package protocol import ( "io" "v2ray.com/core/common" "v2ray.com/core/common/buf" "v2ray.com/core/common/net" "v2ray.com/core/common/serial" ) type AddressOption func(*option) func PortThenAddress() AddressOption { return func(p *option) { p.portFirst = true } } func AddressFamilyByte(b byte, f net.AddressFamily) AddressOption { if b >= 16 { panic("address family byte too big") } return func(p *option) { p.addrTypeMap[b] = f p.addrByteMap[f] = b } } type AddressTypeParser func(byte) byte func WithAddressTypeParser(atp AddressTypeParser) AddressOption { return func(p *option) { p.typeParser = atp } } type AddressSerializer interface { ReadAddressPort(buffer *buf.Buffer, input io.Reader) (net.Address, net.Port, error) WriteAddressPort(writer io.Writer, addr net.Address, port net.Port) error } const afInvalid = 255 type option struct { addrTypeMap [16]net.AddressFamily addrByteMap [16]byte portFirst bool typeParser AddressTypeParser } // NewAddressParser creates a new AddressParser func NewAddressParser(options ...AddressOption) AddressSerializer { var o option for i := range o.addrByteMap { o.addrByteMap[i] = afInvalid } for i := range o.addrTypeMap { o.addrTypeMap[i] = net.AddressFamily(afInvalid) } for _, opt := range options { opt(&o) } ap := &addressParser{ addrByteMap: o.addrByteMap, addrTypeMap: o.addrTypeMap, } if o.typeParser != nil { ap.typeParser = o.typeParser } if o.portFirst { return portFirstAddressParser{ap: ap} } return portLastAddressParser{ap: ap} } type portFirstAddressParser struct { ap *addressParser } func (p portFirstAddressParser) ReadAddressPort(buffer *buf.Buffer, input io.Reader) (net.Address, net.Port, error) { if buffer == nil { buffer = buf.New() defer buffer.Release() } port, err := readPort(buffer, input) if err != nil { return nil, 0, err } addr, err := p.ap.readAddress(buffer, input) if err != nil { return nil, 0, err } return addr, port, nil } func (p portFirstAddressParser) WriteAddressPort(writer io.Writer, addr net.Address, port net.Port) error { if err := writePort(writer, port); err != nil { return err } return p.ap.writeAddress(writer, addr) } type portLastAddressParser struct { ap *addressParser } func (p portLastAddressParser) ReadAddressPort(buffer *buf.Buffer, input io.Reader) (net.Address, net.Port, error) { if buffer == nil { buffer = buf.New() defer buffer.Release() } addr, err := p.ap.readAddress(buffer, input) if err != nil { return nil, 0, err } port, err := readPort(buffer, input) if err != nil { return nil, 0, err } return addr, port, nil } func (p portLastAddressParser) WriteAddressPort(writer io.Writer, addr net.Address, port net.Port) error { if err := p.ap.writeAddress(writer, addr); err != nil { return err } return writePort(writer, port) } func readPort(b *buf.Buffer, reader io.Reader) (net.Port, error) { if _, err := b.ReadFullFrom(reader, 2); err != nil { return 0, err } return net.PortFromBytes(b.BytesFrom(-2)), nil } func writePort(writer io.Writer, port net.Port) error { return common.Error2(serial.WriteUint16(writer, port.Value())) } func maybeIPPrefix(b byte) bool { return b == '[' || (b >= '0' && b <= '9') } func isValidDomain(d string) bool { for _, c := range d { if !((c >= '0' && c <= '9') || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '-' || c == '.' || c == '_') { return false } } return true } type addressParser struct { addrTypeMap [16]net.AddressFamily addrByteMap [16]byte typeParser AddressTypeParser } func (p *addressParser) readAddress(b *buf.Buffer, reader io.Reader) (net.Address, error) { if _, err := b.ReadFullFrom(reader, 1); err != nil { return nil, err } addrType := b.Byte(b.Len() - 1) if p.typeParser != nil { addrType = p.typeParser(addrType) } if addrType >= 16 { return nil, newError("unknown address type: ", addrType) } addrFamily := p.addrTypeMap[addrType] if addrFamily == net.AddressFamily(afInvalid) { return nil, newError("unknown address type: ", addrType) } switch addrFamily { case net.AddressFamilyIPv4: if _, err := b.ReadFullFrom(reader, 4); err != nil { return nil, err } return net.IPAddress(b.BytesFrom(-4)), nil case net.AddressFamilyIPv6: if _, err := b.ReadFullFrom(reader, 16); err != nil { return nil, err } return net.IPAddress(b.BytesFrom(-16)), nil case net.AddressFamilyDomain: if _, err := b.ReadFullFrom(reader, 1); err != nil { return nil, err } domainLength := int32(b.Byte(b.Len() - 1)) if _, err := b.ReadFullFrom(reader, domainLength); err != nil { return nil, err } domain := string(b.BytesFrom(-domainLength)) if maybeIPPrefix(domain[0]) { addr := net.ParseAddress(domain) if addr.Family().IsIP() { return addr, nil } } if !isValidDomain(domain) { return nil, newError("invalid domain name: ", domain) } return net.DomainAddress(domain), nil default: panic("impossible case") } } func (p *addressParser) writeAddress(writer io.Writer, address net.Address) error { tb := p.addrByteMap[address.Family()] if tb == afInvalid { return newError("unknown address family", address.Family()) } switch address.Family() { case net.AddressFamilyIPv4, net.AddressFamilyIPv6: if _, err := writer.Write([]byte{tb}); err != nil { return err } if _, err := writer.Write(address.IP()); err != nil { return err } case net.AddressFamilyDomain: domain := address.Domain() if isDomainTooLong(domain) { return newError("Super long domain is not supported: ", domain) } if _, err := writer.Write([]byte{tb, byte(len(domain))}); err != nil { return err } if _, err := writer.Write([]byte(domain)); err != nil { return err } default: panic("Unknown family type.") } return nil }