--- /dev/null
+---
+edit_link: ''
+title: Permissions
+origin_url: >-
+ https://git.automotivelinux.org/src/app-framework-main/plain/docs/3-permissions.md?h=master
+---
+
+<!-- WARNING: This file is generated by fetch_docs.js using /home/boron/Documents/AGL/docs-webtemplate/site/_data/tocs/apis_services/master/app-framework-main-developer-guides-api-services-book.yml -->
+
+# The permissions
+
+## Permission's names
+
+The proposal here is to specify a naming scheme for permissions
+that allows the system to be as stateless as possible.
+The current specification includes in the naming of permissions either
+the name of the bound binding when existing and the level of the
+permission itself.
+Doing this, there is no real need for the
+framework to keep installed permissions in a database.
+
+The permission names are [URN][URN] of the form:
+
+```bash
+ urn:AGL:permission:<api>:<level>:<hierarchical-name>
+```
+
+where "AGL" is the NID (the namespace identifier) dedicated to AGL.
+(note: a RFC should be produced to standardize this name space)
+
+The permission names are made of NSS (the namespace specific string)
+starting with "permission:" and followed by colon separated
+fields.
+The 2 first fields are `<api>` and `<level>` and the remaining
+fields are grouped to form the `<hierarchical-name>`.
+
+```bash
+ <api> ::= [ <pname> ]
+
+ <pname> ::= 1*<pchars>
+
+ <pchars> ::= <upper> | <lower> | <number> | <extra>
+
+ <extra> ::= "-" | "." | "_" | "@"
+```
+
+The field `<api>` can be made of any valid character for NSS except
+the characters colon and star (:*).
+This field designates the api providing the permission.
+This scheme is used to deduce binding requirements
+from permission requirements.
+The field `<api>` can be the empty string when the permission
+is defined by the AGL system itself.
+
+[PROPOSAL 1] The field `<api>` if starting with the character "@" represents
+a transversal/cross permission not bound to any binding.
+
+[PROPOSAL 2]The field `<api>` if starting with the 2 characters "@@"
+in addition to a permission not bound to any binding, represents a
+permission that must be set at installation and that can not be
+revoked later.
+
+ <level> ::= 1*<lower>
+
+The field `<level>` is made only of letters in lower case.
+The field `<level>` can only take some predefined values:
+
+- system
+- platform
+- partner
+- tiers
+- owner
+- public
+
+The field `<hierarchical-name>` is made of `<pname>` separated
+by colons.
+
+ <hierarchical-name> ::= <pname> 0*(":" <pname>)
+
+The names at left are hierarchically grouping the
+names at right.
+This hierarchical behaviour is intended to
+be used to request permissions using hierarchical grouping.
+
+## Permission value
+
+In some case, it could be worth to add a value to a permission.
+
+Currently, the framework allows it for permissions linked to
+systemd.
+But this not currently used.
+
+Conversely, permissions linked to cynara can't carry data
+except in their name.
+
+Thus to have a simple and cleaner model, it is better to forbid
+attachment of value to permission.
+
+## Example of permissions
+
+Here is a list of some possible permissions.
+These permissions are available the 21th of May 2019.
+
+- urn:AGL:permission::platform:no-oom
+ Set OOMScoreAdjust=-500 to keep the out-of-memory
+ killer away.
+- urn:AGL:permission::partner:real-time
+ Set IOSchedulingClass=realtime to give to the process
+ realtime scheduling.
+ Conversely, not having this permission set RestrictRealtime=on
+ to forbid realtime features.
+- urn:AGL:permission::public:display
+ Adds the group "display" to the list of supplementary groups
+ of the process.
+- urn:AGL:permission::public:syscall:clock
+ Without this permission SystemCallFilter=~@clock is set to
+ forfid call to clock.
+- urn:AGL:permission::public:no-htdocs
+ The http directory served is not "htdocs" but "."
+- urn:AGL:permission::public:applications:read
+ Allows to read data of installed applications (and to
+ access icons).
+- urn:AGL:permission::partner:service:no-ws
+ Forbids services to provide its API through websocket.
+- urn:AGL:permission::partner:service:no-dbus
+ Forbids services to provide its API through D-Bus.
+- urn:AGL:permission::system:run-by-default
+ Starts automatically the application. Example: home-screen.
+- urn:AGL:permission::partner:scope-platform
+ Install the service at the scope of the platform.
+- urn:AGL:permission::system:capability:keep-all
+ Keep all capabilities for the service. Note that implementing
+ that permission is not mandatory or can be adapted for the given
+ system.
+- <http://tizen.org/privilege/internal/dbus>
+ Permission to use D-Bus.
+
+[URN]: https://tools.ietf.org/rfc/rfc2141.txt "RFC 2141: URN Syntax"
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