1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Generic nexthop implementation
5 * Copyright (c) 2017-19 Cumulus Networks
6 * Copyright (c) 2017-19 David Ahern <dsa@cumulusnetworks.com>
9 #ifndef __LINUX_NEXTHOP_H
10 #define __LINUX_NEXTHOP_H
12 #include <linux/netdevice.h>
13 #include <linux/notifier.h>
14 #include <linux/route.h>
15 #include <linux/types.h>
16 #include <net/ip_fib.h>
17 #include <net/ip6_fib.h>
18 #include <net/netlink.h>
20 #define NEXTHOP_VALID_USER_FLAGS RTNH_F_ONLINK
34 struct net_device *dev;
41 struct nlattr *nh_grp;
44 struct nlattr *nh_encap;
48 struct nl_info nlinfo;
52 struct hlist_node dev_hash; /* entry on netns devhash */
53 struct nexthop *nh_parent;
60 struct fib_nh_common fib_nhc;
62 struct fib6_nh fib6_nh;
71 struct list_head nh_list;
72 struct nexthop *nh_parent; /* nexthop of group with this entry */
76 struct nh_group *spare; /* spare group for removals */
81 struct nh_grp_entry nh_entries[];
85 struct rb_node rb_node; /* entry on netns rbtree */
86 struct list_head fi_list; /* v4 entries using nh */
87 struct list_head f6i_list; /* v6 entries using nh */
88 struct list_head fdb_list; /* fdb entries using this nh */
89 struct list_head grp_list; /* nh group entries using this nh */
94 u8 protocol; /* app managing this nh */
102 struct nh_info __rcu *nh_info;
103 struct nh_group __rcu *nh_grp;
107 enum nexthop_event_type {
112 int call_nexthop_notifier(struct notifier_block *nb, struct net *net,
113 enum nexthop_event_type event_type,
115 int register_nexthop_notifier(struct net *net, struct notifier_block *nb);
116 int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb);
118 /* caller is holding rcu or rtnl; no reference taken to nexthop */
119 struct nexthop *nexthop_find_by_id(struct net *net, u32 id);
120 void nexthop_free_rcu(struct rcu_head *head);
122 static inline bool nexthop_get(struct nexthop *nh)
124 return refcount_inc_not_zero(&nh->refcnt);
127 static inline void nexthop_put(struct nexthop *nh)
129 if (refcount_dec_and_test(&nh->refcnt))
130 call_rcu(&nh->rcu, nexthop_free_rcu);
133 static inline bool nexthop_cmp(const struct nexthop *nh1,
134 const struct nexthop *nh2)
139 static inline bool nexthop_is_fdb(const struct nexthop *nh)
142 const struct nh_group *nh_grp;
144 nh_grp = rcu_dereference_rtnl(nh->nh_grp);
145 return nh_grp->fdb_nh;
147 const struct nh_info *nhi;
149 nhi = rcu_dereference_rtnl(nh->nh_info);
154 static inline bool nexthop_has_v4(const struct nexthop *nh)
157 struct nh_group *nh_grp;
159 nh_grp = rcu_dereference_rtnl(nh->nh_grp);
160 return nh_grp->has_v4;
165 static inline bool nexthop_is_multipath(const struct nexthop *nh)
168 struct nh_group *nh_grp;
170 nh_grp = rcu_dereference_rtnl(nh->nh_grp);
171 return nh_grp->mpath;
176 struct nexthop *nexthop_select_path(struct nexthop *nh, int hash);
178 static inline unsigned int nexthop_num_path(const struct nexthop *nh)
183 struct nh_group *nh_grp;
185 nh_grp = rcu_dereference_rtnl(nh->nh_grp);
194 struct nexthop *nexthop_mpath_select(const struct nh_group *nhg, int nhsel)
196 /* for_nexthops macros in fib_semantics.c grabs a pointer to
197 * the nexthop before checking nhsel
199 if (nhsel >= nhg->num_nh)
202 return nhg->nh_entries[nhsel].nh;
206 int nexthop_mpath_fill_node(struct sk_buff *skb, struct nexthop *nh,
209 struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
212 for (i = 0; i < nhg->num_nh; i++) {
213 struct nexthop *nhe = nhg->nh_entries[i].nh;
214 struct nh_info *nhi = rcu_dereference_rtnl(nhe->nh_info);
215 struct fib_nh_common *nhc = &nhi->fib_nhc;
216 int weight = nhg->nh_entries[i].weight;
218 if (fib_add_nexthop(skb, nhc, weight, rt_family) < 0)
225 /* called with rcu lock */
226 static inline bool nexthop_is_blackhole(const struct nexthop *nh)
228 const struct nh_info *nhi;
231 struct nh_group *nh_grp;
233 nh_grp = rcu_dereference_rtnl(nh->nh_grp);
234 if (nh_grp->num_nh > 1)
237 nh = nh_grp->nh_entries[0].nh;
240 nhi = rcu_dereference_rtnl(nh->nh_info);
241 return nhi->reject_nh;
244 static inline void nexthop_path_fib_result(struct fib_result *res, int hash)
249 nh = nexthop_select_path(res->fi->nh, hash);
250 nhi = rcu_dereference(nh->nh_info);
251 res->nhc = &nhi->fib_nhc;
254 /* called with rcu read lock or rtnl held */
256 struct fib_nh_common *nexthop_fib_nhc(struct nexthop *nh, int nhsel)
260 BUILD_BUG_ON(offsetof(struct fib_nh, nh_common) != 0);
261 BUILD_BUG_ON(offsetof(struct fib6_nh, nh_common) != 0);
264 struct nh_group *nh_grp;
266 nh_grp = rcu_dereference_rtnl(nh->nh_grp);
268 nh = nexthop_mpath_select(nh_grp, nhsel);
274 nhi = rcu_dereference_rtnl(nh->nh_info);
275 return &nhi->fib_nhc;
278 /* called from fib_table_lookup with rcu_lock */
280 struct fib_nh_common *nexthop_get_nhc_lookup(const struct nexthop *nh,
282 const struct flowi4 *flp,
288 struct nh_group *nhg = rcu_dereference(nh->nh_grp);
291 for (i = 0; i < nhg->num_nh; i++) {
292 struct nexthop *nhe = nhg->nh_entries[i].nh;
294 nhi = rcu_dereference(nhe->nh_info);
295 if (fib_lookup_good_nhc(&nhi->fib_nhc, fib_flags, flp)) {
297 return &nhi->fib_nhc;
301 nhi = rcu_dereference(nh->nh_info);
302 if (fib_lookup_good_nhc(&nhi->fib_nhc, fib_flags, flp)) {
304 return &nhi->fib_nhc;
311 static inline bool nexthop_uses_dev(const struct nexthop *nh,
312 const struct net_device *dev)
317 struct nh_group *nhg = rcu_dereference(nh->nh_grp);
320 for (i = 0; i < nhg->num_nh; i++) {
321 struct nexthop *nhe = nhg->nh_entries[i].nh;
323 nhi = rcu_dereference(nhe->nh_info);
324 if (nhc_l3mdev_matches_dev(&nhi->fib_nhc, dev))
328 nhi = rcu_dereference(nh->nh_info);
329 if (nhc_l3mdev_matches_dev(&nhi->fib_nhc, dev))
336 static inline unsigned int fib_info_num_path(const struct fib_info *fi)
338 if (unlikely(fi->nh))
339 return nexthop_num_path(fi->nh);
344 int fib_check_nexthop(struct nexthop *nh, u8 scope,
345 struct netlink_ext_ack *extack);
347 static inline struct fib_nh_common *fib_info_nhc(struct fib_info *fi, int nhsel)
349 if (unlikely(fi->nh))
350 return nexthop_fib_nhc(fi->nh, nhsel);
352 return &fi->fib_nh[nhsel].nh_common;
355 /* only used when fib_nh is built into fib_info */
356 static inline struct fib_nh *fib_info_nh(struct fib_info *fi, int nhsel)
360 return &fi->fib_nh[nhsel];
366 int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
367 struct netlink_ext_ack *extack);
369 static inline struct fib6_nh *nexthop_fib6_nh(struct nexthop *nh)
374 struct nh_group *nh_grp;
376 nh_grp = rcu_dereference_rtnl(nh->nh_grp);
377 nh = nexthop_mpath_select(nh_grp, 0);
382 nhi = rcu_dereference_rtnl(nh->nh_info);
383 if (nhi->family == AF_INET6)
384 return &nhi->fib6_nh;
389 static inline struct net_device *fib6_info_nh_dev(struct fib6_info *f6i)
391 struct fib6_nh *fib6_nh;
393 fib6_nh = f6i->nh ? nexthop_fib6_nh(f6i->nh) : f6i->fib6_nh;
394 return fib6_nh->fib_nh_dev;
397 static inline void nexthop_path_fib6_result(struct fib6_result *res, int hash)
399 struct nexthop *nh = res->f6i->nh;
402 nh = nexthop_select_path(nh, hash);
404 nhi = rcu_dereference_rtnl(nh->nh_info);
405 if (nhi->reject_nh) {
406 res->fib6_type = RTN_BLACKHOLE;
407 res->fib6_flags |= RTF_REJECT;
408 res->nh = nexthop_fib6_nh(nh);
410 res->nh = &nhi->fib6_nh;
414 int nexthop_for_each_fib6_nh(struct nexthop *nh,
415 int (*cb)(struct fib6_nh *nh, void *arg),
418 static inline int nexthop_get_family(struct nexthop *nh)
420 struct nh_info *nhi = rcu_dereference_rtnl(nh->nh_info);
426 struct fib_nh_common *nexthop_fdb_nhc(struct nexthop *nh)
428 struct nh_info *nhi = rcu_dereference_rtnl(nh->nh_info);
430 return &nhi->fib_nhc;
433 static inline struct fib_nh_common *nexthop_path_fdb_result(struct nexthop *nh,
439 nhp = nexthop_select_path(nh, hash);
442 nhi = rcu_dereference(nhp->nh_info);
443 return &nhi->fib_nhc;