netfilter: nf_conntrack: restrict runtime expect hashsize modifications

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

diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index 37a703b..4ad7d1d 100644 (file)
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -72,7 +72,8 @@ static unsigned int nf_ct_expect_dst_hash(const struct nf_conntrack_tuple *tuple
        unsigned int hash;
 
        if (unlikely(!nf_ct_expect_hash_rnd_initted)) {
-               get_random_bytes(&nf_ct_expect_hash_rnd, 4);
+               get_random_bytes(&nf_ct_expect_hash_rnd,
+                                sizeof(nf_ct_expect_hash_rnd));
                nf_ct_expect_hash_rnd_initted = 1;
        }
 
@@ -201,9 +202,9 @@ static inline int expect_clash(const struct nf_conntrack_expect *a,
 static inline int expect_matches(const struct nf_conntrack_expect *a,
                                 const struct nf_conntrack_expect *b)
 {
-       return a->master == b->master && a->class == b->class
-               && nf_ct_tuple_equal(&a->tuple, &b->tuple)
-               && nf_ct_tuple_mask_equal(&a->mask, &b->mask);
+       return a->master == b->master && a->class == b->class &&
+               nf_ct_tuple_equal(&a->tuple, &b->tuple) &&
+               nf_ct_tuple_mask_equal(&a->mask, &b->mask);
 }
 
 /* Generally a bad idea to call this: could have matched already. */
@@ -362,7 +363,7 @@ static inline int refresh_timer(struct nf_conntrack_expect *i)
        return 1;
 }
 
-int nf_ct_expect_related(struct nf_conntrack_expect *expect)
+static inline int __nf_ct_expect_check(struct nf_conntrack_expect *expect)
 {
        const struct nf_conntrack_expect_policy *p;
        struct nf_conntrack_expect *i;
@@ -371,11 +372,8 @@ int nf_ct_expect_related(struct nf_conntrack_expect *expect)
        struct net *net = nf_ct_exp_net(expect);
        struct hlist_node *n;
        unsigned int h;
-       int ret;
-
-       NF_CT_ASSERT(master_help);
+       int ret = 1;
 
-       spin_lock_bh(&nf_conntrack_lock);
        if (!master_help->helper) {
                ret = -ESHUTDOWN;
                goto out;
@@ -409,17 +407,31 @@ int nf_ct_expect_related(struct nf_conntrack_expect *expect)
                        printk(KERN_WARNING
                               "nf_conntrack: expectation table full\n");
                ret = -EMFILE;
-               goto out;
        }
+out:
+       return ret;
+}
+
+int nf_ct_expect_related_report(struct nf_conntrack_expect *expect, 
+                               u32 pid, int report)
+{
+       int ret;
+
+       spin_lock_bh(&nf_conntrack_lock);
+       ret = __nf_ct_expect_check(expect);
+       if (ret <= 0)
+               goto out;
 
-       nf_ct_expect_insert(expect);
-       nf_ct_expect_event(IPEXP_NEW, expect);
        ret = 0;
+       nf_ct_expect_insert(expect);
+       spin_unlock_bh(&nf_conntrack_lock);
+       nf_ct_expect_event_report(IPEXP_NEW, expect, pid, report);
+       return ret;
 out:
        spin_unlock_bh(&nf_conntrack_lock);
        return ret;
 }
-EXPORT_SYMBOL_GPL(nf_ct_expect_related);
+EXPORT_SYMBOL_GPL(nf_ct_expect_related_report);
 
 #ifdef CONFIG_PROC_FS
 struct ct_expect_iter_state {
@@ -557,7 +569,7 @@ static void exp_proc_remove(struct net *net)
 #endif /* CONFIG_PROC_FS */
 }
 
-module_param_named(expect_hashsize, nf_ct_expect_hsize, uint, 0600);
+module_param_named(expect_hashsize, nf_ct_expect_hsize, uint, 0400);
 
 int nf_conntrack_expect_init(struct net *net)
 {
@@ -574,7 +586,7 @@ int nf_conntrack_expect_init(struct net *net)
 
        net->ct.expect_count = 0;
        net->ct.expect_hash = nf_ct_alloc_hashtable(&nf_ct_expect_hsize,
-                                                 &net->ct.expect_vmalloc);
+                                                 &net->ct.expect_vmalloc, 0);
        if (net->ct.expect_hash == NULL)
                goto err1;
 
@@ -605,8 +617,10 @@ err1:
 void nf_conntrack_expect_fini(struct net *net)
 {
        exp_proc_remove(net);
-       if (net_eq(net, &init_net))
+       if (net_eq(net, &init_net)) {
+               rcu_barrier(); /* Wait for call_rcu() before destroy */
                kmem_cache_destroy(nf_ct_expect_cachep);
+       }
        nf_ct_free_hashtable(net->ct.expect_hash, net->ct.expect_vmalloc,
                             nf_ct_expect_hsize);
 }