xref: /linux/include/net/l3mdev.h (revision 56d06fa29edd58c448766014afd833b7ff51247b)
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 
26 struct 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 
42 int l3mdev_master_ifindex_rcu(const struct net_device *dev);
43 static 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 static 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  */
76 static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
77 {
78 	return l3mdev_master_ifindex_rcu(dev) ? : dev->ifindex;
79 }
80 
81 static 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 
92 u32 l3mdev_fib_table_rcu(const struct net_device *dev);
93 u32 l3mdev_fib_table_by_index(struct net *net, int ifindex);
94 static 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 
105 static 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 
114 static 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 
133 static 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 
155 static 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 
164 static inline
165 struct 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 
182 static inline int l3mdev_master_ifindex_rcu(const struct net_device *dev)
183 {
184 	return 0;
185 }
186 static inline int l3mdev_master_ifindex(struct net_device *dev)
187 {
188 	return 0;
189 }
190 
191 static inline int l3mdev_master_ifindex_by_index(struct net *net, int ifindex)
192 {
193 	return 0;
194 }
195 
196 static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
197 {
198 	return dev ? dev->ifindex : 0;
199 }
200 static inline int l3mdev_fib_oif(struct net_device *dev)
201 {
202 	return dev ? dev->ifindex : 0;
203 }
204 
205 static inline u32 l3mdev_fib_table_rcu(const struct net_device *dev)
206 {
207 	return 0;
208 }
209 static inline u32 l3mdev_fib_table(const struct net_device *dev)
210 {
211 	return 0;
212 }
213 static inline u32 l3mdev_fib_table_by_index(struct net *net, int ifindex)
214 {
215 	return 0;
216 }
217 
218 static inline struct rtable *l3mdev_get_rtable(const struct net_device *dev,
219 					       const struct flowi4 *fl4)
220 {
221 	return NULL;
222 }
223 
224 static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
225 {
226 	return false;
227 }
228 
229 static inline int l3mdev_get_saddr(struct net *net, int ifindex,
230 				   struct flowi4 *fl4)
231 {
232 	return 0;
233 }
234 
235 static inline
236 struct dst_entry *l3mdev_get_rt6_dst(const struct net_device *dev,
237 				     const struct flowi6 *fl6)
238 {
239 	return NULL;
240 }
241 static inline
242 struct 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_ */
250