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 #define FIB6_SUBTREE(fn) (rcu_dereference_protected((fn)->subtree, 1))
103 struct in6_addr addr;
109 struct rt6_exception_bucket {
110 struct hlist_head chain;
114 struct rt6_exception {
115 struct hlist_node hlist;
116 struct rt6_info *rt6i;
121 #define FIB6_EXCEPTION_BUCKET_SIZE_SHIFT 10
122 #define FIB6_EXCEPTION_BUCKET_SIZE (1 << FIB6_EXCEPTION_BUCKET_SIZE_SHIFT)
123 #define FIB6_MAX_DEPTH 5
126 struct fib_nh_common nh_common;
128 #ifdef CONFIG_IPV6_ROUTER_PREF
129 unsigned long last_probe;
132 struct rt6_info * __percpu *rt6i_pcpu;
133 struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
137 struct fib6_table *fib6_table;
138 struct fib6_info __rcu *fib6_next;
139 struct fib6_node __rcu *fib6_node;
142 * siblings is a list of fib6_info that have the the same metric/weight,
143 * destination, but not the same gateway. nsiblings is just a cache
144 * to speed up lookup.
147 struct list_head fib6_siblings;
148 struct list_head nh_list;
150 unsigned int fib6_nsiblings;
153 unsigned long expires;
154 struct dst_metrics *fib6_metrics;
155 #define fib6_pmtu fib6_metrics->metrics[RTAX_MTU-1]
157 struct rt6key fib6_dst;
159 struct rt6key fib6_src;
160 struct rt6key fib6_prefsrc;
174 struct fib6_nh fib6_nh[0];
178 struct dst_entry dst;
179 struct fib6_info __rcu *from;
181 struct rt6key rt6i_dst;
182 struct rt6key rt6i_src;
183 struct in6_addr rt6i_gateway;
184 struct inet6_dev *rt6i_idev;
187 struct list_head rt6i_uncached;
188 struct uncached_list *rt6i_uncached_list;
190 /* more non-fragment space at head required */
191 unsigned short rt6i_nfheader_len;
196 struct fib6_info *f6i;
199 struct rt6_info *rt6;
202 #define for_each_fib6_node_rt_rcu(fn) \
203 for (rt = rcu_dereference((fn)->leaf); rt; \
204 rt = rcu_dereference(rt->fib6_next))
206 #define for_each_fib6_walker_rt(w) \
207 for (rt = (w)->leaf; rt; \
208 rt = rcu_dereference_protected(rt->fib6_next, 1))
210 static inline struct inet6_dev *ip6_dst_idev(struct dst_entry *dst)
212 return ((struct rt6_info *)dst)->rt6i_idev;
215 static inline void fib6_clean_expires(struct fib6_info *f6i)
217 f6i->fib6_flags &= ~RTF_EXPIRES;
221 static inline void fib6_set_expires(struct fib6_info *f6i,
222 unsigned long expires)
224 f6i->expires = expires;
225 f6i->fib6_flags |= RTF_EXPIRES;
228 static inline bool fib6_check_expired(const struct fib6_info *f6i)
230 if (f6i->fib6_flags & RTF_EXPIRES)
231 return time_after(jiffies, f6i->expires);
235 /* Function to safely get fn->sernum for passed in rt
236 * and store result in passed in cookie.
237 * Return true if we can get cookie safely
238 * Return false if not
240 static inline bool fib6_get_cookie_safe(const struct fib6_info *f6i,
243 struct fib6_node *fn;
246 fn = rcu_dereference(f6i->fib6_node);
249 *cookie = fn->fn_sernum;
250 /* pairs with smp_wmb() in fib6_update_sernum_upto_root() */
258 static inline u32 rt6_get_cookie(const struct rt6_info *rt)
260 struct fib6_info *from;
265 from = rcu_dereference(rt->from);
267 fib6_get_cookie_safe(from, &cookie);
274 static inline void ip6_rt_put(struct rt6_info *rt)
276 /* dst_release() accepts a NULL parameter.
277 * We rely on dst being first structure in struct rt6_info
279 BUILD_BUG_ON(offsetof(struct rt6_info, dst) != 0);
280 dst_release(&rt->dst);
283 struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh);
284 void fib6_info_destroy_rcu(struct rcu_head *head);
286 static inline void fib6_info_hold(struct fib6_info *f6i)
288 refcount_inc(&f6i->fib6_ref);
291 static inline bool fib6_info_hold_safe(struct fib6_info *f6i)
293 return refcount_inc_not_zero(&f6i->fib6_ref);
296 static inline void fib6_info_release(struct fib6_info *f6i)
298 if (f6i && refcount_dec_and_test(&f6i->fib6_ref))
299 call_rcu(&f6i->rcu, fib6_info_destroy_rcu);
302 enum fib6_walk_state {
303 #ifdef CONFIG_IPV6_SUBTREES
314 struct fib6_node *root, *node;
315 struct fib6_info *leaf;
316 enum fib6_walk_state state;
319 unsigned int skip_in_node;
320 int (*func)(struct fib6_walker *);
324 struct rt6_statistics {
325 __u32 fib_nodes; /* all fib6 nodes */
326 __u32 fib_route_nodes; /* intermediate nodes */
327 __u32 fib_rt_entries; /* rt entries in fib table */
328 __u32 fib_rt_cache; /* cached rt entries in exception table */
329 __u32 fib_discarded_routes; /* total number of routes delete */
331 /* The following stats are not protected by any lock */
332 atomic_t fib_rt_alloc; /* total number of routes alloced */
333 atomic_t fib_rt_uncache; /* rt entries in uncached list */
336 #define RTN_TL_ROOT 0x0001
337 #define RTN_ROOT 0x0002 /* tree root node */
338 #define RTN_RTINFO 0x0004 /* node with valid routing info */
341 * priority levels (or metrics)
347 struct hlist_node tb6_hlist;
350 struct fib6_node tb6_root;
351 struct inet_peer_base tb6_peers;
353 unsigned int fib_seq;
354 #define RT6_TABLE_HAS_DFLT_ROUTER BIT(0)
357 #define RT6_TABLE_UNSPEC RT_TABLE_UNSPEC
358 #define RT6_TABLE_MAIN RT_TABLE_MAIN
359 #define RT6_TABLE_DFLT RT6_TABLE_MAIN
360 #define RT6_TABLE_INFO RT6_TABLE_MAIN
361 #define RT6_TABLE_PREFIX RT6_TABLE_MAIN
363 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
364 #define FIB6_TABLE_MIN 1
365 #define FIB6_TABLE_MAX RT_TABLE_MAX
366 #define RT6_TABLE_LOCAL RT_TABLE_LOCAL
368 #define FIB6_TABLE_MIN RT_TABLE_MAIN
369 #define FIB6_TABLE_MAX FIB6_TABLE_MIN
370 #define RT6_TABLE_LOCAL RT6_TABLE_MAIN
373 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
376 const struct sk_buff *, int);
378 struct fib6_entry_notifier_info {
379 struct fib_notifier_info info; /* must be first */
380 struct fib6_info *rt;
381 unsigned int nsiblings;
388 struct fib6_table *fib6_get_table(struct net *net, u32 id);
389 struct fib6_table *fib6_new_table(struct net *net, u32 id);
390 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
391 const struct sk_buff *skb,
392 int flags, pol_lookup_t lookup);
394 /* called with rcu lock held; can return error pointer
395 * caller needs to select path
397 int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
398 struct fib6_result *res, int flags);
400 /* called with rcu lock held; caller needs to select path */
401 int fib6_table_lookup(struct net *net, struct fib6_table *table,
402 int oif, struct flowi6 *fl6, struct fib6_result *res,
405 void fib6_select_path(const struct net *net, struct fib6_result *res,
406 struct flowi6 *fl6, int oif, bool have_oif_match,
407 const struct sk_buff *skb, int strict);
408 struct fib6_node *fib6_node_lookup(struct fib6_node *root,
409 const struct in6_addr *daddr,
410 const struct in6_addr *saddr);
412 struct fib6_node *fib6_locate(struct fib6_node *root,
413 const struct in6_addr *daddr, int dst_len,
414 const struct in6_addr *saddr, int src_len,
417 void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *arg),
419 void fib6_clean_all_skip_notify(struct net *net,
420 int (*func)(struct fib6_info *, void *arg),
423 int fib6_add(struct fib6_node *root, struct fib6_info *rt,
424 struct nl_info *info, struct netlink_ext_ack *extack);
425 int fib6_del(struct fib6_info *rt, struct nl_info *info);
428 void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr)
430 const struct fib6_info *from;
434 from = rcu_dereference(rt->from);
436 *addr = from->fib6_prefsrc.addr;
438 struct in6_addr in6_zero = {};
446 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
447 struct fib6_config *cfg, gfp_t gfp_flags,
448 struct netlink_ext_ack *extack);
449 void fib6_nh_release(struct fib6_nh *fib6_nh);
451 int call_fib6_entry_notifiers(struct net *net,
452 enum fib_event_type event_type,
453 struct fib6_info *rt,
454 struct netlink_ext_ack *extack);
455 int call_fib6_multipath_entry_notifiers(struct net *net,
456 enum fib_event_type event_type,
457 struct fib6_info *rt,
458 unsigned int nsiblings,
459 struct netlink_ext_ack *extack);
460 void fib6_rt_update(struct net *net, struct fib6_info *rt,
461 struct nl_info *info);
462 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
465 void fib6_run_gc(unsigned long expires, struct net *net, bool force);
467 void fib6_gc_cleanup(void);
471 struct ipv6_route_iter {
472 struct seq_net_private p;
473 struct fib6_walker w;
475 struct fib6_table *tbl;
479 extern const struct seq_operations ipv6_route_seq_ops;
481 int call_fib6_notifier(struct notifier_block *nb, struct net *net,
482 enum fib_event_type event_type,
483 struct fib_notifier_info *info);
484 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
485 struct fib_notifier_info *info);
487 int __net_init fib6_notifier_init(struct net *net);
488 void __net_exit fib6_notifier_exit(struct net *net);
490 unsigned int fib6_tables_seq_read(struct net *net);
491 int fib6_tables_dump(struct net *net, struct notifier_block *nb);
493 void fib6_update_sernum(struct net *net, struct fib6_info *rt);
494 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
495 void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i);
497 void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val);
498 static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
500 return !!(f6i->fib6_metrics->metrics[RTAX_LOCK - 1] & (1 << metric));
503 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
504 int fib6_rules_init(void);
505 void fib6_rules_cleanup(void);
506 bool fib6_rule_default(const struct fib_rule *rule);
507 int fib6_rules_dump(struct net *net, struct notifier_block *nb);
508 unsigned int fib6_rules_seq_read(struct net *net);
510 static inline bool fib6_rules_early_flow_dissect(struct net *net,
513 struct flow_keys *flkeys)
515 unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
517 if (!net->ipv6.fib6_rules_require_fldissect)
520 skb_flow_dissect_flow_keys(skb, flkeys, flag);
521 fl6->fl6_sport = flkeys->ports.src;
522 fl6->fl6_dport = flkeys->ports.dst;
523 fl6->flowi6_proto = flkeys->basic.ip_proto;
528 static inline int fib6_rules_init(void)
532 static inline void fib6_rules_cleanup(void)
536 static inline bool fib6_rule_default(const struct fib_rule *rule)
540 static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb)
544 static inline unsigned int fib6_rules_seq_read(struct net *net)
548 static inline bool fib6_rules_early_flow_dissect(struct net *net,
551 struct flow_keys *flkeys)