On Mon, 2011-10-03 at 16:23 -0400, John W. Linville wrote: > This is the latest attempt to address the long-standing complaint from > the aircrack-ng folks about being unable to change the channel on > monitor interfaces. This version checks for the existance of other > "active" interfaces and refuses the channel change if they are present. > > https://bugzilla.redhat.com/show_bug.cgi?id=654344 Thanks for working on this. > @@ -81,10 +81,32 @@ int cfg80211_set_freq(struct cfg80211_registered_device *rdev, > enum nl80211_channel_type channel_type) > { > struct ieee80211_channel *chan; > - int result; > + int result, active_intf_present = 0; > + struct wireless_dev *mon_wdev = NULL; > + > + if (wdev && wdev->iftype == NL80211_IFTYPE_MONITOR) { > + mon_wdev = wdev; > + > + ASSERT_RDEV_LOCK(rdev); > + > + /* rdev->devlist_mtx locked by callers */ > + list_for_each_entry(wdev, &rdev->netdev_list, list) { > + if (wdev && wdev != mon_wdev && > + (wdev->iftype == NL80211_IFTYPE_ADHOC || > + wdev->iftype == NL80211_IFTYPE_AP || > + wdev->iftype == NL80211_IFTYPE_AP_VLAN || > + wdev->iftype == NL80211_IFTYPE_MESH_POINT || > + wdev->iftype == NL80211_IFTYPE_P2P_GO)) { > + active_intf_present = 1; > + break; > + } > + } > + > + if (active_intf_present) > + return -EINVAL; > > - if (wdev && wdev->iftype == NL80211_IFTYPE_MONITOR) > wdev = NULL; > + } This really isn't the problem though, mac80211 will correctly treat monitor interfaces already, and drivers are pretty much expected to do the same thing. > @@ -131,5 +153,8 @@ int cfg80211_set_freq(struct cfg80211_registered_device *rdev, > if (wdev) > wdev->channel = chan; > > + if (mon_wdev) > + mon_wdev->channel = chan; This is the issue, it doesn't work. I'm finally getting to a point where I'm not sure I care any more though, if the people who user monitor mode are happy with this patch and don't care about getting the wrong results then who am I to complain? Maybe you should respin this patch with just the last bit. The checking above is pretty much useless. Also please add *huge* warnings to it that this *will* give the wrong results. Alternatively, it could be fixed up properly, but I think to do that we need a cfg80211 get_channel op to ask mac80211 what channel it really is using. Not that this will help much once we go multi-channel :-) johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
