Fix overflow in relayParsePayload with messages bigger than 255 chars

code/espurna/relay.ino

@@ -276,16 +276,21 @@ unsigned char relayParsePayload(const char * payload) {
     // Payload could be "OFF", "ON", "TOGGLE"
     // or its number equivalents: 0, 1 or 2
 
+    if (payload[0] == '0') return 0;
+    if (payload[0] == '1') return 1;
+    if (payload[0] == '2') return 2;
+
     // trim payload
     char * p = ltrim((char *)payload);
 
     // to lower
-    for (unsigned char i=0; i<strlen(p); i++) {
+    unsigned int l = strlen(p);
+    if (l>6) l=6;
+    for (unsigned char i=0; i<l; i++) {
         p[i] = tolower(p[i]);
     }
 
-    unsigned int value;
-
+    unsigned int value = 0xFF;
     if (strcmp(p, "off") == 0) {
         value = 0;
     } else if (strcmp(p, "on") == 0) {
@@ -294,12 +299,9 @@ unsigned char relayParsePayload(const char * payload) {
         value = 2;
     } else if (strcmp(p, "query") == 0) {
         value = 3;
-    } else {
-        value = p[0] - '0';
     }
 
-    if (0 <= value && value <=3) return value;
-    return 0xFF;
+    return value;
 
 }
 
@@ -583,43 +585,47 @@ void relayMQTTCallback(unsigned int type, const char * topic, const char * paylo
 
     if (type == MQTT_MESSAGE_EVENT) {
 
-        // Get value
-        unsigned char value = relayParsePayload(payload);
-        if (value == 0xFF) {
-            DEBUG_MSG_P(PSTR("[RELAY] Wrong payload (%s)\n"), payload);
+        // Check relay topic
+        String t = mqttSubtopic((char *) topic);
+        if (t.startsWith(MQTT_TOPIC_RELAY)) {
+
+            // Get value
+            unsigned char value = relayParsePayload(payload);
+            if (value == 0xFF) return;
+
+            // Get relay ID
+            unsigned int id = t.substring(strlen(MQTT_TOPIC_RELAY)+1).toInt();
+            if (id >= relayCount()) {
+                DEBUG_MSG_P(PSTR("[RELAY] Wrong relayID (%d)\n"), id);
+            } else {
+                relayStatusWrap(id, value, false);
+            }
+
             return;
+
         }
 
         // Check group topics
-        bool found = false;
         for (unsigned int i=0; i < _relays.size(); i++) {
+
             String t = getSetting("mqttGroup", i, "");
-            if (t.equals(topic)) {
-                unsigned char local_value = value;
-                if (getSetting("mqttGroupInv", i, 0).toInt() == 1) {
-                    if (local_value < 2) local_value = 1 - local_value;
-                }
-                found = true;
-                DEBUG_MSG_P(PSTR("[RELAY] Matched group topic for relayID %d\n"), i);
-                relayStatusWrap(i, local_value, true);
-            }
-        }
 
-        // If found as group topic quit
-        if (found) return;
+            if ((t.length() > 0) && t.equals(topic)) {
 
-        // Else, try to match topic
-        String t = mqttSubtopic((char *) topic);
-        if (!t.startsWith(MQTT_TOPIC_RELAY)) return;
+                unsigned char value = relayParsePayload(payload);
+                if (value == 0xFF) return;
 
-        // Get relay ID
-        unsigned int id = t.substring(strlen(MQTT_TOPIC_RELAY)+1).toInt();
-        if (id >= relayCount()) {
-            DEBUG_MSG_P(PSTR("[RELAY] Wrong relayID (%d)\n"), id);
-            return;
-        }
+                if (value < 2) {
+                    if (getSetting("mqttGroupInv", i, 0).toInt() == 1) {
+                        value = 1 - value;
+                    }
+                }
+
+                DEBUG_MSG_P(PSTR("[RELAY] Matched group topic for relayID %d\n"), i);
+                relayStatusWrap(i, value, true);
 
-        relayStatusWrap(id, value, false);
+            }
+        }
 
     }