2 * Linux INET6 implementation
3 * Forwarding Information Database
6 * Pedro Roque <roque@di.fc.ul.pt>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
14 * Yuji SEKIYA @USAGI: Support default route on router node;
15 * remove ip6_null_entry from the top of
17 * Ville Nuorvala: Fixed routing subtrees.
20 #define pr_fmt(fmt) "IPv6: " fmt
22 #include <linux/errno.h>
23 #include <linux/types.h>
24 #include <linux/net.h>
25 #include <linux/route.h>
26 #include <linux/netdevice.h>
27 #include <linux/in6.h>
28 #include <linux/init.h>
29 #include <linux/list.h>
30 #include <linux/slab.h>
33 #include <net/ndisc.h>
34 #include <net/addrconf.h>
35 #include <net/lwtunnel.h>
36 #include <net/fib_notifier.h>
38 #include <net/ip6_fib.h>
39 #include <net/ip6_route.h>
41 static struct kmem_cache *fib6_node_kmem __read_mostly;
46 int (*func)(struct rt6_info *, void *arg);
51 #ifdef CONFIG_IPV6_SUBTREES
52 #define FWS_INIT FWS_S
54 #define FWS_INIT FWS_L
57 static struct rt6_info *fib6_find_prefix(struct net *net,
58 struct fib6_table *table,
59 struct fib6_node *fn);
60 static struct fib6_node *fib6_repair_tree(struct net *net,
61 struct fib6_table *table,
62 struct fib6_node *fn);
63 static int fib6_walk(struct net *net, struct fib6_walker *w);
64 static int fib6_walk_continue(struct fib6_walker *w);
67 * A routing update causes an increase of the serial number on the
68 * affected subtree. This allows for cached routes to be asynchronously
69 * tested when modifications are made to the destination cache as a
70 * result of redirects, path MTU changes, etc.
73 static void fib6_gc_timer_cb(struct timer_list *t);
75 #define FOR_WALKERS(net, w) \
76 list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh)
78 static void fib6_walker_link(struct net *net, struct fib6_walker *w)
80 write_lock_bh(&net->ipv6.fib6_walker_lock);
81 list_add(&w->lh, &net->ipv6.fib6_walkers);
82 write_unlock_bh(&net->ipv6.fib6_walker_lock);
85 static void fib6_walker_unlink(struct net *net, struct fib6_walker *w)
87 write_lock_bh(&net->ipv6.fib6_walker_lock);
89 write_unlock_bh(&net->ipv6.fib6_walker_lock);
92 static int fib6_new_sernum(struct net *net)
97 old = atomic_read(&net->ipv6.fib6_sernum);
98 new = old < INT_MAX ? old + 1 : 1;
99 } while (atomic_cmpxchg(&net->ipv6.fib6_sernum,
105 FIB6_NO_SERNUM_CHANGE = 0,
108 void fib6_update_sernum(struct rt6_info *rt)
110 struct net *net = dev_net(rt->dst.dev);
111 struct fib6_node *fn;
113 fn = rcu_dereference_protected(rt->rt6i_node,
114 lockdep_is_held(&rt->rt6i_table->tb6_lock));
116 fn->fn_sernum = fib6_new_sernum(net);
120 * Auxiliary address test functions for the radix tree.
122 * These assume a 32bit processor (although it will work on
129 #if defined(__LITTLE_ENDIAN)
130 # define BITOP_BE32_SWIZZLE (0x1F & ~7)
132 # define BITOP_BE32_SWIZZLE 0
135 static __be32 addr_bit_set(const void *token, int fn_bit)
137 const __be32 *addr = token;
140 * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
141 * is optimized version of
142 * htonl(1 << ((~fn_bit)&0x1F))
143 * See include/asm-generic/bitops/le.h.
145 return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) &
149 static struct fib6_node *node_alloc(struct net *net)
151 struct fib6_node *fn;
153 fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
155 net->ipv6.rt6_stats->fib_nodes++;
160 static void node_free_immediate(struct net *net, struct fib6_node *fn)
162 kmem_cache_free(fib6_node_kmem, fn);
163 net->ipv6.rt6_stats->fib_nodes--;
166 static void node_free_rcu(struct rcu_head *head)
168 struct fib6_node *fn = container_of(head, struct fib6_node, rcu);
170 kmem_cache_free(fib6_node_kmem, fn);
173 static void node_free(struct net *net, struct fib6_node *fn)
175 call_rcu(&fn->rcu, node_free_rcu);
176 net->ipv6.rt6_stats->fib_nodes--;
179 void rt6_free_pcpu(struct rt6_info *non_pcpu_rt)
183 if (!non_pcpu_rt->rt6i_pcpu)
186 for_each_possible_cpu(cpu) {
187 struct rt6_info **ppcpu_rt;
188 struct rt6_info *pcpu_rt;
190 ppcpu_rt = per_cpu_ptr(non_pcpu_rt->rt6i_pcpu, cpu);
193 dst_dev_put(&pcpu_rt->dst);
194 dst_release(&pcpu_rt->dst);
199 EXPORT_SYMBOL_GPL(rt6_free_pcpu);
201 static void fib6_free_table(struct fib6_table *table)
203 inetpeer_invalidate_tree(&table->tb6_peers);
207 static void fib6_link_table(struct net *net, struct fib6_table *tb)
212 * Initialize table lock at a single place to give lockdep a key,
213 * tables aren't visible prior to being linked to the list.
215 spin_lock_init(&tb->tb6_lock);
216 h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
219 * No protection necessary, this is the only list mutatation
220 * operation, tables never disappear once they exist.
222 hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
225 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
227 static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
229 struct fib6_table *table;
231 table = kzalloc(sizeof(*table), GFP_ATOMIC);
234 rcu_assign_pointer(table->tb6_root.leaf,
235 net->ipv6.ip6_null_entry);
236 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
237 inet_peer_base_init(&table->tb6_peers);
243 struct fib6_table *fib6_new_table(struct net *net, u32 id)
245 struct fib6_table *tb;
249 tb = fib6_get_table(net, id);
253 tb = fib6_alloc_table(net, id);
255 fib6_link_table(net, tb);
259 EXPORT_SYMBOL_GPL(fib6_new_table);
261 struct fib6_table *fib6_get_table(struct net *net, u32 id)
263 struct fib6_table *tb;
264 struct hlist_head *head;
269 h = id & (FIB6_TABLE_HASHSZ - 1);
271 head = &net->ipv6.fib_table_hash[h];
272 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
273 if (tb->tb6_id == id) {
282 EXPORT_SYMBOL_GPL(fib6_get_table);
284 static void __net_init fib6_tables_init(struct net *net)
286 fib6_link_table(net, net->ipv6.fib6_main_tbl);
287 fib6_link_table(net, net->ipv6.fib6_local_tbl);
291 struct fib6_table *fib6_new_table(struct net *net, u32 id)
293 return fib6_get_table(net, id);
296 struct fib6_table *fib6_get_table(struct net *net, u32 id)
298 return net->ipv6.fib6_main_tbl;
301 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
302 const struct sk_buff *skb,
303 int flags, pol_lookup_t lookup)
307 rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
308 if (rt->dst.error == -EAGAIN) {
310 rt = net->ipv6.ip6_null_entry;
317 static void __net_init fib6_tables_init(struct net *net)
319 fib6_link_table(net, net->ipv6.fib6_main_tbl);
324 unsigned int fib6_tables_seq_read(struct net *net)
326 unsigned int h, fib_seq = 0;
329 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
330 struct hlist_head *head = &net->ipv6.fib_table_hash[h];
331 struct fib6_table *tb;
333 hlist_for_each_entry_rcu(tb, head, tb6_hlist)
334 fib_seq += tb->fib_seq;
341 static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net,
342 enum fib_event_type event_type,
345 struct fib6_entry_notifier_info info = {
349 return call_fib6_notifier(nb, net, event_type, &info.info);
352 static int call_fib6_entry_notifiers(struct net *net,
353 enum fib_event_type event_type,
355 struct netlink_ext_ack *extack)
357 struct fib6_entry_notifier_info info = {
358 .info.extack = extack,
362 rt->rt6i_table->fib_seq++;
363 return call_fib6_notifiers(net, event_type, &info.info);
366 struct fib6_dump_arg {
368 struct notifier_block *nb;
371 static void fib6_rt_dump(struct rt6_info *rt, struct fib6_dump_arg *arg)
373 if (rt == arg->net->ipv6.ip6_null_entry)
375 call_fib6_entry_notifier(arg->nb, arg->net, FIB_EVENT_ENTRY_ADD, rt);
378 static int fib6_node_dump(struct fib6_walker *w)
382 for_each_fib6_walker_rt(w)
383 fib6_rt_dump(rt, w->args);
388 static void fib6_table_dump(struct net *net, struct fib6_table *tb,
389 struct fib6_walker *w)
391 w->root = &tb->tb6_root;
392 spin_lock_bh(&tb->tb6_lock);
394 spin_unlock_bh(&tb->tb6_lock);
397 /* Called with rcu_read_lock() */
398 int fib6_tables_dump(struct net *net, struct notifier_block *nb)
400 struct fib6_dump_arg arg;
401 struct fib6_walker *w;
404 w = kzalloc(sizeof(*w), GFP_ATOMIC);
408 w->func = fib6_node_dump;
413 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
414 struct hlist_head *head = &net->ipv6.fib_table_hash[h];
415 struct fib6_table *tb;
417 hlist_for_each_entry_rcu(tb, head, tb6_hlist)
418 fib6_table_dump(net, tb, w);
426 static int fib6_dump_node(struct fib6_walker *w)
431 for_each_fib6_walker_rt(w) {
432 res = rt6_dump_route(rt, w->args);
434 /* Frame is full, suspend walking */
439 /* Multipath routes are dumped in one route with the
440 * RTA_MULTIPATH attribute. Jump 'rt' to point to the
441 * last sibling of this route (no need to dump the
442 * sibling routes again)
444 if (rt->rt6i_nsiblings)
445 rt = list_last_entry(&rt->rt6i_siblings,
453 static void fib6_dump_end(struct netlink_callback *cb)
455 struct net *net = sock_net(cb->skb->sk);
456 struct fib6_walker *w = (void *)cb->args[2];
461 fib6_walker_unlink(net, w);
466 cb->done = (void *)cb->args[3];
470 static int fib6_dump_done(struct netlink_callback *cb)
473 return cb->done ? cb->done(cb) : 0;
476 static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
477 struct netlink_callback *cb)
479 struct net *net = sock_net(skb->sk);
480 struct fib6_walker *w;
483 w = (void *)cb->args[2];
484 w->root = &table->tb6_root;
486 if (cb->args[4] == 0) {
490 spin_lock_bh(&table->tb6_lock);
491 res = fib6_walk(net, w);
492 spin_unlock_bh(&table->tb6_lock);
495 cb->args[5] = w->root->fn_sernum;
498 if (cb->args[5] != w->root->fn_sernum) {
499 /* Begin at the root if the tree changed */
500 cb->args[5] = w->root->fn_sernum;
507 spin_lock_bh(&table->tb6_lock);
508 res = fib6_walk_continue(w);
509 spin_unlock_bh(&table->tb6_lock);
511 fib6_walker_unlink(net, w);
519 static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
521 struct net *net = sock_net(skb->sk);
523 unsigned int e = 0, s_e;
524 struct rt6_rtnl_dump_arg arg;
525 struct fib6_walker *w;
526 struct fib6_table *tb;
527 struct hlist_head *head;
533 w = (void *)cb->args[2];
537 * 1. hook callback destructor.
539 cb->args[3] = (long)cb->done;
540 cb->done = fib6_dump_done;
543 * 2. allocate and initialize walker.
545 w = kzalloc(sizeof(*w), GFP_ATOMIC);
548 w->func = fib6_dump_node;
549 cb->args[2] = (long)w;
558 for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
560 head = &net->ipv6.fib_table_hash[h];
561 hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
564 res = fib6_dump_table(tb, skb, cb);
576 res = res < 0 ? res : skb->len;
585 * return the appropriate node for a routing tree "add" operation
586 * by either creating and inserting or by returning an existing
590 static struct fib6_node *fib6_add_1(struct net *net,
591 struct fib6_table *table,
592 struct fib6_node *root,
593 struct in6_addr *addr, int plen,
594 int offset, int allow_create,
595 int replace_required,
596 struct netlink_ext_ack *extack)
598 struct fib6_node *fn, *in, *ln;
599 struct fib6_node *pn = NULL;
604 RT6_TRACE("fib6_add_1\n");
606 /* insert node in tree */
611 struct rt6_info *leaf = rcu_dereference_protected(fn->leaf,
612 lockdep_is_held(&table->tb6_lock));
613 key = (struct rt6key *)((u8 *)leaf + offset);
618 if (plen < fn->fn_bit ||
619 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
621 if (replace_required) {
622 NL_SET_ERR_MSG(extack,
623 "Can not replace route - no match found");
624 pr_warn("Can't replace route, no match found\n");
625 return ERR_PTR(-ENOENT);
627 pr_warn("NLM_F_CREATE should be set when creating new route\n");
636 if (plen == fn->fn_bit) {
637 /* clean up an intermediate node */
638 if (!(fn->fn_flags & RTN_RTINFO)) {
639 RCU_INIT_POINTER(fn->leaf, NULL);
641 /* remove null_entry in the root node */
642 } else if (fn->fn_flags & RTN_TL_ROOT &&
643 rcu_access_pointer(fn->leaf) ==
644 net->ipv6.ip6_null_entry) {
645 RCU_INIT_POINTER(fn->leaf, NULL);
652 * We have more bits to go
655 /* Try to walk down on tree. */
656 dir = addr_bit_set(addr, fn->fn_bit);
659 rcu_dereference_protected(fn->right,
660 lockdep_is_held(&table->tb6_lock)) :
661 rcu_dereference_protected(fn->left,
662 lockdep_is_held(&table->tb6_lock));
666 /* We should not create new node because
667 * NLM_F_REPLACE was specified without NLM_F_CREATE
668 * I assume it is safe to require NLM_F_CREATE when
669 * REPLACE flag is used! Later we may want to remove the
670 * check for replace_required, because according
671 * to netlink specification, NLM_F_CREATE
672 * MUST be specified if new route is created.
673 * That would keep IPv6 consistent with IPv4
675 if (replace_required) {
676 NL_SET_ERR_MSG(extack,
677 "Can not replace route - no match found");
678 pr_warn("Can't replace route, no match found\n");
679 return ERR_PTR(-ENOENT);
681 pr_warn("NLM_F_CREATE should be set when creating new route\n");
684 * We walked to the bottom of tree.
685 * Create new leaf node without children.
688 ln = node_alloc(net);
691 return ERR_PTR(-ENOMEM);
693 RCU_INIT_POINTER(ln->parent, pn);
696 rcu_assign_pointer(pn->right, ln);
698 rcu_assign_pointer(pn->left, ln);
705 * split since we don't have a common prefix anymore or
706 * we have a less significant route.
707 * we've to insert an intermediate node on the list
708 * this new node will point to the one we need to create
712 pn = rcu_dereference_protected(fn->parent,
713 lockdep_is_held(&table->tb6_lock));
715 /* find 1st bit in difference between the 2 addrs.
717 See comment in __ipv6_addr_diff: bit may be an invalid value,
718 but if it is >= plen, the value is ignored in any case.
721 bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr));
726 * (new leaf node)[ln] (old node)[fn]
729 in = node_alloc(net);
730 ln = node_alloc(net);
734 node_free_immediate(net, in);
736 node_free_immediate(net, ln);
737 return ERR_PTR(-ENOMEM);
741 * new intermediate node.
743 * be off since that an address that chooses one of
744 * the branches would not match less specific routes
745 * in the other branch
750 RCU_INIT_POINTER(in->parent, pn);
752 atomic_inc(&rcu_dereference_protected(in->leaf,
753 lockdep_is_held(&table->tb6_lock))->rt6i_ref);
755 /* update parent pointer */
757 rcu_assign_pointer(pn->right, in);
759 rcu_assign_pointer(pn->left, in);
763 RCU_INIT_POINTER(ln->parent, in);
764 rcu_assign_pointer(fn->parent, in);
766 if (addr_bit_set(addr, bit)) {
767 rcu_assign_pointer(in->right, ln);
768 rcu_assign_pointer(in->left, fn);
770 rcu_assign_pointer(in->left, ln);
771 rcu_assign_pointer(in->right, fn);
773 } else { /* plen <= bit */
776 * (new leaf node)[ln]
778 * (old node)[fn] NULL
781 ln = node_alloc(net);
784 return ERR_PTR(-ENOMEM);
788 RCU_INIT_POINTER(ln->parent, pn);
790 if (addr_bit_set(&key->addr, plen))
791 RCU_INIT_POINTER(ln->right, fn);
793 RCU_INIT_POINTER(ln->left, fn);
795 rcu_assign_pointer(fn->parent, ln);
798 rcu_assign_pointer(pn->right, ln);
800 rcu_assign_pointer(pn->left, ln);
805 static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc)
809 for (i = 0; i < RTAX_MAX; i++) {
810 if (test_bit(i, mxc->mx_valid))
815 static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc)
820 if (dst->flags & DST_HOST) {
821 u32 *mp = dst_metrics_write_ptr(dst);
826 fib6_copy_metrics(mp, mxc);
828 dst_init_metrics(dst, mxc->mx, false);
830 /* We've stolen mx now. */
837 static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn,
840 struct fib6_table *table = rt->rt6i_table;
842 if (atomic_read(&rt->rt6i_ref) != 1) {
843 /* This route is used as dummy address holder in some split
844 * nodes. It is not leaked, but it still holds other resources,
845 * which must be released in time. So, scan ascendant nodes
846 * and replace dummy references to this route with references
847 * to still alive ones.
850 struct rt6_info *leaf = rcu_dereference_protected(fn->leaf,
851 lockdep_is_held(&table->tb6_lock));
852 struct rt6_info *new_leaf;
853 if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) {
854 new_leaf = fib6_find_prefix(net, table, fn);
855 atomic_inc(&new_leaf->rt6i_ref);
856 rcu_assign_pointer(fn->leaf, new_leaf);
859 fn = rcu_dereference_protected(fn->parent,
860 lockdep_is_held(&table->tb6_lock));
866 * Insert routing information in a node.
869 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
870 struct nl_info *info, struct mx6_config *mxc,
871 struct netlink_ext_ack *extack)
873 struct rt6_info *leaf = rcu_dereference_protected(fn->leaf,
874 lockdep_is_held(&rt->rt6i_table->tb6_lock));
875 struct rt6_info *iter = NULL;
876 struct rt6_info __rcu **ins;
877 struct rt6_info __rcu **fallback_ins = NULL;
878 int replace = (info->nlh &&
879 (info->nlh->nlmsg_flags & NLM_F_REPLACE));
880 int add = (!info->nlh ||
881 (info->nlh->nlmsg_flags & NLM_F_CREATE));
883 bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
884 u16 nlflags = NLM_F_EXCL;
887 if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND))
888 nlflags |= NLM_F_APPEND;
892 for (iter = leaf; iter;
893 iter = rcu_dereference_protected(iter->rt6_next,
894 lockdep_is_held(&rt->rt6i_table->tb6_lock))) {
896 * Search for duplicates
899 if (iter->rt6i_metric == rt->rt6i_metric) {
901 * Same priority level
904 (info->nlh->nlmsg_flags & NLM_F_EXCL))
907 nlflags &= ~NLM_F_EXCL;
909 if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) {
914 fallback_ins = fallback_ins ?: ins;
918 if (rt6_duplicate_nexthop(iter, rt)) {
919 if (rt->rt6i_nsiblings)
920 rt->rt6i_nsiblings = 0;
921 if (!(iter->rt6i_flags & RTF_EXPIRES))
923 if (!(rt->rt6i_flags & RTF_EXPIRES))
924 rt6_clean_expires(iter);
926 rt6_set_expires(iter, rt->dst.expires);
927 iter->rt6i_pmtu = rt->rt6i_pmtu;
930 /* If we have the same destination and the same metric,
931 * but not the same gateway, then the route we try to
932 * add is sibling to this route, increment our counter
933 * of siblings, and later we will add our route to the
935 * Only static routes (which don't have flag
936 * RTF_EXPIRES) are used for ECMPv6.
938 * To avoid long list, we only had siblings if the
939 * route have a gateway.
942 rt6_qualify_for_ecmp(iter))
943 rt->rt6i_nsiblings++;
946 if (iter->rt6i_metric > rt->rt6i_metric)
950 ins = &iter->rt6_next;
953 if (fallback_ins && !found) {
954 /* No ECMP-able route found, replace first non-ECMP one */
956 iter = rcu_dereference_protected(*ins,
957 lockdep_is_held(&rt->rt6i_table->tb6_lock));
961 /* Reset round-robin state, if necessary */
962 if (ins == &fn->leaf)
965 /* Link this route to others same route. */
966 if (rt->rt6i_nsiblings) {
967 unsigned int rt6i_nsiblings;
968 struct rt6_info *sibling, *temp_sibling;
970 /* Find the first route that have the same metric */
973 if (sibling->rt6i_metric == rt->rt6i_metric &&
974 rt6_qualify_for_ecmp(sibling)) {
975 list_add_tail(&rt->rt6i_siblings,
976 &sibling->rt6i_siblings);
979 sibling = rcu_dereference_protected(sibling->rt6_next,
980 lockdep_is_held(&rt->rt6i_table->tb6_lock));
982 /* For each sibling in the list, increment the counter of
983 * siblings. BUG() if counters does not match, list of siblings
987 list_for_each_entry_safe(sibling, temp_sibling,
988 &rt->rt6i_siblings, rt6i_siblings) {
989 sibling->rt6i_nsiblings++;
990 BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings);
993 BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings);
994 rt6_multipath_rebalance(temp_sibling);
1002 pr_warn("NLM_F_CREATE should be set when creating new route\n");
1005 nlflags |= NLM_F_CREATE;
1006 err = fib6_commit_metrics(&rt->dst, mxc);
1010 err = call_fib6_entry_notifiers(info->nl_net,
1011 FIB_EVENT_ENTRY_ADD,
1016 rcu_assign_pointer(rt->rt6_next, iter);
1017 atomic_inc(&rt->rt6i_ref);
1018 rcu_assign_pointer(rt->rt6i_node, fn);
1019 rcu_assign_pointer(*ins, rt);
1020 if (!info->skip_notify)
1021 inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
1022 info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
1024 if (!(fn->fn_flags & RTN_RTINFO)) {
1025 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
1026 fn->fn_flags |= RTN_RTINFO;
1035 pr_warn("NLM_F_REPLACE set, but no existing node found!\n");
1039 err = fib6_commit_metrics(&rt->dst, mxc);
1043 err = call_fib6_entry_notifiers(info->nl_net,
1044 FIB_EVENT_ENTRY_REPLACE,
1049 atomic_inc(&rt->rt6i_ref);
1050 rcu_assign_pointer(rt->rt6i_node, fn);
1051 rt->rt6_next = iter->rt6_next;
1052 rcu_assign_pointer(*ins, rt);
1053 if (!info->skip_notify)
1054 inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE);
1055 if (!(fn->fn_flags & RTN_RTINFO)) {
1056 info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
1057 fn->fn_flags |= RTN_RTINFO;
1059 nsiblings = iter->rt6i_nsiblings;
1060 iter->rt6i_node = NULL;
1061 fib6_purge_rt(iter, fn, info->nl_net);
1062 if (rcu_access_pointer(fn->rr_ptr) == iter)
1067 /* Replacing an ECMP route, remove all siblings */
1068 ins = &rt->rt6_next;
1069 iter = rcu_dereference_protected(*ins,
1070 lockdep_is_held(&rt->rt6i_table->tb6_lock));
1072 if (iter->rt6i_metric > rt->rt6i_metric)
1074 if (rt6_qualify_for_ecmp(iter)) {
1075 *ins = iter->rt6_next;
1076 iter->rt6i_node = NULL;
1077 fib6_purge_rt(iter, fn, info->nl_net);
1078 if (rcu_access_pointer(fn->rr_ptr) == iter)
1082 info->nl_net->ipv6.rt6_stats->fib_rt_entries--;
1084 ins = &iter->rt6_next;
1086 iter = rcu_dereference_protected(*ins,
1087 lockdep_is_held(&rt->rt6i_table->tb6_lock));
1089 WARN_ON(nsiblings != 0);
1096 static void fib6_start_gc(struct net *net, struct rt6_info *rt)
1098 if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
1099 (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE)))
1100 mod_timer(&net->ipv6.ip6_fib_timer,
1101 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
1104 void fib6_force_start_gc(struct net *net)
1106 if (!timer_pending(&net->ipv6.ip6_fib_timer))
1107 mod_timer(&net->ipv6.ip6_fib_timer,
1108 jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
1111 static void __fib6_update_sernum_upto_root(struct rt6_info *rt,
1114 struct fib6_node *fn = rcu_dereference_protected(rt->rt6i_node,
1115 lockdep_is_held(&rt->rt6i_table->tb6_lock));
1117 /* paired with smp_rmb() in rt6_get_cookie_safe() */
1120 fn->fn_sernum = sernum;
1121 fn = rcu_dereference_protected(fn->parent,
1122 lockdep_is_held(&rt->rt6i_table->tb6_lock));
1126 void fib6_update_sernum_upto_root(struct net *net, struct rt6_info *rt)
1128 __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net));
1132 * Add routing information to the routing tree.
1133 * <destination addr>/<source addr>
1134 * with source addr info in sub-trees
1135 * Need to own table->tb6_lock
1138 int fib6_add(struct fib6_node *root, struct rt6_info *rt,
1139 struct nl_info *info, struct mx6_config *mxc,
1140 struct netlink_ext_ack *extack)
1142 struct fib6_table *table = rt->rt6i_table;
1143 struct fib6_node *fn, *pn = NULL;
1145 int allow_create = 1;
1146 int replace_required = 0;
1147 int sernum = fib6_new_sernum(info->nl_net);
1149 if (WARN_ON_ONCE(!atomic_read(&rt->dst.__refcnt)))
1151 if (WARN_ON_ONCE(rt->rt6i_flags & RTF_CACHE))
1155 if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
1157 if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
1158 replace_required = 1;
1160 if (!allow_create && !replace_required)
1161 pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
1163 fn = fib6_add_1(info->nl_net, table, root,
1164 &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
1165 offsetof(struct rt6_info, rt6i_dst), allow_create,
1166 replace_required, extack);
1175 #ifdef CONFIG_IPV6_SUBTREES
1176 if (rt->rt6i_src.plen) {
1177 struct fib6_node *sn;
1179 if (!rcu_access_pointer(fn->subtree)) {
1180 struct fib6_node *sfn;
1192 /* Create subtree root node */
1193 sfn = node_alloc(info->nl_net);
1197 atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
1198 rcu_assign_pointer(sfn->leaf,
1199 info->nl_net->ipv6.ip6_null_entry);
1200 sfn->fn_flags = RTN_ROOT;
1202 /* Now add the first leaf node to new subtree */
1204 sn = fib6_add_1(info->nl_net, table, sfn,
1205 &rt->rt6i_src.addr, rt->rt6i_src.plen,
1206 offsetof(struct rt6_info, rt6i_src),
1207 allow_create, replace_required, extack);
1210 /* If it is failed, discard just allocated
1211 root, and then (in failure) stale node
1214 node_free_immediate(info->nl_net, sfn);
1219 /* Now link new subtree to main tree */
1220 rcu_assign_pointer(sfn->parent, fn);
1221 rcu_assign_pointer(fn->subtree, sfn);
1223 sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn),
1224 &rt->rt6i_src.addr, rt->rt6i_src.plen,
1225 offsetof(struct rt6_info, rt6i_src),
1226 allow_create, replace_required, extack);
1234 if (!rcu_access_pointer(fn->leaf)) {
1235 if (fn->fn_flags & RTN_TL_ROOT) {
1236 /* put back null_entry for root node */
1237 rcu_assign_pointer(fn->leaf,
1238 info->nl_net->ipv6.ip6_null_entry);
1240 atomic_inc(&rt->rt6i_ref);
1241 rcu_assign_pointer(fn->leaf, rt);
1248 err = fib6_add_rt2node(fn, rt, info, mxc, extack);
1250 __fib6_update_sernum_upto_root(rt, sernum);
1251 fib6_start_gc(info->nl_net, rt);
1256 #ifdef CONFIG_IPV6_SUBTREES
1258 * If fib6_add_1 has cleared the old leaf pointer in the
1259 * super-tree leaf node we have to find a new one for it.
1262 struct rt6_info *pn_leaf =
1263 rcu_dereference_protected(pn->leaf,
1264 lockdep_is_held(&table->tb6_lock));
1265 if (pn_leaf == rt) {
1267 RCU_INIT_POINTER(pn->leaf, NULL);
1268 atomic_dec(&rt->rt6i_ref);
1270 if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) {
1271 pn_leaf = fib6_find_prefix(info->nl_net, table,
1277 info->nl_net->ipv6.ip6_null_entry;
1280 atomic_inc(&pn_leaf->rt6i_ref);
1281 rcu_assign_pointer(pn->leaf, pn_leaf);
1290 /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if:
1291 * 1. fn is an intermediate node and we failed to add the new
1292 * route to it in both subtree creation failure and fib6_add_rt2node()
1294 * 2. fn is the root node in the table and we fail to add the first
1295 * default route to it.
1298 (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) ||
1299 (fn->fn_flags & RTN_TL_ROOT &&
1300 !rcu_access_pointer(fn->leaf))))
1301 fib6_repair_tree(info->nl_net, table, fn);
1302 /* Always release dst as dst->__refcnt is guaranteed
1303 * to be taken before entering this function
1305 dst_release_immediate(&rt->dst);
1310 * Routing tree lookup
1314 struct lookup_args {
1315 int offset; /* key offset on rt6_info */
1316 const struct in6_addr *addr; /* search key */
1319 static struct fib6_node *fib6_lookup_1(struct fib6_node *root,
1320 struct lookup_args *args)
1322 struct fib6_node *fn;
1325 if (unlikely(args->offset == 0))
1335 struct fib6_node *next;
1337 dir = addr_bit_set(args->addr, fn->fn_bit);
1339 next = dir ? rcu_dereference(fn->right) :
1340 rcu_dereference(fn->left);
1350 struct fib6_node *subtree = FIB6_SUBTREE(fn);
1352 if (subtree || fn->fn_flags & RTN_RTINFO) {
1353 struct rt6_info *leaf = rcu_dereference(fn->leaf);
1359 key = (struct rt6key *) ((u8 *)leaf + args->offset);
1361 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
1362 #ifdef CONFIG_IPV6_SUBTREES
1364 struct fib6_node *sfn;
1365 sfn = fib6_lookup_1(subtree, args + 1);
1371 if (fn->fn_flags & RTN_RTINFO)
1376 if (fn->fn_flags & RTN_ROOT)
1379 fn = rcu_dereference(fn->parent);
1385 /* called with rcu_read_lock() held
1387 struct fib6_node *fib6_lookup(struct fib6_node *root, const struct in6_addr *daddr,
1388 const struct in6_addr *saddr)
1390 struct fib6_node *fn;
1391 struct lookup_args args[] = {
1393 .offset = offsetof(struct rt6_info, rt6i_dst),
1396 #ifdef CONFIG_IPV6_SUBTREES
1398 .offset = offsetof(struct rt6_info, rt6i_src),
1403 .offset = 0, /* sentinel */
1407 fn = fib6_lookup_1(root, daddr ? args : args + 1);
1408 if (!fn || fn->fn_flags & RTN_TL_ROOT)
1415 * Get node with specified destination prefix (and source prefix,
1416 * if subtrees are used)
1417 * exact_match == true means we try to find fn with exact match of
1418 * the passed in prefix addr
1419 * exact_match == false means we try to find fn with longest prefix
1420 * match of the passed in prefix addr. This is useful for finding fn
1421 * for cached route as it will be stored in the exception table under
1422 * the node with longest prefix length.
1426 static struct fib6_node *fib6_locate_1(struct fib6_node *root,
1427 const struct in6_addr *addr,
1428 int plen, int offset,
1431 struct fib6_node *fn, *prev = NULL;
1433 for (fn = root; fn ; ) {
1434 struct rt6_info *leaf = rcu_dereference(fn->leaf);
1437 /* This node is being deleted */
1439 if (plen <= fn->fn_bit)
1445 key = (struct rt6key *)((u8 *)leaf + offset);
1450 if (plen < fn->fn_bit ||
1451 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
1454 if (plen == fn->fn_bit)
1461 * We have more bits to go
1463 if (addr_bit_set(addr, fn->fn_bit))
1464 fn = rcu_dereference(fn->right);
1466 fn = rcu_dereference(fn->left);
1475 struct fib6_node *fib6_locate(struct fib6_node *root,
1476 const struct in6_addr *daddr, int dst_len,
1477 const struct in6_addr *saddr, int src_len,
1480 struct fib6_node *fn;
1482 fn = fib6_locate_1(root, daddr, dst_len,
1483 offsetof(struct rt6_info, rt6i_dst),
1486 #ifdef CONFIG_IPV6_SUBTREES
1488 WARN_ON(saddr == NULL);
1490 struct fib6_node *subtree = FIB6_SUBTREE(fn);
1493 fn = fib6_locate_1(subtree, saddr, src_len,
1494 offsetof(struct rt6_info, rt6i_src),
1501 if (fn && fn->fn_flags & RTN_RTINFO)
1513 static struct rt6_info *fib6_find_prefix(struct net *net,
1514 struct fib6_table *table,
1515 struct fib6_node *fn)
1517 struct fib6_node *child_left, *child_right;
1519 if (fn->fn_flags & RTN_ROOT)
1520 return net->ipv6.ip6_null_entry;
1523 child_left = rcu_dereference_protected(fn->left,
1524 lockdep_is_held(&table->tb6_lock));
1525 child_right = rcu_dereference_protected(fn->right,
1526 lockdep_is_held(&table->tb6_lock));
1528 return rcu_dereference_protected(child_left->leaf,
1529 lockdep_is_held(&table->tb6_lock));
1531 return rcu_dereference_protected(child_right->leaf,
1532 lockdep_is_held(&table->tb6_lock));
1534 fn = FIB6_SUBTREE(fn);
1540 * Called to trim the tree of intermediate nodes when possible. "fn"
1541 * is the node we want to try and remove.
1542 * Need to own table->tb6_lock
1545 static struct fib6_node *fib6_repair_tree(struct net *net,
1546 struct fib6_table *table,
1547 struct fib6_node *fn)
1551 struct fib6_node *child;
1552 struct fib6_walker *w;
1555 /* Set fn->leaf to null_entry for root node. */
1556 if (fn->fn_flags & RTN_TL_ROOT) {
1557 rcu_assign_pointer(fn->leaf, net->ipv6.ip6_null_entry);
1562 struct fib6_node *fn_r = rcu_dereference_protected(fn->right,
1563 lockdep_is_held(&table->tb6_lock));
1564 struct fib6_node *fn_l = rcu_dereference_protected(fn->left,
1565 lockdep_is_held(&table->tb6_lock));
1566 struct fib6_node *pn = rcu_dereference_protected(fn->parent,
1567 lockdep_is_held(&table->tb6_lock));
1568 struct fib6_node *pn_r = rcu_dereference_protected(pn->right,
1569 lockdep_is_held(&table->tb6_lock));
1570 struct fib6_node *pn_l = rcu_dereference_protected(pn->left,
1571 lockdep_is_held(&table->tb6_lock));
1572 struct rt6_info *fn_leaf = rcu_dereference_protected(fn->leaf,
1573 lockdep_is_held(&table->tb6_lock));
1574 struct rt6_info *pn_leaf = rcu_dereference_protected(pn->leaf,
1575 lockdep_is_held(&table->tb6_lock));
1576 struct rt6_info *new_fn_leaf;
1578 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
1581 WARN_ON(fn->fn_flags & RTN_RTINFO);
1582 WARN_ON(fn->fn_flags & RTN_TL_ROOT);
1588 child = fn_r, children |= 1;
1590 child = fn_l, children |= 2;
1592 if (children == 3 || FIB6_SUBTREE(fn)
1593 #ifdef CONFIG_IPV6_SUBTREES
1594 /* Subtree root (i.e. fn) may have one child */
1595 || (children && fn->fn_flags & RTN_ROOT)
1598 new_fn_leaf = fib6_find_prefix(net, table, fn);
1601 WARN_ON(!new_fn_leaf);
1602 new_fn_leaf = net->ipv6.ip6_null_entry;
1605 atomic_inc(&new_fn_leaf->rt6i_ref);
1606 rcu_assign_pointer(fn->leaf, new_fn_leaf);
1610 #ifdef CONFIG_IPV6_SUBTREES
1611 if (FIB6_SUBTREE(pn) == fn) {
1612 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1613 RCU_INIT_POINTER(pn->subtree, NULL);
1616 WARN_ON(fn->fn_flags & RTN_ROOT);
1619 rcu_assign_pointer(pn->right, child);
1620 else if (pn_l == fn)
1621 rcu_assign_pointer(pn->left, child);
1627 rcu_assign_pointer(child->parent, pn);
1629 #ifdef CONFIG_IPV6_SUBTREES
1633 read_lock(&net->ipv6.fib6_walker_lock);
1634 FOR_WALKERS(net, w) {
1636 if (w->node == fn) {
1637 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
1642 if (w->node == fn) {
1645 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1646 w->state = w->state >= FWS_R ? FWS_U : FWS_INIT;
1648 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
1649 w->state = w->state >= FWS_C ? FWS_U : FWS_INIT;
1654 read_unlock(&net->ipv6.fib6_walker_lock);
1657 if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
1660 RCU_INIT_POINTER(pn->leaf, NULL);
1661 rt6_release(pn_leaf);
1666 static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
1667 struct rt6_info __rcu **rtp, struct nl_info *info)
1669 struct fib6_walker *w;
1670 struct rt6_info *rt = rcu_dereference_protected(*rtp,
1671 lockdep_is_held(&table->tb6_lock));
1672 struct net *net = info->nl_net;
1674 RT6_TRACE("fib6_del_route\n");
1676 WARN_ON_ONCE(rt->rt6i_flags & RTF_CACHE);
1679 *rtp = rt->rt6_next;
1680 rt->rt6i_node = NULL;
1681 net->ipv6.rt6_stats->fib_rt_entries--;
1682 net->ipv6.rt6_stats->fib_discarded_routes++;
1684 /* Flush all cached dst in exception table */
1685 rt6_flush_exceptions(rt);
1687 /* Reset round-robin state, if necessary */
1688 if (rcu_access_pointer(fn->rr_ptr) == rt)
1691 /* Remove this entry from other siblings */
1692 if (rt->rt6i_nsiblings) {
1693 struct rt6_info *sibling, *next_sibling;
1695 list_for_each_entry_safe(sibling, next_sibling,
1696 &rt->rt6i_siblings, rt6i_siblings)
1697 sibling->rt6i_nsiblings--;
1698 rt->rt6i_nsiblings = 0;
1699 list_del_init(&rt->rt6i_siblings);
1700 rt6_multipath_rebalance(next_sibling);
1703 /* Adjust walkers */
1704 read_lock(&net->ipv6.fib6_walker_lock);
1705 FOR_WALKERS(net, w) {
1706 if (w->state == FWS_C && w->leaf == rt) {
1707 RT6_TRACE("walker %p adjusted by delroute\n", w);
1708 w->leaf = rcu_dereference_protected(rt->rt6_next,
1709 lockdep_is_held(&table->tb6_lock));
1714 read_unlock(&net->ipv6.fib6_walker_lock);
1716 /* If it was last route, call fib6_repair_tree() to:
1717 * 1. For root node, put back null_entry as how the table was created.
1718 * 2. For other nodes, expunge its radix tree node.
1720 if (!rcu_access_pointer(fn->leaf)) {
1721 if (!(fn->fn_flags & RTN_TL_ROOT)) {
1722 fn->fn_flags &= ~RTN_RTINFO;
1723 net->ipv6.rt6_stats->fib_route_nodes--;
1725 fn = fib6_repair_tree(net, table, fn);
1728 fib6_purge_rt(rt, fn, net);
1730 call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL);
1731 if (!info->skip_notify)
1732 inet6_rt_notify(RTM_DELROUTE, rt, info, 0);
1736 /* Need to own table->tb6_lock */
1737 int fib6_del(struct rt6_info *rt, struct nl_info *info)
1739 struct fib6_node *fn = rcu_dereference_protected(rt->rt6i_node,
1740 lockdep_is_held(&rt->rt6i_table->tb6_lock));
1741 struct fib6_table *table = rt->rt6i_table;
1742 struct net *net = info->nl_net;
1743 struct rt6_info __rcu **rtp;
1744 struct rt6_info __rcu **rtp_next;
1747 if (rt->dst.obsolete > 0) {
1752 if (!fn || rt == net->ipv6.ip6_null_entry)
1755 WARN_ON(!(fn->fn_flags & RTN_RTINFO));
1757 /* remove cached dst from exception table */
1758 if (rt->rt6i_flags & RTF_CACHE)
1759 return rt6_remove_exception_rt(rt);
1762 * Walk the leaf entries looking for ourself
1765 for (rtp = &fn->leaf; *rtp; rtp = rtp_next) {
1766 struct rt6_info *cur = rcu_dereference_protected(*rtp,
1767 lockdep_is_held(&table->tb6_lock));
1769 fib6_del_route(table, fn, rtp, info);
1772 rtp_next = &cur->rt6_next;
1778 * Tree traversal function.
1780 * Certainly, it is not interrupt safe.
1781 * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1782 * It means, that we can modify tree during walking
1783 * and use this function for garbage collection, clone pruning,
1784 * cleaning tree when a device goes down etc. etc.
1786 * It guarantees that every node will be traversed,
1787 * and that it will be traversed only once.
1789 * Callback function w->func may return:
1790 * 0 -> continue walking.
1791 * positive value -> walking is suspended (used by tree dumps,
1792 * and probably by gc, if it will be split to several slices)
1793 * negative value -> terminate walking.
1795 * The function itself returns:
1796 * 0 -> walk is complete.
1797 * >0 -> walk is incomplete (i.e. suspended)
1798 * <0 -> walk is terminated by an error.
1800 * This function is called with tb6_lock held.
1803 static int fib6_walk_continue(struct fib6_walker *w)
1805 struct fib6_node *fn, *pn, *left, *right;
1807 /* w->root should always be table->tb6_root */
1808 WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT));
1816 #ifdef CONFIG_IPV6_SUBTREES
1818 if (FIB6_SUBTREE(fn)) {
1819 w->node = FIB6_SUBTREE(fn);
1826 left = rcu_dereference_protected(fn->left, 1);
1829 w->state = FWS_INIT;
1835 right = rcu_dereference_protected(fn->right, 1);
1838 w->state = FWS_INIT;
1842 w->leaf = rcu_dereference_protected(fn->leaf, 1);
1845 if (w->leaf && fn->fn_flags & RTN_RTINFO) {
1866 pn = rcu_dereference_protected(fn->parent, 1);
1867 left = rcu_dereference_protected(pn->left, 1);
1868 right = rcu_dereference_protected(pn->right, 1);
1870 #ifdef CONFIG_IPV6_SUBTREES
1871 if (FIB6_SUBTREE(pn) == fn) {
1872 WARN_ON(!(fn->fn_flags & RTN_ROOT));
1883 w->leaf = rcu_dereference_protected(w->node->leaf, 1);
1893 static int fib6_walk(struct net *net, struct fib6_walker *w)
1897 w->state = FWS_INIT;
1900 fib6_walker_link(net, w);
1901 res = fib6_walk_continue(w);
1903 fib6_walker_unlink(net, w);
1907 static int fib6_clean_node(struct fib6_walker *w)
1910 struct rt6_info *rt;
1911 struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w);
1912 struct nl_info info = {
1916 if (c->sernum != FIB6_NO_SERNUM_CHANGE &&
1917 w->node->fn_sernum != c->sernum)
1918 w->node->fn_sernum = c->sernum;
1921 WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE);
1926 for_each_fib6_walker_rt(w) {
1927 res = c->func(rt, c->arg);
1930 res = fib6_del(rt, &info);
1933 pr_debug("%s: del failed: rt=%p@%p err=%d\n",
1935 rcu_access_pointer(rt->rt6i_node),
1941 } else if (res == -2) {
1942 if (WARN_ON(!rt->rt6i_nsiblings))
1944 rt = list_last_entry(&rt->rt6i_siblings,
1945 struct rt6_info, rt6i_siblings);
1955 * Convenient frontend to tree walker.
1957 * func is called on each route.
1958 * It may return -2 -> skip multipath route.
1959 * -1 -> delete this route.
1960 * 0 -> continue walking
1963 static void fib6_clean_tree(struct net *net, struct fib6_node *root,
1964 int (*func)(struct rt6_info *, void *arg),
1965 int sernum, void *arg)
1967 struct fib6_cleaner c;
1970 c.w.func = fib6_clean_node;
1978 fib6_walk(net, &c.w);
1981 static void __fib6_clean_all(struct net *net,
1982 int (*func)(struct rt6_info *, void *),
1983 int sernum, void *arg)
1985 struct fib6_table *table;
1986 struct hlist_head *head;
1990 for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
1991 head = &net->ipv6.fib_table_hash[h];
1992 hlist_for_each_entry_rcu(table, head, tb6_hlist) {
1993 spin_lock_bh(&table->tb6_lock);
1994 fib6_clean_tree(net, &table->tb6_root,
1996 spin_unlock_bh(&table->tb6_lock);
2002 void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *),
2005 __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg);
2008 static void fib6_flush_trees(struct net *net)
2010 int new_sernum = fib6_new_sernum(net);
2012 __fib6_clean_all(net, NULL, new_sernum, NULL);
2016 * Garbage collection
2019 static int fib6_age(struct rt6_info *rt, void *arg)
2021 struct fib6_gc_args *gc_args = arg;
2022 unsigned long now = jiffies;
2025 * check addrconf expiration here.
2026 * Routes are expired even if they are in use.
2029 if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) {
2030 if (time_after(now, rt->dst.expires)) {
2031 RT6_TRACE("expiring %p\n", rt);
2037 /* Also age clones in the exception table.
2038 * Note, that clones are aged out
2039 * only if they are not in use now.
2041 rt6_age_exceptions(rt, gc_args, now);
2046 void fib6_run_gc(unsigned long expires, struct net *net, bool force)
2048 struct fib6_gc_args gc_args;
2052 spin_lock_bh(&net->ipv6.fib6_gc_lock);
2053 } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) {
2054 mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
2057 gc_args.timeout = expires ? (int)expires :
2058 net->ipv6.sysctl.ip6_rt_gc_interval;
2061 fib6_clean_all(net, fib6_age, &gc_args);
2063 net->ipv6.ip6_rt_last_gc = now;
2066 mod_timer(&net->ipv6.ip6_fib_timer,
2068 + net->ipv6.sysctl.ip6_rt_gc_interval));
2070 del_timer(&net->ipv6.ip6_fib_timer);
2071 spin_unlock_bh(&net->ipv6.fib6_gc_lock);
2074 static void fib6_gc_timer_cb(struct timer_list *t)
2076 struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer);
2078 fib6_run_gc(0, arg, true);
2081 static int __net_init fib6_net_init(struct net *net)
2083 size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
2086 err = fib6_notifier_init(net);
2090 spin_lock_init(&net->ipv6.fib6_gc_lock);
2091 rwlock_init(&net->ipv6.fib6_walker_lock);
2092 INIT_LIST_HEAD(&net->ipv6.fib6_walkers);
2093 timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0);
2095 net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
2096 if (!net->ipv6.rt6_stats)
2099 /* Avoid false sharing : Use at least a full cache line */
2100 size = max_t(size_t, size, L1_CACHE_BYTES);
2102 net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL);
2103 if (!net->ipv6.fib_table_hash)
2106 net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
2108 if (!net->ipv6.fib6_main_tbl)
2109 goto out_fib_table_hash;
2111 net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
2112 rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf,
2113 net->ipv6.ip6_null_entry);
2114 net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
2115 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
2116 inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
2118 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2119 net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
2121 if (!net->ipv6.fib6_local_tbl)
2122 goto out_fib6_main_tbl;
2123 net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
2124 rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf,
2125 net->ipv6.ip6_null_entry);
2126 net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
2127 RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
2128 inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);
2130 fib6_tables_init(net);
2134 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
2136 kfree(net->ipv6.fib6_main_tbl);
2139 kfree(net->ipv6.fib_table_hash);
2141 kfree(net->ipv6.rt6_stats);
2143 fib6_notifier_exit(net);
2147 static void fib6_net_exit(struct net *net)
2151 del_timer_sync(&net->ipv6.ip6_fib_timer);
2153 for (i = 0; i < FIB6_TABLE_HASHSZ; i++) {
2154 struct hlist_head *head = &net->ipv6.fib_table_hash[i];
2155 struct hlist_node *tmp;
2156 struct fib6_table *tb;
2158 hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) {
2159 hlist_del(&tb->tb6_hlist);
2160 fib6_free_table(tb);
2164 kfree(net->ipv6.fib_table_hash);
2165 kfree(net->ipv6.rt6_stats);
2166 fib6_notifier_exit(net);
2169 static struct pernet_operations fib6_net_ops = {
2170 .init = fib6_net_init,
2171 .exit = fib6_net_exit,
2174 int __init fib6_init(void)
2178 fib6_node_kmem = kmem_cache_create("fib6_nodes",
2179 sizeof(struct fib6_node),
2180 0, SLAB_HWCACHE_ALIGN,
2182 if (!fib6_node_kmem)
2185 ret = register_pernet_subsys(&fib6_net_ops);
2187 goto out_kmem_cache_create;
2189 ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL,
2192 goto out_unregister_subsys;
2194 __fib6_flush_trees = fib6_flush_trees;
2198 out_unregister_subsys:
2199 unregister_pernet_subsys(&fib6_net_ops);
2200 out_kmem_cache_create:
2201 kmem_cache_destroy(fib6_node_kmem);
2205 void fib6_gc_cleanup(void)
2207 unregister_pernet_subsys(&fib6_net_ops);
2208 kmem_cache_destroy(fib6_node_kmem);
2211 #ifdef CONFIG_PROC_FS
2212 static int ipv6_route_seq_show(struct seq_file *seq, void *v)
2214 struct rt6_info *rt = v;
2215 struct ipv6_route_iter *iter = seq->private;
2217 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen);
2219 #ifdef CONFIG_IPV6_SUBTREES
2220 seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen);
2222 seq_puts(seq, "00000000000000000000000000000000 00 ");
2224 if (rt->rt6i_flags & RTF_GATEWAY)
2225 seq_printf(seq, "%pi6", &rt->rt6i_gateway);
2227 seq_puts(seq, "00000000000000000000000000000000");
2229 seq_printf(seq, " %08x %08x %08x %08x %8s\n",
2230 rt->rt6i_metric, atomic_read(&rt->dst.__refcnt),
2231 rt->dst.__use, rt->rt6i_flags,
2232 rt->dst.dev ? rt->dst.dev->name : "");
2233 iter->w.leaf = NULL;
2237 static int ipv6_route_yield(struct fib6_walker *w)
2239 struct ipv6_route_iter *iter = w->args;
2245 iter->w.leaf = rcu_dereference_protected(
2246 iter->w.leaf->rt6_next,
2247 lockdep_is_held(&iter->tbl->tb6_lock));
2249 if (!iter->skip && iter->w.leaf)
2251 } while (iter->w.leaf);
2256 static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter,
2259 memset(&iter->w, 0, sizeof(iter->w));
2260 iter->w.func = ipv6_route_yield;
2261 iter->w.root = &iter->tbl->tb6_root;
2262 iter->w.state = FWS_INIT;
2263 iter->w.node = iter->w.root;
2264 iter->w.args = iter;
2265 iter->sernum = iter->w.root->fn_sernum;
2266 INIT_LIST_HEAD(&iter->w.lh);
2267 fib6_walker_link(net, &iter->w);
2270 static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl,
2274 struct hlist_node *node;
2277 h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1;
2278 node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist));
2284 while (!node && h < FIB6_TABLE_HASHSZ) {
2285 node = rcu_dereference_bh(
2286 hlist_first_rcu(&net->ipv6.fib_table_hash[h++]));
2288 return hlist_entry_safe(node, struct fib6_table, tb6_hlist);
2291 static void ipv6_route_check_sernum(struct ipv6_route_iter *iter)
2293 if (iter->sernum != iter->w.root->fn_sernum) {
2294 iter->sernum = iter->w.root->fn_sernum;
2295 iter->w.state = FWS_INIT;
2296 iter->w.node = iter->w.root;
2297 WARN_ON(iter->w.skip);
2298 iter->w.skip = iter->w.count;
2302 static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
2306 struct net *net = seq_file_net(seq);
2307 struct ipv6_route_iter *iter = seq->private;
2312 n = rcu_dereference_bh(((struct rt6_info *)v)->rt6_next);
2319 ipv6_route_check_sernum(iter);
2320 spin_lock_bh(&iter->tbl->tb6_lock);
2321 r = fib6_walk_continue(&iter->w);
2322 spin_unlock_bh(&iter->tbl->tb6_lock);
2326 return iter->w.leaf;
2328 fib6_walker_unlink(net, &iter->w);
2331 fib6_walker_unlink(net, &iter->w);
2333 iter->tbl = ipv6_route_seq_next_table(iter->tbl, net);
2337 ipv6_route_seq_setup_walk(iter, net);
2341 static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos)
2344 struct net *net = seq_file_net(seq);
2345 struct ipv6_route_iter *iter = seq->private;
2348 iter->tbl = ipv6_route_seq_next_table(NULL, net);
2352 ipv6_route_seq_setup_walk(iter, net);
2353 return ipv6_route_seq_next(seq, NULL, pos);
2359 static bool ipv6_route_iter_active(struct ipv6_route_iter *iter)
2361 struct fib6_walker *w = &iter->w;
2362 return w->node && !(w->state == FWS_U && w->node == w->root);
2365 static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
2368 struct net *net = seq_file_net(seq);
2369 struct ipv6_route_iter *iter = seq->private;
2371 if (ipv6_route_iter_active(iter))
2372 fib6_walker_unlink(net, &iter->w);
2374 rcu_read_unlock_bh();
2377 const struct seq_operations ipv6_route_seq_ops = {
2378 .start = ipv6_route_seq_start,
2379 .next = ipv6_route_seq_next,
2380 .stop = ipv6_route_seq_stop,
2381 .show = ipv6_route_seq_show
2383 #endif /* CONFIG_PROC_FS */