From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: Re: [PATCH net v4] net: ipv6: allow explicitly choosing optimistic addresses Date: Thu, 05 Feb 2015 11:51:18 +0100 Message-ID: <1423133478.16980.16.camel@stressinduktion.org> References: <1423047683-16267-1-git-send-email-ek@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, lorenzo@google.com To: Erik Kline Return-path: Received: from out1-smtp.messagingengine.com ([66.111.4.25]:34302 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756895AbbBEKvV (ORCPT ); Thu, 5 Feb 2015 05:51:21 -0500 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id EB57E20CB5 for ; Thu, 5 Feb 2015 05:51:20 -0500 (EST) In-Reply-To: <1423047683-16267-1-git-send-email-ek@google.com> Sender: netdev-owner@vger.kernel.org List-ID: Hi, On Mi, 2015-02-04 at 20:01 +0900, Erik Kline wrote: > RFC 4429 ("Optimistic DAD") states that optimistic addresses > should be treated as deprecated addresses. From section 2.1: > > Unless noted otherwise, components of the IPv6 protocol stack > should treat addresses in the Optimistic state equivalently to > those in the Deprecated state, indicating that the address is > available for use but should not be used if another suitable > address is available. > > Optimistic addresses are indeed avoided when other addresses are > available (i.e. at source address selection time), but they have > not heretofore been available for things like explicit bind() and > sendmsg() with struct in6_pktinfo, etc. > > This change makes optimistic addresses treated more like > deprecated addresses than tentative ones. > > Signed-off-by: Erik Kline Acked-by: Hannes Frederic Sowa > --- > include/net/addrconf.h | 3 +++ > net/ipv6/addrconf.c | 19 +++++++++++++++++-- > net/ipv6/ndisc.c | 4 +++- > 3 files changed, 23 insertions(+), 3 deletions(-) > > diff --git a/include/net/addrconf.h b/include/net/addrconf.h > index d13573b..80456f7 100644 > --- a/include/net/addrconf.h > +++ b/include/net/addrconf.h > @@ -62,6 +62,9 @@ int addrconf_set_dstaddr(struct net *net, void __user *arg); > > int ipv6_chk_addr(struct net *net, const struct in6_addr *addr, > const struct net_device *dev, int strict); > +int ipv6_chk_addr_and_flags(struct net *net, const struct in6_addr *addr, > + const struct net_device *dev, int strict, > + u32 banned_flags); > > #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) > int ipv6_chk_home_addr(struct net *net, const struct in6_addr *addr); > diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c > index f7c8bbe..62900ae 100644 > --- a/net/ipv6/addrconf.c > +++ b/net/ipv6/addrconf.c > @@ -1519,15 +1519,30 @@ static int ipv6_count_addresses(struct inet6_dev *idev) > int ipv6_chk_addr(struct net *net, const struct in6_addr *addr, > const struct net_device *dev, int strict) > { > + return ipv6_chk_addr_and_flags(net, addr, dev, strict, IFA_F_TENTATIVE); > +} > +EXPORT_SYMBOL(ipv6_chk_addr); > + > +int ipv6_chk_addr_and_flags(struct net *net, const struct in6_addr *addr, > + const struct net_device *dev, int strict, > + u32 banned_flags) > +{ > struct inet6_ifaddr *ifp; > unsigned int hash = inet6_addr_hash(addr); > + u32 ifp_flags; > > rcu_read_lock_bh(); > hlist_for_each_entry_rcu(ifp, &inet6_addr_lst[hash], addr_lst) { > if (!net_eq(dev_net(ifp->idev->dev), net)) > continue; > + /* Decouple optimistic from tentative for evaluation here. > + * Ban optimistic addresses explicitly, when required. > + */ > + ifp_flags = (ifp->flags&IFA_F_OPTIMISTIC) > + ? (ifp->flags&~IFA_F_TENTATIVE) > + : ifp->flags; > if (ipv6_addr_equal(&ifp->addr, addr) && > - !(ifp->flags&IFA_F_TENTATIVE) && > + !(ifp_flags&banned_flags) && > (dev == NULL || ifp->idev->dev == dev || > !(ifp->scope&(IFA_LINK|IFA_HOST) || strict))) { > rcu_read_unlock_bh(); > @@ -1538,7 +1553,7 @@ int ipv6_chk_addr(struct net *net, const struct in6_addr *addr, > rcu_read_unlock_bh(); > return 0; > } > -EXPORT_SYMBOL(ipv6_chk_addr); > +EXPORT_SYMBOL(ipv6_chk_addr_and_flags); Nit: I don't think the export is necessary. Bye, Hannes