minix/lib/nbsd_libc/gen/pwcache.c

/*	$NetBSD: pwcache.c,v 1.31 2010/03/23 20:28:59 drochner Exp $	*/

/*-
 * Copyright (c) 1992 Keith Muller.
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Keith Muller of the University of California, San Diego.
 *
 * 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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS 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 REGENTS OR 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.
 */

/*-
 * Copyright (c) 2002 The NetBSD Foundation, Inc.
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS 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 FOUNDATION OR 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.
 */

#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)cache.c	8.1 (Berkeley) 5/31/93";
#else
__RCSID("$NetBSD: pwcache.c,v 1.31 2010/03/23 20:28:59 drochner Exp $");
#endif
#endif /* LIBC_SCCS and not lint */

#include "namespace.h"

#include <sys/types.h>
#include <sys/param.h>

#include <assert.h>
#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#if !HAVE_PWCACHE_USERDB || HAVE_NBTOOL_CONFIG_H
#include "pwcache.h"

/*
 * routines that control user, group, uid and gid caches (for the archive
 * member print routine).
 * IMPORTANT:
 * these routines cache BOTH hits and misses, a major performance improvement
 */

/*
 * function pointers to various name lookup routines.
 * these may be changed as necessary.
 */
static	int		(*_pwcache_setgroupent)(int)		= setgroupent;
static	void		(*_pwcache_endgrent)(void)		= endgrent;
static	struct group *	(*_pwcache_getgrnam)(const char *)	= getgrnam;
static	struct group *	(*_pwcache_getgrgid)(gid_t)		= getgrgid;
static	int		(*_pwcache_setpassent)(int)		= setpassent;
static	void		(*_pwcache_endpwent)(void)		= endpwent;
static	struct passwd *	(*_pwcache_getpwnam)(const char *)	= getpwnam;
static	struct passwd *	(*_pwcache_getpwuid)(uid_t)		= getpwuid;

/*
 * internal state
 */
static	int	pwopn;		/* is password file open */
static	int	gropn;		/* is group file open */
static	UIDC	**uidtb;	/* uid to name cache */
static	GIDC	**gidtb;	/* gid to name cache */
static	UIDC	**usrtb;	/* user name to uid cache */
static	GIDC	**grptb;	/* group name to gid cache */

static	int	uidtb_fail;	/* uidtb_start() failed ? */
static	int	gidtb_fail;	/* gidtb_start() failed ? */
static	int	usrtb_fail;	/* usrtb_start() failed ? */
static	int	grptb_fail;	/* grptb_start() failed ? */


static	u_int	st_hash(const char *, size_t, int);
static	int	uidtb_start(void);
static	int	gidtb_start(void);
static	int	usrtb_start(void);
static	int	grptb_start(void);


static u_int
st_hash(const char *name, size_t len, int tabsz)
{
	u_int key = 0;

	_DIAGASSERT(name != NULL);

	while (len--) {
		key += *name++;
		key = (key << 8) | (key >> 24);
	}

	return (key % tabsz);
}

/*
 * uidtb_start
 *	creates an an empty uidtb
 * Return:
 *	0 if ok, -1 otherwise
 */
static int
uidtb_start(void)
{

	if (uidtb != NULL)
		return (0);
	if (uidtb_fail)
		return (-1);
	if ((uidtb = (UIDC **)calloc(UID_SZ, sizeof(UIDC *))) == NULL) {
		++uidtb_fail;
		return (-1);
	}
	return (0);
}

/*
 * gidtb_start
 *	creates an an empty gidtb
 * Return:
 *	0 if ok, -1 otherwise
 */
static int
gidtb_start(void)
{

	if (gidtb != NULL)
		return (0);
	if (gidtb_fail)
		return (-1);
	if ((gidtb = (GIDC **)calloc(GID_SZ, sizeof(GIDC *))) == NULL) {
		++gidtb_fail;
		return (-1);
	}
	return (0);
}

/*
 * usrtb_start
 *	creates an an empty usrtb
 * Return:
 *	0 if ok, -1 otherwise
 */
static int
usrtb_start(void)
{

	if (usrtb != NULL)
		return (0);
	if (usrtb_fail)
		return (-1);
	if ((usrtb = (UIDC **)calloc(UNM_SZ, sizeof(UIDC *))) == NULL) {
		++usrtb_fail;
		return (-1);
	}
	return (0);
}

/*
 * grptb_start
 *	creates an an empty grptb
 * Return:
 *	0 if ok, -1 otherwise
 */
static int
grptb_start(void)
{

	if (grptb != NULL)
		return (0);
	if (grptb_fail)
		return (-1);
	if ((grptb = (GIDC **)calloc(GNM_SZ, sizeof(GIDC *))) == NULL) {
		++grptb_fail;
		return (-1);
	}
	return (0);
}

#define FLUSHTB(arr, len, fail)				\
	do {						\
		if (arr != NULL) {			\
			for (i = 0; i < len; i++)	\
				if (arr[i] != NULL)	\
					free(arr[i]);	\
			arr = NULL;			\
		}					\
		fail = 0;				\
	} while (/* CONSTCOND */0);

int
pwcache_userdb(
	int		(*a_setpassent)(int),
	void		(*a_endpwent)(void),
	struct passwd *	(*a_getpwnam)(const char *),
	struct passwd *	(*a_getpwuid)(uid_t))
{
	int i;

		/* a_setpassent and a_endpwent may be NULL */
	if (a_getpwnam == NULL || a_getpwuid == NULL)
		return (-1);

	if (_pwcache_endpwent != NULL)
		(*_pwcache_endpwent)();
	FLUSHTB(uidtb, UID_SZ, uidtb_fail);
	FLUSHTB(usrtb, UNM_SZ, usrtb_fail);
	pwopn = 0;
	_pwcache_setpassent = a_setpassent;
	_pwcache_endpwent = a_endpwent;
	_pwcache_getpwnam = a_getpwnam;
	_pwcache_getpwuid = a_getpwuid;

	return (0);
}

int
pwcache_groupdb(
	int		(*a_setgroupent)(int),
	void		(*a_endgrent)(void),
	struct group *	(*a_getgrnam)(const char *),
	struct group *	(*a_getgrgid)(gid_t))
{
	int i;

		/* a_setgroupent and a_endgrent may be NULL */
	if (a_getgrnam == NULL || a_getgrgid == NULL)
		return (-1);

	if (_pwcache_endgrent != NULL)
		(*_pwcache_endgrent)();
	FLUSHTB(gidtb, GID_SZ, gidtb_fail);
	FLUSHTB(grptb, GNM_SZ, grptb_fail);
	gropn = 0;
	_pwcache_setgroupent = a_setgroupent;
	_pwcache_endgrent = a_endgrent;
	_pwcache_getgrnam = a_getgrnam;
	_pwcache_getgrgid = a_getgrgid;

	return (0);
}


#ifdef TEST_PWCACHE

struct passwd *
test_getpwnam(const char *name)
{
	static struct passwd foo;

	memset(&foo, 0, sizeof(foo));
	if (strcmp(name, "toor") == 0) {
		foo.pw_uid = 666;
		return &foo;
	}
	return (getpwnam(name));
}

int
main(int argc, char *argv[])
{
	uid_t	u;
	int	r, i;

	printf("pass 1 (default userdb)\n");
	for (i = 1; i < argc; i++) {
		printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n",
		    i, pwopn, usrtb_fail, usrtb);
		r = uid_from_user(argv[i], &u);
		if (r == -1)
			printf("  uid_from_user %s: failed\n", argv[i]);
		else
			printf("  uid_from_user %s: %d\n", argv[i], u);
	}
	printf("pass 1 finish: pwopn %d usrtb_fail %d usrtb %p\n",
		    pwopn, usrtb_fail, usrtb);

	puts("");
	printf("pass 2 (replacement userdb)\n");
	printf("pwcache_userdb returned %d\n",
	    pwcache_userdb(setpassent, test_getpwnam, getpwuid));
	printf("pwopn %d usrtb_fail %d usrtb %p\n", pwopn, usrtb_fail, usrtb);

	for (i = 1; i < argc; i++) {
		printf("i: %d, pwopn %d usrtb_fail %d usrtb %p\n",
		    i, pwopn, usrtb_fail, usrtb);
		u = -1;
		r = uid_from_user(argv[i], &u);
		if (r == -1)
			printf("  uid_from_user %s: failed\n", argv[i]);
		else
			printf("  uid_from_user %s: %d\n", argv[i], u);
	}
	printf("pass 2 finish: pwopn %d usrtb_fail %d usrtb %p\n",
		    pwopn, usrtb_fail, usrtb);

	puts("");
	printf("pass 3 (null pointers)\n");
	printf("pwcache_userdb returned %d\n",
	    pwcache_userdb(NULL, NULL, NULL));

	return (0);
}
#endif	/* TEST_PWCACHE */
#endif	/* !HAVE_PWCACHE_USERDB */