> -----Message d'origine----- > De : [email protected] [mailto:linux-wireless- > [email protected]] De la part de Vasanthakumar Thiagarajan > Envoyé : mercredi 25 janvier 2017 12:31 > À : [email protected] > Cc : [email protected]; Vasanthakumar Thiagarajan > Objet : [RFC 2/3] cfg80211: Disallow moving out of operating DFS channel > in non-ETSI > > For non-ETSI regulatory domain, CAC result on DFS channel may not be valid > once moving out of that channel (as done during remain-on-channel, > scannning and off-channel tx). > Running CAC on an operating DFS channel after every off-channel operation > will only add complexity and disturb the current link. Better do not allow > any off-channel switch from a DFS operating channel in non-ETSI domain. >
Moving out should be forbidden only to "master" devices i.e. AP, mesh, ad-hoc. "Slave" devices i.e. client stations, are not responsible for detecting radars, hence, they can do an off-channel scan and go back to a "DFS operating channel" without waiting for CAC. It looks like your patch would forbid multichannel scan ? > Signed-off-by: Vasanthakumar Thiagarajan <[email protected]> > --- > net/wireless/nl80211.c | 38 ++++++++++++++++++++++++++++++++++++++ > 1 file changed, 38 insertions(+) > > diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index > 63dfa60..c614af4 100644 > --- a/net/wireless/nl80211.c > +++ b/net/wireless/nl80211.c > @@ -6506,6 +6506,17 @@ static int nl80211_parse_random_mac(struct nlattr > **attrs, > return 0; > } > > +static bool cfg80211_off_channel_oper_allowed(struct wireless_dev > +*wdev) { > + if (!cfg80211_beaconing_iface_active(wdev)) > + return true; > + > + if (!(wdev->chandef.chan->flags & IEEE80211_CHAN_RADAR)) > + return true; > + > + return regulatory_pre_cac_allowed(wdev->wiphy); > +} > + > static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info > *info) { > struct cfg80211_registered_device *rdev = info->user_ptr[0]; @@ - > 6631,6 +6642,21 @@ static int nl80211_trigger_scan(struct sk_buff *skb, > struct genl_info *info) > > request->n_channels = i; > > + if (!cfg80211_off_channel_oper_allowed(wdev)) { > + struct ieee80211_channel *chan; > + > + if (request->n_channels != 1) { > + err = -EBUSY; > + goto out_free; > + } > + > + chan = request->channels[0]; > + if (chan->center_freq != wdev->chandef.chan->center_freq) { > + err = -EBUSY; > + goto out_free; > + } > + } > + > i = 0; > if (n_ssids) { > nla_for_each_nested(attr, info- > >attrs[NL80211_ATTR_SCAN_SSIDS], tmp) { @@ -9053,6 +9079,7 @@ static int > nl80211_remain_on_channel(struct sk_buff *skb, > struct cfg80211_registered_device *rdev = info->user_ptr[0]; > struct wireless_dev *wdev = info->user_ptr[1]; > struct cfg80211_chan_def chandef; > + const struct cfg80211_chan_def *compat_chandef; > struct sk_buff *msg; > void *hdr; > u64 cookie; > @@ -9081,6 +9108,14 @@ static int nl80211_remain_on_channel(struct sk_buff > *skb, > if (err) > return err; > > + if (!(cfg80211_off_channel_oper_allowed(wdev) || > + cfg80211_chandef_identical(&wdev->chandef, &chandef))) { > + compat_chandef = cfg80211_chandef_compatible(&wdev->chandef, > + &chandef); > + if (compat_chandef != &chandef) > + return -EBUSY; > + } > + > msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); > if (!msg) > return -ENOMEM; > @@ -9256,6 +9291,9 @@ static int nl80211_tx_mgmt(struct sk_buff *skb, > struct genl_info *info) > if (!chandef.chan && params.offchan) > return -EINVAL; > > + if (params.offchan && !cfg80211_off_channel_oper_allowed(wdev)) > + return -EBUSY; > + > params.buf = nla_data(info->attrs[NL80211_ATTR_FRAME]); > params.len = nla_len(info->attrs[NL80211_ATTR_FRAME]); > > -- > 1.9.1
