binder-trace

Binder Trace

Binder Trace is a tool for intercepting and parsing Android Binder messages. Think of it as "Wireshark for Binder".

Requirements

python version >= 3.9

⚙️ Installation

You'll need a rooted Android device or emulator.

• (Linux only) - install xclip or xsel for "copy to clipboard" functionality

  sudo apt-get install xclip

  sudo apt-get install xsel

• Install from PyPi

  pip install binder-trace

• Check which version of frida is installed (make sure you've pip installed the requirements)

  pip list | grep frida

• Download the matching version of frida-server from the frida releases page

• Make sure adb is running as root, push frida-server to your device and run it

  adb root

  adb push frida-server /data/local/tmp

  adb shell

  chmod u+x /data/local/tmp/frida-server

  /data/local/tmp/frida-server

Arguments

Argument	Description
-h	Prints the argument help.
-d DEVICE	The device to attach to e.g. "emulator-5554". Use adb devices to list available devices. If not provided defaults to the USB device.
-p PID	The pid of the process on DEVICE to attach to.
-n NAME	The name of the process on DEVICE to attach to e.g. "Messaging".
-a [9, 10, 11, 12, 13, 14]	The target device android version. If no struct path is supplied, default structs are used.
-s STRUCTPATH	The path to the directory of structure files.
-c CONFIG	The path to the config file to filter.
--spawn	Spawn process before attaching. -n option must be present and contain a valid process identifier.

▶️ Starting binder trace

To start binder trace we need to pick a device and process to attach to. In the following example we use adb and frida-ps to identify a process to attach to on a local emulator. As it's an Android 11 emulator we choose the Android 11 structs directory. Pick the struct directory that most closely matches your version of Android. If you would like structures for a different version of Android, please let us know. Once it's running start using the target app to generate some binder transactions.

> adb devices
List of devices attached
emulator-5554   device

> frida-ps -Ua
 PID  Name           Identifier
----  -------------  ----------------------------
8334  Messaging      com.android.messaging
7941  Phone          com.android.dialer
9607  Settings       com.android.settings

> cd binder_trace
> binder-trace -d emulator-5554 -n Messaging -a 11

⌨️ Controls

Global

Key	Action
up	Move up
down	Move down
shift + up	Page up
shift + down	Page down
home	Go to top
end	Go to bottom
tab	Next pane
shift + tab	Previous pane
ctrl + c	Copy pane to clipboard
space	Pause/Unpause transaction recording
c	Clear
h	Open help
r	Reload config file
q	Quit

Frequency pane

Key	Action
p	Toggle order asc/desc
w	Jump to next interface
s	Jump to previous interface
a	Toggle all filters on
n	Toggle all filters off
enter	Toggle Filter

Config File

To filter define any or all of the interface, method, type and inclusive options. To not use an option leave it blank ""

Without -c argument

> binder-trace -d emulator-5554 -n Contacts -a 13

With -c argument

config.json

{
    "filters": [
        {
            "interface": "android.gui.IDisplayEventConnection",
            "method": "requestNextVsync",
            "type": "",
            "inclusive": false
        },
        {
            "interface": "android.content.IContentProvider",
            "method": "",
            "type": "call",
            "inclusive": false
        }
    ]
}

> binder-trace -d emulator-5554 -n Contacts -a 13 -c .\binder_trace\binder_trace\config.json

android.gui.IDisplayEventConnection->requestNextVsync->"" and android.content.IContentProvider->"" ->call have been filtered out

Structure Compatibility

Internal binder interfaces can change around between minor versions, and since it's effectively all compiled together with no runtime version information it's hard to provide 100% accurate structure information for every release across Android's highly fragmented ecosystem.

More details on structures can be found in the structures page