/etc/network/if-up.d/00check-network-cable is in ifupdown-extra 0.28.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 | #!/bin/sh
# Check the link status of an ethernet interface
# This script should be installed in /etc/network/if-pre-up.d/
#
# You can use this script to solve bug #120382
# ('ifup should (optionally) check for link before configuring the interface.')
# if you configure ABORT_NO_LINK to 'yes' in /etc/default/network-test
# since this will make the script abort if the interface does not have
# any link.
#
# Note that if you set ABORT_NO_LINK to 'yes' and the Ethernet interface
# does not have a link, the script will abort and ifupdown will *not*
# mark the interface as configured.
#
# It can also be used as a standalone script by setting up
# its environment:
# IFACE=eth0 check-network-cable
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#
# You can also find a copy of the GNU General Public License at
# http://www.gnu.org/licenses/licenses.html#TOCLGPL
#
# Defaults
rc="/etc/default/network-test"
ETHTOOL=/sbin/ethtool
alt_et=/usr/sbin/ethtool
[ -x "$ETHTOOL" ] || [ ! -x "$alt_et" ] || ETHTOOL=$alt_et
MIITOOL=/sbin/mii-tool
IPTOOL=/sbin/ip
DO_SYSLOG=yes
ABORT_NO_LINK=no
# Read system configuration file
[ -r "$rc" ] && . "$rc"
if [ "$DO_SYSLOG" = yes ]; then
OUTPUT="logger -i -p daemon.err -s"
else
OUTPUT=echo
fi
# Set our locale environment, just in case any of the tools get translated
LC_ALL=C
export LC_ALL
check_status_miitool() {
local status=0
if $MIITOOL "$IFACE" 2>&1 | grep -q "no link" ; then
status=1
fi
return $status
}
check_status_ethtool() {
local status=0
local LINK="$($ETHTOOL "$IFACE" 2>&1 | grep "Link detected" 2>/dev/null || :)"
# If ethtool fails to print out the link line we break off
# notice that ethtool cannot get the link status out of all
# possible network interfaces
[ -n "$LINK" ] || return 1
if ! echo $LINK | grep -q "Link detected: yes" ; then
status=1
fi
return $status
}
check_status_iplink() {
local status=0
local info=""
[ -x "$IPTOOL" ] || return 0
info=$($IPTOOL link show "$IFACE" 2>&1 | grep "$IFACE:" 2>/dev/null)
if echo $info | grep -qE "NO-CARRIER|state DOWN|state LOWERLAYERDOWN" ; then
status=1
fi
return $status
}
check_status() {
local status=0 myid=$(id -u)
ifconfig "$IFACE" >/dev/null 2>&1 || {
$OUTPUT "ERROR: Interface $IFACE does not seem to be present" \
"in the system"
return 0
}
# Use ethtool if installed (preferable to mii-tool)
# If none are installed (or not running as root) we will test using
# 'ip link show'
if [ -x "$ETHTOOL" ] && [ $myid -eq 0 ]; then
check_status_ethtool || status=$?
elif [ -x "$MIITOOL" ] && [ $myid -eq 0 ]; then
check_status_miitool || status=$?
else
check_status_iplink || status=$?
fi
[ $status -eq 0 ] ||
$OUTPUT "WARNING: Initialising interface $IFACE which does" \
"not have a link"
return $status
}
check_bond_status() {
local status=1 inf slaves slave_iface
slaves="/sys/class/net/$IFACE/bonding/slaves"
[ -e "$slaves" ] || return 0
# Loop over the list of slaves
while read slave_ifaces; do
for inf in $slave_ifaces; do
# Use ":" command to silence slaves. Run in subshell to preserve IFACE
(OUTPUT=: IFACE="$inf" check_status); status=$?
# One functional slave will suffice
[ $status -ne 0 ] || return 0
done
done <$slaves
$OUTPUT "WARNING: Initialising bond $IFACE which does not have link" \
"on any slave"
return $status
}
[ "$IFACE" ] || {
$OUTPUT "ERROR: Variable IFACE not set in environment"
exit 1
}
# Check our IFACE name, if it does not start with eth, bail out
case $IFACE in
eth*)
check_status || [ "$ABORT_NO_LINK" != "yes" ] || exit 1
;;
bond*)
check_bond_status || [ "$ABORT_NO_LINK" != "yes" ] || exit 1
;;
esac
|