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 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 /* -------------------------------------------------------------------------- **
  25  * Modified July 1998 by CRH.
  26  *  I converted this module to use the canned doubly-linked lists.  I also
  27  *  added comments above the functions where possible.
  28  */
  29
  30 #include "includes.h"
  31
  32 /* -------------------------------------------------------------------------- **
  33  * Variables...
  34  *
  35  *  lmb_browserlist - This is our local master browser list.
  36  */
  37
  38 ubi_dlNewList( lmb_browserlist );
  39
  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   safe_free( ubi_dlRemThis( lmb_browserlist, browc ) );
  57   } /* remove_lmb_browser_entry */
  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   } /* update_browser_death_time */
  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( char *work_name,
  85                                                          char *browser_name,
  86                                                          struct in_addr ip )
  87   {
  88   struct browse_cache_record *browc;
  89   time_t now = time( NULL );
  90
  91   browc = (struct browse_cache_record *)malloc( sizeof( *browc ) );
  92
  93   if( NULL == browc )
  94     {
  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   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   StrnCpy(  browc->lmb_name, browser_name, sizeof(browc->lmb_name)-1 );
 111   StrnCpy(  browc->work_group, work_name, sizeof(browc->work_group)-1 );
 112   strupper( browc->lmb_name );
 113   strupper( browc->work_group );
 114
 115   browc->ip = ip;
 116
 117   (void)ubi_dlAddTail( lmb_browserlist, browc );
 118
 119   if( DEBUGLVL( 3 ) )
 120     {
 121     Debug1( "nmbd_browserdb:create_browser_in_lmb_cache()\n" );
 122     Debug1( "  Added lmb cache entry for workgroup %s ", browc->work_group );
 123     Debug1( "name %s IP %s ", browc->lmb_name, inet_ntoa(ip) );
 124     Debug1( "ttl %d\n", (int)browc->death_time );
 125     }
 126
 127   return( browc );
 128   } /* create_browser_in_lmb_cache */
 129
 130 /* ************************************************************************** **
 131  * Find a browser entry in the local master browser list.
 132  *
 133  *  Input:  browser_name  - The name for which to search.
 134  *
 135  *  Output: A pointer to the matching entry, or NULL if no match was found.
 136  *
 137  * ************************************************************************** **
 138  */
 139 struct browse_cache_record *find_browser_in_lmb_cache( char *browser_name )
 140   {
 141   struct browse_cache_record *browc;
 142
 143   for( browc = (struct browse_cache_record *)ubi_dlFirst( lmb_browserlist );
 144        browc;
 145        browc = (struct browse_cache_record *)ubi_dlNext( browc ) )
 146     if( strequal( browser_name, browc->lmb_name ) )
 147       break;
 148
 149   return( browc );
 150   } /* find_browser_in_lmb_cache */
 151
 152 /* ************************************************************************** **
 153  *  Expire timed out browsers in the browserlist.
 154  *
 155  *  Input:  t - Expiration time.  Entries with death times less than this
 156  *              value will be removed from the list.
 157  *  Output: none.
 158  *
 159  * ************************************************************************** **
 160  */
 161 void expire_lmb_browsers( time_t t )
 162   {
 163   struct browse_cache_record *browc;
 164   struct browse_cache_record *nextbrowc;
 165
 166   for( browc = (struct browse_cache_record *)ubi_dlFirst( lmb_browserlist );
 167        browc;
 168        browc = nextbrowc )
 169     {
 170     nextbrowc = (struct browse_cache_record *)ubi_dlNext( browc );
 171
 172     if( browc->death_time < t )
 173       {
 174       if( DEBUGLVL( 3 ) )
 175         {
 176         Debug1( "nmbd_browserdb:expire_lmb_browsers()\n" );
 177         Debug1( "  Removing timed out lmb entry %s\n", browc->lmb_name );
 178         }
 179       remove_lmb_browser_entry( browc );
 180       }
 181     }
 182   } /* expire_lmb_browsers */