From: Stefano Brivio <sbrivio@redhat.com>
To: David Ahern <dsahern@gmail.com>
Cc: Hangbin Liu <liuhangbin@gmail.com>,
netdev@vger.kernel.org,
Marcelo Ricardo Leitner <mleitner@redhat.com>,
"David S . Miller" <davem@davemloft.net>
Subject: Re: [PATCH net] ipv4/route: do not check saddr dev if iif is LOOPBACK_IFINDEX
Date: Fri, 2 Aug 2019 22:35:49 +0200 [thread overview]
Message-ID: <20190802223549.3f4f387f@elisabeth> (raw)
In-Reply-To: <f44d9f26-046d-38a2-13aa-d25b92419d11@gmail.com>
David,
On Thu, 1 Aug 2019 13:51:25 -0600
David Ahern <dsahern@gmail.com> wrote:
> On 8/1/19 2:29 AM, Hangbin Liu wrote:
> > Jianlin reported a bug that for IPv4, ip route get from src_addr would fail
> > if src_addr is not an address on local system.
> >
> > \# ip route get 1.1.1.1 from 2.2.2.2
> > RTNETLINK answers: Invalid argument
>
> so this is a forwarding lookup in which case iif should be set.
On actual forwarding, yes, it will be set.
But if we are just doing a lookup for a route (iif is
LOOPBACK_IFINDEX), I think this should still give us the matching route,
which is what IPv6 already does and what this patch fixes for IPv4.
Otherwise, we have no way to fetch that route, no matter if source
routing is configured. So I think this patch is correct and to some
extent necessary.
--
Stefano
prev parent reply other threads:[~2019-08-02 20:35 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-01 8:29 [PATCH net] ipv4/route: do not check saddr dev if iif is LOOPBACK_IFINDEX Hangbin Liu
2019-08-01 19:51 ` David Ahern
2019-08-02 4:13 ` Hangbin Liu
2019-08-02 4:16 ` David Ahern
2019-08-12 3:49 ` David Miller
2019-08-12 22:58 ` Stefano Brivio
2019-08-13 0:23 ` David Ahern
2019-08-02 20:35 ` Stefano Brivio [this message]
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=20190802223549.3f4f387f@elisabeth \
--to=sbrivio@redhat.com \
--cc=davem@davemloft.net \
--cc=dsahern@gmail.com \
--cc=liuhangbin@gmail.com \
--cc=mleitner@redhat.com \
--cc=netdev@vger.kernel.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).