how to find which app is listening on port Android

Question

I'm trying to write a port scanner, I managed to get the open ports using sockets.
My problem is how to know which apps are listening on open ports.

Libyan

Are you writing an app? Should the app determine the ports of the device where it is running on or of other devices? – Polder

Answer 1

1. cat /proc/net/tcp

this will give you a list about the android opening ports.e.g.

  sl  local_address rem_address   st tx_queue rx_queue tr tm->when retrnsmt   uid  timeout inode                                                     
   0: 0100007F:13AD 00000000:0000 0A 00000000:00000000 00:00000000 00000000     0        0 3336108 1 0000000000000000 100 0 0 10 0                   
   1: 0100007F:1F90 00000000:0000 0A 00000000:00000000 00:00000000 00000000 10252        0 3579923 1 0000000000000000 100 0 0 10 0                   
   2: 6400A8C0:A90E 6800A8C0:1F90 04 00000001:00000000 00:00000000 00000005     0        0 0 1 0000000000000000 326 4 29 1 5                         
   3: 6400A8C0:A91E 6800A8C0:1F90 04 00000001:00000000 00:00000000 00000005     0        0 0 1 0000000000000000 326 4 29 1 5                         
   4: 6400A8C0:84F2 66DFC2DC:01BB 09 00000001:00000001 00:00000000 00000005     0        0 0 1 0000000000000000 665 4 24 1 5                         

so we know uid =10252 is the APP listening the port 1F90( which is 8080)

2. cat /data/system/packages.list | grep 10252 (the pid you found )

com.target.app 10252 0 /data/user/0/com.target.app default:targetSdkVersion=29 3002,3003 0 1

refer to : https://mcmap.net/q/1021225/-how-to-check-whether-a-service-in-running-on-particular-port-using-adb

Llewellyn

Answer 2

Android is based on a Linux kernel, therefore you can do this using the same approach that works under Linux. See https://mcmap.net/q/516117/-find-original-owning-process-of-a-linux-socket for a description of how to do that. Additionally you would need to determine from a Linux process what the app running in that process is (see Android - How to get the processName or packageName by using PID? for this). Note that your app would have to be running as root to access the files in /proc that it would need to in order to find this information.

Preform