From: Jim Darby <uberscubajim@gmail.com>
To: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: WireGuard mailing list <wireguard@lists.zx2c4.com>
Subject: Re: Timing issue (?) with wg-quick up on Raspberry Pi B+
Date: Mon, 11 Sep 2017 13:35:54 +0100 [thread overview]
Message-ID: <a4c43cd5-7792-b11f-479a-046b5c4fd048@gmail.com> (raw)
In-Reply-To: <CAHmME9ozNXY6xSSLqGR1M6_fJCquGGLjr0P=4XFOnxHefwbg9Q@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 2279 bytes --]
Nailed it!
Specifically, you were spot on about the /etc/default/ifplugd file and
its HOTPLUG_INTERFACES line. Changing that to HOTPLUG_INTERFACES="eth0
eth1" meant that it just worked out of the box.
In fact, I suspect that eth0 could be omitted because it's part of the
hardware (eth1 is a USB dongle so hotplugging may be useful). I'd prefer
a way to specifically /exclude/ wg* interfaces rather then include the
known ones but that may be too complex.
I hope this discussion and its solution will be a useful part of the
WireGuard documentation. It'll hopefully stop others becoming confused
in the future.
Many thanks for your help in resolving this! I'm very much enjoying
playing with WireGuard. I heard about it during your talk at FOSDEM by
the way.
Regards,
Jim.
On 11/09/17 01:52, Jason A. Donenfeld wrote:
> I figured it out. ifplugd clears all addresses when bringing up an
> interface:
>
> void interface_up(int fd, char *iface) {
> ...
> ((struct sockaddr_in *)(&ifr.ifr_addr))->sin_addr.s_addr =
> INADDR_ANY;
> if (ioctl(fd, SIOCSIFADDR, &ifr) < 0) {
> ...
> }
>
> Since wg-quick sets the address before bringing it up, this running in
> between is problematic. One workaround in wg-quick would be for me to
> reverse the order of setting the IP and bringing it up, but this
> introduces other races I'm not very fond of introducing. So, rather,
> we should address the larger question: why on earth is ifplugd being
> started when wg0 is added?
>
> Sep 10 23:57:51 janus ifplugd(wg0)[14109]: ifplugd 0.28 initializing.
> Sep 10 23:57:51 janus ifplugd(wg0)[14109]: Using interface
> wg0/00:00:00:00:00:00
> Sep 10 23:57:51 janus ifplugd(wg0)[14109]: Using detection mode:
> IFF_RUNNING
>
> What causes it to be launched here? Digging a bit deeper, it looks
> like ifplugd is being launched by a udev rule which calls a Debian
> file called ifplugd.agent. It is in here that unholy hotplugging occurs.
>
> I don't actually have a Debian system running to fish around and see,
> but my guess is that you have a file /etc/default/ifplugd that has in
> it HOTPLUG_INTERFACES=all. If you change this to
> HOTPLUG_INTERFACES="wlan0 eth0" or something more restrictive, things
> might work better. Just a guess.
[-- Attachment #2: Type: text/html, Size: 3487 bytes --]
next prev parent reply other threads:[~2017-09-11 12:09 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-10 11:34 Jim Darby
2017-09-10 12:44 ` Jason A. Donenfeld
2017-09-10 13:09 ` Jim Darby
2017-09-10 14:26 ` Jason A. Donenfeld
2017-09-10 15:08 ` Jim Darby
2017-09-10 22:25 ` Jason A. Donenfeld
2017-09-10 22:30 ` Jason A. Donenfeld
2017-09-10 23:23 ` Jim Darby
2017-09-11 0:52 ` Jason A. Donenfeld
2017-09-11 12:35 ` Jim Darby [this message]
2017-09-11 12:37 ` Jason A. Donenfeld
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=a4c43cd5-7792-b11f-479a-046b5c4fd048@gmail.com \
--to=uberscubajim@gmail.com \
--cc=Jason@zx2c4.com \
--cc=wireguard@lists.zx2c4.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.
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).