source/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
  31 /* -------------------------------------------------------------------------- **
  32  * Variables...
  33  *
  34  *  lmb_browserlist - This is our local master browser list.
  35  */
  36
  37 struct browse_cache_record *lmb_browserlist;
  38
  39 /* -------------------------------------------------------------------------- **
  40  * Functions...
  41  */
  42
  43 /* ************************************************************************** **
  44  * Remove and free a browser list entry.
  45  *
  46  *  Input:  browc - A pointer to the entry to be removed from the list and
  47  *                  freed.
  48  *  Output: none.
  49  *
  50  * ************************************************************************** **
  51  */
  52 static void remove_lmb_browser_entry( struct browse_cache_record *browc )
  53 {
  54         DLIST_REMOVE(lmb_browserlist, browc);
  55         SAFE_FREE(browc);
  56 }
  57
  58 /* ************************************************************************** **
  59  * Update a browser death time.
  60  *
  61  *  Input:  browc - Pointer to the entry to be updated.
  62  *  Output: none.
  63  *
  64  * ************************************************************************** **
  65  */
  66 void update_browser_death_time( struct browse_cache_record *browc )
  67 {
  68         /* Allow the new lmb to miss an announce period before we remove it. */
  69         browc->death_time = time(NULL) + ( (CHECK_TIME_MST_ANNOUNCE + 2) * 60 );
  70 }
  71
  72 /* ************************************************************************** **
  73  * Create a browser entry and add it to the local master browser list.
  74  *
  75  *  Input:  work_name
  76  *          browser_name
  77  *          ip
  78  *
  79  *  Output: Pointer to the new entry, or NULL if malloc() failed.
  80  *
  81  * ************************************************************************** **
  82  */
  83 struct browse_cache_record *create_browser_in_lmb_cache( const char *work_name,
  84                                                          const char *browser_name,
  85                                                          struct in_addr ip )
  86 {
  87         struct browse_cache_record *browc;
  88         time_t now = time( NULL );
  89
  90         browc = SMB_MALLOC_P(struct browse_cache_record);
  91
  92         if( NULL == browc ) {
  93                 DEBUG( 0, ("create_browser_in_lmb_cache: malloc fail !\n") );
  94                 return( NULL );
  95         }
  96
  97         memset( (char *)browc, '\0', sizeof( *browc ) );
  98
  99         /* For a new lmb entry we want to sync with it after one minute. This
 100          will allow it time to send out a local announce and build its
 101          browse list.
 102         */
 103
 104         browc->sync_time = now + 60;
 105
 106         /* Allow the new lmb to miss an announce period before we remove it. */
 107         browc->death_time = now + ( (CHECK_TIME_MST_ANNOUNCE + 2) * 60 );
 108
 109         unstrcpy( browc->lmb_name, browser_name);
 110         unstrcpy( browc->work_group, work_name);
 111         strupper_m( browc->lmb_name );
 112         strupper_m( browc->work_group );
 113
 114         browc->ip = ip;
 115
 116         DLIST_ADD_END(lmb_browserlist, browc, struct browse_cache_record *);
 117
 118         if( DEBUGLVL( 3 ) ) {
 119                 Debug1( "nmbd_browserdb:create_browser_in_lmb_cache()\n" );
 120                 Debug1( "  Added lmb cache entry for workgroup %s ", browc->work_group );
 121                 Debug1( "name %s IP %s ", browc->lmb_name, inet_ntoa(ip) );
 122                 Debug1( "ttl %d\n", (int)browc->death_time );
 123         }
 124
 125         return( browc );
 126 }
 127
 128 /* ************************************************************************** **
 129  * Find a browser entry in the local master browser list.
 130  *
 131  *  Input:  browser_name  - The name for which to search.
 132  *
 133  *  Output: A pointer to the matching entry, or NULL if no match was found.
 134  *
 135  * ************************************************************************** **
 136  */
 137 struct browse_cache_record *find_browser_in_lmb_cache( const char *browser_name )
 138 {
 139         struct browse_cache_record *browc;
 140
 141         for( browc = lmb_browserlist; browc; browc = browc->next ) {
 142                 if( strequal( browser_name, browc->lmb_name ) ) {
 143                         break;
 144                 }
 145         }
 146
 147         return browc;
 148 }
 149
 150 /* ************************************************************************** **
 151  *  Expire timed out browsers in the browserlist.
 152  *
 153  *  Input:  t - Expiration time.  Entries with death times less than this
 154  *              value will be removed from the list.
 155  *  Output: none.
 156  *
 157  * ************************************************************************** **
 158  */
 159 void expire_lmb_browsers( time_t t )
 160 {
 161         struct browse_cache_record *browc;
 162         struct browse_cache_record *nextbrowc;
 163
 164         for( browc = lmb_browserlist; browc; browc = nextbrowc) {
 165                 nextbrowc = browc->next;
 166
 167                 if( browc->death_time < t ) {
 168                         if( DEBUGLVL( 3 ) ) {
 169                                 Debug1( "nmbd_browserdb:expire_lmb_browsers()\n" );
 170                                 Debug1( "  Removing timed out lmb entry %s\n", browc->lmb_name );
 171                         }
 172                         remove_lmb_browser_entry( browc );
 173                 }
 174         }
 175 }