1 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
2 /*
3 * Copyright (c) 2018 NITK Surathkal
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 * Author: Viyom Mittal <viyommittal@gmail.com>
19 * Vivek Jain <jain.vivek.anand@gmail.com>
20 * Mohit P. Tahiliani <tahiliani@nitk.edu.in>
21 *
22 */
23
24 #include "tcp-prr-recovery.h"
25 #include "tcp-socket-state.h"
26
27 #include "ns3/log.h"
28
29 namespace ns3 {
30
31 NS_LOG_COMPONENT_DEFINE ("TcpPrrRecovery");
32 NS_OBJECT_ENSURE_REGISTERED (TcpPrrRecovery);
33
34 TypeId
GetTypeId(void)35 TcpPrrRecovery::GetTypeId (void)
36 {
37 static TypeId tid = TypeId ("ns3::TcpPrrRecovery")
38 .SetParent<TcpClassicRecovery> ()
39 .AddConstructor<TcpPrrRecovery> ()
40 .SetGroupName ("Internet")
41 .AddAttribute ("ReductionBound", "Type of Reduction Bound",
42 EnumValue (SSRB),
43 MakeEnumAccessor (&TcpPrrRecovery::m_reductionBoundMode),
44 MakeEnumChecker (CRB, "CRB",
45 SSRB, "SSRB"))
46 ;
47 return tid;
48 }
49
TcpPrrRecovery(void)50 TcpPrrRecovery::TcpPrrRecovery (void)
51 : TcpClassicRecovery ()
52 {
53 NS_LOG_FUNCTION (this);
54 }
55
TcpPrrRecovery(const TcpPrrRecovery & recovery)56 TcpPrrRecovery::TcpPrrRecovery (const TcpPrrRecovery& recovery)
57 : TcpClassicRecovery (recovery),
58 m_prrDelivered (recovery.m_prrDelivered),
59 m_prrOut (recovery.m_prrOut),
60 m_recoveryFlightSize (recovery.m_recoveryFlightSize),
61 m_reductionBoundMode (recovery.m_reductionBoundMode)
62 {
63 NS_LOG_FUNCTION (this);
64 }
65
~TcpPrrRecovery(void)66 TcpPrrRecovery::~TcpPrrRecovery (void)
67 {
68 NS_LOG_FUNCTION (this);
69 }
70
71 void
EnterRecovery(Ptr<TcpSocketState> tcb,uint32_t dupAckCount,uint32_t unAckDataCount,uint32_t deliveredBytes)72 TcpPrrRecovery::EnterRecovery (Ptr<TcpSocketState> tcb, uint32_t dupAckCount,
73 uint32_t unAckDataCount, uint32_t deliveredBytes)
74 {
75 NS_LOG_FUNCTION (this << tcb << dupAckCount << unAckDataCount);
76 NS_UNUSED (dupAckCount);
77
78 m_prrOut = 0;
79 m_prrDelivered = 0;
80 m_recoveryFlightSize = unAckDataCount;
81
82 DoRecovery (tcb, deliveredBytes);
83 }
84
85 void
DoRecovery(Ptr<TcpSocketState> tcb,uint32_t deliveredBytes)86 TcpPrrRecovery::DoRecovery (Ptr<TcpSocketState> tcb, uint32_t deliveredBytes)
87 {
88 NS_LOG_FUNCTION (this << tcb << deliveredBytes);
89 m_prrDelivered += deliveredBytes;
90
91 int sendCount;
92 if (tcb->m_bytesInFlight > tcb->m_ssThresh)
93 {
94 sendCount = std::ceil (m_prrDelivered * tcb->m_ssThresh * 1.0 / m_recoveryFlightSize) - m_prrOut;
95 }
96 else
97 {
98 int limit = static_cast<int> (tcb->m_ssThresh - tcb->m_bytesInFlight);
99 if (m_reductionBoundMode == CRB)
100 {
101 limit = m_prrDelivered - m_prrOut;
102 }
103 else if (m_reductionBoundMode == SSRB)
104 {
105 if (tcb->m_isRetransDataAcked)
106 {
107 limit = std::max (m_prrDelivered - m_prrOut, deliveredBytes) + tcb->m_segmentSize;
108 }
109 else
110 {
111 limit = deliveredBytes;
112 }
113 }
114 sendCount = std::min (limit, static_cast<int> (tcb->m_ssThresh - tcb->m_bytesInFlight));
115 }
116
117 /* Force a fast retransmit upon entering fast recovery */
118 sendCount = std::max (sendCount, static_cast<int> (m_prrOut > 0 ? 0 : tcb->m_segmentSize));
119 tcb->m_cWnd = tcb->m_bytesInFlight + sendCount;
120 tcb->m_cWndInfl = tcb->m_cWnd;
121 }
122
123 void
ExitRecovery(Ptr<TcpSocketState> tcb)124 TcpPrrRecovery::ExitRecovery (Ptr<TcpSocketState> tcb)
125 {
126 NS_LOG_FUNCTION (this << tcb);
127 tcb->m_cWndInfl = tcb->m_cWnd;
128 }
129
130 void
UpdateBytesSent(uint32_t bytesSent)131 TcpPrrRecovery::UpdateBytesSent (uint32_t bytesSent)
132 {
133 NS_LOG_FUNCTION (this << bytesSent);
134 m_prrOut += bytesSent;
135 }
136
137 Ptr<TcpRecoveryOps>
Fork(void)138 TcpPrrRecovery::Fork (void)
139 {
140 return CopyObject<TcpPrrRecovery> (this);
141 }
142
143 std::string
GetName() const144 TcpPrrRecovery::GetName () const
145 {
146 return "PrrRecovery";
147 }
148
149 } // namespace ns3
150