xref: /src/external/bsd/libbind/dist/irs/lcl_pw.c

/*	$NetBSD: lcl_pw.c,v 1.1.1.2 2012/09/09 16:07:58 christos Exp $	*/

/*
 * Copyright (c) 1989, 1993, 1995
 *	The Regents of the University of California.  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 acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Portions Copyright (c) 1996,1999 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static const char rcsid[] = "Id: lcl_pw.c,v 1.3 2005/04/27 04:56:31 sra Exp ";
#endif /* LIBC_SCCS and not lint */

/* Extern */

#include "port_before.h"

#ifndef WANT_IRS_PW
static int __bind_irs_pw_unneeded;
#else

#include <sys/param.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <resolv.h>

#include <db.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <pwd.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <utmp.h>
#include <unistd.h>

#include <isc/memcluster.h>
#include <irs.h>

#include "port_after.h"

#include "irs_p.h"
#include "lcl_p.h"

/*! \file
 * \brief
 * The lookup techniques and data extraction code here must be kept
 * in sync with that in `pwd_mkdb'.
 */


/* Types */

struct  pvt {
	struct passwd	passwd;		/*%< password structure */
	DB 		*pw_db;		/*%< password database */
	int		pw_keynum;	/*%< key counter */
	int		warned;
	u_int		max;
	char *		line;
};

/* Forward */

static void			pw_close(struct irs_pw *);
static struct passwd *		pw_next(struct irs_pw *);
static struct passwd *		pw_byname(struct irs_pw *, const char *);
static struct passwd *		pw_byuid(struct irs_pw *, uid_t);
static void			pw_rewind(struct irs_pw *);
static void			pw_minimize(struct irs_pw *);

static int			initdb(struct pvt *);
static int			hashpw(struct irs_pw *, DBT *);

/* Public */
struct irs_pw *
irs_lcl_pw(struct irs_acc *this) {
	struct irs_pw *pw;
	struct pvt *pvt;

	UNUSED(this);

        if (!(pw = memget(sizeof *pw))) {
		errno = ENOMEM;
		return (NULL);
	}
	memset(pw, 0x5e, sizeof *pw);
	if (!(pvt = memget(sizeof *pvt))) {
		free(pw);
		errno = ENOMEM;
		return (NULL);
	}
	memset(pvt, 0, sizeof *pvt);
	pw->private = pvt;
	pw->close = pw_close;
	pw->next = pw_next;
	pw->byname = pw_byname;
	pw->byuid = pw_byuid;
	pw->rewind = pw_rewind;
	pw->minimize = pw_minimize;
	pw->res_get = NULL;
	pw->res_set = NULL;
	return (pw);
}

/* Methods */

static void
pw_close(struct irs_pw *this) {
	struct pvt *pvt = (struct pvt *)this->private;

	if (pvt->pw_db) {
		(void)(pvt->pw_db->close)(pvt->pw_db);
		pvt->pw_db = NULL;
	}
	if (pvt->line)
		memput(pvt->line, pvt->max);
	memput(pvt, sizeof *pvt);
	memput(this, sizeof *this);
}

static struct passwd *
pw_next(struct irs_pw *this) {
	struct pvt *pvt = (struct pvt *)this->private;

	DBT key;
	char bf[sizeof(pvt->pw_keynum) + 1];

	if (!initdb(pvt))
		return (NULL);

	++pvt->pw_keynum;
	bf[0] = _PW_KEYBYNUM;
	memcpy(bf + 1, (char *)&pvt->pw_keynum, sizeof(pvt->pw_keynum));
	key.data = (u_char *)bf;
	key.size = sizeof(pvt->pw_keynum) + 1;
	return (hashpw(this, &key) ? &pvt->passwd : NULL);
}

static struct passwd *
pw_byname(struct irs_pw *this, const char *name) {
	struct pvt *pvt = (struct pvt *)this->private;
	DBT key;
	int len, rval;
	char bf[UT_NAMESIZE + 1];

	if (!initdb(pvt))
		return (NULL);

	bf[0] = _PW_KEYBYNAME;
	len = strlen(name);
	memcpy(bf + 1, name, MIN(len, UT_NAMESIZE));
	key.data = (u_char *)bf;
	key.size = len + 1;
	rval = hashpw(this, &key);

	return (rval ? &pvt->passwd : NULL);
}


static struct passwd *
pw_byuid(struct irs_pw *this, uid_t uid) {
	struct pvt *pvt = (struct pvt *)this->private;
	DBT key;
	int keyuid, rval;
	char bf[sizeof(keyuid) + 1];

	if (!initdb(pvt))
		return (NULL);

	bf[0] = _PW_KEYBYUID;
	keyuid = uid;
	memcpy(bf + 1, &keyuid, sizeof(keyuid));
	key.data = (u_char *)bf;
	key.size = sizeof(keyuid) + 1;
	rval = hashpw(this, &key);

	return (rval ? &pvt->passwd : NULL);
}

static void
pw_rewind(struct irs_pw *this) {
	struct pvt *pvt = (struct pvt *)this->private;

	pvt->pw_keynum = 0;
}

static void
pw_minimize(struct irs_pw *this) {
	struct pvt *pvt = (struct pvt *)this->private;

	if (pvt->pw_db != NULL) {
		(void) (*pvt->pw_db->close)(pvt->pw_db);
		pvt->pw_db = NULL;
	}
}

/* Private. */

static int
initdb(struct pvt *pvt) {
	const char *p;

	if (pvt->pw_db) {
		if (lseek((*pvt->pw_db->fd)(pvt->pw_db), 0L, SEEK_CUR) >= 0L)
			return (1);
		else
			(void) (*pvt->pw_db->close)(pvt->pw_db);
	}
	pvt->pw_db = dbopen((p = _PATH_SMP_DB), O_RDONLY, 0, DB_HASH, NULL);
	if (!pvt->pw_db)
		pvt->pw_db = dbopen((p =_PATH_MP_DB), O_RDONLY,
				    0, DB_HASH, NULL);
	if (pvt->pw_db)
		return (1);
	if (!pvt->warned) {
		syslog(LOG_ERR, "%s: %m", p);
		pvt->warned++;
	}
	return (0);
}

static int
hashpw(struct irs_pw *this, DBT *key) {
	struct pvt *pvt = (struct pvt *)this->private;
	char *p, *t, *l;
	DBT data;

	if ((pvt->pw_db->get)(pvt->pw_db, key, &data, 0))
		return (0);
	p = (char *)data.data;
	if (data.size > pvt->max) {
		size_t newlen = pvt->max + 1024;
		char *p = memget(newlen);
		if (p == NULL) {
			return (0);
		}
		if (pvt->line != NULL) {
			memcpy(p, pvt->line, pvt->max);
			memput(pvt->line, pvt->max);
		}
		pvt->max = newlen;
		pvt->line = p;
	}

	/* THIS CODE MUST MATCH THAT IN pwd_mkdb. */
	t = pvt->line;
	l = pvt->line + pvt->max;
#define EXPAND(e) if ((e = t) == NULL) return (0); else \
		  do if (t >= l) return (0); while ((*t++ = *p++) != '\0')
#define SCALAR(v) if (t + sizeof v >= l) return (0); else \
		  (memmove(&(v), p, sizeof v), p += sizeof v)
	EXPAND(pvt->passwd.pw_name);
	EXPAND(pvt->passwd.pw_passwd);
	SCALAR(pvt->passwd.pw_uid);
	SCALAR(pvt->passwd.pw_gid);
	SCALAR(pvt->passwd.pw_change);
	EXPAND(pvt->passwd.pw_class);
	EXPAND(pvt->passwd.pw_gecos);
	EXPAND(pvt->passwd.pw_dir);
	EXPAND(pvt->passwd.pw_shell);
	SCALAR(pvt->passwd.pw_expire);
	return (1);
}

#endif /* WANT_IRS_PW */