o_names.c

来自「一个用于点对点传输加密的工具包源码」· C语言 代码 · 共 267 行

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <openssl/lhash.h>
#include <openssl/objects.h>
#include <openssl/safestack.h>

/* I use the ex_data stuff to manage the identifiers for the obj_name_types
 * that applications may define.  I only really use the free function field.
 */
static LHASH *names_lh=NULL;
static int names_type_num=OBJ_NAME_TYPE_NUM;

typedef struct name_funcs_st
	{
	unsigned long (*hash_func)();
	int (*cmp_func)();
	void (*free_func)();
	} NAME_FUNCS;

DECLARE_STACK_OF(NAME_FUNCS)
IMPLEMENT_STACK_OF(NAME_FUNCS)

static STACK_OF(NAME_FUNCS) *name_funcs_stack;

static unsigned long obj_name_hash(OBJ_NAME *a);
static int obj_name_cmp(OBJ_NAME *a,OBJ_NAME *b);

int OBJ_NAME_init(void)
	{
	if (names_lh != NULL) return(1);
	MemCheck_off();
	names_lh=lh_new(obj_name_hash,obj_name_cmp);
	MemCheck_on();
	return(names_lh != NULL);
	}

int OBJ_NAME_new_index(unsigned long (*hash_func)(const char *),
	int (*cmp_func)(const void *, const void *),
	void (*free_func)(const char *, int, const char *))
	{
	int ret;
	int i;
	NAME_FUNCS *name_funcs;

	if (name_funcs_stack == NULL)
		{
		MemCheck_off();
		name_funcs_stack=sk_NAME_FUNCS_new_null();
		MemCheck_on();
		}
	if ((name_funcs_stack == NULL))
		{
		/* ERROR */
		return(0);
		}
	ret=names_type_num;
	names_type_num++;
	for (i=sk_NAME_FUNCS_num(name_funcs_stack); i<names_type_num; i++)
		{
		MemCheck_off();
		name_funcs = OPENSSL_malloc(sizeof(NAME_FUNCS));
		name_funcs->hash_func = lh_strhash;
		name_funcs->cmp_func = (int (*)())strcmp;
		name_funcs->free_func = 0; /* NULL is often declared to
					    * ((void *)0), which according
					    * to Compaq C is not really
					    * compatible with a function
					    * pointer.  -- Richard Levitte*/
		sk_NAME_FUNCS_push(name_funcs_stack,name_funcs);
		MemCheck_on();
		}
	name_funcs = sk_NAME_FUNCS_value(name_funcs_stack, ret);
	if (hash_func != NULL)
		name_funcs->hash_func = hash_func;
	if (cmp_func != NULL)
		name_funcs->cmp_func = cmp_func;
	if (free_func != NULL)
		name_funcs->free_func = free_func;
	return(ret);
	}

static int obj_name_cmp(OBJ_NAME *a, OBJ_NAME *b)
	{
	int ret;

	ret=a->type-b->type;
	if (ret == 0)
		{
		if ((name_funcs_stack != NULL)
			&& (sk_NAME_FUNCS_num(name_funcs_stack) > a->type))
			{
			ret=sk_NAME_FUNCS_value(name_funcs_stack,a->type)
				->cmp_func(a->name,b->name);
			}
		else
			ret=strcmp(a->name,b->name);
		}
	return(ret);
	}

static unsigned long obj_name_hash(OBJ_NAME *a)
	{
	unsigned long ret;

	if ((name_funcs_stack != NULL) && (sk_NAME_FUNCS_num(name_funcs_stack) > a->type))
		{
		ret=sk_NAME_FUNCS_value(name_funcs_stack,a->type)
			->hash_func(a->name);
		}
	else
		{
		ret=lh_strhash(a->name);
		}
	ret^=a->type;
	return(ret);
	}

const char *OBJ_NAME_get(const char *name, int type)
	{
	OBJ_NAME on,*ret;
	int num=0,alias;

	if (name == NULL) return(NULL);
	if ((names_lh == NULL) && !OBJ_NAME_init()) return(NULL);

	alias=type&OBJ_NAME_ALIAS;
	type&= ~OBJ_NAME_ALIAS;

	on.name=name;
	on.type=type;

	for (;;)
		{
		ret=(OBJ_NAME *)lh_retrieve(names_lh,&on);
		if (ret == NULL) return(NULL);
		if ((ret->alias) && !alias)
			{
			if (++num > 10) return(NULL);
			on.name=ret->data;
			}
		else
			{
			return(ret->data);
			}
		}
	}

int OBJ_NAME_add(const char *name, int type, const char *data)
	{
	OBJ_NAME *onp,*ret;
	int alias;

	if ((names_lh == NULL) && !OBJ_NAME_init()) return(0);

	alias=type&OBJ_NAME_ALIAS;
	type&= ~OBJ_NAME_ALIAS;

	onp=(OBJ_NAME *)OPENSSL_malloc(sizeof(OBJ_NAME));
	if (onp == NULL)
		{
		/* ERROR */
		return(0);
		}

	onp->name=name;
	onp->alias=alias;
	onp->type=type;
	onp->data=data;

	ret=(OBJ_NAME *)lh_insert(names_lh,onp);
	if (ret != NULL)
		{
		/* free things */
		if ((name_funcs_stack != NULL) && (sk_NAME_FUNCS_num(name_funcs_stack) > ret->type))
			{
			/* XXX: I'm not sure I understand why the free
			 * function should get three arguments...
			 * -- Richard Levitte
			 */
			sk_NAME_FUNCS_value(name_funcs_stack,ret->type)
				->free_func(ret->name,ret->type,ret->data);
			}
		OPENSSL_free(ret);
		}
	else
		{
		if (lh_error(names_lh))
			{
			/* ERROR */
			return(0);
			}
		}
	return(1);
	}

int OBJ_NAME_remove(const char *name, int type)
	{
	OBJ_NAME on,*ret;

	if (names_lh == NULL) return(0);

	type&= ~OBJ_NAME_ALIAS;
	on.name=name;
	on.type=type;
	ret=(OBJ_NAME *)lh_delete(names_lh,&on);
	if (ret != NULL)
		{
		/* free things */
		if ((name_funcs_stack != NULL) && (sk_NAME_FUNCS_num(name_funcs_stack) > ret->type))
			{
			/* XXX: I'm not sure I understand why the free
			 * function should get three arguments...
			 * -- Richard Levitte
			 */
			sk_NAME_FUNCS_value(name_funcs_stack,ret->type)
				->free_func(ret->name,ret->type,ret->data);
			}
		OPENSSL_free(ret);
		return(1);
		}
	else
		return(0);
	}

static int free_type;

static void names_lh_free(OBJ_NAME *onp, int type)
{
	if(onp == NULL)
	    return;

	if ((free_type < 0) || (free_type == onp->type))
		{
		OBJ_NAME_remove(onp->name,onp->type);
		}
	}

static void name_funcs_free(NAME_FUNCS *ptr)
	{
	OPENSSL_free(ptr);
	}

void OBJ_NAME_cleanup(int type)
	{
	unsigned long down_load;

	if (names_lh == NULL) return;

	free_type=type;
	down_load=names_lh->down_load;
	names_lh->down_load=0;

	lh_doall(names_lh,names_lh_free);
	if (type < 0)
		{
		lh_free(names_lh);
		sk_NAME_FUNCS_pop_free(name_funcs_stack,name_funcs_free);
		names_lh=NULL;
		name_funcs_stack = NULL;
		}
	else
		names_lh->down_load=down_load;
	}