source3/smbwrapper/smbw_cache.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 2.0
   4    SMB wrapper directory functions
   5    Copyright (C) Tim Potter 2000
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23
  24 /* We cache lists of workgroups, lists of servers in workgroups, and lists
  25    of shares exported by servers. */
  26
  27 #define CACHE_TIMEOUT 30
  28
  29 struct name_list {
  30         struct name_list *prev, *next;
  31         char *name;
  32         uint32 stype;
  33         char *comment;
  34 };
  35
  36 struct cached_names {
  37         struct cached_names *prev, *next;
  38         char *key;
  39         struct name_list *name_list;
  40         time_t cache_timeout;
  41         int result;
  42 };
  43
  44 static struct cached_names *cached_names = NULL;
  45
  46 /* Find a list of cached name for a workgroup, server or share list */
  47
  48 static struct cached_names *find_cached_names(char *key)
  49 {
  50         struct cached_names *tmp;
  51
  52         for (tmp = cached_names; tmp; tmp = tmp->next) {
  53                 if (strequal(tmp->key, key)) {
  54                         return tmp;
  55                 }
  56         }
  57
  58         return NULL;
  59 }
  60
  61 /* Add a name to a list stored in the state variable */
  62
  63 static void add_cached_names(const char *name, uint32 stype,
  64                              const char *comment, void *state)
  65 {
  66         struct name_list **name_list = (struct name_list **)state;
  67         struct name_list *new_name;
  68
  69         new_name = (struct name_list *)malloc(sizeof(struct name_list));
  70         if (!new_name) return;
  71
  72         ZERO_STRUCTP(new_name);
  73
  74         new_name->name = strdup(name);
  75         new_name->stype = stype;
  76         new_name->comment = strdup(comment);
  77
  78         DLIST_ADD(*name_list, new_name);
  79 }
  80
  81 static void free_name_list(struct name_list *name_list)
  82 {
  83         struct name_list *tmp = name_list;
  84
  85         while(tmp) {
  86                 struct name_list *next;
  87
  88                 next = tmp->next;
  89
  90                 SAFE_FREE(tmp->name);
  91                 SAFE_FREE(tmp->comment);
  92                 SAFE_FREE(tmp);
  93
  94                 tmp = next;
  95         }
  96 }
  97
  98 /* Wrapper for NetServerEnum function */
  99
 100 BOOL smbw_NetServerEnum(struct cli_state *cli, char *workgroup, uint32 stype,
 101                         void (*fn)(const char *, uint32, const char *, void *),
 102                         void *state)
 103 {
 104         struct cached_names *names;
 105         struct name_list *tmp;
 106         time_t now = time(NULL);
 107         char key[PATH_MAX];
 108         BOOL result = True;
 109
 110         slprintf(key, PATH_MAX - 1, "%s/%s#%s", cli->desthost,
 111                  workgroup, (stype == SV_TYPE_DOMAIN_ENUM ? "DOM" : "SRV"));
 112
 113         names = find_cached_names(key);
 114
 115         if (names == NULL || (now - names->cache_timeout) > CACHE_TIMEOUT) {
 116                 struct cached_names *new_names = NULL;
 117
 118                 /* No names cached for this workgroup */
 119
 120                 if (names == NULL) {
 121                         new_names = (struct cached_names *)
 122                                 malloc(sizeof(struct cached_names));
 123
 124                         ZERO_STRUCTP(new_names);
 125                         DLIST_ADD(cached_names, new_names);
 126
 127                 } else {
 128
 129                         /* Dispose of out of date name list */
 130
 131                         free_name_list(names->name_list);
 132                         names->name_list = NULL;
 133
 134                         new_names = names;
 135                 }
 136
 137                 result = cli_NetServerEnum(cli, workgroup, stype,
 138                                            add_cached_names,
 139                                            &new_names->name_list);
 140
 141                 new_names->cache_timeout = now;
 142                 new_names->result = result;
 143                 new_names->key = strdup(key);
 144
 145                 names = new_names;
 146         }
 147
 148         /* Return names by running callback function. */
 149
 150         for (tmp = names->name_list; tmp; tmp = tmp->next)
 151                 fn(tmp->name, stype, tmp->comment, state);
 152
 153         return names->result;
 154 }
 155
 156 /* Wrapper for RNetShareEnum function */
 157
 158 int smbw_RNetShareEnum(struct cli_state *cli,
 159                        void (*fn)(const char *, uint32, const char *, void *),
 160                        void *state)
 161 {
 162         struct cached_names *names;
 163         struct name_list *tmp;
 164         time_t now = time(NULL);
 165         char key[PATH_MAX];
 166
 167         slprintf(key, PATH_MAX - 1, "SHARE/%s", cli->desthost);
 168
 169         names = find_cached_names(key);
 170
 171         if (names == NULL || (now - names->cache_timeout) > CACHE_TIMEOUT) {
 172                 struct cached_names *new_names = NULL;
 173
 174                 /* No names cached for this server */
 175
 176                 if (names == NULL) {
 177                         new_names = (struct cached_names *)
 178                                 malloc(sizeof(struct cached_names));
 179
 180                         ZERO_STRUCTP(new_names);
 181                         DLIST_ADD(cached_names, new_names);
 182
 183                 } else {
 184
 185                         /* Dispose of out of date name list */
 186
 187                         free_name_list(names->name_list);
 188                         names->name_list = NULL;
 189
 190                         new_names = names;
 191                 }
 192
 193                 new_names->result = cli_RNetShareEnum(cli, add_cached_names,
 194                                                       &new_names->name_list);
 195
 196                 new_names->cache_timeout = now;
 197                 new_names->key = strdup(key);
 198
 199                 names = new_names;
 200         }
 201
 202         /* Return names by running callback function. */
 203
 204         for (tmp = names->name_list; tmp; tmp = tmp->next)
 205                 fn(tmp->name, tmp->stype, tmp->comment, state);
 206
 207         return names->result;
 208 }