netfilter: nf_conntrack_extend: introduce __nf_ct_ext_exist()

some users of nf_ct_ext_exist() know ct->ext isn't NULL. For these users, the
check for ct->ext isn't necessary, the function __nf_ct_ext_exist() can be
used instead.

the type of the return value of nf_ct_ext_exist() is changed to bool.

Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/include/net/netfilter/nf_conntrack_extend.h b/include/net/netfilter/nf_conntrack_extend.h
index 32d15bd..0772d29 100644 (file)
--- a/include/net/netfilter/nf_conntrack_extend.h
+++ b/include/net/netfilter/nf_conntrack_extend.h
@@ -28,9 +28,14 @@ struct nf_ct_ext {
        char data[0];
 };
 
-static inline int nf_ct_ext_exist(const struct nf_conn *ct, u8 id)
+static inline bool __nf_ct_ext_exist(const struct nf_ct_ext *ext, u8 id)
 {
-       return (ct->ext && ct->ext->offset[id]);
+       return !!ext->offset[id];
+}
+
+static inline bool nf_ct_ext_exist(const struct nf_conn *ct, u8 id)
+{
+       return (ct->ext && __nf_ct_ext_exist(ct->ext, id));
 }
 
 static inline void *__nf_ct_ext_find(const struct nf_conn *ct, u8 id)

diff --git a/net/netfilter/nf_conntrack_extend.c b/net/netfilter/nf_conntrack_extend.c
index fdc8fb4..7dcf7a4 100644 (file)
--- a/net/netfilter/nf_conntrack_extend.c
+++ b/net/netfilter/nf_conntrack_extend.c
@@ -23,9 +23,10 @@ void __nf_ct_ext_destroy(struct nf_conn *ct)
 {
        unsigned int i;
        struct nf_ct_ext_type *t;
+       struct nf_ct_ext *ext = ct->ext;
 
        for (i = 0; i < NF_CT_EXT_NUM; i++) {
-               if (!nf_ct_ext_exist(ct, i))
+               if (!__nf_ct_ext_exist(ext, i))
                        continue;
 
                rcu_read_lock();
@@ -73,44 +74,45 @@ static void __nf_ct_ext_free_rcu(struct rcu_head *head)
 
 void *__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
 {
-       struct nf_ct_ext *new;
+       struct nf_ct_ext *old, *new;
        int i, newlen, newoff;
        struct nf_ct_ext_type *t;
 
        /* Conntrack must not be confirmed to avoid races on reallocation. */
        NF_CT_ASSERT(!nf_ct_is_confirmed(ct));
 
-       if (!ct->ext)
+       old = ct->ext;
+       if (!old)
                return nf_ct_ext_create(&ct->ext, id, gfp);
 
-       if (nf_ct_ext_exist(ct, id))
+       if (__nf_ct_ext_exist(old, id))
                return NULL;
 
        rcu_read_lock();
        t = rcu_dereference(nf_ct_ext_types[id]);
        BUG_ON(t == NULL);
 
-       newoff = ALIGN(ct->ext->len, t->align);
+       newoff = ALIGN(old->len, t->align);
        newlen = newoff + t->len;
        rcu_read_unlock();
 
-       new = __krealloc(ct->ext, newlen, gfp);
+       new = __krealloc(old, newlen, gfp);
        if (!new)
                return NULL;
 
-       if (new != ct->ext) {
+       if (new != old) {
                for (i = 0; i < NF_CT_EXT_NUM; i++) {
-                       if (!nf_ct_ext_exist(ct, i))
+                       if (!__nf_ct_ext_exist(old, i))
                                continue;
 
                        rcu_read_lock();
                        t = rcu_dereference(nf_ct_ext_types[i]);
                        if (t && t->move)
                                t->move((void *)new + new->offset[i],
-                                       (void *)ct->ext + ct->ext->offset[i]);
+                                       (void *)old + old->offset[i]);
                        rcu_read_unlock();
                }
-               call_rcu(&ct->ext->rcu, __nf_ct_ext_free_rcu);
+               call_rcu(&old->rcu, __nf_ct_ext_free_rcu);
                ct->ext = new;
        }