mirror of https://github.com/fatedier/frp
117 lines
2.6 KiB
Go
117 lines
2.6 KiB
Go
package proxyproto
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import (
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"bufio"
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"bytes"
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"io"
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"net"
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"strconv"
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"strings"
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)
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const (
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CRLF = "\r\n"
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SEPARATOR = " "
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)
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func initVersion1() *Header {
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header := new(Header)
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header.Version = 1
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// Command doesn't exist in v1
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header.Command = PROXY
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return header
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}
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func parseVersion1(reader *bufio.Reader) (*Header, error) {
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// Make sure we have a v1 header
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line, err := reader.ReadString('\n')
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if !strings.HasSuffix(line, CRLF) {
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return nil, ErrCantReadProtocolVersionAndCommand
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}
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tokens := strings.Split(line[:len(line)-2], SEPARATOR)
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if len(tokens) < 6 {
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return nil, ErrCantReadProtocolVersionAndCommand
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}
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header := initVersion1()
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// Read address family and protocol
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switch tokens[1] {
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case "TCP4":
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header.TransportProtocol = TCPv4
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case "TCP6":
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header.TransportProtocol = TCPv6
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default:
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header.TransportProtocol = UNSPEC
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}
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// Read addresses and ports
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header.SourceAddress, err = parseV1IPAddress(header.TransportProtocol, tokens[2])
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if err != nil {
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return nil, err
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}
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header.DestinationAddress, err = parseV1IPAddress(header.TransportProtocol, tokens[3])
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if err != nil {
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return nil, err
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}
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header.SourcePort, err = parseV1PortNumber(tokens[4])
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if err != nil {
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return nil, err
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}
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header.DestinationPort, err = parseV1PortNumber(tokens[5])
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if err != nil {
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return nil, err
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}
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return header, nil
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}
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func (header *Header) writeVersion1(w io.Writer) (int64, error) {
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// As of version 1, only "TCP4" ( \x54 \x43 \x50 \x34 ) for TCP over IPv4,
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// and "TCP6" ( \x54 \x43 \x50 \x36 ) for TCP over IPv6 are allowed.
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proto := "UNKNOWN"
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if header.TransportProtocol == TCPv4 {
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proto = "TCP4"
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} else if header.TransportProtocol == TCPv6 {
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proto = "TCP6"
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}
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var buf bytes.Buffer
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buf.Write(SIGV1)
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buf.WriteString(SEPARATOR)
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buf.WriteString(proto)
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buf.WriteString(SEPARATOR)
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buf.WriteString(header.SourceAddress.String())
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buf.WriteString(SEPARATOR)
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buf.WriteString(header.DestinationAddress.String())
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buf.WriteString(SEPARATOR)
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buf.WriteString(strconv.Itoa(int(header.SourcePort)))
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buf.WriteString(SEPARATOR)
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buf.WriteString(strconv.Itoa(int(header.DestinationPort)))
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buf.WriteString(CRLF)
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return buf.WriteTo(w)
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}
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func parseV1PortNumber(portStr string) (uint16, error) {
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var port uint16
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_port, err := strconv.Atoi(portStr)
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if err == nil {
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if port < 0 || port > 65535 {
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err = ErrInvalidPortNumber
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}
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port = uint16(_port)
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}
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return port, err
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}
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func parseV1IPAddress(protocol AddressFamilyAndProtocol, addrStr string) (addr net.IP, err error) {
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addr = net.ParseIP(addrStr)
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tryV4 := addr.To4()
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if (protocol == TCPv4 && tryV4 == nil) || (protocol == TCPv6 && tryV4 != nil) {
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err = ErrInvalidAddress
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}
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return
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}
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