Feat/udev hotplug

debian/ifup@.service

@@ -11,7 +11,27 @@ IgnoreOnIsolate=yes
 [Service]
 # avoid stopping on shutdown via stopping system-ifup.slice
 Slice=system.slice
-ExecStart=/sbin/ifup --allow=hotplug %I
-ExecStop=/sbin/ifdown %I
+Environment=HOTPLUG_ARGS=
+Environment=LOCKFILE=/run/network/.lock
+EnvironmentFile=-/etc/default/networking
+ExecStart=/bin/sh -ec "( \
+    /bin/test \"$VERBOSE\" = \"yes\" && EXTRA_ARGS=-v; \
+    /bin/test \"$DEBUG\" = \"yes\" && EXTRA_ARGS=\"$EXTRA_ARGS -d\"; \
+    flock 9; \
+    if $(/sbin/ifquery -L 9 -l --allow=hotplug 2>/dev/null | grep -w -q \"^%I$\"); then \
+        exec /sbin/ifup $EXTRA_ARGS $HOTPLUG_ARGS %I -L 9 --systemd; \
+    fi; \
+    exit 1; \
+) 9>$LOCKFILE"
+ExecStop=/bin/sh -ec "( \
+    /bin/test \"$VERBOSE\" = \"yes\" && EXTRA_ARGS=-v; \
+    /bin/test \"$DEBUG\" = \"yes\" && EXTRA_ARGS=\"$EXTRA_ARGS -d\"; \
+    flock 9; \
+    exec /sbin/ifdown $EXTRA_ARGS %I -L 9 --systemd; \
+) 9>$LOCKFILE"
 RemainAfterExit=true
 TimeoutStartSec=2min
+
+# remove log duplications
+StandardOutput=null
+StandardError=null

debian/ifupdown2-hotplug

@@ -0,0 +1,161 @@
+#!/bin/sh -e
+#
+# run /sbin/{ifup,ifdown} with the --allow=hotplug option.
+#
+
+PATH='/sbin:/bin:/usr/sbin:/usr/bin'
+
+if [ -x /usr/bin/logger ]; then
+	LOGGER=/usr/bin/logger
+elif [ -x /bin/logger ]; then
+	LOGGER=/bin/logger
+else
+	unset LOGGER
+fi
+
+LOCKFILE=/run/network/.lock
+
+# for diagnostics
+if [ -t 1 -a -z "$LOGGER" ] || [ ! -e '/dev/log' ]; then
+	mesg() {
+		echo "$@" >&2
+	}
+elif [ -t 1 ]; then
+	mesg() {
+		echo "$@"
+		$LOGGER -t "${0##*/}[$$]" "$@"
+	}
+else
+	mesg() {
+		$LOGGER -t "${0##*/}[$$]" "$@"
+	}
+fi
+
+if [ -z "$INTERFACE" ]; then
+    mesg "Bad ifupdown udev helper invocation: \$INTERFACE is not set"
+    exit 1
+fi
+
+wait_for_interface() {
+    local interface=$1
+    local state
+
+    while :; do
+	read state /sys/class/net/$interface/operstate 2>/dev/null || true
+	if [ "$state" != down ]; then
+		return 0
+	fi
+	sleep 1
+    done
+}
+
+process_exclusions() {
+    set -- $EXCLUDE_INTERFACES
+    exclusions=""
+    for d; do
+	exclusions="-X $d $exclusions"
+    done
+    echo $exclusions
+}
+
+net_ifup() {
+    . /etc/default/networking 2>/dev/null || true
+
+    exclusions=$(process_exclusions)
+
+    # exit if the interface is not configured as allow-hotplug or excluded (querying does not require a lock)
+    if ! $(/sbin/ifquery --allow=hotplug -l $exclusions 2>/dev/null | grep -w -q "^$INTERFACE$"); then
+	exit 0
+    fi
+
+    if [ -d /run/systemd/system ]; then
+	exec systemctl --no-block start $(systemd-escape --template [email protected] $INTERFACE)
+    fi
+
+    EXTRA_ARGS=
+    [ "$VERBOSE" = yes ] && EXTRA_ARGS=-v
+    [ "$DEBUG"   = yes ] && EXTRA_ARGS="$EXTRA_ARGS -d"
+    [ "$SYSLOG"  = yes ] && EXTRA_ARGS="$EXTRA_ARGS --syslog"
+
+    # Take the lock and wait for lo before exec ifup.
+    (
+	flock 9
+	wait_for_interface lo
+	exec ifup $EXTRA_ARGS $HOTPLUG_ARGS -L 9 $INTERFACE
+    ) 9>$LOCKFILE
+}
+
+net_ifdown() {
+
+    # systemd will automatically ifdown the interface on device
+    # removal by binding the instanced service to the network device
+    if [ -d /run/systemd/system ]; then
+	exit 0
+    fi
+
+    . /etc/default/networking 2>/dev/null || true
+
+    exclusions=$(process_exclusions)
+
+    # exit if the interface is not configured as allow-hotplug or excluded (querying does not require a lock)
+    if ! $(/sbin/ifquery --allow=hotplug -l $exclusions 2>/dev/null | grep -w -q "^$INTERFACE$"); then
+	exit 0
+    fi
+
+    EXTRA_ARGS=
+    [ "$VERBOSE" = yes ] && EXTRA_ARGS=-v
+    [ "$DEBUG"   = yes ] && EXTRA_ARGS="$EXTRA_ARGS -d"
+    [ "$SYSLOG"  = yes ] && EXTRA_ARGS="$EXTRA_ARGS --syslog"
+
+    # Take the lock and exec ifdown.
+    (
+	flock 9
+	exec ifdown $EXTRA_ARGS $INTERFACE -L 9
+    ) 9>$LOCKFILE
+}
+
+do_everything() {
+
+case "$ACTION" in
+    add)
+    # these interfaces generate hotplug events *after* they are brought up
+    case $INTERFACE in
+	ppp*|ippp*|isdn*|plip*|lo|irda*|ipsec*)
+	exit 0 ;;
+    esac
+
+    net_ifup
+    ;;
+
+    remove)
+    # the pppd persist option may have been used, so it should not be killed
+    case $INTERFACE in
+	ppp*)
+	exit 0 ;;
+    esac
+
+    net_ifdown
+    ;;
+
+    *)
+    mesg "NET $ACTION event not supported"
+    exit 1
+    ;;
+esac
+
+}
+
+# under systemd we don't do synchronous operations, so we can run in the
+# foreground; we also need to, as forked children get killed right away under
+# systemd
+if [ -d /run/systemd/system ]; then
+    do_everything
+else
+    # under sysvinit we need to fork as we start the long-running
+    # "ifup". but there, forked processes won't get killed.
+    # When udev_log="debug" stdout and stderr are pipes connected to udevd.
+    # They need to be closed or udevd will wait for this process which will
+    # deadlock with udevsettle until the timeout.
+    exec > /dev/null 2> /dev/null
+    do_everything &
+fi

debian/ifupdown2.install

@@ -1,2 +1,3 @@
 etc/network/ifupdown2/addons.conf /etc/network/ifupdown2/
 etc/network/ifupdown2/ifupdown2.conf /etc/network/ifupdown2/
+debian/ifupdown2-hotplug lib/udev

debian/ifupdown2.udev

@@ -0,0 +1,5 @@
+# Allow rfkill for users in the netdev group
+KERNEL=="rfkill", MODE="0664", GROUP="netdev"
+
+# Handle allow-hotplug interfaces
+SUBSYSTEM=="net", ACTION=="add|remove", RUN+="ifupdown2-hotplug"

debian/rules

@@ -16,6 +16,8 @@ override_dh_install:
 	mkdir -p debian/ifupdown2/lib/systemd/system/
 	install --mode=644 debian/[email protected] debian/ifupdown2/lib/systemd/system/
 
+override_dh_installudev:
+	dh_installudev --priority=80
 
 override_dh_systemd_start:
 	dh_systemd_start --name=networking --no-start

ifupdown2/ifupdown/argv.py

@@ -7,6 +7,7 @@
 #
 
 import sys
+import os
 import argparse
 
 try:
@@ -239,11 +240,18 @@ def update_ifreload_argparser(self, argparser):
 
     def update_common_argparser(self, argparser):
         ''' general parsing rules '''
+        def file_or_fd(value):
+            try:
+                fp = os.fdopen(int(value))
+            except ValueError:
+                fp = os.open(value, os.O_CREAT | os.O_TRUNC | os.O_WRONLY)
+            return fp
 
         argparser.add_argument('-V', '--version', action=VersionAction, nargs=0)
         argparser.add_argument(
             '-L', '--lock', default='/run/network/.lock', dest='lockfile',
-            help='use lock file instead of default /run/network/.lock'
+            help='use lock file instead of default /run/network/.lock (can be fd integer)',
+            type=file_or_fd
         )
         argparser.add_argument(
             "--nldebug",

ifupdown2/ifupdown/utils.py

@@ -224,9 +224,8 @@ def importName(cls, modulename, name):
     @classmethod
     def lockFile(cls, lockfile):
         try:
-            fp = os.open(lockfile, os.O_CREAT | os.O_TRUNC | os.O_WRONLY)
-            fcntl.flock(fp, fcntl.LOCK_EX | fcntl.LOCK_NB)
-            fcntl.fcntl(fp, fcntl.F_SETFD, fcntl.FD_CLOEXEC)
+            fcntl.flock(lockfile, fcntl.LOCK_EX | fcntl.LOCK_NB)
+            fcntl.fcntl(lockfile, fcntl.F_SETFD, fcntl.FD_CLOEXEC)
         except IOError:
             return False
         return True

ifupdown2/sbin/start-networking

@@ -78,25 +78,6 @@ check_network_swap() {
     done < /proc/swaps
 }
 
-ifup_hotplug () {
-    if [ -d /sys/class/net ]
-    then
-	    ifaces=$(for iface in $(ifquery --list --allow=hotplug 2>/dev/null)
-			    do
-				    link=${iface##:*}
-				    link=${link##.*}
-				    if [ -e "/sys/class/net/$link" ]
-				    then
-				        echo "$iface"
-				    fi
-			    done)
-	    if [ -n "$ifaces" ]
-	    then
-		ifup $ifaces "$@" --systemd || true
-	    fi
-    fi
-}
-
 ifup_mgmt () {
 	ifaces=$(ifquery --list --allow=mgmt 2>/dev/null)
 	if [ -n "$ifaces" ]; then
@@ -128,7 +109,6 @@ start)
 	echo ${NAME}':' "Configuring network interfaces"
 	ifup_mgmt
 	ifup -a $EXTRA_ARGS $exclusions $perfoptions --systemd
-	ifup_hotplug $HOTPLUG_ARGS $EXTRA_ARGS $exclusions
 	;;
 stop)
 	if [ "$SKIP_DOWN_AT_SYSRESET" = "yes" ]; then