release/src/router/samba/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 extern int DEBUGLEVEL;
  34
  35 /* -------------------------------------------------------------------------- **
  36  * Variables...
  37  *
  38  *  lmb_browserlist - This is our local master browser list.
  39  */
  40
  41 ubi_dlNewList( lmb_browserlist );
  42
  43
  44 /* -------------------------------------------------------------------------- **
  45  * Functions...
  46  */
  47
  48 /* ************************************************************************** **
  49  * Remove and free a browser list entry.
  50  *
  51  *  Input:  browc - A pointer to the entry to be removed from the list and
  52  *                  freed.
  53  *  Output: none.
  54  *
  55  * ************************************************************************** **
  56  */
  57 static void remove_lmb_browser_entry( struct browse_cache_record *browc )
  58   {
  59   free( (char *)ubi_dlRemThis( lmb_browserlist, browc ) );
  60   } /* remove_lmb_browser_entry */
  61
  62 /* ************************************************************************** **
  63  * Update a browser death time.
  64  *
  65  *  Input:  browc - Pointer to the entry to be updated.
  66  *  Output: none.
  67  *
  68  * ************************************************************************** **
  69  */
  70 void update_browser_death_time( struct browse_cache_record *browc )
  71   {
  72   /* Allow the new lmb to miss an announce period before we remove it. */
  73   browc->death_time = time(NULL) + ( (CHECK_TIME_MST_ANNOUNCE + 2) * 60 );
  74   } /* update_browser_death_time */
  75
  76 /* ************************************************************************** **
  77  * Create a browser entry and add it to the local master browser list.
  78  *
  79  *  Input:  work_name
  80  *          browser_name
  81  *          ip
  82  *
  83  *  Output: Pointer to the new entry, or NULL if malloc() failed.
  84  *
  85  * ************************************************************************** **
  86  */
  87 struct browse_cache_record *create_browser_in_lmb_cache( char *work_name,
  88                                                          char *browser_name,
  89                                                          struct in_addr ip )
  90   {
  91   struct browse_cache_record *browc;
  92   time_t now = time( NULL );
  93
  94   browc = (struct browse_cache_record *)malloc( sizeof( *browc ) );
  95
  96   if( NULL == browc )
  97     {
  98     DEBUG( 0, ("create_browser_in_lmb_cache: malloc fail !\n") );
  99     return( NULL );
 100     }
 101
 102   memset( (char *)browc, '\0', sizeof( *browc ) );
 103
 104   /* For a new lmb entry we want to sync with it after one minute. This
 105      will allow it time to send out a local announce and build its
 106      browse list.
 107    */
 108   browc->sync_time = now + 60;
 109
 110   /* Allow the new lmb to miss an announce period before we remove it. */
 111   browc->death_time = now + ( (CHECK_TIME_MST_ANNOUNCE + 2) * 60 );
 112
 113   StrnCpy(  browc->lmb_name, browser_name, sizeof(browc->lmb_name)-1 );
 114   StrnCpy(  browc->work_group, work_name, sizeof(browc->work_group)-1 );
 115   strupper( browc->lmb_name );
 116   strupper( browc->work_group );
 117
 118   browc->ip = ip;
 119
 120   (void)ubi_dlAddTail( lmb_browserlist, browc );
 121
 122   if( DEBUGLVL( 3 ) )
 123     {
 124     Debug1( "nmbd_browserdb:create_browser_in_lmb_cache()\n" );
 125     Debug1( "  Added lmb cache entry for workgroup %s ", browc->work_group );
 126     Debug1( "name %s IP %s ", browc->lmb_name, inet_ntoa(ip) );
 127     Debug1( "ttl %d\n", (int)browc->death_time );
 128     }
 129
 130   return( browc );
 131   } /* create_browser_in_lmb_cache */
 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( char *browser_name )
 143   {
 144   struct browse_cache_record *browc;
 145
 146   for( browc = (struct browse_cache_record *)ubi_dlFirst( lmb_browserlist );
 147        browc;
 148        browc = (struct browse_cache_record *)ubi_dlNext( browc ) )
 149     if( strequal( browser_name, browc->lmb_name ) )
 150       break;
 151
 152   return( browc );
 153   } /* find_browser_in_lmb_cache */
 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 = (struct browse_cache_record *)ubi_dlFirst( lmb_browserlist );
 170        browc;
 171        browc = nextbrowc )
 172     {
 173     nextbrowc = (struct browse_cache_record *)ubi_dlNext( browc );
 174
 175     if( browc->death_time < t )
 176       {
 177       if( DEBUGLVL( 3 ) )
 178         {
 179         Debug1( "nmbd_browserdb:expire_lmb_browsers()\n" );
 180         Debug1( "  Removing timed out lmb entry %s\n", browc->lmb_name );
 181         }
 182       remove_lmb_browser_entry( browc );
 183       }
 184     }
 185   } /* expire_lmb_browsers */