SWAMPy

✎ CARVE FLESH

EDITING: ifupdown-hotplug

#!/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

# 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

check_program() {
    [ -x $1 ] && return 0

mesg "ERROR: $1 not found. You need to install the ifupdown package."
    mesg "ifupdown udev helper $ACTION event for $INTERFACE not handled."
    exit 1
}

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
}

net_ifup() {
    check_program /sbin/ifup

# exit if the interface is not configured as allow-hotplug or auto
    if ! (ifquery --allow hotplug -l; ifquery --allow auto -l) | grep -q "^${INTERFACE}\$"; then
        exit 0
    fi

if [ -d /run/systemd/system ]; then
        exec systemctl --no-block start $(systemd-escape --template ifup@.service $INTERFACE)
    fi

local out=$(ps -C ifup ho args)
    if [ "${out%$INTERFACE*}" != "$out" ]; then
        mesg "Already ifup-ing interface $INTERFACE"
        exit 0
    fi

wait_for_interface lo

exec ifup --allow=hotplug $INTERFACE
}

net_ifdown() {
    check_program /sbin/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

local out=$(ps -C ifdown ho args)
    if [ "${out%$INTERFACE*}" != "$out" ]; then
	mesg "Already ifdown-ing interface $INTERFACE"
	exit 0
    fi

exec ifdown --allow=hotplug $INTERFACE
}

do_everything() {

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/upstart 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

CANCEL

Name	Type	Size	Modified	Actions
↩ ..	DIR	—	—
📁 hwdb.d/	DIR	—	2025-10-09 12:24
📁 rules.d/	DIR	—	2025-10-09 12:24
📄 ata_id	?	38.4 KB	2023-03-03 04:27	EDIT
📄 bridge-network-interface	?	1.1 KB	2015-08-20 16:51	EDIT
📄 cdrom_id	?	50.4 KB	2023-03-03 04:27	EDIT
📄 collect	?	22.3 KB	2023-03-03 04:27	EDIT
📄 console-setup-tty	?	4.5 KB	2016-04-19 19:21	EDIT
📄 hotplug.functions	FUNCTIONS	1.1 KB	2021-04-02 02:39	EDIT
📄 hwclock-set	?	776 B	2022-06-14 21:28	EDIT
📄 hwdb.bin	BIN	6.5 MB	2025-10-09 12:22	EDIT
📄 ifupdown-hotplug	?	3.1 KB	2016-11-30 17:15	EDIT
📄 mtd_probe	?	10.3 KB	2023-03-03 04:27	EDIT
📄 scsi_id	?	50.9 KB	2023-03-03 04:27	EDIT
📄 snappy-app-dev	?	38.6 KB	2024-12-18 02:17	EDIT
📄 v4l_id	?	14.3 KB	2023-03-03 04:27	EDIT