1 files changed, 223 insertions, 0 deletions
diff --git a/adapter/vppapiclient/vppapiclient.go b/adapter/vppapiclient/vppapiclient.go
new file mode 100644
index 0000000..34ad199
--- /dev/null
+++ b/adapter/vppapiclient/vppapiclient.go
@@ -0,0 +1,223 @@
+// Copyright (c) 2017 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.
+
+// +build !windows,!darwin
+
+package vppapiclient
+
+/*
+#cgo CFLAGS: -DPNG_DEBUG=1
+#cgo LDFLAGS: -lvppapiclient
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <arpa/inet.h>
+#include <vpp-api/client/vppapiclient.h>
+
+extern void go_msg_callback(uint16_t msg_id, void* data, size_t size);
+
+typedef struct __attribute__((__packed__)) _req_header {
+    uint16_t msg_id;
+    uint32_t client_index;
+    uint32_t context;
+} req_header_t;
+
+typedef struct __attribute__((__packed__)) _reply_header {
+    uint16_t msg_id;
+} reply_header_t;
+
+static void
+govpp_msg_callback(unsigned char *data, int size)
+{
+    reply_header_t *header = ((reply_header_t *)data);
+    go_msg_callback(ntohs(header->msg_id), data, size);
+}
+
+static int
+govpp_send(uint32_t context, void *data, size_t size)
+{
+	req_header_t *header = ((req_header_t *)data);
+	header->context = htonl(context);
+    return vac_write(data, size);
+}
+
+static int
+govpp_connect(char *shm)
+{
+    return vac_connect("govpp", shm, govpp_msg_callback, 32);
+}
+
+static int
+govpp_disconnect()
+{
+    return vac_disconnect();
+}
+
+static uint32_t
+govpp_get_msg_index(char *name_and_crc)
+{
+    return vac_get_msg_index(name_and_crc);
+}
+*/
+import "C"
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"reflect"
+	"unsafe"
+
+	"git.fd.io/govpp.git/adapter"
+	"github.com/fsnotify/fsnotify"
+)
+
+const (
+	// shmDir is a directory where shared memory is supposed to be created.
+	shmDir = "/dev/shm/"
+	// vppShmFile is a default name of the file in the shmDir.
+	vppShmFile = "vpe-api"
+)
+
+// global VPP binary API client adapter context
+var client *VppClient
+
+// VppClient is the default implementation of the VppAPI.
+type VppClient struct {
+	shmPrefix   string
+	msgCallback adapter.MsgCallback
+}
+
+// NewVppClient returns a new VPP binary API client.
+func NewVppClient(shmPrefix string) *VppClient {
+	return &VppClient{
+		shmPrefix: shmPrefix,
+	}
+}
+
+// Connect connects the process to VPP.
+func (a *VppClient) Connect() error {
+	if client != nil {
+		return fmt.Errorf("already connected to binary API, disconnect first")
+	}
+
+	var rc _Ctype_int
+	if a.shmPrefix == "" {
+		rc = C.govpp_connect(nil)
+	} else {
+		shm := C.CString(a.shmPrefix)
+		rc = C.govpp_connect(shm)
+	}
+	if rc != 0 {
+		return fmt.Errorf("connecting to VPP binary API failed (rc=%v)", rc)
+	}
+
+	client = a
+	return nil
+}
+
+// Disconnect disconnects the process from VPP.
+func (a *VppClient) Disconnect() error {
+	client = nil
+
+	rc := C.govpp_disconnect()
+	if rc != 0 {
+		return fmt.Errorf("disconnecting from VPP binary API failed (rc=%v)", rc)
+	}
+
+	return nil
+}
+
+// GetMsgID returns a runtime message ID for the given message name and CRC.
+func (a *VppClient) GetMsgID(msgName string, msgCrc string) (uint16, error) {
+	nameAndCrc := C.CString(msgName + "_" + msgCrc)
+	defer C.free(unsafe.Pointer(nameAndCrc))
+
+	msgID := uint16(C.govpp_get_msg_index(nameAndCrc))
+	if msgID == ^uint16(0) {
+		// VPP does not know this message
+		return msgID, fmt.Errorf("unknown message: %v (crc: %v)", msgName, msgCrc)
+	}
+
+	return msgID, nil
+}
+
+// SendMsg sends a binary-encoded message to VPP.
+func (a *VppClient) SendMsg(context uint32, data []byte) error {
+	rc := C.govpp_send(C.uint32_t(context), unsafe.Pointer(&data[0]), C.size_t(len(data)))
+	if rc != 0 {
+		return fmt.Errorf("unable to send the message (rc=%v)", rc)
+	}
+	return nil
+}
+
+// SetMsgCallback sets a callback function that will be called by the adapter
+// whenever a message comes from VPP.
+func (a *VppClient) SetMsgCallback(cb adapter.MsgCallback) {
+	a.msgCallback = cb
+}
+
+// WaitReady blocks until shared memory for sending
+// binary api calls is present on the file system.
+func (a *VppClient) WaitReady() error {
+	var path string
+
+	// join the path to the shared memory segment
+	if a.shmPrefix == "" {
+		path = filepath.Join(shmDir, vppShmFile)
+	} else {
+		path = filepath.Join(shmDir, a.shmPrefix+"-"+vppShmFile)
+	}
+
+	// check if file at the path exists
+	if _, err := os.Stat(path); err == nil {
+		// file exists, we are ready
+		return nil
+	} else if !os.IsNotExist(err) {
+		return err
+	}
+
+	// file does not exist, start watching folder
+	watcher, err := fsnotify.NewWatcher()
+	if err != nil {
+		return err
+	}
+	defer watcher.Close()
+
+	if err := watcher.Add(shmDir); err != nil {
+		return err
+	}
+
+	for {
+		ev := <-watcher.Events
+		if ev.Name == path {
+			if (ev.Op & fsnotify.Create) == fsnotify.Create {
+				// file was created, we are ready
+				break
+			}
+		}
+	}
+
+	return nil
+}
+
+//export go_msg_callback
+func go_msg_callback(msgID C.uint16_t, data unsafe.Pointer, size C.size_t) {
+	// convert unsafe.Pointer to byte slice
+	sliceHeader := &reflect.SliceHeader{Data: uintptr(data), Len: int(size), Cap: int(size)}
+	byteSlice := *(*[]byte)(unsafe.Pointer(sliceHeader))
+
+	client.msgCallback(uint16(msgID), byteSlice)
+}