Look at every packet with promiscuous mode

ESPFirewall/src/main.cpp

@@ -3,6 +3,7 @@
 
 #ifdef ESP32
 #include "WiFi.h"
+#include "esp_wifi.h"
 #elif defined(ESP8266)
 #include "ESP8266WiFi.h"
 #endif
@@ -15,6 +16,23 @@ fw::API *firewallApi;
 
 WiFiServer wifiServer(80);
 
+typedef struct
+{
+  unsigned frame_ctrl : 16;
+  unsigned duration_id : 16;
+  uint8_t addr1[6]; /* receiver address */
+  uint8_t addr2[6]; /* sender address */
+  uint8_t addr3[6]; /* filtering address */
+  unsigned sequence_ctrl : 16;
+  uint8_t addr4[6]; /* optional */
+} wifi_ieee80211_mac_hdr_t;
+
+typedef struct
+{
+  wifi_ieee80211_mac_hdr_t hdr;
+  uint8_t payload[0]; /* network data ended with 4 bytes csum (CRC32) */
+} wifi_ieee80211_packet_t;
+
 void connectToWifi()
 {
   WiFi.begin(ssid, psk);
@@ -47,11 +65,52 @@ void handle_wifi_events(WiFiEvent_t event, WiFiEventInfo_t info)
   }
 }
 
+const char *wifi_sniffer_packet_type2str(wifi_promiscuous_pkt_type_t type)
+{
+  switch (type)
+  {
+  case WIFI_PKT_DATA:
+    return "DATA";
+  default:
+  case WIFI_PKT_MISC:
+    return "MISC";
+  }
+}
+
+void wifi_sniffer_packet_handler(void *buff, wifi_promiscuous_pkt_type_t type)
+{
+  if (type != WIFI_PKT_MGMT)
+    return;
+
+  const wifi_promiscuous_pkt_t *ppkt = (wifi_promiscuous_pkt_t *)buff;
+  const wifi_ieee80211_packet_t *ipkt = (wifi_ieee80211_packet_t *)ppkt->payload;
+  const wifi_ieee80211_mac_hdr_t *hdr = &ipkt->hdr;
+
+  printf("PACKET TYPE=%s, CHAN=%02d, RSSI=%02d,"
+         " ADDR1=%02x:%02x:%02x:%02x:%02x:%02x,"
+         " ADDR2=%02x:%02x:%02x:%02x:%02x:%02x,"
+         " ADDR3=%02x:%02x:%02x:%02x:%02x:%02x\n",
+         wifi_sniffer_packet_type2str(type),
+         ppkt->rx_ctrl.channel,
+         ppkt->rx_ctrl.rssi,
+         /* ADDR1 */
+         hdr->addr1[0], hdr->addr1[1], hdr->addr1[2],
+         hdr->addr1[3], hdr->addr1[4], hdr->addr1[5],
+         /* ADDR2 */
+         hdr->addr2[0], hdr->addr2[1], hdr->addr2[2],
+         hdr->addr2[3], hdr->addr2[4], hdr->addr2[5],
+         /* ADDR3 */
+         hdr->addr3[0], hdr->addr3[1], hdr->addr3[2],
+         hdr->addr3[3], hdr->addr3[4], hdr->addr3[5]);
+}
+
 void setup_wifi()
 {
   WiFi.mode(WIFI_STA);
   WiFi.onEvent(handle_wifi_events, ARDUINO_EVENT_MAX);
   connectToWifi();
+  esp_wifi_set_promiscuous(true);
+  esp_wifi_set_promiscuous_rx_cb(&wifi_sniffer_packet_handler);
 }
 
 void setup()