source4/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 3 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, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "nbt_server/nbt_server.h"
  24 #include "smbd/service_task.h"
  25 #include "lib/socket/socket.h"
  26 #include "librpc/gen_ndr/ndr_nbt.h"
  27 #include "param/param.h"
  28
  29 /*
  30   we received a badly formed packet - log it
  31 */
  32 void nbtd_bad_packet(struct nbt_name_packet *packet,
  33                      const struct socket_address *src, const char *reason)
  34 {
  35         DEBUG(2,("nbtd: bad packet '%s' from %s:%d\n", reason, src->addr, src->port));
  36         if (DEBUGLVL(5)) {
  37                 NDR_PRINT_DEBUG(nbt_name_packet, packet);
  38         }
  39 }
  40
  41
  42 /*
  43   see if an incoming packet is a broadcast packet from one of our own
  44   interfaces
  45 */
  46 bool nbtd_self_packet_and_bcast(struct nbt_name_socket *nbtsock,
  47                                 struct nbt_name_packet *packet,
  48                                 const struct socket_address *src)
  49 {
  50         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private_data,
  51                                                        struct nbtd_interface);
  52
  53         /* if its not a broadcast then its not considered a self packet */
  54         if (!(packet->operation & NBT_FLAG_BROADCAST)) {
  55                 return false;
  56         }
  57
  58         /*
  59          * this uses the fact that iface->nbtsock is the unicast listen address
  60          * if the interface isn't the global bcast interface
  61          *
  62          * so if the request was directed to the unicast address it isn't a broadcast
  63          * message
  64          */
  65         if (iface->nbtsock == nbtsock &&
  66             iface != iface->nbtsrv->bcast_interface) {
  67                 return false;
  68         }
  69
  70         return nbtd_self_packet(nbtsock, packet, src);
  71 }
  72
  73 bool nbtd_self_packet(struct nbt_name_socket *nbtsock,
  74                       struct nbt_name_packet *packet,
  75                       const struct socket_address *src)
  76 {
  77         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private_data,
  78                                                        struct nbtd_interface);
  79         struct nbtd_server *nbtsrv = iface->nbtsrv;
  80
  81         /* if its not from the nbt port, then it wasn't a broadcast from us */
  82         if (src->port != lpcfg_nbt_port(iface->nbtsrv->task->lp_ctx)) {
  83                 return false;
  84         }
  85
  86         /* we have to loop over our interface list, seeing if its from
  87            one of our own interfaces */
  88         for (iface=nbtsrv->interfaces;iface;iface=iface->next) {
  89                 if (strcmp(src->addr, iface->ip_address) == 0) {
  90                         return true;
  91                 }
  92         }
  93
  94         return false;
  95 }
  96
  97 struct nbt_name_packet *nbtd_name_query_reply_packet(
  98         TALLOC_CTX *mem_ctx,
  99         uint16_t trn_id,
 100         uint32_t ttl,
 101         uint16_t nb_flags,
 102         const struct nbt_name *name,
 103         const char **addresses,
 104         size_t num_addresses)
 105 {
 106         struct nbt_name_packet *packet;
 107         size_t i;
 108         struct nbt_res_rec *answer;
 109         struct nbt_rdata_netbios *rdata;
 110         NTSTATUS status;
 111
 112         if (num_addresses == 0) {
 113                 return NULL;
 114         }
 115
 116         packet = talloc_zero(mem_ctx, struct nbt_name_packet);
 117         if (packet == NULL) {
 118                 return NULL;
 119         }
 120
 121         packet->name_trn_id = trn_id;
 122         packet->ancount = 1;
 123         packet->operation =
 124                 NBT_FLAG_REPLY |
 125                 NBT_OPCODE_QUERY |
 126                 NBT_FLAG_AUTHORITATIVE |
 127                 NBT_FLAG_RECURSION_DESIRED |
 128                 NBT_FLAG_RECURSION_AVAIL;
 129
 130         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 131         if (packet->answers == NULL) {
 132                 goto failed;
 133         }
 134         answer = packet->answers;
 135
 136         status = nbt_name_dup(packet->answers, name, &answer->name);
 137         if (!NT_STATUS_IS_OK(status)) {
 138                 goto failed;
 139         }
 140         answer->rr_type  = NBT_QTYPE_NETBIOS;
 141         answer->rr_class = NBT_QCLASS_IP;
 142         answer->ttl      = ttl;
 143
 144         rdata = &answer->rdata.netbios;
 145         rdata->length = num_addresses*6;
 146         rdata->addresses = talloc_array(
 147                 packet->answers,
 148                 struct nbt_rdata_address,
 149                 num_addresses);
 150         if (rdata->addresses == NULL) {
 151                 goto failed;
 152         }
 153
 154         for (i=0; i<num_addresses; i++) {
 155                 struct nbt_rdata_address *addr = &rdata->addresses[i];
 156                 addr->nb_flags = nb_flags;
 157                 addr->ipaddr = talloc_strdup(packet->answers, addresses[i]);
 158                 if (addr->ipaddr == NULL) {
 159                         goto failed;
 160                 }
 161         }
 162
 163         return packet;
 164
 165 failed:
 166         TALLOC_FREE(packet);
 167         return NULL;
 168 }
 169
 170 /*
 171   send a name query reply
 172 */
 173 void nbtd_name_query_reply(struct nbt_name_socket *nbtsock,
 174                            struct nbt_name_packet *request_packet,
 175                            struct socket_address *src,
 176                            struct nbt_name *name, uint32_t ttl,
 177                            uint16_t nb_flags, const char **addresses)
 178 {
 179         struct nbt_name_packet *packet;
 180         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private_data,
 181                                                        struct nbtd_interface);
 182         struct nbtd_server *nbtsrv = iface->nbtsrv;
 183
 184         packet = nbtd_name_query_reply_packet(
 185                 nbtsock,
 186                 request_packet->name_trn_id,
 187                 ttl,
 188                 nb_flags,
 189                 name,
 190                 addresses,
 191                 str_list_length(addresses));
 192         if (packet == NULL) {
 193                 return;
 194         }
 195
 196         DEBUG(7,("Sending name query reply for %s at %s to %s:%d\n",
 197                  nbt_name_string(packet, name), addresses[0], src->addr, src->port));
 198
 199         nbtsrv->stats.total_sent++;
 200         nbt_name_reply_send(nbtsock, src, packet);
 201
 202         talloc_free(packet);
 203 }
 204
 205
 206 /*
 207   send a negative name query reply
 208 */
 209 void nbtd_negative_name_query_reply(struct nbt_name_socket *nbtsock,
 210                                     struct nbt_name_packet *request_packet,
 211                                     struct socket_address *src)
 212 {
 213         struct nbt_name_packet *packet;
 214         struct nbt_name *name = &request_packet->questions[0].name;
 215         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private_data,
 216                                                        struct nbtd_interface);
 217         struct nbtd_server *nbtsrv = iface->nbtsrv;
 218
 219         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 220         if (packet == NULL) return;
 221
 222         packet->name_trn_id = request_packet->name_trn_id;
 223         packet->ancount = 1;
 224         packet->operation =
 225                 NBT_FLAG_REPLY |
 226                 NBT_OPCODE_QUERY |
 227                 NBT_FLAG_AUTHORITATIVE |
 228                 NBT_RCODE_NAM;
 229
 230         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 231         if (packet->answers == NULL) goto failed;
 232
 233         packet->answers[0].name      = *name;
 234         packet->answers[0].rr_type   = NBT_QTYPE_NULL;
 235         packet->answers[0].rr_class  = NBT_QCLASS_IP;
 236         packet->answers[0].ttl       = 0;
 237         ZERO_STRUCT(packet->answers[0].rdata);
 238
 239         DEBUG(7,("Sending negative name query reply for %s to %s:%d\n",
 240                  nbt_name_string(packet, name), src->addr, src->port));
 241
 242         nbtsrv->stats.total_sent++;
 243         nbt_name_reply_send(nbtsock, src, packet);
 244
 245 failed:
 246         talloc_free(packet);
 247 }
 248
 249 /*
 250   send a name registration reply
 251 */
 252 void nbtd_name_registration_reply(struct nbt_name_socket *nbtsock,
 253                                   struct nbt_name_packet *request_packet,
 254                                   struct socket_address *src,
 255                                   uint8_t rcode)
 256 {
 257         struct nbt_name_packet *packet;
 258         struct nbt_name *name = &request_packet->questions[0].name;
 259         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private_data,
 260                                                        struct nbtd_interface);
 261         struct nbtd_server *nbtsrv = iface->nbtsrv;
 262
 263         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 264         if (packet == NULL) return;
 265
 266         packet->name_trn_id = request_packet->name_trn_id;
 267         packet->ancount = 1;
 268         packet->operation =
 269                 NBT_FLAG_REPLY |
 270                 NBT_OPCODE_REGISTER |
 271                 NBT_FLAG_AUTHORITATIVE |
 272                 NBT_FLAG_RECURSION_DESIRED |
 273                 NBT_FLAG_RECURSION_AVAIL |
 274                 rcode;
 275
 276         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 277         if (packet->answers == NULL) goto failed;
 278
 279         packet->answers[0].name     = *name;
 280         packet->answers[0].rr_type  = NBT_QTYPE_NETBIOS;
 281         packet->answers[0].rr_class = NBT_QCLASS_IP;
 282         packet->answers[0].ttl      = request_packet->additional[0].ttl;
 283         packet->answers[0].rdata    = request_packet->additional[0].rdata;
 284
 285         DEBUG(7,("Sending %s name registration reply for %s to %s:%d\n",
 286                  rcode==0?"positive":"negative",
 287                  nbt_name_string(packet, name), src->addr, src->port));
 288
 289         nbtsrv->stats.total_sent++;
 290         nbt_name_reply_send(nbtsock, src, packet);
 291
 292 failed:
 293         talloc_free(packet);
 294 }
 295
 296
 297 /*
 298   send a name release reply
 299 */
 300 void nbtd_name_release_reply(struct nbt_name_socket *nbtsock,
 301                              struct nbt_name_packet *request_packet,
 302                              struct socket_address *src,
 303                              uint8_t rcode)
 304 {
 305         struct nbt_name_packet *packet;
 306         struct nbt_name *name = &request_packet->questions[0].name;
 307         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private_data,
 308                                                        struct nbtd_interface);
 309         struct nbtd_server *nbtsrv = iface->nbtsrv;
 310
 311         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 312         if (packet == NULL) return;
 313
 314         packet->name_trn_id = request_packet->name_trn_id;
 315         packet->ancount = 1;
 316         packet->operation =
 317                 NBT_FLAG_REPLY |
 318                 NBT_OPCODE_RELEASE |
 319                 NBT_FLAG_AUTHORITATIVE |
 320                 rcode;
 321
 322         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 323         if (packet->answers == NULL) goto failed;
 324
 325         packet->answers[0].name     = *name;
 326         packet->answers[0].rr_type  = NBT_QTYPE_NETBIOS;
 327         packet->answers[0].rr_class = NBT_QCLASS_IP;
 328         packet->answers[0].ttl      = request_packet->additional[0].ttl;
 329         packet->answers[0].rdata    = request_packet->additional[0].rdata;
 330
 331         DEBUG(7,("Sending %s name release reply for %s to %s:%d\n",
 332                  rcode==0?"positive":"negative",
 333                  nbt_name_string(packet, name), src->addr, src->port));
 334
 335         nbtsrv->stats.total_sent++;
 336         nbt_name_reply_send(nbtsock, src, packet);
 337
 338 failed:
 339         talloc_free(packet);
 340 }
 341
 342
 343 /*
 344   send a WACK reply
 345 */
 346 void nbtd_wack_reply(struct nbt_name_socket *nbtsock,
 347                      struct nbt_name_packet *request_packet,
 348                      struct socket_address *src,
 349                      uint32_t ttl)
 350 {
 351         struct nbt_name_packet *packet;
 352         struct nbt_name *name = &request_packet->questions[0].name;
 353         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private_data,
 354                                                        struct nbtd_interface);
 355         struct nbtd_server *nbtsrv = iface->nbtsrv;
 356
 357         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 358         if (packet == NULL) return;
 359
 360         packet->name_trn_id = request_packet->name_trn_id;
 361         packet->ancount = 1;
 362         packet->operation =
 363                 NBT_FLAG_REPLY |
 364                 NBT_OPCODE_WACK |
 365                 NBT_FLAG_AUTHORITATIVE;
 366
 367         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 368         if (packet->answers == NULL) goto failed;
 369
 370         packet->answers[0].name              = *name;
 371         packet->answers[0].rr_type           = NBT_QTYPE_NETBIOS;
 372         packet->answers[0].rr_class          = NBT_QCLASS_IP;
 373         packet->answers[0].ttl               = ttl;
 374         packet->answers[0].rdata.data.length = 2;
 375         packet->answers[0].rdata.data.data   = talloc_array(packet, uint8_t, 2);
 376         if (packet->answers[0].rdata.data.data == NULL) goto failed;
 377         RSSVAL(packet->answers[0].rdata.data.data, 0, request_packet->operation);
 378
 379         DEBUG(7,("Sending WACK reply for %s to %s:%d\n",
 380                  nbt_name_string(packet, name), src->addr, src->port));
 381
 382         nbtsrv->stats.total_sent++;
 383         nbt_name_reply_send(nbtsock, src, packet);
 384
 385 failed:
 386         talloc_free(packet);
 387 }