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>

1 files changed, 139 insertions, 0 deletions

diff --git a/include/net/vrf.h b/include/net/vrf.h
new file mode 100644
index 000000000000..0484d29d4589
--- /dev/null
+++ b/include/net/vrf.h
@@ -0,0 +1,139 @@
+/*
+ * include/net/net_vrf.h - adds vrf dev structure definitions
+ * Copyright (c) 2015 Cumulus Networks
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef __LINUX_NET_VRF_H
+#define __LINUX_NET_VRF_H
+
+struct net_vrf_dev {
+	struct rcu_head		rcu;
+	int                     ifindex; /* ifindex of master dev */
+	u32                     tb_id;   /* table id for VRF */
+};
+
+struct slave {
+	struct list_head	list;
+	struct net_device	*dev;
+};
+
+struct slave_queue {
+	struct list_head	all_slaves;
+	int			num_slaves;
+};
+
+struct net_vrf {
+	struct slave_queue	queue;
+	struct rtable           *rth;
+	u32			tb_id;
+};
+
+
+#if IS_ENABLED(CONFIG_NET_VRF)
+/* called with rcu_read_lock() */
+static inline int vrf_master_ifindex_rcu(const struct net_device *dev)
+{
+	struct net_vrf_dev *vrf_ptr;
+	int ifindex = 0;
+
+	if (!dev)
+		return 0;
+
+	if (netif_is_vrf(dev))
+		ifindex = dev->ifindex;
+	else {
+		vrf_ptr = rcu_dereference(dev->vrf_ptr);
+		if (vrf_ptr)
+			ifindex = vrf_ptr->ifindex;
+	}
+
+	return ifindex;
+}
+
+/* called with rcu_read_lock */
+static inline int vrf_dev_table_rcu(const struct net_device *dev)
+{
+	int tb_id = 0;
+
+	if (dev) {
+		struct net_vrf_dev *vrf_ptr;
+
+		vrf_ptr = rcu_dereference(dev->vrf_ptr);
+		if (vrf_ptr)
+			tb_id = vrf_ptr->tb_id;
+	}
+	return tb_id;
+}
+
+static inline int vrf_dev_table(const struct net_device *dev)
+{
+	int tb_id;
+
+	rcu_read_lock();
+	tb_id = vrf_dev_table_rcu(dev);
+	rcu_read_unlock();
+
+	return tb_id;
+}
+
+/* called with rtnl */
+static inline int vrf_dev_table_rtnl(const struct net_device *dev)
+{
+	int tb_id = 0;
+
+	if (dev) {
+		struct net_vrf_dev *vrf_ptr;
+
+		vrf_ptr = rtnl_dereference(dev->vrf_ptr);
+		if (vrf_ptr)
+			tb_id = vrf_ptr->tb_id;
+	}
+	return tb_id;
+}
+
+/* caller has already checked netif_is_vrf(dev) */
+static inline struct rtable *vrf_dev_get_rth(const struct net_device *dev)
+{
+	struct rtable *rth = ERR_PTR(-ENETUNREACH);
+	struct net_vrf *vrf = netdev_priv(dev);
+
+	if (vrf) {
+		rth = vrf->rth;
+		atomic_inc(&rth->dst.__refcnt);
+	}
+	return rth;
+}
+
+#else
+static inline int vrf_master_ifindex_rcu(const struct net_device *dev)
+{
+	return 0;
+}
+
+static inline int vrf_dev_table_rcu(const struct net_device *dev)
+{
+	return 0;
+}
+
+static inline int vrf_dev_table(const struct net_device *dev)
+{
+	return 0;
+}
+
+static inline int vrf_dev_table_rtnl(const struct net_device *dev)
+{
+	return 0;
+}
+
+static inline struct rtable *vrf_dev_get_rth(const struct net_device *dev)
+{
+	return ERR_PTR(-ENETUNREACH);
+}
+#endif
+
+#endif /* __LINUX_NET_VRF_H */