xref: /openbmc/linux/include/net/l3mdev.h (revision a8da474e)
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 	void		(*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(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 /* 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  */
58 static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
59 {
60 	return l3mdev_master_ifindex_rcu(dev) ? : dev->ifindex;
61 }
62 
63 static 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 
74 u32 l3mdev_fib_table_rcu(const struct net_device *dev);
75 u32 l3mdev_fib_table_by_index(struct net *net, int ifindex);
76 static 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 
87 static 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 
96 static 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 
115 static inline void l3mdev_get_saddr(struct net *net, int ifindex,
116 				    struct flowi4 *fl4)
117 {
118 	struct net_device *dev;
119 
120 	if (ifindex) {
121 
122 		rcu_read_lock();
123 
124 		dev = dev_get_by_index_rcu(net, ifindex);
125 		if (dev && netif_is_l3_master(dev) &&
126 		    dev->l3mdev_ops->l3mdev_get_saddr) {
127 			dev->l3mdev_ops->l3mdev_get_saddr(dev, fl4);
128 		}
129 
130 		rcu_read_unlock();
131 	}
132 }
133 
134 static inline struct dst_entry *l3mdev_get_rt6_dst(const struct net_device *dev,
135 						   const struct flowi6 *fl6)
136 {
137 	if (netif_is_l3_master(dev) && dev->l3mdev_ops->l3mdev_get_rt6_dst)
138 		return dev->l3mdev_ops->l3mdev_get_rt6_dst(dev, fl6);
139 
140 	return NULL;
141 }
142 
143 static inline
144 struct dst_entry *l3mdev_rt6_dst_by_oif(struct net *net,
145 					const struct flowi6 *fl6)
146 {
147 	struct dst_entry *dst = NULL;
148 	struct net_device *dev;
149 
150 	dev = dev_get_by_index(net, fl6->flowi6_oif);
151 	if (dev) {
152 		dst = l3mdev_get_rt6_dst(dev, fl6);
153 		dev_put(dev);
154 	}
155 
156 	return dst;
157 }
158 
159 #else
160 
161 static inline int l3mdev_master_ifindex_rcu(struct net_device *dev)
162 {
163 	return 0;
164 }
165 static inline int l3mdev_master_ifindex(struct net_device *dev)
166 {
167 	return 0;
168 }
169 
170 static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
171 {
172 	return dev ? dev->ifindex : 0;
173 }
174 static inline int l3mdev_fib_oif(struct net_device *dev)
175 {
176 	return dev ? dev->ifindex : 0;
177 }
178 
179 static inline u32 l3mdev_fib_table_rcu(const struct net_device *dev)
180 {
181 	return 0;
182 }
183 static inline u32 l3mdev_fib_table(const struct net_device *dev)
184 {
185 	return 0;
186 }
187 static inline u32 l3mdev_fib_table_by_index(struct net *net, int ifindex)
188 {
189 	return 0;
190 }
191 
192 static inline struct rtable *l3mdev_get_rtable(const struct net_device *dev,
193 					       const struct flowi4 *fl4)
194 {
195 	return NULL;
196 }
197 
198 static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
199 {
200 	return false;
201 }
202 
203 static inline void l3mdev_get_saddr(struct net *net, int ifindex,
204 				    struct flowi4 *fl4)
205 {
206 }
207 
208 static inline
209 struct dst_entry *l3mdev_get_rt6_dst(const struct net_device *dev,
210 				     const struct flowi6 *fl6)
211 {
212 	return NULL;
213 }
214 static inline
215 struct dst_entry *l3mdev_rt6_dst_by_oif(struct net *net,
216 					const struct flowi6 *fl6)
217 {
218 	return NULL;
219 }
220 #endif
221 
222 #endif /* _NET_L3MDEV_H_ */
223