- Divert driver and library now fully support multi-threaded code. This

includes making the driver handle I/O requests in parallel, and changing
  the library such that it uses overlapped I/O.  Overall the package is
  now significantly faster.
- The divert driver now only adds WFP callouts when a filter is set,
  instead of when a handle is created.
- The divert driver now attempts to avoid adding WFP callouts that are
  superfluous with respect to the filter.
- The divert driver now explicitly deletes filters and callouts during
  cleanup.  This appears to resolve a bug where network connectivity is
  sometimes lost.
- Added a new sample program: passthru.exe.  This example doesn't do anything
  interesting but is useful for speed testing.
- Rename build.sh to mingw-build.sh to avoid confusion.

examples/dirs

@@ -1,4 +1,5 @@
 DIRS= \
      netdump \
      netfilter \
+     passthru \
      webfilter

examples/passthru/Makefile

@@ -0,0 +1 @@
+!INCLUDE $(NTMAKEENV)\makefile.def

examples/passthru/passthru.c

@@ -0,0 +1,117 @@
+/*
+ * passthru.c
+ * (C) 2011, all rights reserved,
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * DESCRIPTION:
+ * This program does nothing except divert packets and re-inject them.  This is
+ * useful for performance testing.
+ *
+ * usage: netdump.exe divert-filter num-threads
+ */
+
+#include <winsock2.h>
+#include <windows.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "divert.h"
+
+#define MAXBUF  2048
+
+static DWORD passthru(LPVOID arg);
+
+/*
+ * Entry.
+ */
+int __cdecl main(int argc, char **argv)
+{
+    int num_threads, i;
+    HANDLE handle, thread;
+
+    if (argc != 3)
+    {
+        fprintf(stderr, "usage: %s filter num-threads\n", argv[0]);
+        exit(EXIT_FAILURE);
+    }
+    num_threads = atoi(argv[2]);
+    if (num_threads < 1 || num_threads > 64)
+    {
+        fprintf(stderr, "error: invalid number of threads\n");
+        exit(EXIT_FAILURE);
+    }
+
+    // Divert traffic matching the filter:
+    handle = DivertOpen(argv[1]);
+    if (handle == INVALID_HANDLE_VALUE)
+    {
+        if (GetLastError() == ERROR_INVALID_PARAMETER)
+        {
+            fprintf(stderr, "error: filter syntax error\n");
+            exit(EXIT_FAILURE);
+        }
+        fprintf(stderr, "error: failed to open Divert device (%d)\n",
+            GetLastError());
+        exit(EXIT_FAILURE);
+    }
+
+    // Start the threads
+    for (i = 1; i < num_threads; i++)
+    {
+        thread = CreateThread(NULL, 1, passthru, (LPVOID)handle, 0, NULL);
+        if (thread == NULL)
+        {
+            fprintf(stderr, "error: failed to start passthru thread (%u)\n",
+                GetLastError());
+            exit(EXIT_FAILURE);
+        }
+    }
+
+    // Main thread:
+    passthru((LPVOID)handle);
+
+    return 0;
+}
+
+// Passthru thread.
+static DWORD passthru(LPVOID arg)
+{
+    char packet[MAXBUF];
+    UINT packet_len;
+    DIVERT_ADDRESS addr;
+    HANDLE handle = (HANDLE)arg;
+
+    // Main loop:
+    while (TRUE)
+    {
+        // Read a matching packet.
+        if (!DivertRecv(handle, packet, sizeof(packet), &addr, &packet_len))
+        {
+            fprintf(stderr, "warning: failed to read packet (%d)\n",
+                GetLastError());
+            continue;
+        }
+       
+        // Re-inject the matching packet.
+        if (!DivertSend(handle, packet, packet_len, &addr, NULL))
+        {
+            fprintf(stderr, "warning: failed to reinject packet (%d)\n",
+                GetLastError());
+        }
+    }
+}
+

examples/passthru/sources

@@ -0,0 +1,36 @@
+# sources
+# (C) 2011, all rights reserved,
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# 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, see <http://www.gnu.org/licenses/>.
+
+!IF "$(_BUILDARCH)" == "x86"
+CPU=i386
+!ELSE
+CPU=$(_BUILDARCH)
+!ENDIF
+
+TARGETNAME=passthru
+TARGETTYPE=PROGRAM
+TARGETPATH=..\..\install
+TARGETLIBS=\
+    $(SDK_LIB_PATH)\setupapi.lib \
+    $(SDK_LIB_PATH)\user32.lib \
+    $(SDK_LIB_PATH)\ws2_32.lib \
+    $(TARGETPATH)\$(CPU)\divert.lib
+UMTYPE=console
+UMENTRY=main
+USE_MSVCRT=1
+INCLUDES=$(DDK_INC_PATH);$(KMDF_INC_PATH)\$(KMDF_VER_PATH);..\..\include
+SOURCES=passthru.c
+