net: Introduce VRF related flags and helpers

Add a VRF_MASTER flag for interfaces and helper functions for determining
if a device is a VRF_MASTER.

Add link attribute for passing VRF_TABLE id.

Add vrf_ptr to netdevice.

Add various macros for determining if a device is a VRF device, the index
of the master VRF device and table associated with VRF device.

Signed-off-by: Shrijeet Mukherjee <shm@cumulusnetworks.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 607b5f4..f7a6ef2 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -1289,6 +1289,7 @@
 	IFF_XMIT_DST_RELEASE_PERM	= 1<<22,
 	IFF_IPVLAN_MASTER		= 1<<23,
 	IFF_IPVLAN_SLAVE		= 1<<24,
+	IFF_VRF_MASTER			= 1<<25,
 };
 
 #define IFF_802_1Q_VLAN			IFF_802_1Q_VLAN
@@ -1316,6 +1317,7 @@
 #define IFF_XMIT_DST_RELEASE_PERM	IFF_XMIT_DST_RELEASE_PERM
 #define IFF_IPVLAN_MASTER		IFF_IPVLAN_MASTER
 #define IFF_IPVLAN_SLAVE		IFF_IPVLAN_SLAVE
+#define IFF_VRF_MASTER			IFF_VRF_MASTER
 
 /**
  *	struct net_device - The DEVICE structure.
@@ -1432,6 +1434,7 @@
  *	@dn_ptr:	DECnet specific data
  *	@ip6_ptr:	IPv6 specific data
  *	@ax25_ptr:	AX.25 specific data
+ *	@vrf_ptr:	VRF specific data
  *	@ieee80211_ptr:	IEEE 802.11 specific data, assign before registering
  *
  *	@last_rx:	Time of last Rx
@@ -1650,6 +1653,7 @@
 	struct dn_dev __rcu     *dn_ptr;
 	struct inet6_dev __rcu	*ip6_ptr;
 	void			*ax25_ptr;
+	struct net_vrf_dev __rcu *vrf_ptr;
 	struct wireless_dev	*ieee80211_ptr;
 	struct wpan_dev		*ieee802154_ptr;
 #if IS_ENABLED(CONFIG_MPLS_ROUTING)
@@ -3808,6 +3812,22 @@
 	return dev->priv_flags & IFF_SUPP_NOFCS;
 }
 
+static inline bool netif_is_vrf(const struct net_device *dev)
+{
+	return dev->priv_flags & IFF_VRF_MASTER;
+}
+
+static inline bool netif_index_is_vrf(struct net *net, int ifindex)
+{
+	struct net_device *dev = dev_get_by_index_rcu(net, ifindex);
+	bool rc = false;
+
+	if (dev)
+		rc = netif_is_vrf(dev);
+
+	return rc;
+}
+
 /* This device needs to keep skb dst for qdisc enqueue or ndo_start_xmit() */
 static inline void netif_keep_dst(struct net_device *dev)
 {