| Message ID | 1448303241-27747-6-git-send-email-sojkam1@fel.cvut.cz (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Johannes Berg |
| Headers | show |
On Mon, 2015-11-23 at 19:27 +0100, Michal Sojka wrote: > #define NL80211_RRF_PASSIVE_SCAN NL80211_RRF_NO_IR > diff --git a/net/wireless/chan.c b/net/wireless/chan.c > index 59cabc9..b1ab77a 100644 > --- a/net/wireless/chan.c > +++ b/net/wireless/chan.c > @@ -804,7 +804,8 @@ static bool _cfg80211_reg_can_beacon(struct wiphy > *wiphy, > { > bool res; > u32 prohibited_flags = IEEE80211_CHAN_DISABLED | > - IEEE80211_CHAN_RADAR; > + IEEE80211_CHAN_RADAR | > + IEEE80211_CHAN_OCB_ONLY; So ... for the kernel, I don't *like* this approach, because it requires touching every single driver, and every single person who writes code in the future must be aware of the special handling for this flag. For userspace, however, this approach is simply impossible. Consider an older version of wpa_supplicant, that queries the channel list and isn't aware of the OCB_ONLY flag. This version would take the channel list and build a scan request with it, only to get the scan rejected since some channels it picked were only usable for OCB, as far as I can tell. I think the solution to this would be to redefine the CHAN_DISABLED flag to mean "channel disabled for non-ocb mode" and add a CHAN_OCB_ENABLED flag. Then code that knows about OCB would simply not test CHAN_DISABLED, but would instead test CHAN_OCB_ENABLED instead - and if that's clear OCB would not be permitted. However, this would have the side effect of enabling OCB *only* on OCB channels, which might not be a good idea, for testing purposes one might want to use the regular 2.4 or 5 GHz channels? If so, OCB could still be made to do something like ocb_usable = (flags & OCB_ENABLED) || !(flags & DISABLED); or we could even make the channel list internally maintain a CHAN_OCB_USABLE flag that essentially encodes the logic above. In any case, this would collapse the patch down to modifying only OCB code and nothing else, which is nice, and would keep existing userspace working since it would just see disabled channels while ignoring the OCB flag. johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Nov 27 2015, Johannes Berg wrote: > On Mon, 2015-11-23 at 19:27 +0100, Michal Sojka wrote: > >> #define NL80211_RRF_PASSIVE_SCAN NL80211_RRF_NO_IR >> diff --git a/net/wireless/chan.c b/net/wireless/chan.c >> index 59cabc9..b1ab77a 100644 >> --- a/net/wireless/chan.c >> +++ b/net/wireless/chan.c >> @@ -804,7 +804,8 @@ static bool _cfg80211_reg_can_beacon(struct wiphy >> *wiphy, >> { >> bool res; >> u32 prohibited_flags = IEEE80211_CHAN_DISABLED | >> - IEEE80211_CHAN_RADAR; >> + IEEE80211_CHAN_RADAR | >> + IEEE80211_CHAN_OCB_ONLY; > > So ... for the kernel, I don't *like* this approach, because it > requires touching every single driver, and every single person who > writes code in the future must be aware of the special handling for > this flag. > > For userspace, however, this approach is simply impossible. Consider an > older version of wpa_supplicant, that queries the channel list and > isn't aware of the OCB_ONLY flag. This version would take the channel > list and build a scan request with it, only to get the scan rejected > since some channels it picked were only usable for OCB, as far as I can > tell. > > I think the solution to this would be to redefine the CHAN_DISABLED > flag to mean "channel disabled for non-ocb mode" and add a > CHAN_OCB_ENABLED flag. > > Then code that knows about OCB would simply not test CHAN_DISABLED, but > would instead test CHAN_OCB_ENABLED instead - and if that's clear OCB > would not be permitted. > > However, this would have the side effect of enabling OCB *only* on OCB > channels, which might not be a good idea, for testing purposes one > might want to use the regular 2.4 or 5 GHz channels? If so, OCB could > still be made to do something like > > ocb_usable = (flags & OCB_ENABLED) || !(flags & DISABLED); > > or we could even make the channel list internally maintain a > CHAN_OCB_USABLE flag that essentially encodes the logic above. > > In any case, this would collapse the patch down to modifying only OCB > code and nothing else, which is nice, and would keep existing userspace > working since it would just see disabled channels while ignoring the > OCB flag. Yes, this makes perfect sense. I'll rework the patch. -Michal -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index 2c7bdb8..b47ac3e 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -117,6 +117,7 @@ enum ieee80211_band { * on this channel. * @IEEE80211_CHAN_NO_10MHZ: 10 MHz bandwidth is not permitted * on this channel. + * @IEEE80211_CHAN_OCB_ONLY: only OCB mode is allowed on this channel. * */ enum ieee80211_channel_flags { @@ -133,6 +134,7 @@ enum ieee80211_channel_flags { IEEE80211_CHAN_IR_CONCURRENT = 1<<10, IEEE80211_CHAN_NO_20MHZ = 1<<11, IEEE80211_CHAN_NO_10MHZ = 1<<12, + IEEE80211_CHAN_OCB_ONLY = 1<<13, }; #define IEEE80211_CHAN_NO_HT40 \ diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h index 1f0b4cf..07e6105 100644 --- a/include/uapi/linux/nl80211.h +++ b/include/uapi/linux/nl80211.h @@ -2865,6 +2865,7 @@ enum nl80211_sched_scan_match_attr { * @NL80211_RRF_NO_HT40PLUS: channels can't be used in HT40+ operation * @NL80211_RRF_NO_80MHZ: 80MHz operation not allowed * @NL80211_RRF_NO_160MHZ: 160MHz operation not allowed + * @NL80211_RRF_OCB_ONLY: only OCB mode can be used here */ enum nl80211_reg_rule_flags { NL80211_RRF_NO_OFDM = 1<<0, @@ -2882,6 +2883,7 @@ enum nl80211_reg_rule_flags { NL80211_RRF_NO_HT40PLUS = 1<<14, NL80211_RRF_NO_80MHZ = 1<<15, NL80211_RRF_NO_160MHZ = 1<<16, + NL80211_RRF_OCB_ONLY = 1<<17, }; #define NL80211_RRF_PASSIVE_SCAN NL80211_RRF_NO_IR diff --git a/net/wireless/chan.c b/net/wireless/chan.c index 59cabc9..b1ab77a 100644 --- a/net/wireless/chan.c +++ b/net/wireless/chan.c @@ -804,7 +804,8 @@ static bool _cfg80211_reg_can_beacon(struct wiphy *wiphy, { bool res; u32 prohibited_flags = IEEE80211_CHAN_DISABLED | - IEEE80211_CHAN_RADAR; + IEEE80211_CHAN_RADAR | + IEEE80211_CHAN_OCB_ONLY; trace_cfg80211_reg_can_beacon(wiphy, chandef, iftype, check_no_ir); @@ -814,7 +815,8 @@ static bool _cfg80211_reg_can_beacon(struct wiphy *wiphy, if (cfg80211_chandef_dfs_required(wiphy, chandef, iftype) > 0 && cfg80211_chandef_dfs_available(wiphy, chandef)) { /* We can skip IEEE80211_CHAN_NO_IR if chandef dfs available */ - prohibited_flags = IEEE80211_CHAN_DISABLED; + prohibited_flags = IEEE80211_CHAN_DISABLED | + IEEE80211_CHAN_OCB_ONLY; } res = cfg80211_chandef_usable(wiphy, chandef, prohibited_flags); diff --git a/net/wireless/ibss.c b/net/wireless/ibss.c index 4c55fab..d9df7f0 100644 --- a/net/wireless/ibss.c +++ b/net/wireless/ibss.c @@ -258,9 +258,9 @@ int cfg80211_ibss_wext_join(struct cfg80211_registered_device *rdev, for (i = 0; i < sband->n_channels; i++) { chan = &sband->channels[i]; - if (chan->flags & IEEE80211_CHAN_NO_IR) - continue; - if (chan->flags & IEEE80211_CHAN_DISABLED) + if (chan->flags & IEEE80211_CHAN_NO_IR || + chan->flags & IEEE80211_CHAN_DISABLED || + chan->flags & IEEE80211_CHAN_OCB_ONLY) continue; new_chan = chan; break; @@ -277,6 +277,9 @@ int cfg80211_ibss_wext_join(struct cfg80211_registered_device *rdev, NL80211_CHAN_NO_HT); } + if (wdev->wext.ibss.chandef.chan->flags & IEEE80211_CHAN_OCB_ONLY) + return -EINVAL; + /* don't join -- SSID is not there */ if (!wdev->wext.ibss.ssid_len) return 0; @@ -331,7 +334,8 @@ int cfg80211_ibss_wext_siwfreq(struct net_device *dev, if (!chan) return -EINVAL; if (chan->flags & IEEE80211_CHAN_NO_IR || - chan->flags & IEEE80211_CHAN_DISABLED) + chan->flags & IEEE80211_CHAN_DISABLED || + chan->flags & IEEE80211_CHAN_OCB_ONLY) return -EINVAL; } diff --git a/net/wireless/mesh.c b/net/wireless/mesh.c index 092300b..99866ff 100644 --- a/net/wireless/mesh.c +++ b/net/wireless/mesh.c @@ -143,7 +143,8 @@ int __cfg80211_join_mesh(struct cfg80211_registered_device *rdev, chan = &sband->channels[i]; if (chan->flags & (IEEE80211_CHAN_NO_IR | IEEE80211_CHAN_DISABLED | - IEEE80211_CHAN_RADAR)) + IEEE80211_CHAN_RADAR | + IEEE80211_CHAN_OCB_ONLY)) continue; setup->chandef.chan = chan; break; diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index c71e274..85b1df6 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -5860,8 +5860,8 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info) goto out_free; } - /* ignore disabled channels */ - if (chan->flags & IEEE80211_CHAN_DISABLED) + /* ignore disabled and OCB-only channels */ + if (chan->flags & (IEEE80211_CHAN_DISABLED | IEEE80211_CHAN_OCB_ONLY)) continue; request->channels[i] = chan; @@ -5880,7 +5880,7 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info) chan = &wiphy->bands[band]->channels[j]; - if (chan->flags & IEEE80211_CHAN_DISABLED) + if (chan->flags & (IEEE80211_CHAN_DISABLED | IEEE80211_CHAN_OCB_ONLY)) continue; request->channels[i] = chan; @@ -6247,8 +6247,8 @@ nl80211_parse_sched_scan(struct wiphy *wiphy, struct wireless_dev *wdev, goto out_free; } - /* ignore disabled channels */ - if (chan->flags & IEEE80211_CHAN_DISABLED) + /* ignore disabled and OCB-only channels */ + if (chan->flags & (IEEE80211_CHAN_DISABLED | IEEE80211_CHAN_OCB_ONLY)) continue; request->channels[i] = chan; @@ -6265,7 +6265,7 @@ nl80211_parse_sched_scan(struct wiphy *wiphy, struct wireless_dev *wdev, chan = &wiphy->bands[band]->channels[j]; - if (chan->flags & IEEE80211_CHAN_DISABLED) + if (chan->flags & (IEEE80211_CHAN_DISABLED | IEEE80211_CHAN_OCB_ONLY)) continue; request->channels[i] = chan; diff --git a/net/wireless/reg.c b/net/wireless/reg.c index 35eaeeb..8b7110d 100644 --- a/net/wireless/reg.c +++ b/net/wireless/reg.c @@ -1048,6 +1048,8 @@ static u32 map_regdom_flags(u32 rd_flags) channel_flags |= IEEE80211_CHAN_NO_80MHZ; if (rd_flags & NL80211_RRF_NO_160MHZ) channel_flags |= IEEE80211_CHAN_NO_160MHZ; + if (rd_flags & NL80211_RRF_OCB_ONLY) + channel_flags |= IEEE80211_CHAN_OCB_ONLY; return channel_flags; } diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 14d5369..67e4515 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -1236,9 +1236,9 @@ int cfg80211_wext_siwscan(struct net_device *dev, continue; for (j = 0; j < wiphy->bands[band]->n_channels; j++) { - /* ignore disabled channels */ + /* ignore disabled and OCB-only channels */ if (wiphy->bands[band]->channels[j].flags & - IEEE80211_CHAN_DISABLED) + (IEEE80211_CHAN_DISABLED | IEEE80211_CHAN_OCB_ONLY)) continue; /* If we have a wireless request structure and the diff --git a/net/wireless/sme.c b/net/wireless/sme.c index 8020b5b..817c879 100644 --- a/net/wireless/sme.c +++ b/net/wireless/sme.c @@ -103,7 +103,8 @@ static int cfg80211_conn_scan(struct wireless_dev *wdev) continue; for (j = 0; j < bands->n_channels; j++) { channel = &bands->channels[j]; - if (channel->flags & IEEE80211_CHAN_DISABLED) + if (channel->flags & IEEE80211_CHAN_DISABLED || + channel->flags & IEEE80211_CHAN_OCB_ONLY) continue; request->channels[i++] = channel; } diff --git a/net/wireless/wext-sme.c b/net/wireless/wext-sme.c index a4e8af3..34a50c1 100644 --- a/net/wireless/wext-sme.c +++ b/net/wireless/wext-sme.c @@ -83,7 +83,8 @@ int cfg80211_mgd_wext_siwfreq(struct net_device *dev, chan = ieee80211_get_channel(wdev->wiphy, freq); if (!chan) return -EINVAL; - if (chan->flags & IEEE80211_CHAN_DISABLED) + if (chan->flags & IEEE80211_CHAN_DISABLED || + chan->flags & IEEE80211_CHAN_OCB_ONLY) return -EINVAL; }
We don't want channels designated for Intelligent Transportation Systems to be used in other modes than OCB. We therefore introduce regulatory and channel flags that prevent scanning (for performance reasons) and beaconing on these channels. Although regulatory documents do not talk about which modes to use, we limit the mode to OCB in order to prevent accidental use of the band by other applications. Signed-off-by: Michal Sojka <sojkam1@fel.cvut.cz> --- include/net/cfg80211.h | 2 ++ include/uapi/linux/nl80211.h | 2 ++ net/wireless/chan.c | 6 ++++-- net/wireless/ibss.c | 12 ++++++++---- net/wireless/mesh.c | 3 ++- net/wireless/nl80211.c | 12 ++++++------ net/wireless/reg.c | 2 ++ net/wireless/scan.c | 4 ++-- net/wireless/sme.c | 3 ++- net/wireless/wext-sme.c | 3 ++- 10 files changed, 32 insertions(+), 17 deletions(-)