wifi/1.0/IWifiStaIface.hal

/*
 * Copyright 2016 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.hardware.wifi@1.0;

import IWifiIface;
import IWifiStaIfaceEventCallback;

/**
 * Interface used to represent a single STA iface.
 */
interface IWifiStaIface extends IWifiIface {
  /**
   * Mask of capabilities suported by this Iface.
   */
  enum StaIfaceCapabilityMask : uint32_t {
    /**
     * If set indicates that the APF APIs are supported.
     * APF (Android Packet Filter) is a BPF like packet filtering
     * bytecode executed by the firmware.
     */
    APF = 1 << 0,
    /**
     * If set indicates that the Background Scan APIs are supported.
     * Background scan allow the host to send a number of buckets down to the
     * firmware. Each bucket contains a set of channels, a period, and some
     * parameters about how and when to report results.
     */
    BACKGROUND_SCAN = 1 << 1,
  };

  /**
   * Parameters to specify the APF capability of this iface.
   */
  struct ApfPacketFilterCapabilities {
    /**
     * Version of the packet filter interpreter supported
     */
    uint32_t version;
    /**
     * Maximum size of the filter bytecodes in bytes for an iface.
     */
    uint32_t maxLength;
  };

  /**
   * Parameters to specify the Background Scan capability of this iface.
   */
  struct BackgroundScanCapabilities {
    /**
     * Maximum number of bytes available for cached scan results
     */
    uint32_t maxCacheSize;
    /**
     * Maximum number of buckets that can be supplied for a scan
     */
    uint32_t maxBuckets;
    /**
     * Maximum number of APs that must be stored for each scan.
     */
    uint32_t maxApCachePerScan;
    /**
     * Max reporting number of scans threshold that can be specified in the scan
     * parameters.
     */
    int32_t maxReportingThreshold;
  };

  /**
   * Bands that can be specified in Background scan requests.
   */
  enum BackgroundScanBand : uint32_t {
    BAND_UNSPECIFIED,
    /**
     * 2.4 GHz.
     */
    BAND_24GHZ = 1,
    /**
     * 5 GHz without DFS.
     */
    BAND_5GHZ = 2,
    /**
     * 5 GHz DFS only.
     */
    BAND_5GHZ_DFS = 4,
    /**
     * 5 GHz with DFS.
     */
    BAND_5GHZ_WITH_DFS = 6,
    /**
     * 2.4 GHz + 5 GHz; no DFS.
     */
    BAND_24GHZ_5GHZ = 3,
    /**
     * 2.4 GHz + 5 GHz with DFS
     */
    BAND_24GHZ_5GHZ_WITH_DFS = 7
  };

  /**
   * Mask of event reporting schemes that can be specified in background scan
   * requests.
   */
  enum BackgroundScanBucketEventReportSchemeMask : uint32_t {
    /**
     * Report a scan completion event after scan. If this is not set then scan
     * completion events must be reported if report_threshold_percent or
     * report_threshold_num_scans is reached.
     */
    EACH_SCAN = 1 << 0,
    /**
     * 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.
     */
    FULL_RESULTS = 1 << 1,
    /**
     * Controls if scans for this bucket must be placed in the results buffer.
     */
    NO_BATCH = 1 << 2,
  };

  /**
   * Background Scan parameters per bucket that can be specified in background
   * scan requests.
   */
  struct BackgroundScanBucketParameters {
    /**
     * Bands to scan or 0 if frequencies list must be used instead.
     */
    BackgroundScanBand band;
    /**
     * Channel frequencies (in Mhz) to scan if |band| is set to
     * |UNSPECIFIED|.
     */
    vec<uint32_t> frequenciesInMhz;
    /**
     * Period at which this bucket must be scanned (in milliseconds). Must be an integer
     * multiple of the |basePeriodInMs| specified in the BackgroundScanParameters.
     */
    uint32_t periodInMs;
    /**
     * Bitset of |BackgroundScanBucketEventReportSchemeMask| values controlling
     * when events for this bucket must be reported.
     */
    uint32_t eventReportScheme;
    /**
     * For exponential back off. If |exponentialMaxPeriodInMs| is non zero or
     * different than period, then this bucket is an exponential backoff bucket
     * and the scan period must grow exponentially as per formula:
     *   actual_period(N) = period * (base ^ (N/step_count))
     * to this maximum period (in milliseconds).
     */
    uint32_t exponentialMaxPeriodInMs;
    /**
     * For exponential back off. multiplier: new_period=old_period * base
     */
    uint32_t exponentialBase;
    /**
     * For exponential back off. Number of scans to perform for a given
     * period.
     */
    uint32_t exponentialStepCount;
  };

  /**
   * Background Scan parameters that can be specified in background scan
   * requests.
   */
  struct BackgroundScanParameters {
    /**
     * GCD of all bucket periods (in milliseconds).
     */
    uint32_t basePeriodInMs;
    /**
     * Maximum number of APs that must be stored for each scan. If the maximum
     * is reached the highest RSSI results must be returned.
     */
    uint32_t maxApPerScan;
    /**
     * % cache buffer filled threshold at which the host must be notified of
     * batched scan results.
     */
    uint32_t reportThresholdPercent;
    /**
     * Threshold at which the AP must be woken up, in number of scans.
     */
    uint32_t reportThresholdNumScans;
    /**
     * List of buckets to be scheduled.
     */
    vec<BackgroundScanBucketParameters> buckets;
  };

  /**
   * Requests notifications of significant events on this iface. Multiple calls
   * to this must register multiple callbacks each of which must receive all
   * events.
   *
   * @param callback An instance of the |IWifiStaIfaceEventCallback| HIDL interface
   *        object.
   */
  oneway registerEventCallback(IWifiStaIfaceEventCallback callback);

  /**
   * Get the capabilities supported by this STA iface.
   *
   * @return capabilities Bitset of |StaIfaceCapabilityMask| values.
   */
  getCapabilities() generates (uint64_t capabilities);

  /**
   * Used to query additional information about the chip's APF capabilities.
   * Will fail if |StaIfaceCapabilityMask.APF| is not set.
   *
   * @return capabilities Instance of |ApfPacketFilterCapabilities|.
   */
  getApfPacketFilterCapabilities()
      generates (ApfPacketFilterCapabilities capabilities);

  /**
   * Installs an APF program on this iface, replacing an existing
   * program if present.
   * Will fail if |StaIfaceCapabilityMask.APF| is not set.
   *
   * @param cmdId command Id to use for this invocation.
   * @param program APF Program to be set.
   */
  oneway installApfPacketFilter(CommandId cmdId, vec<uint8_t> program);

  /**
   * Used to query additional information about the chip's APF capabilities.
   * Will fail if |StaIfaceCapabilityMask.BACKGROUND_SCAN| is not set.
   *
   * @return capabilities Instance of |BackgroundScanCapabilities|.
   */
  getBackgroundScanCapabilities()
      generates (BackgroundScanCapabilities capabilities);

  /**
   * Start a background scan using the given cmdId as an identifier. Only one
   * active background scan need be supported.
   *
   * When this is called all requested buckets must 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 must 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 must still be recorded with the
   * WIFI_SCAN_FLAG_INTERRUPTED flag set.
   *
   * @param cmdId command Id to use for this invocation.
   * @param params Background scan parameters.
   */
  oneway startBackgroundScan(CommandId cmdId, BackgroundScanParameters params);

  /**
   * Stop the background scan started.
   *
   * @param cmdId command Id corresponding to the request.
   */
  oneway stopBackgroundScan(CommandId cmdId);
};