source/nmbd/nmbd_browserdb.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    NBT netbios routines and daemon - version 2
   5    Copyright (C) Andrew Tridgell 1994-1998
   6    Copyright (C) Luke Kenneth Casson Leighton 1994-1998
   7    Copyright (C) Jeremy Allison 1994-1998
   8    Copyright (C) Christopher R. Hertel 1998
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 2 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program; if not, write to the Free Software
  22    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  23
  24 */
  25 /* -------------------------------------------------------------------------- **
  26  * Modified July 1998 by CRH.
  27  *  I converted this module to use the canned doubly-linked lists.  I also
  28  *  added comments above the functions where possible.
  29  */
  30
  31 #include "includes.h"
  32
  33 /* -------------------------------------------------------------------------- **
  34  * Variables...
  35  *
  36  *  lmb_browserlist - This is our local master browser list.
  37  */
  38
  39 ubi_dlNewList( lmb_browserlist );
  40
  41
  42 /* -------------------------------------------------------------------------- **
  43  * Functions...
  44  */
  45
  46 /* ************************************************************************** **
  47  * Remove and free a browser list entry.
  48  *
  49  *  Input:  browc - A pointer to the entry to be removed from the list and
  50  *                  freed.
  51  *  Output: none.
  52  *
  53  * ************************************************************************** **
  54  */
  55 static void remove_lmb_browser_entry( struct browse_cache_record *browc )
  56   {
  57   free( (char *)ubi_dlRemThis( lmb_browserlist, browc ) );
  58   } /* remove_lmb_browser_entry */
  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   } /* update_browser_death_time */
  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( char *work_name,
  86                                                          char *browser_name,
  87                                                          struct in_addr ip )
  88   {
  89   struct browse_cache_record *browc;
  90   time_t now = time( NULL );
  91
  92   browc = (struct browse_cache_record *)malloc( sizeof( *browc ) );
  93
  94   if( NULL == browc )
  95     {
  96     DEBUG( 0, ("create_browser_in_lmb_cache: malloc fail !\n") );
  97     return( NULL );
  98     }
  99
 100   memset( (char *)browc, '\0', sizeof( *browc ) );
 101
 102   /* For a new lmb entry we want to sync with it after one minute. This
 103      will allow it time to send out a local announce and build its
 104      browse list.
 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   StrnCpy(  browc->lmb_name, browser_name, sizeof(browc->lmb_name)-1 );
 112   StrnCpy(  browc->work_group, work_name, sizeof(browc->work_group)-1 );
 113   strupper( browc->lmb_name );
 114   strupper( browc->work_group );
 115
 116   browc->ip = ip;
 117
 118   (void)ubi_dlAddTail( lmb_browserlist, browc );
 119
 120   if( DEBUGLVL( 3 ) )
 121     {
 122     Debug1( "nmbd_browserdb:create_browser_in_lmb_cache()\n" );
 123     Debug1( "  Added lmb cache entry for workgroup %s ", browc->work_group );
 124     Debug1( "name %s IP %s ", browc->lmb_name, inet_ntoa(ip) );
 125     Debug1( "ttl %d\n", (int)browc->death_time );
 126     }
 127
 128   return( browc );
 129   } /* create_browser_in_lmb_cache */
 130
 131 /* ************************************************************************** **
 132  * Find a browser entry in the local master browser list.
 133  *
 134  *  Input:  browser_name  - The name for which to search.
 135  *
 136  *  Output: A pointer to the matching entry, or NULL if no match was found.
 137  *
 138  * ************************************************************************** **
 139  */
 140 struct browse_cache_record *find_browser_in_lmb_cache( char *browser_name )
 141   {
 142   struct browse_cache_record *browc;
 143
 144   for( browc = (struct browse_cache_record *)ubi_dlFirst( lmb_browserlist );
 145        browc;
 146        browc = (struct browse_cache_record *)ubi_dlNext( browc ) )
 147     if( strequal( browser_name, browc->lmb_name ) )
 148       break;
 149
 150   return( browc );
 151   } /* find_browser_in_lmb_cache */
 152
 153 /* ************************************************************************** **
 154  *  Expire timed out browsers in the browserlist.
 155  *
 156  *  Input:  t - Expiration time.  Entries with death times less than this
 157  *              value will be removed from the list.
 158  *  Output: none.
 159  *
 160  * ************************************************************************** **
 161  */
 162 void expire_lmb_browsers( time_t t )
 163   {
 164   struct browse_cache_record *browc;
 165   struct browse_cache_record *nextbrowc;
 166
 167   for( browc = (struct browse_cache_record *)ubi_dlFirst( lmb_browserlist );
 168        browc;
 169        browc = nextbrowc )
 170     {
 171     nextbrowc = (struct browse_cache_record *)ubi_dlNext( browc );
 172
 173     if( browc->death_time < t )
 174       {
 175       if( DEBUGLVL( 3 ) )
 176         {
 177         Debug1( "nmbd_browserdb:expire_lmb_browsers()\n" );
 178         Debug1( "  Removing timed out lmb entry %s\n", browc->lmb_name );
 179         }
 180       remove_lmb_browser_entry( browc );
 181       }
 182     }
 183   } /* expire_lmb_browsers */