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.
160 Includes the root application directory to
161 the database base of applications.
163 Note that the default root directory for
164 applications is always added. It is defined
165 to be /usr/share/afm/applications (may change).
170 --mode (local|remote)
172 Set the default launch mode.
173 The default value is 'local'
178 Daemonizes the process. It is not needed by sytemd.
183 Reduces the verbosity (can be repeated).
188 Increases the verbosity (can be repeated).
196 <a name="Configuration.of.the.launcher"></a>
197 <h2>Configuration of the launcher</h2>
199 <p>It contains rules for launching applications.
200 When <strong>afm-user-daemon</strong> need to launch an application,
201 it looks to the mode of launch, local or remote, and the
202 type of the application as given by the file <strong><em>config.xml</em></strong>
205 <p>This couple mode and type allows to select the rule.</p>
207 <p>The configuration file is <strong>/etc/afm/afm-launch.conf</strong>.</p>
209 <p>It contains sections and rules. It can also contain comments
210 and empty lines to improve the readability.</p>
212 <p>The separators are space and tabulation, any other character
213 is meaning something.</p>
215 <p>The format is line oriented.
216 The new line character separate the lines.</p>
218 <p>Lines having only separators are blank lines and are skipped.
219 Line having the character # (sharp) as first not separator character
220 are comment lines and are ignored.</p>
222 <p>Lines starting with a not separator character are differents
223 of lines starting with a separator character.</p>
225 <p>The grammar of the configuration file is defined below:</p>
227 <pre><code>CONF: *COMMENT *SECTION
231 RULE: +TYPE VECTOR ?VECTOR
233 MODE: 'mode' +SEP ('local' | 'remote') *SEP EOL
237 VECTOR: +SEP DATA *(+SEP NDATA) *SEP EOL
243 COMMENT: *SEP CMT *(SEP | NCHAR) NL
248 CHAR: '\x00'..'\x08' | '\x0b'..'\x1f' | '\x21' | '\x22' | '\x24'..'\xff'
252 <p>Here is a sample of configuration file for defining how
253 to launch an application declared of types <em>application/x-executable</em>,
254 <em>text/x-shellscript</em> and <em>text/html</em> in mode local:</p>
256 <pre><code>mode local
258 application/x-executable
263 /usr/bin/afb-daemon --mode=local --readyfd=%R --alias=/icons:%I --port=%P --rootdir=%r --token=%S --sessiondir=%D/.afb-daemon
264 /usr/bin/web-runtime http://localhost:%P/%c?token=%S
267 <p>This shows that:</p>
270 <li>within a section, several rules can be defined</li>
271 <li>within a rule, several types can be defined</li>
272 <li>within a rule, one or two vectors can be defined</li>
273 <li>vectors are using %substitution</li>
274 <li>launched binaries must be defined with their full path</li>
278 <a name="mode.local"></a>
281 <p>Within this mode, the launchers have either one or two vectors
282 describing them. All of these vectors are treated as programs
283 and are executed with the system call ‘execve’.</p>
285 <p>The first vector is the leader vector and it defines the process
286 group. The second vector (if any) is attached to the group
287 defined by this first vector.</p>
289 <a name="mode.remote"></a>
292 <p>Within this mode, the launchers have either one or two vectors
295 <p>The first vector is treated as a program and is executed with
296 the system call ‘execve’.</p>
298 <p>The second vector (if any) defines a text that is returned
299 to the caller. This mechanism can be used to return the uri
300 to connect to for executing the application remotely.</p>
302 <p>The daemon <strong><em>afm-user-daemon</em></strong> allocates a port for the
303 running the application remotely.
304 The current implmentation of the port allocation is just
306 A more reliable (cacheable and same-originable) allocation
307 is to be defined.</p>
309 <a name="L.substitutions"></a>
310 <h3>%substitutions</h3>
312 <p>Vectors can include sequences of 2 characters that have a special
313 meaning. These sequences are named <em>%substitution</em> because their
314 first character is the percent sign (%) and because each occurrence
315 of the sequence is replaced, at launch time, by the value associated
318 <p>Here is the list of <em>%substitutions</em>:</p>
321 <li><p><strong><em>%%</em></strong>: %.</p>
323 <p>This simply emits the percent sign %</p></li>
324 <li><p><strong><em>%a</em></strong>: appid</p>
326 <p>This is the application Id of the launched application.</p>
328 <p>Defined by the attribute <strong>id</strong> of the element <strong><widget></strong>
329 of <strong>config.xml</strong>.</p></li>
330 <li><p><strong><em>%c</em></strong>: content</p>
332 <p>The file within the widget directory that is the entry point.</p>
334 <p>For a HTML application, it is the relative path to the main
335 page (aka index.html).</p>
337 <p>Defined by the attribute <strong>src</strong> of the element <strong><content></strong>
338 of <strong>config.xml</strong>.</p></li>
339 <li><p><strong><em>%D</em></strong>: datadir</p>
341 <p>Path of the directory where the application runs (cwd)
342 and stores its data.</p>
344 <p>It is equal to %h/%a.</p></li>
345 <li><p><strong><em>%H</em></strong>: height</p>
347 <p>Requested height for the widget.</p>
349 <p>Defined by the attribute <strong>height</strong> of the element <strong><widget></strong>
350 of <strong>config.xml</strong>.</p></li>
351 <li><p><strong><em>%h</em></strong>: homedir</p>
353 <p>Path of the home directory for all applications.</p>
355 <p>It is generally equal to $HOME/app-data</p></li>
356 <li><p><strong><em>%I</em></strong>: icondir</p>
358 <p>Path of the directory were the icons of the applications can be found.</p></li>
359 <li><p><strong><em>%m</em></strong>: mime-type</p>
361 <p>Mime type of the launched application.</p>
363 <p>Defined by the attribute <strong>type</strong> of the element <strong><content></strong>
364 of <strong>config.xml</strong>.</p></li>
365 <li><p><strong><em>%n</em></strong>: name</p>
367 <p>Name of the application as defined by the content of the
368 element <strong><name></strong> of <strong>config.xml</strong>.</p></li>
369 <li><p><strong><em>%p</em></strong>: plugins</p>
371 <p>Unhandled until now.</p>
373 <p>Will be the colon separated list of plugins and plugins directory.</p></li>
374 <li><p><strong><em>%P</em></strong>: port</p>
376 <p>A port to use. It is currently a kind of random port. The precise
377 model is to be defined later.</p></li>
378 <li><p><strong><em>%R</em></strong>: readyfd</p>
380 <p>Number of the file descriptor to use for signalling
381 readyness of the launched process.</p></li>
382 <li><p><strong><em>%r</em></strong>: rootdir</p>
384 <p>Path of the directory containing the widget and its data.</p></li>
385 <li><p><strong><em>%S</em></strong>: secret</p>
387 <p>An hexadecimal number that can be used to pair the client
388 with its server binder.</p></li>
389 <li><p><strong><em>%W</em></strong>: width</p>
391 <p>Requested width for the widget.</p>
393 <p>Defined by the attribute <strong>width</strong> of the element <strong><widget></strong>
394 of <strong>config.xml</strong>.</p></li>
398 <a name="The.D-Bus.interface"></a>
399 <h2>The D-Bus interface</h2>
401 <a name="Overview.of.the.dbus.interface"></a>
402 <h3>Overview of the dbus interface</h3>
404 <p><strong><em>afm-user-daemon</em></strong> takes its orders from the session instance
405 of D-Bus. The use of D-Bus is great because it allows to implement
406 discovery and signaling.</p>
408 <p>The dbus of the session is by default adressed by the environment
409 variable <strong><em>DBUS_SESSION_BUS_ADDRESS</em></strong>. Using <strong>systemd</strong>
410 the variable <em>DBUS_SESSION_BUS_ADDRESS</em> is automatically set for
413 <p>The <strong>afm-user-daemon</strong> is listening with the destination name
414 <strong><em>org.AGL.afm.user</em></strong> at the object of path <strong><em>/org/AGL/afm/user</em></strong>
415 on the interface <strong><em>org.AGL.afm.user</em></strong> for the below detailed
416 members <strong><em>runnables</em></strong>, <strong><em>detail</em></strong>, <strong><em>start</em></strong>, <strong><em>terminate</em></strong>,
417 <strong><em>stop</em></strong>, <strong><em>continue</em></strong>, <strong><em>runners</em></strong>, <strong><em>state</em></strong>,
418 <strong><em>install</em></strong> and <strong><em>uninstall</em></strong>.</p>
420 <p>D-Bus is mainly used for signaling and discovery. Its optimized
421 typed protocol is not used except for transmitting only one string
422 in both directions.</p>
424 <p>The client and the service are using JSON serialisation to
427 <p>The D-Bus interface is defined by:</p>
430 <li><p>DESTINATION: <strong>org.AGL.afm.user</strong></p></li>
431 <li><p>PATH: <strong>/org/AGL/afm/user</strong></p></li>
432 <li><p>INTERFACE: <strong>org.AGL.afm.user</strong></p></li>
436 <p>The signature of any member of the interface is <strong><em>string -> string</em></strong>
437 for <strong><em>JSON -> JSON</em></strong>.</p>
439 <p>This is the normal case. In case of error, the current implmentation
440 returns a dbus error that is a string.</p>
442 <p>Here is an example that use <em>dbus-send</em> to query data on
443 installed applications.</p>
445 <pre><code>dbus-send --session --print-reply \
446 --dest=org.AGL.afm.user \
448 org.AGL.afm.user.runnables string:true
451 <a name="Using..strong..em.afm-util..em...strong."></a>
452 <h3>Using <strong><em>afm-util</em></strong></h3>
454 <p>The command line tool <strong><em>afm-util</em></strong> uses dbus-send to send
455 orders to <strong>afm-user-daemon</strong>. This small scripts allows to
456 send command to <strong><em>afm-user-daemon</em></strong> either interactively
457 at shell prompt or scriptically.</p>
459 <p>The syntax is simple: it accept a command and if the command
460 requires it, the argument to the command.</p>
462 <p>Here is the summary of <strong><em>afm-util</em></strong>:</p>
465 <li><p><strong>afm-util runnables </strong>:</p>
467 <p>list the runnable widgets installed</p></li>
468 <li><p><strong>afm-util install wgt </strong>:</p>
470 <p>install the wgt file</p></li>
471 <li><p><strong>afm-util uninstall id </strong>:</p>
473 <p>remove the installed widget of id</p></li>
474 <li><p><strong>afm-util detail id </strong>:</p>
476 <p>print detail about the installed widget of id</p></li>
477 <li><p><strong>afm-util runners </strong>:</p>
479 <p>list the running instance</p></li>
480 <li><p><strong>afm-util start id </strong>:</p>
482 <p>start an instance of the widget of id</p></li>
483 <li><p><strong>afm-util terminate rid </strong>:</p>
485 <p>terminate the running instance rid</p></li>
486 <li><p><strong>afm-util stop rid </strong>:</p>
488 <p>stop the running instance rid</p></li>
489 <li><p><strong>afm-util continue rid </strong>:</p>
491 <p>continue the previously rid</p></li>
492 <li><p><strong>afm-util state rid </strong>:</p>
494 <p>get status of the running instance rid</p></li>
498 <p>Here is how to list applications using <strong><em>afm-util</em></strong>:</p>
500 <pre><code>afm-util runnables
505 <a name="The.protocol.over.D-Bus"></a>
506 <h3>The protocol over D-Bus</h3>
511 <li><p><strong>DESTINATION</strong>: org.AGL.afm.user</p></li>
512 <li><p><strong>PATH</strong>: /org/AGL/afm/user</p></li>
513 <li><p><strong>INTERFACE</strong>: org.AGL.afm.user</p></li>
519 <a name="Method.org.AGL.afm.user.detail"></a>
520 <h4>Method org.AGL.afm.user.detail</h4>
522 <p><strong>Description</strong>: Get details about an application from its id.</p>
524 <p><strong>Input</strong>: the id of the application as below.</p>
526 <p>Either just a string:</p>
528 <pre><code>"appli@x.y"
531 <p>Or an object having the field “id” of type string:</p>
533 <pre><code>{"id":"appli@x.y"}
536 <p><strong>Output</strong>: A JSON object describing the application containing
537 the fields described below.</p>
540 "id": string, the application id (id@version)
541 "version": string, the version of the application
542 "width": integer, requested width of the application
543 "height": integer, resqueted height of the application
544 "name": string, the name of the application
545 "description": string, the description of the application
546 "shortname": string, the short name of the application
547 "author": string, the author of the application
553 <a name="Method.org.AGL.afm.user.runnables"></a>
554 <h4>Method org.AGL.afm.user.runnables</h4>
556 <p><strong>Description</strong>: Get the list of applications that can be run.</p>
558 <p><strong>Input</strong>: any valid json entry, can be anything except null.</p>
560 <p><strong>output</strong>: An array of description of the runnable applications.
561 Each item of the array contains an object containing the detail of
562 an application as described above for the method
563 <em>org.AGL.afm.user.detail</em>.</p>
567 <a name="Method.org.AGL.afm.user.install"></a>
568 <h4>Method org.AGL.afm.user.install</h4>
570 <p><strong>Description</strong>: Install an application from its widget file.</p>
572 <p>If an application of the same <em>id</em> and <em>version</em> exists, it is not
573 reinstalled except if <em>force=true</em>.</p>
575 <p>Applications are installed in the subdirectories of the common directory
577 If <em>root</em> is specified, the application is installed under the
578 sub-directories of the <em>root</em> defined.</p>
580 <p>Note that this methods is a simple accessor to the method
581 <strong><em>org.AGL.afm.system.install</em></strong> of <strong><em>afm-system-daemon</em></strong>.</p>
583 <p>After the installation and before returning to the sender,
584 <strong><em>afm-user-daemon</em></strong> sends the signal <strong><em>org.AGL.afm.user.changed</em></strong>.</p>
586 <p><strong>Input</strong>: The <em>path</em> of the widget file to install and, optionaly,
587 a flag to <em>force</em> reinstallation, and, optionaly, a <em>root</em> directory.</p>
589 <p>Either just a string being the absolute path of the widget file:</p>
591 <pre><code>"/a/path/driving/to/the/widget"
597 "wgt": "/a/path/to/the/widget",
599 "root": "/a/path/to/the/root"
603 <p>“wgt” and “root” must be absolute paths.</p>
605 <p><strong>output</strong>: An object with the field “added” being the string for
606 the id of the added application.</p>
608 <pre><code>{"added":"appli@x.y"}
613 <a name="Method.org.AGL.afm.user.uninstall"></a>
614 <h4>Method org.AGL.afm.user.uninstall</h4>
616 <p><strong>Description</strong>: Uninstall an application from its id.</p>
618 <p>Note that this methods is a simple accessor to the method
619 <strong><em>org.AGL.afm.system.uninstall</em></strong> of <strong><em>afm-system-daemon</em></strong>.</p>
621 <p>After the uninstallation and before returning to the sender,
622 <strong><em>afm-user-daemon</em></strong> sends the signal <strong><em>org.AGL.afm.user.changed</em></strong>.</p>
624 <p><strong>Input</strong>: the <em>id</em> of the application and, otpionaly, the path to
625 <em>root</em> of the application.</p>
627 <p>Either a string:</p>
629 <pre><code>"appli@x.y"
636 "root": "/a/path/to/the/root"
640 <p><strong>output</strong>: the value ‘true’.</p>
644 <a name="Method.org.AGL.afm.user.start"></a>
645 <h4>Method org.AGL.afm.user.start</h4>
647 <p><strong>Description</strong>:</p>
649 <p><strong>Input</strong>: the <em>id</em> of the application and, optionaly, the
650 start <em>mode</em> as below.</p>
652 <p>Either just a string:</p>
654 <pre><code>"appli@x.y"
657 <p>Or an object having the field “id” of type string and
658 optionaly a field mode:</p>
660 <pre><code>{"id":"appli@x.y","mode":"local"}
663 <p>The field “mode” as a string value being either “local” or “remote”.</p>
665 <p><strong>output</strong>: The <em>runid</em> of the application launched.
666 The runid is an integer.</p>
670 <a name="Method.org.AGL.afm.user.terminate"></a>
671 <h4>Method org.AGL.afm.user.terminate</h4>
673 <p><strong>Description</strong>: Terminates the application of <em>runid</em>.</p>
675 <p><strong>Input</strong>: The <em>runid</em> (an integer) of the running instance to terminate.</p>
677 <p><strong>output</strong>: the value ‘true’.</p>
681 <a name="Method.org.AGL.afm.user.stop"></a>
682 <h4>Method org.AGL.afm.user.stop</h4>
684 <p><strong>Description</strong>: Stops the application of <em>runid</em> until terminate or continue.</p>
686 <p><strong>Input</strong>: The <em>runid</em> (an integer) of the running instance to stop.</p>
688 <p><strong>output</strong>: the value ‘true’.</p>
692 <a name="Method.org.AGL.afm.user.continue"></a>
693 <h4>Method org.AGL.afm.user.continue</h4>
695 <p><strong>Description</strong>: Continues the application of <em>runid</em> previously stopped.</p>
697 <p><strong>Input</strong>: The <em>runid</em> (an integer) of the running instance to continue.</p>
699 <p><strong>output</strong>: the value ‘true’.</p>
703 <a name="Method.org.AGL.afm.user.state"></a>
704 <h4>Method org.AGL.afm.user.state</h4>
706 <p><strong>Description</strong>: Get informations about a running instance of <em>runid</em>.</p>
708 <p><strong>Input</strong>: The <em>runid</em> (an integer) of the running instance inspected.</p>
710 <p><strong>output</strong>: An object describing the state of the instance. It contains:
711 the runid (an integer), the id of the running application (a string),
712 the state of the application (a string being either “starting”, “running”
713 or “stopped”).</p>
715 <p>Example of returned state:</p>
726 <a name="Method.org.AGL.afm.user.runners"></a>
727 <h4>Method org.AGL.afm.user.runners</h4>
729 <p><strong>Description</strong>: Get the list of the currently running instances.</p>
731 <p><strong>Input</strong>: anything.</p>
733 <p><strong>output</strong>: An array of states, one per running instance, as returned by
734 the methodd <strong><em>org.AGL.afm.user.state</em></strong>.</p>