Local ip address

[yarray]

This update added a "local_ip_address" option in config. This option is quite useful if multiple network interfaces exist and the one connecting to the target device is not the first. Also node's os.networkInterfaces cannot find all interfaces in some cases where providing a binding address may become a must (issue nodejs/node#498).

To make this patch work, updating https://github.com/smka/broadlinkjs-sm is mandatory (however it will not break either if the update does not happen). I also submitted a pull request there smka/broadlinkjs-sm#2.

Use/test case with homebridge-broadlink-platform:

My raspberry pi connected to a router via eth0 along with my iphone. The raspberry pi also has a wireless interface wlan0 which I set as an AP. The network on eth0 has ip 192.168.0.10 and the network on wlan0 has ip 192.168.42.1. An SP1 device connected to wlan0.

Now if without the "local_ip_address" option, when sending the broadcast message to 255.255.255.255, the packet will be sent through only one (random) interface (see https://stackoverflow.com/questions/683624/udp-broadcast-on-all-interfaces) and perhaps under the network 192.168.0. Thus , it will not reach my SP1. By this update we can provide local_ip_address as 192.168.42.1 to solve the problem.

Changes

The changes are simple: get the config and fill it to broadlink.discover. A method is extracted to remove duplicates.

[smka]

@yarray hi! thanks for this update!
Is the "local_ip_address" an option now? And if there is no "local_ip_address" in config - it will work by default?

[yarray]

@smka Yes. When the option does not present, the code is just broadlink.discover(undefined) which would be the same as with no parameter. It may be more complete to add a null-check before calling discover, though.