Package: ifupdown
Version: 0.8.41
Severity: normal
Tags: patch
X-Debbugs-Cc: [email protected]
Dear Maintainer,
For an advanced home router setup, I have ifupdown configure over a dozen
network interfaces at startup. These include the home network's main VSDL2
Internet connection, using the ppp method which has ifupdown spawn a pppd
process for pppoe in the background, as well as multiple WiFi access points,
using the hostapd option that the hostapd package installs as an ifupdown
plugin which spawns hostapd processes in the background.
I am facing the issue that I make any mistakes in the network configuration,
even if it is in interface stanzas completely unrelated to the ppp or wlan ap
interfaces, and the call from networking.service to ifup -a --read-environment
returns an error code, ifup will still have brought both the pppoe as well as
the wlan ap interfaces up, however systemd now considers networking.service
failed and therefore stopped and terminates any processes spawned by ifup for
other network interfaces that were successfully configured, such as pppd and
hostapd processes. As we result, the Internet connection and WiFi access
points, that were initially brought up correctly, are being terminated again.
Also, this produces a system inconsistency as ifupdown still considers these
interface up and running as it is not aware of systemd having killed the
supporting pppd and hostapd processes.
If you look at networking.service, it says in the [Service] section:
ExecStart=/sbin/ifup -a --read-environment
ExecStart=-/bin/sh -c 'if [ -f /run/network/restart-hotplug ]; then /sbin/ifup
-a --read-environment --allow=hotplug; fi'
As you can see, it is designed to not tolerate errors bringing up interfaces
classified as "auto", but it does tolerate errors for interfaces classified as
"hotplug", as the minus prefix in the 2nd ExecStart line tells systemd to
ignore failure return codes in the call to ifup for hotplug devices. I am
wondering, why the difference in behaviour for "auto" and "hotplug" interfaces.
As if I change the above to
ExecStart=-/sbin/ifup -a --read-environment
ExecStart=-/bin/sh -c 'if [ -f /run/network/restart-hotplug ]; then /sbin/ifup
-a --read-environment --allow=hotplug; fi'
I am getting the desired behaviour (for me) of systemd no longer killing pppd
and hostapd processes as the service is still considered running even if ifup
fails to bring up any of the other network interface not related to Internet
connection and WiFi access points. Should this be change for the next release
of ifupdown?
-- Package-specific info:
--- /etc/network/interfaces:
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
source /etc/network/interfaces.d/*
# The loopback network interface
auto lo
iface lo inet loopback
--- /etc/network/interfaces.d/*:
auto wan0 wan0.40
iface wan0 inet manual
mtu 1508
iface wan0.40 inet manual
mtu 1508
auto provider
iface provider inet ppp
unit 0
provider provider
auto wlan0
iface wlan0 inet manual
hostapd /etc/hostapd/wlan0.conf
auto wlan1
iface wlan1 inet manual
hostapd /etc/hostapd/wlan1.conf
auto wlan2
iface wlan2 inet manual
hostapd /etc/hostapd/wlan2.conf
auto eth1
iface eth1 inet static
address 192.168.178.1/25
bridge-ports eth0 wlan1
bridge_hw eth0
bridge_stp off
bridge_maxwait 0
bridge_fd 0
post-up iptables -t nat -w -I POSTROUTING 1 -s 192.168.178.0/25 -o ppp0
-j MASQUERADE
pre-down iptables -t nat -w -D POSTROUTING -s 192.168.178.0/25 -o ppp0
-j MASQUERADE
# introduce deliberate error
auto eth2
iface eth2 inet static
address 192.168.179.1/25
bridge-ports eth0.2
bridge_hw eth0
bridge_stp off
bridge_maxwait 0
bridge_fd 0
post-up false
--- up and down scripts installed:
/etc/network/if-down.d:
total 8
lrwxrwxrwx 1 root root 29 Jan 25 2023 bridge -> /lib/bridge-utils/ifupdown.sh
-rwxr-xr-x 1 root root 372 Jan 25 2023 openvpn
-rwxr-xr-x 1 root root 759 Dec 9 2022 resolved
lrwxrwxrwx 1 root root 32 Aug 5 2024 wpasupplicant ->
../../wpa_supplicant/ifupdown.sh
/etc/network/if-post-down.d:
total 4
lrwxrwxrwx 1 root root 29 Jan 25 2023 bridge -> /lib/bridge-utils/ifupdown.sh
lrwxrwxrwx 1 root root 25 Aug 5 2024 hostapd -> ../../hostapd/ifupdown.sh
-rwxr-xr-x 1 root root 1409 Mar 7 2020 wireless-tools
lrwxrwxrwx 1 root root 32 Aug 5 2024 wpasupplicant ->
../../wpa_supplicant/ifupdown.sh
/etc/network/if-pre-up.d:
total 12
lrwxrwxrwx 1 root root 29 Jan 25 2023 bridge -> /lib/bridge-utils/ifupdown.sh
-rwxr-xr-x 1 root root 344 Dec 20 2022 ethtool
lrwxrwxrwx 1 root root 25 Aug 5 2024 hostapd -> ../../hostapd/ifupdown.sh
-rwxr-xr-x 1 root root 4191 Mar 7 2020 wireless-tools
lrwxrwxrwx 1 root root 32 Aug 5 2024 wpasupplicant ->
../../wpa_supplicant/ifupdown.sh
/etc/network/if-up.d:
total 16
-rwxr-xr-x 1 root root 1685 Dec 20 2022 ethtool
-rwxr-xr-x 1 root root 385 Jan 25 2023 openvpn
-rwxr-xr-x 1 root root 4663 Dec 9 2022 resolved
lrwxrwxrwx 1 root root 32 Aug 5 2024 wpasupplicant ->
../../wpa_supplicant/ifupdown.sh
-- System Information:
Debian Release: 12.9
APT prefers stable-security
APT policy: (500, 'stable-security'), (500, 'stable')
Architecture: amd64 (x86_64)
Kernel: Linux 6.12.9+bpo-amd64 (SMP w/12 CPU threads; PREEMPT)
Locale: LANG=en_CA.UTF-8, LC_CTYPE=en_CA.UTF-8 (charmap=UTF-8),
LANGUAGE=en_CA:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled
Versions of packages ifupdown depends on:
ii adduser 3.134
ii iproute2 6.1.0-3
ii libc6 2.36-9+deb12u9
Versions of packages ifupdown recommends:
ii isc-dhcp-client [dhcp-client] 4.4.3-P1-2
Versions of packages ifupdown suggests:
ii ppp 2.4.9-1+1.1+b1
pn rdnssd <none>
-- Configuration Files:
/etc/default/networking changed [not included]
-- no debconf information
