从proxy获取client ip地址

vendor/github.com/pires/go-proxyproto/v1.go

@@ -0,0 +1,116 @@
+package proxyproto
+
+import (
+	"bufio"
+	"bytes"
+	"net"
+	"strconv"
+	"strings"
+)
+
+const (
+	CRLF      = "\r\n"
+	SEPARATOR = " "
+)
+
+func initVersion1() *Header {
+	header := new(Header)
+	header.Version = 1
+	// Command doesn't exist in v1
+	header.Command = PROXY
+	return header
+}
+
+func parseVersion1(reader *bufio.Reader) (*Header, error) {
+	// Make sure we have a v1 header
+	line, err := reader.ReadString('\n')
+	if !strings.HasSuffix(line, CRLF) {
+		return nil, ErrCantReadProtocolVersionAndCommand
+	}
+	tokens := strings.Split(line[:len(line)-2], SEPARATOR)
+	if len(tokens) < 6 {
+		return nil, ErrCantReadProtocolVersionAndCommand
+	}
+
+	header := initVersion1()
+
+	// Read address family and protocol
+	switch tokens[1] {
+	case "TCP4":
+		header.TransportProtocol = TCPv4
+	case "TCP6":
+		header.TransportProtocol = TCPv6
+	default:
+		header.TransportProtocol = UNSPEC
+	}
+
+	// Read addresses and ports
+	header.SourceAddress, err = parseV1IPAddress(header.TransportProtocol, tokens[2])
+	if err != nil {
+		return nil, err
+	}
+	header.DestinationAddress, err = parseV1IPAddress(header.TransportProtocol, tokens[3])
+	if err != nil {
+		return nil, err
+	}
+	header.SourcePort, err = parseV1PortNumber(tokens[4])
+	if err != nil {
+		return nil, err
+	}
+	header.DestinationPort, err = parseV1PortNumber(tokens[5])
+	if err != nil {
+		return nil, err
+	}
+	return header, nil
+}
+
+func (header *Header) formatVersion1() ([]byte, error) {
+	// As of version 1, only "TCP4" ( \x54 \x43 \x50 \x34 ) for TCP over IPv4,
+	// and "TCP6" ( \x54 \x43 \x50 \x36 ) for TCP over IPv6 are allowed.
+	proto := "UNKNOWN"
+	if header.TransportProtocol == TCPv4 {
+		proto = "TCP4"
+	} else if header.TransportProtocol == TCPv6 {
+		proto = "TCP6"
+	}
+
+	var buf bytes.Buffer
+	buf.Write(SIGV1)
+	buf.WriteString(SEPARATOR)
+	buf.WriteString(proto)
+	buf.WriteString(SEPARATOR)
+	buf.WriteString(header.SourceAddress.String())
+	buf.WriteString(SEPARATOR)
+	buf.WriteString(header.DestinationAddress.String())
+	buf.WriteString(SEPARATOR)
+	buf.WriteString(strconv.Itoa(int(header.SourcePort)))
+	buf.WriteString(SEPARATOR)
+	buf.WriteString(strconv.Itoa(int(header.DestinationPort)))
+	buf.WriteString(CRLF)
+
+	return buf.Bytes(), nil
+}
+
+func parseV1PortNumber(portStr string) (port uint16, err error) {
+	_port, _err := strconv.Atoi(portStr)
+	if _err == nil {
+		if _port < 0 || _port > 65535 {
+			err = ErrInvalidPortNumber
+		} else {
+			port = uint16(_port)
+		}
+	} else {
+		err = ErrInvalidPortNumber
+	}
+
+	return
+}
+
+func parseV1IPAddress(protocol AddressFamilyAndProtocol, addrStr string) (addr net.IP, err error) {
+	addr = net.ParseIP(addrStr)
+	tryV4 := addr.To4()
+	if (protocol == TCPv4 && tryV4 == nil) || (protocol == TCPv6 && tryV4 != nil) {
+		err = ErrInvalidAddress
+	}
+	return
+}