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 #include "chrome/browser/net/preconnect.h"
6
7 #include "base/bind.h"
8 #include "base/logging.h"
9 #include "base/metrics/histogram.h"
10 #include "content/public/browser/browser_thread.h"
11 #include "net/base/net_log.h"
12 #include "net/http/http_network_session.h"
13 #include "net/http/http_request_info.h"
14 #include "net/http/http_stream_factory.h"
15 #include "net/http/http_transaction_factory.h"
16 #include "net/ssl/ssl_config_service.h"
17 #include "net/url_request/http_user_agent_settings.h"
18 #include "net/url_request/url_request_context.h"
19 #include "net/url_request/url_request_context_getter.h"
20
21 using content::BrowserThread;
22
23 namespace chrome_browser_net {
24
PreconnectOnUIThread(const GURL & url,const GURL & first_party_for_cookies,UrlInfo::ResolutionMotivation motivation,int count,net::URLRequestContextGetter * getter)25 void PreconnectOnUIThread(
26 const GURL& url,
27 const GURL& first_party_for_cookies,
28 UrlInfo::ResolutionMotivation motivation,
29 int count,
30 net::URLRequestContextGetter* getter) {
31 // Prewarm connection to Search URL.
32 BrowserThread::PostTask(
33 BrowserThread::IO,
34 FROM_HERE,
35 base::Bind(&PreconnectOnIOThread, url, first_party_for_cookies,
36 motivation, count, make_scoped_refptr(getter)));
37 return;
38 }
39
40
PreconnectOnIOThread(const GURL & url,const GURL & first_party_for_cookies,UrlInfo::ResolutionMotivation motivation,int count,net::URLRequestContextGetter * getter)41 void PreconnectOnIOThread(
42 const GURL& url,
43 const GURL& first_party_for_cookies,
44 UrlInfo::ResolutionMotivation motivation,
45 int count,
46 net::URLRequestContextGetter* getter) {
47 if (!BrowserThread::CurrentlyOn(BrowserThread::IO)) {
48 LOG(DFATAL) << "This must be run only on the IO thread.";
49 return;
50 }
51 if (!getter)
52 return;
53 // We are now commited to doing the async preconnection call.
54 UMA_HISTOGRAM_ENUMERATION("Net.PreconnectMotivation", motivation,
55 UrlInfo::MAX_MOTIVATED);
56
57 net::URLRequestContext* context = getter->GetURLRequestContext();
58 net::HttpTransactionFactory* factory = context->http_transaction_factory();
59 net::HttpNetworkSession* session = factory->GetSession();
60
61 std::string user_agent;
62 if (context->http_user_agent_settings())
63 user_agent = context->http_user_agent_settings()->GetUserAgent();
64 net::HttpRequestInfo request_info;
65 request_info.url = url;
66 request_info.method = "GET";
67 request_info.extra_headers.SetHeader(net::HttpRequestHeaders::kUserAgent,
68 user_agent);
69
70 net::NetworkDelegate* delegate = context->network_delegate();
71 if (delegate->CanEnablePrivacyMode(url, first_party_for_cookies))
72 request_info.privacy_mode = net::PRIVACY_MODE_ENABLED;
73
74 // It almost doesn't matter whether we use net::LOWEST or net::HIGHEST
75 // priority here, as we won't make a request, and will surrender the created
76 // socket to the pool as soon as we can. However, we would like to mark the
77 // speculative socket as such, and IF we use a net::LOWEST priority, and if
78 // a navigation asked for a socket (after us) then it would get our socket,
79 // and we'd get its later-arriving socket, which might make us record that
80 // the speculation didn't help :-/. By using net::HIGHEST, we ensure that
81 // a socket is given to us if "we asked first" and this allows us to mark it
82 // as speculative, and better detect stats (if it gets used).
83 // TODO(jar): histogram to see how often we accidentally use a previously-
84 // unused socket, when a previously used socket was available.
85 net::RequestPriority priority = net::HIGHEST;
86
87 // Translate the motivation from UrlRequest motivations to HttpRequest
88 // motivations.
89 switch (motivation) {
90 case UrlInfo::OMNIBOX_MOTIVATED:
91 request_info.motivation = net::HttpRequestInfo::OMNIBOX_MOTIVATED;
92 break;
93 case UrlInfo::LEARNED_REFERAL_MOTIVATED:
94 request_info.motivation = net::HttpRequestInfo::PRECONNECT_MOTIVATED;
95 break;
96 case UrlInfo::MOUSE_OVER_MOTIVATED:
97 case UrlInfo::SELF_REFERAL_MOTIVATED:
98 case UrlInfo::EARLY_LOAD_MOTIVATED:
99 request_info.motivation = net::HttpRequestInfo::EARLY_LOAD_MOTIVATED;
100 break;
101 default:
102 // Other motivations should never happen here.
103 NOTREACHED();
104 break;
105 }
106
107 // Setup the SSL Configuration.
108 net::SSLConfig ssl_config;
109 session->ssl_config_service()->GetSSLConfig(&ssl_config);
110 session->GetNextProtos(&ssl_config.next_protos);
111
112 // All preconnects should perform EV certificate verification.
113 ssl_config.verify_ev_cert = true;
114
115 net::HttpStreamFactory* http_stream_factory = session->http_stream_factory();
116 http_stream_factory->PreconnectStreams(count, request_info, priority,
117 ssl_config, ssl_config);
118 }
119
120 } // namespace chrome_browser_net
121