mirror of
https://github.com/octoleo/syncthing.git
synced 2024-12-24 20:00:26 +00:00
103 lines
2.8 KiB
Go
103 lines
2.8 KiB
Go
// Copyright 2016, Cong Ding. 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.
|
|
//
|
|
// Author: Cong Ding <dinggnu@gmail.com>
|
|
|
|
package stun
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/hex"
|
|
"errors"
|
|
"net"
|
|
"time"
|
|
)
|
|
|
|
const (
|
|
numRetransmit = 9
|
|
defaultTimeout = 100
|
|
maxTimeout = 1600
|
|
maxPacketSize = 1024
|
|
)
|
|
|
|
func (c *Client) sendBindingReq(conn net.PacketConn, addr net.Addr, changeIP bool, changePort bool) (*response, error) {
|
|
// Construct packet.
|
|
pkt, err := newPacket()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
pkt.types = typeBindingRequest
|
|
attribute := newSoftwareAttribute(c.softwareName)
|
|
pkt.addAttribute(*attribute)
|
|
if changeIP || changePort {
|
|
attribute = newChangeReqAttribute(changeIP, changePort)
|
|
pkt.addAttribute(*attribute)
|
|
}
|
|
attribute = newFingerprintAttribute(pkt)
|
|
pkt.addAttribute(*attribute)
|
|
// Send packet.
|
|
return c.send(pkt, conn, addr)
|
|
}
|
|
|
|
// RFC 3489: Clients SHOULD retransmit the request starting with an interval
|
|
// of 100ms, doubling every retransmit until the interval reaches 1.6s.
|
|
// Retransmissions continue with intervals of 1.6s until a response is
|
|
// received, or a total of 9 requests have been sent.
|
|
func (c *Client) send(pkt *packet, conn net.PacketConn, addr net.Addr) (*response, error) {
|
|
c.logger.Info("\n" + hex.Dump(pkt.bytes()))
|
|
timeout := defaultTimeout
|
|
packetBytes := make([]byte, maxPacketSize)
|
|
for i := 0; i < numRetransmit; i++ {
|
|
// Send packet to the server.
|
|
length, err := conn.WriteTo(pkt.bytes(), addr)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if length != len(pkt.bytes()) {
|
|
return nil, errors.New("Error in sending data.")
|
|
}
|
|
err = conn.SetReadDeadline(time.Now().Add(time.Duration(timeout) * time.Millisecond))
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
if timeout < maxTimeout {
|
|
timeout *= 2
|
|
}
|
|
for {
|
|
// Read from the port.
|
|
length, raddr, err := conn.ReadFrom(packetBytes)
|
|
if err != nil {
|
|
if err.(net.Error).Timeout() {
|
|
break
|
|
}
|
|
return nil, err
|
|
}
|
|
p, err := newPacketFromBytes(packetBytes[0:length])
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
// If transId mismatches, keep reading until get a
|
|
// matched packet or timeout.
|
|
if !bytes.Equal(pkt.transID, p.transID) {
|
|
continue
|
|
}
|
|
c.logger.Info("\n" + hex.Dump(packetBytes[0:length]))
|
|
resp := newResponse(p, conn)
|
|
resp.serverAddr = newHostFromStr(raddr.String())
|
|
return resp, err
|
|
}
|
|
}
|
|
return nil, nil
|
|
}
|