From: Hangbin Liu <liuhangbin@gmail.com>
To: netdev@vger.kernel.org
Cc: Julian Anastasov <ja@ssi.bg>,
Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>,
David Ahern <dsahern@gmail.com>,
Eric Dumazet <edumazet@google.com>,
David Miller <davem@davemloft.net>,
Hangbin Liu <liuhangbin@gmail.com>
Subject: [PATCHv2 net] ipv6/route: should not update neigh confirm time during PMTU update
Date: Tue, 3 Dec 2019 10:11:37 +0800 [thread overview]
Message-ID: <20191203021137.26809-1-liuhangbin@gmail.com> (raw)
In-Reply-To: <20191122061919.26157-1-liuhangbin@gmail.com>
When we setup a pair of gretap, ping each other and create neighbour cache.
Then delete and recreate one side. We will never be able to ping6 to the new
created gretap.
The reason is when we ping6 remote via gretap, we will call like
gre_tap_xmit()
- ip_tunnel_xmit()
- tnl_update_pmtu()
- skb_dst_update_pmtu()
- ip6_rt_update_pmtu()
- __ip6_rt_update_pmtu()
- dst_confirm_neigh()
- ip6_confirm_neigh()
- __ipv6_confirm_neigh()
- n->confirmed = now
As the confirmed time updated, in neigh_timer_handler() the check for
NUD_DELAY confirm time will pass and the neigh state will back to
NUD_REACHABLE. So the old/wrong mac address will be used again.
If we do not update the confirmed time, the neigh state will go to
neigh->nud_state = NUD_PROBE; then go to NUD_FAILED and re-create the
neigh later, which is what IPv4 does.
Fix it by removing the dst_confirm_neigh() in __ip6_rt_update_pmtu() as
there is no two-way communication during PMTU update.
v2: remove dst_confirm_neigh directly as David Miller pointed out.
Fixes: 0dec879f636f ("net: use dst_confirm_neigh for UDP, RAW, ICMP, L2TP")
Reported-by: Jianlin Shi <jishi@redhat.com>
Suggested-by: David Miller <davem@davemloft.net>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
---
net/ipv6/route.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index b59940416cb5..335ed36a5c78 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2710,7 +2710,6 @@ static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
daddr = NULL;
saddr = NULL;
}
- dst_confirm_neigh(dst, daddr);
mtu = max_t(u32, mtu, IPV6_MIN_MTU);
if (mtu >= dst_mtu(dst))
return;
--
2.19.2
next prev parent reply other threads:[~2019-12-03 2:11 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-22 6:19 [PATCH net] ipv6/route: only update neigh confirm time if pmtu changed Hangbin Liu
2019-11-22 18:04 ` David Miller
2019-11-26 9:17 ` Hangbin Liu
2019-12-03 2:11 ` Hangbin Liu [this message]
2019-12-03 2:47 ` [PATCHv2 net] ipv6/route: should not update neigh confirm time during PMTU update David Miller
2019-12-03 10:15 ` Hangbin Liu
2019-12-03 10:25 ` Hangbin Liu
2019-12-03 19:58 ` David Miller
2019-12-10 3:36 ` Hangbin Liu
2019-12-10 17:00 ` Guillaume Nault
2019-12-18 11:53 ` [PATCH net-next 0/8] disable neigh update for tunnels during pmtu update Hangbin Liu
2019-12-18 11:53 ` [PATCH net-next 1/8] net: add bool confirm_neigh parameter for dst_ops.update_pmtu Hangbin Liu
2019-12-18 11:53 ` [PATCH net-next 2/8] ip6_gre: do not confirm neighbor when do pmtu update Hangbin Liu
2019-12-18 11:53 ` [PATCH net-next 3/8] gtp: " Hangbin Liu
2019-12-18 11:53 ` [PATCH net-next 4/8] net/dst: add new function skb_dst_update_pmtu_no_confirm Hangbin Liu
2019-12-18 11:53 ` [PATCH net-next 5/8] tunnel: do not confirm neighbor when do pmtu update Hangbin Liu
2019-12-19 17:47 ` Guillaume Nault
2019-12-20 2:36 ` Hangbin Liu
2019-12-18 11:53 ` [PATCH net-next 6/8] vti: " Hangbin Liu
2019-12-18 11:53 ` [PATCH net-next 7/8] sit: " Hangbin Liu
2019-12-18 11:53 ` [PATCH net-next 8/8] net/dst: do not confirm neighbor for vxlan and geneve " Hangbin Liu
2019-12-19 17:49 ` Guillaume Nault
2019-12-18 12:01 ` [PATCH net-next 0/8] disable neigh update for tunnels during " Hangbin Liu
2019-12-19 17:57 ` Guillaume Nault
2019-12-20 2:48 ` Hangbin Liu
2019-12-19 17:53 ` Guillaume Nault
2019-12-20 3:25 ` [PATCHv4 net " Hangbin Liu
2019-12-20 3:25 ` [PATCHv4 net 1/8] net: add bool confirm_neigh parameter for dst_ops.update_pmtu Hangbin Liu
2019-12-20 3:25 ` [PATCHv4 net 2/8] ip6_gre: do not confirm neighbor when do pmtu update Hangbin Liu
2019-12-20 3:25 ` [PATCHv4 net 3/8] gtp: " Hangbin Liu
2019-12-21 18:35 ` Guillaume Nault
2019-12-20 3:25 ` [PATCHv4 net 4/8] net/dst: add new function skb_dst_update_pmtu_no_confirm Hangbin Liu
2019-12-20 3:25 ` [PATCHv4 net 5/8] tunnel: do not confirm neighbor when do pmtu update Hangbin Liu
2019-12-21 18:43 ` Guillaume Nault
2019-12-20 3:25 ` [PATCHv4 net 6/8] vti: " Hangbin Liu
2019-12-21 18:30 ` Guillaume Nault
2019-12-20 3:25 ` [PATCHv4 net 7/8] sit: " Hangbin Liu
2019-12-20 3:25 ` [PATCHv4 net 8/8] net/dst: do not confirm neighbor for vxlan and geneve " Hangbin Liu
2019-12-21 18:38 ` Guillaume Nault
2019-12-20 16:14 ` [PATCHv4 net 0/8] disable neigh update for tunnels during " David Ahern
2019-12-22 2:51 ` [PATCHv5 " Hangbin Liu
2019-12-22 2:51 ` [PATCHv5 net 1/8] net: add bool confirm_neigh parameter for dst_ops.update_pmtu Hangbin Liu
2019-12-22 2:51 ` [PATCHv5 net 2/8] ip6_gre: do not confirm neighbor when do pmtu update Hangbin Liu
2019-12-22 2:51 ` [PATCHv5 net 3/8] gtp: " Hangbin Liu
2019-12-22 2:51 ` [PATCHv5 net 4/8] net/dst: add new function skb_dst_update_pmtu_no_confirm Hangbin Liu
2019-12-22 2:51 ` [PATCHv5 net 5/8] tunnel: do not confirm neighbor when do pmtu update Hangbin Liu
2019-12-22 2:51 ` [PATCHv5 net 6/8] vti: " Hangbin Liu
2019-12-22 2:51 ` [PATCHv5 net 7/8] sit: " Hangbin Liu
2019-12-22 2:51 ` [PATCHv5 net 8/8] net/dst: do not confirm neighbor for vxlan and geneve " Hangbin Liu
2019-12-22 22:10 ` [PATCHv5 net 0/8] disable neigh update for tunnels during " Guillaume Nault
2019-12-25 6:30 ` David Miller
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