package/ifupdown-scripts: new package

The ifupdown scripts can be used independently of the init system, be it
sysv, busybox or systemd; they could even be used when there is no init
system (i.e. the user is providing his own).

Currently, those ifupdown scripts are bundled in the skeleton.

But we soon will have a skeleton specific to systemd, so we would be
missing those scripts (when systemd-networkd is not enabled).

So, move those scripts to their own package.

To keep the current behaviour (before it is changed in future commits),
we make that package default to y, but depend on the default skeleton.

Instead of being a target-finalize hook, the scripts are installed as
any other package are, with a package install-target command.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Arnout Vandecappelle <arnout@mind.be>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Maxime Hadjinlian <maxime.hadjinlian@gmail.com>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
[Thomas: drop empty IFUPDOWN_SCRIPTS_SOURCE]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/ifupdown-scripts/Config.in

@@ -0,0 +1,8 @@
+config BR2_PACKAGE_IFUPDOWN_SCRIPTS
+	bool
+	depends on BR2_ROOTFS_SKELETON_DEFAULT
+	depends on !BR2_PACKAGE_SYSTEMD_NETWORKD
+	default y
+	help
+	  Set of scripts used by ifupdown (either the standalone one, or the
+	  busybox one) to bring network up, or tear it down.

package/ifupdown-scripts/S40network

@@ -0,0 +1,30 @@
+#!/bin/sh
+#
+# Start the network....
+#
+
+# Debian ifupdown needs the /run/network lock directory
+mkdir -p /run/network
+
+case "$1" in
+  start)
+	printf "Starting network: "
+	/sbin/ifup -a
+	[ $? = 0 ] && echo "OK" || echo "FAIL"
+	;;
+  stop)
+	printf "Stopping network: "
+	/sbin/ifdown -a
+	[ $? = 0 ] && echo "OK" || echo "FAIL"
+	;;
+  restart|reload)
+	"$0" stop
+	"$0" start
+	;;
+  *)
+	echo "Usage: $0 {start|stop|restart}"
+	exit 1
+esac
+
+exit $?
+

package/ifupdown-scripts/ifupdown-scripts.mk

@@ -0,0 +1,55 @@
+################################################################################
+#
+# ifupdown-scripts
+#
+################################################################################
+
+define IFUPDOWN_SCRIPTS_LOCALHOST
+	( \
+		echo "# interface file auto-generated by buildroot"; \
+		echo ; \
+		echo "auto lo"; \
+		echo "iface lo inet loopback"; \
+	) > $(TARGET_DIR)/etc/network/interfaces
+endef
+
+IFUPDOWN_SCRIPTS_DHCP_IFACE = $(call qstrip,$(BR2_SYSTEM_DHCP))
+
+ifneq ($(IFUPDOWN_SCRIPTS_DHCP_IFACE),)
+define IFUPDOWN_SCRIPTS_DHCP
+	( \
+		echo ; \
+		echo "auto $(IFUPDOWN_SCRIPTS_DHCP_IFACE)"; \
+		echo "iface $(IFUPDOWN_SCRIPTS_DHCP_IFACE) inet dhcp"; \
+		echo "  pre-up /etc/network/nfs_check"; \
+		echo "  wait-delay 15"; \
+	) >> $(TARGET_DIR)/etc/network/interfaces
+	$(INSTALL) -m 0755 -D $(IFUPDOWN_SCRIPTS_PKGDIR)/nfs_check \
+		$(TARGET_DIR)/etc/network/nfs_check
+endef
+endif
+
+define IFUPDOWN_SCRIPTS_INSTALL_TARGET_CMDS
+	mkdir -p $(TARGET_DIR)/etc/network
+	cp -a $(IFUPDOWN_SCRIPTS_PKGDIR)/network/* $(TARGET_DIR)/etc/network
+	$(IFUPDOWN_SCRIPTS_LOCALHOST)
+	$(IFUPDOWN_SCRIPTS_DHCP)
+endef
+
+define IFUPDOWN_SCRIPTS_INSTALL_INIT_SYSV
+	$(INSTALL) -D -m 0755 $(IFUPDOWN_SCRIPTS_PKGDIR)/S40network \
+		$(TARGET_DIR)/etc/init.d/S40network
+endef
+
+# ifupdown-scripts can not be selected when systemd-networkd is
+# enabled, so if we are enabled with systemd, we must install our
+# own service file.
+define IFUPDOWN_SCRIPTS_INSTALL_INIT_SYSTEMD
+	$(INSTALL) -D -m 644 $(IFUPDOWN_SCRIPTS_PKGDIR)/network.service \
+		$(TARGET_DIR)/etc/systemd/system/network.service
+	mkdir -p $(TARGET_DIR)/etc/systemd/system/multi-user.target.wants
+	ln -fs ../network.service \
+		$(TARGET_DIR)/etc/systemd/system/multi-user.target.wants/network.service
+endef
+
+$(eval $(generic-package))

package/ifupdown-scripts/network.service

@@ -0,0 +1,21 @@
+[Unit]
+Description=Network Connectivity
+Wants=network.target
+Before=network.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+
+# lo is brought up earlier, which will cause the upcoming "ifup -a" to fail
+# with exit code 1, due to an "ip: RTNETLINK answers: File exists" error during
+# its "ip addr add ..." command, subsequently causing this unit to fail even
+# though it is a benign error. Flushing the lo address with the command below
+# before ifup prevents this failure.
+ExecStart=/sbin/ip addr flush dev lo
+
+ExecStart=/sbin/ifup -a
+ExecStop=/sbin/ifdown -a
+
+[Install]
+WantedBy=multi-user.target

package/ifupdown-scripts/network/if-pre-up.d/wait_iface

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+# In case we have a slow-to-appear interface (e.g. eth-over-USB),
+# and we need to configure it, wait until it appears, but not too
+# long either. IF_WAIT_DELAY is in seconds.
+
+if [ "${IF_WAIT_DELAY}" -a ! -e "/sys/class/net/${IFACE}" ]; then
+    printf "Waiting for interface %s to appear" "${IFACE}"
+    while [ ${IF_WAIT_DELAY} -gt 0 ]; do
+        if [ -e "/sys/class/net/${IFACE}" ]; then
+            printf "\n"
+            exit 0
+        fi
+        sleep 1
+        printf "."
+        : $((IF_WAIT_DELAY -= 1))
+    done
+    printf " timeout!\n"
+    exit 1
+fi
+

package/ifupdown-scripts/nfs_check

@@ -0,0 +1,20 @@
+#!/bin/sh
+
+# This allows NFS booting to work while also being able to configure
+# the network interface via DHCP when not NFS booting.  Otherwise, a
+# NFS booted system will likely hang during DHCP configuration.
+
+# Attempting to configure the network interface used for NFS will
+# initially bring that network down.  Since the root filesystem is
+# accessed over this network, the system hangs.
+
+# This script is run by ifup and will attempt to detect if a NFS root
+# mount uses the interface to be configured (IFACE), and if so does
+# not configure it.  This should allow the same build to be disk/flash
+# booted or NFS booted.
+
+nfsip=`sed -n '/^[^ ]*:.* \/ nfs.*[ ,]addr=\([0-9.]\+\).*/s//\1/p' /proc/mounts`
+if [ -n "$nfsip" ] && ip route get to "$nfsip" | grep -q "dev $IFACE"; then
+	echo Skipping $IFACE, used for NFS from $nfsip
+	exit 1
+fi