xref: /netbsd-src/lib/libc/net/nsdispatch.c (revision 21e37cc72a480a47828990a439cde7ac9ffaf0c6)
1 /*	$NetBSD: nsdispatch.c,v 1.20 2004/05/24 16:16:26 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Luke Mewburn.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #if defined(LIBC_SCCS) && !defined(lint)
41 __RCSID("$NetBSD: nsdispatch.c,v 1.20 2004/05/24 16:16:26 christos Exp $");
42 #endif /* LIBC_SCCS and not lint */
43 
44 #include "namespace.h"
45 
46 #include <sys/types.h>
47 #include <sys/param.h>
48 #include <sys/stat.h>
49 
50 #include <assert.h>
51 #include <err.h>
52 #include <fcntl.h>
53 #define _NS_PRIVATE
54 #include <nsswitch.h>
55 #include <stdarg.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <unistd.h>
60 #include <threadlib.h>
61 
62 extern	FILE 	*_nsyyin;
63 extern	int	 _nsyyparse __P((void));
64 
65 
66 #ifdef __weak_alias
67 __weak_alias(nsdispatch,_nsdispatch)
68 #endif
69 
70 
71 /*
72  * default sourcelist: `files'
73  */
74 const ns_src __nsdefaultsrc[] = {
75 	{ NSSRC_FILES, NS_SUCCESS },
76 	{ 0 },
77 };
78 
79 
80 static	int			 _nsmapsize = 0;
81 static	ns_dbt			*_nsmap = NULL;
82 #ifdef _REENTRANT
83 static 	mutex_t			 _nsmutex = MUTEX_INITIALIZER;
84 #define NSLOCK()		mutex_lock(&_nsmutex)
85 #define NSUNLOCK()		mutex_unlock(&_nsmutex)
86 #else
87 #define NSLOCK()
88 #define NSUNLOCK()
89 #endif
90 
91 
92 /*
93  * size of dynamic array chunk for _nsmap and _nsmap[x].srclist
94  */
95 #define NSELEMSPERCHUNK		8
96 
97 
98 int	_nscmp __P((const void *, const void *));
99 
100 
101 int
102 _nscmp(a, b)
103 	const void *a;
104 	const void *b;
105 {
106 	return (strcasecmp(((const ns_dbt *)a)->name,
107 	    ((const ns_dbt *)b)->name));
108 }
109 
110 
111 int
112 _nsdbtaddsrc(dbt, src)
113 	ns_dbt		*dbt;
114 	const ns_src	*src;
115 {
116 
117 	_DIAGASSERT(dbt != NULL);
118 	_DIAGASSERT(src != NULL);
119 
120 	if ((dbt->srclistsize % NSELEMSPERCHUNK) == 0) {
121 		ns_src *new;
122 
123 		new = (ns_src *)realloc(dbt->srclist,
124 		    (dbt->srclistsize + NSELEMSPERCHUNK) * sizeof(ns_src));
125 		if (new == NULL)
126 			return (-1);
127 		dbt->srclist = new;
128 	}
129 	memmove(&dbt->srclist[dbt->srclistsize++], src, sizeof(ns_src));
130 	return (0);
131 }
132 
133 
134 void
135 _nsdbtdump(dbt)
136 	const ns_dbt *dbt;
137 {
138 	int i;
139 
140 	_DIAGASSERT(dbt != NULL);
141 
142 	printf("%s (%d source%s):", dbt->name, dbt->srclistsize,
143 	    dbt->srclistsize == 1 ? "" : "s");
144 	for (i = 0; i < dbt->srclistsize; i++) {
145 		printf(" %s", dbt->srclist[i].name);
146 		if (!(dbt->srclist[i].flags &
147 		    (NS_UNAVAIL|NS_NOTFOUND|NS_TRYAGAIN)) &&
148 		    (dbt->srclist[i].flags & NS_SUCCESS))
149 			continue;
150 		printf(" [");
151 		if (!(dbt->srclist[i].flags & NS_SUCCESS))
152 			printf(" SUCCESS=continue");
153 		if (dbt->srclist[i].flags & NS_UNAVAIL)
154 			printf(" UNAVAIL=return");
155 		if (dbt->srclist[i].flags & NS_NOTFOUND)
156 			printf(" NOTFOUND=return");
157 		if (dbt->srclist[i].flags & NS_TRYAGAIN)
158 			printf(" TRYAGAIN=return");
159 		printf(" ]");
160 	}
161 	printf("\n");
162 }
163 
164 
165 const ns_dbt *
166 _nsdbtget(name)
167 	const char	*name;
168 {
169 	static	time_t	 confmod;
170 
171 	struct stat	 statbuf;
172 	ns_dbt		 dbt;
173 
174 	_DIAGASSERT(name != NULL);
175 
176 	dbt.name = name;
177 
178 	NSLOCK();
179 	if (stat(_PATH_NS_CONF, &statbuf) == -1)
180 		return (NULL);
181 	if (confmod) {
182 		if (confmod < statbuf.st_mtime) {
183 			int i, j;
184 
185 			for (i = 0; i < _nsmapsize; i++) {
186 				for (j = 0; j < _nsmap[i].srclistsize; j++) {
187 					if (_nsmap[i].srclist[j].name != NULL) {
188 						/*LINTED const cast*/
189 						free((void *)
190 						    _nsmap[i].srclist[j].name);
191 					}
192 				}
193 				if (_nsmap[i].srclist)
194 					free(_nsmap[i].srclist);
195 				if (_nsmap[i].name) {
196 					/*LINTED const cast*/
197 					free((void *)_nsmap[i].name);
198 				}
199 			}
200 			if (_nsmap)
201 				free(_nsmap);
202 			_nsmap = NULL;
203 			_nsmapsize = 0;
204 			confmod = 0;
205 		}
206 	}
207 	if (!confmod) {
208 		_nsyyin = fopen(_PATH_NS_CONF, "r");
209 		if (_nsyyin == NULL) {
210 			NSUNLOCK();
211 			return (NULL);
212 		}
213 		_nsyyparse();
214 		(void)fclose(_nsyyin);
215 		qsort(_nsmap, (size_t)_nsmapsize, sizeof(ns_dbt), _nscmp);
216 		confmod = statbuf.st_mtime;
217 	}
218 	NSUNLOCK();
219 	return (bsearch(&dbt, _nsmap, (size_t)_nsmapsize, sizeof(ns_dbt),
220 	    _nscmp));
221 }
222 
223 
224 int
225 _nsdbtput(dbt)
226 	const ns_dbt *dbt;
227 {
228 	int	i;
229 
230 	_DIAGASSERT(dbt != NULL);
231 
232 	for (i = 0; i < _nsmapsize; i++) {
233 		if (_nscmp(dbt, &_nsmap[i]) == 0) {
234 					/* overwrite existing entry */
235 			if (_nsmap[i].srclist != NULL)
236 				free(_nsmap[i].srclist);
237 			memmove(&_nsmap[i], dbt, sizeof(ns_dbt));
238 			return (0);
239 		}
240 	}
241 
242 	if ((_nsmapsize % NSELEMSPERCHUNK) == 0) {
243 		ns_dbt *new;
244 
245 		new = (ns_dbt *)realloc(_nsmap,
246 		    (_nsmapsize + NSELEMSPERCHUNK) * sizeof(ns_dbt));
247 		if (new == NULL)
248 			return (-1);
249 		_nsmap = new;
250 	}
251 	memmove(&_nsmap[_nsmapsize++], dbt, sizeof(ns_dbt));
252 	return (0);
253 }
254 
255 
256 int
257 /*ARGSUSED*/
258 nsdispatch(void *retval, const ns_dtab disp_tab[], const char *database,
259 	    const char *method, const ns_src defaults[], ...)
260 {
261 	va_list		 ap;
262 	int		 i, curdisp, result;
263 	const ns_dbt	*dbt;
264 	const ns_src	*srclist;
265 	int		 srclistsize;
266 
267 	_DIAGASSERT(database != NULL);
268 	_DIAGASSERT(method != NULL);
269 	if (database == NULL || method == NULL)
270 		return (NS_UNAVAIL);
271 
272 	dbt = _nsdbtget(database);
273 	if (dbt != NULL) {
274 		srclist = dbt->srclist;
275 		srclistsize = dbt->srclistsize;
276 	} else {
277 		srclist = defaults;
278 		srclistsize = 0;
279 		while (srclist[srclistsize].name != NULL)
280 			srclistsize++;
281 	}
282 	result = 0;
283 
284 	for (i = 0; i < srclistsize; i++) {
285 		for (curdisp = 0; disp_tab[curdisp].src != NULL; curdisp++)
286 			if (strcasecmp(disp_tab[curdisp].src,
287 			    srclist[i].name) == 0)
288 				break;
289 		result = 0;
290 		if (disp_tab[curdisp].callback) {
291 			va_start(ap, defaults);
292 			result = disp_tab[curdisp].callback(retval,
293 			    disp_tab[curdisp].cb_data, ap);
294 			va_end(ap);
295 			if (result & srclist[i].flags) {
296 				break;
297 			}
298 		}
299 	}
300 	return (result ? result : NS_NOTFOUND);
301 }
302