ESP-NETIF

The purpose of ESP-NETIF library is twofold:

  • It provides an abstraction layer for the application on top of the TCP/IP stack. This will allow applications to choose between IP stacks in the future.

  • The APIs it provides are thread safe, even if the underlying TCP/IP stack APIs are not.

ESP-IDF currently implements ESP-NETIF for the lwIP TCP/IP stack only. However, the adapter itself is TCP/IP implementation agnostic and different implementations are possible.

Some ESP-NETIF API functions are intended to be called by application code, for example to get/set interface IP addresses, configure DHCP. Other functions are intended for internal ESP-IDF use by the network driver layer.

In many cases, applications do not need to call ESP-NETIF APIs directly as they are called from the default network event handlers.

ESP-NETIF component is a successor of the tcpip_adapter, former network interface abstraction, which has become deprecated since IDF v4.1. Please refer to the TCP/IP Adapter Migration Guide section in case existing applications to be ported to use the esp-netif API instead.

ESP-NETIF architecture

                 |          (A) USER CODE                 |
                 |                                        |
    .............| init          settings      events     |
    .            +----------------------------------------+
    .               .                |           *
    .               .                |           *
--------+        +===========================+   *     +-----------------------+
        |        | new/config     get/set    |   *     |                       |
        |        |                           |...*.....| init                  |
        |        |---------------------------|   *     |                       |
  init  |        |                           |****     |                       |
  start |********|  event handler            |*********|  DHCP                 |
  stop  |        |                           |         |                       |
        |        |---------------------------|         |                       |
        |        |                           |         |    NETIF              |
  +-----|        |                           |         +-----------------+     |
  | glue|----<---|  esp_netif_transmit       |--<------| netif_output    |     |
  |     |        |                           |         |                 |     |
  |     |---->---|  esp_netif_receive        |-->------| netif_input     |     |
  |     |        |                           |         + ----------------+     |
  |     |....<...|  esp_netif_free_rx_buffer |...<.....| packet buffer         |
  +-----|        |                           |         |                       |
        |        |                           |         |         (D)           |
  (B)   |        |          (C)              |         +-----------------------+
--------+        +===========================+
communication                                                NETWORK STACK
DRIVER                   ESP-NETIF

Data and event flow in the diagram

  • ........ Initialization line from user code to ESP-NETIF and communication driver

  • --<--->-- Data packets going from communication media to TCP/IP stack and back

  • ******** Events aggregated in ESP-NETIF propagates to driver, user code and network stack

  • | User settings and runtime configuration

ESP-NETIF interaction

A) User code, boiler plate

Overall application interaction with a specific IO driver for communication media and configured TCP/IP network stack is abstracted using ESP-NETIF APIs and outlined as below:

  1. Initialization code

  1. Initializes IO driver

  2. Creates a new instance of ESP-NETIF and configure with

  • ESP-NETIF specific options (flags, behaviour, name)

  • Network stack options (netif init and input functions, not publicly available)

  • IO driver specific options (transmit, free rx buffer functions, IO driver handle)

  1. Attaches the IO driver handle to the ESP-NETIF instance created in the above steps

  2. Configures event handlers

  • use default handlers for common interfaces defined in IO drivers; or define a specific handlers for customised behaviour/new interfaces

  • register handlers for app related events (such as IP lost/acquired)

  1. Interaction with network interfaces using ESP-NETIF API

  • Getting and setting TCP/IP related parameters (DHCP, IP, etc)

  • Receiving IP events (connect/disconnect)

  • Controlling application lifecycle (set interface up/down)

B) Communication driver, IO driver, media driver

Communication driver plays these two important roles in relation with ESP-NETIF:

  1. Event handlers: Define behaviour patterns of interaction with ESP-NETIF (for example: ethernet link-up -> turn netif on)

  2. Glue IO layer: Adapts the input/output functions to use ESP-NETIF transmit, receive and free receive buffer

  • Installs driver_transmit to appropriate ESP-NETIF object, so that outgoing packets from network stack are passed to the IO driver

  • Calls esp_netif_receive() to pass incoming data to network stack

C) ESP-NETIF, former tcpip_adapter

ESP-NETIF is an intermediary between an IO driver and a network stack, connecting packet data path between these two. As that it provides a set of interfaces for attaching a driver to ESP-NETIF object (runtime) and configuring a network stack (compile time). In addition to that a set of API is provided to control network interface lifecycle and its TCP/IP properties. As an overview, the ESP-NETIF public interface could be divided into these 6 groups:

  1. Initialization APIs (to create and configure ESP-NETIF instance)

  2. Input/Output API (for passing data between IO driver and network stack)

  3. Event or Action API

  • Used for network interface lifecycle management

  • ESP-NETIF provides building blocks for designing event handlers

  1. Setters and Getters for basic network interface properties

  2. Network stack abstraction: enabling user interaction with TCP/IP stack

  • Set interface up or down

  • DHCP server and client API

  • DNS API

  1. Driver conversion utilities

D) Network stack

Network stack has no public interaction with application code with regard to public interfaces and shall be fully abstracted by ESP-NETIF API.

ESP-NETIF programmer’s manual

Please refer to the example section for basic initialization of default interfaces:

For more specific cases please consult this guide: ESP-NETIF Custom I/O Driver.

WiFi default initialization

The initialization code as well as registering event handlers for default interfaces, such as softAP and station, are provided in two separate APIs to facilitate simple startup code for most applications:

Please note that these functions return the esp_netif handle, i.e. a pointer to a network interface object allocated and configured with default settings, which as a consequence, means that:

  • The created object has to be destroyed if a network de-initialization is provided by an application.

  • These default interfaces must not be created multiple times, unless the created handle is deleted using esp_netif_destroy().

  • When using Wifi in AP+STA mode, both these interfaces has to be created.

API Reference

Functions

esp_err_t esp_netif_init(void)

Initialize the underlying TCP/IP stack.

Return

  • ESP_OK on success

  • ESP_FAIL if initializing failed

Note

This function should be called exactly once from application code, when the application starts up.

esp_err_t esp_netif_deinit(void)

Deinitialize the esp-netif component (and the underlying TCP/IP stack)

Note: Deinitialization is not supported yet

Return

  • ESP_ERR_INVALID_STATE if esp_netif not initialized

  • ESP_ERR_NOT_SUPPORTED otherwise

esp_netif_t *esp_netif_new(const esp_netif_config_t *esp_netif_config)

Creates an instance of new esp-netif object based on provided config.

Return

  • pointer to esp-netif object on success

  • NULL otherwise

Parameters
  • [in] esp_netif_config: pointer esp-netif configuration

void esp_netif_destroy(esp_netif_t *esp_netif)

Destroys the esp_netif object.

Parameters
  • [in] esp_netif: pointer to the object to be deleted

esp_err_t esp_netif_set_driver_config(esp_netif_t *esp_netif, const esp_netif_driver_ifconfig_t *driver_config)

Configures driver related options of esp_netif object.

Return

  • ESP_OK on success

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS if invalid parameters provided

Parameters
  • [inout] esp_netif: pointer to the object to be configured

  • [in] driver_config: pointer esp-netif io driver related configuration

esp_err_t esp_netif_attach(esp_netif_t *esp_netif, esp_netif_iodriver_handle driver_handle)

Attaches esp_netif instance to the io driver handle.

Calling this function enables connecting specific esp_netif object with already initialized io driver to update esp_netif object with driver specific configuration (i.e. calls post_attach callback, which typically sets io driver callbacks to esp_netif instance and starts the driver)

Return

  • ESP_OK on success

  • ESP_ERR_ESP_NETIF_DRIVER_ATTACH_FAILED if driver’s pot_attach callback failed

Parameters
  • [inout] esp_netif: pointer to esp_netif object to be attached

  • [in] driver_handle: pointer to the driver handle

esp_err_t esp_netif_receive(esp_netif_t *esp_netif, void *buffer, size_t len, void *eb)

Passes the raw packets from communication media to the appropriate TCP/IP stack.

This function is called from the configured (peripheral) driver layer. The data are then forwarded as frames to the TCP/IP stack.

Return

  • ESP_OK

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [in] buffer: Received data

  • [in] len: Length of the data frame

  • [in] eb: Pointer to internal buffer (used in Wi-Fi driver)

void esp_netif_action_start(void *esp_netif, esp_event_base_t base, int32_t event_id, void *data)

Default building block for network interface action upon IO driver start event Creates network interface, if AUTOUP enabled turns the interface on, if DHCPS enabled starts dhcp server.

Note

This API can be directly used as event handler

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • base:

  • event_id:

  • data:

void esp_netif_action_stop(void *esp_netif, esp_event_base_t base, int32_t event_id, void *data)

Default building block for network interface action upon IO driver stop event.

Note

This API can be directly used as event handler

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • base:

  • event_id:

  • data:

void esp_netif_action_connected(void *esp_netif, esp_event_base_t base, int32_t event_id, void *data)

Default building block for network interface action upon IO driver connected event.

Note

This API can be directly used as event handler

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • base:

  • event_id:

  • data:

void esp_netif_action_disconnected(void *esp_netif, esp_event_base_t base, int32_t event_id, void *data)

Default building block for network interface action upon IO driver disconnected event.

Note

This API can be directly used as event handler

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • base:

  • event_id:

  • data:

void esp_netif_action_got_ip(void *esp_netif, esp_event_base_t base, int32_t event_id, void *data)

Default building block for network interface action upon network got IP event.

Note

This API can be directly used as event handler

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • base:

  • event_id:

  • data:

esp_err_t esp_netif_set_mac(esp_netif_t *esp_netif, uint8_t mac[])

Set the mac address for the interface instance.

Return

  • ESP_OK - success

  • ESP_ERR_ESP_NETIF_IF_NOT_READY - interface status error

  • ESP_ERR_NOT_SUPPORTED - mac not supported on this interface

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [in] mac: Desired mac address for the related network interface

esp_err_t esp_netif_get_mac(esp_netif_t *esp_netif, uint8_t mac[])

Get the mac address for the interface instance.

Return

  • ESP_OK - success

  • ESP_ERR_ESP_NETIF_IF_NOT_READY - interface status error

  • ESP_ERR_NOT_SUPPORTED - mac not supported on this interface

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [out] mac: Resultant mac address for the related network interface

esp_err_t esp_netif_set_hostname(esp_netif_t *esp_netif, const char *hostname)

Set the hostname of an interface.

The configured hostname overrides the default configuration value CONFIG_LWIP_LOCAL_HOSTNAME. Please note that when the hostname is altered after interface started/connected the changes would only be reflected once the interface restarts/reconnects

Return

  • ESP_OK - success

  • ESP_ERR_ESP_NETIF_IF_NOT_READY - interface status error

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS - parameter error

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [in] hostname: New hostname for the interface. Maximum length 32 bytes.

esp_err_t esp_netif_get_hostname(esp_netif_t *esp_netif, const char **hostname)

Get interface hostname.

Return

  • ESP_OK - success

  • ESP_ERR_ESP_NETIF_IF_NOT_READY - interface status error

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS - parameter error

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [out] hostname: Returns a pointer to the hostname. May be NULL if no hostname is set. If set non-NULL, pointer remains valid (and string may change if the hostname changes).

bool esp_netif_is_netif_up(esp_netif_t *esp_netif)

Test if supplied interface is up or down.

Return

  • true - Interface is up

  • false - Interface is down

Parameters
  • [in] esp_netif: Handle to esp-netif instance

esp_err_t esp_netif_get_ip_info(esp_netif_t *esp_netif, esp_netif_ip_info_t *ip_info)

Get interface’s IP address information.

If the interface is up, IP information is read directly from the TCP/IP stack. If the interface is down, IP information is read from a copy kept in the ESP-NETIF instance

Return

  • ESP_OK

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [out] ip_info: If successful, IP information will be returned in this argument.

esp_err_t esp_netif_get_old_ip_info(esp_netif_t *esp_netif, esp_netif_ip_info_t *ip_info)

Get interface’s old IP information.

Returns an “old” IP address previously stored for the interface when the valid IP changed.

If the IP lost timer has expired (meaning the interface was down for longer than the configured interval) then the old IP information will be zero.

Return

  • ESP_OK

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [out] ip_info: If successful, IP information will be returned in this argument.

esp_err_t esp_netif_set_ip_info(esp_netif_t *esp_netif, const esp_netif_ip_info_t *ip_info)

Set interface’s IP address information.

This function is mainly used to set a static IP on an interface.

If the interface is up, the new IP information is set directly in the TCP/IP stack.

The copy of IP information kept in the ESP-NETIF instance is also updated (this copy is returned if the IP is queried while the interface is still down.)

Note

DHCP client/server must be stopped (if enabled for this interface) before setting new IP information.

Note

Calling this interface for may generate a SYSTEM_EVENT_STA_GOT_IP or SYSTEM_EVENT_ETH_GOT_IP event.

Return

  • ESP_OK

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS

  • ESP_ERR_ESP_NETIF_DHCP_NOT_STOPPED If DHCP server or client is still running

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [in] ip_info: IP information to set on the specified interface

esp_err_t esp_netif_set_old_ip_info(esp_netif_t *esp_netif, const esp_netif_ip_info_t *ip_info)

Set interface old IP information.

This function is called from the DHCP client (if enabled), before a new IP is set. It is also called from the default handlers for the SYSTEM_EVENT_STA_CONNECTED and SYSTEM_EVENT_ETH_CONNECTED events.

Calling this function stores the previously configured IP, which can be used to determine if the IP changes in the future.

If the interface is disconnected or down for too long, the “IP lost timer” will expire (after the configured interval) and set the old IP information to zero.

Return

  • ESP_OK

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [in] ip_info: Store the old IP information for the specified interface

int esp_netif_get_netif_impl_index(esp_netif_t *esp_netif)

Get net interface index from network stack implementation.

Note

This index could be used in setsockopt() to bind socket with multicast interface

Return

implementation specific index of interface represented with supplied esp_netif

Parameters
  • [in] esp_netif: Handle to esp-netif instance

esp_err_t esp_netif_get_netif_impl_name(esp_netif_t *esp_netif, char *name)

Get net interface name from network stack implementation.

Note

This name could be used in setsockopt() to bind socket with appropriate interface

Return

  • ESP_OK

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [out] name: Interface name as specified in underlying TCP/IP stack. Note that the actual name will be copied to the specified buffer, which must be allocated to hold maximum interface name size (6 characters for lwIP)

esp_err_t esp_netif_dhcps_option(esp_netif_t *esp_netif, esp_netif_dhcp_option_mode_t opt_op, esp_netif_dhcp_option_id_t opt_id, void *opt_val, uint32_t opt_len)

Set or Get DHCP server option.

Return

  • ESP_OK

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS

  • ESP_ERR_ESP_NETIF_DHCP_ALREADY_STOPPED

  • ESP_ERR_ESP_NETIF_DHCP_ALREADY_STARTED

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [in] opt_op: ESP_NETIF_OP_SET to set an option, ESP_NETIF_OP_GET to get an option.

  • [in] opt_id: Option index to get or set, must be one of the supported enum values.

  • [inout] opt_val: Pointer to the option parameter.

  • [in] opt_len: Length of the option parameter.

esp_err_t esp_netif_dhcpc_option(esp_netif_t *esp_netif, esp_netif_dhcp_option_mode_t opt_op, esp_netif_dhcp_option_id_t opt_id, void *opt_val, uint32_t opt_len)

Set or Get DHCP client option.

Return

  • ESP_OK

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS

  • ESP_ERR_ESP_NETIF_DHCP_ALREADY_STOPPED

  • ESP_ERR_ESP_NETIF_DHCP_ALREADY_STARTED

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [in] opt_op: ESP_NETIF_OP_SET to set an option, ESP_NETIF_OP_GET to get an option.

  • [in] opt_id: Option index to get or set, must be one of the supported enum values.

  • [inout] opt_val: Pointer to the option parameter.

  • [in] opt_len: Length of the option parameter.

esp_err_t esp_netif_dhcpc_start(esp_netif_t *esp_netif)

Start DHCP client (only if enabled in interface object)

Note

The default event handlers for the SYSTEM_EVENT_STA_CONNECTED and SYSTEM_EVENT_ETH_CONNECTED events call this function.

Return

  • ESP_OK

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS

  • ESP_ERR_ESP_NETIF_DHCP_ALREADY_STARTED

  • ESP_ERR_ESP_NETIF_DHCPC_START_FAILED

Parameters
  • [in] esp_netif: Handle to esp-netif instance

esp_err_t esp_netif_dhcpc_stop(esp_netif_t *esp_netif)

Stop DHCP client (only if enabled in interface object)

Note

Calling action_netif_stop() will also stop the DHCP Client if it is running.

Return

  • ESP_OK

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS

  • ESP_ERR_ESP_NETIF_DHCP_ALREADY_STOPPED

  • ESP_ERR_ESP_NETIF_IF_NOT_READY

Parameters
  • [in] esp_netif: Handle to esp-netif instance

esp_err_t esp_netif_dhcpc_get_status(esp_netif_t *esp_netif, esp_netif_dhcp_status_t *status)

Get DHCP client status.

Return

  • ESP_OK

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [out] status: If successful, the status of DHCP client will be returned in this argument.

esp_err_t esp_netif_dhcps_get_status(esp_netif_t *esp_netif, esp_netif_dhcp_status_t *status)

Get DHCP Server status.

Return

  • ESP_OK

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [out] status: If successful, the status of the DHCP server will be returned in this argument.

esp_err_t esp_netif_dhcps_start(esp_netif_t *esp_netif)

Start DHCP server (only if enabled in interface object)

Return

  • ESP_OK

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS

  • ESP_ERR_ESP_NETIF_DHCP_ALREADY_STARTED

Parameters
  • [in] esp_netif: Handle to esp-netif instance

esp_err_t esp_netif_dhcps_stop(esp_netif_t *esp_netif)

Stop DHCP server (only if enabled in interface object)

Return

  • ESP_OK

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS

  • ESP_ERR_ESP_NETIF_DHCP_ALREADY_STOPPED

  • ESP_ERR_ESP_NETIF_IF_NOT_READY

Parameters
  • [in] esp_netif: Handle to esp-netif instance

esp_err_t esp_netif_set_dns_info(esp_netif_t *esp_netif, esp_netif_dns_type_t type, esp_netif_dns_info_t *dns)

Set DNS Server information.

This function behaves differently if DHCP server or client is enabled

If DHCP client is enabled, main and backup DNS servers will be updated automatically from the DHCP lease if the relevant DHCP options are set. Fallback DNS Server is never updated from the DHCP lease and is designed to be set via this API. If DHCP client is disabled, all DNS server types can be set via this API only.

If DHCP server is enabled, the Main DNS Server setting is used by the DHCP server to provide a DNS Server option to DHCP clients (Wi-Fi stations).

  • The default Main DNS server is typically the IP of the DHCP server itself.

  • This function can override it by setting server type ESP_NETIF_DNS_MAIN.

  • Other DNS Server types are not supported for the DHCP server.

  • To propagate the DNS info to client, please stop the DHCP server before using this API.

Return

  • ESP_OK on success

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS invalid params

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [in] type: Type of DNS Server to set: ESP_NETIF_DNS_MAIN, ESP_NETIF_DNS_BACKUP, ESP_NETIF_DNS_FALLBACK

  • [in] dns: DNS Server address to set

esp_err_t esp_netif_get_dns_info(esp_netif_t *esp_netif, esp_netif_dns_type_t type, esp_netif_dns_info_t *dns)

Get DNS Server information.

Return the currently configured DNS Server address for the specified interface and Server type.

This may be result of a previous call to esp_netif_set_dns_info(). If the interface’s DHCP client is enabled, the Main or Backup DNS Server may be set by the current DHCP lease.

Return

  • ESP_OK on success

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS invalid params

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [in] type: Type of DNS Server to get: ESP_NETIF_DNS_MAIN, ESP_NETIF_DNS_BACKUP, ESP_NETIF_DNS_FALLBACK

  • [out] dns: DNS Server result is written here on success

esp_err_t esp_netif_create_ip6_linklocal(esp_netif_t *esp_netif)

Create interface link-local IPv6 address.

Cause the TCP/IP stack to create a link-local IPv6 address for the specified interface.

This function also registers a callback for the specified interface, so that if the link-local address becomes verified as the preferred address then a SYSTEM_EVENT_GOT_IP6 event will be sent.

Return

  • ESP_OK

  • ESP_ERR_ESP_NETIF_INVALID_PARAMS

Parameters
  • [in] esp_netif: Handle to esp-netif instance

esp_err_t esp_netif_get_ip6_linklocal(esp_netif_t *esp_netif, esp_ip6_addr_t *if_ip6)

Get interface link-local IPv6 address.

If the specified interface is up and a preferred link-local IPv6 address has been created for the interface, return a copy of it.

Return

  • ESP_OK

  • ESP_FAIL If interface is down, does not have a link-local IPv6 address, or the link-local IPv6 address is not a preferred address.

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [out] if_ip6: IPv6 information will be returned in this argument if successful.

esp_err_t esp_netif_get_ip6_global(esp_netif_t *esp_netif, esp_ip6_addr_t *if_ip6)

Get interface global IPv6 address.

If the specified interface is up and a preferred global IPv6 address has been created for the interface, return a copy of it.

Return

  • ESP_OK

  • ESP_FAIL If interface is down, does not have a global IPv6 address, or the global IPv6 address is not a preferred address.

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [out] if_ip6: IPv6 information will be returned in this argument if successful.

int esp_netif_get_all_ip6(esp_netif_t *esp_netif, esp_ip6_addr_t if_ip6[])

Get all IPv6 addresses of the specified interface.

Return

number of returned IPv6 addresses

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • [out] if_ip6: Array of IPv6 addresses will be copied to the argument

void esp_netif_set_ip4_addr(esp_ip4_addr_t *addr, uint8_t a, uint8_t b, uint8_t c, uint8_t d)

Sets IPv4 address to the specified octets.

Parameters
  • [out] addr: IP address to be set

  • a: the first octet (127 for IP 127.0.0.1)

  • b:

  • c:

  • d:

char *esp_ip4addr_ntoa(const esp_ip4_addr_t *addr, char *buf, int buflen)

Converts numeric IP address into decimal dotted ASCII representation.

Return

either pointer to buf which now holds the ASCII representation of addr or NULL if buf was too small

Parameters
  • addr: ip address in network order to convert

  • buf: target buffer where the string is stored

  • buflen: length of buf

uint32_t esp_ip4addr_aton(const char *addr)

Ascii internet address interpretation routine The value returned is in network order.

Return

ip address in network order

Parameters
  • addr: IP address in ascii representation (e.g. “127.0.0.1”)

esp_err_t esp_netif_str_to_ip4(const char *src, esp_ip4_addr_t *dst)

Converts Ascii internet IPv4 address into esp_ip4_addr_t.

Return

  • ESP_OK on success

  • ESP_FAIL if conversion failed

  • ESP_ERR_INVALID_ARG if invalid parameter is passed into

Parameters
  • [in] src: IPv4 address in ascii representation (e.g. “127.0.0.1”)

  • [out] dst: Address of the target esp_ip4_addr_t structure to receive converted address

esp_err_t esp_netif_str_to_ip6(const char *src, esp_ip6_addr_t *dst)

Converts Ascii internet IPv6 address into esp_ip4_addr_t Zeros in the IP address can be stripped or completely ommited: “2001:db8:85a3:0:0:0:2:1” or “2001:db8::2:1”)

Return

  • ESP_OK on success

  • ESP_FAIL if conversion failed

  • ESP_ERR_INVALID_ARG if invalid parameter is passed into

Parameters
  • [in] src: IPv6 address in ascii representation (e.g. “”2001:0db8:85a3:0000:0000:0000:0002:0001”)

  • [out] dst: Address of the target esp_ip6_addr_t structure to receive converted address

esp_netif_iodriver_handle esp_netif_get_io_driver(esp_netif_t *esp_netif)

Gets media driver handle for this esp-netif instance.

Return

opaque pointer of related IO driver

Parameters
  • [in] esp_netif: Handle to esp-netif instance

esp_netif_t *esp_netif_get_handle_from_ifkey(const char *if_key)

Searches over a list of created objects to find an instance with supplied if key.

Return

Handle to esp-netif instance

Parameters
  • if_key: Textual description of network interface

esp_netif_flags_t esp_netif_get_flags(esp_netif_t *esp_netif)

Returns configured flags for this interface.

Return

Configuration flags

Parameters
  • [in] esp_netif: Handle to esp-netif instance

const char *esp_netif_get_ifkey(esp_netif_t *esp_netif)

Returns configured interface key for this esp-netif instance.

Return

Textual description of related interface

Parameters
  • [in] esp_netif: Handle to esp-netif instance

const char *esp_netif_get_desc(esp_netif_t *esp_netif)

Returns configured interface type for this esp-netif instance.

Return

Enumerated type of this interface, such as station, AP, ethernet

Parameters
  • [in] esp_netif: Handle to esp-netif instance

int esp_netif_get_route_prio(esp_netif_t *esp_netif)

Returns configured routing priority number.

Return

Integer representing the instance’s route-prio, or -1 if invalid paramters

Parameters
  • [in] esp_netif: Handle to esp-netif instance

int32_t esp_netif_get_event_id(esp_netif_t *esp_netif, esp_netif_ip_event_type_t event_type)

Returns configured event for this esp-netif instance and supplied event type.

Return

specific event id which is configured to be raised if the interface lost or acquired IP address -1 if supplied event_type is not known

Parameters
  • [in] esp_netif: Handle to esp-netif instance

  • event_type: (either get or lost IP)

esp_netif_t *esp_netif_next(esp_netif_t *esp_netif)

Iterates over list of interfaces. Returns first netif if NULL given as parameter.

Return

First netif from the list if supplied parameter is NULL, next one otherwise

Parameters
  • [in] esp_netif: Handle to esp-netif instance

size_t esp_netif_get_nr_of_ifs(void)

Returns number of registered esp_netif objects.

Return

Number of esp_netifs

void esp_netif_netstack_buf_ref(void *netstack_buf)

increase the reference counter of net stack buffer

Parameters
  • [in] netstack_buf: the net stack buffer

void esp_netif_netstack_buf_free(void *netstack_buf)

free the netstack buffer

Parameters
  • [in] netstack_buf: the net stack buffer

Macros

_ESP_NETIF_SUPPRESS_LEGACY_WARNING_

WiFi default API reference

Functions

esp_err_t esp_netif_attach_wifi_station(esp_netif_t *esp_netif)

Attaches wifi station interface to supplied netif.

Return

  • ESP_OK on success

  • ESP_FAIL if attach failed

Parameters
  • esp_netif: instance to attach the wifi station to

esp_err_t esp_netif_attach_wifi_ap(esp_netif_t *esp_netif)

Attaches wifi soft AP interface to supplied netif.

Return

  • ESP_OK on success

  • ESP_FAIL if attach failed

Parameters
  • esp_netif: instance to attach the wifi AP to

esp_err_t esp_wifi_set_default_wifi_sta_handlers(void)

Sets default wifi event handlers for STA interface.

Return

  • ESP_OK on success, error returned from esp_event_handler_register if failed

esp_err_t esp_wifi_set_default_wifi_ap_handlers(void)

Sets default wifi event handlers for AP interface.

Return

  • ESP_OK on success, error returned from esp_event_handler_register if failed

esp_err_t esp_wifi_clear_default_wifi_driver_and_handlers(void *esp_netif)

Clears default wifi event handlers for supplied network interface.

Return

  • ESP_OK on success, error returned from esp_event_handler_register if failed

Parameters
  • esp_netif: instance of corresponding if object

esp_netif_t *esp_netif_create_default_wifi_ap(void)

Creates default WIFI AP. In case of any init error this API aborts.

Return

pointer to esp-netif instance

esp_netif_t *esp_netif_create_default_wifi_sta(void)

Creates default WIFI STA. In case of any init error this API aborts.

Return

pointer to esp-netif instance

esp_netif_t *esp_netif_create_wifi(wifi_interface_t wifi_if, esp_netif_inherent_config_t *esp_netif_config)

Creates esp_netif WiFi object based on the custom configuration.

Attention

This API DOES NOT register default handlers!

Return

pointer to esp-netif instance

Parameters
  • [in] wifi_if: type of wifi interface

  • [in] esp_netif_config: inherent esp-netif configuration pointer

esp_err_t esp_netif_create_default_wifi_mesh_netifs(esp_netif_t **p_netif_sta, esp_netif_t **p_netif_ap)

Creates default STA and AP network interfaces for esp-mesh.

Both netifs are almost identical to the default station and softAP, but with DHCP client and server disabled. Please note that the DHCP client is typically enabled only if the device is promoted to a root node.

Returns created interfaces which could be ignored setting parameters to NULL if an application code does not need to save the interface instances for further processing.

Return

ESP_OK on success

Parameters
  • [out] p_netif_sta: pointer where the resultant STA interface is saved (if non NULL)

  • [out] p_netif_ap: pointer where the resultant AP interface is saved (if non NULL)