2 * Linux INET6 implementation
3 * Forwarding Information Database
6 * Pedro Roque <roque@di.fc.ul.pt>
8 * $Id: ip6_fib.c,v 1.25 2001/10/31 21:55:55 davem Exp $
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License
12 * as published by the Free Software Foundation; either version
13 * 2 of the License, or (at your option) any later version.
18 * Yuji SEKIYA @USAGI: Support default route on router node;
19 * remove ip6_null_entry from the top of
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>
32 #include <linux/proc_fs.h>
36 #include <net/ndisc.h>
37 #include <net/addrconf.h>
39 #include <net/ip6_fib.h>
40 #include <net/ip6_route.h>
45 #define RT6_TRACE(x...) printk(KERN_DEBUG x)
47 #define RT6_TRACE(x...) do { ; } while (0)
50 struct rt6_statistics rt6_stats;
52 static kmem_cache_t * fib6_node_kmem __read_mostly;
56 #ifdef CONFIG_IPV6_SUBTREES
67 struct fib6_walker_t w;
68 int (*func)(struct rt6_info *, void *arg);
72 DEFINE_RWLOCK(fib6_walker_lock);
75 #ifdef CONFIG_IPV6_SUBTREES
76 #define FWS_INIT FWS_S
77 #define SUBTREE(fn) ((fn)->subtree)
79 #define FWS_INIT FWS_L
80 #define SUBTREE(fn) NULL
83 static void fib6_prune_clones(struct fib6_node *fn, struct rt6_info *rt);
84 static struct fib6_node * fib6_repair_tree(struct fib6_node *fn);
87 * A routing update causes an increase of the serial number on the
88 * affected subtree. This allows for cached routes to be asynchronously
89 * tested when modifications are made to the destination cache as a
90 * result of redirects, path MTU changes, etc.
93 static __u32 rt_sernum;
95 static DEFINE_TIMER(ip6_fib_timer, fib6_run_gc, 0, 0);
97 struct fib6_walker_t fib6_walker_list = {
98 .prev = &fib6_walker_list,
99 .next = &fib6_walker_list,
102 #define FOR_WALKERS(w) for ((w)=fib6_walker_list.next; (w) != &fib6_walker_list; (w)=(w)->next)
104 static __inline__ u32 fib6_new_sernum(void)
113 * Auxiliary address test functions for the radix tree.
115 * These assume a 32bit processor (although it will work on
123 static __inline__ int addr_bit_set(void *token, int fn_bit)
127 return htonl(1 << ((~fn_bit)&0x1F)) & addr[fn_bit>>5];
130 static __inline__ struct fib6_node * node_alloc(void)
132 struct fib6_node *fn;
134 if ((fn = kmem_cache_alloc(fib6_node_kmem, SLAB_ATOMIC)) != NULL)
135 memset(fn, 0, sizeof(struct fib6_node));
140 static __inline__ void node_free(struct fib6_node * fn)
142 kmem_cache_free(fib6_node_kmem, fn);
145 static __inline__ void rt6_release(struct rt6_info *rt)
147 if (atomic_dec_and_test(&rt->rt6i_ref))
148 dst_free(&rt->u.dst);
151 static struct fib6_table fib6_main_tbl = {
152 .tb6_id = RT6_TABLE_MAIN,
153 .tb6_lock = RW_LOCK_UNLOCKED,
155 .leaf = &ip6_null_entry,
156 .fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO,
160 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
162 static struct fib6_table fib6_local_tbl = {
163 .tb6_id = RT6_TABLE_LOCAL,
164 .tb6_lock = RW_LOCK_UNLOCKED,
166 .leaf = &ip6_null_entry,
167 .fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO,
171 #define FIB_TABLE_HASHSZ 256
172 static struct hlist_head fib_table_hash[FIB_TABLE_HASHSZ];
174 static struct fib6_table *fib6_alloc_table(u32 id)
176 struct fib6_table *table;
178 table = kzalloc(sizeof(*table), GFP_ATOMIC);
181 table->tb6_lock = RW_LOCK_UNLOCKED;
182 table->tb6_root.leaf = &ip6_null_entry;
183 table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
189 static void fib6_link_table(struct fib6_table *tb)
193 h = tb->tb6_id & (FIB_TABLE_HASHSZ - 1);
196 * No protection necessary, this is the only list mutatation
197 * operation, tables never disappear once they exist.
199 hlist_add_head_rcu(&tb->tb6_hlist, &fib_table_hash[h]);
202 struct fib6_table *fib6_new_table(u32 id)
204 struct fib6_table *tb;
208 tb = fib6_get_table(id);
212 tb = fib6_alloc_table(id);
219 struct fib6_table *fib6_get_table(u32 id)
221 struct fib6_table *tb;
222 struct hlist_node *node;
227 h = id & (FIB_TABLE_HASHSZ - 1);
229 hlist_for_each_entry_rcu(tb, node, &fib_table_hash[h], tb6_hlist) {
230 if (tb->tb6_id == id) {
240 static void __init fib6_tables_init(void)
242 fib6_link_table(&fib6_main_tbl);
243 fib6_link_table(&fib6_local_tbl);
248 struct fib6_table *fib6_new_table(u32 id)
250 return fib6_get_table(id);
253 struct fib6_table *fib6_get_table(u32 id)
255 return &fib6_main_tbl;
258 struct dst_entry *fib6_rule_lookup(struct flowi *fl, int flags,
261 return (struct dst_entry *) lookup(&fib6_main_tbl, fl, flags);
264 static void __init fib6_tables_init(void)
274 * return the appropriate node for a routing tree "add" operation
275 * by either creating and inserting or by returning an existing
279 static struct fib6_node * fib6_add_1(struct fib6_node *root, void *addr,
280 int addrlen, int plen,
283 struct fib6_node *fn, *in, *ln;
284 struct fib6_node *pn = NULL;
288 __u32 sernum = fib6_new_sernum();
290 RT6_TRACE("fib6_add_1\n");
292 /* insert node in tree */
297 key = (struct rt6key *)((u8 *)fn->leaf + offset);
302 if (plen < fn->fn_bit ||
303 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
310 if (plen == fn->fn_bit) {
311 /* clean up an intermediate node */
312 if ((fn->fn_flags & RTN_RTINFO) == 0) {
313 rt6_release(fn->leaf);
317 fn->fn_sernum = sernum;
323 * We have more bits to go
326 /* Try to walk down on tree. */
327 fn->fn_sernum = sernum;
328 dir = addr_bit_set(addr, fn->fn_bit);
330 fn = dir ? fn->right: fn->left;
334 * We walked to the bottom of tree.
335 * Create new leaf node without children.
345 ln->fn_sernum = sernum;
357 * split since we don't have a common prefix anymore or
358 * we have a less significant route.
359 * we've to insert an intermediate node on the list
360 * this new node will point to the one we need to create
366 /* find 1st bit in difference between the 2 addrs.
368 See comment in __ipv6_addr_diff: bit may be an invalid value,
369 but if it is >= plen, the value is ignored in any case.
372 bit = __ipv6_addr_diff(addr, &key->addr, addrlen);
377 * (new leaf node)[ln] (old node)[fn]
383 if (in == NULL || ln == NULL) {
392 * new intermediate node.
394 * be off since that an address that chooses one of
395 * the branches would not match less specific routes
396 * in the other branch
403 atomic_inc(&in->leaf->rt6i_ref);
405 in->fn_sernum = sernum;
407 /* update parent pointer */
418 ln->fn_sernum = sernum;
420 if (addr_bit_set(addr, bit)) {
427 } else { /* plen <= bit */
430 * (new leaf node)[ln]
432 * (old node)[fn] NULL
444 ln->fn_sernum = sernum;
451 if (addr_bit_set(&key->addr, plen))
462 * Insert routing information in a node.
465 static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
466 struct nlmsghdr *nlh, struct netlink_skb_parms *req)
468 struct rt6_info *iter = NULL;
469 struct rt6_info **ins;
473 if (fn->fn_flags&RTN_TL_ROOT &&
474 fn->leaf == &ip6_null_entry &&
475 !(rt->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) ){
481 for (iter = fn->leaf; iter; iter=iter->u.next) {
483 * Search for duplicates
486 if (iter->rt6i_metric == rt->rt6i_metric) {
488 * Same priority level
491 if (iter->rt6i_dev == rt->rt6i_dev &&
492 iter->rt6i_idev == rt->rt6i_idev &&
493 ipv6_addr_equal(&iter->rt6i_gateway,
494 &rt->rt6i_gateway)) {
495 if (!(iter->rt6i_flags&RTF_EXPIRES))
497 iter->rt6i_expires = rt->rt6i_expires;
498 if (!(rt->rt6i_flags&RTF_EXPIRES)) {
499 iter->rt6i_flags &= ~RTF_EXPIRES;
500 iter->rt6i_expires = 0;
506 if (iter->rt6i_metric > rt->rt6i_metric)
520 atomic_inc(&rt->rt6i_ref);
521 inet6_rt_notify(RTM_NEWROUTE, rt, nlh, req);
522 rt6_stats.fib_rt_entries++;
524 if ((fn->fn_flags & RTN_RTINFO) == 0) {
525 rt6_stats.fib_route_nodes++;
526 fn->fn_flags |= RTN_RTINFO;
532 static __inline__ void fib6_start_gc(struct rt6_info *rt)
534 if (ip6_fib_timer.expires == 0 &&
535 (rt->rt6i_flags & (RTF_EXPIRES|RTF_CACHE)))
536 mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval);
539 void fib6_force_start_gc(void)
541 if (ip6_fib_timer.expires == 0)
542 mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval);
546 * Add routing information to the routing tree.
547 * <destination addr>/<source addr>
548 * with source addr info in sub-trees
551 int fib6_add(struct fib6_node *root, struct rt6_info *rt,
552 struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req)
554 struct fib6_node *fn;
557 fn = fib6_add_1(root, &rt->rt6i_dst.addr, sizeof(struct in6_addr),
558 rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst));
563 #ifdef CONFIG_IPV6_SUBTREES
564 if (rt->rt6i_src.plen) {
565 struct fib6_node *sn;
567 if (fn->subtree == NULL) {
568 struct fib6_node *sfn;
580 /* Create subtree root node */
585 sfn->leaf = &ip6_null_entry;
586 atomic_inc(&ip6_null_entry.rt6i_ref);
587 sfn->fn_flags = RTN_ROOT;
588 sfn->fn_sernum = fib6_new_sernum();
590 /* Now add the first leaf node to new subtree */
592 sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
593 sizeof(struct in6_addr), rt->rt6i_src.plen,
594 offsetof(struct rt6_info, rt6i_src));
597 /* If it is failed, discard just allocated
598 root, and then (in st_failure) stale node
605 /* Now link new subtree to main tree */
608 if (fn->leaf == NULL) {
610 atomic_inc(&rt->rt6i_ref);
613 sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
614 sizeof(struct in6_addr), rt->rt6i_src.plen,
615 offsetof(struct rt6_info, rt6i_src));
625 err = fib6_add_rt2node(fn, rt, nlh, req);
629 if (!(rt->rt6i_flags&RTF_CACHE))
630 fib6_prune_clones(fn, rt);
635 dst_free(&rt->u.dst);
638 #ifdef CONFIG_IPV6_SUBTREES
639 /* Subtree creation failed, probably main tree node
640 is orphan. If it is, shoot it.
643 if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
644 fib6_repair_tree(fn);
645 dst_free(&rt->u.dst);
651 * Routing tree lookup
656 int offset; /* key offset on rt6_info */
657 struct in6_addr *addr; /* search key */
660 static struct fib6_node * fib6_lookup_1(struct fib6_node *root,
661 struct lookup_args *args)
663 struct fib6_node *fn;
673 struct fib6_node *next;
675 dir = addr_bit_set(args->addr, fn->fn_bit);
677 next = dir ? fn->right : fn->left;
687 while ((fn->fn_flags & RTN_ROOT) == 0) {
688 #ifdef CONFIG_IPV6_SUBTREES
690 struct fib6_node *st;
691 struct lookup_args *narg;
696 st = fib6_lookup_1(fn->subtree, narg);
698 if (st && !(st->fn_flags & RTN_ROOT))
704 if (fn->fn_flags & RTN_RTINFO) {
707 key = (struct rt6key *) ((u8 *) fn->leaf +
710 if (ipv6_prefix_equal(&key->addr, args->addr, key->plen))
720 struct fib6_node * fib6_lookup(struct fib6_node *root, struct in6_addr *daddr,
721 struct in6_addr *saddr)
723 struct lookup_args args[2];
724 struct fib6_node *fn;
726 args[0].offset = offsetof(struct rt6_info, rt6i_dst);
727 args[0].addr = daddr;
729 #ifdef CONFIG_IPV6_SUBTREES
730 args[1].offset = offsetof(struct rt6_info, rt6i_src);
731 args[1].addr = saddr;
734 fn = fib6_lookup_1(root, args);
736 if (fn == NULL || fn->fn_flags & RTN_TL_ROOT)
743 * Get node with specified destination prefix (and source prefix,
744 * if subtrees are used)
748 static struct fib6_node * fib6_locate_1(struct fib6_node *root,
749 struct in6_addr *addr,
750 int plen, int offset)
752 struct fib6_node *fn;
754 for (fn = root; fn ; ) {
755 struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
760 if (plen < fn->fn_bit ||
761 !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
764 if (plen == fn->fn_bit)
768 * We have more bits to go
770 if (addr_bit_set(addr, fn->fn_bit))
778 struct fib6_node * fib6_locate(struct fib6_node *root,
779 struct in6_addr *daddr, int dst_len,
780 struct in6_addr *saddr, int src_len)
782 struct fib6_node *fn;
784 fn = fib6_locate_1(root, daddr, dst_len,
785 offsetof(struct rt6_info, rt6i_dst));
787 #ifdef CONFIG_IPV6_SUBTREES
789 BUG_TRAP(saddr!=NULL);
793 fn = fib6_locate_1(fn, saddr, src_len,
794 offsetof(struct rt6_info, rt6i_src));
798 if (fn && fn->fn_flags&RTN_RTINFO)
810 static struct rt6_info * fib6_find_prefix(struct fib6_node *fn)
812 if (fn->fn_flags&RTN_ROOT)
813 return &ip6_null_entry;
817 return fn->left->leaf;
820 return fn->right->leaf;
828 * Called to trim the tree of intermediate nodes when possible. "fn"
829 * is the node we want to try and remove.
832 static struct fib6_node * fib6_repair_tree(struct fib6_node *fn)
836 struct fib6_node *child, *pn;
837 struct fib6_walker_t *w;
841 RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
844 BUG_TRAP(!(fn->fn_flags&RTN_RTINFO));
845 BUG_TRAP(!(fn->fn_flags&RTN_TL_ROOT));
846 BUG_TRAP(fn->leaf==NULL);
850 if (fn->right) child = fn->right, children |= 1;
851 if (fn->left) child = fn->left, children |= 2;
853 if (children == 3 || SUBTREE(fn)
854 #ifdef CONFIG_IPV6_SUBTREES
855 /* Subtree root (i.e. fn) may have one child */
856 || (children && fn->fn_flags&RTN_ROOT)
859 fn->leaf = fib6_find_prefix(fn);
861 if (fn->leaf==NULL) {
863 fn->leaf = &ip6_null_entry;
866 atomic_inc(&fn->leaf->rt6i_ref);
871 #ifdef CONFIG_IPV6_SUBTREES
872 if (SUBTREE(pn) == fn) {
873 BUG_TRAP(fn->fn_flags&RTN_ROOT);
877 BUG_TRAP(!(fn->fn_flags&RTN_ROOT));
879 if (pn->right == fn) pn->right = child;
880 else if (pn->left == fn) pn->left = child;
887 #ifdef CONFIG_IPV6_SUBTREES
891 read_lock(&fib6_walker_lock);
895 w->root = w->node = NULL;
896 RT6_TRACE("W %p adjusted by delroot 1\n", w);
897 } else if (w->node == fn) {
898 RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
905 RT6_TRACE("W %p adjusted by delroot 2\n", w);
910 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
911 w->state = w->state>=FWS_R ? FWS_U : FWS_INIT;
913 RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
914 w->state = w->state>=FWS_C ? FWS_U : FWS_INIT;
919 read_unlock(&fib6_walker_lock);
922 if (pn->fn_flags&RTN_RTINFO || SUBTREE(pn))
925 rt6_release(pn->leaf);
931 static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
932 struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req)
934 struct fib6_walker_t *w;
935 struct rt6_info *rt = *rtp;
937 RT6_TRACE("fib6_del_route\n");
941 rt->rt6i_node = NULL;
942 rt6_stats.fib_rt_entries--;
943 rt6_stats.fib_discarded_routes++;
946 read_lock(&fib6_walker_lock);
948 if (w->state == FWS_C && w->leaf == rt) {
949 RT6_TRACE("walker %p adjusted by delroute\n", w);
950 w->leaf = rt->u.next;
955 read_unlock(&fib6_walker_lock);
959 if (fn->leaf == NULL && fn->fn_flags&RTN_TL_ROOT)
960 fn->leaf = &ip6_null_entry;
962 /* If it was last route, expunge its radix tree node */
963 if (fn->leaf == NULL) {
964 fn->fn_flags &= ~RTN_RTINFO;
965 rt6_stats.fib_route_nodes--;
966 fn = fib6_repair_tree(fn);
969 if (atomic_read(&rt->rt6i_ref) != 1) {
970 /* This route is used as dummy address holder in some split
971 * nodes. It is not leaked, but it still holds other resources,
972 * which must be released in time. So, scan ascendant nodes
973 * and replace dummy references to this route with references
974 * to still alive ones.
977 if (!(fn->fn_flags&RTN_RTINFO) && fn->leaf == rt) {
978 fn->leaf = fib6_find_prefix(fn);
979 atomic_inc(&fn->leaf->rt6i_ref);
984 /* No more references are possible at this point. */
985 if (atomic_read(&rt->rt6i_ref) != 1) BUG();
988 inet6_rt_notify(RTM_DELROUTE, rt, nlh, req);
992 int fib6_del(struct rt6_info *rt, struct nlmsghdr *nlh, void *_rtattr, struct netlink_skb_parms *req)
994 struct fib6_node *fn = rt->rt6i_node;
995 struct rt6_info **rtp;
998 if (rt->u.dst.obsolete>0) {
1003 if (fn == NULL || rt == &ip6_null_entry)
1006 BUG_TRAP(fn->fn_flags&RTN_RTINFO);
1008 if (!(rt->rt6i_flags&RTF_CACHE))
1009 fib6_prune_clones(fn, rt);
1012 * Walk the leaf entries looking for ourself
1015 for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->u.next) {
1017 fib6_del_route(fn, rtp, nlh, _rtattr, req);
1025 * Tree traversal function.
1027 * Certainly, it is not interrupt safe.
1028 * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
1029 * It means, that we can modify tree during walking
1030 * and use this function for garbage collection, clone pruning,
1031 * cleaning tree when a device goes down etc. etc.
1033 * It guarantees that every node will be traversed,
1034 * and that it will be traversed only once.
1036 * Callback function w->func may return:
1037 * 0 -> continue walking.
1038 * positive value -> walking is suspended (used by tree dumps,
1039 * and probably by gc, if it will be split to several slices)
1040 * negative value -> terminate walking.
1042 * The function itself returns:
1043 * 0 -> walk is complete.
1044 * >0 -> walk is incomplete (i.e. suspended)
1045 * <0 -> walk is terminated by an error.
1048 int fib6_walk_continue(struct fib6_walker_t *w)
1050 struct fib6_node *fn, *pn;
1057 if (w->prune && fn != w->root &&
1058 fn->fn_flags&RTN_RTINFO && w->state < FWS_C) {
1063 #ifdef CONFIG_IPV6_SUBTREES
1066 w->node = SUBTREE(fn);
1074 w->state = FWS_INIT;
1080 w->node = fn->right;
1081 w->state = FWS_INIT;
1087 if (w->leaf && fn->fn_flags&RTN_RTINFO) {
1088 int err = w->func(w);
1099 #ifdef CONFIG_IPV6_SUBTREES
1100 if (SUBTREE(pn) == fn) {
1101 BUG_TRAP(fn->fn_flags&RTN_ROOT);
1106 if (pn->left == fn) {
1110 if (pn->right == fn) {
1112 w->leaf = w->node->leaf;
1122 int fib6_walk(struct fib6_walker_t *w)
1126 w->state = FWS_INIT;
1129 fib6_walker_link(w);
1130 res = fib6_walk_continue(w);
1132 fib6_walker_unlink(w);
1136 static int fib6_clean_node(struct fib6_walker_t *w)
1139 struct rt6_info *rt;
1140 struct fib6_cleaner_t *c = (struct fib6_cleaner_t*)w;
1142 for (rt = w->leaf; rt; rt = rt->u.next) {
1143 res = c->func(rt, c->arg);
1146 res = fib6_del(rt, NULL, NULL, NULL);
1149 printk(KERN_DEBUG "fib6_clean_node: del failed: rt=%p@%p err=%d\n", rt, rt->rt6i_node, res);
1162 * Convenient frontend to tree walker.
1164 * func is called on each route.
1165 * It may return -1 -> delete this route.
1166 * 0 -> continue walking
1168 * prune==1 -> only immediate children of node (certainly,
1169 * ignoring pure split nodes) will be scanned.
1172 static void fib6_clean_tree(struct fib6_node *root,
1173 int (*func)(struct rt6_info *, void *arg),
1174 int prune, void *arg)
1176 struct fib6_cleaner_t c;
1179 c.w.func = fib6_clean_node;
1187 void fib6_clean_all(int (*func)(struct rt6_info *, void *arg),
1188 int prune, void *arg)
1191 struct fib6_table *table;
1193 for (i = FIB6_TABLE_MIN; i <= FIB6_TABLE_MAX; i++) {
1194 table = fib6_get_table(i);
1195 if (table != NULL) {
1196 write_lock_bh(&table->tb6_lock);
1197 fib6_clean_tree(&table->tb6_root, func, prune, arg);
1198 write_unlock_bh(&table->tb6_lock);
1203 static int fib6_prune_clone(struct rt6_info *rt, void *arg)
1205 if (rt->rt6i_flags & RTF_CACHE) {
1206 RT6_TRACE("pruning clone %p\n", rt);
1213 static void fib6_prune_clones(struct fib6_node *fn, struct rt6_info *rt)
1215 fib6_clean_tree(fn, fib6_prune_clone, 1, rt);
1219 * Garbage collection
1222 static struct fib6_gc_args
1228 static int fib6_age(struct rt6_info *rt, void *arg)
1230 unsigned long now = jiffies;
1233 * check addrconf expiration here.
1234 * Routes are expired even if they are in use.
1236 * Also age clones. Note, that clones are aged out
1237 * only if they are not in use now.
1240 if (rt->rt6i_flags&RTF_EXPIRES && rt->rt6i_expires) {
1241 if (time_after(now, rt->rt6i_expires)) {
1242 RT6_TRACE("expiring %p\n", rt);
1246 } else if (rt->rt6i_flags & RTF_CACHE) {
1247 if (atomic_read(&rt->u.dst.__refcnt) == 0 &&
1248 time_after_eq(now, rt->u.dst.lastuse + gc_args.timeout)) {
1249 RT6_TRACE("aging clone %p\n", rt);
1251 } else if ((rt->rt6i_flags & RTF_GATEWAY) &&
1252 (!(rt->rt6i_nexthop->flags & NTF_ROUTER))) {
1253 RT6_TRACE("purging route %p via non-router but gateway\n",
1263 static DEFINE_SPINLOCK(fib6_gc_lock);
1265 void fib6_run_gc(unsigned long dummy)
1267 if (dummy != ~0UL) {
1268 spin_lock_bh(&fib6_gc_lock);
1269 gc_args.timeout = dummy ? (int)dummy : ip6_rt_gc_interval;
1272 if (!spin_trylock(&fib6_gc_lock)) {
1273 mod_timer(&ip6_fib_timer, jiffies + HZ);
1277 gc_args.timeout = ip6_rt_gc_interval;
1281 ndisc_dst_gc(&gc_args.more);
1282 fib6_clean_all(fib6_age, 0, NULL);
1285 mod_timer(&ip6_fib_timer, jiffies + ip6_rt_gc_interval);
1287 del_timer(&ip6_fib_timer);
1288 ip6_fib_timer.expires = 0;
1290 spin_unlock_bh(&fib6_gc_lock);
1293 void __init fib6_init(void)
1295 fib6_node_kmem = kmem_cache_create("fib6_nodes",
1296 sizeof(struct fib6_node),
1297 0, SLAB_HWCACHE_ALIGN,
1299 if (!fib6_node_kmem)
1300 panic("cannot create fib6_nodes cache");
1305 void fib6_gc_cleanup(void)
1307 del_timer(&ip6_fib_timer);
1308 kmem_cache_destroy(fib6_node_kmem);