netfilter: nf_conntrack: restrict runtime expect hashsize modifications
[safe/jmp/linux-2.6] / net / netfilter / nf_conntrack_expect.c
index e31beeb..4ad7d1d 100644 (file)
 #include <net/netfilter/nf_conntrack_helper.h>
 #include <net/netfilter/nf_conntrack_tuple.h>
 
-struct hlist_head *nf_ct_expect_hash __read_mostly;
-EXPORT_SYMBOL_GPL(nf_ct_expect_hash);
-
 unsigned int nf_ct_expect_hsize __read_mostly;
 EXPORT_SYMBOL_GPL(nf_ct_expect_hsize);
 
 static unsigned int nf_ct_expect_hash_rnd __read_mostly;
-static unsigned int nf_ct_expect_count;
 unsigned int nf_ct_expect_max __read_mostly;
 static int nf_ct_expect_hash_rnd_initted __read_mostly;
-static int nf_ct_expect_vmalloc;
 
 static struct kmem_cache *nf_ct_expect_cachep __read_mostly;
 
@@ -46,18 +41,19 @@ static struct kmem_cache *nf_ct_expect_cachep __read_mostly;
 void nf_ct_unlink_expect(struct nf_conntrack_expect *exp)
 {
        struct nf_conn_help *master_help = nfct_help(exp->master);
+       struct net *net = nf_ct_exp_net(exp);
 
        NF_CT_ASSERT(master_help);
        NF_CT_ASSERT(!timer_pending(&exp->timeout));
 
        hlist_del_rcu(&exp->hnode);
-       nf_ct_expect_count--;
+       net->ct.expect_count--;
 
        hlist_del(&exp->lnode);
        master_help->expecting[exp->class]--;
        nf_ct_expect_put(exp);
 
-       NF_CT_STAT_INC(expect_delete);
+       NF_CT_STAT_INC(net, expect_delete);
 }
 EXPORT_SYMBOL_GPL(nf_ct_unlink_expect);
 
@@ -76,7 +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;
        }
 
@@ -87,17 +84,17 @@ static unsigned int nf_ct_expect_dst_hash(const struct nf_conntrack_tuple *tuple
 }
 
 struct nf_conntrack_expect *
-__nf_ct_expect_find(const struct nf_conntrack_tuple *tuple)
+__nf_ct_expect_find(struct net *net, const struct nf_conntrack_tuple *tuple)
 {
        struct nf_conntrack_expect *i;
        struct hlist_node *n;
        unsigned int h;
 
-       if (!nf_ct_expect_count)
+       if (!net->ct.expect_count)
                return NULL;
 
        h = nf_ct_expect_dst_hash(tuple);
-       hlist_for_each_entry_rcu(i, n, &nf_ct_expect_hash[h], hnode) {
+       hlist_for_each_entry_rcu(i, n, &net->ct.expect_hash[h], hnode) {
                if (nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask))
                        return i;
        }
@@ -107,12 +104,12 @@ EXPORT_SYMBOL_GPL(__nf_ct_expect_find);
 
 /* Just find a expectation corresponding to a tuple. */
 struct nf_conntrack_expect *
-nf_ct_expect_find_get(const struct nf_conntrack_tuple *tuple)
+nf_ct_expect_find_get(struct net *net, const struct nf_conntrack_tuple *tuple)
 {
        struct nf_conntrack_expect *i;
 
        rcu_read_lock();
-       i = __nf_ct_expect_find(tuple);
+       i = __nf_ct_expect_find(net, tuple);
        if (i && !atomic_inc_not_zero(&i->use))
                i = NULL;
        rcu_read_unlock();
@@ -124,17 +121,17 @@ EXPORT_SYMBOL_GPL(nf_ct_expect_find_get);
 /* If an expectation for this connection is found, it gets delete from
  * global list then returned. */
 struct nf_conntrack_expect *
-nf_ct_find_expectation(const struct nf_conntrack_tuple *tuple)
+nf_ct_find_expectation(struct net *net, const struct nf_conntrack_tuple *tuple)
 {
        struct nf_conntrack_expect *i, *exp = NULL;
        struct hlist_node *n;
        unsigned int h;
 
-       if (!nf_ct_expect_count)
+       if (!net->ct.expect_count)
                return NULL;
 
        h = nf_ct_expect_dst_hash(tuple);
-       hlist_for_each_entry(i, n, &nf_ct_expect_hash[h], hnode) {
+       hlist_for_each_entry(i, n, &net->ct.expect_hash[h], hnode) {
                if (!(i->flags & NF_CT_EXPECT_INACTIVE) &&
                    nf_ct_tuple_mask_cmp(tuple, &i->tuple, &i->mask)) {
                        exp = i;
@@ -205,9 +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. */
@@ -241,7 +238,7 @@ struct nf_conntrack_expect *nf_ct_expect_alloc(struct nf_conn *me)
 EXPORT_SYMBOL_GPL(nf_ct_expect_alloc);
 
 void nf_ct_expect_init(struct nf_conntrack_expect *exp, unsigned int class,
-                      int family,
+                      u_int8_t family,
                       const union nf_inet_addr *saddr,
                       const union nf_inet_addr *daddr,
                       u_int8_t proto, const __be16 *src, const __be16 *dst)
@@ -311,6 +308,7 @@ EXPORT_SYMBOL_GPL(nf_ct_expect_put);
 static void nf_ct_expect_insert(struct nf_conntrack_expect *exp)
 {
        struct nf_conn_help *master_help = nfct_help(exp->master);
+       struct net *net = nf_ct_exp_net(exp);
        const struct nf_conntrack_expect_policy *p;
        unsigned int h = nf_ct_expect_dst_hash(&exp->tuple);
 
@@ -319,8 +317,8 @@ static void nf_ct_expect_insert(struct nf_conntrack_expect *exp)
        hlist_add_head(&exp->lnode, &master_help->expectations);
        master_help->expecting[exp->class]++;
 
-       hlist_add_head_rcu(&exp->hnode, &nf_ct_expect_hash[h]);
-       nf_ct_expect_count++;
+       hlist_add_head_rcu(&exp->hnode, &net->ct.expect_hash[h]);
+       net->ct.expect_count++;
 
        setup_timer(&exp->timeout, nf_ct_expectation_timed_out,
                    (unsigned long)exp);
@@ -329,7 +327,7 @@ static void nf_ct_expect_insert(struct nf_conntrack_expect *exp)
        add_timer(&exp->timeout);
 
        atomic_inc(&exp->use);
-       NF_CT_STAT_INC(expect_create);
+       NF_CT_STAT_INC(net, expect_create);
 }
 
 /* Race with expectations being used means we could have none to find; OK. */
@@ -365,25 +363,23 @@ 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;
        struct nf_conn *master = expect->master;
        struct nf_conn_help *master_help = nfct_help(master);
+       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;
        }
        h = nf_ct_expect_dst_hash(&expect->tuple);
-       hlist_for_each_entry(i, n, &nf_ct_expect_hash[h], hnode) {
+       hlist_for_each_entry(i, n, &net->ct.expect_hash[h], hnode) {
                if (expect_matches(i, expect)) {
                        /* Refresh timer: if it's dying, ignore.. */
                        if (refresh_timer(i)) {
@@ -406,35 +402,51 @@ int nf_ct_expect_related(struct nf_conntrack_expect *expect)
                }
        }
 
-       if (nf_ct_expect_count >= nf_ct_expect_max) {
+       if (net->ct.expect_count >= nf_ct_expect_max) {
                if (net_ratelimit())
                        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 {
+       struct seq_net_private p;
        unsigned int bucket;
 };
 
 static struct hlist_node *ct_expect_get_first(struct seq_file *seq)
 {
+       struct net *net = seq_file_net(seq);
        struct ct_expect_iter_state *st = seq->private;
        struct hlist_node *n;
 
        for (st->bucket = 0; st->bucket < nf_ct_expect_hsize; st->bucket++) {
-               n = rcu_dereference(nf_ct_expect_hash[st->bucket].first);
+               n = rcu_dereference(net->ct.expect_hash[st->bucket].first);
                if (n)
                        return n;
        }
@@ -444,13 +456,14 @@ static struct hlist_node *ct_expect_get_first(struct seq_file *seq)
 static struct hlist_node *ct_expect_get_next(struct seq_file *seq,
                                             struct hlist_node *head)
 {
+       struct net *net = seq_file_net(seq);
        struct ct_expect_iter_state *st = seq->private;
 
        head = rcu_dereference(head->next);
        while (head == NULL) {
                if (++st->bucket >= nf_ct_expect_hsize)
                        return NULL;
-               head = rcu_dereference(nf_ct_expect_hash[st->bucket].first);
+               head = rcu_dereference(net->ct.expect_hash[st->bucket].first);
        }
        return head;
 }
@@ -524,7 +537,7 @@ static const struct seq_operations exp_seq_ops = {
 
 static int exp_open(struct inode *inode, struct file *file)
 {
-       return seq_open_private(file, &exp_seq_ops,
+       return seq_open_net(inode, file, &exp_seq_ops,
                        sizeof(struct ct_expect_iter_state));
 }
 
@@ -533,72 +546,81 @@ static const struct file_operations exp_file_ops = {
        .open    = exp_open,
        .read    = seq_read,
        .llseek  = seq_lseek,
-       .release = seq_release_private,
+       .release = seq_release_net,
 };
 #endif /* CONFIG_PROC_FS */
 
-static int __init exp_proc_init(void)
+static int exp_proc_init(struct net *net)
 {
 #ifdef CONFIG_PROC_FS
        struct proc_dir_entry *proc;
 
-       proc = proc_net_fops_create(&init_net, "nf_conntrack_expect", 0440, &exp_file_ops);
+       proc = proc_net_fops_create(net, "nf_conntrack_expect", 0440, &exp_file_ops);
        if (!proc)
                return -ENOMEM;
 #endif /* CONFIG_PROC_FS */
        return 0;
 }
 
-static void exp_proc_remove(void)
+static void exp_proc_remove(struct net *net)
 {
 #ifdef CONFIG_PROC_FS
-       proc_net_remove(&init_net, "nf_conntrack_expect");
+       proc_net_remove(net, "nf_conntrack_expect");
 #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 __init nf_conntrack_expect_init(void)
+int nf_conntrack_expect_init(struct net *net)
 {
        int err = -ENOMEM;
 
-       if (!nf_ct_expect_hsize) {
-               nf_ct_expect_hsize = nf_conntrack_htable_size / 256;
-               if (!nf_ct_expect_hsize)
-                       nf_ct_expect_hsize = 1;
+       if (net_eq(net, &init_net)) {
+               if (!nf_ct_expect_hsize) {
+                       nf_ct_expect_hsize = nf_conntrack_htable_size / 256;
+                       if (!nf_ct_expect_hsize)
+                               nf_ct_expect_hsize = 1;
+               }
+               nf_ct_expect_max = nf_ct_expect_hsize * 4;
        }
-       nf_ct_expect_max = nf_ct_expect_hsize * 4;
 
-       nf_ct_expect_hash = nf_ct_alloc_hashtable(&nf_ct_expect_hsize,
-                                                 &nf_ct_expect_vmalloc);
-       if (nf_ct_expect_hash == NULL)
+       net->ct.expect_count = 0;
+       net->ct.expect_hash = nf_ct_alloc_hashtable(&nf_ct_expect_hsize,
+                                                 &net->ct.expect_vmalloc, 0);
+       if (net->ct.expect_hash == NULL)
                goto err1;
 
-       nf_ct_expect_cachep = kmem_cache_create("nf_conntrack_expect",
+       if (net_eq(net, &init_net)) {
+               nf_ct_expect_cachep = kmem_cache_create("nf_conntrack_expect",
                                        sizeof(struct nf_conntrack_expect),
                                        0, 0, NULL);
-       if (!nf_ct_expect_cachep)
-               goto err2;
+               if (!nf_ct_expect_cachep)
+                       goto err2;
+       }
 
-       err = exp_proc_init();
+       err = exp_proc_init(net);
        if (err < 0)
                goto err3;
 
        return 0;
 
 err3:
-       nf_ct_free_hashtable(nf_ct_expect_hash, nf_ct_expect_vmalloc,
-                            nf_ct_expect_hsize);
+       if (net_eq(net, &init_net))
+               kmem_cache_destroy(nf_ct_expect_cachep);
 err2:
-       kmem_cache_destroy(nf_ct_expect_cachep);
+       nf_ct_free_hashtable(net->ct.expect_hash, net->ct.expect_vmalloc,
+                            nf_ct_expect_hsize);
 err1:
        return err;
 }
 
-void nf_conntrack_expect_fini(void)
+void nf_conntrack_expect_fini(struct net *net)
 {
-       exp_proc_remove();
-       kmem_cache_destroy(nf_ct_expect_cachep);
-       nf_ct_free_hashtable(nf_ct_expect_hash, nf_ct_expect_vmalloc,
+       exp_proc_remove(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);
 }