From: Stefano Brivio <sbrivio@redhat.com>
To: passt-dev@passt.top
Cc: David Gibson <david@gibson.dropbear.id.au>,
Paul Holzinger <pholzing@redhat.com>
Subject: [PATCH v2 0/7] Prevent DAD for link-local addresses in containers
Date: Thu, 15 Aug 2024 10:36:42 +0200 [thread overview]
Message-ID: <20240815083649.4188007-1-sbrivio@redhat.com> (raw)
There's no point in letting a container perform duplicate address
detection as we'll silently discard neighbour solicitations with
unspecified source addresses anyway, without relaying them to anybody.
And we realised that it's not harmless, see the whole discussion around
https://github.com/containers/podman/pull/23561#discussion_r1711639663:
we can't communicate with the container right away because of that,
which is surely annoying for tests, but it could also be an issue for
use cases with very short-lived containers or namespaces.
Disabling DAD via procfs configuration would be simpler than all this,
but we don't own the namespace (unless we spawn a shell), so we
shouldn't mess up with procfs entries, assuming it's even possible.
Set the nodad attribute, and prevent DAD from being triggered before
on link up, before we can set that attribute.
v2:
- in 4/7, instead of doing the whole nl_routes_dup()-vendored dance
to keep addresses in a single buffer, send NLM_F_REPLACE requests
right away, but use nlmsg_send() instead of nl_do(), and check for
answers to our further requests later. Use warn() instead of die()
if we can't set nodad attributes
- in 5/7, make nl_addr_get_ll() get a pointer to struct in6_addr
instead of a generic void pointer, and warn(), don't die(), if
it fails
Stefano Brivio (7):
netlink: Fix typo in function comment for nl_addr_get()
netlink, pasta: Split MTU setting functionality out of nl_link_up()
netlink, pasta: Turn nl_link_up() into a generic function to set link
flags
netlink, pasta: Disable DAD for link-local addresses on namespace
interface
netlink, pasta: Fetch link-local address from namespace interface once
it's up
pasta: Disable neighbour solicitations on device up to prevent DAD
netlink: Fix typo in function comment for nl_addr_set()
netlink.c | 144 +++++++++++++++++++++++++++++++++++++++++++++++++-----
netlink.h | 6 ++-
pasta.c | 29 ++++++++++-
3 files changed, 164 insertions(+), 15 deletions(-)
--
2.43.0
next reply other threads:[~2024-08-15 8:36 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-15 8:36 Stefano Brivio [this message]
2024-08-15 8:36 ` [PATCH v2 1/7] netlink: Fix typo in function comment for nl_addr_get() Stefano Brivio
2024-08-15 8:36 ` [PATCH v2 2/7] netlink, pasta: Split MTU setting functionality out of nl_link_up() Stefano Brivio
2024-08-15 8:36 ` [PATCH v2 3/7] netlink, pasta: Turn nl_link_up() into a generic function to set link flags Stefano Brivio
2024-08-15 8:36 ` [PATCH v2 4/7] netlink, pasta: Disable DAD for link-local addresses on namespace interface Stefano Brivio
2024-08-15 10:38 ` David Gibson
2024-08-15 10:59 ` Stefano Brivio
2024-08-16 0:55 ` David Gibson
2024-08-16 5:45 ` Stefano Brivio
2024-08-15 8:36 ` [PATCH v2 5/7] netlink, pasta: Fetch link-local address from namespace interface once it's up Stefano Brivio
2024-08-15 10:41 ` David Gibson
2024-08-15 8:36 ` [PATCH v2 6/7] pasta: Disable neighbour solicitations on device up to prevent DAD Stefano Brivio
2024-08-15 8:36 ` [PATCH v2 7/7] netlink: Fix typo in function comment for nl_addr_set() Stefano Brivio
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=20240815083649.4188007-1-sbrivio@redhat.com \
--to=sbrivio@redhat.com \
--cc=david@gibson.dropbear.id.au \
--cc=passt-dev@passt.top \
--cc=pholzing@redhat.com \
/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.
Code repositories for project(s) associated with this public inbox
https://passt.top/passt
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 IMAP folder(s).