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/*
Unix SMB/Netbios implementation.
Version 1.9.
NBT netbios routines and daemon - version 2
Copyright (C) Andrew Tridgell 1994-1995
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
Revision History:
14 jan 96: lkcl@pires.co.uk
added multiple workgroup domain master support
*/
#include "includes.h"
#include "smb.h"
extern int ClientNMB;
extern int DEBUGLEVEL;
/* this is our browse master/backup cache database */
static struct browse_cache_record *browserlist = NULL;
/***************************************************************************
add a browser into the list
**************************************************************************/
static void add_browse_cache(struct browse_cache_record *b)
{
struct browse_cache_record *b2;
if (!browserlist)
{
browserlist = b;
b->prev = NULL;
b->next = NULL;
return;
}
for (b2 = browserlist; b2->next; b2 = b2->next) ;
b2->next = b;
b->next = NULL;
b->prev = b2;
}
/*******************************************************************
remove old browse entries
******************************************************************/
void expire_browse_cache(time_t t)
{
struct browse_cache_record *b;
struct browse_cache_record *nextb;
/* expire old entries in the serverlist */
for (b = browserlist; b; b = nextb)
{
if (b->synced && b->sync_time < t)
{
DEBUG(3,("Removing dead cached browser %s\n",b->name));
nextb = b->next;
if (b->prev) b->prev->next = b->next;
if (b->next) b->next->prev = b->prev;
if (browserlist == b) browserlist = b->next;
free(b);
}
else
{
nextb = b->next;
}
}
}
/****************************************************************************
add a browser entry
****************************************************************************/
struct browse_cache_record *add_browser_entry(char *name, int type, char *wg,
time_t ttl, struct in_addr ip)
{
BOOL newentry=False;
struct browse_cache_record *b;
/* search for the entry: if it's already in the cache, update that entry */
for (b = browserlist; b; b = b->next)
{
if (ip_equal(ip,b->ip) && strequal(b->group, wg)) break;
}
if (b && b->synced)
{
/* entries get left in the cache for a while. this stops sync'ing too
often if the network is large */
DEBUG(4, ("browser %s %s %s already sync'd at time %d\n",
b->name, b->group, inet_ntoa(b->ip), b->sync_time));
return NULL;
}
if (!b)
{
newentry = True;
b = (struct browse_cache_record *)malloc(sizeof(*b));
if (!b) return(NULL);
bzero((char *)b,sizeof(*b));
}
/* update the entry */
ttl = time(NULL)+ttl;
StrnCpy(b->name ,name,sizeof(b->name )-1);
StrnCpy(b->group,wg ,sizeof(b->group)-1);
strupper(b->name);
strupper(b->group);
b->ip = ip;
b->type = type;
if (newentry || ttl < b->sync_time)
b->sync_time = ttl;
if (newentry)
{
b->synced = False;
add_browse_cache(b);
DEBUG(3,("Added cache entry %s %s(%2x) %s ttl %d\n",
wg, name, type, inet_ntoa(ip),ttl));
}
else
{
DEBUG(3,("Updated cache entry %s %s(%2x) %s ttl %d\n",
wg, name, type, inet_ntoa(ip),ttl));
}
return(b);
}
/****************************************************************************
find a server responsible for a workgroup, and sync browse lists
**************************************************************************/
static void start_sync_browse_entry(struct browse_cache_record *b)
{
struct subnet_record *d;
struct work_record *work;
if (!(d = find_subnet(b->ip))) return;
/* only sync if we are the master */
if (AM_MASTER(work)) {
/* first check whether the group we intend to sync with exists. if it
doesn't, the server must have died. o dear. */
/* see response_netbios_packet() or expire_netbios_response_entries() */
queue_netbios_packet(d,ClientNMB,NMB_QUERY,NAME_QUERY_SYNC,
b->group,0x20,0,0,
False,False,b->ip);
}
b->synced = True;
}
/****************************************************************************
search through browser list for an entry to sync with
**************************************************************************/
void do_browser_lists(void)
{
struct browse_cache_record *b;
static time_t last = 0;
time_t t = time(NULL);
if (t-last < 20) return; /* don't do too many of these at once! */
/* XXXX equally this period should not be too long
the server may die in the intervening gap */
last = t;
/* pick any entry in the list, preferably one whose time is up */
for (b = browserlist; b && b->next; b = b->next)
{
if (b->sync_time < t && b->synced == False) break;
}
if (b && !b->synced)
{
/* sync with the selected entry then remove some dead entries */
start_sync_browse_entry(b);
expire_browse_cache(t - 60);
}
}
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