source/smbwrapper/smbw_cache.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    SMB wrapper directory functions
   4    Copyright (C) Tim Potter 2000
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22
  23 /* We cache lists of workgroups, lists of servers in workgroups, and lists
  24    of shares exported by servers. */
  25
  26 #define CACHE_TIMEOUT 30
  27
  28 struct name_list {
  29         struct name_list *prev, *next;
  30         char *name;
  31         uint32 stype;
  32         char *comment;
  33 };
  34
  35 struct cached_names {
  36         struct cached_names *prev, *next;
  37         char *key;
  38         struct name_list *name_list;
  39         time_t cache_timeout;
  40         int result;
  41 };
  42
  43 static struct cached_names *cached_names = NULL;
  44
  45 /* Find a list of cached name for a workgroup, server or share list */
  46
  47 static struct cached_names *find_cached_names(char *key)
  48 {
  49         struct cached_names *tmp;
  50
  51         for (tmp = cached_names; tmp; tmp = tmp->next) {
  52                 if (strequal(tmp->key, key)) {
  53                         return tmp;
  54                 }
  55         }
  56
  57         return NULL;
  58 }
  59
  60 /* Add a name to a list stored in the state variable */
  61
  62 static void add_cached_names(const char *name, uint32 stype,
  63                              const char *comment, void *state)
  64 {
  65         struct name_list **name_list = (struct name_list **)state;
  66         struct name_list *new_name;
  67
  68         new_name = SMB_MALLOC_P(struct name_list);
  69         if (!new_name) return;
  70
  71         ZERO_STRUCTP(new_name);
  72
  73         new_name->name = SMB_STRDUP(name);
  74         new_name->stype = stype;
  75         new_name->comment = SMB_STRDUP(comment);
  76
  77         DLIST_ADD(*name_list, new_name);
  78 }
  79
  80 static void free_name_list(struct name_list *name_list)
  81 {
  82         struct name_list *tmp = name_list;
  83
  84         while(tmp) {
  85                 struct name_list *next;
  86
  87                 next = tmp->next;
  88
  89                 SAFE_FREE(tmp->name);
  90                 SAFE_FREE(tmp->comment);
  91                 SAFE_FREE(tmp);
  92
  93                 tmp = next;
  94         }
  95 }
  96
  97 /* Wrapper for NetServerEnum function */
  98
  99 BOOL smbw_NetServerEnum(struct cli_state *cli, char *workgroup, uint32 stype,
 100                         void (*fn)(const char *, uint32, const char *, void *),
 101                         void *state)
 102 {
 103         struct cached_names *names;
 104         struct name_list *tmp;
 105         time_t now = time(NULL);
 106         char key[PATH_MAX];
 107         BOOL result = True;
 108
 109         slprintf(key, PATH_MAX - 1, "%s/%s#%s", cli->desthost,
 110                  workgroup, (stype == SV_TYPE_DOMAIN_ENUM ? "DOM" : "SRV"));
 111
 112         names = find_cached_names(key);
 113
 114         if (names == NULL || (now - names->cache_timeout) > CACHE_TIMEOUT) {
 115                 struct cached_names *new_names = NULL;
 116
 117                 /* No names cached for this workgroup */
 118
 119                 if (names == NULL) {
 120                         new_names = SMB_MALLOC_P(struct cached_names);
 121
 122                         ZERO_STRUCTP(new_names);
 123                         DLIST_ADD(cached_names, new_names);
 124
 125                 } else {
 126
 127                         /* Dispose of out of date name list */
 128
 129                         free_name_list(names->name_list);
 130                         names->name_list = NULL;
 131
 132                         new_names = names;
 133                 }
 134
 135                 result = cli_NetServerEnum(cli, workgroup, stype,
 136                                            add_cached_names,
 137                                            &new_names->name_list);
 138
 139                 new_names->cache_timeout = now;
 140                 new_names->result = result;
 141                 new_names->key = SMB_STRDUP(key);
 142
 143                 names = new_names;
 144         }
 145
 146         /* Return names by running callback function. */
 147
 148         for (tmp = names->name_list; tmp; tmp = tmp->next)
 149                 fn(tmp->name, stype, tmp->comment, state);
 150
 151         return names->result;
 152 }
 153
 154 /* Wrapper for RNetShareEnum function */
 155
 156 int smbw_RNetShareEnum(struct cli_state *cli,
 157                        void (*fn)(const char *, uint32, const char *, void *),
 158                        void *state)
 159 {
 160         struct cached_names *names;
 161         struct name_list *tmp;
 162         time_t now = time(NULL);
 163         char key[PATH_MAX];
 164
 165         slprintf(key, PATH_MAX - 1, "SHARE/%s", cli->desthost);
 166
 167         names = find_cached_names(key);
 168
 169         if (names == NULL || (now - names->cache_timeout) > CACHE_TIMEOUT) {
 170                 struct cached_names *new_names = NULL;
 171
 172                 /* No names cached for this server */
 173
 174                 if (names == NULL) {
 175                         new_names = SMB_MALLOC_P(struct cached_names);
 176
 177                         ZERO_STRUCTP(new_names);
 178                         DLIST_ADD(cached_names, new_names);
 179
 180                 } else {
 181
 182                         /* Dispose of out of date name list */
 183
 184                         free_name_list(names->name_list);
 185                         names->name_list = NULL;
 186
 187                         new_names = names;
 188                 }
 189
 190                 new_names->result = cli_RNetShareEnum(cli, add_cached_names,
 191                                                       &new_names->name_list);
 192
 193                 new_names->cache_timeout = now;
 194                 new_names->key = SMB_STRDUP(key);
 195
 196                 names = new_names;
 197         }
 198
 199         /* Return names by running callback function. */
 200
 201         for (tmp = names->name_list; tmp; tmp = tmp->next)
 202                 fn(tmp->name, tmp->stype, tmp->comment, state);
 203
 204         return names->result;
 205 }