From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Henriksson Subject: [PATCH RFC] net: error on trying to add a duplicate ipip tunnel Date: Wed, 13 Nov 2013 19:21:33 +0100 Message-ID: <20131113182133.GA8760@amd64.fatal.se> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: netdev@vger.kernel.org Return-path: Received: from smtprelay-h32.telenor.se ([213.150.131.5]:38190 "EHLO smtprelay-h32.telenor.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755888Ab3KMS27 (ORCPT ); Wed, 13 Nov 2013 13:28:59 -0500 Received: from ipb1.telenor.se (ipb1.telenor.se [195.54.127.164]) by smtprelay-h32.telenor.se (Postfix) with ESMTP id 9D553E8634 for ; Wed, 13 Nov 2013 19:28:54 +0100 (CET) Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: After patch: $ sudo ip tunnel add test1 mode ipip remote 1.2.3.4 $ sudo ip tunnel add test2 mode ipip remote 1.2.3.4 add tunnel "tunl0" failed: File exists Before the patch, there would be no error and "test2" (silently) not added. Originally reported at http://bugs.debian.org/508450 The originally reported problem with sit tunnel seems to have been resolved since then: $ sudo ip tun add test3 mode sit add tunnel "sit0" failed: No buffer space available The problem still exists for (atleast) ipip tunnels though. Reported-by: martin f krafft Signed-off-by: Andreas Henriksson --- net/ipv4/ip_tunnel.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) Maybe also sit tunnels should explicitly use EEXISTS instead of ENOBUFS? Maybe ipip tunnel code should be refactored to be similar to sit tunnel addition code? Which other tunnel types should be checked for how they behave in similar situations? Other comments? diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index 63a6d6d..1dc4e41 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -732,8 +732,14 @@ int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd) t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type); - if (!t && (cmd == SIOCADDTUNNEL)) - t = ip_tunnel_create(net, itn, p); + if (cmd == SIOCADDTUNNEL) { + if (!t) { + t = ip_tunnel_create(net, itn, p); + } else { + err = -EEXIST; + break; + } + } if (dev != itn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { if (t != NULL) { -- 1.8.4.3