prosody-modules
4cf65afd90f4
mod_devices/mod_devices.lua

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mod_devices/mod_devices.lua @ 3397:4cf65afd90f4

mod_devices: New module for device identification
author Matthew Wild <mwild1@gmail.com>
date Thu, 06 Dec 2018 16:57:01 +0000
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3396:3bf847dbb063 3397:4cf65afd90f4
1 local it = require "util.iterators";
2 local new_id = require "util.id".medium;
3
4 local max_user_devices = module:get_option_number("max_user_devices", 5);
5
6 local device_store = module:open_store("devices");
7 local device_map_store = module:open_store("devices", "map");
8
9 --- Helper functions
10
11 local function _compare_device_timestamps(a, b)
12 return (a.last_activity_at or 0) < (b.last_activity_at or 0);
13 end
14 local function sorted_devices(devices)
15 return it.sorted_pairs(devices, _compare_device_timestamps);
16 end
17
18 local function new_device(username, alt_ids)
19 local current_time = os.time();
20 local device = {
21 id = "dv-"..new_id();
22 created_at = current_time;
23 last_activity = "created";
24 last_activity_at = current_time;
25 alt_ids = alt_ids or {};
26 };
27
28 local devices = device_store:get(username);
29 if not devices then
30 devices = {};
31 end
32 devices[device.id] = device;
33 local devices_ordered = {};
34 for id in sorted_devices(devices) do
35 table.insert(devices_ordered, id);
36 end
37 if #devices_ordered > max_user_devices then
38 -- Iterate through oldest devices that are above limit, backwards
39 for i = #devices_ordered, max_user_devices+1, -1 do
40 local id = table.remove(devices_ordered, i);
41 devices[id] = nil;
42 module:log("debug", "Removing old device for %s: %s", username, id);
43 end
44 end
45 device_store:set(username, devices);
46 return device;
47 end
48
49 local function get_device_with_alt_id(username, alt_id_type, alt_id)
50 local devices = device_store:get(username);
51 if not devices then
52 return nil;
53 end
54
55 for _, device in pairs(devices) do
56 if device.alt_ids[alt_id_type] == alt_id then
57 return device;
58 end
59 end
60 end
61
62 local function set_device_alt_id(username, device_id, alt_id_type, alt_id)
63 local devices = device_store:get(username);
64 if not devices or not devices[device_id] then
65 return nil, "no such device";
66 end
67 devices[device_id].alt_ids[alt_id_type] = alt_id;
68 end
69
70 local function record_device_state(username, device_id, activity, time)
71 local device = device_map_store:get(username, device_id);
72 device.last_activity = activity;
73 device.last_activity_at = time or os.time();
74 device_map_store:set(username, device_id, device);
75 end
76
77 local function find_device(username, info)
78 for _, alt_id_type in ipairs({ "resumption_token", "resource" }) do
79 local alt_id = info[alt_id_type];
80 if alt_id then
81 local device = get_device_with_alt_id(username, alt_id_type, alt_id);
82 if device then
83 return device, alt_id_type;
84 end
85 end
86 end
87 end
88
89 --- Information gathering
90
91 module:hook("pre-resource-bind", function (event)
92 event.session.device_requested_resource = event.resource;
93 end, 1000);
94
95
96 local function store_resumption_token(session, stanza)
97 session.device_requested_resume = stanza.attr.previd;
98 end
99 module:hook_stanza("urn:xmpp:sm:2", "resume", store_resumption_token, 5);
100 module:hook_stanza("urn:xmpp:sm:3", "resume", store_resumption_token, 5);
101
102 --- Identify device after resource bind
103
104 module:hook("resource-bind", function (event)
105 local info = {
106 resource = event.session.device_requested_resource;
107 resumption_token = event.session.device_requested_resume;
108 };
109 local device, source = find_device(event.session.username, info);
110 if device then
111 event.session.log("debug", "Associated with device %s (from %s)", device.id, source);
112 event.session.device_id = device.id;
113 else
114 device = new_device(event.session.username, info);
115 event.session.log("debug", "Creating new device %s for session", device.id);
116 event.session.device_id = device.id;
117 end
118 record_device_state(event.session.username, device.id, "login");
119 end, 1000);
120
121 module:hook("resource-unbind", function (event)
122 if event.session.device_id then
123 record_device_state(event.session.username, event.session.device_id, "logout");
124 end
125 end);