From: Jarod Wilson <ja...@redhat.com>
Date: Tue, 4 Apr 2017 17:32:42 -0400
> People are using bonding over Infiniband IPoIB connections, and who knows
> what else. Infiniband has a hardware address length of 20 octets
> (INFINIBAND_ALEN), and the network core defines a MAX_ADDR_LEN of 32.
> Various places in the bonding code are currently hard-wired to 6 octets
> (ETH_ALEN), such as the 3ad code, which I've left untouched here. Besides,
> only alb is currently possible on Infiniband links right now anyway, due
> to commit 1533e7731522, so the alb code is where most of the changes are.
>
> One major component of this change is the addition of a bond_hw_addr_copy
> function that takes a length argument, instead of using ether_addr_copy
> everywhere that hardware addresses need to be copied about. The other
> major component of this change is converting the bonding code from using
> struct sockaddr for address storage to struct sockaddr_storage, as the
> former has an address storage space of only 14, while the latter is 128
> minus a few, which is necessary to support bonding over device with up to
> MAX_ADDR_LEN octet hardware addresses. Additionally, this probably fixes
> up some memory corruption issues with the current code, where it's
> possible to write an infiniband hardware address into a sockaddr declared
> on the stack.
>
> Lightly tested on a dual mlx4 IPoIB setup, which properly shows a 20-octet
> hardware address now:
...
> CC: Jay Vosburgh <j.vosbu...@gmail.com>
> CC: Veaceslav Falico <vfal...@gmail.com>
> CC: Andy Gospodarek <a...@greyhouse.net>
> CC: netdev@vger.kernel.org
> Signed-off-by: Jarod Wilson <ja...@redhat.com>
Applied, but:
> +static inline void bond_hw_addr_copy(u8 *dst, const u8 *src, unsigned int
> len)
> +{
> + if (len == ETH_ALEN) {
> + ether_addr_copy(dst, src);
> + return;
> + }
> +
> + memcpy(dst, src, len);
> +}
I wonder how much value there is in trying to conditionally use
ether_addr_copy(). Unless some of these calls are in the data
plane, just a straight memcpy() all the time is fine and much
simpler.
Thanks.
