mingw: Defer the falloc warning until falloc is specified by option

1 files changed, 19 insertions, 0 deletions

diff --git a/src/FallocFileAllocationIterator.cc b/src/FallocFileAllocationIterator.cc
index febcf19b..04590557 100644
--- a/src/FallocFileAllocationIterator.cc
+++ b/src/FallocFileAllocationIterator.cc
@@ -34,14 +34,33 @@
 /* copyright --> */
 #include "FallocFileAllocationIterator.h"
 #include "DlAbortEx.h"
+#include "util.h"
+#include "LogFactory.h"
 
 namespace aria2 {
 
+#ifdef __MINGW32__
+bool FallocFileAllocationIterator::gainPrivilegeAttempted_ = false;
+#endif // __MINGW32__
+
 FallocFileAllocationIterator::FallocFileAllocationIterator(BinaryStream* stream,
                                                            int64_t offset,
                                                            int64_t totalLength)
     : stream_(stream), offset_(offset), totalLength_(totalLength)
 {
+#ifdef __MINGW32__
+  // Windows build: --file-allocation=falloc uses SetFileValidData
+  // which requires SE_MANAGE_VOLUME_NAME privilege.  SetFileValidData
+  // has security implications (see
+  // https://msdn.microsoft.com/en-us/library/windows/desktop/aa365544%28v=vs.85%29.aspx).
+  if (!gainPrivilegeAttempted_) {
+    if (!util::gainPrivilege(SE_MANAGE_VOLUME_NAME)) {
+      A2_LOG_WARN("--file-allocation=falloc will not work properly.");
+    }
+
+    gainPrivilegeAttempted_ = true;
+  }
+#endif // __MINGW32__
 }
 
 void FallocFileAllocationIterator::allocateChunk()