utelnetd - yet another remote shell application

[rkomar]

It bothers me that I can't get a nice shell using ssh anymore under the newest firmware versions. So I looked around, and found that @reader42 already ported the utelnetd telnet server to PocketBook devices. Very nice! Using his source code, I packaged up versions for the older 3XX and the newer Pro/360+ devices. I've also included a copy of bash in each package. Pick the right zip file for your device, and unzip the contents in /mnt/ext1/.

Instead of using the Inkview application that @reader42 provided for controlling the daemon, I used a couple of shell scripts instead (utelnetd_start.app and utelnetd_stop.app). I did this because they are smaller, platform-independent, and, most importantly, run in the background. Thus, you can do other stuff on the device while logged in via telnet (which makes it nice for debugging).

Within the Applications tab, click on utelnetd_start to start the server in the background and connect to the net, and click on utelnetd_stop to disconnect from the net and kill the server. While the server is running, you can telnet to the device via port 10000:

telnet <IP-address> 10000

You get a prompt, command history and editting, and even vi behaves nicely.

You can change the port number by editting the applications/utelnetd_start.app script. If you want to put bash somewhere else than /mnt/ext1/system/bin, then you need to rebuild utelnetd for that. Get the sources from: http://sourceforge.net/apps/mediawik...for_PocketBook. I've also uploaded the updated Makefile I used to build utelnetd. You need to change the Makefile if you want to put bash somewhere other than /mnt/ext1/system/bin/.

Thanks @reader42

Edit: I should point out that when you exit the telnet session on the PC, the terminal seems to hang until the server is killed on the device. I don't know how to fix that, so please pipe up anyone that does.

Edit1: Added /mnt/ext1/system/bin automatically to the PATH for the shell.

Edit2: Added pop up dialog that states what IP address and port it is listening to. You have to install sh_ivtool.app (found in the Developer section) and uncomment the line in applications/utelnetd_start.app that starts with "#SH_IVTOOLS=" to see the dialog.

[readMax]

Thank you very much you guys (reader42, rkomar) - it works great!

If I had the find command available for my Pro612 now too, it would be totally awesome.

Greetings
Max

[rkomar]

Actually, most of the utility programs in the Debian Lenny armel distribution are compatible with the recent PocketBook devices. You can pretty much copy them to the device and use them in the terminal. Some of the more complex programs may not have all of the libraries available on the device, but even in those cases you can copy the libraries over and play with LD_LIBRARY_PATH to run them. I know that find works, because that was one of the first programs I copied over myself.

[readMax]

You are absolutely right - thanks again
You just made my day.

[rkomar]

I updated the utelnetd daemon to automatically add "/mnt/ext1/system/bin" to the PATH environmental variable.

[rkomar]

I added a pop-up dialog that states what the IP address and port are that the daemon is listening to. For this to work, you have to install the sh_ivtool.app program to /mnt/ext1/system/bin, and uncomment the line in the applications/utelnetd_start.app script that starts with "#SH_IVTOOL=...". (uncommenting means removing the "#" character at the start of the line). The sh_ivtool program is available in a thread in the Developers section.

[biokomiker]

Hi,

will utelnetd work on Pocketbook 626 or does it neet recompiling?

[rkomar]

I think it should work. I use it on my Inkpad with the 5.4 firmware.

[biokomiker]

YES, it works. Thanks. Sometimes very responsive, sometimes not (in the same session)- any clues?

[rkomar]

I've noticed that on my Inkpad with the 5.4 firmware. The devices with the version 2 or 4 firmwares don't show such pauses. I think parts of the device go to sleep, and it takes a few moments to wake back up again. I don't think it has anything to do with the utelnetd program itself, so there's nothing much I can do to fix it.

[EastEriq]

Reporting that the -Pro version (+sh_ivtool) works on my HD Touch, except for a typo: a missing ` at the end of line 25 of utelnetd_start.app, which should read

  IP=`ifconfig eth0 | grep "inet addr" | cut -d ':' -f 2 | cut -d ' ' -f 1`

[rkomar]

You're right. Thanks. I'm surprised it worked before. Perhaps the shell on the older devices is more lenient.

Edit: No, it didn't work on the old devices either. I probably cut and paste those commands from the working sshd script and missed the trailing backtick. I guess nobody used that part of the script (including me).

[rkomar]

I updated the zip files in the first post with the fix for the missing backtick bug. There is no need to update devices unless you want to use the pop-up dialog to show the IP address of the device.

[robberknight]

Hi,

I just tried your utelnetd-Pro.zip on an Inkpad 3 (PB740), Firmware U740.5.17.1392.

It works out of the box. Thank you!

Login just seems to be to user "reader". Do you know an easy way to get root? Or do I need to cook up some exploit or open the device to access the flash ic or serial interface?

[rkomar]

Originally Posted by robberknight

Login just seems to be to user "reader". Do you know an easy way to get root? Or do I need to cook up some exploit or open the device to access the flash ic or serial interface?

I don't think there is any crack to get root on these devices. The best place to look is in the Russian forums for up-to-date information.

To be honest, you can do a lot without needing root, so I don't think there is a much incentive to try to find a crack.