From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiner Kallweit Subject: [PATCH v2] ipv6: Reparent temporary address(es) if global address was, deleted from userspace Date: Mon, 07 Apr 2014 07:43:12 +0200 Message-ID: <53423AF0.5080308@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit To: "netdev@vger.kernel.org" Return-path: Received: from mout.web.de ([212.227.15.4]:59933 "EHLO mout.web.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750743AbaDGFn1 (ORCPT ); Mon, 7 Apr 2014 01:43:27 -0400 Received: from [192.168.178.101] ([84.142.80.96]) by smtp.web.de (mrweb101) with ESMTPSA (Nemesis) id 0MPYB3-1WbhAV0Caf-004jIK for ; Mon, 07 Apr 2014 07:43:26 +0200 Sender: netdev-owner@vger.kernel.org List-ID: If the kernel takes care of global and temporary addresses it can happen that the global address is deleted from userspace, e.g. by network managers in case the link goes (temporarily) down. In addition to the then orphaned temporary address(es) the next RA will create a new temporary address. Therefore we might end up with more than one non-deprecated temporary address for the same prefix for a longer period of time (>regen_advance). According to RfC4941 sect. 3.4 this should not happen. Fix this by reparenting orphaned temporary addresses. v2: style fixes Signed-off-by: Heiner Kallweit --- net/ipv6/addrconf.c | 30 +++++++++++++++++++++++++++--- 1 file changed, 27 insertions(+), 3 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 6c7fa08..8072968 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2077,14 +2077,33 @@ static void manage_tempaddrs(struct inet6_dev *idev, { u32 flags; struct inet6_ifaddr *ift; + unsigned long regen_advance; read_lock_bh(&idev->lock); + regen_advance = idev->cnf.regen_max_retry * + idev->cnf.dad_transmits * + NEIGH_VAR(idev->nd_parms, RETRANS_TIME) / HZ; /* update all temporary addresses in the list */ list_for_each_entry(ift, &idev->tempaddr_list, tmp_list) { int age, max_valid, max_prefered; + bool reparent = false; - if (ifp != ift->ifpub) - continue; + spin_lock(&ift->lock); + if (ifp != ift->ifpub) { + /* reparent if orphaned temporary address with same + * prefix is found + */ + if (ipv6_prefix_equal(&ift->addr, &ifp->addr, + ift->prefix_len)) { + in6_ifa_hold(ifp); + in6_ifa_put(ift->ifpub); + ift->ifpub = ifp; + reparent = true; + } else { + spin_unlock(&ift->lock); + continue; + } + } /* RFC 4941 section 3.3: * If a received option will extend the lifetime of a public @@ -2110,7 +2129,6 @@ static void manage_tempaddrs(struct inet6_dev *idev, if (prefered_lft > max_prefered) prefered_lft = max_prefered; - spin_lock(&ift->lock); flags = ift->flags; ift->valid_lft = valid_lft; ift->prefered_lft = prefered_lft; @@ -2119,6 +2137,12 @@ static void manage_tempaddrs(struct inet6_dev *idev, ift->flags &= ~IFA_F_DEPRECATED; spin_unlock(&ift->lock); + /* Don't create a temporary address if we reparented one which + * is preferred more than regen_advance + */ + if (reparent && prefered_lft > regen_advance) + create = false; + if (!(flags&IFA_F_TENTATIVE)) ipv6_ifa_notify(0, ift); } -- 1.9.1.315.g3f09db0.dirty