text: // Copyright 2015-2019 Espressif Systems (Shanghai) PTE LTD
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  
  //     http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  #include "esp_netif.h"
  #include "esp_private/wifi.h"
  #include "esp_log.h"
  #include "esp_netif_net_stack.h"
  
  #if CONFIG_ESP_NETIF_TCPIP_ADAPTER_COMPATIBLE_LAYER
  
  #if CONFIG_ETH_ENABLED
  #include "esp_eth.h"
  #endif
  #include "tcpip_adapter_types.h"
  #include "esp_wifi_default.h"
  
  //
  // Accessing some internal default interfaces and esp-netifs
  //
  extern void _esp_wifi_set_default_ap_netif(esp_netif_t* esp_netif);
  extern void _esp_wifi_set_default_sta_netif(esp_netif_t* esp_netif);
  extern esp_err_t _esp_wifi_set_default_wifi_handlers(void);
  extern esp_err_t _esp_wifi_clear_default_wifi_handlers(void);
  extern esp_err_t esp_netif_up(esp_netif_t *esp_netif);
  extern esp_err_t esp_netif_down(esp_netif_t *esp_netif);
  
  //
  // Purpose of this module is to provide backward compatible version of esp-netif
  // with legacy tcpip_adapter interface
  //
  
  static const char* TAG = "tcpip_adapter_compat";
  
  static esp_netif_t *s_esp_netifs[TCPIP_ADAPTER_IF_MAX] = { NULL };
  static const char* s_netif_keyif[TCPIP_ADAPTER_IF_MAX] = {
          "WIFI_STA_DEF",
          "WIFI_AP_DEF",
          "ETH_DEF",
  };
  
  static bool s_tcpip_adapter_compat = false;
  
  static void wifi_create_and_start_ap(void *esp_netif, esp_event_base_t base, int32_t event_id, void *data)
  {
      if (s_esp_netifs[TCPIP_ADAPTER_IF_AP] == NULL) {
          esp_netif_config_t cfg = ESP_NETIF_DEFAULT_WIFI_AP();
          esp_netif_t *ap_netif = esp_netif_new(&cfg);
  
          esp_netif_attach_wifi_ap(ap_netif);
          esp_wifi_set_default_wifi_sta_handlers();
          s_esp_netifs[TCPIP_ADAPTER_IF_AP] = ap_netif;
      }
  }
  
  static void wifi_create_and_start_sta(void *esp_netif, esp_event_base_t base, int32_t event_id, void *data)
  {
      if (s_esp_netifs[TCPIP_ADAPTER_IF_STA] == NULL) {
          esp_netif_config_t cfg = ESP_NETIF_DEFAULT_WIFI_STA();
          esp_netif_t *sta_netif = esp_netif_new(&cfg);
  
          esp_netif_attach_wifi_station(sta_netif);
          esp_wifi_set_default_wifi_sta_handlers();
          s_esp_netifs[TCPIP_ADAPTER_IF_STA] = sta_netif;
      }
  }
  
  static inline esp_netif_t * netif_from_if(tcpip_adapter_if_t interface)
  {
      if (interface < TCPIP_ADAPTER_IF_MAX) {
          if (s_esp_netifs[interface] == NULL) {
              s_esp_netifs[interface] = esp_netif_get_handle_from_ifkey(s_netif_keyif[interface]);
              if (s_esp_netifs[interface] == NULL && s_tcpip_adapter_compat) {
                  // if not found in compat mode -> create it
                  if (interface == TCPIP_ADAPTER_IF_STA) {
                      wifi_create_and_start_sta(NULL, 0, 0, NULL);
                      s_esp_netifs[interface] = esp_netif_get_handle_from_ifkey("WIFI_STA_DEF");
                  } else if (interface == TCPIP_ADAPTER_IF_AP) {
                      wifi_create_and_start_ap(NULL, 0, 0, NULL);
                      s_esp_netifs[interface] = esp_netif_get_handle_from_ifkey("WIFI_AP_DEF");
                  }
              }
          }
          return s_esp_netifs[interface];
      }
      return NULL;
  }
  
  void tcpip_adapter_init(void)
  {
      s_tcpip_adapter_compat = true;
      esp_err_t err;
      if (ESP_OK != (err = esp_netif_init())) {
          ESP_LOGE(TAG, "ESP-NETIF initialization failed with %d in tcpip_adapter compatibility mode", err);
      }
  }
  
  #if CONFIG_ETH_ENABLED
  
  esp_err_t tcpip_adapter_clear_default_eth_handlers(void)
  {
      return esp_eth_clear_default_handlers(netif_from_if(TCPIP_ADAPTER_IF_ETH));
  }
  
  esp_err_t tcpip_adapter_set_default_eth_handlers(void)
  {
      if (s_tcpip_adapter_compat) {
          esp_netif_config_t cfg = ESP_NETIF_DEFAULT_ETH();
          esp_netif_t *eth_netif = esp_netif_new(&cfg);
  
          s_esp_netifs[TCPIP_ADAPTER_IF_ETH] = eth_netif;
  
          return esp_eth_set_default_handlers(eth_netif);
      }
      return ESP_OK;
  
  }
  
  esp_err_t tcpip_adapter_compat_start_eth(void *eth_driver)
  {
      if (s_tcpip_adapter_compat) {
          esp_netif_t *esp_netif = netif_from_if(TCPIP_ADAPTER_IF_ETH);
          if (esp_netif) {
              esp_netif_attach(esp_netif, esp_eth_new_netif_glue(eth_driver));
          }
      }
      return ESP_OK;
  }
  
  #endif
  
  esp_err_t tcpip_adapter_eth_input(void *buffer, uint16_t len, void *eb)
  {
      return esp_netif_receive(netif_from_if(TCPIP_ADAPTER_IF_ETH), buffer, len, eb);
  }
  
  esp_err_t tcpip_adapter_sta_input(void *buffer, uint16_t len, void *eb)
  {
      return esp_netif_receive(netif_from_if(TCPIP_ADAPTER_IF_STA), buffer, len, eb);
  }
  
  esp_err_t tcpip_adapter_ap_input(void *buffer, uint16_t len, void *eb)
  {
      return esp_netif_receive(netif_from_if(TCPIP_ADAPTER_IF_AP), buffer, len, eb);
  }
  
  esp_err_t tcpip_adapter_set_default_wifi_handlers(void)
  {
  #if CONFIG_ESP_NETIF_TCPIP_ADAPTER_COMPATIBLE_LAYER
      if (s_tcpip_adapter_compat) {
          // create instances and register default handlers only on start event
          esp_err_t err = esp_event_handler_register(WIFI_EVENT, WIFI_EVENT_STA_START, wifi_create_and_start_sta, NULL);
          if (err != ESP_OK) {
              return err;
          }
          err = esp_event_handler_register(WIFI_EVENT, WIFI_EVENT_AP_START, wifi_create_and_start_ap, NULL);
          if (err != ESP_OK) {
              return err;
          }
          _esp_wifi_set_default_wifi_handlers();
      }
      return ESP_OK;
  #else
      ESP_LOGE(TAG, "%s: tcpip adapter compatibility layer is disabled", __func__);
      return ESP_ERR_INVALID_STATE;
  #endif
  }
  
  esp_err_t tcpip_adapter_clear_default_wifi_handlers(void)
  {
      return _esp_wifi_clear_default_wifi_handlers();
  }
  
  tcpip_adapter_if_t tcpip_adapter_if_from_esp_netif(esp_netif_t *esp_netif)
  {
      for (int i=0; i<TCPIP_ADAPTER_IF_MAX; ++i) {
          if (esp_netif == s_esp_netifs[i])
              return i;
      }
      return TCPIP_ADAPTER_IF_MAX;
  }
  
  esp_err_t tcpip_adapter_get_ip_info(tcpip_adapter_if_t tcpip_if, tcpip_adapter_ip_info_t *ip_info)
  {
      return esp_netif_get_ip_info(netif_from_if(tcpip_if), (esp_netif_ip_info_t *)ip_info);
  }
  
  esp_err_t tcpip_adapter_get_ip6_linklocal(tcpip_adapter_if_t tcpip_if, ip6_addr_t *if_ip6)
  {
      return esp_netif_get_ip6_linklocal(netif_from_if(tcpip_if), (esp_ip6_addr_t*)if_ip6);
  }
  
  esp_err_t tcpip_adapter_get_ip6_global(tcpip_adapter_if_t tcpip_if, ip6_addr_t *if_ip6)
  {
      return esp_netif_get_ip6_global(netif_from_if(tcpip_if), (esp_ip6_addr_t*)if_ip6);
  }
  
  esp_err_t tcpip_adapter_dhcpc_get_status(tcpip_adapter_if_t tcpip_if, tcpip_adapter_dhcp_status_t *status)
  {
      return esp_netif_dhcpc_get_status(netif_from_if(tcpip_if), status);
  }
  
  bool tcpip_adapter_is_netif_up(tcpip_adapter_if_t tcpip_if)
  {
      return esp_netif_is_netif_up(netif_from_if(tcpip_if));
  }
  
  esp_err_t tcpip_adapter_get_netif(tcpip_adapter_if_t tcpip_if, void ** netif)
  {
      esp_netif_t *esp_netif = netif_from_if(tcpip_if);
      if (esp_netif) {
          void* net_stack_netif = esp_netif_get_netif_impl(esp_netif);
          *netif = net_stack_netif;
          return ESP_OK;
      }
      return ESP_ERR_INVALID_ARG;
  }
  
  esp_err_t tcpip_adapter_create_ip6_linklocal(tcpip_adapter_if_t tcpip_if)
  {
      return esp_netif_create_ip6_linklocal(netif_from_if(tcpip_if));
  }
  
  esp_err_t tcpip_adapter_dhcps_stop(tcpip_adapter_if_t tcpip_if)
  {
      return esp_netif_dhcps_stop(netif_from_if(tcpip_if));
  }
  
  esp_err_t tcpip_adapter_dhcpc_stop(tcpip_adapter_if_t tcpip_if)
  {
      return esp_netif_dhcpc_stop(netif_from_if(tcpip_if));
  }
  
  esp_err_t tcpip_adapter_dhcps_start(tcpip_adapter_if_t tcpip_if)
  {
      return esp_netif_dhcps_start(netif_from_if(tcpip_if));
  }
  
  esp_err_t tcpip_adapter_dhcpc_start(tcpip_adapter_if_t tcpip_if)
  {
      return esp_netif_dhcpc_start(netif_from_if(tcpip_if));
  }
  esp_err_t tcpip_adapter_dhcps_get_status(tcpip_adapter_if_t tcpip_if, tcpip_adapter_dhcp_status_t *status)
  {
      return esp_netif_dhcps_get_status(netif_from_if(tcpip_if), status);
  }
  
  esp_err_t tcpip_adapter_dhcps_option(tcpip_adapter_dhcp_option_mode_t opt_op, tcpip_adapter_dhcp_option_id_t opt_id, void *opt_val, uint32_t opt_len)
  {
      // Note: legacy mode supports dhcps only for default wifi AP
      return esp_netif_dhcps_option(esp_netif_get_handle_from_ifkey("WIFI_AP_DEF"), opt_op, opt_id, opt_val, opt_len);
  }
  
  esp_err_t tcpip_adapter_dhcpc_option(tcpip_adapter_dhcp_option_mode_t opt_op, tcpip_adapter_dhcp_option_id_t opt_id, void *opt_val, uint32_t opt_len)
  {
      return esp_netif_dhcpc_option(netif_from_if(TCPIP_ADAPTER_IF_STA), opt_op, opt_id, opt_val, opt_len);
  }
  
  esp_err_t tcpip_adapter_set_ip_info(tcpip_adapter_if_t tcpip_if, const tcpip_adapter_ip_info_t *ip_info)
  {
      return esp_netif_set_ip_info(netif_from_if(tcpip_if), (esp_netif_ip_info_t *)ip_info);
  }
  
  esp_err_t tcpip_adapter_get_dns_info(tcpip_adapter_if_t tcpip_if, tcpip_adapter_dns_type_t type, tcpip_adapter_dns_info_t *dns)
  {
      return esp_netif_get_dns_info(netif_from_if(tcpip_if), type, dns);
  }
  
  esp_err_t tcpip_adapter_set_dns_info(tcpip_adapter_if_t tcpip_if, tcpip_adapter_dns_type_t type, tcpip_adapter_dns_info_t *dns)
  {
      return esp_netif_set_dns_info(netif_from_if(tcpip_if), type, dns);
  }
  
  int tcpip_adapter_get_netif_index(tcpip_adapter_if_t tcpip_if)
  {
      return esp_netif_get_netif_impl_index(netif_from_if(tcpip_if));
  }
  
  esp_err_t tcpip_adapter_get_sta_list(const wifi_sta_list_t *wifi_sta_list, tcpip_adapter_sta_list_t *tcpip_sta_list)
  {
      return esp_netif_get_sta_list(wifi_sta_list, tcpip_sta_list);
  }
  
  static esp_err_t tcpip_adapter_compat_start_netif(esp_netif_t *netif, uint8_t *mac, tcpip_adapter_ip_info_t *ip_info)
  {
      if (netif == NULL || mac == NULL || ip_info == NULL) {
          return ESP_ERR_TCPIP_ADAPTER_INVALID_PARAMS;
      }
      esp_netif_set_mac(netif, mac);
      esp_netif_set_ip_info(netif, (esp_netif_ip_info_t *)ip_info);
      esp_netif_action_start(netif, NULL, 0, NULL);
      return ESP_OK;
  }
  
  esp_err_t tcpip_adapter_eth_start(uint8_t *mac, tcpip_adapter_ip_info_t *ip_info, void *args)
  {
      return tcpip_adapter_compat_start_netif(netif_from_if(TCPIP_ADAPTER_IF_ETH),
                                              mac, ip_info);
  }
  
  esp_err_t tcpip_adapter_sta_start(uint8_t *mac, tcpip_adapter_ip_info_t *ip_info)
  {
      return tcpip_adapter_compat_start_netif(netif_from_if(TCPIP_ADAPTER_IF_STA),
                                              mac, ip_info);
  }
  
  esp_err_t tcpip_adapter_ap_start(uint8_t *mac, tcpip_adapter_ip_info_t *ip_info)
  {
      return tcpip_adapter_compat_start_netif(netif_from_if(TCPIP_ADAPTER_IF_AP),
                                              mac, ip_info);
  }
  
  esp_err_t tcpip_adapter_stop(tcpip_adapter_if_t tcpip_if)
  {
      esp_netif_t *netif = netif_from_if(tcpip_if);
      if (netif == NULL) {
          return ESP_ERR_TCPIP_ADAPTER_INVALID_PARAMS;
      }
      esp_netif_action_stop(netif_from_if(tcpip_if), NULL, 0, NULL);
      return ESP_OK;
  }
  
  esp_err_t tcpip_adapter_up(tcpip_adapter_if_t tcpip_if)
  {
      return esp_netif_up(netif_from_if(tcpip_if));
  }
  
  esp_err_t tcpip_adapter_down(tcpip_adapter_if_t tcpip_if)
  {
      return esp_netif_down(netif_from_if(tcpip_if));
  }
  
  esp_err_t tcpip_adapter_get_old_ip_info(tcpip_adapter_if_t tcpip_if, tcpip_adapter_ip_info_t *ip_info)
  {
      return esp_netif_get_old_ip_info(netif_from_if(tcpip_if), (esp_netif_ip_info_t *)ip_info);
  }
  
  esp_err_t tcpip_adapter_set_old_ip_info(tcpip_adapter_if_t tcpip_if, const tcpip_adapter_ip_info_t *ip_info)
  {
      return esp_netif_set_old_ip_info(netif_from_if(tcpip_if), (esp_netif_ip_info_t *)ip_info);
  }
  
  esp_interface_t tcpip_adapter_get_esp_if(void *dev)
  {
      esp_netif_t *netif = esp_netif_get_handle_from_netif_impl(dev);
      for (int i=0; i< TCPIP_ADAPTER_IF_MAX; ++i) {
          if (s_esp_netifs[i] == netif) {
              return i;
          }
      }
      return ESP_IF_MAX;
  }
  
  esp_err_t tcpip_adapter_set_hostname(tcpip_adapter_if_t tcpip_if, const char *hostname)
  {
      return esp_netif_set_hostname(netif_from_if(tcpip_if), hostname);
  }
  
  esp_err_t tcpip_adapter_get_hostname(tcpip_adapter_if_t tcpip_if, const char **hostname)
  {
      return esp_netif_get_hostname(netif_from_if(tcpip_if), hostname);
  }
  
  #else
  
  esp_err_t tcpip_adapter_compat_start_eth(void* eth_driver)
  {
      return ESP_OK;
  }
  
  #endif
  