Provides some of the missing POSIX file syscalls

src/shared/platform/win/nacl_host_dir.c

Index: src/shared/platform/win/nacl_host_dir.c
diff --git a/src/shared/platform/win/nacl_host_dir.c b/src/shared/platform/win/nacl_host_dir.c
index 0b1376d269a7d01d881e613b79daa8f105a892dd..ecbbce8c9961ab0aff460ce59ae276e9ac18f052 100644
--- a/src/shared/platform/win/nacl_host_dir.c
+++ b/src/shared/platform/win/nacl_host_dir.c
@@ -228,3 +228,120 @@ int NaClHostDirClose(struct NaClHostDir *d) {
   }
   return 0;
 }
+
+enum OBJECT_INFORMATION_CLASS { ObjectNameInformation = 1 };
+enum FILE_INFORMATION_CLASS { FileNameInformation = 9 };
+struct FILE_NAME_INFORMATION { ULONG FileNameLength; WCHAR FileName[1]; };
+struct IO_STATUS_BLOCK { PVOID Dummy; ULONG_PTR Information; };
+struct UNICODE_STRING { USHORT Length; USHORT MaximumLength; PWSTR Buffer; };
+struct MOUNTMGR_TARGET_NAME { USHORT DeviceNameLength; WCHAR DeviceName[1]; };
+struct MOUNTMGR_VOLUME_PATHS { ULONG MultiSzLength; WCHAR MultiSz[1]; };
+
+extern "C" NTSYSAPI NTSTATUS NTAPI NtQueryObject(IN HANDLE Handle OPTIONAL,
+    IN OBJECT_INFORMATION_CLASS ObjectInformationClass,
+    OUT PVOID ObjectInformation OPTIONAL, IN ULONG ObjectInformationLength,
+    OUT PULONG ReturnLength OPTIONAL);
+extern "C" NTSYSAPI NTSTATUS NTAPI NtQueryInformationFile(IN HANDLE FileHandle,
+    OUT PIO_STATUS_BLOCK IoStatusBlock, OUT PVOID FileInformation,
+    IN ULONG Length, IN FILE_INFORMATION_CLASS FileInformationClass);
+
+#define MOUNTMGRCONTROLTYPE ((ULONG) 'm')
+#define IOCTL_MOUNTMGR_QUERY_DOS_VOLUME_PATH \
+    CTL_CODE(MOUNTMGRCONTROLTYPE, 12, METHOD_BUFFERED, FILE_ANY_ACCESS)
+
+union ANY_BUFFER {
+    MOUNTMGR_TARGET_NAME TargetName;
+    MOUNTMGR_VOLUME_PATHS TargetPaths;
+    FILE_NAME_INFORMATION NameInfo;
+    UNICODE_STRING UnicodeString;
+    WCHAR Buffer[USHRT_MAX];
+};
+
+int NaClHostDescFchdir(struct NaClHostDir *d) {
+  static ANY_BUFFER nameFull, nameRel, nameMnt;
+  ULONG returnedLength;
+  IO_STATUS_BLOCK iosb;
+  NTSTATUS status;
+
+  if (0 != NtQueryObject(d->handle,
+                         ObjectNameInformation,
+                         nameFull.Buffer,
+                         sizeof(nameFull.Buffer),
+                         &returnedLength)) {
+  }
+
+  if (0 != NtQueryInformationFile(hFile,
+                                  &iosb,
+                                  nameRel.Buffer,
+                                  sizeof(nameRel.Buffer),
+                                  FileNameInformation)) {
+  }
+
+  /*I'm not sure how this works with network paths... */
+  assert(nameFull.UnicodeString.Length >= nameRel.NameInfo.FileNameLength);
+  nameMnt.TargetName.DeviceNameLength = (USHORT)(
+      nameFull.UnicodeString.Length - nameRel.NameInfo.FileNameLength);
+  wcsncpy(nameMnt.TargetName.DeviceName, nameFull.UnicodeString.Buffer,
+      nameMnt.TargetName.DeviceNameLength / sizeof(WCHAR));
+  HANDLE hMountPointMgr = CreateFile(_T("\\\\.\\MountPointManager"),
+      0, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
+      NULL, OPEN_EXISTING, 0, NULL);
+  __try
+  {
+      DWORD bytesReturned;
+      BOOL success = DeviceIoControl(hMountPointMgr,
+          IOCTL_MOUNTMGR_QUERY_DOS_VOLUME_PATH, &nameMnt,
+          sizeof(nameMnt), &nameMnt, sizeof(nameMnt),
+          &bytesReturned, NULL);
+      assert(success && nameMnt.TargetPaths.MultiSzLength > 0);
+      wcsncat(nameMnt.TargetPaths.MultiSz, nameRel.NameInfo.FileName,
+          nameRel.NameInfo.FileNameLength / sizeof(WCHAR));
+      return nameMnt.TargetPaths.MultiSz;
+  }
+  __finally { CloseHandle(hMountPointMgr); }
+
+  /*FILE_NAME_INFO name_info;
+
+  if (!GetFileInformationByHandleEx(d->handle,
+                                    FileNameInfo,
+                                    &name_info,
+                                    sizeof name_info)) {
+    err = GetLastError();
+    return -NaClXlateSystemError(err);
+  }*/
+
+  if (-1 == _wchdir(name_info.FileName)) {
+    return -GetErrno(errno);
+  }
+
+  return 0;
+}
+
+int NaClHostDirFchmod(struct NaClHostDir *d, int mode) {
+  if (-1 == _chmod(path, mode)) {
+    return -GetErrno();
+  }
+  return 0;
+}
+
+int NaClHostDirFsync(struct NaClHostDir *d) {
+  DWORD err;
+
+  if (!FlushFileBuffers(d->handle)) {
+    err = GetLastError();
+    return -NaClXlateSystemError(err);
+  }
+
+  return 0;
+}
+
+int NaClHostDirFdatasync(struct NaClHostDir *d) {
+  DWORD err;
+
+  if (!FlushFileBuffers(d->handle)) {
+    err = GetLastError();
+    return -NaClXlateSystemError(err);
+  }
+
+  return 0;
+}