/
source.go
118 lines (107 loc) · 2.65 KB
/
source.go
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// Copyright 2020 SEQSENSE, Inc.
//
// 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 tunnel
import (
"io"
"net"
"sync"
"google.golang.org/protobuf/proto"
"github.com/seqsense/aws-iot-device-sdk-go/v4/internal/ioterr"
"github.com/seqsense/aws-iot-device-sdk-go/v4/tunnel/msg"
)
func proxySource(ws io.ReadWriter, listener net.Listener, eh ErrorHandler) error {
var muConns sync.Mutex
conns := make(map[int32]io.ReadWriteCloser)
go func() {
var streamID int32 = 1
for {
conn, err := listener.Accept()
if err != nil {
if eh != nil {
eh.HandleError(ioterr.New(err, "accepting source connection"))
}
return
}
muConns.Lock()
id := streamID
conns[id] = conn
streamID++
muConns.Unlock()
if err := msg.WriteMessage(ws, &msg.Message{
Type: msg.Message_STREAM_START,
StreamId: id,
}); err != nil {
if eh != nil {
eh.HandleError(ioterr.New(err, "sending message"))
}
continue
}
go readProxy(ws, conn, id, eh)
}
}()
sz := make([]byte, 2)
b := make([]byte, 8192)
for {
if _, err := io.ReadFull(ws, sz); err != nil {
if err == io.EOF {
return nil
}
return ioterr.New(err, "reading length header")
}
l := int(sz[0])<<8 | int(sz[1])
if cap(b) < l {
b = make([]byte, l)
}
b = b[:l]
if _, err := io.ReadFull(ws, b); err != nil {
if err == io.EOF {
return nil
}
return ioterr.New(err, "reading message")
}
m := &msg.Message{}
if err := proto.Unmarshal(b, m); err != nil {
if eh != nil {
eh.HandleError(ioterr.New(err, "unmarshaling message"))
}
continue
}
switch m.Type {
case msg.Message_STREAM_RESET:
muConns.Lock()
if conn, ok := conns[m.StreamId]; ok {
_ = conn.Close()
delete(conns, m.StreamId)
}
muConns.Unlock()
case msg.Message_SESSION_RESET:
muConns.Lock()
for id, c := range conns {
_ = c.Close()
delete(conns, id)
}
muConns.Unlock()
return io.EOF
case msg.Message_DATA:
muConns.Lock()
conn, ok := conns[m.StreamId]
muConns.Unlock()
if ok {
if _, err := conn.Write(m.Payload); err != nil {
eh.HandleError(ioterr.New(err, "writing message"))
}
}
}
}
}