ESP32 Forum

Posted: **Wed Feb 27, 2019 8:56 am**

Hello
I use ESP-IDF v 3.1.2
devbord - ESP32-PICO-KIT.
I try to realize wi-fi sniffer, send via UART captured 802.11 frame. Also in asynchronous mode receive settings from PC.
So, this code is initialize UART

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uart_config_t uart_cfg = {
	.baud_rate = UART_2_PC_BAUD_RATE,
	.data_bits = UART_DATA_8_BITS,
	.parity    = UART_PARITY_DISABLE,
	.stop_bits = UART_STOP_BITS_1,
	.flow_ctrl = UART_HW_FLOWCTRL_DISABLE
							 };
ESP_ERROR_CHECK(uart_param_config(UART_2_PC, &uart_cfg));
ESP_ERROR_CHECK(uart_set_pin(UART_2_PC, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE));
ESP_ERROR_CHECK(uart_driver_install(UART_2_PC, 4096, 4096, 0, NULL, 0));

Also I was created 2 task:

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xReturned = xTaskCreatePinnedToCore(vUartWiFi, "UartWiFi", 8192, NULL, 1, NULL, 1);
	if (xReturned != pdPASS)
		{
			printf("Can't create UartWifi task\n");
			printf("ESP32 will be reset after 3 sec\n");
			vTaskDelay(3000/ portTICK_PERIOD_MS);
			esp_restart();
		}

xReturned = xTaskCreatePinnedToCore(vUartSettings, "UartSettings", 4096, NULL, 12, NULL, 1);
	if (xReturned != pdPASS)
		{
			printf("Can't create UartSettings task\n");
			printf("ESP32 will be reset after 3 sec\n");
			vTaskDelay(3000/ portTICK_PERIOD_MS);
			esp_restart();
		}

task "UartWiFi"
receive 802.11 frame from callback, analyze this frame and send via uart. I use

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uart_write_bytes(UART_2_PC, (char*) pkt, wifi_frame.ESP32_RADIO_METADATA.sig_len);

This function work good. At PC side I receive 802.11 frame correctly.

the main idea of task "UartSettings"
receive settings (set/get channel WiFi, enable/disable promiscuous mode etc) from PC

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void vUartSettings(void *pvParameters)
{

	uint8_t tlv_cmd[CMD_TLV_BUFFER];
//	tlv_cmd_t tlv_cmd;
	size_t len_tlv_cmd =0;
	int rx_bytes;
	uint8_t current_wifi_channel;

	while(1)
	{
		uart_get_buffered_data_len(UART_2_PC, &len_tlv_cmd);
//		printf("\n*******\n");
//		printf("Rx bytes = %d\n", len_tlv_cmd);
//		printf("*******\n");
		if (len_tlv_cmd > 0)
		{
			rx_bytes = uart_read_bytes(UART_2_PC, tlv_cmd, len_tlv_cmd, 10000/portTICK_RATE_MS);
			if (rx_bytes > 0)
			{
				switch(tlv_cmd[0])
				{
					case 1:
						printf("start/stop sniffer\n");
						esp_wifi_set_promiscuous(true);
						break;

					default:
						printf("\n*******\nUnknown cmd\n*****\n");
				}
			}
		}
	}

	vTaskDelete(NULL);
}

The function "uart_get_buffered_data_len" work correct. But when "uart_read_bytes" has executed - promiscuous mode is stop. I also changed the latst argument (ticks_to_wait) set to "0", "NULL" or "other_value". Nothing happen.
Every time "uart_read_bytes" executed -> promiscuous mode if OFF.

What could be wrong?

Thank you.

P.S.
Full code avaible here

ESP32 Forum

Promiscuous mode in WiFi is stoped by UART driver

Promiscuous mode in WiFi is stoped by UART driver