wifi: cfg80211: add option for vif allowed radios

This allows users to prevent a vif from affecting radios other than the
configured ones. This can be useful in cases where e.g. an AP is running
on one radio, and triggering a scan on another radio should not disturb it.

Changing the allowed radios list for a vif is supported, but only while
it is down.

While it is possible to achieve the same by always explicitly specifying
a frequency list for scan requests and ensuring that the wrong channel/band
is never accidentally set on an unrelated interface, this change makes
multi-radio wiphy setups a lot easier to deal with for CLI users.

By itself, this patch only enforces the radio mask for scanning requests
and remain-on-channel. Follow-up changes build on this to limit configured
frequencies.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://patch.msgid.link/eefcb218780f71a1549875d149f1196486762756.1728462320.git-series.nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/net/wireless/util.c b/net/wireless/util.c
index 93a9c32418a6..040d62051eb9 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -2923,3 +2923,32 @@ bool cfg80211_radio_chandef_valid(const struct wiphy_radio *radio,
 	return true;
 }
 EXPORT_SYMBOL(cfg80211_radio_chandef_valid);
+
+bool cfg80211_wdev_channel_allowed(struct wireless_dev *wdev,
+				   struct ieee80211_channel *chan)
+{
+	struct wiphy *wiphy = wdev->wiphy;
+	const struct wiphy_radio *radio;
+	struct cfg80211_chan_def chandef;
+	u32 radio_mask;
+	int i;
+
+	radio_mask = wdev->radio_mask;
+	if (!wiphy->n_radio || radio_mask == BIT(wiphy->n_radio) - 1)
+		return true;
+
+	cfg80211_chandef_create(&chandef, chan, NL80211_CHAN_HT20);
+	for (i = 0; i < wiphy->n_radio; i++) {
+		if (!(radio_mask & BIT(i)))
+			continue;
+
+		radio = &wiphy->radio[i];
+		if (!cfg80211_radio_chandef_valid(radio, &chandef))
+			continue;
+
+		return true;
+	}
+
+	return false;
+}
+EXPORT_SYMBOL(cfg80211_wdev_channel_allowed);