gecko-dev/extensions/permissions/nsContentBlocker.cpp

346 строки
12 KiB
C++

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsContentBlocker.h"
#include "nsIContent.h"
#include "nsIURI.h"
#include "nsIServiceManager.h"
#include "nsIDocShellTreeItem.h"
#include "nsIPrefService.h"
#include "nsIPrefBranch.h"
#include "nsIDocShell.h"
#include "nsString.h"
#include "nsContentPolicyUtils.h"
#include "nsIObjectLoadingContent.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[] = {"other",
"script",
"image",
"stylesheet",
"object",
"document",
"subdocument",
"refresh",
"xbl",
"ping",
"xmlhttprequest",
"objectsubrequest",
"dtd",
"font",
"media",
"websocket"
"csp_report"};
#define NUMBER_OF_TYPES NS_ARRAY_LENGTH(kTypeString)
uint8_t nsContentBlocker::mBehaviorPref[NUMBER_OF_TYPES];
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);
// Migrate old image blocker pref
nsCOMPtr<nsIPrefBranch> oldPrefBranch;
oldPrefBranch = do_QueryInterface(prefService);
int32_t oldPref;
rv = oldPrefBranch->GetIntPref("network.image.imageBehavior", &oldPref);
if (NS_SUCCEEDED(rv) && oldPref) {
int32_t newPref;
switch (oldPref) {
default:
newPref = BEHAVIOR_ACCEPT;
break;
case 1:
newPref = BEHAVIOR_NOFOREIGN;
break;
case 2:
newPref = BEHAVIOR_REJECT;
break;
}
prefBranch->SetIntPref("image", newPref);
oldPrefBranch->ClearUserPref("network.image.imageBehavior");
}
// 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, true);
PrefChanged(prefBranch, nullptr);
return rv;
}
#undef LIMIT
#define LIMIT(x, low, high, default) ((x) >= (low) && (x) <= (high) ? (x) : (default))
void
nsContentBlocker::PrefChanged(nsIPrefBranch *aPrefBranch,
const char *aPref)
{
int32_t val;
#define PREF_CHANGED(_P) (!aPref || !strcmp(aPref, _P))
for(uint32_t 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(uint32_t aContentType,
nsIURI *aContentLocation,
nsIURI *aRequestingLocation,
nsISupports *aRequestingContext,
const nsACString &aMimeGuess,
nsISupports *aExtra,
nsIPrincipal *aRequestPrincipal,
int16_t *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;
// The final type of an object tag may mutate before it reaches
// shouldProcess, so we cannot make any sane blocking decisions here
if (aContentType == nsIContentPolicy::TYPE_OBJECT)
return NS_OK;
// we only want to check http, https, ftp
// for chrome:// and resources and others, no need to check.
nsAutoCString scheme;
aContentLocation->GetScheme(scheme);
if (!scheme.LowerCaseEqualsLiteral("ftp") &&
!scheme.LowerCaseEqualsLiteral("http") &&
!scheme.LowerCaseEqualsLiteral("https"))
return NS_OK;
bool shouldLoad, fromPrefs;
rv = TestPermission(aContentLocation, aRequestingLocation, aContentType,
&shouldLoad, &fromPrefs);
NS_ENSURE_SUCCESS(rv, rv);
if (!shouldLoad) {
if (fromPrefs) {
*aDecision = nsIContentPolicy::REJECT_TYPE;
} else {
*aDecision = nsIContentPolicy::REJECT_SERVER;
}
}
return NS_OK;
}
NS_IMETHODIMP
nsContentBlocker::ShouldProcess(uint32_t aContentType,
nsIURI *aContentLocation,
nsIURI *aRequestingLocation,
nsISupports *aRequestingContext,
const nsACString &aMimeGuess,
nsISupports *aExtra,
nsIPrincipal *aRequestPrincipal,
int16_t *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) {
int32_t type;
item->GetItemType(&type);
if (type == nsIDocShellTreeItem::typeChrome) {
*aDecision = nsIContentPolicy::ACCEPT;
return NS_OK;
}
}
// For objects, we only check policy in shouldProcess, as the final type isn't
// determined until the channel is open -- We don't want to block images in
// object tags because plugins are disallowed.
// NOTE that this bypasses the aContentLocation checks in ShouldLoad - this is
// intentional, as aContentLocation may be null for plugins that load by type
// (e.g. java)
if (aContentType == nsIContentPolicy::TYPE_OBJECT) {
*aDecision = nsIContentPolicy::ACCEPT;
bool shouldLoad, fromPrefs;
nsresult rv = TestPermission(aContentLocation, aRequestingLocation,
aContentType, &shouldLoad, &fromPrefs);
NS_ENSURE_SUCCESS(rv, rv);
if (!shouldLoad) {
if (fromPrefs) {
*aDecision = nsIContentPolicy::REJECT_TYPE;
} else {
*aDecision = nsIContentPolicy::REJECT_SERVER;
}
}
return NS_OK;
}
// This isn't a load from chrome or an object tag - Just do a ShouldLoad()
// check -- we want the same answer here
return ShouldLoad(aContentType, aContentLocation, aRequestingLocation,
aRequestingContext, aMimeGuess, aExtra, aRequestPrincipal,
aDecision);
}
nsresult
nsContentBlocker::TestPermission(nsIURI *aCurrentURI,
nsIURI *aFirstURI,
int32_t aContentType,
bool *aPermission,
bool *aFromPrefs)
{
*aFromPrefs = false;
// 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 = 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
uint32_t 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.
if (!permission) {
permission = mBehaviorPref[aContentType - 1];
*aFromPrefs = true;
}
// Use the fact that the nsIPermissionManager values map to
// the BEHAVIOR_* values above.
switch (permission) {
case BEHAVIOR_ACCEPT:
*aPermission = true;
break;
case BEHAVIOR_REJECT:
*aPermission = false;
break;
case BEHAVIOR_NOFOREIGN:
// Third party checking
// Need a requesting uri for third party checks to work.
if (!aFirstURI)
return NS_OK;
bool trustedSource = false;
rv = aFirstURI->SchemeIs("chrome", &trustedSource);
NS_ENSURE_SUCCESS(rv,rv);
if (!trustedSource) {
rv = aFirstURI->SchemeIs("resource", &trustedSource);
NS_ENSURE_SUCCESS(rv,rv);
}
if (trustedSource)
return NS_OK;
// 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
nsAutoCString 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.
int32_t 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);
nsAutoCString 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 = 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 = 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;
}