xref: /linux/include/net/l3mdev.h (revision 9ee0034b8f49aaaa7e7c2da8db1038915db99c19)
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 void l3mdev_update_flow(struct net *net, struct flowi *fl);
53 
54 int l3mdev_master_ifindex_rcu(const struct net_device *dev);
55 static inline int l3mdev_master_ifindex(struct net_device *dev)
56 {
57 	int ifindex;
58 
59 	rcu_read_lock();
60 	ifindex = l3mdev_master_ifindex_rcu(dev);
61 	rcu_read_unlock();
62 
63 	return ifindex;
64 }
65 
66 static inline int l3mdev_master_ifindex_by_index(struct net *net, int ifindex)
67 {
68 	struct net_device *dev;
69 	int rc = 0;
70 
71 	if (likely(ifindex)) {
72 		rcu_read_lock();
73 
74 		dev = dev_get_by_index_rcu(net, ifindex);
75 		if (dev)
76 			rc = l3mdev_master_ifindex_rcu(dev);
77 
78 		rcu_read_unlock();
79 	}
80 
81 	return rc;
82 }
83 
84 static inline
85 const struct net_device *l3mdev_master_dev_rcu(const struct net_device *_dev)
86 {
87 	/* netdev_master_upper_dev_get_rcu calls
88 	 * list_first_or_null_rcu to walk the upper dev list.
89 	 * list_first_or_null_rcu does not handle a const arg. We aren't
90 	 * making changes, just want the master device from that list so
91 	 * typecast to remove the const
92 	 */
93 	struct net_device *dev = (struct net_device *)_dev;
94 	const struct net_device *master;
95 
96 	if (!dev)
97 		return NULL;
98 
99 	if (netif_is_l3_master(dev))
100 		master = dev;
101 	else if (netif_is_l3_slave(dev))
102 		master = netdev_master_upper_dev_get_rcu(dev);
103 	else
104 		master = NULL;
105 
106 	return master;
107 }
108 
109 /* get index of an interface to use for FIB lookups. For devices
110  * enslaved to an L3 master device FIB lookups are based on the
111  * master index
112  */
113 static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
114 {
115 	return l3mdev_master_ifindex_rcu(dev) ? : dev->ifindex;
116 }
117 
118 static inline int l3mdev_fib_oif(struct net_device *dev)
119 {
120 	int oif;
121 
122 	rcu_read_lock();
123 	oif = l3mdev_fib_oif_rcu(dev);
124 	rcu_read_unlock();
125 
126 	return oif;
127 }
128 
129 u32 l3mdev_fib_table_rcu(const struct net_device *dev);
130 u32 l3mdev_fib_table_by_index(struct net *net, int ifindex);
131 static inline u32 l3mdev_fib_table(const struct net_device *dev)
132 {
133 	u32 tb_id;
134 
135 	rcu_read_lock();
136 	tb_id = l3mdev_fib_table_rcu(dev);
137 	rcu_read_unlock();
138 
139 	return tb_id;
140 }
141 
142 static inline struct rtable *l3mdev_get_rtable(const struct net_device *dev,
143 					       const struct flowi4 *fl4)
144 {
145 	if (netif_is_l3_master(dev) && dev->l3mdev_ops->l3mdev_get_rtable)
146 		return dev->l3mdev_ops->l3mdev_get_rtable(dev, fl4);
147 
148 	return NULL;
149 }
150 
151 static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
152 {
153 	struct net_device *dev;
154 	bool rc = false;
155 
156 	if (ifindex == 0)
157 		return false;
158 
159 	rcu_read_lock();
160 
161 	dev = dev_get_by_index_rcu(net, ifindex);
162 	if (dev)
163 		rc = netif_is_l3_master(dev);
164 
165 	rcu_read_unlock();
166 
167 	return rc;
168 }
169 
170 int l3mdev_get_saddr(struct net *net, int ifindex, struct flowi4 *fl4);
171 
172 struct dst_entry *l3mdev_get_rt6_dst(struct net *net, struct flowi6 *fl6);
173 int l3mdev_get_saddr6(struct net *net, const struct sock *sk,
174 		      struct flowi6 *fl6);
175 
176 static inline
177 struct sk_buff *l3mdev_l3_rcv(struct sk_buff *skb, u16 proto)
178 {
179 	struct net_device *master = NULL;
180 
181 	if (netif_is_l3_slave(skb->dev))
182 		master = netdev_master_upper_dev_get_rcu(skb->dev);
183 	else if (netif_is_l3_master(skb->dev))
184 		master = skb->dev;
185 
186 	if (master && master->l3mdev_ops->l3mdev_l3_rcv)
187 		skb = master->l3mdev_ops->l3mdev_l3_rcv(master, skb, proto);
188 
189 	return skb;
190 }
191 
192 static inline
193 struct sk_buff *l3mdev_ip_rcv(struct sk_buff *skb)
194 {
195 	return l3mdev_l3_rcv(skb, AF_INET);
196 }
197 
198 static inline
199 struct sk_buff *l3mdev_ip6_rcv(struct sk_buff *skb)
200 {
201 	return l3mdev_l3_rcv(skb, AF_INET6);
202 }
203 
204 #else
205 
206 static inline int l3mdev_master_ifindex_rcu(const struct net_device *dev)
207 {
208 	return 0;
209 }
210 static inline int l3mdev_master_ifindex(struct net_device *dev)
211 {
212 	return 0;
213 }
214 
215 static inline int l3mdev_master_ifindex_by_index(struct net *net, int ifindex)
216 {
217 	return 0;
218 }
219 
220 static inline
221 const struct net_device *l3mdev_master_dev_rcu(const struct net_device *dev)
222 {
223 	return NULL;
224 }
225 
226 static inline int l3mdev_fib_oif_rcu(struct net_device *dev)
227 {
228 	return dev ? dev->ifindex : 0;
229 }
230 static inline int l3mdev_fib_oif(struct net_device *dev)
231 {
232 	return dev ? dev->ifindex : 0;
233 }
234 
235 static inline u32 l3mdev_fib_table_rcu(const struct net_device *dev)
236 {
237 	return 0;
238 }
239 static inline u32 l3mdev_fib_table(const struct net_device *dev)
240 {
241 	return 0;
242 }
243 static inline u32 l3mdev_fib_table_by_index(struct net *net, int ifindex)
244 {
245 	return 0;
246 }
247 
248 static inline struct rtable *l3mdev_get_rtable(const struct net_device *dev,
249 					       const struct flowi4 *fl4)
250 {
251 	return NULL;
252 }
253 
254 static inline bool netif_index_is_l3_master(struct net *net, int ifindex)
255 {
256 	return false;
257 }
258 
259 static inline int l3mdev_get_saddr(struct net *net, int ifindex,
260 				   struct flowi4 *fl4)
261 {
262 	return 0;
263 }
264 
265 static inline
266 struct dst_entry *l3mdev_get_rt6_dst(struct net *net, struct flowi6 *fl6)
267 {
268 	return NULL;
269 }
270 
271 static inline int l3mdev_get_saddr6(struct net *net, const struct sock *sk,
272 				    struct flowi6 *fl6)
273 {
274 	return 0;
275 }
276 
277 static inline
278 struct sk_buff *l3mdev_ip_rcv(struct sk_buff *skb)
279 {
280 	return skb;
281 }
282 
283 static inline
284 struct sk_buff *l3mdev_ip6_rcv(struct sk_buff *skb)
285 {
286 	return skb;
287 }
288 
289 static inline
290 int l3mdev_fib_rule_match(struct net *net, struct flowi *fl,
291 			  struct fib_lookup_arg *arg)
292 {
293 	return 1;
294 }
295 static inline
296 void l3mdev_update_flow(struct net *net, struct flowi *fl)
297 {
298 }
299 #endif
300 
301 #endif /* _NET_L3MDEV_H_ */
302