28c164fc1458eceabf99daef5c7536b7965a5b7d
[kai/samba.git] / source3 / nmbd / nmbd_serverlistdb.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 1994-1998
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
25 int updatecount = 0;
26
27 /*******************************************************************
28   Remove all the servers in a work group.
29   ******************************************************************/
30
31 void remove_all_servers(struct work_record *work)
32 {
33         struct server_record *servrec;
34         struct server_record *nexts;
35
36         for (servrec = work->serverlist; servrec; servrec = nexts) {
37                 DEBUG(7,("remove_all_servers: Removing server %s\n",servrec->serv.name));
38                 nexts = servrec->next;
39
40                 if (servrec->prev)
41                         servrec->prev->next = servrec->next;
42                 if (servrec->next)
43                         servrec->next->prev = servrec->prev;
44
45                 if (work->serverlist == servrec)
46                         work->serverlist = servrec->next;
47
48                 ZERO_STRUCTP(servrec);
49                 SAFE_FREE(servrec);
50         }
51
52         work->subnet->work_changed = True;
53 }
54
55 /***************************************************************************
56   Add a server into the a workgroup serverlist.
57   **************************************************************************/
58
59 static void add_server_to_workgroup(struct work_record *work,
60                              struct server_record *servrec)
61 {
62         struct server_record *servrec2;
63
64         if (!work->serverlist) {
65                 work->serverlist = servrec;
66                 servrec->prev = NULL;
67                 servrec->next = NULL;
68                 return;
69         }
70
71         for (servrec2 = work->serverlist; servrec2->next; servrec2 = servrec2->next)
72                 ;
73
74         servrec2->next = servrec;
75         servrec->next = NULL;
76         servrec->prev = servrec2;
77         work->subnet->work_changed = True;
78 }
79
80 /****************************************************************************
81   Find a server in a server list.
82   **************************************************************************/
83
84 struct server_record *find_server_in_workgroup(struct work_record *work, const char *name)
85 {
86         struct server_record *ret;
87   
88         for (ret = work->serverlist; ret; ret = ret->next) {
89                 if (strequal(ret->serv.name,name))
90                         return ret;
91         }
92         return NULL;
93 }
94
95
96 /****************************************************************************
97   Remove a server entry from this workgroup.
98   ****************************************************************************/
99
100 void remove_server_from_workgroup(struct work_record *work, struct server_record *servrec)
101 {
102         if (servrec->prev)
103                 servrec->prev->next = servrec->next;
104         if (servrec->next)
105                 servrec->next->prev = servrec->prev;
106
107         if (work->serverlist == servrec) 
108                 work->serverlist = servrec->next; 
109
110         ZERO_STRUCTP(servrec);
111         SAFE_FREE(servrec);
112         work->subnet->work_changed = True;
113 }
114
115 /****************************************************************************
116   Create a server entry on this workgroup.
117   ****************************************************************************/
118
119 struct server_record *create_server_on_workgroup(struct work_record *work,
120                                                  const char *name,int servertype, 
121                                                  int ttl, const char *comment)
122 {
123         struct server_record *servrec;
124   
125         if (name[0] == '*') {
126                 DEBUG(7,("create_server_on_workgroup: not adding name starting with '*' (%s)\n",
127                         name));
128                 return (NULL);
129         }
130   
131         if((servrec = find_server_in_workgroup(work, name)) != NULL) {
132                 DEBUG(0,("create_server_on_workgroup: Server %s already exists on \
133 workgroup %s. This is a bug.\n", name, work->work_group));
134                 return NULL;
135         }
136   
137         if((servrec = SMB_MALLOC_P(struct server_record)) == NULL) {
138                 DEBUG(0,("create_server_entry_on_workgroup: malloc fail !\n"));
139                 return NULL;
140         }
141
142         memset((char *)servrec,'\0',sizeof(*servrec));
143  
144         servrec->subnet = work->subnet;
145  
146         fstrcpy(servrec->serv.name,name);
147         fstrcpy(servrec->serv.comment,comment);
148         strupper_m(servrec->serv.name);
149         servrec->serv.type  = servertype;
150
151         update_server_ttl(servrec, ttl);
152   
153         add_server_to_workgroup(work, servrec);
154       
155         DEBUG(3,("create_server_on_workgroup: Created server entry %s of type %x (%s) on \
156 workgroup %s.\n", name,servertype,comment, work->work_group));
157  
158         work->subnet->work_changed = True;
159  
160         return(servrec);
161 }
162
163 /*******************************************************************
164  Update the ttl field of a server record.
165 *******************************************************************/
166
167 void update_server_ttl(struct server_record *servrec, int ttl)
168 {
169         if(ttl > lp_max_ttl())
170                 ttl = lp_max_ttl();
171
172         if(is_myname(servrec->serv.name))
173                 servrec->death_time = PERMANENT_TTL;
174         else
175                 servrec->death_time = (ttl != PERMANENT_TTL) ? time(NULL)+(ttl*3) : PERMANENT_TTL;
176
177         servrec->subnet->work_changed = True;
178 }
179
180 /*******************************************************************
181   Expire old servers in the serverlist. A time of -1 indicates 
182   everybody dies except those with a death_time of PERMANENT_TTL (which is 0).
183   This should only be called from expire_workgroups_and_servers().
184   ******************************************************************/
185
186 void expire_servers(struct work_record *work, time_t t)
187 {
188         struct server_record *servrec;
189         struct server_record *nexts;
190   
191         for (servrec = work->serverlist; servrec; servrec = nexts) {
192                 nexts = servrec->next;
193
194                 if ((servrec->death_time != PERMANENT_TTL) && ((t == -1) || (servrec->death_time < t))) {
195                         DEBUG(3,("expire_old_servers: Removing timed out server %s\n",servrec->serv.name));
196                         remove_server_from_workgroup(work, servrec);
197                         work->subnet->work_changed = True;
198                 }
199         }
200 }
201
202 /*******************************************************************
203  Decide if we should write out a server record for this server.
204  We return zero if we should not. Check if we've already written
205  out this server record from an earlier subnet.
206 ******************************************************************/
207
208 static uint32 write_this_server_name( struct subnet_record *subrec,
209                                       struct work_record *work,
210                                       struct server_record *servrec)
211 {
212         struct subnet_record *ssub;
213         struct work_record *iwork;
214
215         /* Go through all the subnets we have already seen. */
216         for (ssub = FIRST_SUBNET; ssub && (ssub != subrec); ssub = NEXT_SUBNET_INCLUDING_UNICAST(ssub)) {
217                 for(iwork = ssub->workgrouplist; iwork; iwork = iwork->next) {
218                         if(find_server_in_workgroup( iwork, servrec->serv.name) != NULL) {
219                                 /*
220                                  * We have already written out this server record, don't
221                                  * do it again. This gives precedence to servers we have seen
222                                  * on the broadcast subnets over servers that may have been
223                                  * added via a sync on the unicast_subet.
224                                  *
225                                  * The correct way to do this is to have a serverlist file
226                                  * per subnet - this means changes to smbd as well. I may
227                                  * add this at a later date (JRA).
228                                  */
229
230                                 return 0;
231                         }
232                 }
233         }
234
235         return servrec->serv.type;
236 }
237
238 /*******************************************************************
239  Decide if we should write out a workgroup record for this workgroup.
240  We return zero if we should not. Don't write out lp_workgroup() (we've
241  already done it) and also don't write out a second workgroup record
242  on the unicast subnet that we've already written out on one of the
243  broadcast subnets.
244 ******************************************************************/
245
246 static uint32 write_this_workgroup_name( struct subnet_record *subrec, 
247                                          struct work_record *work)
248 {
249         struct subnet_record *ssub;
250
251         if(strequal(lp_workgroup(), work->work_group))
252                 return 0;
253
254         /* This is a workgroup we have seen on a broadcast subnet. All
255                 these have the same type. */
256
257         if(subrec != unicast_subnet)
258                 return (SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT|SV_TYPE_LOCAL_LIST_ONLY);
259
260         for(ssub = FIRST_SUBNET; ssub;  ssub = NEXT_SUBNET_EXCLUDING_UNICAST(ssub)) {
261                 /* This is the unicast subnet so check if we've already written out
262                         this subnet when we passed over the broadcast subnets. */
263
264                 if(find_workgroup_on_subnet( ssub, work->work_group) != NULL)
265                         return 0;
266         }
267
268         /* All workgroups on the unicast subnet (except our own, which we
269                 have already written out) cannot be local. */
270
271         return (SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT);
272 }
273
274 /*******************************************************************
275   Write out the browse.dat file.
276   ******************************************************************/
277
278 void write_browse_list_entry(XFILE *fp, const char *name, uint32 rec_type,
279                 const char *local_master_browser_name, const char *description)
280 {
281         fstring tmp;
282
283         slprintf(tmp,sizeof(tmp)-1, "\"%s\"", name);
284         x_fprintf(fp, "%-25s ", tmp);
285         x_fprintf(fp, "%08x ", rec_type);
286         slprintf(tmp, sizeof(tmp)-1, "\"%s\" ", local_master_browser_name);
287         x_fprintf(fp, "%-30s", tmp);
288         x_fprintf(fp, "\"%s\"\n", description);
289 }
290
291 void write_browse_list(time_t t, bool force_write)
292 {
293         struct subnet_record *subrec;
294         struct work_record *work;
295         struct server_record *servrec;
296         char *fname;
297         char *fnamenew;
298         uint32 stype;
299         int i;
300         XFILE *fp;
301         bool list_changed = force_write;
302         static time_t lasttime = 0;
303         TALLOC_CTX *ctx = talloc_tos();
304
305         /* Always dump if we're being told to by a signal. */
306         if(force_write == False) {
307                 if (!lasttime)
308                         lasttime = t;
309                 if (t - lasttime < 5)
310                         return;
311         }
312
313         lasttime = t;
314
315         dump_workgroups(force_write);
316
317         for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
318                 if(subrec->work_changed) {
319                         list_changed = True;
320                         break;
321                 }
322         }
323
324         if(!list_changed)
325                 return;
326
327         updatecount++;
328
329         fname = cache_path(SERVER_LIST);
330         if (!fname) {
331                 return;
332         }
333         fnamenew = talloc_asprintf(ctx, "%s.",
334                                 fname);
335         if (!fnamenew) {
336                 return;
337         }
338
339         fp = x_fopen(fnamenew,O_WRONLY|O_CREAT|O_TRUNC, 0644);
340
341         if (!fp) {
342                 DEBUG(0,("write_browse_list: Can't open file %s. Error was %s\n",
343                         fnamenew,strerror(errno)));
344                 return;
345         }
346
347         /*
348          * Write out a record for our workgroup. Use the record from the first
349          * subnet.
350          */
351
352         if((work = find_workgroup_on_subnet(FIRST_SUBNET, lp_workgroup())) == NULL) { 
353                 DEBUG(0,("write_browse_list: Fatal error - cannot find my workgroup %s\n",
354                         lp_workgroup()));
355                 x_fclose(fp);
356                 return;
357         }
358
359         write_browse_list_entry(fp, work->work_group,
360                 SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT|SV_TYPE_LOCAL_LIST_ONLY,
361                 work->local_master_browser_name, work->work_group);
362
363         /*
364          * We need to do something special for our own names.
365          * This is due to the fact that we may be a local master browser on
366          * one of our broadcast subnets, and a domain master on the unicast
367          * subnet. We iterate over the subnets and only write out the name
368          * once.
369          */
370
371         for (i=0; my_netbios_names(i); i++) {
372                 stype = 0;
373                 for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
374                         if((work = find_workgroup_on_subnet( subrec, lp_workgroup() )) == NULL)
375                                 continue;
376                         if((servrec = find_server_in_workgroup( work, my_netbios_names(i))) == NULL)
377                                 continue;
378
379                         stype |= servrec->serv.type;
380                 }
381
382                 /* Output server details, plus what workgroup they're in. */
383                 write_browse_list_entry(fp, my_netbios_names(i), stype,
384                         string_truncate(lp_serverstring(), MAX_SERVER_STRING_LENGTH), lp_workgroup());
385         }
386
387         for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) { 
388                 subrec->work_changed = False;
389
390                 for (work = subrec->workgrouplist; work ; work = work->next) {
391                         /* Write out a workgroup record for a workgroup. */
392                         uint32 wg_type = write_this_workgroup_name( subrec, work);
393
394                         if(wg_type) {
395                                 write_browse_list_entry(fp, work->work_group, wg_type,
396                                                 work->local_master_browser_name,
397                                                 work->work_group);
398                         }
399
400                         /* Now write out any server records a workgroup may have. */
401
402                         for (servrec = work->serverlist; servrec ; servrec = servrec->next) {
403                                 uint32 serv_type;
404
405                                 /* We have already written our names here. */
406                                 if(is_myname(servrec->serv.name))
407                                         continue;
408
409                                 serv_type = write_this_server_name(subrec, work, servrec);
410                                 if(serv_type) {
411                                         /* Output server details, plus what workgroup they're in. */
412                                         write_browse_list_entry(fp, servrec->serv.name, serv_type,
413                                                 servrec->serv.comment, work->work_group);
414                                 }
415                         }
416                 }
417         }
418
419         x_fclose(fp);
420         unlink(fname);
421         chmod(fnamenew,0644);
422         rename(fnamenew,fname);
423         DEBUG(3,("write_browse_list: Wrote browse list into file %s\n",fname));
424 }