[Debian-ha-maintainers] Bug#720453: findif does not find netmask and NIC automatically

[Harald Weidner]

Package: resource-agents
Version: 1:3.9.2-5+deb7u1

The output of /usr/lib/heartbeat/findif --help suggests that OCF_RESKEY_ip
is the only required parameter for findif:

/usr/lib/heartbeat/findif version 2.99.1 Copyright Alan Robertson

Usage: /usr/lib/heartbeat/findif [-C]
Options:
    -C: Output netmask as the number of bits rather than as 4 octets.
Environment variables:
OCF_RESKEY_ip		 ip address (mandatory!)
OCF_RESKEY_cidr_netmask netmask of interface
OCF_RESKEY_broadcast	 broadcast address for interface
OCF_RESKEY_nic		 interface to assign to

This was true in Debian 6 and earlier. findif used the current routing
table to discover the netmask and NIC unless explicitely set.

However, in Debian wheezy this is no longer true. findif refuses to work
when OCF_RESKEY_cidr_netmask is unset. Moreover, if OCF_RESKEY_nic is unset,
always the interface name of the default gateway is taken, even if the
IP address belogs to an other network.

Example: on a host with this routing table

Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface
0.0.0.0         10.1.10.1       0.0.0.0         UG        0 0          0 bond0
10.1.20.0       0.0.0.0         255.255.255.0   U         0 0          0 bond1 
10.1.10.0       0.0.0.0         255.255.255.0   U         0 0          0 bond0

findif refuses to work without cidr_netmask:

$ OCF_RESKEY_ip=10.1.20.5 /usr/lib/heartbeat/findif -C
ERROR: Cannot use default route w/o netmask [10.1.20.5]

and outputs the wrong interface:

$ OCF_RESKEY_ip=10.1.20.5 OCF_RESKEY_cidr_netmask=24 /usr/lib/heartbeat/findif -C
bond0	netmask 24	broadcast 10.1.20.255

This change makes it necessary to rewrite all the IPaddr2 cluster resoures giving
explicit cidr_netmask and nic parameters.

This changed behaviour should either be reverted or explicitly stated in the
changelog and --help output.

Regards, Harald