gecko-dev/extensions/permissions/nsContentBlocker.cpp

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/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is content blocker code.
*
* The Initial Developer of the Original Code is
* Michiel van Leeuwen <mvl@exedo.nl>.
* Portions created by the Initial Developer are Copyright (C) 2004
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "nsContentBlocker.h"
#include "nsIDocument.h"
#include "nsIContent.h"
#include "nsINodeInfo.h"
#include "nsIURI.h"
#include "nsIServiceManager.h"
#include "nsIScriptGlobalObject.h"
#include "nsIDOMWindow.h"
#include "nsIDOMDocument.h"
#include "nsIDocShellTreeItem.h"
#include "nsIPrefService.h"
#include "nsIPrefBranch.h"
#include "nsIDocShell.h"
#include "nsString.h"
#include "nsContentPolicyUtils.h"
// Possible behavior pref values
// Those map to the nsIPermissionManager values where possible
#define BEHAVIOR_ACCEPT nsIPermissionManager::ALLOW_ACTION
#define BEHAVIOR_REJECT nsIPermissionManager::DENY_ACTION
#define BEHAVIOR_NOFOREIGN 3
// From nsIContentPolicy
static const char *kTypeString[NUMBER_OF_TYPES] = {"other",
"script",
"image",
"stylesheet",
"object",
"document",
"subdocument",
"refresh"};
NS_IMPL_ISUPPORTS3(nsContentBlocker,
nsIContentPolicy,
nsIObserver,
nsSupportsWeakReference)
nsContentBlocker::nsContentBlocker()
{
memset(mBehaviorPref, BEHAVIOR_ACCEPT, NUMBER_OF_TYPES);
}
nsresult
nsContentBlocker::Init()
{
nsresult rv;
mPermissionManager = do_GetService(NS_PERMISSIONMANAGER_CONTRACTID, &rv);
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIPrefService> prefService = do_GetService(NS_PREFSERVICE_CONTRACTID, &rv);
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIPrefBranch> prefBranch;
rv = prefService->GetBranch("permissions.default.", getter_AddRefs(prefBranch));
NS_ENSURE_SUCCESS(rv, rv);
// The branch is not a copy of the prefservice, but a new object, because
// it is a non-default branch. Adding obeservers to it will only work if
// we make sure that the object doesn't die. So, keep a reference to it.
mPrefBranchInternal = do_QueryInterface(prefBranch, &rv);
NS_ENSURE_SUCCESS(rv, rv);
rv = mPrefBranchInternal->AddObserver("", this, PR_TRUE);
PrefChanged(prefBranch, nsnull);
return rv;
}
#undef LIMIT
#define LIMIT(x, low, high, default) ((x) >= (low) && (x) <= (high) ? (x) : (default))
void
nsContentBlocker::PrefChanged(nsIPrefBranch *aPrefBranch,
const char *aPref)
{
PRInt32 val;
#define PREF_CHANGED(_P) (!aPref || !strcmp(aPref, _P))
for(PRUint32 i = 0; i < NUMBER_OF_TYPES; ++i) {
if (PREF_CHANGED(kTypeString[i]) &&
NS_SUCCEEDED(aPrefBranch->GetIntPref(kTypeString[i], &val)))
mBehaviorPref[i] = LIMIT(val, 1, 3, 1);
}
}
// nsIContentPolicy Implementation
NS_IMETHODIMP
nsContentBlocker::ShouldLoad(PRUint32 aContentType,
nsIURI *aContentLocation,
nsIURI *aRequestingLocation,
nsISupports *aRequestingContext,
const nsACString &aMimeGuess,
nsISupports *aExtra,
PRInt16 *aDecision)
{
*aDecision = nsIContentPolicy::ACCEPT;
nsresult rv;
// Ony support NUMBER_OF_TYPES content types. that all there is at the
// moment, but you never know...
if (aContentType > NUMBER_OF_TYPES)
return NS_OK;
// we can't do anything without this
if (!aContentLocation)
return NS_OK;
// we only want to check http, https, ftp
// for chrome:// and resources and others, no need to check.
nsCAutoString scheme;
aContentLocation->GetScheme(scheme);
if (!scheme.LowerCaseEqualsLiteral("ftp") &&
!scheme.LowerCaseEqualsLiteral("http") &&
!scheme.LowerCaseEqualsLiteral("https"))
return NS_OK;
PRBool shouldLoad;
rv = TestPermission(aContentLocation, aRequestingLocation, aContentType, &shouldLoad);
NS_ENSURE_SUCCESS(rv, rv);
if (!shouldLoad)
*aDecision = nsIContentPolicy::REJECT_SERVER;
return NS_OK;
}
NS_IMETHODIMP
nsContentBlocker::ShouldProcess(PRUint32 aContentType,
nsIURI *aContentLocation,
nsIURI *aRequestingLocation,
nsISupports *aRequestingContext,
const nsACString &aMimeGuess,
nsISupports *aExtra,
PRInt16 *aDecision)
{
// For loads where aRequestingContext is chrome, we should just
// accept. Those are most likely toplevel loads in windows, and
// chrome generally knows what it's doing anyway.
nsCOMPtr<nsIDocShellTreeItem> item =
do_QueryInterface(NS_CP_GetDocShellFromContext(aRequestingContext));
if (item) {
PRInt32 type;
item->GetItemType(&type);
if (type == nsIDocShellTreeItem::typeChrome) {
*aDecision = nsIContentPolicy::ACCEPT;
return NS_OK;
}
}
// This isn't a load from chrome. Just do a ShouldLoad() check --
// we want the same answer here
return ShouldLoad(aContentType, aContentLocation, aRequestingLocation,
aRequestingContext, aMimeGuess, aExtra, aDecision);
}
nsresult
nsContentBlocker::TestPermission(nsIURI *aCurrentURI,
nsIURI *aFirstURI,
PRInt32 aContentType,
PRBool *aPermission)
{
// This default will also get used if there is an unknown value in the
// permission list, or if the permission manager returns unknown values.
*aPermission = PR_TRUE;
// check the permission list first; if we find an entry, it overrides
// default prefs.
// Don't forget the aContentType ranges from 1..8, while the
// array is indexed 0..7
PRUint32 permission;
nsresult rv = mPermissionManager->TestPermission(aCurrentURI,
kTypeString[aContentType - 1],
&permission);
NS_ENSURE_SUCCESS(rv, rv);
// If there is nothing on the list, use the default.
// Use the fact that the nsIPermissionManager values map to
// the BEHAVIOR_* values above.
switch (permission) {
case nsIPermissionManager::UNKNOWN_ACTION:
permission = mBehaviorPref[aContentType - 1];
break;
// if we found an entry, use it
case BEHAVIOR_ACCEPT:
*aPermission = PR_TRUE;
break;
case BEHAVIOR_REJECT:
*aPermission = PR_FALSE;
break;
case BEHAVIOR_NOFOREIGN:
// Third party checking
// compare tails of names checking to see if they have a common domain
// we do this by comparing the tails of both names where each tail
// includes at least one dot
// A more generic method somewhere would be nice
nsCAutoString currentHost;
rv = aCurrentURI->GetAsciiHost(currentHost);
NS_ENSURE_SUCCESS(rv, rv);
// Search for two dots, starting at the end.
// If there are no two dots found, ++dot will turn to zero,
// that will return the entire string.
PRInt32 dot = currentHost.RFindChar('.');
dot = currentHost.RFindChar('.', dot-1);
++dot;
// Get the domain, ie the last part of the host (www.domain.com -> domain.com)
// This will break on co.uk
const nsCSubstring &tail =
Substring(currentHost, dot, currentHost.Length() - dot);
nsCAutoString firstHost;
rv = aFirstURI->GetAsciiHost(firstHost);
NS_ENSURE_SUCCESS(rv, rv);
// If the tail is longer then the whole firstHost, it will never match
if (firstHost.Length() < tail.Length()) {
*aPermission = PR_FALSE;
return NS_OK;
}
// Get the last part of the firstUri with the same length as |tail|
const nsCSubstring &firstTail =
Substring(firstHost, firstHost.Length() - tail.Length(), tail.Length());
// Check that both tails are the same, and that just before the tail in
// |firstUri| there is a dot. That means both url are in the same domain
if ((firstHost.Length() > tail.Length() &&
firstHost.CharAt(firstHost.Length() - tail.Length() - 1) != '.') ||
!tail.Equals(firstTail)) {
*aPermission = PR_FALSE;
}
break;
}
return NS_OK;
}
NS_IMETHODIMP
nsContentBlocker::Observe(nsISupports *aSubject,
const char *aTopic,
const PRUnichar *aData)
{
NS_ASSERTION(!strcmp(NS_PREFBRANCH_PREFCHANGE_TOPIC_ID, aTopic),
"unexpected topic - we only deal with pref changes!");
if (mPrefBranchInternal)
PrefChanged(mPrefBranchInternal, NS_LossyConvertUTF16toASCII(aData).get());
return NS_OK;
}