/*********************************************************/

/*  toksvc: a framework-native token broker service      */

/*  Copyright (C) 2020  Z. Gilboa                        */

/*  Released under GPLv2 and GPLv3; see COPYING.TOKSVC.  */

/*********************************************************/

#include <stddef.h>

#include <ntapi/ntapi.h>

#include "toksvc_memfn_impl.h"

#include "toksvc_driver_impl.h"

void * toks_calloc(size_t n, size_t size)

{

	void *                      addr;

	size_t                      bsize;

	struct toks_memory_block *  block;

	if (!n || (size > (size_t)(-1) / n))

		return 0;

	size *= n;

	size += 0xf;

	size &= ~(size_t)0xf;

	addr  = 0;

	bsize = size + sizeof(*block);

	if (ntapi->zw_allocate_virtual_memory(

			NT_CURRENT_PROCESS_HANDLE,

			&addr,

			0,

			&bsize,

			NT_MEM_COMMIT,

			NT_PAGE_READWRITE))

		return 0;

	block        = (struct toks_memory_block *)addr;

	block->addr  = addr;

	block->size  = bsize;

	block->used  = size + offsetof(struct toks_memory_block,buffer);

	block->avail = bsize - block->used;

	return (char *)addr + offsetof(struct toks_memory_block,buffer);

}

void * toks_balloc(

	struct toks_memory_block * cache,

	struct toks_memory_block * block,

	size_t n, size_t size)

{

	void * addr;

	if (!n || (size > (size_t)(-1) / n))

		return 0;

	if (!cache || !cache->addr)

		return toks_calloc(n,size);

	size *= n;

	size += 0xf;

	size &= ~(size_t)0xf;

	if (size > block->avail)

		return toks_calloc(1,size);

	/* cached */

	addr          = &block->buffer[block->used / sizeof(size_t)];

	block->used  += size;

	block->avail -= size;

	return addr;

}

void toks_free(void * addr)

{

	char *                      baddr;

	size_t                      size;

	struct toks_memory_block *  block;

	baddr  = addr;

	baddr -= offsetof(struct toks_memory_block,buffer);

	block = (struct toks_memory_block *)baddr;

	addr  = block->addr;

	size  = block->size;

	ntapi->zw_free_virtual_memory(

		NT_CURRENT_PROCESS_HANDLE,

		&addr,

		&size,

		NT_MEM_RELEASE);

}