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// Copyright (c) 2009 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 "net/proxy/init_proxy_resolver.h"
#include "base/compiler_specific.h"
#include "base/logging.h"
#include "net/base/net_errors.h"
#include "net/proxy/proxy_config.h"
#include "net/proxy/proxy_resolver.h"
#include "net/proxy/proxy_script_fetcher.h"
namespace net {
InitProxyResolver::InitProxyResolver(ProxyResolver* resolver,
ProxyScriptFetcher* proxy_script_fetcher)
: resolver_(resolver),
proxy_script_fetcher_(proxy_script_fetcher),
ALLOW_THIS_IN_INITIALIZER_LIST(io_callback_(
this, &InitProxyResolver::OnIOCompletion)),
user_callback_(NULL),
current_pac_url_index_(0u),
next_state_(STATE_NONE) {
}
InitProxyResolver::~InitProxyResolver() {
switch (next_state_) {
case STATE_FETCH_PAC_SCRIPT_COMPLETE:
proxy_script_fetcher_->Cancel();
break;
case STATE_SET_PAC_SCRIPT_COMPLETE:
resolver_->CancelSetPacScript();
break;
default:
break;
}
}
int InitProxyResolver::Init(const ProxyConfig& config,
CompletionCallback* callback) {
DCHECK_EQ(STATE_NONE, next_state_);
DCHECK(callback);
DCHECK(config.MayRequirePACResolver());
pac_urls_ = BuildPacUrlsFallbackList(config);
DCHECK(!pac_urls_.empty());
next_state_ = GetStartState();
int rv = DoLoop(OK);
if (rv == ERR_IO_PENDING)
user_callback_ = callback;
return rv;
}
// Initialize the fallback rules.
// (1) WPAD
// (2) Custom PAC URL.
InitProxyResolver::UrlList InitProxyResolver::BuildPacUrlsFallbackList(
const ProxyConfig& config) const {
UrlList pac_urls;
if (config.auto_detect) {
GURL pac_url = resolver_->expects_pac_bytes() ?
GURL("http://wpad/wpad.dat") : GURL();
pac_urls.push_back(pac_url);
}
if (config.pac_url.is_valid())
pac_urls.push_back(config.pac_url);
return pac_urls;
}
void InitProxyResolver::OnIOCompletion(int result) {
DCHECK_NE(STATE_NONE, next_state_);
int rv = DoLoop(result);
if (rv != ERR_IO_PENDING)
DoCallback(rv);
}
int InitProxyResolver::DoLoop(int result) {
DCHECK_NE(next_state_, STATE_NONE);
int rv = result;
do {
State state = next_state_;
next_state_ = STATE_NONE;
switch (state) {
case STATE_FETCH_PAC_SCRIPT:
DCHECK_EQ(OK, rv);
rv = DoFetchPacScript();
break;
case STATE_FETCH_PAC_SCRIPT_COMPLETE:
rv = DoFetchPacScriptComplete(rv);
break;
case STATE_SET_PAC_SCRIPT:
DCHECK_EQ(OK, rv);
rv = DoSetPacScript();
break;
case STATE_SET_PAC_SCRIPT_COMPLETE:
rv = DoSetPacScriptComplete(rv);
break;
default:
NOTREACHED() << "bad state";
rv = ERR_UNEXPECTED;
break;
}
} while (rv != ERR_IO_PENDING && next_state_ != STATE_NONE);
return rv;
}
void InitProxyResolver::DoCallback(int result) {
DCHECK_NE(ERR_IO_PENDING, result);
DCHECK(user_callback_);
user_callback_->Run(result);
}
int InitProxyResolver::DoFetchPacScript() {
DCHECK(resolver_->expects_pac_bytes());
next_state_ = STATE_FETCH_PAC_SCRIPT_COMPLETE;
const GURL& pac_url = current_pac_url();
LOG(INFO) << "Starting fetch of PAC script " << pac_url;
return proxy_script_fetcher_->Fetch(pac_url, &pac_bytes_, &io_callback_);
}
int InitProxyResolver::DoFetchPacScriptComplete(int result) {
DCHECK(resolver_->expects_pac_bytes());
LOG(INFO) << "Completed PAC script fetch of " << current_pac_url()
<< " with result " << ErrorToString(result)
<< ". Fetched a total of " << pac_bytes_.size() << " bytes";
if (result != OK)
return TryToFallbackPacUrl(result);
next_state_ = STATE_SET_PAC_SCRIPT;
return result;
}
int InitProxyResolver::DoSetPacScript() {
const GURL& pac_url = current_pac_url();
next_state_ = STATE_SET_PAC_SCRIPT_COMPLETE;
return resolver_->expects_pac_bytes() ?
resolver_->SetPacScriptByData(pac_bytes_, &io_callback_) :
resolver_->SetPacScriptByUrl(pac_url, &io_callback_);
}
int InitProxyResolver::DoSetPacScriptComplete(int result) {
if (result != OK) {
LOG(INFO) << "Failed configuring PAC using " << current_pac_url()
<< " with error " << ErrorToString(result);
return TryToFallbackPacUrl(result);
}
return result;
}
int InitProxyResolver::TryToFallbackPacUrl(int error) {
DCHECK_LT(error, 0);
if (current_pac_url_index_ + 1 >= pac_urls_.size()) {
// Nothing left to fall back to.
return error;
}
// Advance to next URL in our list.
++current_pac_url_index_;
LOG(INFO) << "Falling back to next PAC URL...";
next_state_ = GetStartState();
return OK;
}
InitProxyResolver::State InitProxyResolver::GetStartState() const {
return resolver_->expects_pac_bytes() ?
STATE_FETCH_PAC_SCRIPT : STATE_SET_PAC_SCRIPT;
}
const GURL& InitProxyResolver::current_pac_url() const {
DCHECK_LT(current_pac_url_index_, pac_urls_.size());
return pac_urls_[current_pac_url_index_];
}
} // namespace net
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