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random_head.go
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random_head.go
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package obfs
import (
"encoding/binary"
"hash/crc32"
"math/rand"
"net"
"github.com/xxf098/lite-proxy/common/pool"
)
func init() {
register("random_head", newRandomHead, 0)
}
type randomHead struct {
*Base
}
func newRandomHead(b *Base) Obfs {
return &randomHead{Base: b}
}
type randomHeadConn struct {
net.Conn
*randomHead
hasSentHeader bool
rawTransSent bool
rawTransRecv bool
buf []byte
}
func (r *randomHead) StreamConn(c net.Conn) net.Conn {
return &randomHeadConn{Conn: c, randomHead: r}
}
func (c *randomHeadConn) Read(b []byte) (int, error) {
if c.rawTransRecv {
return c.Conn.Read(b)
}
buf := pool.Get(pool.RelayBufferSize)
defer pool.Put(buf)
c.Conn.Read(buf)
c.rawTransRecv = true
c.Write(nil)
return 0, nil
}
func (c *randomHeadConn) Write(b []byte) (int, error) {
if c.rawTransSent {
return c.Conn.Write(b)
}
c.buf = append(c.buf, b...)
if !c.hasSentHeader {
c.hasSentHeader = true
dataLength := rand.Intn(96) + 4
buf := pool.Get(dataLength + 4)
defer pool.Put(buf)
rand.Read(buf[:dataLength])
binary.LittleEndian.PutUint32(buf[dataLength:], 0xffffffff-crc32.ChecksumIEEE(buf[:dataLength]))
_, err := c.Conn.Write(buf)
return len(b), err
}
if c.rawTransRecv {
_, err := c.Conn.Write(c.buf)
c.buf = nil
c.rawTransSent = true
return len(b), err
}
return len(b), nil
}