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binder.go
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binder.go
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package utils
import (
"errors"
"golang.zx2c4.com/wireguard/conn"
)
type Bind struct {
conn.Bind
reseved [3]byte
}
func NewResevedBind(bind conn.Bind, reserved [3]byte) *Bind {
return &Bind{
Bind: bind,
reseved: reserved,
}
}
func (b *Bind) SetReseved(reserved [3]byte) {
b.reseved = reserved
}
func (b *Bind) Send(buf []byte, ep conn.Endpoint) error {
if len(buf) > 3 {
buf[1] = b.reseved[0]
buf[2] = b.reseved[1]
buf[3] = b.reseved[2]
}
return b.Bind.Send(buf, ep)
}
func (b *Bind) Open(port uint16) (fns []conn.ReceiveFunc, actualPort uint16, err error) {
fns, actualPort, err = b.Bind.Open(port)
if err != nil {
return
}
var tempFns []conn.ReceiveFunc
for _, fn := range fns {
tempFns = append(tempFns,b.NewReceiveFunc(fn))
}
fns = tempFns
return
}
func (b *Bind) NewReceiveFunc(fn conn.ReceiveFunc) conn.ReceiveFunc {
return func(buf []byte) (n int, ep conn.Endpoint, err error) {
n, ep, err = fn(buf)
if err != nil || n < 4 {
return
}
if buf[1] != b.reseved[0] || buf[2] != b.reseved[1] || buf[3] != b.reseved[2] {
err = errors.New("bad reseved")
return
}
buf[1] = 0
buf[2] = 0
buf[3] = 0
return
}
}