ESP32-PaxCounter/src/wifiscan.cpp
2020-10-30 12:24:16 +01:00

98 lines
3.6 KiB
C++

// Basic Config
#include "globals.h"
#include "wifiscan.h"
// Local logging tag
static const char TAG[] = "wifi";
TimerHandle_t WifiChanTimer;
static wifi_country_t wifi_country = {WIFI_MY_COUNTRY, WIFI_CHANNEL_MIN,
WIFI_CHANNEL_MAX, 100,
WIFI_COUNTRY_POLICY_MANUAL};
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;
// using IRAM_:ATTR here to speed up callback function
IRAM_ATTR void wifi_sniffer_packet_handler(void *buff,
wifi_promiscuous_pkt_type_t type) {
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;
if ((cfg.rssilimit) &&
(ppkt->rx_ctrl.rssi < cfg.rssilimit)) // rssi is negative value
ESP_LOGD(TAG, "WiFi RSSI %d -> ignoring (limit: %d)", ppkt->rx_ctrl.rssi,
cfg.rssilimit);
else // count seen MAC
mac_add((uint8_t *)hdr->addr2, ppkt->rx_ctrl.rssi, MAC_SNIFF_WIFI);
}
// Software-timer driven Wifi channel rotation callback function
void switchWifiChannel(TimerHandle_t xTimer) {
_ASSERT(xTimer != NULL);
channel =
(channel % WIFI_CHANNEL_MAX) + 1; // rotate channel 1..WIFI_CHANNEL_MAX
esp_wifi_set_channel(channel, WIFI_SECOND_CHAN_NONE);
}
void wifi_sniffer_init(void) {
wifi_init_config_t wificfg = WIFI_INIT_CONFIG_DEFAULT();
wificfg.nvs_enable = 0; // we don't need any wifi settings from NVRAM
wificfg.wifi_task_core_id = 0; // we want wifi task running on core 0
// wifi_promiscuous_filter_t filter = {
// .filter_mask = WIFI_PROMIS_FILTER_MASK_MGMT}; // only MGMT frames
// .filter_mask = WIFI_PROMIS_FILTER_MASK_ALL}; // we use all frames
wifi_promiscuous_filter_t filter = {.filter_mask =
WIFI_PROMIS_FILTER_MASK_MGMT |
WIFI_PROMIS_FILTER_MASK_DATA};
ESP_ERROR_CHECK(esp_wifi_init(&wificfg)); // configure Wifi with cfg
ESP_ERROR_CHECK(
esp_wifi_set_country(&wifi_country)); // set locales for RF and channels
ESP_ERROR_CHECK(
esp_wifi_set_storage(WIFI_STORAGE_RAM)); // we don't need NVRAM
ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_NULL));
ESP_ERROR_CHECK(esp_wifi_set_ps(WIFI_PS_NONE)); // no modem power saving
ESP_ERROR_CHECK(esp_wifi_set_promiscuous_filter(&filter)); // set frame filter
ESP_ERROR_CHECK(esp_wifi_set_promiscuous_rx_cb(&wifi_sniffer_packet_handler));
ESP_ERROR_CHECK(esp_wifi_set_promiscuous(true)); // now switch on monitor mode
// setup wifi channel rotation timer
WifiChanTimer =
xTimerCreate("WifiChannelTimer", pdMS_TO_TICKS(cfg.wifichancycle * 10),
pdTRUE, (void *)0, switchWifiChannel);
}
void switch_wifi_sniffer(uint8_t state) {
_ASSERT(WifiChanTimer != NULL);
if (state) {
// switch wifi sniffer on
ESP_ERROR_CHECK(esp_wifi_start());
xTimerStart(WifiChanTimer, 0);
esp_wifi_set_promiscuous(true);
} else {
// switch wifi sniffer off
xTimerStop(WifiChanTimer, 0);
esp_wifi_set_promiscuous(false);
ESP_ERROR_CHECK(esp_wifi_stop());
macs_wifi = 0; // clear WIFI counter
}
}