From 4b7a83da168c5f2ae9b999580517083ef1b10f4b Mon Sep 17 00:00:00 2001 From: iosmanthus Date: Mon, 27 May 2024 19:24:41 +0800 Subject: [PATCH] Introduce bittorrent related protocol sniffers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * Introduce bittorrent related protocol sniffers including, sniffers of 1. BitTorrent Protocol (TCP) 2. uTorrent Transport Protocol (UDP) Signed-off-by: iosmanthus Co-authored-by: 世界 --- common/sniff/bittorrent.go | 101 +++++++++++++++++++++++++++ common/sniff/bittorrent_test.go | 70 +++++++++++++++++++ constant/protocol.go | 11 +-- docs/configuration/route/sniff.md | 15 ++-- docs/configuration/route/sniff.zh.md | 15 ++-- route/router.go | 21 +++++- 6 files changed, 212 insertions(+), 21 deletions(-) create mode 100644 common/sniff/bittorrent.go create mode 100644 common/sniff/bittorrent_test.go diff --git a/common/sniff/bittorrent.go b/common/sniff/bittorrent.go new file mode 100644 index 00000000..debc35ca --- /dev/null +++ b/common/sniff/bittorrent.go @@ -0,0 +1,101 @@ +package sniff + +import ( + "bytes" + "context" + "encoding/binary" + "io" + "os" + + "github.com/sagernet/sing-box/adapter" + C "github.com/sagernet/sing-box/constant" +) + +const ( + trackerConnectFlag = 0 + trackerProtocolID = 0x41727101980 + trackerConnectMinSize = 16 +) + +// BitTorrent detects if the stream is a BitTorrent connection. +// For the BitTorrent protocol specification, see https://www.bittorrent.org/beps/bep_0003.html +func BitTorrent(_ context.Context, reader io.Reader) (*adapter.InboundContext, error) { + var first byte + err := binary.Read(reader, binary.BigEndian, &first) + if err != nil { + return nil, err + } + + if first != 19 { + return nil, os.ErrInvalid + } + + var protocol [19]byte + _, err = reader.Read(protocol[:]) + if err != nil { + return nil, err + } + if string(protocol[:]) != "BitTorrent protocol" { + return nil, os.ErrInvalid + } + + return &adapter.InboundContext{ + Protocol: C.ProtocolBitTorrent, + }, nil +} + +// UTP detects if the packet is a uTP connection packet. +// For the uTP protocol specification, see +// 1. https://www.bittorrent.org/beps/bep_0029.html +// 2. https://github.com/bittorrent/libutp/blob/2b364cbb0650bdab64a5de2abb4518f9f228ec44/utp_internal.cpp#L112 +func UTP(_ context.Context, packet []byte) (*adapter.InboundContext, error) { + // A valid uTP packet must be at least 20 bytes long. + if len(packet) < 20 { + return nil, os.ErrInvalid + } + + version := packet[0] & 0x0F + ty := packet[0] >> 4 + if version != 1 || ty > 4 { + return nil, os.ErrInvalid + } + + // Validate the extensions + extension := packet[1] + reader := bytes.NewReader(packet[20:]) + for extension != 0 { + err := binary.Read(reader, binary.BigEndian, &extension) + if err != nil { + return nil, err + } + + var length byte + err = binary.Read(reader, binary.BigEndian, &length) + if err != nil { + return nil, err + } + _, err = reader.Seek(int64(length), io.SeekCurrent) + if err != nil { + return nil, err + } + } + + return &adapter.InboundContext{ + Protocol: C.ProtocolBitTorrent, + }, nil +} + +// UDPTracker detects if the packet is a UDP Tracker Protocol packet. +// For the UDP Tracker Protocol specification, see https://www.bittorrent.org/beps/bep_0015.html +func UDPTracker(_ context.Context, packet []byte) (*adapter.InboundContext, error) { + if len(packet) < trackerConnectMinSize { + return nil, os.ErrInvalid + } + if binary.BigEndian.Uint64(packet[:8]) != trackerProtocolID { + return nil, os.ErrInvalid + } + if binary.BigEndian.Uint32(packet[8:12]) != trackerConnectFlag { + return nil, os.ErrInvalid + } + return &adapter.InboundContext{Protocol: C.ProtocolBitTorrent}, nil +} diff --git a/common/sniff/bittorrent_test.go b/common/sniff/bittorrent_test.go new file mode 100644 index 00000000..6b3ab64e --- /dev/null +++ b/common/sniff/bittorrent_test.go @@ -0,0 +1,70 @@ +package sniff_test + +import ( + "bytes" + "context" + "encoding/hex" + "testing" + + "github.com/sagernet/sing-box/common/sniff" + C "github.com/sagernet/sing-box/constant" + + "github.com/stretchr/testify/require" +) + +func TestSniffBittorrent(t *testing.T) { + t.Parallel() + + packets := []string{ + "13426974546f7272656e742070726f746f636f6c0000000000100000e21ea9569b69bab33c97851d0298bdfa89bc90922d5554313631302dea812fcd6a3563e3be40c1d1", + "13426974546f7272656e742070726f746f636f6c00000000001000052aa4f5a7e209e54b32803d43670971c4c8caaa052d5452333030302d653369733079647675763638", + "13426974546f7272656e742070726f746f636f6c00000000001000052aa4f5a7e209e54b32803d43670971c4c8caaa052d5452343035302d6f7a316c6e79377931716130", + } + + for _, pkt := range packets { + pkt, err := hex.DecodeString(pkt) + require.NoError(t, err) + metadata, err := sniff.BitTorrent(context.TODO(), bytes.NewReader(pkt)) + require.NoError(t, err) + require.Equal(t, C.ProtocolBitTorrent, metadata.Protocol) + } +} + +func TestSniffUTP(t *testing.T) { + t.Parallel() + + packets := []string{ + "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", + "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", + "21001ecb6817f2805d044fd700100000dbd03029", + "410277ef0b1fb1f60000000000040000c233000000080000000000000000", + } + + for _, pkt := range packets { + pkt, err := hex.DecodeString(pkt) + require.NoError(t, err) + + metadata, err := sniff.UTP(context.TODO(), pkt) + require.NoError(t, err) + require.Equal(t, C.ProtocolBitTorrent, metadata.Protocol) + } +} + +func TestSniffUDPTracker(t *testing.T) { + t.Parallel() + + connectPackets := []string{ + "00000417271019800000000078e90560", + "00000417271019800000000022c5d64d", + "000004172710198000000000b3863541", + } + + for _, pkt := range connectPackets { + pkt, err := hex.DecodeString(pkt) + require.NoError(t, err) + + metadata, err := sniff.UDPTracker(context.TODO(), pkt) + require.NoError(t, err) + require.Equal(t, C.ProtocolBitTorrent, metadata.Protocol) + } +} diff --git a/constant/protocol.go b/constant/protocol.go index 810c79ec..2b7a9e0f 100644 --- a/constant/protocol.go +++ b/constant/protocol.go @@ -1,9 +1,10 @@ package constant const ( - ProtocolTLS = "tls" - ProtocolHTTP = "http" - ProtocolQUIC = "quic" - ProtocolDNS = "dns" - ProtocolSTUN = "stun" + ProtocolTLS = "tls" + ProtocolHTTP = "http" + ProtocolQUIC = "quic" + ProtocolDNS = "dns" + ProtocolSTUN = "stun" + ProtocolBitTorrent = "bittorrent" ) diff --git a/docs/configuration/route/sniff.md b/docs/configuration/route/sniff.md index 2ba2c251..7a3de02b 100644 --- a/docs/configuration/route/sniff.md +++ b/docs/configuration/route/sniff.md @@ -2,10 +2,11 @@ If enabled in the inbound, the protocol and domain name (if present) of by the c #### Supported Protocols -| Network | Protocol | Domain Name | -|:-------:|:--------:|:-----------:| -| TCP | HTTP | Host | -| TCP | TLS | Server Name | -| UDP | QUIC | Server Name | -| UDP | STUN | / | -| TCP/UDP | DNS | / | \ No newline at end of file +| Network | Protocol | Domain Name | +|:-------:|:-----------:|:-----------:| +| TCP | HTTP | Host | +| TCP | TLS | Server Name | +| UDP | QUIC | Server Name | +| UDP | STUN | / | +| TCP/UDP | DNS | / | +| TCP/UDP | BitTorrent | / | \ No newline at end of file diff --git a/docs/configuration/route/sniff.zh.md b/docs/configuration/route/sniff.zh.md index c3cdcc4e..553c6ed7 100644 --- a/docs/configuration/route/sniff.zh.md +++ b/docs/configuration/route/sniff.zh.md @@ -2,10 +2,11 @@ #### 支持的协议 -| 网络 | 协议 | 域名 | -|:-------:|:----:|:-----------:| -| TCP | HTTP | Host | -| TCP | TLS | Server Name | -| UDP | QUIC | Server Name | -| UDP | STUN | / | -| TCP/UDP | DNS | / | \ No newline at end of file +| 网络 | 协议 | 域名 | +|:-------:|:-----------:|:-----------:| +| TCP | HTTP | Host | +| TCP | TLS | Server Name | +| UDP | QUIC | Server Name | +| UDP | STUN | / | +| TCP/UDP | DNS | / | +| TCP/UDP | BitTorrent | / | \ No newline at end of file diff --git a/route/router.go b/route/router.go index 5d89b118..ad4ac3da 100644 --- a/route/router.go +++ b/route/router.go @@ -834,7 +834,16 @@ func (r *Router) RouteConnection(ctx context.Context, conn net.Conn, metadata ad if metadata.InboundOptions.SniffEnabled && !sniff.Skip(metadata) { buffer := buf.NewPacket() - sniffMetadata, err := sniff.PeekStream(ctx, conn, buffer, time.Duration(metadata.InboundOptions.SniffTimeout), sniff.StreamDomainNameQuery, sniff.TLSClientHello, sniff.HTTPHost) + sniffMetadata, err := sniff.PeekStream( + ctx, + conn, + buffer, + time.Duration(metadata.InboundOptions.SniffTimeout), + sniff.StreamDomainNameQuery, + sniff.TLSClientHello, + sniff.HTTPHost, + sniff.BitTorrent, + ) if sniffMetadata != nil { metadata.Protocol = sniffMetadata.Protocol metadata.Domain = sniffMetadata.Domain @@ -983,7 +992,15 @@ func (r *Router) RoutePacketConnection(ctx context.Context, conn N.PacketConn, m metadata.Destination = destination } if metadata.InboundOptions.SniffEnabled { - sniffMetadata, _ := sniff.PeekPacket(ctx, buffer.Bytes(), sniff.DomainNameQuery, sniff.QUICClientHello, sniff.STUNMessage) + sniffMetadata, _ := sniff.PeekPacket( + ctx, + buffer.Bytes(), + sniff.DomainNameQuery, + sniff.QUICClientHello, + sniff.STUNMessage, + sniff.UTP, + sniff.UDPTracker, + ) if sniffMetadata != nil { metadata.Protocol = sniffMetadata.Protocol metadata.Domain = sniffMetadata.Domain