From: Florian Westphal <fw@xxxxxxxxx>
When iterating, skip conntrack entries living in a different netns.
We could ignore netns and kill some other non-assured one, but it
has two problems:
- a netns can kill non-assured conntracks in other namespace
- we would start to 'over-subscribe' the affected/overlimit netns.
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/nf_conntrack_core.c | 43 +++++++++++++++++++++++----------------
1 file changed, 25 insertions(+), 18 deletions(-)
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 4c906e7..e3787cf 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -764,18 +764,20 @@ static noinline int early_drop(struct net *net, unsigned int _hash)
{
/* Use oldest entry, which is roughly LRU */
struct nf_conntrack_tuple_hash *h;
- struct nf_conn *ct = NULL, *tmp;
+ struct nf_conn *tmp;
struct hlist_nulls_node *n;
- unsigned int i = 0, cnt = 0;
- int dropped = 0;
- unsigned int hash, sequence;
+ unsigned int i, hash, sequence;
+ struct nf_conn *ct = NULL;
spinlock_t *lockp;
+ bool ret = false;
+
+ i = 0;
local_bh_disable();
restart:
sequence = read_seqcount_begin(&nf_conntrack_generation);
- hash = scale_hash(_hash);
- for (; i < nf_conntrack_htable_size; i++) {
+ for (; i < NF_CT_EVICTION_RANGE; i++) {
+ hash = scale_hash(_hash++);
lockp = &nf_conntrack_locks[hash % CONNTRACK_LOCKS];
nf_conntrack_lock(lockp);
if (read_seqcount_retry(&nf_conntrack_generation, sequence)) {
@@ -785,35 +787,40 @@ restart:
hlist_nulls_for_each_entry_rcu(h, n, &nf_conntrack_hash[hash],
hnnode) {
tmp = nf_ct_tuplehash_to_ctrack(h);
- if (!test_bit(IPS_ASSURED_BIT, &tmp->status) &&
- !nf_ct_is_dying(tmp) &&
- atomic_inc_not_zero(&tmp->ct_general.use)) {
+
+ if (test_bit(IPS_ASSURED_BIT, &tmp->status) ||
+ !net_eq(nf_ct_net(tmp), net) ||
+ nf_ct_is_dying(tmp))
+ continue;
+
+ if (atomic_inc_not_zero(&tmp->ct_general.use)) {
ct = tmp;
break;
}
- cnt++;
}
- hash = (hash + 1) % nf_conntrack_htable_size;
spin_unlock(lockp);
-
- if (ct || cnt >= NF_CT_EVICTION_RANGE)
+ if (ct)
break;
-
}
+
local_bh_enable();
if (!ct)
- return dropped;
+ return false;
- if (del_timer(&ct->timeout)) {
+ /* kill only if in same netns -- might have moved due to
+ * SLAB_DESTROY_BY_RCU rules
+ */
+ if (net_eq(nf_ct_net(ct), net) && del_timer(&ct->timeout)) {
if (nf_ct_delete(ct, 0, 0)) {
- dropped = 1;
NF_CT_STAT_INC_ATOMIC(net, early_drop);
+ ret = true;
}
}
+
nf_ct_put(ct);
- return dropped;
+ return ret;
}
static struct nf_conn *
--
2.1.4
--
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