RE: [PATCH V6] mac80211: Add support for SIOCGIWRATE ioctl to provide rate information

RE: [PATCH V6] mac80211: Add support for SIOCGIWRATE ioctl to provide rate information

[Joerg Pommnitz]

Hello all,
what does SIOCGIWRATE do for IBSS networks? In this case you might have a different rate for every node in your network. Looking up just "sdata->u.sta.bssid" is insufficient because the BSSID of an IBSS network is not a real MAC address (after all, there is no AP).

I would very much like an official way to enumerate the current rates for all known stations in an IBSS network. This information would be useful for AdHoc routing: Currently most approaches use packet loss to weight different links. In this case a link might look better than it actually is, because rate control already lowered the current rate to a level where no packet loss occured whereas another link with higher data rate looks bad because it drops a packet now and than.

Is there a way to get this information?
 
--  
Regards
 
       Joerg
 






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RE: [PATCH V6] mac80211: Add support for SIOCGIWRATE ioctl to provide rate information

[Johannes Berg]

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Joerg,

it is recommended practice to never remove people from CC, that applies
to From: too, so you should have sent a copy of your mail directly to
Larry as well.

> what does SIOCGIWRATE do for IBSS networks? In this case you might
> have a different rate for every node in your network. Looking up just
> "sdata->u.sta.bssid" is insufficient because the BSSID of an IBSS
> network is not a real MAC address (after all, there is no AP).

Nothing. It returns -EOPNOTSUPP, read the code.

> I would very much like an official way to enumerate the current rates
> for all known stations in an IBSS network. This information would be
> useful for AdHoc routing: Currently most approaches use packet loss to
> weight different links. In this case a link might look better than it
> actually is, because rate control already lowered the current rate to
> a level where no packet loss occured whereas another link with higher
> data rate looks bad because it drops a packet now and than.
> 
> Is there a way to get this information?

No. Feel free to come up with a spec and implement it for
cfg80211/nl80211

johannes

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[PATCH V6] mac80211: Add support for SIOCGIWRATE ioctl to provide rate information

[Larry Finger]

At present, transmission rate information for mac80211 is available only
if verbose debugging is turned on, and then only in the logs. This patch
implements the SIOCGIWRATE ioctl, which adds the current transmission rate to
the output of iwconfig.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
---

Index: wireless-dev/net/mac80211/ieee80211_ioctl.c
===================================================================
--- wireless-dev.orig/net/mac80211/ieee80211_ioctl.c
+++ wireless-dev/net/mac80211/ieee80211_ioctl.c
@@ -2013,6 +2013,29 @@ static int ieee80211_ioctl_giwscan(struc
 }
 
 
+static int ieee80211_ioctl_giwrate(struct net_device *dev,
+				  struct iw_request_info *info,
+				  struct iw_param *rate, char *extra)
+{
+	struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+	struct sta_info *sta;
+	struct ieee80211_sub_if_data *sdata;
+
+	sdata = IEEE80211_DEV_TO_SUB_IF(dev);
+	if (sdata->type == IEEE80211_IF_TYPE_STA)
+		sta = sta_info_get(local, sdata->u.sta.bssid);
+	else
+		return -EOPNOTSUPP;
+	if (!sta)
+		return -ENODEV;
+	if (sta->txrate < local->oper_hw_mode->num_rates)
+		rate->value = local->oper_hw_mode->rates[sta->txrate].rate * 100000;
+	else
+		rate->value = 0;
+	sta_info_put(sta);
+	return 0;
+}
+
 static int ieee80211_ioctl_siwrts(struct net_device *dev,
 				  struct iw_request_info *info,
 				  struct iw_param *rts, char *extra)
@@ -3137,7 +3160,7 @@ static const iw_handler ieee80211_handle
 	(iw_handler) NULL,				/* -- hole -- */
 	(iw_handler) NULL,				/* -- hole -- */
 	(iw_handler) NULL,				/* SIOCSIWRATE */
-	(iw_handler) NULL,				/* SIOCGIWRATE */
+	(iw_handler) ieee80211_ioctl_giwrate,		/* SIOCGIWRATE */
 	(iw_handler) ieee80211_ioctl_siwrts,		/* SIOCSIWRTS */
 	(iw_handler) ieee80211_ioctl_giwrts,		/* SIOCGIWRTS */
 	(iw_handler) ieee80211_ioctl_siwfrag,		/* SIOCSIWFRAG */

Re: [PATCH V6] mac80211: Add support for SIOCGIWRATE ioctl to provide rate information

[Michael Wu]

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On Tuesday 22 May 2007 20:14, Larry Finger wrote:
> At present, transmission rate information for mac80211 is available only
> if verbose debugging is turned on, and then only in the logs. This patch
> implements the SIOCGIWRATE ioctl, which adds the current transmission rate
> to the output of iwconfig.
>
> Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
> ---
>
ACK.

Thanks,
-Michael Wu

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