yp_dblookup.c revision 12997
1/* 2 * Copyright (c) 1995 3 * Bill Paul <wpaul@ctr.columbia.edu>. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by Bill Paul. 16 * 4. Neither the name of the author nor the names of any co-contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * $Id: yp_dblookup.c,v 1.1.1.1 1995/12/16 20:54:17 wpaul Exp $ 33 * 34 */ 35#include <stdio.h> 36#include <stdlib.h> 37#include <fcntl.h> 38#include <string.h> 39#include <limits.h> 40#include <unistd.h> 41#include <db.h> 42#include <sys/stat.h> 43#include <errno.h> 44#include <paths.h> 45#include "yp.h" 46#include "yp_extern.h" 47 48int ypdb_debug = 0; 49int yp_errno = YP_TRUE; 50 51#define PERM_SECURE (S_IRUSR|S_IWUSR) 52HASHINFO openinfo = { 53 4096, /* bsize */ 54 32, /* ffactor */ 55 256, /* nelem */ 56 2048 * 1024, /* cachesize */ 57 NULL, /* hash */ 58 0, /* lorder */ 59}; 60 61/* 62 * Open a DB database 63 */ 64DB *yp_open_db(domain, map) 65 const char *domain; 66 const char *map; 67{ 68 DB *dbp; 69 char buf[1025]; 70 71 72 yp_errno = YP_TRUE; 73 74 if (map[0] == '.' || strchr(map, '/')) { 75 yp_errno = YP_BADARGS; 76 return (NULL); 77 } 78 79 snprintf(buf, sizeof(buf), "%s/%s/%s", yp_dir, domain, map); 80 81 dbp = dbopen(buf,O_RDONLY|O_EXCL, PERM_SECURE, DB_HASH, &openinfo); 82 83 if (dbp == NULL) { 84 switch(errno) { 85 case ENOENT: 86 yp_errno = YP_NOMAP; 87 break; 88 case EFTYPE: 89 yp_errno = YP_BADDB; 90 break; 91 default: 92 yp_errno = YP_YPERR; 93 break; 94 } 95 } 96 97 return (dbp); 98} 99 100/* 101 * Database access routines. 102 * 103 * - yp_get_record(): retrieve an arbitrary key/data pair given one key 104 * to match against. 105 * 106 * - yp_first_record(): retrieve first key/data base in a database. 107 * 108 * - yp_next_record(): retrieve key/data pair that sequentially follows 109 * the supplied key value in the database. 110 */ 111 112int yp_get_record(domain,map,key,data,allow) 113 const char *domain; 114 const char *map; 115 const DBT *key; 116 DBT *data; 117 int allow; 118{ 119 DB *dbp; 120 121 if (ypdb_debug) 122 yp_error("Looking up key [%.*s] in map [%s]", 123 key->size, key->data, map); 124 125 /* 126 * Avoid passing back magic "YP_*" entries unless 127 * the caller specifically requested them by setting 128 * the 'allow' flag. 129 */ 130 if (!allow && !strncmp(key->data, "YP_", 3)) 131 return(YP_NOKEY); 132 133 if ((dbp = yp_open_db(domain, map)) == NULL) { 134 return(yp_errno); 135 } 136 137 if ((dbp->get)(dbp,key,data,0)) { 138 (void)(dbp->close)(dbp); 139 return(YP_NOKEY); 140 } 141 142 (void)(dbp->close)(dbp); 143 144 if (ypdb_debug) 145 yp_error("Result of lookup: key: [%.*s] data: [%.*s]", 146 key->size, key->data, data->size, data->data); 147 148 return(YP_TRUE); 149} 150 151int yp_first_record(dbp,key,data) 152 const DB *dbp; 153 DBT *key; 154 DBT *data; 155{ 156 157 if (ypdb_debug) 158 yp_error("Retrieving first key in map."); 159 160 if ((dbp->seq)(dbp,key,data,R_FIRST)) 161 return(YP_BADDB); 162 163 /* Avoid passing back magic "YP_*" records. */ 164 while (!strncmp(key->data, "YP_", 3)) { 165 if ((dbp->seq)(dbp,key,data,R_NEXT)) 166 return(YP_BADDB); 167 } 168 169 if (ypdb_debug) 170 yp_error("Result of lookup: key: [%.*s] data: [%.*s]", 171 key->size, key->data, data->size, data->data); 172 173 return(YP_TRUE); 174} 175 176int yp_next_record(dbp,key,data,all) 177 const DB *dbp; 178 DBT *key; 179 DBT *data; 180 int all; 181{ 182 DBT lkey, ldata; 183 184 if (key == NULL || key->data == NULL) 185 return(yp_first_record(dbp,key,data)); 186 187 if (ypdb_debug) 188 yp_error("Retreiving next key, previous was: [%.*s]", 189 key->size, key->data); 190 191 if (!all) { 192 (dbp->seq)(dbp,&lkey,&ldata,R_FIRST); 193 while(strncmp((char *)key->data,lkey.data,(int)key->size) || 194 key->size != lkey.size) 195 (dbp->seq)(dbp,&lkey,&ldata,R_NEXT); 196 } 197 198 if ((dbp->seq)(dbp,&lkey,&ldata,R_NEXT)) 199 return(YP_NOMORE); 200 201 /* Avoid passing back magic "YP_*" records. */ 202 while (!strncmp(lkey.data, "YP_", 3)) 203 if ((dbp->seq)(dbp,&lkey,&ldata,R_NEXT)) 204 return(YP_NOMORE); 205 206 if ((dbp->get)(dbp,&lkey,&ldata,0)) 207 return(YP_FALSE); 208 209 *key = lkey; 210 *data = ldata; 211 212 if (ypdb_debug) 213 yp_error("Result of lookup: key: [%.*s] data: [%.*s]", 214 key->size, key->data, data->size, data->data); 215 216 return(YP_TRUE); 217} 218