2 Unix SMB/Netbios implementation.
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
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.
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.
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.
27 extern pstring global_myname
;
28 extern fstring global_myworkgroup
;
30 /* Election parameters. */
31 extern time_t StartupTime
;
33 /****************************************************************************
34 Send an election datagram packet.
35 **************************************************************************/
36 static void send_election_dgram(struct subnet_record
*subrec
, char *workgroup_name
,
37 uint32 criterion
, int timeup
,char *server_name
)
42 DEBUG(2,("send_election_dgram: Sending election packet for workgroup %s on subnet %s\n",
43 workgroup_name
, subrec
->subnet_name
));
45 memset(outbuf
,'\0',sizeof(outbuf
));
47 CVAL(p
,0) = ANN_Election
; /* Election opcode. */
50 CVAL(p
,0) = (criterion
== 0 && timeup
== 0) ? 0 : ELECTION_VERSION
;
52 SIVAL(p
,5,timeup
*1000); /* ms - Despite what the spec says. */
54 pstrcpy(p
,server_name
);
58 send_mailslot(False
, BROWSE_MAILSLOT
, outbuf
, PTR_DIFF(p
,outbuf
),
61 subrec
->bcast_ip
, subrec
->myip
, DGRAM_PORT
);
64 /*******************************************************************
65 We found a current master browser on one of our broadcast interfaces.
66 ******************************************************************/
68 static void check_for_master_browser_success(struct subnet_record
*subrec
,
69 struct userdata_struct
*userdata
,
70 struct nmb_name
*answer_name
,
71 struct in_addr answer_ip
, struct res_rec
*rrec
)
73 DEBUG(3,("check_for_master_browser_success: Local master browser for workgroup %s exists at \
74 IP %s (just checking).\n", answer_name
->name
, inet_ntoa(answer_ip
) ));
77 /*******************************************************************
78 We failed to find a current master browser on one of our broadcast interfaces.
79 ******************************************************************/
81 static void check_for_master_browser_fail( struct subnet_record
*subrec
,
82 struct response_record
*rrec
,
83 struct nmb_name
*question_name
,
86 char *workgroup_name
= question_name
->name
;
87 struct work_record
*work
= find_workgroup_on_subnet(subrec
, workgroup_name
);
91 DEBUG(0,("check_for_master_browser_fail: Unable to find workgroup %s on subnet %s.=\n",
92 workgroup_name
, subrec
->subnet_name
));
96 if (strequal(work
->work_group
, global_myworkgroup
))
99 if (lp_local_master())
101 /* We have discovered that there is no local master
102 browser, and we are configured to initiate
103 an election that we will participate in.
105 DEBUG(2,("check_for_master_browser_fail: Forcing election on workgroup %s subnet %s\n",
106 work
->work_group
, subrec
->subnet_name
));
108 /* Setting this means we will participate when the
109 election is run in run_elections(). */
110 work
->needelection
= True
;
114 /* We need to force an election, because we are configured
115 not to become the local master, but we still need one,
116 having detected that one doesn't exist.
118 send_election_dgram(subrec
, work
->work_group
, 0, 0, "");
123 /*******************************************************************
124 Ensure there is a local master browser for a workgroup on our
125 broadcast interfaces.
126 ******************************************************************/
128 void check_master_browser_exists(time_t t
)
130 static time_t lastrun
=0;
131 struct subnet_record
*subrec
;
132 char *workgroup_name
= global_myworkgroup
;
137 if (t
< (lastrun
+ (CHECK_TIME_MST_BROWSE
* 60)))
142 dump_workgroups(False
);
144 for (subrec
= FIRST_SUBNET
; subrec
; subrec
= NEXT_SUBNET_EXCLUDING_UNICAST(subrec
))
146 struct work_record
*work
;
148 for (work
= subrec
->workgrouplist
; work
; work
= work
->next
)
150 if (strequal(work
->work_group
, workgroup_name
) && !AM_LOCAL_MASTER_BROWSER(work
))
152 /* Do a name query for the local master browser on this net. */
153 query_name( subrec
, work
->work_group
, 0x1d,
154 check_for_master_browser_success
,
155 check_for_master_browser_fail
,
162 /*******************************************************************
164 ******************************************************************/
166 void run_elections(time_t t
)
168 static time_t lastime
= 0;
170 struct subnet_record
*subrec
;
172 /* Send election packets once every 2 seconds - note */
173 if (lastime
&& (t
- lastime
< 2))
178 START_PROFILE(run_elections
);
179 for (subrec
= FIRST_SUBNET
; subrec
; subrec
= NEXT_SUBNET_EXCLUDING_UNICAST(subrec
))
181 struct work_record
*work
;
183 for (work
= subrec
->workgrouplist
; work
; work
= work
->next
)
185 if (work
->RunningElection
)
188 * We can only run an election for a workgroup if we have
189 * registered the WORKGROUP<1e> name, as that's the name
192 struct nmb_name nmbname
;
194 make_nmb_name(&nmbname
, work
->work_group
, 0x1e);
195 if(find_name_on_subnet( subrec
, &nmbname
, FIND_SELF_NAME
)==NULL
) {
196 DEBUG(8,("run_elections: Cannot send election packet yet as name %s not \
197 yet registered on subnet %s\n", nmb_namestr(&nmbname
), subrec
->subnet_name
));
201 send_election_dgram(subrec
, work
->work_group
, work
->ElectionCriterion
,
202 t
- StartupTime
, global_myname
);
204 if (work
->ElectionCount
++ >= 4)
206 /* Won election (4 packets were sent out uncontested. */
207 DEBUG(2,("run_elections: >>> Won election for workgroup %s on subnet %s <<<\n",
208 work
->work_group
, subrec
->subnet_name
));
210 work
->RunningElection
= False
;
212 become_local_master_browser(subrec
, work
);
217 END_PROFILE(run_elections
);
220 /*******************************************************************
221 Determine if I win an election.
222 ******************************************************************/
224 static BOOL
win_election(struct work_record
*work
, int version
,
225 uint32 criterion
, int timeup
, char *server_name
)
227 int mytimeup
= time(NULL
) - StartupTime
;
228 uint32 mycriterion
= work
->ElectionCriterion
;
230 /* If local master is false then never win
231 in election broadcasts. */
232 if(!lp_local_master())
234 DEBUG(3,("win_election: Losing election as local master == False\n"));
238 DEBUG(4,("win_election: election comparison: %x:%x %x:%x %d:%d %s:%s\n",
239 version
, ELECTION_VERSION
,
240 criterion
, mycriterion
,
242 server_name
, global_myname
));
244 if (version
> ELECTION_VERSION
)
246 if (version
< ELECTION_VERSION
)
249 if (criterion
> mycriterion
)
251 if (criterion
< mycriterion
)
254 if (timeup
> mytimeup
)
256 if (timeup
< mytimeup
)
259 if (strcasecmp(global_myname
, server_name
) > 0)
265 /*******************************************************************
266 Process an incoming election datagram packet.
267 ******************************************************************/
269 void process_election(struct subnet_record
*subrec
, struct packet_struct
*p
, char *buf
)
271 struct dgram_packet
*dgram
= &p
->packet
.dgram
;
272 int version
= CVAL(buf
,0);
273 uint32 criterion
= IVAL(buf
,1);
274 int timeup
= IVAL(buf
,5)/1000;
275 char *server_name
= buf
+13;
276 struct work_record
*work
;
277 char *workgroup_name
= dgram
->dest_name
.name
;
279 START_PROFILE(election
);
282 DEBUG(3,("process_election: Election request from %s at IP %s on subnet %s for workgroup %s.\n",
283 server_name
,inet_ntoa(p
->ip
), subrec
->subnet_name
, workgroup_name
));
285 DEBUG(5,("process_election: vers=%d criterion=%08x timeup=%d\n", version
,criterion
,timeup
));
287 if(( work
= find_workgroup_on_subnet(subrec
, workgroup_name
)) == NULL
)
289 DEBUG(0,("process_election: Cannot find workgroup %s on subnet %s.\n",
290 workgroup_name
, subrec
->subnet_name
));
294 if (!strequal(work
->work_group
, global_myworkgroup
))
296 DEBUG(3,("process_election: ignoring election request for workgroup %s on subnet %s as this \
297 is not my workgroup.\n", work
->work_group
, subrec
->subnet_name
));
301 if (win_election(work
, version
,criterion
,timeup
,server_name
))
303 /* We take precedence over the requesting server. */
304 if (!work
->RunningElection
)
306 /* We weren't running an election - start running one. */
308 work
->needelection
= True
;
309 work
->ElectionCount
=0;
312 /* Note that if we were running an election for this workgroup on this
313 subnet already, we just ignore the server we take precedence over. */
317 /* We lost. Stop participating. */
318 work
->needelection
= False
;
320 if (work
->RunningElection
|| AM_LOCAL_MASTER_BROWSER(work
))
322 work
->RunningElection
= False
;
323 DEBUG(3,("process_election: >>> Lost election for workgroup %s on subnet %s <<<\n",
324 work
->work_group
, subrec
->subnet_name
));
325 if (AM_LOCAL_MASTER_BROWSER(work
))
326 unbecome_local_master_browser(subrec
, work
, False
);
330 END_PROFILE(election
);
333 /****************************************************************************
334 This function looks over all the workgroups known on all the broadcast
335 subnets and decides if a browser election is to be run on that workgroup.
336 It returns True if any election packets need to be sent (this will then
337 be done by run_elections().
338 ***************************************************************************/
340 BOOL
check_elections(void)
342 struct subnet_record
*subrec
;
343 BOOL run_any_election
= False
;
345 for (subrec
= FIRST_SUBNET
; subrec
; subrec
= NEXT_SUBNET_EXCLUDING_UNICAST(subrec
))
347 struct work_record
*work
;
348 for (work
= subrec
->workgrouplist
; work
; work
= work
->next
)
350 run_any_election
|= work
->RunningElection
;
353 * Start an election if we have any chance of winning.
354 * Note this is a change to the previous code, that would
355 * only run an election if nmbd was in the potential browser
356 * state. We need to run elections in any state if we're told
360 if (work
->needelection
&& !work
->RunningElection
&& lp_local_master())
363 * We can only run an election for a workgroup if we have
364 * registered the WORKGROUP<1e> name, as that's the name
367 struct nmb_name nmbname
;
369 make_nmb_name(&nmbname
, work
->work_group
, 0x1e);
370 if(find_name_on_subnet( subrec
, &nmbname
, FIND_SELF_NAME
)==NULL
) {
371 DEBUG(8,("check_elections: Cannot send election packet yet as name %s not \
372 yet registered on subnet %s\n", nmb_namestr(&nmbname
), subrec
->subnet_name
));
376 DEBUG(3,("check_elections: >>> Starting election for workgroup %s on subnet %s <<<\n",
377 work
->work_group
, subrec
->subnet_name
));
379 work
->ElectionCount
= 0;
380 work
->RunningElection
= True
;
381 work
->needelection
= False
;
385 return run_any_election
;
390 /****************************************************************************
391 process a internal Samba message forcing an election
392 ***************************************************************************/
393 void nmbd_message_election(int msg_type
, pid_t src
, void *buf
, size_t len
)
395 struct subnet_record
*subrec
;
397 for (subrec
= FIRST_SUBNET
; subrec
; subrec
= NEXT_SUBNET_EXCLUDING_UNICAST(subrec
)) {
398 struct work_record
*work
;
399 for (work
= subrec
->workgrouplist
; work
; work
= work
->next
) {
400 if (strequal(work
->work_group
, global_myworkgroup
)) {
401 work
->needelection
= True
;
402 work
->ElectionCount
=0;
403 work
->mst_state
= lp_local_master() ? MST_POTENTIAL
: MST_NONE
;