From d1108ea9e4b0de6bf5f66670a200bcd46d4b5e0b Mon Sep 17 00:00:00 2001
From: Jan Bronicki <janbronicki@gmail.com>
Date: Tue, 25 May 2021 03:02:40 +0200
Subject: [PATCH] [#5] Fixed basic issues in ICMP, now works, but bad checksum

---
 .../NetworkServer/Modules/IcmpServerModule.cs | 50 +++++++++++++------
 1 file changed, 36 insertions(+), 14 deletions(-)

diff --git a/src/Renode/Network/NetworkServer/Modules/IcmpServerModule.cs b/src/Renode/Network/NetworkServer/Modules/IcmpServerModule.cs
index f032e4720..59928b587 100644
--- a/src/Renode/Network/NetworkServer/Modules/IcmpServerModule.cs
+++ b/src/Renode/Network/NetworkServer/Modules/IcmpServerModule.cs
@@ -52,9 +52,9 @@ public void HandleIcmpPacket(Action<EthernetFrame> FrameReady, IPv4Packet ipv4Pa
                 ParentServer.Log(LogLevel.Warning, "Failed to create an ICMPv4 response for this packet: {0}", (ICMPv4Packet)ipv4Packet.PayloadPacket);
                 return;
             }
-
+            ParentServer.Log(LogLevel.Noisy, "Dupa 1");
             var ipv4ResponsePacket = CreateIPv4Packet(ipv4Packet);
-
+            ParentServer.Log(LogLevel.Noisy, "Dupa 2");
             if (!CreateEthernetFramePacket(ipv4ResponsePacket, icmpv4PacketResponse, icmpDestinationAddress, out var response))
             {
                 ParentServer.Log(LogLevel.Warning, "Failed to create an EthernetFramePacket response for this packet: {0}", (ICMPv4Packet)ipv4Packet.PayloadPacket);
@@ -85,7 +85,7 @@ private bool CreateIcmpResponse(IPv4Packet ipv4Packet, out ICMPv4Packet icmpPack
             }
 
             icmpPacketResponse = CreateIcmpv4Packet(ipv4Packet, byteReply);
-            ParentServer.Log(LogLevel.Noisy, "Created an ICMPv4 response: {0}", icmpPacketResponse.PayloadPacket);
+            ParentServer.Log(LogLevel.Noisy, "Created an ICMPv4 response: {0}", icmpPacketResponse);
             return true;
         }
 
@@ -101,10 +101,9 @@ private bool GetReplyIfRequestSupported(IPv4Packet ipv4Packet, out byte[] byteRe
         {
             // byteReply =  null;
             byteReply = new byte[8];
-            for (var i=0; i<byteReply.Length; i++)
-            {
+            for (var i = 0; i < byteReply.Length; i++)
                 byteReply[i] = 0;
-            }
+
 
             var ipv4PacketPayload = (ICMPv4Packet)ipv4Packet.PayloadPacket;
             ParentServer.Log(LogLevel.Noisy, "Getting a reply if we support it");
@@ -124,8 +123,9 @@ private bool GetReplyIfRequestSupported(IPv4Packet ipv4Packet, out byte[] byteRe
             }
             ParentServer.Log(LogLevel.Noisy, "The ICMP code is supported so we service it: {0}", ipv4PacketPayload);
 
-            (BitConverter.GetBytes((ushort)ICMPv4TypeCodes.EchoReply)).CopyTo(byteReply, 0);
-            ParentServer.Log(LogLevel.Noisy, "Created a byte reply to the ICMP request: {0}", String.Join(",", byteReply.ToString()));
+            BitConverter.GetBytes((ushort)ICMPv4TypeCodes.EchoReply).CopyTo(byteReply, 0);
+            BitConverter.GetBytes(ipv4PacketPayload.Checksum).CopyTo(byteReply, 2);
+            ParentServer.Log(LogLevel.Noisy, "Created a byte reply to the ICMP request: {0}", byteReply.Length);
             return true;
         }
 
@@ -140,12 +140,33 @@ private ICMPv4Packet CreateIcmpv4Packet(IPv4Packet ipv4Packet, byte[] byteReply)
         {
             ParentServer.Log(LogLevel.Noisy, "Creating an ICMPv4 response packet");
             var icmpv4Packet = (ICMPv4Packet)ipv4Packet.PayloadPacket;
-            var icmpv4PacketResponse = new ICMPv4Packet(new ByteArraySegment(byteReply));
-
+            ParentServer.Log(LogLevel.Noisy, "1");
+            var byteArrayReply = new ByteArraySegment(byteReply);
+            ParentServer.Log(LogLevel.Noisy, "2");
+            var icmpv4PacketResponse = new ICMPv4Packet(byteArrayReply);
+            ParentServer.Log(LogLevel.Noisy, "3");
+            /****************************************************************
+
+            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+            |     Type      |     Code      |          Checksum             |
+            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+            |           Identifier          |        Sequence Number        |
+            +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+            ****************************************************************/
             // We can copy that from request packet because they are the same in the request and the reply
+            ParentServer.Log(LogLevel.Noisy, "icmpv4PacketResponse.Data length: {0}", icmpv4PacketResponse.Data.Length);
+            ParentServer.Log(LogLevel.Noisy, "icmpv4Packet.Data length: {0}", icmpv4Packet.Data.Length);
+            //TODO: icmp4PacketResponse.Data = new byte[icmpv4Packet.Data.Length];
+            //for(var i=0; i<icmpv4PacketResponse.Data.Length; i++) icmp4PacketResponse.Data[i]=0;
+            icmpv4PacketResponse.Data = new byte[icmpv4Packet.Data.Length];
+            for (var i = 0; i < icmpv4PacketResponse.Data.Length; i++) icmpv4PacketResponse.Data[i] = 0;
             icmpv4Packet.Data.CopyTo(icmpv4PacketResponse.Data, 0);
+            ParentServer.Log(LogLevel.Noisy, "4");
             icmpv4PacketResponse.ID = icmpv4Packet.ID;
+            ParentServer.Log(LogLevel.Noisy, "5");
             icmpv4PacketResponse.Sequence = icmpv4Packet.Sequence;
+            ParentServer.Log(LogLevel.Noisy, "6");
 
             ParentServer.Log(LogLevel.Noisy, "Created ICMPv4 response packet: {0}", icmpv4PacketResponse.PayloadPacket);
             return icmpv4PacketResponse;
@@ -153,15 +174,16 @@ private ICMPv4Packet CreateIcmpv4Packet(IPv4Packet ipv4Packet, byte[] byteReply)
 
 
         /// <summary>
-        /// Creates an IPv4 response packet
+        /// Creates an IPv4 response packet from a given IPv4 packet
         /// </summary>
         /// <param name="ipv4Packet"></param>
         /// <returns></returns>
         private IPv4Packet CreateIPv4Packet(IPv4Packet ipv4Packet)
         {
-            var ipv4PacketResponse = new IPv4Packet(IP,
-                ((IPv4Packet)ipv4Packet.ParentPacket).SourceAddress);
-
+            ParentServer.Log(LogLevel.Noisy, "Creating IPv4 packet response");
+            // var ipv4PacketResponse = new IPv4Packet(IP,
+            //     ((IPv4Packet)ipv4Packet.ParentPacket).SourceAddress);
+            var ipv4PacketResponse = new IPv4Packet(IP, ipv4Packet.SourceAddress);
             ParentServer.Log(LogLevel.Noisy, "Created IPv4 packet response");
             return ipv4PacketResponse;
         }