MdeModulePkg: Use monotonic count to initialize the NetLib random seed.

[mirror_edk2.git] / MdeModulePkg / Library / DxeNetLib / DxeNetLib.c

diff --git a/MdeModulePkg/Library/DxeNetLib/DxeNetLib.c b/MdeModulePkg/Library/DxeNetLib/DxeNetLib.c
index ce26b322bcb2cf619e705ae1e66af847fa019930..57e8f9f27b0dff0cf68a8dfac738800242180a1d 100644 (file)
--- a/MdeModulePkg/Library/DxeNetLib/DxeNetLib.c
+++ b/MdeModulePkg/Library/DxeNetLib/DxeNetLib.c
@@ -853,11 +853,11 @@ Ip6Swap128 (
 }\r
 \r
 /**\r
-  Initialize a random seed using current time.\r
+  Initialize a random seed using current time and monotonic count.\r
 \r
-  Get current time first. Then initialize a random seed based on some basic\r
-  mathematics operation on the hour, day, minute, second, nanosecond and year\r
-  of the current time.\r
+  Get current time and monotonic count first. Then initialize a random seed \r
+  based on some basic mathematics operation on the hour, day, minute, second,\r
+  nanosecond and year of the current time and the monotonic count value.\r
 \r
   @return The random seed initialized with current time.\r
 \r
@@ -870,12 +870,16 @@ NetRandomInitSeed (
 {\r
   EFI_TIME                  Time;\r
   UINT32                    Seed;\r
+  UINT64                    MonotonicCount;\r
 \r
   gRT->GetTime (&Time, NULL);\r
   Seed = (~Time.Hour << 24 | Time.Day << 16 | Time.Minute << 8 | Time.Second);\r
   Seed ^= Time.Nanosecond;\r
   Seed ^= Time.Year << 7;\r
 \r
+  gBS->GetNextMonotonicCount (&MonotonicCount);\r
+  Seed += (UINT32) MonotonicCount;\r
+\r
   return Seed;\r
 }\r
 \r