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 PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Wed, 2 Jan 2019 19:30:53 -0800 From: Cong Wang <xiyou.wangcong@...il.com> To: Bartek Kois <bartek.kois@...il.com> Cc: Linux Kernel Network Developers <netdev@...r.kernel.org> Subject: Re: Problem with queuing vlan tagged packets after migration from 3.16.0 to 4.9.0 On Tue, Jan 1, 2019 at 11:46 AM Bartek Kois <bartek.kois@...il.com> wrote: > > Hi > Yes it did work since I remember (like around 2.4.x) and it changed > since I moved from Debian 8 to 9. I would appreciate fixing that in the > future beacuse it is essential for queueing traffic on the routers, but > the question is why these filters don`t work in that case: > > tc filter add dev $LAN_ETH parent 1:0 protocol ip prio 4 u32 match > u32 0x0a000c08 0xffffffff at 20 classid 1:2001 # for 10.0.12.8 ip > address > tc filter add dev $LAN_ETH parent 1:0 protocol ip prio 4 u32 match > u32 0x0a000c09 0xffffffff at 20 classid 1:2002 # for 10.0.12.9 ip > address > tc filter add dev $LAN_ETH parent 1:0 protocol ip prio 4 u32 match > u32 0x0a000c10 0xffffffff at 20 classid 1:2003 # for 10.0.12.10 ip > address > > I`ve changed "at 16" which works without vlan tags to "at 20" to take > vlan tag into account. Yeah, this confirms my speculation. The problem is essentially a design flaw of u32 filter, the IP header and TCP header offsets are never fixed, for example VLAN tagging and IP options. What's more, it is not easy for user-space to learn the offset for different packets as it requires to parse into each packets. I don't know whether we can fix this either, VLAN call path probably already makes assumptions on the current skb->data position, if we "fix" it for u32, it would probably break other things.
Powered by blists - more mailing lists