Re: [dpdk-dev] [PATCH v3] app/testpmd: fix copying the name of the dynflag

[Ori Kam <orika@mellanox.com>]

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Iremonger, Bernard
> Sent: Tuesday, February 4, 2020 2:18 PM
> To: Ori Kam <orika@mellanox.com>; Yigit, Ferruh <ferruh.yigit@intel.com>;
> Lu, Wenzhuo <wenzhuo.lu@intel.com>; Wu, Jingjing <jingjing.wu@intel.com>
> Cc: dev@dpdk.org; Slava Ovsiienko <viacheslavo@mellanox.com>
> Subject: Re: [dpdk-dev] [PATCH v3] app/testpmd: fix copying the name of the
> dynflag
> 
> Hi Ori,
> 
> <snip>
> 
> 
> > > > > Subject: Re: [PATCH v3] app/testpmd: fix copying the name of the
> > > > > dynflag
> > > > >
> > > > > On 1/30/2020 9:04 PM, Ori Kam wrote:
> > > > > > When working with testpmd and setting the dynflag name, we copy
> > > > > > the name given by the cmd to the dynflag name.
> > > > > >
> > > > > > The issue is that the size of the dynflag name is smaller then
> > > > > > the string used by testpmd.
> > > > > >
> > > > > > This commit solves this issue by checking that the length of the
> > > > > > requested flag name is not too long.
> > > > > >
> > > > > > Coverity issue: 353610
> > > > > >
> > > > > > Fixes: b57b66a97ebf ("app/testpmd: support mbuf dynamic flag")
> > > > > >
> > > > > > Signed-off-by: Ori Kam <orika@mellanox.com>
> > > > > > ---
> > > > > > V3:
> > > > > >  * Fix style issue.
> > > > > >
> > > > > > V2:
> > > > > >  * change to check the requested flag name.
> > > > > > ---
> > > > > >  app/test-pmd/cmdline.c | 4 ++++
> > > > > >  1 file changed, 4 insertions(+)
> > > > > >
> > > > > > diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
> > > > > > index
> > > > > > dab22bc..7ccc778 100644
> > > > > > --- a/app/test-pmd/cmdline.c
> > > > > > +++ b/app/test-pmd/cmdline.c
> > > > > > @@ -18865,6 +18865,10 @@ struct
> > > > > > cmd_config_tx_dynf_specific_result {
> > > > > >
> > > > > >  	if (port_id_is_invalid(res->port_id, ENABLED_WARN))
> > > > > >  		return;
> > > > > > +	if (strlen(res->name) > sizeof(desc_flag.name)) {
> > >
> > > Would it be simpler to use RTE_MBUF_DYN_NAMESIZE instead of
> > > sizeof(desc_flag.name) ?
> > >
> > I don't really care. I used the sizeof approach since it is more used in DPDK.
> > But If you wish I can move to define.
> 
> For me it is simpler and clearer.

O.K will change.

> 
> >
> > > > >
> > > > > Shouldn't it be ">=" since 'strlen' doesn't count terminating char.
> 
> Not sure about ">="  as "=" does not allow space for terminating null.
> 

In new version I changed it to be >= means error.

> > > > > It would be safer to use 'strnlen'.
> > > > >
> > > >
> > > >
> > > > Will fix.
> > > >
> > > > > > +		printf("Flag name too long\n");
> > > > > > +		return;
> > > > > > +	}
> > > > > >  	flag = rte_mbuf_dynflag_lookup(res->name, NULL);
> > > > > >  	if (flag <= 0) {
> > > > > >  		strcpy(desc_flag.name, res->name);
> > > > >
> > > > > And it would be nice to use 'strlcpy' here, to be sure target
> > > > > string will be null terminated.
> > > >
> > > > Will fix.
> > >
> Regards,
> 
> Bernard.