/* crypto/store/str_mem.c -*- mode:C; c-file-style: "eay" -*- */
/* Written by Richard Levitte (richard@levitte.org) for the OpenSSL
 * project 2003.
 */
/* ====================================================================
 * Copyright (c) 2003 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <string.h>
#include <openssl/err.h>
#include "str_locl.h"

/* The memory store is currently highly experimental.  It's meant to become
   a base store used by other stores for internal caching (for full caching
   support, aging needs to be added).

   The database use is meant to support as much attribute association as
   possible, while providing for as small search ranges as possible.
   This is currently provided for by sorting the entries by numbers that
   are composed of bits set at the positions indicated by attribute type
   codes.  This provides for ranges determined by the highest attribute
   type code value.  A better idea might be to sort by values computed
   from the range of attributes associated with the object (basically,
   the difference between the highest and lowest attribute type code)
   and it's distance from a base (basically, the lowest associated
   attribute type code).
*/

struct mem_object_data_st
	{
	STORE_OBJECT *object;
	STORE_ATTR_INFO *attr_info;
	int references;
	};

struct mem_data_st
	{
	STACK *data;		/* A stack of mem_object_data_st,
				   sorted with STORE_ATTR_INFO_compare(). */
	unsigned int compute_components : 1; /* Currently unused, but can
						be used to add attributes
						from parts of the data. */
	};

struct mem_ctx_st
	{
	int type;		/* The type we're searching for */
	STACK *search_attributes; /* Sets of attributes to search for.
				     Each element is a STORE_ATTR_INFO. */
	int search_index;	/* which of the search attributes we found a match
				   for, -1 when we still haven't found any */
	int index;		/* -1 as long as we're searching for the first */
	};

static int mem_init(STORE *s);
static void mem_clean(STORE *s);
static STORE_OBJECT *mem_generate(STORE *s, STORE_OBJECT_TYPES type,
	OPENSSL_ITEM attributes[], OPENSSL_ITEM parameters[]);
static STORE_OBJECT *mem_get(STORE *s, STORE_OBJECT_TYPES type,
	OPENSSL_ITEM attributes[], OPENSSL_ITEM parameters[]);
static int mem_store(STORE *s, STORE_OBJECT_TYPES type,
	STORE_OBJECT *data, OPENSSL_ITEM attributes[],
	OPENSSL_ITEM parameters[]);
static int mem_modify(STORE *s, STORE_OBJECT_TYPES type,
	OPENSSL_ITEM search_attributes[], OPENSSL_ITEM add_attributes[],
	OPENSSL_ITEM modify_attributes[], OPENSSL_ITEM delete_attributes[],
	OPENSSL_ITEM parameters[]);
static int mem_delete(STORE *s, STORE_OBJECT_TYPES type,
	OPENSSL_ITEM attributes[], OPENSSL_ITEM parameters[]);
static void *mem_list_start(STORE *s, STORE_OBJECT_TYPES type,
	OPENSSL_ITEM attributes[], OPENSSL_ITEM parameters[]);
static STORE_OBJECT *mem_list_next(STORE *s, void *handle);
static int mem_list_end(STORE *s, void *handle);
static int mem_list_endp(STORE *s, void *handle);
static int mem_lock(STORE *s, OPENSSL_ITEM attributes[],
	OPENSSL_ITEM parameters[]);
static int mem_unlock(STORE *s, OPENSSL_ITEM attributes[],
	OPENSSL_ITEM parameters[]);
static int mem_ctrl(STORE *s, int cmd, long l, void *p, void (*f)(void));

static STORE_METHOD store_memory =
	{
	"OpenSSL memory store interface",
	mem_init,
	mem_clean,
	mem_generate,
	mem_get,
	mem_store,
	mem_modify,
	NULL, /* revoke */
	mem_delete,
	mem_list_start,
	mem_list_next,
	mem_list_end,
	mem_list_endp,
	NULL, /* update */
	mem_lock,
	mem_unlock,
	mem_ctrl
	};

const STORE_METHOD *STORE_Memory(void)
	{
	return &store_memory;
	}

static int mem_init(STORE *s)
	{
	return 1;
	}

static void mem_clean(STORE *s)
	{
	return;
	}

static STORE_OBJECT *mem_generate(STORE *s, STORE_OBJECT_TYPES type,
	OPENSSL_ITEM attributes[], OPENSSL_ITEM parameters[])
	{
	STOREerr(STORE_F_MEM_GENERATE, STORE_R_NOT_IMPLEMENTED);
	return 0;
	}
static STORE_OBJECT *mem_get(STORE *s, STORE_OBJECT_TYPES type,
	OPENSSL_ITEM attributes[], OPENSSL_ITEM parameters[])
	{
	void *context = mem_list_start(s, type, attributes, parameters);
	
	if (context)
		{
		STORE_OBJECT *object = mem_list_next(s, context);

		if (mem_list_end(s, context))
			return object;
		}
	return NULL;
	}
static int mem_store(STORE *s, STORE_OBJECT_TYPES type,
	STORE_OBJECT *data, OPENSSL_ITEM attributes[],
	OPENSSL_ITEM parameters[])
	{
	STOREerr(STORE_F_MEM_STORE, STORE_R_NOT_IMPLEMENTED);
	return 0;
	}
static int mem_modify(STORE *s, STORE_OBJECT_TYPES type,
	OPENSSL_ITEM search_attributes[], OPENSSL_ITEM add_attributes[],
	OPENSSL_ITEM modify_attributes[], OPENSSL_ITEM delete_attributes[],
	OPENSSL_ITEM parameters[])
	{
	STOREerr(STORE_F_MEM_MODIFY, STORE_R_NOT_IMPLEMENTED);
	return 0;
	}
static int mem_delete(STORE *s, STORE_OBJECT_TYPES type,
	OPENSSL_ITEM attributes[], OPENSSL_ITEM parameters[])
	{
	STOREerr(STORE_F_MEM_DELETE, STORE_R_NOT_IMPLEMENTED);
	return 0;
	}

/* The list functions may be the hardest to understand.  Basically,
   mem_list_start compiles a stack of attribute info elements, and
   puts that stack into the context to be returned.  mem_list_next
   will then find the first matching element in the store, and then
   walk all the way to the end of the store (since any combination
   of attribute bits above the starting point may match the searched
   for bit pattern...). */
static void *mem_list_start(STORE *s, STORE_OBJECT_TYPES type,
	OPENSSL_ITEM attributes[], OPENSSL_ITEM parameters[])
	{
	struct mem_ctx_st *context =
		(struct mem_ctx_st *)OPENSSL_malloc(sizeof(struct mem_ctx_st));
	void *attribute_context = NULL;
	STORE_ATTR_INFO *attrs = NULL;

	if (!context)
		{
		STOREerr(STORE_F_MEM_LIST_START, ERR_R_MALLOC_FAILURE);
		return 0;
		}
	memset(context, 0, sizeof(struct mem_ctx_st));

	attribute_context = STORE_parse_attrs_start(attributes);
	if (!attribute_context)
		{
		STOREerr(STORE_F_MEM_LIST_START, ERR_R_STORE_LIB);
		goto err;
		}

	while((attrs = STORE_parse_attrs_next(attribute_context)))
		{
		if (context->search_attributes == NULL)
			{
			context->search_attributes =
				sk_new((int (*)(const char * const *, const char * const *))STORE_ATTR_INFO_compare);
			if (!context->search_attributes)
				{
				STOREerr(STORE_F_MEM_LIST_START,
					ERR_R_MALLOC_FAILURE);
				goto err;
				}
			}
		sk_push(context->search_attributes,(char *)attrs);
		}
	if (!STORE_parse_attrs_endp(attribute_context))
		goto err;
	STORE_parse_attrs_end(attribute_context);
	context->search_index = -1;
	context->index = -1;
	return context;
 err:
	if (attribute_context) STORE_parse_attrs_end(attribute_context);
	mem_list_end(s, context);
	return NULL;
	}
static STORE_OBJECT *mem_list_next(STORE *s, void *handle)
	{
	int i;
	struct mem_ctx_st *context = (struct mem_ctx_st *)handle;
	struct mem_object_data_st key = { 0, 0, 1 };
	struct mem_data_st *store =
		(struct mem_data_st *)STORE_get_ex_data(s, 1);
	int srch;
	int cres = 0;

	if (!context)
		{
		STOREerr(STORE_F_MEM_LIST_NEXT, ERR_R_PASSED_NULL_PARAMETER);
		return NULL;
		}
	if (!store)
		{
		STOREerr(STORE_F_MEM_LIST_NEXT, STORE_R_NO_STORE);
		return NULL;
		}

	if (context->search_index == -1)
		{
		for (i = 0; i < sk_num(context->search_attributes); i++)
			{
			key.attr_info =
				(STORE_ATTR_INFO *)sk_value(context->search_attributes, i);
			srch = sk_find_ex(store->data, (char *)&key);

			if (srch >= 0)
				{
				context->search_index = srch;
				break;
				}
			}
		}
	if (context->search_index < 0)
		return NULL;
	
	key.attr_info =
		(STORE_ATTR_INFO *)sk_value(context->search_attributes,
			context->search_index);
	for(srch = context->search_index;
	    srch < sk_num(store->data)
		    && STORE_ATTR_INFO_in_range(key.attr_info,
			    (STORE_ATTR_INFO *)sk_value(store->data, srch))
		    && !(cres = STORE_ATTR_INFO_in_ex(key.attr_info,
				 (STORE_ATTR_INFO *)sk_value(store->data, srch)));
	    srch++)
		;

	context->search_index = srch;
	if (cres)
		return ((struct mem_object_data_st *)sk_value(store->data,
				srch))->object;
	return NULL;
	}
static int mem_list_end(STORE *s, void *handle)
	{
	struct mem_ctx_st *context = (struct mem_ctx_st *)handle;

	if (!context)
		{
		STOREerr(STORE_F_MEM_LIST_END, ERR_R_PASSED_NULL_PARAMETER);
		return 0;
		}
	if (context && context->search_attributes)
		sk_free(context->search_attributes);
	if (context) OPENSSL_free(context);
	return 1;
	}
static int mem_list_endp(STORE *s, void *handle)
	{
	struct mem_ctx_st *context = (struct mem_ctx_st *)handle;

	if (!context
		|| context->search_index == sk_num(context->search_attributes))
		return 1;
	return 0;
	}
static int mem_lock(STORE *s, OPENSSL_ITEM attributes[],
	OPENSSL_ITEM parameters[])
	{
	return 1;
	}
static int mem_unlock(STORE *s, OPENSSL_ITEM attributes[],
	OPENSSL_ITEM parameters[])
	{
	return 1;
	}
static int mem_ctrl(STORE *s, int cmd, long l, void *p, void (*f)(void))
	{
	return 1;
	}