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-rw-r--r--kernel/net/ipv6/ip6_fib.c2060
1 files changed, 2060 insertions, 0 deletions
diff --git a/kernel/net/ipv6/ip6_fib.c b/kernel/net/ipv6/ip6_fib.c
new file mode 100644
index 000000000..bde57b113
--- /dev/null
+++ b/kernel/net/ipv6/ip6_fib.c
@@ -0,0 +1,2060 @@
+/*
+ * Linux INET6 implementation
+ * Forwarding Information Database
+ *
+ * Authors:
+ * Pedro Roque <roque@di.fc.ul.pt>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * 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/ipv6.h>
+#include <net/ndisc.h>
+#include <net/addrconf.h>
+
+#include <net/ip6_fib.h>
+#include <net/ip6_route.h>
+
+#define RT6_DEBUG 2
+
+#if RT6_DEBUG >= 3
+#define RT6_TRACE(x...) pr_debug(x)
+#else
+#define RT6_TRACE(x...) do { ; } while (0)
+#endif
+
+static struct kmem_cache *fib6_node_kmem __read_mostly;
+
+struct fib6_cleaner {
+ struct fib6_walker w;
+ struct net *net;
+ int (*func)(struct rt6_info *, void *arg);
+ int sernum;
+ void *arg;
+};
+
+static DEFINE_RWLOCK(fib6_walker_lock);
+
+#ifdef CONFIG_IPV6_SUBTREES
+#define FWS_INIT FWS_S
+#else
+#define FWS_INIT FWS_L
+#endif
+
+static void fib6_prune_clones(struct net *net, struct fib6_node *fn);
+static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn);
+static struct fib6_node *fib6_repair_tree(struct net *net, struct fib6_node *fn);
+static int fib6_walk(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(unsigned long arg);
+
+static LIST_HEAD(fib6_walkers);
+#define FOR_WALKERS(w) list_for_each_entry(w, &fib6_walkers, lh)
+
+static void fib6_walker_link(struct fib6_walker *w)
+{
+ write_lock_bh(&fib6_walker_lock);
+ list_add(&w->lh, &fib6_walkers);
+ write_unlock_bh(&fib6_walker_lock);
+}
+
+static void fib6_walker_unlink(struct fib6_walker *w)
+{
+ write_lock_bh(&fib6_walker_lock);
+ list_del(&w->lh);
+ write_unlock_bh(&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,
+};
+
+/*
+ * 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];
+}
+
+static struct fib6_node *node_alloc(void)
+{
+ struct fib6_node *fn;
+
+ fn = kmem_cache_zalloc(fib6_node_kmem, GFP_ATOMIC);
+
+ return fn;
+}
+
+static void node_free(struct fib6_node *fn)
+{
+ kmem_cache_free(fib6_node_kmem, fn);
+}
+
+static void rt6_release(struct rt6_info *rt)
+{
+ if (atomic_dec_and_test(&rt->rt6i_ref))
+ dst_free(&rt->dst);
+}
+
+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.
+ */
+ rwlock_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;
+ table->tb6_root.leaf = net->ipv6.ip6_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;
+}
+
+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;
+}
+
+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,
+ int flags, pol_lookup_t lookup)
+{
+ return (struct dst_entry *) lookup(net, net->ipv6.fib6_main_tbl, fl6, flags);
+}
+
+static void __net_init fib6_tables_init(struct net *net)
+{
+ fib6_link_table(net, net->ipv6.fib6_main_tbl);
+}
+
+#endif
+
+static int fib6_dump_node(struct fib6_walker *w)
+{
+ int res;
+ struct rt6_info *rt;
+
+ for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
+ res = rt6_dump_route(rt, w->args);
+ if (res < 0) {
+ /* Frame is full, suspend walking */
+ w->leaf = rt;
+ return 1;
+ }
+ }
+ w->leaf = NULL;
+ return 0;
+}
+
+static void fib6_dump_end(struct netlink_callback *cb)
+{
+ struct fib6_walker *w = (void *)cb->args[2];
+
+ if (w) {
+ if (cb->args[4]) {
+ cb->args[4] = 0;
+ fib6_walker_unlink(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 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;
+
+ read_lock_bh(&table->tb6_lock);
+ res = fib6_walk(w);
+ read_unlock_bh(&table->tb6_lock);
+ if (res > 0) {
+ cb->args[4] = 1;
+ cb->args[5] = w->root->fn_sernum;
+ }
+ } else {
+ if (cb->args[5] != w->root->fn_sernum) {
+ /* Begin at the root if the tree changed */
+ cb->args[5] = w->root->fn_sernum;
+ w->state = FWS_INIT;
+ w->node = w->root;
+ w->skip = w->count;
+ } else
+ w->skip = 0;
+
+ read_lock_bh(&table->tb6_lock);
+ res = fib6_walk_continue(w);
+ read_unlock_bh(&table->tb6_lock);
+ if (res <= 0) {
+ fib6_walker_unlink(w);
+ cb->args[4] = 0;
+ }
+ }
+
+ return res;
+}
+
+static int inet6_dump_fib(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct net *net = sock_net(skb->sk);
+ unsigned int h, s_h;
+ unsigned int e = 0, s_e;
+ struct rt6_rtnl_dump_arg arg;
+ struct fib6_walker *w;
+ struct fib6_table *tb;
+ struct hlist_head *head;
+ int res = 0;
+
+ s_h = cb->args[0];
+ s_e = cb->args[1];
+
+ 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;
+
+ 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;
+next:
+ e++;
+ }
+ }
+out:
+ rcu_read_unlock();
+ cb->args[1] = e;
+ cb->args[0] = h;
+
+ res = res < 0 ? res : skb->len;
+ if (res <= 0)
+ fib6_dump_end(cb);
+ return res;
+}
+
+/*
+ * 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 fib6_node *root,
+ struct in6_addr *addr, int plen,
+ int offset, int allow_create,
+ int replace_required, int sernum)
+{
+ 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 {
+ key = (struct rt6key *)((u8 *)fn->leaf + offset);
+
+ /*
+ * Prefix match
+ */
+ if (plen < fn->fn_bit ||
+ !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit)) {
+ if (!allow_create) {
+ if (replace_required) {
+ 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)) {
+ rt6_release(fn->leaf);
+ fn->leaf = NULL;
+ }
+
+ fn->fn_sernum = sernum;
+
+ return fn;
+ }
+
+ /*
+ * We have more bits to go
+ */
+
+ /* Try to walk down on tree. */
+ fn->fn_sernum = sernum;
+ dir = addr_bit_set(addr, fn->fn_bit);
+ pn = fn;
+ fn = dir ? fn->right : fn->left;
+ } 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) {
+ 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();
+
+ if (!ln)
+ return ERR_PTR(-ENOMEM);
+ ln->fn_bit = plen;
+
+ ln->parent = pn;
+ ln->fn_sernum = sernum;
+
+ if (dir)
+ pn->right = ln;
+ else
+ 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 = fn->parent;
+
+ /* 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();
+ ln = node_alloc();
+
+ if (!in || !ln) {
+ if (in)
+ node_free(in);
+ if (ln)
+ node_free(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;
+
+ in->parent = pn;
+ in->leaf = fn->leaf;
+ atomic_inc(&in->leaf->rt6i_ref);
+
+ in->fn_sernum = sernum;
+
+ /* update parent pointer */
+ if (dir)
+ pn->right = in;
+ else
+ pn->left = in;
+
+ ln->fn_bit = plen;
+
+ ln->parent = in;
+ fn->parent = in;
+
+ ln->fn_sernum = sernum;
+
+ if (addr_bit_set(addr, bit)) {
+ in->right = ln;
+ in->left = fn;
+ } else {
+ in->left = ln;
+ in->right = fn;
+ }
+ } else { /* plen <= bit */
+
+ /*
+ * (new leaf node)[ln]
+ * / \
+ * (old node)[fn] NULL
+ */
+
+ ln = node_alloc();
+
+ if (!ln)
+ return ERR_PTR(-ENOMEM);
+
+ ln->fn_bit = plen;
+
+ ln->parent = pn;
+
+ ln->fn_sernum = sernum;
+
+ if (dir)
+ pn->right = ln;
+ else
+ pn->left = ln;
+
+ if (addr_bit_set(&key->addr, plen))
+ ln->right = fn;
+ else
+ ln->left = fn;
+
+ fn->parent = ln;
+ }
+ return ln;
+}
+
+static bool rt6_qualify_for_ecmp(struct rt6_info *rt)
+{
+ return (rt->rt6i_flags & (RTF_GATEWAY|RTF_ADDRCONF|RTF_DYNAMIC)) ==
+ RTF_GATEWAY;
+}
+
+static void fib6_copy_metrics(u32 *mp, const struct mx6_config *mxc)
+{
+ int i;
+
+ for (i = 0; i < RTAX_MAX; i++) {
+ if (test_bit(i, mxc->mx_valid))
+ mp[i] = mxc->mx[i];
+ }
+}
+
+static int fib6_commit_metrics(struct dst_entry *dst, struct mx6_config *mxc)
+{
+ if (!mxc->mx)
+ return 0;
+
+ if (dst->flags & DST_HOST) {
+ u32 *mp = dst_metrics_write_ptr(dst);
+
+ if (unlikely(!mp))
+ return -ENOMEM;
+
+ fib6_copy_metrics(mp, mxc);
+ } else {
+ dst_init_metrics(dst, mxc->mx, false);
+
+ /* We've stolen mx now. */
+ mxc->mx = NULL;
+ }
+
+ return 0;
+}
+
+static void fib6_purge_rt(struct rt6_info *rt, struct fib6_node *fn,
+ struct net *net)
+{
+ if (atomic_read(&rt->rt6i_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) {
+ if (!(fn->fn_flags & RTN_RTINFO) && fn->leaf == rt) {
+ fn->leaf = fib6_find_prefix(net, fn);
+ atomic_inc(&fn->leaf->rt6i_ref);
+ rt6_release(rt);
+ }
+ fn = fn->parent;
+ }
+ /* No more references are possible at this point. */
+ BUG_ON(atomic_read(&rt->rt6i_ref) != 1);
+ }
+}
+
+/*
+ * Insert routing information in a node.
+ */
+
+static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
+ struct nl_info *info, struct mx6_config *mxc)
+{
+ struct rt6_info *iter = NULL;
+ struct rt6_info **ins;
+ struct rt6_info **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);
+ int err;
+
+ ins = &fn->leaf;
+
+ for (iter = fn->leaf; iter; iter = iter->dst.rt6_next) {
+ /*
+ * Search for duplicates
+ */
+
+ if (iter->rt6i_metric == rt->rt6i_metric) {
+ /*
+ * Same priority level
+ */
+ if (info->nlh &&
+ (info->nlh->nlmsg_flags & NLM_F_EXCL))
+ return -EEXIST;
+ if (replace) {
+ if (rt_can_ecmp == rt6_qualify_for_ecmp(iter)) {
+ found++;
+ break;
+ }
+ if (rt_can_ecmp)
+ fallback_ins = fallback_ins ?: ins;
+ goto next_iter;
+ }
+
+ if (iter->dst.dev == rt->dst.dev &&
+ iter->rt6i_idev == rt->rt6i_idev &&
+ ipv6_addr_equal(&iter->rt6i_gateway,
+ &rt->rt6i_gateway)) {
+ if (rt->rt6i_nsiblings)
+ rt->rt6i_nsiblings = 0;
+ if (!(iter->rt6i_flags & RTF_EXPIRES))
+ return -EEXIST;
+ if (!(rt->rt6i_flags & RTF_EXPIRES))
+ rt6_clean_expires(iter);
+ else
+ rt6_set_expires(iter, rt->dst.expires);
+ 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->rt6i_nsiblings++;
+ }
+
+ if (iter->rt6i_metric > rt->rt6i_metric)
+ break;
+
+next_iter:
+ ins = &iter->dst.rt6_next;
+ }
+
+ if (fallback_ins && !found) {
+ /* No ECMP-able route found, replace first non-ECMP one */
+ ins = fallback_ins;
+ iter = *ins;
+ found++;
+ }
+
+ /* Reset round-robin state, if necessary */
+ if (ins == &fn->leaf)
+ fn->rr_ptr = NULL;
+
+ /* Link this route to others same route. */
+ if (rt->rt6i_nsiblings) {
+ unsigned int rt6i_nsiblings;
+ struct rt6_info *sibling, *temp_sibling;
+
+ /* Find the first route that have the same metric */
+ sibling = fn->leaf;
+ while (sibling) {
+ if (sibling->rt6i_metric == rt->rt6i_metric &&
+ rt6_qualify_for_ecmp(sibling)) {
+ list_add_tail(&rt->rt6i_siblings,
+ &sibling->rt6i_siblings);
+ break;
+ }
+ sibling = sibling->dst.rt6_next;
+ }
+ /* For each sibling in the list, increment the counter of
+ * siblings. BUG() if counters does not match, list of siblings
+ * is broken!
+ */
+ rt6i_nsiblings = 0;
+ list_for_each_entry_safe(sibling, temp_sibling,
+ &rt->rt6i_siblings, rt6i_siblings) {
+ sibling->rt6i_nsiblings++;
+ BUG_ON(sibling->rt6i_nsiblings != rt->rt6i_nsiblings);
+ rt6i_nsiblings++;
+ }
+ BUG_ON(rt6i_nsiblings != rt->rt6i_nsiblings);
+ }
+
+ /*
+ * insert node
+ */
+ if (!replace) {
+ if (!add)
+ pr_warn("NLM_F_CREATE should be set when creating new route\n");
+
+add:
+ err = fib6_commit_metrics(&rt->dst, mxc);
+ if (err)
+ return err;
+
+ rt->dst.rt6_next = iter;
+ *ins = rt;
+ rt->rt6i_node = fn;
+ atomic_inc(&rt->rt6i_ref);
+ inet6_rt_notify(RTM_NEWROUTE, rt, info);
+ 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;
+ }
+
+ err = fib6_commit_metrics(&rt->dst, mxc);
+ if (err)
+ return err;
+
+ *ins = rt;
+ rt->rt6i_node = fn;
+ rt->dst.rt6_next = iter->dst.rt6_next;
+ atomic_inc(&rt->rt6i_ref);
+ inet6_rt_notify(RTM_NEWROUTE, rt, info);
+ if (!(fn->fn_flags & RTN_RTINFO)) {
+ info->nl_net->ipv6.rt6_stats->fib_route_nodes++;
+ fn->fn_flags |= RTN_RTINFO;
+ }
+ nsiblings = iter->rt6i_nsiblings;
+ fib6_purge_rt(iter, fn, info->nl_net);
+ rt6_release(iter);
+
+ if (nsiblings) {
+ /* Replacing an ECMP route, remove all siblings */
+ ins = &rt->dst.rt6_next;
+ iter = *ins;
+ while (iter) {
+ if (rt6_qualify_for_ecmp(iter)) {
+ *ins = iter->dst.rt6_next;
+ fib6_purge_rt(iter, fn, info->nl_net);
+ rt6_release(iter);
+ nsiblings--;
+ } else {
+ ins = &iter->dst.rt6_next;
+ }
+ iter = *ins;
+ }
+ WARN_ON(nsiblings != 0);
+ }
+ }
+
+ return 0;
+}
+
+static void fib6_start_gc(struct net *net, struct rt6_info *rt)
+{
+ if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
+ (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE)))
+ 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);
+}
+
+/*
+ * Add routing information to the routing tree.
+ * <destination addr>/<source addr>
+ * with source addr info in sub-trees
+ */
+
+int fib6_add(struct fib6_node *root, struct rt6_info *rt,
+ struct nl_info *info, struct mx6_config *mxc)
+{
+ struct fib6_node *fn, *pn = NULL;
+ int err = -ENOMEM;
+ int allow_create = 1;
+ int replace_required = 0;
+ int sernum = fib6_new_sernum(info->nl_net);
+
+ 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(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
+ offsetof(struct rt6_info, rt6i_dst), allow_create,
+ replace_required, sernum);
+ if (IS_ERR(fn)) {
+ err = PTR_ERR(fn);
+ fn = NULL;
+ goto out;
+ }
+
+ pn = fn;
+
+#ifdef CONFIG_IPV6_SUBTREES
+ if (rt->rt6i_src.plen) {
+ struct fib6_node *sn;
+
+ if (!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();
+ if (!sfn)
+ goto st_failure;
+
+ sfn->leaf = info->nl_net->ipv6.ip6_null_entry;
+ atomic_inc(&info->nl_net->ipv6.ip6_null_entry->rt6i_ref);
+ sfn->fn_flags = RTN_ROOT;
+ sfn->fn_sernum = sernum;
+
+ /* Now add the first leaf node to new subtree */
+
+ sn = fib6_add_1(sfn, &rt->rt6i_src.addr,
+ rt->rt6i_src.plen,
+ offsetof(struct rt6_info, rt6i_src),
+ allow_create, replace_required, sernum);
+
+ if (IS_ERR(sn)) {
+ /* If it is failed, discard just allocated
+ root, and then (in st_failure) stale node
+ in main tree.
+ */
+ node_free(sfn);
+ err = PTR_ERR(sn);
+ goto st_failure;
+ }
+
+ /* Now link new subtree to main tree */
+ sfn->parent = fn;
+ fn->subtree = sfn;
+ } else {
+ sn = fib6_add_1(fn->subtree, &rt->rt6i_src.addr,
+ rt->rt6i_src.plen,
+ offsetof(struct rt6_info, rt6i_src),
+ allow_create, replace_required, sernum);
+
+ if (IS_ERR(sn)) {
+ err = PTR_ERR(sn);
+ goto st_failure;
+ }
+ }
+
+ if (!fn->leaf) {
+ fn->leaf = rt;
+ atomic_inc(&rt->rt6i_ref);
+ }
+ fn = sn;
+ }
+#endif
+
+ err = fib6_add_rt2node(fn, rt, info, mxc);
+ if (!err) {
+ fib6_start_gc(info->nl_net, rt);
+ if (!(rt->rt6i_flags & RTF_CACHE))
+ fib6_prune_clones(info->nl_net, pn);
+ }
+
+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 && pn->leaf == rt) {
+ pn->leaf = NULL;
+ atomic_dec(&rt->rt6i_ref);
+ }
+ if (pn != fn && !pn->leaf && !(pn->fn_flags & RTN_RTINFO)) {
+ pn->leaf = fib6_find_prefix(info->nl_net, pn);
+#if RT6_DEBUG >= 2
+ if (!pn->leaf) {
+ WARN_ON(pn->leaf == NULL);
+ pn->leaf = info->nl_net->ipv6.ip6_null_entry;
+ }
+#endif
+ atomic_inc(&pn->leaf->rt6i_ref);
+ }
+#endif
+ dst_free(&rt->dst);
+ }
+ return err;
+
+#ifdef CONFIG_IPV6_SUBTREES
+ /* Subtree creation failed, probably main tree node
+ is orphan. If it is, shoot it.
+ */
+st_failure:
+ if (fn && !(fn->fn_flags & (RTN_RTINFO|RTN_ROOT)))
+ fib6_repair_tree(info->nl_net, fn);
+ dst_free(&rt->dst);
+ return err;
+#endif
+}
+
+/*
+ * Routing tree lookup
+ *
+ */
+
+struct lookup_args {
+ int offset; /* key offset on rt6_info */
+ const struct in6_addr *addr; /* search key */
+};
+
+static struct fib6_node *fib6_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 ? fn->right : fn->left;
+
+ if (next) {
+ fn = next;
+ continue;
+ }
+ break;
+ }
+
+ while (fn) {
+ if (FIB6_SUBTREE(fn) || fn->fn_flags & RTN_RTINFO) {
+ struct rt6key *key;
+
+ key = (struct rt6key *) ((u8 *) fn->leaf +
+ args->offset);
+
+ if (ipv6_prefix_equal(&key->addr, args->addr, key->plen)) {
+#ifdef CONFIG_IPV6_SUBTREES
+ if (fn->subtree) {
+ struct fib6_node *sfn;
+ sfn = fib6_lookup_1(fn->subtree,
+ args + 1);
+ if (!sfn)
+ goto backtrack;
+ fn = sfn;
+ }
+#endif
+ if (fn->fn_flags & RTN_RTINFO)
+ return fn;
+ }
+ }
+#ifdef CONFIG_IPV6_SUBTREES
+backtrack:
+#endif
+ if (fn->fn_flags & RTN_ROOT)
+ break;
+
+ fn = fn->parent;
+ }
+
+ return NULL;
+}
+
+struct fib6_node *fib6_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 rt6_info, rt6i_dst),
+ .addr = daddr,
+ },
+#ifdef CONFIG_IPV6_SUBTREES
+ {
+ .offset = offsetof(struct rt6_info, rt6i_src),
+ .addr = saddr,
+ },
+#endif
+ {
+ .offset = 0, /* sentinel */
+ }
+ };
+
+ fn = fib6_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)
+ */
+
+
+static struct fib6_node *fib6_locate_1(struct fib6_node *root,
+ const struct in6_addr *addr,
+ int plen, int offset)
+{
+ struct fib6_node *fn;
+
+ for (fn = root; fn ; ) {
+ struct rt6key *key = (struct rt6key *)((u8 *)fn->leaf + offset);
+
+ /*
+ * Prefix match
+ */
+ if (plen < fn->fn_bit ||
+ !ipv6_prefix_equal(&key->addr, addr, fn->fn_bit))
+ return NULL;
+
+ if (plen == fn->fn_bit)
+ return fn;
+
+ /*
+ * We have more bits to go
+ */
+ if (addr_bit_set(addr, fn->fn_bit))
+ fn = fn->right;
+ else
+ fn = fn->left;
+ }
+ return NULL;
+}
+
+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)
+{
+ struct fib6_node *fn;
+
+ fn = fib6_locate_1(root, daddr, dst_len,
+ offsetof(struct rt6_info, rt6i_dst));
+
+#ifdef CONFIG_IPV6_SUBTREES
+ if (src_len) {
+ WARN_ON(saddr == NULL);
+ if (fn && fn->subtree)
+ fn = fib6_locate_1(fn->subtree, saddr, src_len,
+ offsetof(struct rt6_info, rt6i_src));
+ }
+#endif
+
+ if (fn && fn->fn_flags & RTN_RTINFO)
+ return fn;
+
+ return NULL;
+}
+
+
+/*
+ * Deletion
+ *
+ */
+
+static struct rt6_info *fib6_find_prefix(struct net *net, struct fib6_node *fn)
+{
+ if (fn->fn_flags & RTN_ROOT)
+ return net->ipv6.ip6_null_entry;
+
+ while (fn) {
+ if (fn->left)
+ return fn->left->leaf;
+ if (fn->right)
+ return fn->right->leaf;
+
+ 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.
+ */
+
+static struct fib6_node *fib6_repair_tree(struct net *net,
+ struct fib6_node *fn)
+{
+ int children;
+ int nstate;
+ struct fib6_node *child, *pn;
+ struct fib6_walker *w;
+ int iter = 0;
+
+ for (;;) {
+ 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->right)
+ child = fn->right, children |= 1;
+ if (fn->left)
+ child = fn->left, 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
+ ) {
+ fn->leaf = fib6_find_prefix(net, fn);
+#if RT6_DEBUG >= 2
+ if (!fn->leaf) {
+ WARN_ON(!fn->leaf);
+ fn->leaf = net->ipv6.ip6_null_entry;
+ }
+#endif
+ atomic_inc(&fn->leaf->rt6i_ref);
+ return fn->parent;
+ }
+
+ pn = fn->parent;
+#ifdef CONFIG_IPV6_SUBTREES
+ if (FIB6_SUBTREE(pn) == fn) {
+ WARN_ON(!(fn->fn_flags & RTN_ROOT));
+ FIB6_SUBTREE(pn) = NULL;
+ nstate = FWS_L;
+ } else {
+ WARN_ON(fn->fn_flags & RTN_ROOT);
+#endif
+ if (pn->right == fn)
+ pn->right = child;
+ else if (pn->left == fn)
+ pn->left = child;
+#if RT6_DEBUG >= 2
+ else
+ WARN_ON(1);
+#endif
+ if (child)
+ child->parent = pn;
+ nstate = FWS_R;
+#ifdef CONFIG_IPV6_SUBTREES
+ }
+#endif
+
+ read_lock(&fib6_walker_lock);
+ FOR_WALKERS(w) {
+ if (!child) {
+ if (w->root == fn) {
+ w->root = w->node = NULL;
+ RT6_TRACE("W %p adjusted by delroot 1\n", w);
+ } else 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->root == fn) {
+ w->root = child;
+ RT6_TRACE("W %p adjusted by delroot 2\n", w);
+ }
+ 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(&fib6_walker_lock);
+
+ node_free(fn);
+ if (pn->fn_flags & RTN_RTINFO || FIB6_SUBTREE(pn))
+ return pn;
+
+ rt6_release(pn->leaf);
+ pn->leaf = NULL;
+ fn = pn;
+ }
+}
+
+static void fib6_del_route(struct fib6_node *fn, struct rt6_info **rtp,
+ struct nl_info *info)
+{
+ struct fib6_walker *w;
+ struct rt6_info *rt = *rtp;
+ struct net *net = info->nl_net;
+
+ RT6_TRACE("fib6_del_route\n");
+
+ /* Unlink it */
+ *rtp = rt->dst.rt6_next;
+ rt->rt6i_node = NULL;
+ net->ipv6.rt6_stats->fib_rt_entries--;
+ net->ipv6.rt6_stats->fib_discarded_routes++;
+
+ /* Reset round-robin state, if necessary */
+ if (fn->rr_ptr == rt)
+ fn->rr_ptr = NULL;
+
+ /* Remove this entry from other siblings */
+ if (rt->rt6i_nsiblings) {
+ struct rt6_info *sibling, *next_sibling;
+
+ list_for_each_entry_safe(sibling, next_sibling,
+ &rt->rt6i_siblings, rt6i_siblings)
+ sibling->rt6i_nsiblings--;
+ rt->rt6i_nsiblings = 0;
+ list_del_init(&rt->rt6i_siblings);
+ }
+
+ /* Adjust walkers */
+ read_lock(&fib6_walker_lock);
+ FOR_WALKERS(w) {
+ if (w->state == FWS_C && w->leaf == rt) {
+ RT6_TRACE("walker %p adjusted by delroute\n", w);
+ w->leaf = rt->dst.rt6_next;
+ if (!w->leaf)
+ w->state = FWS_U;
+ }
+ }
+ read_unlock(&fib6_walker_lock);
+
+ rt->dst.rt6_next = NULL;
+
+ /* If it was last route, expunge its radix tree node */
+ if (!fn->leaf) {
+ fn->fn_flags &= ~RTN_RTINFO;
+ net->ipv6.rt6_stats->fib_route_nodes--;
+ fn = fib6_repair_tree(net, fn);
+ }
+
+ fib6_purge_rt(rt, fn, net);
+
+ inet6_rt_notify(RTM_DELROUTE, rt, info);
+ rt6_release(rt);
+}
+
+int fib6_del(struct rt6_info *rt, struct nl_info *info)
+{
+ struct net *net = info->nl_net;
+ struct fib6_node *fn = rt->rt6i_node;
+ struct rt6_info **rtp;
+
+#if RT6_DEBUG >= 2
+ if (rt->dst.obsolete > 0) {
+ WARN_ON(fn);
+ return -ENOENT;
+ }
+#endif
+ if (!fn || rt == net->ipv6.ip6_null_entry)
+ return -ENOENT;
+
+ WARN_ON(!(fn->fn_flags & RTN_RTINFO));
+
+ if (!(rt->rt6i_flags & RTF_CACHE)) {
+ struct fib6_node *pn = fn;
+#ifdef CONFIG_IPV6_SUBTREES
+ /* clones of this route might be in another subtree */
+ if (rt->rt6i_src.plen) {
+ while (!(pn->fn_flags & RTN_ROOT))
+ pn = pn->parent;
+ pn = pn->parent;
+ }
+#endif
+ fib6_prune_clones(info->nl_net, pn);
+ }
+
+ /*
+ * Walk the leaf entries looking for ourself
+ */
+
+ for (rtp = &fn->leaf; *rtp; rtp = &(*rtp)->dst.rt6_next) {
+ if (*rtp == rt) {
+ fib6_del_route(fn, rtp, info);
+ return 0;
+ }
+ }
+ 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.
+ */
+
+static int fib6_walk_continue(struct fib6_walker *w)
+{
+ struct fib6_node *fn, *pn;
+
+ for (;;) {
+ fn = w->node;
+ if (!fn)
+ return 0;
+
+ if (w->prune && fn != w->root &&
+ fn->fn_flags & RTN_RTINFO && w->state < FWS_C) {
+ w->state = FWS_C;
+ w->leaf = fn->leaf;
+ }
+ switch (w->state) {
+#ifdef CONFIG_IPV6_SUBTREES
+ case FWS_S:
+ if (FIB6_SUBTREE(fn)) {
+ w->node = FIB6_SUBTREE(fn);
+ continue;
+ }
+ w->state = FWS_L;
+#endif
+ case FWS_L:
+ if (fn->left) {
+ w->node = fn->left;
+ w->state = FWS_INIT;
+ continue;
+ }
+ w->state = FWS_R;
+ case FWS_R:
+ if (fn->right) {
+ w->node = fn->right;
+ w->state = FWS_INIT;
+ continue;
+ }
+ w->state = FWS_C;
+ w->leaf = fn->leaf;
+ 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;
+ case FWS_U:
+ if (fn == w->root)
+ return 0;
+ pn = fn->parent;
+ 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 (pn->left == fn) {
+ w->state = FWS_R;
+ continue;
+ }
+ if (pn->right == fn) {
+ w->state = FWS_C;
+ w->leaf = w->node->leaf;
+ continue;
+ }
+#if RT6_DEBUG >= 2
+ WARN_ON(1);
+#endif
+ }
+ }
+}
+
+static int fib6_walk(struct fib6_walker *w)
+{
+ int res;
+
+ w->state = FWS_INIT;
+ w->node = w->root;
+
+ fib6_walker_link(w);
+ res = fib6_walk_continue(w);
+ if (res <= 0)
+ fib6_walker_unlink(w);
+ return res;
+}
+
+static int fib6_clean_node(struct fib6_walker *w)
+{
+ int res;
+ struct rt6_info *rt;
+ struct fib6_cleaner *c = container_of(w, struct fib6_cleaner, w);
+ struct nl_info info = {
+ .nl_net = c->net,
+ };
+
+ if (c->sernum != FIB6_NO_SERNUM_CHANGE &&
+ w->node->fn_sernum != c->sernum)
+ w->node->fn_sernum = c->sernum;
+
+ if (!c->func) {
+ WARN_ON_ONCE(c->sernum == FIB6_NO_SERNUM_CHANGE);
+ w->leaf = NULL;
+ return 0;
+ }
+
+ for (rt = w->leaf; rt; rt = rt->dst.rt6_next) {
+ res = c->func(rt, c->arg);
+ if (res < 0) {
+ 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, rt->rt6i_node, res);
+#endif
+ continue;
+ }
+ return 0;
+ }
+ WARN_ON(res != 0);
+ }
+ w->leaf = rt;
+ return 0;
+}
+
+/*
+ * Convenient frontend to tree walker.
+ *
+ * func is called on each route.
+ * It may return -1 -> delete this route.
+ * 0 -> continue walking
+ *
+ * prune==1 -> only immediate children of node (certainly,
+ * ignoring pure split nodes) will be scanned.
+ */
+
+static void fib6_clean_tree(struct net *net, struct fib6_node *root,
+ int (*func)(struct rt6_info *, void *arg),
+ bool prune, int sernum, void *arg)
+{
+ struct fib6_cleaner c;
+
+ c.w.root = root;
+ c.w.func = fib6_clean_node;
+ c.w.prune = prune;
+ c.w.count = 0;
+ c.w.skip = 0;
+ c.func = func;
+ c.sernum = sernum;
+ c.arg = arg;
+ c.net = net;
+
+ fib6_walk(&c.w);
+}
+
+static void __fib6_clean_all(struct net *net,
+ int (*func)(struct rt6_info *, void *),
+ int sernum, void *arg)
+{
+ 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) {
+ write_lock_bh(&table->tb6_lock);
+ fib6_clean_tree(net, &table->tb6_root,
+ func, false, sernum, arg);
+ write_unlock_bh(&table->tb6_lock);
+ }
+ }
+ rcu_read_unlock();
+}
+
+void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *),
+ void *arg)
+{
+ __fib6_clean_all(net, func, FIB6_NO_SERNUM_CHANGE, arg);
+}
+
+static int fib6_prune_clone(struct rt6_info *rt, void *arg)
+{
+ if (rt->rt6i_flags & RTF_CACHE) {
+ RT6_TRACE("pruning clone %p\n", rt);
+ return -1;
+ }
+
+ return 0;
+}
+
+static void fib6_prune_clones(struct net *net, struct fib6_node *fn)
+{
+ fib6_clean_tree(net, fn, fib6_prune_clone, true,
+ FIB6_NO_SERNUM_CHANGE, NULL);
+}
+
+static void fib6_flush_trees(struct net *net)
+{
+ int new_sernum = fib6_new_sernum(net);
+
+ __fib6_clean_all(net, NULL, new_sernum, NULL);
+}
+
+/*
+ * Garbage collection
+ */
+
+static struct fib6_gc_args
+{
+ int timeout;
+ int more;
+} gc_args;
+
+static int fib6_age(struct rt6_info *rt, void *arg)
+{
+ unsigned long now = jiffies;
+
+ /*
+ * check addrconf expiration here.
+ * Routes are expired even if they are in use.
+ *
+ * Also age clones. Note, that clones are aged out
+ * only if they are not in use now.
+ */
+
+ if (rt->rt6i_flags & RTF_EXPIRES && rt->dst.expires) {
+ if (time_after(now, rt->dst.expires)) {
+ RT6_TRACE("expiring %p\n", rt);
+ return -1;
+ }
+ gc_args.more++;
+ } else if (rt->rt6i_flags & RTF_CACHE) {
+ if (atomic_read(&rt->dst.__refcnt) == 0 &&
+ time_after_eq(now, rt->dst.lastuse + gc_args.timeout)) {
+ RT6_TRACE("aging clone %p\n", rt);
+ return -1;
+ } else if (rt->rt6i_flags & RTF_GATEWAY) {
+ struct neighbour *neigh;
+ __u8 neigh_flags = 0;
+
+ neigh = dst_neigh_lookup(&rt->dst, &rt->rt6i_gateway);
+ if (neigh) {
+ neigh_flags = neigh->flags;
+ neigh_release(neigh);
+ }
+ if (!(neigh_flags & NTF_ROUTER)) {
+ RT6_TRACE("purging route %p via non-router but gateway\n",
+ rt);
+ return -1;
+ }
+ }
+ gc_args.more++;
+ }
+
+ return 0;
+}
+
+static DEFINE_SPINLOCK(fib6_gc_lock);
+
+void fib6_run_gc(unsigned long expires, struct net *net, bool force)
+{
+ unsigned long now;
+
+ if (force) {
+ spin_lock_bh(&fib6_gc_lock);
+ } else if (!spin_trylock_bh(&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 = icmp6_dst_gc();
+
+ fib6_clean_all(net, fib6_age, NULL);
+ 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(&fib6_gc_lock);
+}
+
+static void fib6_gc_timer_cb(unsigned long arg)
+{
+ fib6_run_gc(0, (struct net *)arg, true);
+}
+
+static int __net_init fib6_net_init(struct net *net)
+{
+ size_t size = sizeof(struct hlist_head) * FIB6_TABLE_HASHSZ;
+
+ setup_timer(&net->ipv6.ip6_fib_timer, fib6_gc_timer_cb, (unsigned long)net);
+
+ 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;
+ net->ipv6.fib6_main_tbl->tb6_root.leaf = net->ipv6.ip6_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;
+ net->ipv6.fib6_local_tbl->tb6_root.leaf = net->ipv6.ip6_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:
+ return -ENOMEM;
+}
+
+static void fib6_net_exit(struct net *net)
+{
+ rt6_ifdown(net, NULL);
+ del_timer_sync(&net->ipv6.ip6_fib_timer);
+
+#ifdef CONFIG_IPV6_MULTIPLE_TABLES
+ inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers);
+ kfree(net->ipv6.fib6_local_tbl);
+#endif
+ inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers);
+ kfree(net->ipv6.fib6_main_tbl);
+ kfree(net->ipv6.fib_table_hash);
+ kfree(net->ipv6.rt6_stats);
+}
+
+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(PF_INET6, RTM_GETROUTE, NULL, inet6_dump_fib,
+ NULL);
+ 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
+
+struct ipv6_route_iter {
+ struct seq_net_private p;
+ struct fib6_walker w;
+ loff_t skip;
+ struct fib6_table *tbl;
+ int sernum;
+};
+
+static int ipv6_route_seq_show(struct seq_file *seq, void *v)
+{
+ struct rt6_info *rt = v;
+ struct ipv6_route_iter *iter = seq->private;
+
+ seq_printf(seq, "%pi6 %02x ", &rt->rt6i_dst.addr, rt->rt6i_dst.plen);
+
+#ifdef CONFIG_IPV6_SUBTREES
+ seq_printf(seq, "%pi6 %02x ", &rt->rt6i_src.addr, rt->rt6i_src.plen);
+#else
+ seq_puts(seq, "00000000000000000000000000000000 00 ");
+#endif
+ if (rt->rt6i_flags & RTF_GATEWAY)
+ seq_printf(seq, "%pi6", &rt->rt6i_gateway);
+ else
+ seq_puts(seq, "00000000000000000000000000000000");
+
+ seq_printf(seq, " %08x %08x %08x %08x %8s\n",
+ rt->rt6i_metric, atomic_read(&rt->dst.__refcnt),
+ rt->dst.__use, rt->rt6i_flags,
+ rt->dst.dev ? rt->dst.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 = iter->w.leaf->dst.rt6_next;
+ 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)
+{
+ 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 = iter->w.root->fn_sernum;
+ INIT_LIST_HEAD(&iter->w.lh);
+ fib6_walker_link(&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)
+{
+ if (iter->sernum != iter->w.root->fn_sernum) {
+ iter->sernum = iter->w.root->fn_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 rt6_info *n;
+ struct net *net = seq_file_net(seq);
+ struct ipv6_route_iter *iter = seq->private;
+
+ if (!v)
+ goto iter_table;
+
+ n = ((struct rt6_info *)v)->dst.rt6_next;
+ if (n) {
+ ++*pos;
+ return n;
+ }
+
+iter_table:
+ ipv6_route_check_sernum(iter);
+ read_lock(&iter->tbl->tb6_lock);
+ r = fib6_walk_continue(&iter->w);
+ read_unlock(&iter->tbl->tb6_lock);
+ if (r > 0) {
+ if (v)
+ ++*pos;
+ return iter->w.leaf;
+ } else if (r < 0) {
+ fib6_walker_unlink(&iter->w);
+ return NULL;
+ }
+ fib6_walker_unlink(&iter->w);
+
+ iter->tbl = ipv6_route_seq_next_table(iter->tbl, net);
+ if (!iter->tbl)
+ return NULL;
+
+ ipv6_route_seq_setup_walk(iter);
+ 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) {
+ ipv6_route_seq_setup_walk(iter);
+ return ipv6_route_seq_next(seq, NULL, pos);
+ } 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_seq_stop(struct seq_file *seq, void *v)
+ __releases(RCU_BH)
+{
+ struct ipv6_route_iter *iter = seq->private;
+
+ if (ipv6_route_iter_active(iter))
+ fib6_walker_unlink(&iter->w);
+
+ rcu_read_unlock_bh();
+}
+
+static 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
+};
+
+int ipv6_route_open(struct inode *inode, struct file *file)
+{
+ return seq_open_net(inode, file, &ipv6_route_seq_ops,
+ sizeof(struct ipv6_route_iter));
+}
+
+#endif /* CONFIG_PROC_FS */