175 lines
3.2 KiB
Go
175 lines
3.2 KiB
Go
package socks
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import (
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"bytes"
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"net"
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"github.com/go-gost/gosocks5"
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"github.com/go-gost/gost/pkg/internal/bufpool"
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)
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var (
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_ net.PacketConn = (*UDPTunConn)(nil)
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_ net.Conn = (*UDPTunConn)(nil)
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_ net.PacketConn = (*UDPConn)(nil)
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_ net.Conn = (*UDPConn)(nil)
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)
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type UDPTunConn struct {
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net.Conn
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taddr net.Addr
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}
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func UDPTunClientConn(c net.Conn, targetAddr net.Addr) *UDPTunConn {
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return &UDPTunConn{
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Conn: c,
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taddr: targetAddr,
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}
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}
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func UDPTunServerConn(c net.Conn) *UDPTunConn {
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return &UDPTunConn{
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Conn: c,
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}
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}
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func (c *UDPTunConn) ReadFrom(b []byte) (n int, addr net.Addr, err error) {
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socksAddr := gosocks5.Addr{}
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header := gosocks5.UDPHeader{
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Addr: &socksAddr,
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}
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dgram := gosocks5.UDPDatagram{
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Header: &header,
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Data: b,
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}
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_, err = dgram.ReadFrom(c.Conn)
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if err != nil {
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return
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}
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n = len(dgram.Data)
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if n > len(b) {
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n = copy(b, dgram.Data)
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}
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addr, err = net.ResolveUDPAddr("udp", socksAddr.String())
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return
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}
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func (c *UDPTunConn) Read(b []byte) (n int, err error) {
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n, _, err = c.ReadFrom(b)
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return
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}
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func (c *UDPTunConn) WriteTo(b []byte, addr net.Addr) (n int, err error) {
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socksAddr := gosocks5.Addr{}
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if err = socksAddr.ParseFrom(addr.String()); err != nil {
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return
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}
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header := gosocks5.UDPHeader{
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Addr: &socksAddr,
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}
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dgram := gosocks5.UDPDatagram{
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Header: &header,
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Data: b,
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}
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dgram.Header.Rsv = uint16(len(dgram.Data))
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dgram.Header.Frag = 0xff // UDP tun relay flag, used by shadowsocks
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_, err = dgram.WriteTo(c.Conn)
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n = len(b)
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return
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}
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func (c *UDPTunConn) Write(b []byte) (n int, err error) {
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return c.WriteTo(b, c.taddr)
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}
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var (
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DefaultBufferSize = 4096
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)
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type UDPConn struct {
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net.PacketConn
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raddr net.Addr
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taddr net.Addr
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bufferSize int
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}
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func NewUDPConn(c net.PacketConn, bufferSize int) *UDPConn {
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return &UDPConn{
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PacketConn: c,
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bufferSize: bufferSize,
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}
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}
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// ReadFrom reads an UDP datagram.
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// NOTE: for server side,
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// the returned addr is the target address the client want to relay to.
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func (c *UDPConn) ReadFrom(b []byte) (n int, addr net.Addr, err error) {
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rbuf := bufpool.Get(c.bufferSize)
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defer bufpool.Put(rbuf)
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n, c.raddr, err = c.PacketConn.ReadFrom(rbuf)
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if err != nil {
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return
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}
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socksAddr := gosocks5.Addr{}
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header := gosocks5.UDPHeader{
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Addr: &socksAddr,
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}
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hlen, err := header.ReadFrom(bytes.NewReader(rbuf[:n]))
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if err != nil {
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return
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}
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n = copy(b, rbuf[hlen:n])
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addr, err = net.ResolveUDPAddr("udp", socksAddr.String())
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return
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}
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func (c *UDPConn) Read(b []byte) (n int, err error) {
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n, _, err = c.ReadFrom(b)
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return
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}
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func (c *UDPConn) WriteTo(b []byte, addr net.Addr) (n int, err error) {
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wbuf := bufpool.Get(c.bufferSize)
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defer bufpool.Put(wbuf)
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socksAddr := gosocks5.Addr{}
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if err = socksAddr.ParseFrom(addr.String()); err != nil {
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return
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}
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header := gosocks5.UDPHeader{
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Addr: &socksAddr,
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}
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dgram := gosocks5.UDPDatagram{
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Header: &header,
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Data: b,
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}
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buf := bytes.NewBuffer(wbuf[:0])
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_, err = dgram.WriteTo(buf)
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if err != nil {
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return
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}
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_, err = c.PacketConn.WriteTo(buf.Bytes(), c.raddr)
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n = len(b)
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return
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}
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func (c *UDPConn) Write(b []byte) (n int, err error) {
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return c.WriteTo(b, c.taddr)
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}
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func (c *UDPConn) RemoteAddr() net.Addr {
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return c.raddr
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}
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