container: use new netlink implementation

This is adapted from the container netlink implementation and is much more reusable.

Signed-off-by: Ophestra <cat@gensokyo.uk>

container/netlink_test.go

@@ -1,72 +0,0 @@
-package container
-
-import (
-	"testing"
-	"unsafe"
-)
-
-func TestSizeof(t *testing.T) {
-	if got := unsafe.Sizeof(newaddrLo{}); got != sizeofNewaddrLo {
-		t.Fatalf("newaddrLo: sizeof = %#x, want %#x", got, sizeofNewaddrLo)
-	}
-
-	if got := unsafe.Sizeof(newlinkLo{}); got != sizeofNewlinkLo {
-		t.Fatalf("newlinkLo: sizeof = %#x, want %#x", got, sizeofNewlinkLo)
-	}
-}
-
-func TestRtnetlinkMessage(t *testing.T) {
-	t.Parallel()
-
-	testCases := []struct {
-		name string
-		msg  interface{ toWireFormat() []byte }
-		want []byte
-	}{
-		{"newaddrLo", (&rtnetlink{pid: 1, seq: 0}).newaddrLo(1), []byte{
-			/* Len   */ 0x28, 0, 0, 0,
-			/* Type  */ 0x14, 0,
-			/* Flags */ 5, 6,
-			/* Seq   */ 0, 0, 0, 0,
-			/* Pid   */ 1, 0, 0, 0,
-
-			/* Family    */ 2,
-			/* Prefixlen */ 8,
-			/* Flags     */ 0x80,
-			/* Scope     */ 0xfe,
-			/* Index     */ 1, 0, 0, 0,
-
-			/* Len     */ 8, 0,
-			/* Type    */ 2, 0,
-			/* in_addr */ 127, 0, 0, 1,
-
-			/* Len     */ 8, 0,
-			/* Type    */ 1, 0,
-			/* in_addr */ 127, 0, 0, 1,
-		}},
-
-		{"newlinkLo", (&rtnetlink{pid: 1, seq: 1}).newlinkLo(1), []byte{
-			/* Len   */ 0x20, 0, 0, 0,
-			/* Type  */ 0x10, 0,
-			/* Flags */ 5, 0,
-			/* Seq   */ 1, 0, 0, 0,
-			/* Pid   */ 1, 0, 0, 0,
-
-			/* Family */ 0,
-			/* pad    */ 0,
-			/* Type   */ 0, 0,
-			/* Index  */ 1, 0, 0, 0,
-			/* Flags  */ 1, 0, 0, 0,
-			/* Change */ 1, 0, 0, 0,
-		}},
-	}
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-
-			if got := tc.msg.toWireFormat(); string(got) != string(tc.want) {
-				t.Fatalf("toWireFormat: %#v, want %#v", got, tc.want)
-			}
-		})
-	}
-}