src/components/data_reduction_proxy/browser/data_reduction_proxy_protocol.cc

   1 // Copyright 2014 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 #include "components/data_reduction_proxy/browser/data_reduction_proxy_protocol.h"
   6
   7 #include "base/memory/ref_counted.h"
   8 #include "base/time/time.h"
   9 #include "components/data_reduction_proxy/browser/data_reduction_proxy_params.h"
  10 #include "components/data_reduction_proxy/browser/data_reduction_proxy_tamper_detection.h"
  11 #include "components/data_reduction_proxy/browser/data_reduction_proxy_usage_stats.h"
  12 #include "components/data_reduction_proxy/common/data_reduction_proxy_headers.h"
  13 #include "net/base/load_flags.h"
  14 #include "net/http/http_response_headers.h"
  15 #include "net/proxy/proxy_config.h"
  16 #include "net/proxy/proxy_info.h"
  17 #include "net/proxy/proxy_list.h"
  18 #include "net/proxy/proxy_retry_info.h"
  19 #include "net/proxy/proxy_server.h"
  20 #include "net/proxy/proxy_service.h"
  21 #include "net/url_request/url_request.h"
  22 #include "net/url_request/url_request_context.h"
  23 #include "url/gurl.h"
  24
  25 namespace {
  26
  27 bool SetProxyServerFromGURL(const GURL& gurl,
  28                             net::ProxyServer* proxy_server) {
  29   DCHECK(proxy_server);
  30   if (!gurl.SchemeIsHTTPOrHTTPS())
  31     return false;
  32   *proxy_server = net::ProxyServer(gurl.SchemeIs("http") ?
  33                                        net::ProxyServer::SCHEME_HTTP :
  34                                        net::ProxyServer::SCHEME_HTTPS,
  35                                    net::HostPortPair::FromURL(gurl));
  36   return true;
  37 }
  38
  39 }  // namespace
  40
  41 namespace data_reduction_proxy {
  42
  43 bool MaybeBypassProxyAndPrepareToRetry(
  44     const DataReductionProxyParams* data_reduction_proxy_params,
  45     net::URLRequest* request,
  46     const net::HttpResponseHeaders* original_response_headers,
  47     scoped_refptr<net::HttpResponseHeaders>* override_response_headers,
  48     DataReductionProxyBypassType* proxy_bypass_type) {
  49   if (!data_reduction_proxy_params)
  50     return false;
  51   DataReductionProxyTypeInfo data_reduction_proxy_type_info;
  52   if (!data_reduction_proxy_params->WasDataReductionProxyUsed(
  53           request, &data_reduction_proxy_type_info)) {
  54     return false;
  55   }
  56   // TODO(bengr): Implement bypass for CONNECT tunnel.
  57   if (data_reduction_proxy_type_info.is_ssl)
  58     return false;
  59
  60   // Empty implies either that the request was served from cache or that
  61   // request was served directly from the origin.
  62   if (request->proxy_server().IsEmpty())
  63     return false;
  64
  65   if (data_reduction_proxy_type_info.proxy_servers.first.is_empty())
  66     return false;
  67
  68   // At this point, the response is expected to have the data reduction proxy
  69   // via header, so detect and report cases where the via header is missing.
  70   DataReductionProxyUsageStats::DetectAndRecordMissingViaHeaderResponseCode(
  71       !data_reduction_proxy_type_info.proxy_servers.second.is_empty(),
  72       original_response_headers);
  73
  74   DataReductionProxyTamperDetection::DetectAndReport(
  75       original_response_headers,
  76       data_reduction_proxy_type_info.proxy_servers.first.SchemeIsSecure());
  77
  78   DataReductionProxyInfo data_reduction_proxy_info;
  79   DataReductionProxyBypassType bypass_type =
  80       GetDataReductionProxyBypassType(original_response_headers,
  81                                       &data_reduction_proxy_info);
  82
  83   if (bypass_type == BYPASS_EVENT_TYPE_MISSING_VIA_HEADER_OTHER &&
  84       DataReductionProxyParams::
  85           IsIncludedInRemoveMissingViaHeaderOtherBypassFieldTrial()) {
  86     // Ignore MISSING_VIA_HEADER_OTHER proxy bypass events if the client is part
  87     // of the field trial to remove these kinds of bypasses.
  88     bypass_type = BYPASS_EVENT_TYPE_MAX;
  89   }
  90
  91   if (proxy_bypass_type)
  92     *proxy_bypass_type = bypass_type;
  93   if (bypass_type == BYPASS_EVENT_TYPE_MAX)
  94     return false;
  95
  96   DCHECK(request->context());
  97   DCHECK(request->context()->proxy_service());
  98   net::ProxyServer proxy_server;
  99   SetProxyServerFromGURL(
 100       data_reduction_proxy_type_info.proxy_servers.first, &proxy_server);
 101
 102   // Only record UMA if the proxy isn't already on the retry list.
 103   const net::ProxyRetryInfoMap& proxy_retry_info =
 104       request->context()->proxy_service()->proxy_retry_info();
 105   if (proxy_retry_info.find(proxy_server.ToURI()) == proxy_retry_info.end()) {
 106     DataReductionProxyUsageStats::RecordDataReductionProxyBypassInfo(
 107         !data_reduction_proxy_type_info.proxy_servers.second.is_empty(),
 108         data_reduction_proxy_info.bypass_all,
 109         proxy_server,
 110         bypass_type);
 111   }
 112
 113   if (data_reduction_proxy_info.mark_proxies_as_bad) {
 114     MarkProxiesAsBadUntil(request,
 115                           data_reduction_proxy_info.bypass_duration,
 116                           data_reduction_proxy_info.bypass_all,
 117                           data_reduction_proxy_type_info.proxy_servers);
 118   }
 119
 120   // Only retry idempotent methods.
 121   if (!IsRequestIdempotent(request))
 122     return false;
 123
 124   OverrideResponseAsRedirect(request,
 125                              original_response_headers,
 126                              override_response_headers);
 127   return true;
 128 }
 129
 130 void OnResolveProxyHandler(const GURL& url,
 131                            int load_flags,
 132                            const net::ProxyConfig& data_reduction_proxy_config,
 133                            const net::ProxyRetryInfoMap& proxy_retry_info,
 134                            const DataReductionProxyParams* params,
 135                            net::ProxyInfo* result) {
 136   if (data_reduction_proxy_config.is_valid() &&
 137       result->proxy_server().is_direct()) {
 138     net::ProxyInfo data_reduction_proxy_info;
 139     data_reduction_proxy_config.proxy_rules().Apply(
 140         url, &data_reduction_proxy_info);
 141     data_reduction_proxy_info.DeprioritizeBadProxies(proxy_retry_info);
 142     result->Use(data_reduction_proxy_info);
 143   }
 144
 145   if ((load_flags & net::LOAD_BYPASS_DATA_REDUCTION_PROXY) &&
 146       DataReductionProxyParams::IsIncludedInCriticalPathBypassFieldTrial() &&
 147       !result->is_empty() &&
 148       !result->is_direct() &&
 149       params &&
 150       params->IsDataReductionProxy(
 151           result->proxy_server().host_port_pair(), NULL)) {
 152     result->UseDirect();
 153   }
 154 }
 155
 156 bool IsRequestIdempotent(const net::URLRequest* request) {
 157   DCHECK(request);
 158   if (request->method() == "GET" ||
 159       request->method() == "OPTIONS" ||
 160       request->method() == "HEAD" ||
 161       request->method() == "PUT" ||
 162       request->method() == "DELETE" ||
 163       request->method() == "TRACE")
 164     return true;
 165   return false;
 166 }
 167
 168 void OverrideResponseAsRedirect(
 169     net::URLRequest* request,
 170     const net::HttpResponseHeaders* original_response_headers,
 171     scoped_refptr<net::HttpResponseHeaders>* override_response_headers) {
 172   DCHECK(request);
 173   DCHECK(original_response_headers);
 174   DCHECK(override_response_headers->get() == NULL);
 175
 176   request->SetLoadFlags(request->load_flags() |
 177                         net::LOAD_DISABLE_CACHE |
 178                         net::LOAD_BYPASS_PROXY);
 179   *override_response_headers = new net::HttpResponseHeaders(
 180       original_response_headers->raw_headers());
 181   (*override_response_headers)->ReplaceStatusLine("HTTP/1.1 302 Found");
 182   (*override_response_headers)->RemoveHeader("Location");
 183   (*override_response_headers)->AddHeader("Location: " +
 184                                           request->url().spec());
 185   std::string http_origin;
 186   const net::HttpRequestHeaders& request_headers =
 187       request->extra_request_headers();
 188   if (request_headers.GetHeader("Origin", &http_origin)) {
 189     // If this redirect is used in a cross-origin request, add CORS headers to
 190     // make sure that the redirect gets through. Note that the destination URL
 191     // is still subject to the usual CORS policy, i.e. the resource will only
 192     // be available to web pages if the server serves the response with the
 193     // required CORS response headers.
 194     (*override_response_headers)->AddHeader(
 195         "Access-Control-Allow-Origin: " + http_origin);
 196     (*override_response_headers)->AddHeader(
 197         "Access-Control-Allow-Credentials: true");
 198   }
 199   // TODO(bengr): Should we pop_back the request->url_chain?
 200 }
 201
 202 void MarkProxiesAsBadUntil(
 203     net::URLRequest* request,
 204     base::TimeDelta& bypass_duration,
 205     bool bypass_all,
 206     const std::pair<GURL, GURL>& data_reduction_proxies) {
 207   DCHECK(!data_reduction_proxies.first.is_empty());
 208   // Synthesize a suitable |ProxyInfo| to add the proxies to the
 209   // |ProxyRetryInfoMap| of the proxy service.
 210   net::ProxyList proxy_list;
 211   net::ProxyServer primary;
 212   SetProxyServerFromGURL(data_reduction_proxies.first, &primary);
 213   if (primary.is_valid())
 214     proxy_list.AddProxyServer(primary);
 215   net::ProxyServer fallback;
 216   if (bypass_all) {
 217     if (!data_reduction_proxies.second.is_empty())
 218       SetProxyServerFromGURL(data_reduction_proxies.second, &fallback);
 219     if (fallback.is_valid())
 220       proxy_list.AddProxyServer(fallback);
 221     proxy_list.AddProxyServer(net::ProxyServer::Direct());
 222   }
 223   net::ProxyInfo proxy_info;
 224   proxy_info.UseProxyList(proxy_list);
 225   DCHECK(request->context());
 226   net::ProxyService* proxy_service = request->context()->proxy_service();
 227   DCHECK(proxy_service);
 228
 229   proxy_service->MarkProxiesAsBadUntil(proxy_info,
 230                                        bypass_duration,
 231                                        fallback,
 232                                        request->net_log());
 233 }
 234
 235 }  // namespace data_reduction_proxy