1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * net/l3mdev/l3mdev.c - L3 master device implementation |
4 | * Copyright (c) 2015 Cumulus Networks |
5 | * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com> |
6 | */ |
7 | |
8 | #include <linux/netdevice.h> |
9 | #include <net/fib_rules.h> |
10 | #include <net/l3mdev.h> |
11 | |
12 | static DEFINE_SPINLOCK(l3mdev_lock); |
13 | |
14 | struct l3mdev_handler { |
15 | lookup_by_table_id_t dev_lookup; |
16 | }; |
17 | |
18 | static struct l3mdev_handler l3mdev_handlers[L3MDEV_TYPE_MAX + 1]; |
19 | |
20 | static int l3mdev_check_type(enum l3mdev_type l3type) |
21 | { |
22 | if (l3type <= L3MDEV_TYPE_UNSPEC || l3type > L3MDEV_TYPE_MAX) |
23 | return -EINVAL; |
24 | |
25 | return 0; |
26 | } |
27 | |
28 | int l3mdev_table_lookup_register(enum l3mdev_type l3type, |
29 | lookup_by_table_id_t fn) |
30 | { |
31 | struct l3mdev_handler *hdlr; |
32 | int res; |
33 | |
34 | res = l3mdev_check_type(l3type); |
35 | if (res) |
36 | return res; |
37 | |
38 | hdlr = &l3mdev_handlers[l3type]; |
39 | |
40 | spin_lock(lock: &l3mdev_lock); |
41 | |
42 | if (hdlr->dev_lookup) { |
43 | res = -EBUSY; |
44 | goto unlock; |
45 | } |
46 | |
47 | hdlr->dev_lookup = fn; |
48 | res = 0; |
49 | |
50 | unlock: |
51 | spin_unlock(lock: &l3mdev_lock); |
52 | |
53 | return res; |
54 | } |
55 | EXPORT_SYMBOL_GPL(l3mdev_table_lookup_register); |
56 | |
57 | void l3mdev_table_lookup_unregister(enum l3mdev_type l3type, |
58 | lookup_by_table_id_t fn) |
59 | { |
60 | struct l3mdev_handler *hdlr; |
61 | |
62 | if (l3mdev_check_type(l3type)) |
63 | return; |
64 | |
65 | hdlr = &l3mdev_handlers[l3type]; |
66 | |
67 | spin_lock(lock: &l3mdev_lock); |
68 | |
69 | if (hdlr->dev_lookup == fn) |
70 | hdlr->dev_lookup = NULL; |
71 | |
72 | spin_unlock(lock: &l3mdev_lock); |
73 | } |
74 | EXPORT_SYMBOL_GPL(l3mdev_table_lookup_unregister); |
75 | |
76 | int l3mdev_ifindex_lookup_by_table_id(enum l3mdev_type l3type, |
77 | struct net *net, u32 table_id) |
78 | { |
79 | lookup_by_table_id_t lookup; |
80 | struct l3mdev_handler *hdlr; |
81 | int ifindex = -EINVAL; |
82 | int res; |
83 | |
84 | res = l3mdev_check_type(l3type); |
85 | if (res) |
86 | return res; |
87 | |
88 | hdlr = &l3mdev_handlers[l3type]; |
89 | |
90 | spin_lock(lock: &l3mdev_lock); |
91 | |
92 | lookup = hdlr->dev_lookup; |
93 | if (!lookup) |
94 | goto unlock; |
95 | |
96 | ifindex = lookup(net, table_id); |
97 | |
98 | unlock: |
99 | spin_unlock(lock: &l3mdev_lock); |
100 | |
101 | return ifindex; |
102 | } |
103 | EXPORT_SYMBOL_GPL(l3mdev_ifindex_lookup_by_table_id); |
104 | |
105 | /** |
106 | * l3mdev_master_ifindex_rcu - get index of L3 master device |
107 | * @dev: targeted interface |
108 | */ |
109 | |
110 | int l3mdev_master_ifindex_rcu(const struct net_device *dev) |
111 | { |
112 | int ifindex = 0; |
113 | |
114 | if (!dev) |
115 | return 0; |
116 | |
117 | if (netif_is_l3_master(dev)) { |
118 | ifindex = dev->ifindex; |
119 | } else if (netif_is_l3_slave(dev)) { |
120 | struct net_device *master; |
121 | struct net_device *_dev = (struct net_device *)dev; |
122 | |
123 | /* netdev_master_upper_dev_get_rcu calls |
124 | * list_first_or_null_rcu to walk the upper dev list. |
125 | * list_first_or_null_rcu does not handle a const arg. We aren't |
126 | * making changes, just want the master device from that list so |
127 | * typecast to remove the const |
128 | */ |
129 | master = netdev_master_upper_dev_get_rcu(dev: _dev); |
130 | if (master) |
131 | ifindex = master->ifindex; |
132 | } |
133 | |
134 | return ifindex; |
135 | } |
136 | EXPORT_SYMBOL_GPL(l3mdev_master_ifindex_rcu); |
137 | |
138 | /** |
139 | * l3mdev_master_upper_ifindex_by_index_rcu - get index of upper l3 master |
140 | * device |
141 | * @net: network namespace for device index lookup |
142 | * @ifindex: targeted interface |
143 | */ |
144 | int l3mdev_master_upper_ifindex_by_index_rcu(struct net *net, int ifindex) |
145 | { |
146 | struct net_device *dev; |
147 | |
148 | dev = dev_get_by_index_rcu(net, ifindex); |
149 | while (dev && !netif_is_l3_master(dev)) |
150 | dev = netdev_master_upper_dev_get_rcu(dev); |
151 | |
152 | return dev ? dev->ifindex : 0; |
153 | } |
154 | EXPORT_SYMBOL_GPL(l3mdev_master_upper_ifindex_by_index_rcu); |
155 | |
156 | /** |
157 | * l3mdev_fib_table_rcu - get FIB table id associated with an L3 |
158 | * master interface |
159 | * @dev: targeted interface |
160 | */ |
161 | |
162 | u32 l3mdev_fib_table_rcu(const struct net_device *dev) |
163 | { |
164 | u32 tb_id = 0; |
165 | |
166 | if (!dev) |
167 | return 0; |
168 | |
169 | if (netif_is_l3_master(dev)) { |
170 | if (dev->l3mdev_ops->l3mdev_fib_table) |
171 | tb_id = dev->l3mdev_ops->l3mdev_fib_table(dev); |
172 | } else if (netif_is_l3_slave(dev)) { |
173 | /* Users of netdev_master_upper_dev_get_rcu need non-const, |
174 | * but current inet_*type functions take a const |
175 | */ |
176 | struct net_device *_dev = (struct net_device *) dev; |
177 | const struct net_device *master; |
178 | |
179 | master = netdev_master_upper_dev_get_rcu(dev: _dev); |
180 | if (master && |
181 | master->l3mdev_ops->l3mdev_fib_table) |
182 | tb_id = master->l3mdev_ops->l3mdev_fib_table(master); |
183 | } |
184 | |
185 | return tb_id; |
186 | } |
187 | EXPORT_SYMBOL_GPL(l3mdev_fib_table_rcu); |
188 | |
189 | u32 l3mdev_fib_table_by_index(struct net *net, int ifindex) |
190 | { |
191 | struct net_device *dev; |
192 | u32 tb_id = 0; |
193 | |
194 | if (!ifindex) |
195 | return 0; |
196 | |
197 | rcu_read_lock(); |
198 | |
199 | dev = dev_get_by_index_rcu(net, ifindex); |
200 | if (dev) |
201 | tb_id = l3mdev_fib_table_rcu(dev); |
202 | |
203 | rcu_read_unlock(); |
204 | |
205 | return tb_id; |
206 | } |
207 | EXPORT_SYMBOL_GPL(l3mdev_fib_table_by_index); |
208 | |
209 | /** |
210 | * l3mdev_link_scope_lookup - IPv6 route lookup based on flow for link |
211 | * local and multicast addresses |
212 | * @net: network namespace for device index lookup |
213 | * @fl6: IPv6 flow struct for lookup |
214 | * This function does not hold refcnt on the returned dst. |
215 | * Caller must hold rcu_read_lock(). |
216 | */ |
217 | |
218 | struct dst_entry *l3mdev_link_scope_lookup(struct net *net, |
219 | struct flowi6 *fl6) |
220 | { |
221 | struct dst_entry *dst = NULL; |
222 | struct net_device *dev; |
223 | |
224 | WARN_ON_ONCE(!rcu_read_lock_held()); |
225 | if (fl6->flowi6_oif) { |
226 | dev = dev_get_by_index_rcu(net, ifindex: fl6->flowi6_oif); |
227 | if (dev && netif_is_l3_slave(dev)) |
228 | dev = netdev_master_upper_dev_get_rcu(dev); |
229 | |
230 | if (dev && netif_is_l3_master(dev) && |
231 | dev->l3mdev_ops->l3mdev_link_scope_lookup) |
232 | dst = dev->l3mdev_ops->l3mdev_link_scope_lookup(dev, fl6); |
233 | } |
234 | |
235 | return dst; |
236 | } |
237 | EXPORT_SYMBOL_GPL(l3mdev_link_scope_lookup); |
238 | |
239 | /** |
240 | * l3mdev_fib_rule_match - Determine if flowi references an |
241 | * L3 master device |
242 | * @net: network namespace for device index lookup |
243 | * @fl: flow struct |
244 | * @arg: store the table the rule matched with here |
245 | */ |
246 | |
247 | int l3mdev_fib_rule_match(struct net *net, struct flowi *fl, |
248 | struct fib_lookup_arg *arg) |
249 | { |
250 | struct net_device *dev; |
251 | int rc = 0; |
252 | |
253 | /* update flow ensures flowi_l3mdev is set when relevant */ |
254 | if (!fl->flowi_l3mdev) |
255 | return 0; |
256 | |
257 | rcu_read_lock(); |
258 | |
259 | dev = dev_get_by_index_rcu(net, ifindex: fl->flowi_l3mdev); |
260 | if (dev && netif_is_l3_master(dev) && |
261 | dev->l3mdev_ops->l3mdev_fib_table) { |
262 | arg->table = dev->l3mdev_ops->l3mdev_fib_table(dev); |
263 | rc = 1; |
264 | } |
265 | |
266 | rcu_read_unlock(); |
267 | |
268 | return rc; |
269 | } |
270 | |
271 | void l3mdev_update_flow(struct net *net, struct flowi *fl) |
272 | { |
273 | struct net_device *dev; |
274 | |
275 | rcu_read_lock(); |
276 | |
277 | if (fl->flowi_oif) { |
278 | dev = dev_get_by_index_rcu(net, ifindex: fl->flowi_oif); |
279 | if (dev) { |
280 | if (!fl->flowi_l3mdev) |
281 | fl->flowi_l3mdev = l3mdev_master_ifindex_rcu(dev); |
282 | |
283 | /* oif set to L3mdev directs lookup to its table; |
284 | * reset to avoid oif match in fib_lookup |
285 | */ |
286 | if (netif_is_l3_master(dev)) |
287 | fl->flowi_oif = 0; |
288 | goto out; |
289 | } |
290 | } |
291 | |
292 | if (fl->flowi_iif > LOOPBACK_IFINDEX && !fl->flowi_l3mdev) { |
293 | dev = dev_get_by_index_rcu(net, ifindex: fl->flowi_iif); |
294 | if (dev) |
295 | fl->flowi_l3mdev = l3mdev_master_ifindex_rcu(dev); |
296 | } |
297 | |
298 | out: |
299 | rcu_read_unlock(); |
300 | } |
301 | EXPORT_SYMBOL_GPL(l3mdev_update_flow); |
302 | |