repository cleanup

server/entranceserver/entrance_server.go

@@ -0,0 +1,122 @@
+package entranceserver
+
+import (
+	"encoding/hex"
+	"fmt"
+	"io"
+	"net"
+	"sync"
+
+	"erupe-ce/config"
+	"erupe-ce/network"
+	"github.com/jmoiron/sqlx"
+	"go.uber.org/zap"
+)
+
+// Server is a MHF entrance server.
+type Server struct {
+	sync.Mutex
+	logger         *zap.Logger
+	erupeConfig    *config.Config
+	db             *sqlx.DB
+	listener       net.Listener
+	isShuttingDown bool
+}
+
+// Config struct allows configuring the server.
+type Config struct {
+	Logger      *zap.Logger
+	DB          *sqlx.DB
+	ErupeConfig *config.Config
+}
+
+// NewServer creates a new Server type.
+func NewServer(config *Config) *Server {
+	s := &Server{
+		logger:      config.Logger,
+		erupeConfig: config.ErupeConfig,
+		db:          config.DB,
+	}
+	return s
+}
+
+// Start starts the server in a new goroutine.
+func (s *Server) Start() error {
+
+	l, err := net.Listen("tcp", fmt.Sprintf(":%d", s.erupeConfig.Entrance.Port))
+	if err != nil {
+		return err
+	}
+
+	s.listener = l
+
+	go s.acceptClients()
+
+	return nil
+}
+
+// Shutdown exits the server gracefully.
+func (s *Server) Shutdown() {
+	s.logger.Debug("Shutting down")
+
+	s.Lock()
+	s.isShuttingDown = true
+	s.Unlock()
+
+	// This will cause the acceptor goroutine to error and exit gracefully.
+	s.listener.Close()
+}
+
+//acceptClients handles accepting new clients in a loop.
+func (s *Server) acceptClients() {
+	for {
+		conn, err := s.listener.Accept()
+		if err != nil {
+			// Check if we are shutting down and exit gracefully if so.
+			s.Lock()
+			shutdown := s.isShuttingDown
+			s.Unlock()
+
+			if shutdown {
+				break
+			} else {
+				continue
+			}
+		}
+
+		// Start a new goroutine for the connection so that we don't block other incoming connections.
+		go s.handleEntranceServerConnection(conn)
+	}
+}
+
+func (s *Server) handleEntranceServerConnection(conn net.Conn) {
+	// Client initalizes the connection with a one-time buffer of 8 NULL bytes.
+	nullInit := make([]byte, 8)
+	n, err := io.ReadFull(conn, nullInit)
+	if err != nil {
+		s.logger.Warn("Failed to read 8 NULL init", zap.Error(err))
+		return
+	} else if n != len(nullInit) {
+		s.logger.Warn("io.ReadFull couldn't read the full 8 byte init.")
+		return
+	}
+
+	// Create a new encrypted connection handler and read a packet from it.
+	cc := network.NewCryptConn(conn)
+	pkt, err := cc.ReadPacket()
+	if err != nil {
+		s.logger.Warn("Error reading packet", zap.Error(err))
+		return
+	}
+
+	s.logger.Debug("Got entrance server command:\n", zap.String("raw", hex.Dump(pkt)))
+
+	data := makeSv2Resp(s.erupeConfig, s)
+	if len(pkt) > 5 {
+		data = append(data, makeUsrResp(pkt, s)...)
+	}
+	cc.SendPacket(data)
+	// Close because we only need to send the response once.
+	// Any further requests from the client will come from a new connection.
+	conn.Close()
+}