source3/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 #include "nmbd/nmbd.h"
  25
  26 /****************************************************************************
  27  Deal with a response packet when releasing one of our names.
  28 ****************************************************************************/
  29
  30 static void release_name_response(struct subnet_record *subrec,
  31                                   struct response_record *rrec, struct packet_struct *p)
  32 {
  33         /*
  34          * If we are releasing broadcast, then getting a response is an
  35          * error. If we are releasing unicast, then we expect to get a response.
  36          */
  37         struct nmb_packet *nmb = &p->packet.nmb;
  38         bool bcast = nmb->header.nm_flags.bcast;
  39         bool success = True;
  40         struct nmb_name *question_name = &rrec->packet->packet.nmb.question.question_name;
  41         struct nmb_name *answer_name = &nmb->answers->rr_name;
  42         struct in_addr released_ip;
  43
  44         /* Sanity check. Ensure that the answer name in the incoming packet is the
  45            same as the requested name in the outgoing packet. */
  46         if (!nmb_name_equal(question_name, answer_name)) {
  47                 DEBUG(0,("release_name_response: Answer name %s differs from question name %s.\n",
  48                          nmb_namestr(answer_name), nmb_namestr(question_name)));
  49                 return;
  50         }
  51
  52         if (bcast) {
  53                 /* Someone sent a response to a bcast release? ignore it. */
  54                 return;
  55         }
  56
  57         /* Unicast - check to see if the response allows us to release the name. */
  58         if (nmb->header.rcode != 0) {
  59                 /* Error code - we were told not to release the name ! What now ! */
  60                 success = False;
  61
  62                 DEBUG(0,("release_name_response: WINS server at IP %s rejected our \
  63 name release of name %s with error code %d.\n",
  64                          inet_ntoa(p->ip),
  65                          nmb_namestr(answer_name), nmb->header.rcode));
  66         } else if (nmb->header.opcode == NMB_WACK_OPCODE) {
  67                 /* WINS server is telling us to wait. Pretend we didn't get
  68                    the response but don't send out any more release requests. */
  69
  70                 DEBUG(5,("release_name_response: WACK from WINS server %s in releasing \
  71 name %s on subnet %s.\n",
  72                          inet_ntoa(p->ip), nmb_namestr(answer_name), subrec->subnet_name));
  73
  74                 rrec->repeat_count = 0;
  75                 /* How long we should wait for. */
  76                 rrec->repeat_time = p->timestamp + nmb->answers->ttl;
  77                 rrec->num_msgs--;
  78                 return;
  79         }
  80
  81         DEBUG(5,("release_name_response: %s in releasing name %s on subnet %s.\n",
  82                  success ? "success" : "failure", nmb_namestr(answer_name), subrec->subnet_name));
  83         if (success) {
  84                 putip((char*)&released_ip ,&nmb->answers->rdata[2]);
  85
  86                 if(rrec->success_fn)
  87                         (*(release_name_success_function)rrec->success_fn)(subrec, rrec->userdata, answer_name, released_ip);
  88                 standard_success_release( subrec, rrec->userdata, answer_name, released_ip);
  89         } else {
  90                 /* We have no standard_fail_release - maybe we should add one ? */
  91                 if (rrec->fail_fn) {
  92                         (*(release_name_fail_function)rrec->fail_fn)(subrec, rrec, answer_name);
  93                 }
  94         }
  95
  96         remove_response_record(subrec, rrec);
  97 }
  98
  99 /****************************************************************************
 100  Deal with a timeout when releasing one of our names.
 101 ****************************************************************************/
 102
 103 static void release_name_timeout_response(struct subnet_record *subrec,
 104                                           struct response_record *rrec)
 105 {
 106         /* a release is *always* considered to be successful when it
 107            times out. This doesn't cause problems as if a WINS server
 108            doesn't respond and someone else wants the name then the
 109            normal WACK/name query from the WINS server will cope */
 110         struct nmb_packet *sent_nmb = &rrec->packet->packet.nmb;
 111         bool bcast = sent_nmb->header.nm_flags.bcast;
 112         struct nmb_name *question_name = &sent_nmb->question.question_name;
 113         struct in_addr released_ip;
 114
 115         /* Get the ip address we were trying to release. */
 116         putip((char*)&released_ip ,&sent_nmb->additional->rdata[2]);
 117
 118         if (!bcast) {
 119                 /* mark the WINS server temporarily dead */
 120                 wins_srv_died(rrec->packet->ip, released_ip);
 121         }
 122
 123         DEBUG(5,("release_name_timeout_response: success in releasing name %s on subnet %s.\n",
 124                  nmb_namestr(question_name), subrec->subnet_name));
 125
 126         if (rrec->success_fn) {
 127                 (*(release_name_success_function)rrec->success_fn)(subrec, rrec->userdata, question_name, released_ip);
 128         }
 129
 130         standard_success_release( subrec, rrec->userdata, question_name, released_ip);
 131         remove_response_record(subrec, rrec);
 132 }
 133
 134
 135 /*
 136   when releasing a name with WINS we need to send the release to each of
 137   the WINS groups
 138 */
 139 static void wins_release_name(struct name_record *namerec,
 140                               release_name_success_function success_fn,
 141                               release_name_fail_function fail_fn,
 142                               struct userdata_struct *userdata)
 143 {
 144         int t, i;
 145         char **wins_tags;
 146
 147         /* get the list of wins tags - we try to release for each of them */
 148         wins_tags = wins_srv_tags();
 149
 150         for (t=0;wins_tags && wins_tags[t]; t++) {
 151                 for (i = 0; i < namerec->data.num_ips; i++) {
 152                         struct in_addr wins_ip = wins_srv_ip_tag(wins_tags[t], namerec->data.ip[i]);
 153
 154                         bool last_one = ((i==namerec->data.num_ips - 1) && !wins_tags[t+1]);
 155                         if (queue_release_name(unicast_subnet,
 156                                                release_name_response,
 157                                                release_name_timeout_response,
 158                                                last_one?success_fn : NULL,
 159                                                last_one? fail_fn : NULL,
 160                                                last_one? userdata : NULL,
 161                                                &namerec->name,
 162                                                namerec->data.nb_flags,
 163                                                namerec->data.ip[i],
 164                                                wins_ip) == NULL) {
 165                                 DEBUG(0,("release_name: Failed to send packet trying to release name %s IP %s\n",
 166                                          nmb_namestr(&namerec->name), inet_ntoa(namerec->data.ip[i]) ));
 167                         }
 168                 }
 169         }
 170
 171         wins_srv_tags_free(wins_tags);
 172 }
 173
 174
 175 /****************************************************************************
 176  Try and release one of our names.
 177 ****************************************************************************/
 178
 179 void release_name(struct subnet_record *subrec, struct name_record *namerec,
 180                   release_name_success_function success_fn,
 181                   release_name_fail_function fail_fn,
 182                   struct userdata_struct *userdata)
 183 {
 184         int i;
 185
 186         /* Ensure it's a SELF name, and in the ACTIVE state. */
 187         if ((namerec->data.source != SELF_NAME) || !NAME_IS_ACTIVE(namerec)) {
 188                 DEBUG(0,("release_name: Cannot release name %s from subnet %s. Source was %d \n",
 189                          nmb_namestr(&namerec->name), subrec->subnet_name, namerec->data.source));
 190                 return;
 191         }
 192
 193         /* Set the name into the deregistering state. */
 194         namerec->data.nb_flags |= NB_DEREG;
 195
 196         /* wins releases are a bit different */
 197         if (subrec == unicast_subnet) {
 198                 wins_release_name(namerec, success_fn, fail_fn, userdata);
 199                 return;
 200         }
 201
 202         /*
 203          * Go through and release the name for all known ip addresses.
 204          * Only call the success/fail function on the last one (it should
 205          * only be done once).
 206          */
 207         for (i = 0; i < namerec->data.num_ips; i++) {
 208                 if (queue_release_name(subrec,
 209                                        release_name_response,
 210                                        release_name_timeout_response,
 211                                        (i == (namerec->data.num_ips - 1)) ? success_fn : NULL,
 212                                        (i == (namerec->data.num_ips - 1)) ? fail_fn : NULL,
 213                                        (i == (namerec->data.num_ips - 1)) ? userdata : NULL,
 214                                        &namerec->name,
 215                                        namerec->data.nb_flags,
 216                                        namerec->data.ip[i],
 217                                        subrec->bcast_ip) == NULL) {
 218                         DEBUG(0,("release_name: Failed to send packet trying to release name %s IP %s\n",
 219                                  nmb_namestr(&namerec->name), inet_ntoa(namerec->data.ip[i]) ));
 220                 }
 221         }
 222 }