Messages in this thread | | | Date | Fri, 7 Mar 1997 15:37:33 +0000 (GMT) | From | Bryn Paul Arnold Jones <> | Subject | Re: ping to broadcast address: permission denied? |
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On Fri, 7 Mar 1997, Paul Slootman wrote:
> Niemi@linux.wauug.org wrote: > > > >I have fetched, compiled, and made available Trygve Gudmundsen's > >Linux-modified version of Eric Wassenaar's excellent "ping" program. It is > >all sitting on on wauug.erols.com in "/pub/net/wassenaar-ping". As Trygve > >mentioned his site was about to be down for 5 days I figured this could be > >a useful service 8^) > > I've picked up this version, compiled it, but it still doesn't > do what I'd hoped (I had already expected it wasn't a ping code > problem). > > The problem is this: > > I'm on a subnetted B-class network (141.93.34.0, netmask 255.255.255.0). > This all works fine, however I cannot ping the broadcast address (which > is 141.93.34.255). Ping says: > > # ./ping 141.93.34.255 > PING 141.93.34.255: 56 data bytes > sendto: Permission denied > no reply from 141.93.34.255 within 1 sec > sendto: Permission denied > > ---- 141.93.34.255 PING Statistics ---- > 2 packets transmitted, 0 packets received, 100% packet loss >
This would be a setuid root problem, ie it isn't. Does it work if you run the binary as root ?
> This works perfectly from a Solaris 2.5 system on the same network... > I tried tracing this into the kernel, but at a certain point I get > lost. It's definitely sendto() that returns -1 EACCES, according to > strace. >
Yep, the solaris binary will be setuid root.
> Same thing when pinging the loopback broadcast address 127.255.255.255, > so it doesn't look like it's a subnetting problem. >
Try setting the setuid bit on the binary:
chown root.root ping; chmod 4555 ping
It should now look like:
-r-sr-xr-x 1 root root 12272 Jan 31 22:32 ping* ^ setuid bit.
> Anyone know what the problem is? Even better, what the solution is? > Vanilla 2.0.29. > > > Paul Slootman > -- Bryn -- PGP key pass phrase forgotten, \ Overload -- core meltdown sequence again :( and I don't care ;) | initiated. / This space is intentionally left | blank, apart from this text ;-) \____________________________________
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