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>

1 files changed, 12 insertions, 10 deletions

diff --git a/net/netfilter/nf_conntrack_extend.c b/net/netfilter/nf_conntrack_extend.c
index fdc8fb4ae10f..7dcf7a404190 100644
--- 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;
         }