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 "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(void *ptr)
  36 {
  37         struct nbt_name_request *req = talloc_get_type(ptr, struct nbt_name_request);
  38
  39         if (req->state == NBT_REQUEST_SEND) {
  40                 DLIST_REMOVE(req->nbtsock->send_queue, req);
  41         }
  42         if (req->state == NBT_REQUEST_WAIT) {
  43                 req->nbtsock->num_pending--;
  44         }
  45         if (req->name_trn_id != 0 && !req->is_reply) {
  46                 idr_remove(req->nbtsock->idr, req->name_trn_id);
  47                 req->name_trn_id = 0;
  48         }
  49         if (req->te) {
  50                 req->te = NULL;
  51         }
  52         if (req->nbtsock->send_queue == NULL) {
  53                 EVENT_FD_NOT_WRITEABLE(req->nbtsock->fde);
  54         }
  55         if (req->nbtsock->num_pending == 0 &&
  56             req->nbtsock->incoming.handler == NULL) {
  57                 EVENT_FD_NOT_READABLE(req->nbtsock->fde);
  58         }
  59         return 0;
  60 }
  61
  62
  63 /*
  64   handle send events on a nbt name socket
  65 */
  66 static void nbt_name_socket_send(struct nbt_name_socket *nbtsock)
  67 {
  68         struct nbt_name_request *req = nbtsock->send_queue;
  69         TALLOC_CTX *tmp_ctx = talloc_new(nbtsock);
  70         NTSTATUS status;
  71
  72         while ((req = nbtsock->send_queue)) {
  73                 size_t len;
  74
  75                 len = req->encoded.length;
  76                 status = socket_sendto(nbtsock->sock, &req->encoded, &len, 0,
  77                                        req->dest);
  78                 if (NT_STATUS_IS_ERR(status)) goto failed;
  79
  80                 if (!NT_STATUS_IS_OK(status)) {
  81                         talloc_free(tmp_ctx);
  82                         return;
  83                 }
  84
  85                 DLIST_REMOVE(nbtsock->send_queue, req);
  86                 req->state = NBT_REQUEST_WAIT;
  87                 if (req->is_reply) {
  88                         talloc_free(req);
  89                 } else {
  90                         EVENT_FD_READABLE(nbtsock->fde);
  91                         nbtsock->num_pending++;
  92                 }
  93         }
  94
  95         EVENT_FD_NOT_WRITEABLE(nbtsock->fde);
  96         talloc_free(tmp_ctx);
  97         return;
  98
  99 failed:
 100         DLIST_REMOVE(nbtsock->send_queue, req);
 101         nbt_name_request_destructor(req);
 102         req->status = status;
 103         req->state = NBT_REQUEST_ERROR;
 104         talloc_free(tmp_ctx);
 105         if (req->async.fn) {
 106                 req->async.fn(req);
 107         }
 108         return;
 109 }
 110
 111
 112 /*
 113   handle a request timeout
 114 */
 115 static void nbt_name_socket_timeout(struct event_context *ev, struct timed_event *te,
 116                                     struct timeval t, void *private)
 117 {
 118         struct nbt_name_request *req = talloc_get_type(private,
 119                                                        struct nbt_name_request);
 120
 121         if (req->num_retries != 0) {
 122                 req->num_retries--;
 123                 req->te = event_add_timed(req->nbtsock->event_ctx, req,
 124                                           timeval_add(&t, req->timeout, 0),
 125                                           nbt_name_socket_timeout, req);
 126                 if (req->state != NBT_REQUEST_SEND) {
 127                         req->state = NBT_REQUEST_SEND;
 128                         DLIST_ADD_END(req->nbtsock->send_queue, req,
 129                                       struct nbt_name_request *);
 130                 }
 131                 EVENT_FD_WRITEABLE(req->nbtsock->fde);
 132                 return;
 133         }
 134
 135         nbt_name_request_destructor(req);
 136         if (req->num_replies == 0) {
 137                 req->state = NBT_REQUEST_TIMEOUT;
 138                 req->status = NT_STATUS_IO_TIMEOUT;
 139         } else {
 140                 req->state = NBT_REQUEST_DONE;
 141                 req->status = NT_STATUS_OK;
 142         }
 143         if (req->async.fn) {
 144                 req->async.fn(req);
 145         }
 146 }
 147
 148
 149
 150 /*
 151   handle recv events on a nbt name socket
 152 */
 153 static void nbt_name_socket_recv(struct nbt_name_socket *nbtsock)
 154 {
 155         TALLOC_CTX *tmp_ctx = talloc_new(nbtsock);
 156         NTSTATUS status;
 157         struct socket_address *src;
 158         DATA_BLOB blob;
 159         size_t nread, dsize;
 160         struct nbt_name_packet *packet;
 161         struct nbt_name_request *req;
 162
 163         status = socket_pending(nbtsock->sock, &dsize);
 164         if (!NT_STATUS_IS_OK(status)) {
 165                 talloc_free(tmp_ctx);
 166                 return;
 167         }
 168
 169         blob = data_blob_talloc(tmp_ctx, NULL, dsize);
 170         if (blob.data == NULL) {
 171                 talloc_free(tmp_ctx);
 172                 return;
 173         }
 174
 175         status = socket_recvfrom(nbtsock->sock, blob.data, blob.length, &nread, 0,
 176                                  tmp_ctx, &src);
 177         if (!NT_STATUS_IS_OK(status)) {
 178                 talloc_free(tmp_ctx);
 179                 return;
 180         }
 181
 182         packet = talloc(tmp_ctx, struct nbt_name_packet);
 183         if (packet == NULL) {
 184                 talloc_free(tmp_ctx);
 185                 return;
 186         }
 187
 188         /* parse the request */
 189         status = ndr_pull_struct_blob(&blob, packet, packet,
 190                                       (ndr_pull_flags_fn_t)ndr_pull_nbt_name_packet);
 191         if (!NT_STATUS_IS_OK(status)) {
 192                 DEBUG(2,("Failed to parse incoming NBT name packet - %s\n",
 193                          nt_errstr(status)));
 194                 talloc_free(tmp_ctx);
 195                 return;
 196         }
 197
 198         if (DEBUGLVL(10)) {
 199                 DEBUG(10,("Received nbt packet of length %d from %s:%d\n",
 200                           (int)blob.length, src->addr, src->port));
 201                 NDR_PRINT_DEBUG(nbt_name_packet, packet);
 202         }
 203
 204         /* if its not a reply then pass it off to the incoming request
 205            handler, if any */
 206         if (!(packet->operation & NBT_FLAG_REPLY)) {
 207                 if (nbtsock->incoming.handler) {
 208                         nbtsock->incoming.handler(nbtsock, packet, src);
 209                 }
 210                 talloc_free(tmp_ctx);
 211                 return;
 212         }
 213
 214         /* find the matching request */
 215         req = idr_find(nbtsock->idr, packet->name_trn_id);
 216         if (req == NULL) {
 217                 if (nbtsock->unexpected.handler) {
 218                         nbtsock->unexpected.handler(nbtsock, packet, src);
 219                 } else {
 220                         DEBUG(2,("Failed to match request for incoming name packet id 0x%04x on %p\n",
 221                                  packet->name_trn_id, nbtsock));
 222                 }
 223                 talloc_free(tmp_ctx);
 224                 return;
 225         }
 226
 227         /* if this is a WACK response, this we need to go back to waiting,
 228            but perhaps increase the timeout */
 229         if ((packet->operation & NBT_OPCODE) == NBT_OPCODE_WACK) {
 230                 if (req->received_wack || packet->ancount < 1) {
 231                         nbt_name_request_destructor(req);
 232                         req->status = NT_STATUS_INVALID_NETWORK_RESPONSE;
 233                         req->state  = NBT_REQUEST_ERROR;
 234                         goto done;
 235                 }
 236                 talloc_free(req->te);
 237                 /* we know we won't need any more retries - the server
 238                    has received our request */
 239                 req->num_retries   = 0;
 240                 req->received_wack = True;
 241                 /* although there can be a timeout in the packet, w2k3 screws it up,
 242                    so better to set it ourselves */
 243                 req->timeout = lp_parm_int(-1, "nbt", "wack_timeout", 30);
 244                 req->te = event_add_timed(req->nbtsock->event_ctx, req,
 245                                           timeval_current_ofs(req->timeout, 0),
 246                                           nbt_name_socket_timeout, req);
 247                 talloc_free(tmp_ctx);
 248                 return;
 249         }
 250
 251
 252         req->replies = talloc_realloc(req, req->replies, struct nbt_name_reply, req->num_replies+1);
 253         if (req->replies == NULL) {
 254                 nbt_name_request_destructor(req);
 255                 req->state  = NBT_REQUEST_ERROR;
 256                 req->status = NT_STATUS_NO_MEMORY;
 257                 goto done;
 258         }
 259
 260         talloc_steal(req, src);
 261         req->replies[req->num_replies].dest   = src;
 262         talloc_steal(req, packet);
 263         req->replies[req->num_replies].packet = packet;
 264         req->num_replies++;
 265
 266         /* if we don't want multiple replies then we are done */
 267         if (req->allow_multiple_replies &&
 268             req->num_replies < NBT_MAX_REPLIES) {
 269                 talloc_free(tmp_ctx);
 270                 return;
 271         }
 272
 273         nbt_name_request_destructor(req);
 274         req->state  = NBT_REQUEST_DONE;
 275         req->status = NT_STATUS_OK;
 276
 277 done:
 278         talloc_free(tmp_ctx);
 279         if (req->async.fn) {
 280                 req->async.fn(req);
 281         }
 282 }
 283
 284 /*
 285   handle fd events on a nbt_name_socket
 286 */
 287 static void nbt_name_socket_handler(struct event_context *ev, struct fd_event *fde,
 288                                     uint16_t flags, void *private)
 289 {
 290         struct nbt_name_socket *nbtsock = talloc_get_type(private,
 291                                                           struct nbt_name_socket);
 292         if (flags & EVENT_FD_WRITE) {
 293                 nbt_name_socket_send(nbtsock);
 294         }
 295         if (flags & EVENT_FD_READ) {
 296                 nbt_name_socket_recv(nbtsock);
 297         }
 298 }
 299
 300
 301 /*
 302   initialise a nbt_name_socket. The event_ctx is optional, if provided
 303   then operations will use that event context
 304 */
 305 struct nbt_name_socket *nbt_name_socket_init(TALLOC_CTX *mem_ctx,
 306                                              struct event_context *event_ctx)
 307 {
 308         struct nbt_name_socket *nbtsock;
 309         NTSTATUS status;
 310
 311         nbtsock = talloc(mem_ctx, struct nbt_name_socket);
 312         if (nbtsock == NULL) goto failed;
 313
 314         if (event_ctx == NULL) {
 315                 nbtsock->event_ctx = event_context_init(nbtsock);
 316         } else {
 317                 nbtsock->event_ctx = talloc_reference(nbtsock, event_ctx);
 318         }
 319         if (nbtsock->event_ctx == NULL) goto failed;
 320
 321         status = socket_create("ip", SOCKET_TYPE_DGRAM, &nbtsock->sock, 0);
 322         if (!NT_STATUS_IS_OK(status)) goto failed;
 323
 324         socket_set_option(nbtsock->sock, "SO_BROADCAST", "1");
 325
 326         talloc_steal(nbtsock, nbtsock->sock);
 327
 328         nbtsock->idr = idr_init(nbtsock);
 329         if (nbtsock->idr == NULL) goto failed;
 330
 331         nbtsock->send_queue = NULL;
 332         nbtsock->num_pending = 0;
 333         nbtsock->incoming.handler = NULL;
 334         nbtsock->unexpected.handler = NULL;
 335
 336         nbtsock->fde = event_add_fd(nbtsock->event_ctx, nbtsock,
 337                                     socket_get_fd(nbtsock->sock), 0,
 338                                     nbt_name_socket_handler, nbtsock);
 339
 340         return nbtsock;
 341
 342 failed:
 343         talloc_free(nbtsock);
 344         return NULL;
 345 }
 346
 347 /*
 348   send off a nbt name request
 349 */
 350 struct nbt_name_request *nbt_name_request_send(struct nbt_name_socket *nbtsock,
 351                                                struct socket_address *dest,
 352                                                struct nbt_name_packet *request,
 353                                                int timeout, int retries,
 354                                                BOOL allow_multiple_replies)
 355 {
 356         struct nbt_name_request *req;
 357         int id;
 358         NTSTATUS status;
 359
 360         req = talloc_zero(nbtsock, struct nbt_name_request);
 361         if (req == NULL) goto failed;
 362
 363         req->nbtsock                = nbtsock;
 364         req->allow_multiple_replies = allow_multiple_replies;
 365         req->state                  = NBT_REQUEST_SEND;
 366         req->is_reply               = False;
 367         req->timeout                = timeout;
 368         req->num_retries            = retries;
 369         req->dest                   = dest;
 370         if (talloc_reference(req, dest) == NULL) goto failed;
 371
 372         /* we select a random transaction id unless the user supplied one */
 373         if (request->name_trn_id == 0) {
 374                 id = idr_get_new_random(req->nbtsock->idr, req, UINT16_MAX);
 375         } else {
 376                 if (idr_find(req->nbtsock->idr, request->name_trn_id)) goto failed;
 377                 id = idr_get_new_above(req->nbtsock->idr, req, request->name_trn_id,
 378                                        UINT16_MAX);
 379         }
 380         if (id == -1) goto failed;
 381
 382         request->name_trn_id = id;
 383         req->name_trn_id     = id;
 384
 385         req->te = event_add_timed(nbtsock->event_ctx, req,
 386                                   timeval_current_ofs(req->timeout, 0),
 387                                   nbt_name_socket_timeout, req);
 388
 389         talloc_set_destructor(req, nbt_name_request_destructor);
 390
 391         status = ndr_push_struct_blob(&req->encoded, req, request,
 392                                       (ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
 393         if (!NT_STATUS_IS_OK(status)) goto failed;
 394
 395         DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
 396
 397         if (DEBUGLVL(10)) {
 398                 DEBUG(10,("Queueing nbt packet to %s:%d\n",
 399                           req->dest->addr, req->dest->port));
 400                 NDR_PRINT_DEBUG(nbt_name_packet, request);
 401         }
 402
 403         EVENT_FD_WRITEABLE(nbtsock->fde);
 404
 405         return req;
 406
 407 failed:
 408         talloc_free(req);
 409         return NULL;
 410 }
 411
 412
 413 /*
 414   send off a nbt name reply
 415 */
 416 NTSTATUS nbt_name_reply_send(struct nbt_name_socket *nbtsock,
 417                              struct socket_address *dest,
 418                              struct nbt_name_packet *request)
 419 {
 420         struct nbt_name_request *req;
 421         NTSTATUS status;
 422
 423         req = talloc_zero(nbtsock, struct nbt_name_request);
 424         NT_STATUS_HAVE_NO_MEMORY(req);
 425
 426         req->nbtsock   = nbtsock;
 427         req->dest = dest;
 428         if (talloc_reference(req, dest) == NULL) goto failed;
 429         req->state     = NBT_REQUEST_SEND;
 430         req->is_reply = True;
 431
 432         talloc_set_destructor(req, nbt_name_request_destructor);
 433
 434         if (DEBUGLVL(10)) {
 435                 NDR_PRINT_DEBUG(nbt_name_packet, request);
 436         }
 437
 438         status = ndr_push_struct_blob(&req->encoded, req, request,
 439                                       (ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
 440         if (!NT_STATUS_IS_OK(status)) {
 441                 talloc_free(req);
 442                 return status;
 443         }
 444
 445         DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
 446
 447         EVENT_FD_WRITEABLE(nbtsock->fde);
 448
 449         return NT_STATUS_OK;
 450
 451 failed:
 452         talloc_free(req);
 453         return NT_STATUS_NO_MEMORY;
 454 }
 455
 456 /*
 457   wait for a nbt request to complete
 458 */
 459 NTSTATUS nbt_name_request_recv(struct nbt_name_request *req)
 460 {
 461         if (!req) return NT_STATUS_NO_MEMORY;
 462
 463         while (req->state < NBT_REQUEST_DONE) {
 464                 if (event_loop_once(req->nbtsock->event_ctx) != 0) {
 465                         req->state = NBT_REQUEST_ERROR;
 466                         req->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
 467                         if (req->async.fn) {
 468                                 req->async.fn(req);
 469                         }
 470                 }
 471         }
 472         return req->status;
 473 }
 474
 475
 476 /*
 477   setup a handler for incoming requests
 478 */
 479 NTSTATUS nbt_set_incoming_handler(struct nbt_name_socket *nbtsock,
 480                                   void (*handler)(struct nbt_name_socket *, struct nbt_name_packet *,
 481                                                   struct socket_address *),
 482                                   void *private)
 483 {
 484         nbtsock->incoming.handler = handler;
 485         nbtsock->incoming.private = private;
 486         EVENT_FD_READABLE(nbtsock->fde);
 487         return NT_STATUS_OK;
 488 }
 489
 490
 491 /*
 492   turn a NBT rcode into a NTSTATUS
 493 */
 494 NTSTATUS nbt_rcode_to_ntstatus(uint8_t rcode)
 495 {
 496         int i;
 497         struct {
 498                 enum nbt_rcode rcode;
 499                 NTSTATUS status;
 500         } map[] = {
 501                 { NBT_RCODE_FMT, NT_STATUS_INVALID_PARAMETER },
 502                 { NBT_RCODE_SVR, NT_STATUS_SERVER_DISABLED },
 503                 { NBT_RCODE_NAM, NT_STATUS_OBJECT_NAME_NOT_FOUND },
 504                 { NBT_RCODE_IMP, NT_STATUS_NOT_SUPPORTED },
 505                 { NBT_RCODE_RFS, NT_STATUS_ACCESS_DENIED },
 506                 { NBT_RCODE_ACT, NT_STATUS_ADDRESS_ALREADY_EXISTS },
 507                 { NBT_RCODE_CFT, NT_STATUS_CONFLICTING_ADDRESSES }
 508         };
 509         for (i=0;i<ARRAY_SIZE(map);i++) {
 510                 if (map[i].rcode == rcode) {
 511                         return map[i].status;
 512                 }
 513         }
 514         return NT_STATUS_UNSUCCESSFUL;
 515 }