netfilter: introduce nf_conntrack_helper_put helper function

And convert module_put invocation to nf_conntrack_helper_put, this is
prepared for the followup patch, which will add a refcnt for cthelper,
so we can reject the deleting request when cthelper is in use.

Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

4 files changed, 13 insertions, 7 deletions

diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index 3a60efa7799b..e17006b6e434 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -181,6 +181,12 @@ nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum)
 }
 EXPORT_SYMBOL_GPL(nf_conntrack_helper_try_module_get);
 
+void nf_conntrack_helper_put(struct nf_conntrack_helper *helper)
+{
+        module_put(helper->me);
+}
+EXPORT_SYMBOL_GPL(nf_conntrack_helper_put);
+
 struct nf_conn_help *
 nf_ct_helper_ext_add(struct nf_conn *ct,
                      struct nf_conntrack_helper *helper, gfp_t gfp)
diff --git a/net/netfilter/nft_ct.c b/net/netfilter/nft_ct.c
index a34ceb38fc55..1678e9e75e8e 100644
--- a/net/netfilter/nft_ct.c
+++ b/net/netfilter/nft_ct.c
@@ -826,9 +826,9 @@ static void nft_ct_helper_obj_destroy(struct nft_object *obj)
         struct nft_ct_helper_obj *priv = nft_obj_data(obj);
 
         if (priv->helper4)
-                module_put(priv->helper4->me);
+                nf_conntrack_helper_put(priv->helper4);
         if (priv->helper6)
-                module_put(priv->helper6->me);
+                nf_conntrack_helper_put(priv->helper6);
 }
 
 static void nft_ct_helper_obj_eval(struct nft_object *obj,
diff --git a/net/netfilter/xt_CT.c b/net/netfilter/xt_CT.c
index bb7ad82dcd56..623ef37de886 100644
--- a/net/netfilter/xt_CT.c
+++ b/net/netfilter/xt_CT.c
@@ -96,7 +96,7 @@ xt_ct_set_helper(struct nf_conn *ct, const char *helper_name,
 
         help = nf_ct_helper_ext_add(ct, helper, GFP_KERNEL);
         if (help == NULL) {
-                module_put(helper->me);
+                nf_conntrack_helper_put(helper);
                 return -ENOMEM;
         }
 
@@ -263,7 +263,7 @@ out:
 err4:
         help = nfct_help(ct);
         if (help)
-                module_put(help->helper->me);
+                nf_conntrack_helper_put(help->helper);
 err3:
         nf_ct_tmpl_free(ct);
 err2:
@@ -346,7 +346,7 @@ static void xt_ct_tg_destroy(const struct xt_tgdtor_param *par,
         if (ct) {
                 help = nfct_help(ct);
                 if (help)
-                        module_put(help->helper->me);
+                        nf_conntrack_helper_put(help->helper);
 
                 nf_ct_netns_put(par->net, par->family);
 
diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index bf602e33c40a..08679ebb3068 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -1123,7 +1123,7 @@ static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
 
         help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
         if (!help) {
-                module_put(helper->me);
+                nf_conntrack_helper_put(helper);
                 return -ENOMEM;
         }
 
@@ -1584,7 +1584,7 @@ void ovs_ct_free_action(const struct nlattr *a)
 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
 {
         if (ct_info->helper)
-                module_put(ct_info->helper->me);
+                nf_conntrack_helper_put(ct_info->helper);
         if (ct_info->ct)
                 nf_ct_tmpl_free(ct_info->ct);
 }