/* pngmem.c - stub functions for memory allocation
*
- * libpng 1.0.3 - January 14, 1999
- * For conditions of distribution and use, see copyright notice in png.h
- * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
- * Copyright (c) 1996, 1997 Andreas Dilger
- * Copyright (c) 1998, 1999 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.0 [February 14, 2013]
+ * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ *
+ * This code is released under the libpng license.
+ * For conditions of distribution and use, see the disclaimer
+ * and license in png.h
*
* This file provides a location for all memory allocation. Users who
* need special memory handling are expected to supply replacement
* identify the replacement functions.
*/
-#define PNG_INTERNAL
-#include "png.h"
-
-/* Borland DOS special memory handler */
-#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__)
-/* if you change this, be sure to change the one in png.h also */
-
-/* Allocate memory for a png_struct. The malloc and memset can be replaced
- by a single call to calloc() if this is thought to improve performance. */
-png_voidp
-png_create_struct(int type)
-{
-#ifdef PNG_USER_MEM_SUPPORTED
- return (png_create_struct_2(type, NULL));
-}
-
-/* Alternate version of png_create_struct, for use with user-defined malloc. */
-png_voidp
-png_create_struct_2(int type, png_malloc_ptr malloc_fn)
-{
-#endif /* PNG_USER_MEM_SUPPORTED */
- png_size_t size;
- png_voidp struct_ptr;
-
- if (type == PNG_STRUCT_INFO)
- size = sizeof(png_info);
- else if (type == PNG_STRUCT_PNG)
- size = sizeof(png_struct);
- else
- return ((png_voidp)NULL);
-
-#ifdef PNG_USER_MEM_SUPPORTED
- if(malloc_fn != NULL)
- {
- if ((struct_ptr = (*(malloc_fn))(NULL, size)) != NULL)
- png_memset(struct_ptr, 0, size);
- return (struct_ptr);
- }
-#endif /* PNG_USER_MEM_SUPPORTED */
- if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL)
- {
- png_memset(struct_ptr, 0, size);
- }
- return (struct_ptr);
-}
-
+#include "pngpriv.h"
-/* Free memory allocated by a png_create_struct() call */
-void
-png_destroy_struct(png_voidp struct_ptr)
+#if defined(PNG_READ_SUPPORTED) || defined(PNG_WRITE_SUPPORTED)
+/* Free a png_struct */
+void /* PRIVATE */
+png_destroy_png_struct(png_structrp png_ptr)
{
-#ifdef PNG_USER_MEM_SUPPORTED
- png_destroy_struct_2(struct_ptr, (png_free_ptr)NULL);
-}
-
-/* Free memory allocated by a png_create_struct() call */
-void
-png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn)
-{
-#endif
- if (struct_ptr != NULL)
+ if (png_ptr != NULL)
{
-#ifdef PNG_USER_MEM_SUPPORTED
- if(free_fn != NULL)
- {
- png_struct dummy_struct;
- png_structp png_ptr = &dummy_struct;
- (*(free_fn))(png_ptr, struct_ptr);
- struct_ptr = NULL;
- return;
- }
-#endif /* PNG_USER_MEM_SUPPORTED */
- farfree (struct_ptr);
- struct_ptr = NULL;
+ /* png_free might call png_error and may certainly call
+ * png_get_mem_ptr, so fake a temporary png_struct to support this.
+ */
+ png_struct dummy_struct = *png_ptr;
+ memset(png_ptr, 0, (sizeof *png_ptr));
+ png_free(&dummy_struct, png_ptr);
+
+# ifdef PNG_SETJMP_SUPPORTED
+ /* We may have a jmp_buf left to deallocate. */
+ png_free_jmpbuf(&dummy_struct);
+# endif
}
}
/* Allocate memory. For reasonable files, size should never exceed
* 64K. However, zlib may allocate more then 64K if you don't tell
- * it not to. See zconf.h and png.h for more information. zlib does
+ * it not to. See zconf.h and png.h for more information. zlib does
* need to allocate exactly 64K, so whatever you call here must
* have the ability to do that.
- *
- * Borland seems to have a problem in DOS mode for exactly 64K.
- * It gives you a segment with an offset of 8 (perhaps to store its
- * memory stuff). zlib doesn't like this at all, so we have to
- * detect and deal with it. This code should not be needed in
- * Windows or OS/2 modes, and only in 16 bit mode. This code has
- * been updated by Alexander Lehmann for version 0.89 to waste less
- * memory.
- *
- * Note that we can't use png_size_t for the "size" declaration,
- * since on some systems a png_size_t is a 16-bit quantity, and as a
- * result, we would be truncating potentially larger memory requests
- * (which should cause a fatal error) and introducing major problems.
*/
-png_voidp
-png_malloc(png_structp png_ptr, png_uint_32 size)
+PNG_FUNCTION(png_voidp,PNGAPI
+png_calloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
{
-#ifndef PNG_USER_MEM_SUPPORTED
png_voidp ret;
-#endif
- if (png_ptr == NULL || size == 0)
- return ((png_voidp)NULL);
-#ifdef PNG_USER_MEM_SUPPORTED
- if(png_ptr->malloc_fn != NULL)
- return ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
- else
- return png_malloc_default(png_ptr, size);
+ ret = png_malloc(png_ptr, size);
+
+ if (ret != NULL)
+ memset(ret, 0, size);
+
+ return ret;
}
-png_voidp
-png_malloc_default(png_structp png_ptr, png_uint_32 size)
+/* png_malloc_base, an internal function added at libpng 1.6.0, does the work of
+ * allocating memory, taking into account limits and PNG_USER_MEM_SUPPORTED.
+ * Checking and error handling must happen outside this routine; it returns NULL
+ * if the allocation cannot be done (for any reason.)
+ */
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_base,(png_const_structrp png_ptr, png_alloc_size_t size),
+ PNG_ALLOCATED)
{
- png_voidp ret;
-#endif /* PNG_USER_MEM_SUPPORTED */
-
-#ifdef PNG_MAX_MALLOC_64K
- if (size > (png_uint_32)65536L)
- png_error(png_ptr, "Cannot Allocate > 64K");
+ /* Moved to png_malloc_base from png_malloc_default in 1.6.0; the DOS
+ * allocators have also been removed in 1.6.0, so any 16-bit system now has
+ * to implement a user memory handler. This checks to be sure it isn't
+ * called with big numbers.
+ */
+#ifdef PNG_USER_MEM_SUPPORTED
+ PNG_UNUSED(png_ptr)
#endif
-
- if (size == (png_uint_32)65536L)
+ if (size > 0 && size <= PNG_SIZE_MAX
+# ifdef PNG_MAX_MALLOC_64K
+ && size <= 65536U
+# endif
+ )
{
- if (png_ptr->offset_table == NULL)
- {
- /* try to see if we need to do any of this fancy stuff */
- ret = farmalloc(size);
- if (ret == NULL || ((png_size_t)ret & 0xffff))
- {
- int num_blocks;
- png_uint_32 total_size;
- png_bytep table;
- int i;
- png_byte huge * hptr;
-
- if (ret != NULL)
- {
- farfree(ret);
- ret = NULL;
- }
-
- num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14));
- if (num_blocks < 1)
- num_blocks = 1;
- if (png_ptr->zlib_mem_level >= 7)
- num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7));
- else
- num_blocks++;
-
- total_size = ((png_uint_32)65536L) * (png_uint_32)num_blocks+16;
-
- table = farmalloc(total_size);
-
- if (table == NULL)
- {
- png_error(png_ptr, "Out Of Memory."); /* Note "O" and "M" */
- }
-
- if ((png_size_t)table & 0xfff0)
- {
- png_error(png_ptr, "Farmalloc didn't return normalized pointer");
- }
-
- png_ptr->offset_table = table;
- png_ptr->offset_table_ptr = farmalloc(num_blocks *
- sizeof (png_bytep));
-
- if (png_ptr->offset_table_ptr == NULL)
- {
- png_error(png_ptr, "Out Of memory.");
- }
-
- hptr = (png_byte huge *)table;
- if ((png_size_t)hptr & 0xf)
- {
- hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L);
- hptr += 16L;
- }
- for (i = 0; i < num_blocks; i++)
- {
- png_ptr->offset_table_ptr[i] = (png_bytep)hptr;
- hptr += (png_uint_32)65536L;
- }
-
- png_ptr->offset_table_number = num_blocks;
- png_ptr->offset_table_count = 0;
- png_ptr->offset_table_count_free = 0;
- }
- }
-
- if (png_ptr->offset_table_count >= png_ptr->offset_table_number)
- png_error(png_ptr, "Out of Memory.");
+#ifdef PNG_USER_MEM_SUPPORTED
+ if (png_ptr != NULL && png_ptr->malloc_fn != NULL)
+ return png_ptr->malloc_fn(png_constcast(png_structrp,png_ptr), size);
- ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++];
+ else
+#endif
+ return malloc((size_t)size); /* checked for truncation above */
}
+
else
- ret = farmalloc(size);
+ return NULL;
+}
- if (ret == NULL)
- {
- png_error(png_ptr, "Out of memory."); /* Note "o" and "m" */
- }
+/* This is really here only to work round a spurious warning in GCC 4.6 and 4.7
+ * that arises because of the checks in png_realloc_array that are repeated in
+ * png_malloc_array.
+ */
+static png_voidp
+png_malloc_array_checked(png_const_structrp png_ptr, int nelements,
+ size_t element_size)
+{
+ png_alloc_size_t req = nelements; /* known to be > 0 */
- return (ret);
+ if (req <= PNG_SIZE_MAX/element_size)
+ return png_malloc_base(png_ptr, req * element_size);
+
+ /* The failure case when the request is too large */
+ return NULL;
}
-/* free a pointer allocated by png_malloc(). In the default
- configuration, png_ptr is not used, but is passed in case it
- is needed. If ptr is NULL, return without taking any action. */
-void
-png_free(png_structp png_ptr, png_voidp ptr)
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_malloc_array,(png_const_structrp png_ptr, int nelements,
+ size_t element_size),PNG_ALLOCATED)
{
- if (png_ptr == NULL || ptr == NULL)
- return;
+ if (nelements <= 0 || element_size == 0)
+ png_error(png_ptr, "internal error: array alloc");
-#ifdef PNG_USER_MEM_SUPPORTED
- if (png_ptr->free_fn != NULL)
- {
- (*(png_ptr->free_fn))(png_ptr, ptr);
- ptr = NULL;
- return;
- }
- else png_free_default(png_ptr, ptr);
+ return png_malloc_array_checked(png_ptr, nelements, element_size);
}
-void
-png_free_default(png_structp png_ptr, png_voidp ptr)
+PNG_FUNCTION(png_voidp /* PRIVATE */,
+png_realloc_array,(png_const_structrp png_ptr, png_const_voidp old_array,
+ int old_elements, int add_elements, size_t element_size),PNG_ALLOCATED)
{
-#endif /* PNG_USER_MEM_SUPPORTED */
-
- if (png_ptr->offset_table != NULL)
+ /* These are internal errors: */
+ if (add_elements <= 0 || element_size == 0 || old_elements < 0 ||
+ (old_array == NULL && old_elements > 0))
+ png_error(png_ptr, "internal error: array realloc");
+
+ /* Check for overflow on the elements count (so the caller does not have to
+ * check.)
+ */
+ if (add_elements <= INT_MAX - old_elements)
{
- int i;
+ png_voidp new_array = png_malloc_array_checked(png_ptr,
+ old_elements+add_elements, element_size);
- for (i = 0; i < png_ptr->offset_table_count; i++)
- {
- if (ptr == png_ptr->offset_table_ptr[i])
- {
- ptr = NULL;
- png_ptr->offset_table_count_free++;
- break;
- }
- }
- if (png_ptr->offset_table_count_free == png_ptr->offset_table_count)
+ if (new_array != NULL)
{
- farfree(png_ptr->offset_table);
- farfree(png_ptr->offset_table_ptr);
- png_ptr->offset_table = NULL;
- png_ptr->offset_table_ptr = NULL;
- }
- }
+ /* Because png_malloc_array worked the size calculations below cannot
+ * overflow.
+ */
+ if (old_elements > 0)
+ memcpy(new_array, old_array, element_size*(unsigned)old_elements);
- if (ptr != NULL)
- {
- farfree(ptr);
- ptr = NULL;
- }
-}
+ memset((char*)new_array + element_size*(unsigned)old_elements, 0,
+ element_size*(unsigned)add_elements);
-#else /* Not the Borland DOS special memory handler */
+ return new_array;
+ }
+ }
-/* Allocate memory for a png_struct or a png_info. The malloc and
- memset can be replaced by a single call to calloc() if this is thought
- to improve performance noticably.*/
-png_voidp
-png_create_struct(int type)
-{
-#ifdef PNG_USER_MEM_SUPPORTED
- return (png_create_struct_2(type, NULL));
+ return NULL; /* error */
}
-/* Allocate memory for a png_struct or a png_info. The malloc and
- memset can be replaced by a single call to calloc() if this is thought
- to improve performance noticably.*/
-png_voidp
-png_create_struct_2(int type, png_malloc_ptr malloc_fn)
+/* Various functions that have different error handling are derived from this.
+ * png_malloc always exists, but if PNG_USER_MEM_SUPPORTED is defined a separate
+ * function png_malloc_default is also provided.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc,(png_const_structrp png_ptr, png_alloc_size_t size),PNG_ALLOCATED)
{
-#endif /* PNG_USER_MEM_SUPPORTED */
- png_size_t size;
- png_voidp struct_ptr;
+ png_voidp ret;
- if (type == PNG_STRUCT_INFO)
- size = sizeof(png_info);
- else if (type == PNG_STRUCT_PNG)
- size = sizeof(png_struct);
- else
- return ((png_voidp)NULL);
+ if (png_ptr == NULL)
+ return NULL;
-#ifdef PNG_USER_MEM_SUPPORTED
- if(malloc_fn != NULL)
- {
- if ((struct_ptr = (*(malloc_fn))(NULL, size)) != NULL)
- png_memset(struct_ptr, 0, size);
- return (struct_ptr);
- }
-#endif /* PNG_USER_MEM_SUPPORTED */
+ ret = png_malloc_base(png_ptr, size);
-#if defined(__TURBOC__) && !defined(__FLAT__)
- if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL)
-#else
-# if defined(_MSC_VER) && defined(MAXSEG_64K)
- if ((struct_ptr = (png_voidp)halloc(size,1)) != NULL)
-# else
- if ((struct_ptr = (png_voidp)malloc(size)) != NULL)
-# endif
-#endif
- {
- png_memset(struct_ptr, 0, size);
- }
+ if (ret == NULL)
+ png_error(png_ptr, "Out of memory"); /* 'm' means png_malloc */
- return (struct_ptr);
+ return ret;
}
-
-/* Free memory allocated by a png_create_struct() call */
-void
-png_destroy_struct(png_voidp struct_ptr)
-{
#ifdef PNG_USER_MEM_SUPPORTED
- png_destroy_struct_2(struct_ptr, (png_free_ptr)NULL);
-}
-
-/* Free memory allocated by a png_create_struct() call */
-void
-png_destroy_struct_2(png_voidp struct_ptr, png_free_ptr free_fn)
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_default,(png_const_structrp png_ptr, png_alloc_size_t size),
+ PNG_ALLOCATED PNG_DEPRECATED)
{
-#endif /* PNG_USER_MEM_SUPPORTED */
- if (struct_ptr != NULL)
- {
-#ifdef PNG_USER_MEM_SUPPORTED
- if(free_fn != NULL)
- {
- png_struct dummy_struct;
- png_structp png_ptr = &dummy_struct;
- (*(free_fn))(png_ptr, struct_ptr);
- struct_ptr = NULL;
- return;
- }
-#endif /* PNG_USER_MEM_SUPPORTED */
-#if defined(__TURBOC__) && !defined(__FLAT__)
- farfree(struct_ptr);
- struct_ptr = NULL;
-#else
-# if defined(_MSC_VER) && defined(MAXSEG_64K)
- hfree(struct_ptr);
- struct_ptr = NULL;
-# else
- free(struct_ptr);
- struct_ptr = NULL;
-# endif
-#endif
- }
-}
+ png_voidp ret;
+ if (png_ptr == NULL)
+ return NULL;
-/* Allocate memory. For reasonable files, size should never exceed
- 64K. However, zlib may allocate more then 64K if you don't tell
- it not to. See zconf.h and png.h for more information. zlib does
- need to allocate exactly 64K, so whatever you call here must
- have the ability to do that. */
+ /* Passing 'NULL' here bypasses the application provided memory handler. */
+ ret = png_malloc_base(NULL/*use malloc*/, size);
-png_voidp
-png_malloc(png_structp png_ptr, png_uint_32 size)
-{
-#ifndef PNG_USER_MEM_SUPPORTED
- png_voidp ret;
-#endif
- if (png_ptr == NULL || size == 0)
- return ((png_voidp)NULL);
+ if (ret == NULL)
+ png_error(png_ptr, "Out of Memory"); /* 'M' means png_malloc_default */
-#ifdef PNG_USER_MEM_SUPPORTED
- if(png_ptr->malloc_fn != NULL)
- return ((png_voidp)(*(png_ptr->malloc_fn))(png_ptr, size));
- else
- return (png_malloc_default(png_ptr, size));
+ return ret;
}
-png_voidp
-png_malloc_default(png_structp png_ptr, png_uint_32 size)
-{
- png_voidp ret;
#endif /* PNG_USER_MEM_SUPPORTED */
-#ifdef PNG_MAX_MALLOC_64K
- if (size > (png_uint_32)65536L)
- png_error(png_ptr, "Cannot Allocate > 64K");
-#endif
+/* This function was added at libpng version 1.2.3. The png_malloc_warn()
+ * function will issue a png_warning and return NULL instead of issuing a
+ * png_error, if it fails to allocate the requested memory.
+ */
+PNG_FUNCTION(png_voidp,PNGAPI
+png_malloc_warn,(png_const_structrp png_ptr, png_alloc_size_t size),
+ PNG_ALLOCATED)
+{
+ if (png_ptr != NULL)
+ {
+ png_voidp ret = png_malloc_base(png_ptr, size);
-#if defined(__TURBOC__) && !defined(__FLAT__)
- ret = farmalloc(size);
-#else
-# if defined(_MSC_VER) && defined(MAXSEG_64K)
- ret = halloc(size, 1);
-# else
- ret = malloc((size_t)size);
-# endif
-#endif
+ if (ret != NULL)
+ return ret;
- if (ret == NULL)
- {
- png_error(png_ptr, "Out of Memory");
+ png_warning(png_ptr, "Out of memory");
}
- return (ret);
+ return NULL;
}
/* Free a pointer allocated by png_malloc(). If ptr is NULL, return
- without taking any action. */
-void
-png_free(png_structp png_ptr, png_voidp ptr)
+ * without taking any action.
+ */
+void PNGAPI
+png_free(png_const_structrp png_ptr, png_voidp ptr)
{
if (png_ptr == NULL || ptr == NULL)
return;
#ifdef PNG_USER_MEM_SUPPORTED
if (png_ptr->free_fn != NULL)
- {
- (*(png_ptr->free_fn))(png_ptr, ptr);
- ptr = NULL;
- return;
- }
- else png_free_default(png_ptr, ptr);
-}
-void
-png_free_default(png_structp png_ptr, png_voidp ptr)
-{
-#endif /* PNG_USER_MEM_SUPPORTED */
+ png_ptr->free_fn(png_constcast(png_structrp,png_ptr), ptr);
-#if defined(__TURBOC__) && !defined(__FLAT__)
- farfree(ptr);
- ptr = NULL;
-#else
-# if defined(_MSC_VER) && defined(MAXSEG_64K)
- hfree(ptr);
- ptr = NULL;
-# else
- free(ptr);
- ptr = NULL;
-# endif
-#endif
-}
-
-#endif /* Not Borland DOS special memory handler */
-
-png_voidp
-png_memcpy_check (png_structp png_ptr, png_voidp s1, png_voidp s2,
- png_uint_32 length)
-{
- png_size_t size;
-
- size = (png_size_t)length;
- if ((png_uint_32)size != length)
- png_error(png_ptr,"Overflow in png_memcpy_check.");
-
- return(png_memcpy (s1, s2, size));
+ else
+ png_free_default(png_ptr, ptr);
}
-png_voidp
-png_memset_check (png_structp png_ptr, png_voidp s1, int value,
- png_uint_32 length)
+PNG_FUNCTION(void,PNGAPI
+png_free_default,(png_const_structrp png_ptr, png_voidp ptr),PNG_DEPRECATED)
{
- png_size_t size;
-
- size = (png_size_t)length;
- if ((png_uint_32)size != length)
- png_error(png_ptr,"Overflow in png_memset_check.");
-
- return (png_memset (s1, value, size));
+ if (png_ptr == NULL || ptr == NULL)
+ return;
+#endif /* PNG_USER_MEM_SUPPORTED */
+ free(ptr);
}
#ifdef PNG_USER_MEM_SUPPORTED
/* This function is called when the application wants to use another method
* of allocating and freeing memory.
*/
-void
-png_set_mem_fn(png_structp png_ptr, png_voidp mem_ptr, png_malloc_ptr
+void PNGAPI
+png_set_mem_fn(png_structrp png_ptr, png_voidp mem_ptr, png_malloc_ptr
malloc_fn, png_free_ptr free_fn)
{
- png_ptr->mem_ptr = mem_ptr;
- png_ptr->malloc_fn = malloc_fn;
- png_ptr->free_fn = free_fn;
+ if (png_ptr != NULL)
+ {
+ png_ptr->mem_ptr = mem_ptr;
+ png_ptr->malloc_fn = malloc_fn;
+ png_ptr->free_fn = free_fn;
+ }
}
/* This function returns a pointer to the mem_ptr associated with the user
* functions. The application should free any memory associated with this
* pointer before png_write_destroy and png_read_destroy are called.
*/
-png_voidp
-png_get_mem_ptr(png_structp png_ptr)
+png_voidp PNGAPI
+png_get_mem_ptr(png_const_structrp png_ptr)
{
- return ((png_voidp)png_ptr->mem_ptr);
+ if (png_ptr == NULL)
+ return NULL;
+
+ return png_ptr->mem_ptr;
}
#endif /* PNG_USER_MEM_SUPPORTED */
+#endif /* PNG_READ_SUPPORTED || PNG_WRITE_SUPPORTED */
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