1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
|
/*
Unix SMB/CIFS implementation.
core wins server handling
Copyright (C) Andrew Tridgell 2005
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.
*/
#include "includes.h"
#include "nbt_server/nbt_server.h"
#include "nbt_server/winsdb.h"
#include "system/time.h"
/*
work out the ttl we will use given a client requested ttl
*/
uint32_t wins_server_ttl(struct wins_server *winssrv, uint32_t ttl)
{
ttl = MIN(ttl, winssrv->max_ttl);
ttl = MAX(ttl, winssrv->min_ttl);
return ttl;
}
/*
register a new name with WINS
*/
static uint8_t wins_register_new(struct nbt_name_socket *nbtsock,
struct nbt_name_packet *packet,
const char *src_address, int src_port)
{
struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
struct nbtd_interface);
struct wins_server *winssrv = iface->nbtsrv->winssrv;
struct nbt_name *name = &packet->questions[0].name;
uint32_t ttl = wins_server_ttl(winssrv, packet->additional[0].ttl);
uint16_t nb_flags = packet->additional[0].rdata.netbios.addresses[0].nb_flags;
const char *address = packet->additional[0].rdata.netbios.addresses[0].ipaddr;
struct winsdb_record rec;
rec.name = name;
rec.nb_flags = nb_flags;
rec.state = WINS_REC_ACTIVE;
rec.expire_time = time(NULL) + ttl;
rec.registered_by = src_address;
if (IS_GROUP_NAME(name, nb_flags)) {
rec.addresses = str_list_make(packet, "255.255.255.255", NULL);
} else {
rec.addresses = str_list_make(packet, address, NULL);
}
if (rec.addresses == NULL) return NBT_RCODE_SVR;
DEBUG(4,("WINS: accepted registration of %s with address %s\n",
nbt_name_string(packet, name), rec.addresses[0]));
return winsdb_add(winssrv, &rec);
}
/*
update the ttl on an existing record
*/
static uint8_t wins_update_ttl(struct nbt_name_socket *nbtsock,
struct nbt_name_packet *packet,
struct winsdb_record *rec,
const char *src_address, int src_port)
{
struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
struct nbtd_interface);
struct wins_server *winssrv = iface->nbtsrv->winssrv;
uint32_t ttl = wins_server_ttl(winssrv, packet->additional[0].ttl);
const char *address = packet->additional[0].rdata.netbios.addresses[0].ipaddr;
time_t now = time(NULL);
if (now + ttl > rec->expire_time) {
rec->expire_time = now + ttl;
}
rec->registered_by = src_address;
DEBUG(5,("WINS: refreshed registration of %s at %s\n",
nbt_name_string(packet, rec->name), address));
return winsdb_modify(winssrv, rec);
}
/*
register a name
*/
static void nbtd_winsserver_register(struct nbt_name_socket *nbtsock,
struct nbt_name_packet *packet,
const char *src_address, int src_port)
{
struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
struct nbtd_interface);
struct wins_server *winssrv = iface->nbtsrv->winssrv;
struct nbt_name *name = &packet->questions[0].name;
struct winsdb_record *rec;
uint8_t rcode = NBT_RCODE_OK;
uint16_t nb_flags = packet->additional[0].rdata.netbios.addresses[0].nb_flags;
const char *address = packet->additional[0].rdata.netbios.addresses[0].ipaddr;
/* as a special case, the local master browser name is always accepted
for registration, but never stored */
if (name->type == NBT_NAME_MASTER) {
goto done;
}
rec = winsdb_load(winssrv, name, packet);
if (rec == NULL) {
rcode = wins_register_new(nbtsock, packet, src_address, src_port);
goto done;
} else if (rec->state != WINS_REC_ACTIVE) {
winsdb_delete(winssrv, rec->name);
rcode = wins_register_new(nbtsock, packet, src_address, src_port);
goto done;
}
/* its an active name - first see if the registration is of the right type */
if ((rec->nb_flags & NBT_NM_GROUP) && !(nb_flags & NBT_NM_GROUP)) {
DEBUG(2,("WINS: Attempt to register unique name %s when group name is active\n",
nbt_name_string(packet, name)));
rcode = NBT_RCODE_ACT;
goto done;
}
/* if its an active unique name, and the registration is for a group, then
see if the unique name owner still wants the name */
if (!(rec->nb_flags & NBT_NM_GROUP) && (nb_flags & NBT_NM_GROUP)) {
wins_register_wack(nbtsock, packet, rec, src_address, src_port);
return;
}
/* if the registration is for a group, then just update the expiry time
and we are done */
if (IS_GROUP_NAME(name, nb_flags)) {
wins_update_ttl(nbtsock, packet, rec, src_address, src_port);
goto done;
}
/* if the registration is for an address that is currently active, then
just update the expiry time */
if (str_list_check(rec->addresses, address)) {
wins_update_ttl(nbtsock, packet, rec, src_address, src_port);
goto done;
}
/* we have to do a WACK to see if the current owner is willing
to give up its claim */
wins_register_wack(nbtsock, packet, rec, src_address, src_port);
return;
done:
nbtd_name_registration_reply(nbtsock, packet, src_address, src_port, rcode);
}
/*
query a name
*/
static void nbtd_winsserver_query(struct nbt_name_socket *nbtsock,
struct nbt_name_packet *packet,
const char *src_address, int src_port)
{
struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
struct nbtd_interface);
struct wins_server *winssrv = iface->nbtsrv->winssrv;
struct nbt_name *name = &packet->questions[0].name;
struct winsdb_record *rec;
rec = winsdb_load(winssrv, name, packet);
if (rec == NULL || rec->state != WINS_REC_ACTIVE) {
nbtd_negative_name_query_reply(nbtsock, packet, src_address, src_port);
return;
}
nbtd_name_query_reply(nbtsock, packet, src_address, src_port, name,
0, rec->nb_flags, rec->addresses);
}
/*
release a name
*/
static void nbtd_winsserver_release(struct nbt_name_socket *nbtsock,
struct nbt_name_packet *packet,
const char *src_address, int src_port)
{
struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
struct nbtd_interface);
struct wins_server *winssrv = iface->nbtsrv->winssrv;
struct nbt_name *name = &packet->questions[0].name;
struct winsdb_record *rec;
rec = winsdb_load(winssrv, name, packet);
if (rec == NULL ||
rec->state != WINS_REC_ACTIVE ||
IS_GROUP_NAME(name, rec->nb_flags)) {
goto done;
}
/* we only allow releases from an owner - other releases are
silently ignored */
if (str_list_check(rec->addresses, src_address)) {
const char *address = packet->additional[0].rdata.netbios.addresses[0].ipaddr;
DEBUG(4,("WINS: released name %s at %s\n", nbt_name_string(rec, rec->name), address));
str_list_remove(rec->addresses, address);
if (rec->addresses[0] == NULL) {
rec->state = WINS_REC_RELEASED;
}
winsdb_modify(winssrv, rec);
}
done:
/* we match w2k3 by always giving a positive reply to name releases. */
nbtd_name_release_reply(nbtsock, packet, src_address, src_port, NBT_RCODE_OK);
}
/*
answer a name query
*/
void nbtd_winsserver_request(struct nbt_name_socket *nbtsock,
struct nbt_name_packet *packet,
const char *src_address, int src_port)
{
struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
struct nbtd_interface);
struct wins_server *winssrv = iface->nbtsrv->winssrv;
if ((packet->operation & NBT_FLAG_BROADCAST) || winssrv == NULL) {
return;
}
switch (packet->operation & NBT_OPCODE) {
case NBT_OPCODE_QUERY:
nbtd_winsserver_query(nbtsock, packet, src_address, src_port);
break;
case NBT_OPCODE_REGISTER:
case NBT_OPCODE_REFRESH:
case NBT_OPCODE_REFRESH2:
case NBT_OPCODE_MULTI_HOME_REG:
nbtd_winsserver_register(nbtsock, packet, src_address, src_port);
break;
case NBT_OPCODE_RELEASE:
nbtd_winsserver_release(nbtsock, packet, src_address, src_port);
break;
}
}
/*
startup the WINS server, if configured
*/
NTSTATUS nbtd_winsserver_init(struct nbtd_server *nbtsrv)
{
if (!lp_wins_support()) {
nbtsrv->winssrv = NULL;
return NT_STATUS_OK;
}
nbtsrv->winssrv = talloc(nbtsrv, struct wins_server);
NT_STATUS_HAVE_NO_MEMORY(nbtsrv->winssrv);
nbtsrv->winssrv->max_ttl = lp_max_wins_ttl();
nbtsrv->winssrv->min_ttl = lp_min_wins_ttl();
return winsdb_init(nbtsrv->winssrv);
}
|
