qcacmn: Strip out MBSSID IE while creating scan entry for TX VAP

While processing an beacon with MBSSID IE/ IEs, the driver
creates scan entries for the TX VAP/ profile and every Non-TX
profile present in the MBSSID IE.
The scan entry generation for nontx profile happens as required,
whereas while generating the scan entry for the TX VAP, driver
copies the MBSSID IE/IEs as well. Because of this, multiple
ML IEs would be part of one frame and as a result sometimes
supplicant fails in adapting/ fetching the proper ML IE.
With this change, the host driver takes care of stripping out
the MBSSID IE/IEs from the full beacon frame and while
generating the scan entry for TX VAP/ profile, it uses the data
that only belongs to the TX VAP.
This helps in resolving the duplicate ML IE issue.

Change-Id: I13b3ce94da1970eea8c16b52b1987edc1a5418bc
CRs-Fixed: 3295496

umac/scan/dispatcher/src/wlan_scan_utils_api.c

@@ -3456,6 +3456,124 @@ static QDF_STATUS util_scan_parse_mbssid(struct wlan_objmgr_pdev *pdev,
 
 	return QDF_STATUS_SUCCESS;
 }
+
+/*
+ * util_scan_gen_txvap_scan_entry() - Strip out the MBSSID tag from the received
+ * frame and update the modified frame length before generating a scan entry.
+ * It is redundant to have MBSSID information as part of the TX vap/ profile
+ * specific scan entry.
+ *
+ * @pdev: pdev context
+ * @frame: Unsoiled frame passed from util_scan_parse_beacon_frame()
+ * @frame_len: Length of the unsoiled frame
+ * @ie_list: Points to the start of IE list in parent/ unsoiled frame
+ * @ielen: Length of the complete IE list from parent/ unsoiled frame
+ * @frm_subtype: Frame subtype
+ * @rx_param: host mgmt header params
+ * @scan_list: Scan entry list of bss candidates after filtering
+ * @mbssid_info: Data structure to carry MBSSID information
+ *
+ * Return: False if the scan entry generation is not successful
+ */
+static QDF_STATUS
+util_scan_gen_txvap_scan_entry(struct wlan_objmgr_pdev *pdev,
+			       uint8_t *frame, qdf_size_t frame_len,
+			       uint8_t *ie_list, uint32_t ielen,
+			       uint32_t frm_subtype,
+			       struct mgmt_rx_event_params *rx_param,
+			       qdf_list_t *scan_list,
+			       struct scan_mbssid_info *mbssid_info)
+{
+	uint8_t *src_ie, *dest_ptr, *container;
+	uint16_t new_frame_len, new_ie_len = 0;
+	uint8_t *trimmed_frame, fixed_len = 0;
+	QDF_STATUS status = QDF_STATUS_SUCCESS;
+
+	/*
+	 * Allocate a buffer to copy only the TX VAP information after
+	 * stripping out the MBSSID IE from the parent beacon.
+	 * The allocation size should be the size of a frame as at
+	 * this point it is unknown what would be the new frame length
+	 * after stripping the MBSSID IE.
+	 */
+	container = qdf_mem_malloc(frame_len);
+	if (!container) {
+		scm_err_rl("Malloc for container failed");
+		return QDF_STATUS_E_NOMEM;
+	}
+
+	dest_ptr = &container[0];
+	fixed_len = sizeof(struct wlan_frame_hdr) +
+		offsetof(struct wlan_bcn_frame, ie);
+
+	/*Copy the data till IE list before procesisng the IE one by one*/
+	qdf_mem_copy(dest_ptr, frame, fixed_len);
+
+	dest_ptr += fixed_len;
+	src_ie = ie_list;
+
+	/*
+	 * Go through the IE list from the parent beacon and copy one by one.
+	 * Skip copying it to the container if it's an MBSSID tag.
+	 */
+	while (((src_ie + src_ie[TAG_LEN_POS] + MIN_IE_LEN) -
+		ie_list) <= ielen) {
+		if (src_ie[ID_POS] == WLAN_ELEMID_MULTIPLE_BSSID) {
+			src_ie += src_ie[TAG_LEN_POS] + MIN_IE_LEN;
+			continue;
+		}
+
+		qdf_mem_copy(dest_ptr, src_ie,
+			     (src_ie[TAG_LEN_POS] + MIN_IE_LEN));
+
+		dest_ptr += src_ie[TAG_LEN_POS] + MIN_IE_LEN;
+		if (((src_ie + src_ie[TAG_LEN_POS] +
+		      MIN_IE_LEN) - ie_list) >= ielen)
+			break;
+
+		src_ie += src_ie[TAG_LEN_POS] + MIN_IE_LEN;
+	}
+
+	if (dest_ptr > container)
+		new_ie_len = dest_ptr - (container + fixed_len);
+
+	new_frame_len = frame_len - ielen + new_ie_len;
+
+	/*
+	 * At the start of this handler, we have allocated a memory block
+	 * of size same as a full beacon frame size, as we are not sure
+	 * of what would be the size of the new frame. After stripping out
+	 * the MBSSID tag from the parent beacon, there are some unused
+	 * memory. Hence do another malloc of the new frame length
+	 * (length of the new frame which has only TX VAP information)
+	 * and copy the needed data from the container, then free the
+	 * memory corresponds to container.
+	 * Post copy, use the trimmed frame and the new frame length
+	 * to generate scan entry for the TX profile.
+	 */
+	trimmed_frame = qdf_mem_malloc(new_frame_len);
+	if (!trimmed_frame) {
+		scm_err_rl("Malloc for trimmed frame failed");
+		qdf_mem_free(container);
+		return QDF_STATUS_E_NOMEM;
+	}
+
+	qdf_mem_copy(trimmed_frame, container, new_frame_len);
+	qdf_mem_free(container);
+
+	status = util_scan_gen_scan_entry(pdev, trimmed_frame,
+					  new_frame_len,
+					  frm_subtype,
+					  rx_param,
+					  mbssid_info,
+					  scan_list);
+
+	if (QDF_IS_STATUS_ERROR(status))
+		scm_debug_rl("Failed to create a scan entry");
+
+	qdf_mem_free(trimmed_frame);
+	return status;
+}
 #else
 static QDF_STATUS util_scan_parse_mbssid(struct wlan_objmgr_pdev *pdev,
 					 uint8_t *frame, qdf_size_t frame_len,
@@ -3465,6 +3583,18 @@ static QDF_STATUS util_scan_parse_mbssid(struct wlan_objmgr_pdev *pdev,
 {
 	return QDF_STATUS_SUCCESS;
 }
+
+static QDF_STATUS
+util_scan_gen_txvap_scan_entry(struct wlan_objmgr_pdev *pdev,
+			       uint8_t *frame, qdf_size_t frame_len,
+			       uint8_t *ie_list, uint32_t ielen,
+			       uint32_t frm_subtype,
+			       struct mgmt_rx_event_params *rx_param,
+			       qdf_list_t *scan_list,
+			       struct scan_mbssid_info *mbssid_info)
+{
+	return QDF_STATUS_SUCCESS;
+}
 #endif
 
 static QDF_STATUS
@@ -3481,13 +3611,15 @@ util_scan_parse_beacon_frame(struct wlan_objmgr_pdev *pdev,
 	uint32_t ie_len = 0;
 	QDF_STATUS status = QDF_STATUS_E_FAILURE;
 	struct scan_mbssid_info mbssid_info = { 0 };
+	uint8_t *ie_list;
 
 	hdr = (struct wlan_frame_hdr *)frame;
 	bcn = (struct wlan_bcn_frame *)
-			   (frame + sizeof(struct wlan_frame_hdr));
+		(frame + sizeof(struct wlan_frame_hdr));
+	ie_list = (uint8_t *)&bcn->ie;
 	ie_len = (uint16_t)(frame_len -
-		sizeof(struct wlan_frame_hdr) -
-		offsetof(struct wlan_bcn_frame, ie));
+			    sizeof(struct wlan_frame_hdr) -
+			    offsetof(struct wlan_bcn_frame, ie));
 
 	extcap_ie = util_scan_find_ie(WLAN_ELEMID_XCAPS,
 				      (uint8_t *)&bcn->ie, ie_len);
@@ -3509,23 +3641,45 @@ util_scan_parse_beacon_frame(struct wlan_objmgr_pdev *pdev,
 		}
 	}
 
-	status = util_scan_gen_scan_entry(pdev, frame, frame_len,
-					  frm_subtype, rx_param,
-					  &mbssid_info,
-					  scan_list);
-
 	/*
 	 * IF MBSSID IE is present in the beacon then
 	 * scan component will create a new entry for
 	 * each BSSID found in the MBSSID
+	 * util_scan_parse_mbssid() takes care of creating
+	 * scan entries for every non tx profile present in
+	 * the MBSSID tag.
+	 * util_scan_gen_txvap_scan_entry() helps in generating
+	 * scan entry for the tx profile.
 	 */
-	if (mbssid_ie)
+	if (mbssid_ie) {
 		status = util_scan_parse_mbssid(pdev, frame, frame_len,
 						frm_subtype, rx_param,
 						scan_list);
 
+		if (QDF_IS_STATUS_ERROR(status)) {
+			scm_debug_rl("NonTx prof: Failed to create scan entry");
+			return status;
+		}
+
+		status = util_scan_gen_txvap_scan_entry(pdev, frame,
+							frame_len, ie_list,
+							ie_len, frm_subtype,
+							rx_param, scan_list,
+							&mbssid_info);
+		if (QDF_IS_STATUS_ERROR(status))
+			scm_debug_rl("TX prof: Failed to create scan entry");
+
+		return status;
+	}
+
+	/*For Non MBSSIE case*/
+	status = util_scan_gen_scan_entry(pdev, frame, frame_len,
+					  frm_subtype, rx_param,
+					  &mbssid_info,
+					  scan_list);
+
 	if (QDF_IS_STATUS_ERROR(status))
-		scm_debug_rl("Failed to create a scan entry");
+		scm_debug_rl("Non-MBSSIE frame: Failed to create scan entry");
 
 	return status;
 }