pjs/uriloader/exthandler/nsExternalProtocolHandler.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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 * 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
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 * for the specific language governing rights and limitations under the
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 * The Original Code is mozilla.org Code.
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 * The Initial Developer of the Original Code is
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 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
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 * Contributor(s):
 *   Scott MacGregor <mscott@netscape.com>
 *   Dan Mosedale <dmose@mozilla.org>
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#include "nsIURI.h"
#include "nsIURL.h"
#include "nsExternalProtocolHandler.h"
#include "nsXPIDLString.h"
#include "nsReadableUtils.h"
#include "nsCOMPtr.h"
#include "nsIServiceManager.h"
#include "nsServiceManagerUtils.h"
#include "nsIInterfaceRequestor.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsIStringBundle.h"
#include "nsIPrefService.h"
#include "nsIPrompt.h"
#include "nsNetUtil.h"
#include "nsIChannelEventSink.h"
#include "nsThreadUtils.h"
#include "nsEscape.h"
#include "nsExternalHelperAppService.h"

// used to dispatch urls to default protocol handlers
#include "nsCExternalHandlerService.h"
#include "nsIExternalProtocolService.h"

////////////////////////////////////////////////////////////////////////
// a stub channel implemenation which will map calls to AsyncRead and OpenInputStream
// to calls in the OS for loading the url.
////////////////////////////////////////////////////////////////////////

class nsExtProtocolChannel : public nsIChannel
{
    friend class nsWebProtocolRedirect;

public:
    NS_DECL_ISUPPORTS
    NS_DECL_NSICHANNEL
    NS_DECL_NSIREQUEST

    nsExtProtocolChannel();
    virtual ~nsExtProtocolChannel();

    nsresult SetURI(nsIURI*);

private:
    nsresult OpenURL();

    nsCOMPtr<nsIURI> mUrl;
    nsCOMPtr<nsIURI> mOriginalURI;
    nsresult mStatus;
    nsLoadFlags mLoadFlags;

    nsCOMPtr<nsIInterfaceRequestor> mCallbacks;
    nsCOMPtr<nsILoadGroup> mLoadGroup;
};

NS_IMPL_THREADSAFE_ADDREF(nsExtProtocolChannel)
NS_IMPL_THREADSAFE_RELEASE(nsExtProtocolChannel)

NS_INTERFACE_MAP_BEGIN(nsExtProtocolChannel)
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIChannel)
   NS_INTERFACE_MAP_ENTRY(nsIChannel)
   NS_INTERFACE_MAP_ENTRY(nsIRequest)
NS_INTERFACE_MAP_END_THREADSAFE

nsExtProtocolChannel::nsExtProtocolChannel() : mStatus(NS_OK)
{
}

nsExtProtocolChannel::~nsExtProtocolChannel()
{}

NS_IMETHODIMP nsExtProtocolChannel::GetLoadGroup(nsILoadGroup * *aLoadGroup)
{
  NS_IF_ADDREF(*aLoadGroup = mLoadGroup);
  return NS_OK;
}

NS_IMETHODIMP nsExtProtocolChannel::SetLoadGroup(nsILoadGroup * aLoadGroup)
{
  mLoadGroup = aLoadGroup;
  return NS_OK;
}

NS_IMETHODIMP nsExtProtocolChannel::GetNotificationCallbacks(nsIInterfaceRequestor* *aCallbacks)
{
  NS_IF_ADDREF(*aCallbacks = mCallbacks);
  return NS_OK;
}

NS_IMETHODIMP nsExtProtocolChannel::SetNotificationCallbacks(nsIInterfaceRequestor* aCallbacks)
{
  mCallbacks = aCallbacks;
  return NS_OK;
}

NS_IMETHODIMP 
nsExtProtocolChannel::GetSecurityInfo(nsISupports * *aSecurityInfo)
{
  *aSecurityInfo = nsnull;
  return NS_OK;
}

NS_IMETHODIMP nsExtProtocolChannel::GetOriginalURI(nsIURI* *aURI)
{
  NS_IF_ADDREF(*aURI = mOriginalURI);
  return NS_OK; 
}
 
NS_IMETHODIMP nsExtProtocolChannel::SetOriginalURI(nsIURI* aURI)
{
  NS_ENSURE_ARG_POINTER(aURI);
  mOriginalURI = aURI;
  return NS_OK;
}
 
NS_IMETHODIMP nsExtProtocolChannel::GetURI(nsIURI* *aURI)
{
  *aURI = mUrl;
  NS_IF_ADDREF(*aURI);
  return NS_OK; 
}
 
nsresult nsExtProtocolChannel::SetURI(nsIURI* aURI)
{
  mUrl = aURI;
  return NS_OK; 
}

nsresult nsExtProtocolChannel::OpenURL()
{
  nsresult rv = NS_ERROR_FAILURE;
  nsCOMPtr<nsIExternalProtocolService> extProtService (do_GetService(NS_EXTERNALPROTOCOLSERVICE_CONTRACTID));

  if (extProtService)
  {
#ifdef DEBUG
    nsCAutoString urlScheme;
    mUrl->GetScheme(urlScheme);
    PRBool haveHandler = PR_FALSE;
    extProtService->ExternalProtocolHandlerExists(urlScheme.get(), &haveHandler);
    NS_ASSERTION(haveHandler, "Why do we have a channel for this url if we don't support the protocol?");
#endif

    // get an nsIPrompt from the channel if we can
    nsCOMPtr<nsIPrompt> prompt;
    NS_QueryNotificationCallbacks(mCallbacks, mLoadGroup, prompt);
    rv = extProtService->LoadURI(mUrl, prompt);
  }

  // Drop notification callbacks to prevent cycles.
  mCallbacks = 0;

  return rv;
}

NS_IMETHODIMP nsExtProtocolChannel::Open(nsIInputStream **_retval)
{
  OpenURL();
  return NS_ERROR_NO_CONTENT; // force caller to abort.
}

class nsWebProtocolRedirect : public nsRunnable {
  public:
    nsWebProtocolRedirect(nsIURI *aURI, const nsACString & aUriTemplate,
                          nsIStreamListener *aListener, nsISupports *aContext,
                          nsExtProtocolChannel *aOriginalChannel)
      : mURI(aURI), mUriTemplate(aUriTemplate), mListener(aListener), 
        mContext(aContext), mOriginalChannel(aOriginalChannel) {}

    NS_IMETHOD Run() 
    {
      // get the URI spec so we can escape it for insertion into the template 
      nsCAutoString uriSpecToHandle;
      nsresult rv = mURI->GetSpec(uriSpecToHandle);
      if (NS_FAILED(rv)) {
        AbandonOriginalChannel(rv);
        return NS_OK; 
      }

      // XXX need to strip passwd & username from URI to handle, as per the
      // WhatWG HTML5 draft.  nsSimpleURL, which is what we're going to get,
      // can't do this directly.  Ideally, we'd fix nsStandardURL to make it
      // possible to turn off all of its quirks handling, and use that...

      // XXX this doesn't exactly match how the HTML5 draft is requesting us to
      // escape; at the very least, it should be escaping @ signs, and there
      // may well be more issues.  However, this code will probably be thrown
      // out when we do the front-end work, as we'll be using a refactored 
      // nsIWebContentConverterInfo to do this work for us
      nsCAutoString escapedUriSpecToHandle;
      NS_EscapeURL(uriSpecToHandle, esc_Minimal | esc_Forced | esc_Colon,
                   escapedUriSpecToHandle);

      // Note that this replace all occurrences of %s with the URL to be
      // handled.  The HTML5 draft doesn't prohibit %s from occurring more than
      // once, and if it does, I can't think of any problems that could
      // cause, (though I don't know why anyone would need or want to do it). 
      mUriTemplate.ReplaceSubstring(NS_LITERAL_CSTRING("%s"),
                                    escapedUriSpecToHandle);
  
      // convert spec to URI; no original charset needed since there's no way
      // to communicate that information to any handler
      nsCOMPtr<nsIURI> uriToSend;
      rv = NS_NewURI(getter_AddRefs(uriToSend), mUriTemplate);
      if (NS_FAILED(rv)) {
        AbandonOriginalChannel(rv);
        return NS_OK; 
      }

      // create a channel
      nsCOMPtr<nsIChannel> newChannel;
      rv = NS_NewChannel(getter_AddRefs(newChannel), uriToSend, nsnull,
                         mOriginalChannel->mLoadGroup,
                         mOriginalChannel->mCallbacks,
                         mOriginalChannel->mLoadFlags);
      if (NS_FAILED(rv)) {
        AbandonOriginalChannel(rv);
        return NS_OK; 
      }

      nsCOMPtr<nsIChannelEventSink> eventSink;
      NS_QueryNotificationCallbacks(mOriginalChannel->mCallbacks,
                                    mOriginalChannel->mLoadGroup, eventSink);

      if (eventSink) {
        // XXX decide on and audit for correct session & global hist behavior 
        rv = eventSink->OnChannelRedirect(mOriginalChannel, newChannel, 
                                          nsIChannelEventSink::REDIRECT_TEMPORARY |
                                          nsIChannelEventSink::REDIRECT_INTERNAL);
        if (NS_FAILED(rv)) {
          AbandonOriginalChannel(rv);
          return NS_OK;
        }
      }

      rv = newChannel->AsyncOpen(mListener, mContext);
      if (NS_FAILED(rv)) {
        AbandonOriginalChannel(rv);
        return NS_OK; 
      }
      
      mOriginalChannel->mStatus = NS_BINDING_REDIRECTED;
      return NS_OK;
    }

  private:
    nsCOMPtr<nsIURI> mURI;
    nsCString mUriTemplate;
    nsCOMPtr<nsIStreamListener> mListener;
    nsCOMPtr<nsISupports> mContext;
    nsCOMPtr<nsExtProtocolChannel> mOriginalChannel;

    // necko guarantees that after an AsyncOpen has succeeded, OnStartRequest
    // and OnStopRequest will get called    
    void AbandonOriginalChannel(const nsresult aStatus)
    {
      mOriginalChannel->mStatus = aStatus;
      (void)mListener->OnStartRequest(mOriginalChannel, mContext);
      (void)mListener->OnStopRequest(mOriginalChannel, mContext, aStatus);

      return;
    }
     
};

NS_IMETHODIMP nsExtProtocolChannel::AsyncOpen(nsIStreamListener *listener, nsISupports *ctxt)
{
  // check whether the scheme is one that we have a web handler for
  nsCAutoString urlScheme;  
  nsresult rv = mUrl->GetScheme(urlScheme);
  NS_ENSURE_SUCCESS(rv, rv);
  
  nsCOMPtr<nsIExternalProtocolService> extProtService =
    do_GetService(NS_EXTERNALPROTOCOLSERVICE_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);
  
  nsCAutoString uriTemplate;
  rv = nsExternalHelperAppService::GetWebProtocolHandlerURITemplate(urlScheme,
       uriTemplate);
  if (NS_SUCCEEDED(rv)) {

    // redirecting to the web handler involvegs calling OnChannelRedirect,
    // which is supposed to happen after AsyncOpen completes, so we do it in an
    // event
    nsCOMPtr<nsIRunnable> event = new nsWebProtocolRedirect(mUrl, uriTemplate,
                                                            listener, ctxt, 
                                                            this);
    // We don't check if |event| was successfully created because
    // |NS_DispatchToCurrentThread| will do that for us.
    rv = NS_DispatchToCurrentThread(event);
    if (NS_SUCCEEDED(rv)) {
      return rv;
    }
  }

  // try for an OS-provided handler
  OpenURL();
  return NS_ERROR_NO_CONTENT; // force caller to abort.
}

NS_IMETHODIMP nsExtProtocolChannel::GetLoadFlags(nsLoadFlags *aLoadFlags)
{
  *aLoadFlags = mLoadFlags;
  return NS_OK;
}

NS_IMETHODIMP nsExtProtocolChannel::SetLoadFlags(nsLoadFlags aLoadFlags)
{
  mLoadFlags = aLoadFlags;
  return NS_OK;
}

NS_IMETHODIMP nsExtProtocolChannel::GetContentType(nsACString &aContentType)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP nsExtProtocolChannel::SetContentType(const nsACString &aContentType)
{
  return NS_ERROR_FAILURE;
}

NS_IMETHODIMP nsExtProtocolChannel::GetContentCharset(nsACString &aContentCharset)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP nsExtProtocolChannel::SetContentCharset(const nsACString &aContentCharset)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP nsExtProtocolChannel::GetContentLength(PRInt32 * aContentLength)
{
  *aContentLength = -1;
  return NS_OK;
}

NS_IMETHODIMP
nsExtProtocolChannel::SetContentLength(PRInt32 aContentLength)
{
  NS_NOTREACHED("SetContentLength");
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP nsExtProtocolChannel::GetOwner(nsISupports * *aPrincipal)
{
  NS_NOTREACHED("GetOwner");
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP nsExtProtocolChannel::SetOwner(nsISupports * aPrincipal)
{
  NS_NOTREACHED("SetOwner");
  return NS_ERROR_NOT_IMPLEMENTED;
}

////////////////////////////////////////////////////////////////////////////////
// From nsIRequest
////////////////////////////////////////////////////////////////////////////////

NS_IMETHODIMP nsExtProtocolChannel::GetName(nsACString &result)
{
  return mUrl->GetSpec(result);
}

NS_IMETHODIMP nsExtProtocolChannel::IsPending(PRBool *result)
{
  *result = PR_TRUE;
  return NS_OK; 
}

NS_IMETHODIMP nsExtProtocolChannel::GetStatus(nsresult *status)
{
  *status = mStatus;
  return NS_OK;
}

NS_IMETHODIMP nsExtProtocolChannel::Cancel(nsresult status)
{
  mStatus = status;
  return NS_OK;
}

NS_IMETHODIMP nsExtProtocolChannel::Suspend()
{
  NS_NOTREACHED("Suspend");
  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP nsExtProtocolChannel::Resume()
{
  NS_NOTREACHED("Resume");
  return NS_ERROR_NOT_IMPLEMENTED;
}

///////////////////////////////////////////////////////////////////////
// the default protocol handler implementation
//////////////////////////////////////////////////////////////////////

nsExternalProtocolHandler::nsExternalProtocolHandler()
{
  m_schemeName = "default";
}


nsExternalProtocolHandler::~nsExternalProtocolHandler()
{}

NS_IMPL_THREADSAFE_ADDREF(nsExternalProtocolHandler)
NS_IMPL_THREADSAFE_RELEASE(nsExternalProtocolHandler)

NS_INTERFACE_MAP_BEGIN(nsExternalProtocolHandler)
   NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIProtocolHandler)
   NS_INTERFACE_MAP_ENTRY(nsIProtocolHandler)
   NS_INTERFACE_MAP_ENTRY(nsIExternalProtocolHandler)
   NS_INTERFACE_MAP_ENTRY(nsISupportsWeakReference)
NS_INTERFACE_MAP_END_THREADSAFE

NS_IMETHODIMP nsExternalProtocolHandler::GetScheme(nsACString &aScheme)
{
  aScheme = m_schemeName;
  return NS_OK;
}

NS_IMETHODIMP nsExternalProtocolHandler::GetDefaultPort(PRInt32 *aDefaultPort)
{
  *aDefaultPort = 0;
    return NS_OK;
}

NS_IMETHODIMP 
nsExternalProtocolHandler::AllowPort(PRInt32 port, const char *scheme, PRBool *_retval)
{
    // don't override anything.  
    *_retval = PR_FALSE;
    return NS_OK;
}
// returns TRUE if the OS can handle this protocol scheme and false otherwise.
PRBool nsExternalProtocolHandler::HaveExternalProtocolHandler(nsIURI * aURI)
{
  PRBool haveHandler = PR_FALSE;
  if (aURI)
  {
    nsCAutoString scheme;
    aURI->GetScheme(scheme);
    if (gExtProtSvc)
      gExtProtSvc->ExternalProtocolHandlerExists(scheme.get(), &haveHandler);
  }

  return haveHandler;
}

NS_IMETHODIMP nsExternalProtocolHandler::GetProtocolFlags(PRUint32 *aUritype)
{
    // Make it norelative since it is a simple uri
    *aUritype = URI_NORELATIVE | URI_NOAUTH | URI_LOADABLE_BY_ANYONE |
        URI_NON_PERSISTABLE;
    return NS_OK;
}

NS_IMETHODIMP nsExternalProtocolHandler::NewURI(const nsACString &aSpec,
                                                const char *aCharset, // ignore charset info
                                                nsIURI *aBaseURI,
                                                nsIURI **_retval)
{
  nsresult rv;
  nsCOMPtr<nsIURI> uri = do_CreateInstance(NS_SIMPLEURI_CONTRACTID, &rv);
  NS_ENSURE_SUCCESS(rv, rv);
  
  rv = uri->SetSpec(aSpec);
  NS_ENSURE_SUCCESS(rv, rv);

  NS_ADDREF(*_retval = uri);
  return NS_OK;
}

NS_IMETHODIMP nsExternalProtocolHandler::NewChannel(nsIURI *aURI, nsIChannel **_retval)
{
  // only try to return a channel if we have a protocol handler for the url

  PRBool haveExternalHandler = HaveExternalProtocolHandler(aURI);
  if (haveExternalHandler)
  {
    nsCOMPtr<nsIChannel> channel;
    NS_NEWXPCOM(channel, nsExtProtocolChannel);
    if (!channel) return NS_ERROR_OUT_OF_MEMORY;

    ((nsExtProtocolChannel*) channel.get())->SetURI(aURI);
    channel->SetOriginalURI(aURI);

    if (_retval)
    {
      *_retval = channel;
      NS_IF_ADDREF(*_retval);
      return NS_OK;
    }
  }

  return NS_ERROR_UNKNOWN_PROTOCOL;
}

///////////////////////////////////////////////////////////////////////
// External protocol handler interface implementation
//////////////////////////////////////////////////////////////////////
NS_IMETHODIMP nsExternalProtocolHandler::ExternalAppExistsForScheme(const nsACString& aScheme, PRBool *_retval)
{
  if (gExtProtSvc)
    return gExtProtSvc->ExternalProtocolHandlerExists(
      PromiseFlatCString(aScheme).get(), _retval);

  // In case we don't have external protocol service.
  *_retval = PR_FALSE;
  return NS_OK;
}

nsBlockedExternalProtocolHandler::nsBlockedExternalProtocolHandler()
{
    m_schemeName = "default-blocked";
}

NS_IMETHODIMP
nsBlockedExternalProtocolHandler::NewChannel(nsIURI *aURI,
                                             nsIChannel **_retval)
{
    *_retval = nsnull;
    return NS_ERROR_UNKNOWN_PROTOCOL;
}