Merge branch '40260-revert-queuepacketconn-ownership' into 'main'

Revert "Take ownership of buffer in QueuePacketConn QueueIncoming/WriteTo"

See merge request tpo/anti-censorship/pluggable-transports/snowflake!140
This commit is contained in:
David Fifield 2023-03-13 19:36:09 +00:00
commit ef51f2063e

View file

@ -42,9 +42,8 @@ func NewQueuePacketConn(localAddr net.Addr, timeout time.Duration) *QueuePacketC
}
}
// QueueIncoming queues an incoming packet and its source address, to be
// returned in a future call to ReadFrom. This function takes ownership of p and
// the caller must not reuse it.
// QueueIncoming queues and incoming packet and its source address, to be
// returned in a future call to ReadFrom.
func (c *QueuePacketConn) QueueIncoming(p []byte, addr net.Addr) {
select {
case <-c.closed:
@ -52,8 +51,11 @@ func (c *QueuePacketConn) QueueIncoming(p []byte, addr net.Addr) {
return
default:
}
// Copy the slice so that the caller may reuse it.
buf := make([]byte, len(p))
copy(buf, p)
select {
case c.recvQueue <- taggedPacket{p, addr}:
case c.recvQueue <- taggedPacket{buf, addr}:
default:
// Drop the incoming packet if the receive queue is full.
}
@ -82,20 +84,22 @@ func (c *QueuePacketConn) ReadFrom(p []byte) (int, net.Addr, error) {
}
// WriteTo queues an outgoing packet for the given address. The queue can later
// be retrieved using the OutgoingQueue method. This function takes ownership of
// p and the caller must not reuse it.
// be retrieved using the OutgoingQueue method.
func (c *QueuePacketConn) WriteTo(p []byte, addr net.Addr) (int, error) {
select {
case <-c.closed:
return 0, &net.OpError{Op: "write", Net: c.LocalAddr().Network(), Addr: c.LocalAddr(), Err: c.err.Load().(error)}
default:
}
// Copy the slice so that the caller may reuse it.
buf := make([]byte, len(p))
copy(buf, p)
select {
case c.clients.SendQueue(addr) <- p:
return len(p), nil
case c.clients.SendQueue(addr) <- buf:
return len(buf), nil
default:
// Drop the outgoing packet if the send queue is full.
return len(p), nil
return len(buf), nil
}
}