| Message ID | 1428717253-1006248-7-git-send-email-kafai@fb.com |
|---|---|
| State | RFC, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Martin KaFai Lau <kafai@fb.com> Date: Fri, 10 Apr 2015 18:54:09 -0700 > Before patch 'Allow pmtu update on /128 via gateway route', > RTF_CACHE route was not created for DST_HOST. It also requires changes on both > delete code path and rt6_select() code patch. > > This patch fixes the delete code path to avoid deleting the RTF_CACHE > route by 'ip -6 r del...' > > Signed-off-by: Martin KaFai Lau <kafai@fb.com> > Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> If a cached route was created in response to say a PMTU event, and it's a clone/copy/cow of the route we are being asked to delete, it absolutely should be removed. In fact this is a critically important aspect of removing routes from the table. So this change does not seem correct. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Apr 20, 2015 at 02:23:05PM -0400, David Miller wrote: > From: Martin KaFai Lau <kafai@fb.com> > Date: Fri, 10 Apr 2015 18:54:09 -0700 > > > Before patch 'Allow pmtu update on /128 via gateway route', > > RTF_CACHE route was not created for DST_HOST. It also requires changes on both > > delete code path and rt6_select() code patch. > > > > This patch fixes the delete code path to avoid deleting the RTF_CACHE > > route by 'ip -6 r del...' > > > > Signed-off-by: Martin KaFai Lau <kafai@fb.com> > > Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> > > If a cached route was created in response to say a PMTU event, and > it's a clone/copy/cow of the route we are being asked to delete, > it absolutely should be removed. > > In fact this is a critically important aspect of removing routes > from the table. When a non-clone routes are removed, its clones are removed together by fib6_prune_clones() in fib6_del(). Hence, 'ip -6 r del' will remove a route and its clones. 'ip -6 r flush table cache will only remove RTF_CACHE routes. I will fix up the commit message. Thanks, --Martin -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Martin KaFai Lau <kafai@fb.com> Date: Mon, 20 Apr 2015 12:33:05 -0700 > On Mon, Apr 20, 2015 at 02:23:05PM -0400, David Miller wrote: >> From: Martin KaFai Lau <kafai@fb.com> >> Date: Fri, 10 Apr 2015 18:54:09 -0700 >> >> > Before patch 'Allow pmtu update on /128 via gateway route', >> > RTF_CACHE route was not created for DST_HOST. It also requires changes on both >> > delete code path and rt6_select() code patch. >> > >> > This patch fixes the delete code path to avoid deleting the RTF_CACHE >> > route by 'ip -6 r del...' >> > >> > Signed-off-by: Martin KaFai Lau <kafai@fb.com> >> > Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> >> >> If a cached route was created in response to say a PMTU event, and >> it's a clone/copy/cow of the route we are being asked to delete, >> it absolutely should be removed. >> >> In fact this is a critically important aspect of removing routes >> from the table. > When a non-clone routes are removed, its clones are removed together by > fib6_prune_clones() in fib6_del(). > > Hence, 'ip -6 r del' will remove a route and its clones. > 'ip -6 r flush table cache will only remove RTF_CACHE routes. > > I will fix up the commit message. Ok, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 75f3b5d..5d0fd6c 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1780,6 +1780,9 @@ static int ip6_route_del(struct fib6_config *cfg) if (fn) { for (rt = fn->leaf; rt; rt = rt->dst.rt6_next) { + if ((rt->rt6i_flags & RTF_CACHE) && + !(cfg->fc_flags & RTF_CACHE)) + continue; if (cfg->fc_ifindex && (!rt->dst.dev || rt->dst.dev->ifindex != cfg->fc_ifindex)) @@ -2424,6 +2427,9 @@ static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh, if (rtm->rtm_type == RTN_LOCAL) cfg->fc_flags |= RTF_LOCAL; + if (rtm->rtm_flags & RTM_F_CLONED) + cfg->fc_flags |= RTF_CACHE; + cfg->fc_nlinfo.portid = NETLINK_CB(skb).portid; cfg->fc_nlinfo.nlh = nlh; cfg->fc_nlinfo.nl_net = sock_net(skb->sk);