Wi-Fi AwareTM (NAN)

[English]

Wi-Fi AwareTM，也可称为 NAN (Neighbor Awareness Networking) 协议，其支持 Wi-Fi 设备发现附近的其他服务。通常情况下，基于位置的服务需通过服务器查询环境信息，并通过 GPS 或其他位置推算技术获取定位。不过，NAN 无需与服务器、GPS 或其他地理位置服务保持实时连接，即可支持设备之间通过 Wi-Fi 直接连接来交换信息。NAN 能够在 Wi-Fi 密集的环境中高效扩展，并通过提供附近人员和服务的信息来完善 Wi-Fi 连接性。

多个邻近的 NAN 设备组成一个 NAN 集群，集群中的设备能够相互通信。NAN 设备还可通过 NAN 服务发现协议，通过发布或订阅功能，在所处集群内提供或查找服务。通过服务名称可以完成服务匹配，一旦找到匹配，设备就可以发送信息，或与匹配到的设备间建立 IPv6 数据路径。

ESP32 支持独立模式下的 Wi-Fi Aware，同时支持服务发现协议和数据路径。Wi-Fi Aware 协议仍在改进中，如需了解更多信息，请前往 Wi-Fi Alliance 官网的 Wi-Fi Aware 页面。大多数 Android 8 及更高版本的 Android 智能手机都支持 Wi-Fi Aware。如需了解更多信息，请参阅 Android 的开发者指南 Wi-Fi Aware。

应用示例

  • wifi/wifi_aware/nan_console 演示如何使用 NAN 协议发现附近的服务、建立数据路径，并在设备之间进行通信，无需互联网或 AP 连接。它提供了配置 NAN 服务、发布或订阅服务、发送消息以及启动或终止数据路径的控制台命令。

  • wifi/wifi_aware/nan_publisher 演示如何使用 NAN 协议发布服务，将服务广播给附近的其他设备，以及如何响应订阅该服务的设备。

  • wifi/wifi_aware/nan_subscriber 演示如何使用 NAN 协议发现附近发布所需服务的其他设备，并通过发送消息或启动数据路径与它们进行通信。

API 参考

Header File

  • components/esp_wifi/wifi_apps/nan_app/include/esp_nan.h

  • This header file can be included with:

    #include "esp_nan.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_wifi_nan_start(const wifi_nan_config_t *nan_cfg)

Start NAN Discovery with provided configuration.

Attention

This API should be called after esp_wifi_init().

参数:

nan_cfg -- NAN related parameters to be configured.

返回:

  • ESP_OK: succeed

  • others: failed

esp_err_t esp_wifi_nan_stop(void)

Stop NAN Discovery, end NAN Services and Datapaths.

返回:

  • ESP_OK: succeed

  • others: failed

uint8_t esp_wifi_nan_publish_service(const wifi_nan_publish_cfg_t *publish_cfg, bool ndp_resp_needed)

Start Publishing a service to the NAN Peers in vicinity.

Attention

This API should be called after esp_wifi_nan_start().

参数:

  • publish_cfg -- Configuration parameters for publishing a service.

  • ndp_resp_needed -- Setting this true will require user response for every NDP Req using esp_wifi_nan_datapath_resp API.

返回:

  • non-zero: Publish service identifier

  • zero: failed

uint8_t esp_wifi_nan_subscribe_service(const wifi_nan_subscribe_cfg_t *subscribe_cfg)

Subscribe for a service within the NAN cluster.

Attention

This API should be called after esp_wifi_nan_start().

参数:

subscribe_cfg -- Configuration parameters for subscribing for a service.

返回:

  • non-zero: Subscribe service identifier

  • zero: failed

esp_err_t esp_wifi_nan_send_message(wifi_nan_followup_params_t *fup_params)

Send a follow-up message to the NAN Peer with matched service.

Attention

This API should be called after a NAN service is discovered due to a match.

参数:

fup_params -- Configuration parameters for sending a Follow-up message.

返回:

  • ESP_OK: succeed

  • others: failed

esp_err_t esp_wifi_nan_cancel_service(uint8_t service_id)

Cancel a NAN service.

参数:

service_id -- Publish/Subscribe service id to be cancelled.

返回:

  • ESP_OK: succeed

  • others: failed

uint8_t esp_wifi_nan_datapath_req(wifi_nan_datapath_req_t *req)

Send NAN Datapath Request to a NAN Publisher with matched service.

Attention

This API should be called by the Subscriber after a match occurs with a Publisher.

参数:

req -- NAN Datapath Request parameters.

返回:

  • non-zero NAN Datapath identifier: If NAN datapath req was accepted by publisher

  • zero: If NAN datapath req was rejected by publisher or a timeout occurs

esp_err_t esp_wifi_nan_datapath_resp(wifi_nan_datapath_resp_t *resp)

Respond to a NAN Datapath request with Accept or Reject.

Attention

This API should be called if ndp_resp_needed is set True by the Publisher and a WIFI_EVENT_NDP_INDICATION event is received due to an incoming NDP request.

参数:

resp -- NAN Datapath Response parameters.

返回:

  • ESP_OK: succeed

  • others: failed

esp_err_t esp_wifi_nan_datapath_end(wifi_nan_datapath_end_req_t *req)

Terminate a NAN Datapath.

参数:

req -- NAN Datapath end request parameters.

返回:

  • ESP_OK: succeed

  • others: failed

void esp_wifi_nan_get_ipv6_linklocal_from_mac(ip6_addr_t *ip6, uint8_t *mac_addr)

Get IPv6 Link Local address using MAC address.

参数:

  • ip6 -- [out] Derived IPv6 Link Local address.

  • mac_addr -- [in] Input MAC Address.

esp_err_t esp_wifi_nan_get_own_svc_info(uint8_t *own_svc_id, char *svc_name, int *num_peer_records)

brief Get own Service information from Service ID OR Name.

Attention

If service information is to be fetched from service name, set own_svc_id as zero.

参数:

  • own_svc_id -- [inout] As input, it indicates Service ID to search for. As output, it indicates Service ID of the service found using Service Name.

  • svc_name -- [inout] As input, it indicates Service Name to search for. As output, it indicates Service Name of the service found using Service ID.

  • num_peer_records -- [out] Number of peers discovered by corresponding service.

返回:

  • ESP_OK: succeed

  • ESP_FAIL: failed

esp_err_t esp_wifi_nan_get_peer_records(int *num_peer_records, uint8_t own_svc_id, struct nan_peer_record *peer_record)

brief Get a list of Peers discovered by the given Service.

参数:

  • num_peer_records -- [inout] As input param, it stores max peers peer_record can hold. As output param, it specifies the actual number of peers this API returns.

  • own_svc_id -- Service ID of own service.

  • peer_record -- [out] Pointer to first peer record.

返回:

  • ESP_OK: succeed

  • ESP_FAIL: failed

esp_err_t esp_wifi_nan_get_peer_info(char *svc_name, uint8_t *peer_mac, struct nan_peer_record *peer_info)

brief Find Peer's Service information using Peer MAC and optionally Service Name.

参数:

  • svc_name -- Service Name of the published/subscribed service.

  • peer_mac -- Peer's NAN Management Interface MAC address.

  • peer_info -- [out] Peer's service information structure.

返回:

  • ESP_OK: succeed

  • ESP_FAIL: failed

Structures

struct nan_peer_record

Parameters of a peer service record

Public Members

uint8_t peer_svc_id

Identifier of Peer's service

uint8_t own_svc_id

Identifier of own service associated with Peer

uint8_t peer_nmi[6]

Peer's NAN Management Interface address

uint8_t peer_svc_type

Peer's service type (Publish/Subscribe)

uint8_t ndp_id

Specifies if the peer has any active datapath

uint8_t peer_ndi[6]

Peer's NAN Data Interface address, only valid when ndp_id is non-zero

Macros

WIFI_NAN_CONFIG_DEFAULT()
NDP_STATUS_ACCEPTED
NDP_STATUS_REJECTED
NAN_MAX_PEERS_RECORD
ESP_NAN_PUBLISH
ESP_NAN_SUBSCRIBE

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