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      1 #include "wifi_hal.h"
      2 
      3 #ifndef __WIFI_HAL_GSCAN_H__
      4 #define __WIFI_HAL_GSCAN_H__
      5 
      6 // Define static_assert() unless already defined by compiler.
      7 #ifndef __has_feature
      8     #define __has_feature(__x) 0
      9 #endif
     10 #if !(__has_feature(cxx_static_assert)) && !defined(static_assert)
     11         #define static_assert(__b, __m) \
     12                 extern int compile_time_assert_failed[ ( __b ) ? 1 : -1 ]  \
     13                                                                    __attribute__( ( unused ) );
     14 #endif
     15 
     16 /* AP Scans */
     17 
     18 typedef enum {
     19     WIFI_BAND_UNSPECIFIED,
     20     WIFI_BAND_BG = 1,                       // 2.4 GHz
     21     WIFI_BAND_A = 2,                        // 5 GHz without DFS
     22     WIFI_BAND_A_DFS = 4,                    // 5 GHz DFS only
     23     WIFI_BAND_A_WITH_DFS = 6,               // 5 GHz with DFS
     24     WIFI_BAND_ABG = 3,                      // 2.4 GHz + 5 GHz; no DFS
     25     WIFI_BAND_ABG_WITH_DFS = 7,             // 2.4 GHz + 5 GHz with DFS
     26 } wifi_band;
     27 
     28 #define MAX_CHANNELS                16
     29 #define MAX_BUCKETS                 16
     30 #define MAX_HOTLIST_APS             128
     31 #define MAX_SIGNIFICANT_CHANGE_APS  64
     32 #define MAX_EPNO_NETWORKS           64
     33 #define MAX_HOTLIST_SSID            8
     34 #define MAX_AP_CACHE_PER_SCAN       32
     35 
     36 wifi_error wifi_get_valid_channels(wifi_interface_handle handle,
     37         int band, int max_channels, wifi_channel *channels, int *num_channels);
     38 
     39 typedef struct {
     40     int max_scan_cache_size;                 // total space allocated for scan (in bytes)
     41     int max_scan_buckets;                    // maximum number of channel buckets
     42     int max_ap_cache_per_scan;               // maximum number of APs that can be stored per scan
     43     int max_rssi_sample_size;                // number of RSSI samples used for averaging RSSI
     44     int max_scan_reporting_threshold;        // max possible report_threshold as described
     45                                              // in wifi_scan_cmd_params
     46     int max_hotlist_bssids;                  // maximum number of entries for hotlist BSSIDs
     47     int max_hotlist_ssids;                   // maximum number of entries for hotlist SSIDs
     48     int max_significant_wifi_change_aps;     // maximum number of entries for
     49                                              // significant wifi change APs
     50     int max_bssid_history_entries;           // number of BSSID/RSSI entries that device can hold
     51     int max_number_epno_networks;            // max number of epno entries
     52     int max_number_epno_networks_by_ssid;    // max number of epno entries if ssid is specified,
     53                                              // that is, epno entries for which an exact match is
     54                                              // required, or entries corresponding to hidden ssids
     55     int max_number_of_white_listed_ssid;     // max number of white listed SSIDs, M target is 2 to 4
     56 } wifi_gscan_capabilities;
     57 
     58 wifi_error wifi_get_gscan_capabilities(wifi_interface_handle handle,
     59         wifi_gscan_capabilities *capabilities);
     60 
     61 typedef enum {
     62     WIFI_SCAN_RESULTS_AVAILABLE,   // reported when REPORT_EVENTS_EACH_SCAN is set and a scan
     63                                    // completes. WIFI_SCAN_THRESHOLD_NUM_SCANS or
     64                                    // WIFI_SCAN_THRESHOLD_PERCENT can be reported instead if the
     65                                    // reason for the event is available; however, at most one of
     66                                    // these events should be reported per scan. If there are
     67                                    // multiple buckets that were scanned this period and one has the
     68                                    // EACH_SCAN flag set then this event should be prefered.
     69     WIFI_SCAN_THRESHOLD_NUM_SCANS, // can be reported when REPORT_EVENTS_EACH_SCAN is not set and
     70                                    // report_threshold_num_scans is reached.
     71     WIFI_SCAN_THRESHOLD_PERCENT,   // can be reported when REPORT_EVENTS_EACH_SCAN is not set and
     72                                    // report_threshold_percent is reached.
     73     WIFI_SCAN_FAILED,              // reported when currently executing gscans have failed.
     74                                    // start_gscan will need to be called again in order to continue
     75                                    // scanning. This is intended to indicate abnormal scan
     76                                    // terminations (not those as a result of stop_gscan).
     77 } wifi_scan_event;
     78 
     79 
     80 /* Format of information elements found in the beacon */
     81 typedef struct {
     82     byte id;                            // element identifier
     83     byte len;                           // number of bytes to follow
     84     byte data[];
     85 } wifi_information_element;
     86 
     87 typedef struct {
     88     wifi_timestamp ts;                  // time since boot (in microsecond) when the result was
     89                                         // retrieved
     90     char ssid[32+1];                    // null terminated
     91     mac_addr bssid;
     92     wifi_channel channel;               // channel frequency in MHz
     93     wifi_rssi rssi;                     // in db
     94     wifi_timespan rtt;                  // in nanoseconds
     95     wifi_timespan rtt_sd;               // standard deviation in rtt
     96     unsigned short beacon_period;       // period advertised in the beacon
     97     unsigned short capability;          // capabilities advertised in the beacon
     98     unsigned int ie_length;             // size of the ie_data blob
     99     char         ie_data[1];            // blob of all the information elements found in the
    100                                         // beacon; this data should be a packed list of
    101                                         // wifi_information_element objects, one after the other.
    102     // other fields
    103 } wifi_scan_result;
    104 
    105 static_assert(MAX_BUCKETS <= 8 * sizeof(unsigned),
    106         "The buckets_scanned bitset is represented by an unsigned int and cannot support this many "
    107         "buckets on this platform.");
    108 typedef struct {
    109     /* reported when each probe response is received, if report_events
    110      * enabled in wifi_scan_cmd_params. buckets_scanned is a bitset of the
    111      * buckets that are currently being scanned. See the buckets_scanned field
    112      * in the wifi_cached_scan_results struct for more details.
    113      */
    114     void (*on_full_scan_result) (wifi_request_id id, wifi_scan_result *result,
    115                                  unsigned buckets_scanned);
    116 
    117     /* indicates progress of scanning statemachine */
    118     void (*on_scan_event) (wifi_request_id id, wifi_scan_event event);
    119 
    120 } wifi_scan_result_handler;
    121 
    122 typedef struct {
    123     wifi_channel channel;               // frequency
    124     int dwellTimeMs;                    // dwell time hint
    125     int passive;                        // 0 => active, 1 => passive scan; ignored for DFS
    126     /* Add channel class */
    127 } wifi_scan_channel_spec;
    128 
    129 #define REPORT_EVENTS_EACH_SCAN        (1 << 0)
    130 #define REPORT_EVENTS_FULL_RESULTS     (1 << 1)
    131 #define REPORT_EVENTS_NO_BATCH         (1 << 2)
    132 
    133 typedef struct {
    134     int bucket;                         // bucket index, 0 based
    135     wifi_band band;                     // when UNSPECIFIED, use channel list
    136     int period;                         // desired period, in millisecond; if this is too
    137                                         // low, the firmware should choose to generate results as
    138                                         // fast as it can instead of failing the command.
    139                                         // for exponential backoff bucket this is the min_period
    140     /* report_events semantics -
    141      *  This is a bit field; which defines following bits -
    142      *  REPORT_EVENTS_EACH_SCAN    => report a scan completion event after scan. If this is not set
    143      *                                 then scan completion events should be reported if
    144      *                                 report_threshold_percent or report_threshold_num_scans is
    145      *                                 reached.
    146      *  REPORT_EVENTS_FULL_RESULTS => forward scan results (beacons/probe responses + IEs)
    147      *                                 in real time to HAL, in addition to completion events
    148      *                                 Note: To keep backward compatibility, fire completion
    149      *                                 events regardless of REPORT_EVENTS_EACH_SCAN.
    150      *  REPORT_EVENTS_NO_BATCH     => controls if scans for this bucket should be placed in the
    151      *                                 history buffer
    152      */
    153     byte report_events;
    154     int max_period; // if max_period is non zero or different than period, then this bucket is
    155                     // an exponential backoff bucket and the scan period will grow exponentially
    156                     // as per formula: actual_period(N) = period * (base ^ (N/step_count))
    157                     // to a maximum period of max_period
    158     int base;       // for exponential back off bucket: multiplier: new_period=old_period*base
    159     int step_count; // for exponential back off bucket, number of scans to perform for a given
    160                     // period
    161 
    162     int num_channels;
    163     // channels to scan; these may include DFS channels
    164     // Note that a given channel may appear in multiple buckets
    165     wifi_scan_channel_spec channels[MAX_CHANNELS];
    166 } wifi_scan_bucket_spec;
    167 
    168 typedef struct {
    169     int base_period;                    // base timer period in ms
    170     int max_ap_per_scan;                // number of access points to store in each scan entry in
    171                                         // the BSSID/RSSI history buffer (keep the highest RSSI
    172                                         // access points)
    173     int report_threshold_percent;       // in %, when scan buffer is this much full, wake up apps
    174                                         // processor
    175     int report_threshold_num_scans;     // in number of scans, wake up AP after these many scans
    176     int num_buckets;
    177     wifi_scan_bucket_spec buckets[MAX_BUCKETS];
    178 } wifi_scan_cmd_params;
    179 
    180 /*
    181  * Start periodic GSCAN
    182  * When this is called all requested buckets should be scanned, starting the beginning of the cycle
    183  *
    184  * For example:
    185  * If there are two buckets specified
    186  *  - Bucket 1: period=10s
    187  *  - Bucket 2: period=20s
    188  *  - Bucket 3: period=30s
    189  * Then the following scans should occur
    190  *  - t=0  buckets 1, 2, and 3 are scanned
    191  *  - t=10 bucket 1 is scanned
    192  *  - t=20 bucket 1 and 2 are scanned
    193  *  - t=30 bucket 1 and 3 are scanned
    194  *  - t=40 bucket 1 and 2 are scanned
    195  *  - t=50 bucket 1 is scanned
    196  *  - t=60 buckets 1, 2, and 3 are scanned
    197  *  - and the patter repeats
    198  *
    199  * If any scan does not occur or is incomplete (error, interrupted, etc) then a cached scan result
    200  * should still be recorded with the WIFI_SCAN_FLAG_INTERRUPTED flag set.
    201  */
    202 wifi_error wifi_start_gscan(wifi_request_id id, wifi_interface_handle iface,
    203         wifi_scan_cmd_params params, wifi_scan_result_handler handler);
    204 
    205 /* Stop periodic GSCAN */
    206 wifi_error wifi_stop_gscan(wifi_request_id id, wifi_interface_handle iface);
    207 
    208 typedef enum {
    209     WIFI_SCAN_FLAG_INTERRUPTED = 1      // Indicates that scan results are not complete because
    210                                         // probes were not sent on some channels
    211 } wifi_scan_flags;
    212 
    213 /* Get the GSCAN cached scan results */
    214 typedef struct {
    215     int scan_id;                                     // a unique identifier for the scan unit
    216     int flags;                                       // a bitmask with additional
    217                                                      // information about scan.
    218     unsigned buckets_scanned;                        // a bitset of the buckets that were scanned.
    219                                                      // for example a value of 13 (0b1101) would
    220                                                      // indicate that buckets 0, 2 and 3 were
    221                                                      // scanned to produce this list of results.
    222                                                      // should be set to 0 if this information is
    223                                                      // not available.
    224     int num_results;                                 // number of bssids retrieved by the scan
    225     wifi_scan_result results[MAX_AP_CACHE_PER_SCAN]; // scan results - one for each bssid
    226 } wifi_cached_scan_results;
    227 
    228 wifi_error wifi_get_cached_gscan_results(wifi_interface_handle iface, byte flush,
    229         int max, wifi_cached_scan_results *results, int *num);
    230 
    231 /* BSSID Hotlist */
    232 typedef struct {
    233     void (*on_hotlist_ap_found)(wifi_request_id id,
    234             unsigned num_results, wifi_scan_result *results);
    235     void (*on_hotlist_ap_lost)(wifi_request_id id,
    236             unsigned num_results, wifi_scan_result *results);
    237 } wifi_hotlist_ap_found_handler;
    238 
    239 typedef struct {
    240     mac_addr  bssid;                    // AP BSSID
    241     wifi_rssi low;                      // low threshold
    242     wifi_rssi high;                     // high threshold
    243 } ap_threshold_param;
    244 
    245 typedef struct {
    246     int lost_ap_sample_size;
    247     int num_bssid;                                 // number of hotlist APs
    248     ap_threshold_param ap[MAX_HOTLIST_APS];     // hotlist APs
    249 } wifi_bssid_hotlist_params;
    250 
    251 /* Set the BSSID Hotlist */
    252 wifi_error wifi_set_bssid_hotlist(wifi_request_id id, wifi_interface_handle iface,
    253         wifi_bssid_hotlist_params params, wifi_hotlist_ap_found_handler handler);
    254 
    255 /* Clear the BSSID Hotlist */
    256 wifi_error wifi_reset_bssid_hotlist(wifi_request_id id, wifi_interface_handle iface);
    257 
    258 /* SSID Hotlist */
    259 typedef struct {
    260     void (*on_hotlist_ssid_found)(wifi_request_id id,
    261             unsigned num_results, wifi_scan_result *results);
    262     void (*on_hotlist_ssid_lost)(wifi_request_id id,
    263             unsigned num_results, wifi_scan_result *results);
    264 } wifi_hotlist_ssid_handler;
    265 
    266 typedef struct {
    267     char  ssid[32+1];                   // SSID
    268     wifi_band band;                     // band for this set of threshold params
    269     wifi_rssi low;                      // low threshold
    270     wifi_rssi high;                     // high threshold
    271 } ssid_threshold_param;
    272 
    273 typedef struct {
    274     int lost_ssid_sample_size;
    275     int num_ssid;                                   // number of hotlist SSIDs
    276     ssid_threshold_param ssid[MAX_HOTLIST_SSID];    // hotlist SSIDs
    277 } wifi_ssid_hotlist_params;
    278 
    279 /* Significant wifi change */
    280 typedef struct {
    281     mac_addr bssid;                     // BSSID
    282     wifi_channel channel;               // channel frequency in MHz
    283     int num_rssi;                       // number of rssi samples
    284     wifi_rssi rssi[];                   // RSSI history in db
    285 } wifi_significant_change_result;
    286 
    287 typedef struct {
    288     void (*on_significant_change)(wifi_request_id id,
    289             unsigned num_results, wifi_significant_change_result **results);
    290 } wifi_significant_change_handler;
    291 
    292 // The sample size parameters in the wifi_significant_change_params structure
    293 // represent the number of occurence of a g-scan where the BSSID was seen and RSSI was
    294 // collected for that BSSID, or, the BSSID was expected to be seen and didn't.
    295 // for instance: lost_ap_sample_size : number of time a g-scan was performed on the
    296 // channel the BSSID was seen last, and the BSSID was not seen during those g-scans
    297 typedef struct {
    298     int rssi_sample_size;               // number of samples for averaging RSSI
    299     int lost_ap_sample_size;            // number of samples to confirm AP loss
    300     int min_breaching;                  // number of APs breaching threshold
    301     int num_bssid;                         // max 64
    302     ap_threshold_param ap[MAX_SIGNIFICANT_CHANGE_APS];
    303 } wifi_significant_change_params;
    304 
    305 /* Set the Signifcant AP change list */
    306 wifi_error wifi_set_significant_change_handler(wifi_request_id id, wifi_interface_handle iface,
    307         wifi_significant_change_params params, wifi_significant_change_handler handler);
    308 
    309 /* Clear the Signifcant AP change list */
    310 wifi_error wifi_reset_significant_change_handler(wifi_request_id id, wifi_interface_handle iface);
    311 
    312 /* Random MAC OUI for PNO */
    313 wifi_error wifi_set_scanning_mac_oui(wifi_interface_handle handle, oui scan_oui);
    314 
    315 
    316 // Enhanced PNO:
    317 // Enhanced PNO feature is expected to be enabled all of the time (e.g. screen lit) and may thus
    318 // require firmware to store a large number of networks, covering the whole list of known networks.
    319 // Therefore, it is acceptable for firmware to store a crc24, crc32 or other short hash of the SSID,
    320 // such that a low but non-zero probability of collision exist. With that scheme it should be
    321 // possible for firmware to keep an entry as small as 4 bytes for each pno network.
    322 // For instance, a firmware pn0 entry can be implemented in the form of:
    323 //          PNO ENTRY = crc24(3 bytes) | flags>>3 (5 bits) | auth flags(3 bits)
    324 //
    325 // No scans should be automatically performed by the chip. Instead all scan results from gscan
    326 // should be scored and the wifi_epno_handler on_network_found callback should be called with
    327 // the scan results.
    328 //
    329 // A PNO network shall be reported once, that is, once a network is reported by firmware
    330 // its entry shall be marked as "done" until framework calls wifi_set_epno_list again.
    331 // Calling wifi_set_epno_list shall reset the "done" status of pno networks in firmware.
    332 //
    333 // A network should only be considered found if its RSSI is above the minimum RSSI for its
    334 // frequency range (min5GHz_rssi and min24GHz_rssi for 5GHz and 2.4GHz networks respectively).
    335 // When disconnected the list of scan results should be returned if any network is found.
    336 // When connected the scan results shall be reported only if the score of any network in the scan
    337 // is greater than that of the currently connected BSSID.
    338 //
    339 // The FW should calculate the score of all the candidates (including currently connected one)
    340 //   with following equation:
    341 //     RSSI score = (RSSI + 85) * 4;
    342 //     If RSSI score > initial_score_max , RSSI score = initial_score_max;
    343 //     final score = RSSI score
    344 //         + current_connection_bonus (if currently connected BSSID)
    345 //         + same_network_bonus (if network has SAME_NETWORK flag)
    346 //         + secure_bonus (if the network is not open)
    347 //         + band5GHz_bonus (if BSSID is on 5G)
    348 //     If there is a BSSIDs score > current BSSIDs score, then report the cached scan results
    349 //         at the end of the scan (excluding the ones on blacklist) to the upper layer.
    350 // Additionally, all BSSIDs that are in the BSSID blacklist should be ignored by Enhanced PNO
    351 
    352 // Whether directed scan needs to be performed (for hidden SSIDs)
    353 #define WIFI_PNO_FLAG_DIRECTED_SCAN (1 << 0)
    354 // Whether PNO event shall be triggered if the network is found on A band
    355 #define WIFI_PNO_FLAG_A_BAND (1 << 1)
    356 // Whether PNO event shall be triggered if the network is found on G band
    357 #define WIFI_PNO_FLAG_G_BAND (1 << 2)
    358 // Whether strict matching is required
    359 // If required then the firmware must store the network's SSID and not just a hash
    360 #define WIFI_PNO_FLAG_STRICT_MATCH (1 << 3)
    361 // If this SSID should be considered the same network as the currently connected one for scoring
    362 #define WIFI_PNO_FLAG_SAME_NETWORK (1 << 4)
    363 
    364 // Code for matching the beacon AUTH IE - additional codes TBD
    365 #define WIFI_PNO_AUTH_CODE_OPEN  (1 << 0) // open
    366 #define WIFI_PNO_AUTH_CODE_PSK   (1 << 1) // WPA_PSK or WPA2PSK
    367 #define WIFI_PNO_AUTH_CODE_EAPOL (1 << 2) // any EAPOL
    368 
    369 typedef struct {
    370     char ssid[32+1];     // null terminated
    371     byte flags;          // WIFI_PNO_FLAG_XXX
    372     byte auth_bit_field; // auth bit field for matching WPA IE
    373 } wifi_epno_network;
    374 
    375 /* ePNO Parameters */
    376 typedef struct {
    377     int min5GHz_rssi;               // minimum 5GHz RSSI for a BSSID to be considered
    378     int min24GHz_rssi;              // minimum 2.4GHz RSSI for a BSSID to be considered
    379     int initial_score_max;          // the maximum score that a network can have before bonuses
    380     int current_connection_bonus;   // only report when there is a network's score this much higher
    381                                     // than the current connection.
    382     int same_network_bonus;         // score bonus for all networks with the same network flag
    383     int secure_bonus;               // score bonus for networks that are not open
    384     int band5GHz_bonus;             // 5GHz RSSI score bonus (applied to all 5GHz networks)
    385     int num_networks;               // number of wifi_epno_network objects
    386     wifi_epno_network networks[MAX_EPNO_NETWORKS];   // PNO networks
    387 } wifi_epno_params;
    388 
    389 typedef struct {
    390     // on results
    391     void (*on_network_found)(wifi_request_id id,
    392             unsigned num_results, wifi_scan_result *results);
    393 } wifi_epno_handler;
    394 
    395 
    396 /* Set the ePNO list - enable ePNO with the given parameters */
    397 wifi_error wifi_set_epno_list(wifi_request_id id, wifi_interface_handle iface,
    398         const wifi_epno_params *epno_params, wifi_epno_handler handler);
    399 
    400 /* Reset the ePNO list - no ePNO networks should be matched after this */
    401 wifi_error wifi_reset_epno_list(wifi_request_id id, wifi_interface_handle iface);
    402 
    403 
    404 typedef struct {
    405     int  id;                            // identifier of this network block, report this in event
    406     char realm[256];                    // null terminated UTF8 encoded realm, 0 if unspecified
    407     int64_t roamingConsortiumIds[16];   // roaming consortium ids to match, 0s if unspecified
    408     byte plmn[3];                       // mcc/mnc combination as per rules, 0s if unspecified
    409 } wifi_passpoint_network;
    410 
    411 typedef struct {
    412     void (*on_passpoint_network_found)(
    413             wifi_request_id id,
    414             int net_id,                        // network block identifier for the matched network
    415             wifi_scan_result *result,          // scan result, with channel and beacon information
    416             int anqp_len,                      // length of ANQP blob
    417             byte *anqp                         // ANQP data, in the information_element format
    418             );
    419 } wifi_passpoint_event_handler;
    420 
    421 /* Sets a list for passpoint networks for PNO purposes; it should be matched
    422  * against any passpoint networks (designated by Interworking element) found
    423  * during regular PNO scan. */
    424 wifi_error wifi_set_passpoint_list(wifi_request_id id, wifi_interface_handle iface, int num,
    425         wifi_passpoint_network *networks, wifi_passpoint_event_handler handler);
    426 
    427 /* Reset passpoint network list - no Passpoint networks should be matched after this */
    428 wifi_error wifi_reset_passpoint_list(wifi_request_id id, wifi_interface_handle iface);
    429 
    430 #endif
    431