1 /* SPDX-License-Identifier: GPL-2.0-or-later */
3 * Linux INET6 implementation
6 * Pedro Roque <roque@di.fc.ul.pt>
12 #include <linux/ipv6_route.h>
13 #include <linux/rtnetlink.h>
14 #include <linux/spinlock.h>
15 #include <linux/notifier.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>
25 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
26 #define FIB6_TABLE_HASHSZ 256
28 #define FIB6_TABLE_HASHSZ 1
34 #define RT6_TRACE(x...) pr_debug(x)
36 #define RT6_TRACE(x...) do { ; } while (0)
50 u16 fc_type; /* only 8 bits are used */
51 u16 fc_delete_all_nh : 1,
56 struct in6_addr fc_dst;
57 struct in6_addr fc_src;
58 struct in6_addr fc_prefsrc;
59 struct in6_addr fc_gateway;
61 unsigned long fc_expires;
67 struct nl_info fc_nlinfo;
68 struct nlattr *fc_encap;
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;
80 struct fib6_info __rcu *leaf;
82 __u16 fn_bit; /* bit key */
85 struct fib6_info __rcu *rr_ptr;
94 #ifndef CONFIG_IPV6_SUBTREES
95 #define FIB6_SUBTREE(fn) NULL
97 static inline bool fib6_routes_require_src(const struct net *net)
102 static inline void fib6_routes_require_src_inc(struct net *net) {}
103 static inline void fib6_routes_require_src_dec(struct net *net) {}
107 static inline bool fib6_routes_require_src(const struct net *net)
109 return net->ipv6.fib6_routes_require_src > 0;
112 static inline void fib6_routes_require_src_inc(struct net *net)
114 net->ipv6.fib6_routes_require_src++;
117 static inline void fib6_routes_require_src_dec(struct net *net)
119 net->ipv6.fib6_routes_require_src--;
122 #define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1))
126 * routing information
131 struct in6_addr addr;
137 struct rt6_exception_bucket {
138 struct hlist_head chain;
142 struct rt6_exception {
143 struct hlist_node hlist;
144 struct rt6_info *rt6i;
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
154 struct fib_nh_common nh_common;
156 #ifdef CONFIG_IPV6_ROUTER_PREF
157 unsigned long last_probe;
160 struct rt6_info * __percpu *rt6i_pcpu;
161 struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
165 struct fib6_table *fib6_table;
166 struct fib6_info __rcu *fib6_next;
167 struct fib6_node __rcu *fib6_node;
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.
175 struct list_head fib6_siblings;
176 struct list_head nh_list;
178 unsigned int fib6_nsiblings;
181 unsigned long expires;
182 struct dst_metrics *fib6_metrics;
183 #define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1]
185 struct rt6key fib6_dst;
187 struct rt6key fib6_src;
188 struct rt6key fib6_prefsrc;
204 struct fib6_nh fib6_nh[];
208 struct dst_entry dst;
209 struct fib6_info __rcu *from;
212 struct rt6key rt6i_dst;
213 struct rt6key rt6i_src;
214 struct in6_addr rt6i_gateway;
215 struct inet6_dev *rt6i_idev;
218 struct list_head rt6i_uncached;
219 struct uncached_list *rt6i_uncached_list;
221 /* more non-fragment space at head required */
222 unsigned short rt6i_nfheader_len;
227 struct fib6_info *f6i;
230 struct rt6_info *rt6;
233 #define for_each_fib6_node_rt_rcu(fn) \
234 for (rt = rcu_dereference((fn)->leaf); rt; \
235 rt = rcu_dereference(rt->fib6_next))
237 #define for_each_fib6_walker_rt(w) \
238 for (rt = (w)->leaf; rt; \
239 rt = rcu_dereference_protected(rt->fib6_next, 1))
241 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
243 return ((struct rt6_info *)dst)->rt6i_idev;
246 static inline bool fib6_requires_src(const struct fib6_info *rt)
248 return rt->fib6_src.plen > 0;
251 static inline void fib6_clean_expires(struct fib6_info *f6i)
253 f6i->fib6_flags &= ~RTF_EXPIRES;
257 static inline void fib6_set_expires(struct fib6_info *f6i,
258 unsigned long expires)
260 f6i->expires = expires;
261 f6i->fib6_flags |= RTF_EXPIRES;
264 static inline bool fib6_check_expired(const struct fib6_info *f6i)
266 if (f6i->fib6_flags & RTF_EXPIRES)
267 return time_after(jiffies, f6i->expires);
271 /* Function to safely get fn->fn_sernum for passed in rt
272 * and store result in passed in cookie.
273 * Return true if we can get cookie safely
274 * Return false if not
276 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i,
279 struct fib6_node *fn;
282 fn = rcu_dereference(f6i->fib6_node);
285 *cookie = READ_ONCE(fn->fn_sernum);
286 /* pairs with smp_wmb() in __fib6_update_sernum_upto_root() */
294 static inline u32 rt6_get_cookie(const struct rt6_info *rt)
296 struct fib6_info *from;
304 from = rcu_dereference(rt->from);
306 fib6_get_cookie_safe(from, &cookie);
313 static inline void ip6_rt_put(struct rt6_info *rt)
315 /* dst_release() accepts a NULL parameter.
316 * We rely on dst being first structure in struct rt6_info
318 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
319 dst_release(&rt->dst);
322 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh);
323 void fib6_info_destroy_rcu(struct rcu_head *head);
325 static inline void fib6_info_hold(struct fib6_info *f6i)
327 refcount_inc(&f6i->fib6_ref);
330 static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
332 return refcount_inc_not_zero(&f6i->fib6_ref);
335 static inline void fib6_info_release(struct fib6_info *f6i)
337 if (f6i && refcount_dec_and_test(&f6i->fib6_ref))
338 call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
341 enum fib6_walk_state {
342 #ifdef CONFIG_IPV6_SUBTREES
353 struct fib6_node *root, *node;
354 struct fib6_info *leaf;
355 enum fib6_walk_state state;
358 unsigned int skip_in_node;
359 int (*func)(struct fib6_walker *);
363 struct rt6_statistics {
364 __u32 fib_nodes; /* all fib6 nodes */
365 __u32 fib_route_nodes; /* intermediate nodes */
366 __u32 fib_rt_entries; /* rt entries in fib table */
367 __u32 fib_rt_cache; /* cached rt entries in exception table */
368 __u32 fib_discarded_routes; /* total number of routes delete */
370 /* The following stats are not protected by any lock */
371 atomic_t fib_rt_alloc; /* total number of routes alloced */
372 atomic_t fib_rt_uncache; /* rt entries in uncached list */
375 #define RTN_TL_ROOT 0x0001
376 #define RTN_ROOT 0x0002 /* tree root node */
377 #define RTN_RTINFO 0x0004 /* node with valid routing info */
380 * priority levels (or metrics)
386 struct hlist_node tb6_hlist;
389 struct fib6_node tb6_root;
390 struct inet_peer_base tb6_peers;
392 unsigned int fib_seq;
393 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0)
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
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
407 #define FIB6_TABLE_MIN RT_TABLE_MAIN
408 #define FIB6_TABLE_MAX FIB6_TABLE_MIN
409 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN
412 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
415 const struct sk_buff *, int);
417 struct fib6_entry_notifier_info {
418 struct fib_notifier_info info; /* must be first */
419 struct fib6_info *rt;
420 unsigned int nsiblings;
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);
433 /* called with rcu lock held; can return error pointer
434 * caller needs to select path
436 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
437 struct fib6_result *res, int flags);
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,
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);
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,
456 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg),
458 void fib6_clean_all_skip_notify(struct net *net,
459 int (*func)(struct fib6_info *, void *arg),
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);
467 void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr)
469 const struct fib6_info *from;
473 from = rcu_dereference(rt->from);
475 *addr = from->fib6_prefsrc.addr;
477 struct in6_addr in6_zero = {};
485 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
486 struct fib6_config *cfg, gfp_t gfp_flags,
487 struct netlink_ext_ack *extack);
488 void fib6_nh_release(struct fib6_nh *fib6_nh);
489 void fib6_nh_release_dsts(struct fib6_nh *fib6_nh);
491 int call_fib6_entry_notifiers(struct net *net,
492 enum fib_event_type event_type,
493 struct fib6_info *rt,
494 struct netlink_ext_ack *extack);
495 int call_fib6_multipath_entry_notifiers(struct net *net,
496 enum fib_event_type event_type,
497 struct fib6_info *rt,
498 unsigned int nsiblings,
499 struct netlink_ext_ack *extack);
500 int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt);
501 void fib6_rt_update(struct net *net, struct fib6_info *rt,
502 struct nl_info *info);
503 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
506 void fib6_run_gc(unsigned long expires, struct net *net, bool force);
508 void fib6_gc_cleanup(void);
512 struct ipv6_route_iter {
513 struct seq_net_private p;
514 struct fib6_walker w;
516 struct fib6_table *tbl;
520 extern const struct seq_operations ipv6_route_seq_ops;
522 int call_fib6_notifier(struct notifier_block *nb,
523 enum fib_event_type event_type,
524 struct fib_notifier_info *info);
525 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
526 struct fib_notifier_info *info);
528 int __net_init fib6_notifier_init(struct net *net);
529 void __net_exit fib6_notifier_exit(struct net *net);
531 unsigned int fib6_tables_seq_read(struct net *net);
532 int fib6_tables_dump(struct net *net, struct notifier_block *nb,
533 struct netlink_ext_ack *extack);
535 void fib6_update_sernum(struct net *net, struct fib6_info *rt);
536 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
537 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i);
539 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
540 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
542 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
544 void fib6_info_hw_flags_set(struct net *net, struct fib6_info *f6i,
545 bool offload, bool trap, bool offload_failed);
547 #if IS_BUILTIN(CONFIG_IPV6) && defined(CONFIG_BPF_SYSCALL)
548 struct bpf_iter__ipv6_route {
549 __bpf_md_ptr(struct bpf_iter_meta *, meta);
550 __bpf_md_ptr(struct fib6_info *, rt);
554 INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_output(struct net *net,
555 struct fib6_table *table,
557 const struct sk_buff *skb,
559 INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_input(struct net *net,
560 struct fib6_table *table,
562 const struct sk_buff *skb,
564 INDIRECT_CALLABLE_DECLARE(struct rt6_info *__ip6_route_redirect(struct net *net,
565 struct fib6_table *table,
567 const struct sk_buff *skb,
569 INDIRECT_CALLABLE_DECLARE(struct rt6_info *ip6_pol_route_lookup(struct net *net,
570 struct fib6_table *table,
572 const struct sk_buff *skb,
574 static inline struct rt6_info *pol_lookup_func(pol_lookup_t lookup,
576 struct fib6_table *table,
578 const struct sk_buff *skb,
581 return INDIRECT_CALL_4(lookup,
582 ip6_pol_route_output,
584 ip6_pol_route_lookup,
585 __ip6_route_redirect,
586 net, table, fl6, skb, flags);
589 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
590 static inline bool fib6_has_custom_rules(const struct net *net)
592 return net->ipv6.fib6_has_custom_rules;
595 int fib6_rules_init(void);
596 void fib6_rules_cleanup(void);
597 bool fib6_rule_default(const struct fib_rule *rule);
598 int fib6_rules_dump(struct net *net, struct notifier_block *nb,
599 struct netlink_ext_ack *extack);
600 unsigned int fib6_rules_seq_read(struct net *net);
602 static inline bool fib6_rules_early_flow_dissect(struct net *net,
605 struct flow_keys *flkeys)
607 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
609 if (!net->ipv6.fib6_rules_require_fldissect)
612 skb_flow_dissect_flow_keys(skb, flkeys, flag);
613 fl6->fl6_sport = flkeys->ports.src;
614 fl6->fl6_dport = flkeys->ports.dst;
615 fl6->flowi6_proto = flkeys->basic.ip_proto;
620 static inline bool fib6_has_custom_rules(const struct net *net)
624 static inline int fib6_rules_init(void)
628 static inline void fib6_rules_cleanup(void)
632 static inline bool fib6_rule_default(const struct fib_rule *rule)
636 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb,
637 struct netlink_ext_ack *extack)
641 static inline unsigned int fib6_rules_seq_read(struct net *net)
645 static inline bool fib6_rules_early_flow_dissect(struct net *net,
648 struct flow_keys *flkeys)