Merge pull request #387 from fabik111/add-limit-on-discovered-ap

Add limit for returning the first 10 access points with high rssi

Author: pennam

libraries/WiFiS3/src/WiFi.cpp

@@ -1,5 +1,7 @@
 #include "WiFi.h"
 
+#define WIFI_MAX_BSSID_STRING_LENGTH 17
+
 using namespace std;
 
 /* -------------------------------------------------------------------------- */
@@ -256,6 +258,42 @@ uint8_t* CWifi::macAddress(uint8_t* _mac) {
    return _mac;
 }
 
+/* -------------------------------------------------------------------------- */
+void CWifi::_sortAPlist(uint8_t num) {
+/* -------------------------------------------------------------------------- */
+   for(uint8_t i = 0; i < num; i++) {
+      for(uint8_t j = i+1; j < num; j++) {
+         if(access_points[j].rssi > access_points[i].rssi) {
+            CAccessPoint temp = access_points[i];
+            access_points[i] = access_points[j];
+            access_points[j] = temp;
+         }
+      }
+   }
+}
+
+static uint8_t Encr2wl_enc(string e) {
+   if (e == string("open")) {
+      return ENC_TYPE_NONE;
+   } else if (e == string("WEP")) {
+      return ENC_TYPE_WEP;
+   } else if (e == string("WPA")) {
+      return ENC_TYPE_WPA;
+   } else if (e == string("WPA2")) {
+      return ENC_TYPE_WPA2;
+   } else if (e == string("WPA+WPA2")) {
+      return ENC_TYPE_WPA2;
+   } else if (e == string("WPA2-EAP")) {
+      return ENC_TYPE_WPA2_ENTERPRISE;
+   } else if (e == string("WPA2+WPA3")) {
+      return ENC_TYPE_WPA3;
+   } else if (e == string("WPA3")) {
+      return ENC_TYPE_WPA3;
+   } else {
+      return ENC_TYPE_UNKNOWN;
+   }
+}
+
 /* -------------------------------------------------------------------------- */
 int8_t CWifi::scanNetworks() {
 /* -------------------------------------------------------------------------- */
@@ -264,30 +302,60 @@ int8_t CWifi::scanNetworks() {
    modem.avoid_trim_results();
    modem.read_using_size();
 
-   access_points.clear();
+   memset(access_points,0x00,sizeof(access_points));
+   _apsFound = 0;
    string res;
-
-   vector<string> aps;
    if(modem.write(string(PROMPT(_WIFISCAN)),res,CMD(_WIFISCAN))) {
+      char *startAp = (char*)res.c_str();
+      char *endAP = strstr(startAp, "\r\n");
+      for(; endAP != NULL; startAp = endAP + 2, endAP = strstr(startAp, "\r\n")) {
+         /* split the modem response in multiple lines and parse once at time.
+          * The output will be something like:
+          * SSID | BSSID | RSSI | CHANNEL | SECURITY
+          */
+         *endAP = '\0'; // Replace \r with \0
+
+         char *token[5];
+         uint8_t i = 1;
+         token[0] = startAp;
+         for(; i < 5; i++){
+            char *endToken = strstr(token[i-1], " | ");
+            if(endToken == NULL){
+               break;
+            }
+            memset(endToken, '\0', 3);
+            token[i] = endToken + 3;
+         }
+
+         if(i < 5 || strlen(token[0]) == 0 || strlen(token[0]) > WL_SSID_MAX_LENGTH ||
+         strlen(token[1]) != WIFI_MAX_BSSID_STRING_LENGTH ||
+         strlen(token[2]) == 0 || strlen(token[3]) == 0 || strlen(token[4]) == 0){
+         /* Skip the row and process the next one */
+         continue;
+         }
 
-      split(aps, res, string("\r\n"));
-      for(uint16_t i = 0; i < aps.size(); i++) {
          CAccessPoint ap;
-         vector<string> tokens;
-         split(tokens, aps[i], string("|"));
-         if(tokens.size() >= 5) {
-            ap.ssid            = tokens[0];
-            ap.bssid           = tokens[1];
-            macStr2macArray(ap.uint_bssid, ap.bssid.c_str());
-            ap.rssi            = tokens[2];
-            ap.channel         = tokens[3];
-            ap.encryption_mode = tokens[4];
-            access_points.push_back(ap);
+         strcpy(ap.ssid, token[0]);
+         macStr2macArray(ap.uint_bssid, token[1]);
+         ap.rssi = atoi(token[2]);
+         ap.channel = atoi(token[3]);
+         ap.encryption_mode = Encr2wl_enc(token[4]);
+
+         // insert in list
+         if( _apsFound < WIFI_MAX_SSID_COUNT ){
+            access_points[_apsFound] = ap;
+            _apsFound++;
+            _sortAPlist(_apsFound);
+         }else{
+            if (ap.rssi > access_points[WIFI_MAX_SSID_COUNT-1].rssi){
+               access_points[WIFI_MAX_SSID_COUNT-1] = ap;
+               _sortAPlist(WIFI_MAX_SSID_COUNT);
+            }
          }
       }
    }
 
-   return (int8_t)access_points.size();
+   return _apsFound;
 }
 
 /* -------------------------------------------------------------------------- */
@@ -376,51 +444,29 @@ IPAddress CWifi::gatewayIP() {
 /* -------------------------------------------------------------------------- */
 const char* CWifi::SSID(uint8_t networkItem) {
 /* -------------------------------------------------------------------------- */
-   if(networkItem < access_points.size()) {
-      return access_points[networkItem].ssid.c_str();
+   if(networkItem < _apsFound) {
+      return access_points[networkItem].ssid;
    }
    return nullptr;
 }
 
 /* -------------------------------------------------------------------------- */
 int32_t CWifi::RSSI(uint8_t networkItem) {
 /* -------------------------------------------------------------------------- */
-   if(networkItem < access_points.size()) {
-      return atoi(access_points[networkItem].rssi.c_str());
+   if(networkItem < _apsFound) {
+      return access_points[networkItem].rssi;
    }
    return -1000;
 }
 
-static uint8_t Encr2wl_enc(string e) {
-   if (e == string("open")) {
-      return ENC_TYPE_NONE;
-   } else if (e == string("WEP")) {
-      return ENC_TYPE_WEP;
-   } else if (e == string("WPA")) {
-      return ENC_TYPE_WPA;
-   } else if (e == string("WPA2")) {
-      return ENC_TYPE_WPA2;
-   } else if (e == string("WPA+WPA2")) {
-      return ENC_TYPE_WPA2;
-   } else if (e == string("WPA2-EAP")) {
-      return ENC_TYPE_WPA2_ENTERPRISE;
-   } else if (e == string("WPA2+WPA3")) {
-      return ENC_TYPE_WPA3;
-   } else if (e == string("WPA3")) {
-      return ENC_TYPE_WPA3;
-   } else {
-      return ENC_TYPE_UNKNOWN;
-   }
-}
-
 /* -------------------------------------------------------------------------- */
 uint8_t CWifi::encryptionType() {
 /* -------------------------------------------------------------------------- */
    scanNetworks();
    string myssid(SSID());
-   for(unsigned int i = 0; i < access_points.size(); i++) {
+   for(unsigned int i = 0; i < _apsFound; i++) {
       if(myssid ==  access_points[i].ssid) {
-         return Encr2wl_enc(access_points[i].encryption_mode);
+         return access_points[i].encryption_mode;
       }
    }
    return ENC_TYPE_UNKNOWN;
@@ -429,16 +475,16 @@ uint8_t CWifi::encryptionType() {
 /* -------------------------------------------------------------------------- */
 uint8_t CWifi::encryptionType(uint8_t networkItem) {
 /* -------------------------------------------------------------------------- */
-   if(networkItem < access_points.size()) {
-      return Encr2wl_enc(access_points[networkItem].encryption_mode);
+   if(networkItem < _apsFound) {
+      return access_points[networkItem].encryption_mode;
    }
    return 0;
 }
 
 /* -------------------------------------------------------------------------- */
 uint8_t* CWifi::BSSID(uint8_t networkItem, uint8_t* bssid) {
 /* -------------------------------------------------------------------------- */
-   if(networkItem < access_points.size()) {
+   if(networkItem < _apsFound) {
       for(int i = 0; i < 6; i++) {
          *(bssid + i) = access_points[networkItem].uint_bssid[i];
       }
@@ -450,8 +496,8 @@ uint8_t* CWifi::BSSID(uint8_t networkItem, uint8_t* bssid) {
 /* -------------------------------------------------------------------------- */
 uint8_t CWifi::channel(uint8_t networkItem) {
 /* -------------------------------------------------------------------------- */
-   if(networkItem < access_points.size()) {
-      return atoi(access_points[networkItem].channel.c_str());
+   if(networkItem < _apsFound) {
+      return access_points[networkItem].channel;
    }
    return 0;
 }

libraries/WiFiS3/src/WiFi.h

@@ -19,24 +19,43 @@
 
 #define WIFI_FIRMWARE_LATEST_VERSION "0.5.2"
 
+#ifndef WIFI_MAX_SSID_COUNT
+  #define WIFI_MAX_SSID_COUNT 10
+#endif
+
 class CAccessPoint {
 public:
-    std::string ssid;
-    std::string bssid;
+    CAccessPoint() {}
+    CAccessPoint(const CAccessPoint &obj)
+    {
+        strcpy(ssid, obj.ssid);
+        rssi = obj.rssi;
+        channel = obj.channel;
+        encryption_mode = obj.encryption_mode;
+        memcpy(uint_bssid, obj.uint_bssid, sizeof(uint_bssid));
+    }
+    CAccessPoint &operator=(const CAccessPoint &obj) {
+        strcpy(ssid, obj.ssid);
+        rssi = obj.rssi;
+        channel = obj.channel;
+        encryption_mode = obj.encryption_mode;
+        memcpy(uint_bssid, obj.uint_bssid, sizeof(uint_bssid));
+    }
+    char ssid[WL_SSID_MAX_LENGTH + 1]; // +1 for null terminator
     uint8_t uint_bssid[6];
-    std::string rssi;
-    std::string channel;
-    std::string encryption_mode;
+    int rssi;
+    uint8_t channel;
+    uint8_t encryption_mode;
 };
 
 
-
-
 class CWifi {
 private:
     void _config(IPAddress local_ip, IPAddress gateway, IPAddress subnet, IPAddress dns1, IPAddress dns2);
+    void _sortAPlist(uint8_t num);
     unsigned long _timeout;
-    std::vector<CAccessPoint> access_points;
+    CAccessPoint access_points[WIFI_MAX_SSID_COUNT];
+    uint8_t _apsFound = 0;
     std::string ssid;
     std::string apssid;