[cgutman] 43637: - Implement UDP checksum calculation - Fixes issues with DHCP (and any other UDP traffic) over bridged networking on vbox and issues with other hardware that doesn't like a checksum of 0 - See bug #4754

Author: cgutman
Date: Tue Oct 20 07:24:37 2009
New Revision: 43637

URL: http://svn.reactos.org/svn/reactos?rev=43637&view=rev
Log:
 - Implement UDP checksum calculation
 - Fixes issues with DHCP (and any other UDP traffic) over bridged networking on vbox and
issues with other hardware that doesn't like a checksum of 0
 - See bug #4754

Modified:
    trunk/reactos/drivers/network/tcpip/include/checksum.h
    trunk/reactos/lib/drivers/ip/network/checksum.c
    trunk/reactos/lib/drivers/ip/transport/udp/udp.c

Modified: trunk/reactos/drivers/network/tcpip/include/checksum.h
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/drivers/network/tcpip/incl…
==============================================================================
--- trunk/reactos/drivers/network/tcpip/include/checksum.h [iso-8859-1] (original)
+++ trunk/reactos/drivers/network/tcpip/include/checksum.h [iso-8859-1] Tue Oct 20
07:24:37 2009
@@ -22,6 +22,12 @@
   int len,
   unsigned int sum);
 
+ULONG
+UDPv4ChecksumCalculate(
+  PIPv4_HEADER IPHeader,
+  PUCHAR PacketBuffer,
+  ULONG DataLength);
+
 #define IPv4Checksum(Data, Count, Seed)(~ChecksumFold(ChecksumCompute(Data, Count,
Seed)))
 #define TCPv4Checksum(Data, Count, Seed)(~ChecksumFold(csum_partial(Data, Count, Seed)))
 //#define TCPv4Checksum(Data, Count, Seed)(~ChecksumFold(ChecksumCompute(Data, Count,
Seed)))

Modified: trunk/reactos/lib/drivers/ip/network/checksum.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/lib/drivers/ip/network/che…
==============================================================================
--- trunk/reactos/lib/drivers/ip/network/checksum.c [iso-8859-1] (original)
+++ trunk/reactos/lib/drivers/ip/network/checksum.c [iso-8859-1] Tue Oct 20 07:24:37 2009
@@ -55,3 +55,53 @@
 
   return Sum;
 }
+
+ULONG
+UDPv4ChecksumCalculate(
+  PIPv4_HEADER IPHeader,
+  PUCHAR PacketBuffer,
+  ULONG DataLength)
+{
+  ULONG Sum = 0;
+  USHORT TmpSum;
+  ULONG i;
+  BOOLEAN Pad;
+
+  /* Pad the data if needed */
+  Pad = (DataLength & 1);
+  if (Pad) {
+      DbgPrint("Odd\n");
+      DataLength++;
+  } else DbgPrint("Even\n");
+
+  /* Add from the UDP header and data */
+  for (i = 0; i < DataLength; i += 2)
+  {
+       TmpSum = ((PacketBuffer[i] << 8) & 0xFF00) +
+                ((Pad && i == DataLength - 1) ? 0 : (PacketBuffer[i+1] &
0x00FF));
+       Sum += TmpSum;
+  }
+
+  /* Add the source address */
+  for (i = 0; i < sizeof(IPv4_RAW_ADDRESS); i += 2)
+  {
+       TmpSum = ((((PUCHAR)&IPHeader->SrcAddr)[i] << 8) & 0xFF00) +
+                (((PUCHAR)&IPHeader->SrcAddr)[i+1] & 0x00FF);
+       Sum += TmpSum;
+  }
+
+  /* Add the destination address */
+  for (i = 0; i < sizeof(IPv4_RAW_ADDRESS); i += 2)
+  {
+       TmpSum = ((((PUCHAR)&IPHeader->DstAddr)[i] << 8) & 0xFF00) +
+                (((PUCHAR)&IPHeader->DstAddr)[i+1] & 0x00FF);
+       Sum += TmpSum;
+  }
+
+  /* Add the proto number and length */
+  Sum += IPPROTO_UDP + (DataLength - (Pad ? 1 : 0));
+
+  /* Fold the checksum and return the one's complement */
+  return ~ChecksumFold(Sum);
+}
+

Modified: trunk/reactos/lib/drivers/ip/transport/udp/udp.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/lib/drivers/ip/transport/u…
==============================================================================
--- trunk/reactos/lib/drivers/ip/transport/udp/udp.c [iso-8859-1] (original)
+++ trunk/reactos/lib/drivers/ip/transport/udp/udp.c [iso-8859-1] Tue Oct 20 07:24:37
2009
@@ -19,6 +19,7 @@
     PIP_ADDRESS LocalAddress,
     USHORT LocalPort,
     PIP_PACKET IPPacket,
+    PVOID Data,
     UINT DataLength)
 /*
  * FUNCTION: Adds an IPv4 and UDP header to an IP packet
@@ -49,10 +50,20 @@
     /* Port values are already big-endian values */
     UDPHeader->SourcePort = LocalPort;
     UDPHeader->DestPort   = RemotePort;
-    /* FIXME: Calculate UDP checksum and put it in UDP header */
     UDPHeader->Checksum   = 0;
     /* Length of UDP header and data */
     UDPHeader->Length     = WH2N(DataLength + sizeof(UDP_HEADER));
+
+    TI_DbgPrint(MID_TRACE, ("Copying data (hdr %x data %x (%d))\n",
+			    IPPacket->Header, IPPacket->Data,
+			    (PCHAR)IPPacket->Data - (PCHAR)IPPacket->Header));
+
+    RtlCopyMemory(IPPacket->Data, Data, DataLength);
+
+    UDPHeader->Checksum = UDPv4ChecksumCalculate((PIPv4_HEADER)IPPacket->Header,
+                                                 (PUCHAR)UDPHeader,
+                                                 DataLength + sizeof(UDP_HEADER));
+    UDPHeader->Checksum = WH2N(UDPHeader->Checksum);
 
     TI_DbgPrint(MID_TRACE, ("Packet: %d ip %d udp %d payload\n",
 			    (PCHAR)UDPHeader - (PCHAR)IPPacket->Header,
@@ -105,7 +116,7 @@
     switch (RemoteAddress->Type) {
     case IP_ADDRESS_V4:
 	Status = AddUDPHeaderIPv4(RemoteAddress, RemotePort,
-				  LocalAddress, LocalPort, Packet, DataLen);
+				  LocalAddress, LocalPort, Packet, DataBuffer, DataLen);
 	break;
     case IP_ADDRESS_V6:
 	/* FIXME: Support IPv6 */
@@ -120,12 +131,6 @@
 	FreeNdisPacket(Packet->NdisPacket);
 	return Status;
     }
-
-    TI_DbgPrint(MID_TRACE, ("Copying data (hdr %x data %x (%d))\n",
-			    Packet->Header, Packet->Data,
-			    (PCHAR)Packet->Data - (PCHAR)Packet->Header));
-
-    RtlCopyMemory( Packet->Data, DataBuffer, DataLen );
 
     TI_DbgPrint(MID_TRACE, ("Displaying packet\n"));
 
@@ -258,7 +263,15 @@
 
   UDPHeader = (PUDP_HEADER)IPPacket->Data;
 
-  /* FIXME: Calculate and validate UDP checksum */
+  /* Calculate and validate UDP checksum */
+  i = UDPv4ChecksumCalculate(IPv4Header,
+                             (PUCHAR)UDPHeader,
+                             WH2N(UDPHeader->Length));
+  if (i != DH2N(0x0000FFFF))
+  {
+      TI_DbgPrint(MIN_TRACE, ("Bad checksum on packet received.\n"));
+      return;
+  }
 
   /* Sanity checks */
   i = WH2N(UDPHeader->Length);