[U-Boot] [PATCH] common: nvedit to protect additional ethernet addresses Part 1/1

[Jerry Van Baren <gvb.uboot@gmail.com>]

Wolfgang Denk wrote:
> Dear Stefan Althoefer,
> 
> In message <ghc625$k37$1@ger.gmane.org> you wrote:
>> This patches cmd_nvedit to reject changes for "ethaddr." in addition to "ethaddr"
>> and "serial#". This is intendend to protect changes to additional ethernet
>> addresses (e.g. "ethernet1").
> 
> The patch is bogus, as additional ethernet addrssses are eth1addr,
> eth2addr, etc. and not ethaddr1, etc.
> 
> 
> Also, please don't remove perfectly god comments.
> 
> NAK.
> 
> Best regards,
> 
> Wolfgang Denk

Arrgh, I was thinking I was so clever with strncmp() and it turns out I 
was being clever based on a totally bogus assumption (wrong format). 
:-(  I *hate* it when that happens.

The following should work for eth[0-9]+addr (untested):

	int ethnum;
	:
	:
		/* "eth[0-9]+addr" is always protected */
		if ((sscanf(name, "eth%daddr", &ethnum) == 1) &&
		    (ethnum < MAX_ETH_ADDRS))
			protected = 1;

Notes:
* The "ethaddr" case is handled prior to the above snippet of code.
* I took out the added check "if (strlen (name) == 8)", I'm not sure why 
that was in there, it would limit us to 10 ethernets.  If extra 
validation is desired, ethnum could be checked to be less than 
MAX_ETH_ADDRS.  On reflection, it seems like a good idea so I added it 
above.
* This is somewhat better than the strncmp() trick because the sscanf() 
will only convert digits.

gvb