source3/nmbd/nmbd_browserdb.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    NBT netbios routines and daemon - version 2
   4    Copyright (C) Andrew Tridgell 1994-1998
   5    Copyright (C) Luke Kenneth Casson Leighton 1994-1998
   6    Copyright (C) Jeremy Allison 1994-1998
   7    Copyright (C) Christopher R. Hertel 1998
   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 3 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, see <http://www.gnu.org/licenses/>.
  21
  22 */
  23 /* -------------------------------------------------------------------------- **
  24  * Modified July 1998 by CRH.
  25  *  I converted this module to use the canned doubly-linked lists.  I also
  26  *  added comments above the functions where possible.
  27  */
  28
  29 #include "includes.h"
  30 #include "nmbd/nmbd.h"
  31 #include "lib/util/string_wrappers.h"
  32
  33 /* -------------------------------------------------------------------------- **
  34  * Variables...
  35  *
  36  *  lmb_browserlist - This is our local master browser list.
  37  */
  38
  39 struct browse_cache_record *lmb_browserlist;
  40
  41 /* -------------------------------------------------------------------------- **
  42  * Functions...
  43  */
  44
  45 /* ************************************************************************** **
  46  * Remove and free a browser list entry.
  47  *
  48  *  Input:  browc - A pointer to the entry to be removed from the list and
  49  *                  freed.
  50  *  Output: none.
  51  *
  52  * ************************************************************************** **
  53  */
  54 static void remove_lmb_browser_entry( struct browse_cache_record *browc )
  55 {
  56         DLIST_REMOVE(lmb_browserlist, browc);
  57         SAFE_FREE(browc);
  58 }
  59
  60 /* ************************************************************************** **
  61  * Update a browser death time.
  62  *
  63  *  Input:  browc - Pointer to the entry to be updated.
  64  *  Output: none.
  65  *
  66  * ************************************************************************** **
  67  */
  68 void update_browser_death_time( struct browse_cache_record *browc )
  69 {
  70         /* Allow the new lmb to miss an announce period before we remove it. */
  71         browc->death_time = time(NULL) + ( (CHECK_TIME_MST_ANNOUNCE + 2) * 60 );
  72 }
  73
  74 /* ************************************************************************** **
  75  * Create a browser entry and add it to the local master browser list.
  76  *
  77  *  Input:  work_name
  78  *          browser_name
  79  *          ip
  80  *
  81  *  Output: Pointer to the new entry, or NULL if malloc() failed.
  82  *
  83  * ************************************************************************** **
  84  */
  85 struct browse_cache_record *create_browser_in_lmb_cache( const char *work_name,
  86                                                          const char *browser_name,
  87                                                          struct in_addr ip )
  88 {
  89         struct browse_cache_record *browc;
  90         time_t now = time( NULL );
  91
  92         browc = SMB_MALLOC_P(struct browse_cache_record);
  93
  94         if( NULL == browc ) {
  95                 DEBUG( 0, ("create_browser_in_lmb_cache: malloc fail !\n") );
  96                 return( NULL );
  97         }
  98
  99         memset( (char *)browc, '\0', sizeof( *browc ) );
 100
 101         /* For a new lmb entry we want to sync with it after one minute. This
 102          will allow it time to send out a local announce and build its
 103          browse list.
 104         */
 105
 106         browc->sync_time = now + 60;
 107
 108         /* Allow the new lmb to miss an announce period before we remove it. */
 109         browc->death_time = now + ( (CHECK_TIME_MST_ANNOUNCE + 2) * 60 );
 110
 111         unstrcpy( browc->lmb_name, browser_name);
 112         unstrcpy( browc->work_group, work_name);
 113         if (!strupper_m( browc->lmb_name )) {
 114                 SAFE_FREE(browc);
 115                 return NULL;
 116         }
 117         if (!strupper_m( browc->work_group )) {
 118                 SAFE_FREE(browc);
 119                 return NULL;
 120         }
 121
 122         browc->ip = ip;
 123
 124         DLIST_ADD_END(lmb_browserlist, browc);
 125
 126         DEBUG(3, ("nmbd_browserdb:create_browser_in_lmb_cache()\n"));
 127         DEBUGADD(3, ("  Added lmb cache entry for workgroup %s name %s IP %s "
 128                      "ttl %d\n", browc->work_group, browc->lmb_name,
 129                      inet_ntoa(ip), (int)browc->death_time));
 130
 131         return( browc );
 132 }
 133
 134 /* ************************************************************************** **
 135  * Find a browser entry in the local master browser list.
 136  *
 137  *  Input:  browser_name  - The name for which to search.
 138  *
 139  *  Output: A pointer to the matching entry, or NULL if no match was found.
 140  *
 141  * ************************************************************************** **
 142  */
 143 struct browse_cache_record *find_browser_in_lmb_cache( const char *browser_name )
 144 {
 145         struct browse_cache_record *browc;
 146
 147         for( browc = lmb_browserlist; browc; browc = browc->next ) {
 148                 if( strequal( browser_name, browc->lmb_name ) ) {
 149                         break;
 150                 }
 151         }
 152
 153         return browc;
 154 }
 155
 156 /* ************************************************************************** **
 157  *  Expire timed out browsers in the browserlist.
 158  *
 159  *  Input:  t - Expiration time.  Entries with death times less than this
 160  *              value will be removed from the list.
 161  *  Output: none.
 162  *
 163  * ************************************************************************** **
 164  */
 165 void expire_lmb_browsers( time_t t )
 166 {
 167         struct browse_cache_record *browc;
 168         struct browse_cache_record *nextbrowc;
 169
 170         for( browc = lmb_browserlist; browc; browc = nextbrowc) {
 171                 nextbrowc = browc->next;
 172
 173                 if( browc->death_time < t ) {
 174                         DEBUG(3, ("nmbd_browserdb:expire_lmb_browsers()\n"));
 175                         DEBUGADD(3, ("  Removing timed out lmb entry %s\n",
 176                                      browc->lmb_name));
 177                         remove_lmb_browser_entry( browc );
 178                 }
 179         }
 180 }