PW Running a command from KUAL using pipes not as expected

bmsleight · 11-22-2020, 12:35 PM

Hi

[TL/DR] Running a command from KUAL using pipes not as expected

I have a PI 3B+ running openwrt and four Amazon Kindle Paperwhite 1 Wi-Fi, I have v2.7.23-g9f3694a of KUAL installed, with USB networking. I can successfully transfer data between machines, by ssh into each machine and running scripts with the scripts and applications using netcat (aka nc).

I am trying to convert to an KUAL extension so finish the project and release. However I must be doing something wrong with piping.

Minimal working example from SSH - not KUAL

On a separate machine (running OpenWRT)

Code:

root@OpenWrt:~# mkfifo /tmp/example.pipe
root@OpenWrt:~# cat /tmp/example.pipe  | netcat -l -vvv  -p  5001 &
root@OpenWrt:~# Listening on any address 5001

Note: "Listening on any address 5001" is the verbose output of netcat

ssh onto Kindle

Code:

[root@kindle root]# nc 192.168.1.126 5001 | tee -i

On the OpenWrt machine, then issue an echo

Code:

root@OpenWrt:~# mkfifo /tmp/example.pipe
root@OpenWrt:~# cat /tmp/example.pipe  | netcat -l -vvv  -p  5001 &
root@OpenWrt:~# Listening on any address 5001
Connection from 192.168.1.105:47765
root@OpenWrt:~# echo "hi" >/tmp/example.pipe 
root@OpenWrt:~#

On Kindle I get:-

Code:

[root@kindle root]# nc 192.168.1.126 5001 | tee -i  
hi

Nb: Note pipe is still open and I can continue to send data from openwrt machine

Minimal working example Using KUAL

Now again using KUAL, using extension as:-

Code:

[root@kindle root]# cat /mnt/us/extensions/OkMonitor/menu.json 
{
	"items": [
	{
		"name": "NC Examples",
		"priority": -998,
		"items": [
		{
			"name": "nc example 1",
			"action": "nc 192.168.1.126 5001 | tee -i ",
			"internal": "Example"
		}
		]
	}
	]
}
[root@kindle root]#

Same commands

Code:

root@OpenWrt:~# mkfifo /tmp/example.pipe
root@OpenWrt:~# cat /tmp/example.pipe  | netcat -l -vvv  -p  5001 &
root@OpenWrt:~# Listening on any address 5001

Then Kindle: KUAL -> NC Examples -> nc example 1

Code:

root@OpenWrt:~# mkfifo /tmp/example.pipe
root@OpenWrt:~# cat /tmp/example.pipe  | netcat -l -vvv  -p  5001 &
root@OpenWrt:~# Listening on any address 5001
Connection from 192.168.1.105:59820
Total received bytes: 0
Total sent bytes: 0

In the second example nc sucessfully but then disconnects. I require nc to remain open. The only difference is that in the first example I running the command when conencted via ssh, the second via KUAL menu.

I need nc to pipe to a different compiled application, but using tee as the application in this examples.

Things I have tried:-

openWRT difference option -c, -k
openWRT difference version of netcat, nc, ncat
From KUAL run a script the ssh localhost then trying to pipe
From login -F root
on Kindle tee -i in the pipe
Pulling hair out and eating chocolate.

Any pointers would be great. Or any ideas how I can debug further.

Thanks,
Brendan

NiLuJe · 11-22-2020, 12:40 PM

There's massive I/O redirections involved in KUAL, so I'm not suite sure this'll ever work, period.

EDIT: (This is what actually ends up being passed to ash -c after being wrapped in an actual shell script).

That said, you definitely should not be doing that straight from an action. Do that in a shell script, and run *that* instead.
That should allow you to deal more sanely with any I/O redirection constraints, and possibly background more sanely so you don't block the UI, because I also don't remember how that's dealt with, but that was never the intended usecase

.

EDIT²: Well, the action is force-backgrounded anyway, see above edit ;p.

bmsleight · 11-22-2020, 12:47 PM

Quote:

Originally Posted by NiLuJe

Do that in a shell script, and run *that* instead.
That should allow you to deal more sanely with any I/O redirection constraints, and possibly background more sanely so you don't block the UI, because I also don't remember how that's dealt with, but that was never the intended usecase

.

Thanks or the reply. Tried running a shell script that does the piping, but that does not work either.

Hey KUAL is so good, wanted to give it a try. Any pointers in making a customers "Book?" .az2 like KUAL ?

Any pointer on the source for KUAL so I can see if I can try and debug further ?

NiLuJe · 11-22-2020, 12:51 PM

See a couple of EDITs in my original answer

. I'd try ripping the I/O & backgrounding stuff out, and see what shakes out.

I would highly, highly, highy recommend *NOT* trying to deal with the Kindlet (deprecated) / Booklet (private, highly obfuscated) APIs yourself, unless you have severe masochistic tendencies

.

As you might find out, even rebuilding KUAL itself requires a shitload of hoop-jumping, and full dumps from scarily old FW versions (or not, I may be mixing things up with CM. Kindlets are hell. Java is pain.). I do know that you won't be able to use anything newer than a JDK 8, as they all dropped support for the crappy old language version we need.

EDIT: Okay, for KUAL, you actually "just" need two or three old dumps, one for the KDK1 API, one for the KDK2 API, and one for the Booklet API. ;p. See the readme in the lib folder, which might not be entirely up-to-date.

Fun example (and I stopped caring a good long while ago, so I probably can't build current CollectionsManager versions).

Code:

┌─(niluje@illyria:pts/4)───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────(~)─┐
└─(0.13:26%:18:51:%)── du -h -d1 ~/Kindle/Kindlet-Dev                                                                                                                                                                                                                                                                                                  ──(Sun, Nov 22)─┘
30M     /home/niluje/Kindle/Kindlet-Dev/fw-520
26M     /home/niluje/Kindle/Kindlet-Dev/fw-538
68M     /home/niluje/Kindle/Kindlet-Dev/JDK-1.4.2_19
26M     /home/niluje/Kindle/Kindlet-Dev/fw-534
15M     /home/niluje/Kindle/Kindlet-Dev/Decompilers
19M     /home/niluje/Kindle/Kindlet-Dev/fw-5371
37M     /home/niluje/Kindle/Kindlet-Dev/fw-5442
20M     /home/niluje/Kindle/Kindlet-Dev/fw-532
26M     /home/niluje/Kindle/Kindlet-Dev/fw-539
40M     /home/niluje/Kindle/Kindlet-Dev/fw-592
20M     /home/niluje/Kindle/Kindlet-Dev/fw-512
26M     /home/niluje/Kindle/Kindlet-Dev/fw-536
26M     /home/niluje/Kindle/Kindlet-Dev/fw-530
26M     /home/niluje/Kindle/Kindlet-Dev/fw-531
19M     /home/niluje/Kindle/Kindlet-Dev/fw-5372
30M     /home/niluje/Kindle/Kindlet-Dev/fw-544
26M     /home/niluje/Kindle/Kindlet-Dev/fw-535
288K    /home/niluje/Kindle/Kindlet-Dev/fw-411
268K    /home/niluje/Kindle/Kindlet-Dev/fw-258
26M     /home/niluje/Kindle/Kindlet-Dev/fw-5381
31M     /home/niluje/Kindle/Kindlet-Dev/fw-5432
26M     /home/niluje/Kindle/Kindlet-Dev/fw-533
31M     /home/niluje/Kindle/Kindlet-Dev/fw-5431
37M     /home/niluje/Kindle/Kindlet-Dev/fw-5451
20M     /home/niluje/Kindle/Kindlet-Dev/fw-5321
30M     /home/niluje/Kindle/Kindlet-Dev/fw-542
30M     /home/niluje/Kindle/Kindlet-Dev/fw-5421
31M     /home/niluje/Kindle/Kindlet-Dev/fw-545
19M     /home/niluje/Kindle/Kindlet-Dev/fw-537
30M     /home/niluje/Kindle/Kindlet-Dev/fw-5441
31M     /home/niluje/Kindle/Kindlet-Dev/fw-543
4.0K    /home/niluje/Kindle/Kindlet-Dev/MAIN
34M     /home/niluje/Kindle/Kindlet-Dev/fw-540
46M     /home/niluje/Kindle/Kindlet-Dev/fw-565
882M    /home/niluje/Kindle/Kindlet-Dev

NiLuJe · 11-22-2020, 01:17 PM

You could also just try strace'ing netcat and/or tee (log to a file), to see what actually makes it die.

(Wild guess: something throws an EPIPE somewhere, somehow).

bmsleight · 11-22-2020, 03:42 PM

Wow - rabbit hole.....

I think I may have an <ugly> way forward.
Automating screen sessions

(Which is ironic)!

bmsleight · 11-22-2020, 04:05 PM

From the openwrt machine

Code:

root@OpenWrt:~# cat ./test.sh 
rm  /tmp/example.pipe
mkfifo /tmp/example.pipe
cat /tmp/example.pipe  | netcat -l -vvv  -p  5001 &
sleep 1

screen -dmS default_session -t screen_name 
screen -S default_session -p screen_name  -X stuff 'ssh  root@192.168.1.105 "nc 192.168.1.126 5001 | tee -i" \r'


sleep 1
echo "hi" >/tmp/example.pipe 
echo "world" >/tmp/example.pipe 

root@OpenWrt:~# /bin/ash test.sh 
Listening on any address 5001
Connection from 192.168.1.105:37688
root@OpenWrt:~# screen -S default_session -p screen_name  -X kill
root@OpenWrt:~# Total received bytes: 0
Total sent bytes: 9

I can have KUAL trigger the openwrt machine

Thanks for the replies. Back to tidying up and finding the next snag.

yparitcher · 11-22-2020, 06:29 PM

Actually rebuilding KUAL is not too hard, the necessary libs are easy to dump straight from the device. I built a stripped down version that just launches Koreader as KUAL was being too slow for me

https://github.com/yparitcher/KUAL_Booklet

NiLuJe · 11-22-2020, 07:53 PM

The Booklet variant has the advantage of only needing a single source, since it gets rid of the two (older) APIs, which means you can actually get those from an Amazon update package, no digging up old devices/backups necessary

.

Unfortunately, the OP appears to be on a K3, so, KDK1

.

11-22-2020, 12:35 PM	#1
bmsleight Member Posts: 24 Karma: 540 Join Date: Aug 2010 Device: Kindle 3	Running a command from KUAL using pipes not as expected Hi [TL/DR] Running a command from KUAL using pipes not as expected I have a PI 3B+ running openwrt and four Amazon Kindle Paperwhite 1 Wi-Fi, I have v2.7.23-g9f3694a of KUAL installed, with USB networking. I can successfully transfer data between machines, by ssh into each machine and running scripts with the scripts and applications using netcat (aka nc). I am trying to convert to an KUAL extension so finish the project and release. However I must be doing something wrong with piping. Minimal working example from SSH - not KUAL On a separate machine (running OpenWRT) Code: root@OpenWrt:~# mkfifo /tmp/example.pipe root@OpenWrt:~# cat /tmp/example.pipe \| netcat -l -vvv -p 5001 & root@OpenWrt:~# Listening on any address 5001 Note: "Listening on any address 5001" is the verbose output of netcat ssh onto Kindle Code: [root@kindle root]# nc 192.168.1.126 5001 \| tee -i On the OpenWrt machine, then issue an echo Code: root@OpenWrt:~# mkfifo /tmp/example.pipe root@OpenWrt:~# cat /tmp/example.pipe \| netcat -l -vvv -p 5001 & root@OpenWrt:~# Listening on any address 5001 Connection from 192.168.1.105:47765 root@OpenWrt:~# echo "hi" >/tmp/example.pipe root@OpenWrt:~# On Kindle I get:- Code: [root@kindle root]# nc 192.168.1.126 5001 \| tee -i hi Nb: Note pipe is still open and I can continue to send data from openwrt machine Minimal working example Using KUAL Now again using KUAL, using extension as:- Code: [root@kindle root]# cat /mnt/us/extensions/OkMonitor/menu.json { "items": [ { "name": "NC Examples", "priority": -998, "items": [ { "name": "nc example 1", "action": "nc 192.168.1.126 5001 \| tee -i ", "internal": "Example" } ] } ] } [root@kindle root]# Same commands Code: root@OpenWrt:~# mkfifo /tmp/example.pipe root@OpenWrt:~# cat /tmp/example.pipe \| netcat -l -vvv -p 5001 & root@OpenWrt:~# Listening on any address 5001 Then Kindle: KUAL -> NC Examples -> nc example 1 Code: root@OpenWrt:~# mkfifo /tmp/example.pipe root@OpenWrt:~# cat /tmp/example.pipe \| netcat -l -vvv -p 5001 & root@OpenWrt:~# Listening on any address 5001 Connection from 192.168.1.105:59820 Total received bytes: 0 Total sent bytes: 0 In the second example nc sucessfully but then disconnects. I require nc to remain open. The only difference is that in the first example I running the command when conencted via ssh, the second via KUAL menu. I need nc to pipe to a different compiled application, but using tee as the application in this examples. Things I have tried:- openWRT difference option -c, -k openWRT difference version of netcat, nc, ncat From KUAL run a script the ssh localhost then trying to pipe From login -F root on Kindle tee -i in the pipe Pulling hair out and eating chocolate. Any pointers would be great. Or any ideas how I can debug further. Thanks, Brendan

11-22-2020, 12:40 PM	#2
NiLuJe BLAM! Posts: 13,506 Karma: 26047202 Join Date: Jun 2010 Location: Paris, France Device: Kindle 2i, 3g, 4, 5w, PW, PW2, PW5; Kobo H2O, Forma, Elipsa, Sage, C2E	There's massive I/O redirections involved in KUAL, so I'm not suite sure this'll ever work, period. EDIT: (This is what actually ends up being passed to ash -c after being wrapped in an actual shell script). That said, you definitely should not be doing that straight from an action. Do that in a shell script, and run that instead. That should allow you to deal more sanely with any I/O redirection constraints, and possibly background more sanely so you don't block the UI, because I also don't remember how that's dealt with, but that was never the intended usecase . EDIT²: Well, the action is force-backgrounded anyway, see above edit ;p. Last edited by NiLuJe; 11-22-2020 at 12:46 PM.

11-22-2020, 01:17 PM	#5
NiLuJe BLAM! Posts: 13,506 Karma: 26047202 Join Date: Jun 2010 Location: Paris, France Device: Kindle 2i, 3g, 4, 5w, PW, PW2, PW5; Kobo H2O, Forma, Elipsa, Sage, C2E	You could also just try strace'ing netcat and/or tee (log to a file), to see what actually makes it die. (Wild guess: something throws an EPIPE somewhere, somehow). Last edited by NiLuJe; 11-22-2020 at 01:20 PM.

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11-22-2020, 03:42 PM	#6
bmsleight Member Posts: 24 Karma: 540 Join Date: Aug 2010 Device: Kindle 3	Wow - rabbit hole..... I think I may have an <ugly> way forward. Automating screen sessions (Which is ironic)!

11-22-2020, 06:29 PM	#8
yparitcher Connoisseur Posts: 52 Karma: 616590 Join Date: Feb 2019 Device: K4 KT4 PW4 PW5	Actually rebuilding KUAL is not too hard, the necessary libs are easy to dump straight from the device. I built a stripped down version that just launches Koreader as KUAL was being too slow for me https://github.com/yparitcher/KUAL_Booklet

11-22-2020, 07:53 PM	#9
NiLuJe BLAM! Posts: 13,506 Karma: 26047202 Join Date: Jun 2010 Location: Paris, France Device: Kindle 2i, 3g, 4, 5w, PW, PW2, PW5; Kobo H2O, Forma, Elipsa, Sage, C2E	The Booklet variant has the advantage of only needing a single source, since it gets rid of the two (older) APIs, which means you can actually get those from an Amazon update package, no digging up old devices/backups necessary . Unfortunately, the OP appears to be on a K3, so, KDK1 .

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