netdev - RE: ipgre rss is broken since gro

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

Date:	Mon, 10 Dec 2012 11:32:50 +0000
From:	"Dmitry Kravkov" <dmitry@...adcom.com>
To:	"Eric Dumazet" <edumazet@...gle.com>
cc:	"netdev@...r.kernel.org" <netdev@...r.kernel.org>
Subject: RE: ipgre rss is broken since gro

> -----Original Message-----
> From: Eric Dumazet [mailto:edumazet@...gle.com]
> Sent: Monday, December 10, 2012 1:27 AM
> To: Dmitry Kravkov
> Cc: netdev@...r.kernel.org
> Subject: Re: ipgre rss is broken since gro
> 
> On Sun, Dec 9, 2012 at 12:49 PM, Dmitry Kravkov <dmitry@...adcom.com>
> wrote:
> 
> > for this item: drop_watch does not show any drops (i've disable all
> > other interfaces for clear env)
> > I will explain a little bit more the setup:
> > bnx2x device (under testing) is configured for RSS for IPGRE packets.
> > Sending multiple (3) TCP_STREAM causes ip_gre interface to disappear
> > packets (even ICMP).
> > This is not happening with single TCP_STREAM, or before gro_cell
> > introduction.
> >
> I dont know, I tried a bnx2x setup, and 100 tcp flows, no special problem.

Current bnx2x do not apply RSS for GRE, non GRE RSS is working w/o problem.

> 
> If you receive a lot of packets on a single RX queue, they might be
> dropped because cpu cant cope with the load
> (This has nothing to do with GRE or GRO )
> 
CPU is not loaded at all 

> cat /proc/net/softnet_stat
Please find attached.

For gre interface RX and DROP statistics are advancing simultaneously (by one each ICMP request):

[root@ ~]# ifconfig gre
gre       Link encap:UNSPEC  HWaddr C0-A8-0A-40-73-72-83-D2-00-00-00-00-00-00-00-00
          inet addr:8.0.0.1  P-t-P:8.0.0.1  Mask:255.255.255.0
          inet6 addr: fe80::5efe:c0a8:a40/64 Scope:Link
          UP POINTOPOINT RUNNING NOARP  MTU:1476  Metric:1
          RX packets:1646824 errors:0 dropped:51610 overruns:0 frame:0
          TX packets:140519 errors:1 dropped:0 overruns:0 carrier:1
          collisions:0 txqueuelen:0
          RX bytes:2357650904 (2.1 GiB)  TX bytes:7309072 (6.9 MiB)

[root@ ~]# ifconfig gre
gre       Link encap:UNSPEC  HWaddr C0-A8-0A-40-73-72-83-82-00-00-00-00-00-00-00-00
          inet addr:8.0.0.1  P-t-P:8.0.0.1  Mask:255.255.255.0
          inet6 addr: fe80::5efe:c0a8:a40/64 Scope:Link
          UP POINTOPOINT RUNNING NOARP  MTU:1476  Metric:1
          RX packets:1646826 errors:0 dropped:51612 overruns:0 frame:0
          TX packets:140519 errors:1 dropped:0 overruns:0 carrier:1
          collisions:0 txqueuelen:0
          RX bytes:2357651072 (2.1 GiB)  TX bytes:7309072 (6.9 MiB) 

[root@ ~]# tcpdump -i gre
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on gre, link-type LINUX_SLL (Linux cooked), capture size 65535 bytes
^C
0 packets captured
0 packets received by filter
0 packets dropped by kernel
2 packets dropped by interface

Download attachment "stat1" of type "application/octet-stream" (3600 bytes)

Download attachment "stat2" of type "application/octet-stream" (3600 bytes)