Re: [RFC PATCH net-next] sched: act_ctinfo: use extack error reporting

[Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>]

On Thu, Jun 13, 2019 at 01:18:52PM +0200, Kevin Darbyshire-Bryant wrote:
> Use extack error reporting mechanism in addition to returning -EINVAL
> 
> Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>

Nice. LGTM!

> ---
>  net/sched/act_ctinfo.c | 23 ++++++++++++++++++-----
>  1 file changed, 18 insertions(+), 5 deletions(-)
> 
> diff --git a/net/sched/act_ctinfo.c b/net/sched/act_ctinfo.c
> index e78b60e47c0f..a7d3679d7e2e 100644
> --- a/net/sched/act_ctinfo.c
> +++ b/net/sched/act_ctinfo.c
> @@ -165,15 +165,20 @@ static int tcf_ctinfo_init(struct net *net, struct nlattr *nla,
>  	u8 dscpmaskshift;
>  	int ret = 0, err;
>  
> -	if (!nla)
> +	if (!nla) {
> +		NL_SET_ERR_MSG_MOD(extack, "ctinfo requires attributes to be passed");
>  		return -EINVAL;
> +	}
>  
> -	err = nla_parse_nested(tb, TCA_CTINFO_MAX, nla, ctinfo_policy, NULL);
> +	err = nla_parse_nested(tb, TCA_CTINFO_MAX, nla, ctinfo_policy, extack);
>  	if (err < 0)
>  		return err;
>  
> -	if (!tb[TCA_CTINFO_ACT])
> +	if (!tb[TCA_CTINFO_ACT]) {
> +		NL_SET_ERR_MSG_MOD(extack,
> +				   "Missing required TCA_CTINFO_ACT attribute");
>  		return -EINVAL;
> +	}
>  	actparm = nla_data(tb[TCA_CTINFO_ACT]);
>  
>  	/* do some basic validation here before dynamically allocating things */
> @@ -182,13 +187,21 @@ static int tcf_ctinfo_init(struct net *net, struct nlattr *nla,
>  		dscpmask = nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_MASK]);
>  		/* need contiguous 6 bit mask */
>  		dscpmaskshift = dscpmask ? __ffs(dscpmask) : 0;
> -		if ((~0 & (dscpmask >> dscpmaskshift)) != 0x3f)
> +		if ((~0 & (dscpmask >> dscpmaskshift)) != 0x3f) {
> +			NL_SET_ERR_MSG_ATTR(extack,
> +					    tb[TCA_CTINFO_PARMS_DSCP_MASK],
> +					    "dscp mask must be 6 contiguous bits");
>  			return -EINVAL;
> +		}
>  		dscpstatemask = tb[TCA_CTINFO_PARMS_DSCP_STATEMASK] ?
>  			nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_STATEMASK]) : 0;
>  		/* mask & statemask must not overlap */
> -		if (dscpmask & dscpstatemask)
> +		if (dscpmask & dscpstatemask) {
> +			NL_SET_ERR_MSG_ATTR(extack,
> +					    tb[TCA_CTINFO_PARMS_DSCP_STATEMASK],
> +					    "dscp statemask must not overlap dscp mask");
>  			return -EINVAL;
> +		}
>  	}
>  
>  	/* done the validation:now to the actual action allocation */
> -- 
> 2.20.1 (Apple Git-117)
>