iwlwifi: mvm: Insert DS Parameter Set placeholder in probes

Since it's too complicated for the fw to insert a DS Parameter Set
element in the middle of the frame, it was decided that it should be
done by the host. The fw will only parse the frame and update the
current channel field.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

1 files changed, 48 insertions, 5 deletions

diff --git a/drivers/net/wireless/iwlwifi/mvm/scan.c b/drivers/net/wireless/iwlwifi/mvm/scan.c
index fb2a8628b8fc..8a1f4a8e80e7 100644
--- a/drivers/net/wireless/iwlwifi/mvm/scan.c
+++ b/drivers/net/wireless/iwlwifi/mvm/scan.c
@@ -366,6 +366,10 @@ static int iwl_mvm_max_scan_ie_fw_cmd_room(struct iwl_mvm *mvm,
 	    !is_sched_scan)
 		max_probe_len -= 32;
 
+	/* DS parameter set element is added on 2.4GHZ band if required */
+	if (iwl_mvm_rrm_scan_needed(mvm))
+		max_probe_len -= 3;
+
 	return max_probe_len;
 }
 
@@ -1155,6 +1159,42 @@ iwl_mvm_lmac_scan_cfg_channels(struct iwl_mvm *mvm,
 	}
 }
 
+static u8 *iwl_mvm_copy_and_insert_ds_elem(struct iwl_mvm *mvm, const u8 *ies,
+					   size_t len, u8 *const pos)
+{
+	static const u8 before_ds_params[] = {
+			WLAN_EID_SSID,
+			WLAN_EID_SUPP_RATES,
+			WLAN_EID_REQUEST,
+			WLAN_EID_EXT_SUPP_RATES,
+	};
+	size_t offs;
+	u8 *newpos = pos;
+
+	if (!iwl_mvm_rrm_scan_needed(mvm)) {
+		memcpy(newpos, ies, len);
+		return newpos + len;
+	}
+
+	offs = ieee80211_ie_split(ies, len,
+				  before_ds_params,
+				  ARRAY_SIZE(before_ds_params),
+				  0);
+
+	memcpy(newpos, ies, offs);
+	newpos += offs;
+
+	/* Add a placeholder for DS Parameter Set element */
+	*newpos++ = WLAN_EID_DS_PARAMS;
+	*newpos++ = 1;
+	*newpos++ = 0;
+
+	memcpy(newpos, ies + offs, len - offs);
+	newpos += len - offs;
+
+	return newpos;
+}
+
 static void
 iwl_mvm_build_unified_scan_probe(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 				 struct ieee80211_scan_ies *ies,
@@ -1164,7 +1204,7 @@ iwl_mvm_build_unified_scan_probe(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 		sizeof(struct iwl_scan_channel_cfg_lmac) *
 			mvm->fw->ucode_capa.n_scan_channels);
 	struct ieee80211_mgmt *frame = (struct ieee80211_mgmt *)preq->buf;
-	u8 *pos;
+	u8 *pos, *newpos;
 
 	frame->frame_control = cpu_to_le16(IEEE80211_STYPE_PROBE_REQ);
 	eth_broadcast_addr(frame->da);
@@ -1179,11 +1219,14 @@ iwl_mvm_build_unified_scan_probe(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 	preq->mac_header.offset = 0;
 	preq->mac_header.len = cpu_to_le16(24 + 2);
 
-	memcpy(pos, ies->ies[IEEE80211_BAND_2GHZ],
-	       ies->len[IEEE80211_BAND_2GHZ]);
+	/* Insert ds parameter set element on 2.4 GHz band */
+	newpos = iwl_mvm_copy_and_insert_ds_elem(mvm,
+						 ies->ies[IEEE80211_BAND_2GHZ],
+						 ies->len[IEEE80211_BAND_2GHZ],
+						 pos);
 	preq->band_data[0].offset = cpu_to_le16(pos - preq->buf);
-	preq->band_data[0].len = cpu_to_le16(ies->len[IEEE80211_BAND_2GHZ]);
-	pos += ies->len[IEEE80211_BAND_2GHZ];
+	preq->band_data[0].len = cpu_to_le16(newpos - pos);
+	pos = newpos;
 
 	memcpy(pos, ies->ies[IEEE80211_BAND_5GHZ],
 	       ies->len[IEEE80211_BAND_5GHZ]);