glider/ss.go
2018-01-17 00:42:24 +08:00

327 lines
6.5 KiB
Go

package main
import (
"errors"
"log"
"net"
"strings"
"sync"
"time"
"github.com/shadowsocks/go-shadowsocks2/core"
)
const udpBufSize = 65536
// SS .
type SS struct {
*Forwarder
sDialer Dialer
core.Cipher
}
// NewSS returns a shadowsocks proxy.
func NewSS(addr, method, pass string, cDialer Dialer, sDialer Dialer) (*SS, error) {
ciph, err := core.PickCipher(method, nil, pass)
if err != nil {
log.Fatalf("PickCipher for '%s', error: %s", method, err)
}
s := &SS{
Forwarder: NewForwarder(addr, cDialer),
sDialer: sDialer,
Cipher: ciph,
}
return s, nil
}
// ListenAndServe serves ss requests.
func (s *SS) ListenAndServe() {
go s.ListenAndServeUDP()
s.ListenAndServeTCP()
}
// ListenAndServeTCP serves tcp ss requests.
func (s *SS) ListenAndServeTCP() {
l, err := net.Listen("tcp", s.addr)
if err != nil {
logf("proxy-ss failed to listen on %s: %v", s.addr, err)
return
}
logf("proxy-ss listening TCP on %s", s.addr)
for {
c, err := l.Accept()
if err != nil {
logf("proxy-ss failed to accept: %v", err)
continue
}
go s.ServeTCP(c)
}
}
// ServeTCP serves tcp ss requests.
func (s *SS) ServeTCP(c net.Conn) {
defer c.Close()
if c, ok := c.(*net.TCPConn); ok {
c.SetKeepAlive(true)
}
c = s.StreamConn(c)
tgt, err := ReadAddr(c)
if err != nil {
logf("proxy-ss failed to get target address: %v", err)
return
}
dialer := s.sDialer.NextDialer(tgt.String())
// udp over tcp?
uot := UoT(tgt[0])
if uot && dialer.Addr() == "DIRECT" {
rc, err := net.ListenPacket("udp", "")
if err != nil {
logf("UDP remote listen error: %v", err)
}
defer rc.Close()
req := make([]byte, udpBufSize)
n, err := c.Read(req)
if err != nil {
logf("error in ioutil.ReadAll: %s\n", err)
return
}
tgtAddr, _ := net.ResolveUDPAddr("udp", tgt.String())
rc.WriteTo(req[:n], tgtAddr)
buf := make([]byte, udpBufSize)
n, _, err = rc.ReadFrom(buf)
if err != nil {
logf("proxy-uottun read error: %v", err)
}
c.Write(buf[:n])
logf("proxy-ss %s <-tcp-> %s - %s <-udp-> %s ", c.RemoteAddr(), c.LocalAddr(), rc.LocalAddr(), tgt)
return
}
network := "tcp"
if uot {
network = "udp"
}
rc, err := dialer.Dial(network, tgt.String())
if err != nil {
logf("proxy-ss failed to connect to target: %v", err)
return
}
defer rc.Close()
logf("proxy-ss %s <-> %s", c.RemoteAddr(), tgt)
_, _, err = relay(c, rc)
if err != nil {
if err, ok := err.(net.Error); ok && err.Timeout() {
return // ignore i/o timeout
}
logf("proxy-ss relay error: %v", err)
}
}
// ListenAndServeUDP serves udp ss requests.
// TODO: Forwarder chain not supported now.
func (s *SS) ListenAndServeUDP() {
c, err := net.ListenPacket("udp", s.addr)
if err != nil {
logf("proxy-ss-udp failed to listen on %s: %v", s.addr, err)
return
}
defer c.Close()
logf("proxy-ss-udp listening UDP on %s", s.addr)
c = s.PacketConn(c)
var nm sync.Map
buf := make([]byte, udpBufSize)
for {
n, raddr, err := c.ReadFrom(buf)
if err != nil {
logf("proxy-ss-udp remote read error: %v", err)
continue
}
tgtAddr := SplitAddr(buf[:n])
if tgtAddr == nil {
logf("proxy-ss-udp failed to split target address from packet: %q", buf[:n])
continue
}
tgtUDPAddr, err := net.ResolveUDPAddr("udp", tgtAddr.String())
if err != nil {
logf("proxy-ss-udp failed to resolve target UDP address: %v", err)
continue
}
logf("proxy-ss-udp %s <-> %s", raddr, tgtAddr)
payload := buf[len(tgtAddr):n]
var pc net.PacketConn
v, ok := nm.Load(raddr.String())
if !ok && v == nil {
pc, err = net.ListenPacket("udp", "")
if err != nil {
logf("proxy-ss-udp remote listen error: %v", err)
continue
}
nm.Store(raddr.String(), pc)
go func() {
timedCopy(c, raddr, pc, 5*time.Minute, true)
pc.Close()
nm.Delete(raddr.String())
}()
} else {
pc = v.(net.PacketConn)
}
_, err = pc.WriteTo(payload, tgtUDPAddr) // accept only UDPAddr despite the signature
if err != nil {
logf("proxy-ss-udp remote write error: %v", err)
continue
}
}
}
// ListCipher .
func ListCipher() string {
return strings.Join(core.ListCipher(), " ")
}
// Dial connects to the address addr on the network net via the proxy.
func (s *SS) Dial(network, addr string) (net.Conn, error) {
target := ParseAddr(addr)
if target == nil {
return nil, errors.New("Unable to parse address: " + addr)
}
if network == "uot" {
target[0] = target[0] | 0x8
}
c, err := s.cDialer.Dial("tcp", s.addr)
if err != nil {
logf("dial to %s error: %s", s.addr, err)
return nil, err
}
if c, ok := c.(*net.TCPConn); ok {
c.SetKeepAlive(true)
}
c = s.StreamConn(c)
if _, err = c.Write(target); err != nil {
c.Close()
return nil, err
}
return c, err
}
// DialUDP connects to the given address via the proxy.
func (s *SS) DialUDP(network, addr string) (pc net.PacketConn, writeTo net.Addr, err error) {
// TODO: check forward chain
pc, nextHop, err := s.cDialer.DialUDP(network, addr)
if err != nil {
logf("proxy-ss dialudp to %s error: %s", addr, err)
return nil, nil, err
}
nextHopAddr := ParseAddr(nextHop.String())
writeTo, err = net.ResolveUDPAddr("udp", s.Addr())
pkc := NewPktConn(s.PacketConn(pc), writeTo, nextHopAddr, true)
return pkc, writeTo, err
}
// PktConn wraps a net.PacketConn and support Write method like net.Conn
type PktConn struct {
net.PacketConn
addr net.Addr // write to and read from addr
target Addr
tgtHeader bool
}
// NewPktConn returns a PktConn
func NewPktConn(c net.PacketConn, addr net.Addr, target Addr, tgtHeader bool) *PktConn {
pc := &PktConn{
PacketConn: c,
addr: addr,
target: target,
tgtHeader: tgtHeader}
return pc
}
func (pc *PktConn) Read(b []byte) (int, error) {
n, _, err := pc.ReadFrom(b)
return n, err
}
func (pc *PktConn) ReadFrom(b []byte) (int, net.Addr, error) {
if !pc.tgtHeader {
return pc.PacketConn.ReadFrom(b)
}
buf := make([]byte, len(b))
n, raddr, err := pc.PacketConn.ReadFrom(buf)
if err != nil {
return n, raddr, err
}
srcAddr := ParseAddr(raddr.String())
copy(b, buf[len(srcAddr):])
return n - len(srcAddr), raddr, err
}
func (pc *PktConn) Write(b []byte) (int, error) {
if !pc.tgtHeader {
return pc.PacketConn.WriteTo(b, pc.addr)
}
buf := make([]byte, len(pc.target)+len(b))
copy(buf, pc.target)
copy(buf[len(pc.target):], b)
// logf("Write: \n%s", hex.Dump(buf))
return pc.PacketConn.WriteTo(buf, pc.addr)
}
func (pc *PktConn) WriteTo(b []byte, addr net.Addr) (int, error) {
return pc.Write(b)
}
func (pc *PktConn) RemoteAddr() net.Addr {
return pc.addr
}