https://contact.alessandrosangiorgi.net/tags/jni/Recent content in Jni on Alessandro Sangiorgi — GPU Performance EngineerHugoenWed, 08 Apr 2026 00:00:00 +0000https://contact.alessandrosangiorgi.net/posts/ip-neigh-android-sdk30-netlink-workaround/Wed, 08 Apr 2026 00:00:00 +0000https://contact.alessandrosangiorgi.net/posts/ip-neigh-android-sdk30-netlink-workaround/<p>Starting with Android 11 (API level 30), Google removed the ability for apps to run <code>ip neigh</code> or bind netlink sockets. This broke every app that relied on reading the ARP table — network scanners, device discovery tools, local network diagnostics. The change was intentional: Google argued that exposing the neighbor table leaks information about other devices on the local network, which is a privacy concern.</p> <p>The problem is that there was no replacement API. Apps that needed neighbor discovery — for example, to find smart home devices, printers, or other hosts on the LAN — were simply out of luck. So I wrote a native library that retrieves the ARP table via RTNetlink without binding the socket, shipped it as an Android library, and <a href="https://github.com/fulvius31/ip-neigh-sdk30">open-sourced it</a>.</p>