#include "wifi_hal.h"
#ifndef __WIFI_HAL_GSCAN_H__
#define __WIFI_HAL_GSCAN_H__
/* AP Scans */
typedef enum {
WIFI_BAND_UNSPECIFIED,
WIFI_BAND_BG = 1, // 2.4 GHz
WIFI_BAND_A = 2, // 5 GHz without DFS
WIFI_BAND_A_DFS = 4, // 5 GHz DFS only
WIFI_BAND_A_WITH_DFS = 6, // 5 GHz with DFS
WIFI_BAND_ABG = 3, // 2.4 GHz + 5 GHz; no DFS
WIFI_BAND_ABG_WITH_DFS = 7, // 2.4 GHz + 5 GHz with DFS
} wifi_band;
const unsigned MAX_CHANNELS = 16;
const unsigned MAX_BUCKETS = 16;
const unsigned MAX_HOTLIST_APS = 128;
const unsigned MAX_SIGNIFICANT_CHANGE_APS = 64;
const unsigned MAX_PNO_SSID = 64;
const unsigned MAX_HOTLIST_SSID = 8;
const unsigned MAX_BLACKLIST_BSSID = 16;
const unsigned MAX_AP_CACHE_PER_SCAN = 32;
wifi_error wifi_get_valid_channels(wifi_interface_handle handle,
int band, int max_channels, wifi_channel *channels, int *num_channels);
typedef struct {
int max_scan_cache_size; // total space allocated for scan (in bytes)
int max_scan_buckets; // maximum number of channel buckets
int max_ap_cache_per_scan; // maximum number of APs that can be stored per scan
int max_rssi_sample_size; // number of RSSI samples used for averaging RSSI
int max_scan_reporting_threshold; // max possible report_threshold as described
// in wifi_scan_cmd_params
int max_hotlist_bssids; // maximum number of entries for hotlist BSSIDs
int max_hotlist_ssids; // maximum number of entries for hotlist SSIDs
int max_significant_wifi_change_aps; // maximum number of entries for
// significant wifi change APs
int max_bssid_history_entries; // number of BSSID/RSSI entries that device can hold
int max_number_epno_networks; // max number of epno entries
int max_number_epno_networks_by_ssid; // max number of epno entries if ssid is specified,
// that is, epno entries for which an exact match is
// required, or entries corresponding to hidden ssids
int max_number_of_white_listed_ssid; // max number of white listed SSIDs, M target is 2 to 4
} wifi_gscan_capabilities;
wifi_error wifi_get_gscan_capabilities(wifi_interface_handle handle,
wifi_gscan_capabilities *capabilities);
typedef enum {
WIFI_SCAN_BUFFER_FULL,
WIFI_SCAN_COMPLETE,
} wifi_scan_event;
/* Format of information elements found in the beacon */
typedef struct {
byte id; // element identifier
byte len; // number of bytes to follow
byte data[];
} wifi_information_element;
typedef struct {
wifi_timestamp ts; // time since boot (in microsecond) when the result was
// retrieved
char ssid[32+1]; // null terminated
mac_addr bssid;
wifi_channel channel; // channel frequency in MHz
wifi_rssi rssi; // in db
wifi_timespan rtt; // in nanoseconds
wifi_timespan rtt_sd; // standard deviation in rtt
unsigned short beacon_period; // period advertised in the beacon
unsigned short capability; // capabilities advertised in the beacon
unsigned int ie_length; // size of the ie_data blob
char ie_data[1]; // blob of all the information elements found in the
// beacon; this data should be a packed list of
// wifi_information_element objects, one after the other.
// other fields
} wifi_scan_result;
typedef struct {
/* reported when report_threshold is reached in scan cache */
void (*on_scan_results_available) (wifi_request_id id, unsigned num_results_available);
/* reported when each probe response is received, if report_events
* enabled in wifi_scan_cmd_params */
void (*on_full_scan_result) (wifi_request_id id, wifi_scan_result *result);
/* optional event - indicates progress of scanning statemachine */
void (*on_scan_event) (wifi_scan_event event, unsigned status);
} wifi_scan_result_handler;
typedef struct {
wifi_channel channel; // frequency
int dwellTimeMs; // dwell time hint
int passive; // 0 => active, 1 => passive scan; ignored for DFS
/* Add channel class */
} wifi_scan_channel_spec;
#define REPORT_EVENTS_BUFFER_FULL 0
#define REPORT_EVENTS_EACH_SCAN 1
#define REPORT_EVENTS_FULL_RESULTS 2
#define REPORT_EVENTS_NO_BATCH 4
typedef struct {
int bucket; // bucket index, 0 based
wifi_band band; // when UNSPECIFIED, use channel list
int period; // desired period, in millisecond; if this is too
// low, the firmware should choose to generate results as
// fast as it can instead of failing the command.
// for exponential backoff bucket this is the min_period
/* report_events semantics -
* This is a bit field; which defines following bits -
* REPORT_EVENTS_BUFFER_FULL => report only when scan history is % full
* REPORT_EVENTS_EACH_SCAN => report a scan completion event after scan
* REPORT_EVENTS_FULL_RESULTS => forward scan results (beacons/probe responses + IEs)
* in real time to HAL, in addition to completion events
* Note: To keep backward compatibility, fire completion
* events regardless of REPORT_EVENTS_EACH_SCAN.
* REPORT_EVENTS_NO_BATCH => controls batching, 0 => batching, 1 => no batching
*/
byte report_events;
int max_period; // if max_period is non zero or different than period, then this bucket is
// an exponential backoff bucket and the scan period will grow exponentially
// as per formula: actual_period(N) = period ^ (N/(step_count+1))
// to a maximum period of max_period
int exponent; // for exponential back off bucket: multiplier: new_period=old_period*exponent
int step_count; // for exponential back off bucket, number of scans performed at a given
// period and until the exponent is applied
int num_channels;
// channels to scan; these may include DFS channels
// Note that a given channel may appear in multiple buckets
wifi_scan_channel_spec channels[MAX_CHANNELS];
} wifi_scan_bucket_spec;
typedef struct {
int base_period; // base timer period in ms
int max_ap_per_scan; // number of APs to store in each scan ientryn the
// BSSID/RSSI history buffer (keep the highest RSSI APs)
int report_threshold_percent; // in %, when scan buffer is this much full, wake up AP
int report_threshold_num_scans; // in number of scans, wake up AP after these many scans
int num_buckets;
wifi_scan_bucket_spec buckets[MAX_BUCKETS];
} wifi_scan_cmd_params;
/* Start periodic GSCAN */
wifi_error wifi_start_gscan(wifi_request_id id, wifi_interface_handle iface,
wifi_scan_cmd_params params, wifi_scan_result_handler handler);
/* Stop periodic GSCAN */
wifi_error wifi_stop_gscan(wifi_request_id id, wifi_interface_handle iface);
typedef enum {
WIFI_SCAN_FLAG_INTERRUPTED = 1 // Indicates that scan results are not complete because
// probes were not sent on some channels
} wifi_scan_flags;
/* Get the GSCAN cached scan results */
typedef struct {
int scan_id; // a unique identifier for the scan unit
int flags; // a bitmask with additional
// information about scan
int num_results; // number of bssids retrieved by the scan
wifi_scan_result results[MAX_AP_CACHE_PER_SCAN]; // scan results - one for each bssid
} wifi_cached_scan_results;
wifi_error wifi_get_cached_gscan_results(wifi_interface_handle iface, byte flush,
int max, wifi_cached_scan_results *results, int *num);
/* BSSID Hotlist */
typedef struct {
void (*on_hotlist_ap_found)(wifi_request_id id,
unsigned num_results, wifi_scan_result *results);
void (*on_hotlist_ap_lost)(wifi_request_id id,
unsigned num_results, wifi_scan_result *results);
} wifi_hotlist_ap_found_handler;
typedef struct {
mac_addr bssid; // AP BSSID
wifi_rssi low; // low threshold
wifi_rssi high; // high threshold
} ap_threshold_param;
typedef struct {
int lost_ap_sample_size;
int num_bssid; // number of hotlist APs
ap_threshold_param ap[MAX_HOTLIST_APS]; // hotlist APs
} wifi_bssid_hotlist_params;
/* Set the BSSID Hotlist */
wifi_error wifi_set_bssid_hotlist(wifi_request_id id, wifi_interface_handle iface,
wifi_bssid_hotlist_params params, wifi_hotlist_ap_found_handler handler);
/* Clear the BSSID Hotlist */
wifi_error wifi_reset_bssid_hotlist(wifi_request_id id, wifi_interface_handle iface);
/* SSID Hotlist */
typedef struct {
void (*on_hotlist_ssid_found)(wifi_request_id id,
unsigned num_results, wifi_scan_result *results);
void (*on_hotlist_ssid_lost)(wifi_request_id id,
unsigned num_results, wifi_scan_result *results);
} wifi_hotlist_ssid_handler;
typedef struct {
char ssid[32+1]; // SSID
wifi_band band; // band for this set of threshold params
wifi_rssi low; // low threshold
wifi_rssi high; // high threshold
} ssid_threshold_param;
typedef struct {
int lost_ssid_sample_size;
int num_ssid; // number of hotlist SSIDs
ssid_threshold_param ssid[MAX_HOTLIST_SSID]; // hotlist SSIDs
} wifi_ssid_hotlist_params;
/* Set the SSID Hotlist */
wifi_error wifi_set_ssid_hotlist(wifi_request_id id, wifi_interface_handle iface,
wifi_ssid_hotlist_params params, wifi_hotlist_ssid_handler handler);
/* Clear the SSID Hotlist */
wifi_error wifi_reset_ssid_hotlist(wifi_request_id id, wifi_interface_handle iface);
/* BSSID blacklist */
typedef struct {
int num_bssid; // number of blacklisted BSSIDs
mac_addr bssids[MAX_BLACKLIST_BSSID]; // blacklisted BSSIDs
} wifi_bssid_params;
/* Set the BSSID blacklist */
wifi_error wifi_set_bssid_blacklist(wifi_request_id id, wifi_interface_handle iface,
wifi_bssid_params params);
/* Significant wifi change */
typedef struct {
mac_addr bssid; // BSSID
wifi_channel channel; // channel frequency in MHz
int num_rssi; // number of rssi samples
wifi_rssi rssi[]; // RSSI history in db
} wifi_significant_change_result;
typedef struct {
void (*on_significant_change)(wifi_request_id id,
unsigned num_results, wifi_significant_change_result **results);
} wifi_significant_change_handler;
// The sample size parameters in the wifi_significant_change_params structure
// represent the number of occurence of a g-scan where the BSSID was seen and RSSI was
// collected for that BSSID, or, the BSSID was expected to be seen and didn't.
// for instance: lost_ap_sample_size : number of time a g-scan was performed on the
// channel the BSSID was seen last, and the BSSID was not seen during those g-scans
typedef struct {
int rssi_sample_size; // number of samples for averaging RSSI
int lost_ap_sample_size; // number of samples to confirm AP loss
int min_breaching; // number of APs breaching threshold
int num_bssid; // max 64
ap_threshold_param ap[MAX_SIGNIFICANT_CHANGE_APS];
} wifi_significant_change_params;
/* Set the Signifcant AP change list */
wifi_error wifi_set_significant_change_handler(wifi_request_id id, wifi_interface_handle iface,
wifi_significant_change_params params, wifi_significant_change_handler handler);
/* Clear the Signifcant AP change list */
wifi_error wifi_reset_significant_change_handler(wifi_request_id id, wifi_interface_handle iface);
/* Random MAC OUI for PNO */
wifi_error wifi_set_scanning_mac_oui(wifi_interface_handle handle, oui scan_oui);
// Whether directed scan needs to be performed (for hidden SSIDs)
#define WIFI_PNO_FLAG_DIRECTED_SCAN = 1
// Whether PNO event shall be triggered if the network is found on A band
#define WIFI_PNO_FLAG_A_BAND = 2
// Whether PNO event shall be triggered if the network is found on G band
#define WIFI_PNO_FLAG_G_BAND = 4
// Whether strict matching is required (i.e. firmware shall not match on the entire SSID)
#define WIFI_PNO_FLAG_STRICT_MATCH = 8
// Code for matching the beacon AUTH IE - additional codes TBD
#define WIFI_PNO_AUTH_CODE_OPEN 1 // open
#define WIFI_PNO_AUTH_CODE_PSK 2 // WPA_PSK or WPA2PSK
#define WIFI_PNO_AUTH_CODE_EAPOL 4 // any EAPOL
// Enhanced PNO:
// Enhanced PNO feature is expected to be enabled all of the time (e.g. screen lit) and may thus
// requires firmware to store a large number of networks, covering the whole list of known network.
// Therefore, it is acceptable for firmware to store a crc24, crc32 or other short hash of the SSID,
// such that a low but non-zero probability of collision exist. With that scheme it should be
// possible for firmware to keep an entry as small as 4 bytes for each pno network.
// For instance, a firmware pn0 entry can be implemented in the form of:
// PNO ENTRY = crc24(3 bytes) | RSSI_THRESHOLD>>3 (5 bits) | auth flags(3 bits)
//
// A PNO network shall be reported once, that is, once a network is reported by firmware
// its entry shall be marked as "done" until framework calls wifi_set_epno_list again.
// Calling wifi_set_epno_list shall reset the "done" status of pno networks in firmware.
typedef struct {
char ssid[32+1];
byte rssi_threshold; // threshold for considering this SSID as found, required granularity for
// this threshold is 4dBm to 8dBm
byte flags; // WIFI_PNO_FLAG_XXX
byte auth_bit_field; // auth bit field for matching WPA IE
} wifi_epno_network;
/* PNO list */
typedef struct {
int num_networks; // number of SSIDs
wifi_epno_network networks[]; // PNO networks
} wifi_epno_params;
typedef struct {
// on results
void (*on_network_found)(wifi_request_id id,
unsigned num_results, wifi_scan_result *results);
} wifi_epno_handler;
/* Set the PNO list */
wifi_error wifi_set_epno_list(wifi_request_id id, wifi_interface_handle iface,
int num_networks, wifi_epno_network *networks, wifi_epno_handler handler);
/* SSID white list */
/* Note that this feature requires firmware to be able to indicate to kernel sme and wpa_supplicant
* that the SSID of the network has changed
* and thus requires further changed in cfg80211 stack, for instance,
* the below function would change:
void __cfg80211_roamed(struct wireless_dev *wdev,
struct cfg80211_bss *bss,
const u8 *req_ie, size_t req_ie_len,
const u8 *resp_ie, size_t resp_ie_len)
* when firmware roam to a new SSID the corresponding link layer stats info need to be updated:
struct wifi_interface_link_layer_info;
*/
typedef struct {
char ssid[32+1]; // null terminated
} wifi_ssid;
wifi_error wifi_set_ssid_white_list(wifi_request_id id, wifi_interface_handle iface,
int num_networks, wifi_ssid *ssids);
/* Set G-SCAN roam parameters */
/**
* Firmware roaming is implemented with two modes:
* 1- "Alert" mode roaming, (Note: alert roaming is the pre-L roaming, whereas firmware is
* "urgently" hunting for another BSSID because the RSSI is low, or because many successive
* beacons have been lost or other bad link conditions).
* 2- "Lazy" mode, where firmware is hunting for a better BSSID or white listed SSID even though
* the RSSI of the link is good.
* Lazy mode is configured thru G-scan, that is, the results of G-scans are compared to the
* current RSSI and fed thru the roaming engine.
* Lazy scan will be enabled (and or throttled down by reducing the number of G-scans) by
* framework only in certain conditions, such as:
* - no real time (VO/VI) traffic at the interface
* - low packet rate for BE/BK packets a the interface
* - system conditions (screen lit/dark) etc...
*
* For consistency, the roam parameters will always be configured by framework such that:
*
* condition 1- A_band_boost_threshold >= (alert_roam_rssi_trigger + 10)
* This condition ensures that Lazy roam doesn't cause the device to roam to a 5GHz BSSID whose RSSI
* is lower than the alert threshold, which would consequently trigger a roam to a low RSSI BSSID,
* hence triggering alert mode roaming.
* In other words, in alert mode, the A_band parameters may safely be ignored by WiFi chipset.
*
* condition 2- A_band_boost_threshold > A_band_penalty_factor
*
*/
/**
* Example:
* A_band_boost_threshold = -65
* A_band_penalty_threshold = -75
* A_band_boost_factor = 4
* A_band_penalty_factor = 2
* A_band_max_boost = 50
*
* a 5GHz RSSI value is transformed as below:
* -20 -> -20+ 50 = 30
* -60 -> -60 + 4 * (-60 - A_band_boost_threshold) = -60 + 16 = -44
* -70 -> -70
* -80 -> -80 - 2 * (A_band_penalty_threshold - (-80)) = -80 - 10 = -90
*/
typedef struct {
// Lazy roam parameters
// A_band_XX parameters are applied to 5GHz BSSIDs when comparing with a 2.4GHz BSSID
// they may not be applied when comparing two 5GHz BSSIDs
int A_band_boost_threshold; // RSSI threshold above which 5GHz RSSI is favored
int A_band_penalty_threshold; // RSSI threshold below which 5GHz RSSI is penalized
int A_band_boost_factor; // factor by which 5GHz RSSI is boosted
// boost=RSSI_measured-5GHz_boost_threshold)*5GHz_boost_factor
int A_band_penalty_factor; // factor by which 5GHz RSSI is penalized
// penalty=(5GHz_penalty_factor-RSSI_measured)*5GHz_penalty_factor
int A_band_max_boost; // maximum boost that can be applied to a 5GHz RSSI
// Hysteresis: ensuring the currently associated BSSID is favored
// so as to prevent ping-pong situations
int lazy_roam_hysteresis; // boost applied to current BSSID
// Alert mode enable, i.e. configuring when firmware enters alert mode
int alert_roam_rssi_trigger; // RSSI below which "Alert" roam is enabled
} wifi_roam_params;
wifi_error wifi_set_gscan_roam_params(wifi_request_id id, wifi_interface_handle iface,
wifi_roam_params * params);
/**
* Enable/Disable "Lazy" roam
*/
wifi_error wifi_enable_lazy_roam(wifi_request_id id, wifi_interface_handle iface, int enable);
/**
* Per BSSID preference
*/
typedef struct {
mac_addr bssid;
int rssi_modifier; // modifier applied to the RSSI of the BSSID for the purpose of comparing
// it with other roam candidate
} wifi_bssid_preference;
wifi_error wifi_set_bssid_preference(wifi_request_id id, wifi_interface_handle iface,
int num_bssid, wifi_bssid_preference *prefs);
typedef struct {
int id; // identifier of this network block, report this in event
char realm[256]; // null terminated UTF8 encoded realm, 0 if unspecified
int64_t roamingConsortiumIds[16]; // roaming consortium ids to match, 0s if unspecified
byte plmn[3]; // mcc/mnc combination as per rules, 0s if unspecified
} wifi_passpoint_network;
typedef struct {
void (*on_passpoint_network_found)(
wifi_request_id id,
int net_id, // network block identifier for the matched network
wifi_scan_result *result, // scan result, with channel and beacon information
int anqp_len, // length of ANQP blob
byte *anqp // ANQP data, in the information_element format
);
} wifi_passpoint_event_handler;
/* Sets a list for passpoint networks for PNO purposes; it should be matched
* against any passpoint networks (designated by Interworking element) found
* during regular PNO scan. */
wifi_error wifi_set_passpoint_list(wifi_request_id id, wifi_interface_handle iface, int num,
wifi_passpoint_network *networks, wifi_passpoint_event_handler handler);
/* Reset passpoint network list - no Passpoint networks should be matched after this */
wifi_error wifi_reset_passpoint_list(wifi_request_id id, wifi_interface_handle iface);
#endif