xref: /csrg-svn/lib/libc/gen/getpwent.c (revision 68953)

/*
 * Copyright (c) 1988, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)getpwent.c	8.2 (Berkeley) 04/27/95";
#endif /* LIBC_SCCS and not lint */

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

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

static struct passwd _pw_passwd;	/* password structure */
static DB *_pw_db;			/* password database */
static int _pw_keynum;			/* key counter */
static int _pw_stayopen;		/* keep fd's open */
static int __hashpw(), __initdb();

struct passwd *
getpwent()
{
	DBT key;
	char bf[sizeof(_pw_keynum) + 1];

	if (!_pw_db && !__initdb())
		return((struct passwd *)NULL);

	++_pw_keynum;
	bf[0] = _PW_KEYBYNUM;
	bcopy((char *)&_pw_keynum, bf + 1, sizeof(_pw_keynum));
	key.data = (u_char *)bf;
	key.size = sizeof(_pw_keynum) + 1;
	return(__hashpw(&key) ? &_pw_passwd : (struct passwd *)NULL);
}

struct passwd *
getpwnam(name)
	const char *name;
{
	DBT key;
	int len, rval;
	char bf[UT_NAMESIZE + 1];

	if (!_pw_db && !__initdb())
		return((struct passwd *)NULL);

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

	if (!_pw_stayopen) {
		(void)(_pw_db->close)(_pw_db);
		_pw_db = (DB *)NULL;
	}
	return(rval ? &_pw_passwd : (struct passwd *)NULL);
}

struct passwd *
getpwuid(uid)
	uid_t uid;
{
	DBT key;
	int keyuid, rval;
	char bf[sizeof(keyuid) + 1];

	if (!_pw_db && !__initdb())
		return((struct passwd *)NULL);

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

	if (!_pw_stayopen) {
		(void)(_pw_db->close)(_pw_db);
		_pw_db = (DB *)NULL;
	}
	return(rval ? &_pw_passwd : (struct passwd *)NULL);
}

int
setpassent(stayopen)
	int stayopen;
{
	_pw_keynum = 0;
	_pw_stayopen = stayopen;
	return(1);
}

int
setpwent()
{
	_pw_keynum = 0;
	_pw_stayopen = 0;
	return(1);
}

void
endpwent()
{
	_pw_keynum = 0;
	if (_pw_db) {
		(void)(_pw_db->close)(_pw_db);
		_pw_db = (DB *)NULL;
	}
}

static
__initdb()
{
	static int warned;
	char *p;

	p = (geteuid()) ? _PATH_MP_DB : _PATH_SMP_DB;
	_pw_db = dbopen(p, O_RDONLY, 0, DB_HASH, NULL);
	if (_pw_db)
		return(1);
	if (!warned)
		syslog(LOG_ERR, "%s: %m", p);
	return(0);
}

static
__hashpw(key)
	DBT *key;
{
	register char *p, *t;
	static u_int max;
	static char *line;
	DBT data;

	if ((_pw_db->get)(_pw_db, key, &data, 0))
		return(0);
	p = (char *)data.data;
	if (data.size > max && !(line = realloc(line, max += 1024)))
		return(0);

	/* THIS CODE MUST MATCH THAT IN pwd_mkdb. */
	t = line;
#define	EXPAND(e)	e = t; while (*t++ = *p++);
#define	SCALAR(v)	memmove(&(v), p, sizeof v); p += sizeof v
	EXPAND(_pw_passwd.pw_name);
	EXPAND(_pw_passwd.pw_passwd);
	SCALAR(_pw_passwd.pw_uid);
	SCALAR(_pw_passwd.pw_gid);
	SCALAR(_pw_passwd.pw_change);
	EXPAND(_pw_passwd.pw_class);
	EXPAND(_pw_passwd.pw_gecos);
	EXPAND(_pw_passwd.pw_dir);
	EXPAND(_pw_passwd.pw_shell);
	SCALAR(_pw_passwd.pw_expire);
	return(1);
}