[Buildroot] [git commit] package/busybox: add init script for sysctl
Peter Korsgaard
peter at korsgaard.com
Sat Aug 3 16:48:09 UTC 2019
commit: https://git.buildroot.net/buildroot/commit/?id=398c1af1d5cbad6cdcf0b2b965f27e86d1755420
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/master
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.
Signed-off-by: Carlos Santos <unixmania at gmail.com>
Reviewed-by: Matthew Weber <matthew.weber at rockwellcollins.com>
Signed-off-by: Peter Korsgaard <peter at korsgaard.com>
---
package/busybox/S02sysctl | 66 ++++++++++++++++++++++++++++++++++++++++++++++
package/busybox/busybox.mk | 12 +++++++++
2 files changed, 78 insertions(+)
diff --git a/package/busybox/S02sysctl b/package/busybox/S02sysctl
new file mode 100644
index 0000000000..6bb2fa165e
--- /dev/null
+++ b/package/busybox/S02sysctl
@@ -0,0 +1,66 @@
+#!/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 the given
+# order. A file may be used more than once, since there can be multiple
+# symlinks to it. No attempt is made to prevent this.
+SYSCTL_SOURCES="/etc/sysctl.d/ /usr/local/lib/sysctl.d/ /usr/lib/sysctl.d/ /lib/sysctl.d/ /etc/sysctl.conf"
+
+# Use some scripting to mimic the --system option of the sysctl provided by
+# procps-ng but still reporting errors. Users not interested on error report
+# can put "-e" in SYSCTL_ARGS.
+#
+# The file redirections do the following:
+#
+# - stdout is redirected to syslog with facility.level "kern.info"
+# - stderr is redirected to syslog with facility.level "kern.err"
+# - file dscriptor 4 is used to pass the result to the "start" function.
+#
+# Testing the sysctl exit code is fruitless, as at the moment, since it ends
+# with status zero even if errors happen. Hopefully this will be fixed in a
+# future version of Busybox.
+#
+run_program() {
+ # shellcheck disable=SC2086 # we need the word splitting
+ find $SYSCTL_SOURCES -maxdepth 1 -name '*.conf' -print0 2> /dev/null | \
+ xargs -0 -r -n 1 readlink -f | {
+ prog_status="OK"
+ while :; do
+ read -r file
+ if [ -z "$file" ]; then
+ echo "$prog_status" >&4
+ break
+ fi
+ echo "* Applying $file ..."
+ /sbin/sysctl -p "$file" $SYSCTL_ARGS || prog_status="FAIL"
+ done 2>&1 >&3 | /usr/bin/logger -t sysctl -p kern.err
+ } 3>&1 | /usr/bin/logger -t sysctl -p kern.info
+}
+
+start() {
+ printf '%s %s: ' "$1" "$PROGRAM"
+ status=$(run_program 4>&1)
+ echo "$status"
+ if [ "$status" = "OK" ]; then
+ return 0
+ fi
+ return 1
+}
+
+case "$1" in
+ start)
+ start "Running";;
+ restart|reload)
+ start "Rerunning";;
+ stop)
+ :;;
+ *)
+ echo "Usage: $0 {start|stop|restart|reload}"
+ exit 1
+esac
diff --git a/package/busybox/busybox.mk b/package/busybox/busybox.mk
index 7a5a37a05d..a154584592 100644
--- a/package/busybox/busybox.mk
+++ b/package/busybox/busybox.mk
@@ -260,6 +260,17 @@ define BUSYBOX_INSTALL_LOGGING_SCRIPT
endef
endif
+# Only install our sysctl scripts if no other package does it.
+ifeq ($(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/S02sysctl \
+ $(TARGET_DIR)/etc/init.d/S02sysctl ; \
+ fi
+endef
+endif
+
ifeq ($(BR2_INIT_BUSYBOX),y)
define BUSYBOX_INSTALL_INITTAB
$(INSTALL) -D -m 0644 package/busybox/inittab $(TARGET_DIR)/etc/inittab
@@ -341,6 +352,7 @@ 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
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