cfg80211: AP mode driver offload for FILS association crypto

Add a driver FILS crypto offload extended capability flag to indicate
that the driver running in AP mode is capable of handling encryption
and decryption of (Re)Association request and response frames.
Add a command to set FILS AAD data to driver.

This feature is supported on drivers running in AP mode only.
This extended capability is exchanged with hostapd during cfg80211
init. If the driver indicates this capability, then before sending the
Authentication response frame, hostapd sets FILS AAD data to the
driver. This allows the driver to decrypt (Re)Association Request
frame and encrypt (Re)Association Response frame. FILS Key derivation
will still be done in hostapd.

Signed-off-by: Subrat Mishra <subratm@codeaurora.org>
Link: https://lore.kernel.org/r/1631685143-13530-1-git-send-email-subratm@codeaurora.org
[fix whitespace]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

3 files changed, 75 insertions, 0 deletions

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 0b4f29d689d2..d7c03f6145f0 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -14936,6 +14936,29 @@ out:
 	return err;
 }
 
+static int nl80211_set_fils_aad(struct sk_buff *skb,
+				struct genl_info *info)
+{
+	struct cfg80211_registered_device *rdev = info->user_ptr[0];
+	struct net_device *dev = info->user_ptr[1];
+	struct cfg80211_fils_aad fils_aad = {};
+	u8 *nonces;
+
+	if (!info->attrs[NL80211_ATTR_MAC] ||
+	    !info->attrs[NL80211_ATTR_FILS_KEK] ||
+	    !info->attrs[NL80211_ATTR_FILS_NONCES])
+		return -EINVAL;
+
+	fils_aad.macaddr = nla_data(info->attrs[NL80211_ATTR_MAC]);
+	fils_aad.kek_len = nla_len(info->attrs[NL80211_ATTR_FILS_KEK]);
+	fils_aad.kek = nla_data(info->attrs[NL80211_ATTR_FILS_KEK]);
+	nonces = nla_data(info->attrs[NL80211_ATTR_FILS_NONCES]);
+	fils_aad.snonce = nonces;
+	fils_aad.anonce = nonces + FILS_NONCE_LEN;
+
+	return rdev_set_fils_aad(rdev, dev, &fils_aad);
+}
+
 #define NL80211_FLAG_NEED_WIPHY		0x01
 #define NL80211_FLAG_NEED_NETDEV	0x02
 #define NL80211_FLAG_NEED_RTNL		0x04
@@ -15937,6 +15960,13 @@ static const struct genl_small_ops nl80211_small_ops[] = {
 		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP |
 				  NL80211_FLAG_NEED_RTNL,
 	},
+	{
+		.cmd = NL80211_CMD_SET_FILS_AAD,
+		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
+		.doit = nl80211_set_fils_aad,
+		.flags = GENL_UNS_ADMIN_PERM,
+		.internal_flags = NL80211_FLAG_NEED_NETDEV_UP,
+	},
 };
 
 static struct genl_family nl80211_fam __ro_after_init = {
diff --git a/net/wireless/rdev-ops.h b/net/wireless/rdev-ops.h
index ce6bf218a1a3..cc1efec4b27b 100644
--- a/net/wireless/rdev-ops.h
+++ b/net/wireless/rdev-ops.h
@@ -1381,4 +1381,18 @@ static inline int rdev_color_change(struct cfg80211_registered_device *rdev,
 	return ret;
 }
 
+static inline int
+rdev_set_fils_aad(struct cfg80211_registered_device *rdev,
+		  struct net_device *dev, struct cfg80211_fils_aad *fils_aad)
+{
+	int ret = -EOPNOTSUPP;
+
+	trace_rdev_set_fils_aad(&rdev->wiphy, dev, fils_aad);
+	if (rdev->ops->set_fils_aad)
+		ret = rdev->ops->set_fils_aad(&rdev->wiphy, dev, fils_aad);
+	trace_rdev_return_int(&rdev->wiphy, ret);
+
+	return ret;
+}
+
 #endif /* __CFG80211_RDEV_OPS */
diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index 19b78d472283..ad6c16a06bcb 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -167,6 +167,19 @@
 			__entry->center_freq1, __entry->freq1_offset,	\
 			__entry->center_freq2
 
+#define FILS_AAD_ASSIGN(fa)						\
+	do {								\
+		if (fa) {						\
+			ether_addr_copy(__entry->macaddr, fa->macaddr);	\
+			__entry->kek_len = fa->kek_len;			\
+		} else {						\
+			eth_zero_addr(__entry->macaddr);		\
+			__entry->kek_len = 0;				\
+		}							\
+	} while (0)
+#define FILS_AAD_PR_FMT							\
+	"macaddr: %pM, kek_len: %d"
+
 #define SINFO_ENTRY __field(int, generation)	    \
 		    __field(u32, connected_time)    \
 		    __field(u32, inactive_time)	    \
@@ -2614,6 +2627,24 @@ DEFINE_EVENT(wiphy_wdev_cookie_evt, rdev_abort_pmsr,
 	TP_ARGS(wiphy, wdev, cookie)
 );
 
+TRACE_EVENT(rdev_set_fils_aad,
+	TP_PROTO(struct wiphy *wiphy, struct net_device *netdev,
+		 struct cfg80211_fils_aad *fils_aad),
+	TP_ARGS(wiphy, netdev, fils_aad),
+	TP_STRUCT__entry(WIPHY_ENTRY
+		NETDEV_ENTRY
+		__array(u8, macaddr, ETH_ALEN)
+		__field(u8, kek_len)
+	),
+	TP_fast_assign(WIPHY_ASSIGN;
+		NETDEV_ASSIGN;
+		FILS_AAD_ASSIGN(fils_aad);
+	),
+	TP_printk(WIPHY_PR_FMT ", " NETDEV_PR_FMT ", " FILS_AAD_PR_FMT,
+		  WIPHY_PR_ARG, NETDEV_PR_ARG, __entry->macaddr,
+		  __entry->kek_len)
+);
+
 /*************************************************************
  *	     cfg80211 exported functions traces		     *
  *************************************************************/