Improvement

CMakeLists.txt

@@ -3,4 +3,4 @@
 cmake_minimum_required(VERSION 3.16)
 
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
-project(wifi-scanner)
+project(wifi-sniffer)

main/Kconfig.projbuild

@@ -0,0 +1,36 @@
+menu "Sniffer Configuration"
+  config BLINK_GPIO_NUM
+    int "The GPIO number that is blinked"
+    range 0 33
+    default 2
+    help
+      "No help :)"
+
+  config BLINK_SPEED
+    int "The time between blinks in milliseconds"
+    range 10 100
+    default 25
+    help
+      "No help :)"
+
+  config PACKET_QUEUE_SIZE
+    int "The size of the packet queue"
+    range 8 128
+    default 32
+    help
+      "The size of the packet queue. Too small of a value may drop some packets."
+
+  config PACKET_QUEUE_TIMEOUT
+    int "The timeout in ms when inserting into the queue"
+    range 1 100
+    default 10
+    help
+      "The timeout in milliseconds of trying to insert a packet into the queue. A too small or too big value may drop packets."
+
+  config CHANNEL_SWITCHER_FREQUENCY
+    int "The time in milliseconds between channel switches"
+    range 10 1000
+    default 100
+    help
+      "No help :)"
+endmenu

main/main.cpp

@@ -2,42 +2,119 @@
 #include "wifi.h"
 
 #include "sdkconfig.h"
+#include <driver/gpio.h>
 #include <esp_event.h>
+#include <esp_log.h>
 #include <esp_wifi.h>
 #include <freertos/FreeRTOS.h>
+#include <freertos/queue.h>
 #include <freertos/task.h>
 #include <inttypes.h>
 #include <string.h>
 
-void packet_callback(void *buf, wifi_promiscuous_pkt_type_t type) {
+constexpr static auto blink_port = (gpio_num_t)CONFIG_BLINK_GPIO_NUM;
+constexpr static auto blink_speed = CONFIG_BLINK_SPEED; // ms
+
+constexpr static auto sniffer_tag = "sniffer";
+
+constexpr static auto queue_size = CONFIG_PACKET_QUEUE_SIZE;
+constexpr static auto queue_timeout = CONFIG_PACKET_QUEUE_TIMEOUT; // ms
+
+constexpr static auto channel_switcher_frequency = CONFIG_CHANNEL_SWITCHER_FREQUENCY; // ms
+
+
+static QueueHandle_t packet_queue;
+
+volatile int new_packet = 0;
+
+struct queue_item {
+  wifi_pkt_rx_ctrl_t rx_ctrl;
+  void *payload;
+};
+
+extern "C" void app_main(void) {
+  packet_queue = xQueueCreate(queue_size, sizeof(queue_item));
+
+  setup_blinker();
+
+  setup_wifi();
+
+
+  while (true) {
+    queue_item item;
+
+    // Block forever until we receive a packet from the queue.
+    if (xQueueReceive(packet_queue, &item, portMAX_DELAY) != pdTRUE) {
+      // Keep trying :)
+      continue;
+    }
+
+    auto *frame = (mac_frame *)item.payload;
+    print_frame_control_type(frame->frame_control);
+
+    printf("rssi: %d\n"
+           "channel: %u\n",
+           item.rx_ctrl.rssi, item.rx_ctrl.channel);
+
+    printf("receiver: ");
+    print_mac_address(frame->receiver_address);
+
+    printf("transmitter: ");
+    print_mac_address(frame->transmitter_address);
+
+    printf("\n\n\n");
+
+    free(item.payload);
+  }
+}
+
+static void packet_callback(void *buf, wifi_promiscuous_pkt_type_t type) {
   auto *pkt = (wifi_promiscuous_pkt_t *)buf;
   auto *rx_ctrl = &pkt->rx_ctrl;
-  auto *frame = (mac_frame *)pkt->payload;
-  print_frame_control_type(frame->frame_control);
 
-  printf("rssi: %d\n"
-         "channel: %u\n"
-         "sig_len: %u\n",
-         rx_ctrl->rssi, rx_ctrl->channel, rx_ctrl->sig_len);
+  auto *new_payload = malloc(rx_ctrl->sig_len);
+  memcpy(new_payload, pkt->payload, rx_ctrl->sig_len);
 
-  printf("duration: %u\n", frame->duration);
+  queue_item item{pkt->rx_ctrl, new_payload};
 
-  printf("receiver: ");
-  print_mac_address(frame->receiver_address);
+  new_packet = 1;
 
-  printf("transmitter: ");
-  print_mac_address(frame->transmitter_address);
+  if (xQueueSend(packet_queue, &item, pdMS_TO_TICKS(queue_timeout)) != pdTRUE) {
+    ESP_LOGE(sniffer_tag, "queue full");
+    free(new_payload);
+  }
+}
 
-  printf("destination: ");
-  print_mac_address(frame->destination_address);
+static void task_blinker(void *parameters) {
+  while (true) {
+    gpio_set_level(blink_port, new_packet);
+    new_packet = 0;
+    vTaskDelay(blink_speed / portTICK_PERIOD_MS);
+    gpio_set_level(blink_port, 0);
+    vTaskDelay(blink_speed / portTICK_PERIOD_MS);
+  }
+}
 
-  printf("source: ");
-  print_mac_address(frame->source_address);
+static void task_channel_hopper(void *parameters) {
+  // TODO: Give more time to channels with more packets.
+  // Ignore packets that are probe requests or beacon as they are outside channels.
+  auto channel = 0;
+  while (true) {
+    esp_wifi_set_channel(channel + 1, WIFI_SECOND_CHAN_NONE);
+    channel = (channel + 1) % 10;
+    vTaskDelay(channel_switcher_frequency / portTICK_PERIOD_MS);
+  }
+}
 
-  printf("\n\n\n");
+static void setup_blinker() {
+  gpio_reset_pin(blink_port);
+  gpio_set_direction(blink_port, GPIO_MODE_OUTPUT);
+
+  xTaskCreate(task_blinker, "blinker", 2048, (void *)nullptr, tskIDLE_PRIORITY,
+              NULL);
 }
 
-extern "C" void app_main(void) {
+static void setup_wifi() {
   esp_netif_init();
   esp_event_loop_create_default();
   auto *sta_netif = esp_netif_create_default_wifi_sta();
@@ -50,4 +127,6 @@ extern "C" void app_main(void) {
 
   esp_wifi_set_promiscuous(true);
   esp_wifi_set_promiscuous_rx_cb(packet_callback);
+
+  xTaskCreate(task_channel_hopper, "channel hopper", 2048, (void*)nullptr, tskIDLE_PRIORITY, NULL);
 }

main/main.h

@@ -1 +1,13 @@
 #pragma once
+
+#include <esp_wifi.h>
+
+static void packet_callback(void *buf, wifi_promiscuous_pkt_type_t type);
+
+static void task_blinker(void* parameters);
+
+static void task_channel_hopper(void *parameters);
+
+static void setup_blinker();
+
+static void setup_wifi();

sdkconfig

@@ -338,12 +338,22 @@ CONFIG_PARTITION_TABLE_OFFSET=0x8000
 CONFIG_PARTITION_TABLE_MD5=y
 # end of Partition Table
 
+#
+# Sniffer Configuration
+#
+CONFIG_BLINK_GPIO_NUM=2
+CONFIG_BLINK_SPEED=25
+CONFIG_PACKET_QUEUE_SIZE=32
+CONFIG_PACKET_QUEUE_TIMEOUT=10
+CONFIG_CHANNEL_SWITCHER_FREQUENCY=100
+# end of Sniffer Configuration
+
 #
 # Compiler options
 #
-CONFIG_COMPILER_OPTIMIZATION_DEFAULT=y
+# CONFIG_COMPILER_OPTIMIZATION_DEFAULT is not set
 # CONFIG_COMPILER_OPTIMIZATION_SIZE is not set
-# CONFIG_COMPILER_OPTIMIZATION_PERF is not set
+CONFIG_COMPILER_OPTIMIZATION_PERF=y
 # CONFIG_COMPILER_OPTIMIZATION_NONE is not set
 CONFIG_COMPILER_OPTIMIZATION_ASSERTIONS_ENABLE=y
 # CONFIG_COMPILER_OPTIMIZATION_ASSERTIONS_SILENT is not set
@@ -358,7 +368,7 @@ CONFIG_COMPILER_STACK_CHECK_MODE_NONE=y
 # CONFIG_COMPILER_STACK_CHECK_MODE_NORM is not set
 # CONFIG_COMPILER_STACK_CHECK_MODE_STRONG is not set
 # CONFIG_COMPILER_STACK_CHECK_MODE_ALL is not set
-# CONFIG_COMPILER_WARN_WRITE_STRINGS is not set
+CONFIG_COMPILER_WARN_WRITE_STRINGS=y
 # CONFIG_COMPILER_DISABLE_GCC12_WARNINGS is not set
 # CONFIG_COMPILER_DUMP_RTL_FILES is not set
 # end of Compiler options
@@ -1124,7 +1134,6 @@ CONFIG_FREERTOS_TASK_NOTIFICATION_ARRAY_ENTRIES=1
 #
 # Port
 #
-CONFIG_FREERTOS_TASK_FUNCTION_WRAPPER=y
 # CONFIG_FREERTOS_WATCHPOINT_END_OF_STACK is not set
 CONFIG_FREERTOS_TLSP_DELETION_CALLBACKS=y
 # CONFIG_FREERTOS_ENABLE_STATIC_TASK_CLEAN_UP is not set
@@ -1738,8 +1747,8 @@ CONFIG_LOG_BOOTLOADER_LEVEL=3
 CONFIG_FLASHMODE_DIO=y
 # CONFIG_FLASHMODE_DOUT is not set
 CONFIG_MONITOR_BAUD=115200
-CONFIG_OPTIMIZATION_LEVEL_DEBUG=y
-CONFIG_COMPILER_OPTIMIZATION_LEVEL_DEBUG=y
+# CONFIG_OPTIMIZATION_LEVEL_DEBUG is not set
+# CONFIG_COMPILER_OPTIMIZATION_LEVEL_DEBUG is not set
 # CONFIG_OPTIMIZATION_LEVEL_RELEASE is not set
 # CONFIG_COMPILER_OPTIMIZATION_LEVEL_RELEASE is not set
 CONFIG_OPTIMIZATION_ASSERTIONS_ENABLED=y
@@ -1751,7 +1760,7 @@ CONFIG_STACK_CHECK_NONE=y
 # CONFIG_STACK_CHECK_NORM is not set
 # CONFIG_STACK_CHECK_STRONG is not set
 # CONFIG_STACK_CHECK_ALL is not set
-# CONFIG_WARN_WRITE_STRINGS is not set
+CONFIG_WARN_WRITE_STRINGS=y
 # CONFIG_ESP32_APPTRACE_DEST_TRAX is not set
 CONFIG_ESP32_APPTRACE_DEST_NONE=y
 CONFIG_ESP32_APPTRACE_LOCK_ENABLE=y