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