Mesh relay

src/chat-relay/EvilChatMesh-Relay.cpp

@@ -0,0 +1,104 @@
+#include <WiFi.h>
+#include <esp_now.h>
+#include <Arduino.h>
+#include <string.h>
+
+#define MAX_HISTORY 32
+#define MSG_LEN 100
+
+struct MeshMessage {
+    char id[9];       
+    char from[16];   
+    char body[MSG_LEN];
+};
+
+char seenMessageIds[MAX_HISTORY][19];
+int seenIndex = 0;
+
+uint8_t broadcastAddress[] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+
+bool hasSeenId(const char* id) {
+    for (int i = 0; i < MAX_HISTORY; i++) {
+        if (strncmp(seenMessageIds[i], id, 8) == 0) {
+            return true;
+        }
+    }
+    return false;
+}
+
+void rememberId(const char* id) {
+    strncpy(seenMessageIds[seenIndex], id, 8);
+    seenMessageIds[seenIndex][8] = '\0';
+    seenIndex = (seenIndex + 1) % MAX_HISTORY;
+}
+
+uint16_t crc16(const uint8_t* data, size_t length) {
+    uint16_t crc = 0xFFFF;
+    for (size_t i = 0; i < length; i++) {
+        crc ^= ((uint16_t)data[i] << 8);
+        for (int j = 0; j < 8; j++) {
+            crc = (crc & 0x8000) ? ((crc << 1) ^ 0x1021) : (crc << 1);
+        }
+    }
+    return crc;
+}
+
+void onDataRecv(const esp_now_recv_info_t *info, const uint8_t *incomingData, int len) {
+    if (len != sizeof(MeshMessage) + sizeof(uint16_t)) {
+        return;
+    }
+
+    uint16_t receivedCrc;
+    memcpy(&receivedCrc, incomingData + sizeof(MeshMessage), sizeof(uint16_t));
+    uint16_t computedCrc = crc16(incomingData, sizeof(MeshMessage));
+    if (receivedCrc != computedCrc) {
+        // Le message est corrompu
+        return;
+    }
+
+    MeshMessage msg;
+    memcpy(&msg, incomingData, sizeof(MeshMessage));
+
+    if (hasSeenId(msg.id)) return;
+    rememberId(msg.id);
+
+    esp_now_send(broadcastAddress, incomingData, len);
+
+    if (strcmp(msg.body, "PING") != 0) {
+        Serial.print("Relayed message from ");
+        Serial.print(msg.from);
+        Serial.print(": ");
+        Serial.println(msg.body);
+    }
+}
+
+
+void setup() {
+    Serial.begin(115200);
+    Serial.println("Initialisation du relais ESP-NOW");
+
+    WiFi.mode(WIFI_STA);
+    WiFi.disconnect();
+
+    if (esp_now_init() != ESP_OK) {
+        Serial.println("Erreur lors de l'initialisation d'ESP-NOW");
+        return;
+    }
+
+    esp_now_register_recv_cb(onDataRecv);
+
+    // Ajout du peer de broadcast
+    esp_now_peer_info_t peerInfo = {};
+    memcpy(peerInfo.peer_addr, broadcastAddress, 6);
+    peerInfo.channel = 1;      
+    peerInfo.encrypt = false;
+    if (!esp_now_is_peer_exist(peerInfo.peer_addr)) {
+        if (esp_now_add_peer(&peerInfo) != ESP_OK) {
+            Serial.println("Erreur lors de l'ajout du peer broadcast");
+        }
+    }
+}
+
+void loop() {
+    delay(10);
+}