[SL-TEMP] Fixing the scan for the WiFi devices (#81)

Co-authored-by: Junior Martinez <67972863+jmartinez-silabs@users.noreply.github.com>

Author: chirag-silabs

examples/platform/silabs/SiWx917/SiWx917/sl_wifi_if.cpp

@@ -545,11 +545,12 @@ sl_status_t show_scan_results(sl_wifi_scan_result_t * scan_result)
 
         cur_scan_result.ssid_length = strnlen((char *) scan_result->scan_info[idx].ssid,
                                               chip::min<size_t>(sizeof(scan_result->scan_info[idx].ssid), WFX_MAX_SSID_LENGTH));
-        chip::Platform::CopyString(cur_scan_result.ssid, cur_scan_result.ssid_length, (char *) scan_result->scan_info[idx].ssid);
+        // cur_scan_result.ssid is of size WFX_MAX_SSID_LENGTH+1, we are safe with the cur_scan_result.ssid_length calculated above
+        chip::Platform::CopyString(cur_scan_result.ssid, cur_scan_result.ssid_length + 1, (char *) scan_result->scan_info[idx].ssid); // +1 for null termination
 
         // if user has provided ssid, then check if the current scan result ssid matches the user provided ssid
         if (wfx_rsi.scan_ssid != NULL &&
-            (strncmp(wfx_rsi.scan_ssid, cur_scan_result.ssid, MIN(strlen(wfx_rsi.scan_ssid), strlen(cur_scan_result.ssid))) ==
+            (strncmp(wfx_rsi.scan_ssid, cur_scan_result.ssid, MIN(strlen(wfx_rsi.scan_ssid), strlen(cur_scan_result.ssid))) !=
              CMP_SUCCESS))
         {
             continue;
@@ -603,8 +604,8 @@ static void wfx_rsi_save_ap_info(void) // translation
 #endif
     sl_wifi_ssid_t ssid_arg;
     memset(&ssid_arg, 0, sizeof(ssid_arg));
-    ssid_arg.length = wfx_rsi.sec.ssid_length;
-    chip::Platform::CopyString((char *) &ssid_arg.value[0], ssid_arg.length, wfx_rsi.sec.ssid);
+    ssid_arg.length = chip::min<size_t>(wfx_rsi.sec.ssid_length, sizeof(ssid_arg.value) - 1);
+    chip::Platform::CopyString((char *) &ssid_arg.value[0], ssid_arg.length + 1, wfx_rsi.sec.ssid); // +1 for null termination
     sl_wifi_set_scan_callback(scan_callback_handler, NULL);
     scan_results_complete = false;
 #ifndef EXP_BOARD

examples/platform/silabs/efr32/rs911x/rsi_if.cpp

@@ -757,7 +757,8 @@ void ProcessEvent(WfxEvent_t inEvent)
             memset(&ap, 0, sizeof(ap));
             ap.ssid_length =
                 strnlen(reinterpret_cast<char *>(scan->ssid), chip::min<size_t>(sizeof(scan->ssid), WFX_MAX_SSID_LENGTH));
-            chip::Platform::CopyString(ap.ssid, ap.ssid_length, reinterpret_cast<char *>(scan->ssid));
+            // ap.ssid is of size WFX_MAX_SSID_LENGTH+1, we are safe with the ap.ssid_length calculated above
+            chip::Platform::CopyString(ap.ssid, ap.ssid_length + 1, reinterpret_cast<char *>(scan->ssid)); // +1 for null termination
 
             // check if the scanned ssid is the one we are looking for
             if (wfx_rsi.scan_ssid_length != 0 && strncmp(wfx_rsi.scan_ssid, ap.ssid, WFX_MAX_SSID_LENGTH) != CMP_SUCCESS)

examples/platform/silabs/efr32/wf200/host_if.cpp

@@ -737,7 +737,8 @@ int32_t wfx_get_ap_info(wfx_wifi_scan_result_t * ap)
     int32_t signal_strength;
 
     ap->ssid_length = strnlen(ap_info.ssid, chip::min<size_t>(sizeof(ap_info.ssid), WFX_MAX_SSID_LENGTH));
-    chip::Platform::CopyString(ap->ssid, ap->ssid_length, ap_info.ssid);
+    // ap->ssid is of size WFX_MAX_SSID_LENGTH+1, we are safe with the ap->ssid_length calculated above
+    chip::Platform::CopyString(ap->ssid, ap->ssid_length + 1, ap_info.ssid); // +1 for null termination
     memcpy(ap->bssid, ap_info.bssid, sizeof(ap_info.bssid));
     ap->security = ap_info.security;
     ap->chan     = ap_info.chan;
@@ -1184,10 +1185,10 @@ bool wfx_start_scan(char * ssid, void (*callback)(wfx_wifi_scan_result_t *))
     VerifyOrReturnError(scan_cb != nullptr, false);
     if (ssid)
     {
-        scan_ssid_length = strnlen(ssid, WFX_MAX_SSID_LENGTH);
-        scan_ssid        = reinterpret_cast<char *>(chip::Platform::MemoryAlloc(scan_ssid_length));
+        scan_ssid_length = strnlen(ssid, chip::min<size_t>(sizeof(ssid), WFX_MAX_SSID_LENGTH));
+        scan_ssid        = reinterpret_cast<char *>(chip::Platform::MemoryAlloc(scan_ssid_length + 1));
         VerifyOrReturnError(scan_ssid != nullptr, false);
-        Platform::CopyString(scan_ssid, scan_ssid_length, ssid);
+        Platform::CopyString(scan_ssid, scan_ssid_length + 1, ssid);
     }
     scan_cb = callback;
     xEventGroupSetBits(sl_wfx_event_group, SL_WFX_SCAN_START);

examples/platform/silabs/wifi/wfx_rsi_host.cpp

@@ -365,15 +365,15 @@ int32_t wfx_reset_counts(void)
 bool wfx_start_scan(char * ssid, void (*callback)(wfx_wifi_scan_result_t *))
 {
     // check if already in progress
-    VerifyOrReturnError(wfx_rsi.scan_cb != nullptr, false);
+    VerifyOrReturnError(wfx_rsi.scan_cb == nullptr, false);
     wfx_rsi.scan_cb = callback;
-
-    VerifyOrReturnError(ssid != nullptr, false);
-    wfx_rsi.scan_ssid_length = strnlen(ssid, chip::min<size_t>(sizeof(ssid), WFX_MAX_SSID_LENGTH));
-    wfx_rsi.scan_ssid        = reinterpret_cast<char *>(chip::Platform::MemoryAlloc(wfx_rsi.scan_ssid_length));
-    VerifyOrReturnError(wfx_rsi.scan_ssid != nullptr, false);
-    chip::Platform::CopyString(wfx_rsi.scan_ssid, wfx_rsi.scan_ssid_length, ssid);
-
+    // if SSID is provided to scan only that SSID
+    if(ssid) {
+        wfx_rsi.scan_ssid_length = strnlen(ssid, chip::min<size_t>(sizeof(ssid), WFX_MAX_SSID_LENGTH));
+        wfx_rsi.scan_ssid        = reinterpret_cast<char *>(chip::Platform::MemoryAlloc(wfx_rsi.scan_ssid_length + 1));
+        VerifyOrReturnError(wfx_rsi.scan_ssid != nullptr, false);
+        chip::Platform::CopyString(wfx_rsi.scan_ssid, wfx_rsi.scan_ssid_length + 1, ssid);
+    }
     WfxEvent_t event;
     event.eventType = WFX_EVT_SCAN;
     WfxPostEvent(&event);