From: prashantkumar dhotre <prashantkumardhotre@gmail.com>
To: netfilter-devel@vger.kernel.org
Subject: EPOLLERR on memory mapped netlink socket
Date: Mon, 23 Jan 2017 09:20:23 +0530 [thread overview]
Message-ID: <CA+VDgmP9MigJxiN5snFmLdHw7cydr4JbnBDDPwzex0Tszqgaag@mail.gmail.com> (raw)
Hi experts,
I am new to netlink sockets.
In my app , I am getting EPOLLERR in epoll_wait() on netlink socket
continuously.
epoll just notifies that there is a read event on socket (it does not
tell if it is read or epollerr).
What could be cause of this and what EPOLLERR on memory mapped netlink
socket mean.is this Other side of netlink (kernel side) closed
connection ?even if kernel side closed connection why non-stop
repeated EPOLLERR s on netlink sockets ?
What action should we take in such cases ? just close the socket or
call getsockopt(SO_ERROR) to retrieve the pending error state from the
socket and just continue without closing socket?
how do we detect if kernel side closed the connection ?
My understanding is :
if we get read event notification from epoll on memory mapped netlink
socket and in RX ring if the frame is neither NL_MMAP_STATUS_VALID and
nor NL_MMAP_STATUS_COPY then we can conclude that this is a 'close()'
from remote kernel socket and I can close connection by calling
close() on my netlink socket.
Is above understanding correct ?
Please
next reply other threads:[~2017-01-23 3:50 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-23 3:50 prashantkumar dhotre [this message]
2017-01-23 17:40 ` EPOLLERR on memory mapped netlink socket prashantkumar dhotre
2017-01-24 6:52 ` Patrick PIGNOL
2017-01-24 19:28 ` Pablo Neira Ayuso
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=CA+VDgmP9MigJxiN5snFmLdHw7cydr4JbnBDDPwzex0Tszqgaag@mail.gmail.com \
--to=prashantkumardhotre@gmail.com \
--cc=netfilter-devel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).