blob: cea2329290af8ed94d54fff0f9efa4ec04a1721f [file] [log] [blame]
// Copyright (c) 2012 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 <stddef.h>
#include <memory>
#include <string>
#include <vector>
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/strings/string16.h"
#include "base/time/time.h"
#include "base/timer/timer.h"
#include "net/base/completion_once_callback.h"
#include "net/base/net_export.h"
#include "net/dns/host_resolver.h"
#include "net/log/net_log_with_source.h"
#include "net/proxy_resolution/proxy_config_with_annotation.h"
#include "net/proxy_resolution/proxy_resolver.h"
#include "url/gurl.h"
namespace base {
class Value;
namespace net {
class DhcpPacFileFetcher;
class NetLog;
class ProxyResolver;
class PacFileFetcher;
// Structure that encapsulates the result a PacFileData along with an
// indication of its origin: was it obtained implicitly from auto-detect,
// or was it read from a more explicitly configured URL.
// Note that |!from_auto_detect| does NOT imply the script was securely
// delivered. Most commonly PAC scripts are configured from http:// URLs,
// both for auto-detect and not.
struct NET_EXPORT_PRIVATE PacFileDataWithSource {
explicit PacFileDataWithSource(const PacFileDataWithSource&);
PacFileDataWithSource& operator=(const PacFileDataWithSource&);
scoped_refptr<PacFileData> data;
bool from_auto_detect = false;
// PacFileDecider is a helper class used by ConfiguredProxyResolutionService to
// determine which PAC script to use given our proxy configuration.
// This involves trying to use PAC scripts in this order:
// (1) WPAD (DHCP) if auto-detect is on.
// (2) WPAD (DNS) if auto-detect is on.
// (3) Custom PAC script if a URL was given.
// If no PAC script was successfully selected, then it fails with either a
// network error, or PAC_SCRIPT_FAILED (indicating it did not pass our
// validation).
// On successful completion, the fetched PAC script data can be accessed using
// script_data().
// Deleting PacFileDecider while Init() is in progress, will
// cancel the request.
class NET_EXPORT_PRIVATE PacFileDecider {
// |pac_file_fetcher|, |dhcp_pac_file_fetcher| and
// |net_log| must remain valid for the lifespan of PacFileDecider.
PacFileDecider(PacFileFetcher* pac_file_fetcher,
DhcpPacFileFetcher* dhcp_pac_file_fetcher,
NetLog* net_log);
// Aborts any in-progress request.
// Evaluates the effective proxy settings for |config|, and downloads the
// associated PAC script.
// If |wait_delay| is positive, the initialization will pause for this
// amount of time before getting started.
// On successful completion, the "effective" proxy settings we ended up
// deciding on will be available vial the effective_settings() accessor.
// Note that this may differ from |config| since we will have stripped any
// manual settings, and decided whether to use auto-detect or the custom PAC
// URL. Finally, if auto-detect was used we may now have resolved that to a
// specific script URL.
int Start(const ProxyConfigWithAnnotation& config,
const base::TimeDelta wait_delay,
bool fetch_pac_bytes,
CompletionOnceCallback callback);
// Shuts down any in-progress DNS requests, and cancels any ScriptFetcher
// requests. Does not call OnShutdown() on the [Dhcp]PacFileFetcher. Any
// pending callback will not be invoked.
void OnShutdown();
const ProxyConfigWithAnnotation& effective_config() const;
const PacFileDataWithSource& script_data() const;
void set_quick_check_enabled(bool enabled) { quick_check_enabled_ = enabled; }
bool quick_check_enabled() const { return quick_check_enabled_; }
// Represents the sources from which we can get PAC files; two types of
// auto-detect or a custom URL.
struct PacSource {
PacSource(Type type, const GURL& url) : type(type), url(url) {}
// Returns a Value representing the PacSource. |effective_pac_url| is the
// URL derived from information contained in
// |this|, if Type is not WPAD_DHCP.
base::Value NetLogParams(const GURL& effective_pac_url) const;
Type type;
GURL url; // Empty unless |type == PAC_SOURCE_CUSTOM|.
typedef std::vector<PacSource> PacSourceList;
enum State {
// Returns ordered list of PAC urls to try for |config|.
PacSourceList BuildPacSourcesFallbackList(const ProxyConfig& config) const;
void OnIOCompletion(int result);
int DoLoop(int result);
int DoWait();
int DoWaitComplete(int result);
int DoQuickCheck();
int DoQuickCheckComplete(int result);
int DoFetchPacScript();
int DoFetchPacScriptComplete(int result);
int DoVerifyPacScript();
int DoVerifyPacScriptComplete(int result);
// Tries restarting using the next fallback PAC URL:
// |pac_sources_[++current_pac_source_index]|.
// Returns OK and rewinds the state machine when there
// is something to try, otherwise returns |error|.
int TryToFallbackPacSource(int error);
// Gets the initial state (we skip fetching when the
// ProxyResolver doesn't |expect_pac_bytes()|.
State GetStartState() const;
void DetermineURL(const PacSource& pac_source, GURL* effective_pac_url);
// Returns the current PAC URL we are fetching/testing.
const PacSource& current_pac_source() const;
void OnWaitTimerFired();
void DidComplete();
void Cancel();
PacFileFetcher* pac_file_fetcher_;
DhcpPacFileFetcher* dhcp_pac_file_fetcher_;
CompletionOnceCallback callback_;
size_t current_pac_source_index_;
// Filled when the PAC script fetch completes.
base::string16 pac_script_;
// Flag indicating whether the caller requested a mandatory PAC script
// (i.e. fallback to direct connections are prohibited).
bool pac_mandatory_;
// Whether we have an existing custom PAC URL.
bool have_custom_pac_url_;
PacSourceList pac_sources_;
State next_state_;
NetLogWithSource net_log_;
bool fetch_pac_bytes_;
base::TimeDelta wait_delay_;
base::OneShotTimer wait_timer_;
net::MutableNetworkTrafficAnnotationTag traffic_annotation_;
// Whether to do DNS quick check
bool quick_check_enabled_;
// Results.
ProxyConfigWithAnnotation effective_config_;
PacFileDataWithSource script_data_;
std::unique_ptr<HostResolver::ResolveHostRequest> resolve_request_;
base::OneShotTimer quick_check_timer_;
} // namespace net