This adds a plugin selection policy for selecting allowed plugins

chrome/browser/chromeos/plugin_selection_policy.cc

+// Copyright (c) 2010 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 "chrome/browser/chromeos/plugin_selection_policy.h"
+
+#include <algorithm>
+#include <iostream>
+#include <map>
+#include <sstream>
+#include <string>
+#include <vector>
+
+#include "base/file_path.h"
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/string_util.h"
+#include "chrome/browser/browser_thread.h"
+#include "googleurl/src/gurl.h"
+
+#if !defined(OS_CHROMEOS)
+#error This file is meant to be compiled on ChromeOS only.
+#endif
+
+using std::vector;
+using std::string;
+using std::pair;
+using std::map;
+
+namespace chromeos {
+
+static const char kPluginSelectionPolicyFile[] =
+    "/usr/share/chromeos-assets/flash/plugin_policy";
+
+PluginSelectionPolicy::PluginSelectionPolicy() : initialized_(false) {
+}
+
+void PluginSelectionPolicy::StartInit() {
+  // Initialize the policy on the FILE thread, since it reads from a
+  // policy file.
+  BrowserThread::PostTask(
+      BrowserThread::FILE, FROM_HERE,
+      NewRunnableMethod(this, &chromeos::PluginSelectionPolicy::Init));
+}
+
+bool PluginSelectionPolicy::Init() {
+  return InitFromFile(FilePath(kPluginSelectionPolicyFile));
+}
+
+bool PluginSelectionPolicy::InitFromFile(const FilePath& policy_file) {
+  // This must always be called from the FILE thread.
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+
+  string data;
+  // This should be a really small file, so we're OK with just
+  // slurping it.
+  if (!file_util::ReadFileToString(policy_file, &data)) {
+    LOG(ERROR) << "Unable to read plugin policy file \""
+               << policy_file.value() << "\".";
+    return false;
+  }
+
+  std::istringstream input_stream(data);
+  string line;
+  map<string, Policy> policies;
+  Policy policy;
+  string last_plugin;
+
+  while (std::getline(input_stream, line)) {
+    // Strip comments.
+    string::size_type pos = line.find("#");
+    if (pos != string::npos) {
+      line = line.substr(0, pos);
+    }
+    TrimWhitespaceASCII(line, TRIM_ALL, &line);
+    if (line.find("allow") == 0) {
+      // Has to be preceeded by a "plugin" statement.
+      if (last_plugin.empty()) {
+        LOG(ERROR) << "Plugin policy file error: 'allow' out of context.";
+        return false;
+      }
+      line = line.substr(6);
+      TrimWhitespaceASCII(line, TRIM_ALL, &line);
+      line = StringToLowerASCII(line);
+      policy.push_back(make_pair(true, line));
+    }
+    if (line.find("deny") == 0) {
+      // Has to be preceeded by a "plugin" statement.
+      if (last_plugin.empty()) {
+        LOG(ERROR) << "Plugin policy file error: 'deny' out of context.";
+        return false;
+      }
+      line = line.substr(5);
+      TrimWhitespaceASCII(line, TRIM_ALL, &line);
+      line = StringToLowerASCII(line);
+      policy.push_back(make_pair(false, line));
+    }
+    if (line.find("plugin") == 0) {
+      line = line.substr(7);
+      TrimWhitespaceASCII(line, TRIM_ALL, &line);
+      if (!policy.empty() && !last_plugin.empty())
+        policies.insert(make_pair(last_plugin, policy));
+      last_plugin = line;
+      policy.clear();
+    }
+  }
+
+  if (!last_plugin.empty())
+    policies.insert(make_pair(last_plugin, policy));
+
+  policies_.swap(policies);
+  initialized_ = true;
+  return true;
+}
+
+int PluginSelectionPolicy::FindFirstAllowed(
+    const GURL& url,
+    const std::vector<WebPluginInfo>& info) {
+  for (std::vector<WebPluginInfo>::size_type i = 0; i < info.size(); ++i) {
+    if (IsAllowed(url, info[i].path))
+      return i;
+  }
+  return -1;
+}
+
+bool PluginSelectionPolicy::IsAllowed(const GURL& url,
+                                      const FilePath& path) {
+  // This must always be called from the FILE thread, to be sure
+  // initialization doesn't happen at the same time.
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE));
+
+  // Make sure that we notice if this starts being called before
+  // initialization is complete.  Right now it is guaranteed only by
+  // the startup order and the fact that InitFromFile runs on the FILE
+  // thread too.
+  DCHECK(initialized_) << "Tried to check policy before policy is initialized.";
+
+  string name = path.BaseName().value();
+
+  PolicyMap::iterator policy_iter = policies_.find(name);
+  if (policy_iter != policies_.end()) {
+    Policy& policy(policy_iter->second);
+
+    // We deny by default. (equivalent to "deny" at the top of the section)
+    bool allow = false;
+
+    for (Policy::iterator iter = policy.begin(); iter != policy.end(); ++iter) {
+      bool policy_allow = iter->first;
+      string& policy_domain = iter->second;
+      if (policy_domain.empty() || url.DomainIs(policy_domain.c_str(),
+                                                policy_domain.size())) {
+        allow = policy_allow;
+      }
+    }
+    return allow;
+  }
+
+  // If it's not in the policy file, then we assume it's OK to allow
+  // it.
+  return true;
+}
+
+}  // namespace chromeos