path: root/modules/luci-base/luasrc/sys.lua

-- Copyright 2008 Steven Barth <steven@midlink.org>
-- Licensed to the public under the Apache License 2.0.

local io     = require "io"
local os     = require "os"
local table  = require "table"
local nixio  = require "nixio"
local fs     = require "nixio.fs"
local uci    = require "luci.model.uci"

local luci  = {}
luci.util   = require "luci.util"
luci.ip     = require "luci.ip"

local tonumber, ipairs, pairs, pcall, type, next, setmetatable, require, select =
	tonumber, ipairs, pairs, pcall, type, next, setmetatable, require, select


--- LuCI Linux and POSIX system utilities.
module "luci.sys"

--- Execute a given shell command and return the error code
-- @class		function
-- @name		call
-- @param 		...		Command to call
-- @return		Error code of the command
function call(...)
	return os.execute(...) / 256
end

--- Execute a given shell command and capture its standard output
-- @class		function
-- @name		exec
-- @param command	Command to call
-- @return			String containg the return the output of the command
exec = luci.util.exec

--- Retrieve information about currently mounted file systems.
-- @return 	Table containing mount information
function mounts()
	local data = {}
	local k = {"fs", "blocks", "used", "available", "percent", "mountpoint"}
	local ps = luci.util.execi("df")

	if not ps then
		return
	else
		ps()
	end

	for line in ps do
		local row = {}

		local j = 1
		for value in line:gmatch("[^%s]+") do
			row[k[j]] = value
			j = j + 1
		end

		if row[k[1]] then

			-- this is a rather ugly workaround to cope with wrapped lines in
			-- the df output:
			--
			--	/dev/scsi/host0/bus0/target0/lun0/part3
			--                   114382024  93566472  15005244  86% /mnt/usb
			--

			if not row[k[2]] then
				j = 2
				line = ps()
				for value in line:gmatch("[^%s]+") do
					row[k[j]] = value
					j = j + 1
				end
			end

			table.insert(data, row)
		end
	end

	return data
end

--- Retrieve environment variables. If no variable is given then a table
-- containing the whole environment is returned otherwise this function returns
-- the corresponding string value for the given name or nil if no such variable
-- exists.
-- @class		function
-- @name		getenv
-- @param var	Name of the environment variable to retrieve (optional)
-- @return		String containg the value of the specified variable
-- @return		Table containing all variables if no variable name is given
getenv = nixio.getenv

--- Get or set the current hostname.
-- @param		String containing a new hostname to set (optional)
-- @return		String containing the system hostname
function hostname(newname)
	if type(newname) == "string" and #newname > 0 then
		fs.writefile( "/proc/sys/kernel/hostname", newname )
		return newname
	else
		return nixio.uname().nodename
	end
end

--- Returns the contents of a documented referred by an URL.
-- @param url	 The URL to retrieve
-- @param stream Return a stream instead of a buffer
-- @param target Directly write to target file name
-- @return		String containing the contents of given the URL
function httpget(url, stream, target)
	if not target then
		local source = stream and io.popen or luci.util.exec
		return source("wget -qO- '"..url:gsub("'", "").."'")
	else
		return os.execute("wget -qO '%s' '%s'" %
			{target:gsub("'", ""), url:gsub("'", "")})
	end
end

--- Initiate a system reboot.
-- @return	Return value of os.execute()
function reboot()
	return os.execute("reboot >/dev/null 2>&1")
end

--- Retrieves the output of the "logread" command.
-- @return	String containing the current log buffer
function syslog()
	return luci.util.exec("logread")
end

--- Retrieves the output of the "dmesg" command.
-- @return	String containing the current log buffer
function dmesg()
	return luci.util.exec("dmesg")
end

--- Generates a random id with specified length.
-- @param bytes	Number of bytes for the unique id
-- @return		String containing hex encoded id
function uniqueid(bytes)
	local rand = fs.readfile("/dev/urandom", bytes)
	return rand and nixio.bin.hexlify(rand)
end

--- Returns the current system uptime stats.
-- @return	String containing total uptime in seconds
function uptime()
	return nixio.sysinfo().uptime
end


--- LuCI system utilities / network related functions.
-- @class	module
-- @name	luci.sys.net
net = {}

--- Returns the current arp-table entries as two-dimensional table.
-- @return	Table of table containing the current arp entries.
--			The following fields are defined for arp entry objects:
--			{ "IP address", "HW address", "HW type", "Flags", "Mask", "Device" }
function net.arptable(callback)
	local arp = (not callback) and {} or nil
	local e, r, v
	if fs.access("/proc/net/arp") then
		for e in io.lines("/proc/net/arp") do
			local r = { }, v
			for v in e:gmatch("%S+") do
				r[#r+1] = v
			end

			if r[1] ~= "IP" then
				local x = {
					["IP address"] = r[1],
					["HW type"]    = r[2],
					["Flags"]      = r[3],
					["HW address"] = r[4],
					["Mask"]       = r[5],
					["Device"]     = r[6]
				}

				if callback then
					callback(x)
				else
					arp = arp or { }
					arp[#arp+1] = x
				end
			end
		end
	end
	return arp
end

local function _nethints(what, callback)
	local _, k, e, mac, ip, name
	local cur = uci.cursor()
	local ifn = { }
	local hosts = { }

	local function _add(i, ...)
		local k = select(i, ...)
		if k then
			if not hosts[k] then hosts[k] = { } end
			hosts[k][1] = select(1, ...) or hosts[k][1]
			hosts[k][2] = select(2, ...) or hosts[k][2]
			hosts[k][3] = select(3, ...) or hosts[k][3]
			hosts[k][4] = select(4, ...) or hosts[k][4]
		end
	end

	if fs.access("/proc/net/arp") then
		for e in io.lines("/proc/net/arp") do
			ip, mac = e:match("^([%d%.]+)%s+%S+%s+%S+%s+([a-fA-F0-9:]+)%s+")
			if ip and mac then
				_add(what, mac:upper(), ip, nil, nil)
			end
		end
	end

	if fs.access("/etc/ethers") then
		for e in io.lines("/etc/ethers") do
			mac, ip = e:match("^([a-f0-9]%S+) (%S+)")
			if mac and ip then
				_add(what, mac:upper(), ip, nil, nil)
			end
		end
	end

	if fs.access("/var/dhcp.leases") then
		for e in io.lines("/var/dhcp.leases") do
			mac, ip, name = e:match("^%d+ (%S+) (%S+) (%S+)")
			if mac and ip then
				_add(what, mac:upper(), ip, nil, name ~= "*" and name)
			end
		end
	end

	cur:foreach("dhcp", "host",
		function(s)
			for mac in luci.util.imatch(s.mac) do
				_add(what, mac:upper(), s.ip, nil, s.name)
			end
		end)

	for _, e in ipairs(nixio.getifaddrs()) do
		if e.name ~= "lo" then
			ifn[e.name] = ifn[e.name] or { }
			if e.family == "packet" and e.addr and #e.addr == 17 then
				ifn[e.name][1] = e.addr:upper()
			elseif e.family == "inet" then
				ifn[e.name][2] = e.addr
			elseif e.family == "inet6" then
				ifn[e.name][3] = e.addr
			end
		end
	end

	for _, e in pairs(ifn) do
		if e[what] and (e[2] or e[3]) then
			_add(what, e[1], e[2], e[3], e[4])
		end
	end

	for _, e in luci.util.kspairs(hosts) do
		callback(e[1], e[2], e[3], e[4])
	end
end

--- Returns a two-dimensional table of mac address hints.
-- @return  Table of table containing known hosts from various sources.
--          Each entry contains the values in the following order:
--          [ "mac", "name" ]
function net.mac_hints(callback)
	if callback then
		_nethints(1, function(mac, v4, v6, name)
			name = name or nixio.getnameinfo(v4 or v6, nil, 100) or v4
			if name and name ~= mac then
				callback(mac, name or nixio.getnameinfo(v4 or v6, nil, 100) or v4)
			end
		end)
	else
		local rv = { }
		_nethints(1, function(mac, v4, v6, name)
			name = name or nixio.getnameinfo(v4 or v6, nil, 100) or v4
			if name and name ~= mac then
				rv[#rv+1] = { mac, name or nixio.getnameinfo(v4 or v6, nil, 100) or v4 }
			end
		end)
		return rv
	end
end

--- Returns a two-dimensional table of IPv4 address hints.
-- @return  Table of table containing known hosts from various sources.
--          Each entry contains the values in the following order:
--          [ "ip", "name" ]
function net.ipv4_hints(callback)
	if callback then
		_nethints(2, function(mac, v4, v6, name)
			name = name or nixio.getnameinfo(v4, nil, 100) or mac
			if name and name ~= v4 then
				callback(v4, name)
			end
		end)
	else
		local rv = { }
		_nethints(2, function(mac, v4, v6, name)
			name = name or nixio.getnameinfo(v4, nil, 100) or mac
			if name and name ~= v4 then
				rv[#rv+1] = { v4, name }
			end
		end)
		return rv
	end
end

--- Returns a two-dimensional table of IPv6 address hints.
-- @return  Table of table containing known hosts from various sources.
--          Each entry contains the values in the following order:
--          [ "ip", "name" ]
function net.ipv6_hints(callback)
	if callback then
		_nethints(3, function(mac, v4, v6, name)
			name = name or nixio.getnameinfo(v6, nil, 100) or mac
			if name and name ~= v6 then
				callback(v6, name)
			end
		end)
	else
		local rv = { }
		_nethints(3, function(mac, v4, v6, name)
			name = name or nixio.getnameinfo(v6, nil, 100) or mac
			if name and name ~= v6 then
				rv[#rv+1] = { v6, name }
			end
		end)
		return rv
	end
end

--- Returns conntrack information
-- @return	Table with the currently tracked IP connections
function net.conntrack(callback)
	local connt = {}
	if fs.access("/proc/net/nf_conntrack", "r") then
		for line in io.lines("/proc/net/nf_conntrack") do
			line = line:match "^(.-( [^ =]+=).-)%2"
			local entry, flags = _parse_mixed_record(line, " +")
			if flags[6] ~= "TIME_WAIT" then
				entry.layer3 = flags[1]
				entry.layer4 = flags[3]
				for i=1, #entry do
					entry[i] = nil
				end

				if callback then
					callback(entry)
				else
					connt[#connt+1] = entry
				end
			end
		end
	elseif fs.access("/proc/net/ip_conntrack", "r") then
		for line in io.lines("/proc/net/ip_conntrack") do
			line = line:match "^(.-( [^ =]+=).-)%2"
			local entry, flags = _parse_mixed_record(line, " +")
			if flags[4] ~= "TIME_WAIT" then
				entry.layer3 = "ipv4"
				entry.layer4 = flags[1]
				for i=1, #entry do
					entry[i] = nil
				end

				if callback then
					callback(entry)
				else
					connt[#connt+1] = entry
				end
			end
		end
	else
		return nil
	end
	return connt
end

--- Determine the current IPv4 default route. If multiple default routes exist,
-- return the one with the lowest metric.
-- @return	Table with the properties of the current default route.
--			The following fields are defined:
--			{ "dest", "gateway", "metric", "refcount", "usecount", "irtt",
--			  "flags", "device" }
function net.defaultroute()
	local route

	net.routes(function(rt)
		if rt.dest:prefix() == 0 and (not route or route.metric > rt.metric) then
			route = rt
		end
	end)

	return route
end

--- Determine the current IPv6 default route. If multiple default routes exist,
-- return the one with the lowest metric.
-- @return	Table with the properties of the current default route.
--			The following fields are defined:
--			{ "source", "dest", "nexthop", "metric", "refcount", "usecount",
--			  "flags", "device" }
function net.defaultroute6()
	local route

	net.routes6(function(rt)
		if rt.dest:prefix() == 0 and rt.device ~= "lo" and
		   (not route or route.metric > rt.metric)
		then
			route = rt
		end
	end)

	if not route then
		local global_unicast = luci.ip.IPv6("2000::/3")
		net.routes6(function(rt)
			if rt.dest:equal(global_unicast) and
			   (not route or route.metric > rt.metric)
			then
				route = rt
			end
		end)
	end

	return route
end

--- Determine the names of available network interfaces.
-- @return	Table containing all current interface names
function net.devices()
	local devs = {}
	for k, v in ipairs(nixio.getifaddrs()) do
		if v.family == "packet" then
			devs[#devs+1] = v.name
		end
	end
	return devs
end


--- Return information about available network interfaces.
-- @return	Table containing all current interface names and their information
function net.deviceinfo()
	local devs = {}
	for k, v in ipairs(nixio.getifaddrs()) do
		if v.family == "packet" then
			local d = v.data
			d[1] = d.rx_bytes
			d[2] = d.rx_packets
			d[3] = d.rx_errors
			d[4] = d.rx_dropped
			d[5] = 0
			d[6] = 0
			d[7] = 0
			d[8] = d.multicast
			d[9] = d.tx_bytes
			d[10] = d.tx_packets
			d[11] = d.tx_errors
			d[12] = d.tx_dropped
			d[13] = 0
			d[14] = d.collisions
			d[15] = 0
			d[16] = 0
			devs[v.name] = d
		end
	end
	return devs
end


-- Determine the MAC address belonging to the given IP address.
-- @param ip	IPv4 address
-- @return		String containing the MAC address or nil if it cannot be found
function net.ip4mac(ip)
	local mac = nil
	net.arptable(function(e)
		if e["IP address"] == ip then
			mac = e["HW address"]
		end
	end)
	return mac
end

--- Returns the current kernel routing table entries.
-- @return	Table of tables with properties of the corresponding routes.
--			The following fields are defined for route entry tables:
--			{ "dest", "gateway", "metric", "refcount", "usecount", "irtt",
--			  "flags", "device" }
function net.routes(callback)
	local routes = { }

	for line in io.lines("/proc/net/route") do

		local dev, dst_ip, gateway, flags, refcnt, usecnt, metric,
			  dst_mask, mtu, win, irtt = line:match(
			"([^%s]+)\t([A-F0-9]+)\t([A-F0-9]+)\t([A-F0-9]+)\t" ..
			"(%d+)\t(%d+)\t(%d+)\t([A-F0-9]+)\t(%d+)\t(%d+)\t(%d+)"
		)

		if dev then
			gateway  = luci.ip.Hex( gateway,  32, luci.ip.FAMILY_INET4 )
			dst_mask = luci.ip.Hex( dst_mask, 32, luci.ip.FAMILY_INET4 )
			dst_ip   = luci.ip.Hex(
				dst_ip, dst_mask:prefix(dst_mask), luci.ip.FAMILY_INET4
			)

			local rt = {
				dest     = dst_ip,
				gateway  = gateway,
				metric   = tonumber(metric),
				refcount = tonumber(refcnt),
				usecount = tonumber(usecnt),
				mtu      = tonumber(mtu),
				window   = tonumber(window),
				irtt     = tonumber(irtt),
				flags    = tonumber(flags, 16),
				device   = dev
			}

			if callback then
				callback(rt)
			else
				routes[#routes+1] = rt
			end
		end
	end

	return routes
end

--- Returns the current ipv6 kernel routing table entries.
-- @return	Table of tables with properties of the corresponding routes.
--			The following fields are defined for route entry tables:
--			{ "source", "dest", "nexthop", "metric", "refcount", "usecount",
--			  "flags", "device" }
function net.routes6(callback)
	if fs.access("/proc/net/ipv6_route", "r") then
		local routes = { }

		for line in io.lines("/proc/net/ipv6_route") do

			local dst_ip, dst_prefix, src_ip, src_prefix, nexthop,
				  metric, refcnt, usecnt, flags, dev = line:match(
				"([a-f0-9]+) ([a-f0-9]+) " ..
				"([a-f0-9]+) ([a-f0-9]+) " ..
				"([a-f0-9]+) ([a-f0-9]+) " ..
				"([a-f0-9]+) ([a-f0-9]+) " ..
				"([a-f0-9]+) +([^%s]+)"
			)

			if dst_ip and dst_prefix and
			   src_ip and src_prefix and
			   nexthop and metric and
			   refcnt and usecnt and
			   flags and dev
			then
				src_ip = luci.ip.Hex(
					src_ip, tonumber(src_prefix, 16), luci.ip.FAMILY_INET6, false
				)

				dst_ip = luci.ip.Hex(
					dst_ip, tonumber(dst_prefix, 16), luci.ip.FAMILY_INET6, false
				)

				nexthop = luci.ip.Hex( nexthop, 128, luci.ip.FAMILY_INET6, false )

				local rt = {
					source   = src_ip,
					dest     = dst_ip,
					nexthop  = nexthop,
					metric   = tonumber(metric, 16),
					refcount = tonumber(refcnt, 16),
					usecount = tonumber(usecnt, 16),
					flags    = tonumber(flags, 16),
					device   = dev,

					-- lua number is too small for storing the metric
					-- add a metric_raw field with the original content
					metric_raw = metric
				}

				if callback then
					callback(rt)
				else
					routes[#routes+1] = rt
				end
			end
		end

		return routes
	end
end

--- Tests whether the given host responds to ping probes.
-- @param host	String containing a hostname or IPv4 address
-- @return		Number containing 0 on success and >= 1 on error
function net.pingtest(host)
	return os.execute("ping -c1 '"..host:gsub("'", '').."' >/dev/null 2>&1")
end


--- LuCI system utilities / process related functions.
-- @class	module
-- @name	luci.sys.process
process = {}

--- Get the current process id.
-- @class function
-- @name  process.info
-- @return	Number containing the current pid
function process.info(key)
	local s = {uid = nixio.getuid(), gid = nixio.getgid()}
	return not key and s or s[key]
end

--- Retrieve information about currently running processes.
-- @return 	Table containing process information
function process.list()
	local data = {}
	local k
	local ps = luci.util.execi("/bin/busybox top -bn1")

	if not ps then
		return
	end

	for line in ps do
		local pid, ppid, user, stat, vsz, mem, cpu, cmd = line:match(
			"^ *(%d+) +(%d+) +(%S.-%S) +([RSDZTW][W ][<N ]) +(%d+) +(%d+%%) +(%d+%%) +(.+)"
		)

		local idx = tonumber(pid)
		if idx then
			data[idx] = {
				['PID']     = pid,
				['PPID']    = ppid,
				['USER']    = user,
				['STAT']    = stat,
				['VSZ']     = vsz,
				['%MEM']    = mem,
				['%CPU']    = cpu,
				['COMMAND'] = cmd
			}
		end
	end

	return data
end

--- Set the gid of a process identified by given pid.
-- @param gid	Number containing the Unix group id
-- @return		Boolean indicating successful operation
-- @return		String containing the error message if failed
-- @return		Number containing the error code if failed
function process.setgroup(gid)
	return nixio.setgid(gid)
end

--- Set the uid of a process identified by given pid.
-- @param uid	Number containing the Unix user id
-- @return		Boolean indicating successful operation
-- @return		String containing the error message if failed
-- @return		Number containing the error code if failed
function process.setuser(uid)
	return nixio.setuid(uid)
end

--- Send a signal to a process identified by given pid.
-- @class function
-- @name  process.signal
-- @param pid	Number containing the process id
-- @param sig	Signal to send (default: 15 [SIGTERM])
-- @return		Boolean indicating successful operation
-- @return		Number containing the error code if failed
process.signal = nixio.kill


--- LuCI system utilities / user related functions.
-- @class	module
-- @name	luci.sys.user
user = {}

--- Retrieve user informations for given uid.
-- @class		function
-- @name		getuser
-- @param uid	Number containing the Unix user id
-- @return		Table containing the following fields:
--				{ "uid", "gid", "name", "passwd", "dir", "shell", "gecos" }
user.getuser = nixio.getpw

--- Retrieve the current user password hash.
-- @param username	String containing the username to retrieve the password for
-- @return			String containing the hash or nil if no password is set.
-- @return			Password database entry
function user.getpasswd(username)
	local pwe = nixio.getsp and nixio.getsp(username) or nixio.getpw(username)
	local pwh = pwe and (pwe.pwdp or pwe.passwd)
	if not pwh or #pwh < 1 or pwh == "!" or pwh == "x" then
		return nil, pwe
	else
		return pwh, pwe
	end
end

--- Test whether given string matches the password of a given system user.
-- @param username	String containing the Unix user name
-- @param pass		String containing the password to compare
-- @return			Boolean indicating wheather the passwords are equal
function user.checkpasswd(username, pass)
	local pwh, pwe = user.getpasswd(username)
	if pwe then
		return (pwh == nil or nixio.crypt(pass, pwh) == pwh)
	end
	return false
end

--- Change the password of given user.
-- @param username	String containing the Unix user name
-- @param password	String containing the password to compare
-- @return			Number containing 0 on success and >= 1 on error
function user.setpasswd(username, password)
	if password then
		password = password:gsub("'", [['"'"']])
	end

	if username then
		username = username:gsub("'", [['"'"']])
	end

	return os.execute(
		"(echo '" .. password .. "'; sleep 1; echo '" .. password .. "') | " ..
		"passwd '" .. username .. "' >/dev/null 2>&1"
	)
end


--- LuCI system utilities / wifi related functions.
-- @class	module
-- @name	luci.sys.wifi
wifi = {}

--- Get wireless information for given interface.
-- @param ifname        String containing the interface name
-- @return              A wrapped iwinfo object instance
function wifi.getiwinfo(ifname)
	local stat, iwinfo = pcall(require, "iwinfo")

	if ifname then
		local c = 0
		local u = uci.cursor_state()
		local d, n = ifname:match("^(%w+)%.network(%d+)")
		if d and n then
			ifname = d
			n = tonumber(n)
			u:foreach("wireless", "wifi-iface",
				function(s)
					if s.device == d then
						c = c + 1
						if c == n then
							ifname = s.ifname or s.device
							return false
						end
					end
				end)
		elseif u:get("wireless", ifname) == "wifi-device" then
			u:foreach("wireless", "wifi-iface",
				function(s)
					if s.device == ifname and s.ifname then
						ifname = s.ifname
						return false
					end
				end)
		end

		local t = stat and iwinfo.type(ifname)
		local x = t and iwinfo[t] or { }
		return setmetatable({}, {
			__index = function(t, k)
				if k == "ifname" then
					return ifname
				elseif x[k] then
					return x[k](ifname)
				end
			end
		})
	end
end


--- LuCI system utilities / init related functions.
-- @class	module
-- @name	luci.sys.init
init = {}
init.dir = "/etc/init.d/"

--- Get the names of all installed init scripts
-- @return	Table containing the names of all inistalled init scripts
function init.names()
	local names = { }
	for name in fs.glob(init.dir.."*") do
		names[#names+1] = fs.basename(name)
	end
	return names
end

--- Get the index of he given init script
-- @param name	Name of the init script
-- @return		Numeric index value
function init.index(name)
	if fs.access(init.dir..name) then
		return call("env -i sh -c 'source %s%s enabled; exit ${START:-255}' >/dev/null"
			%{ init.dir, name })
	end
end

local function init_action(action, name)
	if fs.access(init.dir..name) then
		return call("env -i %s%s %s >/dev/null" %{ init.dir, name, action })
	end
end

--- Test whether the given init script is enabled
-- @param name	Name of the init script
-- @return		Boolean indicating whether init is enabled
function init.enabled(name)
	return (init_action("enabled", name) == 0)
end

--- Enable the given init script
-- @param name	Name of the init script
-- @return		Boolean indicating success
function init.enable(name)
	return (init_action("enable", name) == 1)
end

--- Disable the given init script
-- @param name	Name of the init script
-- @return		Boolean indicating success
function init.disable(name)
	return (init_action("disable", name) == 0)
end

--- Start the given init script
-- @param name	Name of the init script
-- @return		Boolean indicating success
function init.start(name)
	return (init_action("start", name) == 0)
end

--- Stop the given init script
-- @param name	Name of the init script
-- @return		Boolean indicating success
function init.stop(name)
	return (init_action("stop", name) == 0)
end


-- Internal functions

function _parse_mixed_record(cnt, delimiter)
	delimiter = delimiter or "  "
	local data = {}
	local flags = {}

	for i, l in pairs(luci.util.split(luci.util.trim(cnt), "\n")) do
		for j, f in pairs(luci.util.split(luci.util.trim(l), delimiter, nil, true)) do
			local k, x, v = f:match('([^%s][^:=]*) *([:=]*) *"*([^\n"]*)"*')

			if k then
				if x == "" then
					table.insert(flags, k)
				else
					data[k] = v
				end
			end
		end
	end

	return data, flags
end