diff --git a/infra/conf/transport_internet.go b/infra/conf/transport_internet.go index 7bd481652b43..62f3c8036a8d 100644 --- a/infra/conf/transport_internet.go +++ b/infra/conf/transport_internet.go @@ -23,6 +23,7 @@ import ( "github.com/xtls/xray-core/transport/internet" "github.com/xtls/xray-core/transport/internet/finalmask/fragment" "github.com/xtls/xray-core/transport/internet/finalmask/header/custom" + "github.com/xtls/xray-core/transport/internet/finalmask/rawpacket" "github.com/xtls/xray-core/transport/internet/finalmask/header/dns" "github.com/xtls/xray-core/transport/internet/finalmask/header/dtls" "github.com/xtls/xray-core/transport/internet/finalmask/header/srtp" @@ -1237,6 +1238,7 @@ var ( tcpmaskLoader = NewJSONConfigLoader(ConfigCreatorCache{ "header-custom": func() interface{} { return new(HeaderCustomTCP) }, "fragment": func() interface{} { return new(FragmentMask) }, + "rawpacket": func() interface{} { return new(RawpacketMask) }, "sudoku": func() interface{} { return new(Sudoku) }, }, "type", "settings") @@ -1447,6 +1449,23 @@ func (c *FragmentMask) Build() (proto.Message, error) { return config, nil } +type RawpacketMask struct { + Payload string `json:"payload"` + Method string `json:"method"` + TTL int32 `json:"ttl"` + Count int32 `json:"count"` +} + +func (c *RawpacketMask) Build() (proto.Message, error) { + config := &rawpacket.Config{ + Payload: c.Payload, + Method: c.Method, + Ttl: uint32(c.TTL), + Count: c.Count, + } + return config, nil +} + type NoiseItem struct { Rand Int32Range `json:"rand"` RandRange *Int32Range `json:"randRange"` diff --git a/transport/internet/finalmask/rawpacket/config.go b/transport/internet/finalmask/rawpacket/config.go new file mode 100644 index 000000000000..e4ee5d717d25 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/config.go @@ -0,0 +1,14 @@ +package rawpacket + +import "net" + +func (c *Config) TCP() {} + +func (c *Config) WrapConnClient(raw net.Conn) (net.Conn, error) { + return NewConnClient(c, raw) +} + +func (c *Config) WrapConnServer(raw net.Conn) (net.Conn, error) { + // Raw packet injection is client-side only. + return raw, nil +} diff --git a/transport/internet/finalmask/rawpacket/config.pb.go b/transport/internet/finalmask/rawpacket/config.pb.go new file mode 100644 index 000000000000..26f8b63d26ca --- /dev/null +++ b/transport/internet/finalmask/rawpacket/config.pb.go @@ -0,0 +1,156 @@ +// Code generated by protoc-gen-go. DO NOT EDIT. +// versions: +// protoc-gen-go v1.36.11 +// protoc v6.33.5 +// source: transport/internet/finalmask/rawpacket/config.proto + +package rawpacket + +import ( + protoreflect "google.golang.org/protobuf/reflect/protoreflect" + protoimpl "google.golang.org/protobuf/runtime/protoimpl" + reflect "reflect" + sync "sync" + unsafe "unsafe" +) + +const ( + // Verify that this generated code is sufficiently up-to-date. + _ = protoimpl.EnforceVersion(20 - protoimpl.MinVersion) + // Verify that runtime/protoimpl is sufficiently up-to-date. + _ = protoimpl.EnforceVersion(protoimpl.MaxVersion - 20) +) + +type Config struct { + state protoimpl.MessageState `protogen:"open.v1"` + // Base64-encoded fake payload bytes to inject before the real traffic. + Payload string `protobuf:"bytes,1,opt,name=payload,proto3" json:"payload,omitempty"` + // Corruption method to make the fake packet dropped by the server. + // Available: wrong-sequence, wrong-checksum, wrong-ack, wrong-md5, wrong-timestamp. + Method string `protobuf:"bytes,2,opt,name=method,proto3" json:"method,omitempty"` + // TTL of the fake packet. A low value (e.g. 3-5) ensures the packet + // is seen by middleboxes but does not reach the destination server. + Ttl uint32 `protobuf:"varint,3,opt,name=ttl,proto3" json:"ttl,omitempty"` + // How many Write() calls trigger injection. 0 or 1 = single-shot (default). + Count int32 `protobuf:"varint,4,opt,name=count,proto3" json:"count,omitempty"` + unknownFields protoimpl.UnknownFields + sizeCache protoimpl.SizeCache +} + +func (x *Config) Reset() { + *x = Config{} + mi := &file_transport_internet_finalmask_rawpacket_config_proto_msgTypes[0] + ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x)) + ms.StoreMessageInfo(mi) +} + +func (x *Config) String() string { + return protoimpl.X.MessageStringOf(x) +} + +func (*Config) ProtoMessage() {} + +func (x *Config) ProtoReflect() protoreflect.Message { + mi := &file_transport_internet_finalmask_rawpacket_config_proto_msgTypes[0] + if x != nil { + ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x)) + if ms.LoadMessageInfo() == nil { + ms.StoreMessageInfo(mi) + } + return ms + } + return mi.MessageOf(x) +} + +// Deprecated: Use Config.ProtoReflect.Descriptor instead. +func (*Config) Descriptor() ([]byte, []int) { + return file_transport_internet_finalmask_rawpacket_config_proto_rawDescGZIP(), []int{0} +} + +func (x *Config) GetPayload() string { + if x != nil { + return x.Payload + } + return "" +} + +func (x *Config) GetMethod() string { + if x != nil { + return x.Method + } + return "" +} + +func (x *Config) GetTtl() uint32 { + if x != nil { + return x.Ttl + } + return 0 +} + +func (x *Config) GetCount() int32 { + if x != nil { + return x.Count + } + return 0 +} + +var File_transport_internet_finalmask_rawpacket_config_proto protoreflect.FileDescriptor + +const file_transport_internet_finalmask_rawpacket_config_proto_rawDesc = "" + + "\n" + + "3transport/internet/finalmask/rawpacket/config.proto\x12+xray.transport.internet.finalmask.rawpacket\"b\n" + + "\x06Config\x12\x18\n" + + "\apayload\x18\x01 \x01(\tR\apayload\x12\x16\n" + + "\x06method\x18\x02 \x01(\tR\x06method\x12\x10\n" + + "\x03ttl\x18\x03 \x01(\rR\x03ttl\x12\x14\n" + + "\x05count\x18\x04 \x01(\x05R\x05countB\xa3\x01\n" + + "/com.xray.transport.internet.finalmask.rawpacketP\x01Z@github.com/xtls/xray-core/transport/internet/finalmask/rawpacket\xaa\x02+Xray.Transport.Internet.Finalmask.Rawpacketb\x06proto3" + +var ( + file_transport_internet_finalmask_rawpacket_config_proto_rawDescOnce sync.Once + file_transport_internet_finalmask_rawpacket_config_proto_rawDescData []byte +) + +func file_transport_internet_finalmask_rawpacket_config_proto_rawDescGZIP() []byte { + file_transport_internet_finalmask_rawpacket_config_proto_rawDescOnce.Do(func() { + file_transport_internet_finalmask_rawpacket_config_proto_rawDescData = protoimpl.X.CompressGZIP(unsafe.Slice(unsafe.StringData(file_transport_internet_finalmask_rawpacket_config_proto_rawDesc), len(file_transport_internet_finalmask_rawpacket_config_proto_rawDesc))) + }) + return file_transport_internet_finalmask_rawpacket_config_proto_rawDescData +} + +var file_transport_internet_finalmask_rawpacket_config_proto_msgTypes = make([]protoimpl.MessageInfo, 1) +var file_transport_internet_finalmask_rawpacket_config_proto_goTypes = []any{ + (*Config)(nil), // 0: xray.transport.internet.finalmask.rawpacket.Config +} +var file_transport_internet_finalmask_rawpacket_config_proto_depIdxs = []int32{ + 0, // [0:0] is the sub-list for method output_type + 0, // [0:0] is the sub-list for method input_type + 0, // [0:0] is the sub-list for extension type_name + 0, // [0:0] is the sub-list for extension extendee + 0, // [0:0] is the sub-list for field type_name +} + +func init() { file_transport_internet_finalmask_rawpacket_config_proto_init() } +func file_transport_internet_finalmask_rawpacket_config_proto_init() { + if File_transport_internet_finalmask_rawpacket_config_proto != nil { + return + } + type x struct{} + out := protoimpl.TypeBuilder{ + File: protoimpl.DescBuilder{ + GoPackagePath: reflect.TypeOf(x{}).PkgPath(), + RawDescriptor: unsafe.Slice(unsafe.StringData(file_transport_internet_finalmask_rawpacket_config_proto_rawDesc), len(file_transport_internet_finalmask_rawpacket_config_proto_rawDesc)), + NumEnums: 0, + NumMessages: 1, + NumExtensions: 0, + NumServices: 0, + }, + GoTypes: file_transport_internet_finalmask_rawpacket_config_proto_goTypes, + DependencyIndexes: file_transport_internet_finalmask_rawpacket_config_proto_depIdxs, + MessageInfos: file_transport_internet_finalmask_rawpacket_config_proto_msgTypes, + }.Build() + File_transport_internet_finalmask_rawpacket_config_proto = out.File + file_transport_internet_finalmask_rawpacket_config_proto_goTypes = nil + file_transport_internet_finalmask_rawpacket_config_proto_depIdxs = nil +} diff --git a/transport/internet/finalmask/rawpacket/config.proto b/transport/internet/finalmask/rawpacket/config.proto new file mode 100644 index 000000000000..f6b3e8dcb10e --- /dev/null +++ b/transport/internet/finalmask/rawpacket/config.proto @@ -0,0 +1,23 @@ +syntax = "proto3"; + +package xray.transport.internet.finalmask.rawpacket; +option csharp_namespace = "Xray.Transport.Internet.Finalmask.Rawpacket"; +option go_package = "github.com/xtls/xray-core/transport/internet/finalmask/rawpacket"; +option java_package = "com.xray.transport.internet.finalmask.rawpacket"; +option java_multiple_files = true; + +message Config { + // Base64-encoded fake payload bytes to inject before the real traffic. + string payload = 1; + + // Corruption method to make the fake packet dropped by the server. + // Available: wrong-sequence, wrong-checksum, wrong-ack, wrong-md5, wrong-timestamp. + string method = 2; + + // TTL of the fake packet. A low value (e.g. 3-5) ensures the packet + // is seen by middleboxes but does not reach the destination server. + uint32 ttl = 3; + + // How many Write() calls trigger injection. 0 or 1 = single-shot (default). + int32 count = 4; +} diff --git a/transport/internet/finalmask/rawpacket/conn.go b/transport/internet/finalmask/rawpacket/conn.go new file mode 100644 index 000000000000..188b145ea2f7 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/conn.go @@ -0,0 +1,170 @@ +package rawpacket + +import ( + "encoding/base64" + "errors" + "fmt" + "net" + "runtime" + "syscall" +) + +type Method int + +const ( + MethodWrongSequence Method = iota + MethodWrongChecksum + MethodWrongAcknowledgment + MethodWrongMD5Sig + MethodWrongTimestamp +) + +const ( + MethodNameWrongSequence = "wrong-sequence" + MethodNameWrongChecksum = "wrong-checksum" + MethodNameWrongAcknowledgment = "wrong-ack" + MethodNameWrongMD5Sig = "wrong-md5" + MethodNameWrongTimestamp = "wrong-timestamp" +) + +func ParseMethod(s string) (Method, error) { + switch s { + case "", MethodNameWrongSequence: + return MethodWrongSequence, nil + case MethodNameWrongChecksum: + return MethodWrongChecksum, nil + case MethodNameWrongAcknowledgment: + return MethodWrongAcknowledgment, nil + case MethodNameWrongMD5Sig: + return MethodWrongMD5Sig, nil + case MethodNameWrongTimestamp: + return MethodWrongTimestamp, nil + default: + return 0, fmt.Errorf("rawpacket: unknown method: %s", s) + } +} + +func (m Method) String() string { + switch m { + case MethodWrongSequence: + return MethodNameWrongSequence + case MethodWrongChecksum: + return MethodNameWrongChecksum + case MethodWrongAcknowledgment: + return MethodNameWrongAcknowledgment + case MethodWrongMD5Sig: + return MethodNameWrongMD5Sig + case MethodWrongTimestamp: + return MethodNameWrongTimestamp + default: + return "unknown" + } +} + +type rawSpoofer interface { + Inject(payload []byte) error + Close() error +} + +type Conn struct { + net.Conn + spoofer rawSpoofer + fakePayload []byte + injectionCount int + maxInjections int +} + +func NewConnClient(cfg *Config, conn net.Conn) (net.Conn, error) { + if cfg.Payload == "" { + return conn, nil + } + if !PlatformSupported { + return nil, errors.New("rawpacket is not supported on this platform") + } + payload, err := base64.StdEncoding.DecodeString(cfg.Payload) + if err != nil { + return nil, fmt.Errorf("rawpacket: invalid base64 payload: %w", err) + } + if len(payload) == 0 { + return nil, errors.New("rawpacket: payload is empty") + } + method, err := ParseMethod(cfg.Method) + if err != nil { + return nil, err + } + ttl := uint8(cfg.Ttl) + if ttl == 0 { + ttl = 3 + } + spoofer, err := newRawSpoofer(conn, method, ttl) + if err != nil { + return nil, wrapPermissionError(err) + } + maxInjections := int(cfg.Count) + if maxInjections <= 0 { + maxInjections = 1 + } + return &Conn{ + Conn: conn, + spoofer: spoofer, + fakePayload: payload, + maxInjections: maxInjections, + }, nil +} + +func NewConnServer(_ *Config, conn net.Conn) (net.Conn, error) { + return conn, nil +} + +func (c *Conn) Write(b []byte) (n int, err error) { + if c.injectionCount >= c.maxInjections { + return c.Conn.Write(b) + } + err = c.spoofer.Inject(c.fakePayload) + if err != nil { + return 0, fmt.Errorf("rawpacket: inject: %w", err) + } + c.injectionCount++ + if c.injectionCount >= c.maxInjections { + closeErr := c.spoofer.Close() + if closeErr != nil { + return 0, fmt.Errorf("rawpacket: close spoofer: %w", closeErr) + } + } + return c.Conn.Write(b) +} + +func (c *Conn) Close() error { + connErr := c.Conn.Close() + spooferErr := c.spoofer.Close() + if connErr != nil { + return connErr + } + return spooferErr +} + +func (c *Conn) TcpMaskConn() {} + +func (c *Conn) RawConn() net.Conn { + return c.Conn +} + +func (c *Conn) Splice() bool { + return c.injectionCount >= c.maxInjections +} + +func wrapPermissionError(err error) error { + if !errors.Is(err, syscall.EPERM) && !errors.Is(err, syscall.EACCES) { + return err + } + switch runtime.GOOS { + case "linux": + return fmt.Errorf("%w\n Hint: run as root, or grant capabilities:\n sudo setcap cap_net_raw,cap_net_admin+ep /path/to/xray", err) + case "darwin": + return fmt.Errorf("%w\n Hint: rawpacket requires root on macOS. Run with: sudo ./xray", err) + case "freebsd": + return fmt.Errorf("%w\n Hint: rawpacket requires root on FreeBSD. Run with: sudo ./xray", err) + default: + return err + } +} diff --git a/transport/internet/finalmask/rawpacket/conn_test.go b/transport/internet/finalmask/rawpacket/conn_test.go new file mode 100644 index 000000000000..ab77ae584e26 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/conn_test.go @@ -0,0 +1,46 @@ +package rawpacket + +import ( + "testing" +) + +func TestParseMethod(t *testing.T) { + tests := []struct { + input string + expected Method + hasErr bool + }{ + {"", MethodWrongSequence, false}, + {"wrong-sequence", MethodWrongSequence, false}, + {"wrong-checksum", MethodWrongChecksum, false}, + {"wrong-ack", MethodWrongAcknowledgment, false}, + {"wrong-md5", MethodWrongMD5Sig, false}, + {"wrong-timestamp", MethodWrongTimestamp, false}, + {"invalid", 0, true}, + } + for _, tt := range tests { + m, err := ParseMethod(tt.input) + if tt.hasErr { + if err == nil { + t.Errorf("ParseMethod(%q): expected error, got nil", tt.input) + } + continue + } + if err != nil { + t.Errorf("ParseMethod(%q): unexpected error: %v", tt.input, err) + continue + } + if m != tt.expected { + t.Errorf("ParseMethod(%q) = %v, want %v", tt.input, m, tt.expected) + } + } +} + +func TestMethodString(t *testing.T) { + if MethodWrongSequence.String() != "wrong-sequence" { + t.Fatalf("unexpected method string: %s", MethodWrongSequence.String()) + } + if MethodWrongChecksum.String() != "wrong-checksum" { + t.Fatalf("unexpected method string: %s", MethodWrongChecksum.String()) + } +} diff --git a/transport/internet/finalmask/rawpacket/endpoints.go b/transport/internet/finalmask/rawpacket/endpoints.go new file mode 100644 index 000000000000..6c7107eb3987 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/endpoints.go @@ -0,0 +1,27 @@ +package rawpacket + +import ( + "net" + "net/netip" + + "errors" +) + +// The returned addresses are v4-unmapped and share the same family. +func tcpEndpoints(conn net.Conn) (*net.TCPConn, netip.AddrPort, netip.AddrPort, error) { + tcpConn, isTCP := conn.(*net.TCPConn) + if !isTCP { + return nil, netip.AddrPort{}, netip.AddrPort{}, errors.New("rawpacket: underlying conn is not *net.TCPConn") + } + local := tcpConn.LocalAddr().(*net.TCPAddr).AddrPort() + remote := tcpConn.RemoteAddr().(*net.TCPAddr).AddrPort() + if !local.IsValid() || !remote.IsValid() { + return nil, netip.AddrPort{}, netip.AddrPort{}, errors.New("rawpacket: invalid conn address") + } + local = netip.AddrPortFrom(local.Addr().Unmap(), local.Port()) + remote = netip.AddrPortFrom(remote.Addr().Unmap(), remote.Port()) + if local.Addr().Is4() != remote.Addr().Is4() { + return nil, netip.AddrPort{}, netip.AddrPort{}, errors.New("rawpacket: local/remote address family mismatch") + } + return tcpConn, local, remote, nil +} diff --git a/transport/internet/finalmask/rawpacket/packet.go b/transport/internet/finalmask/rawpacket/packet.go new file mode 100644 index 000000000000..914dc04760b8 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/packet.go @@ -0,0 +1,163 @@ +package rawpacket + +import ( + "encoding/binary" + "net/netip" + + "fmt" +) + +const ( + defaultWindowSize uint16 = 0xFFFF + tcpHeaderLen = TCPMinimumSize + + tcpOptionMD5Signature = 19 + tcpOptionMD5SignatureLength = 18 + tcpTimestampBackdate = 3600000 +) + +type spoofPacketInfo struct { + seqNum uint32 + ackNum uint32 + corrupt bool + options []byte +} + +func buildTCPSegment( + src netip.AddrPort, + dst netip.AddrPort, + packetInfo spoofPacketInfo, + payload []byte, + ttl uint8, +) []byte { + if src.Addr().Is4() != dst.Addr().Is4() { + panic("rawpacket: mixed IPv4/IPv6 address family") + } + var ( + frame []byte + ipHeaderLen int + ) + ipPayloadLen := tcpHeaderLen + len(packetInfo.options) + len(payload) + if src.Addr().Is4() { + ipHeaderLen = IPv4MinimumSize + frame = make([]byte, ipHeaderLen+ipPayloadLen) + ip := IPv4(frame[:ipHeaderLen]) + ip.Encode(uint16(len(frame)), 0, ttl, TCPProtocolNumber, src.Addr(), dst.Addr()) + } else { + ipHeaderLen = IPv6MinimumSize + frame = make([]byte, ipHeaderLen+ipPayloadLen) + ip := IPv6(frame[:ipHeaderLen]) + ip.Encode(uint16(ipPayloadLen), TCPProtocolNumber, ttl, src.Addr(), dst.Addr()) + } + encodeTCP(frame, ipHeaderLen, src, dst, packetInfo, payload) + return frame +} + +func encodeTCP(frame []byte, ipHeaderLen int, src, dst netip.AddrPort, packetInfo spoofPacketInfo, payload []byte) { + tcp := TCP(frame[ipHeaderLen:]) + copy(frame[ipHeaderLen+tcpHeaderLen:], packetInfo.options) + optionsLen := len(packetInfo.options) + copy(frame[ipHeaderLen+tcpHeaderLen+optionsLen:], payload) + tcp.Encode(src.Port(), dst.Port(), packetInfo.seqNum, packetInfo.ackNum, uint8(tcpHeaderLen+optionsLen), TCPFlagAck|TCPFlagPsh, defaultWindowSize) + applyTCPChecksum(tcp, src.Addr(), dst.Addr(), payload, packetInfo.corrupt) +} + +func buildSpoofFrame(method Method, src, dst netip.AddrPort, sendNext, receiveNext, timestamp uint32, tcpOptions, payload []byte, ttl uint8) ([]byte, error) { + packetInfo, err := resolveSpoofPacketInfo(method, sendNext, receiveNext, timestamp, tcpOptions, payload) + if err != nil { + return nil, err + } + return buildTCPSegment(src, dst, packetInfo, payload, ttl), nil +} + +// buildSpoofTCPSegment returns a TCP segment without an IP header, for +// platforms where the kernel synthesises the IP header (darwin IPv6). +func buildSpoofTCPSegment(method Method, src, dst netip.AddrPort, sendNext, receiveNext, timestamp uint32, payload []byte) ([]byte, error) { + packetInfo, err := resolveSpoofPacketInfo(method, sendNext, receiveNext, timestamp, nil, payload) + if err != nil { + return nil, err + } + segment := make([]byte, tcpHeaderLen+len(packetInfo.options)+len(payload)) + encodeTCP(segment, 0, src, dst, packetInfo, payload) + return segment, nil +} + +func resolveSpoofPacketInfo(method Method, sendNext, receiveNext, timestamp uint32, tcpOptions, payload []byte) (spoofPacketInfo, error) { + packetInfo := spoofPacketInfo{seqNum: sendNext, ackNum: receiveNext} + switch method { + case MethodWrongSequence: + packetInfo.seqNum = sendNext - uint32(len(payload)) + case MethodWrongChecksum: + packetInfo.corrupt = true + case MethodWrongAcknowledgment: + packetInfo.ackNum = receiveNext - uint32(defaultWindowSize/2) + case MethodWrongMD5Sig: + packetInfo.options = buildMD5SignatureOptions() + case MethodWrongTimestamp: + packetInfo.options = buildWrongTimestampOptions(timestamp, tcpOptions) + default: + return packetInfo, fmt.Errorf("rawpacket: unknown method %v", method) + } + return packetInfo, nil +} + +func buildMD5SignatureOptions() []byte { + options := make([]byte, tcpOptionMD5SignatureLength+2) + options[0] = tcpOptionMD5Signature + options[1] = tcpOptionMD5SignatureLength + return options +} + +func buildWrongTimestampOptions(timestamp uint32, tcpOptions []byte) []byte { + spoofedTimestamp := timestamp + if spoofedTimestamp > tcpTimestampBackdate { + spoofedTimestamp -= tcpTimestampBackdate + } else { + spoofedTimestamp = 0 + } + if rewriteTCPOptionTimestamp(tcpOptions, spoofedTimestamp) { + return tcpOptions + } + options := make([]byte, TCPOptionTSLength+2) + EncodeTSOption(spoofedTimestamp, 0, options) + return options +} + +// rewriteTCPOptionTimestamp finds the TS option in tcpOptions and writes +// timestamp into its TSVal field in place. The caller must own tcpOptions +// (parseTCPPacket already returns a private copy on Windows). +func rewriteTCPOptionTimestamp(tcpOptions []byte, timestamp uint32) bool { + for i := 0; i < len(tcpOptions); { + switch tcpOptions[i] { + case TCPOptionEOL: + return false + case TCPOptionNOP: + i++ + continue + } + if i+1 >= len(tcpOptions) { + return false + } + optionLen := int(tcpOptions[i+1]) + if optionLen < 2 || i+optionLen > len(tcpOptions) { + return false + } + if tcpOptions[i] == TCPOptionTS && optionLen == TCPOptionTSLength { + binary.BigEndian.PutUint32(tcpOptions[i+2:], timestamp) + return true + } + i += optionLen + } + return false +} + +func applyTCPChecksum(tcp TCP, srcAddr, dstAddr netip.Addr, payload []byte, corrupt bool) { + tcpLen := int(tcp.DataOffset()) + len(payload) + pseudo := PseudoHeaderChecksum(TCPProtocolNumber, srcAddr.AsSlice(), dstAddr.AsSlice(), uint16(tcpLen)) + payloadChecksum := Checksum(payload, 0) + tcpChecksum := ^tcp.CalculateChecksum(CombineChecksum(pseudo, payloadChecksum)) + if corrupt { + tcpChecksum ^= 0xFFFF + } + tcp.SetChecksum(tcpChecksum) +} diff --git a/transport/internet/finalmask/rawpacket/raw_darwin.go b/transport/internet/finalmask/rawpacket/raw_darwin.go new file mode 100644 index 000000000000..1b2335565ae2 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/raw_darwin.go @@ -0,0 +1,200 @@ +package rawpacket + +import ( + "encoding/binary" + "net" + "net/netip" + "strconv" + "strings" + "sync" + "syscall" + + "errors" + "fmt" + + "golang.org/x/sys/unix" +) + +const PlatformSupported = true + +// Offsets into xinpcb_n within each net.inet.tcp.pcblist_n record, identical +// to the values used by common/process/searcher_darwin_shared.go. +const ( + darwinXinpgenSize = 24 + darwinXsocketOffset = 104 + darwinXinpcbForeignPort = 16 + darwinXinpcbLocalPort = 18 + darwinXinpcbVFlag = 44 + darwinXinpcbForeignAddr = 48 + darwinXinpcbLocalAddr = 64 + darwinXinpcbIPv4Offset = 12 + + darwinTCPExtraSize = 208 + + darwinXtcpcbSndNxtOffset = 56 + darwinXtcpcbRcvNxtOffset = 80 +) + +// darwinStructSize returns the size of xinpcb_n for the running Darwin kernel. +// Darwin 22 (macOS 13 Ventura) grew the struct from 384 to 408 bytes; there is +// no ABI-stable way to read it, so we key off the kernel version. +var darwinStructSize = sync.OnceValues(func() (int, error) { + value, err := syscall.Sysctl("kern.osrelease") + if err != nil { + return 0, fmt.Errorf("sysctl kern.osrelease: %w", err) + } + major, _, ok := strings.Cut(value, ".") + if !ok { + return 0, fmt.Errorf("unexpected kern.osrelease format: %s", value) + } + n, err := strconv.ParseInt(major, 10, 64) + if err != nil { + return 0, fmt.Errorf("parse kern.osrelease major version: : %w", err) + } + if n >= 22 { + return 408, nil + } + return 384, nil +}) + +type darwinSpoofer struct { + method Method + src netip.AddrPort + dst netip.AddrPort + rawFD int + rawSockAddr unix.Sockaddr + sendNext uint32 + receiveNext uint32 + ttl uint8 +} + +func newRawSpoofer(conn net.Conn, method Method, ttl uint8) (rawSpoofer, error) { + if method == MethodWrongTimestamp { + return nil, errors.New("rawpacket: wrong-timestamp is not supported on macOS") + } + _, src, dst, err := tcpEndpoints(conn) + if err != nil { + return nil, err + } + fd, sockaddr, err := openDarwinRawSocket(src, dst) + if err != nil { + return nil, err + } + sendNext, receiveNext, err := readDarwinTCPSequence(src, dst) + if err != nil { + unix.Close(fd) + return nil, err + } + return &darwinSpoofer{ + method: method, + src: src, + dst: dst, + rawFD: fd, + rawSockAddr: sockaddr, + sendNext: sendNext, + receiveNext: receiveNext, + ttl: ttl, + }, nil +} + +// readDarwinTCPSequence scans net.inet.tcp.pcblist_n for the PCB that matches +// src -> dst and returns (snd_nxt, rcv_nxt). These live in xtcpcb_n at the end +// of each record; see darwin-xnu bsd/netinet/in_pcblist.c:get_pcblist_n. +func readDarwinTCPSequence(src, dst netip.AddrPort) (uint32, uint32, error) { + buffer, err := unix.SysctlRaw("net.inet.tcp.pcblist_n") + if err != nil { + return 0, 0, fmt.Errorf("sysctl net.inet.tcp.pcblist_n: %w", err) + } + structSize, err := darwinStructSize() + if err != nil { + return 0, 0, err + } + itemSize := structSize + darwinTCPExtraSize + for i := darwinXinpgenSize; i+itemSize <= len(buffer); i += itemSize { + inpcb := buffer[i : i+darwinXsocketOffset] + xtcpcb := buffer[i+structSize : i+itemSize] + localPort := binary.BigEndian.Uint16(inpcb[darwinXinpcbLocalPort : darwinXinpcbLocalPort+2]) + remotePort := binary.BigEndian.Uint16(inpcb[darwinXinpcbForeignPort : darwinXinpcbForeignPort+2]) + if localPort != src.Port() || remotePort != dst.Port() { + continue + } + versionFlag := inpcb[darwinXinpcbVFlag] + var localAddr, remoteAddr netip.Addr + switch { + case versionFlag&0x1 != 0: + localAddr = netip.AddrFrom4([4]byte(inpcb[darwinXinpcbLocalAddr+darwinXinpcbIPv4Offset : darwinXinpcbLocalAddr+darwinXinpcbIPv4Offset+4])) + remoteAddr = netip.AddrFrom4([4]byte(inpcb[darwinXinpcbForeignAddr+darwinXinpcbIPv4Offset : darwinXinpcbForeignAddr+darwinXinpcbIPv4Offset+4])) + case versionFlag&0x2 != 0: + localAddr = netip.AddrFrom16([16]byte(inpcb[darwinXinpcbLocalAddr : darwinXinpcbLocalAddr+16])) + remoteAddr = netip.AddrFrom16([16]byte(inpcb[darwinXinpcbForeignAddr : darwinXinpcbForeignAddr+16])) + default: + continue + } + if localAddr.Unmap() != src.Addr() || remoteAddr.Unmap() != dst.Addr() { + continue + } + sendNext := binary.NativeEndian.Uint32(xtcpcb[darwinXtcpcbSndNxtOffset : darwinXtcpcbSndNxtOffset+4]) + receiveNext := binary.NativeEndian.Uint32(xtcpcb[darwinXtcpcbRcvNxtOffset : darwinXtcpcbRcvNxtOffset+4]) + return sendNext, receiveNext, nil + } + return 0, 0, fmt.Errorf("rawpacket: connection %v->%v not found in pcblist_n", src, dst) +} + +func openDarwinRawSocket(src, dst netip.AddrPort) (int, unix.Sockaddr, error) { + if dst.Addr().Is4() { + return openIPv4RawSocket(dst) + } + // macOS does not accept IPV6_HDRINCL on AF_INET6 SOCK_RAW IPPROTO_TCP + // sockets, so the kernel builds the IPv6 header itself. Bind to the real + // connection's source address so in6_selectsrc returns it, and rely on + // in6p_cksum defaulting to -1 so the user-supplied TCP checksum is + // preserved (including deliberately corrupted ones). + fd, err := unix.Socket(unix.AF_INET6, unix.SOCK_RAW, unix.IPPROTO_TCP) + if err != nil { + return -1, nil, fmt.Errorf("open AF_INET6 SOCK_RAW: %w", err) + } + err = unix.Bind(fd, &unix.SockaddrInet6{Addr: src.Addr().As16()}) + if err != nil { + unix.Close(fd) + return -1, nil, fmt.Errorf("bind AF_INET6 SOCK_RAW: %w", err) + } + sockaddr := &unix.SockaddrInet6{Port: int(dst.Port()), Addr: dst.Addr().As16()} + return fd, sockaddr, nil +} + +func (s *darwinSpoofer) Inject(payload []byte) error { + if !s.src.Addr().Is4() { + segment, err := buildSpoofTCPSegment(s.method, s.src, s.dst, s.sendNext, s.receiveNext, 0, payload) + if err != nil { + return err + } + err = unix.Sendto(s.rawFD, segment, 0, s.rawSockAddr) + if err != nil { + return fmt.Errorf("sendto raw socket: %w", err) + } + return nil + } + frame, err := buildSpoofFrame(s.method, s.src, s.dst, s.sendNext, s.receiveNext, 0, nil, payload, s.ttl) + if err != nil { + return err + } + // Darwin inherits the historical BSD quirk: with IP_HDRINCL the kernel + // expects ip_len and ip_off in host byte order, not network byte order. + ip := IPv4(frame) + binary.NativeEndian.PutUint16(ip[2:4], ip.TotalLength()) + binary.NativeEndian.PutUint16(ip[6:8], uint16(ip.Flags())<<13|ip.FragmentOffset()) + err = unix.Sendto(s.rawFD, frame, 0, s.rawSockAddr) + if err != nil { + return fmt.Errorf("sendto raw socket: %w", err) + } + return nil +} + +func (s *darwinSpoofer) Close() error { + if s.rawFD < 0 { + return nil + } + err := unix.Close(s.rawFD) + s.rawFD = -1 + return err +} diff --git a/transport/internet/finalmask/rawpacket/raw_freebsd.go b/transport/internet/finalmask/rawpacket/raw_freebsd.go new file mode 100644 index 000000000000..b3d2e13492a8 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/raw_freebsd.go @@ -0,0 +1,174 @@ +package rawpacket + +import ( + "encoding/binary" + "errors" + "fmt" + "net" + "net/netip" + "syscall" + "unsafe" + + "golang.org/x/sys/unix" +) + +const PlatformSupported = true + +// FreeBSD tcp_info offsets for snd_nxt and rcv_nxt. +// Derived from FreeBSD sys/netinet/tcp.h struct tcp_info layout. +// +// struct tcp_info { +// u8 state, __ca, __retrans, __probes, __backoff, opts, wscale = 8 bytes (with pad) +// u32 rto, __ato, snd_mss, rcv_mss = 16 bytes (offset 8) +// u32 __unacked, __sacked, __lost, __retrans, __fackets = 20 bytes (offset 24) +// u32 __last_data_sent, __last_ack_sent, last_data_recv, __last_ack_recv = 16 bytes (offset 44) +// u32 __pmtu, __rcv_ssthresh, rtt, rttvar, snd_ssthresh, snd_cwnd, __advmss, __reordering = 32 bytes (offset 60) +// u32 __rcv_rtt, rcv_space = 8 bytes (offset 92) +// u32 snd_wnd, snd_bwnd = 8 bytes (offset 100) +// u32 snd_nxt, rcv_nxt = 8 bytes (offset 108) +// ... remaining fields +// } +const ( + freebsdTCPInfoSndNxtOffset = 108 + freebsdTCPInfoRcvNxtOffset = 112 + freebsdTCPInfoMinSize = 116 // must read at least through rcv_nxt +) + +type freebsdSpoofer struct { + method Method + src netip.AddrPort + dst netip.AddrPort + rawFD int + rawSockAddr unix.Sockaddr + sendNext uint32 + receiveNext uint32 + ttl uint8 +} + +func newRawSpoofer(conn net.Conn, method Method, ttl uint8) (rawSpoofer, error) { + if method == MethodWrongTimestamp { + return nil, errors.New("rawpacket: wrong-timestamp is not supported on FreeBSD") + } + tcpConn, src, dst, err := tcpEndpoints(conn) + if err != nil { + return nil, err + } + fd, sockaddr, err := openFreeBSDRawSocket(src, dst) + if err != nil { + return nil, err + } + sendNext, receiveNext, err := readFreeBSDTCPSequence(tcpConn) + if err != nil { + unix.Close(fd) + return nil, err + } + return &freebsdSpoofer{ + method: method, + src: src, + dst: dst, + rawFD: fd, + rawSockAddr: sockaddr, + sendNext: sendNext, + receiveNext: receiveNext, + ttl: ttl, + }, nil +} + +// readFreeBSDTCPSequence retrieves snd_nxt and rcv_nxt via TCP_INFO getsockopt. +func readFreeBSDTCPSequence(conn *net.TCPConn) (uint32, uint32, error) { + raw, err := conn.SyscallConn() + if err != nil { + return 0, 0, fmt.Errorf("rawpacket: SyscallConn: %w", err) + } + var sendNext, receiveNext uint32 + var sockErr error + err = raw.Control(func(fd uintptr) { + buf := make([]byte, 256) // generous buffer for tcp_info + bufLen := uint32(len(buf)) + _, _, errno := syscall.Syscall6( + syscall.SYS_GETSOCKOPT, + fd, + uintptr(syscall.IPPROTO_TCP), + uintptr(0x20), // TCP_INFO = 0x20 + uintptr(unsafe.Pointer(&buf[0])), + uintptr(unsafe.Pointer(&bufLen)), + 0, + ) + if errno != 0 { + sockErr = fmt.Errorf("rawpacket: getsockopt TCP_INFO: %w", errno) + return + } + if bufLen < freebsdTCPInfoMinSize { + sockErr = fmt.Errorf("rawpacket: TCP_INFO too short: %d < %d", bufLen, freebsdTCPInfoMinSize) + return + } + sendNext = binary.NativeEndian.Uint32(buf[freebsdTCPInfoSndNxtOffset : freebsdTCPInfoSndNxtOffset+4]) + receiveNext = binary.NativeEndian.Uint32(buf[freebsdTCPInfoRcvNxtOffset : freebsdTCPInfoRcvNxtOffset+4]) + }) + if err != nil { + return 0, 0, err + } + if sockErr != nil { + return 0, 0, sockErr + } + return sendNext, receiveNext, nil +} + +func openFreeBSDRawSocket(src, dst netip.AddrPort) (int, unix.Sockaddr, error) { + if dst.Addr().Is4() { + return openIPv4RawSocket(dst) + } + // FreeBSD, like macOS, does not support IPV6_HDRINCL on SOCK_RAW/IPPROTO_TCP. + // The kernel constructs the IPv6 header. Bind to the source address + // and let the kernel fill in the IPv6 header automatically. + fd, err := unix.Socket(unix.AF_INET6, unix.SOCK_RAW, unix.IPPROTO_TCP) + if err != nil { + return -1, nil, fmt.Errorf("rawpacket: open AF_INET6 SOCK_RAW: %w", err) + } + err = unix.Bind(fd, &unix.SockaddrInet6{Addr: src.Addr().As16()}) + if err != nil { + unix.Close(fd) + return -1, nil, fmt.Errorf("rawpacket: bind AF_INET6 SOCK_RAW: %w", err) + } + sockaddr := &unix.SockaddrInet6{Port: int(dst.Port()), Addr: dst.Addr().As16()} + return fd, sockaddr, nil +} + +func (s *freebsdSpoofer) Inject(payload []byte) error { + if !s.src.Addr().Is4() { + // IPv6: kernel builds the IP header, we supply TCP segment only. + segment, err := buildSpoofTCPSegment(s.method, s.src, s.dst, s.sendNext, s.receiveNext, 0, payload) + if err != nil { + return err + } + err = unix.Sendto(s.rawFD, segment, 0, s.rawSockAddr) + if err != nil { + return fmt.Errorf("rawpacket: sendto raw socket: %w", err) + } + return nil + } + // IPv4: we build the full IP+TCP frame with IP_HDRINCL. + frame, err := buildSpoofFrame(s.method, s.src, s.dst, s.sendNext, s.receiveNext, 0, nil, payload, s.ttl) + if err != nil { + return err + } + // FreeBSD inherits the historical BSD quirk: with IP_HDRINCL the kernel + // expects ip_len and ip_off in host byte order, not network byte order. + ip := IPv4(frame) + binary.NativeEndian.PutUint16(ip[2:4], ip.TotalLength()) + binary.NativeEndian.PutUint16(ip[6:8], uint16(ip.Flags())<<13|ip.FragmentOffset()) + err = unix.Sendto(s.rawFD, frame, 0, s.rawSockAddr) + if err != nil { + return fmt.Errorf("rawpacket: sendto raw socket: %w", err) + } + return nil +} + +func (s *freebsdSpoofer) Close() error { + if s.rawFD < 0 { + return nil + } + err := unix.Close(s.rawFD) + s.rawFD = -1 + return err +} diff --git a/transport/internet/finalmask/rawpacket/raw_linux.go b/transport/internet/finalmask/rawpacket/raw_linux.go new file mode 100644 index 000000000000..1de3ff862839 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/raw_linux.go @@ -0,0 +1,168 @@ +package rawpacket + +import ( + "fmt" + "net" + "net/netip" + + "golang.org/x/sys/unix" +) + +const PlatformSupported = true + +const ( + // Values of enum { TCP_NO_QUEUE, TCP_RECV_QUEUE, TCP_SEND_QUEUE } from + // include/net/tcp.h; not exported by golang.org/x/sys/unix. + tcpRecvQueue = 1 + tcpSendQueue = 2 +) + +type linuxSpoofer struct { + method Method + src netip.AddrPort + dst netip.AddrPort + rawFD int + rawSockAddr unix.Sockaddr + sendNext uint32 + receiveNext uint32 + timestamp uint32 + ttl uint8 +} + +func newRawSpoofer(conn net.Conn, method Method, ttl uint8) (rawSpoofer, error) { + tcpConn, src, dst, err := tcpEndpoints(conn) + if err != nil { + return nil, err + } + fd, sockaddr, err := openLinuxRawSocket(dst) + if err != nil { + return nil, err + } + spoofer := &linuxSpoofer{ + method: method, + src: src, + dst: dst, + rawFD: fd, + rawSockAddr: sockaddr, + ttl: ttl, + } + err = spoofer.loadSequenceNumbers(tcpConn) + if err != nil { + unix.Close(fd) + return nil, err + } + return spoofer, nil +} + +func openLinuxRawSocket(dst netip.AddrPort) (int, unix.Sockaddr, error) { + if dst.Addr().Is4() { + return openIPv4RawSocket(dst) + } + fd, err := unix.Socket(unix.AF_INET6, unix.SOCK_RAW, unix.IPPROTO_TCP) + if err != nil { + return -1, nil, fmt.Errorf("open AF_INET6 SOCK_RAW: %w", err) + } + err = unix.SetsockoptInt(fd, unix.IPPROTO_IPV6, unix.IPV6_HDRINCL, 1) + if err != nil { + unix.Close(fd) + return -1, nil, fmt.Errorf("set IPV6_HDRINCL: %w", err) + } + // Linux raw IPv6 sockets interpret sin6_port as a nexthdr protocol number + // (see raw(7)); any value other than 0 or the socket's IPPROTO_TCP causes + // sendto to fail with EINVAL. The destination is already encoded in the + // user-supplied IPv6 header under IPV6_HDRINCL. + sockaddr := &unix.SockaddrInet6{Addr: dst.Addr().As16()} + return fd, sockaddr, nil +} + +// loadSequenceNumbers puts the socket briefly into TCP_REPAIR mode to read +// snd_nxt and rcv_nxt from the kernel. TCP_REPAIR requires CAP_NET_ADMIN; +// callers must run as root or grant both CAP_NET_RAW and CAP_NET_ADMIN. +// +// If the TCP_REPAIR_OFF revert fails, the socket would stay in TCP_REPAIR +// state and subsequent Write() calls would silently buffer instead of sending. +// Surface that error so callers can abort. +func (s *linuxSpoofer) loadSequenceNumbers(tcpConn *net.TCPConn) error { + rawConn, err := tcpConn.SyscallConn() + if err != nil { + return err + } + var ctrlErr error + err = rawConn.Control(func(raw uintptr) { + fd := int(raw) + + if s.method == MethodWrongTimestamp { + timestamp, tsErr := unix.GetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_TIMESTAMP) + if tsErr != nil { + ctrlErr = fmt.Errorf("rawpacket: read timestamp: %w", tsErr) + return + } + s.timestamp = uint32(timestamp) + } + + ctrlErr = unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_REPAIR, unix.TCP_REPAIR_ON) + if ctrlErr != nil { + ctrlErr = fmt.Errorf("rawpacket: enter TCP_REPAIR (need CAP_NET_ADMIN): %w", ctrlErr) + return + } + defer func() { + offErr := unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_REPAIR, unix.TCP_REPAIR_OFF) + if offErr != nil { + offErr = fmt.Errorf("rawpacket: leave TCP_REPAIR: %w", offErr) + if ctrlErr == nil { + ctrlErr = offErr + } else { + ctrlErr = fmt.Errorf("%v; also %w", ctrlErr, offErr) + } + } + }() + + ctrlErr = unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_REPAIR_QUEUE, tcpSendQueue) + if ctrlErr != nil { + ctrlErr = fmt.Errorf("rawpacket: select TCP_SEND_QUEUE: %w", ctrlErr) + return + } + sendSequence, seqErr := unix.GetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_QUEUE_SEQ) + if seqErr != nil { + ctrlErr = fmt.Errorf("rawpacket: read send queue sequence: %w", seqErr) + return + } + ctrlErr = unix.SetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_REPAIR_QUEUE, tcpRecvQueue) + if ctrlErr != nil { + ctrlErr = fmt.Errorf("rawpacket: select TCP_RECV_QUEUE: %w", ctrlErr) + return + } + receiveSequence, seqErr := unix.GetsockoptInt(fd, unix.IPPROTO_TCP, unix.TCP_QUEUE_SEQ) + if seqErr != nil { + ctrlErr = fmt.Errorf("rawpacket: read recv queue sequence: %w", seqErr) + return + } + s.sendNext = uint32(sendSequence) + s.receiveNext = uint32(receiveSequence) + }) + if err != nil { + return err + } + return ctrlErr +} + +func (s *linuxSpoofer) Inject(payload []byte) error { + frame, err := buildSpoofFrame(s.method, s.src, s.dst, s.sendNext, s.receiveNext, s.timestamp, nil, payload, s.ttl) + if err != nil { + return err + } + err = unix.Sendto(s.rawFD, frame, 0, s.rawSockAddr) + if err != nil { + return fmt.Errorf("sendto raw socket: %w", err) + } + return nil +} + +func (s *linuxSpoofer) Close() error { + if s.rawFD < 0 { + return nil + } + err := unix.Close(s.rawFD) + s.rawFD = -1 + return err +} diff --git a/transport/internet/finalmask/rawpacket/raw_stub.go b/transport/internet/finalmask/rawpacket/raw_stub.go new file mode 100644 index 000000000000..c06a40f48bb2 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/raw_stub.go @@ -0,0 +1,15 @@ +//go:build !linux && !darwin && !freebsd && !(windows && (amd64 || 386)) + +package rawpacket + +import ( + "net" + + "errors" +) + +const PlatformSupported = false + +func newRawSpoofer(conn net.Conn, method Method, ttl uint8) (rawSpoofer, error) { + return nil, errors.New("rawpacket: unsupported platform") +} diff --git a/transport/internet/finalmask/rawpacket/raw_unix.go b/transport/internet/finalmask/rawpacket/raw_unix.go new file mode 100644 index 000000000000..bccd0fefe0de --- /dev/null +++ b/transport/internet/finalmask/rawpacket/raw_unix.go @@ -0,0 +1,25 @@ +//go:build linux || darwin || freebsd + +package rawpacket + +import ( + "fmt" + "net/netip" + + "golang.org/x/sys/unix" +) + +func openIPv4RawSocket(dst netip.AddrPort) (int, unix.Sockaddr, error) { + fd, err := unix.Socket(unix.AF_INET, unix.SOCK_RAW, unix.IPPROTO_TCP) + if err != nil { + return -1, nil, fmt.Errorf("open AF_INET SOCK_RAW: %w", err) + } + err = unix.SetsockoptInt(fd, unix.IPPROTO_IP, unix.IP_HDRINCL, 1) + if err != nil { + unix.Close(fd) + return -1, nil, fmt.Errorf("set IP_HDRINCL: %w", err) + } + sockaddr := &unix.SockaddrInet4{Port: int(dst.Port())} + sockaddr.Addr = dst.Addr().As4() + return fd, sockaddr, nil +} diff --git a/transport/internet/finalmask/rawpacket/raw_windows.go b/transport/internet/finalmask/rawpacket/raw_windows.go new file mode 100644 index 000000000000..acfed30ff0c8 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/raw_windows.go @@ -0,0 +1,236 @@ +//go:build windows && (amd64 || 386) + +package rawpacket + +import ( + "errors" + "net" + "net/netip" + "slices" + "sync" + "sync/atomic" + "time" + + "github.com/xtls/xray-core/transport/internet/finalmask/rawpacket/windivert" + "golang.org/x/sys/windows" +) + +const PlatformSupported = true + +// closeGracePeriod caps how long Close() waits for the divert goroutine to +// observe the kernel-emitted real ClientHello and perform the reorder +// (fake → real). In practice this completes in microseconds; the cap +// bounds the pathological case where the kernel buffers the packet. +const closeGracePeriod = 2 * time.Second + +// windowsSpoofer uses a single WinDivert handle for both capture and +// injection. Sequential Send() calls on one handle traverse one driver queue, +// so the fake provably precedes the released real on the wire — a guarantee +// two separate handles cannot make because cross-handle order depends on the +// scheduler. +type windowsSpoofer struct { + method Method + src, dst netip.AddrPort + divertH *windivert.Handle + ttl uint8 + + fakeReady chan []byte // buffered(1): staged by Inject + done chan struct{} // closed by run() on exit + closeOnce sync.Once + runErr atomic.Pointer[error] +} + +func newRawSpoofer(conn net.Conn, method Method, ttl uint8) (rawSpoofer, error) { + _, src, dst, err := tcpEndpoints(conn) + if err != nil { + return nil, err + } + filter, err := windivert.OutboundTCP(src, dst) + if err != nil { + return nil, err + } + divertH, err := windivert.Open(filter, windivert.LayerNetwork, 0, 0) + if err != nil { + return nil, err + } + s := &windowsSpoofer{ + method: method, + src: src, + dst: dst, + divertH: divertH, + ttl: ttl, + fakeReady: make(chan []byte, 1), + done: make(chan struct{}), + } + go s.run() + return s, nil +} + +func (s *windowsSpoofer) Inject(payload []byte) error { + select { + case s.fakeReady <- payload: + return nil + case <-s.done: + if p := s.runErr.Load(); p != nil { + return *p + } + return errors.New("rawpacket: spoofer closed before Inject") + } +} + +func (s *windowsSpoofer) Close() error { + s.closeOnce.Do(func() { + // Give run() a grace window to finish handling the real packet. + select { + case <-s.done: + case <-time.After(closeGracePeriod): + // Force Recv() to return by closing the divert handle. + s.divertH.Close() + <-s.done + } + }) + if p := s.runErr.Load(); p != nil { + return *p + } + return nil +} + +func (s *windowsSpoofer) recordErr(err error) { s.runErr.Store(&err) } + +func (s *windowsSpoofer) run() { + defer close(s.done) + defer s.divertH.Close() + + buf := make([]byte, windivert.MTUMax) + for { + n, addr, err := s.divertH.Recv(buf) + if err != nil { + if errors.Is(err, windows.ERROR_OPERATION_ABORTED) || + errors.Is(err, windows.ERROR_NO_DATA) { + return + } + s.recordErr(err) + return + } + pkt := buf[:n] + seq, ack, tcpOptions, payloadLen, ok := parseTCPPacket(pkt, addr.IPv6()) + if !ok { + // Our filter is OutboundTCP(src, dst); a non-TCP or truncated + // match means driver state is suspect. Re-inject so the kernel + // still sees the byte stream, then abort — continuing would risk + // reordering against an unknown reference point. + _, sendErr := s.divertH.Send(pkt, &addr) + if sendErr != nil { + s.recordErr(sendErr) + return + } + s.recordErr(errors.New("windivert received malformed packet matching spoof filter")) + return + } + if payloadLen == 0 { + // Handshake ACK, keepalive, FIN — pass through unchanged. + _, err := s.divertH.Send(pkt, &addr) + if err != nil { + s.recordErr(err) + return + } + continue + } + + // Non-empty outbound TCP payload = the real ClientHello. + var fake []byte + select { + case fake = <-s.fakeReady: + default: + // Inject() not yet called — pass through and keep observing. + _, err := s.divertH.Send(pkt, &addr) + if err != nil { + s.recordErr(err) + return + } + continue + } + + var timestamp uint32 + if tsVal, hasTS := ParseTCPOptions(tcpOptions); hasTS { + timestamp = tsVal + } + frame, err := buildSpoofFrame(s.method, s.src, s.dst, seq, ack, timestamp, tcpOptions, fake, s.ttl) + if err != nil { + s.recordErr(err) + return + } + fakeAddr := addr // inherit Outbound, IfIdx + // buildSpoofFrame emits ready-to-wire bytes. The driver recomputes + // checksums on Send when TCPChecksum/IPChecksum are 0 — which would + // overwrite the intentionally corrupt checksum in WrongChecksum mode. + // Force both to 1 to keep our bytes intact. + fakeAddr.SetIPChecksum(true) + fakeAddr.SetTCPChecksum(true) + _, err = s.divertH.Send(frame, &fakeAddr) + if err != nil { + s.recordErr(err) + return + } + _, err = s.divertH.Send(pkt, &addr) + if err != nil { + s.recordErr(err) + return + } + return // single-shot reorder complete + } +} + +func parseTCPPacket(pkt []byte, isV6 bool) (seq, ack uint32, options []byte, payloadLen int, ok bool) { + if isV6 { + if len(pkt) < IPv6MinimumSize+TCPMinimumSize { + return 0, 0, nil, 0, false + } + ip := IPv6(pkt) + if ip.TransportProtocol() != TCPProtocolNumber { + return 0, 0, nil, 0, false + } + tcp := TCP(pkt[IPv6MinimumSize:]) + tcpHdr := int(tcp.DataOffset()) + if tcpHdr < TCPMinimumSize || IPv6MinimumSize+tcpHdr > len(pkt) { + return 0, 0, nil, 0, false + } + total := IPv6MinimumSize + int(ip.PayloadLength()) + if total == IPv6MinimumSize || total > len(pkt) { + total = len(pkt) + } + if total < IPv6MinimumSize+tcpHdr { + return 0, 0, nil, 0, false + } + return tcp.SequenceNumber(), tcp.AckNumber(), slices.Clone(tcp.Options()), + total - IPv6MinimumSize - tcpHdr, true + } + if len(pkt) < IPv4MinimumSize+TCPMinimumSize { + return 0, 0, nil, 0, false + } + ip := IPv4(pkt) + if ip.Protocol() != TCPProtocolNumber { + return 0, 0, nil, 0, false + } + ihl := int(ip.HeaderLength()) + // ihl+TCPMinimumSize guards the TCP-header field reads below; without + // this, an IPv4 packet with options (ihl>20) against a 40-byte buffer + // reads past the TCP slice when calling DataOffset. + if ihl < IPv4MinimumSize || ihl+TCPMinimumSize > len(pkt) { + return 0, 0, nil, 0, false + } + tcp := TCP(pkt[ihl:]) + tcpHdr := int(tcp.DataOffset()) + if tcpHdr < TCPMinimumSize || ihl+tcpHdr > len(pkt) { + return 0, 0, nil, 0, false + } + total := int(ip.TotalLength()) + if total == 0 || total > len(pkt) { + total = len(pkt) + } + if total < ihl+tcpHdr { + return 0, 0, nil, 0, false + } + return tcp.SequenceNumber(), tcp.AckNumber(), slices.Clone(tcp.Options()), + total - ihl - tcpHdr, true +} diff --git a/transport/internet/finalmask/rawpacket/tcpip.go b/transport/internet/finalmask/rawpacket/tcpip.go new file mode 100644 index 000000000000..8814422e35ed --- /dev/null +++ b/transport/internet/finalmask/rawpacket/tcpip.go @@ -0,0 +1,155 @@ +package rawpacket + +import ( + "encoding/binary" + "net/netip" +) + +const ( + IPv4MinimumSize = 20 + IPv6MinimumSize = 40 + TCPMinimumSize = 20 + TCPProtocolNumber = 6 + + TCPOptionEOL = 0 + TCPOptionNOP = 1 + TCPOptionTS = 8 + TCPOptionTSLength = 10 + + TCPFlagFin = 0x01 + TCPFlagSyn = 0x02 + TCPFlagRst = 0x04 + TCPFlagPsh = 0x08 + TCPFlagAck = 0x10 +) + +func Checksum(data []byte, initial uint16) uint16 { + var csum uint32 = uint32(initial) + for i := 0; i < len(data)-1; i += 2 { + csum += uint32(binary.BigEndian.Uint16(data[i:])) + } + if len(data)%2 == 1 { + csum += uint32(data[len(data)-1]) << 8 + } + for csum > 0xffff { + csum = (csum >> 16) + (csum & 0xffff) + } + return uint16(csum) +} + +func PseudoHeaderChecksum(protocol uint8, srcAddr, dstAddr []byte, totalLen uint16) uint16 { + var csum uint32 + for i := 0; i < len(srcAddr); i += 2 { + csum += uint32(binary.BigEndian.Uint16(srcAddr[i:])) + } + for i := 0; i < len(dstAddr); i += 2 { + csum += uint32(binary.BigEndian.Uint16(dstAddr[i:])) + } + csum += uint32(protocol) + csum += uint32(totalLen) + for csum > 0xffff { + csum = (csum >> 16) + (csum & 0xffff) + } + return uint16(csum) +} + +func CombineChecksum(c1, c2 uint16) uint16 { + csum := uint32(c1) + uint32(c2) + for csum > 0xffff { + csum = (csum >> 16) + (csum & 0xffff) + } + return uint16(csum) +} + +func EncodeTSOption(val uint32, ecr uint32, b []byte) { + b[0] = TCPOptionTS + b[1] = TCPOptionTSLength + binary.BigEndian.PutUint32(b[2:], val) + binary.BigEndian.PutUint32(b[6:], ecr) +} + +func ParseTCPOptions(b []byte) (tsVal uint32, hasTS bool) { + for i := 0; i < len(b); { + if b[i] == TCPOptionEOL { + break + } + if b[i] == TCPOptionNOP { + i++ + continue + } + if i+1 >= len(b) { + break + } + optLen := int(b[i+1]) + if optLen < 2 || i+optLen > len(b) { + break + } + if b[i] == TCPOptionTS && optLen == TCPOptionTSLength { + return binary.BigEndian.Uint32(b[i+2:]), true + } + i += optLen + } + return 0, false +} + +// IPv4 header representation +type IPv4 []byte + +func (b IPv4) TotalLength() uint16 { return binary.BigEndian.Uint16(b[2:]) } +func (b IPv4) Flags() uint8 { return uint8(binary.BigEndian.Uint16(b[6:]) >> 13) } +func (b IPv4) FragmentOffset() uint16 { return binary.BigEndian.Uint16(b[6:]) & 0x1fff } +func (b IPv4) Protocol() uint8 { return b[9] } +func (b IPv4) HeaderLength() uint8 { return (b[0] & 0x0f) * 4 } + +func (b IPv4) Encode(totalLength uint16, id uint16, ttl uint8, protocol uint8, src, dst netip.Addr) { + b[0] = (4 << 4) | 5 // IPv4, Header Length = 20 + b[1] = 0 // TOS + binary.BigEndian.PutUint16(b[2:], totalLength) + binary.BigEndian.PutUint16(b[4:], id) + binary.BigEndian.PutUint16(b[6:], 0) // Flags and Fragment Offset + b[8] = ttl + b[9] = protocol + b[10] = 0 // Checksum (0 for calculation) + copy(b[12:16], src.AsSlice()) + copy(b[16:20], dst.AsSlice()) + csum := Checksum(b[:20], 0) + binary.BigEndian.PutUint16(b[10:], ^csum) +} + +type IPv6 []byte + +func (b IPv6) PayloadLength() uint16 { return binary.BigEndian.Uint16(b[4:]) } +func (b IPv6) TransportProtocol() uint8 { return b[6] } + +func (b IPv6) Encode(payloadLength uint16, transportProtocol uint8, hopLimit uint8, src, dst netip.Addr) { + binary.BigEndian.PutUint32(b[0:], 6<<28) // Version 6, Traffic Class 0, Flow Label 0 + binary.BigEndian.PutUint16(b[4:], payloadLength) + b[6] = transportProtocol + b[7] = hopLimit + copy(b[8:24], src.AsSlice()) + copy(b[24:40], dst.AsSlice()) +} + +type TCP []byte + +func (b TCP) DataOffset() uint8 { return (b[12] >> 4) * 4 } +func (b TCP) SequenceNumber() uint32 { return binary.BigEndian.Uint32(b[4:]) } +func (b TCP) AckNumber() uint32 { return binary.BigEndian.Uint32(b[8:]) } +func (b TCP) Options() []byte { return b[TCPMinimumSize:b.DataOffset()] } +func (b TCP) SetChecksum(csum uint16) { binary.BigEndian.PutUint16(b[16:], csum) } + +func (b TCP) Encode(srcPort, dstPort uint16, seqNum, ackNum uint32, dataOffset uint8, flags uint8, windowSize uint16) { + binary.BigEndian.PutUint16(b[0:], srcPort) + binary.BigEndian.PutUint16(b[2:], dstPort) + binary.BigEndian.PutUint32(b[4:], seqNum) + binary.BigEndian.PutUint32(b[8:], ackNum) + b[12] = (dataOffset / 4) << 4 + b[13] = flags + binary.BigEndian.PutUint16(b[14:], windowSize) + b[16] = 0 // Checksum + binary.BigEndian.PutUint16(b[18:], 0) // Urgent pointer +} + +func (b TCP) CalculateChecksum(initial uint16) uint16 { + return Checksum(b, initial) +} diff --git a/transport/internet/finalmask/rawpacket/windivert/assets/LICENSE.txt b/transport/internet/finalmask/rawpacket/windivert/assets/LICENSE.txt new file mode 100644 index 000000000000..8489a8e773c3 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/windivert/assets/LICENSE.txt @@ -0,0 +1,1191 @@ +WinDivert is dual-licensed under your choice of the GNU Lesser General Public +License (LGPL) Version 3 or the GNU General Public License (GPL) Version 2. +Copies of the LGPLv3, GPLv3 and GPLv2 are provided below. + +============================================================================== + + GNU LESSER GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + + This version of the GNU Lesser General Public License incorporates +the terms and conditions of version 3 of the GNU General Public +License, supplemented by the additional permissions listed below. + + 0. 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You may copy and distribute verbatim copies of the Program's +source code as you receive it, in any medium, provided that you +conspicuously and appropriately publish on each copy an appropriate +copyright notice and disclaimer of warranty; keep intact all the +notices that refer to this License and to the absence of any warranty; +and give any other recipients of the Program a copy of this License +along with the Program. + +You may charge a fee for the physical act of transferring a copy, and +you may at your option offer warranty protection in exchange for a fee. + + 2. You may modify your copy or copies of the Program or any portion +of it, thus forming a work based on the Program, and copy and +distribute such modifications or work under the terms of Section 1 +above, provided that you also meet all of these conditions: + + a) You must cause the modified files to carry prominent notices + stating that you changed the files and the date of any change. + + b) You must cause any work that you distribute or publish, that in + whole or in part contains or is derived from the Program or any + part thereof, to be licensed as a whole at no charge to all third + parties under the terms of this License. + + c) If the modified program normally reads commands interactively + when run, you must cause it, when started running for such + interactive use in the most ordinary way, to print or display an + announcement including an appropriate copyright notice and a + notice that there is no warranty (or else, saying that you provide + a warranty) and that users may redistribute the program under + these conditions, and telling the user how to view a copy of this + License. (Exception: if the Program itself is interactive but + does not normally print such an announcement, your work based on + the Program is not required to print an announcement.) + +These requirements apply to the modified work as a whole. If +identifiable sections of that work are not derived from the Program, +and can be reasonably considered independent and separate works in +themselves, then this License, and its terms, do not apply to those +sections when you distribute them as separate works. But when you +distribute the same sections as part of a whole which is a work based +on the Program, the distribution of the whole must be on the terms of +this License, whose permissions for other licensees extend to the +entire whole, and thus to each and every part regardless of who wrote it. + +Thus, it is not the intent of this section to claim rights or contest +your rights to work written entirely by you; rather, the intent is to +exercise the right to control the distribution of derivative or +collective works based on the Program. + +In addition, mere aggregation of another work not based on the Program +with the Program (or with a work based on the Program) on a volume of +a storage or distribution medium does not bring the other work under +the scope of this License. + + 3. You may copy and distribute the Program (or a work based on it, +under Section 2) in object code or executable form under the terms of +Sections 1 and 2 above provided that you also do one of the following: + + a) Accompany it with the complete corresponding machine-readable + source code, which must be distributed under the terms of Sections + 1 and 2 above on a medium customarily used for software interchange; or, + + b) Accompany it with a written offer, valid for at least three + years, to give any third party, for a charge no more than your + cost of physically performing source distribution, a complete + machine-readable copy of the corresponding source code, to be + distributed under the terms of Sections 1 and 2 above on a medium + customarily used for software interchange; or, + + c) Accompany it with the information you received as to the offer + to distribute corresponding source code. (This alternative is + allowed only for noncommercial distribution and only if you + received the program in object code or executable form with such + an offer, in accord with Subsection b above.) + +The source code for a work means the preferred form of the work for +making modifications to it. For an executable work, complete source +code means all the source code for all modules it contains, plus any +associated interface definition files, plus the scripts used to +control compilation and installation of the executable. However, as a +special exception, the source code distributed need not include +anything that is normally distributed (in either source or binary +form) with the major components (compiler, kernel, and so on) of the +operating system on which the executable runs, unless that component +itself accompanies the executable. + +If distribution of executable or object code is made by offering +access to copy from a designated place, then offering equivalent +access to copy the source code from the same place counts as +distribution of the source code, even though third parties are not +compelled to copy the source along with the object code. + + 4. You may not copy, modify, sublicense, or distribute the Program +except as expressly provided under this License. Any attempt +otherwise to copy, modify, sublicense or distribute the Program is +void, and will automatically terminate your rights under this License. +However, parties who have received copies, or rights, from you under +this License will not have their licenses terminated so long as such +parties remain in full compliance. + + 5. You are not required to accept this License, since you have not +signed it. However, nothing else grants you permission to modify or +distribute the Program or its derivative works. These actions are +prohibited by law if you do not accept this License. Therefore, by +modifying or distributing the Program (or any work based on the +Program), you indicate your acceptance of this License to do so, and +all its terms and conditions for copying, distributing or modifying +the Program or works based on it. + + 6. Each time you redistribute the Program (or any work based on the +Program), the recipient automatically receives a license from the +original licensor to copy, distribute or modify the Program subject to +these terms and conditions. You may not impose any further +restrictions on the recipients' exercise of the rights granted herein. +You are not responsible for enforcing compliance by third parties to +this License. + + 7. If, as a consequence of a court judgment or allegation of patent +infringement or for any other reason (not limited to patent issues), +conditions are imposed on you (whether by court order, agreement or +otherwise) that contradict the conditions of this License, they do not +excuse you from the conditions of this License. If you cannot +distribute so as to satisfy simultaneously your obligations under this +License and any other pertinent obligations, then as a consequence you +may not distribute the Program at all. For example, if a patent +license would not permit royalty-free redistribution of the Program by +all those who receive copies directly or indirectly through you, then +the only way you could satisfy both it and this License would be to +refrain entirely from distribution of the Program. + +If any portion of this section is held invalid or unenforceable under +any particular circumstance, the balance of the section is intended to +apply and the section as a whole is intended to apply in other +circumstances. + +It is not the purpose of this section to induce you to infringe any +patents or other property right claims or to contest validity of any +such claims; this section has the sole purpose of protecting the +integrity of the free software distribution system, which is +implemented by public license practices. Many people have made +generous contributions to the wide range of software distributed +through that system in reliance on consistent application of that +system; it is up to the author/donor to decide if he or she is willing +to distribute software through any other system and a licensee cannot +impose that choice. + +This section is intended to make thoroughly clear what is believed to +be a consequence of the rest of this License. + + 8. If the distribution and/or use of the Program is restricted in +certain countries either by patents or by copyrighted interfaces, the +original copyright holder who places the Program under this License +may add an explicit geographical distribution limitation excluding +those countries, so that distribution is permitted only in or among +countries not thus excluded. In such case, this License incorporates +the limitation as if written in the body of this License. + + 9. The Free Software Foundation may publish revised and/or new versions +of the General Public License from time to time. Such new versions will +be similar in spirit to the present version, but may differ in detail to +address new problems or concerns. + +Each version is given a distinguishing version number. If the Program +specifies a version number of this License which applies to it and "any +later version", you have the option of following the terms and conditions +either of that version or of any later version published by the Free +Software Foundation. If the Program does not specify a version number of +this License, you may choose any version ever published by the Free Software +Foundation. + + 10. If you wish to incorporate parts of the Program into other free +programs whose distribution conditions are different, write to the author +to ask for permission. For software which is copyrighted by the Free +Software Foundation, write to the Free Software Foundation; we sometimes +make exceptions for this. Our decision will be guided by the two goals +of preserving the free status of all derivatives of our free software and +of promoting the sharing and reuse of software generally. + + NO WARRANTY + + 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY +FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN +OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES +PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED +OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF +MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS +TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE +PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, +REPAIR OR CORRECTION. + + 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING +WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR +REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, +INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING +OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED +TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY +YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER +PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE +POSSIBILITY OF SUCH DAMAGES. + + END OF TERMS AND CONDITIONS + + How to Apply These Terms to Your New Programs + + If you develop a new program, and you want it to be of the greatest +possible use to the public, the best way to achieve this is to make it +free software which everyone can redistribute and change under these terms. + + To do so, attach the following notices to the program. It is safest +to attach them to the start of each source file to most effectively +convey the exclusion of warranty; and each file should have at least +the "copyright" line and a pointer to where the full notice is found. + + + Copyright (C) + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License along + with this program; if not, write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + +Also add information on how to contact you by electronic and paper mail. + +If the program is interactive, make it output a short notice like this +when it starts in an interactive mode: + + Gnomovision version 69, Copyright (C) year name of author + Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, the commands you use may +be called something other than `show w' and `show c'; they could even be +mouse-clicks or menu items--whatever suits your program. + +You should also get your employer (if you work as a programmer) or your +school, if any, to sign a "copyright disclaimer" for the program, if +necessary. Here is a sample; alter the names: + + Yoyodyne, Inc., hereby disclaims all copyright interest in the program + `Gnomovision' (which makes passes at compilers) written by James Hacker. + + , 1 April 1989 + Ty Coon, President of Vice + +This General Public License does not permit incorporating your program into +proprietary programs. If your program is a subroutine library, you may +consider it more useful to permit linking proprietary applications with the +library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. + diff --git a/transport/internet/finalmask/rawpacket/windivert/assets/WinDivert32.sys b/transport/internet/finalmask/rawpacket/windivert/assets/WinDivert32.sys new file mode 100644 index 000000000000..d06738cbb783 Binary files /dev/null and b/transport/internet/finalmask/rawpacket/windivert/assets/WinDivert32.sys differ diff --git a/transport/internet/finalmask/rawpacket/windivert/assets/WinDivert64.sys b/transport/internet/finalmask/rawpacket/windivert/assets/WinDivert64.sys new file mode 100644 index 000000000000..218ccaf423ef Binary files /dev/null and b/transport/internet/finalmask/rawpacket/windivert/assets/WinDivert64.sys differ diff --git a/transport/internet/finalmask/rawpacket/windivert/assets_386.go b/transport/internet/finalmask/rawpacket/windivert/assets_386.go new file mode 100644 index 000000000000..0cbf35ed5cbf --- /dev/null +++ b/transport/internet/finalmask/rawpacket/windivert/assets_386.go @@ -0,0 +1,14 @@ +//go:build windows && 386 + +package windivert + +import _ "embed" + +//go:embed assets/WinDivert32.sys +var sysBytes []byte + +func assetFiles() []assetFile { + return []assetFile{{"WinDivert32.sys", sysBytes}} +} + +func driverSysName() string { return "WinDivert32.sys" } diff --git a/transport/internet/finalmask/rawpacket/windivert/assets_amd64.go b/transport/internet/finalmask/rawpacket/windivert/assets_amd64.go new file mode 100644 index 000000000000..2c9fb6c6ad19 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/windivert/assets_amd64.go @@ -0,0 +1,14 @@ +//go:build windows && amd64 + +package windivert + +import _ "embed" + +//go:embed assets/WinDivert64.sys +var sysBytes []byte + +func assetFiles() []assetFile { + return []assetFile{{"WinDivert64.sys", sysBytes}} +} + +func driverSysName() string { return "WinDivert64.sys" } diff --git a/transport/internet/finalmask/rawpacket/windivert/assets_unsupported.go b/transport/internet/finalmask/rawpacket/windivert/assets_unsupported.go new file mode 100644 index 000000000000..04698953fa6b --- /dev/null +++ b/transport/internet/finalmask/rawpacket/windivert/assets_unsupported.go @@ -0,0 +1,7 @@ +//go:build windows && !amd64 && !386 + +package windivert + +func assetFiles() []assetFile { return nil } + +func driverSysName() string { return "" } diff --git a/transport/internet/finalmask/rawpacket/windivert/driver_windows.go b/transport/internet/finalmask/rawpacket/windivert/driver_windows.go new file mode 100644 index 000000000000..50e94c578422 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/windivert/driver_windows.go @@ -0,0 +1,211 @@ +//go:build windows + +package windivert + +import ( + "errors" + "fmt" + "os" + "path/filepath" + "runtime" + "strconv" + "sync" + + "golang.org/x/sys/windows" +) + +const ( + driverServiceName = "WinDivert" + driverDeviceName = `\\.\WinDivert` +) + +var ( + driverOnce sync.Once + driverErr error + // driverDevName is ASCII-safe and must be available before ensureDriver + // so Open can try CreateFile first and only install on FILE_NOT_FOUND. + driverDevName, _ = windows.UTF16PtrFromString(driverDeviceName) +) + +// Requires SeLoadDriverPrivilege (Administrator). Running the 386 build +// under WOW64 on a 64-bit kernel is rejected — use the amd64 build. +func ensureDriver() error { + driverOnce.Do(func() { + driverErr = installDriver() + }) + return driverErr +} + +func installDriver() error { + if runtime.GOARCH == "386" { + var isWow64 bool + err := windows.IsWow64Process(windows.CurrentProcess(), &isWow64) + if err == nil && isWow64 { + return errors.New("windivert: 386 build detected running under WOW64 on a 64-bit kernel; use the amd64 build") + } + } + + dir, err := ensureExtracted() + if err != nil { + return err + } + sysPath := filepath.Join(dir, driverSysName()) + sysPathW, err := windows.UTF16PtrFromString(sysPath) + if err != nil { + return fmt.Errorf("windivert: utf16 driver path: %w", err) + } + + // Serialize driver install across concurrent processes. + mutexName, _ := windows.UTF16PtrFromString("WinDivertDriverInstallMutex") + mutex, err := windows.CreateMutex(nil, false, mutexName) + if err != nil { + return fmt.Errorf("windivert: create install mutex: %w", err) + } + defer windows.CloseHandle(mutex) + _, err = windows.WaitForSingleObject(mutex, windows.INFINITE) + if err != nil { + return fmt.Errorf("windivert: wait install mutex: %w", err) + } + defer windows.ReleaseMutex(mutex) + + manager, err := windows.OpenSCManager(nil, nil, windows.SC_MANAGER_ALL_ACCESS) + if err != nil { + return fmt.Errorf("windivert: open SCM: %w", err) + } + defer windows.CloseServiceHandle(manager) + + serviceNameW, _ := windows.UTF16PtrFromString(driverServiceName) + service, err := windows.OpenService(manager, serviceNameW, windows.SERVICE_ALL_ACCESS) + if err != nil { + service, err = windows.CreateService( + manager, + serviceNameW, + serviceNameW, + windows.SERVICE_ALL_ACCESS, + windows.SERVICE_KERNEL_DRIVER, + windows.SERVICE_DEMAND_START, + windows.SERVICE_ERROR_NORMAL, + sysPathW, + nil, nil, nil, nil, nil, + ) + if err != nil { + if errors.Is(err, windows.ERROR_SERVICE_EXISTS) { + service, err = windows.OpenService(manager, serviceNameW, windows.SERVICE_ALL_ACCESS) + } + if err != nil { + return wrapDriverInstallError(err) + } + } + } + defer windows.CloseServiceHandle(service) + + err = windows.StartService(service, 0, nil) + if err != nil && errors.Is(err, windows.ERROR_SERVICE_DISABLED) { + // A prior process called DeleteService on a still-running kernel + // driver: SCM marks the record for deletion and flips START_TYPE + // to DISABLED until the last handle closes. Re-enable so we can + // start it instead of waiting for a reboot. + err = windows.ChangeServiceConfig( + service, + windows.SERVICE_NO_CHANGE, + windows.SERVICE_DEMAND_START, + windows.SERVICE_NO_CHANGE, + nil, nil, nil, nil, nil, nil, nil, + ) + if err != nil { + return fmt.Errorf("windivert: re-enable disabled service: %w", err) + } + err = windows.StartService(service, 0, nil) + } + if err == nil { + // Mark for deletion so the driver unregisters when the last handle + // closes or on next reboot. Matches the upstream DLL's behavior: + // only the process that actually started the service takes on the + // cleanup responsibility. If another process already started it, + // we leave DeleteService to them. + _ = windows.DeleteService(service) + } else if !errors.Is(err, windows.ERROR_SERVICE_ALREADY_RUNNING) { + return fmt.Errorf("windivert: start service: %w", err) + } + return nil +} + +func wrapDriverInstallError(err error) error { + if errors.Is(err, windows.ERROR_ACCESS_DENIED) { + return fmt.Errorf("windivert: installing the kernel driver requires Administrator privileges: %w", err) + } + return fmt.Errorf("windivert: create service: %w", err) +} + +type assetFile struct { + name string + data []byte +} + +var ( + extractOnce sync.Once + extractErr error + extractDir string +) + +// The on-disk copy is protected by Windows Authenticode signature +// enforcement, which rejects any tampered .sys at StartService time. +func ensureExtracted() (string, error) { + extractOnce.Do(func() { + extractDir, extractErr = extractImpl() + }) + return extractDir, extractErr +} + +func extractImpl() (string, error) { + files := assetFiles() + if len(files) == 0 { + return "", fmt.Errorf("windivert: unsupported architecture %s", runtime.GOARCH) + } + + base, err := os.UserCacheDir() + if err != nil { + return "", fmt.Errorf("windivert: locate user cache dir: %w", err) + } + dir := filepath.Join(base, "xray-core", "windivert", "v"+AssetVersion) + err = os.MkdirAll(dir, 0o755) + if err != nil { + return "", fmt.Errorf("windivert: mkdir %s: %w", dir, err) + } + + for _, asset := range files { + err = ensureAsset(dir, asset) + if err != nil { + return "", err + } + } + return dir, nil +} + +// Concurrent sing-box processes race on os.Rename (atomic on NTFS); +// whichever wins creates the final file. Writers that lose the race +// silently discard their temp copy. +func ensureAsset(dir string, asset assetFile) error { + target := filepath.Join(dir, asset.name) + _, err := os.Stat(target) + if err == nil { + return nil + } + if !os.IsNotExist(err) { + return fmt.Errorf("windivert: stat %s: %w", asset.name, err) + } + tmp := target + ".tmp-" + strconv.Itoa(os.Getpid()) + err = os.WriteFile(tmp, asset.data, 0o644) + if err != nil { + return fmt.Errorf("windivert: write %s: %w", asset.name, err) + } + err = os.Rename(tmp, target) + if err != nil { + os.Remove(tmp) + if _, statErr := os.Stat(target); statErr == nil { + return nil + } + return fmt.Errorf("windivert: rename %s: %w", asset.name, err) + } + return nil +} diff --git a/transport/internet/finalmask/rawpacket/windivert/filter.go b/transport/internet/finalmask/rawpacket/windivert/filter.go new file mode 100644 index 000000000000..d63adae2b630 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/windivert/filter.go @@ -0,0 +1,181 @@ +package windivert + +import ( + "encoding/binary" + "errors" + "net/netip" +) + +// WINDIVERT_FILTER VM instruction layout (24 bytes, #pragma pack(1)): +// +// word 0 (LE): field:11 | test:5 | success:16 +// word 1 (LE): failure:16 | neg:1 | reserved:15 +// words 2..5: arg[4] (native-endian uint32 each) +// +// The driver walks this as a decision tree: evaluate the test at inst i; +// on success jump to success; on failure jump to failure. Continuations +// 0x7FFE and 0x7FFF are ACCEPT and REJECT terminals. +const ( + filterInstBytes = 24 + filterMaxInsts = 256 + + fieldZero = 0 + fieldOutbound = 2 + fieldIP = 5 + fieldIPv6 = 6 + fieldTCP = 8 + fieldIPSrcAddr = 21 + fieldIPDstAddr = 22 + fieldIPv6SrcAddr = 28 + fieldIPv6DstAddr = 29 + fieldTCPSrcPort = 38 + fieldTCPDstPort = 39 + + testEQ = 0 + + resultAccept uint16 = 0x7FFE + resultReject uint16 = 0x7FFF +) + +// Filter flags passed to IOCTL_WINDIVERT_STARTUP alongside the compiled +// filter. These tell the driver what *kinds* of packets the filter might +// match, used as a kernel-side fast-reject. +const ( + filterFlagOutbound uint64 = 0x0020 + filterFlagIP uint64 = 0x0040 + filterFlagIPv6 uint64 = 0x0080 +) + +type filterInst struct { + field uint16 // 11 bits used + test uint8 // 5 bits used + success uint16 + failure uint16 + neg bool + arg [4]uint32 +} + +// Filter is a typed specification of packets to capture. It replaces +// WinDivert's filter string language. +// +// Zero value = "reject all" (match nothing), suitable for send-only handles. +type Filter struct { + insts []filterInst + flags uint64 // filter flags for STARTUP ioctl +} + +// reject returns a filter that matches no packet. The empty insts slice +// is encoded as a single rejecting instruction by encode(). +func reject() *Filter { + return &Filter{} +} + +// OutboundTCP returns a filter matching outbound TCP packets on the given +// 5-tuple. Both addresses must share an address family (IPv4 or IPv6). +func OutboundTCP(src, dst netip.AddrPort) (*Filter, error) { + if !src.IsValid() || !dst.IsValid() { + return nil, errors.New("windivert: filter: invalid address port") + } + if src.Addr().Is4() != dst.Addr().Is4() { + return nil, errors.New("windivert: filter: mixed IPv4/IPv6") + } + f := &Filter{ + flags: filterFlagOutbound, + } + // Insts chain as AND: each test's failure = REJECT, success = next inst. + // The final inst's success = ACCEPT. + f.add(fieldOutbound, testEQ, argUint32(1)) + if src.Addr().Is4() { + f.flags |= filterFlagIP + f.add(fieldIP, testEQ, argUint32(1)) + f.add(fieldTCP, testEQ, argUint32(1)) + f.add(fieldIPSrcAddr, testEQ, argIPv4(src.Addr())) + f.add(fieldIPDstAddr, testEQ, argIPv4(dst.Addr())) + } else { + f.flags |= filterFlagIPv6 + f.add(fieldIPv6, testEQ, argUint32(1)) + f.add(fieldTCP, testEQ, argUint32(1)) + f.add(fieldIPv6SrcAddr, testEQ, argIPv6(src.Addr())) + f.add(fieldIPv6DstAddr, testEQ, argIPv6(dst.Addr())) + } + f.add(fieldTCPSrcPort, testEQ, argUint32(uint32(src.Port()))) + f.add(fieldTCPDstPort, testEQ, argUint32(uint32(dst.Port()))) + return f, nil +} + +func (f *Filter) add(field uint16, test uint8, arg [4]uint32) { + f.insts = append(f.insts, filterInst{field: field, test: test, arg: arg}) +} + +func argUint32(v uint32) [4]uint32 { return [4]uint32{v, 0, 0, 0} } + +// argIPv4 encodes an IPv4 address for IP_SRCADDR/IP_DSTADDR. The driver +// compares against an IPv4-mapped-IPv6 form: {host_order_u32, 0x0000FFFF, +// 0, 0} (see sys/windivert.c windivert_get_ipv4_addr and the IPv4_SRCADDR +// val-word construction). Omitting the 0x0000FFFF marker causes the EQ +// test to fail for every packet. +func argIPv4(addr netip.Addr) [4]uint32 { + b := addr.As4() + return [4]uint32{binary.BigEndian.Uint32(b[:]), 0x0000FFFF, 0, 0} +} + +// argIPv6 encodes an IPv6 address for IPV6_SRCADDR/IPV6_DSTADDR. The +// driver stores the address as four host-order uint32s in REVERSED word +// order: val[0]=low (bytes 12..15), val[3]=high (bytes 0..3). See +// sys/windivert.c windivert_outbound_network_v6_classify val-word +// construction. +func argIPv6(addr netip.Addr) [4]uint32 { + b := addr.As16() + return [4]uint32{ + binary.BigEndian.Uint32(b[12:16]), + binary.BigEndian.Uint32(b[8:12]), + binary.BigEndian.Uint32(b[4:8]), + binary.BigEndian.Uint32(b[0:4]), + } +} + +// encode serializes the Filter to the on-wire WINDIVERT_FILTER[] format +// plus the filter_flags for STARTUP ioctl. +func (f *Filter) encode() ([]byte, uint64, error) { + if len(f.insts) == 0 { + // "Reject all" — one instruction, ZERO == 0 is always true, but we + // invert by setting both success and failure to REJECT. + return encodeInst(filterInst{ + field: fieldZero, + test: testEQ, + success: resultReject, + failure: resultReject, + }), 0, nil + } + if len(f.insts) > filterMaxInsts-1 { + return nil, 0, errors.New("windivert: filter too long") + } + buf := make([]byte, 0, filterInstBytes*len(f.insts)) + for i, inst := range f.insts { + if i == len(f.insts)-1 { + inst.success = resultAccept + } else { + inst.success = uint16(i + 1) + } + inst.failure = resultReject + buf = append(buf, encodeInst(inst)...) + } + return buf, f.flags, nil +} + +func encodeInst(inst filterInst) []byte { + out := make([]byte, filterInstBytes) + word0 := uint32(inst.field&0x7FF) | uint32(inst.test&0x1F)<<11 | + uint32(inst.success)<<16 + word1 := uint32(inst.failure) + if inst.neg { + word1 |= 1 << 16 + } + binary.LittleEndian.PutUint32(out[0:4], word0) + binary.LittleEndian.PutUint32(out[4:8], word1) + binary.LittleEndian.PutUint32(out[8:12], inst.arg[0]) + binary.LittleEndian.PutUint32(out[12:16], inst.arg[1]) + binary.LittleEndian.PutUint32(out[16:20], inst.arg[2]) + binary.LittleEndian.PutUint32(out[20:24], inst.arg[3]) + return out +} diff --git a/transport/internet/finalmask/rawpacket/windivert/handle_windows.go b/transport/internet/finalmask/rawpacket/windivert/handle_windows.go new file mode 100644 index 000000000000..c48e6214c11b --- /dev/null +++ b/transport/internet/finalmask/rawpacket/windivert/handle_windows.go @@ -0,0 +1,323 @@ +//go:build windows + +package windivert + +import ( + "encoding/binary" + "errors" + "fmt" + "runtime" + "sync" + "unsafe" + + "golang.org/x/sys/windows" +) + +// Handle owns a WinDivert kernel device handle plus a private event for +// overlapped I/O. Methods on *Handle are not safe for concurrent use +// across goroutines (there is a single shared event per Handle). +// +// addr is a per-Handle Address buffer the IOCTL struct embeds a pointer +// to. It lives on the heap (as a field of a heap-allocated Handle) so +// the pointer value stored as bytes in the ioctl buffer remains valid +// across stack growth between buildIoctl* and the DeviceIoControl +// syscall — stack-local Address values are not safe for this pattern +// because Go's escape analysis does not see the pointer through the +// unsafe.Pointer → uintptr → bytes conversion. +type Handle struct { + device windows.Handle + event windows.Handle + closing sync.Once + closeErr error + addr Address +} + +// Filter may be nil for "reject all", suitable for send-only handles. +// Requires Administrator on first call per process (installs the kernel +// driver via SCM); subsequent calls reuse the running driver. +func Open(filter *Filter, layer Layer, priority int16, flags Flag) (*Handle, error) { + err := validateOpenArgs(layer, priority, flags) + if err != nil { + return nil, err + } + if filter == nil { + filter = reject() + } + filterBin, filterFlags, err := filter.encode() + if err != nil { + return nil, err + } + device, err := openDevice() + if err != nil { + if !errors.Is(err, windows.ERROR_FILE_NOT_FOUND) && + !errors.Is(err, windows.ERROR_PATH_NOT_FOUND) { + if errors.Is(err, windows.ERROR_ACCESS_DENIED) { + return nil, fmt.Errorf("windivert: open device (administrator required): %w", err) + } + return nil, fmt.Errorf("windivert: open device: %w", err) + } + // Device node missing: kernel driver not loaded. Install + retry. + // Matches WinDivertOpen's lazy-install path; avoids racing StartService + // against a still-loaded driver whose SCM record is marked for deletion. + err = ensureDriver() + if err != nil { + return nil, err + } + device, err = openDevice() + if err != nil { + if errors.Is(err, windows.ERROR_ACCESS_DENIED) { + return nil, fmt.Errorf("windivert: open device (administrator required): %w", err) + } + return nil, fmt.Errorf("windivert: open device: %w", err) + } + } + event, err := windows.CreateEvent(nil, 1, 0, nil) // manual reset, unsignaled + if err != nil { + windows.CloseHandle(device) + return nil, fmt.Errorf("windivert: create event: %w", err) + } + h := &Handle{device: device, event: event} + + err = h.initialize(layer, priority, flags) + if err != nil { + h.Close() + return nil, err + } + err = h.startup(filterBin, filterFlags) + if err != nil { + h.Close() + return nil, err + } + return h, nil +} + +func openDevice() (windows.Handle, error) { + return windows.CreateFile( + driverDevName, + windows.GENERIC_READ|windows.GENERIC_WRITE, + 0, nil, + windows.OPEN_EXISTING, + windows.FILE_ATTRIBUTE_NORMAL|windows.FILE_FLAG_OVERLAPPED, + 0, + ) +} + +func validateOpenArgs(layer Layer, priority int16, flags Flag) error { + if layer != LayerNetwork { + return fmt.Errorf("windivert: invalid layer %d", uint32(layer)) + } + if priority < PriorityLowest || priority > PriorityHighest { + return errors.New("windivert: priority out of range") + } + const supportedFlags = FlagSniff | FlagSendOnly + if flags&^supportedFlags != 0 { + return errors.New("windivert: unknown flag bits") + } + if flags&FlagSniff != 0 && flags&FlagSendOnly != 0 { + return errors.New("windivert: FlagSniff and FlagSendOnly are mutually exclusive") + } + return nil +} + +func (h *Handle) initialize(layer Layer, priority int16, flags Flag) error { + in := buildIoctlInitialize(layer, priority, flags) + // WINDIVERT_VERSION is a 64-byte packed struct; only the first 20 + // bytes (magic, major, minor, bits) carry data, the rest is reserved. + var outBuf [versionStructSize]byte + binary.LittleEndian.PutUint64(outBuf[0:8], magicDLL) + binary.LittleEndian.PutUint32(outBuf[8:12], versionMajor) + binary.LittleEndian.PutUint32(outBuf[12:16], versionMinor) + binary.LittleEndian.PutUint32(outBuf[16:20], uint32(unsafe.Sizeof(uintptr(0))*8)) + _, err := doIoctl(h.device, ioctlInitialize, in[:], outBuf[:], h.event) + if err != nil { + return fmt.Errorf("windivert: initialize ioctl: %w", err) + } + gotMagic := binary.LittleEndian.Uint64(outBuf[0:8]) + if gotMagic != magicSYS { + return fmt.Errorf("windivert: driver magic mismatch (got %d)", gotMagic) + } + gotMajor := binary.LittleEndian.Uint32(outBuf[8:12]) + if gotMajor < versionMajor { + gotMinor := binary.LittleEndian.Uint32(outBuf[12:16]) + return fmt.Errorf("windivert: driver version too old: %d.%d", gotMajor, gotMinor) + } + return nil +} + +func (h *Handle) startup(filterBin []byte, filterFlags uint64) error { + in := buildIoctlStartup(filterFlags) + _, err := doIoctl(h.device, ioctlStartup, in[:], filterBin, h.event) + if err != nil { + return fmt.Errorf("windivert: startup ioctl: %w", err) + } + return nil +} + +// If the handle is closed mid-Recv the error wraps ERROR_OPERATION_ABORTED. +func (h *Handle) Recv(buf []byte) (int, Address, error) { + if len(buf) == 0 { + return 0, Address{}, errors.New("windivert: recv: zero-length buffer") + } + h.addr = Address{} + in := buildIoctlRecv(&h.addr) + n, err := doIoctl(h.device, ioctlRecv, in[:], buf, h.event) + runtime.KeepAlive(h) + if err != nil { + return 0, Address{}, err + } + return int(n), h.addr, nil +} + +// The address's Outbound flag controls whether the packet is sent toward +// the wire (outbound=true) or delivered up the stack (outbound=false). +// IfIdx and SubIfIdx can stay zero — the driver uses the routing table +// when IfIdx=0. +func (h *Handle) Send(packet []byte, addr *Address) (int, error) { + if len(packet) == 0 { + return 0, errors.New("windivert: send: empty packet") + } + if addr == nil { + return 0, errors.New("windivert: send: nil address") + } + h.addr = *addr + in := buildIoctlSend(&h.addr) + n, err := doIoctl(h.device, ioctlSend, in[:], packet, h.event) + runtime.KeepAlive(h) + if err != nil { + return 0, err + } + return int(n), nil +} + +// Idempotent. Aborts any in-flight I/O on the handle. +func (h *Handle) Close() error { + h.closing.Do(func() { + var errs []error + if h.device != 0 { + err := windows.CloseHandle(h.device) + if err != nil { + errs = append(errs, err) + } + h.device = 0 + } + if h.event != 0 { + err := windows.CloseHandle(h.event) + if err != nil { + errs = append(errs, err) + } + h.event = 0 + } + h.closeErr = errors.Join(errs...) + }) + return h.closeErr +} + +// IOCTL codes from windivert_device.h. CTL_CODE macro layout: +// +// (DeviceType << 16) | (Access << 14) | (Function << 2) | Method +const ( + fileDeviceNetwork uint32 = 0x12 + accessReadWrite uint32 = 3 // FILE_READ_DATA | FILE_WRITE_DATA + accessRead uint32 = 1 + + methodInDirect uint32 = 1 + methodOutDirect uint32 = 2 +) + +func ctlCode(deviceType, access, function, method uint32) uint32 { + return (deviceType << 16) | (access << 14) | (function << 2) | method +} + +var ( + ioctlInitialize = ctlCode(fileDeviceNetwork, accessReadWrite, 0x921, methodOutDirect) + ioctlStartup = ctlCode(fileDeviceNetwork, accessReadWrite, 0x922, methodInDirect) + ioctlRecv = ctlCode(fileDeviceNetwork, accessRead, 0x923, methodOutDirect) + ioctlSend = ctlCode(fileDeviceNetwork, accessReadWrite, 0x924, methodInDirect) +) + +// Magic numbers exchanged during INITIALIZE. DLL sends magicDLL in the +// version struct; driver returns magicSYS on success. +const ( + magicDLL uint64 = 0x4C4C447669645724 // "$WdivDLL" in LE bytes + magicSYS uint64 = 0x5359537669645723 // "#WdivSYS" in LE bytes +) + +const ( + versionMajor uint32 = 2 + versionMinor uint32 = 2 +) + +// Size of the WINDIVERT_IOCTL union on wire (packed). +const ioctlSize = 16 + +// Size of WINDIVERT_VERSION on wire (packed). Only the first 20 bytes +// carry data; the rest is reserved zero padding. +const versionStructSize = 64 + +// doIoctl performs a single synchronous (blocking) overlapped +// DeviceIoControl. The handle is opened with FILE_FLAG_OVERLAPPED so +// DeviceIoControl returns ERROR_IO_PENDING; we then wait for completion +// via GetOverlappedResult. Event is passed in so callers can reuse it +// across calls on the same handle (avoids per-call CreateEvent). +func doIoctl(handle windows.Handle, code uint32, in []byte, out []byte, event windows.Handle) (uint32, error) { + var overlapped windows.Overlapped + overlapped.HEvent = event + _ = windows.ResetEvent(event) + + var inPtr *byte + var inLen uint32 + if len(in) > 0 { + inPtr = &in[0] + inLen = uint32(len(in)) + } + var outPtr *byte + var outLen uint32 + if len(out) > 0 { + outPtr = &out[0] + outLen = uint32(len(out)) + } + var returned uint32 + err := windows.DeviceIoControl(handle, code, inPtr, inLen, outPtr, outLen, &returned, &overlapped) + if err != nil && !errors.Is(err, windows.ERROR_IO_PENDING) { + return 0, err + } + err = windows.GetOverlappedResult(handle, &overlapped, &returned, true) + if err != nil { + return 0, err + } + return returned, nil +} + +func buildIoctlInitialize(layer Layer, priority int16, flags Flag) [ioctlSize]byte { + var buf [ioctlSize]byte + binary.LittleEndian.PutUint32(buf[0:4], uint32(layer)) + // The driver expects priority + WINDIVERT_PRIORITY_HIGHEST (30000) so + // the low range maps to non-negative integers. + binary.LittleEndian.PutUint32(buf[4:8], uint32(int32(priority)+int32(PriorityHighest))) + binary.LittleEndian.PutUint64(buf[8:16], uint64(flags)) + return buf +} + +func buildIoctlStartup(filterFlags uint64) [ioctlSize]byte { + var buf [ioctlSize]byte + binary.LittleEndian.PutUint64(buf[0:8], filterFlags) + return buf +} + +// buildIoctlRecv packs a user-space pointer to a WINDIVERT_ADDRESS into +// the ioctl struct. The driver dereferences it to write the address for +// the received packet. Caller must keep the Address alive via +// runtime.KeepAlive. +func buildIoctlRecv(addr *Address) [ioctlSize]byte { + var buf [ioctlSize]byte + binary.LittleEndian.PutUint64(buf[0:8], uint64(uintptr(unsafe.Pointer(addr)))) + binary.LittleEndian.PutUint64(buf[8:16], 0) + return buf +} + +func buildIoctlSend(addr *Address) [ioctlSize]byte { + var buf [ioctlSize]byte + binary.LittleEndian.PutUint64(buf[0:8], uint64(uintptr(unsafe.Pointer(addr)))) + binary.LittleEndian.PutUint64(buf[8:16], uint64(unsafe.Sizeof(Address{}))) + return buf +} diff --git a/transport/internet/finalmask/rawpacket/windivert/windivert.go b/transport/internet/finalmask/rawpacket/windivert/windivert.go new file mode 100644 index 000000000000..9d309886cbe3 --- /dev/null +++ b/transport/internet/finalmask/rawpacket/windivert/windivert.go @@ -0,0 +1,78 @@ +// Package windivert provides a pure-Go binding to the WinDivert kernel +// driver on Windows (amd64 and 386). User-mode WinDivert calls are +// reimplemented in Go; only the signed kernel driver is embedded as an +// asset, since SCM-installed drivers must live on disk and their +// Authenticode signature forbids modification. +// +// Administrator is required for the first Open in a process so SCM can +// load the driver. Upstream: https://github.com/basil00/WinDivert v2.2.2, +// redistributed under its LGPL v3 option; see assets/LICENSE.txt. +package windivert + +import "unsafe" + +const AssetVersion = "2.2.2" + +// MTUMax is WINDIVERT_MTU_MAX from windivert.h (40 + 0xFFFF). Suitable as +// a single-packet receive buffer size. +const MTUMax = 40 + 0xFFFF + +type Layer uint32 + +const LayerNetwork Layer = 0 + +type Flag uint64 + +const ( + // FlagSniff opens a passive observer: the driver copies matching packets + // to userspace without removing them from the network stack. Send is not + // required (and not allowed) on a sniffing handle. + FlagSniff Flag = 0x0001 + // FlagSendOnly opens a write-only injection handle; Recv is not allowed. + FlagSendOnly Flag = 0x0008 +) + +const ( + PriorityHighest int16 = 30000 + PriorityLowest int16 = -30000 +) + +// Address mirrors WINDIVERT_ADDRESS from windivert.h (80 bytes, +// little-endian on both amd64 and 386): +// +// 0: INT64 Timestamp +// 8: UINT32 bitfield: Layer:8 | Event:8 | flags | Reserved1:8 +// 12: UINT32 Reserved2 +// 16: 64 bytes union (WINDIVERT_DATA_NETWORK / FLOW / SOCKET / REFLECT) +type Address struct { + Timestamp int64 + bits uint32 + Reserved2 uint32 + union [64]byte +} + +var _ [80]byte = [unsafe.Sizeof(Address{})]byte{} + +// Bit positions inside the Address's packed flags word. +const ( + addrBitIPv6 = 20 + addrBitIPChecksum = 21 + addrBitTCPChecksum = 22 +) + +func getFlagBit(bits uint32, pos uint) bool { return bits&(1<