content/renderer/savable_resources.cc

   1 // Copyright (c) 2013 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 "content/renderer/savable_resources.h"
   6
   7 #include <set>
   8
   9 #include "base/compiler_specific.h"
  10 #include "base/logging.h"
  11 #include "base/strings/string_util.h"
  12 #include "third_party/WebKit/public/platform/WebString.h"
  13 #include "third_party/WebKit/public/platform/WebVector.h"
  14 #include "third_party/WebKit/public/web/WebDocument.h"
  15 #include "third_party/WebKit/public/web/WebElement.h"
  16 #include "third_party/WebKit/public/web/WebElementCollection.h"
  17 #include "third_party/WebKit/public/web/WebInputElement.h"
  18 #include "third_party/WebKit/public/web/WebLocalFrame.h"
  19 #include "third_party/WebKit/public/web/WebNode.h"
  20 #include "third_party/WebKit/public/web/WebNodeList.h"
  21 #include "third_party/WebKit/public/web/WebView.h"
  22
  23 using blink::WebDocument;
  24 using blink::WebElement;
  25 using blink::WebElementCollection;
  26 using blink::WebFrame;
  27 using blink::WebInputElement;
  28 using blink::WebLocalFrame;
  29 using blink::WebNode;
  30 using blink::WebNodeList;
  31 using blink::WebString;
  32 using blink::WebVector;
  33 using blink::WebView;
  34
  35 namespace content {
  36 namespace {
  37
  38 // Structure for storage the unique set of all savable resource links for
  39 // making sure that no duplicated resource link in final result. The consumer
  40 // of the SavableResourcesUniqueCheck is responsible for keeping these pointers
  41 // valid for the lifetime of the SavableResourcesUniqueCheck instance.
  42 struct SavableResourcesUniqueCheck {
  43   // Unique set of all sub resource links.
  44   std::set<GURL>* resources_set;
  45   // Unique set of all frame links.
  46   std::set<GURL>* frames_set;
  47   // Collection of all frames we go through when getting all savable resource
  48   // links.
  49   std::vector<WebFrame*>* frames;
  50
  51   SavableResourcesUniqueCheck()
  52       : resources_set(NULL),
  53         frames_set(NULL),
  54         frames(NULL) {}
  55
  56   SavableResourcesUniqueCheck(std::set<GURL>* resources_set,
  57       std::set<GURL>* frames_set, std::vector<WebFrame*>* frames)
  58       : resources_set(resources_set),
  59         frames_set(frames_set),
  60         frames(frames) {}
  61 };
  62
  63 // Get all savable resource links from current element. One element might
  64 // have more than one resource link. It is possible to have some links
  65 // in one CSS stylesheet.
  66 void GetSavableResourceLinkForElement(
  67     const WebElement& element,
  68     const WebDocument& current_doc,
  69     SavableResourcesUniqueCheck* unique_check,
  70     SavableResourcesResult* result) {
  71
  72   // Handle frame and iframe tag.
  73   if (element.hasHTMLTagName("iframe") ||
  74       element.hasHTMLTagName("frame")) {
  75     WebFrame* sub_frame = WebLocalFrame::fromFrameOwnerElement(element);
  76     if (sub_frame)
  77       unique_check->frames->push_back(sub_frame);
  78     return;
  79   }
  80
  81   // Check whether the node has sub resource URL or not.
  82   WebString value = GetSubResourceLinkFromElement(element);
  83   if (value.isNull())
  84     return;
  85   // Get absolute URL.
  86   GURL u = current_doc.completeURL(value);
  87   // ignore invalid URL
  88   if (!u.is_valid())
  89     return;
  90   // Ignore those URLs which are not standard protocols. Because FTP
  91   // protocol does no have cache mechanism, we will skip all
  92   // sub-resources if they use FTP protocol.
  93   if (!u.SchemeIsHTTPOrHTTPS() && !u.SchemeIs(url::kFileScheme))
  94     return;
  95   // Ignore duplicated resource link.
  96   if (!unique_check->resources_set->insert(u).second)
  97     return;
  98   result->resources_list->push_back(u);
  99   // Insert referrer for above new resource link.
 100   result->referrer_urls_list->push_back(GURL());
 101   result->referrer_policies_list->push_back(blink::WebReferrerPolicyDefault);
 102 }
 103
 104 // Get all savable resource links from current WebFrameImpl object pointer.
 105 void GetAllSavableResourceLinksForFrame(WebFrame* current_frame,
 106     SavableResourcesUniqueCheck* unique_check,
 107     SavableResourcesResult* result,
 108     const char** savable_schemes) {
 109   // Get current frame's URL.
 110   GURL current_frame_url = current_frame->document().url();
 111
 112   // If url of current frame is invalid, ignore it.
 113   if (!current_frame_url.is_valid())
 114     return;
 115
 116   // If url of current frame is not a savable protocol, ignore it.
 117   bool is_valid_protocol = false;
 118   for (int i = 0; savable_schemes[i] != NULL; ++i) {
 119     if (current_frame_url.SchemeIs(savable_schemes[i])) {
 120       is_valid_protocol = true;
 121       break;
 122     }
 123   }
 124   if (!is_valid_protocol)
 125     return;
 126
 127   // If find same frame we have recorded, ignore it.
 128   if (!unique_check->frames_set->insert(current_frame_url).second)
 129     return;
 130
 131   // Get current using document.
 132   WebDocument current_doc = current_frame->document();
 133   // Go through all descent nodes.
 134   WebElementCollection all = current_doc.all();
 135   // Go through all elements in this frame.
 136   for (WebElement element = all.firstItem(); !element.isNull();
 137        element = all.nextItem()) {
 138     GetSavableResourceLinkForElement(element,
 139                                      current_doc,
 140                                      unique_check,
 141                                      result);
 142   }
 143 }
 144
 145 }  // namespace
 146
 147 WebString GetSubResourceLinkFromElement(const WebElement& element) {
 148   const char* attribute_name = NULL;
 149   if (element.hasHTMLTagName("img") ||
 150       element.hasHTMLTagName("script")) {
 151     attribute_name = "src";
 152   } else if (element.hasHTMLTagName("input")) {
 153     const WebInputElement input = element.toConst<WebInputElement>();
 154     if (input.isImageButton()) {
 155       attribute_name = "src";
 156     }
 157   } else if (element.hasHTMLTagName("body") ||
 158              element.hasHTMLTagName("table") ||
 159              element.hasHTMLTagName("tr") ||
 160              element.hasHTMLTagName("td")) {
 161     attribute_name = "background";
 162   } else if (element.hasHTMLTagName("blockquote") ||
 163              element.hasHTMLTagName("q") ||
 164              element.hasHTMLTagName("del") ||
 165              element.hasHTMLTagName("ins")) {
 166     attribute_name = "cite";
 167   } else if (element.hasHTMLTagName("link")) {
 168     // If the link element is not linked to css, ignore it.
 169     if (LowerCaseEqualsASCII(element.getAttribute("type"), "text/css")) {
 170       // TODO(jnd): Add support for extracting links of sub-resources which
 171       // are inside style-sheet such as @import, url(), etc.
 172       // See bug: http://b/issue?id=1111667.
 173       attribute_name = "href";
 174     }
 175   }
 176   if (!attribute_name)
 177     return WebString();
 178   WebString value = element.getAttribute(WebString::fromUTF8(attribute_name));
 179   // If value has content and not start with "javascript:" then return it,
 180   // otherwise return NULL.
 181   if (!value.isNull() && !value.isEmpty() &&
 182       !StartsWithASCII(value.utf8(), "javascript:", false))
 183     return value;
 184
 185   return WebString();
 186 }
 187
 188 // Get all savable resource links from current webview, include main
 189 // frame and sub-frame
 190 bool GetAllSavableResourceLinksForCurrentPage(WebView* view,
 191     const GURL& page_url, SavableResourcesResult* result,
 192     const char** savable_schemes) {
 193   WebFrame* main_frame = view->mainFrame();
 194   if (!main_frame)
 195     return false;
 196
 197   std::set<GURL> resources_set;
 198   std::set<GURL> frames_set;
 199   std::vector<WebFrame*> frames;
 200   SavableResourcesUniqueCheck unique_check(&resources_set,
 201                                            &frames_set,
 202                                            &frames);
 203
 204   GURL main_page_gurl(main_frame->document().url());
 205
 206   // Make sure we are saving same page between embedder and webkit.
 207   // If page has being navigated, embedder will get three empty vector,
 208   // which will make the saving page job ended.
 209   if (page_url != main_page_gurl)
 210     return true;
 211
 212   // First, process main frame.
 213   frames.push_back(main_frame);
 214
 215   // Check all resource in this page, include sub-frame.
 216   for (int i = 0; i < static_cast<int>(frames.size()); ++i) {
 217     // Get current frame's all savable resource links.
 218     GetAllSavableResourceLinksForFrame(frames[i], &unique_check, result,
 219                                        savable_schemes);
 220   }
 221
 222   // Since frame's src can also point to sub-resources link, so it is possible
 223   // that some URLs in frames_list are also in resources_list. For those
 224   // URLs, we will remove it from frame_list, only keep them in resources_list.
 225   for (std::set<GURL>::iterator it = frames_set.begin();
 226        it != frames_set.end(); ++it) {
 227     // Append unique frame source to savable frame list.
 228     if (resources_set.find(*it) == resources_set.end())
 229       result->frames_list->push_back(*it);
 230   }
 231
 232   return true;
 233 }
 234
 235 }  // namespace content