Don't masquerade traffic to loopback device
Don't masquerade traffic to loopback device

If the out interface of this iptables rule includes loopback device,
when a packet is sent from lo to lo, the source address is changed to
the ethernet interface address. It could cause NFS mounting failure,
since NFS client need send packet to local portmap daemon, if the source
address is not from "local", then portmap will deny the packet.

Pormap maintain a local address list to judge whether the source adress
is from "local". But sometimes portmap starts earlier than ethernet
interface starts, then the local address list don't include ethernet
address, so it denies the packet from NFS client.

To fix it, we use negation on loopback device.

Change-Id: I2c4e5b5526f73011998c023812542e020b03930b

cloudfoundry-incubator/garden-linux,shashidharatd/garden-linux,savaki/garden,tsaleh/garden,shashidharatd/garden-linux,cloudfoundry-incubator/garden,savaki/garden,tangfeixiong/garden,cloudfoundry-incubator/garden,cloudfoundry-incubator/garden-linux,tangfeixiong/garden,tsaleh/garden,shashidharatd/garden-linux,shashidharatd/garden-linux,cloudfoundry-incubator/garden-linux