wifi: cfg80211: add support for advertising multiple radios belonging to a wiphy

The prerequisite for MLO support in cfg80211/mac80211 is that all the links
participating in MLO must be from the same wiphy/ieee80211_hw. To meet this
expectation, some drivers may need to group multiple discrete hardware each
acting as a link in MLO under single wiphy.

With this change, supported frequencies and interface combinations of each
individual radio are reported to user space. This allows user space to figure
out the limitations of what combination of channels can be used concurrently.

Even for non-MLO devices, this improves support for devices capable of
running on multiple channels at the same time.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://patch.msgid.link/18a88f9ce82b1c9f7c12f1672430eaf2bb0be295.1720514221.git-series.nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 102 insertions, 11 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index deacd5f3f256..7397a372c78e 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1632,16 +1632,18 @@ nla_put_failure:
 }
 
 static int nl80211_put_ifcomb_data(struct sk_buff *msg, bool large, int idx,
-				   const struct ieee80211_iface_combination *c)
+				   const struct ieee80211_iface_combination *c,
+				   u16 nested)
 {
 	struct nlattr *nl_combi, *nl_limits;
 	int i;
 
-	nl_combi = nla_nest_start_noflag(msg, idx);
+	nl_combi = nla_nest_start_noflag(msg, idx | nested);
 	if (!nl_combi)
 		goto nla_put_failure;
 
-	nl_limits = nla_nest_start_noflag(msg, NL80211_IFACE_COMB_LIMITS);
+	nl_limits = nla_nest_start_noflag(msg, NL80211_IFACE_COMB_LIMITS |
+					       nested);
 	if (!nl_limits)
 		goto nla_put_failure;
 
@@ -1689,19 +1691,26 @@ nla_put_failure:
 
 static int nl80211_put_iface_combinations(struct wiphy *wiphy,
 					  struct sk_buff *msg,
-					  bool large)
+					  int attr, int radio,
+					  bool large, u16 nested)
 {
+	const struct ieee80211_iface_combination *c;
 	struct nlattr *nl_combis;
-	int i;
+	int i, n;
 
-	nl_combis = nla_nest_start_noflag(msg,
-					  NL80211_ATTR_INTERFACE_COMBINATIONS);
+	nl_combis = nla_nest_start_noflag(msg, attr | nested);
 	if (!nl_combis)
 		goto nla_put_failure;
 
-	for (i = 0; i < wiphy->n_iface_combinations; i++)
-		if (nl80211_put_ifcomb_data(msg, large, i + 1,
-					    &wiphy->iface_combinations[i]))
+	if (radio >= 0) {
+		c = wiphy->radio[0].iface_combinations;
+		n = wiphy->radio[0].n_iface_combinations;
+	} else {
+		c = wiphy->iface_combinations;
+		n = wiphy->n_iface_combinations;
+	}
+	for (i = 0; i < n; i++)
+		if (nl80211_put_ifcomb_data(msg, large, i + 1, &c[i], nested))
 			goto nla_put_failure;
 
 	nla_nest_end(msg, nl_combis);
@@ -2408,6 +2417,80 @@ fail:
 	return -ENOBUFS;
 }
 
+static int nl80211_put_radio(struct wiphy *wiphy, struct sk_buff *msg, int idx)
+{
+	const struct wiphy_radio *r = &wiphy->radio[idx];
+	struct nlattr *radio, *freq;
+	int i;
+
+	radio = nla_nest_start(msg, idx);
+	if (!radio)
+		return -ENOBUFS;
+
+	if (nla_put_u32(msg, NL80211_WIPHY_RADIO_ATTR_INDEX, idx))
+		goto nla_put_failure;
+
+	for (i = 0; i < r->n_freq_range; i++) {
+		const struct wiphy_radio_freq_range *range = &r->freq_range[i];
+
+		freq = nla_nest_start(msg, NL80211_WIPHY_RADIO_ATTR_FREQ_RANGE);
+		if (!freq)
+			goto nla_put_failure;
+
+		if (nla_put_u32(msg, NL80211_WIPHY_RADIO_FREQ_ATTR_START,
+				range->start_freq) ||
+		    nla_put_u32(msg, NL80211_WIPHY_RADIO_FREQ_ATTR_END,
+				range->end_freq))
+			goto nla_put_failure;
+
+		nla_nest_end(msg, freq);
+	}
+
+	for (i = 0; i < r->n_iface_combinations; i++)
+		if (nl80211_put_ifcomb_data(msg, true,
+					    NL80211_WIPHY_RADIO_ATTR_INTERFACE_COMBINATION,
+					    &r->iface_combinations[i],
+					    NLA_F_NESTED))
+			goto nla_put_failure;
+
+	nla_nest_end(msg, radio);
+
+	return 0;
+
+nla_put_failure:
+	return -ENOBUFS;
+}
+
+static int nl80211_put_radios(struct wiphy *wiphy, struct sk_buff *msg)
+{
+	struct nlattr *radios;
+	int i;
+
+	if (!wiphy->n_radio)
+		return 0;
+
+	radios = nla_nest_start(msg, NL80211_ATTR_WIPHY_RADIOS);
+	if (!radios)
+		return -ENOBUFS;
+
+	for (i = 0; i < wiphy->n_radio; i++)
+		if (nl80211_put_radio(wiphy, msg, i))
+			goto fail;
+
+	nla_nest_end(msg, radios);
+
+	if (nl80211_put_iface_combinations(wiphy, msg,
+					   NL80211_ATTR_WIPHY_INTERFACE_COMBINATIONS,
+					   -1, true, NLA_F_NESTED))
+		return -ENOBUFS;
+
+	return 0;
+
+fail:
+	nla_nest_cancel(msg, radios);
+	return -ENOBUFS;
+}
+
 struct nl80211_dump_wiphy_state {
 	s64 filter_wiphy;
 	long start;
@@ -2703,7 +2786,9 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev,
 			goto nla_put_failure;
 
 		if (nl80211_put_iface_combinations(&rdev->wiphy, msg,
-						   state->split))
+						   NL80211_ATTR_INTERFACE_COMBINATIONS,
+						   rdev->wiphy.n_radio ? 0 : -1,
+						   state->split, 0))
 			goto nla_put_failure;
 
 		state->split_start++;
@@ -3017,6 +3102,12 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev,
 				rdev->wiphy.hw_timestamp_max_peers))
 			goto nla_put_failure;
 
+		state->split_start++;
+		break;
+	case 17:
+		if (nl80211_put_radios(&rdev->wiphy, msg))
+			goto nla_put_failure;
+
 		/* done */
 		state->split_start = 0;
 		break;