[Dnsmasq-discuss] [PATCH] Remove NULL check for intname.
Kevin Darbyshire-Bryant
kevin at darbyshire-bryant.me.uk
Thu Oct 5 11:22:10 BST 2017
On 05/10/17 06:20, rosenp at gmail.com wrote:
> On Wed, 2017-10-04 at 20:43 -0700, Kurt H Maier wrote:
>> On Wed, Oct 04, 2017 at 07:23:22PM -0700, Rosen Penev wrote:
>>>
>>> - if (intname && strlen(intname) != 0)
>>> + if (!strlen(intname))
>>> ifindex = if_nametoindex(intname); /* index == 0 when not
>>> binding to an interface */
>>
>> How much testing have you done of these patches?
>>
>
> Compile time. Looks fine to me. To add to my commit message,
> strlen(NULL) causes a segmentation fault, meaning intname cannot be
> NULL.
Which is precisely why the 'intname' guard is there. C evaluation order
is left to right, if 'intname' is NULL then evaluation stops there....
strlen is never called with a NULL intname.
Kevin
More information about the Dnsmasq-discuss
mailing list