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 2 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, write to the Free Software
20   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21
22*/
23
24#include "includes.h"
25
26extern int ClientNMB;
27
28int updatecount = 0;
29
30/*******************************************************************
31  Remove all the servers in a work group.
32  ******************************************************************/
33
34void remove_all_servers(struct work_record *work)
35{
36	struct server_record *servrec;
37	struct server_record *nexts;
38
39	for (servrec = work->serverlist; servrec; servrec = nexts) {
40		DEBUG(7,("remove_all_servers: Removing server %s\n",servrec->serv.name));
41		nexts = servrec->next;
42
43		if (servrec->prev)
44			servrec->prev->next = servrec->next;
45		if (servrec->next)
46			servrec->next->prev = servrec->prev;
47
48		if (work->serverlist == servrec)
49			work->serverlist = servrec->next;
50
51		ZERO_STRUCTP(servrec);
52		SAFE_FREE(servrec);
53	}
54
55	work->subnet->work_changed = True;
56}
57
58/***************************************************************************
59  Add a server into the a workgroup serverlist.
60  **************************************************************************/
61
62static void add_server_to_workgroup(struct work_record *work,
63                             struct server_record *servrec)
64{
65	struct server_record *servrec2;
66
67	if (!work->serverlist) {
68		work->serverlist = servrec;
69		servrec->prev = NULL;
70		servrec->next = NULL;
71		return;
72	}
73
74	for (servrec2 = work->serverlist; servrec2->next; servrec2 = servrec2->next)
75		;
76
77	servrec2->next = servrec;
78	servrec->next = NULL;
79	servrec->prev = servrec2;
80	work->subnet->work_changed = True;
81}
82
83/****************************************************************************
84  Find a server in a server list.
85  **************************************************************************/
86
87struct server_record *find_server_in_workgroup(struct work_record *work, const char *name)
88{
89	struct server_record *ret;
90
91	for (ret = work->serverlist; ret; ret = ret->next) {
92		if (strequal(ret->serv.name,name))
93			return ret;
94	}
95	return NULL;
96}
97
98
99/****************************************************************************
100  Remove a server entry from this workgroup.
101  ****************************************************************************/
102
103void remove_server_from_workgroup(struct work_record *work, struct server_record *servrec)
104{
105	if (servrec->prev)
106		servrec->prev->next = servrec->next;
107	if (servrec->next)
108		servrec->next->prev = servrec->prev;
109
110	if (work->serverlist == servrec)
111		work->serverlist = servrec->next;
112
113	ZERO_STRUCTP(servrec);
114	SAFE_FREE(servrec);
115	work->subnet->work_changed = True;
116}
117
118/****************************************************************************
119  Create a server entry on this workgroup.
120  ****************************************************************************/
121
122struct server_record *create_server_on_workgroup(struct work_record *work,
123                                                 const char *name,int servertype,
124                                                 int ttl, const char *comment)
125{
126	struct server_record *servrec;
127
128	if (name[0] == '*') {
129		DEBUG(7,("create_server_on_workgroup: not adding name starting with '*' (%s)\n",
130			name));
131		return (NULL);
132	}
133
134	if((servrec = find_server_in_workgroup(work, name)) != NULL) {
135		DEBUG(0,("create_server_on_workgroup: Server %s already exists on \
136workgroup %s. This is a bug.\n", name, work->work_group));
137		return NULL;
138	}
139
140	if((servrec = SMB_MALLOC_P(struct server_record)) == NULL) {
141		DEBUG(0,("create_server_entry_on_workgroup: malloc fail !\n"));
142		return NULL;
143	}
144
145	memset((char *)servrec,'\0',sizeof(*servrec));
146
147	servrec->subnet = work->subnet;
148
149	fstrcpy(servrec->serv.name,name);
150	fstrcpy(servrec->serv.comment,comment);
151	strupper_m(servrec->serv.name);
152	servrec->serv.type  = servertype;
153
154	update_server_ttl(servrec, ttl);
155
156	add_server_to_workgroup(work, servrec);
157
158	DEBUG(3,("create_server_on_workgroup: Created server entry %s of type %x (%s) on \
159workgroup %s.\n", name,servertype,comment, work->work_group));
160
161	work->subnet->work_changed = True;
162
163	return(servrec);
164}
165
166/*******************************************************************
167 Update the ttl field of a server record.
168*******************************************************************/
169
170void update_server_ttl(struct server_record *servrec, int ttl)
171{
172	if(ttl > lp_max_ttl())
173		ttl = lp_max_ttl();
174
175	if(is_myname(servrec->serv.name))
176		servrec->death_time = PERMANENT_TTL;
177	else
178		servrec->death_time = (ttl != PERMANENT_TTL) ? time(NULL)+(ttl*3) : PERMANENT_TTL;
179
180	servrec->subnet->work_changed = True;
181}
182
183/*******************************************************************
184  Expire old servers in the serverlist. A time of -1 indicates
185  everybody dies except those with a death_time of PERMANENT_TTL (which is 0).
186  This should only be called from expire_workgroups_and_servers().
187  ******************************************************************/
188
189void expire_servers(struct work_record *work, time_t t)
190{
191	struct server_record *servrec;
192	struct server_record *nexts;
193
194	for (servrec = work->serverlist; servrec; servrec = nexts) {
195		nexts = servrec->next;
196
197		if ((servrec->death_time != PERMANENT_TTL) && ((t == -1) || (servrec->death_time < t))) {
198			DEBUG(3,("expire_old_servers: Removing timed out server %s\n",servrec->serv.name));
199			remove_server_from_workgroup(work, servrec);
200			work->subnet->work_changed = True;
201		}
202	}
203}
204
205/*******************************************************************
206 Decide if we should write out a server record for this server.
207 We return zero if we should not. Check if we've already written
208 out this server record from an earlier subnet.
209******************************************************************/
210
211static uint32 write_this_server_name( struct subnet_record *subrec,
212                                      struct work_record *work,
213                                      struct server_record *servrec)
214{
215	struct subnet_record *ssub;
216	struct work_record *iwork;
217
218	/* Go through all the subnets we have already seen. */
219	for (ssub = FIRST_SUBNET; ssub != subrec; ssub = NEXT_SUBNET_INCLUDING_UNICAST(ssub)) {
220		for(iwork = ssub->workgrouplist; iwork; iwork = iwork->next) {
221			if(find_server_in_workgroup( iwork, servrec->serv.name) != NULL) {
222				/*
223				 * We have already written out this server record, don't
224				 * do it again. This gives precedence to servers we have seen
225				 * on the broadcast subnets over servers that may have been
226				 * added via a sync on the unicast_subet.
227				 *
228				 * The correct way to do this is to have a serverlist file
229				 * per subnet - this means changes to smbd as well. I may
230				 * add this at a later date (JRA).
231				 */
232
233				return 0;
234			}
235		}
236	}
237
238	return servrec->serv.type;
239}
240
241/*******************************************************************
242 Decide if we should write out a workgroup record for this workgroup.
243 We return zero if we should not. Don't write out lp_workgroup() (we've
244 already done it) and also don't write out a second workgroup record
245 on the unicast subnet that we've already written out on one of the
246 broadcast subnets.
247******************************************************************/
248
249static uint32 write_this_workgroup_name( struct subnet_record *subrec,
250                                         struct work_record *work)
251{
252	struct subnet_record *ssub;
253
254	if(strequal(lp_workgroup(), work->work_group))
255		return 0;
256
257	/* This is a workgroup we have seen on a broadcast subnet. All
258		these have the same type. */
259
260	if(subrec != unicast_subnet)
261		return (SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT|SV_TYPE_LOCAL_LIST_ONLY);
262
263	for(ssub = FIRST_SUBNET; ssub;  ssub = NEXT_SUBNET_EXCLUDING_UNICAST(ssub)) {
264		/* This is the unicast subnet so check if we've already written out
265			this subnet when we passed over the broadcast subnets. */
266
267		if(find_workgroup_on_subnet( ssub, work->work_group) != NULL)
268			return 0;
269	}
270
271	/* All workgroups on the unicast subnet (except our own, which we
272		have already written out) cannot be local. */
273
274	return (SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT);
275}
276
277/*******************************************************************
278  Write out the browse.dat file.
279  ******************************************************************/
280
281void write_browse_list_entry(XFILE *fp, const char *name, uint32 rec_type,
282		const char *local_master_browser_name, const char *description)
283{
284	fstring tmp;
285
286	slprintf(tmp,sizeof(tmp)-1, "\"%s\"", name);
287	x_fprintf(fp, "%-25s ", tmp);
288	x_fprintf(fp, "%08x ", rec_type);
289	slprintf(tmp, sizeof(tmp)-1, "\"%s\" ", local_master_browser_name);
290	x_fprintf(fp, "%-30s", tmp);
291	x_fprintf(fp, "\"%s\"\n", description);
292}
293
294void write_browse_list(time_t t, BOOL force_write)
295{
296	struct subnet_record *subrec;
297	struct work_record *work;
298	struct server_record *servrec;
299	pstring fname,fnamenew;
300	uint32 stype;
301	int i;
302	XFILE *fp;
303	BOOL list_changed = force_write;
304	static time_t lasttime = 0;
305
306	/* Always dump if we're being told to by a signal. */
307	if(force_write == False) {
308		if (!lasttime)
309			lasttime = t;
310		if (t - lasttime < 5)
311			return;
312	}
313
314	lasttime = t;
315
316	dump_workgroups(force_write);
317
318	for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
319		if(subrec->work_changed) {
320			list_changed = True;
321			break;
322		}
323	}
324
325	if(!list_changed)
326		return;
327
328	updatecount++;
329
330	pstrcpy(fname,lp_lockdir());
331	trim_char(fname,'\0' ,'/');
332	pstrcat(fname,"/");
333	pstrcat(fname,SERVER_LIST);
334	pstrcpy(fnamenew,fname);
335	pstrcat(fnamenew,".");
336
337	fp = x_fopen(fnamenew,O_WRONLY|O_CREAT|O_TRUNC, 0644);
338
339	if (!fp) {
340		DEBUG(0,("write_browse_list: Can't open file %s. Error was %s\n",
341			fnamenew,strerror(errno)));
342		return;
343	}
344
345	/*
346	 * Write out a record for our workgroup. Use the record from the first
347	 * subnet.
348	 */
349
350	if((work = find_workgroup_on_subnet(FIRST_SUBNET, lp_workgroup())) == NULL) {
351		DEBUG(0,("write_browse_list: Fatal error - cannot find my workgroup %s\n",
352			lp_workgroup()));
353		x_fclose(fp);
354		return;
355	}
356
357	write_browse_list_entry(fp, work->work_group,
358		SV_TYPE_DOMAIN_ENUM|SV_TYPE_NT|SV_TYPE_LOCAL_LIST_ONLY,
359		work->local_master_browser_name, work->work_group);
360
361	/*
362	 * We need to do something special for our own names.
363	 * This is due to the fact that we may be a local master browser on
364	 * one of our broadcast subnets, and a domain master on the unicast
365	 * subnet. We iterate over the subnets and only write out the name
366	 * once.
367	 */
368
369	for (i=0; my_netbios_names(i); i++) {
370		stype = 0;
371		for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
372			if((work = find_workgroup_on_subnet( subrec, lp_workgroup() )) == NULL)
373				continue;
374			if((servrec = find_server_in_workgroup( work, my_netbios_names(i))) == NULL)
375				continue;
376
377			stype |= servrec->serv.type;
378		}
379
380		/* Output server details, plus what workgroup they're in. */
381		write_browse_list_entry(fp, my_netbios_names(i), stype,
382			string_truncate(lp_serverstring(), MAX_SERVER_STRING_LENGTH), lp_workgroup());
383	}
384
385	for (subrec = FIRST_SUBNET; subrec ; subrec = NEXT_SUBNET_INCLUDING_UNICAST(subrec)) {
386		subrec->work_changed = False;
387
388		for (work = subrec->workgrouplist; work ; work = work->next) {
389			/* Write out a workgroup record for a workgroup. */
390			uint32 wg_type = write_this_workgroup_name( subrec, work);
391
392			if(wg_type) {
393				write_browse_list_entry(fp, work->work_group, wg_type,
394						work->local_master_browser_name,
395						work->work_group);
396			}
397
398			/* Now write out any server records a workgroup may have. */
399
400			for (servrec = work->serverlist; servrec ; servrec = servrec->next) {
401				uint32 serv_type;
402
403				/* We have already written our names here. */
404				if(is_myname(servrec->serv.name))
405					continue;
406
407				serv_type = write_this_server_name(subrec, work, servrec);
408				if(serv_type) {
409					/* Output server details, plus what workgroup they're in. */
410					write_browse_list_entry(fp, servrec->serv.name, serv_type,
411						servrec->serv.comment, work->work_group);
412				}
413			}
414		}
415	}
416
417	x_fclose(fp);
418	unlink(fname);
419	chmod(fnamenew,0644);
420	rename(fnamenew,fname);
421	DEBUG(3,("write_browse_list: Wrote browse list into file %s\n",fname));
422}
423