Dropbear process not ending on exit

[Traste]

Hi,

I am running Firmware:380.60_beta2 on an Asus RT-AC68U and from a machine, i am running a monitoring script over SSH every few minutes, this is working great, however after a day or two, the router started acting up, disconnected from the internet, stopped responding to SSH connections, but the http/https was working so i restarted the router.
After manually monitoring the router for a while i noticed that the number of dropbear processes started to build up over time so I figured that my script didn't close the SSH session properly when closing the , so i changed the script to run "exit" at the end, but that doesnt seem to help, they are still building up.
Is this expected behaviour when running exit?
I tried to kill the processes from the script using "killall dropbear" , but that stops SSH from working all together.
I was also considering doing a "/etc/init.d/ssh stop ; /etc/init.d/dropbear start" at the end of the script, but both and killing the processes feels a little heavyhanded and would stop other sessions as well.
Am I doing something wrong, does anyone have any suggestions on how to get around this issue?

Much appreciated,

Traste

 

[RMerlin]

Does your script run anything that might be left running in background after disconnecting?

I log a lot into my router over SSH, and never had any issue with leftover processes.

Might also be worth upgrading, I don't think this beta has the latest dropbear version.

 

[Traste]

Hi RMerlin,

all it does is execute "cat /proc/net/arp" and i changed that to "cat /proc/net/arp; exit"
There are two other scripts that only run once a day each to turn on and off the guest wifi, and that has been running fine for months or rather - at least i didnt notice any issue, but i have had to do a restart or two over the months and maybe that was causing it.

I will start with doing an update and see if that helps.

 

[RMerlin]

I would also check with netstat to confirm whether the client actually disconnects or not.

 

[Traste]

Hi again,
I updated to Firmware: 380.63 and then left the script running every minute for about an hour, i checked with PS and counted 64 instances of dropbear:
4782 admin 1136 S dropbear -p 192.168.1.1:22 -a -j -k

i tried running netstat and sure enough, it lists these as
"tcp 0 0 router.asus.com:ssh 192.168.1.205:50804 ESTABLISHED"
i will need to check on the script to make sure it ends the session on its end as well.
Still, i would have expected the exit command at the end to close the session as it would with Putty for example, but i am no expert.
Thank you very much for your help, i now understand that this is not an issue with Merlin but with my script, sorry for wasting your time.

 

[heliosone]

how can I start / stop / restart dropbear
usually this is done via service stop_$NAME$
but dropbear is started differently (runit/init.d ?? no clue about those 2)
right now when I kill it (to make sure no leftover sessions are blocking a drive I want to unmount at a certain time),the cron job script kills dropbear.
And when I want to ssh into the router later again,I have to open the webGUI/Administration/system,press the apply button,then dropbear is restarted.

any way I can stop / start (restart) dropbear from within a script ?

 

[Martineau]

how can I start / stop / restart dropbear
usually this is done via service stop_$NAME$
but dropbear is started differently (runit/init.d ?? no clue about those 2)
right now when I kill it (to make sure no leftover sessions are blocking a drive I want to unmount at a certain time),the cron job script kills dropbear.
And when I want to ssh into the router later again,I have to open the webGUI/Administration/system,press the apply button,then dropbear is restarted.

any way I can stop / start (restart) dropbear from within a script ?

#!/bin/sh

# Monitor SSH task and auto restart if it goes AWOL
cru a CheckSSHD "*/5 * * * * (/bin/pidof dropbear 2>&1 >/dev/null || /sbin/run_sshd)"

 

[heliosone]

#!/bin/sh

# Monitor SSH task and auto restart if it goes AWOL
cru a CheckSSHD "*/5 * * * * (/bin/pidof dropbear 2>&1 >/dev/null || /sbin/run_sshd)"

BIG THANKS for this !!!!!