Android device acting weird, "no such file..." (Rooted)

Hello,

To start off with, I'd like to say that I'm just getting into these things, I'm semi-experienced with GSM and the signalling system, SS7. I just got my Android device(HTC One M7) yesterday, and I've been playing around with GSM, sniffing and so on, but.. You may already have guessed that I'm looking for the Kc(the ciphering key from the SIM) to decrypt my traffic.

I have tried to do it by sending AT commands, but my device is acting really weird as the title says, whenever I try to contact/access /dev/smd0, but it "doesn't exist" - That's what I get as a reply. I tried to list files in /dev/, I see them all, and I tried to getprop rild.libargs, this is the output:

root@m7:/ # getprop rild.libargs
-d /dev/smd0
root@m7:/ # echo -c "AT\r\n" > /dev/smd0
tmp-mksh: can't create /dev/smd0: No such file or directory
1|root@m7:/ #

I've tried searching on Google multiple times to 6 am, I didn't find any answers to the issue.

If anyone can help me with this issue, I'd be more than happy to give a reward, since my interest in getting this working is extreme.

Thank you.