From 5fd3f3852886c4a4bd2970aed52a47478974b8ac Mon Sep 17 00:00:00 2001
From: Tommaso Pecorella <tommypec@gmail.com>
Date: Tue, 10 Mar 2020 11:06:34 -0700
Subject: [PATCH] applications:  Add SeqTsEchoHeader variant

---
 CHANGES.html                                 |   2 +-
 src/applications/model/seq-ts-echo-header.cc | 135 +++++++++++++++++++
 src/applications/model/seq-ts-echo-header.h  |  98 ++++++++++++++
 src/applications/wscript                     |   6 +-
 4 files changed, 238 insertions(+), 3 deletions(-)
 create mode 100644 src/applications/model/seq-ts-echo-header.cc
 create mode 100644 src/applications/model/seq-ts-echo-header.h

diff --git a/CHANGES.html b/CHANGES.html
index 9de599da5..be0f827b6 100644
--- a/CHANGES.html
+++ b/CHANGES.html
@@ -74,8 +74,8 @@ allows to choose between Block Ack policy and Implicit Block Ack Request policy
 allows to request an acknowledgment after a configurable number of MPDUs have been
 transmitted.</li>
 <li>The MaxSize attribute is removed from the QueueBase base class and moved to subclasses. A new MaxSize attribute is therefore added to the DropTailQueue class, while the MaxQueueSize attribute of the WifiMacQueue class is renamed as MaxSize for API consistency.</li>
-<li>The applications have now a "EnableE2EStats" attribute.</li>
 <li>Added a new trace source <b>PhyRxPayloadBegin</b> in WifiPhy for tracing begin of PSDU reception.</li>
+<li> A new sequence and timestamp header variant for applications has been added.  The SeqTsEchoHeader contains an additional timestamp field for use in echoing a timestamp back to a sender.</li>
 </ul>
 <h2>Changes to existing API:</h2>
 <ul>
diff --git a/src/applications/model/seq-ts-echo-header.cc b/src/applications/model/seq-ts-echo-header.cc
new file mode 100644
index 000000000..d211b9a8a
--- /dev/null
+++ b/src/applications/model/seq-ts-echo-header.cc
@@ -0,0 +1,135 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2016 Universita' di Firenze
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Tommaso Pecorella <tommaso.pecorella@unifi.it>
+ */
+
+#include "ns3/assert.h"
+#include "ns3/log.h"
+#include "ns3/header.h"
+#include "ns3/simulator.h"
+#include "seq-ts-echo-header.h"
+
+namespace ns3 {
+
+NS_LOG_COMPONENT_DEFINE ("SeqTsEchoHeader");
+
+NS_OBJECT_ENSURE_REGISTERED (SeqTsEchoHeader);
+
+SeqTsEchoHeader::SeqTsEchoHeader ()
+  : m_seq (0),
+    m_tsValue (Simulator::Now ()),
+    m_tsEchoReply (Seconds (0))
+{
+  NS_LOG_FUNCTION (this);
+}
+
+void
+SeqTsEchoHeader::SetSeq (uint32_t seq)
+{
+  NS_LOG_FUNCTION (this << seq);
+  m_seq = seq;
+}
+
+uint32_t
+SeqTsEchoHeader::GetSeq (void) const
+{
+  NS_LOG_FUNCTION (this);
+  return m_seq;
+}
+
+void
+SeqTsEchoHeader::SetTsValue (Time ts)
+{
+  NS_LOG_FUNCTION (this);
+  m_tsValue = ts;
+}
+
+Time
+SeqTsEchoHeader::GetTsValue (void) const
+{
+  NS_LOG_FUNCTION (this);
+  return m_tsValue;
+}
+
+void
+SeqTsEchoHeader::SetTsEchoReply (Time ts)
+{
+  NS_LOG_FUNCTION (this);
+  m_tsEchoReply = ts;
+}
+
+Time
+SeqTsEchoHeader::GetTsEchoReply (void) const
+{
+  NS_LOG_FUNCTION (this);
+  return m_tsEchoReply;
+}
+
+TypeId
+SeqTsEchoHeader::GetTypeId (void)
+{
+  static TypeId tid = TypeId ("ns3::SeqTsEchoHeader")
+    .SetParent<Header> ()
+    .SetGroupName ("Applications")
+    .AddConstructor<SeqTsEchoHeader> ()
+  ;
+  return tid;
+}
+
+TypeId
+SeqTsEchoHeader::GetInstanceTypeId (void) const
+{
+  return GetTypeId ();
+}
+
+void
+SeqTsEchoHeader::Print (std::ostream &os) const
+{
+  NS_LOG_FUNCTION (this << &os);
+  os << "(seq=" << m_seq << " Tx time=" << m_tsValue.As (Time::S) << " Rx time=" << m_tsEchoReply.As (Time::S) << ")";
+}
+
+uint32_t
+SeqTsEchoHeader::GetSerializedSize (void) const
+{
+  NS_LOG_FUNCTION (this);
+  return 4+8+8;
+}
+
+void
+SeqTsEchoHeader::Serialize (Buffer::Iterator start) const
+{
+  NS_LOG_FUNCTION (this << &start);
+  Buffer::Iterator i = start;
+  i.WriteHtonU32 (m_seq);
+  i.WriteHtonU64 (m_tsValue.GetTimeStep ());
+  i.WriteHtonU64 (m_tsEchoReply.GetTimeStep ());
+}
+
+uint32_t
+SeqTsEchoHeader::Deserialize (Buffer::Iterator start)
+{
+  NS_LOG_FUNCTION (this << &start);
+  Buffer::Iterator i = start;
+  m_seq = i.ReadNtohU32 ();
+  m_tsValue = TimeStep (i.ReadNtohU64 ());
+  m_tsEchoReply = TimeStep (i.ReadNtohU64 ());
+  return GetSerializedSize ();
+}
+
+} // namespace ns3
diff --git a/src/applications/model/seq-ts-echo-header.h b/src/applications/model/seq-ts-echo-header.h
new file mode 100644
index 000000000..662d60885
--- /dev/null
+++ b/src/applications/model/seq-ts-echo-header.h
@@ -0,0 +1,98 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2016 Universita' di Firenze
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Tommaso Pecorella <tommaso.pecorella@unifi.it>
+ */
+
+#ifndef SEQ_TS_ECHO_HEADER_H
+#define SEQ_TS_ECHO_HEADER_H
+
+#include "ns3/header.h"
+#include "ns3/nstime.h"
+
+namespace ns3 {
+/**
+ * \ingroup applications
+ * \class SeqTsEchoHeader
+ * \brief Packet header to carry sequence number and two timestamps
+ *
+ * The header is made of a 32bits sequence number followed by
+ * two 64bits time stamps (Transmit and Receive).
+ */
+class SeqTsEchoHeader : public Header
+{
+public:
+  /**
+   * \brief Get the type ID.
+   * \return the object TypeId
+   */
+  static TypeId GetTypeId (void);
+
+  /**
+   * \brief constructor
+   */
+  SeqTsEchoHeader ();
+
+  /**
+   * \param seq the sequence number
+   */
+  void SetSeq (uint32_t seq);
+
+  /**
+   * \return the sequence number
+   */
+  uint32_t GetSeq (void) const;
+
+  /**
+   * \return A time value set by the sender
+   */
+  Time GetTsValue (void) const;
+
+  /**
+   * \return A time value echoing the received timestamp
+   */
+  Time GetTsEchoReply (void) const;
+
+  /**
+   * \brief Set the sender's time value
+   * \param ts Time value to set
+   */
+  void SetTsValue (Time ts);
+
+  /**
+   * \brief Upon SeqTsEchoHeader reception, the host answers via echoing
+   * back the received timestamp
+   * \param ts received timestamp. If not called, will contain 0
+   */
+  void SetTsEchoReply (Time ts);
+  
+  // Inherited
+  virtual TypeId GetInstanceTypeId (void) const override;
+  virtual void Print (std::ostream &os) const override;
+  virtual uint32_t GetSerializedSize (void) const override;
+  virtual void Serialize (Buffer::Iterator start) const override;
+  virtual uint32_t Deserialize (Buffer::Iterator start) override;
+
+private:
+  uint32_t m_seq; //!< Sequence number
+  Time m_tsValue; //!< Sender's timestamp
+  Time m_tsEchoReply; //!< Receiver's timestamp
+};
+
+} // namespace ns3
+
+#endif /* SEQ_TS_ECHO_HEADER_H */
diff --git a/src/applications/wscript b/src/applications/wscript
index 68528ec8c..64ebbc8c1 100644
--- a/src/applications/wscript
+++ b/src/applications/wscript
@@ -9,7 +9,8 @@ def build(bld):
         'model/udp-client.cc',
         'model/udp-server.cc',
         'model/seq-ts-header.cc',
-        'model/e2e-stats-header.cc',
+        'model/seq-ts-size-header.cc',
+        'model/seq-ts-echo-header.cc',
         'model/udp-trace-client.cc',
         'model/packet-loss-counter.cc',
         'model/udp-echo-client.cc',
@@ -48,7 +49,8 @@ def build(bld):
         'model/udp-client.h',
         'model/udp-server.h',
         'model/seq-ts-header.h',
-        'model/e2e-stats-header.h',
+        'model/seq-ts-size-header.h',
+        'model/seq-ts-echo-header.h',
         'model/udp-trace-client.h',
         'model/packet-loss-counter.h',
         'model/udp-echo-client.h',