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;
199 struct fib6_nh fib6_nh[0];
203 struct dst_entry dst;
204 struct fib6_info __rcu *from;
206 struct rt6key rt6i_dst;
207 struct rt6key rt6i_src;
208 struct in6_addr rt6i_gateway;
209 struct inet6_dev *rt6i_idev;
212 struct list_head rt6i_uncached;
213 struct uncached_list *rt6i_uncached_list;
215 /* more non-fragment space at head required */
216 unsigned short rt6i_nfheader_len;
221 struct fib6_info *f6i;
224 struct rt6_info *rt6;
227 #define for_each_fib6_node_rt_rcu(fn) \
228 for (rt = rcu_dereference((fn)->leaf); rt; \
229 rt = rcu_dereference(rt->fib6_next))
231 #define for_each_fib6_walker_rt(w) \
232 for (rt = (w)->leaf; rt; \
233 rt = rcu_dereference_protected(rt->fib6_next, 1))
235 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
237 return ((struct rt6_info *)dst)->rt6i_idev;
240 static inline bool fib6_requires_src(const struct fib6_info *rt)
242 return rt->fib6_src.plen > 0;
245 static inline void fib6_clean_expires(struct fib6_info *f6i)
247 f6i->fib6_flags &= ~RTF_EXPIRES;
251 static inline void fib6_set_expires(struct fib6_info *f6i,
252 unsigned long expires)
254 f6i->expires = expires;
255 f6i->fib6_flags |= RTF_EXPIRES;
258 static inline bool fib6_check_expired(const struct fib6_info *f6i)
260 if (f6i->fib6_flags & RTF_EXPIRES)
261 return time_after(jiffies, f6i->expires);
265 /* Function to safely get fn->sernum for passed in rt
266 * and store result in passed in cookie.
267 * Return true if we can get cookie safely
268 * Return false if not
270 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i,
273 struct fib6_node *fn;
276 fn = rcu_dereference(f6i->fib6_node);
279 *cookie = fn->fn_sernum;
280 /* pairs with smp_wmb() in fib6_update_sernum_upto_root() */
288 static inline u32 rt6_get_cookie(const struct rt6_info *rt)
290 struct fib6_info *from;
295 from = rcu_dereference(rt->from);
297 fib6_get_cookie_safe(from, &cookie);
304 static inline void ip6_rt_put(struct rt6_info *rt)
306 /* dst_release() accepts a NULL parameter.
307 * We rely on dst being first structure in struct rt6_info
309 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
310 dst_release(&rt->dst);
313 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh);
314 void fib6_info_destroy_rcu(struct rcu_head *head);
316 static inline void fib6_info_hold(struct fib6_info *f6i)
318 refcount_inc(&f6i->fib6_ref);
321 static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
323 return refcount_inc_not_zero(&f6i->fib6_ref);
326 static inline void fib6_info_release(struct fib6_info *f6i)
328 if (f6i && refcount_dec_and_test(&f6i->fib6_ref))
329 call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
332 enum fib6_walk_state {
333 #ifdef CONFIG_IPV6_SUBTREES
344 struct fib6_node *root, *node;
345 struct fib6_info *leaf;
346 enum fib6_walk_state state;
349 unsigned int skip_in_node;
350 int (*func)(struct fib6_walker *);
354 struct rt6_statistics {
355 __u32 fib_nodes; /* all fib6 nodes */
356 __u32 fib_route_nodes; /* intermediate nodes */
357 __u32 fib_rt_entries; /* rt entries in fib table */
358 __u32 fib_rt_cache; /* cached rt entries in exception table */
359 __u32 fib_discarded_routes; /* total number of routes delete */
361 /* The following stats are not protected by any lock */
362 atomic_t fib_rt_alloc; /* total number of routes alloced */
363 atomic_t fib_rt_uncache; /* rt entries in uncached list */
366 #define RTN_TL_ROOT 0x0001
367 #define RTN_ROOT 0x0002 /* tree root node */
368 #define RTN_RTINFO 0x0004 /* node with valid routing info */
371 * priority levels (or metrics)
377 struct hlist_node tb6_hlist;
380 struct fib6_node tb6_root;
381 struct inet_peer_base tb6_peers;
383 unsigned int fib_seq;
384 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0)
387 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC
388 #define RT6_TABLE_MAIN RT_TABLE_MAIN
389 #define RT6_TABLE_DFLT RT6_TABLE_MAIN
390 #define RT6_TABLE_INFO RT6_TABLE_MAIN
391 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN
393 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
394 #define FIB6_TABLE_MIN 1
395 #define FIB6_TABLE_MAX RT_TABLE_MAX
396 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL
398 #define FIB6_TABLE_MIN RT_TABLE_MAIN
399 #define FIB6_TABLE_MAX FIB6_TABLE_MIN
400 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN
403 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
406 const struct sk_buff *, int);
408 struct fib6_entry_notifier_info {
409 struct fib_notifier_info info; /* must be first */
410 struct fib6_info *rt;
411 unsigned int nsiblings;
418 struct fib6_table *fib6_get_table(struct net *net, u32 id);
419 struct fib6_table *fib6_new_table(struct net *net, u32 id);
420 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
421 const struct sk_buff *skb,
422 int flags, pol_lookup_t lookup);
424 /* called with rcu lock held; can return error pointer
425 * caller needs to select path
427 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
428 struct fib6_result *res, int flags);
430 /* called with rcu lock held; caller needs to select path */
431 int fib6_table_lookup(struct net *net, struct fib6_table *table,
432 int oif, struct flowi6 *fl6, struct fib6_result *res,
435 void fib6_select_path(const struct net *net, struct fib6_result *res,
436 struct flowi6 *fl6, int oif, bool have_oif_match,
437 const struct sk_buff *skb, int strict);
438 struct fib6_node *fib6_node_lookup(struct fib6_node *root,
439 const struct in6_addr *daddr,
440 const struct in6_addr *saddr);
442 struct fib6_node *fib6_locate(struct fib6_node *root,
443 const struct in6_addr *daddr, int dst_len,
444 const struct in6_addr *saddr, int src_len,
447 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg),
449 void fib6_clean_all_skip_notify(struct net *net,
450 int (*func)(struct fib6_info *, void *arg),
453 int fib6_add(struct fib6_node *root, struct fib6_info *rt,
454 struct nl_info *info, struct netlink_ext_ack *extack);
455 int fib6_del(struct fib6_info *rt, struct nl_info *info);
458 void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr)
460 const struct fib6_info *from;
464 from = rcu_dereference(rt->from);
466 *addr = from->fib6_prefsrc.addr;
468 struct in6_addr in6_zero = {};
476 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
477 struct fib6_config *cfg, gfp_t gfp_flags,
478 struct netlink_ext_ack *extack);
479 void fib6_nh_release(struct fib6_nh *fib6_nh);
481 int call_fib6_entry_notifiers(struct net *net,
482 enum fib_event_type event_type,
483 struct fib6_info *rt,
484 struct netlink_ext_ack *extack);
485 int call_fib6_multipath_entry_notifiers(struct net *net,
486 enum fib_event_type event_type,
487 struct fib6_info *rt,
488 unsigned int nsiblings,
489 struct netlink_ext_ack *extack);
490 void fib6_rt_update(struct net *net, struct fib6_info *rt,
491 struct nl_info *info);
492 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
495 void fib6_run_gc(unsigned long expires, struct net *net, bool force);
497 void fib6_gc_cleanup(void);
501 struct ipv6_route_iter {
502 struct seq_net_private p;
503 struct fib6_walker w;
505 struct fib6_table *tbl;
509 extern const struct seq_operations ipv6_route_seq_ops;
511 int call_fib6_notifier(struct notifier_block *nb,
512 enum fib_event_type event_type,
513 struct fib_notifier_info *info);
514 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
515 struct fib_notifier_info *info);
517 int __net_init fib6_notifier_init(struct net *net);
518 void __net_exit fib6_notifier_exit(struct net *net);
520 unsigned int fib6_tables_seq_read(struct net *net);
521 int fib6_tables_dump(struct net *net, struct notifier_block *nb,
522 struct netlink_ext_ack *extack);
524 void fib6_update_sernum(struct net *net, struct fib6_info *rt);
525 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
526 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i);
528 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
529 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
531 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
534 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
535 static inline bool fib6_has_custom_rules(const struct net *net)
537 return net->ipv6.fib6_has_custom_rules;
540 int fib6_rules_init(void);
541 void fib6_rules_cleanup(void);
542 bool fib6_rule_default(const struct fib_rule *rule);
543 int fib6_rules_dump(struct net *net, struct notifier_block *nb,
544 struct netlink_ext_ack *extack);
545 unsigned int fib6_rules_seq_read(struct net *net);
547 static inline bool fib6_rules_early_flow_dissect(struct net *net,
550 struct flow_keys *flkeys)
552 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
554 if (!net->ipv6.fib6_rules_require_fldissect)
557 skb_flow_dissect_flow_keys(skb, flkeys, flag);
558 fl6->fl6_sport = flkeys->ports.src;
559 fl6->fl6_dport = flkeys->ports.dst;
560 fl6->flowi6_proto = flkeys->basic.ip_proto;
565 static inline bool fib6_has_custom_rules(const struct net *net)
569 static inline int fib6_rules_init(void)
573 static inline void fib6_rules_cleanup(void)
577 static inline bool fib6_rule_default(const struct fib_rule *rule)
581 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb,
582 struct netlink_ext_ack *extack)
586 static inline unsigned int fib6_rules_seq_read(struct net *net)
590 static inline bool fib6_rules_early_flow_dissect(struct net *net,
593 struct flow_keys *flkeys)