1/*
2   Unix SMB/Netbios implementation.
3   Version 1.9.
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
8
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.
13
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.
18
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.
22
23*/
24
25#include "includes.h"
26
27extern int DEBUGLEVEL;
28
29/****************************************************************************
30 Deal with a response packet when releasing one of our names.
31****************************************************************************/
32
33static void release_name_response(struct subnet_record *subrec,
34                       struct response_record *rrec, struct packet_struct *p)
35{
36  /*
37   * If we are releasing broadcast, then getting a response is an
38   * error. If we are releasing unicast, then we expect to get a response.
39   */
40
41  struct nmb_packet *nmb = &p->packet.nmb;
42  BOOL bcast = nmb->header.nm_flags.bcast;
43  BOOL success = True;
44  struct nmb_name *question_name = &rrec->packet->packet.nmb.question.question_name;
45  struct nmb_name *answer_name = &nmb->answers->rr_name;
46  struct in_addr released_ip;
47
48  /* Sanity check. Ensure that the answer name in the incoming packet is the
49     same as the requested name in the outgoing packet. */
50
51  if(!nmb_name_equal(question_name, answer_name))
52  {
53    DEBUG(0,("release_name_response: Answer name %s differs from question \
54name %s.\n", nmb_namestr(answer_name), nmb_namestr(question_name)));
55    return;
56  }
57
58  if(bcast)
59  {
60    /* Someone sent a response. This shouldn't happen/ */
61    DEBUG(1,("release_name_response: A response for releasing name %s was received on a \
62broadcast subnet %s. This should not happen !\n", nmb_namestr(answer_name), subrec->subnet_name));
63    return;
64  }
65  else
66  {
67    /* Unicast - check to see if the response allows us to release the name. */
68    if(nmb->header.rcode != 0)
69    {
70      /* Error code - we were told not to release the name ! What now ! */
71      success = False;
72
73      DEBUG(0,("release_name_response: WINS server at IP %s rejected our \
74name release of name %s with error code %d.\n", inet_ntoa(p->ip),
75                  nmb_namestr(answer_name), nmb->header.rcode));
76
77    }
78    else if(nmb->header.opcode == NMB_WACK_OPCODE)
79    {
80      /* WINS server is telling us to wait. Pretend we didn't get
81         the response but don't send out any more release requests. */
82
83      DEBUG(5,("release_name_response: WACK from WINS server %s in releasing \
84name %s on subnet %s.\n", inet_ntoa(p->ip), nmb_namestr(answer_name), subrec->subnet_name));
85
86      rrec->repeat_count = 0;
87      /* How long we should wait for. */
88      rrec->repeat_time = p->timestamp + nmb->answers->ttl;
89      rrec->num_msgs--;
90      return;
91    }
92  }
93
94  DEBUG(5,("release_name_response: %s in releasing name %s on subnet %s.\n",
95        success ? "success" : "failure", nmb_namestr(answer_name), subrec->subnet_name));
96
97  if(success)
98  {
99    putip((char*)&released_ip ,&nmb->answers->rdata[2]);
100
101    if(rrec->success_fn)
102      (*rrec->success_fn)(subrec, rrec->userdata, answer_name, released_ip);
103    standard_success_release( subrec, rrec->userdata, answer_name, released_ip);
104  }
105  else
106  {
107    /* We have no standard_fail_release - maybe we should add one ? */
108    if(rrec->fail_fn)
109      (*rrec->fail_fn)(subrec, rrec, answer_name);
110  }
111
112  remove_response_record(subrec, rrec);
113}
114
115/****************************************************************************
116 Deal with a timeout when releasing one of our names.
117****************************************************************************/
118
119static void release_name_timeout_response(struct subnet_record *subrec,
120                       struct response_record *rrec)
121{
122  /*
123   * If we are releasing unicast, then NOT getting a response is an
124   * error - we could not release the name. If we are releasing broadcast,
125   * then we don't expect to get a response.
126   */
127
128  struct nmb_packet *sent_nmb = &rrec->packet->packet.nmb;
129  BOOL bcast = sent_nmb->header.nm_flags.bcast;
130  BOOL success = False;
131  struct nmb_name *question_name = &sent_nmb->question.question_name;
132  struct in_addr released_ip;
133
134  if(bcast)
135  {
136    if(rrec->num_msgs == 0)
137    {
138      /* Not receiving a message is success for broadcast release. */
139      success = True;
140
141      /* Get the ip address we were trying to release. */
142      putip((char*)&released_ip ,&sent_nmb->additional->rdata[2]);
143    }
144  }
145  else
146  {
147    /* Unicast - if no responses then it's an error. */
148    if(rrec->num_msgs == 0)
149    {
150      DEBUG(2,("release_name_timeout_response: WINS server at address %s is not \
151responding.\n", inet_ntoa(rrec->packet->ip)));
152
153      /* Keep trying to contact the WINS server periodically. This allows
154         us to work correctly if the WINS server is down temporarily when
155         we want to delete the name. */
156
157      /* Reset the number of attempts to zero and double the interval between
158         retries. Max out at 5 minutes. */
159      rrec->repeat_count = 3;
160      rrec->repeat_interval *= 2;
161      if(rrec->repeat_interval > (5 * 60))
162        rrec->repeat_interval = (5 * 60);
163      rrec->repeat_time = time(NULL) + rrec->repeat_interval;
164
165      DEBUG(5,("release_name_timeout_response: increasing WINS timeout to %d seconds.\n",
166              (int)rrec->repeat_interval));
167      return; /* Don't remove the response record. */
168    }
169  }
170
171  DEBUG(5,("release_name_timeout_response: %s in releasing name %s on subnet %s.\n",
172        success ? "success" : "failure", nmb_namestr(question_name), subrec->subnet_name));
173
174  if(success && rrec->success_fn)
175  {
176    if(rrec->success_fn)
177      (*rrec->success_fn)(subrec, rrec->userdata, question_name, released_ip);
178    standard_success_release( subrec, rrec->userdata, question_name, released_ip);
179  }
180  else
181  {
182    /* We have no standard_fail_release - maybe we should add one ? */
183    if( rrec->fail_fn)
184      (*rrec->fail_fn)(subrec, rrec, question_name);
185  }
186
187  remove_response_record(subrec, rrec);
188}
189
190/****************************************************************************
191 Try and release one of our names.
192****************************************************************************/
193
194BOOL release_name(struct subnet_record *subrec, struct name_record *namerec,
195                   release_name_success_function success_fn,
196                   release_name_fail_function fail_fn,
197                   struct userdata_struct *userdata)
198{
199  int i;
200
201  /* Ensure it's a SELF name, and in the ACTIVE state. */
202  if((namerec->data.source != SELF_NAME) || !NAME_IS_ACTIVE(namerec))
203  {
204    DEBUG(0,("release_name: Cannot release name %s from subnet %s. Source was %d \n",
205          nmb_namestr(&namerec->name), subrec->subnet_name, namerec->data.source));
206    return True;
207  }
208
209  /* Set the name into the deregistering state. */
210  namerec->data.nb_flags |= NB_DEREG;
211
212  /*
213   * Go through and release the name for all known ip addresses.
214   * Only call the success/fail function on the last one (it should
215   * only be done once).
216   */
217
218  for( i = 0; i < namerec->data.num_ips; i++)
219  {
220    if(queue_release_name( subrec,
221        release_name_response,
222        release_name_timeout_response,
223        (i == (namerec->data.num_ips - 1)) ? success_fn : NULL,
224        (i == (namerec->data.num_ips - 1)) ? fail_fn : NULL,
225        (i == (namerec->data.num_ips - 1)) ? userdata : NULL,
226        &namerec->name,
227        namerec->data.nb_flags,
228        namerec->data.ip[i]) == NULL)
229    {
230      DEBUG(0,("release_name: Failed to send packet trying to release name %s IP %s\n",
231            nmb_namestr(&namerec->name), inet_ntoa(namerec->data.ip[i]) ));
232      return True;
233    }
234  }
235  return False;
236}
237