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nsdispatch.c revision 1.2 
      1 /*	$NetBSD: nsdispatch.c,v 1.2 1999/01/15 12:53:24 lukem 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/types.h>
     40 #include <sys/param.h>
     41 #include <sys/stat.h>
     42 
     43 #include <err.h>
     44 #include <fcntl.h>
     45 #define _NS_PRIVATE
     46 #define _PATH_NS_CONF "/tmp/nsswitch.conf"
     47 #include <nsswitch.h>
     48 #include <stdio.h>
     49 #include <stdlib.h>
     50 #include <string.h>
     51 #include <unistd.h>
     52 
     53 
     54 static	int			 _nsmapsize = 0;
     55 static	ns_dbt			*_nsmap = NULL;
     56 
     57 /*
     58  * size of dynamic array chunk for _nsmap and _nsmap[x].srclist
     59  */
     60 #define NSELEMSPERCHUNK		8
     61 
     62 
     63 int	_nscmp __P((const void *, const void *));
     64 
     65 
     66 int
     67 _nscmp(a, b)
     68 	const void *a;
     69 	const void *b;
     70 {
     71 	return (strcasecmp(((ns_dbt *)a)->name, ((ns_dbt *)b)->name));
     72 }
     73 
     74 
     75 void
     76 _nsdbtaddsrc(dbt, src)
     77 	ns_dbt		*dbt;
     78 	const ns_src	*src;
     79 {
     80 	if ((dbt->srclistsize % NSELEMSPERCHUNK) == 0) {
     81 		dbt->srclist = (ns_src *)realloc(dbt->srclist,
     82 		    (dbt->srclistsize + NSELEMSPERCHUNK) * sizeof(ns_src));
     83 		if (dbt->srclist == NULL)
     84 			err(1, "nsdispatch: memory allocation failure");
     85 	}
     86 	memmove((void *)&dbt->srclist[dbt->srclistsize++], (void *)src,
     87 	    sizeof(ns_src));
     88 }
     89 
     90 
     91 void
     92 _nsdbtdump(dbt)
     93 	const ns_dbt *dbt;
     94 {
     95 	int i;
     96 
     97 	printf("%s (%d source%s):", dbt->name, dbt->srclistsize,
     98 	    dbt->srclistsize == 1 ? "" : "s");
     99 	for (i = 0; i < dbt->srclistsize; i++) {
    100 		printf(" %s", dbt->srclist[i].name);
    101 		if (!(dbt->srclist[i].flags &
    102 		    (NS_UNAVAIL|NS_NOTFOUND|NS_TRYAGAIN)) &&
    103 		    (dbt->srclist[i].flags & NS_SUCCESS))
    104 			continue;
    105 		printf(" [");
    106 		if (!(dbt->srclist[i].flags & NS_SUCCESS))
    107 			printf(" SUCCESS=continue");
    108 		if (dbt->srclist[i].flags & NS_UNAVAIL)
    109 			printf(" UNAVAIL=return");
    110 		if (dbt->srclist[i].flags & NS_NOTFOUND)
    111 			printf(" NOTFOUND=return");
    112 		if (dbt->srclist[i].flags & NS_TRYAGAIN)
    113 			printf(" TRYAGAIN=return");
    114 		printf(" ]");
    115 	}
    116 	printf("\n");
    117 }
    118 
    119 
    120 const ns_dbt *
    121 _nsdbtget(name)
    122 	const char	*name;
    123 {
    124 	static	time_t	 confmod;
    125 	static	ns_dbt	 dbt;
    126 
    127 	struct stat	 statbuf;
    128 	ns_dbt		*ndbt;
    129 
    130 	extern	FILE 	*_nsyyin;
    131 	extern	int	 _nsyyparse __P((void));
    132 
    133 	if (dbt.name == NULL) {		/* construct dummy `files' entry */
    134 		ns_src	src;
    135 
    136 		src.name = NSSRC_FILES;
    137 		src.flags = NS_SUCCESS;
    138 		dbt.name = name;
    139 		_nsdbtaddsrc(&dbt, &src);
    140 	}
    141 
    142 	if (confmod) {
    143 		if (stat(_PATH_NS_CONF, &statbuf) == -1)
    144 			return (&dbt);
    145 		if (confmod < statbuf.st_mtime) {
    146 			int i, j;
    147 
    148 			for (i = 0; i < _nsmapsize; i++) {
    149 				for (j = 0; j < _nsmap[i].srclistsize; j++) {
    150 					if (_nsmap[i].srclist[j].name != NULL)
    151 						free((char *)
    152 						    _nsmap[i].srclist[j].name);
    153 				}
    154 				if (_nsmap[i].srclist)
    155 					free(_nsmap[i].srclist);
    156 				if (_nsmap[i].name)
    157 					free((char *)_nsmap[i].name);
    158 			}
    159 			if (_nsmap)
    160 				free(_nsmap);
    161 			_nsmap = NULL;
    162 			_nsmapsize = 0;
    163 			confmod = 0;
    164 		}
    165 	}
    166 	if (!confmod) {
    167 		if (stat(_PATH_NS_CONF, &statbuf) == -1)
    168 			return (&dbt);
    169 		_nsyyin = fopen(_PATH_NS_CONF, "r");
    170 		if (_nsyyin == NULL)
    171 			return (&dbt);
    172 		_nsyyparse();
    173 		(void)fclose(_nsyyin);
    174 		qsort(_nsmap, _nsmapsize, sizeof(ns_dbt), _nscmp);
    175 		confmod = statbuf.st_mtime;
    176 	}
    177 	ndbt = bsearch(&dbt, _nsmap, _nsmapsize, sizeof(ns_dbt), _nscmp);
    178 	if (ndbt != NULL)
    179 		return (ndbt);
    180 	return (&dbt);
    181 }
    182 
    183 
    184 void
    185 _nsdbtput(dbt)
    186 	const ns_dbt *dbt;
    187 {
    188 	int	i;
    189 
    190 	for (i = 0; i < _nsmapsize; i++) {
    191 		if (_nscmp(dbt, &_nsmap[i]) == 0) {
    192 					/* overwrite existing entry */
    193 			if (_nsmap[i].srclist != NULL)
    194 				free(_nsmap[i].srclist);
    195 			memmove((void *)&_nsmap[i], (void *)dbt,
    196 				sizeof(ns_dbt));
    197 			return;
    198 		}
    199 	}
    200 
    201 	if ((_nsmapsize % NSELEMSPERCHUNK) == 0) {
    202 		_nsmap = (ns_dbt *)realloc(_nsmap,
    203 		    (_nsmapsize + NSELEMSPERCHUNK) * sizeof(ns_dbt));
    204 		if (_nsmap == NULL)
    205 			err(1, "nsdispatch: memory allocation failure");
    206 	}
    207 	memmove((void *)&_nsmap[_nsmapsize++], (void *)dbt, sizeof(ns_dbt));
    208 }
    209 
    210 
    211 int
    212 #if __STDC__
    213 nsdispatch(void *retval, const ns_dtab disp_tab[], const char *database, ...)
    214 #else
    215 nsdispatch(retval, disp_tab, database, va_alist)
    216 	void		*retval;
    217 	const ns_dtab	 disp_tab[];
    218 	const char	*database;
    219 	va_dcl
    220 #endif
    221 {
    222 	va_list		 ap;
    223 	int		 i, curdisp, result;
    224 	const ns_dbt	*dbt;
    225 
    226 	dbt = _nsdbtget(database);
    227 	result = 0;
    228 
    229 #if _NS_DEBUG
    230 	_nsdumpdbt(dbt);
    231 	fprintf(stderr, "nsdispatch: %s\n", database);
    232 #endif
    233 	for (i = 0; i < dbt->srclistsize; i++) {
    234 #if _NS_DEBUG
    235 		fprintf(stderr, "    source=%s", dbt->srclist[i]->source);
    236 #endif
    237 		for (curdisp = 0; disp_tab[curdisp].src != NULL; curdisp++)
    238 			if (strcasecmp(disp_tab[curdisp].src,
    239 			    dbt->srclist[i].name) == 0)
    240 				break;
    241 		result = 0;
    242 		if (disp_tab[curdisp].callback) {
    243 #if __STDC__
    244 			va_start(ap, database);
    245 #else
    246 			va_start(ap);
    247 #endif
    248 			result = disp_tab[curdisp].callback(retval,
    249 			    disp_tab[curdisp].cb_data, ap);
    250 			va_end(ap);
    251 #if _NS_DEBUG
    252 			fprintf(stderr, " result=%d (%d)", result,
    253 			    (result & dbt->srclist[i].flags));
    254 #endif
    255 			if (result & dbt->srclist[i].flags) {
    256 #if _NS_DEBUG
    257 				fprintf(stderr, " MATCH!\n");
    258 #endif
    259 				break;
    260 			}
    261 		}
    262 #if _NS_DEBUG
    263 		fprintf(stderr, "\n");
    264 #endif
    265 	}
    266 	return (result ? result : NS_NOTFOUND);
    267 }
    268