add kpod stats function

Signed-off-by: Ryan Cole <rcyoalne@gmail.com>

vendor/github.com/vishvananda/netlink/xfrm_monitor_linux.go

@@ -0,0 +1,98 @@
+package netlink
+
+import (
+	"fmt"
+	"syscall"
+
+	"github.com/vishvananda/netns"
+
+	"github.com/vishvananda/netlink/nl"
+)
+
+type XfrmMsg interface {
+	Type() nl.XfrmMsgType
+}
+
+type XfrmMsgExpire struct {
+	XfrmState *XfrmState
+	Hard      bool
+}
+
+func (ue *XfrmMsgExpire) Type() nl.XfrmMsgType {
+	return nl.XFRM_MSG_EXPIRE
+}
+
+func parseXfrmMsgExpire(b []byte) *XfrmMsgExpire {
+	var e XfrmMsgExpire
+
+	msg := nl.DeserializeXfrmUserExpire(b)
+	e.XfrmState = xfrmStateFromXfrmUsersaInfo(&msg.XfrmUsersaInfo)
+	e.Hard = msg.Hard == 1
+
+	return &e
+}
+
+func XfrmMonitor(ch chan<- XfrmMsg, done <-chan struct{}, errorChan chan<- error,
+	types ...nl.XfrmMsgType) error {
+
+	groups, err := xfrmMcastGroups(types)
+	if err != nil {
+		return nil
+	}
+	s, err := nl.SubscribeAt(netns.None(), netns.None(), syscall.NETLINK_XFRM, groups...)
+	if err != nil {
+		return err
+	}
+
+	if done != nil {
+		go func() {
+			<-done
+			s.Close()
+		}()
+
+	}
+
+	go func() {
+		defer close(ch)
+		for {
+			msgs, err := s.Receive()
+			if err != nil {
+				errorChan <- err
+				return
+			}
+			for _, m := range msgs {
+				switch m.Header.Type {
+				case nl.XFRM_MSG_EXPIRE:
+					ch <- parseXfrmMsgExpire(m.Data)
+				default:
+					errorChan <- fmt.Errorf("unsupported msg type: %x", m.Header.Type)
+				}
+			}
+		}
+	}()
+
+	return nil
+}
+
+func xfrmMcastGroups(types []nl.XfrmMsgType) ([]uint, error) {
+	groups := make([]uint, 0)
+
+	if len(types) == 0 {
+		return nil, fmt.Errorf("no xfrm msg type specified")
+	}
+
+	for _, t := range types {
+		var group uint
+
+		switch t {
+		case nl.XFRM_MSG_EXPIRE:
+			group = nl.XFRMNLGRP_EXPIRE
+		default:
+			return nil, fmt.Errorf("unsupported group: %x", t)
+		}
+
+		groups = append(groups, group)
+	}
+
+	return groups, nil
+}