On Wed, Jan 04, 2017 at 04:11:03PM -0500, David Miller wrote:
> From: Andrew Lunn <[email protected]>
> Date: Wed, 4 Jan 2017 19:56:24 +0100
>
> > +static inline u64 ether_addr_to_u64(const u8 *addr)
> > +{
> > + u64 u = 0;
> > + int i;
> > +
> > + for (i = 0; i < ETH_ALEN; i++)
> > + u = u << 8 | addr[i];
> > +
> > + return u;
> > +}
> ...
> > +static inline void u64_to_ether_addr(u64 u, u8 *addr)
> > +{
> > + int i;
> > +
> > + for (i = ETH_ALEN - 1; i >= 0; i--) {
> > + addr[i] = u & 0xff;
> > + u = u >> 8;
> > + }
> > +}
>
> I think these two routines behave differently on big vs little
> endian. And I doubt this was your intention.
I don't have a big endian system to test on.
I tried to avoid the usual pitfalls. I don't cast a collection of
bytes to a u64, which i know has no chance of working. Accessing a MAC
address as a byte array should be endian safe. The shift operation
should also be endian safe.
What exactly do you think will behave differently?
Andrew
