netlink: add func AddrSubscribe on linux

netlink/addr_default.go

@@ -0,0 +1,12 @@
+//go:build !linux && !windows && !darwin
+
+package netlink
+
+import (
+	"context"
+	"errors"
+)
+
+func AddrSubscribe(ctx context.Context, ch chan<- AddrUpdate) error {
+	return errors.ErrUnsupported
+}

netlink/addr_linux.go

@@ -0,0 +1,31 @@
+package netlink
+
+import (
+	"context"
+
+	"github.com/vishvananda/netlink"
+)
+
+func AddrSubscribe(ctx context.Context, ch chan<- AddrUpdate) error {
+	rawChan := make(chan netlink.AddrUpdate)
+	err := netlink.AddrSubscribe(rawChan, ctx.Done())
+	if err != nil {
+		return err
+	}
+	go func() {
+		defer close(ch)
+		for {
+			select {
+			case <-ctx.Done():
+				return
+			case e := <-rawChan:
+				ch <- AddrUpdate{
+					New:       e.NewAddr,
+					Addr:      e.LinkAddress,
+					LinkIndex: e.LinkIndex,
+				}
+			}
+		}
+	}()
+	return nil
+}