Wi-Fi AwareTM (NAN)
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
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 onesp_wifi
, add the following to your CMakeLists.txt:REQUIRES esp_wifi
or
PRIV_REQUIRES esp_wifi
Functions
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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
-
uint8_t peer_svc_id
Macros
-
WIFI_NAN_CONFIG_DEFAULT()
-
NDP_STATUS_ACCEPTED
-
NDP_STATUS_REJECTED
-
NAN_MAX_PEERS_RECORD
-
ESP_NAN_PUBLISH
-
ESP_NAN_SUBSCRIBE