ESP32-PaxCounter/src/wifiscan.cpp
2021-03-22 15:39:44 +01:00

107 lines
3.7 KiB
C++

#ifndef LIBPAX
// Basic Config
#include "globals.h"
#include "wifiscan.h"
// Local logging tag
static const char TAG[] = "wifi";
TimerHandle_t WifiChanTimer;
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;
// process seen MAC
#if MACFILTER
// we guess it's a smartphone, if U/L bit #2 of MAC is set
// bit #2 = 1 -> local mac (randomized) / bit #2 = 0 -> universal mac
if ((hdr->addr2[0] & 0b10) == 0)
return;
else
#endif
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) {
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_country_t wifi_country = {WIFI_MY_COUNTRY, WIFI_CHANNEL_MIN,
WIFI_CHANNEL_MAX, 100,
WIFI_COUNTRY_POLICY_MANUAL};
wifi_init_config_t wifi_cfg = WIFI_INIT_CONFIG_DEFAULT();
wifi_cfg.event_handler = NULL; // we don't need a wifi event handler
wifi_cfg.nvs_enable = 0; // we don't need any wifi settings from NVRAM
wifi_cfg.wifi_task_core_id = 0; // we want wifi task running on core 0
wifi_promiscuous_filter_t wifi_filter = {.filter_mask =
WIFI_PROMIS_FILTER_MASK_MGMT |
WIFI_PROMIS_FILTER_MASK_DATA};
esp_wifi_init(&wifi_cfg); // start Wifi task
esp_wifi_set_country(&wifi_country); // set locales for RF and channels
esp_wifi_set_storage(WIFI_STORAGE_RAM);
esp_wifi_set_mode(WIFI_MODE_NULL);
esp_wifi_set_ps(WIFI_PS_NONE); // no modem power saving
esp_wifi_set_promiscuous_filter(&wifi_filter); // set frame filter
esp_wifi_set_promiscuous_rx_cb(&wifi_sniffer_packet_handler);
// setup wifi channel hopping timer
WifiChanTimer = xTimerCreate("WifiChannelTimer",
(cfg.wifichancycle > 0)
? pdMS_TO_TICKS(cfg.wifichancycle * 10)
: pdMS_TO_TICKS(50),
pdTRUE, (void *)0, switchWifiChannel);
}
void switch_wifi_sniffer(uint8_t state) {
if (state) {
// start sniffer
#if (BLECOUNTER)
// workaround needed for ESP-IDF v3.3
// see https://github.com/espressif/esp-idf/issues/5427
esp_wifi_set_ps(WIFI_PS_MIN_MODEM);
#endif
esp_wifi_start();
esp_wifi_set_promiscuous(true);
esp_wifi_set_channel(WIFI_CHANNEL_MIN, WIFI_SECOND_CHAN_NONE);
// start channel hopping timer
if (cfg.wifichancycle > 0)
xTimerStart(WifiChanTimer, (TickType_t)0);
} else {
// start channel hopping timer
if (xTimerIsTimerActive(WifiChanTimer) != pdFALSE)
xTimerStop(WifiChanTimer, (TickType_t)0);
// stop sniffer
esp_wifi_set_promiscuous(false);
esp_wifi_stop();
}
}
#endif