Reverse order of WinDivert handle priorities.

Higher values now correspond to higher
priorities.

Author: basil00

CHANGELOG

@@ -276,3 +276,7 @@ WinDivert 2.0.0-rc
       ip.TTL/ipv6.HopLimit field of a packet.
     - Add new WinDivertHelperNto*()/WinDivertHelperHton*() helper functions
       for swapping from network to host byte ordering, and vice versa.
+    - WinDivertOpen() priorities now are ascending, meaning that higher
+      values correspond to higher priorities.
+    - The last two arguments for WinDivertRecv() and WinDivertSend() have been
+      swapped.

include/windivert.h

@@ -300,8 +300,8 @@ extern WINDIVERTEXPORT BOOL WinDivertGetParam(
 /*
  * WinDivert constants.
  */
-#define WINDIVERT_PRIORITY_LOWEST               30000
-#define WINDIVERT_PRIORITY_HIGHEST              (-WINDIVERT_PRIORITY_LOWEST)
+#define WINDIVERT_PRIORITY_HIGHEST              30000
+#define WINDIVERT_PRIORITY_LOWEST               (-WINDIVERT_PRIORITY_HIGHEST)
 #define WINDIVERT_PARAM_QUEUE_LENGTH_DEFAULT    4096
 #define WINDIVERT_PARAM_QUEUE_LENGTH_MIN        32
 #define WINDIVERT_PARAM_QUEUE_LENGTH_MAX        16384

include/windivert_device.h

@@ -219,8 +219,8 @@
 /*
  * WinDivert priorities.
  */
-#define WINDIVERT_PRIORITY_MAX                      WINDIVERT_PRIORITY_LOWEST
-#define WINDIVERT_PRIORITY_MIN                      WINDIVERT_PRIORITY_HIGHEST
+#define WINDIVERT_PRIORITY_MAX                      WINDIVERT_PRIORITY_HIGHEST
+#define WINDIVERT_PRIORITY_MIN                      WINDIVERT_PRIORITY_LOWEST
 
 /*
  * WinDivert message definitions.

sys/windivert.c

@@ -317,7 +317,7 @@ static MM_PAGE_PRIORITY no_write_flag = 0;
 static MM_PAGE_PRIORITY no_exec_flag  = 0;
 
 /*
- * Priorities & weights.
+ * Priorities.
  */
 static UINT32 windivert_context_priority(UINT32 priority)
 {
@@ -328,9 +328,6 @@ static UINT32 windivert_context_priority(UINT32 priority)
     return priority;
 }
 
-#define WINDIVERT_FILTER_WEIGHT(priority)                                   \
-    ((UINT64)((UINT64)UINT32_MAX - (priority)))
-
 /*
  * Prototypes.
  */
@@ -1674,7 +1671,7 @@ static NTSTATUS windivert_install_callout(context_t context, UINT idx,
     engine_handle = context->engine_handle;
     KeReleaseInStackQueuedSpinLock(&lock_handle);
 
-    weight = WINDIVERT_FILTER_WEIGHT(priority);
+    weight = (UINT64)priority;
 
     RtlZeroMemory(&scallout, sizeof(scallout));
     scallout.calloutKey              = callout_guid;
@@ -1876,7 +1873,6 @@ extern VOID windivert_cleanup(IN WDFFILEOBJECT object)
     WDFWORKITEM worker;
     LONGLONG timestamp;
     BOOL sniff_mode, timeout, forward;
-    UINT priority;
     NTSTATUS status;
 
     DEBUG("CLEANUP: cleaning up WinDivert context (context=%p)", context);
@@ -1897,7 +1893,6 @@ extern VOID windivert_cleanup(IN WDFFILEOBJECT object)
     context->state = WINDIVERT_CONTEXT_STATE_CLOSING;
     sniff_mode = ((context->flags & WINDIVERT_FLAG_SNIFF) != 0);
     forward = (context->layer == WINDIVERT_LAYER_NETWORK_FORWARD);
-    priority = context->priority;
     while (!IsListEmpty(&context->flow_set))
     {
         entry = RemoveHeadList(&context->flow_set);
@@ -3664,7 +3659,7 @@ static void windivert_network_classify(context_t context,
         packet_state == FWPS_PACKET_PREVIOUSLY_INJECTED_BY_SELF)
     {
         packet_priority = (UINT32)packet_context;
-        if (packet_priority >= priority)
+        if (packet_priority <= priority)
         {
             WdfObjectDereference(object);
             return;

test/test.c

@@ -855,9 +855,9 @@ int main(void)
     // Open handles to:
     // (1) stop normal traffic from interacting with the tests; and
     // (2) stop test packets escaping to the Internet or TCP/IP stack.
-    upper_handle = WinDivertOpen("true", WINDIVERT_LAYER_NETWORK, -999,
+    upper_handle = WinDivertOpen("true", WINDIVERT_LAYER_NETWORK, 9999,
         WINDIVERT_FLAG_DROP);
-    lower_handle = WinDivertOpen("true", WINDIVERT_LAYER_NETWORK, 999,
+    lower_handle = WinDivertOpen("true", WINDIVERT_LAYER_NETWORK, -9999,
         WINDIVERT_FLAG_DROP);
     if (upper_handle == INVALID_HANDLE_VALUE ||
         lower_handle == INVALID_HANDLE_VALUE)
@@ -1018,14 +1018,14 @@ static BOOL run_test(HANDLE inject_handle, const char *filter,
     }
 
     // (1) Open WinDivert handles:
-    handle[0] = WinDivertOpen(object, WINDIVERT_LAYER_NETWORK, 777, 0);
+    handle[0] = WinDivertOpen(object, WINDIVERT_LAYER_NETWORK, 8888, 0);
     if (handle[0] == INVALID_HANDLE_VALUE)
     {
         fprintf(stderr, "error: failed to open WinDivert handle for filter "
             "\"%s\" (err = %d)\n", filter, GetLastError());
         goto failed;
     }
-    handle[1] = WinDivertOpen("true", WINDIVERT_LAYER_NETWORK, 888, 0);
+    handle[1] = WinDivertOpen("true", WINDIVERT_LAYER_NETWORK, 7777, 0);
     if (handle[1] == INVALID_HANDLE_VALUE)
     {
         fprintf(stderr, "error: failed to open WinDivert handle "
@@ -1244,7 +1244,7 @@ static DWORD monitor_worker(LPVOID arg)
     PWINDIVERT_IPHDR iphdr;
     UINT i;
 
-    snprintf(filter, sizeof(filter), "processId=%d and priority=777 and "
+    snprintf(filter, sizeof(filter), "processId=%d and priority=8888 and "
         "event=OPEN", GetCurrentProcessId());
     HANDLE handle = WinDivertOpen(filter, WINDIVERT_LAYER_REFLECT, 0,
         WINDIVERT_FLAG_SNIFF | WINDIVERT_FLAG_RECV_ONLY);