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 "lib/socket/socket.h"
  25 #include "librpc/gen_ndr/ndr_nbt.h"
  26
  27 /*
  28   we received a badly formed packet - log it
  29 */
  30 void nbtd_bad_packet(struct nbt_name_packet *packet,
  31                      const struct socket_address *src, const char *reason)
  32 {
  33         DEBUG(2,("nbtd: bad packet '%s' from %s:%d\n", reason, src->addr, src->port));
  34         if (DEBUGLVL(5)) {
  35                 NDR_PRINT_DEBUG(nbt_name_packet, packet);
  36         }
  37 }
  38
  39
  40 /*
  41   see if an incoming packet is a broadcast packet from one of our own
  42   interfaces
  43 */
  44 BOOL nbtd_self_packet_and_bcast(struct nbt_name_socket *nbtsock,
  45                                 struct nbt_name_packet *packet,
  46                                 const struct socket_address *src)
  47 {
  48         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
  49                                                        struct nbtd_interface);
  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         /*
  57          * this uses the fact that iface->nbtsock is the unicast listen address
  58          * if the interface isn't the global bcast interface
  59          *
  60          * so if the request was directed to the unicast address it isn't a broadcast
  61          * message
  62          */
  63         if (iface->nbtsock == nbtsock &&
  64             iface != iface->nbtsrv->bcast_interface) {
  65                 return False;
  66         }
  67
  68         return nbtd_self_packet(nbtsock, packet, src);
  69 }
  70
  71 BOOL nbtd_self_packet(struct nbt_name_socket *nbtsock,
  72                       struct nbt_name_packet *packet,
  73                       const struct socket_address *src)
  74 {
  75         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
  76                                                        struct nbtd_interface);
  77         struct nbtd_server *nbtsrv = iface->nbtsrv;
  78
  79         /* if its not from the nbt port, then it wasn't a broadcast from us */
  80         if (src->port != lp_nbt_port()) {
  81                 return False;
  82         }
  83
  84         /* we have to loop over our interface list, seeing if its from
  85            one of our own interfaces */
  86         for (iface=nbtsrv->interfaces;iface;iface=iface->next) {
  87                 if (strcmp(src->addr, iface->ip_address) == 0) {
  88                         return True;
  89                 }
  90         }
  91
  92         return False;
  93 }
  94
  95
  96 /*
  97   send a name query reply
  98 */
  99 void nbtd_name_query_reply(struct nbt_name_socket *nbtsock,
 100                            struct nbt_name_packet *request_packet,
 101                            struct socket_address *src,
 102                            struct nbt_name *name, uint32_t ttl,
 103                            uint16_t nb_flags, const char **addresses)
 104 {
 105         struct nbt_name_packet *packet;
 106         size_t num_addresses = str_list_length(addresses);
 107         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
 108                                                        struct nbtd_interface);
 109         struct nbtd_server *nbtsrv = iface->nbtsrv;
 110         int i;
 111
 112         if (num_addresses == 0) {
 113                 DEBUG(3,("No addresses in name query reply - failing\n"));
 114                 return;
 115         }
 116
 117         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 118         if (packet == NULL) return;
 119
 120         packet->name_trn_id = request_packet->name_trn_id;
 121         packet->ancount = 1;
 122         packet->operation =
 123                 NBT_FLAG_REPLY |
 124                 NBT_OPCODE_QUERY |
 125                 NBT_FLAG_AUTHORITIVE |
 126                 NBT_FLAG_RECURSION_DESIRED |
 127                 NBT_FLAG_RECURSION_AVAIL;
 128
 129         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 130         if (packet->answers == NULL) goto failed;
 131
 132         packet->answers[0].name     = *name;
 133         packet->answers[0].rr_type  = NBT_QTYPE_NETBIOS;
 134         packet->answers[0].rr_class = NBT_QCLASS_IP;
 135         packet->answers[0].ttl      = ttl;
 136         packet->answers[0].rdata.netbios.length = num_addresses*6;
 137         packet->answers[0].rdata.netbios.addresses =
 138                 talloc_array(packet->answers, struct nbt_rdata_address, num_addresses);
 139         if (packet->answers[0].rdata.netbios.addresses == NULL) goto failed;
 140
 141         for (i=0;i<num_addresses;i++) {
 142                 struct nbt_rdata_address *addr =
 143                         &packet->answers[0].rdata.netbios.addresses[i];
 144                 addr->nb_flags = nb_flags;
 145                 addr->ipaddr = talloc_strdup(packet->answers, addresses[i]);
 146                 if (addr->ipaddr == NULL) goto failed;
 147         }
 148
 149         DEBUG(7,("Sending name query reply for %s at %s to %s:%d\n",
 150                  nbt_name_string(packet, name), addresses[0], src->addr, src->port));
 151
 152         nbtsrv->stats.total_sent++;
 153         nbt_name_reply_send(nbtsock, src, packet);
 154
 155 failed:
 156         talloc_free(packet);
 157 }
 158
 159
 160 /*
 161   send a negative name query reply
 162 */
 163 void nbtd_negative_name_query_reply(struct nbt_name_socket *nbtsock,
 164                                     struct nbt_name_packet *request_packet,
 165                                     struct socket_address *src)
 166 {
 167         struct nbt_name_packet *packet;
 168         struct nbt_name *name = &request_packet->questions[0].name;
 169         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
 170                                                        struct nbtd_interface);
 171         struct nbtd_server *nbtsrv = iface->nbtsrv;
 172
 173         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 174         if (packet == NULL) return;
 175
 176         packet->name_trn_id = request_packet->name_trn_id;
 177         packet->ancount = 1;
 178         packet->operation =
 179                 NBT_FLAG_REPLY |
 180                 NBT_OPCODE_QUERY |
 181                 NBT_FLAG_AUTHORITIVE |
 182                 NBT_RCODE_NAM;
 183
 184         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 185         if (packet->answers == NULL) goto failed;
 186
 187         packet->answers[0].name      = *name;
 188         packet->answers[0].rr_type   = NBT_QTYPE_NULL;
 189         packet->answers[0].rr_class  = NBT_QCLASS_IP;
 190         packet->answers[0].ttl       = 0;
 191         ZERO_STRUCT(packet->answers[0].rdata);
 192
 193         DEBUG(7,("Sending negative name query reply for %s to %s:%d\n",
 194                  nbt_name_string(packet, name), src->addr, src->port));
 195
 196         nbtsrv->stats.total_sent++;
 197         nbt_name_reply_send(nbtsock, src, packet);
 198
 199 failed:
 200         talloc_free(packet);
 201 }
 202
 203 /*
 204   send a name registration reply
 205 */
 206 void nbtd_name_registration_reply(struct nbt_name_socket *nbtsock,
 207                                   struct nbt_name_packet *request_packet,
 208                                   struct socket_address *src,
 209                                   uint8_t rcode)
 210 {
 211         struct nbt_name_packet *packet;
 212         struct nbt_name *name = &request_packet->questions[0].name;
 213         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
 214                                                        struct nbtd_interface);
 215         struct nbtd_server *nbtsrv = iface->nbtsrv;
 216
 217         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 218         if (packet == NULL) return;
 219
 220         packet->name_trn_id = request_packet->name_trn_id;
 221         packet->ancount = 1;
 222         packet->operation =
 223                 NBT_FLAG_REPLY |
 224                 NBT_OPCODE_REGISTER |
 225                 NBT_FLAG_AUTHORITIVE |
 226                 NBT_FLAG_RECURSION_DESIRED |
 227                 NBT_FLAG_RECURSION_AVAIL |
 228                 rcode;
 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_NETBIOS;
 235         packet->answers[0].rr_class = NBT_QCLASS_IP;
 236         packet->answers[0].ttl      = request_packet->additional[0].ttl;
 237         packet->answers[0].rdata    = request_packet->additional[0].rdata;
 238
 239         DEBUG(7,("Sending %s name registration reply for %s to %s:%d\n",
 240                  rcode==0?"positive":"negative",
 241                  nbt_name_string(packet, name), src->addr, src->port));
 242
 243         nbtsrv->stats.total_sent++;
 244         nbt_name_reply_send(nbtsock, src, packet);
 245
 246 failed:
 247         talloc_free(packet);
 248 }
 249
 250
 251 /*
 252   send a name release reply
 253 */
 254 void nbtd_name_release_reply(struct nbt_name_socket *nbtsock,
 255                              struct nbt_name_packet *request_packet,
 256                              struct socket_address *src,
 257                              uint8_t rcode)
 258 {
 259         struct nbt_name_packet *packet;
 260         struct nbt_name *name = &request_packet->questions[0].name;
 261         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
 262                                                        struct nbtd_interface);
 263         struct nbtd_server *nbtsrv = iface->nbtsrv;
 264
 265         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 266         if (packet == NULL) return;
 267
 268         packet->name_trn_id = request_packet->name_trn_id;
 269         packet->ancount = 1;
 270         packet->operation =
 271                 NBT_FLAG_REPLY |
 272                 NBT_OPCODE_RELEASE |
 273                 NBT_FLAG_AUTHORITIVE |
 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 release 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 WACK reply
 299 */
 300 void nbtd_wack_reply(struct nbt_name_socket *nbtsock,
 301                      struct nbt_name_packet *request_packet,
 302                      struct socket_address *src,
 303                      uint32_t ttl)
 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,
 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_WACK |
 319                 NBT_FLAG_AUTHORITIVE;
 320
 321         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 322         if (packet->answers == NULL) goto failed;
 323
 324         packet->answers[0].name              = *name;
 325         packet->answers[0].rr_type           = NBT_QTYPE_NETBIOS;
 326         packet->answers[0].rr_class          = NBT_QCLASS_IP;
 327         packet->answers[0].ttl               = ttl;
 328         packet->answers[0].rdata.data.length = 2;
 329         packet->answers[0].rdata.data.data   = talloc_size(packet, 2);
 330         if (packet->answers[0].rdata.data.data == NULL) goto failed;
 331         RSSVAL(packet->answers[0].rdata.data.data, 0, request_packet->operation);
 332
 333         DEBUG(7,("Sending WACK reply for %s to %s:%d\n",
 334                  nbt_name_string(packet, name), src->addr, src->port));
 335
 336         nbtsrv->stats.total_sent++;
 337         nbt_name_reply_send(nbtsock, src, packet);
 338
 339 failed:
 340         talloc_free(packet);
 341 }