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;
201 struct fib6_nh fib6_nh[0];
205 struct dst_entry dst;
206 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;
297 from = rcu_dereference(rt->from);
299 fib6_get_cookie_safe(from, &cookie);
306 static inline void ip6_rt_put(struct rt6_info *rt)
308 /* dst_release() accepts a NULL parameter.
309 * We rely on dst being first structure in struct rt6_info
311 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
312 dst_release(&rt->dst);
315 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh);
316 void fib6_info_destroy_rcu(struct rcu_head *head);
318 static inline void fib6_info_hold(struct fib6_info *f6i)
320 refcount_inc(&f6i->fib6_ref);
323 static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
325 return refcount_inc_not_zero(&f6i->fib6_ref);
328 static inline void fib6_info_release(struct fib6_info *f6i)
330 if (f6i && refcount_dec_and_test(&f6i->fib6_ref))
331 call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
334 static inline void fib6_info_hw_flags_set(struct fib6_info *f6i, bool offload,
337 f6i->offload = offload;
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);
490 int call_fib6_entry_notifiers(struct net *net,
491 enum fib_event_type event_type,
492 struct fib6_info *rt,
493 struct netlink_ext_ack *extack);
494 int call_fib6_multipath_entry_notifiers(struct net *net,
495 enum fib_event_type event_type,
496 struct fib6_info *rt,
497 unsigned int nsiblings,
498 struct netlink_ext_ack *extack);
499 int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt);
500 void fib6_rt_update(struct net *net, struct fib6_info *rt,
501 struct nl_info *info);
502 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
505 void fib6_run_gc(unsigned long expires, struct net *net, bool force);
507 void fib6_gc_cleanup(void);
511 struct ipv6_route_iter {
512 struct seq_net_private p;
513 struct fib6_walker w;
515 struct fib6_table *tbl;
519 extern const struct seq_operations ipv6_route_seq_ops;
521 int call_fib6_notifier(struct notifier_block *nb,
522 enum fib_event_type event_type,
523 struct fib_notifier_info *info);
524 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
525 struct fib_notifier_info *info);
527 int __net_init fib6_notifier_init(struct net *net);
528 void __net_exit fib6_notifier_exit(struct net *net);
530 unsigned int fib6_tables_seq_read(struct net *net);
531 int fib6_tables_dump(struct net *net, struct notifier_block *nb,
532 struct netlink_ext_ack *extack);
534 void fib6_update_sernum(struct net *net, struct fib6_info *rt);
535 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
536 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i);
538 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
539 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
541 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
544 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
545 static inline bool fib6_has_custom_rules(const struct net *net)
547 return net->ipv6.fib6_has_custom_rules;
550 int fib6_rules_init(void);
551 void fib6_rules_cleanup(void);
552 bool fib6_rule_default(const struct fib_rule *rule);
553 int fib6_rules_dump(struct net *net, struct notifier_block *nb,
554 struct netlink_ext_ack *extack);
555 unsigned int fib6_rules_seq_read(struct net *net);
557 static inline bool fib6_rules_early_flow_dissect(struct net *net,
560 struct flow_keys *flkeys)
562 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
564 if (!net->ipv6.fib6_rules_require_fldissect)
567 skb_flow_dissect_flow_keys(skb, flkeys, flag);
568 fl6->fl6_sport = flkeys->ports.src;
569 fl6->fl6_dport = flkeys->ports.dst;
570 fl6->flowi6_proto = flkeys->basic.ip_proto;
575 static inline bool fib6_has_custom_rules(const struct net *net)
579 static inline int fib6_rules_init(void)
583 static inline void fib6_rules_cleanup(void)
587 static inline bool fib6_rule_default(const struct fib_rule *rule)
591 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb,
592 struct netlink_ext_ack *extack)
596 static inline unsigned int fib6_rules_seq_read(struct net *net)
600 static inline bool fib6_rules_early_flow_dissect(struct net *net,
603 struct flow_keys *flkeys)