From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mateusz Bajorski Subject: ip rule duplicates Date: Fri, 20 May 2016 14:54:54 +0200 Message-ID: <573F091E.9050205@nokia.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------000107050001000901070705" To: Return-path: Received: from mail-db3on0111.outbound.protection.outlook.com ([157.55.234.111]:44843 "EHLO emea01-db3-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754743AbcETQ0H (ORCPT ); Fri, 20 May 2016 12:26:07 -0400 Sender: netdev-owner@vger.kernel.org List-ID: --------------000107050001000901070705 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Hi, When we add the same rule again with flag NLM_F_EXCL we expect that we receive error: RTNETLINK answers: File exists This behaviour is already in ip routing part. I have noticed that iproute2 when adds new rule it attach flag NLM_F_EXCL to call. (see http://git.kernel.org/cgit/linux/kernel/git/shemminger/iproute2.git/tree/ip/iprule.c#n334) Next thing what I found is that this flag is not handled from kernel side. I implemented this feature and I tested this with qemu x86 on: linux-4.5.4 linux (git) linux-stable (git) Tested with ipv4 and ipv6. current behaviour with ipv4: localhost ~ # ip rule 0: from all lookup local 32766: from all lookup main 32767: from all lookup default localhost ~ # ip rule add from 10.46.177.97 lookup 104 pref 1005 localhost ~ # ip rule add from 10.46.177.97 lookup 104 pref 1005 localhost ~ # ip rule 0: from all lookup local 1005: from 10.46.177.97 lookup 104 1005: from 10.46.177.97 lookup 104 32766: from all lookup main 32767: from all lookup default expected behavior after patch: localhost ~ # ip rule 0: from all lookup local 32766: from all lookup main 32767: from all lookup default localhost ~ # ip rule add from 10.46.177.97 lookup 104 pref 1005 localhost ~ # ip rule add from 10.46.177.97 lookup 104 pref 1005 RTNETLINK answers: File exists localhost ~ # ip rule 0: from all lookup local 1005: from 10.46.177.97 lookup 104 32766: from all lookup main 32767: from all lookup default There was already topic regarding this but I don't see any changes merged and problem still occurs. (see http://marc.info/?l=linux-netdev&m=113577886110391&w=2) -- Best regards, Mateusz Bajorski --------------000107050001000901070705 Content-Type: text/x-patch; name="0001-Added-NLM_F_EXCL-support-to-fib_nl_newrule.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="0001-Added-NLM_F_EXCL-support-to-fib_nl_newrule.patch" >>From 9c3f80dceec414ff31d0c38d0107dec279fc9894 Mon Sep 17 00:00:00 2001 From: Mateusz Bajorski Date: Fri, 20 May 2016 14:29:56 +0200 Subject: [PATCH] Added NLM_F_EXCL support to fib_nl_newrule Signed-off-by: Mateusz Bajorski --- net/core/fib_rules.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c index 840aceb..c1bc07cd 100644 --- a/net/core/fib_rules.c +++ b/net/core/fib_rules.c @@ -291,6 +291,47 @@ static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh) if (err < 0) goto errout; + if (nlh->nlmsg_flags & NLM_F_EXCL) { + list_for_each_entry(rule, &ops->rules_list, list) { + if (frh->action && (frh->action != rule->action)) + continue; + + if (frh_get_table(frh, tb) && + (frh_get_table(frh, tb) != rule->table)) + continue; + + if (tb[FRA_PRIORITY] && + (rule->pref != nla_get_u32(tb[FRA_PRIORITY]))) + continue; + + if (tb[FRA_IIFNAME] && + nla_strcmp(tb[FRA_IIFNAME], rule->iifname)) + continue; + + if (tb[FRA_OIFNAME] && + nla_strcmp(tb[FRA_OIFNAME], rule->oifname)) + continue; + + if (tb[FRA_FWMARK] && + (rule->mark != nla_get_u32(tb[FRA_FWMARK]))) + continue; + + if (tb[FRA_FWMASK] && + (rule->mark_mask != nla_get_u32(tb[FRA_FWMASK]))) + continue; + + if (tb[FRA_TUN_ID] && + (rule->tun_id != nla_get_be64(tb[FRA_TUN_ID]))) + continue; + + if (!ops->compare(rule, frh, tb)) + continue; + + err = -EEXIST; + goto errout; + } + } + rule = kzalloc(ops->rule_size, GFP_KERNEL); if (rule == NULL) { err = -ENOMEM; -- 2.6.4 --------------000107050001000901070705--