tree 71a04122f664e6cea27e7b330419b6efa3ed50f8
parent b7e618d43d8d19560c65133ca1e3bb36c3cce981
author Laszlo Papp <laszlo.papp@hubersuhner.com> 1516044225 +0000
committer Laszlo Papp <laszlo.papp@hubersuhner.com> 1516044225 +0000

Avoid division by zero

Nothing stops an OF agent to return zero for lambda values and ONOS
probably ought to not crash then.

One use case for this is when only one direction is supported on a port,
for example tx. Unfortunately, the openflow specification does not
separate the directions into different properties, so the agent
implementation has to return some frequency value for rx in this case
even if only the tx direction is supported. However, anything non-zero
would probably be untruthful as it would indicate valid reading to the
end user.

Even zero will be problematic for unsupported power reading in a
direction as 0 dBm is a valid value, but not sure how to deal with any
better.

Change-Id: I2597bd7d577d9c2e1a3b44421fe505b8b3b6cc92