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

squidconf = "/etc/squid/squid.conf"

--- the tokenizer functions - must be dislocated into a library later
tokenizer = {}

tokenizer.new = function( str, delim )
	local token = {}
	token.value = str;
	token.delim = delim;
	token.pos   = 1
	return token
end
               
tokenizer.pos = function( value, substr, pos )
	local retval = pos
	local done = false
	while not done and retval <= #value do
		if string.sub( value, retval, retval ) == substr then
			done = true
		else
			retval = retval + 1
		end
	end
	return retval
end
                                                                  
tokenizer.next = function( token )
	if token.pos > #token.value then
		return token, nil
	end
	
	local strpos = tokenizer.pos( token.value, token.delim, token.pos )
	retval = string.sub(token.value, token.pos, strpos-1)
	if retval == token.delim then
		retval = ""
		token.pos = token.pos + 1
	else
		token.pos = strpos + 1
	end
 
	return token, retval
end
---

get_status = function()

	local retval = "stopped"

	local ptr = io.popen( "/bin/pidof squid" )
	local pid = ptr:read( "*a" )
	ptr:close()
	if pid ~= nil then
		if #pid > 1 then
			retval = "running"
		end
	end
	
	return retval
end

service_control = function( control )

	local retval = ""
	
	local ptr = io.popen( "/etc/init.d/squid " .. control, "r" )
	if ptr ~= nil then
		local retmsg = ptr:read( "*a" )
		ptr:close()
		if retmsg ~= nil then
			retval = retmsg
		else
			retval = "service_control(): Failed to read output from initscript!\n"
		end
	else
		retval = "service_control(): Failed to start/stop/restart service!\n"
	end

	return retval
end

get_adv_config = function()

	local retval = ""
	
	local ptr = io.open( "/etc/squid/squid.conf", "r" )
	if ptr ~= nil then
		local retcfg = ptr:read( "*a" )
		ptr:close()
		if retcfg == nil then
			retval = "\n\n    Error: Failed to read /etc/squid/squid.conf!\n\n"
		else
			retval = retcfg
		end
	end

	return retval
end

update_adv_config = function( config )

	local retval = "Successfully updated /etc/squid/squid.conf!"

	local ptr = io.open( "/etc/squid/squid.conf", "wb+" )
	if ptr ~= nil then
		ptr:write( config )
		ptr:close()
	else
		retval = "update_config(): Error, failed to open /etc/squid/squid.conf!\n"
	end

	return retval
end

get_conf_tag = function( tag, gat )

	local retval = ""
	local error = ""
	local found = false
	local done = false
	
	local fptr = io.open( squidconf, "r" )
	if fptr == nil then
		return "", "Failed to open squid config file!"
	end
	
	while not found and not done do
		local line = fptr:read( "*l" )
		if line == nil then
			done = true
		else 
			if string.sub( line, 1, 22 ) == tag then
				found = true
			end
		end
	end
	
	if done then
		fptr:close()
		return "", "TAG not found in squid config!"
	end
	
	found = false
	done = false
	
	while not found and not done do
		local line = fptr:read( "*l" )
		if line == nil then
			done = true
		elseif string.sub( line, 1, 22 ) == gat then
			found = true
		else
			retval = retval .. "\n" .. line
		end
	end
	
	if done then
		fptr:close()
		return "", "End TAG (GAT) not found in squid config! '" .. gat .. "'"
	end
	
	fptr:close()
	
	return retval, error
end

get_basic_config = function()

	local error = ""
	local config = { proxyip = { value="empty", type="text", label="Proxy IP" },
	                 proxyport = { value="", type="text", label="Proxy Port" },
	                 filterip = { value="", type="text", label="Filter IP" },
	                 filterport = { value="", type="text", label="Filter Port" },
	                 filterregex = { value="", type="text", label="FilterRegex" },
	                 safeports = { value="", type="text", label="Safe_ports" },
	                 sslports = { value="", type="text", label="SSL_ports" },
	                 accesslog = { value="", type="select", label="Access Logs", option={ "yes", "no" } },
	                 diskcache = { value="", type="select", label="Disk Cache Parameters", option={ "yes", "no" } },
	                 authmethod = { value="", type="text", label="Authentication Method" }
	               }
	               
	local cfg1, error = get_conf_tag( "### ACF-SQUID-TAG-0001", "### ACF-SQUID-GAT-0001" )
	if #error > 0 then
		return config, error
	end

	local cfg1tok = ""
	local cfg2tok = ""
	local cfg3tok = ""

	--- get proxyip, proxyport
	cfg1tok = tokenizer.new( cfg1, "\n" )
	local done = false
	while not done do
		local str1 = ""
		cfg1tok, str1 = tokenizer.next( cfg1tok )
		if str1 == nil then
			return nil, "Corrupt squid.conf! Missing 'http_port' statement!"
		else
			if string.sub( str1, 1, 10 ) == "http_port " then
				local str2 = ""
				local ipport = ""
				local ip = ""
				local port = ""
				cfg2tok = tokenizer.new( str1, " " )
				cfg2tok, ipport = tokenizer.next( cfg2tok )
				cfg2tok, ipport = tokenizer.next( cfg2tok )
				if ipport == nil then
					return config, "Corrupt squid.conf! Missing parameter #1 for 'http_port' statement!"
				end
				cfg3tok = tokenizer.new( ipport, ":" )
				cfg3tok, ip = tokenizer.next( cfg3tok )
				cfg3tok, port = tokenizer.next( cfg3tok )
				if port == nil then
					port = ip
					ip = ""
				end
				
				config.proxyip.value = ip
				config.proxyport.value = port
				done = true
			end
		end
	end
	cfg1tok = nil
	cfg2tok = nil
	cfg3tok = nil
	
	--- get filterip, filterport
	local cfg1, error = get_conf_tag( "### ACF-SQUID-TAG-0007", "### ACF-SQUID-GAT-0007" )
	if #error > 0 then
		return config, error
	end
	
	cfg1tok = tokenizer.new( cfg1, "\n" )
	done = false
	while not done do
		local str1 = ""
		cfg1tok, str1 = tokenizer.next( cfg1tok )
		if str1 == nil then
			return nil, "Corrupt squid.conf! Missing 'cache_peer' statement!"
		else
			if string.sub( str1, 1, 11 ) == "cache_peer " then
				local str2 = ""
				local tmp = ""
				local ip = ""
				local port = ""
				cfg2tok = tokenizer.new( str1, " " )
				cfg2tok, tmp = tokenizer.next( cfg2tok )
				cfg2tok, ip = tokenizer.next( cfg2tok )
				cfg2tok, tmp = tokenizer.next( cfg2tok )
				cfg2tok, port = tokenizer.next( cfg2tok )
				if ip == nil or port == nil then
					return config, "Corrupt squid.conf! Missing parameters #2 and/or #4 for 'cache_peer' statement!"
				end
				config.filterip.value = ip
				config.filterport.value = port
				done = true
			end
		end
	end
	cfg1tok = nil
	cfg2tok = nil
	cfg3tok = nil
	
	--- get diskcache
	local cfg1, error = get_conf_tag( "### ACF-SQUID-TAG-0002", "### ACF-SQUID-GAT-0002" )
	if #error > 0 then
		return config, error
	end
	
	cfg1tok = tokenizer.new( cfg1, "\n" )
	done = false
	while not done do
		local str1 = ""
		cfg1tok, str1 = tokenizer.next( cfg1tok )
		if str1 == nil then
			return nil, "Corrupt squid.conf! Missing 'cache_dir' statement!"
		else
			if string.sub( str1, 1, 15 ) == "cache_dir diskd" then
				config.diskcache.value = "yes"
				done = true
			elseif string.sub( str1, 1, 14 ) == "cache_dir null" then
				config.diskcache.value = "no"
				done = true
			end
		
		end
	end
	cfg1tok = nil
	
	--- authentication method
	local cfg1, error = get_conf_tag( "### ACF-SQUID-TAG-0004", "### ACF-SQUID-GAT-0004" )
	if #error > 0 then
		return config, error
	end
	
	cfg1tok = tokenizer.new( cfg1, "\n" )
	local done = false
	local auth = ""
	while not done do
		local str1 = ""
		cfg1tok, str1 = tokenizer.next( cfg1tok )
		if str1 == nil then
			done = true
		else
			if string.sub( str1, 1, 18 ) == "auth_param digest " then
				if string.match( auth, "D" ) == nil then
					auth = auth .. "D"
				end
			elseif string.sub( str1, 1, 16 ) == "auth_param ntlm " then
				if string.match( auth, "N" ) == nil then
					auth = auth .. "N"
				end
			elseif string.sub( str1, 1, 17 ) == "auth_param basic " then
				if string.match( auth, "B" ) == nil then
					auth = auth .. "B"
				end
			end
		end
	end
	config.authmethod.value = auth
	cfg1tok = nil
	
	--- get filterregex
	local cfg1, error = get_conf_tag( "### ACF-SQUID-TAG-0005", "### ACF-SQUID-GAT-0005" )
	if #error > 0 then
		return config, error
	end
	
	cfg1tok = tokenizer.new( cfg1, "\n" )
	done = false
	while not done do
		local str1 = ""
		cfg1tok, str1 = tokenizer.next( cfg1tok )
		if str1 == nil then
			return nil, "Corrupt squid.conf! Missing 'acl ContentFilter urlpath_regex -i' statement!"
		else
			if string.sub( str1, 1, 35 ) == "acl ContentFilter urlpath_regex -i " then
				config.filterregex.value = string.sub( str1, 36 )
				done = true
			end
		end
	end
	cfg1tok = nil
	cfg2tok = nil
	cfg3tok = nil
	
	--- get SSL_ports, Safe_ports
	local done1 = false
	local done2 = false
	cfg1tok = tokenizer.new( cfg1, "\n" )
	while not done1 or not done2 do
		local str1 = ""
		cfg1tok, str1 = tokenizer.next( cfg1tok )
		if str1 == nil then
			return nil, "Corrupt squid.conf! Missing 'acl SSL_ports/Safe_ports' statement!"
		else
			if string.sub( str1, 1, 19 ) == "acl SSL_ports port " then
				config.sslports.value = string.sub( str1, 20 )
				done1 = true
			elseif string.sub( str1, 1, 20 ) == "acl Safe_ports port " then
				config.safeports.value = string.sub( str1, 21 )
				done2 = true	
			end
		end
	end
	cfg1tok = nil
	
	return config, error
end