chrome/browser/safe_browsing/malware_details_cache.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4 //
   5 // Implementation of the MalwareDetails class.
   6
   7 #include "chrome/browser/safe_browsing/malware_details.h"
   8
   9 #include "base/bind.h"
  10 #include "base/lazy_instance.h"
  11 #include "base/md5.h"
  12 #include "base/strings/string_util.h"
  13 #include "chrome/browser/net/chrome_url_request_context_getter.h"
  14 #include "chrome/browser/safe_browsing/malware_details_cache.h"
  15 #include "chrome/browser/safe_browsing/report.pb.h"
  16 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
  17 #include "content/public/browser/browser_thread.h"
  18 #include "net/base/host_port_pair.h"
  19 #include "net/base/load_flags.h"
  20 #include "net/base/net_errors.h"
  21 #include "net/http/http_response_headers.h"
  22 #include "net/url_request/url_fetcher.h"
  23 #include "net/url_request/url_request_context_getter.h"
  24 #include "net/url_request/url_request_status.h"
  25
  26 using content::BrowserThread;
  27 using safe_browsing::ClientMalwareReportRequest;
  28
  29 // Only send small files for now, a better strategy would use the size
  30 // of the whole report and the user's bandwidth.
  31 static const uint32 kMaxBodySizeBytes = 1024;
  32
  33 MalwareDetailsCacheCollector::MalwareDetailsCacheCollector()
  34     : resources_(NULL), result_(NULL), has_started_(false) {}
  35
  36 void MalwareDetailsCacheCollector::StartCacheCollection(
  37     net::URLRequestContextGetter* request_context_getter,
  38     safe_browsing::ResourceMap* resources,
  39     bool* result,
  40     const base::Closure& callback) {
  41   // Start the data collection from the HTTP cache. We use a URLFetcher
  42   // and set the right flags so we only hit the cache.
  43   DVLOG(1) << "Getting cache data for all urls...";
  44   request_context_getter_ = request_context_getter;
  45   resources_ = resources;
  46   resources_it_ = resources_->begin();
  47   result_ = result;
  48   callback_ = callback;
  49   has_started_ = true;
  50
  51   // Post a task in the message loop, so the callers don't need to
  52   // check if we call their callback immediately.
  53   BrowserThread::PostTask(
  54       BrowserThread::IO, FROM_HERE,
  55       base::Bind(&MalwareDetailsCacheCollector::OpenEntry, this));
  56 }
  57
  58 bool MalwareDetailsCacheCollector::HasStarted() {
  59   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  60   return has_started_;
  61 }
  62
  63 MalwareDetailsCacheCollector::~MalwareDetailsCacheCollector() {}
  64
  65 // Fetch a URL and advance to the next one when done.
  66 void MalwareDetailsCacheCollector::OpenEntry() {
  67   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
  68   DVLOG(1) << "OpenEntry";
  69
  70   if (resources_it_ == resources_->end()) {
  71     AllDone(true);
  72     return;
  73   }
  74
  75   if (!request_context_getter_.get()) {
  76     DVLOG(1) << "Missing request context getter";
  77     AllDone(false);
  78     return;
  79   }
  80
  81   current_fetch_.reset(net::URLFetcher::Create(
  82       GURL(resources_it_->first), net::URLFetcher::GET, this));
  83   current_fetch_->SetRequestContext(request_context_getter_.get());
  84   // Only from cache, and don't save cookies.
  85   current_fetch_->SetLoadFlags(net::LOAD_ONLY_FROM_CACHE |
  86                                net::LOAD_DO_NOT_SAVE_COOKIES);
  87   current_fetch_->SetAutomaticallyRetryOn5xx(false);  // No retries.
  88   current_fetch_->Start();  // OnURLFetchComplete will be called when done.
  89 }
  90
  91 ClientMalwareReportRequest::Resource* MalwareDetailsCacheCollector::GetResource(
  92     const GURL& url) {
  93   safe_browsing::ResourceMap::iterator it = resources_->find(url.spec());
  94   if (it != resources_->end()) {
  95     return it->second.get();
  96   }
  97   return NULL;
  98 }
  99
 100 void MalwareDetailsCacheCollector::OnURLFetchComplete(
 101     const net::URLFetcher* source) {
 102   DVLOG(1) << "OnUrlFetchComplete";
 103   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 104   DCHECK(current_fetch_.get());
 105   if (source->GetStatus().status() != net::URLRequestStatus::SUCCESS &&
 106       source->GetStatus().error() == net::ERR_CACHE_MISS) {
 107     // Cache miss, skip this resource.
 108     DVLOG(1) << "Cache miss for url: " << source->GetURL();
 109     AdvanceEntry();
 110     return;
 111   }
 112
 113   if (source->GetStatus().status() != net::URLRequestStatus::SUCCESS) {
 114     // Some other error occurred, e.g. the request could have been cancelled.
 115     DVLOG(1) << "Unsuccessful fetch: " << source->GetURL();
 116     AdvanceEntry();
 117     return;
 118   }
 119
 120   // Set the response headers and body to the right resource, which
 121   // might not be the same as the one we asked for.
 122   // For redirects, resources_it_->first != url.spec().
 123   ClientMalwareReportRequest::Resource* resource =
 124       GetResource(source->GetURL());
 125   if (!resource) {
 126     DVLOG(1) << "Cannot find resource for url:" << source->GetURL();
 127     AdvanceEntry();
 128     return;
 129   }
 130
 131   ReadResponse(resource, source);
 132   std::string data;
 133   source->GetResponseAsString(&data);
 134   ReadData(resource, data);
 135   AdvanceEntry();
 136 }
 137
 138 void MalwareDetailsCacheCollector::ReadResponse(
 139     ClientMalwareReportRequest::Resource* pb_resource,
 140     const net::URLFetcher* source) {
 141   DVLOG(1) << "ReadResponse";
 142   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 143   net::HttpResponseHeaders* headers = source->GetResponseHeaders();
 144   if (!headers) {
 145     DVLOG(1) << "Missing response headers.";
 146     return;
 147   }
 148
 149   ClientMalwareReportRequest::HTTPResponse* pb_response =
 150       pb_resource->mutable_response();
 151   pb_response->mutable_firstline()->set_code(headers->response_code());
 152   void* iter = NULL;
 153   std::string name, value;
 154   while (headers->EnumerateHeaderLines(&iter, &name, &value)) {
 155     ClientMalwareReportRequest::HTTPHeader* pb_header =
 156         pb_response->add_headers();
 157     pb_header->set_name(name);
 158     // Strip any Set-Cookie headers.
 159     if (LowerCaseEqualsASCII(name, "set-cookie")) {
 160       pb_header->set_value("");
 161     } else {
 162       pb_header->set_value(value);
 163     }
 164   }
 165
 166   if (!source->WasFetchedViaProxy()) {
 167     pb_response->set_remote_ip(source->GetSocketAddress().ToString());
 168   }
 169 }
 170
 171 void MalwareDetailsCacheCollector::ReadData(
 172     ClientMalwareReportRequest::Resource* pb_resource,
 173     const std::string& data) {
 174   DVLOG(1) << "ReadData";
 175   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 176   ClientMalwareReportRequest::HTTPResponse* pb_response =
 177       pb_resource->mutable_response();
 178   if (data.size() <= kMaxBodySizeBytes) {  // Only send small bodies for now.
 179     pb_response->set_body(data);
 180   }
 181   pb_response->set_bodylength(data.size());
 182   base::MD5Digest digest;
 183   base::MD5Sum(data.c_str(), data.size(), &digest);
 184   pb_response->set_bodydigest(base::MD5DigestToBase16(digest));
 185 }
 186
 187 void MalwareDetailsCacheCollector::AdvanceEntry() {
 188   DVLOG(1) << "AdvanceEntry";
 189   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 190   // Advance to the next resource.
 191   ++resources_it_;
 192   current_fetch_.reset(NULL);
 193
 194   // Create a task so we don't take over the IO thread for too long.
 195   BrowserThread::PostTask(
 196       BrowserThread::IO, FROM_HERE,
 197       base::Bind(&MalwareDetailsCacheCollector::OpenEntry, this));
 198 }
 199
 200 void MalwareDetailsCacheCollector::AllDone(bool success) {
 201   DVLOG(1) << "AllDone";
 202   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 203   *result_ = success;
 204   BrowserThread::PostTask(BrowserThread::IO, FROM_HERE, callback_);
 205   callback_.Reset();
 206 }