Commit 2ba39118 authored by Yi-Hung Wei's avatar Yi-Hung Wei Committed by Pablo Neira Ayuso

netfilter: nf_conncount: Move locking into count_tree()

This patch is originally from Florian Westphal.

This is a preparation patch to allow lockless traversal
of the tree via RCU.
Signed-off-by: default avatarYi-Hung Wei <yihung.wei@gmail.com>
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 976afca1
......@@ -262,18 +262,26 @@ static void tree_nodes_free(struct rb_root *root,
}
static unsigned int
count_tree(struct net *net, struct rb_root *root,
const u32 *key, u8 keylen,
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)
{
struct nf_conncount_rb *gc_nodes[CONNCOUNT_GC_MAX_NODES];
struct rb_root *root;
struct rb_node **rbnode, *parent;
struct nf_conncount_rb *rbconn;
struct nf_conncount_tuple *conn;
unsigned int gc_count;
unsigned int gc_count, hash;
bool no_gc = false;
unsigned int count = 0;
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]);
restart:
gc_count = 0;
parent = NULL;
......@@ -292,20 +300,20 @@ count_tree(struct net *net, struct rb_root *root,
rbnode = &((*rbnode)->rb_right);
} else {
/* same source network -> be counted! */
unsigned int count;
nf_conncount_lookup(net, &rbconn->list, tuple, zone,
&addit);
count = rbconn->list.count;
tree_nodes_free(root, gc_nodes, gc_count);
if (!addit)
return count;
goto out_unlock;
if (!nf_conncount_add(&rbconn->list, tuple, zone))
return 0; /* hotdrop */
count = 0; /* hotdrop */
goto out_unlock;
return count + 1;
count++;
goto out_unlock;
}
if (no_gc || gc_count >= ARRAY_SIZE(gc_nodes))
......@@ -328,18 +336,18 @@ count_tree(struct net *net, struct rb_root *root,
goto restart;
}
count = 0;
if (!tuple)
return 0;
goto out_unlock;
/* no match, need to 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;
......@@ -348,10 +356,13 @@ count_tree(struct net *net, struct rb_root *root,
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'.
......@@ -363,20 +374,7 @@ unsigned int nf_conncount_count(struct net *net,
const struct nf_conntrack_tuple *tuple,
const struct nf_conntrack_zone *zone)
{
struct rb_root *root;
int count;
u32 hash;
hash = jhash2(key, data->keylen, conncount_rnd) % CONNCOUNT_SLOTS;
root = &data->root[hash];
spin_lock_bh(&nf_conncount_locks[hash % CONNCOUNT_LOCK_SLOTS]);
count = count_tree(net, root, key, data->keylen, tuple, zone);
spin_unlock_bh(&nf_conncount_locks[hash % CONNCOUNT_LOCK_SLOTS]);
return count;
return count_tree(net, data, key, tuple, zone);
}
EXPORT_SYMBOL_GPL(nf_conncount_count);
......
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