netdev - Interface without IP address can route??

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]

Message-ID: <4E5443CD.60502@candelatech.com>
Date:	Tue, 23 Aug 2011 17:20:29 -0700
From:	Ben Greear <greearb@...delatech.com>
To:	netdev <netdev@...r.kernel.org>
Subject: Interface without IP address can route??

I just noticed on a 3.0.1 kernel that the system is routing packets
received on an interface without an IP address. (I was trying to use the
interface in a user-space wifi_station-to-wired bridge application).

[root@...301-demo1 lanforge]# cat /proc/sys/net/ipv4/conf/sta1/forwarding
1
[root@...301-demo1 lanforge]# ifconfig sta1
sta1      Link encap:Ethernet  HWaddr 00:03:2D:12:16:0D
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:85248 errors:0 dropped:0 overruns:0 frame:0
           TX packets:1419 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:1000
           RX bytes:67423391 (64.2 MiB)  TX bytes:1087581 (1.0 MiB)

Seems that older stock kernels have forwarding set for interfaces without
IP addresses too, so maybe it's always been this way...

Anyway, I can add some logic to my config to explicitly disable
routing for interfaces w/out IP address, but it seems to me that
it should automatically not route packets received on an interface
that had no IP address on it..

Thanks,
Ben

-- 
Ben Greear <greearb@...delatech.com>
Candela Technologies Inc  http://www.candelatech.com

--
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