From 8cd99af142c00422b4849a1ad80e30b64faf42e0 Mon Sep 17 00:00:00 2001
From: ZakariaHelalArzoo <arzoozakaria@gmail.com>
Date: Sat, 27 Mar 2021 11:52:48 +0000
Subject: [PATCH] point-to-point: (fixes #236) add packet payload comparison to
 the test

---
 .../test/point-to-point-test.cc               | 48 ++++++++++++++++---
 1 file changed, 42 insertions(+), 6 deletions(-)

diff --git a/src/point-to-point/test/point-to-point-test.cc b/src/point-to-point/test/point-to-point-test.cc
index f6221e0fd..c8c1111db 100644
--- a/src/point-to-point/test/point-to-point-test.cc
+++ b/src/point-to-point/test/point-to-point-test.cc
@@ -25,6 +25,8 @@
 #include "ns3/point-to-point-channel.h"
 #include "ns3/net-device-queue-interface.h"
 
+#include <string>
+
 using namespace ns3;
 
 /**
@@ -47,12 +49,27 @@ public:
   virtual void DoRun (void);
 
 private:
+  
+  Ptr<const Packet> m_recvdPacket; //!< received packet
   /**
    * \brief Send one packet to the device specified
    *
-   * \param device NetDevice to send to
+   * \param device NetDevice to send to.
+   * \param buffer Payload content of the packet.
+   * \param size Size of the payload.
    */
-  void SendOnePacket (Ptr<PointToPointNetDevice> device);
+  void SendOnePacket (Ptr<PointToPointNetDevice> device, uint8_t const *buffer, uint32_t size);
+  /**
+   * \brief Callback function which sets the recvdPacket parameter
+   *
+   * \param dev The receiving device.
+   * \param pkt The received packet.
+   * \param mode The protocol mode used.
+   * \param sender The sender address.
+   * 
+   * \return A boolean indicating packet handled properly.
+   */
+  bool RxPacket (Ptr<NetDevice> dev, Ptr<const Packet> pkt, uint16_t mode, const Address &sender);
 };
 
 PointToPointTest::PointToPointTest ()
@@ -61,12 +78,19 @@ PointToPointTest::PointToPointTest ()
 }
 
 void
-PointToPointTest::SendOnePacket (Ptr<PointToPointNetDevice> device)
+PointToPointTest::SendOnePacket (Ptr<PointToPointNetDevice> device, uint8_t const *buffer, uint32_t size)
 {
-  Ptr<Packet> p = Create<Packet> ();
+  Ptr<Packet> p = Create<Packet> (buffer, size);
   device->Send (p, device->GetBroadcast (), 0x800);
 }
 
+bool
+PointToPointTest::RxPacket (Ptr<NetDevice> dev, Ptr<const Packet> pkt, uint16_t mode, const Address &sender)
+{
+  m_recvdPacket = pkt;
+  return true;
+}
+
 
 void
 PointToPointTest::DoRun (void)
@@ -86,11 +110,23 @@ PointToPointTest::DoRun (void)
 
   a->AddDevice (devA);
   b->AddDevice (devB);
-
-  Simulator::Schedule (Seconds (1.0), &PointToPointTest::SendOnePacket, this, devA);
+  
+  devB->SetReceiveCallback (MakeCallback (&PointToPointTest::RxPacket,
+                                          this));
+  uint8_t txBuffer [] = "\"Can you tell me where my country lies?\" \\ said the unifaun to his true love's eyes. \\ \"It lies with me!\" cried the Queen of Maybe \\ - for her merchandise, he traded in his prize.";
+  size_t txBufferSize = sizeof(txBuffer);
+  
+  Simulator::Schedule (Seconds (1.0), &PointToPointTest::SendOnePacket, this, devA, txBuffer, txBufferSize);
 
   Simulator::Run ();
 
+  NS_TEST_EXPECT_MSG_EQ (m_recvdPacket->GetSize (), txBufferSize, "trivial");
+
+  uint8_t rxBuffer [1500]; // As large as the P2P MTU size, assuming that the user didn't change it.
+  
+  m_recvdPacket->CopyData (rxBuffer, txBufferSize);
+  NS_TEST_EXPECT_MSG_EQ (memcmp (rxBuffer, txBuffer, txBufferSize), 0, "trivial");
+  
   Simulator::Destroy ();
 }