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