it's a type name that was not present in the
// transitive dependencies of the registered services.
if st, err := typeForName(name); err == nil {
fd, err = s.fileDescForType(st)
if err != nil {
return nil, err
}
}
}
if fd == nil {
return nil, fmt.Errorf("unknown symbol: %v", name)
}
return fileDescWithDependencies(fd, sentFileDescriptors)
}
// fileDescEncodingContainingExtension finds the file descriptor containing
// given extension, finds all of its previously unsent transitive dependencies,
// does marshalling on them, and returns the marshalled result.
func (s *serverReflectionServer) fileDescEncodingContainingExtension(typeName string, extNum int32, sentFileDescriptors map[string]bool) ([][]byte, error) {
st, err := typeForName(typeName)
if err != nil {
return nil, err
}
fd, err := fileDescContainingExtension(st, extNum)
if err != nil {
return nil, err
}
return fileDescWithDependencies(fd, sentFileDescriptors)
}
// allExtensionNumbersForTypeName returns all extension numbers for the given type.
func (s *serverReflectionServer) allExtensionNumbersForTypeName(name string) ([]int32, error) {
st, err := typeForName(name)
if err != nil {
return nil, err
}
extNums, err := s.allExtensionNumbersForType(st)
if err != nil {
return nil, err
}
return extNums, nil
}
// ServerReflectionInfo is the reflection service handler.
func (s *serverReflectionServer) ServerReflectionInfo(stream rpb.ServerReflection_ServerReflectionInfoServer) error {
sentFileDescriptors := make(map[string]bool)
for {
in, err := stream.Recv()
if err == io.EOF {
return nil
}
if err != nil {
return err
}
out := &rpb.ServerReflectionResponse{
ValidHost: in.Host,
OriginalRequest: in,
}
switch req := in.MessageRequest.(type) {
case *rpb.ServerReflectionRequest_FileByFilename:
b, err := s.fileDescEncodingByFilename(req.FileByFilename, sentFileDescriptors)
if err != nil {
out.MessageResponse = &rpb.ServerReflectionResponse_ErrorResponse{
ErrorResponse: &rpb.ErrorResponse{
ErrorCode: int32(codes.NotFound),
ErrorMessage: err.Error(),
},
}
} else {
out.MessageResponse = &rpb.ServerReflectionResponse_FileDescriptorResponse{
FileDescriptorResponse: &rpb.FileDescriptorResponse{FileDescriptorProto: b},
}
}
case *rpb.ServerReflectionRequest_FileContainingSymbol:
b, err := s.fileDescEncodingContainingSymbol(req.FileContainingSymbol, sentFileDescriptors)
if err != nil {
out.MessageResponse = &rpb.ServerReflectionResponse_ErrorResponse{
ErrorResponse: &rpb.ErrorResponse{
ErrorCode: int32(codes.NotFound),
ErrorMessage: err.Error(),
},
}
} else {
out.MessageResponse = &rpb.ServerReflectionResponse_FileDescriptorResponse{
FileDescriptorResponse: &rpb.FileDescriptorResponse{FileDescriptorProto: b},
}
}
case *rpb.ServerReflectionRequest_FileContainingExtension:
typeName := req.FileContainingExtension.ContainingType
extNum := req.FileContainingExtension.ExtensionNumber
b, err := s.fileDescEncodingContainingExtension(typeName, extNum, sentFileDescriptors)
if err != nil {
out.MessageResponse = &rpb.ServerReflectionResponse_ErrorResponse{
ErrorResponse: &rpb.ErrorResponse{
ErrorCode: int32(codes.NotFound),
ErrorMessage: err.Error(),
},
}
} else {
out.MessageResponse = &rpb.ServerReflectionResponse_FileDescriptorResponse{
FileDescriptorResponse: &rpb.FileDescriptorResponse{FileDescriptorProto: b},
}
}
case *rpb.ServerReflectionRequest_AllExtensionNumbersOfType:
extNums, err := s.allExtensionNumbersForTypeName(req.AllExtensionNumbersOfType)
if err != nil {
out.MessageResponse = &rpb.ServerReflectionResponse_ErrorResponse{
ErrorResponse: &rpb.ErrorResponse{
ErrorCode: int32(codes.NotFound),
ErrorMessage: err.Error(),
},
}
} else {
out.MessageResponse = &rpb.ServerReflectionResponse_AllExtensionNumbersResponse{
AllExtensionNumbersResponse: &rpb.ExtensionNumberResponse{
BaseTypeName: req.AllExtensionNumbersOfType,
ExtensionNumber: extNums,
},
}
}
case *rpb.ServerReflectionRequest_ListServices:
svcNames, _ := s.getSymbols()
serviceResponses := make([]*rpb.ServiceResponse, len(svcNames))
for i, n := range svcNames {
serviceResponses[i] = &rpb.ServiceResponse{
Name: n,
}
}
out.MessageResponse = &rpb.ServerReflectionResponse_ListServicesResponse{
ListServicesResponse: &rpb.ListServiceResponse{
Service: serviceResponses,
},
}
default:
return status.Errorf(codes.InvalidArgument, "invalid MessageRequest: %v", in.MessageRequest)
}
if err := stream.Send(out); err != nil {
return err
}
}
}