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 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 #include "lib/socket/socket.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(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         struct nbtd_server *nbtsrv = iface->nbtsrv;
  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         /* if its not from the nbt port, then it wasn't a broadcast from us */
  58         if (src->port != lp_nbt_port()) {
  59                 return False;
  60         }
  61
  62         /* this uses the fact that iface->nbtsock is our non-broadcast
  63            listen address */
  64         if (iface->nbtsock == nbtsock &&
  65             iface != iface->nbtsrv->bcast_interface) {
  66                 return False;
  67         }
  68
  69         /* we have to loop over our interface list, seeing if its from
  70            one of our own interfaces */
  71         for (iface=nbtsrv->interfaces;iface;iface=iface->next) {
  72                 if (strcmp(src->addr, iface->ip_address) == 0) {
  73                         return True;
  74                 }
  75         }
  76
  77         return False;
  78 }
  79
  80
  81 /*
  82   send a name query reply
  83 */
  84 void nbtd_name_query_reply(struct nbt_name_socket *nbtsock,
  85                            struct nbt_name_packet *request_packet,
  86                            struct socket_address *src,
  87                            struct nbt_name *name, uint32_t ttl,
  88                            uint16_t nb_flags, const char **addresses)
  89 {
  90         struct nbt_name_packet *packet;
  91         size_t num_addresses = str_list_length(addresses);
  92         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
  93                                                        struct nbtd_interface);
  94         struct nbtd_server *nbtsrv = iface->nbtsrv;
  95         int i;
  96
  97         if (num_addresses == 0) {
  98                 DEBUG(3,("No addresses in name query reply - failing\n"));
  99                 return;
 100         }
 101
 102         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 103         if (packet == NULL) return;
 104
 105         packet->name_trn_id = request_packet->name_trn_id;
 106         packet->ancount = 1;
 107         packet->operation =
 108                 NBT_FLAG_REPLY |
 109                 NBT_OPCODE_QUERY |
 110                 NBT_FLAG_AUTHORITIVE |
 111                 NBT_FLAG_RECURSION_DESIRED |
 112                 NBT_FLAG_RECURSION_AVAIL;
 113
 114         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 115         if (packet->answers == NULL) goto failed;
 116
 117         packet->answers[0].name     = *name;
 118         packet->answers[0].rr_type  = NBT_QTYPE_NETBIOS;
 119         packet->answers[0].rr_class = NBT_QCLASS_IP;
 120         packet->answers[0].ttl      = ttl;
 121         packet->answers[0].rdata.netbios.length = num_addresses*6;
 122         packet->answers[0].rdata.netbios.addresses =
 123                 talloc_array(packet->answers, struct nbt_rdata_address, num_addresses);
 124         if (packet->answers[0].rdata.netbios.addresses == NULL) goto failed;
 125
 126         for (i=0;i<num_addresses;i++) {
 127                 struct nbt_rdata_address *addr =
 128                         &packet->answers[0].rdata.netbios.addresses[i];
 129                 addr->nb_flags = nb_flags;
 130                 addr->ipaddr = talloc_strdup(packet->answers, addresses[i]);
 131                 if (addr->ipaddr == NULL) goto failed;
 132         }
 133
 134         DEBUG(7,("Sending name query reply for %s at %s to %s:%d\n",
 135                  nbt_name_string(packet, name), addresses[0], src->addr, src->port));
 136
 137         nbtsrv->stats.total_sent++;
 138         nbt_name_reply_send(nbtsock, src, packet);
 139
 140 failed:
 141         talloc_free(packet);
 142 }
 143
 144
 145 /*
 146   send a negative name query reply
 147 */
 148 void nbtd_negative_name_query_reply(struct nbt_name_socket *nbtsock,
 149                                     struct nbt_name_packet *request_packet,
 150                                     struct socket_address *src)
 151 {
 152         struct nbt_name_packet *packet;
 153         struct nbt_name *name = &request_packet->questions[0].name;
 154         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
 155                                                        struct nbtd_interface);
 156         struct nbtd_server *nbtsrv = iface->nbtsrv;
 157
 158         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 159         if (packet == NULL) return;
 160
 161         packet->name_trn_id = request_packet->name_trn_id;
 162         packet->ancount = 1;
 163         packet->operation =
 164                 NBT_FLAG_REPLY |
 165                 NBT_OPCODE_QUERY |
 166                 NBT_FLAG_AUTHORITIVE |
 167                 NBT_RCODE_NAM;
 168
 169         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 170         if (packet->answers == NULL) goto failed;
 171
 172         packet->answers[0].name      = *name;
 173         packet->answers[0].rr_type   = NBT_QTYPE_NULL;
 174         packet->answers[0].rr_class  = NBT_QCLASS_IP;
 175         packet->answers[0].ttl       = 0;
 176         ZERO_STRUCT(packet->answers[0].rdata);
 177
 178         DEBUG(7,("Sending negative name query reply for %s to %s:%d\n",
 179                  nbt_name_string(packet, name), src->addr, src->port));
 180
 181         nbtsrv->stats.total_sent++;
 182         nbt_name_reply_send(nbtsock, src, packet);
 183
 184 failed:
 185         talloc_free(packet);
 186 }
 187
 188 /*
 189   send a name registration reply
 190 */
 191 void nbtd_name_registration_reply(struct nbt_name_socket *nbtsock,
 192                                   struct nbt_name_packet *request_packet,
 193                                   struct socket_address *src,
 194                                   uint8_t rcode)
 195 {
 196         struct nbt_name_packet *packet;
 197         struct nbt_name *name = &request_packet->questions[0].name;
 198         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
 199                                                        struct nbtd_interface);
 200         struct nbtd_server *nbtsrv = iface->nbtsrv;
 201
 202         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 203         if (packet == NULL) return;
 204
 205         packet->name_trn_id = request_packet->name_trn_id;
 206         packet->ancount = 1;
 207         packet->operation =
 208                 NBT_FLAG_REPLY |
 209                 NBT_OPCODE_REGISTER |
 210                 NBT_FLAG_AUTHORITIVE |
 211                 NBT_FLAG_RECURSION_DESIRED |
 212                 NBT_FLAG_RECURSION_AVAIL |
 213                 rcode;
 214
 215         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 216         if (packet->answers == NULL) goto failed;
 217
 218         packet->answers[0].name     = *name;
 219         packet->answers[0].rr_type  = NBT_QTYPE_NETBIOS;
 220         packet->answers[0].rr_class = NBT_QCLASS_IP;
 221         packet->answers[0].ttl      = request_packet->additional[0].ttl;
 222         packet->answers[0].rdata    = request_packet->additional[0].rdata;
 223
 224         DEBUG(7,("Sending %s name registration reply for %s to %s:%d\n",
 225                  rcode==0?"positive":"negative",
 226                  nbt_name_string(packet, name), src->addr, src->port));
 227
 228         nbtsrv->stats.total_sent++;
 229         nbt_name_reply_send(nbtsock, src, packet);
 230
 231 failed:
 232         talloc_free(packet);
 233 }
 234
 235
 236 /*
 237   send a name release reply
 238 */
 239 void nbtd_name_release_reply(struct nbt_name_socket *nbtsock,
 240                              struct nbt_name_packet *request_packet,
 241                              struct socket_address *src,
 242                              uint8_t rcode)
 243 {
 244         struct nbt_name_packet *packet;
 245         struct nbt_name *name = &request_packet->questions[0].name;
 246         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
 247                                                        struct nbtd_interface);
 248         struct nbtd_server *nbtsrv = iface->nbtsrv;
 249
 250         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 251         if (packet == NULL) return;
 252
 253         packet->name_trn_id = request_packet->name_trn_id;
 254         packet->ancount = 1;
 255         packet->operation =
 256                 NBT_FLAG_REPLY |
 257                 NBT_OPCODE_RELEASE |
 258                 NBT_FLAG_AUTHORITIVE |
 259                 rcode;
 260
 261         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 262         if (packet->answers == NULL) goto failed;
 263
 264         packet->answers[0].name     = *name;
 265         packet->answers[0].rr_type  = NBT_QTYPE_NETBIOS;
 266         packet->answers[0].rr_class = NBT_QCLASS_IP;
 267         packet->answers[0].ttl      = request_packet->additional[0].ttl;
 268         packet->answers[0].rdata    = request_packet->additional[0].rdata;
 269
 270         DEBUG(7,("Sending %s name release reply for %s to %s:%d\n",
 271                  rcode==0?"positive":"negative",
 272                  nbt_name_string(packet, name), src->addr, src->port));
 273
 274         nbtsrv->stats.total_sent++;
 275         nbt_name_reply_send(nbtsock, src, packet);
 276
 277 failed:
 278         talloc_free(packet);
 279 }
 280
 281
 282 /*
 283   send a WACK reply
 284 */
 285 void nbtd_wack_reply(struct nbt_name_socket *nbtsock,
 286                      struct nbt_name_packet *request_packet,
 287                      struct socket_address *src,
 288                      uint32_t ttl)
 289 {
 290         struct nbt_name_packet *packet;
 291         struct nbt_name *name = &request_packet->questions[0].name;
 292         struct nbtd_interface *iface = talloc_get_type(nbtsock->incoming.private,
 293                                                        struct nbtd_interface);
 294         struct nbtd_server *nbtsrv = iface->nbtsrv;
 295
 296         packet = talloc_zero(nbtsock, struct nbt_name_packet);
 297         if (packet == NULL) return;
 298
 299         packet->name_trn_id = request_packet->name_trn_id;
 300         packet->ancount = 1;
 301         packet->operation =
 302                 NBT_FLAG_REPLY |
 303                 NBT_OPCODE_WACK |
 304                 NBT_FLAG_AUTHORITIVE;
 305
 306         packet->answers = talloc_array(packet, struct nbt_res_rec, 1);
 307         if (packet->answers == NULL) goto failed;
 308
 309         packet->answers[0].name              = *name;
 310         packet->answers[0].rr_type           = NBT_QTYPE_NETBIOS;
 311         packet->answers[0].rr_class          = NBT_QCLASS_IP;
 312         packet->answers[0].ttl               = ttl;
 313         packet->answers[0].rdata.data.length = 2;
 314         packet->answers[0].rdata.data.data   = talloc_size(packet, 2);
 315         if (packet->answers[0].rdata.data.data == NULL) goto failed;
 316         RSSVAL(packet->answers[0].rdata.data.data, 0, request_packet->operation);
 317
 318         DEBUG(7,("Sending WACK reply for %s to %s:%d\n",
 319                  nbt_name_string(packet, name), src->addr, src->port));
 320
 321         nbtsrv->stats.total_sent++;
 322         nbt_name_reply_send(nbtsock, src, packet);
 323
 324 failed:
 325         talloc_free(packet);
 326 }