dom/base/nsContentPolicyUtils.h

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 /*
   7  * Utility routines for checking content load/process policy settings,
   8  * and routines helpful for content policy implementors.
   9  *
  10  * XXXbz it would be nice if some of this stuff could be out-of-lined in
  11  * nsContentUtils.  That would work for almost all the callers...
  12  */
  13
  14 #ifndef __nsContentPolicyUtils_h__
  15 #define __nsContentPolicyUtils_h__
  16
  17 #include "mozilla/BasePrincipal.h"
  18
  19 #include "nsContentUtils.h"
  20 #include "nsIContentPolicy.h"
  21 #include "nsIContent.h"
  22 #include "nsIScriptSecurityManager.h"
  23 #include "nsIURI.h"
  24 #include "nsServiceManagerUtils.h"
  25 #include "nsStringFwd.h"
  26 #include "mozilla/dom/nsCSPService.h"
  27
  28 // XXXtw sadly, this makes consumers of nsContentPolicyUtils depend on widget
  29 #include "mozilla/dom/Document.h"
  30 #include "nsPIDOMWindow.h"
  31
  32 #define NS_CONTENTPOLICY_CONTRACTID "@mozilla.org/layout/content-policy;1"
  33 #define NS_CONTENTPOLICY_CATEGORY "content-policy"
  34 #define NS_CONTENTPOLICY_CID                         \
  35   {                                                  \
  36     0x0e3afd3d, 0xeb60, 0x4c2b, {                    \
  37       0x96, 0x3b, 0x56, 0xd7, 0xc4, 0x39, 0xf1, 0x24 \
  38     }                                                \
  39   }
  40
  41 /**
  42  * Evaluates to true if val is ACCEPT.
  43  *
  44  * @param val the status returned from shouldProcess/shouldLoad
  45  */
  46 #define NS_CP_ACCEPTED(val) ((val) == nsIContentPolicy::ACCEPT)
  47
  48 /**
  49  * Evaluates to true if val is a REJECT_* status
  50  *
  51  * @param val the status returned from shouldProcess/shouldLoad
  52  */
  53 #define NS_CP_REJECTED(val) ((val) != nsIContentPolicy::ACCEPT)
  54
  55 // Offer convenient translations of constants -> const char*
  56
  57 // convenience macro to reduce some repetative typing...
  58 // name is the name of a constant from this interface
  59 #define CASE_RETURN(name)      \
  60   case nsIContentPolicy::name: \
  61     return #name
  62
  63 /**
  64  * Returns a string corresponding to the name of the response constant, or
  65  * "<Unknown Response>" if an unknown response value is given.
  66  *
  67  * The return value is static and must not be freed.
  68  *
  69  * @param response the response code
  70  * @return the name of the given response code
  71  */
  72 inline const char* NS_CP_ResponseName(int16_t response) {
  73   switch (response) {
  74     CASE_RETURN(REJECT_REQUEST);
  75     CASE_RETURN(REJECT_TYPE);
  76     CASE_RETURN(REJECT_SERVER);
  77     CASE_RETURN(REJECT_OTHER);
  78     CASE_RETURN(ACCEPT);
  79     default:
  80       return "<Unknown Response>";
  81   }
  82 }
  83
  84 /**
  85  * Returns a string corresponding to the name of the content type constant, or
  86  * "<Unknown Type>" if an unknown content type value is given.
  87  *
  88  * The return value is static and must not be freed.
  89  *
  90  * @param contentType the content type code
  91  * @return the name of the given content type code
  92  */
  93 inline const char* NS_CP_ContentTypeName(uint32_t contentType) {
  94   switch (contentType) {
  95     CASE_RETURN(TYPE_OTHER);
  96     CASE_RETURN(TYPE_SCRIPT);
  97     CASE_RETURN(TYPE_IMAGE);
  98     CASE_RETURN(TYPE_STYLESHEET);
  99     CASE_RETURN(TYPE_OBJECT);
 100     CASE_RETURN(TYPE_DOCUMENT);
 101     CASE_RETURN(TYPE_SUBDOCUMENT);
 102     CASE_RETURN(TYPE_REFRESH);
 103     CASE_RETURN(TYPE_XBL);
 104     CASE_RETURN(TYPE_PING);
 105     CASE_RETURN(TYPE_XMLHTTPREQUEST);
 106     CASE_RETURN(TYPE_OBJECT_SUBREQUEST);
 107     CASE_RETURN(TYPE_DTD);
 108     CASE_RETURN(TYPE_FONT);
 109     CASE_RETURN(TYPE_MEDIA);
 110     CASE_RETURN(TYPE_WEBSOCKET);
 111     CASE_RETURN(TYPE_CSP_REPORT);
 112     CASE_RETURN(TYPE_XSLT);
 113     CASE_RETURN(TYPE_BEACON);
 114     CASE_RETURN(TYPE_FETCH);
 115     CASE_RETURN(TYPE_IMAGESET);
 116     CASE_RETURN(TYPE_WEB_MANIFEST);
 117     CASE_RETURN(TYPE_INTERNAL_SCRIPT);
 118     CASE_RETURN(TYPE_INTERNAL_WORKER);
 119     CASE_RETURN(TYPE_INTERNAL_SHARED_WORKER);
 120     CASE_RETURN(TYPE_INTERNAL_EMBED);
 121     CASE_RETURN(TYPE_INTERNAL_OBJECT);
 122     CASE_RETURN(TYPE_INTERNAL_FRAME);
 123     CASE_RETURN(TYPE_INTERNAL_IFRAME);
 124     CASE_RETURN(TYPE_INTERNAL_AUDIO);
 125     CASE_RETURN(TYPE_INTERNAL_VIDEO);
 126     CASE_RETURN(TYPE_INTERNAL_TRACK);
 127     CASE_RETURN(TYPE_INTERNAL_XMLHTTPREQUEST);
 128     CASE_RETURN(TYPE_INTERNAL_EVENTSOURCE);
 129     CASE_RETURN(TYPE_INTERNAL_SERVICE_WORKER);
 130     CASE_RETURN(TYPE_INTERNAL_SCRIPT_PRELOAD);
 131     CASE_RETURN(TYPE_INTERNAL_IMAGE);
 132     CASE_RETURN(TYPE_INTERNAL_IMAGE_PRELOAD);
 133     CASE_RETURN(TYPE_INTERNAL_IMAGE_FAVICON);
 134     CASE_RETURN(TYPE_INTERNAL_STYLESHEET);
 135     CASE_RETURN(TYPE_INTERNAL_STYLESHEET_PRELOAD);
 136     CASE_RETURN(TYPE_INTERNAL_WORKER_IMPORT_SCRIPTS);
 137     CASE_RETURN(TYPE_SAVEAS_DOWNLOAD);
 138     CASE_RETURN(TYPE_SPECULATIVE);
 139     CASE_RETURN(TYPE_INTERNAL_MODULE);
 140     CASE_RETURN(TYPE_INTERNAL_MODULE_PRELOAD);
 141     default:
 142       return "<Unknown Type>";
 143   }
 144 }
 145
 146 #undef CASE_RETURN
 147
 148 /* Passes on parameters from its "caller"'s context. */
 149 #define CHECK_CONTENT_POLICY(action)                                    \
 150   PR_BEGIN_MACRO                                                        \
 151   nsCOMPtr<nsIContentPolicy> policy =                                   \
 152       do_GetService(NS_CONTENTPOLICY_CONTRACTID);                       \
 153   if (!policy) return NS_ERROR_FAILURE;                                 \
 154                                                                         \
 155   return policy->action(contentLocation, loadInfo, mimeType, decision); \
 156   PR_END_MACRO
 157
 158 /* Passes on parameters from its "caller"'s context. */
 159 #define CHECK_CONTENT_POLICY_WITH_SERVICE(action, _policy)               \
 160   PR_BEGIN_MACRO                                                         \
 161   return _policy->action(contentLocation, loadInfo, mimeType, decision); \
 162   PR_END_MACRO
 163
 164 /**
 165  * Check whether we can short-circuit this check and bail out.  If not, get the
 166  * origin URI to use.
 167  *
 168  * Note: requestOrigin is scoped outside the PR_BEGIN_MACRO/PR_END_MACRO on
 169  * purpose */
 170 #define CHECK_PRINCIPAL_CSP_AND_DATA(action)                                  \
 171   nsCOMPtr<nsIURI> requestOrigin;                                             \
 172   PR_BEGIN_MACRO                                                              \
 173   if (loadingPrincipal) {                                                     \
 174     /* We exempt most loads into any document with the system principal       \
 175      * from content policy (escept CSP) checks, mostly as an optimization.    \
 176      * Which means that we need to apply this check to the loading principal, \
 177      * not the principal that triggered the load. */                          \
 178     bool isSystem = loadingPrincipal->IsSystemPrincipal();                    \
 179     if (isSystem) {                                                           \
 180       /* Check CSP for System Privileged pages */                             \
 181       CSPService::ConsultCSP(contentLocation, loadInfo, mimeType, decision);  \
 182       if (NS_CP_REJECTED(*decision)) {                                        \
 183         return NS_OK;                                                         \
 184       }                                                                       \
 185       if (contentType != nsIContentPolicy::TYPE_DOCUMENT) {                   \
 186         *decision = nsIContentPolicy::ACCEPT;                                 \
 187         nsCOMPtr<nsINode> n = do_QueryInterface(context);                     \
 188         if (!n) {                                                             \
 189           nsCOMPtr<nsPIDOMWindowOuter> win = do_QueryInterface(context);      \
 190           n = win ? win->GetExtantDoc() : nullptr;                            \
 191         }                                                                     \
 192         if (n) {                                                              \
 193           mozilla::dom::Document* d = n->OwnerDoc();                          \
 194           if (d->IsLoadedAsData() || d->IsBeingUsedAsImage() ||               \
 195               d->IsResourceDoc()) {                                           \
 196             nsCOMPtr<nsIContentPolicy> dataPolicy =                           \
 197                 do_GetService("@mozilla.org/data-document-content-policy;1"); \
 198             if (dataPolicy) {                                                 \
 199               dataPolicy->action(contentLocation, loadInfo, mimeType,         \
 200                                  decision);                                   \
 201             }                                                                 \
 202           }                                                                   \
 203         }                                                                     \
 204       }                                                                       \
 205       return NS_OK;                                                           \
 206     }                                                                         \
 207     nsresult rv = loadingPrincipal->GetURI(getter_AddRefs(requestOrigin));    \
 208     NS_ENSURE_SUCCESS(rv, rv);                                                \
 209   }                                                                           \
 210   PR_END_MACRO
 211
 212 /**
 213  * Alias for calling ShouldLoad on the content policy service.  Parameters are
 214  * the same as nsIContentPolicy::shouldLoad, except for the loadingPrincipal
 215  * and triggeringPrincipal parameters (which should be non-null if possible,
 216  * and have the same semantics as in nsLoadInfo), and the last parameter,
 217  * which can be used to pass in a pointer to a useful service if the caller
 218  * already has it.  The origin URI to pass to shouldLoad will be the URI of
 219  * loadingPrincipal, unless loadingPrincipal is null (in which case a null
 220  * origin URI will be passed).
 221  */
 222 inline nsresult NS_CheckContentLoadPolicy(
 223     nsIURI* contentLocation, nsILoadInfo* loadInfo, const nsACString& mimeType,
 224     int16_t* decision, nsIContentPolicy* policyService = nullptr) {
 225   nsIPrincipal* loadingPrincipal = loadInfo->LoadingPrincipal();
 226   nsCOMPtr<nsISupports> context = loadInfo->GetLoadingContext();
 227   nsContentPolicyType contentType = loadInfo->InternalContentPolicyType();
 228   CHECK_PRINCIPAL_CSP_AND_DATA(ShouldLoad);
 229   if (policyService) {
 230     CHECK_CONTENT_POLICY_WITH_SERVICE(ShouldLoad, policyService);
 231   }
 232   CHECK_CONTENT_POLICY(ShouldLoad);
 233 }
 234
 235 /**
 236  * Alias for calling ShouldProcess on the content policy service.
 237  */
 238 inline nsresult NS_CheckContentProcessPolicy(
 239     nsIURI* contentLocation, nsILoadInfo* loadInfo, const nsACString& mimeType,
 240     int16_t* decision, nsIContentPolicy* policyService = nullptr) {
 241   nsIPrincipal* loadingPrincipal = loadInfo->LoadingPrincipal();
 242   nsCOMPtr<nsISupports> context = loadInfo->GetLoadingContext();
 243   nsContentPolicyType contentType = loadInfo->InternalContentPolicyType();
 244   CHECK_PRINCIPAL_CSP_AND_DATA(ShouldProcess);
 245   if (policyService) {
 246     CHECK_CONTENT_POLICY_WITH_SERVICE(ShouldProcess, policyService);
 247   }
 248   CHECK_CONTENT_POLICY(ShouldProcess);
 249 }
 250
 251 #undef CHECK_CONTENT_POLICY
 252 #undef CHECK_CONTENT_POLICY_WITH_SERVICE
 253
 254 /**
 255  * Helper function to get an nsIDocShell given a context.
 256  * If the context is a document or window, the corresponding docshell will be
 257  * returned.
 258  * If the context is a non-document DOM node, the docshell of its ownerDocument
 259  * will be returned.
 260  *
 261  * @param aContext the context to find a docshell for (can be null)
 262  *
 263  * @return a WEAK pointer to the docshell, or nullptr if it could
 264  *     not be obtained
 265  *
 266  * @note  As of this writing, calls to nsIContentPolicy::Should{Load,Process}
 267  * for TYPE_DOCUMENT and TYPE_SUBDOCUMENT pass in an aContext that either
 268  * points to the frameElement of the window the load is happening in
 269  * (in which case NS_CP_GetDocShellFromContext will return the parent of the
 270  * docshell the load is happening in), or points to the window the load is
 271  * happening in (in which case NS_CP_GetDocShellFromContext will return
 272  * the docshell the load is happening in).  It's up to callers to QI aContext
 273  * and handle things accordingly if they want the docshell the load is
 274  * happening in.  These are somewhat odd semantics, and bug 466687 has been
 275  * filed to consider improving them.
 276  */
 277 inline nsIDocShell* NS_CP_GetDocShellFromContext(nsISupports* aContext) {
 278   if (!aContext) {
 279     return nullptr;
 280   }
 281
 282   nsCOMPtr<nsPIDOMWindowOuter> window = do_QueryInterface(aContext);
 283
 284   if (!window) {
 285     // Our context might be a document.
 286     nsCOMPtr<mozilla::dom::Document> doc = do_QueryInterface(aContext);
 287     if (!doc) {
 288       // we were not a document after all, get our ownerDocument,
 289       // hopefully
 290       nsCOMPtr<nsIContent> content = do_QueryInterface(aContext);
 291       if (content) {
 292         doc = content->OwnerDoc();
 293       }
 294     }
 295
 296     if (doc) {
 297       if (doc->GetDisplayDocument()) {
 298         doc = doc->GetDisplayDocument();
 299       }
 300
 301       window = doc->GetWindow();
 302     }
 303   }
 304
 305   if (!window) {
 306     return nullptr;
 307   }
 308
 309   return window->GetDocShell();
 310 }
 311
 312 #endif /* __nsContentPolicyUtils_h__ */