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(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
54/* get index of an interface to use for FIB lookups. For devices
55 * enslaved to an L3 master device FIB lookups are based on the
56 * master index
57 */
58static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
59{
60	return l3mdev_master_ifindex_rcu(dev) ? : dev->ifindex;
61}
62
63static inline int l3mdev_fib_oif(struct net_device *dev)
64{
65	int oif;
66
67	rcu_read_lock();
68	oif = l3mdev_fib_oif_rcu(dev);
69	rcu_read_unlock();
70
71	return oif;
72}
73
74u32 l3mdev_fib_table_rcu(const struct net_device *dev);
75u32 l3mdev_fib_table_by_index(struct net *net, int ifindex);
76static inline u32 l3mdev_fib_table(const struct net_device *dev)
77{
78	u32 tb_id;
79
80	rcu_read_lock();
81	tb_id = l3mdev_fib_table_rcu(dev);
82	rcu_read_unlock();
83
84	return tb_id;
85}
86
87static inline struct rtable *l3mdev_get_rtable(const struct net_device *dev,
88					       const struct flowi4 *fl4)
89{
90	if (netif_is_l3_master(dev) && dev->l3mdev_ops->l3mdev_get_rtable)
91		return dev->l3mdev_ops->l3mdev_get_rtable(dev, fl4);
92
93	return NULL;
94}
95
96static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
97{
98	struct net_device *dev;
99	bool rc = false;
100
101	if (ifindex == 0)
102		return false;
103
104	rcu_read_lock();
105
106	dev = dev_get_by_index_rcu(net, ifindex);
107	if (dev)
108		rc = netif_is_l3_master(dev);
109
110	rcu_read_unlock();
111
112	return rc;
113}
114
115static inline int l3mdev_get_saddr(struct net *net, int ifindex,
116				   struct flowi4 *fl4)
117{
118	struct net_device *dev;
119	int rc = 0;
120
121	if (ifindex) {
122
123		rcu_read_lock();
124
125		dev = dev_get_by_index_rcu(net, ifindex);
126		if (dev && netif_is_l3_master(dev) &&
127		    dev->l3mdev_ops->l3mdev_get_saddr) {
128			rc = dev->l3mdev_ops->l3mdev_get_saddr(dev, fl4);
129		}
130
131		rcu_read_unlock();
132	}
133
134	return rc;
135}
136
137static inline struct dst_entry *l3mdev_get_rt6_dst(const struct net_device *dev,
138						   const struct flowi6 *fl6)
139{
140	if (netif_is_l3_master(dev) && dev->l3mdev_ops->l3mdev_get_rt6_dst)
141		return dev->l3mdev_ops->l3mdev_get_rt6_dst(dev, fl6);
142
143	return NULL;
144}
145
146static inline
147struct dst_entry *l3mdev_rt6_dst_by_oif(struct net *net,
148					const struct flowi6 *fl6)
149{
150	struct dst_entry *dst = NULL;
151	struct net_device *dev;
152
153	dev = dev_get_by_index(net, fl6->flowi6_oif);
154	if (dev) {
155		dst = l3mdev_get_rt6_dst(dev, fl6);
156		dev_put(dev);
157	}
158
159	return dst;
160}
161
162#else
163
164static inline int l3mdev_master_ifindex_rcu(struct net_device *dev)
165{
166	return 0;
167}
168static inline int l3mdev_master_ifindex(struct net_device *dev)
169{
170	return 0;
171}
172
173static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
174{
175	return dev ? dev->ifindex : 0;
176}
177static inline int l3mdev_fib_oif(struct net_device *dev)
178{
179	return dev ? dev->ifindex : 0;
180}
181
182static inline u32 l3mdev_fib_table_rcu(const struct net_device *dev)
183{
184	return 0;
185}
186static inline u32 l3mdev_fib_table(const struct net_device *dev)
187{
188	return 0;
189}
190static inline u32 l3mdev_fib_table_by_index(struct net *net, int ifindex)
191{
192	return 0;
193}
194
195static inline struct rtable *l3mdev_get_rtable(const struct net_device *dev,
196					       const struct flowi4 *fl4)
197{
198	return NULL;
199}
200
201static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
202{
203	return false;
204}
205
206static inline int l3mdev_get_saddr(struct net *net, int ifindex,
207				   struct flowi4 *fl4)
208{
209	return 0;
210}
211
212static inline
213struct dst_entry *l3mdev_get_rt6_dst(const struct net_device *dev,
214				     const struct flowi6 *fl6)
215{
216	return NULL;
217}
218static inline
219struct dst_entry *l3mdev_rt6_dst_by_oif(struct net *net,
220					const struct flowi6 *fl6)
221{
222	return NULL;
223}
224#endif
225
226#endif /* _NET_L3MDEV_H_ */
227