This repo contains a utility to forward the rild socket connection out to non radio account owned processes. It creates a socket on the device under /dev/socket/rilproxy. This socket can also be forwarded via adb, e.g.:

adb forward localfilesystem:/tmp/rilproxy localfilesystem:/dev/socket/rilproxy

The Makefile gives a few hints on the usage. In order to build and run it you need a full Android Open Source Project (AOSP) checkout and the Native Development Kit (NDK) installed. Then set the environment variables AOSP_ROOT and NDK_ROOT accordingly. You can e.g. build and run the rilproxy via:

AOSP_ROOT=/home/username/src/android/aosp NDK_ROOT=/home/username/src/android/android-ndk-r14b make

If it doesn't start up some other process (probably com.android.phone might access the /dev/socket/rild. To prevent that you can make it point somewhere else. Edit from AOSP the frameworks/opt/telephony/src/java/com/android/internal/telephony/RIL.java and change the value(s) of the SOCKET_NAME_RIL constant to something else.

The doc directory contains some information that is outdated, but it still contains some valuable bits, hence it wasn't removed.