gomemif: introduce gomemif
golang native memif driver
Type: feature
Signed-off-by: Jakub Grajciar <jgrajcia@cisco.com>
Change-Id: I693156a44011c80025245d25134f5bf5db6eba82
Signed-off-by: Jakub Grajciar <jgrajcia@cisco.com>
diff --git a/extras/gomemif/memif/control_channel_unsafe.go b/extras/gomemif/memif/control_channel_unsafe.go
new file mode 100644
index 0000000..9e91297
--- /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
+}