mihomo/proxy/socks/utils.go

package socks

import (
	"net"

	"github.com/Dreamacro/clash/common/pool"
	"github.com/Dreamacro/clash/component/socks5"
)

type fakeConn struct {
	net.PacketConn
	remoteAddr net.Addr
	targetAddr socks5.Addr
	payload    []byte
	bufRef     []byte
}

func (c *fakeConn) Data() []byte {
	return c.payload
}

// WriteBack wirtes UDP packet with source(ip, port) = `addr`
func (c *fakeConn) WriteBack(b []byte, addr net.Addr) (n int, err error) {
	from := c.targetAddr
	if addr != nil {
		// if addr is provided, use the parsed addr
		from = socks5.ParseAddrToSocksAddr(addr)
	}
	packet, err := socks5.EncodeUDPPacket(from, b)
	if err != nil {
		return
	}
	return c.PacketConn.WriteTo(packet, c.remoteAddr)
}

// LocalAddr returns the source IP/Port of UDP Packet
func (c *fakeConn) LocalAddr() net.Addr {
	return c.remoteAddr
}

func (c *fakeConn) Close() error {
	err := c.PacketConn.Close()
	pool.BufPool.Put(c.bufRef[:cap(c.bufRef)])
	return err
}