Subject: Re: [PATCH 2/6] netlink: make validation more configurable for future
 strictness
To:     Johannes Berg <johannes@sipsolutions.net>,
        linux-wireless@vger.kernel.org, netdev@vger.kernel.org
Cc:     Pablo Neira Ayuso <pablo@netfilter.org>,
        Johannes Berg <johannes.berg@intel.com>
References: <20190404065408.5864-1-johannes@sipsolutions.net>
 <20190404065408.5864-3-johannes@sipsolutions.net>
From:   David Ahern <dsa@cumulusnetworks.com>
Message-ID: <86911e8d-2818-67f8-058b-ab2f4db33e55@cumulusnetworks.com>
Date:   Wed, 10 Apr 2019 09:55:23 -0700
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:52.0)
 Gecko/20100101 Thunderbird/52.9.1
MIME-Version: 1.0
In-Reply-To: <20190404065408.5864-3-johannes@sipsolutions.net>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

On 4/3/19 11:54 PM, Johannes Berg wrote:
> @@ -280,6 +287,12 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
>  		break;
>  
>  	case NLA_UNSPEC:
> +		if (validate & NL_VALIDATE_UNSPEC) {
> +			NL_SET_ERR_MSG_ATTR(extack, nla,
> +					    "Attribute not understood");

I found that confusing when I did a trial run for a new route attribute.
How about "Unsupported attribute"?

> +			return -EINVAL;
> +		}
> +		/* fall through */
>  	case NLA_MIN_LEN:
>  		if (attrlen < pt->len)
>  			goto out_err;