}
	return c.fd.writeTo(b, sa)
}

func (c *IPConn) writeMsg(b, oob []byte, addr *IPAddr) (n, oobn int, err error) {
	if c.fd.isConnected {
		return 0, 0, ErrWriteToConnected
	}
	if addr == nil {
		return 0, 0, errMissingAddress
	}
	sa, err := addr.sockaddr(c.fd.family)
	if err != nil {
		return 0, 0, err
	}
	return c.fd.writeMsg(b, oob, sa)
}

	return 0, 0, 0, nil, syscall.EPLAN9
}

func (c *IPConn) writeTo(b []byte, addr *IPAddr) (int, error) {
	return 0, syscall.EPLAN9
}

func (c *IPConn) writeMsg(b, oob []byte, addr *IPAddr) (n, oobn int, err error) {
	return 0, 0, syscall.EPLAN9
}

func (sd *sysDialer) dialIP(ctx context.Context, laddr, raddr *IPAddr) (*IPConn, error) {
	return nil, syscall.EPLAN9
}

	return 0, 0, 0, nil, syscall.EPLAN9
}

func (c *UnixConn) writeTo(b []byte, addr *UnixAddr) (int, error) {
	return 0, syscall.EPLAN9
}

func (c *UnixConn) writeMsg(b, oob []byte, addr *UnixAddr) (n, oobn int, err error) {
	return 0, 0, syscall.EPLAN9
}

func (sd *sysDialer) dialUnix(ctx context.Context, laddr, raddr *UnixAddr) (*UnixConn, error) {
	return nil, syscall.EPLAN9
}

	n, err = fd.pfd.WriteToInet6(p, sa)
	runtime.KeepAlive(fd)
	return n, wrapSyscallError(writeToSyscallName, err)
}

func (fd *netFD) writeMsg(p []byte, oob []byte, sa syscall.Sockaddr) (n int, oobn int, err error) {
	n, oobn, err = fd.pfd.WriteMsg(p, oob, sa)
	runtime.KeepAlive(fd)
	return n, oobn, wrapSyscallError(writeMsgSyscallName, err)
}

	}
	if addr.Net != sotypeToNet(c.fd.sotype) {
		return 0, syscall.EAFNOSUPPORT
	}
	sa := &syscall.SockaddrUnix{Name: addr.Name}
	return c.fd.writeTo(b, sa)
}

func (c *UnixConn) writeMsg(b, oob []byte, addr *UnixAddr) (n, oobn int, err error) {
	if c.fd.sotype == syscall.SOCK_DGRAM && c.fd.isConnected {
		return 0, 0, ErrWriteToConnected
	}
	var sa syscall.Sockaddr
	if addr != nil {

	}
}

func (c *UDPConn) writeMsg(b, oob []byte, addr *UDPAddr) (n, oobn int, err error) {
	if c.fd.isConnected && addr != nil {
		return 0, 0, ErrWriteToConnected
	}
	if !c.fd.isConnected && addr == nil {
		return 0, 0, errMissingAddress
	}
	sa, err := addr.sockaddr(c.fd.family)
	if err != nil {
		return 0, 0, err
	}
	return c.fd.writeMsg(b, oob, sa)
}

			return false
		}
	}

	return true
}

func condFatalf(t *testing.T, network string, format string, args ...any) {
	t.Helper()
	// A few APIs like File and Read/WriteMsg{UDP,IP} are not
	// fully implemented yet on Plan 9 and Windows.
	switch runtime.GOOS {
	case "windows", "js", "wasip1":
		if network == "file+net" {
			t.Logf(format, args...)
			return
		}

	return len(b), nil
}

func (c *UDPConn) writeToAddrPort(b []byte, addr netip.AddrPort) (int, error) {
	return c.writeTo(b, UDPAddrFromAddrPort(addr)) // TODO: optimize instead of allocating
}

func (c *UDPConn) writeMsg(b, oob []byte, addr *UDPAddr) (n, oobn int, err error) {
	return 0, 0, syscall.EPLAN9
}

func (c *UDPConn) writeMsgAddrPort(b, oob []byte, addr netip.AddrPort) (n, oobn int, err error) {
	return 0, 0, syscall.EPLAN9
}

			case dns.TypeANY:
				msg.Rcode = dns.RcodeRefused
			default:
				msg.Rcode = dns.RcodeNotImplemented
			}
		} else {
			msg.Rcode = dns.RcodeNameError
		}
	}
	if err := w.WriteMsg(msg); err != nil {
		scopes.Framework.Errorf("failed writing fake DNS response: %v", err)
	}
}

func (s *fakeDNSServer) setHosts(hosts sets.String) {
	s.mu.Lock()
	defer s.mu.Unlock()

// used to manipulate IP-level socket options in oob.
func (c *IPConn) WriteMsgIP(b, oob []byte, addr *IPAddr) (n, oobn int, err error) {
	if !c.ok() {
		return 0, 0, syscall.EINVAL
	}
	n, oobn, err = c.writeMsg(b, oob, addr)
	if err != nil {
		err = &OpError{Op: "write", Net: c.fd.net, Source: c.fd.laddr, Addr: addr.opAddr(), Err: err}
	}
	return
}

func newIPConn(fd *netFD) *IPConn { return &IPConn{conn{fd}} }