[PATCH v2] Use default IEs in wpa_supplicant_trigger_scan

Matthew Wang matthewmwang at chromium.org
Mon Aug 23 14:55:19 PDT 2021


wpa_supplicant_trigger_scan previously wouldn't include any of the IEs
generated by wpa_supplicant_extra_ies. Instruct it to do so in most
cases. This is necessary because MBO STAs are required to include MBO
capabilities in their probe requests.

Signed-off-by: Matthew Wang <matthewmwang at chromium.org>
---
 doc/dbus.doxygen                        |  2 +-
 wpa_supplicant/bgscan_learn.c           |  2 +-
 wpa_supplicant/bgscan_simple.c          |  2 +-
 wpa_supplicant/dbus/dbus_new_handlers.c |  6 +++--
 wpa_supplicant/rrm.c                    |  2 +-
 wpa_supplicant/scan.c                   | 29 ++++++++++++++++++++++---
 wpa_supplicant/scan.h                   |  4 +++-
 wpa_supplicant/sme.c                    |  2 +-
 8 files changed, 38 insertions(+), 11 deletions(-)

diff --git a/doc/dbus.doxygen b/doc/dbus.doxygen
index 8231aac41..1d93a1d78 100644
--- a/doc/dbus.doxygen
+++ b/doc/dbus.doxygen
@@ -206,7 +206,7 @@ fi.w1.wpa_supplicant1.CreateInterface.
 	      <tr><th>Key</th><th>Value type</th><th>Description</th><th>Required</th>
 	      <tr><td>Type</td><td>s</td><td>Type of the scan. Possible values: "active", "passive"</td><td>Yes</td>
 	      <tr><td>SSIDs</td><td>aay</td><td>Array of SSIDs to scan for (applies only if scan type is active)</td><td>No</td>
-	      <tr><td>IEs</td><td>aay</td><td>Information elements to used in active scan (applies only if scan type is active)</td><td>No</td>
+	      <tr><td>IEs</td><td>aay</td><td>Information elements to used in active scan (applies only if scan type is active). Default IEs will be used in absence of this option.</td><td>No</td>
 	      <tr><td>Channels</td><td>a(uu)</td><td>Array of frequencies to scan in form of (center, width) in MHz.</td><td>No</td>
 	      <tr><td>AllowRoam</td><td>b</td><td>TRUE (or absent) to allow a roaming decision based on the results of this scan, FALSE to prevent a roaming decision.</td><td>No</td>
 	    </table>
diff --git a/wpa_supplicant/bgscan_learn.c b/wpa_supplicant/bgscan_learn.c
index cb732f709..3d10d9118 100644
--- a/wpa_supplicant/bgscan_learn.c
+++ b/wpa_supplicant/bgscan_learn.c
@@ -305,7 +305,7 @@ static void bgscan_learn_timeout(void *eloop_ctx, void *timeout_ctx)
 	}
 
 	wpa_printf(MSG_DEBUG, "bgscan learn: Request a background scan");
-	if (wpa_supplicant_trigger_scan(wpa_s, &params)) {
+	if (wpa_supplicant_trigger_scan(wpa_s, &params, true)) {
 		wpa_printf(MSG_DEBUG, "bgscan learn: Failed to trigger scan");
 		eloop_register_timeout(data->scan_interval, 0,
 				       bgscan_learn_timeout, data, NULL);
diff --git a/wpa_supplicant/bgscan_simple.c b/wpa_supplicant/bgscan_simple.c
index 41a26df0d..4dd212b21 100644
--- a/wpa_supplicant/bgscan_simple.c
+++ b/wpa_supplicant/bgscan_simple.c
@@ -49,7 +49,7 @@ static void bgscan_simple_timeout(void *eloop_ctx, void *timeout_ctx)
 	 */
 
 	wpa_printf(MSG_DEBUG, "bgscan simple: Request a background scan");
-	if (wpa_supplicant_trigger_scan(wpa_s, &params)) {
+	if (wpa_supplicant_trigger_scan(wpa_s, &params, true)) {
 		wpa_printf(MSG_DEBUG, "bgscan simple: Failed to trigger scan");
 		eloop_register_timeout(data->scan_interval, 0,
 				       bgscan_simple_timeout, data, NULL);
diff --git a/wpa_supplicant/dbus/dbus_new_handlers.c b/wpa_supplicant/dbus/dbus_new_handlers.c
index db9f30c9a..08be9da3b 100644
--- a/wpa_supplicant/dbus/dbus_new_handlers.c
+++ b/wpa_supplicant/dbus/dbus_new_handlers.c
@@ -1371,6 +1371,7 @@ DBusMessage * wpas_dbus_handler_scan(DBusMessage *message,
 	struct wpa_driver_scan_params params;
 	size_t i;
 	dbus_bool_t allow_roam = 1;
+	bool custom_ies = false;
 
 	os_memset(&params, 0, sizeof(params));
 
@@ -1397,6 +1398,7 @@ DBusMessage * wpas_dbus_handler_scan(DBusMessage *message,
 			if (wpas_dbus_get_scan_ies(message, &variant_iter,
 						   &params, &reply) < 0)
 				goto out;
+			custom_ies = true;
 		} else if (os_strcmp(key, "Channels") == 0) {
 			if (wpas_dbus_get_scan_channels(message, &variant_iter,
 							&params, &reply) < 0)
@@ -1444,7 +1446,7 @@ DBusMessage * wpas_dbus_handler_scan(DBusMessage *message,
 			if (params.freqs && params.freqs[0]) {
 				wpa_s->last_scan_req = MANUAL_SCAN_REQ;
 				if (wpa_supplicant_trigger_scan(wpa_s,
-								&params)) {
+								&params, false)) {
 					reply = wpas_dbus_error_scan_error(
 						message,
 						"Scan request rejected");
@@ -1470,7 +1472,7 @@ DBusMessage * wpas_dbus_handler_scan(DBusMessage *message,
 		}
 
 		wpa_s->last_scan_req = MANUAL_SCAN_REQ;
-		if (wpa_supplicant_trigger_scan(wpa_s, &params)) {
+		if (wpa_supplicant_trigger_scan(wpa_s, &params, !custom_ies)) {
 			reply = wpas_dbus_error_scan_error(
 				message, "Scan request rejected");
 		}
diff --git a/wpa_supplicant/rrm.c b/wpa_supplicant/rrm.c
index cf107ebaf..0e079380b 100644
--- a/wpa_supplicant/rrm.c
+++ b/wpa_supplicant/rrm.c
@@ -1034,7 +1034,7 @@ static void wpas_rrm_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 	}
 	os_get_reltime(&wpa_s->beacon_rep_scan);
 	if (wpa_s->scanning || wpas_p2p_in_progress(wpa_s) ||
-	    wpa_supplicant_trigger_scan(wpa_s, params))
+	    wpa_supplicant_trigger_scan(wpa_s, params, true))
 		wpas_rrm_refuse_request(wpa_s);
 	params->duration = prev_duration;
 }
diff --git a/wpa_supplicant/scan.c b/wpa_supplicant/scan.c
index 97a8d9a63..5a7b8a46f 100644
--- a/wpa_supplicant/scan.c
+++ b/wpa_supplicant/scan.c
@@ -278,19 +278,42 @@ static void wpas_trigger_scan_cb(struct wpa_radio_work *work, int deinit)
  * wpa_supplicant_trigger_scan - Request driver to start a scan
  * @wpa_s: Pointer to wpa_supplicant data
  * @params: Scan parameters
+ * @default_ies: Whether or not to use the default IEs in the probe request.
+ * Note that this will free any existing IEs set in @params, so this shouldn't
+ * be set if the IEs have already been set with wpa_supplicant_extra_ies.
+ * Otherwise, wpabuf_free will lead to a double-free.
  * Returns: 0 on success, -1 on failure
  */
 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
-				struct wpa_driver_scan_params *params)
+				struct wpa_driver_scan_params *params,
+				bool default_ies)
 {
 	struct wpa_driver_scan_params *ctx;
+	struct wpabuf *ies = NULL;
 
 	if (wpa_s->scan_work) {
 		wpa_dbg(wpa_s, MSG_INFO, "Reject scan trigger since one is already pending");
 		return -1;
 	}
 
+	if (default_ies) {
+		if (params->extra_ies_len) {
+			os_free((u8 *) params->extra_ies);
+			params->extra_ies = NULL;
+			params->extra_ies_len = 0;
+		}
+		ies = wpa_supplicant_extra_ies(wpa_s);
+		if (ies) {
+			params->extra_ies = wpabuf_head(ies);
+			params->extra_ies_len = wpabuf_len(ies);
+		}
+	}
 	ctx = wpa_scan_clone_params(params);
+	if (ies) {
+		wpabuf_free(ies);
+		params->extra_ies = NULL;
+		params->extra_ies_len = 0;
+	}
 	if (!ctx ||
 	    radio_add_work(wpa_s, 0, "scan", 0, wpas_trigger_scan_cb, ctx) < 0)
 	{
@@ -566,7 +589,7 @@ void wpa_supplicant_set_default_scan_ies(struct wpa_supplicant *wpa_s)
 }
 
 
-static struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
+struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s)
 {
 	struct wpabuf *extra_ie = NULL;
 	u8 ext_capab[18];
@@ -1339,7 +1362,7 @@ scan:
 	}
 #endif /* CONFIG_P2P */
 
-	ret = wpa_supplicant_trigger_scan(wpa_s, scan_params);
+	ret = wpa_supplicant_trigger_scan(wpa_s, scan_params, false);
 
 	if (ret && wpa_s->last_scan_req == MANUAL_SCAN_REQ && params.freqs &&
 	    !wpa_s->manual_scan_freqs) {
diff --git a/wpa_supplicant/scan.h b/wpa_supplicant/scan.h
index d1780eb09..c74c79f2d 100644
--- a/wpa_supplicant/scan.h
+++ b/wpa_supplicant/scan.h
@@ -45,7 +45,8 @@ void wpa_supplicant_notify_scanning(struct wpa_supplicant *wpa_s,
 				    int scanning);
 struct wpa_driver_scan_params;
 int wpa_supplicant_trigger_scan(struct wpa_supplicant *wpa_s,
-				struct wpa_driver_scan_params *params);
+				struct wpa_driver_scan_params *params,
+				bool default_ies);
 struct wpa_scan_results *
 wpa_supplicant_get_scan_results(struct wpa_supplicant *wpa_s,
 				struct scan_info *info, int new_scan);
@@ -92,5 +93,6 @@ int wpa_add_scan_freqs_list(struct wpa_supplicant *wpa_s,
 			    enum hostapd_hw_mode band,
 			    struct wpa_driver_scan_params *params,
 			    bool is_6ghz);
+struct wpabuf * wpa_supplicant_extra_ies(struct wpa_supplicant *wpa_s);
 
 #endif /* SCAN_H */
diff --git a/wpa_supplicant/sme.c b/wpa_supplicant/sme.c
index f2c42ff35..494407ad6 100644
--- a/wpa_supplicant/sme.c
+++ b/wpa_supplicant/sme.c
@@ -2549,7 +2549,7 @@ static void sme_obss_scan_timeout(void *eloop_ctx, void *timeout_ctx)
 	params.low_priority = 1;
 	wpa_printf(MSG_DEBUG, "SME OBSS: Request an OBSS scan");
 
-	if (wpa_supplicant_trigger_scan(wpa_s, &params))
+	if (wpa_supplicant_trigger_scan(wpa_s, &params, true))
 		wpa_printf(MSG_DEBUG, "SME OBSS: Failed to trigger scan");
 	else
 		wpa_s->sme.sched_obss_scan = 1;
-- 
2.33.0.rc2.250.ged5fa647cd-goog




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