1
0
mirror of https://github.com/fumiama/WireGold.git synced 2026-06-08 01:24:57 +08:00
Files
WireGold/gold/link/recv.go
2023-08-05 13:53:09 +08:00

81 lines
2.0 KiB
Go

package link
import (
"encoding/binary"
"encoding/hex"
"unsafe"
"github.com/fumiama/WireGold/gold/head"
"github.com/sirupsen/logrus"
)
// Read 从 peer 收包
func (l *Link) Read() *head.Packet {
return <-l.pipe
}
func (m *Me) wait(data []byte) *head.Packet {
if len(data) < 60 { // not a valid packet
return nil
}
bound := 64
endl := "..."
if len(data) < bound {
bound = len(data)
endl = "."
}
logrus.Debugln("[recv] data bytes", hex.EncodeToString(data[:bound]), endl)
data = m.xordec(data)
logrus.Debugln("[recv] data xored", hex.EncodeToString(data[:bound]), endl)
flags := binary.LittleEndian.Uint16(data[10:12])
if flags&0x8000 != 0 { // not a valid packet
logrus.Debugln("[recv] drop invalid flags packet:", hex.EncodeToString(data[11:12]), hex.EncodeToString(data[10:11]))
return nil
}
crc := binary.LittleEndian.Uint64(data[52:60])
if m.recved.Get(crc) { // 是重放攻击
return nil
}
logrus.Debugln("[recv]", len(data), "bytes data with flag", hex.EncodeToString(data[11:12]), hex.EncodeToString(data[10:11]))
if flags == 0 || flags == 0x4000 {
h := head.SelectPacket()
_, err := h.Unmarshal(data)
if err != nil {
logrus.Errorln("[recv] unmarshal err:", err)
return nil
}
m.recved.Set(crc, true)
return h
}
hashd := data[20:52]
hsh := *(*[32]byte)(*(*unsafe.Pointer)(unsafe.Pointer(&hashd)))
h := m.recving.Get(hsh)
if h != nil {
logrus.Debugln("[recv] get another frag part of", hex.EncodeToString(hashd))
ok, err := h.Unmarshal(data)
if err == nil {
if ok {
m.recving.Delete(hsh)
m.recved.Set(crc, true)
logrus.Debugln("[recv] all parts of", hex.EncodeToString(hashd), "has reached")
return h
}
} else {
h.Put()
logrus.Errorln("[recv] unmarshal err:", err)
}
return nil
}
logrus.Debugln("[recv] get new frag part of", hex.EncodeToString(hashd))
h = head.SelectPacket()
_, err := h.Unmarshal(data)
if err != nil {
h.Put()
logrus.Errorln("[recv] unmarshal err:", err)
return nil
}
m.recving.Set(hsh, h)
return nil
}