fixes for safe conversation and avoid panics (#1213)

* fixes for safe convertation

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

* fix client publish panic

If broker connect returns error we dont check it status and use
it later to publish message, mostly this is unexpected because
broker connection failed and we cant use it.
Also proposed solution have benefit - we flag connection status
only when we have succeseful broker connection

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

* api/handler/broker: fix possible broker publish panic

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

server/grpc/codec.go

@@ -2,7 +2,6 @@ package grpc
 
 import (
 	"encoding/json"
-	"fmt"
 	"strings"
 
 	b "bytes"
@@ -71,11 +70,19 @@ func (w wrapCodec) Unmarshal(data []byte, v interface{}) error {
 }
 
 func (protoCodec) Marshal(v interface{}) ([]byte, error) {
-	return proto.Marshal(v.(proto.Message))
+	m, ok := v.(proto.Message)
+	if !ok {
+		return nil, codec.ErrInvalidMessage
+	}
+	return proto.Marshal(m)
 }
 
 func (protoCodec) Unmarshal(data []byte, v interface{}) error {
-	return proto.Unmarshal(data, v.(proto.Message))
+	m, ok := v.(proto.Message)
+	if !ok {
+		return codec.ErrInvalidMessage
+	}
+	return proto.Unmarshal(data, m)
 }
 
 func (protoCodec) Name() string {
@@ -85,7 +92,6 @@ func (protoCodec) Name() string {
 func (jsonCodec) Marshal(v interface{}) ([]byte, error) {
 	if pb, ok := v.(proto.Message); ok {
 		s, err := jsonpbMarshaler.MarshalToString(pb)
-
 		return []byte(s), err
 	}
 
@@ -109,7 +115,7 @@ func (jsonCodec) Name() string {
 func (bytesCodec) Marshal(v interface{}) ([]byte, error) {
 	b, ok := v.(*[]byte)
 	if !ok {
-		return nil, fmt.Errorf("failed to marshal: %v is not type of *[]byte", v)
+		return nil, codec.ErrInvalidMessage
 	}
 	return *b, nil
 }
@@ -117,7 +123,7 @@ func (bytesCodec) Marshal(v interface{}) ([]byte, error) {
 func (bytesCodec) Unmarshal(data []byte, v interface{}) error {
 	b, ok := v.(*[]byte)
 	if !ok {
-		return fmt.Errorf("failed to unmarshal: %v is not type of *[]byte", v)
+		return codec.ErrInvalidMessage
 	}
 	*b = data
 	return nil

server/grpc/context.go

@@ -0,0 +1,16 @@
+package grpc
+
+import (
+	"context"
+
+	"github.com/micro/go-micro/v2/server"
+)
+
+func setServerOption(k, v interface{}) server.Option {
+	return func(o *server.Options) {
+		if o.Context == nil {
+			o.Context = context.Background()
+		}
+		o.Context = context.WithValue(o.Context, k, v)
+	}
+}

server/grpc/grpc.go

@@ -143,9 +143,8 @@ func (g *grpcServer) getMaxMsgSize() int {
 
 func (g *grpcServer) getCredentials() credentials.TransportCredentials {
 	if g.opts.Context != nil {
-		if v := g.opts.Context.Value(tlsAuth{}); v != nil {
-			tls := v.(*tls.Config)
-			return credentials.NewTLS(tls)
+		if v, ok := g.opts.Context.Value(tlsAuth{}).(*tls.Config); ok && v != nil {
+			return credentials.NewTLS(v)
 		}
 	}
 	return nil
@@ -156,15 +155,8 @@ func (g *grpcServer) getGrpcOptions() []grpc.ServerOption {
 		return nil
 	}
 
-	v := g.opts.Context.Value(grpcOptions{})
-
-	if v == nil {
-		return nil
-	}
-
-	opts, ok := v.([]grpc.ServerOption)
-
-	if !ok {
+	opts, ok := g.opts.Context.Value(grpcOptions{}).([]grpc.ServerOption)
+	if !ok || opts == nil {
 		return nil
 	}
 
@@ -505,8 +497,8 @@ func (g *grpcServer) processStream(stream grpc.ServerStream, service *service, m
 func (g *grpcServer) newGRPCCodec(contentType string) (encoding.Codec, error) {
 	codecs := make(map[string]encoding.Codec)
 	if g.opts.Context != nil {
-		if v := g.opts.Context.Value(codecsKey{}); v != nil {
-			codecs = v.(map[string]encoding.Codec)
+		if v, ok := g.opts.Context.Value(codecsKey{}).(map[string]encoding.Codec); ok && v != nil {
+			codecs = v
 		}
 	}
 	if c, ok := codecs[contentType]; ok {
@@ -573,10 +565,10 @@ func (g *grpcServer) Subscribe(sb server.Subscriber) error {
 
 	g.Lock()
 
-	_, ok = g.subscribers[sub]
-	if ok {
+	if _, ok = g.subscribers[sub]; ok {
 		return fmt.Errorf("subscriber %v already exists", sub)
 	}
+
 	g.subscribers[sub] = nil
 	g.Unlock()
 	return nil

server/grpc/options.go

@@ -27,8 +27,8 @@ func Codec(contentType string, c encoding.Codec) server.Option {
 		if o.Context == nil {
 			o.Context = context.Background()
 		}
-		if v := o.Context.Value(codecsKey{}); v != nil {
-			codecs = v.(map[string]encoding.Codec)
+		if v, ok := o.Context.Value(codecsKey{}).(map[string]encoding.Codec); ok && v != nil {
+			codecs = v
 		}
 		codecs[contentType] = c
 		o.Context = context.WithValue(o.Context, codecsKey{}, codecs)
@@ -37,32 +37,17 @@ func Codec(contentType string, c encoding.Codec) server.Option {
 
 // AuthTLS should be used to setup a secure authentication using TLS
 func AuthTLS(t *tls.Config) server.Option {
-	return func(o *server.Options) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, tlsAuth{}, t)
-	}
+	return setServerOption(tlsAuth{}, t)
 }
 
 // Listener specifies the net.Listener to use instead of the default
 func Listener(l net.Listener) server.Option {
-	return func(o *server.Options) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, netListener{}, l)
-	}
+	return setServerOption(netListener{}, l)
 }
 
 // Options to be used to configure gRPC options
 func Options(opts ...grpc.ServerOption) server.Option {
-	return func(o *server.Options) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, grpcOptions{}, opts)
-	}
+	return setServerOption(grpcOptions{}, opts)
 }
 
 //
@@ -70,51 +55,25 @@ func Options(opts ...grpc.ServerOption) server.Option {
 // send.  Default maximum message size is 4 MB.
 //
 func MaxMsgSize(s int) server.Option {
-	return func(o *server.Options) {
-		if o.Context == nil {
-			o.Context = context.Background()
-		}
-		o.Context = context.WithValue(o.Context, maxMsgSizeKey{}, s)
-	}
+	return setServerOption(maxMsgSizeKey{}, s)
 }
 
 func newOptions(opt ...server.Option) server.Options {
 	opts := server.Options{
-		Codecs:   make(map[string]codec.NewCodec),
-		Metadata: map[string]string{},
+		Codecs:    make(map[string]codec.NewCodec),
+		Metadata:  map[string]string{},
+		Broker:    broker.DefaultBroker,
+		Registry:  registry.DefaultRegistry,
+		Transport: transport.DefaultTransport,
+		Address:   server.DefaultAddress,
+		Name:      server.DefaultName,
+		Id:        server.DefaultId,
+		Version:   server.DefaultVersion,
 	}
 
 	for _, o := range opt {
 		o(&opts)
 	}
 
-	if opts.Broker == nil {
-		opts.Broker = broker.DefaultBroker
-	}
-
-	if opts.Registry == nil {
-		opts.Registry = registry.DefaultRegistry
-	}
-
-	if opts.Transport == nil {
-		opts.Transport = transport.DefaultTransport
-	}
-
-	if len(opts.Address) == 0 {
-		opts.Address = server.DefaultAddress
-	}
-
-	if len(opts.Name) == 0 {
-		opts.Name = server.DefaultName
-	}
-
-	if len(opts.Id) == 0 {
-		opts.Id = server.DefaultId
-	}
-
-	if len(opts.Version) == 0 {
-		opts.Version = server.DefaultVersion
-	}
-
 	return opts
 }