nmbd/nmbd_responserecordsdb.c

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/* 
   Unix SMB/CIFS implementation.
   NBT netbios library routines
   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"

int num_response_packets = 0;

/***************************************************************************
  Add an expected response record into the list
  **************************************************************************/

static void add_response_record(struct subnet_record *subrec,
                                struct response_record *rrec)
{
        num_response_packets++; /* count of total number of packets still around */

        DEBUG(4,("add_response_record: adding response record id:%hu to subnet %s. num_records:%d\n",
                rrec->response_id, subrec->subnet_name, num_response_packets));

        DLIST_ADD_END(subrec->responselist, rrec, struct response_record *);
}

/***************************************************************************
  Remove an expected response record from the list
  **************************************************************************/

void remove_response_record(struct subnet_record *subrec,
                                struct response_record *rrec)
{
        /* It is possible this can be called twice,
           with a rrec pointer that has been freed. So
           before we inderect into rrec, search for it
           on the responselist first. Bug #3617. JRA. */

        struct response_record *p = NULL;

        for (p = subrec->responselist; p; p = p->next) {
                if (p == rrec) {
                        break;
                }
        }

        if (p == NULL) {
                /* We didn't find rrec on the list. */
                return;
        }

        DLIST_REMOVE(subrec->responselist, rrec);

        if(rrec->userdata) {
                if(rrec->userdata->free_fn) {
                        (*rrec->userdata->free_fn)(rrec->userdata);
                } else {
                        ZERO_STRUCTP(rrec->userdata);
                        SAFE_FREE(rrec->userdata);
                }
        }

        /* Ensure we can delete. */
        rrec->packet->locked = False;
        free_packet(rrec->packet);

        ZERO_STRUCTP(rrec);
        SAFE_FREE(rrec);

        num_response_packets--; /* count of total number of packets still around */
}

/****************************************************************************
  Create a response record for an outgoing packet.
  **************************************************************************/

struct response_record *make_response_record( struct subnet_record *subrec,
                                              struct packet_struct *p,
                                              response_function resp_fn,
                                              timeout_response_function timeout_fn,
                                              success_function success_fn,
                                              fail_function fail_fn,
                                              struct userdata_struct *userdata)
{
        struct response_record *rrec;
        struct nmb_packet *nmb = &p->packet.nmb;

        if (!(rrec = SMB_MALLOC_P(struct response_record))) {
                DEBUG(0,("make_response_queue_record: malloc fail for response_record.\n"));
                return NULL;
        }

        memset((char *)rrec, '\0', sizeof(*rrec));

        rrec->response_id = nmb->header.name_trn_id;

        rrec->resp_fn = resp_fn;
        rrec->timeout_fn = timeout_fn;
        rrec->success_fn = success_fn;
        rrec->fail_fn = fail_fn;

        rrec->packet = p;

        if(userdata) {
                /* Intelligent userdata. */
                if(userdata->copy_fn) {
                        if((rrec->userdata = (*userdata->copy_fn)(userdata)) == NULL) {
                                DEBUG(0,("make_response_queue_record: copy fail for userdata.\n"));
                                ZERO_STRUCTP(rrec);
                                SAFE_FREE(rrec);
                                return NULL;
                        }
                } else {
                        /* Primitive userdata, do a memcpy. */
                        if((rrec->userdata = (struct userdata_struct *)
                                        SMB_MALLOC(sizeof(struct userdata_struct)+userdata->userdata_len)) == NULL) {
                                DEBUG(0,("make_response_queue_record: malloc fail for userdata.\n"));
                                ZERO_STRUCTP(rrec);
                                SAFE_FREE(rrec);
                                return NULL;
                        }
                        rrec->userdata->copy_fn = userdata->copy_fn;
                        rrec->userdata->free_fn = userdata->free_fn;
                        rrec->userdata->userdata_len = userdata->userdata_len;
                        memcpy(rrec->userdata->data, userdata->data, userdata->userdata_len);
                }
        } else {
                rrec->userdata = NULL;
        }

        rrec->num_msgs = 0;

        if(!nmb->header.nm_flags.bcast)
                rrec->repeat_interval = 5; /* 5 seconds for unicast packets. */
        else
                rrec->repeat_interval = 1; /* XXXX should be in ms */
        rrec->repeat_count = 3; /* 3 retries */
        rrec->repeat_time = time(NULL) + rrec->repeat_interval; /* initial retry time */

        /* This packet is not being processed. */
        rrec->in_expiration_processing = False;

        /* Lock the packet so we won't lose it while it's on the list. */
        p->locked = True;

        add_response_record(subrec, rrec);

        return rrec;
}

/****************************************************************************
  Find a response in a subnet's name query response list. 
  **************************************************************************/

static struct response_record *find_response_record_on_subnet(
                                struct subnet_record *subrec, uint16 id)
{  
        struct response_record *rrec = NULL;

        for (rrec = subrec->responselist; rrec; rrec = rrec->next) {
                if (rrec->response_id == id) {
                        DEBUG(4, ("find_response_record: found response record id = %hu on subnet %s\n",
                                id, subrec->subnet_name));
                        break;
                }
        }
        return rrec;
}

/****************************************************************************
  Find a response in any subnet's name query response list. 
  **************************************************************************/

struct response_record *find_response_record(struct subnet_record **ppsubrec,
                                uint16 id)
{  
        struct response_record *rrec = NULL;

        for ((*ppsubrec) = FIRST_SUBNET; (*ppsubrec); 
                                (*ppsubrec) = NEXT_SUBNET_INCLUDING_UNICAST(*ppsubrec)) {
                if((rrec = find_response_record_on_subnet(*ppsubrec, id)) != NULL)
                        return rrec;
        }

        /* There should never be response records on the remote_broadcast subnet.
                        Sanity check to ensure this is so. */
        if(remote_broadcast_subnet->responselist != NULL) {
                DEBUG(0,("find_response_record: response record found on subnet %s. This should \
never happen !\n", remote_broadcast_subnet->subnet_name));
        }

        /* Now check the WINS server subnet if it exists. */
        if(wins_server_subnet != NULL) {
                *ppsubrec = wins_server_subnet;
                if((rrec = find_response_record_on_subnet(*ppsubrec, id))!= NULL)
                        return rrec;
        }

        DEBUG(3,("find_response_record: response packet id %hu received with no \
matching record.\n", id));
 
        *ppsubrec = NULL;

        return NULL;
}

/****************************************************************************
  Check if a refresh is queued for a particular name on a particular subnet.
  **************************************************************************/
   
BOOL is_refresh_already_queued(struct subnet_record *subrec, struct name_record *namerec)
{  
        struct response_record *rrec = NULL;
   
        for (rrec = subrec->responselist; rrec; rrec = rrec->next) {
                struct packet_struct *p = rrec->packet;
                struct nmb_packet *nmb = &p->packet.nmb;

                if((nmb->header.opcode == NMB_NAME_REFRESH_OPCODE_8) ||
                                (nmb->header.opcode == NMB_NAME_REFRESH_OPCODE_9)) {
                        /* Yes it's a queued refresh - check if the name is correct. */
                        if(nmb_name_equal(&nmb->question.question_name, &namerec->name))
                        return True;
                }
        }

        return False;
}

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