RPC over UDP support, --port udp://192.168.1.23:8910/

Device library is https://github.com/mongoose-os-libs/rpc-udp

CL: mos: RPC over UDP support, --port udp://192.168.1.23:8910/

common/mgrpc/codec/codec.go

@@ -51,6 +51,7 @@ type Options struct {
 	GCP     GCPCodecOptions
 	MQTT    MQTTCodecOptions
 	Serial  SerialCodecOptions
+	UDP     UDPCodecOptions
 	Watson  WatsonCodecOptions
 }
 

common/mgrpc/codec/udp.go

@@ -0,0 +1,93 @@
+//
+// Copyright (c) 2014-2019 Cesanta Software Limited
+// All rights reserved
+//
+// 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 codec
+
+import (
+	"context"
+	"encoding/json"
+	"net"
+
+	"github.com/cesanta/errors"
+
+	"github.com/mongoose-os/mos/common/mgrpc/frame"
+)
+
+const (
+	UDPURLScheme = "udp"
+)
+
+type UDPCodecOptions struct {
+}
+
+type udpCodec struct {
+	conn net.Conn
+}
+
+func UDP(addr string) Codec {
+	conn, err := net.Dial("udp", addr)
+	if err != nil {
+		return nil
+	}
+	return &udpCodec{conn: conn}
+}
+
+func (c *udpCodec) Recv(ctx context.Context) (*frame.Frame, error) {
+	buf := make([]byte, 10000)
+	readLen, err := c.conn.Read(buf)
+	if err != nil {
+		c.Close()
+		return nil, errors.Trace(err)
+	}
+	var f frame.Frame
+	if err = json.Unmarshal(buf[:readLen], &f); err != nil {
+		return nil, errors.Trace(err)
+	}
+	return &f, nil
+}
+
+func (c *udpCodec) Send(ctx context.Context, f *frame.Frame) error {
+	b, err := json.Marshal(f)
+	if err != nil {
+		return errors.Trace(err)
+	}
+	_, err = c.conn.Write(b)
+	return errors.Trace(err)
+}
+
+func (c *udpCodec) Close() {
+	c.conn.Close()
+}
+
+func (c *udpCodec) CloseNotify() <-chan struct{} {
+	return nil
+}
+
+func (c *udpCodec) MaxNumFrames() int {
+	return -1
+}
+
+func (c *udpCodec) Info() ConnectionInfo {
+	return ConnectionInfo{
+		IsConnected: true,
+		TLS:         false,
+		RemoteAddr:  c.conn.RemoteAddr().String(),
+	}
+}
+
+func (c *udpCodec) SetOptions(opts *Options) error {
+	return errors.NotImplementedf("SetOptions")
+}

common/mgrpc/connection.go

@@ -23,8 +23,8 @@ import (
 	"io/ioutil"
 	"net/url"
 
-	"github.com/mongoose-os/mos/common/mgrpc/codec"
 	"github.com/cesanta/errors"
+	"github.com/mongoose-os/mos/common/mgrpc/codec"
 )
 
 type connectOptions struct {
@@ -121,6 +121,8 @@ func connectTo(connectURL string) ConnectOption {
 		t, a = tGCP, url.String()
 	case url.Scheme == codec.WatsonURLScheme:
 		t, a = tWatson, url.String()
+	case url.Scheme == codec.UDPURLScheme:
+		t, a = tUDP, url.Host
 	default:
 		return badConnectOption(errors.Errorf("invalid ConnectTo protocol %q", url.Scheme))
 	}

common/mgrpc/mgrpc.go

@@ -32,10 +32,10 @@ import (
 
 	"golang.org/x/net/websocket"
 
-	"github.com/mongoose-os/mos/common/mgrpc/codec"
-	"github.com/mongoose-os/mos/common/mgrpc/frame"
 	"github.com/cesanta/errors"
 	"github.com/golang/glog"
+	"github.com/mongoose-os/mos/common/mgrpc/codec"
+	"github.com/mongoose-os/mos/common/mgrpc/frame"
 )
 
 const (
@@ -261,6 +261,8 @@ func (r *mgRPCImpl) connect(ctx context.Context, opts ...ConnectOption) error {
 				c, err := r.tcpConnect(tcpAddress, r.opts)
 				return c, errors.Trace(err)
 			})
+	case tUDP:
+		r.codec = codec.UDP(r.opts.connectAddress)
 	case tSerial:
 		if r.opts.enableReconnect {
 			r.codec = codec.NewReconnectWrapperCodec(

common/mgrpc/transport.go

@@ -36,4 +36,5 @@ const (
 	tAzureDM
 	tGCP
 	tWatson
+	tUDP
 )