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Re: make ping executable by normal users?



Dnia 2016-06-06, pon o godzinie 11:26 -0500, David Wright pisze:
> On Mon 06 Jun 2016 at 18:11:27 (+0200), Norbert Kiszka wrote:
> > Dnia 2016-06-06, pon o godzinie 11:00 -0500, David Wright pisze:
> > > On Mon 06 Jun 2016 at 15:27:16 (+0000), Mark Fletcher wrote:
> > > > On Mon, 6 Jun 2016 at 23:15, Santiago Vila <sanvila@unex.es> wrote:
> > > > 
> > > > > On Mon, Jun 06, 2016 at 10:06:54AM +1200, Jan Bakuwel wrote:
> > > > > > Check your firewall rules.
> > > > >
> > > > > It can't be firewall rules. Try this to block outgoing ping:
> > > > >
> > > > > iptables -A OUTPUT -p icmp --icmp-type echo-request -j REJECT
> > > > >
> > > > > then try to ping anywhere. You will get a different error message,
> > > > > namely "Destination Port Unreachable".
> > > > >
> > > > > [ Why people do not read all messages in the thread before answering
> > > > >   is a mystery to me ].
> > > 
> > > > No, that's not true, you definitely can get this very error due to
> > > > something to do with the firewall, maybe it's not able to resolve the ping
> > > > target rather than not able to reach the resulting host, I'm damned if I
> > > > can remember the specifics but I've definitely seen this happen on an lfs
> > > > box before and it was nothing to do with perms (as I said before, to your
> > > > point about people not reading the whole thread...)
> > > 
> > > I don't understand this argument.
> > > 
> > > Why would ping bother to open a socket to a host it couldn't resolve?
> > > 
> > > I know precious little about firewall rules, but AIUI the rules
> > > determine whether to respond with things like Drop, Reject, Deny.
> > > Now the OP didn't manage to open a socket; that's in the error message:
> > > "ping: icmp open socket: Operation not permitted"
> > > So how would ping find out how the firewall was going to react to its
> > > ping message without opening a socket to send something?
> > 
> > Did You change linux kernel, kernel modules or something lastly?
> 
> I now know even less about what you're talking about. I don't have a
> problem. I have easily duplicated the OP's error message in the
> following way:
> 
> $ cp -ip /bin/ping /tmp
> $ /tmp/ping alum.local
> ping: icmp open socket: Operation not permitted
> $ /sbin/getcap /tmp/ping 
> $ /sbin/getcap /bin/ping 
> /bin/ping = cap_net_raw+ep
> $ 
> 
> That's jessie. On wheezy:
> 
> $ ls -l /bin/ping /tmp/ping
> -rwsr-xr-x 1 root  root  31104 Apr 12  2011 /bin/ping
> -rwxr-xr-x 1 david david 31104 Apr 12  2011 /tmp/ping
> 
> Cheers,
> David.
> 


Show output of those commands:

# iptables -L
# lsmod
$ uname -a
$ cat /etc/issue



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