4.9-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit b91d532928dff2141ea9c107c3e73104d9843767 ]
After commit c2ed1880fd61 ("net: ipv6: check route protocol when deleting routes"), ipv6 route checks rt protocol when trying to remove a rt entry.
It introduced a side effect causing 'ip -6 route flush cache' not to work well. When flushing caches with iproute, all route caches get dumped from kernel then removed one by one by sending DELROUTE requests to kernel for each cache.
The thing is iproute sends the request with the cache whose proto is set with RTPROT_REDIRECT by rt6_fill_node() when kernel dumps it. But in kernel the rt_cache protocol is still 0, which causes the cache not to be matched and removed.
So the real reason is rt6i_protocol in the route is not set when it is allocated. As David Ahern's suggestion, this patch is to set rt6i_protocol properly in the route when it is installed and remove the codes setting rtm_protocol according to rt6i_flags in rt6_fill_node.
This is also an improvement to keep rt6i_protocol consistent with rtm_protocol.
Fixes: c2ed1880fd61 ("net: ipv6: check route protocol when deleting routes") Reported-by: Jianlin Shi jishi@redhat.com Suggested-by: David Ahern dsahern@gmail.com Signed-off-by: Xin Long lucien.xin@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv6/route.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 70fa31e37360..4cc12eeca7ab 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -2289,6 +2289,7 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu if (on_link) nrt->rt6i_flags &= ~RTF_GATEWAY;
+ nrt->rt6i_protocol = RTPROT_REDIRECT; nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
if (ip6_ins_rt(nrt)) @@ -2393,6 +2394,7 @@ static struct rt6_info *rt6_add_route_info(struct net *net, .fc_dst_len = prefixlen, .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO | RTF_UP | RTF_PREF(pref), + .fc_protocol = RTPROT_RA, .fc_nlinfo.portid = 0, .fc_nlinfo.nlh = NULL, .fc_nlinfo.nl_net = net, @@ -2445,6 +2447,7 @@ struct rt6_info *rt6_add_dflt_router(const struct in6_addr *gwaddr, .fc_ifindex = dev->ifindex, .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT | RTF_UP | RTF_EXPIRES | RTF_PREF(pref), + .fc_protocol = RTPROT_RA, .fc_nlinfo.portid = 0, .fc_nlinfo.nlh = NULL, .fc_nlinfo.nl_net = dev_net(dev), @@ -3241,14 +3244,6 @@ static int rt6_fill_node(struct net *net, } rtm->rtm_scope = RT_SCOPE_UNIVERSE; rtm->rtm_protocol = rt->rt6i_protocol; - if (rt->rt6i_flags & RTF_DYNAMIC) - rtm->rtm_protocol = RTPROT_REDIRECT; - else if (rt->rt6i_flags & RTF_ADDRCONF) { - if (rt->rt6i_flags & (RTF_DEFAULT | RTF_ROUTEINFO)) - rtm->rtm_protocol = RTPROT_RA; - else - rtm->rtm_protocol = RTPROT_KERNEL; - }
if (rt->rt6i_flags & RTF_CACHE) rtm->rtm_flags |= RTM_F_CLONED;