move udpproxy files into repo root

session.go

@@ -0,0 +1,105 @@
+package udpproxy
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"strings"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+)
+
+type session struct {
+	serverConn *net.UDPConn
+	proxyConn  *net.UDPConn
+	caddr      *net.UDPAddr
+	updateTime time.Time
+
+	validator
+}
+
+func newSession(caddr *net.UDPAddr, raddr *net.UDPAddr, proxyConn *net.UDPConn) (*session, error) {
+	serverConn, err := net.DialUDP("udp", nil, raddr)
+	if err != nil {
+		return nil, err
+	}
+
+	session := &session{
+		serverConn: serverConn,
+		proxyConn:  proxyConn,
+		caddr:      caddr,
+		updateTime: time.Now(),
+		validator:  newValidator(),
+	}
+
+	go session.listen()
+
+	return session, nil
+}
+
+func (s *session) listen() error {
+	buf := make([]byte, 2048)
+	for {
+		n, err := s.serverConn.Read(buf)
+		if err != nil {
+			log.Error(err)
+			continue
+		}
+
+		go s.proxyFrom(buf[:n])
+	}
+}
+
+func (s *session) proxyFrom(buf []byte) error {
+	if !s.isValidResponsePacket(buf) {
+		err := errors.New("not a rcon or query response packet")
+		log.Error(err.Error())
+		return err
+	}
+
+	s.updateTime = time.Now()
+	_, err := s.proxyConn.WriteToUDP(buf, s.caddr)
+	if err != nil {
+		log.Error(err)
+		return err
+	}
+
+	if s.isRconResponsePacket(buf) {
+		if s.isBadRconResponse(buf) {
+			log.Infof("Response: Bad rcon from %s", s.caddr.IP)
+		} else {
+			log.Debugf("Response: %s", string(buf[len(s.rconResponseHeader):]))
+		}
+	}
+
+	return nil
+}
+
+func (s *session) proxyTo(buf []byte) error {
+	if !s.isValidRequestPacket(buf) {
+		var err error
+		if s.isChallengeRequestPacket(buf) {
+			parts := strings.SplitN(string(buf), " ", 3)
+			err = fmt.Errorf("invalid challenge from %s with GUID: %s", s.caddr.IP, parts[len(parts)-1])
+		} else {
+			err = errors.New("not a rcon or query request packet")
+		}
+		log.Error(err.Error())
+		return err
+	}
+
+	s.updateTime = time.Now()
+	_, err := s.serverConn.Write(buf)
+	if err != nil {
+		log.Error(err)
+		return err
+	}
+
+	if s.isRconRequestPacket(buf) {
+		parts := strings.SplitN(string(buf), " ", 3)
+		log.Infof("From [%s] To [%s] Command: %s", s.caddr.IP, s.serverConn.RemoteAddr(), parts[len(parts)-1])
+	}
+
+	return nil
+}