3 <link rel="stylesheet" type="text/css" href="doc.css">
7 <a name="The.afm-user-daemon"></a>
8 <h1>The afm-user-daemon</h1>
15 <a name="Foreword"></a>
18 <p>This document describes what we intend to do. It may happen that our
19 current implementation and the content of this document differ.</p>
21 <p>In case of differences, it is assumed that this document is right
22 and the implementation is wrong.</p>
24 <a name="Introduction"></a>
27 <p>The daemon <strong>afm-user-daemon</strong> is in charge of handling
28 applications for one user. Its main tasks are:</p>
31 <li><p>enumerate the applications that the user can run
32 and keep the list avalable on demand</p></li>
33 <li><p>start applications for the user, set their running
34 environment, set their security context</p></li>
35 <li><p>list the current runner applications</p></li>
36 <li><p>stop (aka pause), continue (aka resume), terminate
37 the running instance of application</p></li>
38 <li><p>transfer requests for installation or uninstallation
39 of applications to the dedicated system daemon
40 <strong>afm-system-daemon</strong></p></li>
44 <p>The <strong>afm-user-daemon</strong> takes its orders from the session
45 instance of D-Bus.</p>
47 <p>The figure below summarizes the situation of the
48 <strong>afm-user-daemon</strong> in the system.</p>
50 <pre><code>+------------------------------------------------------------+
52 | +---------------------+ |
53 | +---------------------+ | Smack isolated | |
54 | | D-Bus session + | APPLICATIONS | |
55 | +----------+----------+ +---------+-----------+ |
58 | +----------+--------------------------+-----------+ |
60 | | afm-user-daemon | |
62 | +----------+----------------------+----------+----+ |
65 :================|======================|==========:=========:
67 | +----------+----------+ +-----+-----+ : |
68 | | D-Bus system +-----+ CYNARA | : |
69 | +----------+----------+ +-----+-----+ : |
71 | +----------+---------+ +-------+----------+----+ |
72 | | afm-system-daemon +----+ SECURITY-MANAGER | |
73 | +--------------------+ +-----------------------+ |
76 +------------------------------------------------------------+
79 <a name="Tasks.of..strong.afm-user-daemon..strong."></a>
80 <h2>Tasks of <strong>afm-user-daemon</strong></h2>
82 <a name="Maintaining.list.of.applications"></a>
83 <h3>Maintaining list of applications</h3>
85 <p>At start <strong>afm-user-daemon</strong> scans the directories containing
86 the applications and load in memory the list applications
87 availables to the current user.</p>
89 <p>When <strong>afm-system-daemon</strong> installs or removes an application,
90 it sends the signal <em>org.AGL.afm.system.changed</em> on success.
91 If it receives that signal, <strong>afm-user-daemon</strong> rebuild its
92 list of applications.</p>
94 <p><strong>afm-user-daemon</strong> provides the data that it collected about
95 application to its clients that either want to get that list
96 or to get information about one application.</p>
98 <a name="Launching.applications"></a>
99 <h3>Launching applications</h3>
101 <p><strong>afm-user-daemon</strong> launchs the applications. This means
102 that its builds a secure environment for the application
103 and then start it inside that secured environment.</p>
105 <p>Applications of different kind can be launched.</p>
107 <p>This is set using a configuration file that describes
108 how to launch an application of a given kind for a given
111 <p>There is two launching modes: local or remote.</p>
113 <p>Launching an application locally means that
114 the application and its binder are launcher together.</p>
116 <p>Launching application remotely means that only the
117 binder is launched for the application.</p>
119 <p>Once launched, running instances of application receive
120 a runid that identify them.</p>
122 <a name="Managing.instances.of.running.applications"></a>
123 <h3>Managing instances of running applications</h3>
125 <p><strong>afm-user-daemon</strong> manages the list of applications
126 that it launched.</p>
128 <p>With the good permissions, a client can get the list
129 of the running instances and details about a specific
130 running instance. It can also terminate, stop or
131 continue a given application.</p>
133 <a name="Installing.and.uninstalling.applications"></a>
134 <h3>Installing and uninstalling applications</h3>
136 <p>If the client has the good permission,
137 <strong>afm-user-daemon</strong> delegates that task
138 to <strong>afm-system-daemon</strong>.</p>
140 <a name="Starting..strong.afm-user-daemon..strong."></a>
141 <h2>Starting <strong>afm-user-daemon</strong></h2>
143 <p><strong>afm-user-daemon</strong> is launched as a <strong>systemd</strong> service
144 attached to user sessions. Normally, the service file is
145 located at /usr/lib/systemd/user/afm-user-daemon.service.</p>
147 <p>The options for launching <strong>afm-user-daemon</strong> are:</p>
150 --application directory
152 Includes the given application directory to
153 the database base of applications.
158 Includes the root application directory to
159 the database base of applications.
161 Note that the default root directory for
162 applications is always added. It is defined
163 to be /usr/share/afm/applications (may change).
166 --mode (local|remote)
168 Set the default launch mode.
169 The default value is 'local'
174 Daemonizes the process. It is not needed by sytemd.
179 Reduces the verbosity (can be repeated).
184 Increases the verbosity (can be repeated).
192 <a name="Configuration.of.the.launcher"></a>
193 <h2>Configuration of the launcher</h2>
195 <p>It contains rules for launching applications.
196 When <strong>afm-user-daemon</strong> need to launch an application,
197 it looks to the mode of launch, local or remote, and the
198 type of the application as given by the file <strong><em>config.xml</em></strong>
201 <p>This couple mode and type allows to select the rule.</p>
203 <p>The configuration file is <strong>/etc/afm/afm-launch.conf</strong>.</p>
205 <p>It contains sections and rules. It can also contain comments
206 and empty lines to improve the readability.</p>
208 <p>The separators are space and tabulation, any other character
209 is meaning something.</p>
211 <p>The format is line oriented.
212 The new line character separate the lines.</p>
214 <p>Lines having only separators are blank lines and are skipped.
215 Line having the character # (sharp) as first not separator character
216 are comment lines and are ignored.</p>
218 <p>Lines starting with a not separator character are differents
219 of lines starting with a separator character.</p>
221 <p>The grammar of the configuration file is defined below:</p>
223 <pre><code>CONF: *COMMENT *SECTION
227 RULE: +TYPE VECTOR ?VECTOR
229 MODE: 'mode' +SEP ('local' | 'remote') *SEP EOL
233 VECTOR: +SEP DATA *(+SEP NDATA) *SEP EOL
239 COMMENT: *SEP CMT *(SEP | NCHAR) NL
244 CHAR: '\x00'..'\x08' | '\x0b'..'\x1f' | '\x21' | '\x22' | '\x24'..'\xff'
248 <p>Here is a sample of configuration file for defining how
249 to launch an application declared of types <em>application/x-executable</em>,
250 <em>text/x-shellscript</em> and <em>text/html</em> in mode local:</p>
252 <pre><code>mode local
254 application/x-executable
259 /usr/bin/afb-daemon --mode=local --readyfd=%R --alias=/icons:%I --port=%P --rootdir=%r --token=%S --sessiondir=%D/.afb-daemon
260 /usr/bin/web-runtime http://localhost:%P/%c?token=%S
263 <p>This shows that:</p>
266 <li>within a section, several rules can be defined</li>
267 <li>within a rule, several types can be defined</li>
268 <li>within a rule, one or two vectors can be defined</li>
269 <li>vectors are using %substitution</li>
270 <li>launched binaries must be defined with their full path</li>
274 <a name="mode.local"></a>
277 <p>Within this mode, the launchers have either one or two vectors
278 describing them. All of these vectors are treated as programs
279 and are executed with the system call ‘execve’.</p>
281 <p>The first vector is the leader vector and it defines the process
282 group. The second vector (if any) is attached to the group
283 defined by this first vector.</p>
285 <a name="mode.remote"></a>
288 <p>Within this mode, the launchers have either one or two vectors
291 <p>The first vector is treated as a program and is executed with
292 the system call ‘execve’.</p>
294 <p>The second vector (if any) defines a text that is returned
295 to the caller. This mechanism can be used to return the uri
296 to connect to for executing the application remotely.</p>
298 <p>The daemon <strong><em>afm-user-daemon</em></strong> allocates a port for the
299 running the application remotely.
300 The current implmentation of the port allocation is just
302 A more reliable (cacheable and same-originable) allocation
303 is to be defined.</p>
305 <a name="L.substitutions"></a>
306 <h3>%substitutions</h3>
308 <p>Vectors can include sequences of 2 characters that have a special
309 meaning. These sequences are named <em>%substitution</em> because their
310 first character is the percent sign (%) and because each occurrence
311 of the sequence is replaced, at launch time, by the value associated
314 <p>Here is the list of <em>%substitutions</em>:</p>
317 <li><p><strong><em>%%</em></strong>: %.</p>
319 <p>This simply emits the percent sign %</p></li>
320 <li><p><strong><em>%a</em></strong>: appid</p>
322 <p>This is the application Id of the launched application.</p>
324 <p>Defined by the attribute <strong>id</strong> of the element <strong><widget></strong>
325 of <strong>config.xml</strong>.</p></li>
326 <li><p><strong><em>%c</em></strong>: content</p>
328 <p>The file within the widget directory that is the entry point.</p>
330 <p>For a HTML application, it is the relative path to the main
331 page (aka index.html).</p>
333 <p>Defined by the attribute <strong>src</strong> of the element <strong><content></strong>
334 of <strong>config.xml</strong>.</p></li>
335 <li><p><strong><em>%D</em></strong>: datadir</p>
337 <p>Path of the directory where the application runs (cwd)
338 and stores its data.</p>
340 <p>It is equal to %h/%a.</p></li>
341 <li><p><strong><em>%H</em></strong>: height</p>
343 <p>Requested height for the widget.</p>
345 <p>Defined by the attribute <strong>height</strong> of the element <strong><widget></strong>
346 of <strong>config.xml</strong>.</p></li>
347 <li><p><strong><em>%h</em></strong>: homedir</p>
349 <p>Path of the home directory for all applications.</p>
351 <p>It is generally equal to $HOME/app-data</p></li>
352 <li><p><strong><em>%I</em></strong>: icondir</p>
354 <p>Path of the directory were the icons of the applications can be found.</p></li>
355 <li><p><strong><em>%m</em></strong>: mime-type</p>
357 <p>Mime type of the launched application.</p>
359 <p>Defined by the attribute <strong>type</strong> of the element <strong><content></strong>
360 of <strong>config.xml</strong>.</p></li>
361 <li><p><strong><em>%n</em></strong>: name</p>
363 <p>Name of the application as defined by the content of the
364 element <strong><name></strong> of <strong>config.xml</strong>.</p></li>
365 <li><p><strong><em>%p</em></strong>: plugins</p>
367 <p>Unhandled until now.</p>
369 <p>Will be the colon separated list of plugins and plugins directory.</p></li>
370 <li><p><strong><em>%P</em></strong>: port</p>
372 <p>A port to use. It is currently a kind of random port. The precise
373 model is to be defined later.</p></li>
374 <li><p><strong><em>%R</em></strong>: readyfd</p>
376 <p>Number of the file descriptor to use for signalling
377 readyness of the launched process.</p></li>
378 <li><p><strong><em>%r</em></strong>: rootdir</p>
380 <p>Path of the directory containing the widget and its data.</p></li>
381 <li><p><strong><em>%S</em></strong>: secret</p>
383 <p>An hexadecimal number that can be used to pair the client
384 with its server binder.</p></li>
385 <li><p><strong><em>%W</em></strong>: width</p>
387 <p>Requested width for the widget.</p>
389 <p>Defined by the attribute <strong>width</strong> of the element <strong><widget></strong>
390 of <strong>config.xml</strong>.</p></li>
394 <a name="The.D-Bus.interface"></a>
395 <h2>The D-Bus interface</h2>
397 <a name="Overview.of.the.dbus.interface"></a>
398 <h3>Overview of the dbus interface</h3>
400 <p><strong><em>afm-user-daemon</em></strong> takes its orders from the session instance
401 of D-Bus. The use of D-Bus is great because it allows to implement
402 discovery and signaling.</p>
404 <p>The dbus of the session is by default adressed by the environment
405 variable <strong><em>DBUS_SESSION_BUS_ADDRESS</em></strong>. Using <strong>systemd</strong>
406 the variable <em>DBUS_SESSION_BUS_ADDRESS</em> is automatically set for
409 <p>The <strong>afm-user-daemon</strong> is listening with the destination name
410 <strong><em>org.AGL.afm.user</em></strong> at the object of path <strong><em>/org/AGL/afm/user</em></strong>
411 on the interface <strong><em>org.AGL.afm.user</em></strong> for the below detailed
412 members <strong><em>runnables</em></strong>, <strong><em>detail</em></strong>, <strong><em>start</em></strong>, <strong><em>terminate</em></strong>,
413 <strong><em>stop</em></strong>, <strong><em>continue</em></strong>, <strong><em>runners</em></strong>, <strong><em>state</em></strong>,
414 <strong><em>install</em></strong> and <strong><em>uninstall</em></strong>.</p>
416 <p>D-Bus is mainly used for signaling and discovery. Its optimized
417 typed protocol is not used except for transmitting only one string
418 in both directions.</p>
420 <p>The client and the service are using JSON serialisation to
423 <p>The D-Bus interface is defined by:</p>
426 <li><p>DESTINATION: <strong>org.AGL.afm.user</strong></p></li>
427 <li><p>PATH: <strong>/org/AGL/afm/user</strong></p></li>
428 <li><p>INTERFACE: <strong>org.AGL.afm.user</strong></p></li>
432 <p>The signature of any member of the interface is <strong><em>string -> string</em></strong>
433 for <strong><em>JSON -> JSON</em></strong>.</p>
435 <p>This is the normal case. In case of error, the current implmentation
436 returns a dbus error that is a string.</p>
438 <p>Here is an example that use <em>dbus-send</em> to query data on
439 installed applications.</p>
441 <pre><code>dbus-send --session --print-reply \
442 --dest=org.AGL.afm.user \
444 org.AGL.afm.user.runnables string:true
447 <a name="Using..strong..em.afm-util..em...strong."></a>
448 <h3>Using <strong><em>afm-util</em></strong></h3>
450 <p>The command line tool <strong><em>afm-util</em></strong> uses dbus-send to send
451 orders to <strong>afm-user-daemon</strong>. This small scripts allows to
452 send command to <strong><em>afm-user-daemon</em></strong> either interactively
453 at shell prompt or scriptically.</p>
455 <p>The syntax is simple: it accept a command and if the command
456 requires it, the argument to the command.</p>
458 <p>Here is the summary of <strong><em>afm-util</em></strong>:</p>
461 <li><p><strong>afm-util runnables </strong>:</p>
463 <p>list the runnable widgets installed</p></li>
464 <li><p><strong>afm-util install wgt </strong>:</p>
466 <p>install the wgt file</p></li>
467 <li><p><strong>afm-util uninstall id </strong>:</p>
469 <p>remove the installed widget of id</p></li>
470 <li><p><strong>afm-util detail id </strong>:</p>
472 <p>print detail about the installed widget of id</p></li>
473 <li><p><strong>afm-util runners </strong>:</p>
475 <p>list the running instance</p></li>
476 <li><p><strong>afm-util start id </strong>:</p>
478 <p>start an instance of the widget of id</p></li>
479 <li><p><strong>afm-util terminate rid </strong>:</p>
481 <p>terminate the running instance rid</p></li>
482 <li><p><strong>afm-util stop rid </strong>:</p>
484 <p>stop the running instance rid</p></li>
485 <li><p><strong>afm-util continue rid </strong>:</p>
487 <p>continue the previously rid</p></li>
488 <li><p><strong>afm-util state rid </strong>:</p>
490 <p>get status of the running instance rid</p></li>
494 <p>Here is how to list applications using <strong><em>afm-util</em></strong>:</p>
496 <pre><code>afm-util runnables
501 <a name="The.protocol.over.D-Bus"></a>
502 <h3>The protocol over D-Bus</h3>
507 <li><p><strong>DESTINATION</strong>: org.AGL.afm.user</p></li>
508 <li><p><strong>PATH</strong>: /org/AGL/afm/user</p></li>
509 <li><p><strong>INTERFACE</strong>: org.AGL.afm.user</p></li>
515 <a name="Method.org.AGL.afm.user.detail"></a>
516 <h4>Method org.AGL.afm.user.detail</h4>
518 <p><strong>Description</strong>: Get details about an application from its id.</p>
520 <p><strong>Input</strong>: the id of the application as below.</p>
522 <p>Either just a string:</p>
524 <pre><code>"appli@x.y"
527 <p>Or an object having the field “id” of type string:</p>
529 <pre><code>{"id":"appli@x.y"}
532 <p><strong>Output</strong>: A JSON object describing the application containing
533 the fields described below.</p>
536 "id": string, the application id (id@version)
537 "version": string, the version of the application
538 "width": integer, requested width of the application
539 "height": integer, resqueted height of the application
540 "name": string, the name of the application
541 "description": string, the description of the application
542 "shortname": string, the short name of the application
543 "author": string, the author of the application
549 <a name="Method.org.AGL.afm.user.runnables"></a>
550 <h4>Method org.AGL.afm.user.runnables</h4>
552 <p><strong>Description</strong>: Get the list of applications that can be run.</p>
554 <p><strong>Input</strong>: any valid json entry, can be anything except null.</p>
556 <p><strong>output</strong>: An array of description of the runnable applications.
557 Each item of the array contains an object containing the detail of
558 an application as described above for the method
559 <em>org.AGL.afm.user.detail</em>.</p>
563 <a name="Method.org.AGL.afm.user.install"></a>
564 <h4>Method org.AGL.afm.user.install</h4>
566 <p><strong>Description</strong>: Install an application from its widget file.</p>
568 <p>If an application of the same <em>id</em> and <em>version</em> exists, it is not
569 reinstalled except if <em>force=true</em>.</p>
571 <p>Applications are installed in the subdirectories of the common directory
573 If <em>root</em> is specified, the application is installed under the
574 sub-directories of the <em>root</em> defined.</p>
576 <p>Note that this methods is a simple accessor to the method
577 <strong><em>org.AGL.afm.system.install</em></strong> of <strong><em>afm-system-daemon</em></strong>.</p>
579 <p>After the installation and before returning to the sender,
580 <strong><em>afm-user-daemon</em></strong> sends the signal <strong><em>org.AGL.afm.user.changed</em></strong>.</p>
582 <p><strong>Input</strong>: The <em>path</em> of the widget file to install and, optionaly,
583 a flag to <em>force</em> reinstallation, and, optionaly, a <em>root</em> directory.</p>
585 <p>Either just a string being the absolute path of the widget file:</p>
587 <pre><code>"/a/path/driving/to/the/widget"
593 "wgt": "/a/path/to/the/widget",
595 "root": "/a/path/to/the/root"
599 <p>“wgt” and “root” must be absolute paths.</p>
601 <p><strong>output</strong>: An object with the field “added” being the string for
602 the id of the added application.</p>
604 <pre><code>{"added":"appli@x.y" }
609 <a name="Method.org.AGL.afm.user.uninstall"></a>
610 <h4>Method org.AGL.afm.user.uninstall</h4>
612 <p><strong>Description</strong>: Uninstall an application from its id.</p>
614 <p>Note that this methods is a simple accessor to the method
615 <strong><em>org.AGL.afm.system.uninstall</em></strong> of <strong><em>afm-system-daemon</em></strong>.</p>
617 <p>After the uninstallation and before returning to the sender,
618 <strong><em>afm-user-daemon</em></strong> sends the signal <strong><em>org.AGL.afm.user.changed</em></strong>.</p>
620 <p><strong>Input</strong>: the <em>id</em> of the application and, otpionaly, the path to
621 <em>root</em> of the application.</p>
623 <p>Either a string:</p>
625 <pre><code>"appli@x.y"
632 "root": "/a/path/to/the/root"
636 <p><strong>output</strong>: the value ‘true’.</p>
640 <a name="Method.org.AGL.afm.user.start"></a>
641 <h4>Method org.AGL.afm.user.start</h4>
643 <p><strong>Description</strong>:</p>
645 <p><strong>Input</strong>: the <em>id</em> of the application and, optionaly, the
646 start <em>mode</em> as below.</p>
648 <p>Either just a string:</p>
650 <pre><code>"appli@x.y"
653 <p>Or an object having the field “id” of type string and
654 optionaly a field mode:</p>
656 <pre><code>{"id":"appli@x.y","mode":"local"}
659 <p>The field “mode” as a string value being either “local” or “remote”.</p>
661 <p><strong>output</strong>: The <em>runid</em> of the application launched.
662 The runid is an integer.</p>
666 <a name="Method.org.AGL.afm.user.terminate"></a>
667 <h4>Method org.AGL.afm.user.terminate</h4>
669 <p><strong>Description</strong>: Terminates the application of <em>runid</em>.</p>
671 <p><strong>Input</strong>: The <em>runid</em> (an integer) of the running instance to terminate.</p>
673 <p><strong>output</strong>: the value ‘true’.</p>
677 <a name="Method.org.AGL.afm.user.stop"></a>
678 <h4>Method org.AGL.afm.user.stop</h4>
680 <p><strong>Description</strong>: Stops the application of <em>runid</em> until terminate or continue.</p>
682 <p><strong>Input</strong>: The <em>runid</em> (an integer) of the running instance to stop.</p>
684 <p><strong>output</strong>: the value ‘true’.</p>
688 <a name="Method.org.AGL.afm.user.continue"></a>
689 <h4>Method org.AGL.afm.user.continue</h4>
691 <p><strong>Description</strong>: Continues the application of <em>runid</em> previously stopped.</p>
693 <p><strong>Input</strong>: The <em>runid</em> (an integer) of the running instance to continue.</p>
695 <p><strong>output</strong>: the value ‘true’.</p>
699 <a name="Method.org.AGL.afm.user.state"></a>
700 <h4>Method org.AGL.afm.user.state</h4>
702 <p><strong>Description</strong>: Get informations about a running instance of <em>runid</em>.</p>
704 <p><strong>Input</strong>: The <em>runid</em> (an integer) of the running instance inspected.</p>
706 <p><strong>output</strong>: An object describing the state of the instance. It contains:
707 the runid (an integer), the id of the running application (a string),
708 the state of the application (a string being either “starting”, “running”
709 or “stopped”).</p>
711 <p>Example of returned state:</p>
722 <a name="Method.org.AGL.afm.user.runners"></a>
723 <h4>Method org.AGL.afm.user.runners</h4>
725 <p><strong>Description</strong>: Get the list of the currently running instances.</p>
727 <p><strong>Input</strong>: anything.</p>
729 <p><strong>output</strong>: An array of states, one per running instance, as returned by
730 the methodd <strong><em>org.AGL.afm.user.state</em></strong>.</p>
732 <a name="The.afb.plugin"></a>
733 <h2>The afb plugin</h2>
735 <p>The base of the path is FWKAPI = /api/fwk</p>
737 <p>request FWKAPI/runnables
738 – get the list of applications
739 => [ APPDESC… ]</p>
741 <p>request FWKAPI/detail?id=APPID
742 subject to languages tuning
743 => { “id”: “APPID”, “name”: “name”, “description”: “description”, “license”: “license”, “author”: “author” }</p>
746 request FWKAPI/icon?id=APPID
747 subject to languages tuning
751 <p>request FWKAPI/run?id=APPID
752 => { “status”: “done/error”, “data”: { “runid”: “RUNID” } }</p>
754 <p>request FWKAPI/running
755 => [ { “id”: “RUNID”, “appid”: “APPID”, “state”: … }… ]</p>
757 <p>request FWKAPI/state?id=RUNID
758 => { “id”: “RUNID”, “appid”: “APPID”, “state”: … }</p>
760 <p>request FWKAPI/stop?id=RUNID
761 => { “error”: “message” ou “done”: “RUNID” }</p>
763 <p>request FWKAPI/suspend?id=RUNID
764 => { “error”: “message” ou “done”: “RUNID” }</p>
766 <p>request FWKAPI/resume?id=RUNID
767 => { “error”: “message” ou “done”: “RUNID” }</p>
770 request FWKAPI/features
771 => returns the features of the current application</p>
773 <p>request FWKAPI/preferences
774 => returns the features of the current application