#!/bin/bash
#
# netconsole This loads the netconsole module with the configured parameters.
#
# chkconfig: - 11 89
# description: Initializes network console logging
# config: /etc/sysconfig/netconsole
#
# Copyright 2002 Red Hat, Inc.
#
# Based in part on a shell script by
# Andreas Dilger <[email protected]> Sep 26, 2001

PATH=/sbin:/usr/sbin:$PATH
RETVAL=0
SERVER_ADDRESS_RESOLUTION=

# Check that networking is up.
. /etc/sysconfig/network

# Source function library.
. /etc/rc.d/init.d/functions

# Default values
LOCALPORT=6666
DEV=

SYSLOGADDR=
SYSLOGPORT=514
SYSLOGMACADDR=

kernel=$(uname -r | cut -d. -f1-2)

usage ()
{
echo $"Usage: $0 {start|stop|status|restart|condrestart}" 1>&2
RETVAL=2
}

print_address_info ()
{
local host=$1
local route via target

route=$(LANG=C ip -o route get to $host/32)

[ -z "$DEV" ] && DEV=$(echo $route | sed "s|.* dev \([^ ]*\).*|\1|")
echo "DEV=$DEV"
echo "LOCALADDR=$(echo $route | sed "s|.* src \([^ ]*\).*|\1|")"
if [[ $route == *" via "* ]] ; then
via=$(echo $route | sed "s|.* via \([^ ]*\).*|\1|")
target=$via
else
target=$host
fi
if [ -z "$SYSLOGMACADDR" ]; then
arp=$(LANG=C /sbin/arping -f -c 1 -I $DEV $target 2>/dev/null | awk '/ reply from .*[.*]/ { print gensub(".* reply from .* \\[(.*)\\].*","\\1","G"); exit }')
[ -n "$arp" ] && echo "SYSLOGMACADDR=$arp"
fi
}

start ()
{
[ -f /etc/sysconfig/netconsole ] || exit 6
. /etc/sysconfig/netconsole

SYSLOGOPTS=
# syslogd server, if any
if [ -n "$SYSLOGADDR" ]; then
# IPv6 regex also covers 4to6, zero-compressed, and link-local addresses with zone-index addresses.
# It should also cover IPv4-embedded, IPv4-mapped, and IPv4-translated IPv6 addresses.
# Taken from: http://stackoverflow.com/a/17871737/3481531
IPv4_regex="^([0-9]{1,3}\.){3}[0-9]{1,3}$"
IPv6_regex="^(([0-9a-fA-F]{1,4}:){7,7}[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,7}:|([0-9a-fA-F]{1,4}:){1,6}:[0-9a-fA-F]{1,4}|([0-9a-fA-F]{1,4}:){1,5}(:[0-9a-fA-F]{1,4}){1,2}|([0-9a-fA-F]{1,4}:){1,4}(:[0-9a-fA-F]{1,4}){1,3}|([0-9a-fA-F]{1,4}:){1,3}(:[0-9a-fA-F]{1,4}){1,4}|([0-9a-fA-F]{1,4}:){1,2}(:[0-9a-fA-F]{1,4}){1,5}|[0-9a-fA-F]{1,4}:((:[0-9a-fA-F]{1,4}){1,6})|:((:[0-9a-fA-F]{1,4}){1,7}|:)|fe80:(:[0-9a-fA-F]{0,4}){0,4}%[0-9a-zA-Z]{1,}|::(ffff(:0{1,4}){0,1}:){0,1}((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])|([0-9a-fA-F]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9])\.){3,3}(25[0-5]|(2[0-4]|1{0,1}[0-9]){0,1}[0-9]))$"
if ! [[ "$SYSLOGADDR" =~ $IPv4_regex ]] && ! [[ "$SYSLOGADDR" =~ $IPv6_regex ]]; then
# Use IPv4 by default:
SYSLOGADDR="$(LANG=C getent ahostsv4 $SYSLOGADDR 2> /dev/null)"

# Try IPv6 in case IPv4 resolution has failed:
if [[ $? -eq 2 ]]; then
SYSLOGADDR="$(LANG=C getent ahostsv6 $SYSLOGADDR 2> /dev/null)"
fi

if [[ $? -ne 0 ]]; then
echo $"Unable to resolve IP address specified in /etc/sysconfig/netconsole" 1>&2
exit 6
fi

SYSLOGADDR="$(echo "$SYSLOGADDR" | head -1 | cut --delimiter=' ' --fields=1)"
fi
fi
if [ -z "$SYSLOGADDR" ] ; then
echo $"Server address not specified in /etc/sysconfig/netconsole" 1>&2
exit 6
fi
eval $(print_address_info $SYSLOGADDR)

if [ -z "$SYSLOGMACADDR" ]; then
echo $"netconsole: can't resolve MAC address of $SYSLOGADDR" 1>&2
exit 1
fi

SYSLOGOPTS="netconsole=$LOCALPORT@$LOCALADDR/$DEV,$SYSLOGPORT@$SYSLOGADDR/$SYSLOGMACADDR "

/usr/bin/logger -p daemon.info -t netconsole: inserting netconsole module with arguments \
$SYSLOGOPTS
if [ -n "$SYSLOGOPTS" ]; then
action $"Initializing netconsole" modprobe netconsole \
$SYSLOGOPTS
[ "$?" != "0" ] && RETVAL=1
fi
touch /var/lock/subsys/netconsole
}

stop ()
{
if /sbin/lsmod | grep netconsole >/dev/null 2>&1 ; then
action $"Disabling netconsole" rmmod netconsole;
[ "$?" != "0" ] && RETVAL=1
fi

rm -f /var/lock/subsys/netconsole
}

status ()
{
if /sbin/lsmod | grep netconsole >/dev/null 2>&1 ; then
echo $"netconsole module loaded"
RETVAL=0
else
echo $"netconsole module not loaded"
RETVAL=3
fi
}


restart ()
{
stop
start
}

condrestart ()
{
[ -e /var/lock/subsys/netconsole ] && restart
}


case "$1" in
stop) stop ;;
status) status ;;
start|restart|reload|force-reload) restart ;;
condrestart) condrestart ;;
*) usage ;;
esac

exit $RETVAL