blob: 7025e72696eabac7052e0a45a9f5c39f57e9110c [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/proxy_script_fetcher_impl.h"
#include "base/compiler_specific.h"
#include "base/i18n/icu_string_conversions.h"
#include "base/logging.h"
#include "base/message_loop.h"
#include "base/string_util.h"
#include "net/base/data_url.h"
#include "net/base/io_buffer.h"
#include "net/base/load_flags.h"
#include "net/base/net_errors.h"
#include "net/http/http_response_headers.h"
#include "net/url_request/url_request_context.h"
// TODO(eroman):
// - Support auth-prompts (http://crbug.com/77366)
namespace net {
namespace {
// The maximum size (in bytes) allowed for a PAC script. Responses exceeding
// this will fail with ERR_FILE_TOO_BIG.
const int kDefaultMaxResponseBytes = 1048576; // 1 megabyte
// The maximum duration (in milliseconds) allowed for fetching the PAC script.
// Responses exceeding this will fail with ERR_TIMED_OUT.
const int kDefaultMaxDurationMs = 300000; // 5 minutes
// Returns true if |mime_type| is one of the known PAC mime type.
bool IsPacMimeType(const std::string& mime_type) {
static const char * const kSupportedPacMimeTypes[] = {
"application/x-ns-proxy-autoconfig",
"application/x-javascript-config",
};
for (size_t i = 0; i < arraysize(kSupportedPacMimeTypes); ++i) {
if (LowerCaseEqualsASCII(mime_type, kSupportedPacMimeTypes[i]))
return true;
}
return false;
}
// Converts |bytes| (which is encoded by |charset|) to UTF16, saving the resul
// to |*utf16|.
// If |charset| is empty, then we don't know what it was and guess.
void ConvertResponseToUTF16(const std::string& charset,
const std::string& bytes,
string16* utf16) {
const char* codepage;
if (charset.empty()) {
// Assume ISO-8859-1 if no charset was specified.
codepage = base::kCodepageLatin1;
} else {
// Otherwise trust the charset that was provided.
codepage = charset.c_str();
}
// We will be generous in the conversion -- if any characters lie
// outside of |charset| (i.e. invalid), then substitute them with
// U+FFFD rather than failing.
base::CodepageToUTF16(bytes, codepage,
base::OnStringConversionError::SUBSTITUTE,
utf16);
}
} // namespace
ProxyScriptFetcherImpl::ProxyScriptFetcherImpl(
URLRequestContext* url_request_context)
: ALLOW_THIS_IN_INITIALIZER_LIST(task_factory_(this)),
url_request_context_(url_request_context),
buf_(new IOBuffer(kBufSize)),
next_id_(0),
cur_request_(NULL),
cur_request_id_(0),
callback_(NULL),
result_code_(OK),
result_text_(NULL),
max_response_bytes_(kDefaultMaxResponseBytes),
max_duration_(base::TimeDelta::FromMilliseconds(kDefaultMaxDurationMs)) {
DCHECK(url_request_context);
}
ProxyScriptFetcherImpl::~ProxyScriptFetcherImpl() {
// The URLRequest's destructor will cancel the outstanding request, and
// ensure that the delegate (this) is not called again.
}
base::TimeDelta ProxyScriptFetcherImpl::SetTimeoutConstraint(
base::TimeDelta timeout) {
base::TimeDelta prev = max_duration_;
max_duration_ = timeout;
return prev;
}
size_t ProxyScriptFetcherImpl::SetSizeConstraint(size_t size_bytes) {
size_t prev = max_response_bytes_;
max_response_bytes_ = size_bytes;
return prev;
}
void ProxyScriptFetcherImpl::OnResponseCompleted(URLRequest* request) {
DCHECK_EQ(request, cur_request_.get());
// Use |result_code_| as the request's error if we have already set it to
// something specific.
if (result_code_ == OK && !request->status().is_success())
result_code_ = request->status().error();
FetchCompleted();
}
int ProxyScriptFetcherImpl::Fetch(const GURL& url,
string16* text,
CompletionCallback* callback) {
// It is invalid to call Fetch() while a request is already in progress.
DCHECK(!cur_request_.get());
DCHECK(callback);
DCHECK(text);
// Handle base-64 encoded data-urls that contain custom PAC scripts.
if (url.SchemeIs("data")) {
std::string mime_type;
std::string charset;
std::string data;
if (!DataURL::Parse(url, &mime_type, &charset, &data))
return ERR_FAILED;
ConvertResponseToUTF16(charset, data, text);
return OK;
}
cur_request_.reset(new URLRequest(url, this));
cur_request_->set_context(url_request_context_);
cur_request_->set_method("GET");
// Make sure that the PAC script is downloaded using a direct connection,
// to avoid circular dependencies (fetching is a part of proxy resolution).
// Also disable the use of the disk cache. The cache is disabled so that if
// the user switches networks we don't potentially use the cached response
// from old network when we should in fact be re-fetching on the new network.
// If the PAC script is hosted on an HTTPS server we bypass revocation
// checking in order to avoid a circular dependency when attempting to fetch
// the OCSP response or CRL. We could make the revocation check go direct but
// the proxy might be the only way to the outside world.
cur_request_->set_load_flags(LOAD_BYPASS_PROXY | LOAD_DISABLE_CACHE |
LOAD_DISABLE_CERT_REVOCATION_CHECKING);
// Save the caller's info for notification on completion.
callback_ = callback;
result_text_ = text;
bytes_read_so_far_.clear();
// Post a task to timeout this request if it takes too long.
cur_request_id_ = ++next_id_;
MessageLoop::current()->PostDelayedTask(FROM_HERE,
task_factory_.NewRunnableMethod(&ProxyScriptFetcherImpl::OnTimeout,
cur_request_id_),
static_cast<int>(max_duration_.InMilliseconds()));
// Start the request.
cur_request_->Start();
return ERR_IO_PENDING;
}
void ProxyScriptFetcherImpl::Cancel() {
// ResetCurRequestState will free the URLRequest, which will cause
// cancellation.
ResetCurRequestState();
}
URLRequestContext* ProxyScriptFetcherImpl::GetRequestContext() const {
return url_request_context_;
}
void ProxyScriptFetcherImpl::OnAuthRequired(URLRequest* request,
AuthChallengeInfo* auth_info) {
DCHECK_EQ(request, cur_request_.get());
// TODO(eroman): http://crbug.com/77366
LOG(WARNING) << "Auth required to fetch PAC script, aborting.";
result_code_ = ERR_NOT_IMPLEMENTED;
request->CancelAuth();
}
void ProxyScriptFetcherImpl::OnSSLCertificateError(URLRequest* request,
int cert_error,
X509Certificate* cert) {
DCHECK_EQ(request, cur_request_.get());
LOG(WARNING) << "SSL certificate error when fetching PAC script, aborting.";
// Certificate errors are in same space as net errors.
result_code_ = cert_error;
request->Cancel();
}
void ProxyScriptFetcherImpl::OnResponseStarted(URLRequest* request) {
DCHECK_EQ(request, cur_request_.get());
if (!request->status().is_success()) {
OnResponseCompleted(request);
return;
}
// Require HTTP responses to have a success status code.
if (request->url().SchemeIs("http") || request->url().SchemeIs("https")) {
// NOTE about status codes: We are like Firefox 3 in this respect.
// {IE 7, Safari 3, Opera 9.5} do not care about the status code.
if (request->GetResponseCode() != 200) {
VLOG(1) << "Fetched PAC script had (bad) status line: "
<< request->response_headers()->GetStatusLine();
result_code_ = ERR_PAC_STATUS_NOT_OK;
request->Cancel();
return;
}
// NOTE about mime types: We do not enforce mime types on PAC files.
// This is for compatibility with {IE 7, Firefox 3, Opera 9.5}. We will
// however log mismatches to help with debugging.
std::string mime_type;
cur_request_->GetMimeType(&mime_type);
if (!IsPacMimeType(mime_type)) {
VLOG(1) << "Fetched PAC script does not have a proper mime type: "
<< mime_type;
}
}
ReadBody(request);
}
void ProxyScriptFetcherImpl::OnReadCompleted(URLRequest* request,
int num_bytes) {
DCHECK_EQ(request, cur_request_.get());
if (ConsumeBytesRead(request, num_bytes)) {
// Keep reading.
ReadBody(request);
}
}
void ProxyScriptFetcherImpl::ReadBody(URLRequest* request) {
// Read as many bytes as are available synchronously.
while (true) {
int num_bytes;
if (!request->Read(buf_, kBufSize, &num_bytes)) {
// Check whether the read failed synchronously.
if (!request->status().is_io_pending())
OnResponseCompleted(request);
return;
}
if (!ConsumeBytesRead(request, num_bytes))
return;
}
}
bool ProxyScriptFetcherImpl::ConsumeBytesRead(URLRequest* request,
int num_bytes) {
if (num_bytes <= 0) {
// Error while reading, or EOF.
OnResponseCompleted(request);
return false;
}
// Enforce maximum size bound.
if (num_bytes + bytes_read_so_far_.size() >
static_cast<size_t>(max_response_bytes_)) {
result_code_ = ERR_FILE_TOO_BIG;
request->Cancel();
return false;
}
bytes_read_so_far_.append(buf_->data(), num_bytes);
return true;
}
void ProxyScriptFetcherImpl::FetchCompleted() {
if (result_code_ == OK) {
// The caller expects the response to be encoded as UTF16.
std::string charset;
cur_request_->GetCharset(&charset);
ConvertResponseToUTF16(charset, bytes_read_so_far_, result_text_);
} else {
// On error, the caller expects empty string for bytes.
result_text_->clear();
}
int result_code = result_code_;
CompletionCallback* callback = callback_;
// Hold a reference to the URLRequestContext to prevent re-entrancy from
// ~URLRequestContext.
scoped_refptr<const URLRequestContext> context(cur_request_->context());
ResetCurRequestState();
callback->Run(result_code);
}
void ProxyScriptFetcherImpl::ResetCurRequestState() {
cur_request_.reset();
cur_request_id_ = 0;
callback_ = NULL;
result_code_ = OK;
result_text_ = NULL;
}
void ProxyScriptFetcherImpl::OnTimeout(int id) {
// Timeout tasks may outlive the URLRequest they reference. Make sure it
// is still applicable.
if (cur_request_id_ != id)
return;
DCHECK(cur_request_.get());
result_code_ = ERR_TIMED_OUT;
cur_request_->Cancel();
}
} // namespace net