source4/libcli/nbt/nbtsocket.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    low level socket handling for nbt requests
   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 "lib/events/events.h"
  25 #include "lib/util/dlinklist.h"
  26 #include "libcli/nbt/libnbt.h"
  27 #include "lib/socket/socket.h"
  28 #include "librpc/gen_ndr/ndr_nbt.h"
  29
  30 #define NBT_MAX_REPLIES 1000
  31
  32 /*
  33   destroy a pending request
  34 */
  35 static int nbt_name_request_destructor(struct nbt_name_request *req)
  36 {
  37         if (req->state == NBT_REQUEST_SEND) {
  38                 DLIST_REMOVE(req->nbtsock->send_queue, req);
  39         }
  40         if (req->state == NBT_REQUEST_WAIT) {
  41                 req->nbtsock->num_pending--;
  42         }
  43         if (req->name_trn_id != 0 && !req->is_reply) {
  44                 idr_remove(req->nbtsock->idr, req->name_trn_id);
  45                 req->name_trn_id = 0;
  46         }
  47         if (req->te) {
  48                 req->te = NULL;
  49         }
  50         if (req->nbtsock->send_queue == NULL) {
  51                 EVENT_FD_NOT_WRITEABLE(req->nbtsock->fde);
  52         }
  53         if (req->nbtsock->num_pending == 0 &&
  54             req->nbtsock->incoming.handler == NULL) {
  55                 EVENT_FD_NOT_READABLE(req->nbtsock->fde);
  56         }
  57         return 0;
  58 }
  59
  60
  61 /*
  62   handle send events on a nbt name socket
  63 */
  64 static void nbt_name_socket_send(struct nbt_name_socket *nbtsock)
  65 {
  66         struct nbt_name_request *req = nbtsock->send_queue;
  67         TALLOC_CTX *tmp_ctx = talloc_new(nbtsock);
  68         NTSTATUS status;
  69
  70         while ((req = nbtsock->send_queue)) {
  71                 size_t len;
  72
  73                 len = req->encoded.length;
  74                 status = socket_sendto(nbtsock->sock, &req->encoded, &len,
  75                                        req->dest);
  76                 if (NT_STATUS_IS_ERR(status)) goto failed;
  77
  78                 if (!NT_STATUS_IS_OK(status)) {
  79                         talloc_free(tmp_ctx);
  80                         return;
  81                 }
  82
  83                 DLIST_REMOVE(nbtsock->send_queue, req);
  84                 req->state = NBT_REQUEST_WAIT;
  85                 if (req->is_reply) {
  86                         talloc_free(req);
  87                 } else {
  88                         EVENT_FD_READABLE(nbtsock->fde);
  89                         nbtsock->num_pending++;
  90                 }
  91         }
  92
  93         EVENT_FD_NOT_WRITEABLE(nbtsock->fde);
  94         talloc_free(tmp_ctx);
  95         return;
  96
  97 failed:
  98         DLIST_REMOVE(nbtsock->send_queue, req);
  99         nbt_name_request_destructor(req);
 100         req->status = status;
 101         req->state = NBT_REQUEST_ERROR;
 102         talloc_free(tmp_ctx);
 103         if (req->async.fn) {
 104                 req->async.fn(req);
 105         }
 106         return;
 107 }
 108
 109
 110 /*
 111   handle a request timeout
 112 */
 113 static void nbt_name_socket_timeout(struct event_context *ev, struct timed_event *te,
 114                                     struct timeval t, void *private)
 115 {
 116         struct nbt_name_request *req = talloc_get_type(private,
 117                                                        struct nbt_name_request);
 118
 119         if (req->num_retries != 0) {
 120                 req->num_retries--;
 121                 req->te = event_add_timed(req->nbtsock->event_ctx, req,
 122                                           timeval_add(&t, req->timeout, 0),
 123                                           nbt_name_socket_timeout, req);
 124                 if (req->state != NBT_REQUEST_SEND) {
 125                         req->state = NBT_REQUEST_SEND;
 126                         DLIST_ADD_END(req->nbtsock->send_queue, req,
 127                                       struct nbt_name_request *);
 128                 }
 129                 EVENT_FD_WRITEABLE(req->nbtsock->fde);
 130                 return;
 131         }
 132
 133         nbt_name_request_destructor(req);
 134         if (req->num_replies == 0) {
 135                 req->state = NBT_REQUEST_TIMEOUT;
 136                 req->status = NT_STATUS_IO_TIMEOUT;
 137         } else {
 138                 req->state = NBT_REQUEST_DONE;
 139                 req->status = NT_STATUS_OK;
 140         }
 141         if (req->async.fn) {
 142                 req->async.fn(req);
 143         }
 144 }
 145
 146
 147
 148 /*
 149   handle recv events on a nbt name socket
 150 */
 151 static void nbt_name_socket_recv(struct nbt_name_socket *nbtsock)
 152 {
 153         TALLOC_CTX *tmp_ctx = talloc_new(nbtsock);
 154         NTSTATUS status;
 155         struct socket_address *src;
 156         DATA_BLOB blob;
 157         size_t nread, dsize;
 158         struct nbt_name_packet *packet;
 159         struct nbt_name_request *req;
 160
 161         status = socket_pending(nbtsock->sock, &dsize);
 162         if (!NT_STATUS_IS_OK(status)) {
 163                 talloc_free(tmp_ctx);
 164                 return;
 165         }
 166
 167         blob = data_blob_talloc(tmp_ctx, NULL, dsize);
 168         if (blob.data == NULL) {
 169                 talloc_free(tmp_ctx);
 170                 return;
 171         }
 172
 173         status = socket_recvfrom(nbtsock->sock, blob.data, blob.length, &nread,
 174                                  tmp_ctx, &src);
 175         if (!NT_STATUS_IS_OK(status)) {
 176                 talloc_free(tmp_ctx);
 177                 return;
 178         }
 179
 180         packet = talloc(tmp_ctx, struct nbt_name_packet);
 181         if (packet == NULL) {
 182                 talloc_free(tmp_ctx);
 183                 return;
 184         }
 185
 186         /* parse the request */
 187         status = ndr_pull_struct_blob(&blob, packet, packet,
 188                                       (ndr_pull_flags_fn_t)ndr_pull_nbt_name_packet);
 189         if (!NT_STATUS_IS_OK(status)) {
 190                 DEBUG(2,("Failed to parse incoming NBT name packet - %s\n",
 191                          nt_errstr(status)));
 192                 talloc_free(tmp_ctx);
 193                 return;
 194         }
 195
 196         if (DEBUGLVL(10)) {
 197                 DEBUG(10,("Received nbt packet of length %d from %s:%d\n",
 198                           (int)blob.length, src->addr, src->port));
 199                 NDR_PRINT_DEBUG(nbt_name_packet, packet);
 200         }
 201
 202         /* if its not a reply then pass it off to the incoming request
 203            handler, if any */
 204         if (!(packet->operation & NBT_FLAG_REPLY)) {
 205                 if (nbtsock->incoming.handler) {
 206                         nbtsock->incoming.handler(nbtsock, packet, src);
 207                 }
 208                 talloc_free(tmp_ctx);
 209                 return;
 210         }
 211
 212         /* find the matching request */
 213         req = idr_find(nbtsock->idr, packet->name_trn_id);
 214         if (req == NULL) {
 215                 if (nbtsock->unexpected.handler) {
 216                         nbtsock->unexpected.handler(nbtsock, packet, src);
 217                 } else {
 218                         DEBUG(2,("Failed to match request for incoming name packet id 0x%04x on %p\n",
 219                                  packet->name_trn_id, nbtsock));
 220                 }
 221                 talloc_free(tmp_ctx);
 222                 return;
 223         }
 224
 225         /* if this is a WACK response, this we need to go back to waiting,
 226            but perhaps increase the timeout */
 227         if ((packet->operation & NBT_OPCODE) == NBT_OPCODE_WACK) {
 228                 if (req->received_wack || packet->ancount < 1) {
 229                         nbt_name_request_destructor(req);
 230                         req->status = NT_STATUS_INVALID_NETWORK_RESPONSE;
 231                         req->state  = NBT_REQUEST_ERROR;
 232                         goto done;
 233                 }
 234                 talloc_free(req->te);
 235                 /* we know we won't need any more retries - the server
 236                    has received our request */
 237                 req->num_retries   = 0;
 238                 req->received_wack = True;
 239                 /* although there can be a timeout in the packet, w2k3 screws it up,
 240                    so better to set it ourselves */
 241                 req->timeout = lp_parm_int(-1, "nbt", "wack_timeout", 30);
 242                 req->te = event_add_timed(req->nbtsock->event_ctx, req,
 243                                           timeval_current_ofs(req->timeout, 0),
 244                                           nbt_name_socket_timeout, req);
 245                 talloc_free(tmp_ctx);
 246                 return;
 247         }
 248
 249
 250         req->replies = talloc_realloc(req, req->replies, struct nbt_name_reply, req->num_replies+1);
 251         if (req->replies == NULL) {
 252                 nbt_name_request_destructor(req);
 253                 req->state  = NBT_REQUEST_ERROR;
 254                 req->status = NT_STATUS_NO_MEMORY;
 255                 goto done;
 256         }
 257
 258         talloc_steal(req, src);
 259         req->replies[req->num_replies].dest   = src;
 260         talloc_steal(req, packet);
 261         req->replies[req->num_replies].packet = packet;
 262         req->num_replies++;
 263
 264         /* if we don't want multiple replies then we are done */
 265         if (req->allow_multiple_replies &&
 266             req->num_replies < NBT_MAX_REPLIES) {
 267                 talloc_free(tmp_ctx);
 268                 return;
 269         }
 270
 271         nbt_name_request_destructor(req);
 272         req->state  = NBT_REQUEST_DONE;
 273         req->status = NT_STATUS_OK;
 274
 275 done:
 276         talloc_free(tmp_ctx);
 277         if (req->async.fn) {
 278                 req->async.fn(req);
 279         }
 280 }
 281
 282 /*
 283   handle fd events on a nbt_name_socket
 284 */
 285 static void nbt_name_socket_handler(struct event_context *ev, struct fd_event *fde,
 286                                     uint16_t flags, void *private)
 287 {
 288         struct nbt_name_socket *nbtsock = talloc_get_type(private,
 289                                                           struct nbt_name_socket);
 290         if (flags & EVENT_FD_WRITE) {
 291                 nbt_name_socket_send(nbtsock);
 292         }
 293         if (flags & EVENT_FD_READ) {
 294                 nbt_name_socket_recv(nbtsock);
 295         }
 296 }
 297
 298
 299 /*
 300   initialise a nbt_name_socket. The event_ctx is optional, if provided
 301   then operations will use that event context
 302 */
 303 _PUBLIC_ struct nbt_name_socket *nbt_name_socket_init(TALLOC_CTX *mem_ctx,
 304                                              struct event_context *event_ctx)
 305 {
 306         struct nbt_name_socket *nbtsock;
 307         NTSTATUS status;
 308
 309         nbtsock = talloc(mem_ctx, struct nbt_name_socket);
 310         if (nbtsock == NULL) goto failed;
 311
 312         if (event_ctx == NULL) {
 313                 nbtsock->event_ctx = event_context_init(nbtsock);
 314         } else {
 315                 nbtsock->event_ctx = talloc_reference(nbtsock, event_ctx);
 316         }
 317         if (nbtsock->event_ctx == NULL) goto failed;
 318
 319         status = socket_create("ip", SOCKET_TYPE_DGRAM, &nbtsock->sock, 0);
 320         if (!NT_STATUS_IS_OK(status)) goto failed;
 321
 322         socket_set_option(nbtsock->sock, "SO_BROADCAST", "1");
 323
 324         talloc_steal(nbtsock, nbtsock->sock);
 325
 326         nbtsock->idr = idr_init(nbtsock);
 327         if (nbtsock->idr == NULL) goto failed;
 328
 329         nbtsock->send_queue = NULL;
 330         nbtsock->num_pending = 0;
 331         nbtsock->incoming.handler = NULL;
 332         nbtsock->unexpected.handler = NULL;
 333
 334         nbtsock->fde = event_add_fd(nbtsock->event_ctx, nbtsock,
 335                                     socket_get_fd(nbtsock->sock), 0,
 336                                     nbt_name_socket_handler, nbtsock);
 337
 338         return nbtsock;
 339
 340 failed:
 341         talloc_free(nbtsock);
 342         return NULL;
 343 }
 344
 345 /*
 346   send off a nbt name request
 347 */
 348 struct nbt_name_request *nbt_name_request_send(struct nbt_name_socket *nbtsock,
 349                                                struct socket_address *dest,
 350                                                struct nbt_name_packet *request,
 351                                                int timeout, int retries,
 352                                                BOOL allow_multiple_replies)
 353 {
 354         struct nbt_name_request *req;
 355         int id;
 356         NTSTATUS status;
 357
 358         req = talloc_zero(nbtsock, struct nbt_name_request);
 359         if (req == NULL) goto failed;
 360
 361         req->nbtsock                = nbtsock;
 362         req->allow_multiple_replies = allow_multiple_replies;
 363         req->state                  = NBT_REQUEST_SEND;
 364         req->is_reply               = False;
 365         req->timeout                = timeout;
 366         req->num_retries            = retries;
 367         req->dest                   = dest;
 368         if (talloc_reference(req, dest) == NULL) goto failed;
 369
 370         /* we select a random transaction id unless the user supplied one */
 371         if (request->name_trn_id == 0) {
 372                 id = idr_get_new_random(req->nbtsock->idr, req, UINT16_MAX);
 373         } else {
 374                 if (idr_find(req->nbtsock->idr, request->name_trn_id)) goto failed;
 375                 id = idr_get_new_above(req->nbtsock->idr, req, request->name_trn_id,
 376                                        UINT16_MAX);
 377         }
 378         if (id == -1) goto failed;
 379
 380         request->name_trn_id = id;
 381         req->name_trn_id     = id;
 382
 383         req->te = event_add_timed(nbtsock->event_ctx, req,
 384                                   timeval_current_ofs(req->timeout, 0),
 385                                   nbt_name_socket_timeout, req);
 386
 387         talloc_set_destructor(req, nbt_name_request_destructor);
 388
 389         status = ndr_push_struct_blob(&req->encoded, req, request,
 390                                       (ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
 391         if (!NT_STATUS_IS_OK(status)) goto failed;
 392
 393         DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
 394
 395         if (DEBUGLVL(10)) {
 396                 DEBUG(10,("Queueing nbt packet to %s:%d\n",
 397                           req->dest->addr, req->dest->port));
 398                 NDR_PRINT_DEBUG(nbt_name_packet, request);
 399         }
 400
 401         EVENT_FD_WRITEABLE(nbtsock->fde);
 402
 403         return req;
 404
 405 failed:
 406         talloc_free(req);
 407         return NULL;
 408 }
 409
 410
 411 /*
 412   send off a nbt name reply
 413 */
 414 NTSTATUS nbt_name_reply_send(struct nbt_name_socket *nbtsock,
 415                              struct socket_address *dest,
 416                              struct nbt_name_packet *request)
 417 {
 418         struct nbt_name_request *req;
 419         NTSTATUS status;
 420
 421         req = talloc_zero(nbtsock, struct nbt_name_request);
 422         NT_STATUS_HAVE_NO_MEMORY(req);
 423
 424         req->nbtsock   = nbtsock;
 425         req->dest = dest;
 426         if (talloc_reference(req, dest) == NULL) goto failed;
 427         req->state     = NBT_REQUEST_SEND;
 428         req->is_reply = True;
 429
 430         talloc_set_destructor(req, nbt_name_request_destructor);
 431
 432         if (DEBUGLVL(10)) {
 433                 NDR_PRINT_DEBUG(nbt_name_packet, request);
 434         }
 435
 436         status = ndr_push_struct_blob(&req->encoded, req, request,
 437                                       (ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
 438         if (!NT_STATUS_IS_OK(status)) {
 439                 talloc_free(req);
 440                 return status;
 441         }
 442
 443         DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
 444
 445         EVENT_FD_WRITEABLE(nbtsock->fde);
 446
 447         return NT_STATUS_OK;
 448
 449 failed:
 450         talloc_free(req);
 451         return NT_STATUS_NO_MEMORY;
 452 }
 453
 454 /*
 455   wait for a nbt request to complete
 456 */
 457 NTSTATUS nbt_name_request_recv(struct nbt_name_request *req)
 458 {
 459         if (!req) return NT_STATUS_NO_MEMORY;
 460
 461         while (req->state < NBT_REQUEST_DONE) {
 462                 if (event_loop_once(req->nbtsock->event_ctx) != 0) {
 463                         req->state = NBT_REQUEST_ERROR;
 464                         req->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
 465                         if (req->async.fn) {
 466                                 req->async.fn(req);
 467                         }
 468                 }
 469         }
 470         return req->status;
 471 }
 472
 473
 474 /*
 475   setup a handler for incoming requests
 476 */
 477 NTSTATUS nbt_set_incoming_handler(struct nbt_name_socket *nbtsock,
 478                                   void (*handler)(struct nbt_name_socket *, struct nbt_name_packet *,
 479                                                   struct socket_address *),
 480                                   void *private)
 481 {
 482         nbtsock->incoming.handler = handler;
 483         nbtsock->incoming.private = private;
 484         EVENT_FD_READABLE(nbtsock->fde);
 485         return NT_STATUS_OK;
 486 }
 487
 488
 489 /*
 490   turn a NBT rcode into a NTSTATUS
 491 */
 492 NTSTATUS nbt_rcode_to_ntstatus(uint8_t rcode)
 493 {
 494         int i;
 495         struct {
 496                 enum nbt_rcode rcode;
 497                 NTSTATUS status;
 498         } map[] = {
 499                 { NBT_RCODE_FMT, NT_STATUS_INVALID_PARAMETER },
 500                 { NBT_RCODE_SVR, NT_STATUS_SERVER_DISABLED },
 501                 { NBT_RCODE_NAM, NT_STATUS_OBJECT_NAME_NOT_FOUND },
 502                 { NBT_RCODE_IMP, NT_STATUS_NOT_SUPPORTED },
 503                 { NBT_RCODE_RFS, NT_STATUS_ACCESS_DENIED },
 504                 { NBT_RCODE_ACT, NT_STATUS_ADDRESS_ALREADY_EXISTS },
 505                 { NBT_RCODE_CFT, NT_STATUS_CONFLICTING_ADDRESSES }
 506         };
 507         for (i=0;i<ARRAY_SIZE(map);i++) {
 508                 if (map[i].rcode == rcode) {
 509                         return map[i].status;
 510                 }
 511         }
 512         return NT_STATUS_UNSUCCESSFUL;
 513 }