From: David Ahern <dsahern@gmail.com>
To: Hangbin Liu <liuhangbin@gmail.com>, netdev@vger.kernel.org
Cc: Julian Anastasov <ja@ssi.bg>,
Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>,
Eric Dumazet <edumazet@google.com>,
Guillaume Nault <gnault@redhat.com>,
David Miller <davem@davemloft.net>,
Pablo Neira <pablo@netfilter.org>,
Stephen Hemminger <stephen@networkplumber.org>,
Alexey Kodanev <alexey.kodanev@oracle.com>
Subject: Re: [PATCHv4 net 0/8] disable neigh update for tunnels during pmtu update
Date: Fri, 20 Dec 2019 09:14:09 -0700 [thread overview]
Message-ID: <2e9e485e-c400-3463-9095-013c5ae1df85@gmail.com> (raw)
In-Reply-To: <20191220032525.26909-1-liuhangbin@gmail.com>
On 12/19/19 8:25 PM, Hangbin Liu wrote:
> 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.
>
> We couldn't remove the ip6_confirm_neigh() directly as we still need it
> for TCP flows. To fix it, we have to pass a bool parameter to
> dst_ops.update_pmtu() and only disable neighbor update for tunnels.
>
seems reasonable to me.
Acked-by: David Ahern <dsahern@gmail.com>
next prev parent reply other threads:[~2019-12-20 16:14 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 ` [PATCHv2 net] ipv6/route: should not update neigh confirm time during PMTU update Hangbin Liu
2019-12-03 2:47 ` 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 ` David Ahern [this message]
2019-12-22 2:51 ` [PATCHv5 net 0/8] disable neigh update for tunnels during " 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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=2e9e485e-c400-3463-9095-013c5ae1df85@gmail.com \
--to=dsahern@gmail.com \
--cc=alexey.kodanev@oracle.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=gnault@redhat.com \
--cc=ja@ssi.bg \
--cc=liuhangbin@gmail.com \
--cc=marcelo.leitner@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=pablo@netfilter.org \
--cc=stephen@networkplumber.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).