[dpdk-dev] [PATCH] net/tap: fix coverity warning on strncpy

[Wiles, Keith]

> On Feb 17, 2017, at 9:02 AM, Richardson, Bruce <bruce.richardson at intel.com> wrote:
> 
> On Fri, Feb 17, 2017 at 08:44:26AM -0600, Keith Wiles wrote:
>> Calling strncpy with a maximum size argument of 16 bytes on destination
>> array "ifr.ifr_ifrn.ifrn_name" of size 16 bytes might leave the
>> destination string unterminated.
>> 
>> Signed-off-by: Keith Wiles <keith.wiles at intel.com>
>> ---
>> drivers/net/tap/rte_eth_tap.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>> 
>> diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
>> index efc4426..f9938d7 100644
>> --- a/drivers/net/tap/rte_eth_tap.c
>> +++ b/drivers/net/tap/rte_eth_tap.c
>> @@ -297,7 +297,7 @@ tap_link_set_flags(struct pmd_internals *pmd, short flags, int add)
>> 		return -1;
>> 	}
>> 	memset(&ifr, 0, sizeof(ifr));
>> -	strncpy(ifr.ifr_name, pmd->name, IFNAMSIZ);
>> +	strncpy(ifr.ifr_name, pmd->name, IFNAMSIZ-1);
> This is why I always prefer to use snprintf for copying strings, you
> can't avoid null terminating.

Normally I use snprintf to not sure why I reverted to strncpy. Maybe leftover from a previous driver I used as the template.

> 
> 	snprintf(ifr.ifr_name, IFNAMSIZ, "%s", pmd->name);
> 
> 	/Bruce

Regards,
Keith