Load sysctl config files from sysctl.d

This patch implement loading of sysctl config files as described in
http://0pointer.de/public/systemd-man/sysctl.d.html

This is a very conveniant way of configuring sysctl option for sysadmin
which can drop sysctl config files inside this directory to enable some
feature.

Dropping a file like disableipv6.conf inside this directory will disable ipv6
$ cat disableipv6.conf
net.ipv6.conf.all.disable_ipv6 = 1

There is atm no package which use this functionnality

Signed-off-by: Sebastien Luttringer <seblu@seblu.net>

3 files changed, 34 insertions, 3 deletions

diff --git a/Makefile b/Makefile
index 4916387..a6262e2 100644
--- a/Makefile
+++ b/Makefile
@@ -8,6 +8,8 @@ DIRS := \
 	/usr/sbin \
 	/etc/tmpfiles.d \
 	/usr/lib/tmpfiles.d \
+	/etc/sysctl.d \
+	/usr/lib/sysctl.d \
 	/usr/lib/initscripts \
 	/etc/bash_completion.d \
 	/usr/share/zsh/site-functions
@@ -25,7 +27,7 @@ install: minilogd installdirs
 	install -m755 -t $(DESTDIR)/etc/rc.d hwclock network netfs
 	install -m755 -t $(DESTDIR)/etc/profile.d locale.sh
 	install -m755 -t $(DESTDIR)/usr/sbin minilogd rc.d
-	install -m755 -t $(DESTDIR)/usr/lib/initscripts arch-tmpfiles
+	install -m755 -t $(DESTDIR)/usr/lib/initscripts arch-tmpfiles arch-sysctl
 	install -m644 tmpfiles.conf $(DESTDIR)/usr/lib/tmpfiles.d/arch.conf
 	install -m644 -T bash-completion $(DESTDIR)/etc/bash_completion.d/rc.d
 	install -m644 -T zsh-completion $(DESTDIR)/usr/share/zsh/site-functions/_rc.d
diff --git a/arch-sysctl b/arch-sysctl
new file mode 100755
index 0000000..4856df6
--- /dev/null
+++ b/arch-sysctl
@@ -0,0 +1,29 @@
+#!/bin/bash
+#
+# /usr/lib/initscripts/arch-sysctl
+#
+# Load sysctl configuration files following
+# http://0pointer.de/public/systemd-man/sysctl.d.html
+#
+
+shopt -s nullglob
+
+declare -a sysctl_d=(
+	/usr/lib/sysctl.d/*.conf
+	/etc/sysctl.d/*.conf
+	/run/sysctl.d/*.conf
+	/etc/sysctl.conf
+)
+declare -A fragments
+
+# files declared later in the sysctl_d array will override earlier
+# Example: `/etc/sysctl.d/foo.conf' supersedes `/usr/lib/sysctl.d/foo.conf'.
+for path in "${sysctl_d[@]}"; do
+  [[ -f $path ]] && fragments[${path##*/}]=$path
+done
+
+for path in "${fragments[@]}"; do
+	sysctl -q -p "$path"
+done
+
+# vim: set ts=2 sw=2 noet:
diff --git a/rc.multi b/rc.multi
index 16fa83a..19623d8 100755
--- a/rc.multi
+++ b/rc.multi
@@ -8,8 +8,8 @@
 
 run_hook multi_start
 
-# Load sysctl variables if sysctl.conf is present
-[[ -r /etc/sysctl.conf ]] && sysctl -q -p &>/dev/null
+# Load sysctl config files
+[[ -x /usr/lib/initscripts/arch-sysctl ]] && /usr/lib/initscripts/arch-sysctl
 
 # Start daemons
 for daemon in "${DAEMONS[@]}"; do