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Message-Id: <201007191623.40423.lists@egidy.de> Date: Mon, 19 Jul 2010 16:23:40 +0200 From: "Gerd v. Egidy" <lists@...dy.de> To: netfilter-devel@...r.kernel.org Cc: netdev@...r.kernel.org Subject: Are concurrent calls to tc action ipt safe? Hi, AFAIK, current iptables has a short race condition when two rules within the same table are changed at once. E.g. when two users simultaneously call something like this iptables -t filter -A INPUT -s 192.168.1.1 -j MARK --set-mark 1 and iptables -t filter -A INPUT -s 192.168.1.2 -j MARK --set-mark 2 one of these entries can get lost. Jan Engelhard recently posted his xt2 patchset to overcome problems like this, but it seems to still have performance issues. I have a set of simple rules which need to change often and are subject to this problem. I now wonder if I can solve this by using tc and the ipt action: tc filter add dev eth0 parent ffff: protocol ip prio 1 u32 \ match ip src 192.168.1.1 \ action ipt -j MARK --set-mark 1 Since this call uses the xtables targets I'm currently not sure if the same problem regarding concurrent changes exists or not. Can anyone tell me if concurrent calls like this are safe? Thank you very much. Kind regards, Gerd -- Address (better: trap) for people I really don't want to get mail from: jonas@...tusamerica.com -- 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
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