Xray-core/common/protocol/address.go

259 lines
5.8 KiB
Go

package protocol
import (
"io"
"github.com/xtls/xray-core/common"
"github.com/xtls/xray-core/common/buf"
"github.com/xtls/xray-core/common/net"
"github.com/xtls/xray-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
}