Refactor: TPROXY inbound UDP write back

https://t.me/projectXray/119670

虽然不一定是最终的版本,但值得记录,感谢协助测试的各位朋友,特别感谢 @yichya @huyz
This commit is contained in:
RPRX 2020-12-31 15:57:15 +00:00 committed by GitHub
parent 310a938511
commit c41a1a56fe
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
3 changed files with 157 additions and 32 deletions

View file

@ -163,6 +163,25 @@ func (d *DokodemoDoor) Process(ctx context.Context, network net.Network, conn in
if !destinationOverridden {
writer = &buf.SequentialWriter{Writer: conn}
} else {
var addr *net.UDPAddr
var mark int
if dest.Address.Family().IsIP() {
addr = &net.UDPAddr{
IP: dest.Address.IP(),
Port: int(dest.Port),
}
}
if d.sockopt != nil {
mark = int(d.sockopt.Mark)
}
pConn, err := FakeUDP(addr, mark)
if err != nil {
return err
}
back := net.DestinationFromAddr(conn.RemoteAddr())
writer = NewPacketWriter(pConn, &dest, mark, &back)
defer writer.(*PacketWriter).Close()
/*
sockopt := &internet.SocketConfig{
Tproxy: internet.SocketConfig_TProxy,
}
@ -173,15 +192,12 @@ func (d *DokodemoDoor) Process(ctx context.Context, network net.Network, conn in
if d.sockopt != nil {
sockopt.Mark = d.sockopt.Mark
}
to := net.DestinationFromAddr(conn.RemoteAddr())
tConn, err := internet.DialSystem(ctx, to, sockopt)
tConn, err := internet.DialSystem(ctx, net.DestinationFromAddr(conn.RemoteAddr()), sockopt)
if err != nil {
return err
}
writer = NewPacketWriter(tConn, &dest, ctx, &to, sockopt)
defer writer.(*PacketWriter).Close()
/*
defer tConn.Close()
writer = &buf.SequentialWriter{Writer: tConn}
tReader := buf.NewPacketReader(tConn)
requestCount++
@ -220,24 +236,25 @@ func (d *DokodemoDoor) Process(ctx context.Context, network net.Network, conn in
return nil
}
func NewPacketWriter(conn net.Conn, d *net.Destination, ctx context.Context, to *net.Destination, sockopt *internet.SocketConfig) buf.Writer {
func NewPacketWriter(conn net.PacketConn, d *net.Destination, mark int, back *net.Destination) buf.Writer {
writer := &PacketWriter{
conn: conn,
conns: make(map[net.Destination]net.Conn),
ctx: ctx,
to: to,
sockopt: sockopt,
conns: make(map[net.Destination]net.PacketConn),
mark: mark,
back: &net.UDPAddr{
IP: back.Address.IP(),
Port: int(back.Port),
},
}
writer.conns[*d] = conn
return writer
}
type PacketWriter struct {
conn net.Conn
conns map[net.Destination]net.Conn
ctx context.Context
to *net.Destination
sockopt *internet.SocketConfig
conn net.PacketConn
conns map[net.Destination]net.PacketConn
mark int
back *net.UDPAddr
}
func (w *PacketWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
@ -251,25 +268,36 @@ func (w *PacketWriter) WriteMultiBuffer(mb buf.MultiBuffer) error {
if b.UDP != nil && b.UDP.Address.Family().IsIP() {
conn := w.conns[*b.UDP]
if conn == nil {
w.sockopt.BindAddress = b.UDP.Address.IP()
w.sockopt.BindPort = uint32(b.UDP.Port)
conn, _ = internet.DialSystem(w.ctx, *w.to, w.sockopt)
if conn == nil {
conn, err = FakeUDP(
&net.UDPAddr{
IP: b.UDP.Address.IP(),
Port: int(b.UDP.Port),
},
w.mark,
)
if err != nil {
b.Release()
continue
buf.ReleaseMulti(mb)
return err
}
w.conns[*b.UDP] = conn
}
_, err = conn.Write(b.Bytes())
} else {
_, err = w.conn.Write(b.Bytes())
_, err = conn.WriteTo(b.Bytes(), w.back)
if err != nil {
conn.Close()
w.conns[*b.UDP] = nil
newError(err).WriteToLog()
}
b.Release()
} else {
_, err = w.conn.WriteTo(b.Bytes(), w.back)
b.Release()
if err != nil {
buf.ReleaseMulti(mb)
return err
}
}
}
return nil
}

View file

@ -0,0 +1,85 @@
// +build linux
package dokodemo
import (
"fmt"
"net"
"os"
"strconv"
"syscall"
)
func FakeUDP(addr *net.UDPAddr, mark int) (net.PacketConn, error) {
if addr == nil {
addr = &net.UDPAddr{
IP: []byte{0, 0, 0, 0},
Port: 0,
}
}
localSocketAddress, af, err := udpAddrToSocketAddr(addr)
if err != nil {
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("build local socket address: %s", err)}
}
fileDescriptor, err := syscall.Socket(af, syscall.SOCK_DGRAM, 0)
if err != nil {
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("socket open: %s", err)}
}
if mark != 0 {
if err = syscall.SetsockoptInt(fileDescriptor, syscall.SOL_SOCKET, syscall.SO_MARK, mark); err != nil {
syscall.Close(fileDescriptor)
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("set socket option: SO_MARK: %s", err)}
}
}
if err = syscall.SetsockoptInt(fileDescriptor, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1); err != nil {
syscall.Close(fileDescriptor)
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("set socket option: SO_REUSEADDR: %s", err)}
}
if err = syscall.SetsockoptInt(fileDescriptor, syscall.SOL_IP, syscall.IP_TRANSPARENT, 1); err != nil {
syscall.Close(fileDescriptor)
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("set socket option: IP_TRANSPARENT: %s", err)}
}
if err = syscall.Bind(fileDescriptor, localSocketAddress); err != nil {
syscall.Close(fileDescriptor)
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("socket bind: %s", err)}
}
fdFile := os.NewFile(uintptr(fileDescriptor), fmt.Sprintf("net-udp-fake-%s", addr.String()))
defer fdFile.Close()
packetConn, err := net.FilePacketConn(fdFile)
if err != nil {
syscall.Close(fileDescriptor)
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("convert file descriptor to connection: %s", err)}
}
return packetConn, nil
}
func udpAddrToSocketAddr(addr *net.UDPAddr) (syscall.Sockaddr, int, error) {
switch {
case addr.IP.To4() != nil:
ip := [4]byte{}
copy(ip[:], addr.IP.To4())
return &syscall.SockaddrInet4{Addr: ip, Port: addr.Port}, syscall.AF_INET, nil
default:
ip := [16]byte{}
copy(ip[:], addr.IP.To16())
zoneID, err := strconv.ParseUint(addr.Zone, 10, 32)
if err != nil {
return nil, 0, err
}
return &syscall.SockaddrInet6{Addr: ip, Port: addr.Port, ZoneId: uint32(zoneID)}, syscall.AF_INET6, nil
}
}

View file

@ -0,0 +1,12 @@
// +build !linux
package dokodemo
import (
"fmt"
"net"
)
func FakeUDP(addr *net.UDPAddr, mark int) (net.PacketConn, error) {
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("!linux")}
}