[PPAPI] Quarantine files that are writeable by a Pepper plugin.

content/common/quarantine/quarantine_linux.cc

Index: content/common/quarantine/quarantine_linux.cc
diff --git a/content/browser/download/quarantine_linux.cc b/content/common/quarantine/quarantine_linux.cc
similarity index 64%
rename from content/browser/download/quarantine_linux.cc
rename to content/common/quarantine/quarantine_linux.cc
index 293dd46f107e4579b45b91af4b36a1c822c1d573..af207836d758758c495114eae6674f5bdad655e8 100644
--- a/content/browser/download/quarantine_linux.cc
+++ b/content/common/quarantine/quarantine_linux.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "content/browser/download/quarantine.h"
+#include "content/public/common/quarantine.h"
 
 #include <stddef.h>
 #include <sys/types.h>
@@ -12,7 +12,7 @@
 #include "base/files/file_util.h"
 #include "base/logging.h"
 #include "base/threading/thread_restrictions.h"
-#include "content/browser/download/quarantine_constants_linux.h"
+#include "content/common/quarantine/quarantine_constants_linux.h"
 #include "url/gurl.h"
 
 namespace content {
@@ -37,6 +37,19 @@ bool SetExtendedFileAttribute(const char* path,
   return true;
 }
 
+std::string GetExtendedFileAttribute(const char* path, const char* name) {
+  base::ThreadRestrictions::AssertIOAllowed();
+  ssize_t len = getxattr(path, name, nullptr, 0);
+  if (len <= 0)
+    return std::string();
+
+  std::vector<char> buffer(len);
+  len = getxattr(path, name, buffer.data(), buffer.size());
+  if (len < static_cast<ssize_t>(buffer.size()))
+    return std::string();
+  return std::string(buffer.begin(), buffer.end());
+}
+
 }  // namespace
 
 QuarantineFileResult QuarantineFile(const base::FilePath& file,
@@ -63,4 +76,24 @@ QuarantineFileResult QuarantineFile(const base::FilePath& file,
              : QuarantineFileResult::ANNOTATION_FAILED;
 }
 
+bool IsFileQuarantined(const base::FilePath& file,
+                       const GURL& source_url,
+                       const GURL& referrer_url) {
+  if (!base::PathExists(file))
+    return false;
+
+  std::string url_value = GetExtendedFileAttribute(file.value().c_str(),
+                                                   kSourceURLExtendedAttrName);
+  if (source_url.is_empty())
+    return !url_value.empty();
+
+  if (source_url != GURL(url_value))
+    return false;
+
+  return !referrer_url.is_valid() ||
+         GURL(GetExtendedFileAttribute(file.value().c_str(),
+                                       kReferrerURLExtendedAttrName)) ==
+             referrer_url;
+}
+
 }  // namespace content