From ea3f4ec5ac55cfa789510c7efe480edeba204c18 Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Fri, 3 Feb 2023 12:22:16 +0100
Subject: [dhcpc-busybox] Don't wait for dhcp on br0 anymore

We did this to avoid issues if the hostname changes after Xorg
started up. But sometimes, DHCP is really slow, and we delay the
startup of the login screen by a good 10 seconds. Avoid this
by instead just touching the flag file that prevents the udhcpc
trigger script from changing the hostname. Running with a
potentially wrong hostname should be an acceptable tradeoff.
---
 .../system/lightdm.service.d/lock-hostname.conf       |  2 ++
 .../data/opt/openslx/scripts/udhcpc-openslx           | 19 ++++++++++++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 core/modules/dhcpc-busybox/data/etc/systemd/system/lightdm.service.d/lock-hostname.conf

(limited to 'core/modules/dhcpc-busybox')

diff --git a/core/modules/dhcpc-busybox/data/etc/systemd/system/lightdm.service.d/lock-hostname.conf b/core/modules/dhcpc-busybox/data/etc/systemd/system/lightdm.service.d/lock-hostname.conf
new file mode 100644
index 00000000..cf079a5b
--- /dev/null
+++ b/core/modules/dhcpc-busybox/data/etc/systemd/system/lightdm.service.d/lock-hostname.conf
@@ -0,0 +1,2 @@
+[Service]
+ExecStartPre=-/opt/openslx/scripts/udhcpc-openslx --lock-hostname-updates
diff --git a/core/modules/dhcpc-busybox/data/opt/openslx/scripts/udhcpc-openslx b/core/modules/dhcpc-busybox/data/opt/openslx/scripts/udhcpc-openslx
index 0d74e832..327bdaa4 100755
--- a/core/modules/dhcpc-busybox/data/opt/openslx/scripts/udhcpc-openslx
+++ b/core/modules/dhcpc-busybox/data/opt/openslx/scripts/udhcpc-openslx
@@ -29,6 +29,22 @@ declare -rg RESOLV_CONF="/opt/openslx/resolv.conf"
 declare -rg THIS_RESOLV="/run/network/${interface}.resolv"
 declare -rg flag="/run/network/primary-dhcp.flag"
 
+if [ "$1" = "--lock-hostname-updates" ]; then
+	# If we change the hostname while Xorg is running, this might
+	# cause issues, depending on how it's set up. So we run this
+	# script with the lock argument to touch the flag file right
+	# before we try to launch lightdm/Xorg. In case the DHCP request
+	# is too slow, this means we'll run with the wrong hostname
+	# (potentially), but that's better than delaying the bootup
+	# unnecessarily.
+	# So also note that if you ever change this script's name/location
+	# (JUST DON'T), you'd need to update all call sites, i.e. the
+	# udhcpc startup script, and the lightdm service drop-in.
+	mkdir -p /run/network
+	touch "$flag"
+	exit 0
+fi
+
 shopt -s extglob
 
 rebuild_resolv_conf () {
@@ -186,7 +202,8 @@ case "$1" in
 				echo "SLX_NET_WINS='$wins'" >> /opt/openslx/config
 			fi
 			
-			# Only if network is not ready yet
+			# Only update hostname if network is not ready yet
+			# later on this might cause issues
 			if ! [ -e "$flag" ]; then
 				# Update hostname
 				if [ -z "$dns_fqdn" ] && [ -n "$domain" ] && [ -n "$hostname" ]; then
-- 
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