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- // SPDX-License-Identifier: GPL-2.0-or-later
- /*
- * Linux INET6 implementation
- * Forwarding Information Database
- *
- * Authors:
- * Pedro Roque <roque@di.fc.ul.pt>
- *
- * Changes:
- * Yuji SEKIYA @USAGI: Support default route on router node;
- * remove ip6_null_entry from the top of
- * routing table.
- * Ville Nuorvala: Fixed routing subtrees.
- */
- #define pr_fmt(fmt) "IPv6: " fmt
- #include <linux/errno.h>
- #include <linux/types.h>
- #include <linux/net.h>
- #include <linux/route.h>
- #include <linux/netdevice.h>
- #include <linux/in6.h>
- #include <linux/init.h>
- #include <linux/list.h>
- #include <linux/slab.h>
- #include <net/ip.h>
- #include <net/ipv6.h>
- #include <net/ndisc.h>
- #include <net/addrconf.h>
- #include <net/lwtunnel.h>
- #include <net/fib_notifier.h>
- #include <net/ip6_fib.h>
- #include <net/ip6_route.h>
- static struct kmem_cache *fib6_node_kmem __read_mostly;
- struct fib6_cleaner {
- struct fib6_walker w;
- struct net *net;
- int (*func)(struct fib6_info *, void *arg);
- int sernum;
- void *arg;
- bool skip_notify;
- };
- #ifdef CONFIG_IPV6_SUBTREES
- #define FWS_INIT FWS_S
- #else
- #define FWS_INIT FWS_L
- #endif
- static struct fib6_info *fib6_find_prefix(struct net *net,
- struct fib6_table *table,
- struct fib6_node *fn);
- static struct fib6_node *fib6_repair_tree(struct net *net,
- struct fib6_table *table,
- struct fib6_node *fn);
- static int fib6_walk(struct net *net, struct fib6_walker *w);
- static int fib6_walk_continue(struct fib6_walker *w);
- /*
- * A routing update causes an increase of the serial number on the
- * affected subtree. This allows for cached routes to be asynchronously
- * tested when modifications are made to the destination cache as a
- * result of redirects, path MTU changes, etc.
- */
- static void fib6_gc_timer_cb(struct timer_list *t);
- #define FOR_WALKERS(net, w) \
- list_for_each_entry(w, &(net)->ipv6.fib6_walkers, lh)
- static void fib6_walker_link(struct net *net, struct fib6_walker *w)
- {
- write_lock_bh(&net->ipv6.fib6_walker_lock);
- list_add(&w->lh, &net->ipv6.fib6_walkers);
- write_unlock_bh(&net->ipv6.fib6_walker_lock);
- }
- static void fib6_walker_unlink(struct net *net, struct fib6_walker *w)
- {
- write_lock_bh(&net->ipv6.fib6_walker_lock);
- list_del(&w->lh);
- write_unlock_bh(&net->ipv6.fib6_walker_lock);
- }
- static int fib6_new_sernum(struct net *net)
- {
- int new, old;
- do {
- old = atomic_read(&net->ipv6.fib6_sernum);
- new = old < INT_MAX ? old + 1 : 1;
- } while (atomic_cmpxchg(&net->ipv6.fib6_sernum,
- old, new) != old);
- return new;
- }
- enum {
- FIB6_NO_SERNUM_CHANGE = 0,
- };
- void fib6_update_sernum(struct net *net, struct fib6_info *f6i)
- {
- struct fib6_node *fn;
- fn = rcu_dereference_protected(f6i->fib6_node,
- lockdep_is_held(&f6i->fib6_table->tb6_lock));
- if (fn)
- WRITE_ONCE(fn->fn_sernum, fib6_new_sernum(net));
- }
- /*
- * Auxiliary address test functions for the radix tree.
- *
- * These assume a 32bit processor (although it will work on
- * 64bit processors)
- */
- /*
- * test bit
- */
- #if defined(__LITTLE_ENDIAN)
- # define BITOP_BE32_SWIZZLE (0x1F & ~7)
- #else
- # define BITOP_BE32_SWIZZLE 0
- #endif
- static __be32 addr_bit_set(const void *token, int fn_bit)
- {
- const __be32 *addr = token;
- /*
- * Here,
- * 1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)
- * is optimized version of
- * htonl(1 << ((~fn_bit)&0x1F))
- * See include/asm-generic/bitops/le.h.
- */
- return (__force __be32)(1 << ((~fn_bit ^ BITOP_BE32_SWIZZLE) & 0x1f)) &
- addr[fn_bit >> 5];
- }
- struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh)
- {
- struct fib6_info *f6i;
- size_t sz = sizeof(*f6i);
- if (with_fib6_nh)
- sz += sizeof(struct fib6_nh);
- f6i = kzalloc(sz, gfp_flags);
- if (!f6i)
- return NULL;
- /* fib6_siblings is a union with nh_list, so this initializes both */
- INIT_LIST_HEAD(&f6i->fib6_siblings);
- refcount_set(&f6i->fib6_ref, 1);
- return f6i;
- }
- void fib6_info_destroy_rcu(struct rcu_head *head)
- {
- struct fib6_info *f6i = container_of(head, struct fib6_info, rcu);
- WARN_ON(f6i->fib6_node);
- if (f6i->nh)
- nexthop_put(f6i->nh);
- else
- fib6_nh_release(f6i->fib6_nh);
- ip_fib_metrics_put(f6i->fib6_metrics);
- kfree(f6i);
- }
- EXPORT_SYMBOL_GPL(fib6_info_destroy_rcu);
- static struct fib6_node *node_alloc(struct net *net)
- {
- struct fib6_node *fn;
- fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
- if (fn)
- net->ipv6.rt6_stats->fib_nodes++;
- return fn;
- }
- static void node_free_immediate(struct net *net, struct fib6_node *fn)
- {
- kmem_cache_free(fib6_node_kmem, fn);
- net->ipv6.rt6_stats->fib_nodes--;
- }
- static void node_free_rcu(struct rcu_head *head)
- {
- struct fib6_node *fn = container_of(head, struct fib6_node, rcu);
- kmem_cache_free(fib6_node_kmem, fn);
- }
- static void node_free(struct net *net, struct fib6_node *fn)
- {
- call_rcu(&fn->rcu, node_free_rcu);
- net->ipv6.rt6_stats->fib_nodes--;
- }
- static void fib6_free_table(struct fib6_table *table)
- {
- inetpeer_invalidate_tree(&table->tb6_peers);
- kfree(table);
- }
- static void fib6_link_table(struct net *net, struct fib6_table *tb)
- {
- unsigned int h;
- /*
- * Initialize table lock at a single place to give lockdep a key,
- * tables aren't visible prior to being linked to the list.
- */
- spin_lock_init(&tb->tb6_lock);
- h = tb->tb6_id & (FIB6_TABLE_HASHSZ - 1);
- /*
- * No protection necessary, this is the only list mutatation
- * operation, tables never disappear once they exist.
- */
- hlist_add_head_rcu(&tb->tb6_hlist, &net->ipv6.fib_table_hash[h]);
- }
- #ifdef CONFIG_IPV6_MULTIPLE_TABLES
- static struct fib6_table *fib6_alloc_table(struct net *net, u32 id)
- {
- struct fib6_table *table;
- table = kzalloc(sizeof(*table), GFP_ATOMIC);
- if (table) {
- table->tb6_id = id;
- rcu_assign_pointer(table->tb6_root.leaf,
- net->ipv6.fib6_null_entry);
- table->tb6_root.fn_flags = RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
- inet_peer_base_init(&table->tb6_peers);
- }
- return table;
- }
- struct fib6_table *fib6_new_table(struct net *net, u32 id)
- {
- struct fib6_table *tb;
- if (id == 0)
- id = RT6_TABLE_MAIN;
- tb = fib6_get_table(net, id);
- if (tb)
- return tb;
- tb = fib6_alloc_table(net, id);
- if (tb)
- fib6_link_table(net, tb);
- return tb;
- }
- EXPORT_SYMBOL_GPL(fib6_new_table);
- struct fib6_table *fib6_get_table(struct net *net, u32 id)
- {
- struct fib6_table *tb;
- struct hlist_head *head;
- unsigned int h;
- if (id == 0)
- id = RT6_TABLE_MAIN;
- h = id & (FIB6_TABLE_HASHSZ - 1);
- rcu_read_lock();
- head = &net->ipv6.fib_table_hash[h];
- hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
- if (tb->tb6_id == id) {
- rcu_read_unlock();
- return tb;
- }
- }
- rcu_read_unlock();
- return NULL;
- }
- EXPORT_SYMBOL_GPL(fib6_get_table);
- static void __net_init fib6_tables_init(struct net *net)
- {
- fib6_link_table(net, net->ipv6.fib6_main_tbl);
- fib6_link_table(net, net->ipv6.fib6_local_tbl);
- }
- #else
- struct fib6_table *fib6_new_table(struct net *net, u32 id)
- {
- return fib6_get_table(net, id);
- }
- struct fib6_table *fib6_get_table(struct net *net, u32 id)
- {
- return net->ipv6.fib6_main_tbl;
- }
- struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
- const struct sk_buff *skb,
- int flags, pol_lookup_t lookup)
- {
- struct rt6_info *rt;
- rt = pol_lookup_func(lookup,
- net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
- if (rt->dst.error == -EAGAIN) {
- ip6_rt_put_flags(rt, flags);
- rt = net->ipv6.ip6_null_entry;
- if (!(flags & RT6_LOOKUP_F_DST_NOREF))
- dst_hold(&rt->dst);
- }
- return &rt->dst;
- }
- /* called with rcu lock held; no reference taken on fib6_info */
- int fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
- struct fib6_result *res, int flags)
- {
- return fib6_table_lookup(net, net->ipv6.fib6_main_tbl, oif, fl6,
- res, flags);
- }
- static void __net_init fib6_tables_init(struct net *net)
- {
- fib6_link_table(net, net->ipv6.fib6_main_tbl);
- }
- #endif
- unsigned int fib6_tables_seq_read(struct net *net)
- {
- unsigned int h, fib_seq = 0;
- rcu_read_lock();
- for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
- struct hlist_head *head = &net->ipv6.fib_table_hash[h];
- struct fib6_table *tb;
- hlist_for_each_entry_rcu(tb, head, tb6_hlist)
- fib_seq += tb->fib_seq;
- }
- rcu_read_unlock();
- return fib_seq;
- }
- static int call_fib6_entry_notifier(struct notifier_block *nb,
- enum fib_event_type event_type,
- struct fib6_info *rt,
- struct netlink_ext_ack *extack)
- {
- struct fib6_entry_notifier_info info = {
- .info.extack = extack,
- .rt = rt,
- };
- return call_fib6_notifier(nb, event_type, &info.info);
- }
- static int call_fib6_multipath_entry_notifier(struct notifier_block *nb,
- enum fib_event_type event_type,
- struct fib6_info *rt,
- unsigned int nsiblings,
- struct netlink_ext_ack *extack)
- {
- struct fib6_entry_notifier_info info = {
- .info.extack = extack,
- .rt = rt,
- .nsiblings = nsiblings,
- };
- return call_fib6_notifier(nb, event_type, &info.info);
- }
- int call_fib6_entry_notifiers(struct net *net,
- enum fib_event_type event_type,
- struct fib6_info *rt,
- struct netlink_ext_ack *extack)
- {
- struct fib6_entry_notifier_info info = {
- .info.extack = extack,
- .rt = rt,
- };
- rt->fib6_table->fib_seq++;
- return call_fib6_notifiers(net, event_type, &info.info);
- }
- int call_fib6_multipath_entry_notifiers(struct net *net,
- enum fib_event_type event_type,
- struct fib6_info *rt,
- unsigned int nsiblings,
- struct netlink_ext_ack *extack)
- {
- struct fib6_entry_notifier_info info = {
- .info.extack = extack,
- .rt = rt,
- .nsiblings = nsiblings,
- };
- rt->fib6_table->fib_seq++;
- return call_fib6_notifiers(net, event_type, &info.info);
- }
- int call_fib6_entry_notifiers_replace(struct net *net, struct fib6_info *rt)
- {
- struct fib6_entry_notifier_info info = {
- .rt = rt,
- .nsiblings = rt->fib6_nsiblings,
- };
- rt->fib6_table->fib_seq++;
- return call_fib6_notifiers(net, FIB_EVENT_ENTRY_REPLACE, &info.info);
- }
- struct fib6_dump_arg {
- struct net *net;
- struct notifier_block *nb;
- struct netlink_ext_ack *extack;
- };
- static int fib6_rt_dump(struct fib6_info *rt, struct fib6_dump_arg *arg)
- {
- enum fib_event_type fib_event = FIB_EVENT_ENTRY_REPLACE;
- int err;
- if (!rt || rt == arg->net->ipv6.fib6_null_entry)
- return 0;
- if (rt->fib6_nsiblings)
- err = call_fib6_multipath_entry_notifier(arg->nb, fib_event,
- rt,
- rt->fib6_nsiblings,
- arg->extack);
- else
- err = call_fib6_entry_notifier(arg->nb, fib_event, rt,
- arg->extack);
- return err;
- }
- static int fib6_node_dump(struct fib6_walker *w)
- {
- int err;
- err = fib6_rt_dump(w->leaf, w->args);
- w->leaf = NULL;
- return err;
- }
- static int fib6_table_dump(struct net *net, struct fib6_table *tb,
- struct fib6_walker *w)
- {
- int err;
- w->root = &tb->tb6_root;
- spin_lock_bh(&tb->tb6_lock);
- err = fib6_walk(net, w);
- spin_unlock_bh(&tb->tb6_lock);
- return err;
- }
- /* Called with rcu_read_lock() */
- int fib6_tables_dump(struct net *net, struct notifier_block *nb,
- struct netlink_ext_ack *extack)
- {
- struct fib6_dump_arg arg;
- struct fib6_walker *w;
- unsigned int h;
- int err = 0;
- w = kzalloc(sizeof(*w), GFP_ATOMIC);
- if (!w)
- return -ENOMEM;
- w->func = fib6_node_dump;
- arg.net = net;
- arg.nb = nb;
- arg.extack = extack;
- w->args = &arg;
- for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
- struct hlist_head *head = &net->ipv6.fib_table_hash[h];
- struct fib6_table *tb;
- hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
- err = fib6_table_dump(net, tb, w);
- if (err < 0)
- goto out;
- }
- }
- out:
- kfree(w);
- return err;
- }
- static int fib6_dump_node(struct fib6_walker *w)
- {
- int res;
- struct fib6_info *rt;
- for_each_fib6_walker_rt(w) {
- res = rt6_dump_route(rt, w->args, w->skip_in_node);
- if (res >= 0) {
- /* Frame is full, suspend walking */
- w->leaf = rt;
- /* We'll restart from this node, so if some routes were
- * already dumped, skip them next time.
- */
- w->skip_in_node += res;
- return 1;
- }
- w->skip_in_node = 0;
- /* Multipath routes are dumped in one route with the
- * RTA_MULTIPATH attribute. Jump 'rt' to point to the
- * last sibling of this route (no need to dump the
- * sibling routes again)
- */
- if (rt->fib6_nsiblings)
- rt = list_last_entry(&rt->fib6_siblings,
- struct fib6_info,
- fib6_siblings);
- }
- w->leaf = NULL;
- return 0;
- }
- static void fib6_dump_end(struct netlink_callback *cb)
- {
- struct net *net = sock_net(cb->skb->sk);
- struct fib6_walker *w = (void *)cb->args[2];
- if (w) {
- if (cb->args[4]) {
- cb->args[4] = 0;
- fib6_walker_unlink(net, w);
- }
- cb->args[2] = 0;
- kfree(w);
- }
- cb->done = (void *)cb->args[3];
- cb->args[1] = 3;
- }
- static int fib6_dump_done(struct netlink_callback *cb)
- {
- fib6_dump_end(cb);
- return cb->done ? cb->done(cb) : 0;
- }
- static int fib6_dump_table(struct fib6_table *table, struct sk_buff *skb,
- struct netlink_callback *cb)
- {
- struct net *net = sock_net(skb->sk);
- struct fib6_walker *w;
- int res;
- w = (void *)cb->args[2];
- w->root = &table->tb6_root;
- if (cb->args[4] == 0) {
- w->count = 0;
- w->skip = 0;
- w->skip_in_node = 0;
- spin_lock_bh(&table->tb6_lock);
- res = fib6_walk(net, w);
- spin_unlock_bh(&table->tb6_lock);
- if (res > 0) {
- cb->args[4] = 1;
- cb->args[5] = READ_ONCE(w->root->fn_sernum);
- }
- } else {
- int sernum = READ_ONCE(w->root->fn_sernum);
- if (cb->args[5] != sernum) {
- /* Begin at the root if the tree changed */
- cb->args[5] = sernum;
- w->state = FWS_INIT;
- w->node = w->root;
- w->skip = w->count;
- w->skip_in_node = 0;
- } else
- w->skip = 0;
- spin_lock_bh(&table->tb6_lock);
- res = fib6_walk_continue(w);
- spin_unlock_bh(&table->tb6_lock);
- if (res <= 0) {
- fib6_walker_unlink(net, w);
- cb->args[4] = 0;
- }
- }
- return res;
- }
- static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
- {
- struct rt6_rtnl_dump_arg arg = { .filter.dump_exceptions = true,
- .filter.dump_routes = true };
- const struct nlmsghdr *nlh = cb->nlh;
- struct net *net = sock_net(skb->sk);
- unsigned int h, s_h;
- unsigned int e = 0, s_e;
- struct fib6_walker *w;
- struct fib6_table *tb;
- struct hlist_head *head;
- int res = 0;
- if (cb->strict_check) {
- int err;
- err = ip_valid_fib_dump_req(net, nlh, &arg.filter, cb);
- if (err < 0)
- return err;
- } else if (nlmsg_len(nlh) >= sizeof(struct rtmsg)) {
- struct rtmsg *rtm = nlmsg_data(nlh);
- if (rtm->rtm_flags & RTM_F_PREFIX)
- arg.filter.flags = RTM_F_PREFIX;
- }
- w = (void *)cb->args[2];
- if (!w) {
- /* New dump:
- *
- * 1. hook callback destructor.
- */
- cb->args[3] = (long)cb->done;
- cb->done = fib6_dump_done;
- /*
- * 2. allocate and initialize walker.
- */
- w = kzalloc(sizeof(*w), GFP_ATOMIC);
- if (!w)
- return -ENOMEM;
- w->func = fib6_dump_node;
- cb->args[2] = (long)w;
- }
- arg.skb = skb;
- arg.cb = cb;
- arg.net = net;
- w->args = &arg;
- if (arg.filter.table_id) {
- tb = fib6_get_table(net, arg.filter.table_id);
- if (!tb) {
- if (rtnl_msg_family(cb->nlh) != PF_INET6)
- goto out;
- NL_SET_ERR_MSG_MOD(cb->extack, "FIB table does not exist");
- return -ENOENT;
- }
- if (!cb->args[0]) {
- res = fib6_dump_table(tb, skb, cb);
- if (!res)
- cb->args[0] = 1;
- }
- goto out;
- }
- s_h = cb->args[0];
- s_e = cb->args[1];
- rcu_read_lock();
- for (h = s_h; h < FIB6_TABLE_HASHSZ; h++, s_e = 0) {
- e = 0;
- head = &net->ipv6.fib_table_hash[h];
- hlist_for_each_entry_rcu(tb, head, tb6_hlist) {
- if (e < s_e)
- goto next;
- res = fib6_dump_table(tb, skb, cb);
- if (res != 0)
- goto out_unlock;
- next:
- e++;
- }
- }
- out_unlock:
- rcu_read_unlock();
- cb->args[1] = e;
- cb->args[0] = h;
- out:
- res = res < 0 ? res : skb->len;
- if (res <= 0)
- fib6_dump_end(cb);
- return res;
- }
- void fib6_metric_set(struct fib6_info *f6i, int metric, u32 val)
- {
- if (!f6i)
- return;
- if (f6i->fib6_metrics == &dst_default_metrics) {
- struct dst_metrics *p = kzalloc(sizeof(*p), GFP_ATOMIC);
- if (!p)
- return;
- refcount_set(&p->refcnt, 1);
- f6i->fib6_metrics = p;
- }
- f6i->fib6_metrics->metrics[metric - 1] = val;
- }
- /*
- * Routing Table
- *
- * return the appropriate node for a routing tree "add" operation
- * by either creating and inserting or by returning an existing
- * node.
- */
- static struct fib6_node *fib6_add_1(struct net *net,
- struct fib6_table *table,
- struct fib6_node *root,
- struct in6_addr *addr, int plen,
- int offset, int allow_create,
- int replace_required,
- struct netlink_ext_ack *extack)
- {
- struct fib6_node *fn, *in, *ln;
- struct fib6_node *pn = NULL;
- struct rt6key *key;
- int bit;
- __be32 dir = 0;
- RT6_TRACE("fib6_add_1\n");
- /* insert node in tree */
- fn = root;
- do {
- struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
- lockdep_is_held(&table->tb6_lock));
- key = (struct rt6key *)((u8 *)leaf + offset);
- /*
- * Prefix match
- */
- if (plen < fn->fn_bit ||
- !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
- if (!allow_create) {
- if (replace_required) {
- NL_SET_ERR_MSG(extack,
- "Can not replace route - no match found");
- pr_warn("Can't replace route, no match found\n");
- return ERR_PTR(-ENOENT);
- }
- pr_warn("NLM_F_CREATE should be set when creating new route\n");
- }
- goto insert_above;
- }
- /*
- * Exact match ?
- */
- if (plen == fn->fn_bit) {
- /* clean up an intermediate node */
- if (!(fn->fn_flags & RTN_RTINFO)) {
- RCU_INIT_POINTER(fn->leaf, NULL);
- fib6_info_release(leaf);
- /* remove null_entry in the root node */
- } else if (fn->fn_flags & RTN_TL_ROOT &&
- rcu_access_pointer(fn->leaf) ==
- net->ipv6.fib6_null_entry) {
- RCU_INIT_POINTER(fn->leaf, NULL);
- }
- return fn;
- }
- /*
- * We have more bits to go
- */
- /* Try to walk down on tree. */
- dir = addr_bit_set(addr, fn->fn_bit);
- pn = fn;
- fn = dir ?
- rcu_dereference_protected(fn->right,
- lockdep_is_held(&table->tb6_lock)) :
- rcu_dereference_protected(fn->left,
- lockdep_is_held(&table->tb6_lock));
- } while (fn);
- if (!allow_create) {
- /* We should not create new node because
- * NLM_F_REPLACE was specified without NLM_F_CREATE
- * I assume it is safe to require NLM_F_CREATE when
- * REPLACE flag is used! Later we may want to remove the
- * check for replace_required, because according
- * to netlink specification, NLM_F_CREATE
- * MUST be specified if new route is created.
- * That would keep IPv6 consistent with IPv4
- */
- if (replace_required) {
- NL_SET_ERR_MSG(extack,
- "Can not replace route - no match found");
- pr_warn("Can't replace route, no match found\n");
- return ERR_PTR(-ENOENT);
- }
- pr_warn("NLM_F_CREATE should be set when creating new route\n");
- }
- /*
- * We walked to the bottom of tree.
- * Create new leaf node without children.
- */
- ln = node_alloc(net);
- if (!ln)
- return ERR_PTR(-ENOMEM);
- ln->fn_bit = plen;
- RCU_INIT_POINTER(ln->parent, pn);
- if (dir)
- rcu_assign_pointer(pn->right, ln);
- else
- rcu_assign_pointer(pn->left, ln);
- return ln;
- insert_above:
- /*
- * split since we don't have a common prefix anymore or
- * we have a less significant route.
- * we've to insert an intermediate node on the list
- * this new node will point to the one we need to create
- * and the current
- */
- pn = rcu_dereference_protected(fn->parent,
- lockdep_is_held(&table->tb6_lock));
- /* find 1st bit in difference between the 2 addrs.
- See comment in __ipv6_addr_diff: bit may be an invalid value,
- but if it is >= plen, the value is ignored in any case.
- */
- bit = __ipv6_addr_diff(addr, &key->addr, sizeof(*addr));
- /*
- * (intermediate)[in]
- * / \
- * (new leaf node)[ln] (old node)[fn]
- */
- if (plen > bit) {
- in = node_alloc(net);
- ln = node_alloc(net);
- if (!in || !ln) {
- if (in)
- node_free_immediate(net, in);
- if (ln)
- node_free_immediate(net, ln);
- return ERR_PTR(-ENOMEM);
- }
- /*
- * new intermediate node.
- * RTN_RTINFO will
- * be off since that an address that chooses one of
- * the branches would not match less specific routes
- * in the other branch
- */
- in->fn_bit = bit;
- RCU_INIT_POINTER(in->parent, pn);
- in->leaf = fn->leaf;
- fib6_info_hold(rcu_dereference_protected(in->leaf,
- lockdep_is_held(&table->tb6_lock)));
- /* update parent pointer */
- if (dir)
- rcu_assign_pointer(pn->right, in);
- else
- rcu_assign_pointer(pn->left, in);
- ln->fn_bit = plen;
- RCU_INIT_POINTER(ln->parent, in);
- rcu_assign_pointer(fn->parent, in);
- if (addr_bit_set(addr, bit)) {
- rcu_assign_pointer(in->right, ln);
- rcu_assign_pointer(in->left, fn);
- } else {
- rcu_assign_pointer(in->left, ln);
- rcu_assign_pointer(in->right, fn);
- }
- } else { /* plen <= bit */
- /*
- * (new leaf node)[ln]
- * / \
- * (old node)[fn] NULL
- */
- ln = node_alloc(net);
- if (!ln)
- return ERR_PTR(-ENOMEM);
- ln->fn_bit = plen;
- RCU_INIT_POINTER(ln->parent, pn);
- if (addr_bit_set(&key->addr, plen))
- RCU_INIT_POINTER(ln->right, fn);
- else
- RCU_INIT_POINTER(ln->left, fn);
- rcu_assign_pointer(fn->parent, ln);
- if (dir)
- rcu_assign_pointer(pn->right, ln);
- else
- rcu_assign_pointer(pn->left, ln);
- }
- return ln;
- }
- static void __fib6_drop_pcpu_from(struct fib6_nh *fib6_nh,
- const struct fib6_info *match,
- const struct fib6_table *table)
- {
- int cpu;
- if (!fib6_nh->rt6i_pcpu)
- return;
- /* release the reference to this fib entry from
- * all of its cached pcpu routes
- */
- for_each_possible_cpu(cpu) {
- struct rt6_info **ppcpu_rt;
- struct rt6_info *pcpu_rt;
- ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
- pcpu_rt = *ppcpu_rt;
- /* only dropping the 'from' reference if the cached route
- * is using 'match'. The cached pcpu_rt->from only changes
- * from a fib6_info to NULL (ip6_dst_destroy); it can never
- * change from one fib6_info reference to another
- */
- if (pcpu_rt && rcu_access_pointer(pcpu_rt->from) == match) {
- struct fib6_info *from;
- from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
- fib6_info_release(from);
- }
- }
- }
- struct fib6_nh_pcpu_arg {
- struct fib6_info *from;
- const struct fib6_table *table;
- };
- static int fib6_nh_drop_pcpu_from(struct fib6_nh *nh, void *_arg)
- {
- struct fib6_nh_pcpu_arg *arg = _arg;
- __fib6_drop_pcpu_from(nh, arg->from, arg->table);
- return 0;
- }
- static void fib6_drop_pcpu_from(struct fib6_info *f6i,
- const struct fib6_table *table)
- {
- /* Make sure rt6_make_pcpu_route() wont add other percpu routes
- * while we are cleaning them here.
- */
- f6i->fib6_destroying = 1;
- mb(); /* paired with the cmpxchg() in rt6_make_pcpu_route() */
- if (f6i->nh) {
- struct fib6_nh_pcpu_arg arg = {
- .from = f6i,
- .table = table
- };
- nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_drop_pcpu_from,
- &arg);
- } else {
- struct fib6_nh *fib6_nh;
- fib6_nh = f6i->fib6_nh;
- __fib6_drop_pcpu_from(fib6_nh, f6i, table);
- }
- }
- static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn,
- struct net *net)
- {
- struct fib6_table *table = rt->fib6_table;
- /* Flush all cached dst in exception table */
- rt6_flush_exceptions(rt);
- fib6_drop_pcpu_from(rt, table);
- if (rt->nh && !list_empty(&rt->nh_list))
- list_del_init(&rt->nh_list);
- if (refcount_read(&rt->fib6_ref) != 1) {
- /* This route is used as dummy address holder in some split
- * nodes. It is not leaked, but it still holds other resources,
- * which must be released in time. So, scan ascendant nodes
- * and replace dummy references to this route with references
- * to still alive ones.
- */
- while (fn) {
- struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
- lockdep_is_held(&table->tb6_lock));
- struct fib6_info *new_leaf;
- if (!(fn->fn_flags & RTN_RTINFO) && leaf == rt) {
- new_leaf = fib6_find_prefix(net, table, fn);
- fib6_info_hold(new_leaf);
- rcu_assign_pointer(fn->leaf, new_leaf);
- fib6_info_release(rt);
- }
- fn = rcu_dereference_protected(fn->parent,
- lockdep_is_held(&table->tb6_lock));
- }
- }
- }
- /*
- * Insert routing information in a node.
- */
- static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
- struct nl_info *info,
- struct netlink_ext_ack *extack)
- {
- struct fib6_info *leaf = rcu_dereference_protected(fn->leaf,
- lockdep_is_held(&rt->fib6_table->tb6_lock));
- struct fib6_info *iter = NULL;
- struct fib6_info __rcu **ins;
- struct fib6_info __rcu **fallback_ins = NULL;
- int replace = (info->nlh &&
- (info->nlh->nlmsg_flags & NLM_F_REPLACE));
- int add = (!info->nlh ||
- (info->nlh->nlmsg_flags & NLM_F_CREATE));
- int found = 0;
- bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
- bool notify_sibling_rt = false;
- u16 nlflags = NLM_F_EXCL;
- int err;
- if (info->nlh && (info->nlh->nlmsg_flags & NLM_F_APPEND))
- nlflags |= NLM_F_APPEND;
- ins = &fn->leaf;
- for (iter = leaf; iter;
- iter = rcu_dereference_protected(iter->fib6_next,
- lockdep_is_held(&rt->fib6_table->tb6_lock))) {
- /*
- * Search for duplicates
- */
- if (iter->fib6_metric == rt->fib6_metric) {
- /*
- * Same priority level
- */
- if (info->nlh &&
- (info->nlh->nlmsg_flags & NLM_F_EXCL))
- return -EEXIST;
- nlflags &= ~NLM_F_EXCL;
- if (replace) {
- if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) {
- found++;
- break;
- }
- fallback_ins = fallback_ins ?: ins;
- goto next_iter;
- }
- if (rt6_duplicate_nexthop(iter, rt)) {
- if (rt->fib6_nsiblings)
- rt->fib6_nsiblings = 0;
- if (!(iter->fib6_flags & RTF_EXPIRES))
- return -EEXIST;
- if (!(rt->fib6_flags & RTF_EXPIRES))
- fib6_clean_expires(iter);
- else
- fib6_set_expires(iter, rt->expires);
- if (rt->fib6_pmtu)
- fib6_metric_set(iter, RTAX_MTU,
- rt->fib6_pmtu);
- return -EEXIST;
- }
- /* If we have the same destination and the same metric,
- * but not the same gateway, then the route we try to
- * add is sibling to this route, increment our counter
- * of siblings, and later we will add our route to the
- * list.
- * Only static routes (which don't have flag
- * RTF_EXPIRES) are used for ECMPv6.
- *
- * To avoid long list, we only had siblings if the
- * route have a gateway.
- */
- if (rt_can_ecmp &&
- rt6_qualify_for_ecmp(iter))
- rt->fib6_nsiblings++;
- }
- if (iter->fib6_metric > rt->fib6_metric)
- break;
- next_iter:
- ins = &iter->fib6_next;
- }
- if (fallback_ins && !found) {
- /* No matching route with same ecmp-able-ness found, replace
- * first matching route
- */
- ins = fallback_ins;
- iter = rcu_dereference_protected(*ins,
- lockdep_is_held(&rt->fib6_table->tb6_lock));
- found++;
- }
- /* Reset round-robin state, if necessary */
- if (ins == &fn->leaf)
- fn->rr_ptr = NULL;
- /* Link this route to others same route. */
- if (rt->fib6_nsiblings) {
- unsigned int fib6_nsiblings;
- struct fib6_info *sibling, *temp_sibling;
- /* Find the first route that have the same metric */
- sibling = leaf;
- notify_sibling_rt = true;
- while (sibling) {
- if (sibling->fib6_metric == rt->fib6_metric &&
- rt6_qualify_for_ecmp(sibling)) {
- list_add_tail(&rt->fib6_siblings,
- &sibling->fib6_siblings);
- break;
- }
- sibling = rcu_dereference_protected(sibling->fib6_next,
- lockdep_is_held(&rt->fib6_table->tb6_lock));
- notify_sibling_rt = false;
- }
- /* For each sibling in the list, increment the counter of
- * siblings. BUG() if counters does not match, list of siblings
- * is broken!
- */
- fib6_nsiblings = 0;
- list_for_each_entry_safe(sibling, temp_sibling,
- &rt->fib6_siblings, fib6_siblings) {
- sibling->fib6_nsiblings++;
- BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings);
- fib6_nsiblings++;
- }
- BUG_ON(fib6_nsiblings != rt->fib6_nsiblings);
- rt6_multipath_rebalance(temp_sibling);
- }
- /*
- * insert node
- */
- if (!replace) {
- if (!add)
- pr_warn("NLM_F_CREATE should be set when creating new route\n");
- add:
- nlflags |= NLM_F_CREATE;
- /* The route should only be notified if it is the first
- * route in the node or if it is added as a sibling
- * route to the first route in the node.
- */
- if (!info->skip_notify_kernel &&
- (notify_sibling_rt || ins == &fn->leaf)) {
- enum fib_event_type fib_event;
- if (notify_sibling_rt)
- fib_event = FIB_EVENT_ENTRY_APPEND;
- else
- fib_event = FIB_EVENT_ENTRY_REPLACE;
- err = call_fib6_entry_notifiers(info->nl_net,
- fib_event, rt,
- extack);
- if (err) {
- struct fib6_info *sibling, *next_sibling;
- /* If the route has siblings, then it first
- * needs to be unlinked from them.
- */
- if (!rt->fib6_nsiblings)
- return err;
- list_for_each_entry_safe(sibling, next_sibling,
- &rt->fib6_siblings,
- fib6_siblings)
- sibling->fib6_nsiblings--;
- rt->fib6_nsiblings = 0;
- list_del_init(&rt->fib6_siblings);
- rt6_multipath_rebalance(next_sibling);
- return err;
- }
- }
- rcu_assign_pointer(rt->fib6_next, iter);
- fib6_info_hold(rt);
- rcu_assign_pointer(rt->fib6_node, fn);
- rcu_assign_pointer(*ins, rt);
- if (!info->skip_notify)
- inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
- info->nl_net->ipv6.rt6_stats->fib_rt_entries++;
- if (!(fn->fn_flags & RTN_RTINFO)) {
- info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
- fn->fn_flags |= RTN_RTINFO;
- }
- } else {
- int nsiblings;
- if (!found) {
- if (add)
- goto add;
- pr_warn("NLM_F_REPLACE set, but no existing node found!\n");
- return -ENOENT;
- }
- if (!info->skip_notify_kernel && ins == &fn->leaf) {
- err = call_fib6_entry_notifiers(info->nl_net,
- FIB_EVENT_ENTRY_REPLACE,
- rt, extack);
- if (err)
- return err;
- }
- fib6_info_hold(rt);
- rcu_assign_pointer(rt->fib6_node, fn);
- rt->fib6_next = iter->fib6_next;
- rcu_assign_pointer(*ins, rt);
- if (!info->skip_notify)
- inet6_rt_notify(RTM_NEWROUTE, rt, info, NLM_F_REPLACE);
- if (!(fn->fn_flags & RTN_RTINFO)) {
- info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
- fn->fn_flags |= RTN_RTINFO;
- }
- nsiblings = iter->fib6_nsiblings;
- iter->fib6_node = NULL;
- fib6_purge_rt(iter, fn, info->nl_net);
- if (rcu_access_pointer(fn->rr_ptr) == iter)
- fn->rr_ptr = NULL;
- fib6_info_release(iter);
- if (nsiblings) {
- /* Replacing an ECMP route, remove all siblings */
- ins = &rt->fib6_next;
- iter = rcu_dereference_protected(*ins,
- lockdep_is_held(&rt->fib6_table->tb6_lock));
- while (iter) {
- if (iter->fib6_metric > rt->fib6_metric)
- break;
- if (rt6_qualify_for_ecmp(iter)) {
- *ins = iter->fib6_next;
- iter->fib6_node = NULL;
- fib6_purge_rt(iter, fn, info->nl_net);
- if (rcu_access_pointer(fn->rr_ptr) == iter)
- fn->rr_ptr = NULL;
- fib6_info_release(iter);
- nsiblings--;
- info->nl_net->ipv6.rt6_stats->fib_rt_entries--;
- } else {
- ins = &iter->fib6_next;
- }
- iter = rcu_dereference_protected(*ins,
- lockdep_is_held(&rt->fib6_table->tb6_lock));
- }
- WARN_ON(nsiblings != 0);
- }
- }
- return 0;
- }
- static void fib6_start_gc(struct net *net, struct fib6_info *rt)
- {
- if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
- (rt->fib6_flags & RTF_EXPIRES))
- mod_timer(&net->ipv6.ip6_fib_timer,
- jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
- }
- void fib6_force_start_gc(struct net *net)
- {
- if (!timer_pending(&net->ipv6.ip6_fib_timer))
- mod_timer(&net->ipv6.ip6_fib_timer,
- jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
- }
- static void __fib6_update_sernum_upto_root(struct fib6_info *rt,
- int sernum)
- {
- struct fib6_node *fn = rcu_dereference_protected(rt->fib6_node,
- lockdep_is_held(&rt->fib6_table->tb6_lock));
- /* paired with smp_rmb() in rt6_get_cookie_safe() */
- smp_wmb();
- while (fn) {
- WRITE_ONCE(fn->fn_sernum, sernum);
- fn = rcu_dereference_protected(fn->parent,
- lockdep_is_held(&rt->fib6_table->tb6_lock));
- }
- }
- void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt)
- {
- __fib6_update_sernum_upto_root(rt, fib6_new_sernum(net));
- }
- /* allow ipv4 to update sernum via ipv6_stub */
- void fib6_update_sernum_stub(struct net *net, struct fib6_info *f6i)
- {
- spin_lock_bh(&f6i->fib6_table->tb6_lock);
- fib6_update_sernum_upto_root(net, f6i);
- spin_unlock_bh(&f6i->fib6_table->tb6_lock);
- }
- /*
- * Add routing information to the routing tree.
- * <destination addr>/<source addr>
- * with source addr info in sub-trees
- * Need to own table->tb6_lock
- */
- int fib6_add(struct fib6_node *root, struct fib6_info *rt,
- struct nl_info *info, struct netlink_ext_ack *extack)
- {
- struct fib6_table *table = rt->fib6_table;
- struct fib6_node *fn, *pn = NULL;
- int err = -ENOMEM;
- int allow_create = 1;
- int replace_required = 0;
- if (info->nlh) {
- if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
- allow_create = 0;
- if (info->nlh->nlmsg_flags & NLM_F_REPLACE)
- replace_required = 1;
- }
- if (!allow_create && !replace_required)
- pr_warn("RTM_NEWROUTE with no NLM_F_CREATE or NLM_F_REPLACE\n");
- fn = fib6_add_1(info->nl_net, table, root,
- &rt->fib6_dst.addr, rt->fib6_dst.plen,
- offsetof(struct fib6_info, fib6_dst), allow_create,
- replace_required, extack);
- if (IS_ERR(fn)) {
- err = PTR_ERR(fn);
- fn = NULL;
- goto out;
- }
- pn = fn;
- #ifdef CONFIG_IPV6_SUBTREES
- if (rt->fib6_src.plen) {
- struct fib6_node *sn;
- if (!rcu_access_pointer(fn->subtree)) {
- struct fib6_node *sfn;
- /*
- * Create subtree.
- *
- * fn[main tree]
- * |
- * sfn[subtree root]
- * \
- * sn[new leaf node]
- */
- /* Create subtree root node */
- sfn = node_alloc(info->nl_net);
- if (!sfn)
- goto failure;
- fib6_info_hold(info->nl_net->ipv6.fib6_null_entry);
- rcu_assign_pointer(sfn->leaf,
- info->nl_net->ipv6.fib6_null_entry);
- sfn->fn_flags = RTN_ROOT;
- /* Now add the first leaf node to new subtree */
- sn = fib6_add_1(info->nl_net, table, sfn,
- &rt->fib6_src.addr, rt->fib6_src.plen,
- offsetof(struct fib6_info, fib6_src),
- allow_create, replace_required, extack);
- if (IS_ERR(sn)) {
- /* If it is failed, discard just allocated
- root, and then (in failure) stale node
- in main tree.
- */
- node_free_immediate(info->nl_net, sfn);
- err = PTR_ERR(sn);
- goto failure;
- }
- /* Now link new subtree to main tree */
- rcu_assign_pointer(sfn->parent, fn);
- rcu_assign_pointer(fn->subtree, sfn);
- } else {
- sn = fib6_add_1(info->nl_net, table, FIB6_SUBTREE(fn),
- &rt->fib6_src.addr, rt->fib6_src.plen,
- offsetof(struct fib6_info, fib6_src),
- allow_create, replace_required, extack);
- if (IS_ERR(sn)) {
- err = PTR_ERR(sn);
- goto failure;
- }
- }
- if (!rcu_access_pointer(fn->leaf)) {
- if (fn->fn_flags & RTN_TL_ROOT) {
- /* put back null_entry for root node */
- rcu_assign_pointer(fn->leaf,
- info->nl_net->ipv6.fib6_null_entry);
- } else {
- fib6_info_hold(rt);
- rcu_assign_pointer(fn->leaf, rt);
- }
- }
- fn = sn;
- }
- #endif
- err = fib6_add_rt2node(fn, rt, info, extack);
- if (!err) {
- if (rt->nh)
- list_add(&rt->nh_list, &rt->nh->f6i_list);
- __fib6_update_sernum_upto_root(rt, fib6_new_sernum(info->nl_net));
- fib6_start_gc(info->nl_net, rt);
- }
- out:
- if (err) {
- #ifdef CONFIG_IPV6_SUBTREES
- /*
- * If fib6_add_1 has cleared the old leaf pointer in the
- * super-tree leaf node we have to find a new one for it.
- */
- if (pn != fn) {
- struct fib6_info *pn_leaf =
- rcu_dereference_protected(pn->leaf,
- lockdep_is_held(&table->tb6_lock));
- if (pn_leaf == rt) {
- pn_leaf = NULL;
- RCU_INIT_POINTER(pn->leaf, NULL);
- fib6_info_release(rt);
- }
- if (!pn_leaf && !(pn->fn_flags & RTN_RTINFO)) {
- pn_leaf = fib6_find_prefix(info->nl_net, table,
- pn);
- #if RT6_DEBUG >= 2
- if (!pn_leaf) {
- WARN_ON(!pn_leaf);
- pn_leaf =
- info->nl_net->ipv6.fib6_null_entry;
- }
- #endif
- fib6_info_hold(pn_leaf);
- rcu_assign_pointer(pn->leaf, pn_leaf);
- }
- }
- #endif
- goto failure;
- } else if (fib6_requires_src(rt)) {
- fib6_routes_require_src_inc(info->nl_net);
- }
- return err;
- failure:
- /* fn->leaf could be NULL and fib6_repair_tree() needs to be called if:
- * 1. fn is an intermediate node and we failed to add the new
- * route to it in both subtree creation failure and fib6_add_rt2node()
- * failure case.
- * 2. fn is the root node in the table and we fail to add the first
- * default route to it.
- */
- if (fn &&
- (!(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)) ||
- (fn->fn_flags & RTN_TL_ROOT &&
- !rcu_access_pointer(fn->leaf))))
- fib6_repair_tree(info->nl_net, table, fn);
- return err;
- }
- /*
- * Routing tree lookup
- *
- */
- struct lookup_args {
- int offset; /* key offset on fib6_info */
- const struct in6_addr *addr; /* search key */
- };
- static struct fib6_node *fib6_node_lookup_1(struct fib6_node *root,
- struct lookup_args *args)
- {
- struct fib6_node *fn;
- __be32 dir;
- if (unlikely(args->offset == 0))
- return NULL;
- /*
- * Descend on a tree
- */
- fn = root;
- for (;;) {
- struct fib6_node *next;
- dir = addr_bit_set(args->addr, fn->fn_bit);
- next = dir ? rcu_dereference(fn->right) :
- rcu_dereference(fn->left);
- if (next) {
- fn = next;
- continue;
- }
- break;
- }
- while (fn) {
- struct fib6_node *subtree = FIB6_SUBTREE(fn);
- if (subtree || fn->fn_flags & RTN_RTINFO) {
- struct fib6_info *leaf = rcu_dereference(fn->leaf);
- struct rt6key *key;
- if (!leaf)
- goto backtrack;
- key = (struct rt6key *) ((u8 *)leaf + args->offset);
- if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
- #ifdef CONFIG_IPV6_SUBTREES
- if (subtree) {
- struct fib6_node *sfn;
- sfn = fib6_node_lookup_1(subtree,
- args + 1);
- if (!sfn)
- goto backtrack;
- fn = sfn;
- }
- #endif
- if (fn->fn_flags & RTN_RTINFO)
- return fn;
- }
- }
- backtrack:
- if (fn->fn_flags & RTN_ROOT)
- break;
- fn = rcu_dereference(fn->parent);
- }
- return NULL;
- }
- /* called with rcu_read_lock() held
- */
- struct fib6_node *fib6_node_lookup(struct fib6_node *root,
- const struct in6_addr *daddr,
- const struct in6_addr *saddr)
- {
- struct fib6_node *fn;
- struct lookup_args args[] = {
- {
- .offset = offsetof(struct fib6_info, fib6_dst),
- .addr = daddr,
- },
- #ifdef CONFIG_IPV6_SUBTREES
- {
- .offset = offsetof(struct fib6_info, fib6_src),
- .addr = saddr,
- },
- #endif
- {
- .offset = 0, /* sentinel */
- }
- };
- fn = fib6_node_lookup_1(root, daddr ? args : args + 1);
- if (!fn || fn->fn_flags & RTN_TL_ROOT)
- fn = root;
- return fn;
- }
- /*
- * Get node with specified destination prefix (and source prefix,
- * if subtrees are used)
- * exact_match == true means we try to find fn with exact match of
- * the passed in prefix addr
- * exact_match == false means we try to find fn with longest prefix
- * match of the passed in prefix addr. This is useful for finding fn
- * for cached route as it will be stored in the exception table under
- * the node with longest prefix length.
- */
- static struct fib6_node *fib6_locate_1(struct fib6_node *root,
- const struct in6_addr *addr,
- int plen, int offset,
- bool exact_match)
- {
- struct fib6_node *fn, *prev = NULL;
- for (fn = root; fn ; ) {
- struct fib6_info *leaf = rcu_dereference(fn->leaf);
- struct rt6key *key;
- /* This node is being deleted */
- if (!leaf) {
- if (plen <= fn->fn_bit)
- goto out;
- else
- goto next;
- }
- key = (struct rt6key *)((u8 *)leaf + offset);
- /*
- * Prefix match
- */
- if (plen < fn->fn_bit ||
- !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
- goto out;
- if (plen == fn->fn_bit)
- return fn;
- if (fn->fn_flags & RTN_RTINFO)
- prev = fn;
- next:
- /*
- * We have more bits to go
- */
- if (addr_bit_set(addr, fn->fn_bit))
- fn = rcu_dereference(fn->right);
- else
- fn = rcu_dereference(fn->left);
- }
- out:
- if (exact_match)
- return NULL;
- else
- return prev;
- }
- struct fib6_node *fib6_locate(struct fib6_node *root,
- const struct in6_addr *daddr, int dst_len,
- const struct in6_addr *saddr, int src_len,
- bool exact_match)
- {
- struct fib6_node *fn;
- fn = fib6_locate_1(root, daddr, dst_len,
- offsetof(struct fib6_info, fib6_dst),
- exact_match);
- #ifdef CONFIG_IPV6_SUBTREES
- if (src_len) {
- WARN_ON(saddr == NULL);
- if (fn) {
- struct fib6_node *subtree = FIB6_SUBTREE(fn);
- if (subtree) {
- fn = fib6_locate_1(subtree, saddr, src_len,
- offsetof(struct fib6_info, fib6_src),
- exact_match);
- }
- }
- }
- #endif
- if (fn && fn->fn_flags & RTN_RTINFO)
- return fn;
- return NULL;
- }
- /*
- * Deletion
- *
- */
- static struct fib6_info *fib6_find_prefix(struct net *net,
- struct fib6_table *table,
- struct fib6_node *fn)
- {
- struct fib6_node *child_left, *child_right;
- if (fn->fn_flags & RTN_ROOT)
- return net->ipv6.fib6_null_entry;
- while (fn) {
- child_left = rcu_dereference_protected(fn->left,
- lockdep_is_held(&table->tb6_lock));
- child_right = rcu_dereference_protected(fn->right,
- lockdep_is_held(&table->tb6_lock));
- if (child_left)
- return rcu_dereference_protected(child_left->leaf,
- lockdep_is_held(&table->tb6_lock));
- if (child_right)
- return rcu_dereference_protected(child_right->leaf,
- lockdep_is_held(&table->tb6_lock));
- fn = FIB6_SUBTREE(fn);
- }
- return NULL;
- }
- /*
- * Called to trim the tree of intermediate nodes when possible. "fn"
- * is the node we want to try and remove.
- * Need to own table->tb6_lock
- */
- static struct fib6_node *fib6_repair_tree(struct net *net,
- struct fib6_table *table,
- struct fib6_node *fn)
- {
- int children;
- int nstate;
- struct fib6_node *child;
- struct fib6_walker *w;
- int iter = 0;
- /* Set fn->leaf to null_entry for root node. */
- if (fn->fn_flags & RTN_TL_ROOT) {
- rcu_assign_pointer(fn->leaf, net->ipv6.fib6_null_entry);
- return fn;
- }
- for (;;) {
- struct fib6_node *fn_r = rcu_dereference_protected(fn->right,
- lockdep_is_held(&table->tb6_lock));
- struct fib6_node *fn_l = rcu_dereference_protected(fn->left,
- lockdep_is_held(&table->tb6_lock));
- struct fib6_node *pn = rcu_dereference_protected(fn->parent,
- lockdep_is_held(&table->tb6_lock));
- struct fib6_node *pn_r = rcu_dereference_protected(pn->right,
- lockdep_is_held(&table->tb6_lock));
- struct fib6_node *pn_l = rcu_dereference_protected(pn->left,
- lockdep_is_held(&table->tb6_lock));
- struct fib6_info *fn_leaf = rcu_dereference_protected(fn->leaf,
- lockdep_is_held(&table->tb6_lock));
- struct fib6_info *pn_leaf = rcu_dereference_protected(pn->leaf,
- lockdep_is_held(&table->tb6_lock));
- struct fib6_info *new_fn_leaf;
- RT6_TRACE("fixing tree: plen=%d iter=%d\n", fn->fn_bit, iter);
- iter++;
- WARN_ON(fn->fn_flags & RTN_RTINFO);
- WARN_ON(fn->fn_flags & RTN_TL_ROOT);
- WARN_ON(fn_leaf);
- children = 0;
- child = NULL;
- if (fn_r) {
- child = fn_r;
- children |= 1;
- }
- if (fn_l) {
- child = fn_l;
- children |= 2;
- }
- if (children == 3 || FIB6_SUBTREE(fn)
- #ifdef CONFIG_IPV6_SUBTREES
- /* Subtree root (i.e. fn) may have one child */
- || (children && fn->fn_flags & RTN_ROOT)
- #endif
- ) {
- new_fn_leaf = fib6_find_prefix(net, table, fn);
- #if RT6_DEBUG >= 2
- if (!new_fn_leaf) {
- WARN_ON(!new_fn_leaf);
- new_fn_leaf = net->ipv6.fib6_null_entry;
- }
- #endif
- fib6_info_hold(new_fn_leaf);
- rcu_assign_pointer(fn->leaf, new_fn_leaf);
- return pn;
- }
- #ifdef CONFIG_IPV6_SUBTREES
- if (FIB6_SUBTREE(pn) == fn) {
- WARN_ON(!(fn->fn_flags & RTN_ROOT));
- RCU_INIT_POINTER(pn->subtree, NULL);
- nstate = FWS_L;
- } else {
- WARN_ON(fn->fn_flags & RTN_ROOT);
- #endif
- if (pn_r == fn)
- rcu_assign_pointer(pn->right, child);
- else if (pn_l == fn)
- rcu_assign_pointer(pn->left, child);
- #if RT6_DEBUG >= 2
- else
- WARN_ON(1);
- #endif
- if (child)
- rcu_assign_pointer(child->parent, pn);
- nstate = FWS_R;
- #ifdef CONFIG_IPV6_SUBTREES
- }
- #endif
- read_lock(&net->ipv6.fib6_walker_lock);
- FOR_WALKERS(net, w) {
- if (!child) {
- if (w->node == fn) {
- RT6_TRACE("W %p adjusted by delnode 1, s=%d/%d\n", w, w->state, nstate);
- w->node = pn;
- w->state = nstate;
- }
- } else {
- if (w->node == fn) {
- w->node = child;
- if (children&2) {
- RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
- w->state = w->state >= FWS_R ? FWS_U : FWS_INIT;
- } else {
- RT6_TRACE("W %p adjusted by delnode 2, s=%d\n", w, w->state);
- w->state = w->state >= FWS_C ? FWS_U : FWS_INIT;
- }
- }
- }
- }
- read_unlock(&net->ipv6.fib6_walker_lock);
- node_free(net, fn);
- if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
- return pn;
- RCU_INIT_POINTER(pn->leaf, NULL);
- fib6_info_release(pn_leaf);
- fn = pn;
- }
- }
- static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
- struct fib6_info __rcu **rtp, struct nl_info *info)
- {
- struct fib6_info *leaf, *replace_rt = NULL;
- struct fib6_walker *w;
- struct fib6_info *rt = rcu_dereference_protected(*rtp,
- lockdep_is_held(&table->tb6_lock));
- struct net *net = info->nl_net;
- bool notify_del = false;
- RT6_TRACE("fib6_del_route\n");
- /* If the deleted route is the first in the node and it is not part of
- * a multipath route, then we need to replace it with the next route
- * in the node, if exists.
- */
- leaf = rcu_dereference_protected(fn->leaf,
- lockdep_is_held(&table->tb6_lock));
- if (leaf == rt && !rt->fib6_nsiblings) {
- if (rcu_access_pointer(rt->fib6_next))
- replace_rt = rcu_dereference_protected(rt->fib6_next,
- lockdep_is_held(&table->tb6_lock));
- else
- notify_del = true;
- }
- /* Unlink it */
- *rtp = rt->fib6_next;
- rt->fib6_node = NULL;
- net->ipv6.rt6_stats->fib_rt_entries--;
- net->ipv6.rt6_stats->fib_discarded_routes++;
- /* Reset round-robin state, if necessary */
- if (rcu_access_pointer(fn->rr_ptr) == rt)
- fn->rr_ptr = NULL;
- /* Remove this entry from other siblings */
- if (rt->fib6_nsiblings) {
- struct fib6_info *sibling, *next_sibling;
- /* The route is deleted from a multipath route. If this
- * multipath route is the first route in the node, then we need
- * to emit a delete notification. Otherwise, we need to skip
- * the notification.
- */
- if (rt->fib6_metric == leaf->fib6_metric &&
- rt6_qualify_for_ecmp(leaf))
- notify_del = true;
- list_for_each_entry_safe(sibling, next_sibling,
- &rt->fib6_siblings, fib6_siblings)
- sibling->fib6_nsiblings--;
- rt->fib6_nsiblings = 0;
- list_del_init(&rt->fib6_siblings);
- rt6_multipath_rebalance(next_sibling);
- }
- /* Adjust walkers */
- read_lock(&net->ipv6.fib6_walker_lock);
- FOR_WALKERS(net, w) {
- if (w->state == FWS_C && w->leaf == rt) {
- RT6_TRACE("walker %p adjusted by delroute\n", w);
- w->leaf = rcu_dereference_protected(rt->fib6_next,
- lockdep_is_held(&table->tb6_lock));
- if (!w->leaf)
- w->state = FWS_U;
- }
- }
- read_unlock(&net->ipv6.fib6_walker_lock);
- /* If it was last route, call fib6_repair_tree() to:
- * 1. For root node, put back null_entry as how the table was created.
- * 2. For other nodes, expunge its radix tree node.
- */
- if (!rcu_access_pointer(fn->leaf)) {
- if (!(fn->fn_flags & RTN_TL_ROOT)) {
- fn->fn_flags &= ~RTN_RTINFO;
- net->ipv6.rt6_stats->fib_route_nodes--;
- }
- fn = fib6_repair_tree(net, table, fn);
- }
- fib6_purge_rt(rt, fn, net);
- if (!info->skip_notify_kernel) {
- if (notify_del)
- call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL,
- rt, NULL);
- else if (replace_rt)
- call_fib6_entry_notifiers_replace(net, replace_rt);
- }
- if (!info->skip_notify)
- inet6_rt_notify(RTM_DELROUTE, rt, info, 0);
- fib6_info_release(rt);
- }
- /* Need to own table->tb6_lock */
- int fib6_del(struct fib6_info *rt, struct nl_info *info)
- {
- struct net *net = info->nl_net;
- struct fib6_info __rcu **rtp;
- struct fib6_info __rcu **rtp_next;
- struct fib6_table *table;
- struct fib6_node *fn;
- if (rt == net->ipv6.fib6_null_entry)
- return -ENOENT;
- table = rt->fib6_table;
- fn = rcu_dereference_protected(rt->fib6_node,
- lockdep_is_held(&table->tb6_lock));
- if (!fn)
- return -ENOENT;
- WARN_ON(!(fn->fn_flags & RTN_RTINFO));
- /*
- * Walk the leaf entries looking for ourself
- */
- for (rtp = &fn->leaf; *rtp; rtp = rtp_next) {
- struct fib6_info *cur = rcu_dereference_protected(*rtp,
- lockdep_is_held(&table->tb6_lock));
- if (rt == cur) {
- if (fib6_requires_src(cur))
- fib6_routes_require_src_dec(info->nl_net);
- fib6_del_route(table, fn, rtp, info);
- return 0;
- }
- rtp_next = &cur->fib6_next;
- }
- return -ENOENT;
- }
- /*
- * Tree traversal function.
- *
- * Certainly, it is not interrupt safe.
- * However, it is internally reenterable wrt itself and fib6_add/fib6_del.
- * It means, that we can modify tree during walking
- * and use this function for garbage collection, clone pruning,
- * cleaning tree when a device goes down etc. etc.
- *
- * It guarantees that every node will be traversed,
- * and that it will be traversed only once.
- *
- * Callback function w->func may return:
- * 0 -> continue walking.
- * positive value -> walking is suspended (used by tree dumps,
- * and probably by gc, if it will be split to several slices)
- * negative value -> terminate walking.
- *
- * The function itself returns:
- * 0 -> walk is complete.
- * >0 -> walk is incomplete (i.e. suspended)
- * <0 -> walk is terminated by an error.
- *
- * This function is called with tb6_lock held.
- */
- static int fib6_walk_continue(struct fib6_walker *w)
- {
- struct fib6_node *fn, *pn, *left, *right;
- /* w->root should always be table->tb6_root */
- WARN_ON_ONCE(!(w->root->fn_flags & RTN_TL_ROOT));
- for (;;) {
- fn = w->node;
- if (!fn)
- return 0;
- switch (w->state) {
- #ifdef CONFIG_IPV6_SUBTREES
- case FWS_S:
- if (FIB6_SUBTREE(fn)) {
- w->node = FIB6_SUBTREE(fn);
- continue;
- }
- w->state = FWS_L;
- fallthrough;
- #endif
- case FWS_L:
- left = rcu_dereference_protected(fn->left, 1);
- if (left) {
- w->node = left;
- w->state = FWS_INIT;
- continue;
- }
- w->state = FWS_R;
- fallthrough;
- case FWS_R:
- right = rcu_dereference_protected(fn->right, 1);
- if (right) {
- w->node = right;
- w->state = FWS_INIT;
- continue;
- }
- w->state = FWS_C;
- w->leaf = rcu_dereference_protected(fn->leaf, 1);
- fallthrough;
- case FWS_C:
- if (w->leaf && fn->fn_flags & RTN_RTINFO) {
- int err;
- if (w->skip) {
- w->skip--;
- goto skip;
- }
- err = w->func(w);
- if (err)
- return err;
- w->count++;
- continue;
- }
- skip:
- w->state = FWS_U;
- fallthrough;
- case FWS_U:
- if (fn == w->root)
- return 0;
- pn = rcu_dereference_protected(fn->parent, 1);
- left = rcu_dereference_protected(pn->left, 1);
- right = rcu_dereference_protected(pn->right, 1);
- w->node = pn;
- #ifdef CONFIG_IPV6_SUBTREES
- if (FIB6_SUBTREE(pn) == fn) {
- WARN_ON(!(fn->fn_flags & RTN_ROOT));
- w->state = FWS_L;
- continue;
- }
- #endif
- if (left == fn) {
- w->state = FWS_R;
- continue;
- }
- if (right == fn) {
- w->state = FWS_C;
- w->leaf = rcu_dereference_protected(w->node->leaf, 1);
- continue;
- }
- #if RT6_DEBUG >= 2
- WARN_ON(1);
- #endif
- }
- }
- }
- static int fib6_walk(struct net *net, struct fib6_walker *w)
- {
- int res;
- w->state = FWS_INIT;
- w->node = w->root;
- fib6_walker_link(net, w);
- res = fib6_walk_continue(w);
- if (res <= 0)
- fib6_walker_unlink(net, w);
- return res;
- }
- static int fib6_clean_node(struct fib6_walker *w)
- {
- int res;
- struct fib6_info *rt;
- struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w);
- struct nl_info info = {
- .nl_net = c->net,
- .skip_notify = c->skip_notify,
- };
- if (c->sernum != FIB6_NO_SERNUM_CHANGE &&
- READ_ONCE(w->node->fn_sernum) != c->sernum)
- WRITE_ONCE(w->node->fn_sernum, c->sernum);
- if (!c->func) {
- WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE);
- w->leaf = NULL;
- return 0;
- }
- for_each_fib6_walker_rt(w) {
- res = c->func(rt, c->arg);
- if (res == -1) {
- w->leaf = rt;
- res = fib6_del(rt, &info);
- if (res) {
- #if RT6_DEBUG >= 2
- pr_debug("%s: del failed: rt=%p@%p err=%d\n",
- __func__, rt,
- rcu_access_pointer(rt->fib6_node),
- res);
- #endif
- continue;
- }
- return 0;
- } else if (res == -2) {
- if (WARN_ON(!rt->fib6_nsiblings))
- continue;
- rt = list_last_entry(&rt->fib6_siblings,
- struct fib6_info, fib6_siblings);
- continue;
- }
- WARN_ON(res != 0);
- }
- w->leaf = rt;
- return 0;
- }
- /*
- * Convenient frontend to tree walker.
- *
- * func is called on each route.
- * It may return -2 -> skip multipath route.
- * -1 -> delete this route.
- * 0 -> continue walking
- */
- static void fib6_clean_tree(struct net *net, struct fib6_node *root,
- int (*func)(struct fib6_info *, void *arg),
- int sernum, void *arg, bool skip_notify)
- {
- struct fib6_cleaner c;
- c.w.root = root;
- c.w.func = fib6_clean_node;
- c.w.count = 0;
- c.w.skip = 0;
- c.w.skip_in_node = 0;
- c.func = func;
- c.sernum = sernum;
- c.arg = arg;
- c.net = net;
- c.skip_notify = skip_notify;
- fib6_walk(net, &c.w);
- }
- static void __fib6_clean_all(struct net *net,
- int (*func)(struct fib6_info *, void *),
- int sernum, void *arg, bool skip_notify)
- {
- struct fib6_table *table;
- struct hlist_head *head;
- unsigned int h;
- rcu_read_lock();
- for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
- head = &net->ipv6.fib_table_hash[h];
- hlist_for_each_entry_rcu(table, head, tb6_hlist) {
- spin_lock_bh(&table->tb6_lock);
- fib6_clean_tree(net, &table->tb6_root,
- func, sernum, arg, skip_notify);
- spin_unlock_bh(&table->tb6_lock);
- }
- }
- rcu_read_unlock();
- }
- void fib6_clean_all(struct net *net, int (*func)(struct fib6_info *, void *),
- void *arg)
- {
- __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, false);
- }
- void fib6_clean_all_skip_notify(struct net *net,
- int (*func)(struct fib6_info *, void *),
- void *arg)
- {
- __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg, true);
- }
- static void fib6_flush_trees(struct net *net)
- {
- int new_sernum = fib6_new_sernum(net);
- __fib6_clean_all(net, NULL, new_sernum, NULL, false);
- }
- /*
- * Garbage collection
- */
- static int fib6_age(struct fib6_info *rt, void *arg)
- {
- struct fib6_gc_args *gc_args = arg;
- unsigned long now = jiffies;
- /*
- * check addrconf expiration here.
- * Routes are expired even if they are in use.
- */
- if (rt->fib6_flags & RTF_EXPIRES && rt->expires) {
- if (time_after(now, rt->expires)) {
- RT6_TRACE("expiring %p\n", rt);
- return -1;
- }
- gc_args->more++;
- }
- /* Also age clones in the exception table.
- * Note, that clones are aged out
- * only if they are not in use now.
- */
- rt6_age_exceptions(rt, gc_args, now);
- return 0;
- }
- void fib6_run_gc(unsigned long expires, struct net *net, bool force)
- {
- struct fib6_gc_args gc_args;
- unsigned long now;
- if (force) {
- spin_lock_bh(&net->ipv6.fib6_gc_lock);
- } else if (!spin_trylock_bh(&net->ipv6.fib6_gc_lock)) {
- mod_timer(&net->ipv6.ip6_fib_timer, jiffies + HZ);
- return;
- }
- gc_args.timeout = expires ? (int)expires :
- net->ipv6.sysctl.ip6_rt_gc_interval;
- gc_args.more = 0;
- fib6_clean_all(net, fib6_age, &gc_args);
- now = jiffies;
- net->ipv6.ip6_rt_last_gc = now;
- if (gc_args.more)
- mod_timer(&net->ipv6.ip6_fib_timer,
- round_jiffies(now
- + net->ipv6.sysctl.ip6_rt_gc_interval));
- else
- del_timer(&net->ipv6.ip6_fib_timer);
- spin_unlock_bh(&net->ipv6.fib6_gc_lock);
- }
- static void fib6_gc_timer_cb(struct timer_list *t)
- {
- struct net *arg = from_timer(arg, t, ipv6.ip6_fib_timer);
- fib6_run_gc(0, arg, true);
- }
- static int __net_init fib6_net_init(struct net *net)
- {
- size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
- int err;
- err = fib6_notifier_init(net);
- if (err)
- return err;
- spin_lock_init(&net->ipv6.fib6_gc_lock);
- rwlock_init(&net->ipv6.fib6_walker_lock);
- INIT_LIST_HEAD(&net->ipv6.fib6_walkers);
- timer_setup(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, 0);
- net->ipv6.rt6_stats = kzalloc(sizeof(*net->ipv6.rt6_stats), GFP_KERNEL);
- if (!net->ipv6.rt6_stats)
- goto out_timer;
- /* Avoid false sharing : Use at least a full cache line */
- size = max_t(size_t, size, L1_CACHE_BYTES);
- net->ipv6.fib_table_hash = kzalloc(size, GFP_KERNEL);
- if (!net->ipv6.fib_table_hash)
- goto out_rt6_stats;
- net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl),
- GFP_KERNEL);
- if (!net->ipv6.fib6_main_tbl)
- goto out_fib_table_hash;
- net->ipv6.fib6_main_tbl->tb6_id = RT6_TABLE_MAIN;
- rcu_assign_pointer(net->ipv6.fib6_main_tbl->tb6_root.leaf,
- net->ipv6.fib6_null_entry);
- net->ipv6.fib6_main_tbl->tb6_root.fn_flags =
- RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
- inet_peer_base_init(&net->ipv6.fib6_main_tbl->tb6_peers);
- #ifdef CONFIG_IPV6_MULTIPLE_TABLES
- net->ipv6.fib6_local_tbl = kzalloc(sizeof(*net->ipv6.fib6_local_tbl),
- GFP_KERNEL);
- if (!net->ipv6.fib6_local_tbl)
- goto out_fib6_main_tbl;
- net->ipv6.fib6_local_tbl->tb6_id = RT6_TABLE_LOCAL;
- rcu_assign_pointer(net->ipv6.fib6_local_tbl->tb6_root.leaf,
- net->ipv6.fib6_null_entry);
- net->ipv6.fib6_local_tbl->tb6_root.fn_flags =
- RTN_ROOT | RTN_TL_ROOT | RTN_RTINFO;
- inet_peer_base_init(&net->ipv6.fib6_local_tbl->tb6_peers);
- #endif
- fib6_tables_init(net);
- return 0;
- #ifdef CONFIG_IPV6_MULTIPLE_TABLES
- out_fib6_main_tbl:
- kfree(net->ipv6.fib6_main_tbl);
- #endif
- out_fib_table_hash:
- kfree(net->ipv6.fib_table_hash);
- out_rt6_stats:
- kfree(net->ipv6.rt6_stats);
- out_timer:
- fib6_notifier_exit(net);
- return -ENOMEM;
- }
- static void fib6_net_exit(struct net *net)
- {
- unsigned int i;
- del_timer_sync(&net->ipv6.ip6_fib_timer);
- for (i = 0; i < FIB6_TABLE_HASHSZ; i++) {
- struct hlist_head *head = &net->ipv6.fib_table_hash[i];
- struct hlist_node *tmp;
- struct fib6_table *tb;
- hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) {
- hlist_del(&tb->tb6_hlist);
- fib6_free_table(tb);
- }
- }
- kfree(net->ipv6.fib_table_hash);
- kfree(net->ipv6.rt6_stats);
- fib6_notifier_exit(net);
- }
- static struct pernet_operations fib6_net_ops = {
- .init = fib6_net_init,
- .exit = fib6_net_exit,
- };
- int __init fib6_init(void)
- {
- int ret = -ENOMEM;
- fib6_node_kmem = kmem_cache_create("fib6_nodes",
- sizeof(struct fib6_node),
- 0, SLAB_HWCACHE_ALIGN,
- NULL);
- if (!fib6_node_kmem)
- goto out;
- ret = register_pernet_subsys(&fib6_net_ops);
- if (ret)
- goto out_kmem_cache_create;
- ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, NULL,
- inet6_dump_fib, 0);
- if (ret)
- goto out_unregister_subsys;
- __fib6_flush_trees = fib6_flush_trees;
- out:
- return ret;
- out_unregister_subsys:
- unregister_pernet_subsys(&fib6_net_ops);
- out_kmem_cache_create:
- kmem_cache_destroy(fib6_node_kmem);
- goto out;
- }
- void fib6_gc_cleanup(void)
- {
- unregister_pernet_subsys(&fib6_net_ops);
- kmem_cache_destroy(fib6_node_kmem);
- }
- #ifdef CONFIG_PROC_FS
- static int ipv6_route_native_seq_show(struct seq_file *seq, void *v)
- {
- struct fib6_info *rt = v;
- struct ipv6_route_iter *iter = seq->private;
- struct fib6_nh *fib6_nh = rt->fib6_nh;
- unsigned int flags = rt->fib6_flags;
- const struct net_device *dev;
- if (rt->nh)
- fib6_nh = nexthop_fib6_nh_bh(rt->nh);
- seq_printf(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen);
- #ifdef CONFIG_IPV6_SUBTREES
- seq_printf(seq, "%pi6 %02x ", &rt->fib6_src.addr, rt->fib6_src.plen);
- #else
- seq_puts(seq, "00000000000000000000000000000000 00 ");
- #endif
- if (fib6_nh->fib_nh_gw_family) {
- flags |= RTF_GATEWAY;
- seq_printf(seq, "%pi6", &fib6_nh->fib_nh_gw6);
- } else {
- seq_puts(seq, "00000000000000000000000000000000");
- }
- dev = fib6_nh->fib_nh_dev;
- seq_printf(seq, " %08x %08x %08x %08x %8s\n",
- rt->fib6_metric, refcount_read(&rt->fib6_ref), 0,
- flags, dev ? dev->name : "");
- iter->w.leaf = NULL;
- return 0;
- }
- static int ipv6_route_yield(struct fib6_walker *w)
- {
- struct ipv6_route_iter *iter = w->args;
- if (!iter->skip)
- return 1;
- do {
- iter->w.leaf = rcu_dereference_protected(
- iter->w.leaf->fib6_next,
- lockdep_is_held(&iter->tbl->tb6_lock));
- iter->skip--;
- if (!iter->skip && iter->w.leaf)
- return 1;
- } while (iter->w.leaf);
- return 0;
- }
- static void ipv6_route_seq_setup_walk(struct ipv6_route_iter *iter,
- struct net *net)
- {
- memset(&iter->w, 0, sizeof(iter->w));
- iter->w.func = ipv6_route_yield;
- iter->w.root = &iter->tbl->tb6_root;
- iter->w.state = FWS_INIT;
- iter->w.node = iter->w.root;
- iter->w.args = iter;
- iter->sernum = READ_ONCE(iter->w.root->fn_sernum);
- INIT_LIST_HEAD(&iter->w.lh);
- fib6_walker_link(net, &iter->w);
- }
- static struct fib6_table *ipv6_route_seq_next_table(struct fib6_table *tbl,
- struct net *net)
- {
- unsigned int h;
- struct hlist_node *node;
- if (tbl) {
- h = (tbl->tb6_id & (FIB6_TABLE_HASHSZ - 1)) + 1;
- node = rcu_dereference_bh(hlist_next_rcu(&tbl->tb6_hlist));
- } else {
- h = 0;
- node = NULL;
- }
- while (!node && h < FIB6_TABLE_HASHSZ) {
- node = rcu_dereference_bh(
- hlist_first_rcu(&net->ipv6.fib_table_hash[h++]));
- }
- return hlist_entry_safe(node, struct fib6_table, tb6_hlist);
- }
- static void ipv6_route_check_sernum(struct ipv6_route_iter *iter)
- {
- int sernum = READ_ONCE(iter->w.root->fn_sernum);
- if (iter->sernum != sernum) {
- iter->sernum = sernum;
- iter->w.state = FWS_INIT;
- iter->w.node = iter->w.root;
- WARN_ON(iter->w.skip);
- iter->w.skip = iter->w.count;
- }
- }
- static void *ipv6_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
- {
- int r;
- struct fib6_info *n;
- struct net *net = seq_file_net(seq);
- struct ipv6_route_iter *iter = seq->private;
- ++(*pos);
- if (!v)
- goto iter_table;
- n = rcu_dereference_bh(((struct fib6_info *)v)->fib6_next);
- if (n)
- return n;
- iter_table:
- ipv6_route_check_sernum(iter);
- spin_lock_bh(&iter->tbl->tb6_lock);
- r = fib6_walk_continue(&iter->w);
- spin_unlock_bh(&iter->tbl->tb6_lock);
- if (r > 0) {
- return iter->w.leaf;
- } else if (r < 0) {
- fib6_walker_unlink(net, &iter->w);
- return NULL;
- }
- fib6_walker_unlink(net, &iter->w);
- iter->tbl = ipv6_route_seq_next_table(iter->tbl, net);
- if (!iter->tbl)
- return NULL;
- ipv6_route_seq_setup_walk(iter, net);
- goto iter_table;
- }
- static void *ipv6_route_seq_start(struct seq_file *seq, loff_t *pos)
- __acquires(RCU_BH)
- {
- struct net *net = seq_file_net(seq);
- struct ipv6_route_iter *iter = seq->private;
- rcu_read_lock_bh();
- iter->tbl = ipv6_route_seq_next_table(NULL, net);
- iter->skip = *pos;
- if (iter->tbl) {
- loff_t p = 0;
- ipv6_route_seq_setup_walk(iter, net);
- return ipv6_route_seq_next(seq, NULL, &p);
- } else {
- return NULL;
- }
- }
- static bool ipv6_route_iter_active(struct ipv6_route_iter *iter)
- {
- struct fib6_walker *w = &iter->w;
- return w->node && !(w->state == FWS_U && w->node == w->root);
- }
- static void ipv6_route_native_seq_stop(struct seq_file *seq, void *v)
- __releases(RCU_BH)
- {
- struct net *net = seq_file_net(seq);
- struct ipv6_route_iter *iter = seq->private;
- if (ipv6_route_iter_active(iter))
- fib6_walker_unlink(net, &iter->w);
- rcu_read_unlock_bh();
- }
- #if IS_BUILTIN(CONFIG_IPV6) && defined(CONFIG_BPF_SYSCALL)
- static int ipv6_route_prog_seq_show(struct bpf_prog *prog,
- struct bpf_iter_meta *meta,
- void *v)
- {
- struct bpf_iter__ipv6_route ctx;
- ctx.meta = meta;
- ctx.rt = v;
- return bpf_iter_run_prog(prog, &ctx);
- }
- static int ipv6_route_seq_show(struct seq_file *seq, void *v)
- {
- struct ipv6_route_iter *iter = seq->private;
- struct bpf_iter_meta meta;
- struct bpf_prog *prog;
- int ret;
- meta.seq = seq;
- prog = bpf_iter_get_info(&meta, false);
- if (!prog)
- return ipv6_route_native_seq_show(seq, v);
- ret = ipv6_route_prog_seq_show(prog, &meta, v);
- iter->w.leaf = NULL;
- return ret;
- }
- static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
- {
- struct bpf_iter_meta meta;
- struct bpf_prog *prog;
- if (!v) {
- meta.seq = seq;
- prog = bpf_iter_get_info(&meta, true);
- if (prog)
- (void)ipv6_route_prog_seq_show(prog, &meta, v);
- }
- ipv6_route_native_seq_stop(seq, v);
- }
- #else
- static int ipv6_route_seq_show(struct seq_file *seq, void *v)
- {
- return ipv6_route_native_seq_show(seq, v);
- }
- static void ipv6_route_seq_stop(struct seq_file *seq, void *v)
- {
- ipv6_route_native_seq_stop(seq, v);
- }
- #endif
- const struct seq_operations ipv6_route_seq_ops = {
- .start = ipv6_route_seq_start,
- .next = ipv6_route_seq_next,
- .stop = ipv6_route_seq_stop,
- .show = ipv6_route_seq_show
- };
- #endif /* CONFIG_PROC_FS */
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