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;
71 struct fib6_node __rcu *parent;
72 struct fib6_node __rcu *left;
73 struct fib6_node __rcu *right;
74 #ifdef CONFIG_IPV6_SUBTREES
75 struct fib6_node __rcu *subtree;
77 struct fib6_info __rcu *leaf;
79 __u16 fn_bit; /* bit key */
82 struct fib6_info __rcu *rr_ptr;
91 #ifndef CONFIG_IPV6_SUBTREES
92 #define FIB6_SUBTREE(fn) NULL
94 static inline bool fib6_routes_require_src(const struct net *net)
99 static inline void fib6_routes_require_src_inc(struct net *net) {}
100 static inline void fib6_routes_require_src_dec(struct net *net) {}
104 static inline bool fib6_routes_require_src(const struct net *net)
106 return net->ipv6.fib6_routes_require_src > 0;
109 static inline void fib6_routes_require_src_inc(struct net *net)
111 net->ipv6.fib6_routes_require_src++;
114 static inline void fib6_routes_require_src_dec(struct net *net)
116 net->ipv6.fib6_routes_require_src--;
119 #define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1))
123 * routing information
128 struct in6_addr addr;
134 struct rt6_exception_bucket {
135 struct hlist_head chain;
139 struct rt6_exception {
140 struct hlist_node hlist;
141 struct rt6_info *rt6i;
146 #define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10
147 #define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT)
148 #define FIB6_MAX_DEPTH 5
151 struct fib_nh_common nh_common;
153 #ifdef CONFIG_IPV6_ROUTER_PREF
154 unsigned long last_probe;
157 struct rt6_info * __percpu *rt6i_pcpu;
158 struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
162 struct fib6_table *fib6_table;
163 struct fib6_info __rcu *fib6_next;
164 struct fib6_node __rcu *fib6_node;
167 * siblings is a list of fib6_info that have the the same metric/weight,
168 * destination, but not the same gateway. nsiblings is just a cache
169 * to speed up lookup.
172 struct list_head fib6_siblings;
173 struct list_head nh_list;
175 unsigned int fib6_nsiblings;
178 unsigned long expires;
179 struct dst_metrics *fib6_metrics;
180 #define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1]
182 struct rt6key fib6_dst;
184 struct rt6key fib6_src;
185 struct rt6key fib6_prefsrc;
200 struct fib6_nh fib6_nh[];
204 struct dst_entry dst;
205 struct fib6_info __rcu *from;
208 struct rt6key rt6i_dst;
209 struct rt6key rt6i_src;
210 struct in6_addr rt6i_gateway;
211 struct inet6_dev *rt6i_idev;
214 struct list_head rt6i_uncached;
215 struct uncached_list *rt6i_uncached_list;
217 /* more non-fragment space at head required */
218 unsigned short rt6i_nfheader_len;
223 struct fib6_info *f6i;
226 struct rt6_info *rt6;
229 #define for_each_fib6_node_rt_rcu(fn) \
230 for (rt = rcu_dereference((fn)->leaf); rt; \
231 rt = rcu_dereference(rt->fib6_next))
233 #define for_each_fib6_walker_rt(w) \
234 for (rt = (w)->leaf; rt; \
235 rt = rcu_dereference_protected(rt->fib6_next, 1))
237 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
239 return ((struct rt6_info *)dst)->rt6i_idev;
242 static inline bool fib6_requires_src(const struct fib6_info *rt)
244 return rt->fib6_src.plen > 0;
247 static inline void fib6_clean_expires(struct fib6_info *f6i)
249 f6i->fib6_flags &= ~RTF_EXPIRES;
253 static inline void fib6_set_expires(struct fib6_info *f6i,
254 unsigned long expires)
256 f6i->expires = expires;
257 f6i->fib6_flags |= RTF_EXPIRES;
260 static inline bool fib6_check_expired(const struct fib6_info *f6i)
262 if (f6i->fib6_flags & RTF_EXPIRES)
263 return time_after(jiffies, f6i->expires);
267 /* Function to safely get fn->sernum for passed in rt
268 * and store result in passed in cookie.
269 * Return true if we can get cookie safely
270 * Return false if not
272 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i,
275 struct fib6_node *fn;
278 fn = rcu_dereference(f6i->fib6_node);
281 *cookie = fn->fn_sernum;
282 /* pairs with smp_wmb() in fib6_update_sernum_upto_root() */
290 static inline u32 rt6_get_cookie(const struct rt6_info *rt)
292 struct fib6_info *from;
300 from = rcu_dereference(rt->from);
302 fib6_get_cookie_safe(from, &cookie);
309 static inline void ip6_rt_put(struct rt6_info *rt)
311 /* dst_release() accepts a NULL parameter.
312 * We rely on dst being first structure in struct rt6_info
314 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
315 dst_release(&rt->dst);
318 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh);
319 void fib6_info_destroy_rcu(struct rcu_head *head);
321 static inline void fib6_info_hold(struct fib6_info *f6i)
323 refcount_inc(&f6i->fib6_ref);
326 static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
328 return refcount_inc_not_zero(&f6i->fib6_ref);
331 static inline void fib6_info_release(struct fib6_info *f6i)
333 if (f6i && refcount_dec_and_test(&f6i->fib6_ref))
334 call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
337 static inline void fib6_info_hw_flags_set(struct fib6_info *f6i, bool offload,
340 f6i->offload = offload;
344 enum fib6_walk_state {
345 #ifdef CONFIG_IPV6_SUBTREES
356 struct fib6_node *root, *node;
357 struct fib6_info *leaf;
358 enum fib6_walk_state state;
361 unsigned int skip_in_node;
362 int (*func)(struct fib6_walker *);
366 struct rt6_statistics {
367 __u32 fib_nodes; /* all fib6 nodes */
368 __u32 fib_route_nodes; /* intermediate nodes */
369 __u32 fib_rt_entries; /* rt entries in fib table */
370 __u32 fib_rt_cache; /* cached rt entries in exception table */
371 __u32 fib_discarded_routes; /* total number of routes delete */
373 /* The following stats are not protected by any lock */
374 atomic_t fib_rt_alloc; /* total number of routes alloced */
375 atomic_t fib_rt_uncache; /* rt entries in uncached list */
378 #define RTN_TL_ROOT 0x0001
379 #define RTN_ROOT 0x0002 /* tree root node */
380 #define RTN_RTINFO 0x0004 /* node with valid routing info */
383 * priority levels (or metrics)
389 struct hlist_node tb6_hlist;
392 struct fib6_node tb6_root;
393 struct inet_peer_base tb6_peers;
395 unsigned int fib_seq;
396 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0)
399 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC
400 #define RT6_TABLE_MAIN RT_TABLE_MAIN
401 #define RT6_TABLE_DFLT RT6_TABLE_MAIN
402 #define RT6_TABLE_INFO RT6_TABLE_MAIN
403 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN
405 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
406 #define FIB6_TABLE_MIN 1
407 #define FIB6_TABLE_MAX RT_TABLE_MAX
408 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL
410 #define FIB6_TABLE_MIN RT_TABLE_MAIN
411 #define FIB6_TABLE_MAX FIB6_TABLE_MIN
412 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN
415 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
418 const struct sk_buff *, int);
420 struct fib6_entry_notifier_info {
421 struct fib_notifier_info info; /* must be first */
422 struct fib6_info *rt;
423 unsigned int nsiblings;
430 struct fib6_table *fib6_get_table(struct net *net, u32 id);
431 struct fib6_table *fib6_new_table(struct net *net, u32 id);
432 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
433 const struct sk_buff *skb,
434 int flags, pol_lookup_t lookup);
436 /* called with rcu lock held; can return error pointer
437 * caller needs to select path
439 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
440 struct fib6_result *res, int flags);
442 /* called with rcu lock held; caller needs to select path */
443 int fib6_table_lookup(struct net *net, struct fib6_table *table,
444 int oif, struct flowi6 *fl6, struct fib6_result *res,
447 void fib6_select_path(const struct net *net, struct fib6_result *res,
448 struct flowi6 *fl6, int oif, bool have_oif_match,
449 const struct sk_buff *skb, int strict);
450 struct fib6_node *fib6_node_lookup(struct fib6_node *root,
451 const struct in6_addr *daddr,
452 const struct in6_addr *saddr);
454 struct fib6_node *fib6_locate(struct fib6_node *root,
455 const struct in6_addr *daddr, int dst_len,
456 const struct in6_addr *saddr, int src_len,
459 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg),
461 void fib6_clean_all_skip_notify(struct net *net,
462 int (*func)(struct fib6_info *, void *arg),
465 int fib6_add(struct fib6_node *root, struct fib6_info *rt,
466 struct nl_info *info, struct netlink_ext_ack *extack);
467 int fib6_del(struct fib6_info *rt, struct nl_info *info);
470 void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr)
472 const struct fib6_info *from;
476 from = rcu_dereference(rt->from);
478 *addr = from->fib6_prefsrc.addr;
480 struct in6_addr in6_zero = {};
488 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
489 struct fib6_config *cfg, gfp_t gfp_flags,
490 struct netlink_ext_ack *extack);
491 void fib6_nh_release(struct fib6_nh *fib6_nh);
493 int call_fib6_entry_notifiers(struct net *net,
494 enum fib_event_type event_type,
495 struct fib6_info *rt,
496 struct netlink_ext_ack *extack);
497 int call_fib6_multipath_entry_notifiers(struct net *net,
498 enum fib_event_type event_type,
499 struct fib6_info *rt,
500 unsigned int nsiblings,
501 struct netlink_ext_ack *extack);
502 int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt);
503 void fib6_rt_update(struct net *net, struct fib6_info *rt,
504 struct nl_info *info);
505 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
508 void fib6_run_gc(unsigned long expires, struct net *net, bool force);
510 void fib6_gc_cleanup(void);
514 struct ipv6_route_iter {
515 struct seq_net_private p;
516 struct fib6_walker w;
518 struct fib6_table *tbl;
522 extern const struct seq_operations ipv6_route_seq_ops;
524 int call_fib6_notifier(struct notifier_block *nb,
525 enum fib_event_type event_type,
526 struct fib_notifier_info *info);
527 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
528 struct fib_notifier_info *info);
530 int __net_init fib6_notifier_init(struct net *net);
531 void __net_exit fib6_notifier_exit(struct net *net);
533 unsigned int fib6_tables_seq_read(struct net *net);
534 int fib6_tables_dump(struct net *net, struct notifier_block *nb,
535 struct netlink_ext_ack *extack);
537 void fib6_update_sernum(struct net *net, struct fib6_info *rt);
538 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
539 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i);
541 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
542 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
544 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
547 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
548 static inline bool fib6_has_custom_rules(const struct net *net)
550 return net->ipv6.fib6_has_custom_rules;
553 int fib6_rules_init(void);
554 void fib6_rules_cleanup(void);
555 bool fib6_rule_default(const struct fib_rule *rule);
556 int fib6_rules_dump(struct net *net, struct notifier_block *nb,
557 struct netlink_ext_ack *extack);
558 unsigned int fib6_rules_seq_read(struct net *net);
560 static inline bool fib6_rules_early_flow_dissect(struct net *net,
563 struct flow_keys *flkeys)
565 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
567 if (!net->ipv6.fib6_rules_require_fldissect)
570 skb_flow_dissect_flow_keys(skb, flkeys, flag);
571 fl6->fl6_sport = flkeys->ports.src;
572 fl6->fl6_dport = flkeys->ports.dst;
573 fl6->flowi6_proto = flkeys->basic.ip_proto;
578 static inline bool fib6_has_custom_rules(const struct net *net)
582 static inline int fib6_rules_init(void)
586 static inline void fib6_rules_cleanup(void)
590 static inline bool fib6_rule_default(const struct fib_rule *rule)
594 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb,
595 struct netlink_ext_ack *extack)
599 static inline unsigned int fib6_rules_seq_read(struct net *net)
603 static inline bool fib6_rules_early_flow_dissect(struct net *net,
606 struct flow_keys *flkeys)