/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

// vim: ft=cpp tw=78 sw=4 et ts=8

/* 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/. */

/*

 * Implementation of the "@mozilla.org/layout/content-policy;1" contract.

 */

#include "mozilla/Logging.h"

#include "nsISupports.h"

#include "nsXPCOM.h"

#include "nsContentPolicyUtils.h"

#include "mozilla/dom/nsCSPService.h"

#include "nsContentPolicy.h"

#include "nsIURI.h"

#include "nsIDocShell.h"

#include "nsIDOMWindow.h"

#include "nsITabChild.h"

#include "nsIContent.h"

#include "nsIImageLoadingContent.h"

#include "nsILoadContext.h"

#include "nsCOMArray.h"

#include "nsContentUtils.h"

#include "mozilla/dom/nsMixedContentBlocker.h"

#include "nsIContentSecurityPolicy.h"

#include "mozilla/dom/TabGroup.h"

#include "mozilla/TaskCategory.h"

using mozilla::LogLevel;

NS_IMPL_ISUPPORTS(nsContentPolicy, nsIContentPolicy)

static mozilla::LazyLogModule gConPolLog("nsContentPolicy");

nsresult

NS_NewContentPolicy(nsIContentPolicy **aResult)

{

  *aResult = new nsContentPolicy;

  NS_ADDREF(*aResult);

  return NS_OK;

}

nsContentPolicy::nsContentPolicy()

    : mPolicies(NS_CONTENTPOLICY_CATEGORY)

{

}

nsContentPolicy::~nsContentPolicy()

{

}

#ifdef DEBUG

#define WARN_IF_URI_UNINITIALIZED(uri,name)                         \

  PR_BEGIN_MACRO                                                    \

    if ((uri)) {                                                    \

        nsAutoCString spec;                                         \

        (uri)->GetAsciiSpec(spec);                                  \

        if (spec.IsEmpty()) {                                       \

            NS_WARNING(name " is uninitialized, fix caller");       \

        }                                                           \

    }                                                               \

  PR_END_MACRO

#else  // ! defined(DEBUG)

#define WARN_IF_URI_UNINITIALIZED(uri,name)

#endif // defined(DEBUG)

inline nsresult

nsContentPolicy::CheckPolicy(CPMethod          policyMethod,

                             nsIURI           *contentLocation,

                             nsILoadInfo      *loadInfo,

                             const nsACString &mimeType,

                             int16_t           *decision)

{

    nsContentPolicyType contentType = loadInfo->InternalContentPolicyType();

    nsCOMPtr<nsISupports> requestingContext = loadInfo->GetLoadingContext();

    nsCOMPtr<nsIPrincipal> requestPrincipal = loadInfo->TriggeringPrincipal();

    nsCOMPtr<nsIURI> requestingLocation;

    nsCOMPtr<nsIPrincipal> loadingPrincipal = loadInfo->LoadingPrincipal();

    if (loadingPrincipal) {

      loadingPrincipal->GetURI(getter_AddRefs(requestingLocation));

    }

    //sanity-check passed-through parameters

    MOZ_ASSERT(decision, "Null out pointer");

    WARN_IF_URI_UNINITIALIZED(contentLocation, "Request URI");

    WARN_IF_URI_UNINITIALIZED(requestingLocation, "Requesting URI");

#ifdef DEBUG

    {

        nsCOMPtr<nsINode> node(do_QueryInterface(requestingContext));

        nsCOMPtr<nsIDOMWindow> window(do_QueryInterface(requestingContext));

        nsCOMPtr<nsITabChild> tabChild(do_QueryInterface(requestingContext));

        NS_ASSERTION(!requestingContext || node || window || tabChild,

                     "Context should be a DOM node, DOM window or a tabChild!");

    }

#endif

    /*

     * There might not be a requestinglocation. This can happen for

     * iframes with an image as src. Get the uri from the dom node.

     * See bug 254510

     */

    if (!requestingLocation) {

        nsCOMPtr<nsIDocument> doc;

        nsCOMPtr<nsIContent> node = do_QueryInterface(requestingContext);

        if (node) {

            doc = node->OwnerDoc();

        }

        if (!doc) {

            doc = do_QueryInterface(requestingContext);

        }

        if (doc) {

            requestingLocation = doc->GetDocumentURI();

        }

    }

    nsContentPolicyType externalType =

        nsContentUtils::InternalContentPolicyTypeToExternal(contentType);

    /*

     * Enumerate mPolicies and ask each of them, taking the logical AND of

     * their permissions.

     */

    nsresult rv;

    const nsCOMArray<nsIContentPolicy>& entries = mPolicies.GetCachedEntries();

    nsCOMPtr<nsPIDOMWindowOuter> window;

    if (nsCOMPtr<nsINode> node = do_QueryInterface(requestingContext)) {

        window = node->OwnerDoc()->GetWindow();

    } else {

        window = do_QueryInterface(requestingContext);

    }

    if (requestPrincipal) {

        nsCOMPtr<nsIContentSecurityPolicy> csp;

        requestPrincipal->GetCsp(getter_AddRefs(csp));

        if (csp && window) {

            csp->EnsureEventTarget(window->EventTargetFor(mozilla::TaskCategory::Other));

        }

    }

    int32_t count = entries.Count();

    for (int32_t i = 0; i < count; i++) {

        /* check the appropriate policy */

        rv = (entries[i]->*policyMethod)(contentLocation, loadInfo,

                                         mimeType, decision);

        if (NS_SUCCEEDED(rv) && NS_CP_REJECTED(*decision)) {

            // If we are blocking an image, we have to let the

            // ImageLoadingContent know that we blocked the load.

            if (externalType == nsIContentPolicy::TYPE_IMAGE ||

                externalType == nsIContentPolicy::TYPE_IMAGESET) {

              nsCOMPtr<nsIImageLoadingContent> img =

                do_QueryInterface(requestingContext);

              if (img) {

                img->SetBlockedRequest(*decision);

              }

            }

            /* policy says no, no point continuing to check */

            return NS_OK;

        }

    }

    // everyone returned failure, or no policies: sanitize result

    *decision = nsIContentPolicy::ACCEPT;

    return NS_OK;

}

//uses the parameters from ShouldXYZ to produce and log a message

//logType must be a literal string constant

#define LOG_CHECK(logType)                                                     \

  PR_BEGIN_MACRO                                                               \

    nsCOMPtr<nsIURI> requestingLocation;                                       \

    nsCOMPtr<nsIPrincipal> loadingPrincipal = loadInfo->LoadingPrincipal();    \

    if (loadingPrincipal) {                                                    \

      loadingPrincipal->GetURI(getter_AddRefs(requestingLocation));            \

    }                                                                          \

    /* skip all this nonsense if the call failed or logging is disabled */     \

    if (NS_SUCCEEDED(rv) && MOZ_LOG_TEST(gConPolLog, LogLevel::Debug)) {       \

      const char *resultName;                                                  \

      if (decision) {                                                          \

        resultName = NS_CP_ResponseName(*decision);                            \

      } else {                                                                 \

        resultName = "(null ptr)";                                             \

      }                                                                        \

      MOZ_LOG(gConPolLog, LogLevel::Debug,                                     \

             ("Content Policy: " logType ": <%s> <Ref:%s> result=%s",          \

              contentLocation ? contentLocation->GetSpecOrDefault().get()      \

                              : "None",                                        \

              requestingLocation ? requestingLocation->GetSpecOrDefault().get()\

                                 : "None",                                     \

              resultName)                                                      \

             );                                                                \

    }                                                                          \

  PR_END_MACRO

NS_IMETHODIMP

nsContentPolicy::ShouldLoad(nsIURI           *contentLocation,

                            nsILoadInfo      *loadInfo,

                            const nsACString &mimeType,

                            int16_t          *decision)

{

    // ShouldProcess does not need a content location, but we do

    MOZ_ASSERT(contentLocation, "Must provide request location");

    nsresult rv = CheckPolicy(&nsIContentPolicy::ShouldLoad,

                              contentLocation, loadInfo,

                              mimeType, decision);

    LOG_CHECK("ShouldLoad");

    return rv;

}

NS_IMETHODIMP

nsContentPolicy::ShouldProcess(nsIURI           *contentLocation,

                               nsILoadInfo      *loadInfo,

                               const nsACString &mimeType,

                               int16_t          *decision)

{

    nsresult rv = CheckPolicy(&nsIContentPolicy::ShouldProcess,

                              contentLocation, loadInfo,

                              mimeType, decision);

    LOG_CHECK("ShouldProcess");

    return rv;

}