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 3 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, see <http://www.gnu.org/licenses/>.
  19
  20 */
  21
  22 #include "includes.h"
  23
  24 /****************************************************************************
  25 Function called when the name lookup succeeded.
  26 ****************************************************************************/
  27
  28 static void wins_proxy_name_query_request_success( struct subnet_record *subrec,
  29                         struct userdata_struct *userdata,
  30                         struct nmb_name *nmbname, struct in_addr ip, struct res_rec *rrec)
  31 {
  32         unstring name;
  33         struct packet_struct *original_packet;
  34         struct subnet_record *orig_broadcast_subnet;
  35         struct name_record *namerec = NULL;
  36         uint16 nb_flags;
  37         int num_ips;
  38         int i;
  39         int ttl = 3600; /* By default one hour in the cache. */
  40         struct in_addr *iplist;
  41
  42         /* Extract the original packet and the original broadcast subnet from
  43                         the userdata. */
  44
  45         memcpy( (char *)&orig_broadcast_subnet, userdata->data, sizeof(struct subnet_record *) );
  46         memcpy( (char *)&original_packet, &userdata->data[sizeof(struct subnet_record *)],
  47                         sizeof(struct packet_struct *) );
  48
  49         if (rrec) {
  50                 nb_flags = get_nb_flags( rrec->rdata );
  51                 num_ips = rrec->rdlength / 6;
  52         } else {
  53                 nb_flags = 0;
  54                 num_ips = 0;
  55         }
  56
  57         if(num_ips == 0) {
  58                 DEBUG(0,("wins_proxy_name_query_request_success: Invalid number of IP records (0) \
  59 returned for name %s.\n", nmb_namestr(nmbname) ));
  60                 return;
  61         }
  62
  63         if(num_ips == 1) {
  64                 iplist = &ip;
  65         } else {
  66                 if((iplist = SMB_MALLOC_ARRAY( struct in_addr, num_ips )) == NULL) {
  67                         DEBUG(0,("wins_proxy_name_query_request_success: malloc fail !\n"));
  68                         return;
  69                 }
  70
  71                 for(i = 0; i < num_ips; i++) {
  72                         putip( (char *)&iplist[i], (char *)&rrec->rdata[ (i*6) + 2]);
  73                 }
  74         }
  75
  76         /* Add the queried name to the original subnet as a WINS_PROXY_NAME. */
  77
  78         if(rrec->ttl == PERMANENT_TTL) {
  79                 ttl = lp_max_ttl();
  80         }
  81
  82         pull_ascii_nstring(name, sizeof(name), nmbname->name);
  83         add_name_to_subnet( orig_broadcast_subnet, name,
  84                                         nmbname->name_type, nb_flags, ttl,
  85                                         WINS_PROXY_NAME, num_ips, iplist );
  86
  87         if(iplist != &ip) {
  88                 SAFE_FREE(iplist);
  89         }
  90
  91         namerec = find_name_on_subnet(orig_broadcast_subnet, nmbname, FIND_ANY_NAME);
  92         if (!namerec) {
  93                 DEBUG(0,("wins_proxy_name_query_request_success: failed to add "
  94                         "name %s to subnet %s !\n",
  95                         name,
  96                         orig_broadcast_subnet->subnet_name ));
  97                 return;
  98         }
  99
 100         /*
 101          * Check that none of the IP addresses we are returning is on the
 102          * same broadcast subnet as the original requesting packet. If it
 103          * is then don't reply (although we still need to add the name
 104          * to the cache) as the actual machine will be replying also
 105          * and we don't want two replies to a broadcast query.
 106          */
 107
 108         if(namerec && original_packet->packet.nmb.header.nm_flags.bcast) {
 109                 for( i = 0; i < namerec->data.num_ips; i++) {
 110                         if( same_net_v4( namerec->data.ip[i], orig_broadcast_subnet->myip,
 111                                         orig_broadcast_subnet->mask_ip ) ) {
 112                                 DEBUG( 5, ( "wins_proxy_name_query_request_success: name %s is a WINS \
 113 proxy name and is also on the same subnet (%s) as the requestor. \
 114 Not replying.\n", nmb_namestr(&namerec->name), orig_broadcast_subnet->subnet_name ) );
 115                                 return;
 116                         }
 117                 }
 118         }
 119
 120         /* Finally reply to the original name query. */
 121         reply_netbios_packet(original_packet,                /* Packet to reply to. */
 122                                 0,                              /* Result code. */
 123                                 NMB_QUERY,                      /* nmbd type code. */
 124                                 NMB_NAME_QUERY_OPCODE,          /* opcode. */
 125                                 ttl,                            /* ttl. */
 126                                 rrec->rdata,                    /* data to send. */
 127                                 rrec->rdlength);                /* data length. */
 128 }
 129
 130 /****************************************************************************
 131 Function called when the name lookup failed.
 132 ****************************************************************************/
 133
 134 static void wins_proxy_name_query_request_fail(struct subnet_record *subrec,
 135                                     struct response_record *rrec,
 136                                     struct nmb_name *question_name, int fail_code)
 137 {
 138         DEBUG(4,("wins_proxy_name_query_request_fail: WINS server returned error code %d for lookup \
 139 of name %s.\n", fail_code, nmb_namestr(question_name) ));
 140 }
 141
 142 /****************************************************************************
 143 Function to make a deep copy of the userdata we will need when the WINS
 144 proxy query returns.
 145 ****************************************************************************/
 146
 147 static struct userdata_struct *wins_proxy_userdata_copy_fn(struct userdata_struct *userdata)
 148 {
 149         struct packet_struct *p, *copy_of_p;
 150         struct userdata_struct *new_userdata = (struct userdata_struct *)SMB_MALLOC( userdata->userdata_len );
 151
 152         if(new_userdata == NULL)
 153                 return NULL;
 154
 155         new_userdata->copy_fn = userdata->copy_fn;
 156         new_userdata->free_fn = userdata->free_fn;
 157         new_userdata->userdata_len = userdata->userdata_len;
 158
 159         /* Copy the subnet_record pointer. */
 160         memcpy( new_userdata->data, userdata->data, sizeof(struct subnet_record *) );
 161
 162         /* Extract the pointer to the packet struct */
 163         memcpy((char *)&p, &userdata->data[sizeof(struct subnet_record *)], sizeof(struct packet_struct *) );
 164
 165         /* Do a deep copy of the packet. */
 166         if((copy_of_p = copy_packet(p)) == NULL) {
 167                 SAFE_FREE(new_userdata);
 168                 return NULL;
 169         }
 170
 171         /* Lock the copy. */
 172         copy_of_p->locked = True;
 173
 174         memcpy( &new_userdata->data[sizeof(struct subnet_record *)], (char *)&copy_of_p,
 175                 sizeof(struct packet_struct *) );
 176
 177         return new_userdata;
 178 }
 179
 180 /****************************************************************************
 181 Function to free the deep copy of the userdata we used when the WINS
 182 proxy query returned.
 183 ****************************************************************************/
 184
 185 static void wins_proxy_userdata_free_fn(struct userdata_struct *userdata)
 186 {
 187         struct packet_struct *p;
 188
 189         /* Extract the pointer to the packet struct */
 190         memcpy((char *)&p, &userdata->data[sizeof(struct subnet_record *)],
 191                 sizeof(struct packet_struct *));
 192
 193         /* Unlock the packet. */
 194         p->locked = False;
 195
 196         free_packet(p);
 197         ZERO_STRUCTP(userdata);
 198         SAFE_FREE(userdata);
 199 }
 200
 201 /****************************************************************************
 202  Make a WINS query on behalf of a broadcast client name query request.
 203 ****************************************************************************/
 204
 205 void make_wins_proxy_name_query_request( struct subnet_record *subrec,
 206                                          struct packet_struct *incoming_packet,
 207                                          struct nmb_name *question_name)
 208 {
 209         union {
 210             struct userdata_struct ud;
 211             char c[sizeof(struct userdata_struct) + sizeof(struct subrec *) +
 212                 sizeof(struct packet_struct *)+sizeof(long*)];
 213         } ud;
 214         struct userdata_struct *userdata = &ud.ud;
 215         unstring qname;
 216
 217         memset(&ud, '\0', sizeof(ud));
 218
 219         userdata->copy_fn = wins_proxy_userdata_copy_fn;
 220         userdata->free_fn = wins_proxy_userdata_free_fn;
 221         userdata->userdata_len = sizeof(ud);
 222         memcpy( userdata->data, (char *)&subrec, sizeof(struct subnet_record *));
 223         memcpy( &userdata->data[sizeof(struct subnet_record *)], (char *)&incoming_packet,
 224                         sizeof(struct packet_struct *));
 225
 226         /* Now use the unicast subnet to query the name with the WINS server. */
 227         pull_ascii_nstring(qname, sizeof(qname), question_name->name);
 228         query_name( unicast_subnet, qname, question_name->name_type,
 229                 wins_proxy_name_query_request_success,
 230                 wins_proxy_name_query_request_fail,
 231                 userdata);
 232 }