cfg80211: Advertise extended capabilities per interface type to userspace

The driver extended capabilities may differ for different
interface types which the userspace needs to know (for
example the fine timing measurement initiator and responder
bits might differ for a station and AP). Add a new nl80211
attribute to provide extended capabilities per interface type
to userspace.

Signed-off-by: Vidyullatha Kanchanapally <vkanchan@qti.qualcomm.com>
Reviewed-by: Jouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

2 files changed, 72 insertions, 1 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index d25c82bc1bbe..b8e10a952111 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -750,6 +750,36 @@ int wiphy_register(struct wiphy *wiphy)
 		nl80211_send_reg_change_event(&request);
 	}
 
+	/* Check that nobody globally advertises any capabilities they do not
+	 * advertise on all possible interface types.
+	 */
+	if (wiphy->extended_capabilities_len &&
+	    wiphy->num_iftype_ext_capab &&
+	    wiphy->iftype_ext_capab) {
+		u8 supported_on_all, j;
+		const struct wiphy_iftype_ext_capab *capab;
+
+		capab = wiphy->iftype_ext_capab;
+		for (j = 0; j < wiphy->extended_capabilities_len; j++) {
+			if (capab[0].extended_capabilities_len > j)
+				supported_on_all =
+					capab[0].extended_capabilities[j];
+			else
+				supported_on_all = 0x00;
+			for (i = 1; i < wiphy->num_iftype_ext_capab; i++) {
+				if (j >= capab[i].extended_capabilities_len) {
+					supported_on_all = 0x00;
+					break;
+				}
+				supported_on_all &=
+					capab[i].extended_capabilities[j];
+			}
+			if (WARN_ON(wiphy->extended_capabilities[j] &
+				    ~supported_on_all))
+				break;
+		}
+	}
+
 	rdev->wiphy.registered = true;
 	rtnl_unlock();
 
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 03ac2ba8b174..d12044996a0e 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1264,7 +1264,7 @@ nl80211_send_mgmt_stypes(struct sk_buff *msg,
 struct nl80211_dump_wiphy_state {
 	s64 filter_wiphy;
 	long start;
-	long split_start, band_start, chan_start;
+	long split_start, band_start, chan_start, capa_start;
 	bool split;
 };
 
@@ -1761,6 +1761,47 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev,
 			nla_nest_end(msg, nested);
 		}
 
+		state->split_start++;
+		break;
+	case 13:
+		if (rdev->wiphy.num_iftype_ext_capab &&
+		    rdev->wiphy.iftype_ext_capab) {
+			struct nlattr *nested_ext_capab, *nested;
+
+			nested = nla_nest_start(msg,
+						NL80211_ATTR_IFTYPE_EXT_CAPA);
+			if (!nested)
+				goto nla_put_failure;
+
+			for (i = state->capa_start;
+			     i < rdev->wiphy.num_iftype_ext_capab; i++) {
+				const struct wiphy_iftype_ext_capab *capab;
+
+				capab = &rdev->wiphy.iftype_ext_capab[i];
+
+				nested_ext_capab = nla_nest_start(msg, i);
+				if (!nested_ext_capab ||
+				    nla_put_u32(msg, NL80211_ATTR_IFTYPE,
+						capab->iftype) ||
+				    nla_put(msg, NL80211_ATTR_EXT_CAPA,
+					    capab->extended_capabilities_len,
+					    capab->extended_capabilities) ||
+				    nla_put(msg, NL80211_ATTR_EXT_CAPA_MASK,
+					    capab->extended_capabilities_len,
+					    capab->extended_capabilities_mask))
+					goto nla_put_failure;
+
+				nla_nest_end(msg, nested_ext_capab);
+				if (state->split)
+					break;
+			}
+			nla_nest_end(msg, nested);
+			if (i < rdev->wiphy.num_iftype_ext_capab) {
+				state->capa_start = i + 1;
+				break;
+			}
+		}
+
 		/* done */
 		state->split_start = 0;
 		break;