Re: [gentoo-user] Ifplugd breaks services

[Matti Nykyri]

On Sun, Jun 08, 2014 at 11:25:53AM +0100, Mick wrote:
> On Sunday 08 Jun 2014 10:25:40 Matti Nykyri wrote:
> > Hi
> >
> > I also have other problems in my life. One of them is on one of my gentoo
> > server. This server has two network cards one serves intranet and the
> > other internet. The on that is on the internet is attached to a cable
> > modem. The modem is buggy and some times reboots it self losing the link
> > so I have ifplugd there get new address via dhcp immediately. Intranet
> > card is configured not to use ifplugd. I'm using OpenRC.
>
> Are you sure of this?  How have you configured your intranet card to not be
> acted upon by ifplugd?  From what I see, ifplugd will pick up any interface in
> /etc/init.d:
>
>   EXEC="/etc/init.d/net.$1"

Actually it's not ifplugd's fault. It is just the one that restarts services... 
The restarting is the thing that breaks stuff:

--------------------------------------------

server% [13:44] /var/log$ sudo iptables -v -L -t nat
Chain POSTROUTING (policy ACCEPT 10142 packets, 743K bytes)
 pkts bytes target     prot opt in     out     source               destination         
 8307  616K MASQUERADE  all  --  any    enp0s10  anywhere             anywhere            
server% [13:45] /var/log$ sudo /etc/init.d/net.enp0s10 stop
 * Stopping NIS Server ...                                   [ ok ]
 * samba -> stop: smbd ...                                   [ ok ]
 * samba -> stop: nmbd ...
 * start-stop-daemon: 2 process(es) refused to stop          [ !! ]
 * Unmounting network filesystems ...                        [ ok ]
 * Stopping chrooted named ...
 * Umounting chroot dirs ...
 * umounting /chroot/dns/usr/share/GeoIP ...                 [ ok ]
 * umounting /chroot/dns/etc/bind ...                        [ ok ]
 * umounting /chroot/dns/var/log/named ...                   [ ok ]
 * umounting /chroot/dns/var/bind ...                        [ ok ]
 * Stopping dhcpd ...                                        [ ok ]
 * Bringing down interface enp0s10
 *   Stopping dhclient on enp0s10 ...                        [ ok ]
 *   Stopping ifplugd on enp0s10 ...                         [ ok ]
server% [13:45] /var/log$ sudo iptables -v -L -t nat
Chain POSTROUTING (policy ACCEPT 10147 packets, 743K bytes)
 pkts bytes target     prot opt in     out     source               destination         
 8309  617K MASQUERADE  all  --  any    enp0s10  anywhere             anywhere            
server% [13:45] /var/log$ sudo /etc/init.d/net.enp0s10 start
 * Bringing up interface enp0s10
 *   Changing MAC address of enp0s10 ...                     [ ok ]
 *     changed to 00:80:23:7A:8A:A4
 *   Starting ifplugd on enp0s10 ...                         [ ok ]
 *     Backgrounding ...
 * WARNING: net.enp0s10 has started, but is inactive
server% [13:45] /var/log$ sudo iptables -v -L -t nat
Chain POSTROUTING (policy ACCEPT 10147 packets, 743K bytes)
 pkts bytes target     prot opt in     out     source               destination         
 8309  617K MASQUERADE  all  --  any    enp0s10  anywhere             anywhere            

--------------------------------------------
It takes around 40 seconds for dhclient to address from ISP (net-misc/dhcp-4.2.5_p1)
After it gets the address iptables is changed:
--------------------------------------------

server% [13:45] /var/log$ sudo iptables -v -L -t nat
Chain POSTROUTING (policy ACCEPT 2 packets, 152 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 MASQUERADE  all  --  any    eth1    anywhere             anywhere            
server% [13:48] /var/log$ ps aux | grep dhclient  
root     22011  0.0  0.2  16200  7108 ?        Ss   13:46   0:00 /sbin/dhclient -e PEER_NTP=no -e IF_METRIC=3 -q -1 -pf /var/run/dhclient-enp0s10.pid enp0s10
server% [13:48] /var/log$ ls /etc/init.d/net*
lrwxrwxrwx 1 root root     6 Oct  4  2011 /etc/init.d/net.enp0s10 -> net.lo*
lrwxrwxrwx 1 root root     6 Oct  4  2011 /etc/init.d/net.enp5s12 -> net.lo*
-rwxr-xr-x 1 root root 17412 Jan  2 23:42 /etc/init.d/net.lo*

--------------------------------------------

> > The problems are related to iptables and samba.
> >
> > Samba: when ifplugd runs down the internet card samba is killed. This
> > shouldn't happen. Samba is configured only to use intranet card. Samba
> > always fails to start when ifplugd starts the internet card. Manual
> > starting is required.
> >
> > Iptables: the system uses new nic names (enp7s0 etc). Iptables has them
> > correctly in the rules and in rules save. However when ifplugd cycles the
> > internet nic all the nic names in the in-kernel rules change to eth0 an
> > eth1. I need to zap iptables and then start it to reset the rules.
>
> This does not happen here.  When ifplugd restarts a NIC it always comes back
> with the new consistent naming.  Do you have some udev rules defined which are
> picked up on the second time that the ifplugd brings up the card, but not the
> first?

No I don't. And as stated when dhclient sets the address that is the point 
when the names change.

> > Any suggestions where to start? Or just disable ifplugd?
>
> Have you tried configuring static IP addresses, broadcast and gateways for
> each card using the /etc/cong.d/net file?  You can still set dhcp as a fall
> back if you want, although I am not sure it is necessary for a server in a
> static LAN.

lol. Yeap... I had an old rules set file that was set to run in 
postup()-function. Quite embarrassing :/ I don't know how I missed this...

modules_enp5s12="!plug"
modules_enp0s10="dhclient"

So enp5s12 is static and enp0s10 is dynamic with plug and dhcp.

> The file /usr/share/doc/netifrc-0.2.2/net.example.bz2 provides suggestions for
> different set ups.

In the past there was option in the rc.conf to say that eth1 is sufficient for
net. I don't wan't any services shutdown if anything drives down the enp0s10 
NIC. Is there a way to do that with OpenRC? As you see when I stop enp0s10 all
the services that serve intranet are driven down...

-- 
-Matti