[NETFILTER]: nf_conntrack: introduce expectation classes and policies
Introduce expectation classes and policies. An expectation class
is used to distinguish different types of expectations by the
same helper (for example audio/video/t.120). The expectation
policy is used to hold the maximum number of expectations and
the initial timeout for each class.
The individual classes are isolated from each other, which means
that for example an audio expectation will only evict other audio
expectations.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index 882602f..e31beeb 100644
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -54,7 +54,7 @@
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 @@
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_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 @@
}
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 @@
len = 16;
exp->flags = 0;
+ exp->class = class;
exp->expectfn = NULL;
exp->helper = NULL;
exp->tuple.src.l3num = family;
@@ -309,19 +311,21 @@
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 @@
}
/* 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 @@
}
}
/* 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())