Code Review 7022269: clean up fscanf usage in soalris networking native code

[Chris Hegarty]

On 02/25/11 02:39 PM, Michael McMahon wrote:
> Alan Bateman wrote:
>> Chris Hegarty wrote:
>>> Michael, Alan,
>>>
>>> Some small cleanups to the use of scanf with specified string width.
>>> The buffers should be sized large enough to handle the specified
>>> width and the null terminator.
>>>
>>> http://cr.openjdk.java.net/~chegar/7022269/webrev.00/webrev/
>>>
>>> -Chris.
>> Looks okay although slightly inconsistent in that the code in
>> initLocalIfs allows a device name up to 32 chars but the other places
>> it is 20. I don't know what the right answer is.
>>
>> -Alan
> Would it be better to #define a constant and use constant+1 then where
> the array
> is allocated. Maybe use the same 32 byte storage in all places.
> Not a big deal really.

In net/ipv6/addrconf.c (kernel source) they use %8s, but then size the 
char array using IFNAMSIZ (16). Adding a new definition for the sizing 
may be a little misleading. We should probably use these values, but 
then I'd be nervous about making any reductions in size.

I guess one issue is that the string width in scanf is always going to 
be a hardcoded value no matter what definitions you make. And that value 
has a direct impact on the array sizing.

It's common practice to use scanf ( and its variants ) with defined 
string widths and arrays. You just need to be aware of the potential 
overflows. For this reason I don't see any value in a #define.

-Chris.

>
> - Michael