[NETFILTER]: nf_conntrack: introduce expectation classes and policies

[deliverable/linux.git] / net / netfilter / nf_conntrack_expect.c

diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index 882602f1c0ef9ac062dc5c54550aaffb16feebfa..e31beeb33b2b10ca8e0bc6c43aedcbe4a1c8c990 100644 (file)
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -54,7 +54,7 @@ void nf_ct_unlink_expect(struct nf_conntrack_expect *exp)
        nf_ct_expect_count--;
 
        hlist_del(&exp->lnode);
-       master_help->expecting--;
+       master_help->expecting[exp->class]--;
        nf_ct_expect_put(exp);
 
        NF_CT_STAT_INC(expect_delete);
@@ -171,7 +171,7 @@ void nf_ct_remove_expectations(struct nf_conn *ct)
        struct hlist_node *n, *next;
 
        /* Optimization: most connection never expect any others. */
-       if (!help || help->expecting == 0)
+       if (!help)
                return;
 
        hlist_for_each_entry_safe(exp, n, next, &help->expectations, lnode) {
@@ -205,7 +205,7 @@ 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
+       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);
 }
@@ -240,7 +240,8 @@ 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, int family,
+void nf_ct_expect_init(struct nf_conntrack_expect *exp, unsigned int class,
+                      int family,
                       const union nf_inet_addr *saddr,
                       const union nf_inet_addr *daddr,
                       u_int8_t proto, const __be16 *src, const __be16 *dst)
@@ -253,6 +254,7 @@ void nf_ct_expect_init(struct nf_conntrack_expect *exp, int family,
                len = 16;
 
        exp->flags = 0;
+       exp->class = class;
        exp->expectfn = NULL;
        exp->helper = NULL;
        exp->tuple.src.l3num = family;
@@ -309,19 +311,21 @@ 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);
+       const struct nf_conntrack_expect_policy *p;
        unsigned int h = nf_ct_expect_dst_hash(&exp->tuple);
 
        atomic_inc(&exp->use);
 
        hlist_add_head(&exp->lnode, &master_help->expectations);
-       master_help->expecting++;
+       master_help->expecting[exp->class]++;
 
        hlist_add_head_rcu(&exp->hnode, &nf_ct_expect_hash[h]);
        nf_ct_expect_count++;
 
        setup_timer(&exp->timeout, nf_ct_expectation_timed_out,
                    (unsigned long)exp);
-       exp->timeout.expires = jiffies + master_help->helper->timeout * HZ;
+       p = &master_help->helper->expect_policy[exp->class];
+       exp->timeout.expires = jiffies + p->timeout * HZ;
        add_timer(&exp->timeout);
 
        atomic_inc(&exp->use);
@@ -329,35 +333,41 @@ static void nf_ct_expect_insert(struct nf_conntrack_expect *exp)
 }
 
 /* Race with expectations being used means we could have none to find; OK. */
-static void evict_oldest_expect(struct nf_conn *master)
+static void evict_oldest_expect(struct nf_conn *master,
+                               struct nf_conntrack_expect *new)
 {
        struct nf_conn_help *master_help = nfct_help(master);
-       struct nf_conntrack_expect *exp = NULL;
+       struct nf_conntrack_expect *exp, *last = NULL;
        struct hlist_node *n;
 
-       hlist_for_each_entry(exp, n, &master_help->expectations, lnode)
-               ; /* nothing */
+       hlist_for_each_entry(exp, n, &master_help->expectations, lnode) {
+               if (exp->class == new->class)
+                       last = exp;
+       }
 
-       if (exp && del_timer(&exp->timeout)) {
-               nf_ct_unlink_expect(exp);
-               nf_ct_expect_put(exp);
+       if (last && del_timer(&last->timeout)) {
+               nf_ct_unlink_expect(last);
+               nf_ct_expect_put(last);
        }
 }
 
 static inline int refresh_timer(struct nf_conntrack_expect *i)
 {
        struct nf_conn_help *master_help = nfct_help(i->master);
+       const struct nf_conntrack_expect_policy *p;
 
        if (!del_timer(&i->timeout))
                return 0;
 
-       i->timeout.expires = jiffies + master_help->helper->timeout*HZ;
+       p = &master_help->helper->expect_policy[i->class];
+       i->timeout.expires = jiffies + p->timeout * HZ;
        add_timer(&i->timeout);
        return 1;
 }
 
 int nf_ct_expect_related(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);
@@ -386,9 +396,15 @@ int nf_ct_expect_related(struct nf_conntrack_expect *expect)
                }
        }
        /* Will be over limit? */
-       if (master_help->helper->max_expected &&
-           master_help->expecting >= master_help->helper->max_expected)
-               evict_oldest_expect(master);
+       p = &master_help->helper->expect_policy[expect->class];
+       if (p->max_expected &&
+           master_help->expecting[expect->class] >= p->max_expected) {
+               evict_oldest_expect(master, expect);
+               if (master_help->expecting[expect->class] >= p->max_expected) {
+                       ret = -EMFILE;
+                       goto out;
+               }
+       }
 
        if (nf_ct_expect_count >= nf_ct_expect_max) {
                if (net_ratelimit())