From: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
commit 5e5cbc7b23eaf13e18652c03efbad5be6995de6a upstream.
This patch provides an interface to maintain the list of connections and
the lookup function to obtain the number of connections in the list.
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
[mfo: backport: refresh context lines and use older symbol/file names:
- nf_conntrack_count.h: new file, add include guards.
- nf_conncount.c -> xt_connlimit.c.
- nf_conncount_rb -> xt_connlimit_rb
- nf_conncount_tuple -> xt_connlimit_conn
- conncount_rb_cachep -> connlimit_rb_cachep
- conncount_conn_cachep -> connlimit_conn_cachep]
Signed-off-by: Mauricio Faria de Oliveira <mfo@xxxxxxxxxxxxx>
---
include/net/netfilter/nf_conntrack_count.h | 14 ++++++++++++
net/netfilter/xt_connlimit.c | 36 +++++++++++++++++++-----------
2 files changed, 37 insertions(+), 13 deletions(-)
create mode 100644 include/net/netfilter/nf_conntrack_count.h
diff --git a/include/net/netfilter/nf_conntrack_count.h b/include/net/netfilter/nf_conntrack_count.h
new file mode 100644
index 0000000..54e43b8
--- /dev/null
+++ b/include/net/netfilter/nf_conntrack_count.h
@@ -0,0 +1,14 @@
+#ifndef _NF_CONNTRACK_COUNT_H
+#define _NF_CONNTRACK_COUNT_H
+
+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);
+
+bool nf_conncount_add(struct hlist_head *head,
+ const struct nf_conntrack_tuple *tuple);
+
+void nf_conncount_cache_free(struct hlist_head *hhead);
+
+#endif
diff --git a/net/netfilter/xt_connlimit.c b/net/netfilter/xt_connlimit.c
index 79d4151..7af5875 100644
--- a/net/netfilter/xt_connlimit.c
+++ b/net/netfilter/xt_connlimit.c
@@ -114,7 +114,7 @@ same_source_net(const union nf_inet_addr *addr,
}
}
-static bool add_hlist(struct hlist_head *head,
+bool nf_conncount_add(struct hlist_head *head,
const struct nf_conntrack_tuple *tuple)
{
struct xt_connlimit_conn *conn;
@@ -126,12 +126,12 @@ static bool add_hlist(struct hlist_head *head,
hlist_add_head(&conn->node, head);
return true;
}
+EXPORT_SYMBOL_GPL(nf_conncount_add);
-static unsigned int check_hlist(struct net *net,
- struct hlist_head *head,
- const struct nf_conntrack_tuple *tuple,
- const struct nf_conntrack_zone *zone,
- bool *addit)
+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)
{
const struct nf_conntrack_tuple_hash *found;
struct xt_connlimit_conn *conn;
@@ -176,6 +176,7 @@ static unsigned int check_hlist(struct net *net,
return length;
}
+EXPORT_SYMBOL_GPL(nf_conncount_lookup);
static void tree_nodes_free(struct rb_root *root,
struct xt_connlimit_rb *gc_nodes[],
@@ -222,13 +223,15 @@ count_tree(struct net *net, struct rb_root *root,
} else {
/* same source network -> be counted! */
unsigned int count;
- count = check_hlist(net, &rbconn->hhead, tuple, zone, &addit);
+
+ count = nf_conncount_lookup(net, &rbconn->hhead, tuple,
+ zone, &addit);
tree_nodes_free(root, gc_nodes, gc_count);
if (!addit)
return count;
- if (!add_hlist(&rbconn->hhead, tuple))
+ if (!nf_conncount_add(&rbconn->hhead, tuple))
return 0; /* hotdrop */
return count + 1;
@@ -238,7 +241,7 @@ count_tree(struct net *net, struct rb_root *root,
continue;
/* only used for GC on hhead, retval and 'addit' ignored */
- check_hlist(net, &rbconn->hhead, tuple, zone, &addit);
+ nf_conncount_lookup(net, &rbconn->hhead, tuple, zone, &addit);
if (hlist_empty(&rbconn->hhead))
gc_nodes[gc_count++] = rbconn;
}
@@ -378,11 +381,19 @@ static int connlimit_mt_check(const struct xt_mtchk_param *par)
return 0;
}
-static void destroy_tree(struct rb_root *r)
+void nf_conncount_cache_free(struct hlist_head *hhead)
{
struct xt_connlimit_conn *conn;
- struct xt_connlimit_rb *rbconn;
struct hlist_node *n;
+
+ hlist_for_each_entry_safe(conn, n, hhead, node)
+ kmem_cache_free(connlimit_conn_cachep, conn);
+}
+EXPORT_SYMBOL_GPL(nf_conncount_cache_free);
+
+static void destroy_tree(struct rb_root *r)
+{
+ struct xt_connlimit_rb *rbconn;
struct rb_node *node;
while ((node = rb_first(r)) != NULL) {
@@ -390,8 +401,7 @@ static void destroy_tree(struct rb_root *r)
rb_erase(node, r);
- hlist_for_each_entry_safe(conn, n, &rbconn->hhead, node)
- kmem_cache_free(connlimit_conn_cachep, conn);
+ nf_conncount_cache_free(&rbconn->hhead);
kmem_cache_free(connlimit_rb_cachep, rbconn);
}
--
2.7.4
