1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 /*
26  *	getspent.c
27  *
28  * lib/nsswitch/compat/getspent.c -- name-service-switch backend for getspnam()
29  *   It looks in /etc/shadow; if it finds shadow entries there that begin
30  *   with "+" or "-", it consults other services.  By default it uses NIS (YP),
31  *   but the user can override this with a "passwd_compat" entry in
32  *   /etc/nsswitch.conf, e.g.
33  *			passwd_compat: ldap
34  * The main criterion for this code is that it behave in the same way as
35  * the code for getpwnam() and friends (in getpwent.c).  Note that it uses
36  * the same nsswitch.conf entry, not a separate entry for "shadow_compat".
37  *
38  * Caveats:
39  *    -	More than one source may be specified, with the usual switch semantics,
40  *	but having multiple sources here is definitely odd.
41  *    -	People who recursively specify "compat" deserve what they get.
42  *    -	Entries that begin with "+@" or "-@" are interpreted using
43  *	getnetgrent() and innetgr(), which use the "netgroup" entry in
44  *	/etc/nsswitch.conf.  If the sources for "passwd_compat" and "netgroup"
45  *	differ, everything should work fine, but the semantics will be pretty
46  *	confusing.
47  */
48 
49 #include <shadow.h>
50 #include <string.h>
51 #include <stdlib.h>
52 #include "compat_common.h"
53 
54 static DEFINE_NSS_DB_ROOT(db_root);
55 
56 static void
_nss_initf_shadow_compat(p)57 _nss_initf_shadow_compat(p)
58 	nss_db_params_t	*p;
59 {
60 	p->name		  = NSS_DBNAM_SHADOW;
61 	p->config_name	  = NSS_DBNAM_PASSWD_COMPAT;
62 	p->default_config = NSS_DEFCONF_PASSWD_COMPAT;
63 }
64 
65 static const char *
get_spnamp(argp)66 get_spnamp(argp)
67 	nss_XbyY_args_t		*argp;
68 {
69 	struct spwd		*s = (struct spwd *)argp->returnval;
70 
71 	return (s->sp_namp);
72 }
73 
74 static int
check_spnamp(argp)75 check_spnamp(argp)
76 	nss_XbyY_args_t		*argp;
77 {
78 	struct spwd		*s = (struct spwd *)argp->returnval;
79 
80 	return (strcmp(s->sp_namp, argp->key.name) == 0);
81 }
82 
83 static nss_status_t
getbyname(be,a)84 getbyname(be, a)
85 	compat_backend_ptr_t	be;
86 	void			*a;
87 {
88 	nss_XbyY_args_t		*argp = (nss_XbyY_args_t *)a;
89 
90 	return (_nss_compat_XY_all(be, argp, check_spnamp,
91 				NSS_DBOP_SHADOW_BYNAME));
92 }
93 
94 /*ARGSUSED*/
95 static int
merge_spents(be,argp,fields)96 merge_spents(be, argp, fields)
97 	compat_backend_ptr_t	be;
98 	nss_XbyY_args_t		*argp;
99 	const char		**fields;
100 {
101 	struct spwd		*sp	= (struct spwd *)argp->buf.result;
102 
103 	/*
104 	 * Don't allow overriding of the username;  apart from that,
105 	 *   anything is fair game.
106 	 */
107 
108 	if (fields[1] != 0) {
109 		size_t	namelen = strlen(sp->sp_namp) + 1;
110 		size_t	passlen = strlen(fields[1])   + 1;
111 
112 		/* ===> Probably merits an explanation... */
113 		if (namelen + passlen > argp->buf.buflen) {
114 			return (NSS_STR_PARSE_ERANGE);
115 		}
116 		if (sp->sp_namp != argp->buf.buffer) {
117 			(void) memmove(argp->buf.buffer,
118 				sp->sp_namp, namelen);
119 			sp->sp_namp = argp->buf.buffer;
120 		}
121 		(void) memcpy(argp->buf.buffer + namelen,
122 			fields[1], passlen);
123 	}
124 
125 #define	override(field, longp)				\
126 	if ((field) != 0) {				\
127 		char	*end;				\
128 		long	val = strtol(field, &end, 10);	\
129 							\
130 		if (*end == '\0') {			\
131 			*(longp) = val;			\
132 		} else {				\
133 			return (NSS_STR_PARSE_PARSE);	\
134 		}					\
135 	}
136 
137 	/* do not override last changed date, it never gets reset. */
138 	/* override(fields[2], &sp->sp_lstchg); */
139 	override(fields[3], &sp->sp_min);
140 	override(fields[4], &sp->sp_max);
141 	override(fields[5], &sp->sp_warn);
142 	override(fields[6], &sp->sp_inact);
143 	override(fields[7], &sp->sp_expire);
144 	override(fields[8], &sp->sp_flag);
145 
146 	/*
147 	 * if asked, return the data in /etc file format
148 	 */
149 	if (be->return_string_data == 1) {
150 		int	n;
151 		char	b[16 * 7];
152 
153 		/* reset the result ptr to the original value */
154 		argp->buf.result = NULL;
155 
156 #define	printnum(i, num)	\
157     sprintf(b + (i * 16), "%d", num)) ? b + (i * 16) : ""
158 
159 		n = snprintf(argp->buf.buffer, argp->buf.buflen,
160 			"%s:%s:%s:%s:%s:%s:%s:%s:%s", sp->sp_namp,
161 			(sp->sp_pwdp ? sp->sp_pwdp : ""),
162 			(sp->sp_lstchg >= 0 && printnum(0, sp->sp_lstchg),
163 			(sp->sp_min >= 0 && printnum(1, sp->sp_min),
164 			(sp->sp_max >= 0 && printnum(2, sp->sp_max),
165 			(sp->sp_warn > 0 && printnum(3, sp->sp_warn),
166 			(sp->sp_inact > 0 && printnum(4, sp->sp_inact),
167 			(sp->sp_expire > 0 && printnum(5, sp->sp_expire),
168 			(sp->sp_flag != 0 && printnum(6, sp->sp_flag));
169 
170 		if (n > argp->buf.buflen)
171 			return (NSS_STR_PARSE_ERANGE);
172 		else {
173 			argp->returnlen = n - 1;
174 			return (NSS_SUCCESS);
175 		}
176 
177 	} else
178 		return (NSS_STR_PARSE_SUCCESS);
179 }
180 
181 static compat_backend_op_t shadow_ops[] = {
182 	_nss_compat_destr,
183 	_nss_compat_endent,
184 	_nss_compat_setent,
185 	_nss_compat_getent,
186 	getbyname
187 };
188 
189 /*ARGSUSED*/
190 nss_backend_t *
191 _nss_compat_shadow_constr(dummy1, dummy2, dummy3)
192 	const char	*dummy1, *dummy2, *dummy3;
193 {
194 	return (_nss_compat_constr(shadow_ops,
195 				sizeof (shadow_ops) / sizeof (shadow_ops[0]),
196 				SHADOW,
197 				NSS_LINELEN_SHADOW,
198 				&db_root,
199 				_nss_initf_shadow_compat,
200 				1,
201 				get_spnamp,
202 				merge_spents));
203 }
204