Xray-core/transport/internet/system_dialer.go
2024-02-06 10:41:39 -05:00

225 lines
5.9 KiB
Go

package internet
import (
"context"
"syscall"
"time"
"github.com/sagernet/sing/common/control"
"github.com/xtls/xray-core/common/net"
"github.com/xtls/xray-core/common/session"
"github.com/xtls/xray-core/features/dns"
"github.com/xtls/xray-core/features/outbound"
)
var effectiveSystemDialer SystemDialer = &DefaultSystemDialer{}
type SystemDialer interface {
Dial(ctx context.Context, source net.Address, destination net.Destination, sockopt *SocketConfig) (net.Conn, error)
DestIpAddress() net.IP
}
type DefaultSystemDialer struct {
controllers []control.Func
dns dns.Client
obm outbound.Manager
}
func resolveSrcAddr(network net.Network, src net.Address) net.Addr {
if src == nil || src == net.AnyIP {
return nil
}
if network == net.Network_TCP {
return &net.TCPAddr{
IP: src.IP(),
Port: 0,
}
}
return &net.UDPAddr{
IP: src.IP(),
Port: 0,
}
}
func hasBindAddr(sockopt *SocketConfig) bool {
return sockopt != nil && len(sockopt.BindAddress) > 0 && sockopt.BindPort > 0
}
func (d *DefaultSystemDialer) Dial(ctx context.Context, src net.Address, dest net.Destination, sockopt *SocketConfig) (net.Conn, error) {
newError("dialing to " + dest.String()).AtDebug().WriteToLog()
if dest.Network == net.Network_UDP && !hasBindAddr(sockopt) {
srcAddr := resolveSrcAddr(net.Network_UDP, src)
if srcAddr == nil {
srcAddr = &net.UDPAddr{
IP: []byte{0, 0, 0, 0},
Port: 0,
}
}
packetConn, err := ListenSystemPacket(ctx, srcAddr, sockopt)
if err != nil {
return nil, err
}
destAddr, err := net.ResolveUDPAddr("udp", dest.NetAddr())
if err != nil {
return nil, err
}
if sockopt != nil || len(d.controllers) > 0 {
file, err := packetConn.(*net.UDPConn).File()
if err != nil {
return nil, err
}
fd := file.Fd()
if sockopt != nil {
if err := applyOutboundSocketOptions("udp", dest.NetAddr(), fd, sockopt); err != nil {
newError("failed to apply socket options").Base(err).WriteToLog(session.ExportIDToError(ctx))
}
}
}
return &PacketConnWrapper{
Conn: packetConn,
Dest: destAddr,
}, nil
}
goStdKeepAlive := time.Duration(0)
if sockopt != nil && (sockopt.TcpKeepAliveInterval != 0 || sockopt.TcpKeepAliveIdle != 0) {
goStdKeepAlive = time.Duration(-1)
}
dialer := &net.Dialer{
Timeout: time.Second * 16,
LocalAddr: resolveSrcAddr(dest.Network, src),
KeepAlive: goStdKeepAlive,
}
if sockopt != nil || len(d.controllers) > 0 {
if sockopt != nil && sockopt.TcpMptcp {
dialer.SetMultipathTCP(true)
}
dialer.Control = func(network, address string, c syscall.RawConn) error {
for _, ctl := range d.controllers {
if err := ctl(network, address, c); err != nil {
newError("failed to apply external controller").Base(err).WriteToLog(session.ExportIDToError(ctx))
}
}
return c.Control(func(fd uintptr) {
if sockopt != nil {
if err := applyOutboundSocketOptions(network, address, fd, sockopt); err != nil {
newError("failed to apply socket options").Base(err).WriteToLog(session.ExportIDToError(ctx))
}
if dest.Network == net.Network_UDP && hasBindAddr(sockopt) {
if err := bindAddr(fd, sockopt.BindAddress, sockopt.BindPort); err != nil {
newError("failed to bind source address to ", sockopt.BindAddress).Base(err).WriteToLog(session.ExportIDToError(ctx))
}
}
}
})
}
}
return dialer.DialContext(ctx, dest.Network.SystemString(), dest.NetAddr())
}
func (d *DefaultSystemDialer) DestIpAddress() net.IP {
return nil
}
type PacketConnWrapper struct {
Conn net.PacketConn
Dest net.Addr
}
func (c *PacketConnWrapper) Close() error {
return c.Conn.Close()
}
func (c *PacketConnWrapper) LocalAddr() net.Addr {
return c.Conn.LocalAddr()
}
func (c *PacketConnWrapper) RemoteAddr() net.Addr {
return c.Dest
}
func (c *PacketConnWrapper) Write(p []byte) (int, error) {
return c.Conn.WriteTo(p, c.Dest)
}
func (c *PacketConnWrapper) Read(p []byte) (int, error) {
n, _, err := c.Conn.ReadFrom(p)
return n, err
}
func (c *PacketConnWrapper) WriteTo(p []byte, d net.Addr) (int, error) {
return c.Conn.WriteTo(p, d)
}
func (c *PacketConnWrapper) ReadFrom(p []byte) (int, net.Addr, error) {
return c.Conn.ReadFrom(p)
}
func (c *PacketConnWrapper) SetDeadline(t time.Time) error {
return c.Conn.SetDeadline(t)
}
func (c *PacketConnWrapper) SetReadDeadline(t time.Time) error {
return c.Conn.SetReadDeadline(t)
}
func (c *PacketConnWrapper) SetWriteDeadline(t time.Time) error {
return c.Conn.SetWriteDeadline(t)
}
type SystemDialerAdapter interface {
Dial(network string, address string) (net.Conn, error)
}
type SimpleSystemDialer struct {
adapter SystemDialerAdapter
}
func WithAdapter(dialer SystemDialerAdapter) SystemDialer {
return &SimpleSystemDialer{
adapter: dialer,
}
}
func (v *SimpleSystemDialer) Dial(ctx context.Context, src net.Address, dest net.Destination, sockopt *SocketConfig) (net.Conn, error) {
return v.adapter.Dial(dest.Network.SystemString(), dest.NetAddr())
}
func (d *SimpleSystemDialer) DestIpAddress() net.IP {
return nil
}
// UseAlternativeSystemDialer replaces the current system dialer with a given one.
// Caller must ensure there is no race condition.
//
// xray:api:stable
func UseAlternativeSystemDialer(dialer SystemDialer) {
if dialer == nil {
dialer = &DefaultSystemDialer{}
}
effectiveSystemDialer = dialer
}
// RegisterDialerController adds a controller to the effective system dialer.
// The controller can be used to operate on file descriptors before they are put into use.
// It only works when effective dialer is the default dialer.
//
// xray:api:beta
func RegisterDialerController(ctl control.Func) error {
if ctl == nil {
return newError("nil listener controller")
}
dialer, ok := effectiveSystemDialer.(*DefaultSystemDialer)
if !ok {
return newError("RegisterListenerController not supported in custom dialer")
}
dialer.controllers = append(dialer.controllers, ctl)
return nil
}