Add RDP sniffer

common/sniff/rdp.go

@@ -0,0 +1,90 @@
+package sniff
+
+import (
+	"context"
+	"encoding/binary"
+	"io"
+	"os"
+
+	"github.com/sagernet/sing-box/adapter"
+	C "github.com/sagernet/sing-box/constant"
+	"github.com/sagernet/sing/common/rw"
+)
+
+func RDP(_ context.Context, metadata *adapter.InboundContext, reader io.Reader) error {
+	var tpktVersion uint8
+	err := binary.Read(reader, binary.BigEndian, &tpktVersion)
+	if err != nil {
+		return err
+	}
+	if tpktVersion != 0x03 {
+		return os.ErrInvalid
+	}
+
+	var tpktReserved uint8
+	err = binary.Read(reader, binary.BigEndian, &tpktReserved)
+	if err != nil {
+		return err
+	}
+	if tpktReserved != 0x00 {
+		return os.ErrInvalid
+	}
+
+	var tpktLength uint16
+	err = binary.Read(reader, binary.BigEndian, &tpktLength)
+	if err != nil {
+		return err
+	}
+
+	if tpktLength != 19 {
+		return os.ErrInvalid
+	}
+
+	var cotpLength uint8
+	err = binary.Read(reader, binary.BigEndian, &cotpLength)
+	if err != nil {
+		return err
+	}
+
+	if cotpLength != 14 {
+		return os.ErrInvalid
+	}
+
+	var cotpTpduType uint8
+	err = binary.Read(reader, binary.BigEndian, &cotpTpduType)
+	if err != nil {
+		return err
+	}
+	if cotpTpduType != 0xE0 {
+		return os.ErrInvalid
+	}
+
+	err = rw.SkipN(reader, 5)
+	if err != nil {
+		return err
+	}
+
+	var rdpType uint8
+	err = binary.Read(reader, binary.BigEndian, &rdpType)
+	if err != nil {
+		return err
+	}
+	if rdpType != 0x01 {
+		return os.ErrInvalid
+	}
+	var rdpFlags uint8
+	err = binary.Read(reader, binary.BigEndian, &rdpFlags)
+	if err != nil {
+		return err
+	}
+	var rdpLength uint8
+	err = binary.Read(reader, binary.BigEndian, &rdpLength)
+	if err != nil {
+		return err
+	}
+	if rdpLength != 8 {
+		return os.ErrInvalid
+	}
+	metadata.Protocol = C.ProtocolRDP
+	return nil
+}

common/sniff/rdp_test.go

@@ -0,0 +1,25 @@
+package sniff_test
+
+import (
+	"bytes"
+	"context"
+	"encoding/hex"
+	"testing"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/common/sniff"
+	C "github.com/sagernet/sing-box/constant"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSniffRDP(t *testing.T) {
+	t.Parallel()
+
+	pkt, err := hex.DecodeString("030000130ee00000000000010008000b000000010008000b000000")
+	require.NoError(t, err)
+	var metadata adapter.InboundContext
+	err = sniff.RDP(context.TODO(), &metadata, bytes.NewReader(pkt))
+	require.NoError(t, err)
+	require.Equal(t, C.ProtocolRDP, metadata.Protocol)
+}

constant/protocol.go

@@ -9,6 +9,7 @@ const (
 	ProtocolBitTorrent = "bittorrent"
 	ProtocolDTLS       = "dtls"
 	ProtocolSSH        = "ssh"
+	ProtocolRDP        = "rdp"
 )
 
 const (

docs/configuration/route/sniff.md

@@ -9,13 +9,14 @@ icon: material/new-box
     :material-plus: BitTorrent support  
     :material-plus: DTLS support  
     :material-plus: SSH support  
+    :material-plus: RDP support
 
 If enabled in the inbound, the protocol and domain name (if present) of by the connection can be sniffed.
 
 #### Supported Protocols
 
 | Network |   Protocol   | Domain Name |      Client      |
-| :-----: | :----------: | :---------: | :--------------: |
+|:-------:|:------------:|:-----------:|:----------------:|
 |   TCP   |    `http`    |    Host     |        /         |
 |   TCP   |    `tls`     | Server Name |        /         |
 |   UDP   |    `quic`    | Server Name | QUIC Client Type |
@@ -24,9 +25,10 @@ If enabled in the inbound, the protocol and domain name (if present) of by the c
 | TCP/UDP | `bittorrent` |      /      |        /         |
 |   UDP   |    `dtls`    |      /      |        /         |
 |   TCP   |    `ssh`     |      /      | SSH Client Name  |
+|   TCP   |    `rdp`     |      /      |        /         |
 
 |       QUIC Client        |    Type    |
-| :----------------------: | :--------: |
+|:------------------------:|:----------:|
 |     Chromium/Cronet      | `chrimium` |
 | Safari/Apple Network API |  `safari`  |
 | Firefox / uquic firefox  | `firefox`  |

docs/configuration/route/sniff.zh.md

@@ -9,13 +9,14 @@ icon: material/new-box
     :material-plus: BitTorrent 支持  
     :material-plus: DTLS 支持  
     :material-plus: SSH 支持  
+    :material-plus: RDP 支持
 
 如果在入站中启用，则可以嗅探连接的协议和域名（如果存在）。
 
 #### 支持的协议
 
 |   网络    |      协议      |     域名      |    客户端     |
-| :-----: | :----------: | :---------: | :-------------: |
+|:-------:|:------------:|:-----------:|:----------:|
 |   TCP   |    `http`    |    Host     |     /      |
 |   TCP   |    `tls`     | Server Name |     /      |
 |   UDP   |    `quic`    | Server Name | QUIC 客户端类型 |
@@ -23,10 +24,11 @@ icon: material/new-box
 | TCP/UDP |    `dns`     |      /      |     /      |
 | TCP/UDP | `bittorrent` |      /      |     /      |
 |   UDP   |    `dtls`    |      /      |     /      |
-|   TCP   |    `SSH`     |      /      | SSH 客户端名称  |
+|   TCP   |    `ssh`     |      /      | SSH 客户端名称  |
+|   TCP   |    `rdp`     |      /      |     /      |
 
 |         QUIC 客户端         |     类型     |
-| :----------------------: | :--------: |
+|:------------------------:|:----------:|
 |     Chromium/Cronet      | `chrimium` |
 | Safari/Apple Network API |  `safari`  |
 | Firefox / uquic firefox  | `firefox`  |