lib/wlan/mlme/include/wlan/mlme/assoc_context.h

// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef GARNET_LIB_WLAN_MLME_INCLUDE_WLAN_MLME_ASSOC_CONTEXT_H_
#define GARNET_LIB_WLAN_MLME_INCLUDE_WLAN_MLME_ASSOC_CONTEXT_H_

#include <wlan/common/element.h>
#include <wlan/common/span.h>
#include <wlan/mlme/mac_frame.h>
#include <wlan/protocol/mac.h>

#include <optional>
#include <vector>

namespace wlan {
// Information defined only within a context of association
// Beware the subtle interpretation of each field: they are designed to
// reflect the parameters safe to use within an association
// Many parameters do not distinguish Rx capability from Tx capability.
// In those cases, a capability is commonly applied to both Rx and Tx.
// Some parameters are distinctively for Rx only, and some are Tx only.
struct AssocContext {
    // TODO(porce): Move association-related variables of class Station to here
    zx::time ts_start;  // timestamp of the beginning of the association

    // BSSID of the association.
    // Not necessarily the same as the BSSID that is used outside this context.
    // E.g., during joining, authenticating, asssociating, off-channel scanning.
    common::MacAddr bssid;

    CapabilityInfo cap;
    uint16_t aid = 0;
    uint16_t listen_interval = 0;

    // Negotiated configurations
    // This is an outcome of intersection of capabilities and configurations.

    // Concatenation of SupportedRates and ExtendedSupportedRates
    std::vector<SupportedRate> rates;

    // Rx MCS Bitmask in Supported MCS Set field represents the set of MCS
    // the peer can receive at from this device, considering this device's Tx capability.
    std::optional<HtCapabilities> ht_cap = std::nullopt;
    std::optional<HtOperation> ht_op = std::nullopt;
    std::optional<VhtCapabilities> vht_cap = std::nullopt;
    std::optional<VhtOperation> vht_op = std::nullopt;

    PHY phy = WLAN_PHY_OFDM;
    wlan_channel_t chan;

    bool is_cbw40_rx = false;
    bool is_cbw40_tx = false;

    PHY DerivePhy() const;
    wlan_assoc_ctx_t ToDdk() const;
};

std::optional<std::vector<SupportedRate>> BuildAssocReqSuppRates(
    const std::vector<uint8_t>& ap_basic_rate_set,
    const std::vector<uint8_t>& ap_op_rate_set,
    const std::vector<SupportedRate>& client_rates);

// Visable only for unit testing.
std::optional<AssocContext> ParseAssocRespIe(Span<const uint8_t> ie_chains);

AssocContext MakeClientAssocCtx(const wlan_info_t& ifc_info, const wlan_channel_t join_chan);
std::optional<AssocContext> MakeBssAssocCtx(const AssociationResponse& assoc_resp,
                                            Span<const uint8_t> ie_chains,
                                            const common::MacAddr& peer);

AssocContext IntersectAssocCtx(const AssocContext& bss, const AssocContext& client);

}  // namespace wlan
#endif  // GARNET_LIB_WLAN_MLME_INCLUDE_WLAN_MLME_ASSOC_CONTEXT_H_