summaryrefslogtreecommitdiffstats
path: root/net/ipv6/ip6_fib.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /net/ipv6/ip6_fib.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/ipv6/ip6_fib.c')
-rw-r--r--net/ipv6/ip6_fib.c2717
1 files changed, 2717 insertions, 0 deletions
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
new file mode 100644
index 0000000000..4fc2cae0d1
--- /dev/null
+++ b/net/ipv6/ip6_fib.c
@@ -0,0 +1,2717 @@
+// 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/bpf.h>
+#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/ip_fib.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 = atomic_read(&net->ipv6.fib6_sernum);
+
+ do {
+ new = old < INT_MAX ? old + 1 : 1;
+ } while (!atomic_try_cmpxchg(&net->ipv6.fib6_sernum, &old, new));
+
+ 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)
+ goto out;
+ }
+ }
+
+out:
+ kfree(w);
+
+ /* The tree traversal function should never return a positive value. */
+ return err > 0 ? -EINVAL : 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 fib6_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 (!pn_leaf)
+ pn_leaf =
+ info->nl_net->ipv6.fib6_null_entry;
+ 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;
+
+ /* Default to 3-tuple */
+ net->ipv6.sysctl.multipath_hash_fields =
+ FIB_MULTIPATH_HASH_FIELD_DEFAULT_MASK;
+
+ 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_notifier;
+
+ /* 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_notifier:
+ 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 | SLAB_ACCOUNT,
+ 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(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(hlist_next_rcu(&tbl->tb6_hlist));
+ } else {
+ h = 0;
+ node = NULL;
+ }
+
+ while (!node && h < FIB6_TABLE_HASHSZ) {
+ node = rcu_dereference(
+ 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(((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)
+{
+ struct net *net = seq_file_net(seq);
+ struct ipv6_route_iter *iter = seq->private;
+
+ rcu_read_lock();
+ 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)
+{
+ 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();
+}
+
+#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 */