Support any number of overlay packages. Support any target package.
UPDATED PACKAGE MATCHING
------------------------
In Runtime resource overlay, iteration 1, only a single overlay package
was considered. Package matching was based on file paths:
/vendor/overlay/system/framework-res.apk corresponded to
/system/framework-res.apk. Introduce a more flexible matching scheme
where any package is an overlay package if its manifest includes
<overlay targetPackage="com.target.package"/>
For security reasons, an overlay package must fulfill certain criteria
to take effect: see below.
THE IDMAP TOOL AND IDMAP FILES
------------------------------
Idmap files are created by the 'idmap' binary; idmap files must be
present when loading packages. For the Android system, Zygote calls
'idmap' as part of the resource pre-loading. For application packages,
'idmap' is invoked via 'installd' during package installation (similar
to 'dexopt').
UPDATED FLOW
------------
The following is an outline of the start-up sequences for the Android
system and Android apps. Steps marked with '+' are introduced by this
commit.
Zygote initialization
Initial AssetManager object created
+ idmap --scan creates idmaps for overlays targeting 'android', \
stores list of overlays in /data/resource-cache/overlays.list
AssetManager caches framework-res.apk
+ AssetManager caches overlay packages listed in overlays.list
Android boot
New AssetManager's ResTable acquired
AssetManager re-uses cached framework-res.apk
+ AssetManager re-uses cached 'android' overlays (if any)
App boot
ActivityThread prepares AssetManager to load app.apk
+ ActivityThread prepares AssetManager to load app overlays (if any)
New AssetManager's ResTable acquired as per Android boot
SECURITY
--------
Overlay packages are required to be pre-loaded (in /vendor/overlay).
These packages are trusted by definition. A future iteration of runtime
resource overlay may add support for downloaded overlays, which would
likely require target and overlay signatures match for the overlay to
be trusted.
LOOKUP PRIORITY
---------------
During resource lookup, packages are sequentially queried to provide a
best match, given the constraints of the current configuration. If any
package provide a better match than what has been found so far, it
replaces the previous match. The target package is always queried last.
When loading a package with more than one overlay, the order in which
the overlays are added become significant if several packages overlay
the same resource.
Had downloaded overlays been supported, the install time could have been
used to determine the load order. Regardless, for pre-installed
overlays, the install time is randomly determined by the order in which
the Package Manager locates the packages during initial boot. To support
a well-defined order, pre-installed overlay packages are expected to
define an additional 'priority' attribute in their <overlay> tags:
<overlay targetPackage="com.target.package" priority="1234"/>
Pre-installed overlays are loaded in order of their priority attributes,
sorted in ascending order.
Assigning the same priority to several overlays targeting the same base
package leads to undefined behaviour. It is the responsibility of the
vendor to avoid this.
The following example shows the ResTable and PackageGroups after loading
an application and two overlays. The resource lookup framework will
query the packages in the order C, B, A.
+------+------+- -+------+------+
| 0x01 | | ... | | 0x7f |
+------+------+- -+------+------+
| |
"android" Target package A
|
Pre-installed overlay B (priority 1)
|
Pre-installed overlay C (priority 2)
Change-Id: If49c963149369b1957f7d2303b3dd27f669ed24e
Add seinfo paramater to appropriate make directory
functions. This allows proper labeling for multi-user
scenarios.
Change-Id: Iaba7c40645bc7b6cc823d613da0c3782acf6ddd5
Signed-off-by: rpcraig <rpcraig@tycho.ncsc.mil>
Restarting installd upon policy reloads has reportedly caused
stability problems for some users. Stop restarting installd
and instead handle policy reloads within it.
Change-Id: I697a736d8e414cfc6cfa131ed7b97c7f7694d022
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
...app storage size for apps w/ .so files
The lib directories are tagged with the apk install number,
so must be explicitly passed down to installd.
Change-Id: Iae8815afd6ba964f5b2ed86a0d04a91827391ed6
This patch set allows the PMS to parse the
mac_permissions.xml file which contains the
seinfo values. Each package that is installed
on the device will be assigned an seinfo value
based on policy. This seinfo value will help label
the app process and data directory. Modifications
include adjustments to ApplicationInfo.java
to store the seinfo tag per package as well as
adjustments to installd to communicate the seinfo
tag to libselinux.
Change-Id: I61ad1ea12fb6a9a6d0b108ec163bc4bf4c954b58
Signed-off-by: rpcraig <rpcraig@tycho.ncsc.mil>
Have installd set an app's home directory permissions to
0700 if the app has targetSdkVersion > 17.
Bug: 7208882
Change-Id: Iaa4fc42fec69bc1abdfae53704d6264dd6fa965f
setfilecon is not required on libsymlinks when target
doesn't exist. A bootloop is caused without this
change.
Change-Id: Ia895d9063f42885a3db6e8ca30cee5dceb8c1bac
Signed-off-by: rpcraig <rpcraig@tycho.ncsc.mil>
