Add support to request a scan with specific SSIDs

Support a request to scan specific SSIDs given by user with the SCAN
command. The SSID list can be suffixed to the scan command as follows.
For example, if SSIDs "ABC" and "abc123" need to be specifically
scanned, the command should be "SCAN ssid 414243 ssid 616263313233". The
value of the SSID is passed in hexadecimal representation.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

wpa_supplicant/ctrl_iface.c

@@ -6982,6 +6982,8 @@ static void wpas_ctrl_scan(struct wpa_supplicant *wpa_s, char *params,
 	void (*scan_res_handler)(struct wpa_supplicant *wpa_s,
 				 struct wpa_scan_results *scan_res);
 	int *manual_scan_freqs = NULL;
+	struct wpa_ssid_value *ssid = NULL, *ns;
+	unsigned int ssid_count = 0;
 
 	if (wpa_s->wpa_state == WPA_INTERFACE_DISABLED) {
 		*reply_len = -1;
@@ -7036,6 +7038,60 @@ static void wpas_ctrl_scan(struct wpa_supplicant *wpa_s, char *params,
 			*reply_len = -1;
 			goto done;
 		}
+
+		pos = params;
+		while (pos && *pos != '\0') {
+			if (os_strncmp(pos, "ssid ", 5) == 0) {
+				char *end;
+
+				pos += 5;
+				end = pos;
+				while (*end) {
+					if (*end == '\0' || *end == ' ')
+						break;
+					end++;
+				}
+
+				ns = os_realloc_array(
+					ssid, ssid_count + 1,
+					sizeof(struct wpa_ssid_value));
+				if (ns == NULL) {
+					*reply_len = -1;
+					goto done;
+				}
+				ssid = ns;
+
+				if ((end - pos) & 0x01 ||
+				    end - pos > 2 * SSID_MAX_LEN ||
+				    hexstr2bin(pos, ssid[ssid_count].ssid,
+					       (end - pos) / 2) < 0) {
+					wpa_printf(MSG_DEBUG,
+						   "Invalid SSID value '%s'",
+						   pos);
+					*reply_len = -1;
+					goto done;
+				}
+				ssid[ssid_count].ssid_len = (end - pos) / 2;
+				wpa_hexdump_ascii(MSG_DEBUG, "scan SSID",
+						  ssid[ssid_count].ssid,
+						  ssid[ssid_count].ssid_len);
+				ssid_count++;
+				pos = end;
+			}
+
+			pos = os_strchr(pos, ' ');
+			if (pos)
+				pos++;
+		}
+	}
+
+	wpa_s->num_ssids_from_scan_req = ssid_count;
+	os_free(wpa_s->ssids_from_scan_req);
+	if (ssid_count) {
+		wpa_s->ssids_from_scan_req = ssid;
+		ssid = NULL;
+	} else {
+		wpa_s->ssids_from_scan_req = NULL;
 	}
 
 	if (scan_only)
@@ -7099,6 +7155,7 @@ static void wpas_ctrl_scan(struct wpa_supplicant *wpa_s, char *params,
 
 done:
 	os_free(manual_scan_freqs);
+	os_free(ssid);
 }
 
 

wpa_supplicant/scan.c

@@ -614,6 +614,37 @@ static void wpa_set_scan_ssids(struct wpa_supplicant *wpa_s,
 }
 
 
+static int wpa_set_ssids_from_scan_req(struct wpa_supplicant *wpa_s,
+				       struct wpa_driver_scan_params *params,
+				       size_t max_ssids)
+{
+	unsigned int i;
+
+	if (wpa_s->ssids_from_scan_req == NULL ||
+	    wpa_s->num_ssids_from_scan_req == 0)
+		return 0;
+
+	if (wpa_s->num_ssids_from_scan_req > max_ssids) {
+		wpa_s->num_ssids_from_scan_req = max_ssids;
+		wpa_printf(MSG_DEBUG, "Over max scan SSIDs from scan req: %u",
+			   (unsigned int) max_ssids);
+	}
+
+	for (i = 0; i < wpa_s->num_ssids_from_scan_req; i++) {
+		params->ssids[i].ssid = wpa_s->ssids_from_scan_req[i].ssid;
+		params->ssids[i].ssid_len =
+			wpa_s->ssids_from_scan_req[i].ssid_len;
+		wpa_hexdump_ascii(MSG_DEBUG, "specific SSID",
+				  params->ssids[i].ssid,
+				  params->ssids[i].ssid_len);
+	}
+
+	params->num_ssids = wpa_s->num_ssids_from_scan_req;
+	wpa_s->num_ssids_from_scan_req = 0;
+	return 1;
+}
+
+
 static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 {
 	struct wpa_supplicant *wpa_s = eloop_ctx;
@@ -726,6 +757,12 @@ static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 		goto scan;
 	}
 
+	if (wpa_s->last_scan_req == MANUAL_SCAN_REQ &&
+	    wpa_set_ssids_from_scan_req(wpa_s, &params, max_ssids)) {
+		wpa_printf(MSG_DEBUG, "Use specific SSIDs from SCAN command");
+		goto ssid_list_set;
+	}
+
 #ifdef CONFIG_P2P
 	if ((wpa_s->p2p_in_provisioning || wpa_s->show_group_started) &&
 	    wpa_s->go_params && !wpa_s->conf->passive_scan) {
@@ -891,10 +928,8 @@ static void wpa_supplicant_scan(void *eloop_ctx, void *timeout_ctx)
 		wpa_dbg(wpa_s, MSG_DEBUG, "Starting AP scan for wildcard "
 			"SSID");
 	}
-#ifdef CONFIG_P2P
-ssid_list_set:
-#endif /* CONFIG_P2P */
 
+ssid_list_set:
 	wpa_supplicant_optimize_freqs(wpa_s, &params);
 	extra_ie = wpa_supplicant_extra_ies(wpa_s);
 

wpa_supplicant/wpa_supplicant.c

@@ -4336,6 +4336,8 @@ static void wpa_supplicant_deinit_iface(struct wpa_supplicant *wpa_s,
 		wpa_s->conf = NULL;
 	}
 
+	os_free(wpa_s->ssids_from_scan_req);
+
 	os_free(wpa_s);
 }
 

wpa_supplicant/wpa_supplicant_i.h

@@ -609,6 +609,9 @@ struct wpa_supplicant {
 	int scan_id[MAX_SCAN_ID];
 	unsigned int scan_id_count;
 
+	struct wpa_ssid_value *ssids_from_scan_req;
+	unsigned int num_ssids_from_scan_req;
+
 	u64 drv_flags;
 	unsigned int drv_enc;
 	unsigned int drv_smps_modes;