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
33struct rt6_info;
34struct fib6_info;
35
36struct fib6_config {
37 u32 fc_table;
38 u32 fc_metric;
39 int fc_dst_len;
40 int fc_src_len;
41 int fc_ifindex;
42 u32 fc_flags;
43 u32 fc_protocol;
44 u16 fc_type; /* only 8 bits are used */
45 u16 fc_delete_all_nh : 1,
46 fc_ignore_dev_down:1,
47 __unused : 14;
48 u32 fc_nh_id;
49
50 struct in6_addr fc_dst;
51 struct in6_addr fc_src;
52 struct in6_addr fc_prefsrc;
53 struct in6_addr fc_gateway;
54
55 unsigned long fc_expires;
56 struct nlattr *fc_mx;
57 int fc_mx_len;
58 int fc_mp_len;
59 struct nlattr *fc_mp;
60
61 struct nl_info fc_nlinfo;
62 struct nlattr *fc_encap;
63 u16 fc_encap_type;
64 bool fc_is_fdb;
65};
66
67struct fib6_node {
68 struct fib6_node __rcu *parent;
69 struct fib6_node __rcu *left;
70 struct fib6_node __rcu *right;
71#ifdef CONFIG_IPV6_SUBTREES
72 struct fib6_node __rcu *subtree;
73#endif
74 struct fib6_info __rcu *leaf;
75
76 __u16 fn_bit; /* bit key */
77 __u16 fn_flags;
78 int fn_sernum;
79 struct fib6_info __rcu *rr_ptr;
80 struct rcu_head rcu;
81};
82
83struct fib6_gc_args {
84 int timeout;
85 int more;
86};
87
88#ifndef CONFIG_IPV6_SUBTREES
89#define FIB6_SUBTREE(fn) NULL
90
91static inline bool fib6_routes_require_src(const struct net *net)
92{
93 return false;
94}
95
96static inline void fib6_routes_require_src_inc(struct net *net) {}
97static inline void fib6_routes_require_src_dec(struct net *net) {}
98
99#else
100
101static inline bool fib6_routes_require_src(const struct net *net)
102{
103 return net->ipv6.fib6_routes_require_src > 0;
104}
105
106static inline void fib6_routes_require_src_inc(struct net *net)
107{
108 net->ipv6.fib6_routes_require_src++;
109}
110
111static inline void fib6_routes_require_src_dec(struct net *net)
112{
113 net->ipv6.fib6_routes_require_src--;
114}
115
116#define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1))
117#endif
118
119/*
120 * routing information
121 *
122 */
123
124struct rt6key {
125 struct in6_addr addr;
126 int plen;
127};
128
129struct fib6_table;
130
131struct rt6_exception_bucket {
132 struct hlist_head chain;
133 int depth;
134};
135
136struct rt6_exception {
137 struct hlist_node hlist;
138 struct rt6_info *rt6i;
139 unsigned long stamp;
140 struct rcu_head rcu;
141};
142
143#define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10
144#define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT)
145#define FIB6_MAX_DEPTH 5
146
147struct fib6_nh {
148 struct fib_nh_common nh_common;
149
150#ifdef CONFIG_IPV6_ROUTER_PREF
151 unsigned long last_probe;
152#endif
153
154 struct rt6_info * __percpu *rt6i_pcpu;
155 struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
156};
157
158struct fib6_info {
159 struct fib6_table *fib6_table;
160 struct fib6_info __rcu *fib6_next;
161 struct fib6_node __rcu *fib6_node;
162
163 /* Multipath routes:
164 * siblings is a list of fib6_info that have the same metric/weight,
165 * destination, but not the same gateway. nsiblings is just a cache
166 * to speed up lookup.
167 */
168 union {
169 struct list_head fib6_siblings;
170 struct list_head nh_list;
171 };
172 unsigned int fib6_nsiblings;
173
174 refcount_t fib6_ref;
175 unsigned long expires;
176
177 struct hlist_node gc_link;
178
179 struct dst_metrics *fib6_metrics;
180#define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1]
181
182 struct rt6key fib6_dst;
183 u32 fib6_flags;
184 struct rt6key fib6_src;
185 struct rt6key fib6_prefsrc;
186
187 u32 fib6_metric;
188 u8 fib6_protocol;
189 u8 fib6_type;
190
191 u8 offload;
192 u8 trap;
193 u8 offload_failed;
194
195 u8 should_flush:1,
196 dst_nocount:1,
197 dst_nopolicy:1,
198 fib6_destroying:1,
199 unused:4;
200
201 struct list_head purge_link;
202 struct rcu_head rcu;
203 struct nexthop *nh;
204 struct fib6_nh fib6_nh[];
205};
206
207struct rt6_info {
208 struct dst_entry dst;
209 struct fib6_info __rcu *from;
210 int sernum;
211
212 struct rt6key rt6i_dst;
213 struct rt6key rt6i_src;
214 struct in6_addr rt6i_gateway;
215 struct inet6_dev *rt6i_idev;
216 u32 rt6i_flags;
217
218 /* more non-fragment space at head required */
219 unsigned short rt6i_nfheader_len;
220};
221
222struct fib6_result {
223 struct fib6_nh *nh;
224 struct fib6_info *f6i;
225 u32 fib6_flags;
226 u8 fib6_type;
227 struct rt6_info *rt6;
228};
229
230#define for_each_fib6_node_rt_rcu(fn) \
231 for (rt = rcu_dereference((fn)->leaf); rt; \
232 rt = rcu_dereference(rt->fib6_next))
233
234#define for_each_fib6_walker_rt(w) \
235 for (rt = (w)->leaf; rt; \
236 rt = rcu_dereference_protected(rt->fib6_next, 1))
237
238#define dst_rt6_info(_ptr) container_of_const(_ptr, struct rt6_info, dst)
239
240static inline struct inet6_dev *ip6_dst_idev(const struct dst_entry *dst)
241{
242 return dst_rt6_info(dst)->rt6i_idev;
243}
244
245static inline bool fib6_requires_src(const struct fib6_info *rt)
246{
247 return rt->fib6_src.plen > 0;
248}
249
250/* The callers should hold f6i->fib6_table->tb6_lock if a route has ever
251 * been added to a table before.
252 */
253static inline void fib6_clean_expires(struct fib6_info *f6i)
254{
255 f6i->fib6_flags &= ~RTF_EXPIRES;
256 f6i->expires = 0;
257}
258
259/* The callers should hold f6i->fib6_table->tb6_lock if a route has ever
260 * been added to a table before.
261 */
262static inline void fib6_set_expires(struct fib6_info *f6i,
263 unsigned long expires)
264{
265 f6i->expires = expires;
266 f6i->fib6_flags |= RTF_EXPIRES;
267}
268
269static inline bool fib6_check_expired(const struct fib6_info *f6i)
270{
271 if (f6i->fib6_flags & RTF_EXPIRES)
272 return time_after(jiffies, f6i->expires);
273 return false;
274}
275
276/* Function to safely get fn->fn_sernum for passed in rt
277 * and store result in passed in cookie.
278 * Return true if we can get cookie safely
279 * Return false if not
280 */
281static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i,
282 u32 *cookie)
283{
284 struct fib6_node *fn;
285 bool status = false;
286
287 fn = rcu_dereference(f6i->fib6_node);
288
289 if (fn) {
290 *cookie = READ_ONCE(fn->fn_sernum);
291 /* pairs with smp_wmb() in __fib6_update_sernum_upto_root() */
292 smp_rmb();
293 status = true;
294 }
295
296 return status;
297}
298
299static inline u32 rt6_get_cookie(const struct rt6_info *rt)
300{
301 struct fib6_info *from;
302 u32 cookie = 0;
303
304 if (rt->sernum)
305 return rt->sernum;
306
307 rcu_read_lock();
308
309 from = rcu_dereference(rt->from);
310 if (from)
311 fib6_get_cookie_safe(f6i: from, cookie: &cookie);
312
313 rcu_read_unlock();
314
315 return cookie;
316}
317
318static inline void ip6_rt_put(struct rt6_info *rt)
319{
320 /* dst_release() accepts a NULL parameter.
321 * We rely on dst being first structure in struct rt6_info
322 */
323 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
324 dst_release(dst: &rt->dst);
325}
326
327struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh);
328void fib6_info_destroy_rcu(struct rcu_head *head);
329
330static inline void fib6_info_hold(struct fib6_info *f6i)
331{
332 refcount_inc(r: &f6i->fib6_ref);
333}
334
335static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
336{
337 return refcount_inc_not_zero(r: &f6i->fib6_ref);
338}
339
340static inline void fib6_info_release(struct fib6_info *f6i)
341{
342 if (f6i && refcount_dec_and_test(r: &f6i->fib6_ref)) {
343 DEBUG_NET_WARN_ON_ONCE(!hlist_unhashed(&f6i->gc_link));
344 call_rcu_hurry(head: &f6i->rcu, func: fib6_info_destroy_rcu);
345 }
346}
347
348enum fib6_walk_state {
349#ifdef CONFIG_IPV6_SUBTREES
350 FWS_S,
351#endif
352 FWS_L,
353 FWS_R,
354 FWS_C,
355 FWS_U
356};
357
358struct fib6_walker {
359 struct list_head lh;
360 struct fib6_node *root, *node;
361 struct fib6_info *leaf;
362 enum fib6_walk_state state;
363 unsigned int skip;
364 unsigned int count;
365 unsigned int skip_in_node;
366 int (*func)(struct fib6_walker *);
367 void *args;
368};
369
370struct rt6_statistics {
371 __u32 fib_nodes; /* all fib6 nodes */
372 __u32 fib_route_nodes; /* intermediate nodes */
373 __u32 fib_rt_entries; /* rt entries in fib table */
374 __u32 fib_rt_cache; /* cached rt entries in exception table */
375 __u32 fib_discarded_routes; /* total number of routes delete */
376
377 /* The following stat is not protected by any lock */
378 atomic_t fib_rt_alloc; /* total number of routes alloced */
379};
380
381#define RTN_TL_ROOT 0x0001
382#define RTN_ROOT 0x0002 /* tree root node */
383#define RTN_RTINFO 0x0004 /* node with valid routing info */
384
385/*
386 * priority levels (or metrics)
387 *
388 */
389
390
391struct fib6_table {
392 struct hlist_node tb6_hlist;
393 u32 tb6_id;
394 spinlock_t tb6_lock;
395 struct fib6_node tb6_root;
396 struct inet_peer_base tb6_peers;
397 unsigned int flags;
398 unsigned int fib_seq; /* writes protected by rtnl_mutex */
399 struct hlist_head tb6_gc_hlist; /* GC candidates */
400#define RT6_TABLE_HAS_DFLT_ROUTER BIT(0)
401};
402
403#define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC
404#define RT6_TABLE_MAIN RT_TABLE_MAIN
405#define RT6_TABLE_DFLT RT6_TABLE_MAIN
406#define RT6_TABLE_INFO RT6_TABLE_MAIN
407#define RT6_TABLE_PREFIX RT6_TABLE_MAIN
408
409#ifdef CONFIG_IPV6_MULTIPLE_TABLES
410#define FIB6_TABLE_MIN 1
411#define FIB6_TABLE_MAX RT_TABLE_MAX
412#define RT6_TABLE_LOCAL RT_TABLE_LOCAL
413#else
414#define FIB6_TABLE_MIN RT_TABLE_MAIN
415#define FIB6_TABLE_MAX FIB6_TABLE_MIN
416#define RT6_TABLE_LOCAL RT6_TABLE_MAIN
417#endif
418
419typedef struct rt6_info *(*pol_lookup_t)(struct net *,
420 struct fib6_table *,
421 struct flowi6 *,
422 const struct sk_buff *, int);
423
424struct fib6_entry_notifier_info {
425 struct fib_notifier_info info; /* must be first */
426 struct fib6_info *rt;
427 unsigned int nsiblings;
428};
429
430/*
431 * exported functions
432 */
433
434struct fib6_table *fib6_get_table(struct net *net, u32 id);
435struct fib6_table *fib6_new_table(struct net *net, u32 id);
436struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
437 const struct sk_buff *skb,
438 int flags, pol_lookup_t lookup);
439
440/* called with rcu lock held; can return error pointer
441 * caller needs to select path
442 */
443int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
444 struct fib6_result *res, int flags);
445
446/* called with rcu lock held; caller needs to select path */
447int fib6_table_lookup(struct net *net, struct fib6_table *table,
448 int oif, struct flowi6 *fl6, struct fib6_result *res,
449 int strict);
450
451void fib6_select_path(const struct net *net, struct fib6_result *res,
452 struct flowi6 *fl6, int oif, bool have_oif_match,
453 const struct sk_buff *skb, int strict);
454struct fib6_node *fib6_node_lookup(struct fib6_node *root,
455 const struct in6_addr *daddr,
456 const struct in6_addr *saddr);
457
458struct fib6_node *fib6_locate(struct fib6_node *root,
459 const struct in6_addr *daddr, int dst_len,
460 const struct in6_addr *saddr, int src_len,
461 bool exact_match);
462
463void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg),
464 void *arg);
465void fib6_clean_all_skip_notify(struct net *net,
466 int (*func)(struct fib6_info *, void *arg),
467 void *arg);
468
469int fib6_add(struct fib6_node *root, struct fib6_info *rt,
470 struct nl_info *info, struct netlink_ext_ack *extack);
471int fib6_del(struct fib6_info *rt, struct nl_info *info);
472
473static inline
474void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr)
475{
476 const struct fib6_info *from;
477
478 rcu_read_lock();
479
480 from = rcu_dereference(rt->from);
481 if (from)
482 *addr = from->fib6_prefsrc.addr;
483 else
484 *addr = in6addr_any;
485
486 rcu_read_unlock();
487}
488
489int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
490 struct fib6_config *cfg, gfp_t gfp_flags,
491 struct netlink_ext_ack *extack);
492void fib6_nh_release(struct fib6_nh *fib6_nh);
493void fib6_nh_release_dsts(struct fib6_nh *fib6_nh);
494
495int call_fib6_entry_notifiers(struct net *net,
496 enum fib_event_type event_type,
497 struct fib6_info *rt,
498 struct netlink_ext_ack *extack);
499int call_fib6_multipath_entry_notifiers(struct net *net,
500 enum fib_event_type event_type,
501 struct fib6_info *rt,
502 unsigned int nsiblings,
503 struct netlink_ext_ack *extack);
504int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt);
505void fib6_rt_update(struct net *net, struct fib6_info *rt,
506 struct nl_info *info);
507void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
508 unsigned int flags);
509
510void fib6_run_gc(unsigned long expires, struct net *net, bool force);
511
512void fib6_gc_cleanup(void);
513
514int fib6_init(void);
515
516/* Add the route to the gc list if it is not already there
517 *
518 * The callers should hold f6i->fib6_table->tb6_lock.
519 */
520static inline void fib6_add_gc_list(struct fib6_info *f6i)
521{
522 /* If fib6_node is null, the f6i is not in (or removed from) the
523 * table.
524 *
525 * There is a gap between finding the f6i from the table and
526 * calling this function without the protection of the tb6_lock.
527 * This check makes sure the f6i is not added to the gc list when
528 * it is not on the table.
529 */
530 if (!rcu_dereference_protected(f6i->fib6_node,
531 lockdep_is_held(&f6i->fib6_table->tb6_lock)))
532 return;
533
534 if (hlist_unhashed(h: &f6i->gc_link))
535 hlist_add_head(n: &f6i->gc_link, h: &f6i->fib6_table->tb6_gc_hlist);
536}
537
538/* Remove the route from the gc list if it is on the list.
539 *
540 * The callers should hold f6i->fib6_table->tb6_lock.
541 */
542static inline void fib6_remove_gc_list(struct fib6_info *f6i)
543{
544 if (!hlist_unhashed(h: &f6i->gc_link))
545 hlist_del_init(n: &f6i->gc_link);
546}
547
548struct ipv6_route_iter {
549 struct seq_net_private p;
550 struct fib6_walker w;
551 loff_t skip;
552 struct fib6_table *tbl;
553 int sernum;
554};
555
556extern const struct seq_operations ipv6_route_seq_ops;
557
558int call_fib6_notifier(struct notifier_block *nb,
559 enum fib_event_type event_type,
560 struct fib_notifier_info *info);
561int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
562 struct fib_notifier_info *info);
563
564int __net_init fib6_notifier_init(struct net *net);
565void __net_exit fib6_notifier_exit(struct net *net);
566
567unsigned int fib6_tables_seq_read(const struct net *net);
568int fib6_tables_dump(struct net *net, struct notifier_block *nb,
569 struct netlink_ext_ack *extack);
570
571void fib6_update_sernum(struct net *net, struct fib6_info *rt);
572void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
573void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i);
574
575void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
576static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
577{
578 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
579}
580void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
581 bool offload, bool trap, bool offload_failed);
582
583#if IS_BUILTIN(CONFIG_IPV6) && defined(CONFIG_BPF_SYSCALL)
584struct bpf_iter__ipv6_route {
585 __bpf_md_ptr(struct bpf_iter_meta *, meta);
586 __bpf_md_ptr(struct fib6_info *, rt);
587};
588#endif
589
590INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_output(struct net *net,
591 struct fib6_table *table,
592 struct flowi6 *fl6,
593 const struct sk_buff *skb,
594 int flags));
595INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_input(struct net *net,
596 struct fib6_table *table,
597 struct flowi6 *fl6,
598 const struct sk_buff *skb,
599 int flags));
600INDIRECT_CALLABLE_DECLARE(struct rt6_info *__ip6_route_redirect(struct net *net,
601 struct fib6_table *table,
602 struct flowi6 *fl6,
603 const struct sk_buff *skb,
604 int flags));
605INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_lookup(struct net *net,
606 struct fib6_table *table,
607 struct flowi6 *fl6,
608 const struct sk_buff *skb,
609 int flags));
610static inline struct rt6_info *pol_lookup_func(pol_lookup_t lookup,
611 struct net *net,
612 struct fib6_table *table,
613 struct flowi6 *fl6,
614 const struct sk_buff *skb,
615 int flags)
616{
617 return INDIRECT_CALL_4(lookup,
618 ip6_pol_route_output,
619 ip6_pol_route_input,
620 ip6_pol_route_lookup,
621 __ip6_route_redirect,
622 net, table, fl6, skb, flags);
623}
624
625#ifdef CONFIG_IPV6_MULTIPLE_TABLES
626static inline bool fib6_has_custom_rules(const struct net *net)
627{
628 return net->ipv6.fib6_has_custom_rules;
629}
630
631int fib6_rules_init(void);
632void fib6_rules_cleanup(void);
633bool fib6_rule_default(const struct fib_rule *rule);
634int fib6_rules_dump(struct net *net, struct notifier_block *nb,
635 struct netlink_ext_ack *extack);
636unsigned int fib6_rules_seq_read(const struct net *net);
637
638static inline bool fib6_rules_early_flow_dissect(struct net *net,
639 struct sk_buff *skb,
640 struct flowi6 *fl6,
641 struct flow_keys *flkeys)
642{
643 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
644
645 if (!net->ipv6.fib6_rules_require_fldissect)
646 return false;
647
648 memset(flkeys, 0, sizeof(*flkeys));
649 __skb_flow_dissect(net, skb, &flow_keys_dissector,
650 flkeys, NULL, 0, 0, 0, flag);
651
652 fl6->fl6_sport = flkeys->ports.src;
653 fl6->fl6_dport = flkeys->ports.dst;
654 fl6->flowi6_proto = flkeys->basic.ip_proto;
655
656 return true;
657}
658#else
659static inline bool fib6_has_custom_rules(const struct net *net)
660{
661 return false;
662}
663static inline int fib6_rules_init(void)
664{
665 return 0;
666}
667static inline void fib6_rules_cleanup(void)
668{
669 return ;
670}
671static inline bool fib6_rule_default(const struct fib_rule *rule)
672{
673 return true;
674}
675static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb,
676 struct netlink_ext_ack *extack)
677{
678 return 0;
679}
680static inline unsigned int fib6_rules_seq_read(const struct net *net)
681{
682 return 0;
683}
684static inline bool fib6_rules_early_flow_dissect(struct net *net,
685 struct sk_buff *skb,
686 struct flowi6 *fl6,
687 struct flow_keys *flkeys)
688{
689 return false;
690}
691#endif
692#endif
693