[Buildroot] [PATCH 2/2] package/busybox: add init script for sysctl
Carlos Santos
casantos at datacom.com.br
Tue Dec 18 05:02:35 UTC 2018
Add a simple init script that invokes sysctl early in the initialization
process to configure kernel parameters. This is already performed by
systemd (systemd-sysctl) but there is no sysvinit/busybox counterpart.
Files are read from directories in the following list in the given order
from top to bottom:
/run/sysctl.d/*.conf
/etc/sysctl.d/*.conf
/usr/local/lib/sysctl.d/*.conf
/usr/lib/sysctl.d/*.conf
/lib/sysctl.d/*.conf
/etc/sysctl.conf
A file may be used more than once, since there can be multiple symlinks
to it. No attempt is made to prevent this.
Busybox's sysctl does not support "--quiet --system" arguments like the
sysctl provided by procps-ng, so we resort to some scripting to mimic
its behavior.
Signed-off-by: Carlos Santos <casantos at datacom.com.br>
---
package/busybox/S01sysctl | 63 ++++++++++++++++++++++++++++++++++++++
package/busybox/busybox.mk | 12 ++++++++
2 files changed, 75 insertions(+)
create mode 100644 package/busybox/S01sysctl
diff --git a/package/busybox/S01sysctl b/package/busybox/S01sysctl
new file mode 100644
index 0000000000..35e0cef291
--- /dev/null
+++ b/package/busybox/S01sysctl
@@ -0,0 +1,63 @@
+#!/bin/sh
+
+PROGRAM="sysctl"
+
+SYSCTL_ARGS=""
+
+# shellcheck source=/dev/null
+[ -r "/etc/default/$PROGRAM" ] && . "/etc/default/$PROGRAM"
+
+# Files are read from directories in the SYSCTL_SOURCES list, in given order.
+SYSCTL_SOURCES="/etc/sysctl.d/ /usr/local/lib/sysctl.d/ /usr/lib/sysctl.d/ /lib/sysctl.d/ /etc/sysctl.conf"
+
+# A file may be used more than once, since there can be multiple symlinks to
+# it. No attempt is made to prevent this.
+#
+# Busybox's sysctl does not support "--quiet --system" arguments like the
+# sysctl provided by procps-ng, so we resort to some scripting to mimic its
+# behavior.
+#
+# The "return 1" below is fruitless, at the moment, since sysctl ends with
+# status zero even if errors happen. Hopefully this will be fixed in a future
+# version of Busybox.
+apply_configs() {
+ # shellcheck disable=SC2086 # we need the word splitting
+ find $SYSCTL_SOURCES -maxdepth 1 -name '*.conf' -print0 2> /dev/null | \
+ xargs -0 -r readlink -f | \
+ {
+ read -r file
+ [ -z "$file" ] || /sbin/sysctl -q -p "$file" $SYSCTL_ARGS || return 1
+ }
+}
+
+start() {
+ printf 'Starting %s: ' "$PROGRAM"
+ apply_configs
+ status=$?
+ if [ "$status" -eq 0 ]; then
+ echo "OK"
+ else
+ echo "FAIL"
+ fi
+ return "$status"
+}
+
+stop() {
+ printf 'Stopping %s: OK\n' "$PROGRAM"
+}
+
+restart() {
+ stop
+ sleep 1
+ start
+}
+
+case "$1" in
+ start|stop)
+ "$1";;
+ restart|reload)
+ restart;;
+ *)
+ echo "Usage: $0 {start|stop|restart|reload}"
+ exit 1
+esac
diff --git a/package/busybox/busybox.mk b/package/busybox/busybox.mk
index bfcca6ed3e..bf101d7d46 100644
--- a/package/busybox/busybox.mk
+++ b/package/busybox/busybox.mk
@@ -259,6 +259,17 @@ define BUSYBOX_INSTALL_LOGGING_SCRIPT
endef
endif
+# Only install our sysctl scripts if no other package does it.
+ifeq ($(BR2_PACKAGE_PROCPS_NG),)
+define BUSYBOX_INSTALL_SYSCTL_SCRIPT
+ if grep -q CONFIG_BB_SYSCTL=y $(@D)/.config; \
+ then \
+ $(INSTALL) -m 0755 -D package/busybox/S01sysctl \
+ $(TARGET_DIR)/etc/init.d/S01sysctl ; \
+ fi
+endef
+endif
+
ifeq ($(BR2_INIT_BUSYBOX),y)
define BUSYBOX_INSTALL_INITTAB
$(INSTALL) -D -m 0644 package/busybox/inittab $(TARGET_DIR)/etc/inittab
@@ -344,6 +355,7 @@ define BUSYBOX_INSTALL_INIT_SYSV
$(BUSYBOX_INSTALL_MDEV_SCRIPT)
$(BUSYBOX_INSTALL_LOGGING_SCRIPT)
$(BUSYBOX_INSTALL_WATCHDOG_SCRIPT)
+ $(BUSYBOX_INSTALL_SYSCTL_SCRIPT)
$(BUSYBOX_INSTALL_TELNET_SCRIPT)
$(BUSYBOX_INSTALL_INDIVIDUAL_BINARIES)
endef
--
2.19.2
More information about the buildroot
mailing list