ubus: expose unix timestamp in ubus system call

[fjamarquez]

Expose the unix timestamp in the ubus system call. In case the local time is different from UTC, the ubus call gets the local time and the unix timestamp.

root@c82c2b100000:~# ubus call system info
{
	"localtime": 1741345176,
	"unixtime": 1741341576,
	"uptime": 528,
	"load": [
		64,
		21984,
		20096
	],
	"memory": {
		"total": 124801024,
		"free": 46555136,
		"shared": 159744,
		"buffered": 53248,
		"available": 39346176,
		"cached": 33030144
	},
	"root": {
		"total": 1280,
		"free": 200,
		"used": 1080,
		"avail": 200
	},
	"tmp": {
		"total": 60936,
		"free": 60780,
		"used": 156,
		"avail": 60780
	},
	"swap": {
		"total": 0,
		"free": 0
	}
}

[Rondom]

Out of interest: What is the use case behind this?

[fjamarquez]

The main use case is to always get a unix timestamp from the AP, even if the AP is configured in another time zone. In that case, you will get the timestamp relative to the timezone configured and relative to unix time without the need of any manual conversion. For example, if the AP must always send the timestamp to any application in unix, it is easier if the AP gets the time directly in unixtime, than needing to know the local time zone configured in the AP in order to obtain unix timestamp. In case you have many APs configured with different time zones, you need to know the time zone of each one to get the unix of all of them. In addition, the configured timezone is not obtained from this ubus output. I think that it can be useful, but if you think it is out of interest, it is good.