release/src/router/samba/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 extern int DEBUGLEVEL;
  28
  29 /****************************************************************************
  30  Deal with a response packet when releasing one of our names.
  31 ****************************************************************************/
  32
  33 static 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 \
  54 name %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 \
  62 broadcast 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 \
  74 name 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 \
  84 name %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
 119 static 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 \
 151 responding.\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
 194 BOOL 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 }