netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* EACCES sending UDP to broadcast address?
@ 2015-04-10  1:04 Ben Greear
  2015-04-10  1:12 ` Eric Dumazet
  2015-04-10  2:28 ` David Miller
  0 siblings, 2 replies; 4+ messages in thread
From: Ben Greear @ 2015-04-10  1:04 UTC (permalink / raw)
  To: netdev

I'm running as root user, 4.0-rc6 + hack kernel.

User-space app is (or should be) trying to send a UDP frame
to 255.255.255.255 destination.

I am getting EACCESS from sendmmsg.

Is this expected?  Is there something even more special than root these
days?

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: EACCES sending UDP to broadcast address?
  2015-04-10  1:04 EACCES sending UDP to broadcast address? Ben Greear
@ 2015-04-10  1:12 ` Eric Dumazet
  2015-04-10  1:14   ` Ben Greear
  2015-04-10  2:28 ` David Miller
  1 sibling, 1 reply; 4+ messages in thread
From: Eric Dumazet @ 2015-04-10  1:12 UTC (permalink / raw)
  To: Ben Greear; +Cc: netdev

On Thu, 2015-04-09 at 18:04 -0700, Ben Greear wrote:
> I'm running as root user, 4.0-rc6 + hack kernel.
> 
> User-space app is (or should be) trying to send a UDP frame
> to 255.255.255.255 destination.
> 
> I am getting EACCESS from sendmmsg.
> 
> Is this expected?  Is there something even more special than root these
> days?

man 7 socket

       SO_BROADCAST
              Set  or  get  the  broadcast flag.  When enabled, datagram
sockets are allowed to send packets to a broadcast address.  This option
has no effect on stream-oriented
              sockets.



root user still has to use this option.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: EACCES sending UDP to broadcast address?
  2015-04-10  1:12 ` Eric Dumazet
@ 2015-04-10  1:14   ` Ben Greear
  0 siblings, 0 replies; 4+ messages in thread
From: Ben Greear @ 2015-04-10  1:14 UTC (permalink / raw)
  To: Eric Dumazet; +Cc: netdev

On 04/09/2015 06:12 PM, Eric Dumazet wrote:
> On Thu, 2015-04-09 at 18:04 -0700, Ben Greear wrote:
>> I'm running as root user, 4.0-rc6 + hack kernel.
>>
>> User-space app is (or should be) trying to send a UDP frame
>> to 255.255.255.255 destination.
>>
>> I am getting EACCESS from sendmmsg.
>>
>> Is this expected?  Is there something even more special than root these
>> days?
> 
> man 7 socket
> 
>        SO_BROADCAST
>               Set  or  get  the  broadcast flag.  When enabled, datagram
> sockets are allowed to send packets to a broadcast address.  This option
> has no effect on stream-oriented
>               sockets.
> 
> 
> 
> root user still has to use this option.


Thanks, I'll go do that.

Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: EACCES sending UDP to broadcast address?
  2015-04-10  1:04 EACCES sending UDP to broadcast address? Ben Greear
  2015-04-10  1:12 ` Eric Dumazet
@ 2015-04-10  2:28 ` David Miller
  1 sibling, 0 replies; 4+ messages in thread
From: David Miller @ 2015-04-10  2:28 UTC (permalink / raw)
  To: greearb; +Cc: netdev

From: Ben Greear <greearb@candelatech.com>
Date: Thu, 09 Apr 2015 18:04:44 -0700

> I'm running as root user, 4.0-rc6 + hack kernel.
> 
> User-space app is (or should be) trying to send a UDP frame
> to 255.255.255.255 destination.
> 
> I am getting EACCESS from sendmmsg.
> 
> Is this expected?  Is there something even more special than root these
> days?

You can't send to broadcast addresses without setting the
SOCK_BROADCAST socket option.

I didn't know the answer to this, it took me 10 seconds of grepping
around under net/ipv4 to figure it out.  You could have done this
too.

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2015-04-10  2:28 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2015-04-10  1:04 EACCES sending UDP to broadcast address? Ben Greear
2015-04-10  1:12 ` Eric Dumazet
2015-04-10  1:14   ` Ben Greear
2015-04-10  2:28 ` David Miller

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).