| commit | 124a88288f50cdb0802c6747510d7c0a11a34306 | [log] [tgz] |
|---|---|---|
| author | LuK1337 <priv.luk@gmail.com> | Wed Sep 16 19:35:05 2020 +0200 |
| committer | Michael Bestas <mkbestas@lineageos.org> | Tue Aug 23 01:09:05 2022 +0300 |
| tree | 28df4a52951ccd067a6a1b13b9d0eab1f782b739 | |
| parent | 71002e98e2b0707dd52a58e0d8939cfcd32488cc [diff] |
Squashed import of adb root patches
Author: Luca Stefani <luca.stefani.ge1@gmail.com>
Date: Sat Nov 2 22:46:12 2019 +0100
Add adb_root daemon
Change-Id: I516f1b85e28f5d061c8c54282a7657d53162bccb
Author: Luca Stefani <luca.stefani.ge1@gmail.com>
Date: Sat Nov 2 23:54:43 2019 +0100
Add adb root hooks
Change-Id: I6b42ae84ab22ed4e86b92c3c1276a44a14d61781
Author: Luca Stefani <luca.stefani.ge1@gmail.com>
Date: Fri Nov 8 11:36:04 2019 +0100
Make adb use a custom prop for adb root
Change-Id: Ie2b8c5e9d75371da43305f003607869370bbd1a4
Author: dianlujitao <dianlujitao@lineageos.org>
Date: Sun Nov 17 23:21:36 2019 +0800
Create /data/adbroot on post-fs-data
* The real /data partition is not available before this stage.
Change-Id: I2cbcd788f35a2d51c823a71e2c944502812c1cfd
Author: dianlujitao <dianlujitao@lineageos.org>
Date: Sat Nov 23 20:55:42 2019 +0800
adbd: Initialize adbroot status to false
Change-Id: I6d5dc84974dff1a219702fb628e08517848977eb
Author: dianlujitao <dianlujitao@lineageos.org>
Date: Sat Nov 23 20:58:31 2019 +0800
adbd: Make adbroot interface a static lib
Change-Id: I40e46b8312ec77992fc1c11d2190b611bfd049cb
Author: dianlujitao <dianlujitao@lineageos.org>
Date: Sun Nov 24 16:24:27 2019 +0800
adb_root: Enforce caller UID
* AID_SYSTEM - Settings app
* AID_SHELL - adbd
* Apply minor clean up while at it
Change-Id: I15a5d18204a96cc2f8352a6cc7f6f901193aa5b9
Author: dianlujitao <dianlujitao@lineageos.org>
Date: Sun Nov 24 16:39:11 2019 +0800
adb_root: Add mutex to binder interface
* Binder IPC is not implemented in a thread-safe manner, add mutex to
avoid possible race.
Change-Id: I37cdca33d519b0fc960960272790d1f55874e2e2
Author: dianlujitao <dianlujitao@lineageos.org>
Date: Sun Nov 24 17:01:49 2019 +0800
adb_root: Restart adbd when turning off root
* The running adbd session remains rooted after turning off from UI.
Change-Id: Iedd5282b4e3c11ef6c0959ae6867448521cb2c78
Author: Alessandro Astone <ales.astone@gmail.com>
Date: Fri Mar 20 19:47:03 2020 +0100
adb: go back to standard adb root prop
* This reverts change Ie2b8c5e9d75371da43305f003607869370bbd1a4
plus more changes
Change-Id: Ia17239e3671d2c1a92664810ed53175110699473
Author: Alessandro Astone <ales.astone@gmail.com>
Date: Thu Jan 6 22:07:54 2022 +0100
adb_root: Move to system_ext
Change-Id: If9840afe40d19b785080681dc92527330fca595a
Author: LuK1337 <priv.luk@gmail.com>
Date: Thu Mar 24 09:05:17 2022 +0100
adb_root: Add isSupported() method to determine if we are debuggable
This allows us to show the preference in Settings even if
Build.IS_DEBUGGABLE is false.
Change-Id: If94294f980ccdc10f2473b6f1a858e36547fc258
[LuK1337]: Rework for Android 11.
Change-Id: Ie8db34705d36f3e9f2c53617ec59a26087cbcc87
Signed-off-by: Francescodario Cuzzocrea <bosconovic@gmail.com>
If you are new to adb source code, you should start by reading OVERVIEW.TXT which describes the three components of adb pipeline.
This document is here to boost what can be achieved within a "window of naive interest". You will not find function or class documentation here but rather the "big picture" which should allow you to build a mental map to help navigate the code.
As outlined in the overview, this codebase generates three components (Client, Server (a.k.a Host), and Daemon (a.k.a adbd)). The central part is the Server which runs on the Host computer. On one side the Server exposes a "Smart Socket" to Clients such as adb or DDMLIB. On the other side, the Server continuously monitors for connecting Daemons (as USB devices or TCP emulator). Communication with a device is done with a Transport.
+----------+ +------------------------+
| ADB +----------+ | ADB SERVER | +----------+
| CLIENT | | | | (USB)| ADBD |
+----------+ | | Transport+-------------+ (DEVICE) |
| | | +----------+
+----------- | | |
| ADB | v + | +----------+
| CLIENT +--------->SmartSocket | (USB)| ADBD |
+----------+ ^ | (TCP/IP) Transport+-------------+ (DEVICE) |
| | | +----------+
+----------+ | | |
| DDMLIB | | | Transport+--+ +----------+
| CLIENT +----------+ | | | (TCP/IP)| ADBD |
+----------+ +------------------------+ +----------|(EMULATOR)|
+----------+
The Client and the Server are contained in the same executable and both run on the Host machine. Code sections specific to the Host is enclosed within ADB_HOST guard. adbd runs on the Android Device. Daemon specific code is enclosed in !ADB_HOST but also sometimes with-in __ANDROID__ guard.
A smart socket is a simple TCP socket with a smart protocol built on top of it. This is what Clients connect onto from the Host side. The Client must always initiate communication via a human readable request but the response format varies. The smart protocol is documented in SERVICES.TXT.
On the other side, the Server communicates with a device via a Transport. adb initially targeted devices connecting over USB, which is restricted to a fixed number of data streams. Therefore, adb multiplexes multiple byte streams over a single pipe via Transport. When devices connecting over other mechanisms (e.g. emulators over TCP) were introduced, the existing transport protocol was maintained.
At the heart of both the Server and Daemon is a main thread running an fdevent loop, which is a platform-independent abstraction over poll/epoll/WSAPoll monitoring file descriptors events. Requests and services are usually served from the main thread but some service requests result in new threads being spawned.
To allow for operations to run on the Main thread, fdevent features a RunQueue combined with an interrupt fd to force polling to return.
+------------+ +-------------------------^ | RUNQUEUE | | | +------------+ | POLLING (Main thread) | | Function<> | | | +------------+ | | | Function<> | ^-^-------^-------^------^^ +------------+ | | | | | ... | | | | | +------------+ | | | | | | | | | | |============| | | | | |Interrupt fd+------+ +----+ +----+ +----+ +------------+ fd Socket Pipe
The asocket, apacket, and amessage constructs exist only to wrap data while it transits on a Transport. An asocket handles a stream of apackets. An apacket consists in a amessage header featuring a command (A_SYNC, A_OPEN, A_CLSE, A_WRTE, A_OKAY, ...) followed by a payload (find more documentation in protocol.txt. There is no A_READ command because an asocket is unidirectional. To model a bi-directional stream, asocket have a peer which go in the opposite direction.
An asocket features a buffer where the elemental unit is an apacket. If traffic is inbound, the buffer stores the apacket until it is consumed. If the traffic is oubound, the buffer stores apackets until they are sent down the wire (with A_WRTE commands).
+---------------------ASocket------------------------+ | | | +----------------APacket Queue------------------+ | | | | | | | APacket APacket APacket | | | | +--------+ +--------+ +--------+ | | | | |AMessage| |AMessage| |AMessage| | | | | +--------+ +--------+ +--------+ | | | | | | | | | | | | | | ..... | | | | | | | | | | | Data | | Data | | Data | | | | | | | | | | | | | | | | | | | | | | | | | +--------+ +--------+ +--------+ | | | | | | | +-----------------------------------------------+ | +---------------------------------------------------+
This system allows to multiplex data streams on an unique byte stream. Without entering too much into details, the amessage fields arg1 and arg2 are used alike in the TCP protocol where local and remote ports identify an unique stream. Note that unlike TCP which feature an "unacknowledged-send window", an apacket is sent only after the previous one has been confirmed to be received.
The two types of asocket (Remote and Local) differentiate between outbound and inbound traffic.
This pipeline is detailed in daemon/jdwp_service.cpp with ASCII drawings! The JDWP extension implemented by Dalvik/ART are documented in: