blob: aaefc27349ca9f3e00816943feecbdaa4f7d6424 [file] [log] [blame]
// 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 "net/proxy/dhcp_proxy_script_adapter_fetcher_win.h"
#include "base/message_loop_proxy.h"
#include "base/metrics/histogram.h"
#include "base/sys_string_conversions.h"
#include "base/task.h"
#include "base/threading/worker_pool.h"
#include "base/time.h"
#include "net/base/net_errors.h"
#include "net/proxy/dhcpcsvc_init_win.h"
#include "net/proxy/proxy_script_fetcher_impl.h"
#include "net/url_request/url_request_context.h"
#include <windows.h>
#include <winsock2.h>
#include <dhcpcsdk.h>
#pragma comment(lib, "dhcpcsvc.lib")
namespace {
// Maximum amount of time to wait for response from the Win32 DHCP API.
const int kTimeoutMs = 2000;
} // namespace
namespace net {
DhcpProxyScriptAdapterFetcher::DhcpProxyScriptAdapterFetcher(
URLRequestContext* url_request_context)
: state_(STATE_START),
result_(ERR_IO_PENDING),
callback_(NULL),
ALLOW_THIS_IN_INITIALIZER_LIST(
script_fetcher_callback_(
this, &DhcpProxyScriptAdapterFetcher::OnFetcherDone)),
url_request_context_(url_request_context) {
}
DhcpProxyScriptAdapterFetcher::~DhcpProxyScriptAdapterFetcher() {
Cancel();
// The WeakPtr we passed to the worker thread may be destroyed on the
// worker thread. This detaches any outstanding WeakPtr state from
// the current thread.
base::SupportsWeakPtr<DhcpProxyScriptAdapterFetcher>::DetachFromThread();
}
void DhcpProxyScriptAdapterFetcher::Fetch(
const std::string& adapter_name, CompletionCallback* callback) {
DCHECK(CalledOnValidThread());
DCHECK_EQ(state_, STATE_START);
result_ = ERR_IO_PENDING;
pac_script_ = string16();
state_ = STATE_WAIT_DHCP;
callback_ = callback;
wait_timer_.Start(FROM_HERE, ImplGetTimeout(),
this, &DhcpProxyScriptAdapterFetcher::OnTimeout);
worker_thread_ = ImplCreateWorkerThread(AsWeakPtr());
worker_thread_->Start(adapter_name);
}
void DhcpProxyScriptAdapterFetcher::Cancel() {
DCHECK(CalledOnValidThread());
callback_ = NULL;
wait_timer_.Stop();
script_fetcher_.reset();
switch (state_) {
case STATE_WAIT_DHCP:
// Nothing to do here, we let the worker thread run to completion,
// the task it posts back when it completes will check the state.
break;
case STATE_WAIT_URL:
break;
case STATE_START:
case STATE_FINISH:
case STATE_CANCEL:
break;
}
if (state_ != STATE_FINISH) {
result_ = ERR_ABORTED;
state_ = STATE_CANCEL;
}
}
bool DhcpProxyScriptAdapterFetcher::DidFinish() const {
DCHECK(CalledOnValidThread());
return state_ == STATE_FINISH;
}
int DhcpProxyScriptAdapterFetcher::GetResult() const {
DCHECK(CalledOnValidThread());
return result_;
}
string16 DhcpProxyScriptAdapterFetcher::GetPacScript() const {
DCHECK(CalledOnValidThread());
return pac_script_;
}
GURL DhcpProxyScriptAdapterFetcher::GetPacURL() const {
DCHECK(CalledOnValidThread());
return pac_url_;
}
DhcpProxyScriptAdapterFetcher::WorkerThread::WorkerThread(
const base::WeakPtr<DhcpProxyScriptAdapterFetcher>& owner)
: owner_(owner),
origin_loop_(base::MessageLoopProxy::current()) {
}
DhcpProxyScriptAdapterFetcher::WorkerThread::~WorkerThread() {
}
void DhcpProxyScriptAdapterFetcher::WorkerThread::Start(
const std::string& adapter_name) {
bool succeeded = base::WorkerPool::PostTask(
FROM_HERE,
NewRunnableMethod(
this,
&DhcpProxyScriptAdapterFetcher::WorkerThread::ThreadFunc,
adapter_name),
true);
DCHECK(succeeded);
}
void DhcpProxyScriptAdapterFetcher::WorkerThread::ThreadFunc(
const std::string& adapter_name) {
std::string url = ImplGetPacURLFromDhcp(adapter_name);
bool succeeded = origin_loop_->PostTask(
FROM_HERE,
NewRunnableMethod(
this,
&DhcpProxyScriptAdapterFetcher::WorkerThread::OnThreadDone,
url));
DCHECK(succeeded);
}
void DhcpProxyScriptAdapterFetcher::WorkerThread::OnThreadDone(
const std::string& url) {
DCHECK(thread_checker_.CalledOnValidThread());
if (owner_)
owner_->OnQueryDhcpDone(url);
}
std::string
DhcpProxyScriptAdapterFetcher::WorkerThread::ImplGetPacURLFromDhcp(
const std::string& adapter_name) {
return DhcpProxyScriptAdapterFetcher::GetPacURLFromDhcp(adapter_name);
}
void DhcpProxyScriptAdapterFetcher::OnQueryDhcpDone(
const std::string& url) {
DCHECK(CalledOnValidThread());
// Because we can't cancel the call to the Win32 API, we can expect
// it to finish while we are in a few different states. The expected
// one is WAIT_DHCP, but it could be in CANCEL if Cancel() was called,
// or FINISH if timeout occurred.
DCHECK(state_ == STATE_WAIT_DHCP || state_ == STATE_CANCEL ||
state_ == STATE_FINISH);
if (state_ != STATE_WAIT_DHCP)
return;
wait_timer_.Stop();
pac_url_ = GURL(url);
if (pac_url_.is_empty() || !pac_url_.is_valid()) {
result_ = ERR_PAC_NOT_IN_DHCP;
TransitionToFinish();
} else {
state_ = STATE_WAIT_URL;
script_fetcher_.reset(ImplCreateScriptFetcher());
script_fetcher_->Fetch(pac_url_, &pac_script_, &script_fetcher_callback_);
}
}
void DhcpProxyScriptAdapterFetcher::OnTimeout() {
DCHECK_EQ(state_, STATE_WAIT_DHCP);
result_ = ERR_TIMED_OUT;
TransitionToFinish();
}
void DhcpProxyScriptAdapterFetcher::OnFetcherDone(int result) {
DCHECK(CalledOnValidThread());
DCHECK(state_ == STATE_WAIT_URL || state_ == STATE_CANCEL);
if (state_ == STATE_CANCEL)
return;
// At this point, pac_script_ has already been written to.
script_fetcher_.reset();
result_ = result;
TransitionToFinish();
}
void DhcpProxyScriptAdapterFetcher::TransitionToFinish() {
DCHECK(state_ == STATE_WAIT_DHCP || state_ == STATE_WAIT_URL);
state_ = STATE_FINISH;
CompletionCallback* callback = callback_;
callback_ = NULL;
// Be careful not to touch any member state after this, as the client
// may delete us during this callback.
callback->Run(result_);
}
DhcpProxyScriptAdapterFetcher::State
DhcpProxyScriptAdapterFetcher::state() const {
return state_;
}
ProxyScriptFetcher* DhcpProxyScriptAdapterFetcher::ImplCreateScriptFetcher() {
return new ProxyScriptFetcherImpl(url_request_context_);
}
DhcpProxyScriptAdapterFetcher::WorkerThread*
DhcpProxyScriptAdapterFetcher::ImplCreateWorkerThread(
const base::WeakPtr<DhcpProxyScriptAdapterFetcher>& owner) {
return new WorkerThread(owner);
}
base::TimeDelta DhcpProxyScriptAdapterFetcher::ImplGetTimeout() const {
return base::TimeDelta::FromMilliseconds(kTimeoutMs);
}
// static
std::string DhcpProxyScriptAdapterFetcher::GetPacURLFromDhcp(
const std::string& adapter_name) {
EnsureDhcpcsvcInit();
std::wstring adapter_name_wide = base::SysMultiByteToWide(adapter_name,
CP_ACP);
DHCPCAPI_PARAMS_ARRAY send_params = { 0, NULL };
BYTE option_data[] = { 1, 252 };
DHCPCAPI_PARAMS wpad_params = { 0 };
wpad_params.OptionId = 252;
wpad_params.IsVendor = FALSE; // Surprising, but intentional.
DHCPCAPI_PARAMS_ARRAY request_params = { 0 };
request_params.nParams = 1;
request_params.Params = &wpad_params;
// The maximum message size is typically 4096 bytes on Windows per
// http://support.microsoft.com/kb/321592
DWORD result_buffer_size = 4096;
scoped_ptr_malloc<BYTE> result_buffer;
int retry_count = 0;
DWORD res = NO_ERROR;
do {
result_buffer.reset(reinterpret_cast<BYTE*>(malloc(result_buffer_size)));
// Note that while the DHCPCAPI_REQUEST_SYNCHRONOUS flag seems to indicate
// there might be an asynchronous mode, there seems to be (at least in
// terms of well-documented use of this API) only a synchronous mode, with
// an optional "async notifications later if the option changes" mode.
// Even IE9, which we hope to emulate as IE is the most widely deployed
// previous implementation of the DHCP aspect of WPAD and the only one
// on Windows (Konqueror is the other, on Linux), uses this API with the
// synchronous flag. There seem to be several Microsoft Knowledge Base
// articles about calls to this function failing when other flags are used
// (e.g. http://support.microsoft.com/kb/885270) so we won't take any
// chances on non-standard, poorly documented usage.
res = ::DhcpRequestParams(DHCPCAPI_REQUEST_SYNCHRONOUS,
NULL,
const_cast<LPWSTR>(adapter_name_wide.c_str()),
NULL,
send_params, request_params,
result_buffer.get(), &result_buffer_size,
NULL);
++retry_count;
} while (res == ERROR_MORE_DATA && retry_count <= 3);
if (res != NO_ERROR) {
LOG(INFO) << "Error fetching PAC URL from DHCP: " << res;
UMA_HISTOGRAM_COUNTS("Net.DhcpWpadUnhandledDhcpError", 1);
} else if (wpad_params.nBytesData) {
// The result should be ASCII, not wide character.
DCHECK_EQ(strlen(reinterpret_cast<const char*>(wpad_params.Data)) + 1,
wpad_params.nBytesData);
// Return only up to the first null in case of embedded NULLs; if the
// server is giving us back a buffer with embedded NULLs, something is
// broken anyway.
return std::string(reinterpret_cast<const char *>(wpad_params.Data));
}
return "";
}
} // namespace net