source/nmbd/nmbd_winsproxy.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    NBT netbios routines and daemon - version 2
   4
   5    Copyright (C) Jeremy Allison 1994-1998
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20
  21 */
  22
  23 #include "includes.h"
  24
  25 /****************************************************************************
  26 Function called when the name lookup succeeded.
  27 ****************************************************************************/
  28
  29 static void wins_proxy_name_query_request_success( struct subnet_record *subrec,
  30                         struct userdata_struct *userdata,
  31                         struct nmb_name *nmbname, struct in_addr ip, struct res_rec *rrec)
  32 {
  33         unstring name;
  34         struct packet_struct *original_packet;
  35         struct subnet_record *orig_broadcast_subnet;
  36         struct name_record *namerec;
  37         uint16 nb_flags;
  38         int num_ips;
  39         int i;
  40         int ttl = 3600; /* By default one hour in the cache. */
  41         struct in_addr *iplist;
  42
  43         /* Extract the original packet and the original broadcast subnet from
  44                         the userdata. */
  45
  46         memcpy( (char *)&orig_broadcast_subnet, userdata->data, sizeof(struct subnet_record *) );
  47         memcpy( (char *)&original_packet, &userdata->data[sizeof(struct subnet_record *)],
  48                         sizeof(struct packet_struct *) );
  49
  50         nb_flags = get_nb_flags( rrec->rdata );
  51
  52         num_ips = rrec->rdlength / 6;
  53         if(num_ips == 0) {
  54                 DEBUG(0,("wins_proxy_name_query_request_success: Invalid number of IP records (0) \
  55 returned for name %s.\n", nmb_namestr(nmbname) ));
  56                 return;
  57         }
  58
  59         if(num_ips == 1) {
  60                 iplist = &ip;
  61         } else {
  62                 if((iplist = SMB_MALLOC_ARRAY( struct in_addr, num_ips )) == NULL) {
  63                         DEBUG(0,("wins_proxy_name_query_request_success: malloc fail !\n"));
  64                         return;
  65                 }
  66
  67                 for(i = 0; i < num_ips; i++)
  68                         putip( (char *)&iplist[i], (char *)&rrec->rdata[ (i*6) + 2]);
  69         }
  70
  71         /* Add the queried name to the original subnet as a WINS_PROXY_NAME. */
  72
  73         if(rrec == PERMANENT_TTL)
  74                 ttl = lp_max_ttl();
  75
  76         pull_ascii_nstring(name, sizeof(name), nmbname->name);
  77         namerec = add_name_to_subnet( orig_broadcast_subnet, name,
  78                                         nmbname->name_type, nb_flags, ttl,
  79                                         WINS_PROXY_NAME, num_ips, iplist );
  80
  81         if(iplist != &ip)
  82                 SAFE_FREE(iplist);
  83
  84         /*
  85          * Check that none of the IP addresses we are returning is on the
  86          * same broadcast subnet as the original requesting packet. If it
  87          * is then don't reply (although we still need to add the name
  88          * to the cache) as the actual machine will be replying also
  89          * and we don't want two replies to a broadcast query.
  90          */
  91
  92         if(namerec && original_packet->packet.nmb.header.nm_flags.bcast) {
  93                 for( i = 0; i < namerec->data.num_ips; i++) {
  94                         if( same_net( namerec->data.ip[i], orig_broadcast_subnet->myip,
  95                                         orig_broadcast_subnet->mask_ip ) ) {
  96                                 DEBUG( 5, ( "wins_proxy_name_query_request_success: name %s is a WINS \
  97 proxy name and is also on the same subnet (%s) as the requestor. \
  98 Not replying.\n", nmb_namestr(&namerec->name), orig_broadcast_subnet->subnet_name ) );
  99                                 return;
 100                         }
 101                 }
 102         }
 103
 104         /* Finally reply to the original name query. */
 105         reply_netbios_packet(original_packet,                /* Packet to reply to. */
 106                                 0,                              /* Result code. */
 107                                 NMB_QUERY,                      /* nmbd type code. */
 108                                 NMB_NAME_QUERY_OPCODE,          /* opcode. */
 109                                 ttl,                            /* ttl. */
 110                                 rrec->rdata,                    /* data to send. */
 111                                 rrec->rdlength);                /* data length. */
 112 }
 113
 114 /****************************************************************************
 115 Function called when the name lookup failed.
 116 ****************************************************************************/
 117
 118 static void wins_proxy_name_query_request_fail(struct subnet_record *subrec,
 119                                     struct response_record *rrec,
 120                                     struct nmb_name *question_name, int fail_code)
 121 {
 122         DEBUG(4,("wins_proxy_name_query_request_fail: WINS server returned error code %d for lookup \
 123 of name %s.\n", fail_code, nmb_namestr(question_name) ));
 124 }
 125
 126 /****************************************************************************
 127 Function to make a deep copy of the userdata we will need when the WINS
 128 proxy query returns.
 129 ****************************************************************************/
 130
 131 static struct userdata_struct *wins_proxy_userdata_copy_fn(struct userdata_struct *userdata)
 132 {
 133         struct packet_struct *p, *copy_of_p;
 134         struct userdata_struct *new_userdata = (struct userdata_struct *)SMB_MALLOC( userdata->userdata_len );
 135
 136         if(new_userdata == NULL)
 137                 return NULL;
 138
 139         new_userdata->copy_fn = userdata->copy_fn;
 140         new_userdata->free_fn = userdata->free_fn;
 141         new_userdata->userdata_len = userdata->userdata_len;
 142
 143         /* Copy the subnet_record pointer. */
 144         memcpy( new_userdata->data, userdata->data, sizeof(struct subnet_record *) );
 145
 146         /* Extract the pointer to the packet struct */
 147         memcpy((char *)&p, &userdata->data[sizeof(struct subnet_record *)], sizeof(struct packet_struct *) );
 148
 149         /* Do a deep copy of the packet. */
 150         if((copy_of_p = copy_packet(p)) == NULL) {
 151                 SAFE_FREE(new_userdata);
 152                 return NULL;
 153         }
 154
 155         /* Lock the copy. */
 156         copy_of_p->locked = True;
 157
 158         memcpy( &new_userdata->data[sizeof(struct subnet_record *)], (char *)&copy_of_p,
 159                 sizeof(struct packet_struct *) );
 160
 161         return new_userdata;
 162 }
 163
 164 /****************************************************************************
 165 Function to free the deep copy of the userdata we used when the WINS
 166 proxy query returned.
 167 ****************************************************************************/
 168
 169 static void wins_proxy_userdata_free_fn(struct userdata_struct *userdata)
 170 {
 171         struct packet_struct *p;
 172
 173         /* Extract the pointer to the packet struct */
 174         memcpy((char *)&p, &userdata->data[sizeof(struct subnet_record *)],
 175                 sizeof(struct packet_struct *));
 176
 177         /* Unlock the packet. */
 178         p->locked = False;
 179
 180         free_packet(p);
 181         ZERO_STRUCTP(userdata);
 182         SAFE_FREE(userdata);
 183 }
 184
 185 /****************************************************************************
 186  Make a WINS query on behalf of a broadcast client name query request.
 187 ****************************************************************************/
 188
 189 void make_wins_proxy_name_query_request( struct subnet_record *subrec,
 190                                          struct packet_struct *incoming_packet,
 191                                          struct nmb_name *question_name)
 192 {
 193         union {
 194             struct userdata_struct ud;
 195             char c[sizeof(struct userdata_struct) + sizeof(struct subrec *) +
 196                 sizeof(struct packet_struct *)+sizeof(long*)];
 197         } ud;
 198         struct userdata_struct *userdata = &ud.ud;
 199         unstring qname;
 200
 201         memset(&ud, '\0', sizeof(ud));
 202
 203         userdata->copy_fn = wins_proxy_userdata_copy_fn;
 204         userdata->free_fn = wins_proxy_userdata_free_fn;
 205         userdata->userdata_len = sizeof(ud);
 206         memcpy( userdata->data, (char *)&subrec, sizeof(struct subnet_record *));
 207         memcpy( &userdata->data[sizeof(struct subnet_record *)], (char *)&incoming_packet,
 208                         sizeof(struct packet_struct *));
 209
 210         /* Now use the unicast subnet to query the name with the WINS server. */
 211         pull_ascii_nstring(qname, sizeof(qname), question_name->name);
 212         query_name( unicast_subnet, qname, question_name->name_type,
 213                 wins_proxy_name_query_request_success,
 214                 wins_proxy_name_query_request_fail,
 215                 userdata);
 216 }