clash/adapter/outbound/snell.go
2022-05-02 06:28:27 +08:00

179 lines
4.7 KiB
Go

package outbound
import (
"context"
"fmt"
"net"
"strconv"
"github.com/Dreamacro/clash/common/structure"
"github.com/Dreamacro/clash/component/dialer"
C "github.com/Dreamacro/clash/constant"
obfs "github.com/Dreamacro/clash/transport/simple-obfs"
"github.com/Dreamacro/clash/transport/snell"
)
type Snell struct {
*Base
psk []byte
pool *snell.Pool
obfsOption *simpleObfsOption
version int
}
type SnellOption struct {
BasicOption
Name string `proxy:"name"`
Server string `proxy:"server"`
Port int `proxy:"port"`
Psk string `proxy:"psk"`
UDP bool `proxy:"udp,omitempty"`
Version int `proxy:"version,omitempty"`
ObfsOpts map[string]any `proxy:"obfs-opts,omitempty"`
}
type streamOption struct {
psk []byte
version int
addr string
obfsOption *simpleObfsOption
}
func streamConn(c net.Conn, option streamOption) *snell.Snell {
switch option.obfsOption.Mode {
case "tls":
c = obfs.NewTLSObfs(c, option.obfsOption.Host)
case "http":
_, port, _ := net.SplitHostPort(option.addr)
c = obfs.NewHTTPObfs(c, option.obfsOption.Host, port)
}
return snell.StreamConn(c, option.psk, option.version)
}
// StreamConn implements C.ProxyAdapter
func (s *Snell) StreamConn(c net.Conn, metadata *C.Metadata) (net.Conn, error) {
c = streamConn(c, streamOption{s.psk, s.version, s.addr, s.obfsOption})
if metadata.NetWork == C.UDP {
err := snell.WriteUDPHeader(c, s.version)
return c, err
}
port, _ := strconv.ParseUint(metadata.DstPort, 10, 16)
err := snell.WriteHeader(c, metadata.String(), uint(port), s.version)
return c, err
}
// DialContext implements C.ProxyAdapter
func (s *Snell) DialContext(ctx context.Context, metadata *C.Metadata, opts ...dialer.Option) (_ C.Conn, err error) {
if s.version == snell.Version2 && len(opts) == 0 {
c, err := s.pool.Get()
if err != nil {
return nil, err
}
port, _ := strconv.ParseUint(metadata.DstPort, 10, 16)
if err = snell.WriteHeader(c, metadata.String(), uint(port), s.version); err != nil {
c.Close()
return nil, err
}
return NewConn(c, s), err
}
c, err := dialer.DialContext(ctx, "tcp", s.addr, s.Base.DialOptions(opts...)...)
if err != nil {
return nil, fmt.Errorf("%s connect error: %w", s.addr, err)
}
tcpKeepAlive(c)
defer safeConnClose(c, err)
c, err = s.StreamConn(c, metadata)
return NewConn(c, s), err
}
// ListenPacketContext implements C.ProxyAdapter
func (s *Snell) ListenPacketContext(ctx context.Context, metadata *C.Metadata, opts ...dialer.Option) (C.PacketConn, error) {
c, err := dialer.DialContext(ctx, "tcp", s.addr, s.Base.DialOptions(opts...)...)
if err != nil {
return nil, err
}
tcpKeepAlive(c)
c = streamConn(c, streamOption{s.psk, s.version, s.addr, s.obfsOption})
err = snell.WriteUDPHeader(c, s.version)
if err != nil {
return nil, err
}
pc := snell.PacketConn(c)
return newPacketConn(pc, s), nil
}
// ListenPacketOnStreamConn implements C.ProxyAdapter
func (s *Snell) ListenPacketOnStreamConn(c net.Conn, metadata *C.Metadata) (_ C.PacketConn, err error) {
pc := snell.PacketConn(c)
return newPacketConn(pc, s), nil
}
// SupportUOT implements C.ProxyAdapter
func (s *Snell) SupportUOT() bool {
return true
}
func NewSnell(option SnellOption) (*Snell, error) {
addr := net.JoinHostPort(option.Server, strconv.Itoa(option.Port))
psk := []byte(option.Psk)
decoder := structure.NewDecoder(structure.Option{TagName: "obfs", WeaklyTypedInput: true})
obfsOption := &simpleObfsOption{Host: "bing.com"}
if err := decoder.Decode(option.ObfsOpts, obfsOption); err != nil {
return nil, fmt.Errorf("snell %s initialize obfs error: %w", addr, err)
}
switch obfsOption.Mode {
case "tls", "http", "":
break
default:
return nil, fmt.Errorf("snell %s obfs mode error: %s", addr, obfsOption.Mode)
}
// backward compatible
if option.Version == 0 {
option.Version = snell.DefaultSnellVersion
}
switch option.Version {
case snell.Version1, snell.Version2:
if option.UDP {
return nil, fmt.Errorf("snell version %d not support UDP", option.Version)
}
case snell.Version3:
default:
return nil, fmt.Errorf("snell version error: %d", option.Version)
}
s := &Snell{
Base: &Base{
name: option.Name,
addr: addr,
tp: C.Snell,
udp: option.UDP,
iface: option.Interface,
rmark: option.RoutingMark,
},
psk: psk,
obfsOption: obfsOption,
version: option.Version,
}
if option.Version == snell.Version2 {
s.pool = snell.NewPool(func(ctx context.Context) (*snell.Snell, error) {
c, err := dialer.DialContext(ctx, "tcp", addr, s.Base.DialOptions()...)
if err != nil {
return nil, err
}
tcpKeepAlive(c)
return streamConn(c, streamOption{psk, option.Version, addr, obfsOption}), nil
})
}
return s, nil
}