1/*
  2 * include/net/l3mdev.h - L3 master device API
  3 * Copyright (c) 2015 Cumulus Networks
  4 * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com>
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of the GNU General Public License as published by
  8 * the Free Software Foundation; either version 2 of the License, or
  9 * (at your option) any later version.
 10 */
 11#ifndef _NET_L3MDEV_H_
 12#define _NET_L3MDEV_H_
 13
 14/**
 15 * struct l3mdev_ops - l3mdev operations
 16 *
 17 * @l3mdev_fib_table: Get FIB table id to use for lookups
 18 *
 19 * @l3mdev_get_rtable: Get cached IPv4 rtable (dst_entry) for device
 20 *
 21 * @l3mdev_get_saddr: Get source address for a flow
 22 *
 23 * @l3mdev_get_rt6_dst: Get cached IPv6 rt6_info (dst_entry) for device
 24 */
 25
 26struct l3mdev_ops {
 27	u32		(*l3mdev_fib_table)(const struct net_device *dev);
 28
 29	/* IPv4 ops */
 30	struct rtable *	(*l3mdev_get_rtable)(const struct net_device *dev,
 31					     const struct flowi4 *fl4);
 32	int		(*l3mdev_get_saddr)(struct net_device *dev,
 33					    struct flowi4 *fl4);
 34
 35	/* IPv6 ops */
 36	struct dst_entry * (*l3mdev_get_rt6_dst)(const struct net_device *dev,
 37						 const struct flowi6 *fl6);
 38};
 39
 40#ifdef CONFIG_NET_L3_MASTER_DEV
 41
 42int l3mdev_master_ifindex_rcu(const struct net_device *dev);
 43static inline int l3mdev_master_ifindex(struct net_device *dev)
 44{
 45	int ifindex;
 46
 47	rcu_read_lock();
 48	ifindex = l3mdev_master_ifindex_rcu(dev);
 49	rcu_read_unlock();
 50
 51	return ifindex;
 52}
 53
 54static inline int l3mdev_master_ifindex_by_index(struct net *net, int ifindex)
 55{
 56	struct net_device *dev;
 57	int rc = 0;
 58
 59	if (likely(ifindex)) {
 60		rcu_read_lock();
 61
 62		dev = dev_get_by_index_rcu(net, ifindex);
 63		if (dev)
 64			rc = l3mdev_master_ifindex_rcu(dev);
 65
 66		rcu_read_unlock();
 67	}
 68
 69	return rc;
 70}
 71
 72/* get index of an interface to use for FIB lookups. For devices
 73 * enslaved to an L3 master device FIB lookups are based on the
 74 * master index
 75 */
 76static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
 77{
 78	return l3mdev_master_ifindex_rcu(dev) ? : dev->ifindex;
 79}
 80
 81static inline int l3mdev_fib_oif(struct net_device *dev)
 82{
 83	int oif;
 84
 85	rcu_read_lock();
 86	oif = l3mdev_fib_oif_rcu(dev);
 87	rcu_read_unlock();
 88
 89	return oif;
 90}
 91
 92u32 l3mdev_fib_table_rcu(const struct net_device *dev);
 93u32 l3mdev_fib_table_by_index(struct net *net, int ifindex);
 94static inline u32 l3mdev_fib_table(const struct net_device *dev)
 95{
 96	u32 tb_id;
 97
 98	rcu_read_lock();
 99	tb_id = l3mdev_fib_table_rcu(dev);
100	rcu_read_unlock();
101
102	return tb_id;
103}
104
105static inline struct rtable *l3mdev_get_rtable(const struct net_device *dev,
106					       const struct flowi4 *fl4)
107{
108	if (netif_is_l3_master(dev) && dev->l3mdev_ops->l3mdev_get_rtable)
109		return dev->l3mdev_ops->l3mdev_get_rtable(dev, fl4);
110
111	return NULL;
112}
113
114static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
115{
116	struct net_device *dev;
117	bool rc = false;
118
119	if (ifindex == 0)
120		return false;
121
122	rcu_read_lock();
123
124	dev = dev_get_by_index_rcu(net, ifindex);
125	if (dev)
126		rc = netif_is_l3_master(dev);
127
128	rcu_read_unlock();
129
130	return rc;
131}
132
133static inline int l3mdev_get_saddr(struct net *net, int ifindex,
134				   struct flowi4 *fl4)
135{
136	struct net_device *dev;
137	int rc = 0;
138
139	if (ifindex) {
140
141		rcu_read_lock();
142
143		dev = dev_get_by_index_rcu(net, ifindex);
144		if (dev && netif_is_l3_master(dev) &&
145		    dev->l3mdev_ops->l3mdev_get_saddr) {
146			rc = dev->l3mdev_ops->l3mdev_get_saddr(dev, fl4);
147		}
148
149		rcu_read_unlock();
150	}
151
152	return rc;
153}
154
155static inline struct dst_entry *l3mdev_get_rt6_dst(const struct net_device *dev,
156						   const struct flowi6 *fl6)
157{
158	if (netif_is_l3_master(dev) && dev->l3mdev_ops->l3mdev_get_rt6_dst)
159		return dev->l3mdev_ops->l3mdev_get_rt6_dst(dev, fl6);
160
161	return NULL;
162}
163
164static inline
165struct dst_entry *l3mdev_rt6_dst_by_oif(struct net *net,
166					const struct flowi6 *fl6)
167{
168	struct dst_entry *dst = NULL;
169	struct net_device *dev;
170
171	dev = dev_get_by_index(net, fl6->flowi6_oif);
172	if (dev) {
173		dst = l3mdev_get_rt6_dst(dev, fl6);
174		dev_put(dev);
175	}
176
177	return dst;
178}
179
180#else
181
182static inline int l3mdev_master_ifindex_rcu(const struct net_device *dev)
183{
184	return 0;
185}
186static inline int l3mdev_master_ifindex(struct net_device *dev)
187{
188	return 0;
189}
190
191static inline int l3mdev_master_ifindex_by_index(struct net *net, int ifindex)
192{
193	return 0;
194}
195
196static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
197{
198	return dev ? dev->ifindex : 0;
199}
200static inline int l3mdev_fib_oif(struct net_device *dev)
201{
202	return dev ? dev->ifindex : 0;
203}
204
205static inline u32 l3mdev_fib_table_rcu(const struct net_device *dev)
206{
207	return 0;
208}
209static inline u32 l3mdev_fib_table(const struct net_device *dev)
210{
211	return 0;
212}
213static inline u32 l3mdev_fib_table_by_index(struct net *net, int ifindex)
214{
215	return 0;
216}
217
218static inline struct rtable *l3mdev_get_rtable(const struct net_device *dev,
219					       const struct flowi4 *fl4)
220{
221	return NULL;
222}
223
224static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
225{
226	return false;
227}
228
229static inline int l3mdev_get_saddr(struct net *net, int ifindex,
230				   struct flowi4 *fl4)
231{
232	return 0;
233}
234
235static inline
236struct dst_entry *l3mdev_get_rt6_dst(const struct net_device *dev,
237				     const struct flowi6 *fl6)
238{
239	return NULL;
240}
241static inline
242struct dst_entry *l3mdev_rt6_dst_by_oif(struct net *net,
243					const struct flowi6 *fl6)
244{
245	return NULL;
246}
247#endif
248
249#endif /* _NET_L3MDEV_H_ */