On Thu, Dec 17, 2015 at 10:34 PM, Stefan Sperling <s...@stsp.name> wrote:
> On Thu, Dec 17, 2015 at 08:13:03PM +0100, Stefan Sperling wrote:
>> This should fix the infinite scanning loops people have been
>> reporting with 11n-enabled iwn(4), as well as the issue where
>> clients associating to 11g APs end up in 11b mode and can't
>> use OFDM data rates.
>>
>> ok?
>
> Updated diff which allows scanning to work after somebody decided
> to run 'ifconfig iwn0 media autoselect mode 11n' for some reason.
> (Don't do that, it won't enforce 11n -- 11n cannot really be set
> a priori because it's negotiated during association.)
>
> Also delete a bit of code from ieee80211_newstate() in ieee80211_proto.c
> which is pointless now that ieee80211_chan2mode() won't return MODE_11N.
A minor problem I've noticed was dhclient being slower to get the link
from my AP.
The patch below fixed it.
Thanks again
David
> Index: ieee80211.c
> ===================================================================
> RCS file: /cvs/src/sys/net80211/ieee80211.c,v
> retrieving revision 1.52
> diff -u -p -r1.52 ieee80211.c
> --- ieee80211.c 16 Dec 2015 12:52:03 -0000 1.52
> +++ ieee80211.c 17 Dec 2015 21:16:03 -0000
> @@ -856,10 +856,12 @@ ieee80211_next_mode(struct ifnet *ifp)
> {
> struct ieee80211com *ic = (void *)ifp;
>
> - if (IFM_MODE(ic->ic_media.ifm_cur->ifm_media) != IFM_AUTO) {
> + if (IFM_MODE(ic->ic_media.ifm_cur->ifm_media) != IFM_AUTO &&
> + ic->ic_curmode != IEEE80211_MODE_11N) {
> /*
> * Reset the scan state and indicate a wrap around
> * if we're running in a fixed, user-specified phy mode.
> + * But 11n is not a valid phy mode for scanning (see below).
> */
> ieee80211_reset_scan(ifp);
> return (IEEE80211_MODE_AUTO);
> @@ -874,6 +876,16 @@ ieee80211_next_mode(struct ifnet *ifp)
> /* Wrap around and ignore turbo mode */
> if (ic->ic_curmode == IEEE80211_MODE_TURBO)
> continue;
> +#ifndef IEEE80211_NO_HT
> + /*
> + * Skip 11n mode while scanning. Its set of channels is
> + * the superset of all channels supported by other modes
> + * and 11n features cannot be negotiated without exchanging
> + * frames in another mode first.
> + */
> + if (ic->ic_curmode == IEEE80211_MODE_11N)
> + continue;
> +#endif
> if (ic->ic_curmode >= IEEE80211_MODE_MAX) {
> ic->ic_curmode = IEEE80211_MODE_AUTO;
> break;
> @@ -893,6 +905,11 @@ ieee80211_next_mode(struct ifnet *ifp)
> * caller can select a rate set. This is problematic and the
> * work here assumes how things work elsewhere in this code.
> *
> + * Because the result of this function is ultimately used to select
> + * a rate from the rate set of the returned mode, it must not return
> + * IEEE80211_MODE_11N. This function may be called in 11n mode to find
> + * a non-MCS rate to use for sending frames to non-HT STAs.
> + *
> * XXX never returns turbo modes -dcy
> */
> enum ieee80211_phymode
> @@ -911,11 +928,6 @@ ieee80211_chan2mode(struct ieee80211com
> * characteristics. We assume that turbo-only channels
> * are not considered when the channel set is constructed.
> */
> -#ifndef IEEE80211_NO_HT
> - if (IEEE80211_IS_CHAN_N(chan))
> - return IEEE80211_MODE_11N;
> - else
> -#endif
> if (IEEE80211_IS_CHAN_T(chan))
> return IEEE80211_MODE_TURBO;
> else if (IEEE80211_IS_CHAN_5GHZ(chan))
> Index: ieee80211_input.c
> ===================================================================
> RCS file: /cvs/src/sys/net80211/ieee80211_input.c,v
> retrieving revision 1.145
> diff -u -p -r1.145 ieee80211_input.c
> --- ieee80211_input.c 12 Dec 2015 13:56:10 -0000 1.145
> +++ ieee80211_input.c 17 Dec 2015 18:42:06 -0000
> @@ -2257,16 +2257,8 @@ ieee80211_recv_assoc_resp(struct ieee802
>
> /* Hop out of 11n mode after associating to a non-HT AP. */
> if (ic->ic_curmode == IEEE80211_MODE_11N &&
> - (ni->ni_flags & IEEE80211_NODE_HT) == 0) {
> - if (IEEE80211_IS_CHAN_T(ni->ni_chan))
> - ieee80211_setmode(ic, IEEE80211_MODE_TURBO);
> - else if (IEEE80211_IS_CHAN_A(ni->ni_chan))
> - ieee80211_setmode(ic, IEEE80211_MODE_11A);
> - else if (IEEE80211_IS_CHAN_G(ni->ni_chan))
> - ieee80211_setmode(ic, IEEE80211_MODE_11G);
> - else
> - ieee80211_setmode(ic, IEEE80211_MODE_11B);
> - }
> + (ni->ni_flags & IEEE80211_NODE_HT) == 0)
> + ieee80211_setmode(ic, ieee80211_chan2mode(ic, ni->ni_chan));
> #endif
> /*
> * Configure state now that we are associated.
> Index: ieee80211_proto.c
> ===================================================================
> RCS file: /cvs/src/sys/net80211/ieee80211_proto.c,v
> retrieving revision 1.56
> diff -u -p -r1.56 ieee80211_proto.c
> --- ieee80211_proto.c 24 Nov 2015 13:45:06 -0000 1.56
> +++ ieee80211_proto.c 17 Dec 2015 20:58:40 -0000
> @@ -894,15 +894,8 @@ justcleanup:
> /* initialize bss for probe request */
> IEEE80211_ADDR_COPY(ni->ni_macaddr, etherbroadcastaddr);
> IEEE80211_ADDR_COPY(ni->ni_bssid, etherbroadcastaddr);
> -#ifndef IEEE80211_NO_HT
> - if (ic->ic_curmode == IEEE80211_MODE_11N)
> - ni->ni_rates = ic->ic_sup_rates[
> - IEEE80211_IS_CHAN_2GHZ(ni->ni_chan) ?
> - IEEE80211_MODE_11G : IEEE80211_MODE_11A];
> - else
> -#endif
> - ni->ni_rates = ic->ic_sup_rates[
> - ieee80211_chan2mode(ic, ni->ni_chan)];
> + ni->ni_rates = ic->ic_sup_rates[
> + ieee80211_chan2mode(ic, ni->ni_chan)];
> ni->ni_associd = 0;
> ni->ni_rstamp = 0;
> switch (ostate) {
>
--
"If you try a few times and give up, you'll never get there. But if
you keep at it... There's a lot of problems in the world which can
really be solved by applying two or three times the persistence that
other people will."
-- Stewart Nelson
