refactoring; moved client to protocol package

2025-10-05 01:00:41 +00:00 · 2023-03-07 17:04:57 -06:00
parent 4c7696dc92
commit 1fff485f93
4 changed files with 34 additions and 42 deletions
--- a/protocol/client.go
+++ b/protocol/client.go
@@ -0,0 +1,136 @@
+package protocol
+
+import (
+	"encoding/binary"
+	"fmt"
+	"log"
+	"net"
+	"time"
+)
+
+const (
+	USE_E = iota
+	USE_FE
+)
+
+type ClientHandler interface {
+	HandlePacket(client *Client, typeID uint32, pkt *Packet)
+	Disconnect(client *Client)
+}
+
+type Client struct {
+	handler  ClientHandler
+	conn     net.Conn
+	e_key    []byte
+	fe_key   []byte
+	whichKey int
+}
+
+func NewClient(handler ClientHandler, conn net.Conn) *Client {
+	return &Client{
+		handler:  handler,
+		conn:     conn,
+		e_key:    []byte(DEFAULT_KEY),
+		whichKey: USE_E,
+	}
+}
+
+func (client *Client) Send(data interface{}, typeID uint32) {
+	// encode
+	pkt := NewPacket(make([]byte, 0))
+	pkt.Encode(data)
+	log.Printf("Sending %#v, sizeof: %d", data, len(pkt.Buf))
+
+	// write packet size
+	tmp := make([]byte, 4)
+	binary.LittleEndian.PutUint32(tmp, uint32(len(pkt.Buf)+4))
+	if _, err := client.conn.Write(tmp); err != nil {
+		panic(fmt.Errorf("[FATAL] failed to write packet size! %v", err))
+	}
+
+	// prepend the typeID to the packet body
+	binary.LittleEndian.PutUint32(tmp, uint32(typeID))
+	tmp = append(tmp, pkt.Buf...)
+
+	// encrypt typeID & body
+	switch client.whichKey {
+	case USE_E:
+		EncryptData(tmp, client.e_key)
+	case USE_FE:
+		EncryptData(tmp, client.fe_key)
+	}
+
+	// write packet body
+	if _, err := client.conn.Write(tmp); err != nil {
+		panic(fmt.Errorf("[FATAL] failed to write packet body! %v", err))
+	}
+}
+
+func (client *Client) AcceptLogin(SZID string, IClientVerC int32, ISlotNum int8, data []SP_LS2CL_REP_CHAR_INFO) {
+	resp := &SP_LS2CL_REP_LOGIN_SUCC{
+		SzID:          SZID,
+		ICharCount:    int8(len(data)),
+		ISlotNum:      ISlotNum,
+		IPaymentFlag:  1,
+		IOpenBetaFlag: 0,
+		UiSvrTime:     uint64(time.Now().Unix()),
+	}
+
+	client.Send(resp, P_LS2CL_REP_LOGIN_SUCC)
+	client.e_key = CreateNewKey(
+		resp.UiSvrTime,
+		uint64(resp.ICharCount+1),
+		uint64(resp.ISlotNum+1),
+	)
+	client.fe_key = CreateNewKey(
+		binary.LittleEndian.Uint64([]byte(DEFAULT_KEY)),
+		uint64(IClientVerC),
+		1,
+	)
+
+	// send characters (if any)
+	for i := 0; i < len(data); i++ {
+		client.Send(data[i], P_LS2CL_REP_CHAR_INFO)
+	}
+}
+
+func (client *Client) ClientHandler() {
+	defer func() {
+		if err := recover(); err != nil {
+			log.Printf("Client %p panic'd! %v", client, err)
+		}
+		client.conn.Close()
+		client.handler.Disconnect(client)
+	}()
+
+	tmp := make([]byte, 4, CN_PACKET_BUFFER_SIZE)
+	for {
+		// read packet size
+		if _, err := client.conn.Read(tmp); err != nil {
+			panic(fmt.Errorf("[FATAL] failed to read packet size! %v", err))
+		}
+		sz := int(binary.LittleEndian.Uint32(tmp))
+
+		// client should never send a packet size outside of this range
+		if sz > CN_PACKET_BUFFER_SIZE || sz < 4 {
+			panic(fmt.Errorf("[FATAL] malicious packet size received! %d", sz))
+		}
+
+		// read packet body
+		if _, err := client.conn.Read(tmp[:sz]); err != nil {
+			panic(fmt.Errorf("[FATAL] failed to read packet body! %v", err))
+		}
+
+		// decrypt && grab typeID
+		DecryptData(tmp[:sz], client.e_key)
+		typeID := uint32(binary.LittleEndian.Uint32(tmp[:4]))
+
+		// dispatch packet
+		log.Printf("Got packet ID: %x, with a sizeof: %d\n", typeID, sz)
+		pkt := NewPacket(tmp[4:sz])
+		client.handler.HandlePacket(client, typeID, pkt)
+
+		// reset tmp
+		tmp = tmp[:4]
+	}
+}