-- acf model for /etc/dhcp/*
-- Copyright(c) 2007 A. Brodmann - Licensed under terms of GPL2
module (..., package.seeall)

require("lfs")
require("validator")

local subnet = { }
local cfgdir = "/etc/dhcp/"

dep_check = function ()

	icode = 0
	retval = {}

	lpos = require "posix"
	ptr, msg, code = lpos.access("/etc/dhcp")
	if ptr == nil then
		table.insert(retval, "/etc/dhcp")
		icode = icode + 1
	end
	
	ptr, msg, code = lpos.access("/usr/sbin/dhcpd")
	if ptr == nil then
		table.insert(retval, "/usr/sbin/dhcpd")
		icode = icode + 1
	end
	
	ptr, msg, code = lpos.access("/etc/init.d/dhcpd")
	if ptr == nil then
		table.insert(retval, "/etc/init.d/dhcpd")
		icode = icode + 1
	end

	if icode == 0 then
		retval = nil
	end	
	
	return retval
end

subnet_read = function( name )
	local filename = cfgdir .. name .. ".subnet"
	local net = { name = cfe({ type="message", value=name, label="Name" }),
	              defleasetime = cfe({ label="Default Lease Time" }),
	              maxleasetime = cfe({ label="Maximum Lease Time" }),
	              gateway = cfe({ label="Gateway"}),
	              domainname = cfe({ label="Domainname" }),
	              dnssrv1 = cfe({ label="DNS Server 1" }),
	              dnssrv2 = cfe({ label="DNS Server 2" }),
	              subnet = cfe({ label="Subnet" }),
	              netmask = cfe({ label="Netmask" }),
	              leaserangestart = cfe({ label="Lease Range Start" }),
	              leaserangeend = cfe({ label="Lease Range End" }),
	              wpad = cfe({ label="Web Proxy Auto Discovery", type="select", option = { "yes", "no" } })
	            }

	for line in io.lines(filename) do
		if (string.sub(line, 1, 15) == "def-lease-time:") then
			net.defleasetime.value = string.sub(line, 17)
		elseif (string.sub(line, 1, 15) == "max-lease-time:") then
			net.maxleasetime.value = string.sub(line, 17)
		elseif (string.sub(line, 1, 8) == "gateway:") then
			net.gateway.value = string.sub(line, 10)
		elseif (string.sub(line, 1, 12) == "domain-name:") then
			net.domainname.value = string.sub(line, 14)
		elseif (string.sub(line, 1, 10) == "dns-srv-1:") then
			net.dnssrv1.value = string.sub(line, 12)
		elseif (string.sub(line, 1, 10) == "dns-srv-2:") then
			net.dnssrv2.value = string.sub(line, 12)
		elseif (string.sub(line, 1, 7) == "subnet:") then
			net.subnet.value = string.sub(line, 9)
		elseif (string.sub(line, 1, 8) == "netmask:") then
			net.netmask.value = string.sub(line, 10)
		elseif (string.sub(line, 1, 18) == "lease-range-start:") then
			net.leaserangestart.value = string.sub(line, 20)
		elseif (string.sub(line, 1, 16) == "lease-range-end:") then
			net.leaserangeend.value = string.sub(line, 18)
		elseif (string.sub(line, 1, 5) == "wpad:") then
			net.wpad.value = string.sub(line, 7)
		end
	end
	
	return net
end

subnet_write = function( net )
	msg, fields = validate_network( net )
	if #msg > 0 then
		return cfe({ msg = msg, fields = fields }), net
	end
	local filename = cfgdir .. net.name.value .. ".subnet"
	local file = io.open( filename, "w+" )
	file:write( "def-lease-time: " .. net.defleasetime.value .. "\n" )
	file:write( "max-lease-time: " .. net.maxleasetime.value .. "\n" )
	file:write( "gateway: " .. net.gateway.value .. "\n" )
	file:write( "domain-name: " .. net.domainname.value .. "\n" )
	file:write( "dns-srv-1: " .. net.dnssrv1.value .. "\n" )
	file:write( "dns-srv-2: " .. net.dnssrv2.value .. "\n" )
	file:write( "subnet: " .. net.subnet.value .. "\n" )
	file:write( "netmask: " .. net.netmask.value .. "\n" )
	file:write( "lease-range-start: " .. net.leaserangestart.value .. "\n" )
	file:write( "lease-range-end: " .. net.leaserangeend.value .. "\n" )
	file:write( "wpad: " .. net.wpad.value .. "\n" )
	file:close()
	return cfe({ msg = "", fields = {}}), net
end

subnet_create = function( net )
	if file_exists( net.name.value ) then
		return cfe({ msg = "This subnet already exists!", fields = {}}), net
	end
	retcode, net = subnet_write( net )	
	return retcode, net
end

_tonumber = function( value )
	ret = tonumber( value )
	if (ret == nil) then
		ret = 0
	end
	return ret
end

validate_network = function( net )
	fields = { "none" }
	msg = ""
	if #net.name.value < 4 then
		table.insert(fields, "name")
		msg = msg .. "Minimum network name length is 4 characters!\n"
	end
	if net.name.value == "<new>" then
		table.insert(fields, "name")
		msg = msg .. "&lt;new&gt; is not a valid network name!\n"
	end
	if not validator.is_integer_in_range(_tonumber(net.defleasetime.value), 1800, 86400) then
		table.insert(fields, "defleasetime")
		msg = msg .. "Default-Lease-Time must be: 1800 < x < 86400\n"
	end
	if not validator.is_integer_in_range(_tonumber(net.maxleasetime.value), 1800, 86400) then
		table.insert(fields, "maxleasetime")
		msg = msg .. "Maximum-Lease-Time must be: 1800 < x < 86400\n"
	end
	if not validator.is_ipv4(net.gateway.value) then
		table.insert(fields, "gateway")
		msg = msg .. "Gateway: invalid IPv4 address!\n"
	end
	if not validator.is_ipv4(net.dnssrv1.value) then
		table.insert(fields, "dnssrv1")
		msg = msg .. "DNS Server 1: invalid IPv4 address!\n"
	end
	if not validator.is_ipv4(net.dnssrv2.value) then
		if #net.dnssrv2.value > 0 then
			table.insert(fields, "dnssrv2")
			msg = msg .. "DNS Server 2: invalid IPv4 address!\n"
		end
	end
	if not validator.is_ipv4(net.subnet.value) then
		table.insert(fields, "subnet")
		msg = msg .. "Subnet: invalid IPv4 address!\n"
	end
	if not validator.is_ipv4(net.netmask.value) then
		table.insert(fields, "netmask")
		msg = msg .. "Netmask: invalid IPv4 address!\n"
	end
	if not validator.is_ipv4(net.leaserangestart.value) then
		if #net.leaserangestart.value > 0 then
			table.insert(fields, "leaserangestart")
			msg = msg .. "Lease-Range-Start: invalid IPv4 address!\n"
		end
	end
	if not validator.is_ipv4(net.leaserangeend.value) then
		if #net.leaserangeend.value > 0 then
			table.insert(fields, "leaserangeend")
			msg = msg .. "Lease-Range-End: invalid IPv4 address!\n"
		end
	end

	return msg, fields
end

file_exists = function( filename )
	retval = false
	fn = cfgdir .. net.name.value .. ".subnet"
	file = io.open( fn, "r" )
	if file ~= nil then
		retval = true
		file:close()
	end
	return retval
end

read_file = function ( filename )
	local contents = ""
        local line = ""
	local file = io.open( filename, "r" )
	if file ~= nil then
	        line = file:read( "*l" )
	        while line ~= nil do
			contents = contents .. "\n" .. line
			line = file:read( "*l" )
		end
		file:close()
	else
		contents = "\n   Error: File not found!\n\n"
	end

	return contents
end

is_running = function( process )
	local retval = false
	local file = io.popen("pidof " .. process)
	if file ~= nil then
		local line = file:read( "*l" )
		file:close()
		if #line > 0 then
			retval = true
		end
	end
	
	return retval
end

get_dhcpd_version = function()
	local retval = "dhcpd"
	local file = io.popen("/usr/sbin/dhcpd --version")
	if file ~= nil then
		local line = file:read( "*a" )
		if #line > 0 then
			retval = line
		end
		file:close()
	end

	return retval
end

service_control = function ( command ) 

	local retval = ""
	local line = ""
	local file = io.popen( "/etc/init.d/dhcpd " .. command )
	if file ~= nil then
		line = file:read( "*a" )
		while line ~= nil do
			retval = retval .. "\n" .. line
			line = file:read( "*l" )
		end
		file:close()
	end

	return retval
end

function nonil( value )
	local retval = ""
	if value ~= nil then
		retval = value
	end
                                        
	return retval
end

get_subnets = function ()
	
	local retval = retval or {}

	for sn in lfs.dir( cfgdir ) do
		if string.sub(sn, -7) == ".subnet" then
			table.insert(retval, string.sub(sn, 1, -8))
		end
	end
	
	return retval
end

create_new_net = function( name, defleasetime, maxleasetime, gateway, domainname, dnssrv1, dnssrv2, subnet, netmask, leaserangestart, leaserangeend, wpad )
	net = { name         = { label="Name", value=nonil(name), type="message" },
	        defleasetime = { label="Default Lease Time", value=nonil(defleasetime), type="text" },
	        maxleasetime = { label="Maximum Lease Time", value=nonil(maxleasetime), type="text" },
	        gateway      = { label="Gateway", value=nonil(gateway), type="text" },
	        domainname   = { label="Domainname", value=nonil(domainname), type="text" },
	        dnssrv1      = { label="DNS Server 1", value=nonil(dnssrv1), type="text" },
	        dnssrv2      = { label="DNS Server 2", value=nonil(dnssrv2), type="text" },
	        subnet       = { label="Subnet", value=nonil(subnet), type="text" },
	        netmask      = { label="Netmask", value=nonil(netmask), type="text" },
	        leaserangestart = { label="Lease Range Start", value=nonil(leaserangestart), type="text" },
	        leaserangeend   = { label="Lease Range End", value=nonil(leaserangeend), type="text" },
	        wpad         = { label="Web Proxy Auto Discovery", value=nonil(wpad),
	        type="select", value=nonil(wpad), option = { "yes", "no"} }
	      }
	if net.wpad.value == "" then
		net.wpad.value = "no"
	end
	      
	return net
end