alloc.h

00001 /* alloc - Convenience routines for safely allocating memory
00002  * Copyright (C) 2007-2009  Josh Coalson
00003  * Copyright (C) 2011-2014  Xiph.Org Foundation
00004  *
00005  * Redistribution and use in source and binary forms, with or without
00006  * modification, are permitted provided that the following conditions
00007  * are met:
00008  *
00009  * - Redistributions of source code must retain the above copyright
00010  * notice, this list of conditions and the following disclaimer.
00011  *
00012  * - Redistributions in binary form must reproduce the above copyright
00013  * notice, this list of conditions and the following disclaimer in the
00014  * documentation and/or other materials provided with the distribution.
00015  *
00016  * - Neither the name of the Xiph.org Foundation nor the names of its
00017  * contributors may be used to endorse or promote products derived from
00018  * this software without specific prior written permission.
00019  *
00020  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
00021  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
00022  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
00023  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
00024  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00025  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
00026  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
00027  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
00028  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
00029  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00030  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00031  */
00032 
00033 #ifndef FLAC__SHARE__ALLOC_H
00034 #define FLAC__SHARE__ALLOC_H
00035 
00036 #ifdef HAVE_CONFIG_H
00037 #  include <config.h>
00038 #endif
00039 
00040 /* WATCHOUT: for c++ you may have to #define __STDC_LIMIT_MACROS 1 real early
00041  * before #including this file,  otherwise SIZE_MAX might not be defined
00042  */
00043 
00044 #include <limits.h> /* for SIZE_MAX */
00045 #if HAVE_STDINT_H
00046 #include <stdint.h> /* for SIZE_MAX in case limits.h didn't get it */
00047 #endif
00048 #include <stdlib.h> /* for size_t, malloc(), etc */
00049 #include "share/compat.h"
00050 
00051 #ifndef SIZE_MAX
00052 # ifndef SIZE_T_MAX
00053 #  ifdef _MSC_VER
00054 #   ifdef _WIN64
00055 #    define SIZE_T_MAX 0xffffffffffffffffui64
00056 #   else
00057 #    define SIZE_T_MAX 0xffffffff
00058 #   endif
00059 #  else
00060 #   error
00061 #  endif
00062 # endif
00063 # define SIZE_MAX SIZE_T_MAX
00064 #endif
00065 
00066 /* avoid malloc()ing 0 bytes, see:
00067  * https://www.securecoding.cert.org/confluence/display/seccode/MEM04-A.+Do+not+make+assumptions+about+the+result+of+allocating+0+bytes?focusedCommentId=5407003
00068 */
00069 static inline void *safe_malloc_(size_t size)
00070 {
00071     /* malloc(0) is undefined; FLAC src convention is to always allocate */
00072     if(!size)
00073         size++;
00074     return malloc(size);
00075 }
00076 
00077 static inline void *safe_calloc_(size_t nmemb, size_t size)
00078 {
00079     if(!nmemb || !size)
00080         return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
00081     return calloc(nmemb, size);
00082 }
00083 
00084 /*@@@@ there's probably a better way to prevent overflows when allocating untrusted sums but this works for now */
00085 
00086 static inline void *safe_malloc_add_2op_(size_t size1, size_t size2)
00087 {
00088     size2 += size1;
00089     if(size2 < size1)
00090         return 0;
00091     return safe_malloc_(size2);
00092 }
00093 
00094 static inline void *safe_malloc_add_3op_(size_t size1, size_t size2, size_t size3)
00095 {
00096     size2 += size1;
00097     if(size2 < size1)
00098         return 0;
00099     size3 += size2;
00100     if(size3 < size2)
00101         return 0;
00102     return safe_malloc_(size3);
00103 }
00104 
00105 static inline void *safe_malloc_add_4op_(size_t size1, size_t size2, size_t size3, size_t size4)
00106 {
00107     size2 += size1;
00108     if(size2 < size1)
00109         return 0;
00110     size3 += size2;
00111     if(size3 < size2)
00112         return 0;
00113     size4 += size3;
00114     if(size4 < size3)
00115         return 0;
00116     return safe_malloc_(size4);
00117 }
00118 
00119 void *safe_malloc_mul_2op_(size_t size1, size_t size2) ;
00120 
00121 static inline void *safe_malloc_mul_3op_(size_t size1, size_t size2, size_t size3)
00122 {
00123     if(!size1 || !size2 || !size3)
00124         return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
00125     if(size1 > SIZE_MAX / size2)
00126         return 0;
00127     size1 *= size2;
00128     if(size1 > SIZE_MAX / size3)
00129         return 0;
00130     return malloc(size1*size3);
00131 }
00132 
00133 /* size1*size2 + size3 */
00134 static inline void *safe_malloc_mul2add_(size_t size1, size_t size2, size_t size3)
00135 {
00136     if(!size1 || !size2)
00137         return safe_malloc_(size3);
00138     if(size1 > SIZE_MAX / size2)
00139         return 0;
00140     return safe_malloc_add_2op_(size1*size2, size3);
00141 }
00142 
00143 /* size1 * (size2 + size3) */
00144 static inline void *safe_malloc_muladd2_(size_t size1, size_t size2, size_t size3)
00145 {
00146     if(!size1 || (!size2 && !size3))
00147         return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
00148     size2 += size3;
00149     if(size2 < size3)
00150         return 0;
00151     if(size1 > SIZE_MAX / size2)
00152         return 0;
00153     return malloc(size1*size2);
00154 }
00155 
00156 static inline void *safe_realloc_add_2op_(void *ptr, size_t size1, size_t size2)
00157 {
00158     size2 += size1;
00159     if(size2 < size1)
00160         return 0;
00161     return realloc(ptr, size2);
00162 }
00163 
00164 static inline void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3)
00165 {
00166     size2 += size1;
00167     if(size2 < size1)
00168         return 0;
00169     size3 += size2;
00170     if(size3 < size2)
00171         return 0;
00172     return realloc(ptr, size3);
00173 }
00174 
00175 static inline void *safe_realloc_add_4op_(void *ptr, size_t size1, size_t size2, size_t size3, size_t size4)
00176 {
00177     size2 += size1;
00178     if(size2 < size1)
00179         return 0;
00180     size3 += size2;
00181     if(size3 < size2)
00182         return 0;
00183     size4 += size3;
00184     if(size4 < size3)
00185         return 0;
00186     return realloc(ptr, size4);
00187 }
00188 
00189 static inline void *safe_realloc_mul_2op_(void *ptr, size_t size1, size_t size2)
00190 {
00191     if(!size1 || !size2)
00192         return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
00193     if(size1 > SIZE_MAX / size2)
00194         return 0;
00195     return realloc(ptr, size1*size2);
00196 }
00197 
00198 /* size1 * (size2 + size3) */
00199 static inline void *safe_realloc_muladd2_(void *ptr, size_t size1, size_t size2, size_t size3)
00200 {
00201     if(!size1 || (!size2 && !size3))
00202         return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
00203     size2 += size3;
00204     if(size2 < size3)
00205         return 0;
00206     return safe_realloc_mul_2op_(ptr, size1, size2);
00207 }
00208 
00209 #endif