2 *------------------------------------------------------------------
3 * Copyright (c) 2020 Cisco and/or its affiliates.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 *------------------------------------------------------------------
27 // sendMsg sends a control message from contorl channels message queue
28 func (cc *controlChannel) sendMsg() (err error) {
29 if len(cc.msgQueue) < 1 {
35 cc.msgQueue = cc.msgQueue[1:]
37 iov := &syscall.Iovec{
38 Base: &msg.Buffer.Bytes()[0],
42 msgh := syscall.Msghdr{
48 oob := syscall.UnixRights(msg.Fd)
49 msgh.Control = &oob[0]
50 msgh.Controllen = uint64(syscall.CmsgSpace(4))
53 _, _, errno := syscall.Syscall(syscall.SYS_SENDMSG, uintptr(cc.event.Fd), uintptr(unsafe.Pointer(&msgh)), uintptr(0))
55 err = os.NewSyscallError("sendmsg", errno)
56 return fmt.Errorf("SYS_SENDMSG: %s", errno)