Date: Fri, 19 Sep 2008 10:42:01 +0200 From: "Alexey Shuvaev" <shuvaev@physik.uni-wuerzburg.de> To: freebsd-current@freebsd.org Subject: Re: Interface auto-cloning bug or feature? Message-ID: <20080919084201.GD44330@wep4035.physik.uni-wuerzburg.de> In-Reply-To: <48D2F942.4070801@FreeBSD.org> References: <48D2F942.4070801@FreeBSD.org>
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On Thu, Sep 18, 2008 at 05:58:42PM -0700, Maxim Sobolev wrote: > Hi, > > I've noticed that stat/open call on /dev/tun always creates new > interface, despite the fact that existing spare interfaces may be > available. I believe that it's a bug, since the whole purpose of > auto-cloning is to create new instance only when no existing one could > be allocated. At least that's my reading of the manual page for the tun(4). > > <quote> > If the sysctl(8) variable net.link.tun.devfs_cloning is non-zero, > the tun > interface permits opens on the special control device /dev/tun. When > this device is opened, tun will return a handle for the lowest > unused tun > device (use devname(3) to determine which). > </quote> > > -Maxim > > [root@sp1 /usr/home/sobomax]# ifconfig -a > tun0: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 > [root@sp1 /usr/home/sobomax]# stat /dev/tun > 67174144 96 crw------- 1 uucp dialer 96 0 "May 2 22:21:28 2008" "May 2 > 22:21:28 2008" "May 2 22:21:28 2008" "Dec 31 23:59:59 1969" 4096 0 0 > /dev/tun > [root@sp1 /usr/home/sobomax]# ifconfig -a > tun0: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 > tun1: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 > [root@sp1 /usr/home/sobomax]# stat /dev/tun > 67174144 99 crw------- 1 uucp dialer 99 0 "May 2 22:21:28 2008" "May 2 > 22:21:28 2008" "May 2 22:21:28 2008" "Dec 31 23:59:59 1969" 4096 0 0 > /dev/tun > [root@sp1 /usr/home/sobomax]# ifconfig -a > tun0: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 > tun1: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 > tun2: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 > [root@sp1 /usr/home/sobomax]# stat /dev/tun > 67174144 105 crw------- 1 uucp dialer 105 0 "May 2 22:21:28 2008" "May > 2 22:21:28 2008" "May 2 22:21:28 2008" "Dec 31 23:59:59 1969" 4096 0 > 0 /dev/tun > [root@sp1 /usr/home/sobomax]# ifconfig -a > tun0: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 > tun1: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 > tun2: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 > tun3: flags=8010<POINTOPOINT,MULTICAST> mtu 1500 > Me too. I have seen that using ppp(8) and security/vpnc. Alexey.
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