Merge branch 'for-linus2' of git://git.kernel.dk/linux-2.6-block

[safe/jmp/linux-2.6] / net / netfilter / nf_conntrack_extend.c

diff --git a/net/netfilter/nf_conntrack_extend.c b/net/netfilter/nf_conntrack_extend.c
index 8b9be1e..fdc8fb4 100644 (file)
--- a/net/netfilter/nf_conntrack_extend.c
+++ b/net/netfilter/nf_conntrack_extend.c
@@ -19,14 +19,6 @@
 static struct nf_ct_ext_type *nf_ct_ext_types[NF_CT_EXT_NUM];
 static DEFINE_MUTEX(nf_ct_ext_type_mutex);
 
-/* Horrible trick to figure out smallest amount worth kmallocing. */
-#define CACHE(x) (x) + 0 *
-enum {
-       NF_CT_EXT_MIN_SIZE =
-#include <linux/kmalloc_sizes.h>
-       1 };
-#undef CACHE
-
 void __nf_ct_ext_destroy(struct nf_conn *ct)
 {
        unsigned int i;
@@ -53,7 +45,7 @@ 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, real_len;
+       unsigned int off, len;
        struct nf_ct_ext_type *t;
 
        rcu_read_lock();
@@ -61,26 +53,33 @@ nf_ct_ext_create(struct nf_ct_ext **ext, enum nf_ct_ext_id id, gfp_t gfp)
        BUG_ON(t == NULL);
        off = ALIGN(sizeof(struct nf_ct_ext), t->align);
        len = off + t->len;
-       real_len = t->alloc_size;
        rcu_read_unlock();
 
-       *ext = kzalloc(real_len, gfp);
+       *ext = kzalloc(t->alloc_size, gfp);
        if (!*ext)
                return NULL;
 
        (*ext)->offset[id] = off;
        (*ext)->len = len;
-       (*ext)->real_len = real_len;
 
        return (void *)(*ext) + off;
 }
 
+static void __nf_ct_ext_free_rcu(struct rcu_head *head)
+{
+       struct nf_ct_ext *ext = container_of(head, struct nf_ct_ext, rcu);
+       kfree(ext);
+}
+
 void *__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
 {
        struct nf_ct_ext *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)
                return nf_ct_ext_create(&ct->ext, id, gfp);
 
@@ -95,13 +94,11 @@ void *__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
        newlen = newoff + t->len;
        rcu_read_unlock();
 
-       if (newlen >= ct->ext->real_len) {
-               new = kmalloc(newlen, gfp);
-               if (!new)
-                       return NULL;
-
-               memcpy(new, ct->ext, ct->ext->len);
+       new = __krealloc(ct->ext, newlen, gfp);
+       if (!new)
+               return NULL;
 
+       if (new != ct->ext) {
                for (i = 0; i < NF_CT_EXT_NUM; i++) {
                        if (!nf_ct_ext_exist(ct, i))
                                continue;
@@ -113,15 +110,14 @@ void *__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
                                        (void *)ct->ext + ct->ext->offset[i]);
                        rcu_read_unlock();
                }
-               kfree(ct->ext);
-               new->real_len = newlen;
+               call_rcu(&ct->ext->rcu, __nf_ct_ext_free_rcu);
                ct->ext = new;
        }
 
-       ct->ext->offset[id] = newoff;
-       ct->ext->len = newlen;
-       memset((void *)ct->ext + newoff, 0, newlen - newoff);
-       return (void *)ct->ext + newoff;
+       new->offset[id] = newoff;
+       new->len = newlen;
+       memset((void *)new + newoff, 0, newlen - newoff);
+       return (void *)new + newoff;
 }
 EXPORT_SYMBOL(__nf_ct_ext_add);
 
@@ -156,8 +152,6 @@ static void update_alloc_size(struct nf_ct_ext_type *type)
                        t1->alloc_size = ALIGN(t1->alloc_size, t2->align)
                                         + t2->len;
                }
-               if (t1->alloc_size < NF_CT_EXT_MIN_SIZE)
-                       t1->alloc_size = NF_CT_EXT_MIN_SIZE;
        }
 }
 
@@ -191,6 +185,6 @@ void nf_ct_extend_unregister(struct nf_ct_ext_type *type)
        rcu_assign_pointer(nf_ct_ext_types[type->id], NULL);
        update_alloc_size(type);
        mutex_unlock(&nf_ct_ext_type_mutex);
-       synchronize_rcu();
+       rcu_barrier(); /* Wait for completion of call_rcu()'s */
 }
 EXPORT_SYMBOL_GPL(nf_ct_extend_unregister);