AP.cpp

/*
 * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include "WiFi.h"
#include "WiFiGeneric.h"
#include "WiFiAP.h"
#if SOC_WIFI_SUPPORTED
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <inttypes.h>
#include <string.h>
#include <esp_err.h>
#include <esp_mac.h>
#include <esp_wifi.h>
#include <esp_event.h>
#include <lwip/ip_addr.h>
#include "dhcpserver/dhcpserver_options.h"
#include "esp_netif.h"


esp_netif_t* get_esp_interface_netif(esp_interface_t interface);

static size_t _wifi_strncpy(char * dst, const char * src, size_t dst_len){
    if(!dst || !src || !dst_len){
        return 0;
    }
    size_t src_len = strlen(src);
    if(src_len >= dst_len){
        src_len = dst_len;
    } else {
        src_len += 1;
    }
    memcpy(dst, src, src_len);
    return src_len;
}

/**
 * compare two AP configurations
 * @param lhs softap_config
 * @param rhs softap_config
 * @return equal
 */
static bool softap_config_equal(const wifi_config_t& lhs, const wifi_config_t& rhs)
{
    if(strncmp(reinterpret_cast<const char*>(lhs.ap.ssid), reinterpret_cast<const char*>(rhs.ap.ssid), 32) != 0) {
        return false;
    }
    if(strncmp(reinterpret_cast<const char*>(lhs.ap.password), reinterpret_cast<const char*>(rhs.ap.password), 64) != 0) {
        return false;
    }
    if(lhs.ap.channel != rhs.ap.channel) {
        return false;
    }
    if(lhs.ap.authmode != rhs.ap.authmode) {
        return false;
    }
    if(lhs.ap.ssid_hidden != rhs.ap.ssid_hidden) {
        return false;
    }
    if(lhs.ap.max_connection != rhs.ap.max_connection) {
        return false;
    }
    if(lhs.ap.pairwise_cipher != rhs.ap.pairwise_cipher) {
        return false;
    }
    if(lhs.ap.ftm_responder != rhs.ap.ftm_responder) {
        return false;
    }
    return true;
}

static APClass * _ap_network_if = NULL;

static esp_event_handler_instance_t _ap_ev_instance = NULL;
static void _ap_event_cb(void* arg, esp_event_base_t event_base, int32_t event_id, void* event_data) {
    if (event_base == WIFI_EVENT){
        ((APClass*)arg)->_onApEvent(event_id, event_data);
    }
}

static void _onApArduinoEvent(arduino_event_t *ev)
{
    if(_ap_network_if == NULL || ev->event_id < ARDUINO_EVENT_WIFI_AP_START || ev->event_id > ARDUINO_EVENT_WIFI_AP_GOT_IP6){
        return;
    }
    log_d("Arduino AP Event: %d - %s", ev->event_id, Network.eventName(ev->event_id));
    if(ev->event_id == ARDUINO_EVENT_WIFI_AP_START) {
        if (_ap_network_if->getStatusBits() & ESP_NETIF_WANT_IP6_BIT){
            esp_err_t err = esp_netif_create_ip6_linklocal(_ap_network_if->netif());
            if(err != ESP_OK){
                log_e("Failed to enable IPv6 Link Local on AP:  0x%x: %s", err, esp_err_to_name(err));
            } else {
                log_v("Enabled IPv6 Link Local on %s", _ap_network_if->desc());
            }
        }
    }
}

void APClass::_onApEvent(int32_t event_id, void* event_data){
    arduino_event_t arduino_event;
    arduino_event.event_id = ARDUINO_EVENT_MAX;
    
    if (event_id == WIFI_EVENT_AP_START) {
        log_v("AP Started");
        arduino_event.event_id = ARDUINO_EVENT_WIFI_AP_START;
        setStatusBits(ESP_NETIF_STARTED_BIT);
    } else if (event_id == WIFI_EVENT_AP_STOP) {
        log_v("AP Stopped");
        arduino_event.event_id = ARDUINO_EVENT_WIFI_AP_STOP;
        clearStatusBits(ESP_NETIF_STARTED_BIT | ESP_NETIF_CONNECTED_BIT | ESP_NETIF_HAS_IP_BIT | ESP_NETIF_HAS_LOCAL_IP6_BIT | ESP_NETIF_HAS_GLOBAL_IP6_BIT);
    } else if (event_id == WIFI_EVENT_AP_PROBEREQRECVED) {
        #if ARDUHAL_LOG_LEVEL >= ARDUHAL_LOG_LEVEL_VERBOSE
            wifi_event_ap_probe_req_rx_t * event = (wifi_event_ap_probe_req_rx_t*)event_data;
            log_v("AP Probe Request: RSSI: %d, MAC: " MACSTR, event->rssi, MAC2STR(event->mac));
        #endif
        arduino_event.event_id = ARDUINO_EVENT_WIFI_AP_PROBEREQRECVED;
        memcpy(&arduino_event.event_info.wifi_ap_probereqrecved, event_data, sizeof(wifi_event_ap_probe_req_rx_t));
    } else if (event_id == WIFI_EVENT_AP_STACONNECTED) {
        #if ARDUHAL_LOG_LEVEL >= ARDUHAL_LOG_LEVEL_VERBOSE
            wifi_event_ap_staconnected_t* event = (wifi_event_ap_staconnected_t*) event_data;
            log_v("AP Station Connected: MAC: " MACSTR ", AID: %d", MAC2STR(event->mac), event->aid);
        #endif
        arduino_event.event_id = ARDUINO_EVENT_WIFI_AP_STACONNECTED;
        memcpy(&arduino_event.event_info.wifi_ap_staconnected, event_data, sizeof(wifi_event_ap_staconnected_t));
        setStatusBits(ESP_NETIF_CONNECTED_BIT);
    } else if (event_id == WIFI_EVENT_AP_STADISCONNECTED) {
        #if ARDUHAL_LOG_LEVEL >= ARDUHAL_LOG_LEVEL_VERBOSE
            wifi_event_ap_stadisconnected_t* event = (wifi_event_ap_stadisconnected_t*) event_data;
            log_v("AP Station Disconnected: MAC: " MACSTR ", AID: %d", MAC2STR(event->mac), event->aid);
        #endif
        arduino_event.event_id = ARDUINO_EVENT_WIFI_AP_STADISCONNECTED;
        memcpy(&arduino_event.event_info.wifi_ap_stadisconnected, event_data, sizeof(wifi_event_ap_stadisconnected_t));
        // If no more clients are left
        wifi_sta_list_t clients;
        if(esp_wifi_ap_get_sta_list(&clients) != ESP_OK || clients.num == 0) {
            clearStatusBits(ESP_NETIF_CONNECTED_BIT);
        }
    } else {
        return;
    }

    if(arduino_event.event_id < ARDUINO_EVENT_MAX){
        Network.postEvent(&arduino_event);
    }
}

APClass::APClass(){
    _ap_network_if = this;
}

APClass::~APClass(){
    end();
    _ap_network_if = NULL;
}

bool APClass::onEnable(){
    if(_ap_ev_instance == NULL && esp_event_handler_instance_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &_ap_event_cb, this, &_ap_ev_instance)){
        log_e("event_handler_instance_register for WIFI_EVENT Failed!");
        return false;
    }
    if(_esp_netif == NULL){
        Network.onSysEvent(_onApArduinoEvent);
        _esp_netif = get_esp_interface_netif(ESP_IF_WIFI_AP);
        /* attach to receive events */
        initNetif(ESP_NETIF_ID_AP);
    }
    return true;
}

bool APClass::onDisable(){
    Network.removeEvent(_onApArduinoEvent);
    // we just set _esp_netif to NULL here, so destroyNetif() does not try to destroy it.
    // That would be done by WiFi.enableAP(false) if STA is not enabled, or when it gets disabled
    _esp_netif = NULL;
    destroyNetif();
    if(_ap_ev_instance != NULL){
        esp_event_handler_unregister(WIFI_EVENT, ESP_EVENT_ANY_ID, &_ap_event_cb);
        _ap_ev_instance = NULL;
    }
    return true;
}

bool APClass::begin(){
    if(!WiFi.enableAP(true)) {
        log_e("AP enable failed!");
        return false;
    }
    return true;
}

bool APClass::end(){
    if(!WiFi.enableAP(false)) {
        log_e("AP disable failed!");
        return false;
    }
    return true;
}

bool APClass::create(const char* ssid, const char* passphrase, int channel, int ssid_hidden, int max_connection, bool ftm_responder, wifi_auth_mode_t auth_mode, wifi_cipher_type_t cipher){
    if(!ssid || *ssid == 0) {
        log_e("SSID missing!");
        return false;
    }

    if(passphrase && (strlen(passphrase) > 0 && strlen(passphrase) < 8)) {
        log_e("passphrase too short!");
        return false;
    }

    if(!begin()) {
        return false;
    }

    wifi_config_t conf;
    memset(&conf, 0, sizeof(wifi_config_t));
    conf.ap.channel = channel;
    conf.ap.max_connection = max_connection;
    conf.ap.beacon_interval = 100;
    conf.ap.ssid_hidden = ssid_hidden;
    conf.ap.ftm_responder = ftm_responder;
    if(ssid != NULL && ssid[0] != 0){
        _wifi_strncpy((char*)conf.ap.ssid, ssid, 32);
        conf.ap.ssid_len = strlen(ssid);
        if(passphrase != NULL && passphrase[0] != 0){
            conf.ap.authmode = auth_mode;
            conf.ap.pairwise_cipher = cipher;
            _wifi_strncpy((char*)conf.ap.password, passphrase, 64);
        }
    }

    wifi_config_t conf_current;
    esp_err_t err = esp_wifi_get_config(WIFI_IF_AP, &conf_current);
    if(err){
        log_e("Get AP config failed! 0x%x: %s", err, esp_err_to_name(err));
        return false;
    }
    if(!softap_config_equal(conf, conf_current)) {
        err = esp_wifi_set_config(WIFI_IF_AP, &conf);
        if(err){
            log_e("Set AP config failed! 0x%x: %s", err, esp_err_to_name(err));
            return false;
        }
    }

    return true;
}

bool APClass::clear(){
    if(!begin()) {
        return false;
    }
    wifi_config_t conf;
    memset(&conf, 0, sizeof(wifi_config_t));
    conf.ap.channel = 1;
    conf.ap.max_connection = 4;
    conf.ap.beacon_interval = 100;
    esp_err_t err = esp_wifi_set_config(WIFI_IF_AP, &conf);
    if(err){
        log_e("Set AP config failed! 0x%x: %s", err, esp_err_to_name(err));
        return false;
    }
    return true;
}

bool APClass::bandwidth(wifi_bandwidth_t bandwidth){
    if(!begin()) {
        return false;
    }
    esp_err_t err = esp_wifi_set_bandwidth(WIFI_IF_AP, bandwidth);
    if(err){
        log_e("Could not set AP bandwidth! 0x%x: %s", err, esp_err_to_name(err));
        return false;
    }

    return true;
}

bool APClass::enableNAPT(bool enable){
    if(!started()) {
        log_e("AP must be first started to enable/disable NAPT");
        return false;
    }
    esp_err_t err = ESP_OK;
    if(enable){
        err = esp_netif_napt_enable(_esp_netif);
    } else {
        err = esp_netif_napt_disable(_esp_netif);
    }
    if(err){
        log_e("Could not set enable/disable NAPT! 0x%x: %s", err, esp_err_to_name(err));
        return false;
    }
    return true;
}

String APClass::SSID(void) const{
    if(!started()){
        return String();
    }
    wifi_config_t info;
    if(!esp_wifi_get_config(WIFI_IF_AP, &info)) {
        return String(reinterpret_cast<char*>(info.ap.ssid));
    }
    return String();
}

uint8_t APClass::stationCount(){
    wifi_sta_list_t clients;
    if(!started()){
        return 0;
    }
    if(esp_wifi_ap_get_sta_list(&clients) == ESP_OK) {
        return clients.num;
    }
    return 0;
}

size_t APClass::printDriverInfo(Print & out) const{
    size_t bytes = 0;
    wifi_config_t info;
    wifi_sta_list_t clients;
    if(!started()){
        return bytes;
    }
    if(esp_wifi_get_config(WIFI_IF_AP, &info) != ESP_OK){
        return bytes;
    }
    bytes += out.print(",");
    bytes += out.print((const char*)info.ap.ssid);
    bytes += out.print(",CH:");
    bytes += out.print(info.ap.channel);

    if(info.ap.authmode == WIFI_AUTH_OPEN){ bytes += out.print(",OPEN"); }
    else if(info.ap.authmode == WIFI_AUTH_WEP){ bytes += out.print(",WEP"); }
    else if(info.ap.authmode == WIFI_AUTH_WPA_PSK){ bytes += out.print(",WPA_PSK"); }
    else if(info.ap.authmode == WIFI_AUTH_WPA2_PSK){ bytes += out.print(",WPA2_PSK"); }
    else if(info.ap.authmode == WIFI_AUTH_WPA_WPA2_PSK){ bytes += out.print(",WPA_WPA2_PSK"); }
    else if(info.ap.authmode == WIFI_AUTH_ENTERPRISE){ bytes += out.print(",WEAP"); }
    else if(info.ap.authmode == WIFI_AUTH_WPA3_PSK){ bytes += out.print(",WPA3_PSK"); }
    else if(info.ap.authmode == WIFI_AUTH_WPA2_WPA3_PSK){ bytes += out.print(",WPA2_WPA3_PSK"); }
    else if(info.ap.authmode == WIFI_AUTH_WAPI_PSK){ bytes += out.print(",WAPI_PSK"); }
    else if(info.ap.authmode == WIFI_AUTH_OWE){ bytes += out.print(",OWE"); }
    else if(info.ap.authmode == WIFI_AUTH_WPA3_ENT_192){ bytes += out.print(",WPA3_ENT_SUITE_B_192_BIT"); }

    if(esp_wifi_ap_get_sta_list(&clients) == ESP_OK) {
        bytes += out.print(",STA:");
        bytes += out.print(clients.num);
    }
    return bytes;
}

#endif /* SOC_WIFI_SUPPORTED */