The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 1 | |
| 2 | /* pngmem.c - stub functions for memory allocation |
| 3 | * |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 4 | * Last changed in libpng 1.6.0 [February 14, 2013] |
| 5 | * Copyright (c) 1998-2013 Glenn Randers-Pehrson |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 6 | * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) |
| 7 | * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) |
| 8 | * |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 9 | * This code is released under the libpng license. |
| 10 | * For conditions of distribution and use, see the disclaimer |
| 11 | * and license in png.h |
| 12 | * |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 13 | * This file provides a location for all memory allocation. Users who |
| 14 | * need special memory handling are expected to supply replacement |
| 15 | * functions for png_malloc() and png_free(), and to use |
| 16 | * png_create_read_struct_2() and png_create_write_struct_2() to |
| 17 | * identify the replacement functions. |
| 18 | */ |
| 19 | |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 20 | #include "pngpriv.h" |
| 21 | |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 22 | #if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED) |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 23 | /* Free a png_struct */ |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 24 | void /* PRIVATE */ |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 25 | png_destroy_png_struct(png_structrp png_ptr) |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 26 | { |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 27 | if (png_ptr != NULL) |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 28 | { |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 29 | /* png_free might call png_error and may certainly call |
| 30 | * png_get_mem_ptr, so fake a temporary png_struct to support this. |
| 31 | */ |
| 32 | png_struct dummy_struct = *png_ptr; |
| 33 | memset(png_ptr, 0, (sizeof *png_ptr)); |
| 34 | png_free(&dummy_struct, png_ptr); |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 35 | |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 36 | # ifdef PNG_SETJMP_SUPPORTED |
| 37 | /* We may have a jmp_buf left to deallocate. */ |
| 38 | png_free_jmpbuf(&dummy_struct); |
| 39 | # endif |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 40 | } |
| 41 | } |
| 42 | |
| 43 | /* Allocate memory. For reasonable files, size should never exceed |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 44 | * 64K. However, zlib may allocate more then 64K if you don't tell |
| 45 | * it not to. See zconf.h and png.h for more information. zlib does |
| 46 | * need to allocate exactly 64K, so whatever you call here must |
| 47 | * have the ability to do that. |
| 48 | */ |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 49 | PNG_FUNCTION(png_voidp,PNGAPI |
| 50 | png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) |
Patrick Scott | 5f6bd84 | 2010-06-28 16:55:16 -0400 | [diff] [blame] | 51 | { |
| 52 | png_voidp ret; |
| 53 | |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 54 | ret = png_malloc(png_ptr, size); |
| 55 | |
Patrick Scott | 5f6bd84 | 2010-06-28 16:55:16 -0400 | [diff] [blame] | 56 | if (ret != NULL) |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 57 | memset(ret, 0, size); |
| 58 | |
| 59 | return ret; |
Patrick Scott | 5f6bd84 | 2010-06-28 16:55:16 -0400 | [diff] [blame] | 60 | } |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 61 | |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 62 | /* png_malloc_base, an internal function added at libpng 1.6.0, does the work of |
| 63 | * allocating memory, taking into account limits and PNG_USER_MEM_SUPPORTED. |
| 64 | * Checking and error handling must happen outside this routine; it returns NULL |
| 65 | * if the allocation cannot be done (for any reason.) |
| 66 | */ |
| 67 | PNG_FUNCTION(png_voidp /* PRIVATE */, |
| 68 | png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size), |
| 69 | PNG_ALLOCATED) |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 70 | { |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 71 | /* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS |
| 72 | * allocators have also been removed in 1.6.0, so any 16-bit system now has |
| 73 | * to implement a user memory handler. This checks to be sure it isn't |
| 74 | * called with big numbers. |
| 75 | */ |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 76 | #ifdef PNG_USER_MEM_SUPPORTED |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 77 | PNG_UNUSED(png_ptr) |
| 78 | #endif |
| 79 | if (size > 0 && size <= PNG_SIZE_MAX |
| 80 | # ifdef PNG_MAX_MALLOC_64K |
| 81 | && size <= 65536U |
| 82 | # endif |
| 83 | ) |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 84 | { |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 85 | #ifdef PNG_USER_MEM_SUPPORTED |
| 86 | if (png_ptr != NULL && png_ptr->malloc_fn != NULL) |
| 87 | return png_ptr->malloc_fn(png_constcast(png_structrp,png_ptr), size); |
| 88 | |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 89 | else |
| 90 | #endif |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 91 | return malloc((size_t)size); /* checked for truncation above */ |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 92 | } |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 93 | |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 94 | else |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 95 | return NULL; |
| 96 | } |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 97 | |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 98 | /* This is really here only to work round a spurious warning in GCC 4.6 and 4.7 |
| 99 | * that arises because of the checks in png_realloc_array that are repeated in |
| 100 | * png_malloc_array. |
| 101 | */ |
| 102 | static png_voidp |
| 103 | png_malloc_array_checked(png_const_structrp png_ptr, int nelements, |
| 104 | size_t element_size) |
| 105 | { |
| 106 | png_alloc_size_t req = nelements; /* known to be > 0 */ |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 107 | |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 108 | if (req <= PNG_SIZE_MAX/element_size) |
| 109 | return png_malloc_base(png_ptr, req * element_size); |
| 110 | |
| 111 | /* The failure case when the request is too large */ |
| 112 | return NULL; |
| 113 | } |
| 114 | |
| 115 | PNG_FUNCTION(png_voidp /* PRIVATE */, |
| 116 | png_malloc_array,(png_const_structrp png_ptr, int nelements, |
| 117 | size_t element_size),PNG_ALLOCATED) |
| 118 | { |
| 119 | if (nelements <= 0 || element_size == 0) |
| 120 | png_error(png_ptr, "internal error: array alloc"); |
| 121 | |
| 122 | return png_malloc_array_checked(png_ptr, nelements, element_size); |
| 123 | } |
| 124 | |
| 125 | PNG_FUNCTION(png_voidp /* PRIVATE */, |
| 126 | png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array, |
| 127 | int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED) |
| 128 | { |
| 129 | /* These are internal errors: */ |
| 130 | if (add_elements <= 0 || element_size == 0 || old_elements < 0 || |
| 131 | (old_array == NULL && old_elements > 0)) |
| 132 | png_error(png_ptr, "internal error: array realloc"); |
| 133 | |
| 134 | /* Check for overflow on the elements count (so the caller does not have to |
| 135 | * check.) |
| 136 | */ |
| 137 | if (add_elements <= INT_MAX - old_elements) |
| 138 | { |
| 139 | png_voidp new_array = png_malloc_array_checked(png_ptr, |
| 140 | old_elements+add_elements, element_size); |
| 141 | |
| 142 | if (new_array != NULL) |
| 143 | { |
| 144 | /* Because png_malloc_array worked the size calculations below cannot |
| 145 | * overflow. |
| 146 | */ |
| 147 | if (old_elements > 0) |
| 148 | memcpy(new_array, old_array, element_size*(unsigned)old_elements); |
| 149 | |
| 150 | memset((char*)new_array + element_size*(unsigned)old_elements, 0, |
| 151 | element_size*(unsigned)add_elements); |
| 152 | |
| 153 | return new_array; |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | return NULL; /* error */ |
| 158 | } |
| 159 | |
| 160 | /* Various functions that have different error handling are derived from this. |
| 161 | * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate |
| 162 | * function png_malloc_default is also provided. |
| 163 | */ |
| 164 | PNG_FUNCTION(png_voidp,PNGAPI |
| 165 | png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED) |
| 166 | { |
| 167 | png_voidp ret; |
| 168 | |
| 169 | if (png_ptr == NULL) |
| 170 | return NULL; |
| 171 | |
| 172 | ret = png_malloc_base(png_ptr, size); |
| 173 | |
| 174 | if (ret == NULL) |
| 175 | png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */ |
| 176 | |
| 177 | return ret; |
| 178 | } |
| 179 | |
| 180 | #ifdef PNG_USER_MEM_SUPPORTED |
| 181 | PNG_FUNCTION(png_voidp,PNGAPI |
| 182 | png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size), |
| 183 | PNG_ALLOCATED PNG_DEPRECATED) |
| 184 | { |
| 185 | png_voidp ret; |
| 186 | |
| 187 | if (png_ptr == NULL) |
| 188 | return NULL; |
| 189 | |
| 190 | /* Passing 'NULL' here bypasses the application provided memory handler. */ |
| 191 | ret = png_malloc_base(NULL/*use malloc*/, size); |
| 192 | |
| 193 | if (ret == NULL) |
| 194 | png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */ |
| 195 | |
| 196 | return ret; |
| 197 | } |
| 198 | #endif /* PNG_USER_MEM_SUPPORTED */ |
| 199 | |
| 200 | /* This function was added at libpng version 1.2.3. The png_malloc_warn() |
| 201 | * function will issue a png_warning and return NULL instead of issuing a |
| 202 | * png_error, if it fails to allocate the requested memory. |
| 203 | */ |
| 204 | PNG_FUNCTION(png_voidp,PNGAPI |
| 205 | png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size), |
| 206 | PNG_ALLOCATED) |
| 207 | { |
| 208 | if (png_ptr != NULL) |
| 209 | { |
| 210 | png_voidp ret = png_malloc_base(png_ptr, size); |
| 211 | |
| 212 | if (ret != NULL) |
| 213 | return ret; |
| 214 | |
| 215 | png_warning(png_ptr, "Out of memory"); |
| 216 | } |
| 217 | |
| 218 | return NULL; |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 219 | } |
| 220 | |
| 221 | /* Free a pointer allocated by png_malloc(). If ptr is NULL, return |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 222 | * without taking any action. |
| 223 | */ |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 224 | void PNGAPI |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 225 | png_free(png_const_structrp png_ptr, png_voidp ptr) |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 226 | { |
| 227 | if (png_ptr == NULL || ptr == NULL) |
| 228 | return; |
| 229 | |
| 230 | #ifdef PNG_USER_MEM_SUPPORTED |
| 231 | if (png_ptr->free_fn != NULL) |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 232 | png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr); |
| 233 | |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 234 | else |
| 235 | png_free_default(png_ptr, ptr); |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 236 | } |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 237 | |
| 238 | PNG_FUNCTION(void,PNGAPI |
| 239 | png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED) |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 240 | { |
| 241 | if (png_ptr == NULL || ptr == NULL) |
| 242 | return; |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 243 | #endif /* PNG_USER_MEM_SUPPORTED */ |
| 244 | |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 245 | free(ptr); |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 246 | } |
| 247 | |
| 248 | #ifdef PNG_USER_MEM_SUPPORTED |
| 249 | /* This function is called when the application wants to use another method |
| 250 | * of allocating and freeing memory. |
| 251 | */ |
| 252 | void PNGAPI |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 253 | png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 254 | malloc_fn, png_free_ptr free_fn) |
| 255 | { |
The Android Open Source Project | 4215dd1 | 2009-03-09 11:52:12 -0700 | [diff] [blame] | 256 | if (png_ptr != NULL) |
| 257 | { |
| 258 | png_ptr->mem_ptr = mem_ptr; |
| 259 | png_ptr->malloc_fn = malloc_fn; |
| 260 | png_ptr->free_fn = free_fn; |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 261 | } |
| 262 | } |
| 263 | |
| 264 | /* This function returns a pointer to the mem_ptr associated with the user |
| 265 | * functions. The application should free any memory associated with this |
| 266 | * pointer before png_write_destroy and png_read_destroy are called. |
| 267 | */ |
| 268 | png_voidp PNGAPI |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 269 | png_get_mem_ptr(png_const_structrp png_ptr) |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 270 | { |
Patrick Scott | a0bb96c | 2009-07-22 11:50:02 -0400 | [diff] [blame] | 271 | if (png_ptr == NULL) |
Chris Craik | b50c217 | 2013-07-29 15:28:30 -0700 | [diff] [blame^] | 272 | return NULL; |
| 273 | |
| 274 | return png_ptr->mem_ptr; |
The Android Open Source Project | 893912b | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 275 | } |
| 276 | #endif /* PNG_USER_MEM_SUPPORTED */ |
| 277 | #endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */ |