diff options
Diffstat (limited to 'net/netfilter/nf_conncount.c')
-rw-r--r-- | net/netfilter/nf_conncount.c | 386 |
1 files changed, 299 insertions, 87 deletions
diff --git a/net/netfilter/nf_conncount.c b/net/netfilter/nf_conncount.c index 510039862aa9..02ca7df793f5 100644 --- a/net/netfilter/nf_conncount.c +++ b/net/netfilter/nf_conncount.c @@ -44,17 +44,19 @@ /* we will save the tuples of all connections we care about */ struct nf_conncount_tuple { - struct hlist_node node; + struct list_head node; struct nf_conntrack_tuple tuple; struct nf_conntrack_zone zone; int cpu; u32 jiffies32; + struct rcu_head rcu_head; }; struct nf_conncount_rb { struct rb_node node; - struct hlist_head hhead; /* connections/hosts in same subnet */ + struct nf_conncount_list list; u32 key[MAX_KEYLEN]; + struct rcu_head rcu_head; }; static spinlock_t nf_conncount_locks[CONNCOUNT_LOCK_SLOTS] __cacheline_aligned_in_smp; @@ -62,6 +64,10 @@ static spinlock_t nf_conncount_locks[CONNCOUNT_LOCK_SLOTS] __cacheline_aligned_i struct nf_conncount_data { unsigned int keylen; struct rb_root root[CONNCOUNT_SLOTS]; + struct net *net; + struct work_struct gc_work; + unsigned long pending_trees[BITS_TO_LONGS(CONNCOUNT_SLOTS)]; + unsigned int gc_tree; }; static u_int32_t conncount_rnd __read_mostly; @@ -82,26 +88,70 @@ static int key_diff(const u32 *a, const u32 *b, unsigned int klen) return memcmp(a, b, klen * sizeof(u32)); } -bool nf_conncount_add(struct hlist_head *head, - const struct nf_conntrack_tuple *tuple, - const struct nf_conntrack_zone *zone) +enum nf_conncount_list_add +nf_conncount_add(struct nf_conncount_list *list, + const struct nf_conntrack_tuple *tuple, + const struct nf_conntrack_zone *zone) { struct nf_conncount_tuple *conn; + if (WARN_ON_ONCE(list->count > INT_MAX)) + return NF_CONNCOUNT_ERR; + conn = kmem_cache_alloc(conncount_conn_cachep, GFP_ATOMIC); if (conn == NULL) - return false; + return NF_CONNCOUNT_ERR; + conn->tuple = *tuple; conn->zone = *zone; conn->cpu = raw_smp_processor_id(); conn->jiffies32 = (u32)jiffies; - hlist_add_head(&conn->node, head); - return true; + spin_lock(&list->list_lock); + if (list->dead == true) { + kmem_cache_free(conncount_conn_cachep, conn); + spin_unlock(&list->list_lock); + return NF_CONNCOUNT_SKIP; + } + list_add_tail(&conn->node, &list->head); + list->count++; + spin_unlock(&list->list_lock); + return NF_CONNCOUNT_ADDED; } EXPORT_SYMBOL_GPL(nf_conncount_add); +static void __conn_free(struct rcu_head *h) +{ + struct nf_conncount_tuple *conn; + + conn = container_of(h, struct nf_conncount_tuple, rcu_head); + kmem_cache_free(conncount_conn_cachep, conn); +} + +static bool conn_free(struct nf_conncount_list *list, + struct nf_conncount_tuple *conn) +{ + bool free_entry = false; + + spin_lock(&list->list_lock); + + if (list->count == 0) { + spin_unlock(&list->list_lock); + return free_entry; + } + + list->count--; + list_del_rcu(&conn->node); + if (list->count == 0) + free_entry = true; + + spin_unlock(&list->list_lock); + call_rcu(&conn->rcu_head, __conn_free); + return free_entry; +} + static const struct nf_conntrack_tuple_hash * -find_or_evict(struct net *net, struct nf_conncount_tuple *conn) +find_or_evict(struct net *net, struct nf_conncount_list *list, + struct nf_conncount_tuple *conn, bool *free_entry) { const struct nf_conntrack_tuple_hash *found; unsigned long a, b; @@ -121,34 +171,37 @@ find_or_evict(struct net *net, struct nf_conncount_tuple *conn) */ age = a - b; if (conn->cpu == cpu || age >= 2) { - hlist_del(&conn->node); - kmem_cache_free(conncount_conn_cachep, conn); + *free_entry = conn_free(list, conn); return ERR_PTR(-ENOENT); } return ERR_PTR(-EAGAIN); } -unsigned int nf_conncount_lookup(struct net *net, struct hlist_head *head, - const struct nf_conntrack_tuple *tuple, - const struct nf_conntrack_zone *zone, - bool *addit) +void nf_conncount_lookup(struct net *net, + struct nf_conncount_list *list, + const struct nf_conntrack_tuple *tuple, + const struct nf_conntrack_zone *zone, + bool *addit) { const struct nf_conntrack_tuple_hash *found; - struct nf_conncount_tuple *conn; + struct nf_conncount_tuple *conn, *conn_n; struct nf_conn *found_ct; - struct hlist_node *n; - unsigned int length = 0; + unsigned int collect = 0; + bool free_entry = false; + /* best effort only */ *addit = tuple ? true : false; /* check the saved connections */ - hlist_for_each_entry_safe(conn, n, head, node) { - found = find_or_evict(net, conn); + list_for_each_entry_safe(conn, conn_n, &list->head, node) { + if (collect > CONNCOUNT_GC_MAX_NODES) + break; + + found = find_or_evict(net, list, conn, &free_entry); if (IS_ERR(found)) { /* Not found, but might be about to be confirmed */ if (PTR_ERR(found) == -EAGAIN) { - length++; if (!tuple) continue; @@ -156,7 +209,8 @@ unsigned int nf_conncount_lookup(struct net *net, struct hlist_head *head, nf_ct_zone_id(&conn->zone, conn->zone.dir) == nf_ct_zone_id(zone, zone->dir)) *addit = false; - } + } else if (PTR_ERR(found) == -ENOENT) + collect++; continue; } @@ -165,9 +219,10 @@ unsigned int nf_conncount_lookup(struct net *net, struct hlist_head *head, if (tuple && nf_ct_tuple_equal(&conn->tuple, tuple) && nf_ct_zone_equal(found_ct, zone, zone->dir)) { /* - * Just to be sure we have it only once in the list. * We should not see tuples twice unless someone hooks * this into a table without "-p tcp --syn". + * + * Attempt to avoid a re-add in this case. */ *addit = false; } else if (already_closed(found_ct)) { @@ -176,19 +231,75 @@ unsigned int nf_conncount_lookup(struct net *net, struct hlist_head *head, * closed already -> ditch it */ nf_ct_put(found_ct); - hlist_del(&conn->node); - kmem_cache_free(conncount_conn_cachep, conn); + conn_free(list, conn); + collect++; continue; } nf_ct_put(found_ct); - length++; } - - return length; } EXPORT_SYMBOL_GPL(nf_conncount_lookup); +void nf_conncount_list_init(struct nf_conncount_list *list) +{ + spin_lock_init(&list->list_lock); + INIT_LIST_HEAD(&list->head); + list->count = 1; + list->dead = false; +} +EXPORT_SYMBOL_GPL(nf_conncount_list_init); + +/* Return true if the list is empty */ +bool nf_conncount_gc_list(struct net *net, + struct nf_conncount_list *list) +{ + const struct nf_conntrack_tuple_hash *found; + struct nf_conncount_tuple *conn, *conn_n; + struct nf_conn *found_ct; + unsigned int collected = 0; + bool free_entry = false; + + list_for_each_entry_safe(conn, conn_n, &list->head, node) { + found = find_or_evict(net, list, conn, &free_entry); + if (IS_ERR(found)) { + if (PTR_ERR(found) == -ENOENT) { + if (free_entry) + return true; + collected++; + } + continue; + } + + found_ct = nf_ct_tuplehash_to_ctrack(found); + if (already_closed(found_ct)) { + /* + * we do not care about connections which are + * closed already -> ditch it + */ + nf_ct_put(found_ct); + if (conn_free(list, conn)) + return true; + collected++; + continue; + } + + nf_ct_put(found_ct); + if (collected > CONNCOUNT_GC_MAX_NODES) + return false; + } + return false; +} +EXPORT_SYMBOL_GPL(nf_conncount_gc_list); + +static void __tree_nodes_free(struct rcu_head *h) +{ + struct nf_conncount_rb *rbconn; + + rbconn = container_of(h, struct nf_conncount_rb, rcu_head); + kmem_cache_free(conncount_rb_cachep, rbconn); +} + static void tree_nodes_free(struct rb_root *root, struct nf_conncount_rb *gc_nodes[], unsigned int gc_count) @@ -197,32 +308,46 @@ static void tree_nodes_free(struct rb_root *root, while (gc_count) { rbconn = gc_nodes[--gc_count]; - rb_erase(&rbconn->node, root); - kmem_cache_free(conncount_rb_cachep, rbconn); + spin_lock(&rbconn->list.list_lock); + if (rbconn->list.count == 0 && rbconn->list.dead == false) { + rbconn->list.dead = true; + rb_erase(&rbconn->node, root); + call_rcu(&rbconn->rcu_head, __tree_nodes_free); + } + spin_unlock(&rbconn->list.list_lock); } } +static void schedule_gc_worker(struct nf_conncount_data *data, int tree) +{ + set_bit(tree, data->pending_trees); + schedule_work(&data->gc_work); +} + static unsigned int -count_tree(struct net *net, struct rb_root *root, - const u32 *key, u8 keylen, - const struct nf_conntrack_tuple *tuple, - const struct nf_conntrack_zone *zone) +insert_tree(struct net *net, + struct nf_conncount_data *data, + struct rb_root *root, + unsigned int hash, + const u32 *key, + u8 keylen, + const struct nf_conntrack_tuple *tuple, + const struct nf_conntrack_zone *zone) { + enum nf_conncount_list_add ret; struct nf_conncount_rb *gc_nodes[CONNCOUNT_GC_MAX_NODES]; struct rb_node **rbnode, *parent; struct nf_conncount_rb *rbconn; struct nf_conncount_tuple *conn; - unsigned int gc_count; - bool no_gc = false; + unsigned int count = 0, gc_count = 0; + bool node_found = false; + + spin_lock_bh(&nf_conncount_locks[hash % CONNCOUNT_LOCK_SLOTS]); - restart: - gc_count = 0; parent = NULL; rbnode = &(root->rb_node); while (*rbnode) { int diff; - bool addit; - rbconn = rb_entry(*rbnode, struct nf_conncount_rb, node); parent = *rbnode; @@ -232,33 +357,30 @@ count_tree(struct net *net, struct rb_root *root, } else if (diff > 0) { rbnode = &((*rbnode)->rb_right); } else { - /* same source network -> be counted! */ - unsigned int count; - - count = nf_conncount_lookup(net, &rbconn->hhead, tuple, - zone, &addit); - - tree_nodes_free(root, gc_nodes, gc_count); - if (!addit) - return count; - - if (!nf_conncount_add(&rbconn->hhead, tuple, zone)) - return 0; /* hotdrop */ - - return count + 1; + /* unlikely: other cpu added node already */ + node_found = true; + ret = nf_conncount_add(&rbconn->list, tuple, zone); + if (ret == NF_CONNCOUNT_ERR) { + count = 0; /* hotdrop */ + } else if (ret == NF_CONNCOUNT_ADDED) { + count = rbconn->list.count; + } else { + /* NF_CONNCOUNT_SKIP, rbconn is already + * reclaimed by gc, insert a new tree node + */ + node_found = false; + } + break; } - if (no_gc || gc_count >= ARRAY_SIZE(gc_nodes)) + if (gc_count >= ARRAY_SIZE(gc_nodes)) continue; - /* only used for GC on hhead, retval and 'addit' ignored */ - nf_conncount_lookup(net, &rbconn->hhead, tuple, zone, &addit); - if (hlist_empty(&rbconn->hhead)) + if (nf_conncount_gc_list(net, &rbconn->list)) gc_nodes[gc_count++] = rbconn; } if (gc_count) { - no_gc = true; tree_nodes_free(root, gc_nodes, gc_count); /* tree_node_free before new allocation permits * allocator to re-use newly free'd object. @@ -266,58 +388,146 @@ count_tree(struct net *net, struct rb_root *root, * This is a rare event; in most cases we will find * existing node to re-use. (or gc_count is 0). */ - goto restart; + + if (gc_count >= ARRAY_SIZE(gc_nodes)) + schedule_gc_worker(data, hash); } - if (!tuple) - return 0; + if (node_found) + goto out_unlock; - /* no match, need to insert new node */ + /* expected case: match, insert new node */ rbconn = kmem_cache_alloc(conncount_rb_cachep, GFP_ATOMIC); if (rbconn == NULL) - return 0; + goto out_unlock; conn = kmem_cache_alloc(conncount_conn_cachep, GFP_ATOMIC); if (conn == NULL) { kmem_cache_free(conncount_rb_cachep, rbconn); - return 0; + goto out_unlock; } conn->tuple = *tuple; conn->zone = *zone; memcpy(rbconn->key, key, sizeof(u32) * keylen); - INIT_HLIST_HEAD(&rbconn->hhead); - hlist_add_head(&conn->node, &rbconn->hhead); + nf_conncount_list_init(&rbconn->list); + list_add(&conn->node, &rbconn->list.head); + count = 1; rb_link_node(&rbconn->node, parent, rbnode); rb_insert_color(&rbconn->node, root); - return 1; +out_unlock: + spin_unlock_bh(&nf_conncount_locks[hash % CONNCOUNT_LOCK_SLOTS]); + return count; } -/* Count and return number of conntrack entries in 'net' with particular 'key'. - * If 'tuple' is not null, insert it into the accounting data structure. - */ -unsigned int nf_conncount_count(struct net *net, - struct nf_conncount_data *data, - const u32 *key, - const struct nf_conntrack_tuple *tuple, - const struct nf_conntrack_zone *zone) +static unsigned int +count_tree(struct net *net, + struct nf_conncount_data *data, + const u32 *key, + const struct nf_conntrack_tuple *tuple, + const struct nf_conntrack_zone *zone) { + enum nf_conncount_list_add ret; struct rb_root *root; - int count; - u32 hash; + struct rb_node *parent; + struct nf_conncount_rb *rbconn; + unsigned int hash; + u8 keylen = data->keylen; hash = jhash2(key, data->keylen, conncount_rnd) % CONNCOUNT_SLOTS; root = &data->root[hash]; - spin_lock_bh(&nf_conncount_locks[hash % CONNCOUNT_LOCK_SLOTS]); + parent = rcu_dereference_raw(root->rb_node); + while (parent) { + int diff; + bool addit; - count = count_tree(net, root, key, data->keylen, tuple, zone); + rbconn = rb_entry(parent, struct nf_conncount_rb, node); - spin_unlock_bh(&nf_conncount_locks[hash % CONNCOUNT_LOCK_SLOTS]); + diff = key_diff(key, rbconn->key, keylen); + if (diff < 0) { + parent = rcu_dereference_raw(parent->rb_left); + } else if (diff > 0) { + parent = rcu_dereference_raw(parent->rb_right); + } else { + /* same source network -> be counted! */ + nf_conncount_lookup(net, &rbconn->list, tuple, zone, + &addit); - return count; + if (!addit) + return rbconn->list.count; + + ret = nf_conncount_add(&rbconn->list, tuple, zone); + if (ret == NF_CONNCOUNT_ERR) { + return 0; /* hotdrop */ + } else if (ret == NF_CONNCOUNT_ADDED) { + return rbconn->list.count; + } else { + /* NF_CONNCOUNT_SKIP, rbconn is already + * reclaimed by gc, insert a new tree node + */ + break; + } + } + } + + if (!tuple) + return 0; + + return insert_tree(net, data, root, hash, key, keylen, tuple, zone); +} + +static void tree_gc_worker(struct work_struct *work) +{ + struct nf_conncount_data *data = container_of(work, struct nf_conncount_data, gc_work); + struct nf_conncount_rb *gc_nodes[CONNCOUNT_GC_MAX_NODES], *rbconn; + struct rb_root *root; + struct rb_node *node; + unsigned int tree, next_tree, gc_count = 0; + + tree = data->gc_tree % CONNCOUNT_LOCK_SLOTS; + root = &data->root[tree]; + + rcu_read_lock(); + for (node = rb_first(root); node != NULL; node = rb_next(node)) { + rbconn = rb_entry(node, struct nf_conncount_rb, node); + if (nf_conncount_gc_list(data->net, &rbconn->list)) + gc_nodes[gc_count++] = rbconn; + } + rcu_read_unlock(); + + spin_lock_bh(&nf_conncount_locks[tree]); + + if (gc_count) { + tree_nodes_free(root, gc_nodes, gc_count); + } + + clear_bit(tree, data->pending_trees); + + next_tree = (tree + 1) % CONNCOUNT_SLOTS; + next_tree = find_next_bit(data->pending_trees, next_tree, CONNCOUNT_SLOTS); + + if (next_tree < CONNCOUNT_SLOTS) { + data->gc_tree = next_tree; + schedule_work(work); + } + + spin_unlock_bh(&nf_conncount_locks[tree]); +} + +/* Count and return number of conntrack entries in 'net' with particular 'key'. + * If 'tuple' is not null, insert it into the accounting data structure. + * Call with RCU read lock. + */ +unsigned int nf_conncount_count(struct net *net, + struct nf_conncount_data *data, + const u32 *key, + const struct nf_conntrack_tuple *tuple, + const struct nf_conntrack_zone *zone) +{ + return count_tree(net, data, key, tuple, zone); } EXPORT_SYMBOL_GPL(nf_conncount_count); @@ -348,17 +558,18 @@ struct nf_conncount_data *nf_conncount_init(struct net *net, unsigned int family data->root[i] = RB_ROOT; data->keylen = keylen / sizeof(u32); + data->net = net; + INIT_WORK(&data->gc_work, tree_gc_worker); return data; } EXPORT_SYMBOL_GPL(nf_conncount_init); -void nf_conncount_cache_free(struct hlist_head *hhead) +void nf_conncount_cache_free(struct nf_conncount_list *list) { - struct nf_conncount_tuple *conn; - struct hlist_node *n; + struct nf_conncount_tuple *conn, *conn_n; - hlist_for_each_entry_safe(conn, n, hhead, node) + list_for_each_entry_safe(conn, conn_n, &list->head, node) kmem_cache_free(conncount_conn_cachep, conn); } EXPORT_SYMBOL_GPL(nf_conncount_cache_free); @@ -373,7 +584,7 @@ static void destroy_tree(struct rb_root *r) rb_erase(node, r); - nf_conncount_cache_free(&rbconn->hhead); + nf_conncount_cache_free(&rbconn->list); kmem_cache_free(conncount_rb_cachep, rbconn); } @@ -384,6 +595,7 @@ void nf_conncount_destroy(struct net *net, unsigned int family, { unsigned int i; + cancel_work_sync(&data->gc_work); nf_ct_netns_put(net, family); for (i = 0; i < ARRAY_SIZE(data->root); ++i) |