fdconn.go RawHistoryFolder

1// SPDX-License-Identifier: MIT
2
3package guest
4
5import (
6	"os"
7
8	"golang.org/x/sys/unix"
9)
10
11// fdConn is a connected stream socket as a ReadWriteCloser registered with the
12// runtime poller (net.FileConn does not know AF_VSOCK). It can shut down its
13// write side, which the cache relay passes on from the client.
14type fdConn struct{ *os.File }
15
16func newFDConn(fd int) (*fdConn, error) {
17	if err := unix.SetNonblock(fd, true); err != nil {
18		_ = unix.Close(fd)
19		return nil, err
20	}
21	return &fdConn{os.NewFile(uintptr(fd), "vsock")}, nil
22}
23
24// CloseWrite sends the end of the stream (shutdown(SHUT_WR)) and keeps reading.
25func (c *fdConn) CloseWrite() error {
26	rc, err := c.SyscallConn()
27	if err != nil {
28		return err
29	}
30	var serr error
31	if err := rc.Control(func(fd uintptr) { serr = unix.Shutdown(int(fd), unix.SHUT_WR) }); err != nil {
32		return err
33	}
34	return serr
35}