Disallow links from being seen by the extensions via the fileapi.

base/file_util_posix.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/file_util.h"
 
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <fnmatch.h>
@@ skipping 504 matching lines @@
     // Mkdir failed, but it might have failed with EEXIST, or some other error
     // due to the the directory appearing out of thin air. This can occur if
     // two processes are trying to create the same file system tree at the same
     // time. Check to see if it exists and make sure it is a directory.
     if (!DirectoryExists(*i))
       return false;
   }
   return true;
 }
 
+// TODO(rkc): Refactor GetFileInfo and FileEnumerator to handle symlinks
+// correctly. http://code.google.com/p/chromium-os/issues/detail?id=15948
+bool IsLink(const FilePath& file_path) {
+  struct stat st;
+  // If we can't lstat the file, it's safe to assume that the file won't at
+  // least be a 'followable' link.
+  if (lstat(file_path.value().c_str(), &st) != 0)
+    return false;
+
+  if (S_ISLNK(st.st_mode))
+    return true;
+  else
+    return false;
+}
+
 bool GetFileInfo(const FilePath& file_path, base::PlatformFileInfo* results) {
   stat_wrapper_t file_info;
   if (CallStat(file_path.value().c_str(), &file_info) != 0)
     return false;
   results->is_directory = S_ISDIR(file_info.st_mode);
   results->size = file_info.st_size;
   results->last_modified = base::Time::FromTimeT(file_info.st_mtime);
   results->last_accessed = base::Time::FromTimeT(file_info.st_atime);
   results->creation_time = base::Time::FromTimeT(file_info.st_ctime);
   return true;
@@ skipping 360 matching lines @@
   if (HANDLE_EINTR(close(infile)) < 0)
     result = false;
   if (HANDLE_EINTR(close(outfile)) < 0)
     result = false;
 
   return result;
 }
 #endif  // defined(OS_MACOSX)
 
 }  // namespace file_util