From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Westphal Subject: [PATCH v3 nf-next 4/7] netfilter: evict stale entries on netlink dumps Date: Thu, 25 Aug 2016 15:33:32 +0200 Message-ID: <1472132015-10264-5-git-send-email-fw@strlen.de> References: <1472132015-10264-1-git-send-email-fw@strlen.de> Cc: Florian Westphal To: Return-path: Received: from Chamillionaire.breakpoint.cc ([146.0.238.67]:49996 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933523AbcHYNdo (ORCPT ); Thu, 25 Aug 2016 09:33:44 -0400 In-Reply-To: <1472132015-10264-1-git-send-email-fw@strlen.de> Sender: netfilter-devel-owner@vger.kernel.org List-ID: When dumping we already have to look at the entire table, so we might as well toss those entries whose timeout value is in the past. We also look at every entry during resize operations. However, eviction there is not as simple because we hold the global resize lock so we can't evict without adding a 'expired' list to drop from later. Considering that resizes are very rare it doesn't seem worth doing it. Signed-off-by: Florian Westphal Acked-by: Eric Dumazet --- net/netfilter/nf_conntrack_netlink.c | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 81fd34c..dedbe4b 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -815,14 +815,23 @@ ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb) struct hlist_nulls_node *n; struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh); u_int8_t l3proto = nfmsg->nfgen_family; - int res; + struct nf_conn *nf_ct_evict[8]; + int res, i; spinlock_t *lockp; last = (struct nf_conn *)cb->args[1]; + i = 0; local_bh_disable(); for (; cb->args[0] < nf_conntrack_htable_size; cb->args[0]++) { restart: + while (i) { + i--; + if (nf_ct_should_gc(nf_ct_evict[i])) + nf_ct_kill(nf_ct_evict[i]); + nf_ct_put(nf_ct_evict[i]); + } + lockp = &nf_conntrack_locks[cb->args[0] % CONNTRACK_LOCKS]; nf_conntrack_lock(lockp); if (cb->args[0] >= nf_conntrack_htable_size) { @@ -834,6 +843,13 @@ restart: if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL) continue; ct = nf_ct_tuplehash_to_ctrack(h); + if (nf_ct_is_expired(ct)) { + if (i < ARRAY_SIZE(nf_ct_evict) && + atomic_inc_not_zero(&ct->ct_general.use)) + nf_ct_evict[i++] = ct; + continue; + } + if (!net_eq(net, nf_ct_net(ct))) continue; @@ -875,6 +891,13 @@ out: if (last) nf_ct_put(last); + while (i) { + i--; + if (nf_ct_should_gc(nf_ct_evict[i])) + nf_ct_kill(nf_ct_evict[i]); + nf_ct_put(nf_ct_evict[i]); + } + return skb->len; } -- 2.7.3