No mod yet, but lost telnet

[b-fitzpatrick]

I know this isn't related to this project, but I'm hoping someone here may have some insight. I will probably end up installing this mod, but I first wanted to see if I could get by with just some minor tweaks using root access. I started down that path using the process here: Root access However, after the first step, I could not telnet into the printer. I get "Connection refused". I can ping it.

Some things that may or may not be related:

• I updated to 2.6.5 OTA when I first got it.
• I was able to connect via telnet at some point. I made a couple stupid password attempts and moved on.
• I downgraded to 2.4.5 as part of the root process. I thought a full firmware "flash" was required to run the script, and 2.6.5 isn't available for download. I've since learned that I can just run whatever I want in the script.
• During the first step of the root process, I included the 'adduser "$USERNAME" sudo' that's shown in the screenshot. I don't think this did anything, as there's no 'sudo' group.
• I enabled the new "LAN mode" in 2.6.5. I think it was enabled when I downgraded to 2.4.5. I reinstalled 2.6.5 to disable it in case it's somehow related.
• There are what appear to be backups of /etc/passwd, /etc/group, and /etc/shadow. They don't have the user that I added in the first step of attempting root access. They have a dash appended to the filename. I found these by copying /etc/* to the USB drive.

Any ideas to restore telnet access?

[consp]

I enabled the new "LAN mode" in 2.6.5. I think it was enabled when I downgraded to 2.4.5.

Looking at the scripts for the OTA update, I'm pretty sure they are persistent after downgrade. There are some network changes in there, haven't looked too much into them to check if they alter telnet or eth0

I could not telnet into the printer. I get "Connection refused". I can ping it.
Any ideas to restore telnet access?

What does nmap -sT -T4 [printer ip] say?

Easiest would be to install the mod, ssh to the machine, goto /mnt/orig_mnt/ (dir name might be a bit different but you get the gist, it's the original filesystem). Goto /mnt/orig_mnt/etc and check if telnet is still available in init.d and enabled or check the /mnt/orig_mnt/var/log dir for errors. Might also want to do mount -o remount,rw /mnt/orig_mnt to get write access if needed.

YMMV applies when messing with the original filesystem, especially in write mode.

[consp]

I've attempted to downgrade back to 2.4.5 to install the mod, but it's not working.

I think it would be easier to change the install script of the mod (device_files/flashforge_init.sh) and remove the following lines:

    FF_VERSION="$(cat /root/version)"
    if [ "$FF_VERSION" != "2.4.5" ]
    then
        echo "Printer software version not supported."
        xzcat $WORK_DIR/img/install_fail_vers.img.xz > /dev/fb0
        exit 0
    fi

And replace the one in the mod tarball (or edit that one specifically). Note: the tgz files are not gzipped despite their name.
Easiest would be to just copy all contents to a usb drive (extract), you do not need the tarball at all. That way you also ignore the autorun.sh. I'm pretty sure the original flashforge_init.sh will also check for one single version so "downgrade" is not really a thing that way (have not confirmed!).

Note: while not recommended yet (simply because it's in testing), I've had no problems so far installing the mod on 2.6.5 since no system files have changed so altering the flashforge_init.sh script should be fine.

Do make sure you do not do rm -rf / or something similar in the flashforge_init.sh script ;)

[b-fitzpatrick]

I deleted a comment about the root partition being full. Turns out that was my mistake. Once when I was dumping files to the USB drive to poke around, I forgot "$WORK_DIR", so it was copying files to a folder in the root partition.

[consp]

Once when I was dumping files to the USB drive to poke around, I forgot "$WORK_DIR", so it was copying files to a folder in the root partition.

Would have been surprized. Afaik it's a 8GB eMMC chip so there should be plenty of space.

[b-fitzpatrick]

The root partition is limited to 1.2G:

Filesystem                Size      Used Available Use% Mounted on
/dev/root                 1.2G    760.3M    463.6M  62% /
tmpfs                    53.9M     28.0K     53.9M   0% /tmp
tmpfs                    53.9M     28.0K     53.9M   0% /run
devtmpfs                 44.7M         0     44.7M   0% /dev
/dev/mmcblk0p7            5.8G    479.3M      5.0G   9% /data
/dev/sda1                14.3G    969.2M     13.4G   7% /mnt

This is AFTER I fixed it. Mod installed and working well, now. Thanks to all who have contributed!

[consp]

The root partition is limited to 1.2G:

Ah, forgot the data partition is separate ... make sense now. Good call.

Mod installed and working well, now.

You can fix the telnet now on the original firmware :)