Revert vendor directory to support old golang (GOPATH mode)

gomodule is still in progress to migrate for now, hence multus
team decide to keep vendor directory to support build without
gomodule.

vendor/github.com/vishvananda/netlink/nl/xfrm_policy_linux.go

@@ -0,0 +1,119 @@
+package nl
+
+import (
+	"unsafe"
+)
+
+const (
+	SizeofXfrmUserpolicyId   = 0x40
+	SizeofXfrmUserpolicyInfo = 0xa8
+	SizeofXfrmUserTmpl       = 0x40
+)
+
+// struct xfrm_userpolicy_id {
+//   struct xfrm_selector    sel;
+//   __u32       index;
+//   __u8        dir;
+// };
+//
+
+type XfrmUserpolicyId struct {
+	Sel   XfrmSelector
+	Index uint32
+	Dir   uint8
+	Pad   [3]byte
+}
+
+func (msg *XfrmUserpolicyId) Len() int {
+	return SizeofXfrmUserpolicyId
+}
+
+func DeserializeXfrmUserpolicyId(b []byte) *XfrmUserpolicyId {
+	return (*XfrmUserpolicyId)(unsafe.Pointer(&b[0:SizeofXfrmUserpolicyId][0]))
+}
+
+func (msg *XfrmUserpolicyId) Serialize() []byte {
+	return (*(*[SizeofXfrmUserpolicyId]byte)(unsafe.Pointer(msg)))[:]
+}
+
+// struct xfrm_userpolicy_info {
+//   struct xfrm_selector    sel;
+//   struct xfrm_lifetime_cfg  lft;
+//   struct xfrm_lifetime_cur  curlft;
+//   __u32       priority;
+//   __u32       index;
+//   __u8        dir;
+//   __u8        action;
+// #define XFRM_POLICY_ALLOW 0
+// #define XFRM_POLICY_BLOCK 1
+//   __u8        flags;
+// #define XFRM_POLICY_LOCALOK 1 /* Allow user to override global policy */
+//   /* Automatically expand selector to include matching ICMP payloads. */
+// #define XFRM_POLICY_ICMP  2
+//   __u8        share;
+// };
+
+type XfrmUserpolicyInfo struct {
+	Sel      XfrmSelector
+	Lft      XfrmLifetimeCfg
+	Curlft   XfrmLifetimeCur
+	Priority uint32
+	Index    uint32
+	Dir      uint8
+	Action   uint8
+	Flags    uint8
+	Share    uint8
+	Pad      [4]byte
+}
+
+func (msg *XfrmUserpolicyInfo) Len() int {
+	return SizeofXfrmUserpolicyInfo
+}
+
+func DeserializeXfrmUserpolicyInfo(b []byte) *XfrmUserpolicyInfo {
+	return (*XfrmUserpolicyInfo)(unsafe.Pointer(&b[0:SizeofXfrmUserpolicyInfo][0]))
+}
+
+func (msg *XfrmUserpolicyInfo) Serialize() []byte {
+	return (*(*[SizeofXfrmUserpolicyInfo]byte)(unsafe.Pointer(msg)))[:]
+}
+
+// struct xfrm_user_tmpl {
+//   struct xfrm_id    id;
+//   __u16     family;
+//   xfrm_address_t    saddr;
+//   __u32     reqid;
+//   __u8      mode;
+//   __u8      share;
+//   __u8      optional;
+//   __u32     aalgos;
+//   __u32     ealgos;
+//   __u32     calgos;
+// }
+
+type XfrmUserTmpl struct {
+	XfrmId   XfrmId
+	Family   uint16
+	Pad1     [2]byte
+	Saddr    XfrmAddress
+	Reqid    uint32
+	Mode     uint8
+	Share    uint8
+	Optional uint8
+	Pad2     byte
+	Aalgos   uint32
+	Ealgos   uint32
+	Calgos   uint32
+}
+
+func (msg *XfrmUserTmpl) Len() int {
+	return SizeofXfrmUserTmpl
+}
+
+func DeserializeXfrmUserTmpl(b []byte) *XfrmUserTmpl {
+	return (*XfrmUserTmpl)(unsafe.Pointer(&b[0:SizeofXfrmUserTmpl][0]))
+}
+
+func (msg *XfrmUserTmpl) Serialize() []byte {
+	return (*(*[SizeofXfrmUserTmpl]byte)(unsafe.Pointer(msg)))[:]
+}