/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 * Copyright (c) 2016 by Delphix. All rights reserved.
 */

#include "lint.h"
#include <mtlib.h>
#include <sys/types.h>
#include <shadow.h>
#include <stdlib.h>
#include <string.h>
#include <nss_dbdefs.h>
#include <stdio.h>
#include <synch.h>

int str2spwd(const char *, int, void *,
	char *, int);

static DEFINE_NSS_DB_ROOT(db_root);
static DEFINE_NSS_GETENT(context);

void
_nss_initf_shadow(nss_db_params_t *p)
{
	p->name	= NSS_DBNAM_SHADOW;
	p->config_name    = NSS_DBNAM_PASSWD;	/* Use config for "passwd" */
	p->default_config = NSS_DEFCONF_PASSWD;
}

struct spwd *
getspnam_r(const char *name, struct spwd *result, char *buffer, int buflen)
{
	nss_XbyY_args_t arg;

	NSS_XbyY_INIT(&arg, result, buffer, buflen, str2spwd);
	arg.key.name = name;
	(void) nss_search(&db_root, _nss_initf_shadow,
	    NSS_DBOP_SHADOW_BYNAME, &arg);
	return ((struct spwd *)NSS_XbyY_FINI(&arg));
}

void
setspent(void)
{
	nss_setent(&db_root, _nss_initf_shadow, &context);
}

void
endspent(void)
{
	nss_endent(&db_root, _nss_initf_shadow, &context);
	nss_delete(&db_root);
}

struct spwd *
getspent_r(struct spwd *result, char *buffer, int buflen)
{
	nss_XbyY_args_t arg;
	char		*nam;

	/* In getXXent_r(), protect the unsuspecting caller from +/- entries */

	do {
		NSS_XbyY_INIT(&arg, result, buffer, buflen, str2spwd);
		/* No key to fill in */
		(void) nss_getent(&db_root, _nss_initf_shadow, &context, &arg);
	} while (arg.returnval != 0 &&
	    (nam = ((struct spwd *)arg.returnval)->sp_namp) != 0 &&
	    (*nam == '+' || *nam == '-'));

	return (struct spwd *)NSS_XbyY_FINI(&arg);
}

struct spwd *
fgetspent_r(FILE *f, struct spwd *result, char *buffer, int buflen)
{
	extern void	_nss_XbyY_fgets(FILE *, nss_XbyY_args_t *);
	nss_XbyY_args_t	arg;

	/* ... but in fgetXXent_r, the caller deserves any +/- entry it gets */

	/* No key to fill in */
	NSS_XbyY_INIT(&arg, result, buffer, buflen, str2spwd);
	_nss_XbyY_fgets(f, &arg);
	return (struct spwd *)NSS_XbyY_FINI(&arg);
}

typedef const char *constp;

static int	/* 1 means success and more input, 0 means error or no more */
getfield(constp *nextp, constp limit, int uns, void *valp)
{
	constp		p = *nextp;
	char		*endfield;
	char		numbuf[12];  /* Holds -2^31 and trailing ':' */
	size_t		len;

	if (p == 0 || p >= limit) {
		return (0);
	}
	if (*p == ':') {
		p++;
		*nextp = p;
		return (p < limit);
	}
	if ((len = limit - p) > sizeof (numbuf) - 1) {
		len = sizeof (numbuf) - 1;
	}
	/*
	 * We want to use strtol() and we have a readonly non-zero-terminated
	 *   string, so first we copy and terminate the interesting bit.
	 *   Ugh.  (It's convenient to terminate with a colon rather than \0).
	 */
	if ((endfield = memccpy(numbuf, p, ':', len)) == 0) {
		if (len != limit - p) {
			/* Error -- field is too big to be a legit number */
			return (0);
		}
		numbuf[len] = ':';
		p = limit;
	} else {
		p += (endfield - numbuf);
	}
	if (uns) {
		unsigned long ux = strtoul(numbuf, &endfield, 10);
		if (*endfield != ':') {
			/* Error -- expected <integer><colon> */
			return (0);
		}
		*((unsigned int *)valp) = (unsigned int)ux;
	} else {
		long x = strtol(numbuf, &endfield, 10);
		if (*endfield != ':') {
			/* Error -- expected <integer><colon> */
			return (0);
		}
		*((int *)valp) = (int)x;
	}
	*nextp = p;
	return (p < limit);
}

/*
 *  str2spwd() -- convert a string to a shadow passwd entry.  The parser is
 *	more liberal than the passwd or group parsers;  since it's legitimate
 *	for almost all the fields here to be blank, the parser lets one omit
 *	any number of blank fields at the end of the entry.  The acceptable
 *	forms for '+' and '-' entries are the same as those for normal entries.
 *  === Is this likely to do more harm than good?
 *
 * Return values: 0 = success, 1 = parse error, 2 = erange ...
 * The structure pointer passed in is a structure in the caller's space
 * wherein the field pointers would be set to areas in the buffer if
 * need be. instring and buffer should be separate areas.
 */
int
str2spwd(const char *instr, int lenstr, void *ent, char *buffer, int buflen)
{
	struct spwd	*shadow	= (struct spwd *)ent;
	const char	*p = instr, *limit;
	char	*bufp;
	int	black_magic;
	size_t	lencopy;

	limit = p + lenstr;
	if ((p = memchr(instr, ':', lenstr)) == 0 ||
	    ++p >= limit ||
	    (p = memchr(p, ':', limit - p)) == 0) {
		lencopy = (size_t)lenstr;
		p = 0;
	} else {
		lencopy = p - instr;
		p++;
	}
	if (lencopy + 1 > buflen) {
		return (NSS_STR_PARSE_ERANGE);
	}

	if (instr != buffer) {
		/* Overlapping buffer copies are OK */
		(void) memmove(buffer, instr, lencopy);
		buffer[lencopy] = 0;
	}

	/* quick exit do not entry fill if not needed */
	if (ent == (void *)NULL)
		return (NSS_STR_PARSE_SUCCESS);

	black_magic = (*instr == '+' || *instr == '-');
	shadow->sp_namp = bufp = buffer;
	shadow->sp_pwdp	= 0;
	shadow->sp_lstchg = -1;
	shadow->sp_min	= -1;
	shadow->sp_max	= -1;
	shadow->sp_warn	= -1;
	shadow->sp_inact = -1;
	shadow->sp_expire = -1;
	shadow->sp_flag	= 0;

	if ((bufp = strchr(bufp, ':')) == 0) {
		if (black_magic)
			return (NSS_STR_PARSE_SUCCESS);
		else
			return (NSS_STR_PARSE_PARSE);
	}
	*bufp++ = '\0';

	shadow->sp_pwdp = bufp;
	if (instr == 0) {
		if ((bufp = strchr(bufp, ':')) == 0) {
			if (black_magic)
				return (NSS_STR_PARSE_SUCCESS);
			else
				return (NSS_STR_PARSE_PARSE);
		}
		*bufp++ = '\0';
		p = bufp;
	} /* else p was set when we copied name and passwd into the buffer */

	if (!getfield(&p, limit, 0, &shadow->sp_lstchg))
			return (NSS_STR_PARSE_SUCCESS);
	if (!getfield(&p, limit, 0, &shadow->sp_min))
			return (NSS_STR_PARSE_SUCCESS);
	if (!getfield(&p, limit, 0, &shadow->sp_max))
			return (NSS_STR_PARSE_SUCCESS);
	if (!getfield(&p, limit, 0, &shadow->sp_warn))
			return (NSS_STR_PARSE_SUCCESS);
	if (!getfield(&p, limit, 0, &shadow->sp_inact))
			return (NSS_STR_PARSE_SUCCESS);
	if (!getfield(&p, limit, 0, &shadow->sp_expire))
			return (NSS_STR_PARSE_SUCCESS);
	if (!getfield(&p, limit, 1, &shadow->sp_flag))
			return (NSS_STR_PARSE_SUCCESS);
	if (p != limit) {
		/* Syntax error -- garbage at end of line */
		return (NSS_STR_PARSE_PARSE);
	}
	return (NSS_STR_PARSE_SUCCESS);
}