ESP32 Forum

Posted: **Mon Jan 03, 2022 2:38 pm**

Colleagues, hello!
As a beginner, I ask for your support

According to the documentation, ESP32 can receive 3 types of frames: Control, Management, Data.

My program receives frames: Management, Data and does not receives Control.

What am I doing wrong?

Code: Untitled.c Select all




/*

  ===========================================

       Copyright (c) 2017 Stefan Kremser

              github.com/spacehuhn

  ===========================================

*/





/* include all necessary libraries */ 

#include "freertos/FreeRTOS.h"

#include "esp_wifi.h"

//#include "esp_wifi_internal.h"

#include "lwip/err.h"

#include "esp_system.h"

#include "esp_event.h"

#include "esp_event_loop.h"

#include "nvs_flash.h"

#include "driver/gpio.h"



#include <Arduino.h>

#include "TimeLib.h"

#include "FS.h"

#include "SD.h"

#include "SPI.h"

#include "PCAP.h"





//===== SETTINGS =====//

#define CHANNEL           5

#define BAUD_RATE         921600

#define CHANNEL_HOPPING   false     //if true it will scan on all channels

#define MAX_CHANNEL       11        //(only necessary if channelHopping is true)

#define HOP_INTERVAL      214       //in ms (only necessary if channelHopping is true)



//===== Run-Time variables =====//

PCAP pcap = PCAP();

int ch = CHANNEL;

unsigned long lastChannelChange = 0;



wifi_promiscuous_filter_t filter = {

  //.filter_mask = WIFI_PROMIS_FILTER_MASK_ALL 

  //.filter_mask = WIFI_PROMIS_CTRL_FILTER_MASK_ALL

  .filter_mask = WIFI_PROMIS_FILTER_MASK_MGMT | WIFI_PROMIS_FILTER_MASK_CTRL | WIFI_PROMIS_FILTER_MASK_DATA

};



//===== FUNCTIONS =====//



/* will be executed on every packet the ESP32 gets while beeing in promiscuous mode */

void sniffer(void *buf, wifi_promiscuous_pkt_type_t type)

{

  wifi_promiscuous_pkt_t* pkt = (wifi_promiscuous_pkt_t*)buf;

  wifi_pkt_rx_ctrl_t ctrl = (wifi_pkt_rx_ctrl_t)pkt->rx_ctrl;

  

  uint32_t timestamp = now(); //current timestamp 

  uint32_t microseconds = (unsigned int)(micros() - millis() * 1000); //micro seconds offset (0 - 999)

  

  pcap.newPacketSerial(timestamp, microseconds, ctrl.sig_len, pkt->payload); //send packet via Serial  

}



esp_err_t event_handler(void *ctx, system_event_t *event){ return ESP_OK; }





//===== SETUP =====//

void setup()

{

  /* start Serial */

  Serial.begin(BAUD_RATE);

  delay(2000);

  Serial.println();

  

  Serial.println("<<START>>");

  pcap.startSerial();



  /* setup wifi */

  nvs_flash_init();

  tcpip_adapter_init();

  ESP_ERROR_CHECK( esp_event_loop_init(event_handler, NULL) );

  wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();

  ESP_ERROR_CHECK( esp_wifi_init(&cfg) );

  ESP_ERROR_CHECK( esp_wifi_set_storage(WIFI_STORAGE_RAM) );

  //ESP_ERROR_CHECK( esp_wifi_set_mode(WIFI_MODE_AP) );  

  ESP_ERROR_CHECK( esp_wifi_set_mode(WIFI_MODE_NULL) );  

  //ESP_ERROR_CHECK( esp_wifi_set_mode(WIFI_MODE_STA) );  

  ESP_ERROR_CHECK( esp_wifi_start() );

  esp_wifi_set_promiscuous(false);

  esp_wifi_set_promiscuous_filter(&filter);

  esp_wifi_set_promiscuous_rx_cb(sniffer);

  esp_wifi_set_promiscuous(true);

  wifi_second_chan_t secondCh = (wifi_second_chan_t)NULL;

  esp_wifi_set_channel(ch,secondCh);

}



//===== LOOP =====//

void loop()

{

    /* Channel Hopping */

  if(CHANNEL_HOPPING)

  {

    unsigned long currentTime = millis();

    if(currentTime - lastChannelChange >= HOP_INTERVAL)

    {

      lastChannelChange = currentTime;

      ch++; //increase channel

      if(ch > MAX_CHANNEL) ch = 1;

      wifi_second_chan_t secondCh = (wifi_second_chan_t)NULL;

      esp_wifi_set_channel(ch,secondCh);

    }

  }

}

Posted: **Sun Feb 05, 2023 3:14 pm**

To get control packets, use
esp_err_t esp_wifi_set_promiscuous_ctrl_filter(const wifi_promiscuous_filter_t *filter);

ESP32 Forum

ESP32 Wi-Fi Sniffer Mode

ESP32 Wi-Fi Sniffer Mode

Re: ESP32 Wi-Fi Sniffer Mode