James Lentini wrote:

On Tue, 21 Mar 2006, Jason Gunthorpe wrote:

On Tue, Mar 21, 2006 at 03:56:17PM -0800, Stephen Hemminger wrote:

Okay, but there are number of other places in iproute2 that call 
ll_addr_a2n() with ifr.ifr_hwaddr.sa_data. And that is 14 bytes.  
If you want to fix those it will be harder since it would increase 
the sizeof(struct sockaddr) and potentially break compatibility.

Maybe the best thing is to upgrade ip (and or netlink?) to use 
netlink messages instead of ioctls for the remaining problematic 
operations. Since netlink already supports an arbitary length hwaddr 
there should be no compatability problem.

Just browsing I see usages of SIOCSIFHWBROADCAST, SIOCSIFHWADDR, 
SIOCADDMULTI, SIOCDELMULTI and SIOCGIFHWADDR that use a struct 
ifreq..

I know SIOCGIFHWADDR can be done over netlink, but I'm not too 
familiar with the others..


Making ip neighbor work with IPoIB address is what I'm interested in 
now.

As you and Jason point out there are a lot of places where ifreqs are 
used and hence options that will not support IPoIB addresses.

The sockaddr union is at the end of struct ifreq. Couldn't the union sockaddr members be changed to sockaddr_storage, and the SIOCxxxx encoded size bits be changed? dev_ifsioc() would just need to mask out (or substitute) the size bits before the switch statement.

- Mark