netdev - [PATCH 23/25] netfilter: nf_ct_expect: partially implement ctnetlink_change

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1336436539-5880-24-git-send-email-pablo@netfilter.org>
Date:	Tue,  8 May 2012 02:22:17 +0200
From:	pablo@...filter.org
To:	netfilter-devel@...r.kernel.org
Cc:	davem@...emloft.net, netdev@...r.kernel.org
Subject: [PATCH 23/25] netfilter: nf_ct_expect: partially implement ctnetlink_change_expect

From: Kelvie Wong <kelvie@...e.org>

This refreshes the "timeout" attribute in existing expectations if one is
given.

The use case for this would be for userspace helpers to extend the lifetime
of the expectation when requested, as this is not possible right now
without deleting/recreating the expectation.

I use this specifically for forwarding DCERPC traffic through:

DCERPC has a port mapper daemon that chooses a (seemingly) random port for
future traffic to go to. We expect this traffic (with a reasonable
timeout), but sometimes the port mapper will tell the client to continue
using the same port. This allows us to extend the expectation accordingly.

Signed-off-by: Kelvie Wong <kelvie@...e.org>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
---
 net/netfilter/nf_conntrack_netlink.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 462ec2d..6f4b00a 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -2080,7 +2080,15 @@ static int
 ctnetlink_change_expect(struct nf_conntrack_expect *x,
 			const struct nlattr * const cda[])
 {
-	return -EOPNOTSUPP;
+	if (cda[CTA_EXPECT_TIMEOUT]) {
+		if (!del_timer(&x->timeout))
+			return -ETIME;
+
+		x->timeout.expires = jiffies +
+			ntohl(nla_get_be32(cda[CTA_EXPECT_TIMEOUT])) * HZ;
+		add_timer(&x->timeout);
+	}
+	return 0;
 }

 static const struct nla_policy exp_nat_nla_policy[CTA_EXPECT_NAT_MAX+1] = {
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html