xref: /openbmc/linux/include/net/l3mdev.h (revision 77a87824)
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 #include <net/fib_rules.h>
15 
16 /**
17  * struct l3mdev_ops - l3mdev operations
18  *
19  * @l3mdev_fib_table: Get FIB table id to use for lookups
20  *
21  * @l3mdev_get_rtable: Get cached IPv4 rtable (dst_entry) for device
22  *
23  * @l3mdev_get_saddr: Get source address for a flow
24  *
25  * @l3mdev_get_rt6_dst: Get cached IPv6 rt6_info (dst_entry) for device
26  */
27 
28 struct l3mdev_ops {
29 	u32		(*l3mdev_fib_table)(const struct net_device *dev);
30 	struct sk_buff * (*l3mdev_l3_rcv)(struct net_device *dev,
31 					  struct sk_buff *skb, u16 proto);
32 
33 	/* IPv4 ops */
34 	struct rtable *	(*l3mdev_get_rtable)(const struct net_device *dev,
35 					     const struct flowi4 *fl4);
36 	int		(*l3mdev_get_saddr)(struct net_device *dev,
37 					    struct flowi4 *fl4);
38 
39 	/* IPv6 ops */
40 	struct dst_entry * (*l3mdev_get_rt6_dst)(const struct net_device *dev,
41 						 struct flowi6 *fl6);
42 	int		   (*l3mdev_get_saddr6)(struct net_device *dev,
43 						const struct sock *sk,
44 						struct flowi6 *fl6);
45 };
46 
47 #ifdef CONFIG_NET_L3_MASTER_DEV
48 
49 int l3mdev_fib_rule_match(struct net *net, struct flowi *fl,
50 			  struct fib_lookup_arg *arg);
51 
52 int l3mdev_master_ifindex_rcu(const struct net_device *dev);
53 static inline int l3mdev_master_ifindex(struct net_device *dev)
54 {
55 	int ifindex;
56 
57 	rcu_read_lock();
58 	ifindex = l3mdev_master_ifindex_rcu(dev);
59 	rcu_read_unlock();
60 
61 	return ifindex;
62 }
63 
64 static inline int l3mdev_master_ifindex_by_index(struct net *net, int ifindex)
65 {
66 	struct net_device *dev;
67 	int rc = 0;
68 
69 	if (likely(ifindex)) {
70 		rcu_read_lock();
71 
72 		dev = dev_get_by_index_rcu(net, ifindex);
73 		if (dev)
74 			rc = l3mdev_master_ifindex_rcu(dev);
75 
76 		rcu_read_unlock();
77 	}
78 
79 	return rc;
80 }
81 
82 static inline
83 const struct net_device *l3mdev_master_dev_rcu(const struct net_device *_dev)
84 {
85 	/* netdev_master_upper_dev_get_rcu calls
86 	 * list_first_or_null_rcu to walk the upper dev list.
87 	 * list_first_or_null_rcu does not handle a const arg. We aren't
88 	 * making changes, just want the master device from that list so
89 	 * typecast to remove the const
90 	 */
91 	struct net_device *dev = (struct net_device *)_dev;
92 	const struct net_device *master;
93 
94 	if (!dev)
95 		return NULL;
96 
97 	if (netif_is_l3_master(dev))
98 		master = dev;
99 	else if (netif_is_l3_slave(dev))
100 		master = netdev_master_upper_dev_get_rcu(dev);
101 	else
102 		master = NULL;
103 
104 	return master;
105 }
106 
107 /* get index of an interface to use for FIB lookups. For devices
108  * enslaved to an L3 master device FIB lookups are based on the
109  * master index
110  */
111 static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
112 {
113 	return l3mdev_master_ifindex_rcu(dev) ? : dev->ifindex;
114 }
115 
116 static inline int l3mdev_fib_oif(struct net_device *dev)
117 {
118 	int oif;
119 
120 	rcu_read_lock();
121 	oif = l3mdev_fib_oif_rcu(dev);
122 	rcu_read_unlock();
123 
124 	return oif;
125 }
126 
127 u32 l3mdev_fib_table_rcu(const struct net_device *dev);
128 u32 l3mdev_fib_table_by_index(struct net *net, int ifindex);
129 static inline u32 l3mdev_fib_table(const struct net_device *dev)
130 {
131 	u32 tb_id;
132 
133 	rcu_read_lock();
134 	tb_id = l3mdev_fib_table_rcu(dev);
135 	rcu_read_unlock();
136 
137 	return tb_id;
138 }
139 
140 static inline struct rtable *l3mdev_get_rtable(const struct net_device *dev,
141 					       const struct flowi4 *fl4)
142 {
143 	if (netif_is_l3_master(dev) && dev->l3mdev_ops->l3mdev_get_rtable)
144 		return dev->l3mdev_ops->l3mdev_get_rtable(dev, fl4);
145 
146 	return NULL;
147 }
148 
149 static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
150 {
151 	struct net_device *dev;
152 	bool rc = false;
153 
154 	if (ifindex == 0)
155 		return false;
156 
157 	rcu_read_lock();
158 
159 	dev = dev_get_by_index_rcu(net, ifindex);
160 	if (dev)
161 		rc = netif_is_l3_master(dev);
162 
163 	rcu_read_unlock();
164 
165 	return rc;
166 }
167 
168 int l3mdev_get_saddr(struct net *net, int ifindex, struct flowi4 *fl4);
169 
170 struct dst_entry *l3mdev_get_rt6_dst(struct net *net, struct flowi6 *fl6);
171 int l3mdev_get_saddr6(struct net *net, const struct sock *sk,
172 		      struct flowi6 *fl6);
173 
174 static inline
175 struct sk_buff *l3mdev_l3_rcv(struct sk_buff *skb, u16 proto)
176 {
177 	struct net_device *master = NULL;
178 
179 	if (netif_is_l3_slave(skb->dev))
180 		master = netdev_master_upper_dev_get_rcu(skb->dev);
181 	else if (netif_is_l3_master(skb->dev))
182 		master = skb->dev;
183 
184 	if (master && master->l3mdev_ops->l3mdev_l3_rcv)
185 		skb = master->l3mdev_ops->l3mdev_l3_rcv(master, skb, proto);
186 
187 	return skb;
188 }
189 
190 static inline
191 struct sk_buff *l3mdev_ip_rcv(struct sk_buff *skb)
192 {
193 	return l3mdev_l3_rcv(skb, AF_INET);
194 }
195 
196 static inline
197 struct sk_buff *l3mdev_ip6_rcv(struct sk_buff *skb)
198 {
199 	return l3mdev_l3_rcv(skb, AF_INET6);
200 }
201 
202 #else
203 
204 static inline int l3mdev_master_ifindex_rcu(const struct net_device *dev)
205 {
206 	return 0;
207 }
208 static inline int l3mdev_master_ifindex(struct net_device *dev)
209 {
210 	return 0;
211 }
212 
213 static inline int l3mdev_master_ifindex_by_index(struct net *net, int ifindex)
214 {
215 	return 0;
216 }
217 
218 static inline
219 const struct net_device *l3mdev_master_dev_rcu(const struct net_device *dev)
220 {
221 	return NULL;
222 }
223 
224 static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
225 {
226 	return dev ? dev->ifindex : 0;
227 }
228 static inline int l3mdev_fib_oif(struct net_device *dev)
229 {
230 	return dev ? dev->ifindex : 0;
231 }
232 
233 static inline u32 l3mdev_fib_table_rcu(const struct net_device *dev)
234 {
235 	return 0;
236 }
237 static inline u32 l3mdev_fib_table(const struct net_device *dev)
238 {
239 	return 0;
240 }
241 static inline u32 l3mdev_fib_table_by_index(struct net *net, int ifindex)
242 {
243 	return 0;
244 }
245 
246 static inline struct rtable *l3mdev_get_rtable(const struct net_device *dev,
247 					       const struct flowi4 *fl4)
248 {
249 	return NULL;
250 }
251 
252 static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
253 {
254 	return false;
255 }
256 
257 static inline int l3mdev_get_saddr(struct net *net, int ifindex,
258 				   struct flowi4 *fl4)
259 {
260 	return 0;
261 }
262 
263 static inline
264 struct dst_entry *l3mdev_get_rt6_dst(struct net *net, struct flowi6 *fl6)
265 {
266 	return NULL;
267 }
268 
269 static inline int l3mdev_get_saddr6(struct net *net, const struct sock *sk,
270 				    struct flowi6 *fl6)
271 {
272 	return 0;
273 }
274 
275 static inline
276 struct sk_buff *l3mdev_ip_rcv(struct sk_buff *skb)
277 {
278 	return skb;
279 }
280 
281 static inline
282 struct sk_buff *l3mdev_ip6_rcv(struct sk_buff *skb)
283 {
284 	return skb;
285 }
286 
287 static inline
288 int l3mdev_fib_rule_match(struct net *net, struct flowi *fl,
289 			  struct fib_lookup_arg *arg)
290 {
291 	return 1;
292 }
293 #endif
294 
295 #endif /* _NET_L3MDEV_H_ */
296