1/* alloc - Convenience routines for safely allocating memory
2 * Copyright (C) 2007  Josh Coalson
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
17 */
18
19#ifndef FLAC__SHARE__ALLOC_H
20#define FLAC__SHARE__ALLOC_H
21
22#if HAVE_CONFIG_H
23#  include <config.h>
24#endif
25
26/* WATCHOUT: for c++ you may have to #define __STDC_LIMIT_MACROS 1 real early
27 * before #including this file,  otherwise SIZE_MAX might not be defined
28 */
29
30#include <limits.h> /* for SIZE_MAX */
31#if !defined _MSC_VER && !defined __MINGW32__ && !defined __EMX__
32#include <stdint.h> /* for SIZE_MAX in case limits.h didn't get it */
33#endif
34#include <stdlib.h> /* for size_t, malloc(), etc */
35
36#ifndef SIZE_MAX
37# ifndef SIZE_T_MAX
38#  ifdef _MSC_VER
39#   define SIZE_T_MAX UINT_MAX
40#  else
41#   error
42#  endif
43# endif
44# define SIZE_MAX SIZE_T_MAX
45#endif
46
47#ifndef FLaC__INLINE
48#define FLaC__INLINE
49#endif
50
51/* avoid malloc()ing 0 bytes, see:
52 * https://www.securecoding.cert.org/confluence/display/seccode/MEM04-A.+Do+not+make+assumptions+about+the+result+of+allocating+0+bytes?focusedCommentId=5407003
53*/
54static FLaC__INLINE void *safe_malloc_(size_t size)
55{
56	/* malloc(0) is undefined; FLAC src convention is to always allocate */
57	if(!size)
58		size++;
59	return malloc(size);
60}
61
62static FLaC__INLINE void *safe_calloc_(size_t nmemb, size_t size)
63{
64	if(!nmemb || !size)
65		return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
66	return calloc(nmemb, size);
67}
68
69/*@@@@ there's probably a better way to prevent overflows when allocating untrusted sums but this works for now */
70
71static FLaC__INLINE void *safe_malloc_add_2op_(size_t size1, size_t size2)
72{
73	size2 += size1;
74	if(size2 < size1)
75		return 0;
76	return safe_malloc_(size2);
77}
78
79static FLaC__INLINE void *safe_malloc_add_3op_(size_t size1, size_t size2, size_t size3)
80{
81	size2 += size1;
82	if(size2 < size1)
83		return 0;
84	size3 += size2;
85	if(size3 < size2)
86		return 0;
87	return safe_malloc_(size3);
88}
89
90static FLaC__INLINE void *safe_malloc_add_4op_(size_t size1, size_t size2, size_t size3, size_t size4)
91{
92	size2 += size1;
93	if(size2 < size1)
94		return 0;
95	size3 += size2;
96	if(size3 < size2)
97		return 0;
98	size4 += size3;
99	if(size4 < size3)
100		return 0;
101	return safe_malloc_(size4);
102}
103
104static FLaC__INLINE void *safe_malloc_mul_2op_(size_t size1, size_t size2)
105#if 0
106needs support for cases where sizeof(size_t) != 4
107{
108	/* could be faster #ifdef'ing off SIZEOF_SIZE_T */
109	if(sizeof(size_t) == 4) {
110		if ((double)size1 * (double)size2 < 4294967296.0)
111			return malloc(size1*size2);
112	}
113	return 0;
114}
115#else
116/* better? */
117{
118	if(!size1 || !size2)
119		return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
120	if(size1 > SIZE_MAX / size2)
121		return 0;
122	return malloc(size1*size2);
123}
124#endif
125
126static FLaC__INLINE void *safe_malloc_mul_3op_(size_t size1, size_t size2, size_t size3)
127{
128	if(!size1 || !size2 || !size3)
129		return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
130	if(size1 > SIZE_MAX / size2)
131		return 0;
132	size1 *= size2;
133	if(size1 > SIZE_MAX / size3)
134		return 0;
135	return malloc(size1*size3);
136}
137
138/* size1*size2 + size3 */
139static FLaC__INLINE void *safe_malloc_mul2add_(size_t size1, size_t size2, size_t size3)
140{
141	if(!size1 || !size2)
142		return safe_malloc_(size3);
143	if(size1 > SIZE_MAX / size2)
144		return 0;
145	return safe_malloc_add_2op_(size1*size2, size3);
146}
147
148/* size1 * (size2 + size3) */
149static FLaC__INLINE void *safe_malloc_muladd2_(size_t size1, size_t size2, size_t size3)
150{
151	if(!size1 || (!size2 && !size3))
152		return malloc(1); /* malloc(0) is undefined; FLAC src convention is to always allocate */
153	size2 += size3;
154	if(size2 < size3)
155		return 0;
156	return safe_malloc_mul_2op_(size1, size2);
157}
158
159static FLaC__INLINE void *safe_realloc_add_2op_(void *ptr, size_t size1, size_t size2)
160{
161	size2 += size1;
162	if(size2 < size1)
163		return 0;
164	return realloc(ptr, size2);
165}
166
167static FLaC__INLINE void *safe_realloc_add_3op_(void *ptr, size_t size1, size_t size2, size_t size3)
168{
169	size2 += size1;
170	if(size2 < size1)
171		return 0;
172	size3 += size2;
173	if(size3 < size2)
174		return 0;
175	return realloc(ptr, size3);
176}
177
178static FLaC__INLINE void *safe_realloc_add_4op_(void *ptr, size_t size1, size_t size2, size_t size3, size_t size4)
179{
180	size2 += size1;
181	if(size2 < size1)
182		return 0;
183	size3 += size2;
184	if(size3 < size2)
185		return 0;
186	size4 += size3;
187	if(size4 < size3)
188		return 0;
189	return realloc(ptr, size4);
190}
191
192static FLaC__INLINE void *safe_realloc_mul_2op_(void *ptr, size_t size1, size_t size2)
193{
194	if(!size1 || !size2)
195		return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
196	if(size1 > SIZE_MAX / size2)
197		return 0;
198	return realloc(ptr, size1*size2);
199}
200
201/* size1 * (size2 + size3) */
202static FLaC__INLINE void *safe_realloc_muladd2_(void *ptr, size_t size1, size_t size2, size_t size3)
203{
204	if(!size1 || (!size2 && !size3))
205		return realloc(ptr, 0); /* preserve POSIX realloc(ptr, 0) semantics */
206	size2 += size3;
207	if(size2 < size3)
208		return 0;
209	return safe_realloc_mul_2op_(ptr, size1, size2);
210}
211
212#endif
213