Missing dbus permission for dhcp

[Rafael D'Halleweyn]

Binary package hint: dhcdbd

On my system dhclient runs as the user "dhcp". But when it tries to send messages to dhcdbd through dbus, this fails, because it doesn't have the right permission.

I added the following to /etc/dbus-1/system.d/dhcdbd.conf:
    <policy user="dhcp">
            <allow own="com.redhat.dhcp"/>
            <allow send_interface="com.redhat.dhcp"/>
            <allow send_destination="com.redhat.dhcp"/>
    </policy>

This seems to work better now.

[Rafael D'Halleweyn (list-noduck)]

Bug #51283 might be related.

[Scott James Remnant (Canonical) (canonical-scott)]

The dhclient-script runs as root, no?

[Rafael D'Halleweyn (list-noduck)]

# ps aux | grep dhcli
dhcp 14697 0.0 0.1 2408 1196 ? S 13:34 0:00 /sbin/dhclient -1 -lf /var/lib/dhcp3/dhclient.eth0.leases -pf /var/run/dhclient.eth0.pid -q -e dhc_dbus=31 -d eth0

The Debian/Ubuntu dhcp3 package includes two patches droppriv.dpatch and deroot-client.dpatch that perform a setuid to dhcp.

[Rafael D'Halleweyn (list-noduck)]

Okay, you must be right: /lib/dhcp3-client/call-dhclient-script is +s for root

[Rafael D'Halleweyn (list-noduck)]

I guess my mistake was to uncomment

#script "/etc/dhcp3/dhclient-script";

in dhclient.conf. I guess when you do that dhclient-script really runs as dhcp, not as root. It all goes downhill from there.

I'll test this tomorrow.