[openib-general] [iproute2] IPoIB link layer address bug

[James Lentini]

The ip(8) command has a bug when dealing with IPoIB link layer 
addresses. Specifically it does not correctly handle the addition of 
new entries in the neighbor/arp table. For example, this command will 
fail:

ip neigh add 192.168.0.138 lladdr 00:00:04:04:fe:80:00:00:00:00:00:00:00:01:73:00:00:00:8a:91 nud permanent dev ib0

An IPoIB link layer address is 20-bytes (see 
http://www.ietf.org/internet-drafts/draft-ietf-ipoib-ip-over-infiniband-09.txt, 
section 9.1.1).

The command line parsing code expects link layer addresses to be a 
maximum of 16-bytes. Addresses over 16-bytes are truncated.

This patch (against the iproute2 cvs repository) fixes the problem:

============================================
--- iproute2/ip/ipneigh.c.orig	2005-09-01 15:21:50.000000000 -0400
+++ iproute2/ip/ipneigh.c	2006-03-16 17:03:41.339759000 -0500
@@ -165,7 +165,7 @@ static int ipneigh_modify(int cmd, int f
 	addattr_l(&req.n, sizeof(req), NDA_DST, &dst.data, dst.bytelen);
 
 	if (lla && strcmp(lla, "null")) {
-		char llabuf[16];
+		char llabuf[20];
 		int l;
 
 		l = ll_addr_a2n(llabuf, sizeof(llabuf), lla);
============================================

P.S. - I've found a similar issue with the arp command, see

http://openib.org/pipermail/openib-general/2006-March/018270.html