1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3 * Copyright (c) 2009, 2010 MIRKO BANCHI
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation;
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Authors: Mirko Banchi <mk.banchi@gmail.com>
19 * Tommaso Pecorella <tommaso.pecorella@unifi.it>
20 */
21
22 #include "ns3/log.h"
23 #include "originator-block-ack-agreement.h"
24 #include "wifi-mac-queue-item.h"
25 #include "wifi-utils.h"
26
27 namespace ns3 {
28
29 NS_LOG_COMPONENT_DEFINE ("OriginatorBlockAckAgreement");
30
OriginatorBlockAckAgreement(Mac48Address recipient,uint8_t tid)31 OriginatorBlockAckAgreement::OriginatorBlockAckAgreement (Mac48Address recipient, uint8_t tid)
32 : BlockAckAgreement (recipient, tid),
33 m_state (PENDING)
34 {
35 }
36
~OriginatorBlockAckAgreement()37 OriginatorBlockAckAgreement::~OriginatorBlockAckAgreement ()
38 {
39 }
40
41 void
SetState(State state)42 OriginatorBlockAckAgreement::SetState (State state)
43 {
44 m_state = state;
45 }
46
47 bool
IsPending(void) const48 OriginatorBlockAckAgreement::IsPending (void) const
49 {
50 return (m_state == PENDING) ? true : false;
51 }
52
53 bool
IsEstablished(void) const54 OriginatorBlockAckAgreement::IsEstablished (void) const
55 {
56 return (m_state == ESTABLISHED) ? true : false;
57 }
58
59 bool
IsRejected(void) const60 OriginatorBlockAckAgreement::IsRejected (void) const
61 {
62 return (m_state == REJECTED) ? true : false;
63 }
64
65 bool
IsNoReply(void) const66 OriginatorBlockAckAgreement::IsNoReply (void) const
67 {
68 return (m_state == NO_REPLY) ? true : false;
69 }
70
71 bool
IsReset(void) const72 OriginatorBlockAckAgreement::IsReset (void) const
73 {
74 return (m_state == RESET) ? true : false;
75 }
76
77 uint16_t
GetStartingSequence(void) const78 OriginatorBlockAckAgreement::GetStartingSequence (void) const
79 {
80 if (m_txWindow.GetWinSize () == 0)
81 {
82 // the TX window has not been initialized yet
83 return m_startingSeq;
84 }
85 return m_txWindow.GetWinStart ();
86 }
87
88 std::size_t
GetDistance(uint16_t seqNumber) const89 OriginatorBlockAckAgreement::GetDistance (uint16_t seqNumber) const
90 {
91 return BlockAckAgreement::GetDistance (seqNumber, m_txWindow.GetWinStart ());
92 }
93
94 void
InitTxWindow(void)95 OriginatorBlockAckAgreement::InitTxWindow (void)
96 {
97 m_txWindow.Init (m_startingSeq, m_bufferSize);
98 }
99
100 void
AdvanceTxWindow(void)101 OriginatorBlockAckAgreement::AdvanceTxWindow (void)
102 {
103 while (m_txWindow.At (0))
104 {
105 m_txWindow.Advance (1); // reset the current head -- ensures loop termination
106 }
107 }
108
109 void
NotifyTransmittedMpdu(Ptr<const WifiMacQueueItem> mpdu)110 OriginatorBlockAckAgreement::NotifyTransmittedMpdu (Ptr<const WifiMacQueueItem> mpdu)
111 {
112 uint16_t mpduSeqNumber = mpdu->GetHeader ().GetSequenceNumber ();
113 uint16_t distance = GetDistance (mpduSeqNumber);
114
115 if (distance >= SEQNO_SPACE_HALF_SIZE)
116 {
117 NS_LOG_DEBUG ("Transmitted an old MPDU, do nothing.");
118 return;
119 }
120
121 // advance the transmit window if an MPDU beyond the current transmit window
122 // is transmitted (see Section 10.24.7.7 of 802.11-2016)
123 if (distance >= m_txWindow.GetWinSize ())
124 {
125 std::size_t count = distance - m_txWindow.GetWinSize () + 1;
126 m_txWindow.Advance (count);
127 // transmit window may advance further
128 AdvanceTxWindow ();
129 NS_LOG_DEBUG ("Transmitted MPDU beyond current transmit window. New starting sequence number: "
130 << m_txWindow.GetWinStart ());
131 }
132 }
133
134 void
NotifyAckedMpdu(Ptr<const WifiMacQueueItem> mpdu)135 OriginatorBlockAckAgreement::NotifyAckedMpdu (Ptr<const WifiMacQueueItem> mpdu)
136 {
137 uint16_t mpduSeqNumber = mpdu->GetHeader ().GetSequenceNumber ();
138 uint16_t distance = GetDistance (mpduSeqNumber);
139
140 if (distance >= SEQNO_SPACE_HALF_SIZE)
141 {
142 NS_LOG_DEBUG ("Acked an old MPDU, do nothing.");
143 return;
144 }
145
146 // when an MPDU is transmitted, the transmit window is updated such that the
147 // transmitted MPDU is in the window, hence we cannot be notified of the
148 // acknowledgment of an MPDU which is beyond the transmit window
149 m_txWindow.At (distance) = true;
150
151 // the starting sequence number can be advanced to the sequence number of
152 // the nearest unacknowledged MPDU
153 AdvanceTxWindow ();
154 NS_LOG_DEBUG ("Starting sequence number: " << m_txWindow.GetWinStart ());
155 }
156
157 void
NotifyDiscardedMpdu(Ptr<const WifiMacQueueItem> mpdu)158 OriginatorBlockAckAgreement::NotifyDiscardedMpdu (Ptr<const WifiMacQueueItem> mpdu)
159 {
160 uint16_t mpduSeqNumber = mpdu->GetHeader ().GetSequenceNumber ();
161 uint16_t distance = GetDistance (mpduSeqNumber);
162
163 if (distance >= SEQNO_SPACE_HALF_SIZE)
164 {
165 NS_LOG_DEBUG ("Discarded an old MPDU, do nothing.");
166 return;
167 }
168
169 m_txWindow.Advance (distance + 1);
170 // transmit window may advance further
171 AdvanceTxWindow ();
172 NS_LOG_DEBUG ("Discarded MPDU within current transmit window. New starting sequence number: "
173 << m_txWindow.GetWinStart ());
174 }
175
176 } //namespace ns3
177