path: root/woff.c

/* -*- Mode: C; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * ***** 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 WOFF font packaging code.
 *
 * The Initial Developer of the Original Code is Mozilla Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2009
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Jonathan Kew <jfkthame@gmail.com>
 *   Bram Stein <b.l.stein@gmail.com>
 *
 * 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 "woff-private.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <zlib.h>
#include "zlib_container.h"

#ifdef WOFF_MOZILLA_CLIENT /* define this when building as part of Gecko */
# include "prmem.h"
# define malloc  PR_Malloc
# define realloc PR_Realloc
# define free    PR_Free
#endif

/*
 * Just simple whole-file encoding and decoding functions; a more extensive
 * WOFF library could provide support for accessing individual tables from a
 * compressed font, alternative options for memory allocation/ownership and
 * error handling, etc.
 */

/* on errors, each function sets a status variable and jumps to failure: */
#undef FAIL
#define FAIL(err) do { status |= err; goto failure; } while (0)

/* adjust an offset for longword alignment */
#define LONGALIGN(x) (((x) + 3) & ~3)

static int
compareOffsets(const void * lhs, const void * rhs)
{
  const tableOrderRec * a = (const tableOrderRec *) lhs;
  const tableOrderRec * b = (const tableOrderRec *) rhs;
  /* don't simply return a->offset - b->offset because these are unsigned
     offset values; could convert to int, but possible integer overflow */
  return a->offset > b->offset ? 1 :
         a->offset < b->offset ? -1 :
         0;
}

#ifndef WOFF_MOZILLA_CLIENT

/******************************************************************/
/* * * * * * * * * * * * * * ENCODING * * * * * * * * * * * * * * */
/******************************************************************/

static uint32_t
calcChecksum(const sfntDirEntry * dirEntry,
             const uint8_t * sfntData, uint32_t sfntLen)
{
  /* just returns zero on errors, they will be detected again elsewhere */
  const uint32_t * csumPtr;
  const uint32_t * csumEnd;
  uint32_t csum = 0;
  uint32_t length = LONGALIGN(READ32BE(dirEntry->length));
  uint32_t offset = READ32BE(dirEntry->offset);
  uint32_t tag;
  if ((offset & 3) != 0) {
    return csum;
  }
  if (length > sfntLen || offset > sfntLen - length) {
    return csum;
  }
  csumPtr = (const uint32_t *) (sfntData + offset);
  csumEnd = csumPtr + length / 4;
  while (csumPtr < csumEnd) {
    csum += READ32BE(*csumPtr);
    csumPtr++;