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