Out bridge unsubs which causes problems when not authorised to unsub

[ralight]

migrated from Bugzilla #456899
status RESOLVED severity normal in component Mosquitto for 1.4
Reported in version unspecified on platform PC
Assigned to: Roger Light

On 2015-01-07 06:27:20 -0500, Dave Locke wrote:

We are using an out bridge config to move messages from mosquitto to a remote broker. The remote broker is kicking off the bridges MQTT connection because the bridge is attempting to unsubscribe and unsubscribe is not authorised by the remote broker. The remote broker is not under our control - it allows publish to the topic so it should be possible for an out bridge to work.

From http:https://dev.eclipse.org/mhonarc/lists/mosquitto-dev/msg00148.html it explains the background to why an unsub is sent. Unfortunately this does not help in the case where unsub is not allowed. Given security is a hot topic I suspect this is something that is going to come up more and more. Maybe there could be an option to enable / disable the unsub ?

"Why does the bridge do an UNSUBSCRIBE ?

If you have a bridge topic that is "out" only, the broker sends an
UNSUBSCRIBE to handle the case that you've changed from an "in" or
"both" direction. Without this it can be very confusing if you are
playing with a bridge changing the topic directions. "

On 2015-01-07 17:06:37 -0500, Roger Light wrote:

Yup, sounds reasonable to me and is a simple fix. I've pushed a change that should fix it.

On 2015-01-08 03:52:08 -0500, Dave Locke wrote:

many thanks for the quick update.

Does the change require any bridge config changes or has the unsub been removed?

Is the change in org.eclipse.mosquitto.git ? the only recent update that shows up in the summary is the disconnet websocket client properly change

On 2015-01-08 06:33:34 -0500, Roger Light wrote:

It's five commits prior to the one you mentioned.

The default behaviour isn't changed, I've added the option to disable it though:

bridge_attempt_unsubscribe false

That is a per-bridge setting.

On 2015-01-08 10:56:08 -0500, Thomas Walz wrote:

Hi Roger,
when will a wheezy Debian (7.6) be available ? Version V1.4 ?

On 2015-01-08 11:39:05 -0500, Roger Light wrote:

Hi Thomas - there should be debian packages available on repo.mosquitto.org shortly after it is released, which should be within a month.

Cheers,

Roger