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 "nsIURI.h"
  23 #include "nsServiceManagerUtils.h"
  24 #include "nsStringFwd.h"
  25 #include "mozilla/dom/nsCSPService.h"
  26
  27 // XXXtw sadly, this makes consumers of nsContentPolicyUtils depend on widget
  28 #include "mozilla/dom/Document.h"
  29 #include "nsPIDOMWindow.h"
  30
  31 #define NS_CONTENTPOLICY_CONTRACTID "@mozilla.org/layout/content-policy;1"
  32 #define NS_CONTENTPOLICY_CATEGORY "content-policy"
  33 #define NS_CONTENTPOLICY_CID                         \
  34   {                                                  \
  35     0x0e3afd3d, 0xeb60, 0x4c2b, {                    \
  36       0x96, 0x3b, 0x56, 0xd7, 0xc4, 0x39, 0xf1, 0x24 \
  37     }                                                \
  38   }
  39
  40 /**
  41  * Evaluates to true if val is ACCEPT.
  42  *
  43  * @param val the status returned from shouldProcess/shouldLoad
  44  */
  45 #define NS_CP_ACCEPTED(val) ((val) == nsIContentPolicy::ACCEPT)
  46
  47 /**
  48  * Evaluates to true if val is a REJECT_* status
  49  *
  50  * @param val the status returned from shouldProcess/shouldLoad
  51  */
  52 #define NS_CP_REJECTED(val) ((val) != nsIContentPolicy::ACCEPT)
  53
  54 // Offer convenient translations of constants -> const char*
  55
  56 // convenience macro to reduce some repetative typing...
  57 // name is the name of a constant from this interface
  58 #define CASE_RETURN(name)      \
  59   case nsIContentPolicy::name: \
  60     return #name
  61
  62 /**
  63  * Returns a string corresponding to the name of the response constant, or
  64  * "<Unknown Response>" if an unknown response value is given.
  65  *
  66  * The return value is static and must not be freed.
  67  *
  68  * @param response the response code
  69  * @return the name of the given response code
  70  */
  71 inline const char* NS_CP_ResponseName(int16_t response) {
  72   switch (response) {
  73     CASE_RETURN(REJECT_REQUEST);
  74     CASE_RETURN(REJECT_TYPE);
  75     CASE_RETURN(REJECT_SERVER);
  76     CASE_RETURN(REJECT_OTHER);
  77     CASE_RETURN(ACCEPT);
  78     default:
  79       return "<Unknown Response>";
  80   }
  81 }
  82
  83 /**
  84  * Returns a string corresponding to the name of the content type constant, or
  85  * "<Unknown Type>" if an unknown content type value is given.
  86  *
  87  * The return value is static and must not be freed.
  88  *
  89  * @param contentType the content type code
  90  * @return the name of the given content type code
  91  */
  92 inline const char* NS_CP_ContentTypeName(nsContentPolicyType contentType) {
  93   switch (contentType) {
  94     CASE_RETURN(TYPE_OTHER);
  95     CASE_RETURN(TYPE_SCRIPT);
  96     CASE_RETURN(TYPE_IMAGE);
  97     CASE_RETURN(TYPE_STYLESHEET);
  98     CASE_RETURN(TYPE_OBJECT);
  99     CASE_RETURN(TYPE_DOCUMENT);
 100     CASE_RETURN(TYPE_SUBDOCUMENT);
 101     CASE_RETURN(TYPE_PING);
 102     CASE_RETURN(TYPE_XMLHTTPREQUEST);
 103     CASE_RETURN(TYPE_OBJECT_SUBREQUEST);
 104     CASE_RETURN(TYPE_DTD);
 105     CASE_RETURN(TYPE_FONT);
 106     CASE_RETURN(TYPE_MEDIA);
 107     CASE_RETURN(TYPE_WEBSOCKET);
 108     CASE_RETURN(TYPE_CSP_REPORT);
 109     CASE_RETURN(TYPE_XSLT);
 110     CASE_RETURN(TYPE_BEACON);
 111     CASE_RETURN(TYPE_FETCH);
 112     CASE_RETURN(TYPE_IMAGESET);
 113     CASE_RETURN(TYPE_WEB_MANIFEST);
 114     CASE_RETURN(TYPE_INTERNAL_SCRIPT);
 115     CASE_RETURN(TYPE_INTERNAL_WORKER);
 116     CASE_RETURN(TYPE_INTERNAL_SHARED_WORKER);
 117     CASE_RETURN(TYPE_INTERNAL_EMBED);
 118     CASE_RETURN(TYPE_INTERNAL_OBJECT);
 119     CASE_RETURN(TYPE_INTERNAL_FRAME);
 120     CASE_RETURN(TYPE_INTERNAL_IFRAME);
 121     CASE_RETURN(TYPE_INTERNAL_AUDIO);
 122     CASE_RETURN(TYPE_INTERNAL_VIDEO);
 123     CASE_RETURN(TYPE_INTERNAL_TRACK);
 124     CASE_RETURN(TYPE_INTERNAL_XMLHTTPREQUEST);
 125     CASE_RETURN(TYPE_INTERNAL_EVENTSOURCE);
 126     CASE_RETURN(TYPE_INTERNAL_SERVICE_WORKER);
 127     CASE_RETURN(TYPE_INTERNAL_SCRIPT_PRELOAD);
 128     CASE_RETURN(TYPE_INTERNAL_IMAGE);
 129     CASE_RETURN(TYPE_INTERNAL_IMAGE_PRELOAD);
 130     CASE_RETURN(TYPE_INTERNAL_IMAGE_FAVICON);
 131     CASE_RETURN(TYPE_INTERNAL_STYLESHEET);
 132     CASE_RETURN(TYPE_INTERNAL_STYLESHEET_PRELOAD);
 133     CASE_RETURN(TYPE_INTERNAL_WORKER_IMPORT_SCRIPTS);
 134     CASE_RETURN(TYPE_SAVEAS_DOWNLOAD);
 135     CASE_RETURN(TYPE_SPECULATIVE);
 136     CASE_RETURN(TYPE_INTERNAL_MODULE);
 137     CASE_RETURN(TYPE_INTERNAL_MODULE_PRELOAD);
 138     CASE_RETURN(TYPE_INTERNAL_DTD);
 139     CASE_RETURN(TYPE_INTERNAL_FORCE_ALLOWED_DTD);
 140     CASE_RETURN(TYPE_INTERNAL_AUDIOWORKLET);
 141     CASE_RETURN(TYPE_INTERNAL_PAINTWORKLET);
 142     CASE_RETURN(TYPE_INTERNAL_FONT_PRELOAD);
 143     CASE_RETURN(TYPE_INTERNAL_CHROMEUTILS_COMPILED_SCRIPT);
 144     CASE_RETURN(TYPE_INTERNAL_FRAME_MESSAGEMANAGER_SCRIPT);
 145     CASE_RETURN(TYPE_INTERNAL_FETCH_PRELOAD);
 146     case nsIContentPolicy::TYPE_INVALID:
 147       break;
 148       // Do not add default: so that compilers can catch the missing case.
 149   }
 150   return "<Unknown Type>";
 151 }
 152
 153 #undef CASE_RETURN
 154
 155 inline const char* NS_CP_ContentTypeName(ExtContentPolicyType contentType) {
 156   return NS_CP_ContentTypeName(static_cast<nsContentPolicyType>(contentType));
 157 }
 158
 159 /* Passes on parameters from its "caller"'s context. */
 160 #define CHECK_CONTENT_POLICY(action)                                    \
 161   PR_BEGIN_MACRO                                                        \
 162   nsCOMPtr<nsIContentPolicy> policy =                                   \
 163       do_GetService(NS_CONTENTPOLICY_CONTRACTID);                       \
 164   if (!policy) return NS_ERROR_FAILURE;                                 \
 165                                                                         \
 166   return policy->action(contentLocation, loadInfo, mimeType, decision); \
 167   PR_END_MACRO
 168
 169 /* Passes on parameters from its "caller"'s context. */
 170 #define CHECK_CONTENT_POLICY_WITH_SERVICE(action, _policy)               \
 171   PR_BEGIN_MACRO                                                         \
 172   return _policy->action(contentLocation, loadInfo, mimeType, decision); \
 173   PR_END_MACRO
 174
 175 /**
 176  * Check whether we can short-circuit this check and bail out.  If not, get the
 177  * origin URI to use.
 178  *
 179  * Note: requestOrigin is scoped outside the PR_BEGIN_MACRO/PR_END_MACRO on
 180  * purpose */
 181 #define CHECK_PRINCIPAL_CSP_AND_DATA(action)                                   \
 182   PR_BEGIN_MACRO                                                               \
 183   if (loadingPrincipal && loadingPrincipal->IsSystemPrincipal()) {             \
 184     /* We exempt most loads into any document with the system principal        \
 185      * from content policy (except CSP) checks, mostly as an optimization.     \
 186      * Which means that we need to apply this check to the loading principal,  \
 187      * not the principal that triggered the load. */                           \
 188     /* Check CSP for System Privileged pages */                                \
 189     CSPService::ConsultCSP(contentLocation, loadInfo, mimeType, decision);     \
 190     if (NS_CP_REJECTED(*decision)) {                                           \
 191       return NS_OK;                                                            \
 192     }                                                                          \
 193     if (contentType != nsIContentPolicy::TYPE_DOCUMENT) {                      \
 194       *decision = nsIContentPolicy::ACCEPT;                                    \
 195       nsCOMPtr<nsINode> n = do_QueryInterface(context);                        \
 196       if (!n) {                                                                \
 197         nsCOMPtr<nsPIDOMWindowOuter> win = do_QueryInterface(context);         \
 198         n = win ? win->GetExtantDoc() : nullptr;                               \
 199       }                                                                        \
 200       if (n) {                                                                 \
 201         mozilla::dom::Document* d = n->OwnerDoc();                             \
 202         if (d->IsLoadedAsData() || d->IsBeingUsedAsImage() ||                  \
 203             d->IsResourceDoc()) {                                              \
 204           nsCOMPtr<nsIContentPolicy> dataPolicy =                              \
 205               do_GetService("@mozilla.org/data-document-content-policy;1");    \
 206           if (dataPolicy) {                                                    \
 207             dataPolicy->action(contentLocation, loadInfo, mimeType, decision); \
 208           }                                                                    \
 209         }                                                                      \
 210       }                                                                        \
 211     }                                                                          \
 212     return NS_OK;                                                              \
 213   }                                                                            \
 214   PR_END_MACRO
 215
 216 /**
 217  * Alias for calling ShouldLoad on the content policy service.  Parameters are
 218  * the same as nsIContentPolicy::shouldLoad, except for the loadingPrincipal
 219  * and triggeringPrincipal parameters (which should be non-null if possible,
 220  * and have the same semantics as in nsLoadInfo), and the last parameter,
 221  * which can be used to pass in a pointer to a useful service if the caller
 222  * already has it.  The origin URI to pass to shouldLoad will be the URI of
 223  * loadingPrincipal, unless loadingPrincipal is null (in which case a null
 224  * origin URI will be passed).
 225  */
 226 inline nsresult NS_CheckContentLoadPolicy(
 227     nsIURI* contentLocation, nsILoadInfo* loadInfo, const nsACString& mimeType,
 228     int16_t* decision, nsIContentPolicy* policyService = nullptr) {
 229   nsIPrincipal* loadingPrincipal = loadInfo->GetLoadingPrincipal();
 230   nsCOMPtr<nsISupports> context = loadInfo->GetLoadingContext();
 231   nsContentPolicyType contentType = loadInfo->InternalContentPolicyType();
 232   CHECK_PRINCIPAL_CSP_AND_DATA(ShouldLoad);
 233   if (policyService) {
 234     CHECK_CONTENT_POLICY_WITH_SERVICE(ShouldLoad, policyService);
 235   }
 236   CHECK_CONTENT_POLICY(ShouldLoad);
 237 }
 238
 239 /**
 240  * Alias for calling ShouldProcess on the content policy service.
 241  */
 242 inline nsresult NS_CheckContentProcessPolicy(
 243     nsIURI* contentLocation, nsILoadInfo* loadInfo, const nsACString& mimeType,
 244     int16_t* decision, nsIContentPolicy* policyService = nullptr) {
 245   nsIPrincipal* loadingPrincipal = loadInfo->GetLoadingPrincipal();
 246   nsCOMPtr<nsISupports> context = loadInfo->GetLoadingContext();
 247   nsContentPolicyType contentType = loadInfo->InternalContentPolicyType();
 248   CHECK_PRINCIPAL_CSP_AND_DATA(ShouldProcess);
 249   if (policyService) {
 250     CHECK_CONTENT_POLICY_WITH_SERVICE(ShouldProcess, policyService);
 251   }
 252   CHECK_CONTENT_POLICY(ShouldProcess);
 253 }
 254
 255 #undef CHECK_CONTENT_POLICY
 256 #undef CHECK_CONTENT_POLICY_WITH_SERVICE
 257
 258 /**
 259  * Helper function to get an nsIDocShell given a context.
 260  * If the context is a document or window, the corresponding docshell will be
 261  * returned.
 262  * If the context is a non-document DOM node, the docshell of its ownerDocument
 263  * will be returned.
 264  *
 265  * @param aContext the context to find a docshell for (can be null)
 266  *
 267  * @return a WEAK pointer to the docshell, or nullptr if it could
 268  *     not be obtained
 269  *
 270  * @note  As of this writing, calls to nsIContentPolicy::Should{Load,Process}
 271  * for TYPE_DOCUMENT and TYPE_SUBDOCUMENT pass in an aContext that either
 272  * points to the frameElement of the window the load is happening in
 273  * (in which case NS_CP_GetDocShellFromContext will return the parent of the
 274  * docshell the load is happening in), or points to the window the load is
 275  * happening in (in which case NS_CP_GetDocShellFromContext will return
 276  * the docshell the load is happening in).  It's up to callers to QI aContext
 277  * and handle things accordingly if they want the docshell the load is
 278  * happening in.  These are somewhat odd semantics, and bug 466687 has been
 279  * filed to consider improving them.
 280  */
 281 inline nsIDocShell* NS_CP_GetDocShellFromContext(nsISupports* aContext) {
 282   if (!aContext) {
 283     return nullptr;
 284   }
 285
 286   nsCOMPtr<nsPIDOMWindowOuter> window = do_QueryInterface(aContext);
 287
 288   if (!window) {
 289     // Our context might be a document.
 290     nsCOMPtr<mozilla::dom::Document> doc = do_QueryInterface(aContext);
 291     if (!doc) {
 292       // we were not a document after all, get our ownerDocument,
 293       // hopefully
 294       nsCOMPtr<nsIContent> content = do_QueryInterface(aContext);
 295       if (content) {
 296         doc = content->OwnerDoc();
 297       }
 298     }
 299
 300     if (doc) {
 301       if (doc->GetDisplayDocument()) {
 302         doc = doc->GetDisplayDocument();
 303       }
 304
 305       window = doc->GetWindow();
 306     }
 307   }
 308
 309   if (!window) {
 310     return nullptr;
 311   }
 312
 313   return window->GetDocShell();
 314 }
 315
 316 #endif /* __nsContentPolicyUtils_h__ */