1 /*
2  * Copyright 2019, The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #pragma once
18 
19 #include "macaddress.h"
20 
21 #include <stdint.h>
22 
23 #include <array>
24 #include <vector>
25 
26 #define IEEE80211_TX_MAX_RATES 4
27 
28 struct hwsim_tx_rate {
29     signed char idx;
30     unsigned char count;
31 } __attribute__((__packed__));
32 
33 enum class FrameType : uint8_t {
34     Unknown,
35     Ack,
36     Data,
37 };
38 
39 enum class AccessCategory {
40     Voice,
41     Video,
42     BestEffort,
43     Background,
44 };
45 
46 FrameType frameTypeFromByte(uint8_t byte);
47 
48 using Rates = std::array<hwsim_tx_rate, IEEE80211_TX_MAX_RATES>;
49 
50 class FrameInfo {
51 public:
52     FrameInfo() = default;
53     FrameInfo(const FrameInfo&) = default;
54     FrameInfo(FrameInfo&&) = default;
55     FrameInfo(const MacAddress& transmitter,
56               uint64_t cookie,
57               uint32_t flags,
58               uint32_t channel,
59               const hwsim_tx_rate* rates,
60               size_t numRates);
61 
62     FrameInfo& operator=(const FrameInfo&) = default;
63     FrameInfo& operator=(FrameInfo&&) = default;
64 
rates()65     const Rates& rates() const { return mTxRates; }
rates()66     Rates& rates() { return mTxRates; }
67 
transmitter()68     const MacAddress& transmitter() const { return mTransmitter; }
cookie()69     uint64_t cookie() const { return mCookie; }
flags()70     uint32_t flags() const { return mFlags; }
channel()71     uint32_t channel() const { return mChannel; }
72 
73     bool shouldAck() const;
74 
75 private:
76     Rates mTxRates;
77     MacAddress mTransmitter;
78     uint64_t mCookie = 0;
79     uint32_t mFlags = 0;
80     uint32_t mChannel = 0;
81 };
82 
83 class Frame {
84 public:
85     Frame() = default;
86     Frame(const uint8_t* data, size_t size);
87     Frame(const uint8_t* data,
88           size_t size,
89           const MacAddress& transmitter,
90           uint64_t cookie,
91           uint32_t flags,
92           uint32_t channel,
93           const hwsim_tx_rate* rates,
94           size_t numRates);
95     Frame(Frame&& other) = default;
96 
97     Frame& operator=(Frame&& other) = default;
98 
size()99     size_t size() const { return mData.size(); }
data()100     const uint8_t* data() const { return mData.data(); }
data()101     uint8_t* data() { return mData.data(); }
cookie()102     uint64_t cookie() const { return mInfo.cookie(); }
flags()103     uint32_t flags() const { return mInfo.flags(); }
channel()104     uint32_t channel() const { return mInfo.channel(); }
105 
rates()106     Rates& rates() { return mInfo.rates(); }
rates()107     const Rates& rates() const { return mInfo.rates(); }
108 
initialRates()109     const Rates& initialRates() const { return mInitialTxRates; }
110 
111     // Increment the number of attempts made in the tx rates
112     bool incrementAttempts();
113     bool hasRemainingAttempts();
114 
115     // The transmitter as indicated by hwsim
transmitter()116     const MacAddress& transmitter() const { return mInfo.transmitter(); }
117     // The source as indicated by the 802.11 frame
118     const MacAddress& source() const;
119     // The destination as indicated by the 802.11 frame
120     const MacAddress& destination() const;
121 
122     std::string str() const;
123 
info()124     const FrameInfo& info() const { return mInfo; }
info()125     FrameInfo& info() { return mInfo; }
126 
127     bool isBeacon() const;
128     bool isData() const;
129     bool isDataQoS() const;
130 
131     uint16_t getQoSControl() const;
132 
shouldAck()133     bool shouldAck() const { return mInfo.shouldAck(); }
134 
135     uint64_t calcNextTimeout();
136 
setRadioDestination(const MacAddress & destination)137     void setRadioDestination(const MacAddress& destination) {
138         mRadioDestination = destination;
139     }
radioDestination()140     const MacAddress& radioDestination() const { return mRadioDestination; }
141 private:
142     Frame(const Frame&) = delete;
143     Frame& operator=(const Frame&) = delete;
144 
145     AccessCategory getAc() const;
146 
147     std::vector<uint8_t> mData;
148     FrameInfo mInfo;
149     MacAddress mRadioDestination;
150     Rates mInitialTxRates;
151     uint64_t mNextTimeout = 0;
152     // The contention winow determines how much time to back off on each retry.
153     // The contention window initial value and max value are determined by the
154     // access category of the frame.
155     uint32_t mContentionWindow = 0;
156     uint32_t mContentionWindowMax = 0;
157 };
158 
159