xref: /openbmc/linux/include/net/l3mdev.h (revision abfbd895)
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(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 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 
137 static 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 
146 static inline
147 struct 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 
164 static inline int l3mdev_master_ifindex_rcu(struct net_device *dev)
165 {
166 	return 0;
167 }
168 static inline int l3mdev_master_ifindex(struct net_device *dev)
169 {
170 	return 0;
171 }
172 
173 static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
174 {
175 	return dev ? dev->ifindex : 0;
176 }
177 static inline int l3mdev_fib_oif(struct net_device *dev)
178 {
179 	return dev ? dev->ifindex : 0;
180 }
181 
182 static inline u32 l3mdev_fib_table_rcu(const struct net_device *dev)
183 {
184 	return 0;
185 }
186 static inline u32 l3mdev_fib_table(const struct net_device *dev)
187 {
188 	return 0;
189 }
190 static inline u32 l3mdev_fib_table_by_index(struct net *net, int ifindex)
191 {
192 	return 0;
193 }
194 
195 static inline struct rtable *l3mdev_get_rtable(const struct net_device *dev,
196 					       const struct flowi4 *fl4)
197 {
198 	return NULL;
199 }
200 
201 static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
202 {
203 	return false;
204 }
205 
206 static inline int l3mdev_get_saddr(struct net *net, int ifindex,
207 				   struct flowi4 *fl4)
208 {
209 	return 0;
210 }
211 
212 static inline
213 struct dst_entry *l3mdev_get_rt6_dst(const struct net_device *dev,
214 				     const struct flowi6 *fl6)
215 {
216 	return NULL;
217 }
218 static inline
219 struct 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