/* * Linux INET6 implementation * Forwarding Information Database * * Authors: * Pedro Roque * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #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); 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 atomic_t rt_sernum = ATOMIC_INIT(1); 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(void) { int new, old; do { old = atomic_read(&rt_sernum); new = old < INT_MAX ? old + 1 : 1; } while (atomic_cmpxchg(&rt_sernum, old, new) != old); return new; } /* * 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; } WARN_ON(res == 0); } 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) { struct fib6_node *fn, *in, *ln; struct fib6_node *pn = NULL; struct rt6key *key; int bit; __be32 dir = 0; int sernum = fib6_new_sernum(); 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 int fib6_commit_metrics(struct dst_entry *dst, struct nlattr *mx, int mx_len) { struct nlattr *nla; int remaining; u32 *mp; if (dst->flags & DST_HOST) { mp = dst_metrics_write_ptr(dst); } else { mp = kzalloc(sizeof(u32) * RTAX_MAX, GFP_ATOMIC); if (!mp) return -ENOMEM; dst_init_metrics(dst, mp, 0); } nla_for_each_attr(nla, mx, mx_len, remaining) { int type = nla_type(nla); if (type) { if (type > RTAX_MAX) return -EINVAL; mp[type - 1] = nla_get_u32(nla); } } return 0; } /* * Insert routing information in a node. */ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt, struct nl_info *info, struct nlattr *mx, int mx_len) { struct rt6_info *iter = NULL; struct rt6_info **ins; 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) { found++; break; } 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; ins = &iter->dst.rt6_next; } /* 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: if (mx) { err = fib6_commit_metrics(&rt->dst, mx, mx_len); 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 { if (!found) { if (add) goto add; pr_warn("NLM_F_REPLACE set, but no existing node found!\n"); return -ENOENT; } if (mx) { err = fib6_commit_metrics(&rt->dst, mx, mx_len); 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); rt6_release(iter); if (!(fn->fn_flags & RTN_RTINFO)) { info->nl_net->ipv6.rt6_stats->fib_route_nodes++; fn->fn_flags |= RTN_RTINFO; } } 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. * / * with source addr info in sub-trees */ int fib6_add(struct fib6_node *root, struct rt6_info *rt, struct nl_info *info, struct nlattr *mx, int mx_len) { 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(root, &rt->rt6i_dst.addr, rt->rt6i_dst.plen, offsetof(struct rt6_info, rt6i_dst), allow_create, replace_required); 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 = fib6_new_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); 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); 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, mx, mx_len); 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 != NULL); 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); } 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); } 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 != NULL); 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, }; 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, 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.arg = arg; c.net = net; fib6_walk(&c.w); } void fib6_clean_all(struct net *net, int (*func)(struct rt6_info *, void *arg), 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, arg); write_unlock_bh(&table->tb6_lock); } } rcu_read_unlock(); } 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, NULL); } static int fib6_update_sernum(struct rt6_info *rt, void *arg) { int sernum = *(int *)arg; if (rt->rt6i_node && rt->rt6i_node->fn_sernum != sernum) rt->rt6i_node->fn_sernum = sernum; return 0; } static void fib6_flush_trees(struct net *net) { int new_sernum = fib6_new_sernum(); fib6_clean_all(net, fib6_update_sernum, &new_sernum); } /* * 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 */