source/nbt_server/packet.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    packet utility functions
   5
   6    Copyright (C) Andrew Tridgell        2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 #include "includes.h"
  24 #include "nbt_server/nbt_server.h"
  25
  26 /*
  27   we received a badly formed packet - log it
  28 */
  29 void nbtd_bad_packet(struct nbt_name_packet *packet,
  30                      const struct nbt_peer_socket *src, const char *reason)
  31 {
  32         DEBUG(2,("nbtd: bad packet '%s' from %s:%d\n", reason, src->addr, src->port));
  33         if (DEBUGLVL(5)) {
  34                 NDR_PRINT_DEBUG(nbt_name_packet, packet);
  35         }
  36 }
  37
  38
  39 /*
  40   see if an incoming packet is a broadcast packet from one of our own
  41   interfaces
  42 */
  43 BOOL nbtd_self_packet(struct nbt_name_socket *nbtsock,
  44                       struct nbt_name_packet *packet,
  45                       const struct nbt_peer_socket *src)
  46 {
  47         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
  48                                                        struct nbtd_interface);
  49         struct nbtd_server *nbtsrv = iface->nbtsrv;
  50
  51         /* if its not a broadcast then its not considered a self packet */
  52         if (!(packet->operation & NBT_FLAG_BROADCAST)) {
  53                 return False;
  54         }
  55
  56         /* if its not from the nbt port, then it wasn't a broadcast from us */
  57         if (src->port != lp_nbt_port()) {
  58                 return False;
  59         }
  60
  61         /* this uses the fact that iface->nbtsock is our non-broadcast
  62            listen address */
  63         if (iface->nbtsock == nbtsock &&
  64             iface != iface->nbtsrv->bcast_interface) {
  65                 return False;
  66         }
  67
  68         /* we have to loop over our interface list, seeing if its from
  69            one of our own interfaces */
  70         for (iface=nbtsrv->interfaces;iface;iface=iface->next) {
  71                 if (strcmp(src->addr, iface->ip_address) == 0) {
  72                         return True;
  73                 }
  74         }
  75
  76         return False;
  77 }
  78
  79
  80 /*
  81   send a name query reply
  82 */
  83 void nbtd_name_query_reply(struct nbt_name_socket *nbtsock,
  84                            struct nbt_name_packet *request_packet,
  85                            const struct nbt_peer_socket *src,
  86                            struct nbt_name *name, uint32_t ttl,
  87                            uint16_t nb_flags, const char **addresses)
  88 {
  89         struct nbt_name_packet *packet;
  90         size_t num_addresses = str_list_length(addresses);
  91         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
  92                                                        struct nbtd_interface);
  93         struct nbtd_server *nbtsrv = iface->nbtsrv;
  94         int i;
  95
  96         if (num_addresses == 0) {
  97                 DEBUG(3,("No addresses in name query reply - failing\n"));
  98                 return;
  99         }
 100
 101         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 102         if (packet == NULL) return;
 103
 104         packet->name_trn_id = request_packet->name_trn_id;
 105         packet->ancount = 1;
 106         packet->operation =
 107                 NBT_FLAG_REPLY |
 108                 NBT_OPCODE_QUERY |
 109                 NBT_FLAG_AUTHORITIVE |
 110                 NBT_FLAG_RECURSION_DESIRED |
 111                 NBT_FLAG_RECURSION_AVAIL;
 112
 113         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 114         if (packet->answers == NULL) goto failed;
 115
 116         packet->answers[0].name     = *name;
 117         packet->answers[0].rr_type  = NBT_QTYPE_NETBIOS;
 118         packet->answers[0].rr_class = NBT_QCLASS_IP;
 119         packet->answers[0].ttl      = ttl;
 120         packet->answers[0].rdata.netbios.length = num_addresses*6;
 121         packet->answers[0].rdata.netbios.addresses =
 122                 talloc_array(packet->answers, struct nbt_rdata_address, num_addresses);
 123         if (packet->answers[0].rdata.netbios.addresses == NULL) goto failed;
 124
 125         for (i=0;i<num_addresses;i++) {
 126                 struct nbt_rdata_address *addr =
 127                         &packet->answers[0].rdata.netbios.addresses[i];
 128                 addr->nb_flags = nb_flags;
 129                 addr->ipaddr = talloc_strdup(packet->answers, addresses[i]);
 130                 if (addr->ipaddr == NULL) goto failed;
 131         }
 132
 133         DEBUG(7,("Sending name query reply for %s at %s to %s:%d\n",
 134                  nbt_name_string(packet, name), addresses[0], src->addr, src->port));
 135
 136         nbtsrv->stats.total_sent++;
 137         nbt_name_reply_send(nbtsock, src, packet);
 138
 139 failed:
 140         talloc_free(packet);
 141 }
 142
 143
 144 /*
 145   send a negative name query reply
 146 */
 147 void nbtd_negative_name_query_reply(struct nbt_name_socket *nbtsock,
 148                                     struct nbt_name_packet *request_packet,
 149                                     const struct nbt_peer_socket *src)
 150 {
 151         struct nbt_name_packet *packet;
 152         struct nbt_name *name = &request_packet->questions[0].name;
 153         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
 154                                                        struct nbtd_interface);
 155         struct nbtd_server *nbtsrv = iface->nbtsrv;
 156
 157         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 158         if (packet == NULL) return;
 159
 160         packet->name_trn_id = request_packet->name_trn_id;
 161         packet->ancount = 1;
 162         packet->operation =
 163                 NBT_FLAG_REPLY |
 164                 NBT_OPCODE_QUERY |
 165                 NBT_FLAG_AUTHORITIVE |
 166                 NBT_RCODE_NAM;
 167
 168         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 169         if (packet->answers == NULL) goto failed;
 170
 171         packet->answers[0].name      = *name;
 172         packet->answers[0].rr_type   = NBT_QTYPE_NULL;
 173         packet->answers[0].rr_class  = NBT_QCLASS_IP;
 174         packet->answers[0].ttl       = 0;
 175         ZERO_STRUCT(packet->answers[0].rdata);
 176
 177         DEBUG(7,("Sending negative name query reply for %s to %s:%d\n",
 178                  nbt_name_string(packet, name), src->addr, src->port));
 179
 180         nbtsrv->stats.total_sent++;
 181         nbt_name_reply_send(nbtsock, src, packet);
 182
 183 failed:
 184         talloc_free(packet);
 185 }
 186
 187 /*
 188   send a name registration reply
 189 */
 190 void nbtd_name_registration_reply(struct nbt_name_socket *nbtsock,
 191                                   struct nbt_name_packet *request_packet,
 192                                   const struct nbt_peer_socket *src,
 193                                   uint8_t rcode)
 194 {
 195         struct nbt_name_packet *packet;
 196         struct nbt_name *name = &request_packet->questions[0].name;
 197         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
 198                                                        struct nbtd_interface);
 199         struct nbtd_server *nbtsrv = iface->nbtsrv;
 200
 201         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 202         if (packet == NULL) return;
 203
 204         packet->name_trn_id = request_packet->name_trn_id;
 205         packet->ancount = 1;
 206         packet->operation =
 207                 NBT_FLAG_REPLY |
 208                 NBT_OPCODE_REGISTER |
 209                 NBT_FLAG_AUTHORITIVE |
 210                 NBT_FLAG_RECURSION_DESIRED |
 211                 NBT_FLAG_RECURSION_AVAIL |
 212                 rcode;
 213
 214         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 215         if (packet->answers == NULL) goto failed;
 216
 217         packet->answers[0].name     = *name;
 218         packet->answers[0].rr_type  = NBT_QTYPE_NETBIOS;
 219         packet->answers[0].rr_class = NBT_QCLASS_IP;
 220         packet->answers[0].ttl      = request_packet->additional[0].ttl;
 221         packet->answers[0].rdata    = request_packet->additional[0].rdata;
 222
 223         DEBUG(7,("Sending %s name registration reply for %s to %s:%d\n",
 224                  rcode==0?"positive":"negative",
 225                  nbt_name_string(packet, name), src->addr, src->port));
 226
 227         nbtsrv->stats.total_sent++;
 228         nbt_name_reply_send(nbtsock, src, packet);
 229
 230 failed:
 231         talloc_free(packet);
 232 }
 233
 234
 235 /*
 236   send a name release reply
 237 */
 238 void nbtd_name_release_reply(struct nbt_name_socket *nbtsock,
 239                              struct nbt_name_packet *request_packet,
 240                              const struct nbt_peer_socket *src,
 241                              uint8_t rcode)
 242 {
 243         struct nbt_name_packet *packet;
 244         struct nbt_name *name = &request_packet->questions[0].name;
 245         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
 246                                                        struct nbtd_interface);
 247         struct nbtd_server *nbtsrv = iface->nbtsrv;
 248
 249         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 250         if (packet == NULL) return;
 251
 252         packet->name_trn_id = request_packet->name_trn_id;
 253         packet->ancount = 1;
 254         packet->operation =
 255                 NBT_FLAG_REPLY |
 256                 NBT_OPCODE_RELEASE |
 257                 NBT_FLAG_AUTHORITIVE |
 258                 rcode;
 259
 260         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 261         if (packet->answers == NULL) goto failed;
 262
 263         packet->answers[0].name     = *name;
 264         packet->answers[0].rr_type  = NBT_QTYPE_NETBIOS;
 265         packet->answers[0].rr_class = NBT_QCLASS_IP;
 266         packet->answers[0].ttl      = request_packet->additional[0].ttl;
 267         packet->answers[0].rdata    = request_packet->additional[0].rdata;
 268
 269         DEBUG(7,("Sending %s name release reply for %s to %s:%d\n",
 270                  rcode==0?"positive":"negative",
 271                  nbt_name_string(packet, name), src->addr, src->port));
 272
 273         nbtsrv->stats.total_sent++;
 274         nbt_name_reply_send(nbtsock, src, packet);
 275
 276 failed:
 277         talloc_free(packet);
 278 }
 279
 280
 281 /*
 282   send a WACK reply
 283 */
 284 void nbtd_wack_reply(struct nbt_name_socket *nbtsock,
 285                      struct nbt_name_packet *request_packet,
 286                      const struct nbt_peer_socket *src,
 287                      uint32_t ttl)
 288 {
 289         struct nbt_name_packet *packet;
 290         struct nbt_name *name = &request_packet->questions[0].name;
 291         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
 292                                                        struct nbtd_interface);
 293         struct nbtd_server *nbtsrv = iface->nbtsrv;
 294
 295         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 296         if (packet == NULL) return;
 297
 298         packet->name_trn_id = request_packet->name_trn_id;
 299         packet->ancount = 1;
 300         packet->operation =
 301                 NBT_FLAG_REPLY |
 302                 NBT_OPCODE_WACK |
 303                 NBT_FLAG_AUTHORITIVE;
 304
 305         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 306         if (packet->answers == NULL) goto failed;
 307
 308         packet->answers[0].name              = *name;
 309         packet->answers[0].rr_type           = NBT_QTYPE_NETBIOS;
 310         packet->answers[0].rr_class          = NBT_QCLASS_IP;
 311         packet->answers[0].ttl               = ttl;
 312         packet->answers[0].rdata.data.length = 2;
 313         packet->answers[0].rdata.data.data   = talloc_size(packet, 2);
 314         if (packet->answers[0].rdata.data.data == NULL) goto failed;
 315         RSSVAL(packet->answers[0].rdata.data.data, 0, request_packet->operation);
 316
 317         DEBUG(7,("Sending WACK reply for %s to %s:%d\n",
 318                  nbt_name_string(packet, name), src->addr, src->port));
 319
 320         nbtsrv->stats.total_sent++;
 321         nbt_name_reply_send(nbtsock, src, packet);
 322
 323 failed:
 324         talloc_free(packet);
 325 }