mac80211: add vendor-specific capabilities to assoc request

When sending an association request, add any vendor specific
capabilities at the end of the frame. This way, mac80211 is
still completely in charge of building the frame, but drivers
can determine what should be added depending on the band and
interface type.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210618133832.80d716d69a5f.I28097ff19be6b22aebdc33a72795d2662755d41f@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mlme.c

@@ -8,7 +8,7 @@
  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
  * Copyright (C) 2015 - 2017 Intel Deutschland GmbH
- * Copyright (C) 2018 - 2020 Intel Corporation
+ * Copyright (C) 2018 - 2021 Intel Corporation
  */
 
 #include <linux/delay.h>
@@ -681,6 +681,8 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
 	u32 rates = 0;
 	__le16 listen_int;
 	struct element *ext_capa = NULL;
+	enum nl80211_iftype iftype = ieee80211_vif_type_p2p(&sdata->vif);
+	const struct ieee80211_sband_iftype_data *iftd;
 
 	/* we know it's writable, cast away the const */
 	if (assoc_data->ie_len)
@@ -725,6 +727,8 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
 		}
 	}
 
+	iftd = ieee80211_get_sband_iftype_data(sband, iftype);
+
 	skb = alloc_skb(local->hw.extra_tx_headroom +
 			sizeof(*mgmt) + /* bit too much but doesn't matter */
 			2 + assoc_data->ssid_len + /* SSID */
@@ -739,7 +743,8 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
 			2 + 1 + sizeof(struct ieee80211_he_6ghz_capa) +
 			assoc_data->ie_len + /* extra IEs */
 			(assoc_data->fils_kek_len ? 16 /* AES-SIV */ : 0) +
-			9, /* WMM */
+			9 + /* WMM */
+			(iftd ? iftd->vendor_elems.len : 0),
 			GFP_KERNEL);
 	if (!skb)
 		return;
@@ -1012,6 +1017,9 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata)
 		ieee80211_add_s1g_capab_ie(sdata, &sband->s1g_cap, skb);
 	}
 
+	if (iftd && iftd->vendor_elems.data && iftd->vendor_elems.len)
+		skb_put_data(skb, iftd->vendor_elems.data, iftd->vendor_elems.len);
+
 	/* add any remaining custom (i.e. vendor specific here) IEs */
 	if (assoc_data->ie_len) {
 		noffset = assoc_data->ie_len;