pingtunnel/pingtunnel.go
2019-10-26 12:01:30 +08:00

142 lines
2.9 KiB
Go

package pingtunnel
import (
"crypto/md5"
"crypto/rand"
"encoding/base64"
"encoding/binary"
"encoding/hex"
"github.com/esrrhs/go-engine/src/loggo"
"github.com/golang/protobuf/proto"
"golang.org/x/net/icmp"
"golang.org/x/net/ipv4"
"io"
"net"
"syscall"
"time"
)
func sendICMP(id int, sequence int, conn icmp.PacketConn, server *net.IPAddr, target string,
connId string, msgType uint32, data []byte, sproto int, rproto int, key int,
tcpmode int, tcpmode_buffer_size int, tcpmode_maxwin int, tcpmode_resend_time int) {
m := &MyMsg{
Id: connId,
Type: (int32)(msgType),
Target: target,
Data: data,
Rproto: (int32)(rproto),
Key: (int32)(key),
Tcpmode: (int32)(tcpmode),
TcpmodeBuffersize: (int32)(tcpmode_buffer_size),
TcpmodeMaxwin: (int32)(tcpmode_maxwin),
TcpmodeResendTimems: (int32)(tcpmode_resend_time),
Magic: (int32)(MyMsg_MAGIC),
}
mb, err := proto.Marshal(m)
if err != nil {
loggo.Error("sendICMP Marshal MyMsg error %s %s", server.String(), err)
return
}
body := &icmp.Echo{
ID: id,
Seq: sequence,
Data: mb,
}
msg := &icmp.Message{
Type: (ipv4.ICMPType)(sproto),
Code: 0,
Body: body,
}
bytes, err := msg.Marshal(nil)
if err != nil {
loggo.Error("sendICMP Marshal error %s %s", server.String(), err)
return
}
for {
if _, err := conn.WriteTo(bytes, server); err != nil {
if neterr, ok := err.(*net.OpError); ok {
if neterr.Err == syscall.ENOBUFS {
continue
}
}
loggo.Info("sendICMP WriteTo error %s %s", server.String(), err)
}
break
}
return
}
func recvICMP(conn icmp.PacketConn, recv chan<- *Packet) {
bytes := make([]byte, 10240)
for {
conn.SetReadDeadline(time.Now().Add(time.Millisecond * 100))
n, srcaddr, err := conn.ReadFrom(bytes)
if err != nil {
nerr, ok := err.(net.Error)
if !ok || !nerr.Timeout() {
loggo.Info("Error read icmp message %s", err)
continue
}
}
if n <= 0 {
continue
}
echoId := int(binary.BigEndian.Uint16(bytes[4:6]))
echoSeq := int(binary.BigEndian.Uint16(bytes[6:8]))
my := &MyMsg{}
err = proto.Unmarshal(bytes[8:n], my)
if err != nil {
loggo.Debug("Unmarshal MyMsg error: %s", err)
continue
}
if my.Magic != (int32)(MyMsg_MAGIC) {
loggo.Debug("processPacket data invalid %s", my.Id)
continue
}
recv <- &Packet{my: my,
src: srcaddr.(*net.IPAddr),
echoId: echoId, echoSeq: echoSeq}
}
}
type Packet struct {
my *MyMsg
src *net.IPAddr
echoId int
echoSeq int
}
func UniqueId() string {
b := make([]byte, 48)
if _, err := io.ReadFull(rand.Reader, b); err != nil {
return ""
}
return GetMd5String(base64.URLEncoding.EncodeToString(b))
}
func GetMd5String(s string) string {
h := md5.New()
h.Write([]byte(s))
return hex.EncodeToString(h.Sum(nil))
}
const (
FRAME_MAX_SIZE int = 888
FRAME_MAX_ID int = 10000
)