Why is dhclient claiming : "SIOCSIFADDR : Permission refuted"?

I have actually run into a really unusual mistake on ubuntu - server (8.04 ), I have no suggestion why dhclient is not permitted to set the network setups! I'm not the one that mounted the server to begin with, so i do not recognize much concerning the arrangement. The server is just made use of as a firewall/gateway (personalized iptables manuscript) it is obtained 3 nic is one for net, one for LAN and also one for DMZ. Currently the ISP have actually transformed setups from fixed ip to "fixed" ip appointed via dhcp, and also i cant actually utilize it.

Regretfully I can not simply set the IP statically given that the ISP shuts my link when the dhcp lease finishes: o

This is the mistake i get : (and afterwards it simply hangs there.)

[email protected]:~# dhclient eth2
Internet Systems Consortium DHCP Client V3.0.6
Copyright 2004-2007 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

SIOCSIFADDR: Permission denied
SIOCSIFFLAGS: Permission denied
SIOCSIFFLAGS: Permission denied
Listening on LPF/eth2/00:50:52:c1:a1:32
Sending on   LPF/eth2/00:50:52:c1:a1:32
Sending on   Socket/fallback
DHCPDISCOVER on eth2 to port 67 interval 8
DHCPREQUEST of on eth2 to port 67
DHCPACK of from
SIOCSIFADDR: Permission denied
SIOCSIFFLAGS: Permission denied
SIOCSIFNETMASK: Permission denied
SIOCSIFBRDADDR: Permission denied
SIOCSIFFLAGS: Permission denied
SIOCADDRT: Operation not permitted

in the meantime i've repaired it by running killall dhclient; dhclient eth2 every hr and afterwards establishing fixed IP setups for the user interface, this suffices to maintain the link live! yet it is a rather hideous hack in my point of view.

2019-05-13 05:02:13
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Answers: 5

What does your "dmesg" result show when you run dhclient?

If you are running Hardy, AppArmor becomes part of the default install. It is feasible that the dhclient account has actually gone crazy. Examine "sudo aa - standing" to see what is taking place there.

In addition just how does your/ etc/network/interfaces submit read? Probably you have contrasting addresses, courses, etc that dhclient does not intend to have fun with?

2019-05-19 22:04:28

This is in fact a bug in Ubuntu 8.04. For numerous usage instances you NEED to have actually nscd mounted (as an example when making use of openvpn) or dhclient will not function. This does not take place in more recent Ubuntu launches.

2019-05-19 21:40:26

Based on the pile trace at http://silenzio.dk/pi/dhc.strace the first SIOCSIFADDR: Permission denied mistake takes place at line 735, throughout implementation of procedure 26092: ifconfig eth2 inet 0 up. Currently just root can ifconfig something up, so allow is map the chain of fork()/ exec() and also seek UID adjustments. It ends up that:

  1. procedure 26092is a youngster of 26090( line 689)
  2. procedure 26090runs with UID 101 and also GID 102 (lines 355 - - 358)
  3. procedure 26090tries to set its UID/GID back to 0, yet falls short (line 310)
  4. procedure 26090is a youngster of 26089( line 286)
  5. procedure 26089switched its UID: GID to 101:102 (lines 282 - - 283)

So, the mistakes take place due to the fact that the implementing youngster procedure does not have the essential origin advantages. Why does this take place? The debian/changelog documents in the dhcp3-3.0.6.dfsg resources claims:

dhcp3 (3.0.1-2ubuntu4) breezy; urgency=low

  Derooted the DHCP client:
  * Added debian/patches/deroot-client.patch:
    - client/dhclient.c: After initialization, dro privileges to dhcp:dhcp and
      only keep CAP_NET_RAW and CAP_NET_BIND_SERVICE.
    - Add a setuid wrapper call-dhclient-script to call
      /etc/dhcp3/dhclient-script as root.
    - Install call-dhclient-script into /lib/dhcp3-client/.

My hunch is that call-dhclient-script has actually shed its set - UID little bit, and also is hence not implementing with origin advantages as it need to (According to the debian/dhcp3-client.postinst documents in the resources, it should. be possessed by root:dhcp and also setting 4754)

2019-05-19 21:05:43

Please run sudo dpkg --configure -a simply to see to it it is not a rep of the scenario in https://bugs.launchpad.net/ubuntu/+source/dhcp3/+bug/19740/comments/67

2019-05-17 16:41:13

I would certainly attempt mounting nscd if that plan is missing out on, and also if it does not collaborate with this, install additionally libnss - db.

Not exactly sure if that will certainly address your trouble, nonetheless, those are things that your trace is searching for and also it falls short.

2019-05-17 01:38:39