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
39 struct rt6_info;
40 struct fib6_info;
41
42 struct 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
73 struct 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
89 struct fib6_gc_args {
90 int timeout;
91 int more;
92 };
93
94 #ifndef CONFIG_IPV6_SUBTREES
95 #define FIB6_SUBTREE(fn) NULL
96
fib6_routes_require_src(const struct net * net)97 static inline bool fib6_routes_require_src(const struct net *net)
98 {
99 return false;
100 }
101
fib6_routes_require_src_inc(struct net * net)102 static inline void fib6_routes_require_src_inc(struct net *net) {}
fib6_routes_require_src_dec(struct net * net)103 static inline void fib6_routes_require_src_dec(struct net *net) {}
104
105 #else
106
fib6_routes_require_src(const struct net * net)107 static inline bool fib6_routes_require_src(const struct net *net)
108 {
109 return net->ipv6.fib6_routes_require_src > 0;
110 }
111
fib6_routes_require_src_inc(struct net * net)112 static inline void fib6_routes_require_src_inc(struct net *net)
113 {
114 net->ipv6.fib6_routes_require_src++;
115 }
116
fib6_routes_require_src_dec(struct net * net)117 static 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
130 struct rt6key {
131 struct in6_addr addr;
132 int plen;
133 };
134
135 struct fib6_table;
136
137 struct rt6_exception_bucket {
138 struct hlist_head chain;
139 int depth;
140 };
141
142 struct 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
153 struct 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
164 struct 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 struct dst_metrics *fib6_metrics;
183 #define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1]
184
185 struct rt6key fib6_dst;
186 u32 fib6_flags;
187 struct rt6key fib6_src;
188 struct rt6key fib6_prefsrc;
189
190 u32 fib6_metric;
191 u8 fib6_protocol;
192 u8 fib6_type;
193
194 u8 offload;
195 u8 trap;
196 u8 offload_failed;
197
198 u8 should_flush:1,
199 dst_nocount:1,
200 dst_nopolicy:1,
201 fib6_destroying:1,
202 unused:4;
203
204 struct rcu_head rcu;
205 struct nexthop *nh;
206 struct fib6_nh fib6_nh[];
207 };
208
209 struct rt6_info {
210 struct dst_entry dst;
211 struct fib6_info __rcu *from;
212 int sernum;
213
214 struct rt6key rt6i_dst;
215 struct rt6key rt6i_src;
216 struct in6_addr rt6i_gateway;
217 struct inet6_dev *rt6i_idev;
218 u32 rt6i_flags;
219
220 /* more non-fragment space at head required */
221 unsigned short rt6i_nfheader_len;
222 };
223
224 struct fib6_result {
225 struct fib6_nh *nh;
226 struct fib6_info *f6i;
227 u32 fib6_flags;
228 u8 fib6_type;
229 struct rt6_info *rt6;
230 };
231
232 #define for_each_fib6_node_rt_rcu(fn) \
233 for (rt = rcu_dereference((fn)->leaf); rt; \
234 rt = rcu_dereference(rt->fib6_next))
235
236 #define for_each_fib6_walker_rt(w) \
237 for (rt = (w)->leaf; rt; \
238 rt = rcu_dereference_protected(rt->fib6_next, 1))
239
240 #define dst_rt6_info(_ptr) container_of_const(_ptr, struct rt6_info, dst)
241
ip6_dst_idev(const struct dst_entry * dst)242 static inline struct inet6_dev *ip6_dst_idev(const struct dst_entry *dst)
243 {
244 return dst_rt6_info(dst)->rt6i_idev;
245 }
246
fib6_requires_src(const struct fib6_info * rt)247 static inline bool fib6_requires_src(const struct fib6_info *rt)
248 {
249 return rt->fib6_src.plen > 0;
250 }
251
fib6_clean_expires(struct fib6_info * f6i)252 static inline void fib6_clean_expires(struct fib6_info *f6i)
253 {
254 f6i->fib6_flags &= ~RTF_EXPIRES;
255 f6i->expires = 0;
256 }
257
fib6_set_expires(struct fib6_info * f6i,unsigned long expires)258 static inline void fib6_set_expires(struct fib6_info *f6i,
259 unsigned long expires)
260 {
261 f6i->expires = expires;
262 f6i->fib6_flags |= RTF_EXPIRES;
263 }
264
fib6_check_expired(const struct fib6_info * f6i)265 static inline bool fib6_check_expired(const struct fib6_info *f6i)
266 {
267 if (f6i->fib6_flags & RTF_EXPIRES)
268 return time_after(jiffies, f6i->expires);
269 return false;
270 }
271
272 /* Function to safely get fn->fn_sernum for passed in rt
273 * and store result in passed in cookie.
274 * Return true if we can get cookie safely
275 * Return false if not
276 */
fib6_get_cookie_safe(const struct fib6_info * f6i,u32 * cookie)277 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i,
278 u32 *cookie)
279 {
280 struct fib6_node *fn;
281 bool status = false;
282
283 fn = rcu_dereference(f6i->fib6_node);
284
285 if (fn) {
286 *cookie = READ_ONCE(fn->fn_sernum);
287 /* pairs with smp_wmb() in __fib6_update_sernum_upto_root() */
288 smp_rmb();
289 status = true;
290 }
291
292 return status;
293 }
294
rt6_get_cookie(const struct rt6_info * rt)295 static inline u32 rt6_get_cookie(const struct rt6_info *rt)
296 {
297 struct fib6_info *from;
298 u32 cookie = 0;
299
300 if (rt->sernum)
301 return rt->sernum;
302
303 rcu_read_lock();
304
305 from = rcu_dereference(rt->from);
306 if (from)
307 fib6_get_cookie_safe(from, &cookie);
308
309 rcu_read_unlock();
310
311 return cookie;
312 }
313
ip6_rt_put(struct rt6_info * rt)314 static inline void ip6_rt_put(struct rt6_info *rt)
315 {
316 /* dst_release() accepts a NULL parameter.
317 * We rely on dst being first structure in struct rt6_info
318 */
319 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
320 dst_release(&rt->dst);
321 }
322
323 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh);
324 void fib6_info_destroy_rcu(struct rcu_head *head);
325
fib6_info_hold(struct fib6_info * f6i)326 static inline void fib6_info_hold(struct fib6_info *f6i)
327 {
328 refcount_inc(&f6i->fib6_ref);
329 }
330
fib6_info_hold_safe(struct fib6_info * f6i)331 static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
332 {
333 return refcount_inc_not_zero(&f6i->fib6_ref);
334 }
335
fib6_info_release(struct fib6_info * f6i)336 static inline void fib6_info_release(struct fib6_info *f6i)
337 {
338 if (f6i && refcount_dec_and_test(&f6i->fib6_ref))
339 call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
340 }
341
342 enum fib6_walk_state {
343 #ifdef CONFIG_IPV6_SUBTREES
344 FWS_S,
345 #endif
346 FWS_L,
347 FWS_R,
348 FWS_C,
349 FWS_U
350 };
351
352 struct fib6_walker {
353 struct list_head lh;
354 struct fib6_node *root, *node;
355 struct fib6_info *leaf;
356 enum fib6_walk_state state;
357 unsigned int skip;
358 unsigned int count;
359 unsigned int skip_in_node;
360 int (*func)(struct fib6_walker *);
361 void *args;
362 };
363
364 struct rt6_statistics {
365 __u32 fib_nodes; /* all fib6 nodes */
366 __u32 fib_route_nodes; /* intermediate nodes */
367 __u32 fib_rt_entries; /* rt entries in fib table */
368 __u32 fib_rt_cache; /* cached rt entries in exception table */
369 __u32 fib_discarded_routes; /* total number of routes delete */
370
371 /* The following stat is not protected by any lock */
372 atomic_t fib_rt_alloc; /* total number of routes alloced */
373 };
374
375 #define RTN_TL_ROOT 0x0001
376 #define RTN_ROOT 0x0002 /* tree root node */
377 #define RTN_RTINFO 0x0004 /* node with valid routing info */
378
379 /*
380 * priority levels (or metrics)
381 *
382 */
383
384
385 struct fib6_table {
386 struct hlist_node tb6_hlist;
387 u32 tb6_id;
388 spinlock_t tb6_lock;
389 struct fib6_node tb6_root;
390 struct inet_peer_base tb6_peers;
391 unsigned int flags;
392 unsigned int fib_seq;
393 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0)
394 };
395
396 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC
397 #define RT6_TABLE_MAIN RT_TABLE_MAIN
398 #define RT6_TABLE_DFLT RT6_TABLE_MAIN
399 #define RT6_TABLE_INFO RT6_TABLE_MAIN
400 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN
401
402 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
403 #define FIB6_TABLE_MIN 1
404 #define FIB6_TABLE_MAX RT_TABLE_MAX
405 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL
406 #else
407 #define FIB6_TABLE_MIN RT_TABLE_MAIN
408 #define FIB6_TABLE_MAX FIB6_TABLE_MIN
409 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN
410 #endif
411
412 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
413 struct fib6_table *,
414 struct flowi6 *,
415 const struct sk_buff *, int);
416
417 struct fib6_entry_notifier_info {
418 struct fib_notifier_info info; /* must be first */
419 struct fib6_info *rt;
420 unsigned int nsiblings;
421 };
422
423 /*
424 * exported functions
425 */
426
427 struct fib6_table *fib6_get_table(struct net *net, u32 id);
428 struct fib6_table *fib6_new_table(struct net *net, u32 id);
429 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
430 const struct sk_buff *skb,
431 int flags, pol_lookup_t lookup);
432
433 /* called with rcu lock held; can return error pointer
434 * caller needs to select path
435 */
436 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
437 struct fib6_result *res, int flags);
438
439 /* called with rcu lock held; caller needs to select path */
440 int fib6_table_lookup(struct net *net, struct fib6_table *table,
441 int oif, struct flowi6 *fl6, struct fib6_result *res,
442 int strict);
443
444 void fib6_select_path(const struct net *net, struct fib6_result *res,
445 struct flowi6 *fl6, int oif, bool have_oif_match,
446 const struct sk_buff *skb, int strict);
447 struct fib6_node *fib6_node_lookup(struct fib6_node *root,
448 const struct in6_addr *daddr,
449 const struct in6_addr *saddr);
450
451 struct fib6_node *fib6_locate(struct fib6_node *root,
452 const struct in6_addr *daddr, int dst_len,
453 const struct in6_addr *saddr, int src_len,
454 bool exact_match);
455
456 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg),
457 void *arg);
458 void fib6_clean_all_skip_notify(struct net *net,
459 int (*func)(struct fib6_info *, void *arg),
460 void *arg);
461
462 int fib6_add(struct fib6_node *root, struct fib6_info *rt,
463 struct nl_info *info, struct netlink_ext_ack *extack);
464 int fib6_del(struct fib6_info *rt, struct nl_info *info);
465
466 static inline
rt6_get_prefsrc(const struct rt6_info * rt,struct in6_addr * addr)467 void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr)
468 {
469 const struct fib6_info *from;
470
471 rcu_read_lock();
472
473 from = rcu_dereference(rt->from);
474 if (from)
475 *addr = from->fib6_prefsrc.addr;
476 else
477 *addr = in6addr_any;
478
479 rcu_read_unlock();
480 }
481
482 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
483 struct fib6_config *cfg, gfp_t gfp_flags,
484 struct netlink_ext_ack *extack);
485 void fib6_nh_release(struct fib6_nh *fib6_nh);
486 void fib6_nh_release_dsts(struct fib6_nh *fib6_nh);
487
488 int call_fib6_entry_notifiers(struct net *net,
489 enum fib_event_type event_type,
490 struct fib6_info *rt,
491 struct netlink_ext_ack *extack);
492 int call_fib6_multipath_entry_notifiers(struct net *net,
493 enum fib_event_type event_type,
494 struct fib6_info *rt,
495 unsigned int nsiblings,
496 struct netlink_ext_ack *extack);
497 int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt);
498 void fib6_rt_update(struct net *net, struct fib6_info *rt,
499 struct nl_info *info);
500 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
501 unsigned int flags);
502
503 void fib6_run_gc(unsigned long expires, struct net *net, bool force);
504
505 void fib6_gc_cleanup(void);
506
507 int fib6_init(void);
508
509 struct ipv6_route_iter {
510 struct seq_net_private p;
511 struct fib6_walker w;
512 loff_t skip;
513 struct fib6_table *tbl;
514 int sernum;
515 };
516
517 extern const struct seq_operations ipv6_route_seq_ops;
518
519 int call_fib6_notifier(struct notifier_block *nb,
520 enum fib_event_type event_type,
521 struct fib_notifier_info *info);
522 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
523 struct fib_notifier_info *info);
524
525 int __net_init fib6_notifier_init(struct net *net);
526 void __net_exit fib6_notifier_exit(struct net *net);
527
528 unsigned int fib6_tables_seq_read(struct net *net);
529 int fib6_tables_dump(struct net *net, struct notifier_block *nb,
530 struct netlink_ext_ack *extack);
531
532 void fib6_update_sernum(struct net *net, struct fib6_info *rt);
533 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
534 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i);
535
536 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
fib6_metric_locked(struct fib6_info * f6i,int metric)537 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
538 {
539 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
540 }
541 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
542 bool offload, bool trap, bool offload_failed);
543
544 #if IS_BUILTIN(CONFIG_IPV6) && defined(CONFIG_BPF_SYSCALL)
545 struct bpf_iter__ipv6_route {
546 __bpf_md_ptr(struct bpf_iter_meta *, meta);
547 __bpf_md_ptr(struct fib6_info *, rt);
548 };
549 #endif
550
551 INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_output(struct net *net,
552 struct fib6_table *table,
553 struct flowi6 *fl6,
554 const struct sk_buff *skb,
555 int flags));
556 INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_input(struct net *net,
557 struct fib6_table *table,
558 struct flowi6 *fl6,
559 const struct sk_buff *skb,
560 int flags));
561 INDIRECT_CALLABLE_DECLARE(struct rt6_info *__ip6_route_redirect(struct net *net,
562 struct fib6_table *table,
563 struct flowi6 *fl6,
564 const struct sk_buff *skb,
565 int flags));
566 INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_lookup(struct net *net,
567 struct fib6_table *table,
568 struct flowi6 *fl6,
569 const struct sk_buff *skb,
570 int flags));
pol_lookup_func(pol_lookup_t lookup,struct net * net,struct fib6_table * table,struct flowi6 * fl6,const struct sk_buff * skb,int flags)571 static inline struct rt6_info *pol_lookup_func(pol_lookup_t lookup,
572 struct net *net,
573 struct fib6_table *table,
574 struct flowi6 *fl6,
575 const struct sk_buff *skb,
576 int flags)
577 {
578 return INDIRECT_CALL_4(lookup,
579 ip6_pol_route_output,
580 ip6_pol_route_input,
581 ip6_pol_route_lookup,
582 __ip6_route_redirect,
583 net, table, fl6, skb, flags);
584 }
585
586 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
fib6_has_custom_rules(const struct net * net)587 static inline bool fib6_has_custom_rules(const struct net *net)
588 {
589 return net->ipv6.fib6_has_custom_rules;
590 }
591
592 int fib6_rules_init(void);
593 void fib6_rules_cleanup(void);
594 bool fib6_rule_default(const struct fib_rule *rule);
595 int fib6_rules_dump(struct net *net, struct notifier_block *nb,
596 struct netlink_ext_ack *extack);
597 unsigned int fib6_rules_seq_read(struct net *net);
598
fib6_rules_early_flow_dissect(struct net * net,struct sk_buff * skb,struct flowi6 * fl6,struct flow_keys * flkeys)599 static inline bool fib6_rules_early_flow_dissect(struct net *net,
600 struct sk_buff *skb,
601 struct flowi6 *fl6,
602 struct flow_keys *flkeys)
603 {
604 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
605
606 if (!net->ipv6.fib6_rules_require_fldissect)
607 return false;
608
609 memset(flkeys, 0, sizeof(*flkeys));
610 __skb_flow_dissect(net, skb, &flow_keys_dissector,
611 flkeys, NULL, 0, 0, 0, flag);
612
613 fl6->fl6_sport = flkeys->ports.src;
614 fl6->fl6_dport = flkeys->ports.dst;
615 fl6->flowi6_proto = flkeys->basic.ip_proto;
616
617 return true;
618 }
619 #else
fib6_has_custom_rules(const struct net * net)620 static inline bool fib6_has_custom_rules(const struct net *net)
621 {
622 return false;
623 }
fib6_rules_init(void)624 static inline int fib6_rules_init(void)
625 {
626 return 0;
627 }
fib6_rules_cleanup(void)628 static inline void fib6_rules_cleanup(void)
629 {
630 return ;
631 }
fib6_rule_default(const struct fib_rule * rule)632 static inline bool fib6_rule_default(const struct fib_rule *rule)
633 {
634 return true;
635 }
fib6_rules_dump(struct net * net,struct notifier_block * nb,struct netlink_ext_ack * extack)636 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb,
637 struct netlink_ext_ack *extack)
638 {
639 return 0;
640 }
fib6_rules_seq_read(struct net * net)641 static inline unsigned int fib6_rules_seq_read(struct net *net)
642 {
643 return 0;
644 }
fib6_rules_early_flow_dissect(struct net * net,struct sk_buff * skb,struct flowi6 * fl6,struct flow_keys * flkeys)645 static inline bool fib6_rules_early_flow_dissect(struct net *net,
646 struct sk_buff *skb,
647 struct flowi6 *fl6,
648 struct flow_keys *flkeys)
649 {
650 return false;
651 }
652 #endif
653 #endif
654