tcpdump mailing list archives
Re: bandwidth by user or process id
From: Patrick Kurz <kurzpatrick () ymail com>
Date: Wed, 6 Oct 2010 01:29:58 -0700 (PDT)
----- Original Message ----
From: Rob Hasselbaum <rob () hasselbaum net> To: tcpdump-workers () lists tcpdump org Sent: Tue, October 5, 2010 4:07:14 PM Subject: Re: [tcpdump-workers] bandwidth by user or process id Right, generally, the local or remote port will be different for different PIDs even if the IP addresses are the same. There is one catch, though. It is possible on Linux to share sockets (network connections) between two or more processes. For example, the openSSH daemon spawns a new process for each new connection, and if you look at the "/proc/*/fd" tables of the parent and child processes, you'll see the same socket appears to be owned by both. When this happens. it's likely only one of them is actually using the connection, but I have not found a way to tell which one, and I suspect it's not possible in userland because even "netstat" balks at this case.
This may be a serious problem in my application. But as you have noticed from my previous posts, I'm not too familiar with networking technicalities, so that I may have misunderstood something. Let's say 10 users transfer large amounts of data through ssh at the same time. I assume in this situation 10 different processes would share the same socket, and your workaround to assign traffic to either the newest or oldest process wouldn't help. Am I wrong? Thanks Patrick - This is the tcpdump-workers list. Visit https://cod.sandelman.ca/ to unsubscribe.
Current thread:
- bandwidth by user or process id Patrick Kurz (Oct 04)
- Re: bandwidth by user or process id Rob Hasselbaum (Oct 04)
- Re: bandwidth by user or process id Patrick Kurz (Oct 04)
- Re: bandwidth by user or process id Rob Hasselbaum (Oct 04)
- Re: bandwidth by user or process id Rob Hasselbaum (Oct 04)
- Re: bandwidth by user or process id Patrick Kurz (Oct 05)
- Re: bandwidth by user or process id Gert Doering (Oct 05)
- Re: bandwidth by user or process id Rob Hasselbaum (Oct 05)
- Re: bandwidth by user or process id Patrick Kurz (Oct 06)
- Re: bandwidth by user or process id Gert Doering (Oct 06)
- Re: bandwidth by user or process id Patrick Kurz (Oct 04)
- Re: bandwidth by user or process id Rob Hasselbaum (Oct 04)
- Re: bandwidth by user or process id Gerald Combs (Oct 05)
- Re: bandwidth by user or process id Patrick Kurz (Oct 06)