netdev - iproute uses too small of a receive buffer

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: <4AE77F64.3090302@candelatech.com>
Date:	Tue, 27 Oct 2009 16:16:52 -0700
From:	Ben Greear <greearb@...delatech.com>
To:	NetDev <netdev@...r.kernel.org>
Subject: iproute uses too small of a receive buffer

I have a very busy system with a bunch of xorp router processes (mis)configured.

This thing is rapidly making route changes for whatever reason.

The 'ip monitor route' command was failing:

[root@...dqc-1 ]# ip monitor route
netlink receive error No buffer space available (105)
Dump terminated


It is only using a 32k rcv buffer, and it seems the OS was
overdriving it.

Please consider making the rcv buffer larger, perhaps something
like this (inline is white-space damaged...attachment should apply
if deemed useful.):

Signed-off-by:  Ben Greear <greearb@...delatech.com>

diff --git a/lib/libnetlink.c b/lib/libnetlink.c
index b68e2fd..95a7d1d 100644
--- a/lib/libnetlink.c
+++ b/lib/libnetlink.c
@@ -38,7 +38,7 @@ int rtnl_open_byproto(struct rtnl_handle *rth, unsigned subscriptions,
  {
         socklen_t addr_len;
         int sndbuf = 32768;
-       int rcvbuf = 32768;
+       int rcvbuf = 3276800;

         memset(rth, 0, sizeof(*rth));


Thanks,
Ben

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


View attachment "iputils.patch" of type "text/plain" (344 bytes)