dhcpcd-discuss

Hi Roy
I have sometimes an unexpected behavior after start /etc/init.d/networking restart.

First output after restart without a running dhcp server in the network

root@dxr2:~# /etc/init.d/networking restart
Reconfiguring network interfaces...
Deconfiguring network interfaces... dhcpcd[1713]: sending signal ARLM to pid 1687
dhcpcd[1713]: waiting for pid 1687 to exit
done.
Configuring network interfaces... use hw-init-network

Configuring bridge sys1...
bridge sys1 already exists
Configuring bridge sys1... done.
dhcpcd[1780]: version 6.6.1 starting
dhcpcd[1780]: sys1: executing `/usr/libexec/dhcpcd-run-hooks' PREINIT
dhcpcd[1780]: sys1: executing `/usr/libexec/dhcpcd-run-hooks' CARRIER
dhcpcd[1780]: DUID 00:01:00:01:c7:92:bc:8f:d6:96:42:ed:5a:dd
dhcpcd[1780]: sys1: IAID 42:ed:5a:dd
dhcpcd[1780]: sys1: delaying IPv6 router solicitation for 0.2 seconds
dhcpcd[1780]: sys1: delaying IPv4 for 0.7 seconds
dhcpcd[1780]: sys1: soliciting an IPv6 router
dhcpcd[1780]: sys1: delaying Router Solicitation for LL address
dhcpcd[1780]: sys1: using hwaddr d6:96:42:ed:5a:dd
dhcpcd[1780]: sys1: soliciting a DHCP lease
dhcpcd[1780]: sys1: sending DISCOVER (xid 0x4284437b), next in 4.0 seconds
dhcpcd[1780]: sys1: sending Router Solicitation
dhcpcd[1780]: sys1: sending DISCOVER (xid 0x4284437b), next in 7.6 seconds
dhcpcd[1780]: sys1: sending Router Solicitation
dhcpcd[1780]: sys1: probing for an IPv4LL address
dhcpcd[1780]: sys1: probing for 169.254.119.27
dhcpcd[1780]: sys1: sending ARP probe (1 of 3), next in 1.3 seconds
dhcpcd[1780]: sys1: sending ARP probe (2 of 3), next in 1.0 seconds
dhcpcd[1780]: sys1: sending ARP probe (3 of 3), next in 2.0 seconds
dhcpcd[1780]: sys1: sending Router Solicitation
dhcpcd[1780]: sys1: using IPv4LL address 169.254.119.27
dhcpcd[1780]: sys1: writing lease `/var/db/dhcpcd-sys1.lease'
dhcpcd[1780]: sys1: adding IP address 169.254.119.27/16
dhcpcd[1780]: sys1: adding route to 169.254.0.0/16
dhcpcd[1780]: sys1: executing `/usr/libexec/dhcpcd-run-hooks' IPV4LL
dhcpcd[1780]: forking to background
dhcpcd[1780]: forked to background, child pid 1793
done.
Reconfiguring done.


When I than restart the network with a dhcp server inside the network I got sometimes this unexpected behavior:

root@dxr2:~# /etc/init.d/networking restart
Reconfiguring network interfaces...
Deconfiguring network interfaces... dhcpcd[1838]: sending signal ARLM to pid 1793
dhcpcd[1838]: waiting for pid 1793 to exit
done.
Configuring network interfaces... use hw-init-network

Configuring bridge sys1...
bridge sys1 already exists
Configuring bridge sys1... done.
dhcpcd[1905]: version 6.6.1 starting
dhcpcd[1905]: sys1: executing `/usr/libexec/dhcpcd-run-hooks' PREINIT
dhcpcd[1905]: sys1: executing `/usr/libexec/dhcpcd-run-hooks' CARRIER
dhcpcd[1905]: DUID 00:01:00:01:c7:92:bc:8f:d6:96:42:ed:5a:dd
dhcpcd[1905]: sys1: IAID 42:ed:5a:dd
dhcpcd[1905]: sys1: delaying IPv6 router solicitation for 0.6 seconds
dhcpcd[1905]: sys1: delaying IPv4 for 1.0 seconds
dhcpcd[1905]: sys1: soliciting an IPv6 router
dhcpcd[1905]: sys1: delaying Router Solicitation for LL address
dhcpcd[1905]: sys1: using hwaddr d6:96:42:ed:5a:dd
dhcpcd[1905]: sys1: soliciting a DHCP lease
dhcpcd[1905]: sys1: sending DISCOVER (xid 0x8bce5991), next in 4.9 seconds
dhcpcd[1905]: sys1: sending Router Solicitation
dhcpcd[1905]: sys1: xid 0x8c0cfa86 is for hwaddr d6:96:42:ed:5a:df:00:00:00:00:00:00:00:00:00:00
dhcpcd[1905]: sys1: sending Router Solicitation
dhcpcd[1905]: sys1: sending DISCOVER (xid 0x8bce5991), next in 8.4 seconds
dhcpcd[1905]: sys1: probing for an IPv4LL address
dhcpcd[1905]: sys1: probing for 169.254.119.27
dhcpcd[1905]: sys1: sending ARP probe (1 of 3), next in 1.1 seconds
dhcpcd[1905]: sys1: offered 192.168.251.187 from 192.168.251.99 `'
dhcpcd[1905]: sys1: sending REQUEST (xid 0x8bce5991), next in 3.3 seconds
dhcpcd[1905]: sys1: acknowledged 192.168.251.187 from 192.168.251.99 `'
dhcpcd[1905]: sys1: probing for 192.168.251.187
dhcpcd[1905]: sys1: sending ARP probe (1 of 3), next in 1.5 seconds
dhcpcd[1905]: sys1: sending ARP probe (2 of 3), next in 1.3 seconds
dhcpcd[1905]: sys1: sending ARP probe (2 of 3), next in 1.7 seconds
dhcpcd[1905]: sys1: sending ARP probe (3 of 3), next in 2.0 seconds
dhcpcd[1905]: sys1: sending Router Solicitation
dhcpcd[1905]: sys1: sending ARP probe (3 of 3), next in 2.0 seconds
dhcpcd[1905]: sys1: using IPv4LL address 169.254.119.27
dhcpcd[1905]: sys1: writing lease `/var/db/dhcpcd-sys1.lease'
dhcpcd[1905]: sys1: adding IP address 169.254.119.27/16
dhcpcd[1905]: sys1: adding route to 169.254.0.0/16
dhcpcd[1905]: sys1: executing `/usr/libexec/dhcpcd-run-hooks' IPV4LL
dhcpcd[1905]: forking to background
dhcpcd[1905]: forked to background, child pid 1918
done.
Reconfiguring done.

This behavior is not the same as in older versions of dhcpcd.
What I have done and it seem that I got the same old behavior
I undo this patch from your source code.



--- dhcpcd-6.6.1/ipv4ll.c-orig  2014-10-29 01:53:02.000000000 +0100
+++ dhcpcd-6.6.1/ipv4ll.c       2014-11-07 12:04:29.186406539 +0100
@@ -106,17 +106,19 @@
 {
        struct dhcp_state *state = D_STATE(astate->iface);
        struct dhcp_message *offer;

-       /* A DHCP lease could have already been offered.
-        * Backup this lease and replace once the IPv4LL addres is bound */
-       offer = state->offer;
-       state->offer = ipv4ll_make_lease(astate->addr.s_addr);
-       if (state->offer == NULL)
-               syslog(LOG_ERR, "%s: %m", __func__);
-       else
-               dhcp_bind(astate->iface, astate);
-       state->offer = offer;
+       if (state->state != DHS_BOUND) {
+               /* A DHCP lease could have already been offered.
+                * Backup and replace once the IPv4LL addres is bound */
+               offer = state->offer;
+               state->offer = ipv4ll_make_lease(astate->addr.s_addr);
+               if (state->offer == NULL)
+                       syslog(LOG_ERR, "%s: %m", __func__);
+               else
+                       dhcp_bind(astate->iface, astate);
+               state->offer = offer;
+       }
 }

So please help me to understand the following code line
        if (state->state != DHS_BOUND)

Because without this if statement I got the behavior I expect.
Did I miss something? Or why did you add this line of code?

Thank you for your suggestions & time
Matthias Michel