Feature/645 Test devices authentication

[JahleelAbraham]

Issue #645 requests that a feature be added to the Web UI that allows the end user to test and preview the connection status the their devices in an effort to make it more obvious when authentication settings and paths are not correct.

This PR contains changes to the editip stack (/templates/ajax/editip.php, /templates/dist/js/editip.js, /ajax/editip.php) and the function already contained within lib.php titled checkConnection().

This function previously incorrectly made a request for the header data of http URLs and assumed a 200 code would mean that the authentication succeeded. This was not the case. These have been substituted for an ffprobe command with a timeout of 5 seconds.

[andrey-utkin]

Thanks for the pull request!

Two requirements:

1. Revert the old MJPEG logic back to how it was.
2. Explain why show lastTimeChecked, or drop it.

If you could make screenshots of the changed web layouts, that would be fantastic.

[andrey-utkin]

Why LD_LIBRARY_PATH=/usr/lib/bluecherry/ ? I think it works without.

[andrey-utkin]

Just a note to our future selves regarding -timeout option.

I thought we want -timeout option, which comes from RTSP demuxer, per the docs:
https://ffmpeg.org//ffmpeg-protocols.html#rtsp

But using timeout instead of stimeout makes it try to listen for incoming connections in our bundled ffmpeg version (4.2.1).

This option used to be called stimeout up to a certain release, and our current bundled ffmpeg version is still using that, but in latest ffmpeg releases it is called timeout and we'll have to change this bit later.

So this bit is ok, just a note to self for when we'll be updating the bundled ffmpeg.

[andrey-utkin]

Why show time?

I think this time is essentially "now" anyways, so I see no need to show it at all.

Or is lastTimeChecked somehow persisted long-term? I don't think it is.

[andrey-utkin]

So this forms an HTTP URL to run ffprobe on.
This doesn't seem to work with the current bundled ffmpeg:

root@jahleel-dev:~# /usr/lib/bluecherry/ffprobe  -hide_banner -show_format -show_streams -print_format json  http://autkin.net/ua-war.jpg
{
http://autkin.net/ua-war.jpg: Invalid data found when processing input

}

Although that does seem to work with newer ffmpeg.
So perhaps let's pinch our nose and leave the old code intact for the IP-MJPEG case.

[andrey-utkin]

One more thing. Shouldn't be a deal breaker, but.
By default ffmpeg's RTSP demuxer tries to use UDP. We could match what we do in bc-server:
https://github.com/bluecherrydvr/bluecherry-apps/blob/master/lib/lavf_device.cpp#L90

[andrey-utkin]

Hand-coded command line argument quoting is unsafe.
escapeshellarg($url) is needed here.

Below suggestion block is not for immediate application, but to illustrate the point:

Suggested change

	$path = '-rtsp_transport tcp "rtsp://'.((empty($this->info['rtsp_username'])) ? '' : $this->info['rtsp_username'].':'.$this->info['rtsp_password'].'@').$this->info['ipAddr'].':'.$this->info['port'].$this->info['rtsp'].'"';
	$url = 'rtsp://'.((empty($this->info['rtsp_username'])) ? '' : $this->info['rtsp_username'].':'.$this->info['rtsp_password'].'@').$this->info['ipAddr'].':'.$this->info['port'].$this->info['rtsp'];
	$rtsp_options = '-rtsp_transport tcp'; // TODO according to device config, see https://github.com/bluecherrydvr/bluecherry-apps/blob/master/lib/lavf_device.cpp#L90
	$cmdline = "/usr/lib/bluecherry/ffprobe -stimeout 5000000 -hide_banner -show_format -show_streams -print_format json ' . $rtsp_options . ' ' . escapeshellarg($url);

Hand-coded URL composing seems to work as intended here. (Would preferred to see some "URL builder" API usage here, but couldn't actually find a good one in PHP in a brief search.)

[andrey-utkin]

Please do

• proper escaping for RTSP URL,
• RTSP protocol flags for ffprobe command as here: https://github.com/bluecherrydvr/bluecherry-apps/blob/master/lib/lavf_device.cpp#L90 . The protocol string I expect to be in $this->info['protocol']

[andrey-utkin]

One nit to fix and let's merge it.