pjs/netwerk/streamconv/converters/nsUnknownDecoder.cpp

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: NPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Netscape 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/NPL/
*
* 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 mozilla.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1999
* 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 NPL, 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 NPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "nsUnknownDecoder.h"
#include "nsIServiceManager.h"
#include "nsIStreamConverterService.h"
#include "nsIPipe.h"
#include "nsIInputStream.h"
#include "nsIOutputStream.h"
#include "nsMimeTypes.h"
#include "netCore.h"
#include "nsXPIDLString.h"
#include "nsIPref.h"
#define MAX_BUFFER_SIZE 1024
static NS_DEFINE_CID(kStreamConverterServiceCID, NS_STREAMCONVERTERSERVICE_CID);
static NS_DEFINE_IID(kPrefServiceCID, NS_PREF_CID);
nsUnknownDecoder::nsUnknownDecoder()
{
NS_INIT_ISUPPORTS();
mBuffer = nsnull;
mBufferLen = 0;
mRequireHTMLsuffix = PR_FALSE;
nsresult rv;
nsCOMPtr<nsIPref> pPrefService = do_GetService(kPrefServiceCID, &rv);
if (NS_SUCCEEDED(rv)) {
rv = pPrefService->GetBoolPref("security.requireHTMLsuffix", &mRequireHTMLsuffix);
}
}
nsUnknownDecoder::~nsUnknownDecoder()
{
if (mBuffer) {
delete [] mBuffer;
mBuffer = nsnull;
}
}
// ----
//
// nsISupports implementation...
//
// ----
NS_IMPL_ADDREF(nsUnknownDecoder);
NS_IMPL_RELEASE(nsUnknownDecoder);
NS_INTERFACE_MAP_BEGIN(nsUnknownDecoder)
NS_INTERFACE_MAP_ENTRY(nsIStreamConverter)
NS_INTERFACE_MAP_ENTRY(nsIStreamListener)
NS_INTERFACE_MAP_ENTRY(nsIRequestObserver)
NS_INTERFACE_MAP_ENTRY(nsISupports)
NS_INTERFACE_MAP_END
// ----
//
// nsIStreamConverter methods...
//
// ----
NS_IMETHODIMP
nsUnknownDecoder::Convert(nsIInputStream *aFromStream,
const PRUnichar *aFromType,
const PRUnichar *aToType,
nsISupports *aCtxt,
nsIInputStream **aResultStream)
{
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsUnknownDecoder::AsyncConvertData(const PRUnichar *aFromType,
const PRUnichar *aToType,
nsIStreamListener *aListener,
nsISupports *aCtxt)
{
NS_ASSERTION(aListener && aFromType && aToType,
"null pointer passed into multi mixed converter");
// hook up our final listener. this guy gets the various On*() calls we want to throw
// at him.
//
mNextListener = aListener;
return (aListener) ? NS_OK : NS_ERROR_FAILURE;
}
// ----
//
// nsIStreamListener methods...
//
// ----
NS_IMETHODIMP
nsUnknownDecoder::OnDataAvailable(nsIRequest* request,
nsISupports *aCtxt,
nsIInputStream *aStream,
PRUint32 aSourceOffset,
PRUint32 aCount)
{
nsresult rv = NS_OK;
if (!mNextListener) return NS_ERROR_FAILURE;
if (mContentType.IsEmpty()) {
PRUint32 count, len;
// If the buffer has not been allocated by now, just fail...
if (!mBuffer) return NS_ERROR_OUT_OF_MEMORY;
//
// Determine how much of the stream should be read to fill up the
// sniffer buffer...
//
if (mBufferLen + aCount >= MAX_BUFFER_SIZE) {
count = MAX_BUFFER_SIZE-mBufferLen;
} else {
count = aCount;
}
// Read the data into the buffer...
rv = aStream->Read((mBuffer+mBufferLen), count, &len);
if (NS_FAILED(rv)) return rv;
mBufferLen += len;
aCount -= len;
if (aCount) {
//
// Adjust the source offset... The call to FireListenerNotifications(...)
// will make the first OnDataAvailable(...) call with an offset of 0.
// So, this offset needs to be adjusted to reflect that...
//
aSourceOffset += mBufferLen;
DetermineContentType(request);
NS_ASSERTION(!mContentType.IsEmpty(),
"Content type should be known by now.");
rv = FireListenerNotifications(request, aCtxt);
}
}
if (aCount) {
NS_ASSERTION(!mContentType.IsEmpty(),
"Content type should be known by now.");
rv = mNextListener->OnDataAvailable(request, aCtxt, aStream,
aSourceOffset, aCount);
}
return rv;
}
// ----
//
// nsIRequestObserver methods...
//
// ----
NS_IMETHODIMP
nsUnknownDecoder::OnStartRequest(nsIRequest* request, nsISupports *aCtxt)
{
nsresult rv = NS_OK;
if (!mNextListener) return NS_ERROR_FAILURE;
// Allocate the sniffer buffer...
if (NS_SUCCEEDED(rv) && !mBuffer) {
mBuffer = new char[MAX_BUFFER_SIZE];
if (!mBuffer) {
rv = NS_ERROR_OUT_OF_MEMORY;
}
}
// Do not pass the OnStartRequest on to the next listener (yet)...
return rv;
}
NS_IMETHODIMP
nsUnknownDecoder::OnStopRequest(nsIRequest* request, nsISupports *aCtxt,
nsresult aStatus)
{
nsresult rv = NS_OK;
if (!mNextListener) return NS_ERROR_FAILURE;
//
// The total amount of data is less than the size of the sniffer buffer.
// Analyze the buffer now...
//
if (mContentType.IsEmpty()) {
DetermineContentType(request);
NS_ASSERTION(!mContentType.IsEmpty(),
"Content type should be known by now.");
rv = FireListenerNotifications(request, aCtxt);
if (NS_FAILED(rv)) {
aStatus = rv;
}
}
rv = mNextListener->OnStopRequest(request, aCtxt, aStatus);
mNextListener = 0;
return rv;
}
void nsUnknownDecoder::DetermineContentType(nsIRequest* request)
{
PRUint32 i;
NS_ASSERTION(mContentType.IsEmpty(), "Content type is already known.");
if (!mContentType.IsEmpty()) return;
CBufDescriptor bufDesc((const char*)mBuffer, PR_TRUE, mBufferLen, mBufferLen);
nsCAutoString str(bufDesc);
//
// If the buffer begins with "#!" or "%!" then it is a script of some
// sort...
//
// This false match happened all the time... For example, CGI scripts
// written in sh or perl that emit HTML.
//
if (str.EqualsWithConversion("#!", PR_FALSE, 2) ||
str.EqualsWithConversion("%!", PR_FALSE, 2)) {
mContentType = TEXT_PLAIN;
}
//
// If the buffer begins with a mailbox delimiter then it is not HTML
//
else if (str.EqualsWithConversion("From ", PR_TRUE, 5) ||
str.EqualsWithConversion(">From ", PR_TRUE, 6)) {
mContentType = TEXT_PLAIN;
}
//
// If the buffer contains "common" HTML tags then lets call it HTML :-)
//
else {
/*
* To prevent a possible attack, we will not consider this to be html
* content if it comes from the local file system
*/
PRBool isLocalFile = PR_FALSE;
if (request) {
nsCOMPtr<nsIChannel> aChannel = do_QueryInterface(request);
if (!request) { NS_WARNING("QI failed"); return; }
nsCOMPtr<nsIURI> pURL;
if (NS_SUCCEEDED(aChannel->GetURI(getter_AddRefs(pURL))))
pURL->SchemeIs("file", &isLocalFile);
}
if (!mRequireHTMLsuffix || !isLocalFile) {
PRInt32 offset;
offset = str.Find("<HTML", PR_TRUE);
if (offset < 0) {
offset = str.Find("<TITLE", PR_TRUE);
if (offset < 0) {
offset = str.Find("<FRAMESET", PR_TRUE);
if (offset < 0) {
offset = str.Find("<SCRIPT", PR_TRUE);
if (offset < 0) {
offset = str.Find("<BODY", PR_TRUE);
if (offset < 0) {
offset = str.Find("<A HREF", PR_TRUE);
if (offset < 0) {
offset = str.Find("<APPLET", PR_TRUE);
}
}
}
}
}
}
if (offset >= 0) {
mContentType = TEXT_HTML;
}
}
}
if (mContentType.IsEmpty()) {
// sniff the first couple bytes to see if we are dealing with an image
// Unlike html, it is safe to sniff for image content types for local files so
// we don't need to check for isLocalFile here..
SniffForImageMimeType((const char*)mBuffer, mBufferLen);
}
//
// See if the buffer has any embedded nulls. If not, then lets just
// call it text/plain...
//
if (mContentType.IsEmpty()) {
for (i=0; i<mBufferLen && mBuffer[i]; i++);
if (i == mBufferLen) {
mContentType = TEXT_PLAIN;
}
}
//
// If the buffer is not text, then just call it application/octet-stream
//
if (mContentType.IsEmpty()) {
mContentType = APPLICATION_OCTET_STREAM;
}
}
// the following routine was ripped directly from some code in libpr0n...
void nsUnknownDecoder::SniffForImageMimeType(const char *buf, PRUint32 len)
{
/* Is it a GIF? */
if (len >= 4 && !nsCRT::strncmp(buf, "GIF8", 4)) {
mContentType = NS_LITERAL_CSTRING("image/gif");
return;
}
/* or a PNG? */
if (len >= 4 && ((unsigned char)buf[0]==0x89 &&
(unsigned char)buf[1]==0x50 &&
(unsigned char)buf[2]==0x4E &&
(unsigned char)buf[3]==0x47))
{
mContentType = NS_LITERAL_CSTRING("image/png");
return;
}
/* maybe a JPEG (JFIF)? */
/* JFIF files start with SOI APP0 but older files can start with SOI DQT
* so we test for SOI followed by any marker, i.e. FF D8 FF
* this will also work for SPIFF JPEG files if they appear in the future.
*
* (JFIF is 0XFF 0XD8 0XFF 0XE0 <skip 2> 0X4A 0X46 0X49 0X46 0X00)
*/
if (len >= 3 &&
((unsigned char)buf[0])==0xFF &&
((unsigned char)buf[1])==0xD8 &&
((unsigned char)buf[2])==0xFF)
{
mContentType = NS_LITERAL_CSTRING("image/jpeg");
return;
}
/* or how about ART? */
/* ART begins with JG (4A 47). Major version offset 2.
* Minor version offset 3. Offset 4 must be NULL.
*/
if (len >= 5 &&
((unsigned char) buf[0])==0x4a &&
((unsigned char) buf[1])==0x47 &&
((unsigned char) buf[4])==0x00 )
{
mContentType = NS_LITERAL_CSTRING("image/x-jg");
return;
}
/* none of the above? I give up */
}
nsresult nsUnknownDecoder::FireListenerNotifications(nsIRequest* request,
nsISupports *aCtxt)
{
nsresult rv = NS_OK;
if (!mNextListener) return NS_ERROR_FAILURE;
if (!mBuffer) return NS_ERROR_OUT_OF_MEMORY;
nsCOMPtr<nsIChannel> channel = do_QueryInterface(request, &rv);
if (NS_FAILED(rv)) return rv;
// Set the new content type on the channel...
rv = channel->SetContentType(mContentType);
NS_ASSERTION(NS_SUCCEEDED(rv), "Unable to set content type on channel!");
if (NS_FAILED(rv))
return rv;
// Fire the OnStartRequest(...)
rv = mNextListener->OnStartRequest(request, aCtxt);
// Fire the first OnDataAvailable for the data that was read from the
// stream into the sniffer buffer...
if (NS_SUCCEEDED(rv) && (mBufferLen > 0)) {
PRUint32 len = 0;
nsCOMPtr<nsIInputStream> in;
nsCOMPtr<nsIOutputStream> out;
// Create a pipe and fill it with the data from the sniffer buffer.
rv = NS_NewPipe(getter_AddRefs(in), getter_AddRefs(out),
MAX_BUFFER_SIZE, MAX_BUFFER_SIZE);
if (NS_SUCCEEDED(rv)) {
rv = out->Write(mBuffer, mBufferLen, &len);
if (NS_SUCCEEDED(rv)) {
if (len == mBufferLen) {
rv = mNextListener->OnDataAvailable(request, aCtxt, in, 0, len);
} else {
NS_ASSERTION(0, "Unable to write all the data into the pipe.");
rv = NS_ERROR_FAILURE;
}
}
}
}
delete [] mBuffer;
mBuffer = nsnull;
mBufferLen = 0;
return rv;
}