source/nmbd/nmbd_namerelease.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 /****************************************************************************
  26  Deal with a response packet when releasing one of our names.
  27 ****************************************************************************/
  28
  29 static void release_name_response(struct subnet_record *subrec,
  30                                   struct response_record *rrec, struct packet_struct *p)
  31 {
  32         /*
  33          * If we are releasing broadcast, then getting a response is an
  34          * error. If we are releasing unicast, then we expect to get a response.
  35          */
  36         struct nmb_packet *nmb = &p->packet.nmb;
  37         bool bcast = nmb->header.nm_flags.bcast;
  38         bool success = True;
  39         struct nmb_name *question_name = &rrec->packet->packet.nmb.question.question_name;
  40         struct nmb_name *answer_name = &nmb->answers->rr_name;
  41         struct in_addr released_ip;
  42
  43         /* Sanity check. Ensure that the answer name in the incoming packet is the
  44            same as the requested name in the outgoing packet. */
  45         if (!nmb_name_equal(question_name, answer_name)) {
  46                 DEBUG(0,("release_name_response: Answer name %s differs from question name %s.\n",
  47                          nmb_namestr(answer_name), nmb_namestr(question_name)));
  48                 return;
  49         }
  50
  51         if (bcast) {
  52                 /* Someone sent a response to a bcast release? ignore it. */
  53                 return;
  54         }
  55
  56         /* Unicast - check to see if the response allows us to release the name. */
  57         if (nmb->header.rcode != 0) {
  58                 /* Error code - we were told not to release the name ! What now ! */
  59                 success = False;
  60
  61                 DEBUG(0,("release_name_response: WINS server at IP %s rejected our \
  62 name release of name %s with error code %d.\n",
  63                          inet_ntoa(p->ip),
  64                          nmb_namestr(answer_name), nmb->header.rcode));
  65         } else if (nmb->header.opcode == NMB_WACK_OPCODE) {
  66                 /* WINS server is telling us to wait. Pretend we didn't get
  67                    the response but don't send out any more release requests. */
  68
  69                 DEBUG(5,("release_name_response: WACK from WINS server %s in releasing \
  70 name %s on subnet %s.\n",
  71                          inet_ntoa(p->ip), nmb_namestr(answer_name), subrec->subnet_name));
  72
  73                 rrec->repeat_count = 0;
  74                 /* How long we should wait for. */
  75                 rrec->repeat_time = p->timestamp + nmb->answers->ttl;
  76                 rrec->num_msgs--;
  77                 return;
  78         }
  79
  80         DEBUG(5,("release_name_response: %s in releasing name %s on subnet %s.\n",
  81                  success ? "success" : "failure", nmb_namestr(answer_name), subrec->subnet_name));
  82         if (success) {
  83                 putip((char*)&released_ip ,&nmb->answers->rdata[2]);
  84
  85                 if(rrec->success_fn)
  86                         (*(release_name_success_function)rrec->success_fn)(subrec, rrec->userdata, answer_name, released_ip);
  87                 standard_success_release( subrec, rrec->userdata, answer_name, released_ip);
  88         } else {
  89                 /* We have no standard_fail_release - maybe we should add one ? */
  90                 if (rrec->fail_fn) {
  91                         (*(release_name_fail_function)rrec->fail_fn)(subrec, rrec, answer_name);
  92                 }
  93         }
  94
  95         remove_response_record(subrec, rrec);
  96 }
  97
  98 /****************************************************************************
  99  Deal with a timeout when releasing one of our names.
 100 ****************************************************************************/
 101
 102 static void release_name_timeout_response(struct subnet_record *subrec,
 103                                           struct response_record *rrec)
 104 {
 105         /* a release is *always* considered to be successful when it
 106            times out. This doesn't cause problems as if a WINS server
 107            doesn't respond and someone else wants the name then the
 108            normal WACK/name query from the WINS server will cope */
 109         struct nmb_packet *sent_nmb = &rrec->packet->packet.nmb;
 110         bool bcast = sent_nmb->header.nm_flags.bcast;
 111         struct nmb_name *question_name = &sent_nmb->question.question_name;
 112         struct in_addr released_ip;
 113
 114         /* Get the ip address we were trying to release. */
 115         putip((char*)&released_ip ,&sent_nmb->additional->rdata[2]);
 116
 117         if (!bcast) {
 118                 /* mark the WINS server temporarily dead */
 119                 wins_srv_died(rrec->packet->ip, released_ip);
 120         }
 121
 122         DEBUG(5,("release_name_timeout_response: success in releasing name %s on subnet %s.\n",
 123                  nmb_namestr(question_name), subrec->subnet_name));
 124
 125         if (rrec->success_fn) {
 126                 (*(release_name_success_function)rrec->success_fn)(subrec, rrec->userdata, question_name, released_ip);
 127         }
 128
 129         standard_success_release( subrec, rrec->userdata, question_name, released_ip);
 130         remove_response_record(subrec, rrec);
 131 }
 132
 133
 134 /*
 135   when releasing a name with WINS we need to send the release to each of
 136   the WINS groups
 137 */
 138 static void wins_release_name(struct name_record *namerec,
 139                               release_name_success_function success_fn,
 140                               release_name_fail_function fail_fn,
 141                               struct userdata_struct *userdata)
 142 {
 143         int t, i;
 144         char **wins_tags;
 145
 146         /* get the list of wins tags - we try to release for each of them */
 147         wins_tags = wins_srv_tags();
 148
 149         for (t=0;wins_tags && wins_tags[t]; t++) {
 150                 for (i = 0; i < namerec->data.num_ips; i++) {
 151                         struct in_addr wins_ip = wins_srv_ip_tag(wins_tags[t], namerec->data.ip[i]);
 152
 153                         bool last_one = ((i==namerec->data.num_ips - 1) && !wins_tags[t+1]);
 154                         if (queue_release_name(unicast_subnet,
 155                                                release_name_response,
 156                                                release_name_timeout_response,
 157                                                last_one?success_fn : NULL,
 158                                                last_one? fail_fn : NULL,
 159                                                last_one? userdata : NULL,
 160                                                &namerec->name,
 161                                                namerec->data.nb_flags,
 162                                                namerec->data.ip[i],
 163                                                wins_ip) == NULL) {
 164                                 DEBUG(0,("release_name: Failed to send packet trying to release name %s IP %s\n",
 165                                          nmb_namestr(&namerec->name), inet_ntoa(namerec->data.ip[i]) ));
 166                         }
 167                 }
 168         }
 169
 170         wins_srv_tags_free(wins_tags);
 171 }
 172
 173
 174 /****************************************************************************
 175  Try and release one of our names.
 176 ****************************************************************************/
 177
 178 void release_name(struct subnet_record *subrec, struct name_record *namerec,
 179                   release_name_success_function success_fn,
 180                   release_name_fail_function fail_fn,
 181                   struct userdata_struct *userdata)
 182 {
 183         int i;
 184
 185         /* Ensure it's a SELF name, and in the ACTIVE state. */
 186         if ((namerec->data.source != SELF_NAME) || !NAME_IS_ACTIVE(namerec)) {
 187                 DEBUG(0,("release_name: Cannot release name %s from subnet %s. Source was %d \n",
 188                          nmb_namestr(&namerec->name), subrec->subnet_name, namerec->data.source));
 189                 return;
 190         }
 191
 192         /* Set the name into the deregistering state. */
 193         namerec->data.nb_flags |= NB_DEREG;
 194
 195         /* wins releases are a bit different */
 196         if (subrec == unicast_subnet) {
 197                 wins_release_name(namerec, success_fn, fail_fn, userdata);
 198                 return;
 199         }
 200
 201         /*
 202          * Go through and release the name for all known ip addresses.
 203          * Only call the success/fail function on the last one (it should
 204          * only be done once).
 205          */
 206         for (i = 0; i < namerec->data.num_ips; i++) {
 207                 if (queue_release_name(subrec,
 208                                        release_name_response,
 209                                        release_name_timeout_response,
 210                                        (i == (namerec->data.num_ips - 1)) ? success_fn : NULL,
 211                                        (i == (namerec->data.num_ips - 1)) ? fail_fn : NULL,
 212                                        (i == (namerec->data.num_ips - 1)) ? userdata : NULL,
 213                                        &namerec->name,
 214                                        namerec->data.nb_flags,
 215                                        namerec->data.ip[i],
 216                                        subrec->bcast_ip) == NULL) {
 217                         DEBUG(0,("release_name: Failed to send packet trying to release name %s IP %s\n",
 218                                  nmb_namestr(&namerec->name), inet_ntoa(namerec->data.ip[i]) ));
 219                 }
 220         }
 221 }