Convert all uses of uint8/16/32 to _t in nmbd and the include file.
[samba.git] / source3 / nmbd / nmbd_elections.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 1994-2003
7    
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 3 of the License, or
11    (at your option) any later version.
12    
13    This program is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17    
18    You should have received a copy of the GNU General Public License
19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
20    
21 */
22
23 #include "includes.h"
24 #include "nmbd/nmbd.h"
25
26 /* Election parameters. */
27 extern time_t StartupTime;
28
29 /****************************************************************************
30   Send an election datagram packet.
31 **************************************************************************/
32
33 static void send_election_dgram(struct subnet_record *subrec, const char *workgroup_name,
34                                 uint32_t criterion, int timeup,const char *server_name)
35 {
36         char outbuf[1024];
37         unstring srv_name;
38         char *p;
39
40         DEBUG(2,("send_election_dgram: Sending election packet for workgroup %s on subnet %s\n",
41                 workgroup_name, subrec->subnet_name ));
42
43         memset(outbuf,'\0',sizeof(outbuf));
44         p = outbuf;
45         SCVAL(p,0,ANN_Election); /* Election opcode. */
46         p++;
47
48         SCVAL(p,0,((criterion == 0 && timeup == 0) ? 0 : ELECTION_VERSION));
49         SIVAL(p,1,criterion);
50         SIVAL(p,5,timeup*1000); /* ms - Despite what the spec says. */
51         p += 13;
52         unstrcpy(srv_name, server_name);
53         if (!strupper_m(srv_name)) {
54                 DEBUG(2,("strupper_m failed for %s\n", srv_name));
55                 return;
56         }
57         /* The following call does UNIX -> DOS charset conversion. */
58         push_ascii(p, srv_name, sizeof(outbuf)-PTR_DIFF(p,outbuf)-1, STR_TERMINATE);
59         p = skip_string(outbuf,sizeof(outbuf),p);
60
61         send_mailslot(False, BROWSE_MAILSLOT, outbuf, PTR_DIFF(p,outbuf),
62                 lp_netbios_name(), 0,
63                 workgroup_name, 0x1e,
64                 subrec->bcast_ip, subrec->myip, DGRAM_PORT);
65 }
66
67 /*******************************************************************
68  We found a current master browser on one of our broadcast interfaces.
69 ******************************************************************/
70
71 static void check_for_master_browser_success(struct subnet_record *subrec,
72                                  struct userdata_struct *userdata,
73                                  struct nmb_name *answer_name,
74                                  struct in_addr answer_ip, struct res_rec *rrec)
75 {
76         unstring aname;
77         pull_ascii_nstring(aname, sizeof(aname), answer_name->name);
78         DEBUG(3,("check_for_master_browser_success: Local master browser for workgroup %s exists at \
79 IP %s (just checking).\n", aname, inet_ntoa(answer_ip) ));
80 }
81
82 /*******************************************************************
83  We failed to find a current master browser on one of our broadcast interfaces.
84 ******************************************************************/
85
86 static void check_for_master_browser_fail( struct subnet_record *subrec,
87                                            struct response_record *rrec,
88                                            struct nmb_name *question_name,
89                                            int fail_code)
90 {
91         unstring workgroup_name;
92         struct work_record *work;
93
94         pull_ascii_nstring(workgroup_name,sizeof(workgroup_name),question_name->name);
95
96         work = find_workgroup_on_subnet(subrec, workgroup_name);
97         if(work == NULL) {
98                 DEBUG(0,("check_for_master_browser_fail: Unable to find workgroup %s on subnet %s.=\n",
99                         workgroup_name, subrec->subnet_name ));
100                 return;
101         }
102
103         if (strequal(work->work_group, lp_workgroup())) {
104
105                 if (lp_local_master()) {
106                         /* We have discovered that there is no local master
107                                 browser, and we are configured to initiate
108                                 an election that we will participate in.
109                         */
110                         DEBUG(2,("check_for_master_browser_fail: Forcing election on workgroup %s subnet %s\n",
111                                 work->work_group, subrec->subnet_name ));
112
113                         /* Setting this means we will participate when the
114                                 election is run in run_elections(). */
115                         work->needelection = True;
116                 } else {
117                         /* We need to force an election, because we are configured
118                                 not to become the local master, but we still need one,
119                                 having detected that one doesn't exist.
120                         */
121                         send_election_dgram(subrec, work->work_group, 0, 0, "");
122                 }
123         }
124 }
125
126 /*******************************************************************
127   Ensure there is a local master browser for a workgroup on our
128   broadcast interfaces.
129 ******************************************************************/
130
131 void check_master_browser_exists(time_t t)
132 {
133         static time_t lastrun=0;
134         struct subnet_record *subrec;
135         const char *workgroup_name = lp_workgroup();
136
137         if (t < (lastrun + (CHECK_TIME_MST_BROWSE * 60)))
138                 return;
139
140         lastrun = t;
141
142         dump_workgroups(False);
143
144         for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec)) {
145                 struct work_record *work;
146
147                 for (work = subrec->workgrouplist; work; work = work->next) {
148                         if (strequal(work->work_group, workgroup_name) && !AM_LOCAL_MASTER_BROWSER(work)) {
149                                 /* Do a name query for the local master browser on this net. */
150                                 query_name( subrec, work->work_group, 0x1d,
151                                         check_for_master_browser_success,
152                                         check_for_master_browser_fail,
153                                         NULL);
154                         }
155                 }
156         }
157 }
158
159 /*******************************************************************
160   Run an election.
161 ******************************************************************/
162
163 void run_elections(time_t t)
164 {
165         static time_t lastime = 0;
166   
167         struct subnet_record *subrec;
168   
169         /* Send election packets once every 2 seconds - note */
170         if (lastime && (t - lastime < 2)) {
171                 return;
172         }
173   
174         lastime = t;
175   
176         for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec)) {
177                 struct work_record *work;
178
179                 for (work = subrec->workgrouplist; work; work = work->next) {
180                         if (work->RunningElection) {
181                                 /*
182                                  * We can only run an election for a workgroup if we have
183                                  * registered the WORKGROUP<1e> name, as that's the name
184                                  * we must listen to.
185                                  */
186                                 struct nmb_name nmbname;
187
188                                 make_nmb_name(&nmbname, work->work_group, 0x1e);
189                                 if(find_name_on_subnet( subrec, &nmbname, FIND_SELF_NAME)==NULL) {
190                                         DEBUG(8,("run_elections: Cannot send election packet yet as name %s not \
191 yet registered on subnet %s\n", nmb_namestr(&nmbname), subrec->subnet_name ));
192                                         continue;
193                                 }
194
195                                 send_election_dgram(subrec, work->work_group, work->ElectionCriterion,
196                                                 t - StartupTime, lp_netbios_name());
197               
198                                 if (work->ElectionCount++ >= 4) {
199                                         /* Won election (4 packets were sent out uncontested. */
200                                         DEBUG(2,("run_elections: >>> Won election for workgroup %s on subnet %s <<<\n",
201                                                 work->work_group, subrec->subnet_name ));
202
203                                         work->RunningElection = False;
204
205                                         become_local_master_browser(subrec, work);
206                                 }
207                         }
208                 }
209         }
210 }
211
212 /*******************************************************************
213   Determine if I win an election.
214 ******************************************************************/
215
216 static bool win_election(struct work_record *work, int version,
217                          uint32_t criterion, int timeup, const char *server_name)
218 {  
219         int mytimeup = time(NULL) - StartupTime;
220         uint32_t mycriterion = work->ElectionCriterion;
221
222         /* If local master is false then never win in election broadcasts. */
223         if(!lp_local_master()) {
224                 DEBUG(3,("win_election: Losing election as local master == False\n"));
225                 return False;
226         }
227  
228         DEBUG(4,("win_election: election comparison: %x:%x %x:%x %d:%d %s:%s\n",
229                         version, ELECTION_VERSION,
230                         criterion, mycriterion,
231                         timeup, mytimeup,
232                         server_name, lp_netbios_name()));
233
234         if (version > ELECTION_VERSION)
235                 return(False);
236         if (version < ELECTION_VERSION)
237                 return(True);
238   
239         if (criterion > mycriterion)
240                 return(False);
241         if (criterion < mycriterion)
242                 return(True);
243
244         if (timeup > mytimeup)
245                 return(False);
246         if (timeup < mytimeup)
247                 return(True);
248
249         if (strcasecmp_m(lp_netbios_name(), server_name) > 0)
250                 return(False);
251   
252         return(True);
253 }
254
255 /*******************************************************************
256   Process an incoming election datagram packet.
257 ******************************************************************/
258
259 void process_election(struct subnet_record *subrec, struct packet_struct *p, const char *buf)
260 {
261         struct dgram_packet *dgram = &p->packet.dgram;
262         int version = CVAL(buf,0);
263         uint32_t criterion = IVAL(buf,1);
264         int timeup = IVAL(buf,5)/1000;
265         unstring server_name;
266         struct work_record *work;
267         unstring workgroup_name;
268
269         pull_ascii_nstring(server_name, sizeof(server_name), buf+13);
270         pull_ascii_nstring(workgroup_name, sizeof(workgroup_name), dgram->dest_name.name);
271
272         server_name[15] = 0;  
273
274         DEBUG(3,("process_election: Election request from %s at IP %s on subnet %s for workgroup %s.\n",
275                 server_name,inet_ntoa(p->ip), subrec->subnet_name, workgroup_name ));
276
277         DEBUG(5,("process_election: vers=%d criterion=%08x timeup=%d\n", version,criterion,timeup));
278
279         if(( work = find_workgroup_on_subnet(subrec, workgroup_name)) == NULL) {
280                 DEBUG(0,("process_election: Cannot find workgroup %s on subnet %s.\n",
281                         workgroup_name, subrec->subnet_name ));
282                 goto done;
283         }
284
285         if (!strequal(work->work_group, lp_workgroup())) {
286                 DEBUG(3,("process_election: ignoring election request for workgroup %s on subnet %s as this \
287 is not my workgroup.\n", work->work_group, subrec->subnet_name ));
288                 goto done;
289         }
290
291         if (win_election(work, version,criterion,timeup,server_name)) {
292                 /* We take precedence over the requesting server. */
293                 if (!work->RunningElection) {
294                         /* We weren't running an election - start running one. */
295
296                         work->needelection = True;
297                         work->ElectionCount=0;
298                 }
299
300                 /* Note that if we were running an election for this workgroup on this
301                         subnet already, we just ignore the server we take precedence over. */
302         } else {
303                 /* We lost. Stop participating. */
304                 work->needelection = False;
305
306                 if (work->RunningElection || AM_LOCAL_MASTER_BROWSER(work)) {
307                         work->RunningElection = False;
308                         DEBUG(3,("process_election: >>> Lost election for workgroup %s on subnet %s <<<\n",
309                                 work->work_group, subrec->subnet_name ));
310                         if (AM_LOCAL_MASTER_BROWSER(work))
311                                 unbecome_local_master_browser(subrec, work, False);
312                 }
313         }
314 done:
315         return;
316 }
317
318 /****************************************************************************
319   This function looks over all the workgroups known on all the broadcast
320   subnets and decides if a browser election is to be run on that workgroup.
321   It returns True if any election packets need to be sent (this will then
322   be done by run_elections().
323 ***************************************************************************/
324
325 bool check_elections(void)
326 {
327         struct subnet_record *subrec;
328         bool run_any_election = False;
329
330         for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec)) {
331                 struct work_record *work;
332                 for (work = subrec->workgrouplist; work; work = work->next) {
333                         if (work->RunningElection) {
334                                 run_any_election = work->RunningElection;
335                         }
336
337                         /* 
338                          * Start an election if we have any chance of winning.
339                          * Note this is a change to the previous code, that would
340                          * only run an election if nmbd was in the potential browser
341                          * state. We need to run elections in any state if we're told
342                          * to. JRA.
343                          */
344
345                         if (work->needelection && !work->RunningElection && lp_local_master()) {
346                                 /*
347                                  * We can only run an election for a workgroup if we have
348                                  * registered the WORKGROUP<1e> name, as that's the name
349                                  * we must listen to.
350                                  */
351                                 struct nmb_name nmbname;
352
353                                 make_nmb_name(&nmbname, work->work_group, 0x1e);
354                                 if(find_name_on_subnet( subrec, &nmbname, FIND_SELF_NAME)==NULL) {
355                                         DEBUG(8,("check_elections: Cannot send election packet yet as name %s not \
356 yet registered on subnet %s\n", nmb_namestr(&nmbname), subrec->subnet_name ));
357                                         continue;
358                                 }
359
360                                 DEBUG(3,("check_elections: >>> Starting election for workgroup %s on subnet %s <<<\n",
361                                         work->work_group, subrec->subnet_name ));
362
363                                 work->ElectionCount = 0;
364                                 work->RunningElection = True;
365                                 work->needelection = False;
366                         }
367                 }
368         }
369         return run_any_election;
370 }
371
372 /****************************************************************************
373  Process a internal Samba message forcing an election.
374 ***************************************************************************/
375
376 void nmbd_message_election(struct messaging_context *msg,
377                            void *private_data,
378                            uint32_t msg_type,
379                            struct server_id server_id,
380                            DATA_BLOB *data)
381 {
382         struct subnet_record *subrec;
383
384         for (subrec = FIRST_SUBNET; subrec; subrec = NEXT_SUBNET_EXCLUDING_UNICAST(subrec)) {
385                 struct work_record *work;
386                 for (work = subrec->workgrouplist; work; work = work->next) {
387                         if (strequal(work->work_group, lp_workgroup())) {
388                                 work->needelection = True;
389                                 work->ElectionCount=0;
390                                 work->mst_state = lp_local_master() ? MST_POTENTIAL : MST_NONE;
391                         }
392                 }
393         }
394 }