From 07363a45fe4a7fe693acf438f0b56f927bdd3fbd Mon Sep 17 00:00:00 2001 From: Jakub Grajciar Date: Thu, 2 Apr 2020 10:02:17 +0200 Subject: gomemif: introduce gomemif golang native memif driver Type: feature Signed-off-by: Jakub Grajciar Change-Id: I693156a44011c80025245d25134f5bf5db6eba82 Signed-off-by: Jakub Grajciar --- extras/gomemif/memif/control_channel_unsafe.go | 60 ++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 extras/gomemif/memif/control_channel_unsafe.go (limited to 'extras/gomemif/memif/control_channel_unsafe.go') diff --git a/extras/gomemif/memif/control_channel_unsafe.go b/extras/gomemif/memif/control_channel_unsafe.go new file mode 100644 index 00000000000..9e91297b160 --- /dev/null +++ b/extras/gomemif/memif/control_channel_unsafe.go @@ -0,0 +1,60 @@ +/* + *------------------------------------------------------------------ + * Copyright (c) 2020 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + *------------------------------------------------------------------ + */ + +package memif + +import ( + "fmt" + "os" + "syscall" + "unsafe" +) + +// sendMsg sends a control message from contorl channels message queue +func (cc *controlChannel) sendMsg() (err error) { + if len(cc.msgQueue) < 1 { + return nil + } + // Get message buffer + msg := cc.msgQueue[0] + // Dequeue + cc.msgQueue = cc.msgQueue[1:] + + iov := &syscall.Iovec{ + Base: &msg.Buffer.Bytes()[0], + Len: msgSize, + } + + msgh := syscall.Msghdr{ + Iov: iov, + Iovlen: 1, + } + + if msg.Fd > 0 { + oob := syscall.UnixRights(msg.Fd) + msgh.Control = &oob[0] + msgh.Controllen = uint64(syscall.CmsgSpace(4)) + } + + _, _, errno := syscall.Syscall(syscall.SYS_SENDMSG, uintptr(cc.event.Fd), uintptr(unsafe.Pointer(&msgh)), uintptr(0)) + if errno != 0 { + err = os.NewSyscallError("sendmsg", errno) + return fmt.Errorf("SYS_SENDMSG: %s", errno) + } + + return nil +} -- cgit 1.2.3-korg