netdev - netstat and dual stack sockets

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 15 Jun 2015 22:54:21 +0200
From:	Phil Sutter <phil@....cc>
To:	netdev@...r.kernel.org
Subject: netstat and dual stack sockets

Hi,

A socket listening on any AF_INET6 address will receive IPv4 traffic as
well, as long as it does not set IPV6_V6ONLY (or sysctl
net.ipv6.bindv6only is set). Apache APR e.g. explicitly disables
IPV6_V6ONLY for listening sockets.

As I see it, a user has no way of detecting the listening socket in this
address family: it does not show in /proc/net/{tcp,udp} nor do
'netstat', 'ss' or 'lsof' print any additional information about those
sockets over pure IPv6 ones.

Is this correct? If so, are there any intentions to export the missing
information to userspace?

Phil
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html