Luci tutorial or introduction?

twinkleLED · February 27, 2019, 5:35pm

When I press the gui REBOOT button, it seems to call this JS

function reboot(button) {
		(new XHR()).post('/cgi-bin/luci/admin/system/reboot/call', { token: 'xyzz' }, check);
	}

Similarly doing a gui reset to defaults calls /cgi-bin/luci/admin/system/flashops/reset

On the filesystem I find the single file /www/cgi-bin/luci which seems to somehow dispatch generically.

Where are these functions on the router? Is the a good writeup on how luci gui actions translate into cgi code running on the router? Or maybe a tutorial somewhere?

tmomas · February 27, 2019, 5:42pm

Does this help? https://github.com/openwrt/luci/wiki/Documentation

twinkleLED · February 27, 2019, 5:59pm

Mmmmmm Interesting.

So let me map out what I know.

https://github.com/openwrt/luci/wiki/ModulesHowTo#show-me-the-way-the-dispatching-process tells me that the cgi link I mentioned, /cgi-bin/luci/admin/system/flashops/reset, will be accessible if somebody has called the lua function entry( ... "flashops" ... )

Greping within the router finds me the function I want
/usr/lib/lua/luci# grep -r flashops * | grep entry
controller/admin/system.lua: entry({"admin", "system", "flashops"}, call("action_flashops"), _("Backup / Flash Firmware"), 70)
controller/admin/system.lua: entry({"admin", "system", "flashops", "reset"}, post("action_reset"))
controller/admin/system.lua: entry({"admin", "system", "flashops", "backup"}, post("action_backup"))
controller/admin/system.lua: entry({"admin", "system", "flashops", "backupfiles"}, form("admin_system/backupfiles"))
controller/admin/system.lua: entry({"admin", "system", "flashops", "restore"}, call("action_restore"))
controller/admin/system.lua: entry({"admin", "system", "flashops", "sysupgrade"}, call("action_sysupgrade"))

hnyman · February 27, 2019, 7:22pm

What do you actually want to do?

The action_reset function is pretty clearly foundable:
https://github.com/openwrt/luci/search?q=action_reset&unscoped_q=action_reset

Direct link to the function (actual reset on line 269):

github.com

openwrt/luci/blob/447f0c81713e567706c970d5c8fdea732dac52d4/modules/luci-mod-system/luasrc/controller/admin/system.lua#L261


				upgrade_avail = supports_sysupgrade(),
				backup_invalid = true
			})
		end
		return
	end


	http.redirect(luci.dispatcher.build_url('admin/system/flashops'))
end


function action_reset()
	if supports_reset() then
		luci.template.render("admin_system/applyreboot", {
			title = luci.i18n.translate("Erasing..."),
			msg   = luci.i18n.translate("The system is erasing the configuration partition now and will reboot itself when finished."),
			addr  = "192.168.1.1"
		})


		luci.sys.process.exec({ "/bin/sh", "-c", "sleep 1; killall dropbear uhttpd; sleep 1; jffs2reset -y && reboot" }, nil, nil, true)
		return
	end

And reboot:
admin / system and then "action_reboot" function:

github.com

openwrt/luci/blob/4bbe32548c407ec6ae104934b3f1fe53539de9f6/modules/luci-mod-system/luasrc/controller/admin/system.lua#L283


		if p1 == p2 then
			stat = luci.sys.user.setpasswd("root", p1)
		else
			stat = 10
		end
	end


	luci.template.render("admin_system/passwd", {stat=stat})
end


function action_reboot()
	luci.sys.reboot()
end

which leads to sys.lua and the actual "reboot" functionality:

github.com

openwrt/luci/blob/4bbe32548c407ec6ae104934b3f1fe53539de9f6/modules/luci-base/luasrc/sys.lua#L115


function httpget(url, stream, target)
	if not target then
		local source = stream and io.popen or luci.util.exec
		return source("wget -qO- %s" % luci.util.shellquote(url))
	else
		return os.execute("wget -qO %s %s" %
			{luci.util.shellquote(target), luci.util.shellquote(url)})
	end
end


function reboot()
	return os.execute("reboot >/dev/null 2>&1")
end


function syslog()
	return luci.util.exec("logread")
end


function dmesg()
	return luci.util.exec("dmesg")
end

twinkleLED · February 28, 2019, 3:23am

I actually wanted to understand the linkage between luci buttons (and other gui elements) and the code which is run for them. At this point it is just learning, and trying to understand some behaviour I see.

slh · February 28, 2019, 3:25am

At some point learning about the details involves actually looking into the details - the good news, the source is open, for everyone to see and change.