Lua DISA Example
About
Lua script contributed by Brian Foster to perform D.I.S.A. (Direct Inward System Access) function in FreeSWITCH™.
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Usage
SECURITY WARNING
NOTICE: There are some inherit security concerns when allowing DISA. Mainly, we're transferring an untrusted external call into the default context after first collecting credentials in the form of an extension number and a voicemail PIN. You need to be aware of what's happening on YOUR phone system. The author disclaims any liability and places the script here for purposes of proof of concept.
Having said that, this script is pretty easy to use. Place 'disa' in the toll_allow variable in any user's directory record to allow DISA access (you can have multiple comma separated values in toll_allow). This script checks for the existence of the letter combination 'disa' somewhere in the toll_allow variable.
Dialplan
Call this script using the following dialplan:
DISA dialplan example
<extension name="disa">
<condition field="destination_number" expression="^disa$">
<action application="lua" data="disa.lua"/>
</condition>
</extension>
Code
Name the following file 'disa.lua' and place under your FreeSWITCH scripts folder. This script was tested on FreeSWITCH version 1.4.15 and using Lua 5.1 (sorry, we use libraries in other scripts that require 5.1 so we're already set up for it). If it doesn't work in 5.2, please send me a message at Brian Foster.
disa.lua
api = freeswitch.API();
domain = freeswitch.getGlobalVariable("domain_name");
user_id = "";
creds_tries = 0;
creds_tries_limit = 3;
authorized = false;
invalid_entry_sound = "ivr/ivr-that_was_an_invalid_entry.wav";
no_permissions_sound = "ivr/ivr-not_have_permission.wav";
dialtone = "tone_stream://%(10000,0,350,440)";
end_call_sound = "tone_stream://%L=3;(100,100,350,440)";
session:answer();
if (session:ready()) then
-- Line is live, start talking
session:flushDigits();
session:execute("playback", "silence_stream://1500");
session:execute("playback", "ivr/ivr-hello.wav");
-- Try authentication
while (creds_tries_limit >= creds_tries) do
-- Prompt for user id
user_id = session:playAndGetDigits(1, 10, creds_tries_limit, 3000, "#", "ivr/ivr-please_enter_extension_followed_by_pound.wav", invalid_entry_sound, "\\d+", "", 3000);
if (user_id == "") then
-- Exceeded tries
creds_tries = creds_tries_limit;
elseif (api:executeString("user_exists id ".. user_id .. " " .. domain)) then
-- User id exists, prompt for pin
pin = session:playAndGetDigits(1, 64, 3, 3000, "#", "ivr/ivr-please_enter_pin_followed_by_pound.wav", invalid_entry_sound, "\\d+", "", 3000);
pin_valid = "";
freeswitch.consoleLog("info", "PIN valid: " .. pin_valid);
if (pin == "") then
-- Exceeded tries
creds_tries = creds_tries_limit;
else
pin_valid = api:executeString("vm_fsdb_auth_login default " .. domain .. " " .. user_id .. " " .. pin);
freeswitch.consoleLog("info", "PIN valid: " .. pin_valid);
if (pin_valid == "-OK") then
-- DISA Authenticated
-- Make sure user is authorized for DISA
toll_allow = api:executeString("user_data " .. user_id .. "@" .. domain .. " var toll_allow");
if(string.match(toll_allow, "disa")) then
-- Authorized for service
authorized = true;
break;
else
-- Not authorized for service
session:execute("playback", no_permissions_sound);
break;
end
else
-- Bad pin
session:execute("playback", invalid_entry_sound);
creds_tries = creds_tries + 1;
end
end
else
-- Bad user id
session:execute("playback", invalid_entry_sound);
creds_tries = creds_tries + 1;
end
end
if (authorized) then
-- Authorized for service, play instructions and give dialtone
session:execute("playback", "ivr/ivr-please_enter_the_phone_number.wav");
session:execute("playback", "ivr/ivr-followed_by_pound.wav");
digits = session:playAndGetDigits(2, 15, 1, 15000, "#", dialtone, invalid_entry_sound, "\\d+", "", "3000");
if (digits == "") then
session:execute("playback", "voicemail/vm-goodbye.wav");
else
-- Set user using set_user dialplan application, then transfer the call
session:execute("set_user", user_id .. "@" .. domain);
session:execute("transfer", digits .. " XML default");
end
else
session:execute("playback", "voicemail/vm-goodbye.wav");
end
end