source3/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 #include "nmbd/nmbd.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 = NULL;
  37         uint16_t 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         if (rrec) {
  51                 nb_flags = get_nb_flags( rrec->rdata );
  52                 num_ips = rrec->rdlength / 6;
  53         } else {
  54                 nb_flags = 0;
  55                 num_ips = 0;
  56         }
  57
  58         if(num_ips == 0) {
  59                 DEBUG(0,("wins_proxy_name_query_request_success: Invalid number of IP records (0) \
  60 returned for name %s.\n", nmb_namestr(nmbname) ));
  61                 return;
  62         }
  63
  64         if(num_ips == 1) {
  65                 iplist = &ip;
  66         } else {
  67                 if((iplist = SMB_MALLOC_ARRAY( struct in_addr, num_ips )) == NULL) {
  68                         DEBUG(0,("wins_proxy_name_query_request_success: malloc fail !\n"));
  69                         return;
  70                 }
  71
  72                 for(i = 0; i < num_ips; i++) {
  73                         putip( (char *)&iplist[i], (char *)&rrec->rdata[ (i*6) + 2]);
  74                 }
  75         }
  76
  77         /* Add the queried name to the original subnet as a WINS_PROXY_NAME. */
  78
  79         if(rrec->ttl == PERMANENT_TTL) {
  80                 ttl = lp_max_ttl();
  81         }
  82
  83         pull_ascii_nstring(name, sizeof(name), nmbname->name);
  84         add_name_to_subnet( orig_broadcast_subnet, name,
  85                                         nmbname->name_type, nb_flags, ttl,
  86                                         WINS_PROXY_NAME, num_ips, iplist );
  87
  88         if(iplist != &ip) {
  89                 SAFE_FREE(iplist);
  90         }
  91
  92         namerec = find_name_on_subnet(orig_broadcast_subnet, nmbname, FIND_ANY_NAME);
  93         if (!namerec) {
  94                 DEBUG(0,("wins_proxy_name_query_request_success: failed to add "
  95                         "name %s to subnet %s !\n",
  96                         name,
  97                         orig_broadcast_subnet->subnet_name ));
  98                 return;
  99         }
 100
 101         /*
 102          * Check that none of the IP addresses we are returning is on the
 103          * same broadcast subnet as the original requesting packet. If it
 104          * is then don't reply (although we still need to add the name
 105          * to the cache) as the actual machine will be replying also
 106          * and we don't want two replies to a broadcast query.
 107          */
 108
 109         if(namerec && original_packet->packet.nmb.header.nm_flags.bcast) {
 110                 for( i = 0; i < namerec->data.num_ips; i++) {
 111                         if( same_net_v4( namerec->data.ip[i], orig_broadcast_subnet->myip,
 112                                         orig_broadcast_subnet->mask_ip ) ) {
 113                                 DEBUG( 5, ( "wins_proxy_name_query_request_success: name %s is a WINS \
 114 proxy name and is also on the same subnet (%s) as the requester. \
 115 Not replying.\n", nmb_namestr(&namerec->name), orig_broadcast_subnet->subnet_name ) );
 116                                 return;
 117                         }
 118                 }
 119         }
 120
 121         /* Finally reply to the original name query. */
 122         reply_netbios_packet(original_packet,                /* Packet to reply to. */
 123                                 0,                              /* Result code. */
 124                                 NMB_QUERY,                      /* nmbd type code. */
 125                                 NMB_NAME_QUERY_OPCODE,          /* opcode. */
 126                                 ttl,                            /* ttl. */
 127                                 rrec->rdata,                    /* data to send. */
 128                                 rrec->rdlength);                /* data length. */
 129 }
 130
 131 /****************************************************************************
 132 Function called when the name lookup failed.
 133 ****************************************************************************/
 134
 135 static void wins_proxy_name_query_request_fail(struct subnet_record *subrec,
 136                                     struct response_record *rrec,
 137                                     struct nmb_name *question_name, int fail_code)
 138 {
 139         DEBUG(4,("wins_proxy_name_query_request_fail: WINS server returned error code %d for lookup \
 140 of name %s.\n", fail_code, nmb_namestr(question_name) ));
 141 }
 142
 143 /****************************************************************************
 144 Function to make a deep copy of the userdata we will need when the WINS
 145 proxy query returns.
 146 ****************************************************************************/
 147
 148 static struct userdata_struct *wins_proxy_userdata_copy_fn(struct userdata_struct *userdata)
 149 {
 150         struct packet_struct *p, *copy_of_p;
 151         struct userdata_struct *new_userdata = (struct userdata_struct *)SMB_MALLOC( userdata->userdata_len );
 152
 153         if(new_userdata == NULL)
 154                 return NULL;
 155
 156         new_userdata->copy_fn = userdata->copy_fn;
 157         new_userdata->free_fn = userdata->free_fn;
 158         new_userdata->userdata_len = userdata->userdata_len;
 159
 160         /* Copy the subnet_record pointer. */
 161         memcpy( new_userdata->data, userdata->data, sizeof(struct subnet_record *) );
 162
 163         /* Extract the pointer to the packet struct */
 164         memcpy((char *)&p, &userdata->data[sizeof(struct subnet_record *)], sizeof(struct packet_struct *) );
 165
 166         /* Do a deep copy of the packet. */
 167         if((copy_of_p = copy_packet(p)) == NULL) {
 168                 SAFE_FREE(new_userdata);
 169                 return NULL;
 170         }
 171
 172         /* Lock the copy. */
 173         copy_of_p->locked = True;
 174
 175         memcpy( &new_userdata->data[sizeof(struct subnet_record *)], (char *)&copy_of_p,
 176                 sizeof(struct packet_struct *) );
 177
 178         return new_userdata;
 179 }
 180
 181 /****************************************************************************
 182 Function to free the deep copy of the userdata we used when the WINS
 183 proxy query returned.
 184 ****************************************************************************/
 185
 186 static void wins_proxy_userdata_free_fn(struct userdata_struct *userdata)
 187 {
 188         struct packet_struct *p;
 189
 190         /* Extract the pointer to the packet struct */
 191         memcpy((char *)&p, &userdata->data[sizeof(struct subnet_record *)],
 192                 sizeof(struct packet_struct *));
 193
 194         /* Unlock the packet. */
 195         p->locked = False;
 196
 197         free_packet(p);
 198         ZERO_STRUCTP(userdata);
 199         SAFE_FREE(userdata);
 200 }
 201
 202 /****************************************************************************
 203  Make a WINS query on behalf of a broadcast client name query request.
 204 ****************************************************************************/
 205
 206 void make_wins_proxy_name_query_request( struct subnet_record *subrec,
 207                                          struct packet_struct *incoming_packet,
 208                                          struct nmb_name *question_name)
 209 {
 210         union {
 211             struct userdata_struct ud;
 212             char c[sizeof(struct userdata_struct) + sizeof(struct subrec *) +
 213                 sizeof(struct packet_struct *)+sizeof(long*)];
 214         } ud;
 215         struct userdata_struct *userdata = &ud.ud;
 216         unstring qname;
 217
 218         memset(&ud, '\0', sizeof(ud));
 219
 220         userdata->copy_fn = wins_proxy_userdata_copy_fn;
 221         userdata->free_fn = wins_proxy_userdata_free_fn;
 222         userdata->userdata_len = sizeof(ud);
 223         memcpy( userdata->data, (char *)&subrec, sizeof(struct subnet_record *));
 224         memcpy( &userdata->data[sizeof(struct subnet_record *)], (char *)&incoming_packet,
 225                         sizeof(struct packet_struct *));
 226
 227         /* Now use the unicast subnet to query the name with the WINS server. */
 228         pull_ascii_nstring(qname, sizeof(qname), question_name->name);
 229         query_name( unicast_subnet, qname, question_name->name_type,
 230                 wins_proxy_name_query_request_success,
 231                 wins_proxy_name_query_request_fail,
 232                 userdata);
 233 }