从proxy获取client ip地址

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

@@ -0,0 +1,149 @@
+// Package proxyproto implements Proxy Protocol (v1 and v2) parser and writer, as per specification:
+// http://www.haproxy.org/download/1.5/doc/proxy-protocol.txt
+package proxyproto
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"io"
+	"net"
+	"time"
+)
+
+var (
+	// Protocol
+	SIGV1 = []byte{'\x50', '\x52', '\x4F', '\x58', '\x59'}
+	SIGV2 = []byte{'\x0D', '\x0A', '\x0D', '\x0A', '\x00', '\x0D', '\x0A', '\x51', '\x55', '\x49', '\x54', '\x0A'}
+
+	ErrCantReadProtocolVersionAndCommand    = errors.New("Can't read proxy protocol version and command")
+	ErrCantReadAddressFamilyAndProtocol     = errors.New("Can't read address family or protocol")
+	ErrCantReadLength                       = errors.New("Can't read length")
+	ErrCantResolveSourceUnixAddress         = errors.New("Can't resolve source Unix address")
+	ErrCantResolveDestinationUnixAddress    = errors.New("Can't resolve destination Unix address")
+	ErrNoProxyProtocol                      = errors.New("Proxy protocol signature not present")
+	ErrUnknownProxyProtocolVersion          = errors.New("Unknown proxy protocol version")
+	ErrUnsupportedProtocolVersionAndCommand = errors.New("Unsupported proxy protocol version and command")
+	ErrUnsupportedAddressFamilyAndProtocol  = errors.New("Unsupported address family and protocol")
+	ErrInvalidLength                        = errors.New("Invalid length")
+	ErrInvalidAddress                       = errors.New("Invalid address")
+	ErrInvalidPortNumber                    = errors.New("Invalid port number")
+)
+
+// Header is the placeholder for proxy protocol header.
+type Header struct {
+	Version            byte
+	Command            ProtocolVersionAndCommand
+	TransportProtocol  AddressFamilyAndProtocol
+	SourceAddress      net.IP
+	DestinationAddress net.IP
+	SourcePort         uint16
+	DestinationPort    uint16
+}
+
+// RemoteAddr returns the address of the remote endpoint of the connection.
+func (header *Header) RemoteAddr() net.Addr {
+	return &net.TCPAddr{
+		IP:   header.SourceAddress,
+		Port: int(header.SourcePort),
+	}
+}
+
+// LocalAddr returns the address of the local endpoint of the connection.
+func (header *Header) LocalAddr() net.Addr {
+	return &net.TCPAddr{
+		IP:   header.DestinationAddress,
+		Port: int(header.DestinationPort),
+	}
+}
+
+// EqualTo returns true if headers are equivalent, false otherwise.
+// Deprecated: use EqualsTo instead. This method will eventually be removed.
+func (header *Header) EqualTo(otherHeader *Header) bool {
+	return header.EqualsTo(otherHeader)
+}
+
+// EqualsTo returns true if headers are equivalent, false otherwise.
+func (header *Header) EqualsTo(otherHeader *Header) bool {
+	if otherHeader == nil {
+		return false
+	}
+	if header.Command.IsLocal() {
+		return true
+	}
+	return header.Version == otherHeader.Version &&
+		header.TransportProtocol == otherHeader.TransportProtocol &&
+		header.SourceAddress.String() == otherHeader.SourceAddress.String() &&
+		header.DestinationAddress.String() == otherHeader.DestinationAddress.String() &&
+		header.SourcePort == otherHeader.SourcePort &&
+		header.DestinationPort == otherHeader.DestinationPort
+}
+
+// WriteTo renders a proxy protocol header in a format and writes it to an io.Writer.
+func (header *Header) WriteTo(w io.Writer) (int64, error) {
+	buf, err := header.Format()
+	if err != nil {
+		return 0, err
+	}
+
+	return bytes.NewBuffer(buf).WriteTo(w)
+}
+
+// Format renders a proxy protocol header in a format to write over the wire.
+func (header *Header) Format() ([]byte, error) {
+	switch header.Version {
+	case 1:
+		return header.formatVersion1()
+	case 2:
+		return header.formatVersion2()
+	default:
+		return nil, ErrUnknownProxyProtocolVersion
+	}
+}
+
+// Read identifies the proxy protocol version and reads the remaining of
+// the header, accordingly.
+//
+// If proxy protocol header signature is not present, the reader buffer remains untouched
+// and is safe for reading outside of this code.
+//
+// If proxy protocol header signature is present but an error is raised while processing
+// the remaining header, assume the reader buffer to be in a corrupt state.
+// Also, this operation will block until enough bytes are available for peeking.
+func Read(reader *bufio.Reader) (*Header, error) {
+	// In order to improve speed for small non-PROXYed packets, take a peek at the first byte alone.
+	if b1, err := reader.Peek(1); err == nil && (bytes.Equal(b1[:1], SIGV1[:1]) || bytes.Equal(b1[:1], SIGV2[:1])) {
+		if signature, err := reader.Peek(5); err == nil && bytes.Equal(signature[:5], SIGV1) {
+			return parseVersion1(reader)
+		} else if signature, err := reader.Peek(12); err == nil && bytes.Equal(signature[:12], SIGV2) {
+			return parseVersion2(reader)
+		}
+	}
+
+	return nil, ErrNoProxyProtocol
+}
+
+// ReadTimeout acts as Read but takes a timeout. If that timeout is reached, it's assumed
+// there's no proxy protocol header.
+func ReadTimeout(reader *bufio.Reader, timeout time.Duration) (*Header, error) {
+	type header struct {
+		h *Header
+		e error
+	}
+	read := make(chan *header, 1)
+
+	go func() {
+		h := &header{}
+		h.h, h.e = Read(reader)
+		read <- h
+	}()
+
+	timer := time.NewTimer(timeout)
+	select {
+	case result := <-read:
+		timer.Stop()
+		return result.h, result.e
+	case <-timer.C:
+		return nil, ErrNoProxyProtocol
+	}
+}