1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Linux INET6 implementation
4 *
5 * Authors:
6 * Pedro Roque <roque@di.fc.ul.pt>
7 */
8
9#ifndef _IP6_FIB_H
10#define _IP6_FIB_H
11
12#include <linux/ipv6_route.h>
13#include <linux/rtnetlink.h>
14#include <linux/spinlock.h>
15#include <linux/notifier.h>
16#include <net/dst.h>
17#include <net/flow.h>
18#include <net/ip_fib.h>
19#include <net/netlink.h>
20#include <net/inetpeer.h>
21#include <net/fib_notifier.h>
22#include <linux/indirect_call_wrapper.h>
23#include <uapi/linux/bpf.h>
24
25#ifdef CONFIG_IPV6_MULTIPLE_TABLES
26#define FIB6_TABLE_HASHSZ 256
27#else
28#define FIB6_TABLE_HASHSZ 1
29#endif
30
31#define RT6_DEBUG 2
32
33#if RT6_DEBUG >= 3
34#define RT6_TRACE(x...) pr_debug(x)
35#else
36#define RT6_TRACE(x...) do { ; } while (0)
37#endif
38
39struct rt6_info;
40struct fib6_info;
41
42struct fib6_config {
43 u32 fc_table;
44 u32 fc_metric;
45 int fc_dst_len;
46 int fc_src_len;
47 int fc_ifindex;
48 u32 fc_flags;
49 u32 fc_protocol;
50 u16 fc_type; /* only 8 bits are used */
51 u16 fc_delete_all_nh : 1,
52 fc_ignore_dev_down:1,
53 __unused : 14;
54 u32 fc_nh_id;
55
56 struct in6_addr fc_dst;
57 struct in6_addr fc_src;
58 struct in6_addr fc_prefsrc;
59 struct in6_addr fc_gateway;
60
61 unsigned long fc_expires;
62 struct nlattr *fc_mx;
63 int fc_mx_len;
64 int fc_mp_len;
65 struct nlattr *fc_mp;
66
67 struct nl_info fc_nlinfo;
68 struct nlattr *fc_encap;
69 u16 fc_encap_type;
70 bool fc_is_fdb;
71};
72
73struct fib6_node {
74 struct fib6_node __rcu *parent;
75 struct fib6_node __rcu *left;
76 struct fib6_node __rcu *right;
77#ifdef CONFIG_IPV6_SUBTREES
78 struct fib6_node __rcu *subtree;
79#endif
80 struct fib6_info __rcu *leaf;
81
82 __u16 fn_bit; /* bit key */
83 __u16 fn_flags;
84 int fn_sernum;
85 struct fib6_info __rcu *rr_ptr;
86 struct rcu_head rcu;
87};
88
89struct fib6_gc_args {
90 int timeout;
91 int more;
92};
93
94#ifndef CONFIG_IPV6_SUBTREES
95#define FIB6_SUBTREE(fn) NULL
96
97static inline bool fib6_routes_require_src(const struct net *net)
98{
99 return false;
100}
101
102static inline void fib6_routes_require_src_inc(struct net *net) {}
103static inline void fib6_routes_require_src_dec(struct net *net) {}
104
105#else
106
107static inline bool fib6_routes_require_src(const struct net *net)
108{
109 return net->ipv6.fib6_routes_require_src > 0;
110}
111
112static inline void fib6_routes_require_src_inc(struct net *net)
113{
114 net->ipv6.fib6_routes_require_src++;
115}
116
117static inline void fib6_routes_require_src_dec(struct net *net)
118{
119 net->ipv6.fib6_routes_require_src--;
120}
121
122#define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1))
123#endif
124
125/*
126 * routing information
127 *
128 */
129
130struct rt6key {
131 struct in6_addr addr;
132 int plen;
133};
134
135struct fib6_table;
136
137struct rt6_exception_bucket {
138 struct hlist_head chain;
139 int depth;
140};
141
142struct rt6_exception {
143 struct hlist_node hlist;
144 struct rt6_info *rt6i;
145 unsigned long stamp;
146 struct rcu_head rcu;
147};
148
149#define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10
150#define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT)
151#define FIB6_MAX_DEPTH 5
152
153struct fib6_nh {
154 struct fib_nh_common nh_common;
155
156#ifdef CONFIG_IPV6_ROUTER_PREF
157 unsigned long last_probe;
158#endif
159
160 struct rt6_info * __percpu *rt6i_pcpu;
161 struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
162};
163
164struct fib6_info {
165 struct fib6_table *fib6_table;
166 struct fib6_info __rcu *fib6_next;
167 struct fib6_node __rcu *fib6_node;
168
169 /* Multipath routes:
170 * siblings is a list of fib6_info that have the same metric/weight,
171 * destination, but not the same gateway. nsiblings is just a cache
172 * to speed up lookup.
173 */
174 union {
175 struct list_head fib6_siblings;
176 struct list_head nh_list;
177 };
178 unsigned int fib6_nsiblings;
179
180 refcount_t fib6_ref;
181 unsigned long expires;
182
183 struct hlist_node gc_link;
184
185 struct dst_metrics *fib6_metrics;
186#define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1]
187
188 struct rt6key fib6_dst;
189 u32 fib6_flags;
190 struct rt6key fib6_src;
191 struct rt6key fib6_prefsrc;
192
193 u32 fib6_metric;
194 u8 fib6_protocol;
195 u8 fib6_type;
196
197 u8 offload;
198 u8 trap;
199 u8 offload_failed;
200
201 u8 should_flush:1,
202 dst_nocount:1,
203 dst_nopolicy:1,
204 fib6_destroying:1,
205 unused:4;
206
207 struct rcu_head rcu;
208 struct nexthop *nh;
209 struct fib6_nh fib6_nh[];
210};
211
212struct rt6_info {
213 struct dst_entry dst;
214 struct fib6_info __rcu *from;
215 int sernum;
216
217 struct rt6key rt6i_dst;
218 struct rt6key rt6i_src;
219 struct in6_addr rt6i_gateway;
220 struct inet6_dev *rt6i_idev;
221 u32 rt6i_flags;
222
223 /* more non-fragment space at head required */
224 unsigned short rt6i_nfheader_len;
225};
226
227struct fib6_result {
228 struct fib6_nh *nh;
229 struct fib6_info *f6i;
230 u32 fib6_flags;
231 u8 fib6_type;
232 struct rt6_info *rt6;
233};
234
235#define for_each_fib6_node_rt_rcu(fn) \
236 for (rt = rcu_dereference((fn)->leaf); rt; \
237 rt = rcu_dereference(rt->fib6_next))
238
239#define for_each_fib6_walker_rt(w) \
240 for (rt = (w)->leaf; rt; \
241 rt = rcu_dereference_protected(rt->fib6_next, 1))
242
243static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
244{
245 return ((struct rt6_info *)dst)->rt6i_idev;
246}
247
248static inline bool fib6_requires_src(const struct fib6_info *rt)
249{
250 return rt->fib6_src.plen > 0;
251}
252
253static inline bool fib6_check_expired(const struct fib6_info *f6i)
254{
255 if (f6i->fib6_flags & RTF_EXPIRES)
256 return time_after(jiffies, f6i->expires);
257 return false;
258}
259
260static inline bool fib6_has_expires(const struct fib6_info *f6i)
261{
262 return f6i->fib6_flags & RTF_EXPIRES;
263}
264
265/* Function to safely get fn->fn_sernum for passed in rt
266 * and store result in passed in cookie.
267 * Return true if we can get cookie safely
268 * Return false if not
269 */
270static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i,
271 u32 *cookie)
272{
273 struct fib6_node *fn;
274 bool status = false;
275
276 fn = rcu_dereference(f6i->fib6_node);
277
278 if (fn) {
279 *cookie = READ_ONCE(fn->fn_sernum);
280 /* pairs with smp_wmb() in __fib6_update_sernum_upto_root() */
281 smp_rmb();
282 status = true;
283 }
284
285 return status;
286}
287
288static inline u32 rt6_get_cookie(const struct rt6_info *rt)
289{
290 struct fib6_info *from;
291 u32 cookie = 0;
292
293 if (rt->sernum)
294 return rt->sernum;
295
296 rcu_read_lock();
297
298 from = rcu_dereference(rt->from);
299 if (from)
300 fib6_get_cookie_safe(f6i: from, cookie: &cookie);
301
302 rcu_read_unlock();
303
304 return cookie;
305}
306
307static inline void ip6_rt_put(struct rt6_info *rt)
308{
309 /* dst_release() accepts a NULL parameter.
310 * We rely on dst being first structure in struct rt6_info
311 */
312 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
313 dst_release(dst: &rt->dst);
314}
315
316struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh);
317void fib6_info_destroy_rcu(struct rcu_head *head);
318
319static inline void fib6_info_hold(struct fib6_info *f6i)
320{
321 refcount_inc(r: &f6i->fib6_ref);
322}
323
324static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
325{
326 return refcount_inc_not_zero(r: &f6i->fib6_ref);
327}
328
329static inline void fib6_info_release(struct fib6_info *f6i)
330{
331 if (f6i && refcount_dec_and_test(r: &f6i->fib6_ref))
332 call_rcu(head: &f6i->rcu, func: fib6_info_destroy_rcu);
333}
334
335enum fib6_walk_state {
336#ifdef CONFIG_IPV6_SUBTREES
337 FWS_S,
338#endif
339 FWS_L,
340 FWS_R,
341 FWS_C,
342 FWS_U
343};
344
345struct fib6_walker {
346 struct list_head lh;
347 struct fib6_node *root, *node;
348 struct fib6_info *leaf;
349 enum fib6_walk_state state;
350 unsigned int skip;
351 unsigned int count;
352 unsigned int skip_in_node;
353 int (*func)(struct fib6_walker *);
354 void *args;
355};
356
357struct rt6_statistics {
358 __u32 fib_nodes; /* all fib6 nodes */
359 __u32 fib_route_nodes; /* intermediate nodes */
360 __u32 fib_rt_entries; /* rt entries in fib table */
361 __u32 fib_rt_cache; /* cached rt entries in exception table */
362 __u32 fib_discarded_routes; /* total number of routes delete */
363
364 /* The following stat is not protected by any lock */
365 atomic_t fib_rt_alloc; /* total number of routes alloced */
366};
367
368#define RTN_TL_ROOT 0x0001
369#define RTN_ROOT 0x0002 /* tree root node */
370#define RTN_RTINFO 0x0004 /* node with valid routing info */
371
372/*
373 * priority levels (or metrics)
374 *
375 */
376
377
378struct fib6_table {
379 struct hlist_node tb6_hlist;
380 u32 tb6_id;
381 spinlock_t tb6_lock;
382 struct fib6_node tb6_root;
383 struct inet_peer_base tb6_peers;
384 unsigned int flags;
385 unsigned int fib_seq;
386 struct hlist_head tb6_gc_hlist; /* GC candidates */
387#define RT6_TABLE_HAS_DFLT_ROUTER BIT(0)
388};
389
390#define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC
391#define RT6_TABLE_MAIN RT_TABLE_MAIN
392#define RT6_TABLE_DFLT RT6_TABLE_MAIN
393#define RT6_TABLE_INFO RT6_TABLE_MAIN
394#define RT6_TABLE_PREFIX RT6_TABLE_MAIN
395
396#ifdef CONFIG_IPV6_MULTIPLE_TABLES
397#define FIB6_TABLE_MIN 1
398#define FIB6_TABLE_MAX RT_TABLE_MAX
399#define RT6_TABLE_LOCAL RT_TABLE_LOCAL
400#else
401#define FIB6_TABLE_MIN RT_TABLE_MAIN
402#define FIB6_TABLE_MAX FIB6_TABLE_MIN
403#define RT6_TABLE_LOCAL RT6_TABLE_MAIN
404#endif
405
406typedef struct rt6_info *(*pol_lookup_t)(struct net *,
407 struct fib6_table *,
408 struct flowi6 *,
409 const struct sk_buff *, int);
410
411struct fib6_entry_notifier_info {
412 struct fib_notifier_info info; /* must be first */
413 struct fib6_info *rt;
414 unsigned int nsiblings;
415};
416
417/*
418 * exported functions
419 */
420
421struct fib6_table *fib6_get_table(struct net *net, u32 id);
422struct fib6_table *fib6_new_table(struct net *net, u32 id);
423struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
424 const struct sk_buff *skb,
425 int flags, pol_lookup_t lookup);
426
427/* called with rcu lock held; can return error pointer
428 * caller needs to select path
429 */
430int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
431 struct fib6_result *res, int flags);
432
433/* called with rcu lock held; caller needs to select path */
434int fib6_table_lookup(struct net *net, struct fib6_table *table,
435 int oif, struct flowi6 *fl6, struct fib6_result *res,
436 int strict);
437
438void fib6_select_path(const struct net *net, struct fib6_result *res,
439 struct flowi6 *fl6, int oif, bool have_oif_match,
440 const struct sk_buff *skb, int strict);
441struct fib6_node *fib6_node_lookup(struct fib6_node *root,
442 const struct in6_addr *daddr,
443 const struct in6_addr *saddr);
444
445struct fib6_node *fib6_locate(struct fib6_node *root,
446 const struct in6_addr *daddr, int dst_len,
447 const struct in6_addr *saddr, int src_len,
448 bool exact_match);
449
450void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg),
451 void *arg);
452void fib6_clean_all_skip_notify(struct net *net,
453 int (*func)(struct fib6_info *, void *arg),
454 void *arg);
455
456int fib6_add(struct fib6_node *root, struct fib6_info *rt,
457 struct nl_info *info, struct netlink_ext_ack *extack);
458int fib6_del(struct fib6_info *rt, struct nl_info *info);
459
460static inline
461void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr)
462{
463 const struct fib6_info *from;
464
465 rcu_read_lock();
466
467 from = rcu_dereference(rt->from);
468 if (from)
469 *addr = from->fib6_prefsrc.addr;
470 else
471 *addr = in6addr_any;
472
473 rcu_read_unlock();
474}
475
476int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
477 struct fib6_config *cfg, gfp_t gfp_flags,
478 struct netlink_ext_ack *extack);
479void fib6_nh_release(struct fib6_nh *fib6_nh);
480void fib6_nh_release_dsts(struct fib6_nh *fib6_nh);
481
482int call_fib6_entry_notifiers(struct net *net,
483 enum fib_event_type event_type,
484 struct fib6_info *rt,
485 struct netlink_ext_ack *extack);
486int call_fib6_multipath_entry_notifiers(struct net *net,
487 enum fib_event_type event_type,
488 struct fib6_info *rt,
489 unsigned int nsiblings,
490 struct netlink_ext_ack *extack);
491int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt);
492void fib6_rt_update(struct net *net, struct fib6_info *rt,
493 struct nl_info *info);
494void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
495 unsigned int flags);
496
497void fib6_run_gc(unsigned long expires, struct net *net, bool force);
498
499void fib6_gc_cleanup(void);
500
501int fib6_init(void);
502
503/* fib6_info must be locked by the caller, and fib6_info->fib6_table can be
504 * NULL.
505 */
506static inline void fib6_set_expires_locked(struct fib6_info *f6i,
507 unsigned long expires)
508{
509 struct fib6_table *tb6;
510
511 tb6 = f6i->fib6_table;
512 f6i->expires = expires;
513 if (tb6 && !fib6_has_expires(f6i))
514 hlist_add_head(n: &f6i->gc_link, h: &tb6->tb6_gc_hlist);
515 f6i->fib6_flags |= RTF_EXPIRES;
516}
517
518/* fib6_info must be locked by the caller, and fib6_info->fib6_table can be
519 * NULL. If fib6_table is NULL, the fib6_info will no be inserted into the
520 * list of GC candidates until it is inserted into a table.
521 */
522static inline void fib6_set_expires(struct fib6_info *f6i,
523 unsigned long expires)
524{
525 spin_lock_bh(lock: &f6i->fib6_table->tb6_lock);
526 fib6_set_expires_locked(f6i, expires);
527 spin_unlock_bh(lock: &f6i->fib6_table->tb6_lock);
528}
529
530static inline void fib6_clean_expires_locked(struct fib6_info *f6i)
531{
532 if (fib6_has_expires(f6i))
533 hlist_del_init(n: &f6i->gc_link);
534 f6i->fib6_flags &= ~RTF_EXPIRES;
535 f6i->expires = 0;
536}
537
538static inline void fib6_clean_expires(struct fib6_info *f6i)
539{
540 spin_lock_bh(lock: &f6i->fib6_table->tb6_lock);
541 fib6_clean_expires_locked(f6i);
542 spin_unlock_bh(lock: &f6i->fib6_table->tb6_lock);
543}
544
545struct ipv6_route_iter {
546 struct seq_net_private p;
547 struct fib6_walker w;
548 loff_t skip;
549 struct fib6_table *tbl;
550 int sernum;
551};
552
553extern const struct seq_operations ipv6_route_seq_ops;
554
555int call_fib6_notifier(struct notifier_block *nb,
556 enum fib_event_type event_type,
557 struct fib_notifier_info *info);
558int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
559 struct fib_notifier_info *info);
560
561int __net_init fib6_notifier_init(struct net *net);
562void __net_exit fib6_notifier_exit(struct net *net);
563
564unsigned int fib6_tables_seq_read(struct net *net);
565int fib6_tables_dump(struct net *net, struct notifier_block *nb,
566 struct netlink_ext_ack *extack);
567
568void fib6_update_sernum(struct net *net, struct fib6_info *rt);
569void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
570void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i);
571
572void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
573static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
574{
575 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
576}
577void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
578 bool offload, bool trap, bool offload_failed);
579
580#if IS_BUILTIN(CONFIG_IPV6) && defined(CONFIG_BPF_SYSCALL)
581struct bpf_iter__ipv6_route {
582 __bpf_md_ptr(struct bpf_iter_meta *, meta);
583 __bpf_md_ptr(struct fib6_info *, rt);
584};
585#endif
586
587INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_output(struct net *net,
588 struct fib6_table *table,
589 struct flowi6 *fl6,
590 const struct sk_buff *skb,
591 int flags));
592INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_input(struct net *net,
593 struct fib6_table *table,
594 struct flowi6 *fl6,
595 const struct sk_buff *skb,
596 int flags));
597INDIRECT_CALLABLE_DECLARE(struct rt6_info *__ip6_route_redirect(struct net *net,
598 struct fib6_table *table,
599 struct flowi6 *fl6,
600 const struct sk_buff *skb,
601 int flags));
602INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_lookup(struct net *net,
603 struct fib6_table *table,
604 struct flowi6 *fl6,
605 const struct sk_buff *skb,
606 int flags));
607static inline struct rt6_info *pol_lookup_func(pol_lookup_t lookup,
608 struct net *net,
609 struct fib6_table *table,
610 struct flowi6 *fl6,
611 const struct sk_buff *skb,
612 int flags)
613{
614 return INDIRECT_CALL_4(lookup,
615 ip6_pol_route_output,
616 ip6_pol_route_input,
617 ip6_pol_route_lookup,
618 __ip6_route_redirect,
619 net, table, fl6, skb, flags);
620}
621
622#ifdef CONFIG_IPV6_MULTIPLE_TABLES
623static inline bool fib6_has_custom_rules(const struct net *net)
624{
625 return net->ipv6.fib6_has_custom_rules;
626}
627
628int fib6_rules_init(void);
629void fib6_rules_cleanup(void);
630bool fib6_rule_default(const struct fib_rule *rule);
631int fib6_rules_dump(struct net *net, struct notifier_block *nb,
632 struct netlink_ext_ack *extack);
633unsigned int fib6_rules_seq_read(struct net *net);
634
635static inline bool fib6_rules_early_flow_dissect(struct net *net,
636 struct sk_buff *skb,
637 struct flowi6 *fl6,
638 struct flow_keys *flkeys)
639{
640 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
641
642 if (!net->ipv6.fib6_rules_require_fldissect)
643 return false;
644
645 memset(flkeys, 0, sizeof(*flkeys));
646 __skb_flow_dissect(net, skb, flow_dissector: &flow_keys_dissector,
647 target_container: flkeys, NULL, proto: 0, nhoff: 0, hlen: 0, flags: flag);
648
649 fl6->fl6_sport = flkeys->ports.src;
650 fl6->fl6_dport = flkeys->ports.dst;
651 fl6->flowi6_proto = flkeys->basic.ip_proto;
652
653 return true;
654}
655#else
656static inline bool fib6_has_custom_rules(const struct net *net)
657{
658 return false;
659}
660static inline int fib6_rules_init(void)
661{
662 return 0;
663}
664static inline void fib6_rules_cleanup(void)
665{
666 return ;
667}
668static inline bool fib6_rule_default(const struct fib_rule *rule)
669{
670 return true;
671}
672static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb,
673 struct netlink_ext_ack *extack)
674{
675 return 0;
676}
677static inline unsigned int fib6_rules_seq_read(struct net *net)
678{
679 return 0;
680}
681static inline bool fib6_rules_early_flow_dissect(struct net *net,
682 struct sk_buff *skb,
683 struct flowi6 *fl6,
684 struct flow_keys *flkeys)
685{
686 return false;
687}
688#endif
689#endif
690

source code of linux/include/net/ip6_fib.h