Git conversion: Make reactos the root directory, move rosapps, rostests, wallpapers into modules, and delete rossubsys.

2025-07-23 09:43:40 +00:00 · 2017-10-03 07:45:34 +00:00 · 2017-10-03 07:45:34 +00:00 · c2c66aff7d
commit c2c66aff7d
parent b94e2d8ca0
24198 changed files with 0 additions and 37285 deletions
--- a/sdk/lib/drivers/ip/network/checksum.c
+++ b/sdk/lib/drivers/ip/network/checksum.c
@ -0,0 +1,105 @@
+/*
+ * COPYRIGHT:   See COPYING in the top level directory
+ * PROJECT:     ReactOS TCP/IP protocol driver
+ * FILE:        tcpip/checksum.c
+ * PURPOSE:     Checksum routines
+ * NOTES:       The checksum routine is from RFC 1071
+ * PROGRAMMERS: Casper S. Hornstrup (chorns@users.sourceforge.net)
+ * REVISIONS:
+ *   CSH 01/08-2000 Created
+ */
+
+#include "precomp.h"
+
+
+ULONG ChecksumFold(
+  ULONG Sum)
+{
+  /* Fold 32-bit sum to 16 bits */
+  while (Sum >> 16)
+    {
+      Sum = (Sum & 0xFFFF) + (Sum >> 16);
+    }
+
+  return Sum;
+}
+
+ULONG ChecksumCompute(
+  PVOID Data,
+  UINT Count,
+  ULONG Seed)
+/*
+ * FUNCTION: Calculate checksum of a buffer
+ * ARGUMENTS:
+ *     Data  = Pointer to buffer with data
+ *     Count = Number of bytes in buffer
+ *     Seed  = Previously calculated checksum (if any)
+ * RETURNS:
+ *     Checksum of buffer
+ */
+{
+  register ULONG Sum = Seed;
+
+  while (Count > 1)
+    {
+      Sum += *(PUSHORT)Data;
+      Count -= 2;
+      Data = (PVOID)((ULONG_PTR) Data + 2);
+    }
+
+  /* Add left-over byte, if any */
+  if (Count > 0)
+    {
+      Sum += *(PUCHAR)Data;
+    }
+
+  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)
+      DataLength++;
+
+  /* Add from the UDP header and data */
+  for (i = 0; i < DataLength; i += 2)
+  {
+       TmpSum = ((PacketBuffer[i] << 8) & 0xFF00) +
+                ((Pad && i == DataLength - 2) ? 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);
+}
+