tree fdf9ac5d381071d750adb9cb81e406a2b16fd58f
parent a64d90fd962c2956da7505f98a302408450365e2
author David Gibson <david@gibson.dropbear.id.au> 1398298955 +1000
committer David S. Miller <davem@davemloft.net> 1398361974 -0400

rtnetlink: Warn when interface's information won't fit in our packet

Without IFLA_EXT_MASK specified, the information reported for a single
interface in response to RTM_GETLINK is expected to fit within a netlink
packet of NLMSG_GOODSIZE.

If it doesn't, however, things will go badly wrong,  When listing all
interfaces, netlink_dump() will incorrectly treat -EMSGSIZE on the first
message in a packet as the end of the listing and omit information for
that interface and all subsequent ones.  This can cause getifaddrs(3) to
enter an infinite loop.

This patch won't fix the problem, but it will WARN_ON() making it easier to
track down what's going wrong.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>