packet: refactoring; use go's binary package for encoding *most* things

This commit is contained in:
CPunch 2023-03-10 17:10:57 -06:00
parent 52f0c4b1c7
commit 5cc3f275c1
2 changed files with 40 additions and 99 deletions

View File

@ -3,10 +3,11 @@ package protocol
import (
"encoding/binary"
"fmt"
"io"
"log"
"reflect"
"strconv"
"unicode/utf16"
"unsafe"
)
/*
@ -17,60 +18,61 @@ import (
type Packet struct {
ByteOrder binary.ByteOrder
Buf []byte
cursor int // to keep track of things like member alignment for easier debugging
}
func NewPacket(buf []byte) *Packet {
pkt := &Packet{
ByteOrder: binary.LittleEndian,
Buf: buf,
cursor: 0,
}
return pkt
}
func (pkt *Packet) ResetCursor() {
pkt.cursor = 0
}
func (pkt *Packet) writeRaw(data []byte) {
pkt.Buf = append(pkt.Buf, data...)
pkt.cursor += len(data)
}
func (pkt *Packet) Write(data []byte) {
func (pkt *Packet) Write(data []byte) (int, error) {
pkt.writeRaw(data)
if len(pkt.Buf) > CN_PACKET_BUFFER_SIZE {
panic(fmt.Errorf("Failed to write to packet, invalid size!"))
return 0, fmt.Errorf("Failed to write to packet, invalid size!")
}
return len(data), nil
}
func (pkt *Packet) writeByte(data byte) {
pkt.Write([]byte{data})
}
func (pkt *Packet) readRaw(sz int) []byte {
data := pkt.Buf[:sz]
func (pkt *Packet) readRaw(data []byte) (int, error) {
sz := copy(data, pkt.Buf)
pkt.Buf = pkt.Buf[sz:]
pkt.cursor += sz
return data
if sz != len(data) {
return sz, io.EOF
}
func (pkt *Packet) Read(sz int) []byte {
if sz > len(pkt.Buf) {
panic(fmt.Errorf("Failed to read from packet, invalid size!"))
return sz, nil
}
return pkt.readRaw(sz)
func (pkt *Packet) Read(data []byte) (int, error) {
if len(data) > len(pkt.Buf) {
return 0, fmt.Errorf("Failed to read from packet, invalid size!")
}
return pkt.readRaw(data)
}
func (pkt *Packet) readByte() byte {
return pkt.Read(1)[0]
data := pkt.Buf[0]
pkt.Buf = pkt.Buf[1:]
return data
}
func (pkt *Packet) encodeStructField(field reflect.StructField, value reflect.Value) {
// log.Printf("Encoding '%s', current cursor: %d", field.Name, len(pkt.Buf))
log.Printf("Encoding '%s'", field.Name)
switch field.Type.Kind() {
case reflect.String: // all strings in fusionfall packets are encoded as utf16, we'll need to encode it
@ -79,22 +81,21 @@ func (pkt *Packet) encodeStructField(field reflect.StructField, value reflect.Va
panic(fmt.Errorf("Failed to grab string 'size' tag!!"))
}
sz *= 2
buf16 := utf16.Encode([]rune(value.String()))
buf := *(*[]byte)(unsafe.Pointer(&buf16))
// len(buf) needs to be the same size as sz
if len(buf) > sz {
// len(buf16) needs to be the same size as sz
if len(buf16) > sz {
// truncate
buf = buf[:sz]
buf16 = buf16[:sz]
} else {
// grow
for len(buf) < sz {
buf = append(buf, 0)
for len(buf16) < sz {
buf16 = append(buf16, 0)
}
}
pkt.Write(buf)
// write
binary.Write(pkt, pkt.ByteOrder, buf16)
default:
pkt.Encode(value.Addr().Interface())
}
@ -118,48 +119,14 @@ func (pkt *Packet) Encode(data interface{}) {
for i := 0; i < sz; i++ {
pkt.encodeStructField(rv.Type().Field(i), rv.Field(i))
}
case reflect.Array:
sz := rv.Len()
// encode data
for i := 0; i < sz; i++ {
elem := rv.Index(i)
pkt.Encode(elem.Addr().Interface())
}
case reflect.Uint8:
pkt.writeByte(byte(rv.Uint()))
case reflect.Uint16:
tmp := make([]byte, 2)
pkt.ByteOrder.PutUint16(tmp, uint16(rv.Uint()))
pkt.Write(tmp)
case reflect.Uint32:
tmp := make([]byte, 4)
pkt.ByteOrder.PutUint32(tmp, uint32(rv.Uint()))
pkt.Write(tmp)
case reflect.Uint64:
tmp := make([]byte, 8)
pkt.ByteOrder.PutUint64(tmp, uint64(rv.Uint()))
pkt.Write(tmp)
// im using the PutUintX() api here because it's functionally the same and apparently PutIntX doesn't exist?
case reflect.Int8:
pkt.writeByte(byte(rv.Int()))
case reflect.Int16:
tmp := make([]byte, 2)
pkt.ByteOrder.PutUint16(tmp, uint16(rv.Int()))
pkt.Write(tmp)
case reflect.Int32:
tmp := make([]byte, 4)
pkt.ByteOrder.PutUint32(tmp, uint32(rv.Int()))
pkt.Write(tmp)
case reflect.Int64:
tmp := make([]byte, 8)
pkt.ByteOrder.PutUint64(tmp, uint64(rv.Int()))
pkt.Write(tmp)
default:
// we pass everything else to go's binary package
binary.Write(pkt, pkt.ByteOrder, data)
}
}
func (pkt *Packet) decodeStructField(field reflect.StructField, value reflect.Value) {
// log.Printf("Decoding '%s', current cursor: %d", field.Name, pkt.cursor)
log.Printf("Decoding '%s'", field.Name)
switch field.Type.Kind() {
case reflect.String: // all strings in fusionfall packets are encoded as utf16, we'll need to decode it
@ -168,12 +135,8 @@ func (pkt *Packet) decodeStructField(field reflect.StructField, value reflect.Va
panic(fmt.Errorf("Failed to grab string 'size' tag!!"))
}
// sz * sizeof(char16_t)
sz *= 2
buf := make([]byte, 0, sz)
buf = append(buf, pkt.Read(sz)...)
buf16 := *(*[]uint16)(unsafe.Pointer(&buf))
buf16 := make([]uint16, sz)
binary.Read(pkt, pkt.ByteOrder, buf16)
// find null terminator
var realSize int
@ -183,8 +146,7 @@ func (pkt *Packet) decodeStructField(field reflect.StructField, value reflect.Va
}
}
str := string(utf16.Decode(buf16[:realSize]))
value.SetString(str)
value.SetString(string(utf16.Decode(buf16[:realSize])))
default:
pkt.Decode(value.Addr().Interface())
}
@ -208,29 +170,7 @@ func (pkt *Packet) Decode(data interface{}) {
for i := 0; i < sz; i++ {
pkt.decodeStructField(rv.Type().Field(i), rv.Field(i))
}
case reflect.Array:
sz := rv.Len()
// decode data
for i := 0; i < sz; i++ {
elem := rv.Index(i)
pkt.Decode(elem.Addr().Interface())
}
case reflect.Uint8:
rv.SetUint(uint64(pkt.readByte()))
case reflect.Uint16:
rv.SetUint(uint64(pkt.ByteOrder.Uint16(pkt.Read(2))))
case reflect.Uint32:
rv.SetUint(uint64(pkt.ByteOrder.Uint32(pkt.Read(4))))
case reflect.Uint64:
rv.SetUint(pkt.ByteOrder.Uint64(pkt.Read(8)))
case reflect.Int8:
rv.SetInt(int64(pkt.readByte()))
case reflect.Int16:
rv.SetInt(int64(pkt.ByteOrder.Uint16(pkt.Read(2))))
case reflect.Int32:
rv.SetInt(int64(pkt.ByteOrder.Uint32(pkt.Read(4))))
case reflect.Int64:
rv.SetInt(int64(pkt.ByteOrder.Uint64(pkt.Read(8))))
default:
binary.Read(pkt, pkt.ByteOrder, data)
}
}

View File

@ -35,6 +35,7 @@ func (server *LoginServer) AcceptLogin(peer *Peer, SzID string, IClientVerC int3
UiSvrTime: uint64(time.Now().Unix()),
}
// swap keys
peer.Send(resp, protocol.P_LS2CL_REP_LOGIN_SUCC)
peer.E_key = protocol.CreateNewKey(
resp.UiSvrTime,