Re: [BackupPC-users] Wake-on-LAN setup - no ping response
Hi,
Russ Russ wrote on 2015-03-06 09:07:30 +0300 [[BackupPC-users] Wake-on-LAN
setup - no ping response]:
[...]
I have backuppc server on Gentoo which works fine with regular client
backups. Now I am configuring wake-on-lan to wake windows clients up before
backup.
[...]
3. Appropriate 777 rights have been granted to wolping.sh.
a=rwx is hardly appropriate. Actually, having 'others' being able to modify
the script is an attack waiting to happen. Anyone at all with access to the
machine can put anything they want into the script and just have to wait for
it to be executed by the BackupPC daemon with its associated privileges. That
is basically the same as giving anyone a free backuppc uid shell, including
full access to all backups and presumably root access to all client machines
you are backing up. Not necessarily a good idea ;-).
I don't believe BackupPC actually checks the permissions before executing the
PingCmd (or any other), but I wouldn't blame *anything* (BackupPC, Perl, bash,
kernel) for blandly refusing to execute a world-writable file as a general
security measure.
This is output of ls ???l:
-rwxrwxrwx 1 backuppc backuppc 1246 12:00 wolping.sh
The ownership looks good enough, though 'root:root' might be more suitable,
now you just have to 'chmod go-w' it. And afterwards check it has not been
modified. We'll just assume no malicious party has the file opened for writing
across your chmod and review, but for the record I'll mention the theoretical
possibility.
Curious that your 'ls -l' output contains no date :-).
4. I have tested wolping.sh and it works great from terminal under backuppc
user
Well, you use 'sudo'. You haven't by chance previously input a sudo password
in your terminal session? You are sure you are executing
/usr/local/bin/wolping.sh and not a different version of the script somewhere
in your path? ;-) What is the return code of the script when you execute it
from a shell? Your standard shell usually doesn't tell you if you don't ask
explicitly, but it might make a difference for BackupPC.
Seems that backuppc does not even fire the script as ???logger??? does not
appear in tail -f /var/log/messages
You should see more in BackupPC's log files.
I don't regularly use the 'logger' command, so I'm not familiar with its
intricacies. Is it not called, or does it fail to log, or does it log
somewhere else than you are looking? Does the command line invocation of
wolping.sh cause a log entry (in /var/log/messages)?
Looking at your script, I am wondering what your $Conf{PingCmd} looks like
(out of habit, I'd also like to see $Conf{PingPath}). It's obviously not the
default ('$pingPath -c 1 $host'), because you get your host name from $5:
[...]
WAKEHOST=$5
[...]
function fwol {
TO_WAKEUP=$1
(apparently never used)
sudo $ETHWAKE $1
I suppose you've got an entry similar to this in your /etc/sudoers:
backuppc ALL=NOPASSWD: /sbin/etherwake -i enp3s0 *
You use different invocations of the ping command - is that intentional?
[...]
$PING $ARG1 $ARG2 $ARG3 $ARG4 $WAKEHOST /dev/null 21
$PING $ARG1 $ARG2 $WAKEHOST
$PING $ARG1 $ARG2 $ARG3 $ARG4 $WAKEHOST
Wouldn't it make more sense to control that in the script and call it with the
parameters that are truely variable, e.g.
wolping.sh hostname interval
Your script is implying semantics for $ARG3 and $ARG4, so you can't really
configure PingCmd to use wolping.sh with arbitrary 'ping' switches (let alone
a variable number of them) in arbitrary order, as it might first appear. You
might also want to replace the sleep command with a fancy ping invocation to
be more adaptive to the time an individual host actually requires to boot. You
could experiment with something like
ping -i 10 -c 18 -A -q hostname
which should wait at most 180 seconds (like your sleep command), probe your
host in 10 second intervals and terminate shortly after the host begins to
respond. That way, you could increase the tolerance (raise the -c argument) to
accomodate for slow hosts and yet not have to unnecessarily wait for a fixed
long time for fast hosts. Of course, you would also wait the maximum time for
hosts which simply fail to wake up.
Hope that helps.
Regards,
Holger
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Re: [BackupPC-users] Wake-on-LAN setup - no ping response
I took a slightly different approach. The ping replacement script is
called with 1 argument (the hostname) for ping, or 2 arguments hostname
MAC_address for wol. It means putting the mac address in $conf{PingCmd}
for hosts that need wol rather than in a separate file like Michael uses.
My default PingCmd is:
$Conf{PingCmd} = '$pingPath $host'
On WOL hosts I over ride it with:
$Conf{PingCmd} = '$pingPath $host mac_address'
where mac_address is replaced with the actual value for that host.
My script is messy since I did home-rolled wake-on-lan with xxd and
netcat. That avoided installing wakeonlan as an extra dependency on
FreeBSD. If you already have wakeonlan you'd want to change the script
to use that instead of xxd.
WOL of course needs to be configured on the windows machines, possibly
in bios as well as in windows. I'd test that from the command line
before putting it into backuppc.
RP
The script:
#!/bin/sh
# BackupPC_pingwol
# Ping replacement for use with BackupPC that sends optional wake on lan
packets
# Russ Poyner 9/8/2014
PATH=/sbin:/bin:/usr/bin:/usr/local/bin
export PATH
# No wol by default
wakeme=
# Send wol with xxd.
# Best re-write this to use linux wakeonlan if you have it.
wol()
{
# Convert the wol packet to binary with xxd
# and send it to the client through netcat.
echo Sending wake on lan packet to $hostname at $cleanmac
echo $packet | xxd -r -p | nc -w 1 -v -u $hostname 9
}
# Minimal argument parsing
if [ $# = 2 ]
then
wakeme=yes
hostname=$1
# Construct the wol packet in hexadecimal
cleanmac=`echo $2 | sed -r 's/:|-//g' | tr '[:lower:]' '[:upper:]'`
# Next 2 lines not needed if you use a real wakeonlan utility
mac4=${cleanmac}${cleanmac}${cleanmac}${cleanmac}
packet=${mac4}${mac4}${mac4}${mac4}
elif [ $# = 1 ]
then
hostname=$1
else
echo Usage:
echo $0 hostname [mac address]
echo Including the mac address will cause $0 to send WOL packets
echo if the host doesn't answer the first ping
fi
ping -qc 1 $hostname
ret=$?
if [ $ret != 0 -a $wakeme = yes ]
then
for n in $(seq 1 15)
do
wol
ping -qc 1 $hostname
ret=$?
if [ $ret = 0 ]
then
exit 0
fi
done
fi
exit $ret
On 03/06/2015 12:07 AM, Russ Russ wrote:
Dear all,
Any ideas/assistance will be highly appreciated.
I have backuppc server on Gentoo which works fine with regular client
backups. Now I am configuring wake-on-lan to wake windows clients up
before backup.
The following has been done:
1.Bash script has been a bit modified from the one suggested on this
forum (details of the current script are provided at the end of the
message).
2.Config.pl has been modified on server as the following:
$Conf{PingPath} = '/usr/local/bin/wolping.sh';
$Conf{NmbLookupFindHostCmd} = ' ';
3.Appropriate 777 rights have been granted to wolping.sh. This is
output of ls –l:
-rwxrwxrwx 1 backuppc backuppc 1246 12:00 wolping.sh
4.I have tested wolping.sh and it works great from terminal under
backuppc user
But when I fire manual backup on any client which is in standby mode,
I got the following message: “2015-03-06 11:29:14 no ping response”
Seems that backuppc does not even fire the script as “logger”does not
appear in tail -f /var/log/messages
Could you please advise what might cause such an issue
Many thanks
wolping.sh:
--
#!/bin/bash
#this script is totally designed for the backuppc ping command
#which is the first thing it does before it starts a backup
#this is a substitute which pings the machine, if it is not
#awake then it wakes it using a magic packet - using the wol.bsh script
#then pings again to make sure
PING=/bin/ping
ARG1=$1
ARG2=$2
ARG3=$3
ARG4=$4
WAKEHOST=$5
ETHWAKE=/sbin/ether-wake -i enp3s0
SLEEPTIME=3m
logger Backuppc pinging$1 $2 $3 $4 $5
function fwol {
TO_WAKEUP=$1
sudo $ETHWAKE $1
if [ $? -eq 0 ]
then
WOL_RES=OK
else
WOL_RES=FAIL
fi
}
$PING $ARG1 $ARG2 $ARG3 $ARG4 $WAKEHOST /dev/null 21
if [ $? -ne 0 ]; then
fwol $WAKEHOST
if [ $WOL_RES = FAIL ]; then
exit 1
fi
sleep $SLEEPTIME
$PING $ARG1 $ARG2 $WAKEHOST
if [ $? -eq 0 ]
then
logger success waking $WAKEHOST.
else
logger unable to wake $WAKEHOST.
exit 1
fi
else
$PING $ARG1 $ARG2 $ARG3 $ARG4 $WAKEHOST
fi
exit 0
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Re: [BackupPC-users] Wake-on-LAN setup - no ping response
On 2015-03-06 00:07, Russ Russ wrote: Dear all, Any ideas/assistance will be highly appreciated. I have backuppc server on Gentoo which works fine with regular client backups. Now I am configuring wake-on-lan to wake windows clients up before backup. Not that I see anything wrong with what you've put together, but I my BackupPC server also happens to be running on Gentoo, nor do I have a theory on why it would behave any differently for automatic and manual backups. For what it's worth, the complete scripts I use are here: http://www.michaelstowe.com/backuppc/ -- Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ ___ BackupPC-users mailing list BackupPC-users@lists.sourceforge.net List:https://lists.sourceforge.net/lists/listinfo/backuppc-users Wiki:http://backuppc.wiki.sourceforge.net Project: http://backuppc.sourceforge.net/
[BackupPC-users] Wake-on-LAN setup - no ping response
Dear all,
Any ideas/assistance will be highly appreciated.
I have backuppc server on Gentoo which works fine with regular client backups.
Now I am configuring wake-on-lan to wake windows clients up before backup.
The following has been done:
1. Bash script has been a bit modified from the one suggested on this
forum (details of the current script are provided at the end of the message).
2. Config.pl has been modified on server as the following:
$Conf{PingPath} = '/usr/local/bin/wolping.sh';
$Conf{NmbLookupFindHostCmd} = ' ';
3. Appropriate 777 rights have been granted to wolping.sh. This is
output of ls –l:
-rwxrwxrwx 1 backuppc backuppc 1246 12:00 wolping.sh
4. I have tested wolping.sh and it works great from terminal under
backuppc user
But when I fire manual backup on any client which is in standby mode, I got the
following message: “2015-03-06 11:29:14 no ping response”
Seems that backuppc does not even fire the script as “logger” does not
appear in tail -f /var/log/messages
Could you please advise what might cause such an issue
Many thanks
wolping.sh:
--
#!/bin/bash
#this script is totally designed for the backuppc ping command
#which is the first thing it does before it starts a backup
#this is a substitute which pings the machine, if it is not
#awake then it wakes it using a magic packet - using the wol.bsh script
#then pings again to make sure
PING=/bin/ping
ARG1=$1
ARG2=$2
ARG3=$3
ARG4=$4
WAKEHOST=$5
ETHWAKE=/sbin/ether-wake -i enp3s0
SLEEPTIME=3m
logger Backuppc pinging $1 $2 $3 $4 $5
function fwol {
TO_WAKEUP=$1
sudo $ETHWAKE $1
if [ $? -eq 0 ]
then
WOL_RES=OK
else
WOL_RES=FAIL
fi
}
$PING $ARG1 $ARG2 $ARG3 $ARG4 $WAKEHOST /dev/null 21
if [ $? -ne 0 ]; then
fwol $WAKEHOST
if [ $WOL_RES = FAIL ]; then
exit 1
fi
sleep $SLEEPTIME
$PING $ARG1 $ARG2 $WAKEHOST
if [ $? -eq 0 ]
then
logger success waking $WAKEHOST.
else
logger unable to wake $WAKEHOST.
exit 1
fi
else
$PING $ARG1 $ARG2 $ARG3 $ARG4 $WAKEHOST
fi
exit 0
--
Dive into the World of Parallel Programming The Go Parallel Website, sponsored
by Intel and developed in partnership with Slashdot Media, is your hub for all
things parallel software development, from weekly thought leadership blogs to
news, videos, case studies, tutorials and more. Take a look and join the
conversation now. http://goparallel.sourceforge.net/___
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BackupPC-users@lists.sourceforge.net
List:https://lists.sourceforge.net/lists/listinfo/backuppc-users
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Project: http://backuppc.sourceforge.net/
