source/nmbd/nmbd_namerelease.c

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