proxy: move proxyprotocol as a seperate package

Makefile

@@ -31,9 +31,7 @@ EXECUTABLE_TARGETS := $(patsubst cmd/%,cmd_%,$(wildcard cmd/*))
 
 default: cmd
 
-dev: cmd lint test
-
-cache: build lint test
+dev: build lint test
 
 cmd: $(EXECUTABLE_TARGETS)
 
@@ -55,8 +53,7 @@ gocovmerge:
 tidy:
 	go mod tidy
 	cd lib && go mod tidy
-
-cache:
+build:
 	go build ./...
 	cd lib && go build ./...
 

pkg/proxy/backend/authenticator.go

@@ -23,6 +23,7 @@ import (
 
 	"github.com/pingcap/TiProxy/lib/util/errors"
 	pnet "github.com/pingcap/TiProxy/pkg/proxy/net"
+	"github.com/pingcap/TiProxy/pkg/proxy/proxyprotocol"
 	"github.com/pingcap/tidb/parser/mysql"
 	"github.com/pingcap/tidb/util/hack"
 	"go.uber.org/zap"
@@ -65,14 +66,14 @@ func (auth *Authenticator) writeProxyProtocol(clientIO, backendIO *pnet.PacketIO
 	if auth.proxyProtocol {
 		proxy := clientIO.Proxy()
 		if proxy == nil {
-			proxy = &pnet.Proxy{
+			proxy = &proxyprotocol.Proxy{
 				SrcAddress: clientIO.RemoteAddr(),
 				DstAddress: backendIO.RemoteAddr(),
-				Version:    pnet.ProxyVersion2,
+				Version:    proxyprotocol.ProxyVersion2,
 			}
 		}
 		// either from another proxy or directly from clients, we are acting as a proxy
-		proxy.Command = pnet.ProxyCommandProxy
+		proxy.Command = proxyprotocol.ProxyCommandProxy
 		if err := backendIO.WriteProxyV2(proxy); err != nil {
 			return err
 		}

pkg/proxy/net/packetio.go

@@ -47,14 +47,14 @@ import (
 	"github.com/pingcap/TiProxy/lib/config"
 	"github.com/pingcap/TiProxy/lib/util/errors"
 	"github.com/pingcap/TiProxy/pkg/proxy/keepalive"
+	"github.com/pingcap/TiProxy/pkg/proxy/proxyprotocol"
 	"github.com/pingcap/tidb/errno"
 	"github.com/pingcap/tidb/parser/mysql"
 	"github.com/pingcap/tidb/util/dbterror"
 )
 
 var (
 	errInvalidSequence = dbterror.ClassServer.NewStd(errno.ErrInvalidSequence)
-	proxyV2Magic       = []byte{0xD, 0xA, 0xD, 0xA, 0x0, 0xD, 0xA, 0x51, 0x55, 0x49, 0x54, 0xA}
 )
 
 const (
@@ -84,7 +84,7 @@ type PacketIO struct {
 	rawConn       net.Conn
 	buf           *bufio.ReadWriter
 	proxyInited   atomic.Bool
-	proxy         *Proxy
+	proxy         *proxyprotocol.Proxy
 	remoteAddr    net.Addr
 	wrap          error
 	sequence      uint8
@@ -117,7 +117,7 @@ func (p *PacketIO) wrapErr(err error) error {
 }
 
 // Proxy returned parsed proxy header from clients if any.
-func (p *PacketIO) Proxy() *Proxy {
+func (p *PacketIO) Proxy() *proxyprotocol.Proxy {
 	if p.proxyInited.Load() {
 		return p.proxy
 	}
@@ -155,7 +155,7 @@ func (p *PacketIO) readOnePacket() ([]byte, bool, error) {
 	// probe proxy V2
 	refill := false
 	if !p.proxyInited.Load() {
-		if bytes.Equal(header[:], proxyV2Magic[:4]) {
+		if bytes.Equal(header[:], proxyprotocol.MagicV2[:4]) {
 			proxyHeader, err := p.parseProxyV2()
 			if err != nil {
 				return nil, false, errors.Wrap(ErrReadConn, err)

pkg/proxy/net/packetio_options.go

@@ -16,6 +16,8 @@ package net
 
 import (
 	"net"
+
+	"github.com/pingcap/TiProxy/pkg/proxy/proxyprotocol"
 )
 
 type PacketIOption = func(*PacketIO)
@@ -31,13 +33,17 @@ func WithWrapError(err error) func(pi *PacketIO) {
 }
 
 // WithRemoteAddr
-var _ net.Addr = &originAddr{}
+var _ proxyprotocol.AddressWrapper = &originAddr{}
 
 type originAddr struct {
 	net.Addr
 	addr string
 }
 
+func (o *originAddr) Unwrap() net.Addr {
+	return o.Addr
+}
+
 func (o *originAddr) String() string {
 	return o.addr
 }
@@ -47,10 +53,3 @@ func WithRemoteAddr(readdr string, addr net.Addr) func(pi *PacketIO) {
 		pi.remoteAddr = &originAddr{Addr: addr, addr: readdr}
 	}
 }
-
-func unwrapOriginAddr(addr net.Addr) net.Addr {
-	if oaddr, ok := addr.(*originAddr); ok {
-		return oaddr.Addr
-	}
-	return addr
-}