abubelinha commented 3 years ago

Describe the issue you are having.

I try to use my phone to connect my office VPN, with openfortivpn (a Linux client for PPP+SSL VPN tunnel services)
This is what I have tried so far: I installed the software without problems. But looks like it depends on PPP daemon, which for some reason is not present in Debian or Ubuntu kernels available in UserLAnd. See full details here in this openfortivpn thread: https://github.com/adrienverge/openfortivpn/issues/825 There @DimitriPapadopoulos answered me: the Linux kernel on your Android phone does not support PPP. Since pppd requires PPP support in the kernel, pppd cannot run.

Describe how your task behaves in a regular Linux environment

In the aforementioned openfortivpn issue thread I replicated exactly the same steps in both a Ubuntu VM (Virtualbox) and in UserLAnd Debian session (Android 5, not rooted). The Ubuntu VM and the phone running UserLAnd are both in the same LAN, and they tried to connect to the same VPN.

Although openfortivpn version is different, looks like the origin of the connection error comes from differences in PPP availability in both kernels.

I gave another chance to UserLAnd, and repeated the same steps using an Ubuntu session, but the problem remains the same (openfortivpn blames the system for not having PPP kernel support):

I am an ignorant about how PPP works, but here are some tests I made following this PPP guide:

Ubuntu in VirtualBox machine:

me@ubuntu20-vm:~$  pppd --version
pppd version 2.4.7 
me@ubuntu20-vm:~$ dmesg | grep -i ppp
[    0.925027] PPP generic driver version 2.4.2

Ubuntu in UserLAnd:

me@UserLAnd-debian:~$  pppd --version
pppd version 2.4.7
me@UserLAnd-debian:~$ dmesg | grep -i ppp
dmesg: read kernel buffer failed: Permission denied
me@UserLAnd-debian:~$ pppd
Couldn't open the /dev/ppp device: Permission denied
/usr/sbin/pppd: Sorry - this system lacks PPP kernel support

Same results as above if all commands are run with sudo

I wonder if another Android version would make any differences, but I have no way to test this in another phone.

abubelinha commented 3 years ago

I can confirm the same problem happens to Arch Linux systems:

[me@UserLAn-Arch ~]$ sudo pacman -Sy ppp openfortivpn

[me@UserLAn-Arch ~]$ sudo pppd
Couldn't open the /dev/ppp device: Permission denied
pppd: Sorry - this system lacks PPP kernel support

Neustradamus commented 3 years ago

PPP 2.4.9: https://github.com/paulusmack/ppp

CypherpunkArmory / UserLAnd

Debian / Ubuntu system lacks PPP kernel support #1335

Describe the issue you are having.

Describe how your task behaves in a regular Linux environment