Commit Graph

28 Commits

Author SHA1 Message Date
topjohnwu
1e2f776b83 Move logging.hpp 2020-06-17 01:17:28 -07:00
topjohnwu
ec3705f2ed Redesign of MagiskSU's sepolicy model
Introduce new domain `magisk_client` and new file type `magisk_exec`.

Connection to magiskd's always-on socket is restricted to magisk_client
only. Whitelisted process domains can transit to magisk_client through
executing files labelled magisk_exec. The main magisk binary shall be
the only file labelled as magisk_exec throughout the whole system.
All processes thus are no longer allowed to connect to magiskd directly
without going through the proper magisk binary.

Connection failures are silenced from audit logs with dontaudit rules,
so crazy processes which traverse through all unix domain sockets to try
connection can no longer check logcat to know the actual reason behind
EACCES, leaking the denied process policy (which is u:r:magisk:s0).

This also allows us to remove many rules that open up holes in
untrusted_app domains that were used to make remote shell work properly.
Since all processes establishing the remote shell are now restricted to
the magisk_client domain, all these rules are moved to magisk_client.
This makes Magisk require fewer compromises in Android's security model.

Note: as of this commit, requesting new root access via Magisk Manager
will stop working as Magisk Manager can no longer communicate with
magiskd directly. This will be addressed in a future commit that
involves changes in both native and application side.
2020-06-03 23:29:42 -07:00
topjohnwu
a0998009c1 Small native code reorganization 2020-03-09 01:50:30 -07:00
topjohnwu
0f74e89b44 Introduce component agnostic communication
Usually, the communication between native and the app is done via
sending intents to either broadcast or activity. These communication
channels are for launching root requests dialogs, sending root request
notifications (the toast you see when an app gained root access), and
root request logging.

Sending intents by am (activity manager) usually requires specifying
the component name in the format of <pkg>/<class name>. This means parts
of Magisk Manager cannot be randomized or else the native daemon is
unable to know where to send data to the app.

On modern Android (not sure which API is it introduced), it is possible
to send broadcasts to a package, not a specific component. Which
component will receive the intent depends on the intent filter declared
in AndroidManifest.xml. Since we already have a mechanism in native code
to keep track of the package name of Magisk Manager, this makes it
perfect to pass intents to Magisk Manager that have components being
randomly obfuscated (stub APKs).

There are a few caveats though. Although this broadcasting method works
perfectly fine on AOSP and most systems, there are OEMs out there
shipping ROMs blocking broadcasts unexpectedly. In order to make sure
Magisk works in all kinds of scenarios, we run actual tests every boot
to determine which communication method should be used.

We have 3 methods in total, ordered in preference:
1. Broadcasting to a package
2. Broadcasting to a specific component
3. Starting a specific activity component

Method 3 will always work on any device, but the downside is anytime
a communication happens, Magisk Manager will steal foreground focus
regardless of whether UI is drawn. Method 1 is the only way to support
obfuscated stub APKs. The communication test will test method 1 and 2,
and if Magisk Manager is able to receive the messages, it will then
update the daemon configuration to use whichever is preferable. If none
of the broadcasts can be delivered, then the fallback method 3 will be
used.
2019-10-21 13:59:04 -04:00
topjohnwu
b763b81f56 Use mutex_guard to lock su_info 2019-09-26 01:49:50 -04:00
topjohnwu
947dae4900 Rename classes and small adjustments 2019-09-25 23:55:39 -04:00
topjohnwu
ef1b928532 LD_LIBRARY_PATH patch for apex should not propagate
Fix #1832
2019-09-13 15:22:49 -04:00
topjohnwu
6e46d394b1 Fix su_info cache yet again... 2019-09-13 14:05:28 -04:00
topjohnwu
cdb53ca049 Fix su_info cache bug 2019-09-04 11:04:59 -04:00
topjohnwu
51ff724691 Unblock all signals in root shell process
Fix #1563
2019-07-07 12:30:57 -07:00
topjohnwu
291bf93f9d Proper timing 2019-07-07 12:20:47 -07:00
topjohnwu
5fcd629f16 Rearrange su daemon routine 2019-07-07 12:20:19 -07:00
topjohnwu
ab90901793 Use C++ smart pointer for caching su_info 2019-07-07 00:31:49 -07:00
topjohnwu
ff3710de66 Minor code changes across all sources 2019-06-30 19:09:31 -07:00
topjohnwu
9f8d4e1022 Properly isolate mount namespace 2019-06-04 21:21:27 -07:00
topjohnwu
80cd85b061 Try to use broadcast for su logging and notify
In commit 8d4c407, native Magisk always launches an activity for
communicating with Magisk Manager. While this works extremely well,
since it also workaround stupid OEMs that blocks broadcasts, it has a
problem: launching an activity will claim the focus of the device,
which could be super annoying in some circumstances.

This commit adds a new feature to run a broadcast test on boot complete.
If Magisk Manager successfully receives the broadcast, it will toggle
a setting in magiskd so all future su loggings and notifies will always
use broadcasts instead of launching activities.

Fix #1412
2019-05-13 02:01:10 -07:00
topjohnwu
00a9f18a1e Build with -Wall 2019-04-29 21:26:43 -04:00
topjohnwu
370015a853 Modernize database code (again) 2019-03-06 08:16:12 -05:00
topjohnwu
71ecbb3af3 Clean/refactor includes 2019-02-10 03:57:51 -05:00
vvb2060
2cf33d635d Setuid after read proc 2019-02-01 15:55:29 -05:00
topjohnwu
523e66294b Simpler su_info caching system 2018-12-26 11:56:49 +08:00
topjohnwu
762b678d24 Prevent any SELinux issues of root shell streams 2018-11-23 21:08:06 -05:00
topjohnwu
2ab999f4ca Fix bug in DB query wrapper 2018-11-20 02:20:49 -05:00
topjohnwu
c9f390d6e0 Abort upon any error occurred 2018-11-20 02:20:49 -05:00
topjohnwu
ab5fedda0b Prevent Magisk database race condition
The database should only be accessed by a single process, which is magiskd.
This means 'magisk --sqlite [SQL]' has to be updated to pass the SQL command to the daemon.
In addition, open the database connection with SQLITE_OPEN_FULLMUTEX to support multithread in magiskd.
2018-11-16 03:20:30 -05:00
topjohnwu
c61c3ae0e9 Fix su shell environment setup 2018-11-10 02:17:13 -05:00
topjohnwu
0742901cd2 Modernize database code 2018-11-04 18:24:08 -05:00
topjohnwu
cda57dd4b4 Fully migrate Magisk to C++ 2018-11-04 04:15:51 -05:00