netfilter: conntrack: mark extension structs as const

[mirror_ubuntu-artful-kernel.git] / net / netfilter / nf_conntrack_extend.c

diff --git a/net/netfilter/nf_conntrack_extend.c b/net/netfilter/nf_conntrack_extend.c
index b5879a9c748d0c392234312152455bafef1ed92a..5c66816eb965129cc0bc8dcfe76d5fbc9351142e 100644 (file)
--- a/net/netfilter/nf_conntrack_extend.c
+++ b/net/netfilter/nf_conntrack_extend.c
@@ -18,6 +18,7 @@
 
 static struct nf_ct_ext_type __rcu *nf_ct_ext_types[NF_CT_EXT_NUM];
 static DEFINE_MUTEX(nf_ct_ext_type_mutex);
+#define NF_CT_EXT_PREALLOC     128u /* conntrack events are on by default */
 
 void __nf_ct_ext_destroy(struct nf_conn *ct)
 {
@@ -46,9 +47,8 @@ EXPORT_SYMBOL(__nf_ct_ext_destroy);
 static void *
 nf_ct_ext_create(struct nf_ct_ext **ext, enum nf_ct_ext_id id, gfp_t gfp)
 {
-       unsigned int off, len;
+       unsigned int off, len, alloc;
        struct nf_ct_ext_type *t;
-       size_t alloc_size;
 
        rcu_read_lock();
        t = rcu_dereference(nf_ct_ext_types[id]);
@@ -59,10 +59,10 @@ nf_ct_ext_create(struct nf_ct_ext **ext, enum nf_ct_ext_id id, gfp_t gfp)
 
        off = ALIGN(sizeof(struct nf_ct_ext), t->align);
        len = off + t->len;
-       alloc_size = t->alloc_size;
        rcu_read_unlock();
 
-       *ext = kzalloc(alloc_size, gfp);
+       alloc = max(len, NF_CT_EXT_PREALLOC);
+       *ext = kzalloc(alloc, gfp);
        if (!*ext)
                return NULL;
 
@@ -115,43 +115,8 @@ void *nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
 }
 EXPORT_SYMBOL(nf_ct_ext_add);
 
-static void update_alloc_size(struct nf_ct_ext_type *type)
-{
-       int i, j;
-       struct nf_ct_ext_type *t1, *t2;
-       enum nf_ct_ext_id min = 0, max = NF_CT_EXT_NUM - 1;
-
-       /* unnecessary to update all types */
-       if ((type->flags & NF_CT_EXT_F_PREALLOC) == 0) {
-               min = type->id;
-               max = type->id;
-       }
-
-       /* This assumes that extended areas in conntrack for the types
-          whose NF_CT_EXT_F_PREALLOC bit set are allocated in order */
-       for (i = min; i <= max; i++) {
-               t1 = rcu_dereference_protected(nf_ct_ext_types[i],
-                               lockdep_is_held(&nf_ct_ext_type_mutex));
-               if (!t1)
-                       continue;
-
-               t1->alloc_size = ALIGN(sizeof(struct nf_ct_ext), t1->align) +
-                                t1->len;
-               for (j = 0; j < NF_CT_EXT_NUM; j++) {
-                       t2 = rcu_dereference_protected(nf_ct_ext_types[j],
-                               lockdep_is_held(&nf_ct_ext_type_mutex));
-                       if (t2 == NULL || t2 == t1 ||
-                           (t2->flags & NF_CT_EXT_F_PREALLOC) == 0)
-                               continue;
-
-                       t1->alloc_size = ALIGN(t1->alloc_size, t2->align)
-                                        + t2->len;
-               }
-       }
-}
-
 /* This MUST be called in process context. */
-int nf_ct_extend_register(struct nf_ct_ext_type *type)
+int nf_ct_extend_register(const struct nf_ct_ext_type *type)
 {
        int ret = 0;
 
@@ -161,12 +126,7 @@ int nf_ct_extend_register(struct nf_ct_ext_type *type)
                goto out;
        }
 
-       /* This ensures that nf_ct_ext_create() can allocate enough area
-          before updating alloc_size */
-       type->alloc_size = ALIGN(sizeof(struct nf_ct_ext), type->align)
-                          + type->len;
        rcu_assign_pointer(nf_ct_ext_types[type->id], type);
-       update_alloc_size(type);
 out:
        mutex_unlock(&nf_ct_ext_type_mutex);
        return ret;
@@ -174,11 +134,10 @@ out:
 EXPORT_SYMBOL_GPL(nf_ct_extend_register);
 
 /* This MUST be called in process context. */
-void nf_ct_extend_unregister(struct nf_ct_ext_type *type)
+void nf_ct_extend_unregister(const struct nf_ct_ext_type *type)
 {
        mutex_lock(&nf_ct_ext_type_mutex);
        RCU_INIT_POINTER(nf_ct_ext_types[type->id], NULL);
-       update_alloc_size(type);
        mutex_unlock(&nf_ct_ext_type_mutex);
        synchronize_rcu();
 }