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>
23 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
24 #define FIB6_TABLE_HASHSZ 256
26 #define FIB6_TABLE_HASHSZ 1
32 #define RT6_TRACE(x...) pr_debug(x)
34 #define RT6_TRACE(x...) do { ; } while (0)
48 u16 fc_type; /* only 8 bits are used */
49 u16 fc_delete_all_nh : 1,
54 struct in6_addr fc_dst;
55 struct in6_addr fc_src;
56 struct in6_addr fc_prefsrc;
57 struct in6_addr fc_gateway;
59 unsigned long fc_expires;
65 struct nl_info fc_nlinfo;
66 struct nlattr *fc_encap;
72 struct fib6_node __rcu *parent;
73 struct fib6_node __rcu *left;
74 struct fib6_node __rcu *right;
75 #ifdef CONFIG_IPV6_SUBTREES
76 struct fib6_node __rcu *subtree;
78 struct fib6_info __rcu *leaf;
80 __u16 fn_bit; /* bit key */
83 struct fib6_info __rcu *rr_ptr;
92 #ifndef CONFIG_IPV6_SUBTREES
93 #define FIB6_SUBTREE(fn) NULL
95 static inline bool fib6_routes_require_src(const struct net *net)
100 static inline void fib6_routes_require_src_inc(struct net *net) {}
101 static inline void fib6_routes_require_src_dec(struct net *net) {}
105 static inline bool fib6_routes_require_src(const struct net *net)
107 return net->ipv6.fib6_routes_require_src > 0;
110 static inline void fib6_routes_require_src_inc(struct net *net)
112 net->ipv6.fib6_routes_require_src++;
115 static inline void fib6_routes_require_src_dec(struct net *net)
117 net->ipv6.fib6_routes_require_src--;
120 #define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1))
124 * routing information
129 struct in6_addr addr;
135 struct rt6_exception_bucket {
136 struct hlist_head chain;
140 struct rt6_exception {
141 struct hlist_node hlist;
142 struct rt6_info *rt6i;
147 #define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10
148 #define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT)
149 #define FIB6_MAX_DEPTH 5
152 struct fib_nh_common nh_common;
154 #ifdef CONFIG_IPV6_ROUTER_PREF
155 unsigned long last_probe;
158 struct rt6_info * __percpu *rt6i_pcpu;
159 struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
163 struct fib6_table *fib6_table;
164 struct fib6_info __rcu *fib6_next;
165 struct fib6_node __rcu *fib6_node;
168 * siblings is a list of fib6_info that have the the same metric/weight,
169 * destination, but not the same gateway. nsiblings is just a cache
170 * to speed up lookup.
173 struct list_head fib6_siblings;
174 struct list_head nh_list;
176 unsigned int fib6_nsiblings;
179 unsigned long expires;
180 struct dst_metrics *fib6_metrics;
181 #define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1]
183 struct rt6key fib6_dst;
185 struct rt6key fib6_src;
186 struct rt6key fib6_prefsrc;
201 struct fib6_nh fib6_nh[];
205 struct dst_entry dst;
206 struct fib6_info __rcu *from;
209 struct rt6key rt6i_dst;
210 struct rt6key rt6i_src;
211 struct in6_addr rt6i_gateway;
212 struct inet6_dev *rt6i_idev;
215 struct list_head rt6i_uncached;
216 struct uncached_list *rt6i_uncached_list;
218 /* more non-fragment space at head required */
219 unsigned short rt6i_nfheader_len;
224 struct fib6_info *f6i;
227 struct rt6_info *rt6;
230 #define for_each_fib6_node_rt_rcu(fn) \
231 for (rt = rcu_dereference((fn)->leaf); rt; \
232 rt = rcu_dereference(rt->fib6_next))
234 #define for_each_fib6_walker_rt(w) \
235 for (rt = (w)->leaf; rt; \
236 rt = rcu_dereference_protected(rt->fib6_next, 1))
238 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
240 return ((struct rt6_info *)dst)->rt6i_idev;
243 static inline bool fib6_requires_src(const struct fib6_info *rt)
245 return rt->fib6_src.plen > 0;
248 static inline void fib6_clean_expires(struct fib6_info *f6i)
250 f6i->fib6_flags &= ~RTF_EXPIRES;
254 static inline void fib6_set_expires(struct fib6_info *f6i,
255 unsigned long expires)
257 f6i->expires = expires;
258 f6i->fib6_flags |= RTF_EXPIRES;
261 static inline bool fib6_check_expired(const struct fib6_info *f6i)
263 if (f6i->fib6_flags & RTF_EXPIRES)
264 return time_after(jiffies, f6i->expires);
268 /* Function to safely get fn->sernum for passed in rt
269 * and store result in passed in cookie.
270 * Return true if we can get cookie safely
271 * Return false if not
273 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i,
276 struct fib6_node *fn;
279 fn = rcu_dereference(f6i->fib6_node);
282 *cookie = fn->fn_sernum;
283 /* pairs with smp_wmb() in fib6_update_sernum_upto_root() */
291 static inline u32 rt6_get_cookie(const struct rt6_info *rt)
293 struct fib6_info *from;
301 from = rcu_dereference(rt->from);
303 fib6_get_cookie_safe(from, &cookie);
310 static inline void ip6_rt_put(struct rt6_info *rt)
312 /* dst_release() accepts a NULL parameter.
313 * We rely on dst being first structure in struct rt6_info
315 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
316 dst_release(&rt->dst);
319 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh);
320 void fib6_info_destroy_rcu(struct rcu_head *head);
322 static inline void fib6_info_hold(struct fib6_info *f6i)
324 refcount_inc(&f6i->fib6_ref);
327 static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
329 return refcount_inc_not_zero(&f6i->fib6_ref);
332 static inline void fib6_info_release(struct fib6_info *f6i)
334 if (f6i && refcount_dec_and_test(&f6i->fib6_ref))
335 call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
338 static inline void fib6_info_hw_flags_set(struct fib6_info *f6i, bool offload,
341 f6i->offload = offload;
345 enum fib6_walk_state {
346 #ifdef CONFIG_IPV6_SUBTREES
357 struct fib6_node *root, *node;
358 struct fib6_info *leaf;
359 enum fib6_walk_state state;
362 unsigned int skip_in_node;
363 int (*func)(struct fib6_walker *);
367 struct rt6_statistics {
368 __u32 fib_nodes; /* all fib6 nodes */
369 __u32 fib_route_nodes; /* intermediate nodes */
370 __u32 fib_rt_entries; /* rt entries in fib table */
371 __u32 fib_rt_cache; /* cached rt entries in exception table */
372 __u32 fib_discarded_routes; /* total number of routes delete */
374 /* The following stats are not protected by any lock */
375 atomic_t fib_rt_alloc; /* total number of routes alloced */
376 atomic_t fib_rt_uncache; /* rt entries in uncached list */
379 #define RTN_TL_ROOT 0x0001
380 #define RTN_ROOT 0x0002 /* tree root node */
381 #define RTN_RTINFO 0x0004 /* node with valid routing info */
384 * priority levels (or metrics)
390 struct hlist_node tb6_hlist;
393 struct fib6_node tb6_root;
394 struct inet_peer_base tb6_peers;
396 unsigned int fib_seq;
397 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0)
400 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC
401 #define RT6_TABLE_MAIN RT_TABLE_MAIN
402 #define RT6_TABLE_DFLT RT6_TABLE_MAIN
403 #define RT6_TABLE_INFO RT6_TABLE_MAIN
404 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN
406 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
407 #define FIB6_TABLE_MIN 1
408 #define FIB6_TABLE_MAX RT_TABLE_MAX
409 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL
411 #define FIB6_TABLE_MIN RT_TABLE_MAIN
412 #define FIB6_TABLE_MAX FIB6_TABLE_MIN
413 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN
416 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
419 const struct sk_buff *, int);
421 struct fib6_entry_notifier_info {
422 struct fib_notifier_info info; /* must be first */
423 struct fib6_info *rt;
424 unsigned int nsiblings;
431 struct fib6_table *fib6_get_table(struct net *net, u32 id);
432 struct fib6_table *fib6_new_table(struct net *net, u32 id);
433 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
434 const struct sk_buff *skb,
435 int flags, pol_lookup_t lookup);
437 /* called with rcu lock held; can return error pointer
438 * caller needs to select path
440 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
441 struct fib6_result *res, int flags);
443 /* called with rcu lock held; caller needs to select path */
444 int fib6_table_lookup(struct net *net, struct fib6_table *table,
445 int oif, struct flowi6 *fl6, struct fib6_result *res,
448 void fib6_select_path(const struct net *net, struct fib6_result *res,
449 struct flowi6 *fl6, int oif, bool have_oif_match,
450 const struct sk_buff *skb, int strict);
451 struct fib6_node *fib6_node_lookup(struct fib6_node *root,
452 const struct in6_addr *daddr,
453 const struct in6_addr *saddr);
455 struct fib6_node *fib6_locate(struct fib6_node *root,
456 const struct in6_addr *daddr, int dst_len,
457 const struct in6_addr *saddr, int src_len,
460 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg),
462 void fib6_clean_all_skip_notify(struct net *net,
463 int (*func)(struct fib6_info *, void *arg),
466 int fib6_add(struct fib6_node *root, struct fib6_info *rt,
467 struct nl_info *info, struct netlink_ext_ack *extack);
468 int fib6_del(struct fib6_info *rt, struct nl_info *info);
471 void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr)
473 const struct fib6_info *from;
477 from = rcu_dereference(rt->from);
479 *addr = from->fib6_prefsrc.addr;
481 struct in6_addr in6_zero = {};
489 int 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);
492 void fib6_nh_release(struct fib6_nh *fib6_nh);
494 int call_fib6_entry_notifiers(struct net *net,
495 enum fib_event_type event_type,
496 struct fib6_info *rt,
497 struct netlink_ext_ack *extack);
498 int call_fib6_multipath_entry_notifiers(struct net *net,
499 enum fib_event_type event_type,
500 struct fib6_info *rt,
501 unsigned int nsiblings,
502 struct netlink_ext_ack *extack);
503 int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt);
504 void fib6_rt_update(struct net *net, struct fib6_info *rt,
505 struct nl_info *info);
506 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
509 void fib6_run_gc(unsigned long expires, struct net *net, bool force);
511 void fib6_gc_cleanup(void);
515 struct ipv6_route_iter {
516 struct seq_net_private p;
517 struct fib6_walker w;
519 struct fib6_table *tbl;
523 extern const struct seq_operations ipv6_route_seq_ops;
525 int call_fib6_notifier(struct notifier_block *nb,
526 enum fib_event_type event_type,
527 struct fib_notifier_info *info);
528 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
529 struct fib_notifier_info *info);
531 int __net_init fib6_notifier_init(struct net *net);
532 void __net_exit fib6_notifier_exit(struct net *net);
534 unsigned int fib6_tables_seq_read(struct net *net);
535 int fib6_tables_dump(struct net *net, struct notifier_block *nb,
536 struct netlink_ext_ack *extack);
538 void fib6_update_sernum(struct net *net, struct fib6_info *rt);
539 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
540 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i);
542 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
543 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
545 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
548 #if IS_BUILTIN(CONFIG_IPV6) && defined(CONFIG_BPF_SYSCALL)
549 struct bpf_iter__ipv6_route {
550 __bpf_md_ptr(struct bpf_iter_meta *, meta);
551 __bpf_md_ptr(struct fib6_info *, rt);
555 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
556 static inline bool fib6_has_custom_rules(const struct net *net)
558 return net->ipv6.fib6_has_custom_rules;
561 int fib6_rules_init(void);
562 void fib6_rules_cleanup(void);
563 bool fib6_rule_default(const struct fib_rule *rule);
564 int fib6_rules_dump(struct net *net, struct notifier_block *nb,
565 struct netlink_ext_ack *extack);
566 unsigned int fib6_rules_seq_read(struct net *net);
568 static inline bool fib6_rules_early_flow_dissect(struct net *net,
571 struct flow_keys *flkeys)
573 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
575 if (!net->ipv6.fib6_rules_require_fldissect)
578 skb_flow_dissect_flow_keys(skb, flkeys, flag);
579 fl6->fl6_sport = flkeys->ports.src;
580 fl6->fl6_dport = flkeys->ports.dst;
581 fl6->flowi6_proto = flkeys->basic.ip_proto;
586 static inline bool fib6_has_custom_rules(const struct net *net)
590 static inline int fib6_rules_init(void)
594 static inline void fib6_rules_cleanup(void)
598 static inline bool fib6_rule_default(const struct fib_rule *rule)
602 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb,
603 struct netlink_ext_ack *extack)
607 static inline unsigned int fib6_rules_seq_read(struct net *net)
611 static inline bool fib6_rules_early_flow_dissect(struct net *net,
614 struct flow_keys *flkeys)