netdev - [net PATCH 0/2] IPv4 FIB suffix length fixes

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: <20161201121605.15499.13176.stgit@ahduyck-blue-test.jf.intel.com>
Date:   Thu, 01 Dec 2016 07:27:47 -0500
From:   Alexander Duyck <alexander.h.duyck@...el.com>
To:     netdev@...r.kernel.org, rshearma@...cade.com
Cc:     davem@...emloft.net
Subject: [net PATCH 0/2] IPv4 FIB suffix length fixes

In reviewing the patch from Robert Shearman and looking over the code I
realized there were a few different bugs we were still carrying in the IPv4
FIB lookup code.

These two patches are based off of Robert's original patch, but take things
one step further by splitting them up to address two additional issues I
found.

So first have Robert's original patch which was addressing the fact that
us calling update_suffix in resize is expensive when it is called per add.
To address that I incorporated the core bit of the patch which was us
dropping the update_suffix call from resize.

The first patch in the series does a rename and fix on the push_suffix and
pull_suffix code.  Specifically we drop the need to pass a leaf and
secondly we fix things so we pull the suffix as long as the value of the
suffix in the node is dropping.

The second patch addresses the original issue reported as well as
optimizing the code for the fact that update_suffix is only really meant to
go through and clean things up when we are decreasing a suffix.  I had
originally added code for it to somehow cause an increase, but if we push
the suffix when a new leaf is added we only ever have to handle pulling
down the suffix with update_suffix so I updated the code to reflect that.

As far as side effects the only ones I think that will be obvious should be
the fact that some routes may be able to be found earlier since before we
relied on resize to update the suffix lengths, and now we are updating them
before we add or remove the leaf.

---

Alexander Duyck (2):
      ipv4: Drop leaf from suffix pull/push functions
      ipv4: Drop suffix update from resize code

 net/ipv4/fib_trie.c |   68 ++++++++++++++++++++++++++-------------------------
 1 file changed, 35 insertions(+), 33 deletions(-)

--