nmbd/nmbd_namerelease.c

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/* 
   Unix SMB/CIFS implementation.
   NBT netbios routines and daemon - version 2
   Copyright (C) Andrew Tridgell 1994-1998
   Copyright (C) Luke Kenneth Casson Leighton 1994-1998
   Copyright (C) Jeremy Allison 1994-1998
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   
*/

#include "includes.h"

/****************************************************************************
 Deal with a response packet when releasing one of our names.
****************************************************************************/

static void release_name_response(struct subnet_record *subrec,
                                  struct response_record *rrec, struct packet_struct *p)
{
        /* 
         * If we are releasing broadcast, then getting a response is an
         * error. If we are releasing unicast, then we expect to get a response.
         */
        struct nmb_packet *nmb = &p->packet.nmb;
        BOOL bcast = nmb->header.nm_flags.bcast;
        BOOL success = True;
        struct nmb_name *question_name = &rrec->packet->packet.nmb.question.question_name;
        struct nmb_name *answer_name = &nmb->answers->rr_name;
        struct in_addr released_ip;

        /* Sanity check. Ensure that the answer name in the incoming packet is the
           same as the requested name in the outgoing packet. */
        if (!nmb_name_equal(question_name, answer_name)) {
                DEBUG(0,("release_name_response: Answer name %s differs from question name %s.\n", 
                         nmb_namestr(answer_name), nmb_namestr(question_name)));
                return;
        }

        if (bcast) {
                /* Someone sent a response to a bcast release? ignore it. */
                return;
        }

        /* Unicast - check to see if the response allows us to release the name. */
        if (nmb->header.rcode != 0) {
                /* Error code - we were told not to release the name ! What now ! */
                success = False;

                DEBUG(0,("release_name_response: WINS server at IP %s rejected our \
name release of name %s with error code %d.\n", 
                         inet_ntoa(p->ip), 
                         nmb_namestr(answer_name), nmb->header.rcode));
        } else if (nmb->header.opcode == NMB_WACK_OPCODE) {
                /* WINS server is telling us to wait. Pretend we didn't get
                   the response but don't send out any more release requests. */

                DEBUG(5,("release_name_response: WACK from WINS server %s in releasing \
name %s on subnet %s.\n", 
                         inet_ntoa(p->ip), nmb_namestr(answer_name), subrec->subnet_name));

                rrec->repeat_count = 0;
                /* How long we should wait for. */
                rrec->repeat_time = p->timestamp + nmb->answers->ttl;
                rrec->num_msgs--;
                return;
        }

        DEBUG(5,("release_name_response: %s in releasing name %s on subnet %s.\n",
                 success ? "success" : "failure", nmb_namestr(answer_name), subrec->subnet_name));
        if (success) {
                putip((char*)&released_ip ,&nmb->answers->rdata[2]);

                if(rrec->success_fn)
                        (*(release_name_success_function)rrec->success_fn)(subrec, rrec->userdata, answer_name, released_ip);
                standard_success_release( subrec, rrec->userdata, answer_name, released_ip);
        } else {
                /* We have no standard_fail_release - maybe we should add one ? */
                if (rrec->fail_fn) {
                        (*(release_name_fail_function)rrec->fail_fn)(subrec, rrec, answer_name);
                }
        }

        remove_response_record(subrec, rrec);
}

/****************************************************************************
 Deal with a timeout when releasing one of our names.
****************************************************************************/

static void release_name_timeout_response(struct subnet_record *subrec,
                                          struct response_record *rrec)
{
        /* a release is *always* considered to be successful when it
           times out. This doesn't cause problems as if a WINS server
           doesn't respond and someone else wants the name then the
           normal WACK/name query from the WINS server will cope */
        struct nmb_packet *sent_nmb = &rrec->packet->packet.nmb;
        BOOL bcast = sent_nmb->header.nm_flags.bcast;
        struct nmb_name *question_name = &sent_nmb->question.question_name;
        struct in_addr released_ip;

        /* Get the ip address we were trying to release. */
        putip((char*)&released_ip ,&sent_nmb->additional->rdata[2]);

        if (!bcast) {
                /* mark the WINS server temporarily dead */
                wins_srv_died(rrec->packet->ip, released_ip);
        }

        DEBUG(5,("release_name_timeout_response: success in releasing name %s on subnet %s.\n",
                 nmb_namestr(question_name), subrec->subnet_name));

        if (rrec->success_fn) {
                (*(release_name_success_function)rrec->success_fn)(subrec, rrec->userdata, question_name, released_ip);
        }

        standard_success_release( subrec, rrec->userdata, question_name, released_ip);
        remove_response_record(subrec, rrec);
}


/*
  when releasing a name with WINS we need to send the release to each of
  the WINS groups
*/
static void wins_release_name(struct name_record *namerec,
                              release_name_success_function success_fn,
                              release_name_fail_function fail_fn,
                              struct userdata_struct *userdata)                       
{
        int t, i;
        char **wins_tags;

        /* get the list of wins tags - we try to release for each of them */
        wins_tags = wins_srv_tags();

        for (t=0;wins_tags && wins_tags[t]; t++) {
                for (i = 0; i < namerec->data.num_ips; i++) {
                        struct in_addr wins_ip = wins_srv_ip_tag(wins_tags[t], namerec->data.ip[i]);

                        BOOL last_one = ((i==namerec->data.num_ips - 1) && !wins_tags[t+1]);
                        if (queue_release_name(unicast_subnet,
                                               release_name_response,
                                               release_name_timeout_response,
                                               last_one?success_fn : NULL,
                                               last_one? fail_fn : NULL,
                                               last_one? userdata : NULL,
                                               &namerec->name,
                                               namerec->data.nb_flags,
                                               namerec->data.ip[i],
                                               wins_ip) == NULL) {
                                DEBUG(0,("release_name: Failed to send packet trying to release name %s IP %s\n",
                                         nmb_namestr(&namerec->name), inet_ntoa(namerec->data.ip[i]) ));
                        }
                }
        }

        wins_srv_tags_free(wins_tags);
}


/****************************************************************************
 Try and release one of our names.
****************************************************************************/

void release_name(struct subnet_record *subrec, struct name_record *namerec,
                  release_name_success_function success_fn,
                  release_name_fail_function fail_fn,
                  struct userdata_struct *userdata)
{
        int i;

        /* Ensure it's a SELF name, and in the ACTIVE state. */
        if ((namerec->data.source != SELF_NAME) || !NAME_IS_ACTIVE(namerec)) {
                DEBUG(0,("release_name: Cannot release name %s from subnet %s. Source was %d \n",
                         nmb_namestr(&namerec->name), subrec->subnet_name, namerec->data.source)); 
                return;
        }

        /* Set the name into the deregistering state. */
        namerec->data.nb_flags |= NB_DEREG;

        /* wins releases are a bit different */
        if (subrec == unicast_subnet) {
                wins_release_name(namerec, success_fn, fail_fn, userdata);
                return;
        }

        /*  
         * Go through and release the name for all known ip addresses.
         * Only call the success/fail function on the last one (it should
         * only be done once).
         */
        for (i = 0; i < namerec->data.num_ips; i++) {
                if (queue_release_name(subrec,
                                       release_name_response,
                                       release_name_timeout_response,
                                       (i == (namerec->data.num_ips - 1)) ? success_fn : NULL,
                                       (i == (namerec->data.num_ips - 1)) ? fail_fn : NULL,
                                       (i == (namerec->data.num_ips - 1)) ? userdata : NULL,
                                       &namerec->name,
                                       namerec->data.nb_flags,
                                       namerec->data.ip[i],
                                       subrec->bcast_ip) == NULL) {
                        DEBUG(0,("release_name: Failed to send packet trying to release name %s IP %s\n",
                                 nmb_namestr(&namerec->name), inet_ntoa(namerec->data.ip[i]) ));
                }
        }
}

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