xref: /titanic_51/usr/src/lib/libc/port/gen/getnetgrent.c (revision c81d47afd05baeb768e2f032636019b717899efd)
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 
26 #pragma ident	"%Z%%M%	%I%	%E% SMI"
27 
28 /*
29  * getnetgrent.c
30  *
31  *	- name-service switch frontend routines for the netgroup API.
32  *
33  * Policy decision:
34  *	If netgroup A refers to netgroup B, both must occur in the same
35  *	source (any other choice gives very confusing semantics).  This
36  *	assumption is deeply embedded in the code below and in the backends.
37  *
38  * innetgr() is implemented on top of something called __multi_innetgr(),
39  * which replaces each (char *) argument of innetgr() with a counted vector
40  * of (char *).  The semantics are the same as an OR of the results of
41  * innetgr() operations on each possible 4-tuple picked from the arguments,
42  * but it's possible to implement some cases more efficiently.  This is
43  * important for mountd, which used to read YP netgroup.byhost directly in
44  * order to determine efficiently whether a given host belonged to any one
45  * of a long list of netgroups.  Wildcarded arguments are indicated by a
46  * count of zero.
47  */
48 
49 #include "synonyms.h"
50 #include <string.h>
51 #include <synch.h>
52 #include <nss_dbdefs.h>
53 #include <mtlib.h>
54 #include <libc.h>
55 
56 static DEFINE_NSS_DB_ROOT(db_root);
57 
58 void
59 _nss_initf_netgroup(p)
60 	nss_db_params_t	*p;
61 {
62 	p->name	= NSS_DBNAM_NETGROUP;
63 	p->default_config = NSS_DEFCONF_NETGROUP;
64 }
65 
66 /*
67  * The netgroup routines aren't quite like the majority of the switch clients.
68  *   innetgr() more-or-less fits the getXXXbyYYY mould, but for the others:
69  *	- setnetgrent("netgroup") is really a getXXXbyYYY routine, i.e. it
70  *	  searches the sources until it finds an entry with the given name.
71  *	  Rather than returning the (potentially large) entry, it simply
72  *	  initializes a cursor, and then...
73  *      - getnetgrent(...) is repeatedly invoked by the user to extract the
74  *	  contents of the entry found by setnetgrent().
75  *	- endnetgrent() is almost like a real endXXXent routine.
76  * The behaviour in NSS was:
77  *  If we were certain that all the backends could provide netgroup information
78  *  in a common form, we could make the setnetgrent() backend return the entire
79  *  entry to the frontend, then implement getnetgrent() and endnetgrent()
80  *  strictly in the frontend (aka here).  But we're not certain, so we won't.
81  * In NSS2:
82  *  Since nscd returns the results, and it is nscd that accumulates
83  *  the results, then we can return the entire result on the setnetgrent.
84  *
85  * NOTE:
86  *	In the SunOS 4.x (YP) version of this code, innetgr() did not
87  *	affect the state of {set,get,end}netgrent().  Somewhere out
88  *	there probably lurks a program that depends on this behaviour,
89  *	so this version (both frontend and backends) had better
90  *	behave the same way.
91  */
92 
93 /* ===> ?? fix "__" name */
94 int
95 __multi_innetgr(ngroup,	pgroup,
96 		nhost,	phost,
97 		nuser,	puser,
98 		ndomain, pdomain)
99 	nss_innetgr_argc	ngroup, nhost, nuser, ndomain;
100 	nss_innetgr_argv	pgroup, phost, puser, pdomain;
101 {
102 	struct nss_innetgr_args	ia;
103 
104 	if (ngroup == 0) {
105 		return (0);	/* One thing fewer to worry backends */
106 	}
107 
108 	ia.groups.argc			= ngroup;
109 	ia.groups.argv			= pgroup;
110 	ia.arg[NSS_NETGR_MACHINE].argc	= nhost;
111 	ia.arg[NSS_NETGR_MACHINE].argv	= phost;
112 	ia.arg[NSS_NETGR_USER].argc	= nuser;
113 	ia.arg[NSS_NETGR_USER].argv	= puser;
114 	ia.arg[NSS_NETGR_DOMAIN].argc	= ndomain;
115 	ia.arg[NSS_NETGR_DOMAIN].argv	= pdomain;
116 	ia.status			= NSS_NETGR_NO;
117 
118 	(void) nss_search(&db_root, _nss_initf_netgroup,
119 	    NSS_DBOP_NETGROUP_IN, &ia);
120 	return (ia.status == NSS_NETGR_FOUND);
121 }
122 
123 int
124 innetgr(group, host, user, domain)
125 	const char *group, *host, *user, *domain;
126 {
127 #define	IA(charp)	\
128 	(nss_innetgr_argc)((charp) != 0), (nss_innetgr_argv)(&(charp))
129 
130 	return (__multi_innetgr(IA(group), IA(host), IA(user), IA(domain)));
131 }
132 
133 /*
134  * Context for setnetgrent()/getnetgrent().  If the user is being sensible
135  * the requests will be serialized anyway, but let's play safe and
136  * serialize them ourselves (anything to prevent a coredump)...
137  * We can't use lmutex_lock() here because we don't know what the backends
138  * that we call may call in turn.  They might call malloc()/free().
139  * So we use the brute-force fork_lock_enter() instead.
140  */
141 static nss_backend_t	*getnetgrent_backend;
142 
143 int
144 setnetgrent(const char *netgroup)
145 {
146 	nss_backend_t	*be;
147 
148 	if (netgroup == NULL) {
149 		/* Prevent coredump, otherwise don't do anything profound */
150 		netgroup = "";
151 	}
152 
153 	(void) fork_lock_enter(NULL);
154 	be = getnetgrent_backend;
155 	if (be != NULL && NSS_INVOKE_DBOP(be, NSS_DBOP_SETENT,
156 	    (void *)netgroup) != NSS_SUCCESS) {
157 		(void) NSS_INVOKE_DBOP(be, NSS_DBOP_DESTRUCTOR, 0);
158 		be = NULL;
159 	}
160 	if (be == NULL) {
161 		struct nss_setnetgrent_args	args;
162 
163 		args.netgroup	= netgroup;
164 		args.iterator	= 0;
165 		(void) nss_search(&db_root, _nss_initf_netgroup,
166 		    NSS_DBOP_NETGROUP_SET, &args);
167 		be = args.iterator;
168 	}
169 	getnetgrent_backend = be;
170 	fork_lock_exit();
171 	return (0);
172 }
173 
174 int
175 getnetgrent_r(machinep, namep, domainp, buffer, buflen)
176 	char		**machinep;
177 	char		**namep;
178 	char		**domainp;
179 	char		*buffer;
180 	int		buflen;
181 {
182 	struct nss_getnetgrent_args	args;
183 
184 	args.buffer	= buffer;
185 	args.buflen	= buflen;
186 	args.status	= NSS_NETGR_NO;
187 
188 	(void) fork_lock_enter(NULL);
189 	if (getnetgrent_backend != 0) {
190 		(void) NSS_INVOKE_DBOP(getnetgrent_backend,
191 			NSS_DBOP_GETENT, &args);
192 	}
193 	fork_lock_exit();
194 
195 	if (args.status == NSS_NETGR_FOUND) {
196 		*machinep = args.retp[NSS_NETGR_MACHINE];
197 		*namep	  = args.retp[NSS_NETGR_USER];
198 		*domainp  = args.retp[NSS_NETGR_DOMAIN];
199 		return (1);
200 	} else {
201 		return (0);
202 	}
203 }
204 
205 static nss_XbyY_buf_t *buf;
206 
207 int
208 getnetgrent(machinep, namep, domainp)
209 	char		**machinep;
210 	char		**namep;
211 	char		**domainp;
212 {
213 	(void) NSS_XbyY_ALLOC(&buf, 0, NSS_BUFLEN_NETGROUP);
214 	return (getnetgrent_r(machinep, namep, domainp,
215 	    buf->buffer, buf->buflen));
216 }
217 
218 int
219 endnetgrent()
220 {
221 	(void) fork_lock_enter(NULL);
222 	if (getnetgrent_backend != 0) {
223 		(void) NSS_INVOKE_DBOP(getnetgrent_backend,
224 			NSS_DBOP_DESTRUCTOR, 0);
225 		getnetgrent_backend = 0;
226 	}
227 	fork_lock_exit();
228 	nss_delete(&db_root);	/* === ? */
229 	NSS_XbyY_FREE(&buf);
230 	return (0);
231 }
232