lib/libc/uuid/uuid_name_lookup.c

   1 /*
   2  * Copyright (c) 2007 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/lib/libc/uuid/uuid_name_lookup.c,v 1.4 2007/06/17 07:56:58 dillon Exp $
  35  */
  36 /*
  37  * Implement UUID-to-NAME and NAME-to-UUID functions
  38  */
  39
  40 #include <sys/types.h>
  41 #include <sys/tree.h>
  42 #include <uuid.h>
  43 #include <errno.h>
  44 #include <string.h>
  45 #include <stdio.h>
  46
  47 /*
  48  * Implement a Red-Black tree to cache the UUID table and perform lookups
  49  */
  50 struct uuid_rbnode {
  51         RB_ENTRY(uuid_rbnode) unode;
  52         RB_ENTRY(uuid_rbnode) nnode;
  53         struct uuid uuid;
  54         char *name;
  55 };
  56
  57 static void uuid_loadcache(const char *path);
  58
  59 static int uuid_name_loaded;
  60
  61 RB_HEAD(uuid_urbtree, uuid_rbnode);
  62 RB_STATIC_PROTOTYPE(uuid_urbtree, uuid_rbnode, unode, uuid_urbcmp);
  63 static struct uuid_urbtree uuid_urbroot = RB_INITIALIZER(uuid_urbroot);
  64
  65 RB_HEAD(uuid_nrbtree, uuid_rbnode);
  66 RB_STATIC_PROTOTYPE(uuid_nrbtree, uuid_rbnode, nnode, uuid_nrbcmp);
  67 static struct uuid_nrbtree uuid_nrbroot = RB_INITIALIZER(uuid_nrbroot);
  68
  69 static int
  70 uuid_urbcmp(struct uuid_rbnode *n1, struct uuid_rbnode *n2)
  71 {
  72         return(uuid_compare(&n1->uuid, &n2->uuid, NULL));
  73 }
  74
  75 static int
  76 uuid_nrbcmp(struct uuid_rbnode *n1, struct uuid_rbnode *n2)
  77 {
  78         return(strcasecmp(n1->name, n2->name));
  79 }
  80
  81 static int
  82 uuid_rbnamecmp(const char *name, struct uuid_rbnode *node)
  83 {
  84         return (strcasecmp(name, node->name));
  85 }
  86
  87 static int
  88 uuid_rbuuidcmp(const struct uuid *uuid, struct uuid_rbnode *node)
  89 {
  90         return(uuid_compare(uuid, &node->uuid, NULL));
  91 }
  92
  93 RB_STATIC_GENERATE(uuid_urbtree, uuid_rbnode, unode, uuid_urbcmp)
  94 RB_STATIC_GENERATE(uuid_nrbtree, uuid_rbnode, nnode, uuid_nrbcmp)
  95 RB_STATIC_GENERATE_XLOOKUP(uuid_urbtree, UUID, uuid_rbnode, unode,
  96                            uuid_rbuuidcmp, const struct uuid *)
  97 RB_STATIC_GENERATE_XLOOKUP(uuid_nrbtree, NAME, uuid_rbnode, nnode,
  98                            uuid_rbnamecmp, const char *)
  99
 100
 101 /*
 102  * Look up a UUID by its address.  Returns 0 on success or an error
 103  */
 104 void
 105 uuid_addr_lookup(const uuid_t *u, char **strp, uint32_t *status)
 106 {
 107         struct uuid_rbnode *node;
 108
 109         if (*strp) {
 110                 free(*strp);
 111                 *strp = NULL;
 112         }
 113         if (u) {
 114                 if (uuid_name_loaded == 0) {
 115                         /*
 116                          * /etc/uuids will override /etc/defaults/uuids
 117                          */
 118                         uuid_loadcache("/etc/uuids");
 119                         uuid_loadcache("/etc/defaults/uuids");
 120                         uuid_name_loaded = 1;
 121                 }
 122                 node = uuid_urbtree_RB_LOOKUP_UUID(&uuid_urbroot, u);
 123                 if (node) {
 124                         *strp = strdup(node->name);
 125                         if (status)
 126                                 *status = uuid_s_ok;
 127                         return;
 128                 }
 129         }
 130         if (status)
 131                 *status = uuid_s_not_found;
 132 }
 133
 134 /*
 135  * Look up a UUID by its name.  Returns 0 on success or an error.
 136  */
 137 void
 138 uuid_name_lookup(uuid_t *u, const char *name, uint32_t *status)
 139 {
 140         struct uuid_rbnode *node;
 141
 142         if (name) {
 143                 if (uuid_name_loaded == 0) {
 144                         uuid_loadcache("/etc/uuids");
 145                         uuid_loadcache("/etc/defaults/uuids");
 146                         uuid_name_loaded = 1;
 147                 }
 148                 node = uuid_nrbtree_RB_LOOKUP_NAME(&uuid_nrbroot, name);
 149                 if (node) {
 150                         if (u)
 151                                 *u = node->uuid;
 152                         if (status)
 153                                 *status = uuid_s_ok;
 154                         return;
 155                 }
 156         }
 157         if (u)
 158                 bzero(u, sizeof(*u));
 159         if (status)
 160                 *status = uuid_s_not_found;
 161 }
 162
 163 /*
 164  * Clear out the lookup cache.  The next lookup will reload the database
 165  * or re-query or whatever.
 166  */
 167 static
 168 int
 169 uuid_freenode(struct uuid_rbnode *node, void *arg __unused)
 170 {
 171         uuid_urbtree_RB_REMOVE(&uuid_urbroot, node);
 172         uuid_nrbtree_RB_REMOVE(&uuid_nrbroot, node);
 173         free(node->name);
 174         free(node);
 175 }
 176
 177 void
 178 uuid_reset_lookup(void)
 179 {
 180         uuid_urbtree_RB_SCAN(&uuid_urbroot, NULL, uuid_freenode, NULL);
 181         uuid_name_loaded = 0;
 182 }
 183
 184 static
 185 void
 186 uuid_loadcache(const char *path)
 187 {
 188         struct uuid_rbnode *node;
 189         uint32_t status;
 190         FILE *fp;
 191         char *line;
 192         char *uuid;
 193         char *name;
 194         char *last;
 195         size_t len;
 196
 197         if ((fp = fopen(path, "r")) == NULL)
 198                 return;
 199         while ((line = fgetln(fp, &len)) != NULL) {
 200                 if (len == 0 || *line == '#')
 201                         continue;
 202                 line[len-1] = 0;
 203                 uuid = strtok_r(line, " \t\r", &last);
 204                 if (uuid == NULL)
 205                         continue;
 206                 name = strtok_r(NULL, "", &last);
 207                 name = strchr(name, '"');
 208                 if (name == NULL)
 209                         continue;
 210                 *name++ = 0;
 211                 if (strchr(name, '"') == NULL)
 212                         continue;
 213                 *strchr(name, '"') = 0;
 214                 node = malloc(sizeof(*node));
 215                 node->name = strdup(name);
 216                 uuid_from_string(uuid, &node->uuid, &status);
 217                 if (status == 0) {
 218                         if (uuid_urbtree_RB_FIND(&uuid_urbroot, node) ||
 219                             uuid_nrbtree_RB_FIND(&uuid_nrbroot, node))
 220                                 status = 1;
 221                 }
 222                 if (status == 0) {
 223                         uuid_urbtree_RB_INSERT(&uuid_urbroot, node);
 224                         uuid_nrbtree_RB_INSERT(&uuid_nrbroot, node);
 225                 } else {
 226                         free(node);
 227                         free(node->name);
 228                 }
 229         }
 230         fclose(fp);
 231 }
 232
 233