The terminal process cannot be closed correctly

[vsbc2010]

The terminal process cannot be closed correctly.

My reproduction steps:

1. open ssh client A and login as root
2. open ssh client B and login as root, run "tcpdump -i any -n -s 0 -w test.pcap"
3. close ssh console B.
4. check with shell from console A "ps -axu | grep tcpdump", then found tcpdump nerver exit
5. but if close console A , then tcpdump exit

[mkj]

Which OS is it? I can't think of anything Dropbear would be doing to cause it

[mkj]

If 2020.81 worked OK it could be a similar issue to 544f28a

Thanks for checking, sounds like I should be able to reproduce it

[vsbc2010]

Check f17400e

XShell open with "Duplicate SSH Channel", then get issue

[mkj]

I think the correct behaviour is for tcpdump to exit. It's running in a PTY, so the kernel sends SIGHUP to any processes in that terminal when the SSH session exits (and closes the master side).

It's probably a bug in Dropbear that multiple-channel-per-session doesn't close the master side (until the whole connection goes away). The behaviour of channel closing is tricky though, so I'm not going to change it right now. I'll leave this issue open though.

If you run nohup tcpdump -i any -n -s 0 -w test.pcap it should run OK when the terminal exits.

[vsbc2010]

Revert f17400e, then issue solved.