1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
|
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="generator" content="pandoc">
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
<meta name="author" content="José Bollo">
<title>Overview of AFB-DAEMON</title>
<style type="text/css">code{white-space: pre;}</style>
<!--[if lt IE 9]>
<script src="http://html5shim.googlecode.com/svn/trunk/html5.js"></script>
<![endif]-->
<link rel="stylesheet" href="doc.css">
</head>
<body>
<header>
<h1 class="title">Overview of AFB-DAEMON</h1>
<h2 class="author">José Bollo</h2>
<h3 class="date">24 juin 2016</h3>
</header>
<nav id="TOC">
<ul>
<li><a href="#overview-of-afb-daemon">Overview of AFB-DAEMON</a><ul>
<li><a href="#roles-of-afb-daemon">Roles of afb-daemon</a></li>
<li><a href="#use-cases-of-the-binder-afb-daemon">Use cases of the binder afb-daemon</a><ul>
<li><a href="#remotely-running-application">Remotely running application</a></li>
<li><a href="#adding-native-features-to-html5qml-applications">Adding native features to HTML5/QML applications</a></li>
<li><a href="#offering-services-to-the-system">Offering services to the system</a></li>
</ul></li>
<li><a href="#the-bindings-of-the-binder-afb-daemon">The bindings of the binder afb-daemon</a></li>
<li><a href="#launching-the-binder-afb-daemon">Launching the binder afb-daemon</a></li>
<li><a href="#future-development-of-afb-daemon">Future development of afb-daemon</a></li>
</ul></li>
</ul>
</nav>
<h1 id="overview-of-afb-daemon">Overview of AFB-DAEMON</h1>
<h2 id="roles-of-afb-daemon">Roles of afb-daemon</h2>
<p>The name <strong>afb-daemon</strong> stands for <em>Application Framework Binder Daemon</em>. That is why afb-daemon is also named <strong><em>the binder</em></strong>.</p>
<p><strong>Afb-daemon</strong> is in charge to bind one instance of an application to the AGL framework and AGL system.</p>
<p>On the following figure, you can use a typical use of afb-daemon:</p>
<a id="binder-fig-basis">
<h4>
Figure: binder afb-daemon, basis
</h4>
<p></a></p>
<pre><code>. . . . . . . . . . . . . . . . . . . . . . . . . .
. Isolated security context .
. .
. +------------------------------+ .
. | | .
. | A P P L I C A T I O N | .
. | | .
. +--------------+---------------+ .
. | .
. | .
. +-------------------+----------------------+ .
. | : | .
. | b i n d e r : | .
. | A F B - D A E M O N : BINDINGS | .
. | : | .
. +-------------------+----------------------+ .
. | .
. . . . . . . . . . . . | . . . . . . . . . . . . .
|
v
AGL SYSTEM</code></pre>
<p>The application and its companion binder run in secured and isolated environment set for them. Applications are intended to access to AGL system through the binder.</p>
<p>The binder afb-daemon serves multiple purposes:</p>
<ol type="1">
<li><p>It acts as a gateway for the application to access the system;</p></li>
<li><p>It acts as an HTTP server for serving files to HTML5 applications;</p></li>
<li><p>It allows HTML5 applications to have native extensions subject to security enforcement for accessing hardware ressources or for speeding parts of algorithm.</p></li>
</ol>
<h2 id="use-cases-of-the-binder-afb-daemon">Use cases of the binder afb-daemon</h2>
<p>This section tries to give a better understanding of the binder usage through several use cases.</p>
<h3 id="remotely-running-application">Remotely running application</h3>
<p>One of the most interresting aspect of using the binder afb-daemon is the ability to run applications remotely. This feature is possible because the binder afb-daemon implements native web protocols.</p>
<p>So the <a href="#binder-fig-1">figure binder, basis</a> would become when the application is run remotely:</p>
<a id="binder-fig-remote">
<h4>
Figure: binder afb-daemon and remotely running application
</h4>
<p></a></p>
<pre><code> +------------------------------+
| |
| A P P L I C A T I O N |
| |
+--------------+---------------+
|
~ ~ ~ ~ ~ ~
: NETWORK :
~ ~ ~ ~ ~ ~
|
. . . . . . . . . . . . . . | . . . . . . . . . . . . . .
. Isolated security | .
. context | .
. | .
. . . . . . . . . . . . . . . . . . . . . . . . . .
. . . .
. . F I R E W A L L . .
. . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .
. | .
. +-------------------+----------------------+ .
. | : | .
. | A F B - D A E M O N : BINDINGS | .
. | : | .
. +-------------------+----------------------+ .
. | .
. . . . . . . . . . . . . . | . . . . . . . . . . . . . .
|
v
AGL SYSTEM</code></pre>
<h3 id="adding-native-features-to-html5qml-applications">Adding native features to HTML5/QML applications</h3>
<p>Applications can provide with their packaged delivery a binding. That binding will be instanciated for each application instance. The methods of the binding will be accessible by applications and will be excuted within the security context.</p>
<h3 id="offering-services-to-the-system">Offering services to the system</h3>
<p>It is possible to run the binder afb-daemon as a daemon that provides the API of its bindings.</p>
<p>This will be used for:</p>
<ol type="1">
<li><p>offering common APIs</p></li>
<li><p>provide application's services (services provided as application)</p></li>
</ol>
<p>In that case, the figure showing the whole aspects is</p>
<a id="binder-fig-remote">
<h4>
Figure: binder afb-daemon for services
</h4>
<p></a></p>
<pre><code>. . . . . . . . . . . . . . . . . . . . . .
. Isolated security context application .
. .
. +------------------------------+ .
. | | .
. | A P P L I C A T I O N | .
. | | .
. +--------------+---------------+ . . . . . . . . . . . . . . . . . . . . . . .
. | . . Isolated security context A .
. | . . .
. +-----------------+------------------+ . . +------------------------------------+ .
. | : | . . | : | .
. | b i n d e r : | . . | b i n d e r : service | .
. | A F B - D A E M O N : BINDINGS | . . | A F B - D A E M O N : BINDINGS | .
. | : | . . | : A | .
. +-----------------+------------------+ . . +-----------------+------------------+ .
. | . . | .
. . . . . . . . . . | . . . . . . . . . . . . . . . . . . . . . | . . . . . . . . . . .
| |
v v
================================================================================
D - B U S & C Y N A R A
================================================================================
^ ^
| |
. . . . . . . . . . | . . . . . . . . . . . . . . . . . . . . . | . . . . . . . . . . .
. | . . | .
. +-----------------+------------------+ . . +-----------------+------------------+ .
. | : | . . | : | .
. | b i n d e r : service | . . | b i n d e r : service | .
. | A F B - D A E M O N : BINDINGS | . . | A F B - D A E M O N : BINDINGS | .
. | : B | . . | : C | .
. +------------------------------------+ . . +------------------------------------+ .
. . . .
. Isolated security context B . . Isolated security context C .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .</code></pre>
<p>For this case, the binder afb-daemon takes care to attribute one single session context to each client instance. It allows bindings to store and retrieve data associated to each of its client.</p>
<h2 id="the-bindings-of-the-binder-afb-daemon">The bindings of the binder afb-daemon</h2>
<p>The binder can instanciate bindings. The primary use of bindings is to add native methods that can be accessed by applications written with any language through web technologies ala JSON RPC.</p>
<p>This simple idea is declined to serves multiple purposes:</p>
<ol type="1">
<li><p>add native feature to applications</p></li>
<li><p>add common API available by any applications</p></li>
<li><p>provide customers services</p></li>
</ol>
<p>A specific document explains how to write an afb-daemon binder binding: <a href="afb-binding-writing.html">HOWTO WRITE a BINDING for AFB-DAEMON</a></p>
<h2 id="launching-the-binder-afb-daemon">Launching the binder afb-daemon</h2>
<p>The launch options for binder <strong>afb-daemon</strong> are:</p>
<pre><code> --help
Prints help with available options
--version
Display version and copyright
--verbose
Increases the verbosity, can be repeated
--port=xxxx
HTTP listening TCP port [default 1234]
--rootdir=xxxx
HTTP Root Directory [default $AFBDIR or else $HOME/.AFB]
--rootbase=xxxx
Angular Base Root URL [default /opa]
This is used for any application of kind OPA (one page application).
When set, any missing document whose url has the form /opa/zzz
is translated to /opa/#!zzz
--rootapi=xxxx
HTML Root API URL [default /api]
The bindings are available within that url.
--alias=xxxx
Maps a path located anywhere in the file system to the
a subdirectory. The syntax for mapping a PATH to the
subdirectory NAME is: --alias=/NAME:PATH.
Example: --alias=/icons:/usr/share/icons maps the
content of /usr/share/icons within the subpath /icons.
This option can be repeated.
--apitimeout=xxxx
binding API timeout in seconds [default 20]
Defines how many seconds maximum a method is allowed to run.
0 means no limit.
--cntxtimeout=xxxx
Client Session Timeout in seconds [default 3600]
--cache-eol=xxxx
Client cache end of live [default 100000 that is 27,7 hours]
--sessiondir=xxxx
Sessions file path [default rootdir/sessions]
--session-max=xxxx
Maximum count of simultaneous sessions [default 10]
--ldpaths=xxxx
Load bindings from given paths separated by colons
as for dir1:dir2:binding1.so:... [default = $libdir/afb]
You can mix path to directories and to bindings.
The sub-directories of the given directories are searched
recursively.
The bindings are the files terminated by '.so' (the extension
so denotes shared object) that contain the public entry symbol.
--binding=xxxx
Load the binding of given path.
--token=xxxx
Initial Secret token to authenticate.
If not set, no client can authenticate.
If set to the empty string, then any initial token is accepted.
--mode=xxxx
Set the mode: either local, remote or global.
The mode indicate if the application is run locally on the host
or remotely through network.
--readyfd=xxxx
Set the #fd to signal when ready
If set, the binder afb-daemon will write "READY=1\n" on the file
descriptor whose number if given (/proc/self/fd/xxx).
--dbus-client=xxxx
Transparent binding to a binder afb-daemon service through dbus.
It creates an API of name xxxx that is implemented remotely
and queried via DBUS.
--dbus-server=xxxx
Provides a binder afb-daemon service through dbus.
The name xxxx must be the name of an API defined by a binding.
This API is exported through DBUS.
--foreground
Get all in foreground mode (default)
--daemon
Get all in background mode</code></pre>
<h2 id="future-development-of-afb-daemon">Future development of afb-daemon</h2>
<ul>
<li><p>The binder afb-daemon would launch the applications directly.</p></li>
<li><p>The current setting of mode (local/remote/global) might be reworked to a mechanism for querying configuration variables.</p></li>
<li><p>Implements "one-shot" initial token. It means that after its first authenticated use, the initial token is removed and no client can connect anymore.</p></li>
<li><p>Creates some intrinsic APIs.</p></li>
<li><p>Make the service connection using WebSocket not DBUS.</p></li>
<li><p>Management of targetted events.</p></li>
<li><p>Securisation of LOA.</p></li>
<li><p>Integration of the protocol JSON-RPC for the websockets.</p></li>
</ul>
</body>
</html>
|
