Files
sing-box/protocol/mysql/outbound.go
2026-02-12 17:50:48 +08:00

269 lines
6.5 KiB
Go

package mysql
import (
"context"
"crypto/tls"
"net"
"os"
"sync"
"github.com/sagernet/sing-box/adapter"
"github.com/sagernet/sing-box/adapter/outbound"
"github.com/sagernet/sing-box/common/dialer"
C "github.com/sagernet/sing-box/constant"
"github.com/sagernet/sing-box/log"
"github.com/sagernet/sing-box/option"
"github.com/sagernet/sing/common"
"github.com/sagernet/sing/common/bufio"
E "github.com/sagernet/sing/common/exceptions"
"github.com/sagernet/sing/common/logger"
M "github.com/sagernet/sing/common/metadata"
N "github.com/sagernet/sing/common/network"
"github.com/sagernet/smux"
"github.com/go-mysql-org/go-mysql/client"
)
func RegisterOutbound(registry *outbound.Registry) {
outbound.Register[option.MySQLOutboundOptions](registry, C.TypeMySQL, NewOutbound)
}
var _ adapter.InterfaceUpdateListener = (*Outbound)(nil)
type Outbound struct {
outbound.Adapter
ctx context.Context
logger logger.ContextLogger
dialer N.Dialer
serverAddr M.Socksaddr
username string
password string
tlsConfig *tls.Config
sessionAccess sync.Mutex
session *smux.Session
sessionConn net.Conn
}
func NewOutbound(ctx context.Context, router adapter.Router, logger log.ContextLogger, tag string, options option.MySQLOutboundOptions) (adapter.Outbound, error) {
outboundDialer, err := dialer.New(ctx, options.DialerOptions, options.ServerIsDomain())
if err != nil {
return nil, err
}
outbound := &Outbound{
Adapter: outbound.NewAdapterWithDialerOptions(C.TypeMySQL, tag, []string{N.NetworkTCP, N.NetworkUDP}, options.DialerOptions),
ctx: ctx,
logger: logger,
dialer: outboundDialer,
serverAddr: options.ServerOptions.Build(),
username: options.Username,
password: options.Password,
}
if outbound.serverAddr.Port == 0 {
outbound.serverAddr.Port = 3306
}
if outbound.username == "" {
outbound.username = "root"
}
// Build TLS config for MySQL client handshake
if options.TLS != nil && options.TLS.Enabled {
outbound.tlsConfig = &tls.Config{
InsecureSkipVerify: options.TLS.Insecure,
ServerName: options.TLS.ServerName,
}
if outbound.tlsConfig.ServerName == "" {
outbound.tlsConfig.ServerName = options.Server
}
} else {
// Default: use insecure TLS (since this is for tunneling, not real MySQL)
outbound.tlsConfig = &tls.Config{
InsecureSkipVerify: true,
}
}
return outbound, nil
}
func (h *Outbound) getSession() (*smux.Session, error) {
h.sessionAccess.Lock()
defer h.sessionAccess.Unlock()
if h.session != nil && !h.session.IsClosed() {
return h.session, nil
}
// Dial TCP connection to server
conn, err := h.dialer.DialContext(h.ctx, N.NetworkTCP, h.serverAddr)
if err != nil {
return nil, E.Cause(err, "dial server")
}
// Perform MySQL handshake with TLS
mysqlConn, err := client.ConnectWithDialer(
h.ctx,
"tcp",
h.serverAddr.String(),
h.username,
h.password,
"",
func(ctx context.Context, network, address string) (net.Conn, error) {
// Return the already-established connection
return conn, nil
},
func(c *client.Conn) error {
c.SetTLSConfig(h.tlsConfig)
return nil
},
)
if err != nil {
conn.Close()
return nil, E.Cause(err, "MySQL handshake")
}
// After MySQL handshake, the underlying connection is TLS-encrypted.
// Get the underlying net.Conn.
tlsConn := mysqlConn.Conn.Conn
// Create smux session over the TLS connection
session, err := smux.Client(tlsConn, smuxConfig())
if err != nil {
tlsConn.Close()
return nil, E.Cause(err, "create mux session")
}
h.session = session
h.sessionConn = tlsConn
go func() {
// When session is closed, clean up
<-session.CloseChan()
h.sessionAccess.Lock()
if h.session == session {
h.session = nil
h.sessionConn = nil
}
h.sessionAccess.Unlock()
tlsConn.Close()
}()
return session, nil
}
func (h *Outbound) openStream(ctx context.Context, command byte, destination M.Socksaddr) (net.Conn, error) {
session, err := h.getSession()
if err != nil {
return nil, err
}
stream, err := session.OpenStream()
if err != nil {
// Session might be stale, try once more with a new session
h.sessionAccess.Lock()
if h.session == session {
h.session = nil
if h.sessionConn != nil {
h.sessionConn.Close()
h.sessionConn = nil
}
}
h.sessionAccess.Unlock()
session, err = h.getSession()
if err != nil {
return nil, err
}
stream, err = session.OpenStream()
if err != nil {
return nil, E.Cause(err, "open mux stream")
}
}
// Write stream header: command + destination
_, err = stream.Write([]byte{command})
if err != nil {
stream.Close()
return nil, E.Cause(err, "write stream header command")
}
err = M.SocksaddrSerializer.WriteAddrPort(stream, destination)
if err != nil {
stream.Close()
return nil, E.Cause(err, "write stream header destination")
}
return stream, nil
}
func (h *Outbound) DialContext(ctx context.Context, network string, destination M.Socksaddr) (net.Conn, error) {
switch N.NetworkName(network) {
case N.NetworkTCP:
h.logger.InfoContext(ctx, "outbound connection to ", destination)
return h.openStream(ctx, commandTCP, destination)
case N.NetworkUDP:
h.logger.InfoContext(ctx, "outbound packet connection to ", destination)
conn, err := h.openStream(ctx, commandUDP, destination)
if err != nil {
return nil, err
}
return bufio.NewBindPacketConn(&packetConn{conn}, destination), nil
default:
return nil, E.New("unsupported network: ", network)
}
}
func (h *Outbound) ListenPacket(ctx context.Context, destination M.Socksaddr) (net.PacketConn, error) {
h.logger.InfoContext(ctx, "outbound packet connection to ", destination)
conn, err := h.openStream(ctx, commandUDP, destination)
if err != nil {
return nil, err
}
return &packetConn{conn}, nil
}
func (h *Outbound) InterfaceUpdated() {
h.sessionAccess.Lock()
defer h.sessionAccess.Unlock()
if h.session != nil {
h.session.Close()
h.session = nil
}
if h.sessionConn != nil {
h.sessionConn.Close()
h.sessionConn = nil
}
}
func (h *Outbound) Close() error {
h.sessionAccess.Lock()
defer h.sessionAccess.Unlock()
var err error
if h.session != nil {
err = h.session.Close()
h.session = nil
}
if h.sessionConn != nil {
common.Close(h.sessionConn)
h.sessionConn = nil
}
return err
}
// packetConn wraps a net.Conn as a net.PacketConn for UDP-over-TCP
type packetConn struct {
net.Conn
}
func (c *packetConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
n, err = c.Conn.Read(p)
return
}
func (c *packetConn) WriteTo(p []byte, addr net.Addr) (n int, err error) {
return c.Conn.Write(p)
}
var _ = os.ErrInvalid // keep import