Received-SPF: pass (google.com: best guess record for domain of linux-wireless-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Message-ID: <0452a0cbb36bcffa8371a58dfd931864c1f79eef.camel@sipsolutions.net>
Subject: Re: Implementing Mikrotik IE
From:   Johannes Berg <johannes@sipsolutions.net>
To:     Josef Miegl <josef@miegl.cz>
Cc:     Sebastian Gottschall <s.gottschall@newmedia-net.de>,
        linux-wireless <linux-wireless@vger.kernel.org>
Date:   Thu, 22 Aug 2019 22:08:13 +0200
In-Reply-To: <5ee160209eb1f9e70f6224c393389266280d7d80.camel@sipsolutions.net> (sfid-20190822_090033_537095_4B41631C)
References: <20190815152844.k5mmddvbwrohkzr6@pepin-laptop.localdomain>
         <3a079683-6f57-3b42-f909-90c46e14f14f@newmedia-net.de>
         <20190816111044.4ntizgmpa3twbzcg@pepin-laptop.localdomain>
         <e8129acb-fc32-c85c-b504-ab8777a3f1a3@newmedia-net.de>
         <20190816113818.ohktykc4fyetzyvq@pepin-laptop.localdomain>
         <9985fddfb059640f36665efc9c1ef2dc0bdb7662.camel@sipsolutions.net>
         <20190819113706.ujsz67sxcwt2ulmt@pepin-laptop.localdomain>
         <b3b7a99971f1512b4cd9c72920b699c252c1ae83.camel@sipsolutions.net>
         <A3C14EA9-BA2D-4745-BBB9-E10028B6DE13@miegl.cz>
         <6efb9b56c77cd9ea945f89c3371b49c301dc2b4e.camel@sipsolutions.net>
         <58A25955-2A17-4DE7-82FB-3B20E00C96EC@miegl.cz>
         <5ee160209eb1f9e70f6224c393389266280d7d80.camel@sipsolutions.net>
         (sfid-20190822_090033_537095_4B41631C)
Content-Type: text/plain; charset="UTF-8"
User-Agent: Evolution 3.30.5 (3.30.5-1.fc29) 
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

On Thu, 2019-08-22 at 09:00 +0200, Johannes Berg wrote:
> 
> Perhaps it expects the 4-way-HS to already be in 4-addr frame format, or
> something else special in the 4-way-HS if you have WDS?

I think this is actually the right guess.

The working capture you sent me has the EAPOL 2/4 in a 4-addr frame:

ToDS=1, FromDS=1
A1/RA = AP
A2/TA = STA
A3/DA = AP
A4/SA = STA

The non-working capture has the EAPOL 2/4 in 3-addr format, as you'd
expect in the Linux 4-addr AP/STA case:

ToDS=1, FromDS=0
A1/RA    = AP
A2/TA,SA = STA
A3/DA    = AP

Since it's basically ignoring the message 2 (it just says "handshake
timed out" later) it's almost certainly expecting *only* the 4-addr
format.

As a hack, you could do

--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2623,8 +2623,7 @@ static struct sk_buff *ieee80211_build_hdr(struct ieee80211_sub_if_data *sdata,
                        memcpy(hdr.addr2, skb->data + ETH_ALEN, ETH_ALEN);
                        memcpy(hdr.addr3, sdata->u.mgd.bssid, ETH_ALEN);
                        hdrlen = 24;
-               }  else if (sdata->u.mgd.use_4addr &&
-                           cpu_to_be16(ethertype) != sdata->control_port_protocol) {
+               }  else if (sdata->u.mgd.use_4addr) {
                        fc |= cpu_to_le16(IEEE80211_FCTL_FROMDS |
                                          IEEE80211_FCTL_TODS);
                        /* RA TA DA SA */


in mac80211, then it should send 4-addr frames even for EAPOL.

johannes