cfg80211: Enhance the AKM advertizement to support per interface.

Commit ab4dfa20534e ("cfg80211: Allow drivers to advertise supported AKM
suites") introduces the support to advertize supported AKMs to userspace.

This needs an enhancement to advertize the AKM support per interface type,
specifically for the cfg80211-based drivers that implement SME and use
different mechanisms to support the AKM's for each interface type (e.g.,
the support for SAE, OWE AKM's take different paths for such drivers on
STA/AP mode).

This commit aims the same and enhances the earlier mechanism of advertizing
the AKMs per wiphy. Add new nl80211 attributes and data structure to
provide supported AKMs per interface type to userspace.

the AKMs advertized in akm_suites are default capabilities if not
advertized for a specific interface type in iftype_akm_suites.

Signed-off-by: Veerendranath Jakkam <vjakkam@codeaurora.org>
Link: https://lore.kernel.org/r/20200126203032.21934-1-vjakkam@codeaurora.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index d8cdbf07aeec..3ad937d0a256 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1896,6 +1896,46 @@ static int nl80211_send_pmsr_capa(struct cfg80211_registered_device *rdev,
 	return 0;
 }
 
+static int
+nl80211_put_iftype_akm_suites(struct cfg80211_registered_device *rdev,
+			      struct sk_buff *msg)
+{
+	int i;
+	struct nlattr *nested, *nested_akms;
+	const struct wiphy_iftype_akm_suites *iftype_akms;
+
+	if (!rdev->wiphy.num_iftype_akm_suites ||
+	    !rdev->wiphy.iftype_akm_suites)
+		return 0;
+
+	nested = nla_nest_start(msg, NL80211_ATTR_IFTYPE_AKM_SUITES);
+	if (!nested)
+		return -ENOBUFS;
+
+	for (i = 0; i < rdev->wiphy.num_iftype_akm_suites; i++) {
+		nested_akms = nla_nest_start(msg, i + 1);
+		if (!nested_akms)
+			return -ENOBUFS;
+
+		iftype_akms = &rdev->wiphy.iftype_akm_suites[i];
+
+		if (nl80211_put_iftypes(msg, NL80211_IFTYPE_AKM_ATTR_IFTYPES,
+					iftype_akms->iftypes_mask))
+			return -ENOBUFS;
+
+		if (nla_put(msg, NL80211_IFTYPE_AKM_ATTR_SUITES,
+			    sizeof(u32) * iftype_akms->n_akm_suites,
+			    iftype_akms->akm_suites)) {
+			return -ENOBUFS;
+		}
+		nla_nest_end(msg, nested_akms);
+	}
+
+	nla_nest_end(msg, nested);
+
+	return 0;
+}
+
 struct nl80211_dump_wiphy_state {
 	s64 filter_wiphy;
 	long start;
@@ -2454,6 +2494,9 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev,
 			    rdev->wiphy.akm_suites))
 			goto nla_put_failure;
 
+		if (nl80211_put_iftype_akm_suites(rdev, msg))
+			goto nla_put_failure;
+
 		/* done */
 		state->split_start = 0;
 		break;