vtun/udp/udpclient.go
2021-09-23 22:31:49 +08:00

69 lines
1.4 KiB
Go

package udp
import (
"log"
"net"
"github.com/net-byte/vtun/common/cipher"
"github.com/net-byte/vtun/common/config"
"github.com/net-byte/vtun/tun"
"github.com/songgao/water/waterutil"
)
// StartClient starts udp client
func StartClient(config config.Config) {
iface := tun.CreateTun(config)
serverAddr, err := net.ResolveUDPAddr("udp", config.ServerAddr)
if err != nil {
log.Fatalln("failed to resolve server addr:", err)
}
localAddr, err := net.ResolveUDPAddr("udp", config.LocalAddr)
if err != nil {
log.Fatalln("failed to get udp socket:", err)
}
conn, err := net.ListenUDP("udp", localAddr)
if err != nil {
log.Fatalln("failed to listen on udp socket:", err)
}
defer conn.Close()
log.Printf("vtun udp client started on %v", config.LocalAddr)
// server -> client
go func() {
buf := make([]byte, 1500)
for {
n, _, err := conn.ReadFromUDP(buf)
if err != nil || n == 0 {
continue
}
var b []byte
if config.Obfuscate {
b = cipher.XOR(buf[:n])
} else {
b = buf[:n]
}
if !waterutil.IsIPv4(b) {
continue
}
iface.Write(b)
}
}()
// client -> server
packet := make([]byte, 1500)
for {
n, err := iface.Read(packet)
if err != nil || n == 0 {
continue
}
if !waterutil.IsIPv4(packet) {
continue
}
var b []byte
if config.Obfuscate {
b = cipher.XOR(packet[:n])
} else {
b = packet[:n]
}
conn.WriteToUDP(b, serverAddr)
}
}