ESP-NETIF Programmers Manual

Configure IP, Gateway, and DNS

Typically, IP addresses -- including the gateway, network mask, and DNS servers -- are automatically obtained through a DHCP server or Router Advertisement services. Notifications regarding IP address assignments are received via the IP_EVENT, which provides the relevant IP address information. You can also retrieve the current address details using the function esp_netif_get_ip_info(). This function returns a structure, esp_netif_ip_info_t, that contains the IPv4 address of the network interface, along with its network mask and gateway address. Similarly, the function esp_netif_get_all_ip6() can be used to obtain all IPv6 addresses associated with the interface.

In order to configure static IP addresses and DNS servers, it's necessary to disable or stop DHCP client (which is enabled by default on some network interfaces, such as the default Ethernet, or the default WiFi station). Please refer to the example /protocols/static_ip for more details.

To set IPv4 address, you can use esp_netif_set_ip_info(). For IPv6, these two functions can be used for adding or removing addresses: esp_netif_add_ip6_address(), esp_netif_remove_ip6_address(). To configure DNS servers, please use esp_netif_set_dns_info() API.

Configure DHCP options

Some network interfaces are pre-configured to use either a DHCP client (commonly for Ethernet interfaces) or a DHCP server (typically for Wi-Fi software access points). When manually creating a custom network interface, the configuration flags esp_netif_flags_t are used to specify the behavior of the interface. Adding ESP_NETIF_DHCP_CLIENT or ESP_NETIF_DHCP_SERVER will enable the DHCP client or server, respectively.

It is important to note that these two options are mutually exclusive and cannot be changed at runtime. If an interface is configured as a DHCP client upon creation, it cannot later be used as a DHCP server. The only option is to destroy the existing network interface and create a new one with the desired configuration.

To set or get a specific DHCP option, the common type esp_netif_dhcp_option_id_t is used for both the DHCP server and client. However, not all options are supported for both. For details on the available options for the DHCP client, refer to the API documentation for esp_netif_dhcpc_option(). Similarly, for the options available for the DHCP server, consult the API documentation for esp_netif_dhcps_option().

SNTP Service

A brief introduction to SNTP, its initialization code, and basic modes can be found in Section SNTP Time Synchronization in System Time.

This section provides more details on specific use cases for the SNTP service, such as using statically configured servers, DHCP-provided servers, or both. The workflow is typically straightforward:

Initialize and configure the service using esp_netif_sntp_init(). This function can only be called once unless the SNTP service has been destroyed using esp_netif_sntp_deinit().
Start the service with esp_netif_sntp_start(). This step is not necessary if the service was auto-started in the previous step (default behavior). However, it can be useful to start the service explicitly after connecting if DHCP-provided NTP servers are being used. Note that this option needs to be enabled before connecting, but the SNTP service should only be started afterward.
Wait for the system time to synchronize using esp_netif_sntp_sync_wait() (if required).
Stop and destroy the service using esp_netif_sntp_deinit().

Basic Mode with Statically Defined Server(s)

Initialize the module with the default configuration after connecting to the network. Note that it is possible to provide multiple NTP servers in the configuration struct:

esp_sntp_config_t config = ESP_NETIF_SNTP_DEFAULT_CONFIG_MULTIPLE(2,
                           ESP_SNTP_SERVER_LIST("time.windows.com", "pool.ntp.org" ) );
esp_netif_sntp_init(&config);

Note

If you want to configure multiple SNTP servers, update the lwIP configuration option CONFIG_LWIP_SNTP_MAX_SERVERS.

Use DHCP-Obtained SNTP Server(s)

First, you need to enable the lwIP configuration option CONFIG_LWIP_DHCP_GET_NTP_SRV. Then, initialize the SNTP module with the DHCP option, without specifying an NTP server.

esp_sntp_config_t config = ESP_NETIF_SNTP_DEFAULT_CONFIG_MULTIPLE(0, {} );
config.start = false;                       // start the SNTP service explicitly
config.server_from_dhcp = true;             // accept the NTP offer from the DHCP server
esp_netif_sntp_init(&config);

Once connected, you can start the service using:

esp_netif_sntp_start();

Note

It is also possible to start the service during initialization (with the default config.start=true). However, this may cause the initial SNTP request to fail since you are not connected yet, which could result in a back-off period for subsequent requests.

Use Both Static and Dynamic Servers

This scenario is similar to using DHCP-provided SNTP servers. However, in this configuration, you need to ensure that the static server configuration is refreshed when obtaining NTP servers via DHCP. The underlying lwIP code removes the existing list of NTP servers when DHCP-provided information is accepted. Therefore, the ESP-NETIF SNTP module retains the statically configured server(s) and appends them to the list after obtaining a DHCP lease.

The typical configuration now looks as per below, providing the specific IP_EVENT to update the config and index of the first server to reconfigure (for example setting config.index_of_first_server=1 would keep the DHCP provided server at index 0, and the statically configured server at index 1).

esp_sntp_config_t config = ESP_NETIF_SNTP_DEFAULT_CONFIG("pool.ntp.org");
config.start = false;                       // start the SNTP service explicitly (after connecting)
config.server_from_dhcp = true;             // accept the NTP offers from DHCP server
config.renew_servers_after_new_IP = true;   // let esp-netif update the configured SNTP server(s) after receiving the DHCP lease
config.index_of_first_server = 1;           // updates from server num 1, leaving server 0 (from DHCP) intact
config.ip_event_to_renew = IP_EVENT_STA_GOT_IP;  // IP event on which you refresh your configuration

Then you start the service normally with esp_netif_sntp_start().

L2 TAP Interface Usage

The ESP-NETIF L2 TAP interface is used to access Data Link Layer, please refer to the ESP-NETIF Architecture diagram to see how L2 TAP interacts with ESP-NETIF and application.

From a user perspective, the ESP-NETIF L2 TAP interface is accessed using file descriptors of VFS, which provides file-like interfacing (using functions like open(), read(), write(), etc). To learn more, refer to Virtual Filesystem Component.

There is only one ESP-NETIF L2 TAP interface device (path name) available, but you can open multiple file descriptors from it, each with its own unique configuration. Think of the ESP-NETIF L2 TAP interface as a general gateway to the Layer 2 network infrastructure. The key point is that each file descriptor can be individually configured, which is crucial. For example, a file descriptor can be set up to access a specific network interface identified by if_key (like ETH_DEF) and to filter specific types of frames (such as filtering by Ethernet type for IEEE 802.3 frames).

This filtering is essential because the ESP-NETIF L2 TAP works alongside the IP stack, meaning that IP-related traffic (like IP, ARP, etc.) should not be sent directly to your application. Although this option is still possible, it is not recommended in standard use cases. The benefit of filtering is that it allows your application to receive only the frame types it cares about, while other traffic is either routed to different L2 TAP file descriptors or handled by the IP stack.

Initialization

To be able to use the ESP-NETIF L2 TAP interface, it needs to be enabled in Kconfig by CONFIG_ESP_NETIF_L2_TAP first and then registered by esp_vfs_l2tap_intf_register() prior usage of any VFS function.

`open()`

Once the ESP-NETIF L2 TAP is registered, it can be opened at path name "/dev/net/tap". The same path name can be opened multiple times up to CONFIG_ESP_NETIF_L2_TAP_MAX_FDS and multiple file descriptors with a different configuration may access the Data Link Layer frames.

The ESP-NETIF L2 TAP can be opened with the O_NONBLOCK file status flag to make sure the read() does not block. Note that the write() may block in the current implementation when accessing a Network interface since it is a shared resource among multiple ESP-NETIF L2 TAP file descriptors and IP stack, and there is currently no queuing mechanism deployed. The file status flag can be retrieved and modified using fcntl().

On success, open() returns the new file descriptor (a nonnegative integer). On error, -1 is returned, and errno is set to indicate the error.

`ioctl()`

The newly opened ESP-NETIF L2 TAP file descriptor needs to be configured prior to its usage since it is not bounded to any specific Network Interface and no frame type filter is configured. The following configuration options are available to do so:

L2TAP_S_INTF_DEVICE - bounds the file descriptor to a specific Network Interface that is identified by its if_key. ESP-NETIF Network Interface if_key is passed to ioctl() as the third parameter. Note that default Network Interfaces if_key's used in ESP-IDF can be found in esp_netif/include/esp_netif_defaults.h.

L2TAP_S_DEVICE_DRV_HNDL - is another way to bound the file descriptor to a specific Network Interface. In this case, the Network interface is identified directly by IO Driver handle (e.g., esp_eth_handle_t in case of Ethernet). The IO Driver handle is passed to ioctl() as the third parameter.

L2TAP_S_RCV_FILTER - sets the filter to frames with the type to be passed to the file descriptor. In the case of Ethernet frames, the frames are to be filtered based on the Length and Ethernet type field. In case the filter value is set less than or equal to 0x05DC, the Ethernet type field is considered to represent IEEE802.3 Length Field, and all frames with values in interval <0, 0x05DC> at that field are passed to the file descriptor. The IEEE802.2 logical link control (LLC) resolution is then expected to be performed by the user's application. In case the filter value is set greater than 0x05DC, the Ethernet type field is considered to represent protocol identification and only frames that are equal to the set value are to be passed to the file descriptor.

All above-set configuration options have a getter counterpart option to read the current settings.

Warning

The file descriptor needs to be firstly bounded to a specific Network Interface by L2TAP_S_INTF_DEVICE or L2TAP_S_DEVICE_DRV_HNDL to make L2TAP_S_RCV_FILTER option available.

Note

VLAN-tagged frames are currently not recognized. If the user needs to process VLAN-tagged frames, they need a set filter to be equal to the VLAN tag (i.e., 0x8100 or 0x88A8) and process the VLAN-tagged frames in the user application.

Note

L2TAP_S_DEVICE_DRV_HNDL is particularly useful when the user's application does not require the usage of an IP stack and so ESP-NETIF is not required to be initialized too. As a result, Network Interface cannot be identified by its if_key and hence it needs to be identified directly by its IO Driver handle.

On success, ioctl() returns 0. On error, -1 is returned, and errno is set to indicate the error.
* EBADF - not a valid file descriptor.
* EACCES - options change is denied in this state (e.g., file descriptor has not been bounded to Network interface yet).
* EINVAL - invalid configuration argument. Ethernet type filter is already used by other file descriptors on that same Network interface.
* ENODEV - no such Network Interface which is tried to be assigned to the file descriptor exists.
* ENOSYS - unsupported operation, passed configuration option does not exist.

`fcntl()`

fcntl() is used to manipulate with properties of opened ESP-NETIF L2 TAP file descriptor.

The following commands manipulate the status flags associated with the file descriptor:

F_GETFD - the function returns the file descriptor flags, and the third argument is ignored.

F_SETFD - sets the file descriptor flags to the value specified by the third argument. Zero is returned.

On success, ioctl() returns 0. On error, -1 is returned, and errno is set to indicate the error.
* EBADF - not a valid file descriptor.
* ENOSYS - unsupported command.

`read()`

Opened and configured ESP-NETIF L2 TAP file descriptor can be accessed by read() to get inbound frames. The read operation can be either blocking or non-blocking based on the actual state of the O_NONBLOCK file status flag. When the file status flag is set to blocking, the read operation waits until a frame is received and the context is switched to other tasks. When the file status flag is set to non-blocking, the read operation returns immediately. In such case, either a frame is returned if it was already queued or the function indicates the queue is empty. The number of queued frames associated with one file descriptor is limited by CONFIG_ESP_NETIF_L2_TAP_RX_QUEUE_SIZE Kconfig option. Once the number of queued frames reached a configured threshold, the newly arrived frames are dropped until the queue has enough room to accept incoming traffic (Tail Drop queue management).

On success, read() returns the number of bytes read. Zero is returned when the size of the destination buffer is 0. On error, -1 is returned, and errno is set to indicate the error.
* EBADF - not a valid file descriptor.
* EAGAIN - the file descriptor has been marked non-blocking (O_NONBLOCK), and the read would block.

`write()`

A raw Data Link Layer frame can be sent to Network Interface via opened and configured ESP-NETIF L2 TAP file descriptor. The user's application is responsible to construct the whole frame except for fields which are added automatically by the physical interface device. The following fields need to be constructed by the user's application in case of an Ethernet link: source/destination MAC addresses, Ethernet type, actual protocol header, and user data. The length of these fields is as follows:

Destination MAC	Source MAC	Type/Length	Payload (protocol header/data)
6 B	6 B	2 B	0-1486 B

In other words, there is no additional frame processing performed by the ESP-NETIF L2 TAP interface. It only checks the Ethernet type of the frame is the same as the filter configured in the file descriptor. If the Ethernet type is different, an error is returned and the frame is not sent. Note that the write() may block in the current implementation when accessing a Network interface since it is a shared resource among multiple ESP-NETIF L2 TAP file descriptors and IP stack, and there is currently no queuing mechanism deployed.

On success, write() returns the number of bytes written. Zero is returned when the size of the input buffer is 0. On error, -1 is returned, and errno is set to indicate the error.
* EBADF - not a valid file descriptor.
* EBADMSG - The Ethernet type of the frame is different from the file descriptor configured filter.
* EIO - Network interface not available or busy.

`close()`

Opened ESP-NETIF L2 TAP file descriptor can be closed by the close() to free its allocated resources. The ESP-NETIF L2 TAP implementation of close() may block. On the other hand, it is thread-safe and can be called from a different task than the file descriptor is actually used. If such a situation occurs and one task is blocked in the I/O operation and another task tries to close the file descriptor, the first task is unblocked. The first's task read operation then ends with an error.

On success, close() returns zero. On error, -1 is returned, and errno is set to indicate the error.

* EBADF - not a valid file descriptor.

`select()`

Select is used in a standard way, just CONFIG_VFS_SUPPORT_SELECT needs to be enabled to make the select() function available.

IP Event: Transmit/Receive Packet

This event, IP_EVENT_TX_RX, is triggered for every transmitted or received IP packet. It provides information about packet transmission or reception, data length, and the esp_netif handle.

Enabling the Event

Compile Time:

The feature can be completely disabled during compilation time using the flag CONFIG_ESP_NETIF_REPORT_DATA_TRAFFIC in the kconfig.

Run Time:

At runtime, you can enable or disable this event using the functions esp_netif_tx_rx_event_enable() and esp_netif_tx_rx_event_disable().

Event Registration

To handle this event, you need to register a handler using the following syntax:

static void
tx_rx_event_handler(void *arg, esp_event_base_t event_base,
                                int32_t event_id, void *event_data)
{
    ip_event_tx_rx_t *event = (ip_event_tx_rx_t *)event_data;

    if (event->dir == ESP_NETIF_TX) {
        ESP_LOGI(TAG, "Got TX event: Interface \"%s\" data len: %d", esp_netif_get_desc(event->esp_netif), event->len);
    } else if (event->dir == ESP_NETIF_RX) {
        ESP_LOGI(TAG, "Got RX event: Interface \"%s\" data len: %d", esp_netif_get_desc(event->esp_netif), event->len);
    } else {
        ESP_LOGI(TAG, "Got Unknown event: Interface \"%s\"", esp_netif_get_desc(event->esp_netif));
    }
}

esp_event_handler_register(IP_EVENT, IP_EVENT_TX_RX, &tx_rx_event_handler, NULL);

Here, tx_rx_event_handler is the name of the function that will handle the event.

Event Data Structure

The event data structure, ip_event_tx_rx_t, contains the following fields:

ip_event_tx_rx_t::dir: Indicates whether the packet was transmitted (ESP_NETIF_TX) or received (ESP_NETIF_RX).
ip_event_tx_rx_t::len: Length of the data frame.
ip_event_tx_rx_t::esp_netif: The network interface on which the packet was sent or received.

API Reference

Header File

components/esp_netif/include/esp_netif.h
This header file can be included with:
#include "esp_netif.h"
This header file is a part of the API provided by the esp_netif component. To declare that your component depends on esp_netif, add the following to your CMakeLists.txt:
REQUIRES esp_netif
or
PRIV_REQUIRES esp_netif

Functions

esp_err_t esp_netif_init(void)

Initialize the underlying TCP/IP stack.

Note

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

Returns

ESP_OK on success
ESP_FAIL if initializing failed

esp_err_t esp_netif_deinit(void)

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

     Note: Deinitialization is not supported yet

Returns

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.

Parameters

esp_netif_config -- [in] pointer esp-netif configuration

Returns

pointer to esp-netif object on success
NULL otherwise

void esp_netif_destroy(esp_netif_t *esp_netif)

Destroys the esp_netif object.

Parameters: esp_netif -- [in] 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.

Parameters

esp_netif -- [inout] pointer to the object to be configured
driver_config -- [in] pointer esp-netif io driver related configuration

Returns

ESP_OK on success
ESP_ERR_ESP_NETIF_INVALID_PARAMS if invalid parameters provided

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)

Parameters

esp_netif -- [inout] pointer to esp_netif object to be attached
driver_handle -- [in] pointer to the driver handle

Returns

ESP_OK on success
ESP_ERR_ESP_NETIF_DRIVER_ATTACH_FAILED if driver's pot_attach callback failed

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.

Parameters

esp_netif -- [in] Handle to esp-netif instance
buffer -- [in] Received data
len -- [in] Length of the data frame
eb -- [in] Pointer to internal buffer (used in Wi-Fi driver)

Returns

ESP_OK

esp_err_t esp_netif_tx_rx_event_enable(esp_netif_t *esp_netif)

Enables transmit/receive event reporting for a network interface.

These functions enables transmit and receive events reporting for a given esp-netif instance. Event reporting can be used to track data transfer activity and trigger application-specific actions.

Parameters

esp_netif -- [in] Handle to esp-netif instance

Returns

ESP_OK: Successfully enabled event reporting
ESP_FAIL: Event reporting not configured

esp_err_t esp_netif_tx_rx_event_disable(esp_netif_t *esp_netif)

Disables transmit/receive event reporting for a network interface.

These functions disables transmit and receive events reporting for a given esp-netif instance.

Parameters

esp_netif -- [in] Handle to esp-netif instance

Returns

ESP_OK: Successfully disabled event reporting
ESP_FAIL: Event reporting not configured

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

esp_netif -- [in] Handle to esp-netif instance
base -- The base type of the event
event_id -- The specific ID of the event
data -- Optional data associated with the event

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

esp_netif -- [in] Handle to esp-netif instance
base -- The base type of the event
event_id -- The specific ID of the event
data -- Optional data associated with the event

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

esp_netif -- [in] Handle to esp-netif instance
base -- The base type of the event
event_id -- The specific ID of the event
data -- Optional data associated with the event

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

esp_netif -- [in] Handle to esp-netif instance
base -- The base type of the event
event_id -- The specific ID of the event
data -- Optional data associated with the event

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

esp_netif -- [in] Handle to esp-netif instance
base -- The base type of the event
event_id -- The specific ID of the event
data -- Optional data associated with the event

void esp_netif_action_join_ip6_multicast_group(void *esp_netif, esp_event_base_t base, int32_t event_id, void *data)

Default building block for network interface action upon IPv6 multicast group join.

Note

This API can be directly used as event handler

Parameters

esp_netif -- [in] Handle to esp-netif instance
base -- The base type of the event
event_id -- The specific ID of the event
data -- Optional data associated with the event

void esp_netif_action_leave_ip6_multicast_group(void *esp_netif, esp_event_base_t base, int32_t event_id, void *data)

Default building block for network interface action upon IPv6 multicast group leave.

Note

This API can be directly used as event handler

Parameters

esp_netif -- [in] Handle to esp-netif instance
base -- The base type of the event
event_id -- The specific ID of the event
data -- Optional data associated with the event

void esp_netif_action_add_ip6_address(void *esp_netif, esp_event_base_t base, int32_t event_id, void *data)

Default building block for network interface action upon IPv6 address added by the underlying stack.

Note

This API can be directly used as event handler

Parameters

esp_netif -- [in] Handle to esp-netif instance
base -- The base type of the event
event_id -- The specific ID of the event
data -- Optional data associated with the event

void esp_netif_action_remove_ip6_address(void *esp_netif, esp_event_base_t base, int32_t event_id, void *data)

Default building block for network interface action upon IPv6 address removed by the underlying stack.

Note

This API can be directly used as event handler

Parameters

esp_netif -- [in] Handle to esp-netif instance
base -- The base type of the event
event_id -- The specific ID of the event
data -- Optional data associated with the event

esp_err_t esp_netif_set_default_netif(esp_netif_t *esp_netif)

Manual configuration of the default netif.

This API overrides the automatic configuration of the default interface based on the route_prio If the selected netif is set default using this API, no other interface could be set-default disregarding its route_prio number (unless the selected netif gets destroyed)

Parameters: esp_netif -- [in] Handle to esp-netif instance
Returns: ESP_OK on success

esp_netif_t *esp_netif_get_default_netif(void)

Getter function of the default netif.

This API returns the selected default netif.

Returns: Handle to esp-netif instance of the default netif.

esp_err_t esp_netif_join_ip6_multicast_group(esp_netif_t *esp_netif, const esp_ip6_addr_t *addr)

Cause the TCP/IP stack to join a IPv6 multicast group.

Parameters

esp_netif -- [in] Handle to esp-netif instance
addr -- [in] The multicast group to join

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS
ESP_ERR_ESP_NETIF_MLD6_FAILED
ESP_ERR_NO_MEM

esp_err_t esp_netif_leave_ip6_multicast_group(esp_netif_t *esp_netif, const esp_ip6_addr_t *addr)

Cause the TCP/IP stack to leave a IPv6 multicast group.

Parameters

esp_netif -- [in] Handle to esp-netif instance
addr -- [in] The multicast group to leave

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS
ESP_ERR_ESP_NETIF_MLD6_FAILED
ESP_ERR_NO_MEM

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

Set the mac address for the interface instance.

Parameters

esp_netif -- [in] Handle to esp-netif instance
mac -- [in] Desired mac address for the related network interface

Returns

ESP_OK - success
ESP_ERR_ESP_NETIF_IF_NOT_READY - interface status error
ESP_ERR_NOT_SUPPORTED - mac not supported on this interface

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

Get the mac address for the interface instance.

Parameters

esp_netif -- [in] Handle to esp-netif instance
mac -- [out] Resultant mac address for the related network interface

Returns

ESP_OK - success
ESP_ERR_ESP_NETIF_IF_NOT_READY - interface status error
ESP_ERR_NOT_SUPPORTED - mac not supported on this 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

Parameters

esp_netif -- [in] Handle to esp-netif instance
hostname -- [in] New hostname for the interface. Maximum length 32 bytes.

Returns

ESP_OK - success
ESP_ERR_ESP_NETIF_IF_NOT_READY - interface status error
ESP_ERR_ESP_NETIF_INVALID_PARAMS - parameter error

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

Get interface hostname.

Parameters

esp_netif -- [in] Handle to esp-netif instance
hostname -- [out] 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).

Returns

ESP_OK - success
ESP_ERR_ESP_NETIF_IF_NOT_READY - interface status error
ESP_ERR_ESP_NETIF_INVALID_PARAMS - parameter error

bool esp_netif_is_netif_up(esp_netif_t *esp_netif)

Test if supplied interface is up or down.

Parameters

esp_netif -- [in] Handle to esp-netif instance

Returns

true - Interface is up
false - Interface is down

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

Parameters

esp_netif -- [in] Handle to esp-netif instance
ip_info -- [out] If successful, IP information will be returned in this argument.

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS

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.

Parameters

esp_netif -- [in] Handle to esp-netif instance
ip_info -- [out] If successful, IP information will be returned in this argument.

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS

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.

Parameters

esp_netif -- [in] Handle to esp-netif instance
ip_info -- [in] IP information to set on the specified interface

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS
ESP_ERR_ESP_NETIF_DHCP_NOT_STOPPED If DHCP server or client is still running

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.

Parameters

esp_netif -- [in] Handle to esp-netif instance
ip_info -- [in] Store the old IP information for the specified interface

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS

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

Parameters: esp_netif -- [in] Handle to esp-netif instance
Returns: implementation specific index of interface represented with supplied esp_netif

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

Parameters

esp_netif -- [in] Handle to esp-netif instance
name -- [out] 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)

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS

esp_err_t esp_netif_napt_enable(esp_netif_t *esp_netif)

Enable NAPT on an interface.

Note

Enable operation can be performed only on one interface at a time. NAPT cannot be enabled on multiple interfaces according to this implementation.

Parameters

esp_netif -- [in] Handle to esp-netif instance

Returns

ESP_OK
ESP_FAIL
ESP_ERR_NOT_SUPPORTED

esp_err_t esp_netif_napt_disable(esp_netif_t *esp_netif)

Disable NAPT on an interface.

Parameters

esp_netif -- [in] Handle to esp-netif instance

Returns

ESP_OK
ESP_FAIL
ESP_ERR_NOT_SUPPORTED

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.

Get operations:

IP_ADDRESS_LEASE_TIME
ESP_NETIF_SUBNET_MASK/REQUESTED_IP_ADDRESS (both options do the same, they reflect dhcps_lease_t)
ROUTER_SOLICITATION_ADDRESS
DOMAIN_NAME_SERVER

Set operations:

IP_ADDRESS_LEASE_TIME
ESP_NETIF_SUBNET_MASK – set operation is allowed only if the configured mask corresponds to the settings, if not, please use esp_netif_set_ip_info() to prevent misconfiguration of DHCPS.
REQUESTED_IP_ADDRESS – if the address pool is enabled, a sanity check for start/end addresses is performed before setting.
ROUTER_SOLICITATION_ADDRESS
DOMAIN_NAME_SERVER
ESP_NETIF_CAPTIVEPORTAL_URI – set operation copies the pointer to the URI, so it is owned by the application and needs to be maintained valid throughout the entire DHCP Server lifetime.

Note

Please note that not all combinations of identifiers and options are supported.

Parameters

esp_netif -- [in] Handle to esp-netif instance
opt_op -- [in] ESP_NETIF_OP_SET to set an option, ESP_NETIF_OP_GET to get an option.
opt_id -- [in] Option index to get or set, must be one of the supported enum values.
opt_val -- [inout] Pointer to the option parameter.
opt_len -- [in] Length of the option parameter.

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS
ESP_ERR_ESP_NETIF_DHCP_ALREADY_STOPPED
ESP_ERR_ESP_NETIF_DHCP_ALREADY_STARTED

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.

Get operations:

ESP_NETIF_IP_REQUEST_RETRY_TIME
ESP_NETIF_VENDOR_SPECIFIC_INFO – only available if ESP_DHCP_DISABLE_VENDOR_CLASS_IDENTIFIER=n

Set operations:

ESP_NETIF_IP_REQUEST_RETRY_TIME
ESP_NETIF_VENDOR_SPECIFIC_INFO – only available if ESP_DHCP_DISABLE_VENDOR_CLASS_IDENTIFIER=n lwip layer creates its own copy of the supplied identifier. (the internal copy could be feed by calling dhcp_free_vendor_class_identifier())

Note

Please note that not all combinations of identifiers and options are supported.

Parameters

esp_netif -- [in] Handle to esp-netif instance
opt_op -- [in] ESP_NETIF_OP_SET to set an option, ESP_NETIF_OP_GET to get an option.
opt_id -- [in] Option index to get or set, must be one of the supported enum values.
opt_val -- [inout] Pointer to the option parameter.
opt_len -- [in] Length of the option parameter.

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS
ESP_ERR_ESP_NETIF_DHCP_ALREADY_STOPPED
ESP_ERR_ESP_NETIF_DHCP_ALREADY_STARTED

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.

Parameters

esp_netif -- [in] Handle to esp-netif instance

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS
ESP_ERR_ESP_NETIF_DHCP_ALREADY_STARTED
ESP_ERR_ESP_NETIF_DHCPC_START_FAILED

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.

Parameters

esp_netif -- [in] Handle to esp-netif instance

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS
ESP_ERR_ESP_NETIF_DHCP_ALREADY_STOPPED
ESP_ERR_ESP_NETIF_IF_NOT_READY

esp_err_t esp_netif_dhcpc_get_status(esp_netif_t *esp_netif, esp_netif_dhcp_status_t *status)

Get DHCP client status.

Parameters

esp_netif -- [in] Handle to esp-netif instance
status -- [out] If successful, the status of DHCP client will be returned in this argument.

Returns

ESP_OK

esp_err_t esp_netif_dhcps_get_status(esp_netif_t *esp_netif, esp_netif_dhcp_status_t *status)

Get DHCP Server status.

Parameters

esp_netif -- [in] Handle to esp-netif instance
status -- [out] If successful, the status of the DHCP server will be returned in this argument.

Returns

ESP_OK

esp_err_t esp_netif_dhcps_start(esp_netif_t *esp_netif)

Start DHCP server (only if enabled in interface object)

Parameters

esp_netif -- [in] Handle to esp-netif instance

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS
ESP_ERR_ESP_NETIF_DHCP_ALREADY_STARTED

esp_err_t esp_netif_dhcps_stop(esp_netif_t *esp_netif)

Stop DHCP server (only if enabled in interface object)

Parameters

esp_netif -- [in] Handle to esp-netif instance

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS
ESP_ERR_ESP_NETIF_DHCP_ALREADY_STOPPED
ESP_ERR_ESP_NETIF_IF_NOT_READY

esp_err_t esp_netif_dhcps_get_clients_by_mac(esp_netif_t *esp_netif, int num, esp_netif_pair_mac_ip_t *mac_ip_pair)

Populate IP addresses of clients connected to DHCP server listed by their MAC addresses.

Parameters

esp_netif -- [in] Handle to esp-netif instance
num -- [in] Number of clients with specified MAC addresses in the array of pairs
mac_ip_pair -- [inout] Array of pairs of MAC and IP addresses (MAC are inputs, IP outputs)

Returns

ESP_OK on success
ESP_ERR_ESP_NETIF_INVALID_PARAMS on invalid params
ESP_ERR_NOT_SUPPORTED if DHCP server not enabled

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.

Note that LWIP stores DNS server information globally, not per interface, so the first parameter is unused in the default LWIP configuration. If CONFIG_ESP_NETIF_SET_DNS_PER_DEFAULT_NETIF=1 this API sets internal DNS server information per netif. It's also possible to set the global DNS server info by supplying esp_netif=NULL

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.

Parameters

esp_netif -- [in] Handle to esp-netif instance
type -- [in] Type of DNS Server to set: ESP_NETIF_DNS_MAIN, ESP_NETIF_DNS_BACKUP, ESP_NETIF_DNS_FALLBACK
dns -- [in] DNS Server address to set

Returns

ESP_OK on success
ESP_ERR_ESP_NETIF_INVALID_PARAMS invalid params

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.

Note that LWIP stores DNS server information globally, not per interface, so the first parameter is unused in the default LWIP configuration. If CONFIG_ESP_NETIF_SET_DNS_PER_DEFAULT_NETIF=1 this API returns internally saved DNS server information per netif. It's also possible to ask for the global DNS server info by supplying esp_netif=NULL

Parameters

esp_netif -- [in] Handle to esp-netif instance
type -- [in] Type of DNS Server to get: ESP_NETIF_DNS_MAIN, ESP_NETIF_DNS_BACKUP, ESP_NETIF_DNS_FALLBACK
dns -- [out] DNS Server result is written here on success

Returns

ESP_OK on success
ESP_ERR_ESP_NETIF_INVALID_PARAMS invalid params

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.

Parameters

esp_netif -- [in] Handle to esp-netif instance

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS

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.

Parameters

esp_netif -- [in] Handle to esp-netif instance
if_ip6 -- [out] IPv6 information will be returned in this argument if successful.

Returns

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.

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.

Parameters

esp_netif -- [in] Handle to esp-netif instance
if_ip6 -- [out] IPv6 information will be returned in this argument if successful.

Returns

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.

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.

Parameters

esp_netif -- [in] Handle to esp-netif instance
if_ip6 -- [out] Array of IPv6 addresses will be copied to the argument

Returns

number of returned IPv6 addresses

int esp_netif_get_all_preferred_ip6(esp_netif_t *esp_netif, esp_ip6_addr_t if_ip6[])

Get all preferred IPv6 addresses of the specified interface.

Parameters

esp_netif -- [in] Handle to esp-netif instance
if_ip6 -- [out] Array of IPv6 addresses will be copied to the argument

Returns

number of returned IPv6 addresses

esp_err_t esp_netif_add_ip6_address(esp_netif_t *esp_netif, const esp_ip6_addr_t addr, bool preferred)

Cause the TCP/IP stack to add an IPv6 address to the interface.

Parameters

esp_netif -- [in] Handle to esp-netif instance
addr -- [in] The address to be added
preferred -- [in] The preferred status of the address

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS
ESP_ERR_ESP_NETIF_IP6_ADDR_FAILED
ESP_ERR_NO_MEM

esp_err_t esp_netif_remove_ip6_address(esp_netif_t *esp_netif, const esp_ip6_addr_t *addr)

Cause the TCP/IP stack to remove an IPv6 address from the interface.

Parameters

esp_netif -- [in] Handle to esp-netif instance
addr -- [in] The address to be removed

Returns

ESP_OK
ESP_ERR_ESP_NETIF_INVALID_PARAMS
ESP_ERR_ESP_NETIF_IP6_ADDR_FAILED
ESP_ERR_NO_MEM

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

addr -- [out] 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.

Parameters

addr -- ip address in network order to convert
buf -- target buffer where the string is stored
buflen -- length of buf

Returns

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

uint32_t esp_ip4addr_aton(const char *addr)

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

Parameters: addr -- IP address in ascii representation (e.g. "127.0.0.1")
Returns: ip address in network order

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.

Parameters

src -- [in] IPv4 address in ascii representation (e.g. "127.0.0.1")
dst -- [out] Address of the target esp_ip4_addr_t structure to receive converted address

Returns

ESP_OK on success
ESP_FAIL if conversion failed
ESP_ERR_INVALID_ARG if invalid parameter is passed into

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 omitted: "2001:db8:85a3:0:0:0:2:1" or "2001:db8::2:1")

Parameters

src -- [in] IPv6 address in ascii representation (e.g. ""2001:0db8:85a3:0000:0000:0000:0002:0001")
dst -- [out] Address of the target esp_ip6_addr_t structure to receive converted address

Returns

ESP_OK on success
ESP_FAIL if conversion failed
ESP_ERR_INVALID_ARG if invalid parameter is passed into

esp_netif_iodriver_handle esp_netif_get_io_driver(esp_netif_t *esp_netif)

Gets media driver handle for this esp-netif instance.

Parameters: esp_netif -- [in] Handle to esp-netif instance
Returns: opaque pointer of related IO driver

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.

Parameters: if_key -- Textual description of network interface
Returns: Handle to esp-netif instance

esp_netif_flags_t esp_netif_get_flags(esp_netif_t *esp_netif)

Returns configured flags for this interface.

Parameters: esp_netif -- [in] Handle to esp-netif instance
Returns: Configuration flags

const char *esp_netif_get_ifkey(esp_netif_t *esp_netif)

Returns configured interface key for this esp-netif instance.

Parameters: esp_netif -- [in] Handle to esp-netif instance
Returns: Textual description of related interface

const char *esp_netif_get_desc(esp_netif_t *esp_netif)

Returns configured interface type for this esp-netif instance.

Parameters: esp_netif -- [in] Handle to esp-netif instance
Returns: Enumerated type of this interface, such as station, AP, ethernet

int esp_netif_get_route_prio(esp_netif_t *esp_netif)

Returns configured routing priority number.

Parameters: esp_netif -- [in] Handle to esp-netif instance
Returns: Integer representing the instance's route-prio, or -1 if invalid parameters

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.

Parameters

esp_netif -- [in] Handle to esp-netif instance
event_type -- (either get or lost IP)

Returns

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

esp_netif_t *esp_netif_next(esp_netif_t *esp_netif)

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

Note

This API doesn't lock the list, nor the TCPIP context, as this it's usually required to get atomic access between iteration steps rather that within a single iteration. Therefore it is recommended to iterate over the interfaces inside esp_netif_tcpip_exec()

Note

This API is deprecated. Please use esp_netif_next_unsafe() directly if all the system interfaces are under your control and you can safely iterate over them. Otherwise, iterate over interfaces using esp_netif_tcpip_exec(), or use esp_netif_find_if() to search in the list of netifs with defined predicate.

Parameters: esp_netif -- [in] Handle to esp-netif instance
Returns: First netif from the list if supplied parameter is NULL, next one otherwise

esp_netif_t *esp_netif_next_unsafe(esp_netif_t *esp_netif)

Iterates over list of interfaces without list locking. Returns first netif if NULL given as parameter.

Used for bulk search loops within TCPIP context, e.g. using esp_netif_tcpip_exec(), or if we're sure that the iteration is safe from our application perspective (e.g. no interface is removed between iterations)

Parameters: esp_netif -- [in] Handle to esp-netif instance
Returns: First netif from the list if supplied parameter is NULL, next one otherwise

esp_netif_t *esp_netif_find_if(esp_netif_find_predicate_t fn, void *ctx)

Return a netif pointer for the first interface that meets criteria defined by the callback.

Parameters

fn -- Predicate function returning true for the desired interface
ctx -- Context pointer passed to the predicate, typically a descriptor to compare with

Returns

valid netif pointer if found, NULL if not

size_t esp_netif_get_nr_of_ifs(void)

Returns number of registered esp_netif objects.

Returns: Number of esp_netifs

void esp_netif_netstack_buf_ref(void *netstack_buf)

increase the reference counter of net stack buffer

Parameters: netstack_buf -- [in] the net stack buffer

void esp_netif_netstack_buf_free(void *netstack_buf)

free the netstack buffer

Parameters: netstack_buf -- [in] the net stack buffer

esp_err_t esp_netif_tcpip_exec(esp_netif_callback_fn fn, void *ctx)

Utility to execute the supplied callback in TCP/IP context.

Parameters

fn -- Pointer to the callback
ctx -- Parameter to the callback

Returns

The error code (esp_err_t) returned by the callback

Type Definitions

typedef bool (*esp_netif_find_predicate_t)(esp_netif_t *netif, void *ctx): Predicate callback for esp_netif_find_if() used to find interface which meets defined criteria.

typedef esp_err_t (*esp_netif_callback_fn)(void *ctx): TCPIP thread safe callback used with esp_netif_tcpip_exec()

Header File

components/esp_netif/include/esp_netif_sntp.h
This header file can be included with:
#include "esp_netif_sntp.h"
This header file is a part of the API provided by the esp_netif component. To declare that your component depends on esp_netif, add the following to your CMakeLists.txt:
REQUIRES esp_netif
or
PRIV_REQUIRES esp_netif

Functions

esp_err_t esp_netif_sntp_init(const esp_sntp_config_t *config)

Initialize SNTP with supplied config struct.

Parameters: config -- Config struct
Returns: ESP_OK on success

esp_err_t esp_netif_sntp_start(void)

Start SNTP service if it wasn't started during init (config.start = false) or restart it if already started.

Returns: ESP_OK on success

void esp_netif_sntp_deinit(void): Deinitialize esp_netif SNTP module.

esp_err_t esp_netif_sntp_sync_wait(TickType_t tout)

Wait for time sync event.

Parameters: tout -- Specified timeout in RTOS ticks
Returns: ESP_TIMEOUT if sync event didn't came withing the timeout ESP_ERR_NOT_FINISHED if the sync event came, but we're in smooth update mode and still in progress (SNTP_SYNC_STATUS_IN_PROGRESS) ESP_OK if time sync'ed

esp_err_t esp_netif_sntp_reachability(unsigned int index, unsigned int *reachability)

Returns SNTP server's reachability shift register as described in RFC 5905.

Parameters

index -- Index of the SERVER
reachability -- reachability shift register

Returns

ESP_OK on success, ESP_ERR_INVALID_STATE if SNTP not initialized ESP_ERR_INVALID_ARG if invalid arguments

Structures

struct esp_sntp_config

SNTP configuration struct.

Public Members

bool smooth_sync: set to true if smooth sync required

bool server_from_dhcp: set to true to request NTP server config from DHCP

bool wait_for_sync: if true, we create a semaphore to signal time sync event

bool start: set to true to automatically start the SNTP service

esp_sntp_time_cb_t sync_cb: optionally sets callback function on time sync event

bool renew_servers_after_new_IP: this is used to refresh server list if NTP provided by DHCP (which cleans other pre-configured servers)

ip_event_t ip_event_to_renew: set the IP event id on which we refresh server list (if renew_servers_after_new_IP=true)

size_t index_of_first_server: refresh server list after this server (if renew_servers_after_new_IP=true)

size_t num_of_servers: number of preconfigured NTP servers

const char *servers[1]: list of servers

Macros

ESP_SNTP_SERVER_LIST(...): Utility macro for providing multiple servers in parentheses.

ESP_NETIF_SNTP_DEFAULT_CONFIG_MULTIPLE(servers_in_list, list_of_servers)

Default configuration to init SNTP with multiple servers.

Parameters

servers_in_list -- Number of servers in the list
list_of_servers -- List of servers (use ESP_SNTP_SERVER_LIST(...))

ESP_NETIF_SNTP_DEFAULT_CONFIG(server): Default configuration with a single server.

Type Definitions

typedef void (*esp_sntp_time_cb_t)(struct timeval *tv): Time sync notification function.

typedef struct esp_sntp_config esp_sntp_config_t: SNTP configuration struct.

Header File

components/esp_netif/include/esp_netif_types.h
This header file can be included with:
#include "esp_netif_types.h"
This header file is a part of the API provided by the esp_netif component. To declare that your component depends on esp_netif, add the following to your CMakeLists.txt:
REQUIRES esp_netif
or
PRIV_REQUIRES esp_netif

Structures

struct esp_netif_dns_info_t

DNS server info.

Public Members

esp_ip_addr_t ip: IPV4 address of DNS server

struct esp_netif_ip_info_t

Event structure for IP_EVENT_STA_GOT_IP, IP_EVENT_ETH_GOT_IP events

Public Members

esp_ip4_addr_t ip: Interface IPV4 address

esp_ip4_addr_t netmask: Interface IPV4 netmask

esp_ip4_addr_t gw: Interface IPV4 gateway address

struct esp_netif_ip6_info_t

IPV6 IP address information.

Public Members

esp_ip6_addr_t ip: Interface IPV6 address

struct ip_event_got_ip_t

Event structure for IP_EVENT_GOT_IP event.

Public Members

esp_netif_t *esp_netif: Pointer to corresponding esp-netif object

esp_netif_ip_info_t ip_info: IP address, netmask, gateway IP address

bool ip_changed: Whether the assigned IP has changed or not

struct ip_event_got_ip6_t

Event structure for IP_EVENT_GOT_IP6 event

Public Members

esp_netif_t *esp_netif: Pointer to corresponding esp-netif object

esp_netif_ip6_info_t ip6_info: IPv6 address of the interface

int ip_index: IPv6 address index

struct ip_event_add_ip6_t

Event structure for ADD_IP6 event

Public Members

esp_ip6_addr_t addr: The address to be added to the interface

bool preferred: The default preference of the address

struct ip_event_ap_staipassigned_t

Event structure for IP_EVENT_AP_STAIPASSIGNED event

Public Members

esp_netif_t *esp_netif: Pointer to the associated netif handle

esp_ip4_addr_t ip: IP address which was assigned to the station

uint8_t mac[6]: MAC address of the connected client

struct ip_event_tx_rx_t

Event structure for IP_EVENT_TRANSMIT and IP_EVENT_RECEIVE

Public Members

esp_netif_t *esp_netif: Pointer to the associated netif handle

size_t len: Length of the data

esp_netif_tx_rx_direction_t dir: Directions for data transfer >

struct bridgeif_config

LwIP bridge configuration

Public Members

uint16_t max_fdb_dyn_entries: maximum number of entries in dynamic forwarding database

uint16_t max_fdb_sta_entries: maximum number of entries in static forwarding database

uint8_t max_ports: maximum number of ports the bridge can consist of

struct esp_netif_inherent_config

ESP-netif inherent config parameters.

Public Members

esp_netif_flags_t flags: flags that define esp-netif behavior

uint8_t mac[6]: initial mac address for this interface

const esp_netif_ip_info_t *ip_info: initial ip address for this interface

uint32_t get_ip_event: event id to be raised when interface gets an IP

uint32_t lost_ip_event: event id to be raised when interface losts its IP

const char *if_key: string identifier of the interface

const char *if_desc: textual description of the interface

int route_prio: numeric priority of this interface to become a default routing if (if other netifs are up). A higher value of route_prio indicates a higher priority

bridgeif_config_t *bridge_info: LwIP bridge configuration

struct esp_netif_driver_base_s

ESP-netif driver base handle.

Public Members

esp_err_t (*post_attach)(esp_netif_t *netif, esp_netif_iodriver_handle h): post attach function pointer

esp_netif_t *netif: netif handle

struct esp_netif_driver_ifconfig

Specific IO driver configuration.

Public Members

esp_netif_iodriver_handle handle: io-driver handle

esp_err_t (*transmit)(void *h, void *buffer, size_t len): transmit function pointer

esp_err_t (*transmit_wrap)(void *h, void *buffer, size_t len, void *netstack_buffer): transmit wrap function pointer

void (*driver_free_rx_buffer)(void *h, void *buffer): free rx buffer function pointer

struct esp_netif_config

Generic esp_netif configuration.

Public Members

const esp_netif_inherent_config_t *base: base config

const esp_netif_driver_ifconfig_t *driver: driver config

const esp_netif_netstack_config_t *stack: stack config

struct esp_netif_pair_mac_ip_t

DHCP client's addr info (pair of MAC and IP address)

Public Members

uint8_t mac[6]: Clients MAC address

esp_ip4_addr_t ip: Clients IP address

Macros

ESP_ERR_ESP_NETIF_BASE: Definition of ESP-NETIF based errors.

ESP_ERR_ESP_NETIF_INVALID_PARAMS

ESP_ERR_ESP_NETIF_IF_NOT_READY

ESP_ERR_ESP_NETIF_DHCPC_START_FAILED

ESP_ERR_ESP_NETIF_DHCP_ALREADY_STARTED

ESP_ERR_ESP_NETIF_DHCP_ALREADY_STOPPED

ESP_ERR_ESP_NETIF_NO_MEM

ESP_ERR_ESP_NETIF_DHCP_NOT_STOPPED

ESP_ERR_ESP_NETIF_DRIVER_ATTACH_FAILED

ESP_ERR_ESP_NETIF_INIT_FAILED

ESP_ERR_ESP_NETIF_DNS_NOT_CONFIGURED

ESP_ERR_ESP_NETIF_MLD6_FAILED

ESP_ERR_ESP_NETIF_IP6_ADDR_FAILED

ESP_ERR_ESP_NETIF_DHCPS_START_FAILED

ESP_ERR_ESP_NETIF_TX_FAILED

ESP_NETIF_BR_FLOOD: Definition of ESP-NETIF bridge control.

ESP_NETIF_BR_DROP

ESP_NETIF_BR_FDW_CPU

Type Definitions

typedef struct esp_netif_obj esp_netif_t

typedef enum esp_netif_flags esp_netif_flags_t

typedef enum esp_netif_ip_event_type esp_netif_ip_event_type_t

typedef struct bridgeif_config bridgeif_config_t: LwIP bridge configuration

typedef struct esp_netif_inherent_config esp_netif_inherent_config_t: ESP-netif inherent config parameters.

typedef struct esp_netif_config esp_netif_config_t

typedef void *esp_netif_iodriver_handle: IO driver handle type.

typedef struct esp_netif_driver_base_s esp_netif_driver_base_t: ESP-netif driver base handle.

typedef struct esp_netif_driver_ifconfig esp_netif_driver_ifconfig_t

typedef struct esp_netif_netstack_config esp_netif_netstack_config_t: Specific L3 network stack configuration.

typedef esp_err_t (*esp_netif_receive_t)(esp_netif_t *esp_netif, void *buffer, size_t len, void *eb): ESP-NETIF Receive function type.

Enumerations

enum esp_netif_dns_type_t

Type of DNS server.

Values:

enumerator ESP_NETIF_DNS_MAIN: DNS main server address

enumerator ESP_NETIF_DNS_BACKUP: DNS backup server address (Wi-Fi STA and Ethernet only)

enumerator ESP_NETIF_DNS_FALLBACK: DNS fallback server address (Wi-Fi STA and Ethernet only)

enumerator ESP_NETIF_DNS_MAX

enum esp_netif_dhcp_status_t

Status of DHCP client or DHCP server.

Values:

enumerator ESP_NETIF_DHCP_INIT: DHCP client/server is in initial state (not yet started)

enumerator ESP_NETIF_DHCP_STARTED: DHCP client/server has been started

enumerator ESP_NETIF_DHCP_STOPPED: DHCP client/server has been stopped

enumerator ESP_NETIF_DHCP_STATUS_MAX

enum esp_netif_dhcp_option_mode_t

Mode for DHCP client or DHCP server option functions.

Values:

enumerator ESP_NETIF_OP_START

enumerator ESP_NETIF_OP_SET: Set option

enumerator ESP_NETIF_OP_GET: Get option

enumerator ESP_NETIF_OP_MAX

enum esp_netif_dhcp_option_id_t

Supported options for DHCP client or DHCP server.

Values:

enumerator ESP_NETIF_SUBNET_MASK: Network mask

enumerator ESP_NETIF_DOMAIN_NAME_SERVER: Domain name server

enumerator ESP_NETIF_ROUTER_SOLICITATION_ADDRESS: Solicitation router address

enumerator ESP_NETIF_REQUESTED_IP_ADDRESS: Request specific IP address

enumerator ESP_NETIF_IP_ADDRESS_LEASE_TIME: Request IP address lease time

enumerator ESP_NETIF_IP_REQUEST_RETRY_TIME: Request IP address retry counter

enumerator ESP_NETIF_VENDOR_CLASS_IDENTIFIER: Vendor Class Identifier of a DHCP client

enumerator ESP_NETIF_VENDOR_SPECIFIC_INFO: Vendor Specific Information of a DHCP server

enumerator ESP_NETIF_CAPTIVEPORTAL_URI: Captive Portal Identification

enum ip_event_t

IP event declarations

Values:

enumerator IP_EVENT_STA_GOT_IP: station got IP from connected AP

enumerator IP_EVENT_STA_LOST_IP: station lost IP and the IP is reset to 0

enumerator IP_EVENT_AP_STAIPASSIGNED: soft-AP assign an IP to a connected station

enumerator IP_EVENT_GOT_IP6: station or ap or ethernet interface v6IP addr is preferred

enumerator IP_EVENT_ETH_GOT_IP: ethernet got IP from connected AP

enumerator IP_EVENT_ETH_LOST_IP: ethernet lost IP and the IP is reset to 0

enumerator IP_EVENT_PPP_GOT_IP: PPP interface got IP

enumerator IP_EVENT_PPP_LOST_IP: PPP interface lost IP

enumerator IP_EVENT_TX_RX: transmitting/receiving data packet

enum esp_netif_tx_rx_direction_t

Values:

enumerator ESP_NETIF_TX

enumerator ESP_NETIF_RX

enum esp_netif_flags

Values:

enumerator ESP_NETIF_DHCP_CLIENT

enumerator ESP_NETIF_DHCP_SERVER

enumerator ESP_NETIF_FLAG_AUTOUP

enumerator ESP_NETIF_FLAG_GARP

enumerator ESP_NETIF_FLAG_EVENT_IP_MODIFIED

enumerator ESP_NETIF_FLAG_IS_PPP

enumerator ESP_NETIF_FLAG_IS_BRIDGE

enumerator ESP_NETIF_FLAG_MLDV6_REPORT

enumerator ESP_NETIF_FLAG_IPV6_AUTOCONFIG_ENABLED

enum esp_netif_ip_event_type

Values:

enumerator ESP_NETIF_IP_EVENT_GOT_IP

enumerator ESP_NETIF_IP_EVENT_LOST_IP

Header File

components/esp_netif/include/esp_netif_ip_addr.h
This header file can be included with:
#include "esp_netif_ip_addr.h"
This header file is a part of the API provided by the esp_netif component. To declare that your component depends on esp_netif, add the following to your CMakeLists.txt:
REQUIRES esp_netif
or
PRIV_REQUIRES esp_netif

Functions

esp_ip6_addr_type_t esp_netif_ip6_get_addr_type(esp_ip6_addr_t *ip6_addr)

Get the IPv6 address type.

Parameters: ip6_addr -- [in] IPv6 type
Returns: IPv6 type in form of enum esp_ip6_addr_type_t

static inline void esp_netif_ip_addr_copy(esp_ip_addr_t *dest, const esp_ip_addr_t *src)

Copy IP addresses.

Parameters

dest -- [out] destination IP
src -- [in] source IP

Structures

struct esp_ip6_addr

IPv6 address.

Public Members

uint32_t addr[4]: IPv6 address

uint8_t zone: zone ID

struct esp_ip4_addr

IPv4 address.

Public Members

uint32_t addr: IPv4 address

struct _ip_addr

IP address.

Public Members

esp_ip6_addr_t ip6: IPv6 address type

esp_ip4_addr_t ip4: IPv4 address type

union _ip_addr::[anonymous] u_addr: IP address union

uint8_t type: ipaddress type

Macros

esp_netif_htonl(x)

esp_netif_ip4_makeu32(a, b, c, d)

ESP_IP6_ADDR_BLOCK1(ip6addr)

ESP_IP6_ADDR_BLOCK2(ip6addr)

ESP_IP6_ADDR_BLOCK3(ip6addr)

ESP_IP6_ADDR_BLOCK4(ip6addr)

ESP_IP6_ADDR_BLOCK5(ip6addr)

ESP_IP6_ADDR_BLOCK6(ip6addr)

ESP_IP6_ADDR_BLOCK7(ip6addr)

ESP_IP6_ADDR_BLOCK8(ip6addr)

IPSTR

esp_ip4_addr_get_byte(ipaddr, idx)

esp_ip4_addr1(ipaddr)

esp_ip4_addr2(ipaddr)

esp_ip4_addr3(ipaddr)

esp_ip4_addr4(ipaddr)

esp_ip4_addr1_16(ipaddr)

esp_ip4_addr2_16(ipaddr)

esp_ip4_addr3_16(ipaddr)

esp_ip4_addr4_16(ipaddr)

IP2STR(ipaddr)

IPV6STR

IPV62STR(ipaddr)

ESP_IPADDR_TYPE_V4

ESP_IPADDR_TYPE_V6

ESP_IPADDR_TYPE_ANY

ESP_IP4TOUINT32(a, b, c, d)

ESP_IP4TOADDR(a, b, c, d)

ESP_IP4ADDR_INIT(a, b, c, d)

ESP_IP6ADDR_INIT(a, b, c, d)

IP4ADDR_STRLEN_MAX

ESP_IP_IS_ANY(addr)

Type Definitions

typedef struct esp_ip4_addr esp_ip4_addr_t

typedef struct esp_ip6_addr esp_ip6_addr_t

typedef struct _ip_addr esp_ip_addr_t: IP address.

Enumerations

enum esp_ip6_addr_type_t

Values:

enumerator ESP_IP6_ADDR_IS_UNKNOWN

enumerator ESP_IP6_ADDR_IS_GLOBAL

enumerator ESP_IP6_ADDR_IS_LINK_LOCAL

enumerator ESP_IP6_ADDR_IS_SITE_LOCAL

enumerator ESP_IP6_ADDR_IS_UNIQUE_LOCAL

enumerator ESP_IP6_ADDR_IS_IPV4_MAPPED_IPV6

Header File

components/esp_netif/include/esp_vfs_l2tap.h
This header file can be included with:
#include "esp_vfs_l2tap.h"
This header file is a part of the API provided by the esp_netif component. To declare that your component depends on esp_netif, add the following to your CMakeLists.txt:
REQUIRES esp_netif
or
PRIV_REQUIRES esp_netif

Functions

esp_err_t esp_vfs_l2tap_intf_register(l2tap_vfs_config_t *config)

Add L2 TAP virtual filesystem driver.

This function must be called prior usage of ESP-NETIF L2 TAP Interface

Parameters

config -- L2 TAP virtual filesystem driver configuration. Default base path /dev/net/tap is used when this paramenter is NULL.

Returns

esp_err_t

ESP_OK on success

esp_err_t esp_vfs_l2tap_intf_unregister(const char *base_path)

Removes L2 TAP virtual filesystem driver.

Parameters

base_path -- Base path to the L2 TAP virtual filesystem driver. Default path /dev/net/tap is used when this paramenter is NULL.

Returns

esp_err_t

ESP_OK on success

esp_err_t esp_vfs_l2tap_eth_filter(l2tap_iodriver_handle driver_handle, void *buff, size_t *size)

Filters received Ethernet L2 frames into L2 TAP infrastructure.

Parameters

driver_handle -- handle of driver at which the frame was received
buff -- received L2 frame
size -- input length of the L2 frame which is set to 0 when frame is filtered into L2 TAP

Returns

esp_err_t

ESP_OK is always returned

Structures

struct l2tap_vfs_config_t

L2Tap VFS config parameters.

Public Members

const char *base_path: vfs base path

Macros

L2TAP_VFS_DEFAULT_PATH

L2TAP_VFS_CONFIG_DEFAULT()

Type Definitions

typedef void *l2tap_iodriver_handle

Enumerations

enum l2tap_ioctl_opt_t

Values:

enumerator L2TAP_S_RCV_FILTER

enumerator L2TAP_G_RCV_FILTER

enumerator L2TAP_S_INTF_DEVICE

enumerator L2TAP_G_INTF_DEVICE

enumerator L2TAP_S_DEVICE_DRV_HNDL

enumerator L2TAP_G_DEVICE_DRV_HNDL

Wi-Fi Default API Reference

Header File

components/esp_wifi/include/esp_wifi_default.h
This header file can be included with:
#include "esp_wifi_default.h"
This header file is a part of the API provided by the esp_wifi component. To declare that your component depends on esp_wifi, add the following to your CMakeLists.txt:
REQUIRES esp_wifi
or
PRIV_REQUIRES esp_wifi

Functions

esp_err_t esp_netif_attach_wifi_station(esp_netif_t *esp_netif)

Attaches wifi station interface to supplied netif.

Parameters

esp_netif -- instance to attach the wifi station to

Returns

ESP_OK on success
ESP_FAIL if attach failed

esp_err_t esp_netif_attach_wifi_ap(esp_netif_t *esp_netif)

Attaches wifi soft AP interface to supplied netif.

Parameters

esp_netif -- instance to attach the wifi AP to

Returns

ESP_OK on success
ESP_FAIL if attach failed

esp_err_t esp_wifi_set_default_wifi_sta_handlers(void)

Sets default wifi event handlers for STA interface.

Returns

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.

Returns

ESP_OK on success, error returned from esp_event_handler_register if failed

esp_err_t esp_wifi_set_default_wifi_nan_handlers(void)

Sets default wifi event handlers for NAN interface.

Returns

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.

Parameters

esp_netif -- instance of corresponding if object

Returns

ESP_OK on success, error returned from esp_event_handler_register if failed

esp_netif_t *esp_netif_create_default_wifi_ap(void)

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

Note

The API creates esp_netif object with default WiFi access point config, attaches the netif to wifi and registers wifi handlers to the default event loop. This API uses assert() to check for potential errors, so it could abort the program. (Note that the default event loop needs to be created prior to calling this API)

Returns: 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.

Note

The API creates esp_netif object with default WiFi station config, attaches the netif to wifi and registers wifi handlers to the default event loop. This API uses assert() to check for potential errors, so it could abort the program. (Note that the default event loop needs to be created prior to calling this API)

Returns: pointer to esp-netif instance

esp_netif_t *esp_netif_create_default_wifi_nan(void)

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

Note

The API creates esp_netif object with default WiFi station config, attaches the netif to wifi and registers wifi handlers to the default event loop. (Note that the default event loop needs to be created prior to calling this API)

Returns: pointer to esp-netif instance

void esp_netif_destroy_default_wifi(void *esp_netif)

Destroys default WIFI netif created with esp_netif_create_default_wifi_...() API.

Note

This API unregisters wifi handlers and detaches the created object from the wifi. (this function is a no-operation if esp_netif is NULL)

Parameters: esp_netif -- [in] object to detach from WiFi and destroy

esp_netif_t *esp_netif_create_wifi(wifi_interface_t wifi_if, const 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!

Parameters

wifi_if -- [in] type of wifi interface
esp_netif_config -- [in] inherent esp-netif configuration pointer

Returns

pointer to esp-netif instance

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.

Parameters

p_netif_sta -- [out] pointer where the resultant STA interface is saved (if non NULL)
p_netif_ap -- [out] pointer where the resultant AP interface is saved (if non NULL)

Returns

ESP_OK on success

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ESP-NETIF Programmers Manual

Configure IP, Gateway, and DNS

Configure DHCP options

SNTP Service

Basic Mode with Statically Defined Server(s)

Use DHCP-Obtained SNTP Server(s)

Use Both Static and Dynamic Servers

L2 TAP Interface Usage

Initialization

open()

ioctl()

fcntl()

read()

write()

close()

select()

IP Event: Transmit/Receive Packet

Enabling the Event

Event Registration

Event Data Structure

API Reference

Header File

Functions

Type Definitions

Header File

Functions

Structures

Macros

Type Definitions

Header File

Structures

Macros

Type Definitions

Enumerations

Header File

Functions

Structures

Macros

Type Definitions

Enumerations

Header File

Functions

Structures

Macros

Type Definitions

Enumerations

Wi-Fi Default API Reference

Header File

Functions

`open()`

`ioctl()`

`fcntl()`

`read()`

`write()`

`close()`

`select()`