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Message-ID: <9936de52da43347ba0ccfb8737440a9698fb4585.camel@sipsolutions.net>
Subject: Re: [PATCH] wifi: nl80211: fix mbssid nesting
From:   Johannes Berg <johannes@sipsolutions.net>
To:     Koen Vandeputte <koen.vandeputte@citymesh.com>,
        linux-wireless@vger.kernel.org
Cc:     John Crispin <john@phrozen.org>,
        Aloka Dixit <alokad@codeaurora.org>, stable@vger.kernel.org
Date:   Wed, 12 Jul 2023 10:44:17 +0200
In-Reply-To: <20230712083841.222607-1-koen.vandeputte@citymesh.com>
References: <20230712083841.222607-1-koen.vandeputte@citymesh.com>
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On Wed, 2023-07-12 at 10:38 +0200, Koen Vandeputte wrote:
> Executing command NL80211_CMD_GET_WIPHY and parsing it's output
> natively without libnl shows following attributes as part of
> the nl80211 generated netlink message (part 16):
>=20
> GetWiphy: Type: 1
> GetWiphy: Type: 2
> GetWiphy: Type: 46
> GetWiphy: Type: 33074 <-- wrong enum value, above MAX also ..

That's not wrong, that's just NLA_F_NESTED | NL80211_ATTR_MBSSID_CONFIG,
since it *is* in fact a nested attribute.

> Switching to nla_nest_start_noflag() which ommits the NLA_F_NESTED
> flag (like most other similar functions do) fixes this:
>=20
> GetWiphy: Type: 1
> GetWiphy: Type: 2
> GetWiphy: Type: 46
> GetWiphy: Type: 306 <-- correct enum value
> GetWiphy: Type: 316

Let's say it _changes_ it, but it doesn't _fix_ it, since it's not
broken.

Using nla_nest_start_noflag() is a legacy thing, it shouldn't be done
any more. You need to update your userspace, I'm not applying this
patch.

johannes