source/libsmb/libsmb_cache.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    SMB client library implementation (server cache)
   4    Copyright (C) Andrew Tridgell 1998
   5    Copyright (C) Richard Sharpe 2000
   6    Copyright (C) John Terpstra 2000
   7    Copyright (C) Tom Jansen (Ninja ISD) 2002
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 #include "includes.h"
  25
  26 /*
  27  * Define this to get the real SMBCFILE and SMBCSRV structures
  28  */
  29 #define _SMBC_INTERNAL
  30 #include "include/libsmbclient.h"
  31
  32 /*
  33  * Structure we use if internal caching mechanism is used
  34  * nothing fancy here.
  35  */
  36 struct smbc_server_cache {
  37         char *server_name;
  38         char *share_name;
  39         char *workgroup;
  40         char *username;
  41         SMBCSRV *server;
  42
  43         struct smbc_server_cache *next, *prev;
  44 };
  45
  46
  47
  48 /*
  49  * Add a new connection to the server cache.
  50  * This function is only used if the external cache is not enabled
  51  */
  52 static int smbc_add_cached_server(SMBCCTX * context, SMBCSRV * new,
  53                                   const char * server, const char * share,
  54                                   const char * workgroup, const char * username)
  55 {
  56         struct smbc_server_cache * srvcache = NULL;
  57
  58         if (!(srvcache = SMB_MALLOC_P(struct smbc_server_cache))) {
  59                 errno = ENOMEM;
  60                 DEBUG(3, ("Not enough space for server cache allocation\n"));
  61                 return 1;
  62         }
  63
  64         ZERO_STRUCTP(srvcache);
  65
  66         srvcache->server = new;
  67
  68         srvcache->server_name = SMB_STRDUP(server);
  69         if (!srvcache->server_name) {
  70                 errno = ENOMEM;
  71                 goto failed;
  72         }
  73
  74         srvcache->share_name = SMB_STRDUP(share);
  75         if (!srvcache->share_name) {
  76                 errno = ENOMEM;
  77                 goto failed;
  78         }
  79
  80         srvcache->workgroup = SMB_STRDUP(workgroup);
  81         if (!srvcache->workgroup) {
  82                 errno = ENOMEM;
  83                 goto failed;
  84         }
  85
  86         srvcache->username = SMB_STRDUP(username);
  87         if (!srvcache->username) {
  88                 errno = ENOMEM;
  89                 goto failed;
  90         }
  91
  92         DLIST_ADD((context->server_cache), srvcache);
  93         return 0;
  94
  95  failed:
  96         SAFE_FREE(srvcache->server_name);
  97         SAFE_FREE(srvcache->share_name);
  98         SAFE_FREE(srvcache->workgroup);
  99         SAFE_FREE(srvcache->username);
 100
 101         return 1;
 102 }
 103
 104
 105
 106 /*
 107  * Search the server cache for a server
 108  * returns server_fd on success, -1 on error (not found)
 109  * This function is only used if the external cache is not enabled
 110  */
 111 static SMBCSRV * smbc_get_cached_server(SMBCCTX * context, const char * server,
 112                                   const char * share, const char * workgroup, const char * user)
 113 {
 114         struct smbc_server_cache * srv = NULL;
 115
 116         /* Search the cache lines */
 117         for (srv=((struct smbc_server_cache *)context->server_cache);srv;srv=srv->next) {
 118                 if (strcmp(server,srv->server_name)  == 0 &&
 119                     strcmp(share,srv->share_name)    == 0 &&
 120                     strcmp(workgroup,srv->workgroup) == 0 &&
 121                     strcmp(user, srv->username)  == 0)
 122                         return srv->server;
 123         }
 124
 125         return NULL;
 126 }
 127
 128
 129 /*
 130  * Search the server cache for a server and remove it
 131  * returns 0 on success
 132  * This function is only used if the external cache is not enabled
 133  */
 134 static int smbc_remove_cached_server(SMBCCTX * context, SMBCSRV * server)
 135 {
 136         struct smbc_server_cache * srv = NULL;
 137
 138         for (srv=((struct smbc_server_cache *)context->server_cache);srv;srv=srv->next) {
 139                 if (server == srv->server) {
 140
 141                         /* remove this sucker */
 142                         DLIST_REMOVE(context->server_cache, srv);
 143                         SAFE_FREE(srv->server_name);
 144                         SAFE_FREE(srv->share_name);
 145                         SAFE_FREE(srv->workgroup);
 146                         SAFE_FREE(srv->username);
 147                         SAFE_FREE(srv);
 148                         return 0;
 149                 }
 150         }
 151         /* server not found */
 152         return 1;
 153 }
 154
 155
 156 /*
 157  * Try to remove all the servers in cache
 158  * returns 1 on failure and 0 if all servers could be removed.
 159  */
 160 static int smbc_purge_cached(SMBCCTX * context)
 161 {
 162         struct smbc_server_cache * srv;
 163         struct smbc_server_cache * next;
 164         int could_not_purge_all = 0;
 165
 166         for (srv = ((struct smbc_server_cache *) context->server_cache),
 167                  next = (srv ? srv->next :NULL);
 168              srv;
 169              srv = next, next = (srv ? srv->next : NULL)) {
 170
 171                 if (smbc_remove_unused_server(context, srv->server)) {
 172                         /* could not be removed */
 173                         could_not_purge_all = 1;
 174                 }
 175         }
 176         return could_not_purge_all;
 177 }
 178
 179
 180
 181 /*
 182  * This functions initializes all server-cache related functions
 183  * to the default (internal) system.
 184  *
 185  * We use this to make the rest of the cache system static.
 186  */
 187
 188 int smbc_default_cache_functions(SMBCCTX * context)
 189 {
 190         context->callbacks.add_cached_srv_fn    = smbc_add_cached_server;
 191         context->callbacks.get_cached_srv_fn    = smbc_get_cached_server;
 192         context->callbacks.remove_cached_srv_fn = smbc_remove_cached_server;
 193         context->callbacks.purge_cached_fn      = smbc_purge_cached;
 194
 195         return 0;
 196 }