#include "wifi_hal.h"
#ifndef __WIFI_HAL_GSCAN_H__
#define __WIFI_HAL_GSCAN_H__
// Define static_assert() unless already defined by compiler.
#ifndef __has_feature
#define __has_feature(__x) 0
#endif
#if !(__has_feature(cxx_static_assert)) && !defined(static_assert)
#define static_assert(__b, __m) \
extern int compile_time_assert_failed[ ( __b ) ? 1 : -1 ] \
__attribute__( ( unused ) );
#endif
/* 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;
#define MAX_CHANNELS 16
#define MAX_BUCKETS 16
#define MAX_HOTLIST_APS 128
#define MAX_SIGNIFICANT_CHANGE_APS 64
#define MAX_EPNO_NETWORKS 64
#define MAX_HOTLIST_SSID 8
#define 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_RESULTS_AVAILABLE, // reported when REPORT_EVENTS_EACH_SCAN is set and a scan
// completes. WIFI_SCAN_THRESHOLD_NUM_SCANS or
// WIFI_SCAN_THRESHOLD_PERCENT can be reported instead if the
// reason for the event is available; however, at most one of
// these events should be reported per scan. If there are
// multiple buckets that were scanned this period and one has the
// EACH_SCAN flag set then this event should be prefered.
WIFI_SCAN_THRESHOLD_NUM_SCANS, // can be reported when REPORT_EVENTS_EACH_SCAN is not set and
// report_threshold_num_scans is reached.
WIFI_SCAN_THRESHOLD_PERCENT, // can be reported when REPORT_EVENTS_EACH_SCAN is not set and
// report_threshold_percent is reached.
WIFI_SCAN_FAILED, // reported when currently executing gscans have failed.
// start_gscan will need to be called again in order to continue
// scanning. This is intended to indicate abnormal scan
// terminations (not those as a result of stop_gscan).
} 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;
static_assert(MAX_BUCKETS <= 8 * sizeof(unsigned),
"The buckets_scanned bitset is represented by an unsigned int and cannot support this many "
"buckets on this platform.");
typedef struct {
/* reported when each probe response is received, if report_events
* enabled in wifi_scan_cmd_params. buckets_scanned is a bitset of the
* buckets that are currently being scanned. See the buckets_scanned field
* in the wifi_cached_scan_results struct for more details.
*/
void (*on_full_scan_result) (wifi_request_id id, wifi_scan_result *result,
unsigned buckets_scanned);
/* indicates progress of scanning statemachine */
void (*on_scan_event) (wifi_request_id id, wifi_scan_event event);
} 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_EACH_SCAN (1 << 0)
#define REPORT_EVENTS_FULL_RESULTS (1 << 1)
#define REPORT_EVENTS_NO_BATCH (1 << 2)
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_EACH_SCAN => report a scan completion event after scan. If this is not set
* then scan completion events should be reported if
* report_threshold_percent or report_threshold_num_scans is
* reached.
* 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 if scans for this bucket should be placed in the
* history buffer
*/
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 * (base ^ (N/step_count))
// to a maximum period of max_period
int base; // for exponential back off bucket: multiplier: new_period=old_period*base
int step_count; // for exponential back off bucket, number of scans to perform for a given
// period
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 access points to store in each scan entry in
// the BSSID/RSSI history buffer (keep the highest RSSI
// access points)
int report_threshold_percent; // in %, when scan buffer is this much full, wake up apps
// processor
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
* When this is called all requested buckets should be scanned, starting the beginning of the cycle
*
* For example:
* If there are two buckets specified
* - Bucket 1: period=10s
* - Bucket 2: period=20s
* - Bucket 3: period=30s
* Then the following scans should occur
* - t=0 buckets 1, 2, and 3 are scanned
* - t=10 bucket 1 is scanned
* - t=20 bucket 1 and 2 are scanned
* - t=30 bucket 1 and 3 are scanned
* - t=40 bucket 1 and 2 are scanned
* - t=50 bucket 1 is scanned
* - t=60 buckets 1, 2, and 3 are scanned
* - and the patter repeats
*
* If any scan does not occur or is incomplete (error, interrupted, etc) then a cached scan result
* should still be recorded with the WIFI_SCAN_FLAG_INTERRUPTED flag set.
*/
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.
unsigned buckets_scanned; // a bitset of the buckets that were scanned.
// for example a value of 13 (0b1101) would
// indicate that buckets 0, 2 and 3 were
// scanned to produce this list of results.
// should be set to 0 if this information is
// not available.
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;
/* 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);
// Enhanced PNO:
// Enhanced PNO feature is expected to be enabled all of the time (e.g. screen lit) and may thus
// require firmware to store a large number of networks, covering the whole list of known networks.
// 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) | flags>>3 (5 bits) | auth flags(3 bits)
//
// No scans should be automatically performed by the chip. Instead all scan results from gscan
// should be scored and the wifi_epno_handler on_network_found callback should be called with
// the scan results.
//
// 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.
//
// A network should only be considered found if its RSSI is above the minimum RSSI for its
// frequency range (min5GHz_rssi and min24GHz_rssi for 5GHz and 2.4GHz networks respectively).
// When disconnected the list of scan results should be returned if any network is found.
// When connected the scan results shall be reported only if the score of any network in the scan
// is greater than that of the currently connected BSSID.
//
// The FW should calculate the score of all the candidates (including currently connected one)
// with following equation:
// RSSI score = (RSSI + 85) * 4;
// If RSSI score > initial_score_max , RSSI score = initial_score_max;
// final score = RSSI score
// + current_connection_bonus (if currently connected BSSID)
// + same_network_bonus (if network has SAME_NETWORK flag)
// + secure_bonus (if the network is not open)
// + band5GHz_bonus (if BSSID is on 5G)
// If there is a BSSID’s score > current BSSID’s score, then report the cached scan results
// at the end of the scan (excluding the ones on blacklist) to the upper layer.
// Additionally, all BSSIDs that are in the BSSID blacklist should be ignored by Enhanced PNO
// Whether directed scan needs to be performed (for hidden SSIDs)
#define WIFI_PNO_FLAG_DIRECTED_SCAN (1 << 0)
// Whether PNO event shall be triggered if the network is found on A band
#define WIFI_PNO_FLAG_A_BAND (1 << 1)
// Whether PNO event shall be triggered if the network is found on G band
#define WIFI_PNO_FLAG_G_BAND (1 << 2)
// Whether strict matching is required
// If required then the firmware must store the network's SSID and not just a hash
#define WIFI_PNO_FLAG_STRICT_MATCH (1 << 3)
// If this SSID should be considered the same network as the currently connected one for scoring
#define WIFI_PNO_FLAG_SAME_NETWORK (1 << 4)
// Code for matching the beacon AUTH IE - additional codes TBD
#define WIFI_PNO_AUTH_CODE_OPEN (1 << 0) // open
#define WIFI_PNO_AUTH_CODE_PSK (1 << 1) // WPA_PSK or WPA2PSK
#define WIFI_PNO_AUTH_CODE_EAPOL (1 << 2) // any EAPOL
typedef struct {
char ssid[32+1]; // null terminated
byte flags; // WIFI_PNO_FLAG_XXX
byte auth_bit_field; // auth bit field for matching WPA IE
} wifi_epno_network;
/* ePNO Parameters */
typedef struct {
int min5GHz_rssi; // minimum 5GHz RSSI for a BSSID to be considered
int min24GHz_rssi; // minimum 2.4GHz RSSI for a BSSID to be considered
int initial_score_max; // the maximum score that a network can have before bonuses
int current_connection_bonus; // only report when there is a network's score this much higher
// than the current connection.
int same_network_bonus; // score bonus for all networks with the same network flag
int secure_bonus; // score bonus for networks that are not open
int band5GHz_bonus; // 5GHz RSSI score bonus (applied to all 5GHz networks)
int num_networks; // number of wifi_epno_network objects
wifi_epno_network networks[MAX_EPNO_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 ePNO list - enable ePNO with the given parameters */
wifi_error wifi_set_epno_list(wifi_request_id id, wifi_interface_handle iface,
const wifi_epno_params *epno_params, wifi_epno_handler handler);
/* Reset the ePNO list - no ePNO networks should be matched after this */
wifi_error wifi_reset_epno_list(wifi_request_id id, wifi_interface_handle iface);
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