getpwent.c revision 2830:5228d1267a01 
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 2006 Sun Microsystems, Inc.  All rights reserved.
23 * Use is subject to license terms.
24 *
25 *	getpwent.c
26 *
27 * lib/nsswitch/compat/getpwent.c -- name-service-switch backend for getpwnam()
28 *   et al that does 4.x compatibility.  It looks in /etc/passwd; if it finds
29 *   passwd entries there that begin with "+" or "-", it consults other
30 *   services.  By default it uses NIS (YP), but the user can override this
31 *   with a "passwd_compat" entry in /etc/nsswitch.conf, e.g.
32 *			passwd_compat: nisplus
33 *
34 * This code tries to produce the same results as the 4.x code, even when
35 *   the latter seems ill thought-out (mostly in the handling of netgroups,
36 *   "-", and the combination thereof).  Bug-compatible, in other words.
37 *   Though we do try to be more reasonable about the format of "+" and "-"
38 *   entries here, i.e. you don't have to pad them with spurious colons and
39 *   bogus uid/gid values.
40 *
41 * Caveats:
42 *    -	More than one source may be specified, with the usual switch semantics,
43 *	but having multiple sources here is definitely odd.
44 *    -	People who recursively specify "compat" deserve what they get.
45 *    -	Entries that begin with "+@" or "-@" are interpreted using
46 *	getnetgrent() and innetgr(), which use the "netgroup" entry in
47 *	/etc/nsswitch.conf.  If the sources for "passwd_compat" and "netgroup"
48 *	differ, everything should work fine, but the semantics will be pretty
49 *	confusing.
50 */
51
52#pragma ident	"%Z%%M%	%I%	%E% SMI"
53
54#include <pwd.h>
55#include <shadow.h>		/* For PASSWD (pathname to passwd file) */
56#include <stdlib.h>
57#include <strings.h>
58#include "compat_common.h"
59
60static DEFINE_NSS_DB_ROOT(db_root);
61
62static void
63_nss_initf_passwd_compat(p)
64	nss_db_params_t	*p;
65{
66	p->name		  = NSS_DBNAM_PASSWD;
67	p->config_name	  = NSS_DBNAM_PASSWD_COMPAT;
68	p->default_config = NSS_DEFCONF_PASSWD_COMPAT;
69}
70
71static const char *
72get_pwname(argp)
73	nss_XbyY_args_t		*argp;
74{
75	struct passwd		*p = (struct passwd *)argp->returnval;
76
77	return (p->pw_name);
78}
79
80static int
81check_pwname(argp)
82	nss_XbyY_args_t		*argp;
83{
84	struct passwd		*p = (struct passwd *)argp->returnval;
85
86	return (strcmp(p->pw_name, argp->key.name) == 0);
87}
88
89static nss_status_t
90getbyname(be, a)
91	compat_backend_ptr_t	be;
92	void			*a;
93{
94	nss_XbyY_args_t		*argp = (nss_XbyY_args_t *)a;
95
96	return (_nss_compat_XY_all(be, argp,
97				check_pwname, NSS_DBOP_PASSWD_BYNAME));
98}
99
100static int
101check_pwuid(argp)
102	nss_XbyY_args_t		*argp;
103{
104	struct passwd		*p = (struct passwd *)argp->returnval;
105
106	return (p->pw_uid == argp->key.uid);
107}
108
109static nss_status_t
110getbyuid(be, a)
111	compat_backend_ptr_t	be;
112	void			*a;
113{
114	nss_XbyY_args_t		*argp = (nss_XbyY_args_t *)a;
115
116	return (_nss_compat_XY_all(be, argp,
117				check_pwuid, NSS_DBOP_PASSWD_BYUID));
118}
119
120/*ARGSUSED*/
121static int
122merge_pwents(be, argp, fields)
123	compat_backend_ptr_t	be;
124	nss_XbyY_args_t		*argp;
125	const char		**fields;
126{
127	struct passwd		*pw	= (struct passwd *)argp->buf.result;
128	char			*buf	= malloc(NSS_LINELEN_PASSWD);
129	char			*s;
130	int			parsestat;
131	int			len;
132	int			buflen;
133
134	if (buf == 0) {
135		return (NSS_STR_PARSE_PARSE);
136		/* Really "out of memory", but PARSE_PARSE will have to do */
137	}
138	/*
139	 * Don't allow overriding of
140	 *	- username
141	 *	- uid
142	 *	- gid
143	 * That's what the SunOS 4.x code did;  who are we to question it...
144	 */
145	s = buf;
146	buflen = argp->buf.buflen;
147
148	if (fields[1] != 0)
149		len = snprintf(s, buflen, "%s:%s",
150				pw->pw_name, fields[1]);
151	else {
152/* ====> Does this do the right thing? */
153		if (pw->pw_age != 0 && *pw->pw_age != '\0')
154			len = snprintf(s, buflen, "%s:%s,%s",
155				pw->pw_name, pw->pw_passwd, pw->pw_age);
156		else
157			len = snprintf(s, buflen, "%s:%s",
158				pw->pw_name, pw->pw_passwd);
159	}
160
161	if (len > buflen)
162		return (NSS_STR_PARSE_ERANGE);
163
164	s += len;
165	buflen -= len;
166	len = snprintf(s, buflen, ":%ld:%ld:%s:%s:%s",
167		pw->pw_uid,
168		pw->pw_gid,
169		fields[4] != 0 ? fields[4] : pw->pw_gecos,
170		fields[5] != 0 ? fields[5] : pw->pw_dir,
171		fields[6] != 0 ? fields[6] : pw->pw_shell);
172
173	if (len > buflen)
174		return (NSS_STR_PARSE_ERANGE);
175
176	s += len;
177	len = s - buf;
178
179	/*
180	 * if asked, return the data in /etc file format
181	 */
182	if (be->return_string_data == 1) {
183		/* reset the result ptr to the original value */
184		argp->buf.result = NULL;
185
186		if (len > argp->buf.buflen) {
187			parsestat = NSS_STR_PARSE_ERANGE;
188		} else {
189			(void) strncpy(argp->buf.buffer, buf, len);
190			argp->returnval = argp->buf.buffer;
191			argp->returnlen = len;
192			parsestat = NSS_SUCCESS;
193		}
194	} else {
195		parsestat = (*argp->str2ent)(buf, len,
196				    argp->buf.result,
197				    argp->buf.buffer,
198				    argp->buf.buflen);
199	}
200	free(buf);
201	return (parsestat);
202}
203
204static compat_backend_op_t passwd_ops[] = {
205	_nss_compat_destr,
206	_nss_compat_endent,
207	_nss_compat_setent,
208	_nss_compat_getent,
209	getbyname,
210	getbyuid
211};
212
213/*ARGSUSED*/
214nss_backend_t *
215_nss_compat_passwd_constr(dummy1, dummy2, dummy3)
216	const char	*dummy1, *dummy2, *dummy3;
217{
218	return (_nss_compat_constr(passwd_ops,
219				sizeof (passwd_ops) / sizeof (passwd_ops[0]),
220				PASSWD,
221				NSS_LINELEN_PASSWD,
222				&db_root,
223				_nss_initf_passwd_compat,
224				1,
225				get_pwname,
226				merge_pwents));
227}
228