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
  29 #define NBT_MAX_REPLIES 1000
  30
  31 /*
  32   destroy a pending request
  33 */
  34 static int nbt_name_request_destructor(void *ptr)
  35 {
  36         struct nbt_name_request *req = talloc_get_type(ptr, struct nbt_name_request);
  37
  38         if (req->state == NBT_REQUEST_SEND) {
  39                 DLIST_REMOVE(req->nbtsock->send_queue, req);
  40         }
  41         if (req->state == NBT_REQUEST_WAIT) {
  42                 req->nbtsock->num_pending--;
  43         }
  44         if (req->name_trn_id != 0 && !req->is_reply) {
  45                 idr_remove(req->nbtsock->idr, req->name_trn_id);
  46                 req->name_trn_id = 0;
  47         }
  48         if (req->te) {
  49                 req->te = NULL;
  50         }
  51         if (req->nbtsock->send_queue == NULL) {
  52                 EVENT_FD_NOT_WRITEABLE(req->nbtsock->fde);
  53         }
  54         if (req->nbtsock->num_pending == 0 &&
  55             req->nbtsock->incoming.handler == NULL) {
  56                 EVENT_FD_NOT_READABLE(req->nbtsock->fde);
  57         }
  58         return 0;
  59 }
  60
  61
  62 /*
  63   handle send events on a nbt name socket
  64 */
  65 static void nbt_name_socket_send(struct nbt_name_socket *nbtsock)
  66 {
  67         struct nbt_name_request *req = nbtsock->send_queue;
  68         TALLOC_CTX *tmp_ctx = talloc_new(nbtsock);
  69         NTSTATUS status;
  70
  71         while ((req = nbtsock->send_queue)) {
  72                 size_t len;
  73
  74                 len = req->encoded.length;
  75                 status = socket_sendto(nbtsock->sock, &req->encoded, &len, 0,
  76                                        req->dest.addr, req->dest.port);
  77                 if (NT_STATUS_IS_ERR(status)) goto failed;
  78
  79                 if (!NT_STATUS_IS_OK(status)) {
  80                         talloc_free(tmp_ctx);
  81                         return;
  82                 }
  83
  84                 DLIST_REMOVE(nbtsock->send_queue, req);
  85                 req->state = NBT_REQUEST_WAIT;
  86                 if (req->is_reply) {
  87                         talloc_free(req);
  88                 } else {
  89                         EVENT_FD_READABLE(nbtsock->fde);
  90                         nbtsock->num_pending++;
  91                 }
  92         }
  93
  94         EVENT_FD_NOT_WRITEABLE(nbtsock->fde);
  95         talloc_free(tmp_ctx);
  96         return;
  97
  98 failed:
  99         DLIST_REMOVE(nbtsock->send_queue, req);
 100         nbt_name_request_destructor(req);
 101         req->status = status;
 102         req->state = NBT_REQUEST_ERROR;
 103         talloc_free(tmp_ctx);
 104         if (req->async.fn) {
 105                 req->async.fn(req);
 106         }
 107         return;
 108 }
 109
 110
 111 /*
 112   handle a request timeout
 113 */
 114 static void nbt_name_socket_timeout(struct event_context *ev, struct timed_event *te,
 115                                     struct timeval t, void *private)
 116 {
 117         struct nbt_name_request *req = talloc_get_type(private,
 118                                                        struct nbt_name_request);
 119
 120         if (req->num_retries != 0) {
 121                 req->num_retries--;
 122                 req->te = event_add_timed(req->nbtsock->event_ctx, req,
 123                                           timeval_add(&t, req->timeout, 0),
 124                                           nbt_name_socket_timeout, req);
 125                 if (req->state != NBT_REQUEST_SEND) {
 126                         req->state = NBT_REQUEST_SEND;
 127                         DLIST_ADD_END(req->nbtsock->send_queue, req,
 128                                       struct nbt_name_request *);
 129                 }
 130                 EVENT_FD_WRITEABLE(req->nbtsock->fde);
 131                 return;
 132         }
 133
 134         nbt_name_request_destructor(req);
 135         if (req->num_replies == 0) {
 136                 req->state = NBT_REQUEST_TIMEOUT;
 137                 req->status = NT_STATUS_IO_TIMEOUT;
 138         } else {
 139                 req->state = NBT_REQUEST_DONE;
 140                 req->status = NT_STATUS_OK;
 141         }
 142         if (req->async.fn) {
 143                 req->async.fn(req);
 144         }
 145 }
 146
 147
 148
 149 /*
 150   handle recv events on a nbt name socket
 151 */
 152 static void nbt_name_socket_recv(struct nbt_name_socket *nbtsock)
 153 {
 154         TALLOC_CTX *tmp_ctx = talloc_new(nbtsock);
 155         NTSTATUS status;
 156         struct nbt_peer_socket src;
 157         DATA_BLOB blob;
 158         size_t nread, dsize;
 159         struct nbt_name_packet *packet;
 160         struct nbt_name_request *req;
 161
 162         status = socket_pending(nbtsock->sock, &dsize);
 163         if (!NT_STATUS_IS_OK(status)) {
 164                 talloc_free(tmp_ctx);
 165                 return;
 166         }
 167
 168         blob = data_blob_talloc(tmp_ctx, NULL, dsize);
 169         if (blob.data == NULL) {
 170                 talloc_free(tmp_ctx);
 171                 return;
 172         }
 173
 174         status = socket_recvfrom(nbtsock->sock, blob.data, blob.length, &nread, 0,
 175                                  &src.addr, &src.port);
 176         if (!NT_STATUS_IS_OK(status)) {
 177                 talloc_free(tmp_ctx);
 178                 return;
 179         }
 180         talloc_steal(tmp_ctx, src.addr);
 181         blob.length = nread;
 182
 183         packet = talloc(tmp_ctx, struct nbt_name_packet);
 184         if (packet == NULL) {
 185                 talloc_free(tmp_ctx);
 186                 return;
 187         }
 188
 189         /* parse the request */
 190         status = ndr_pull_struct_blob(&blob, packet, packet,
 191                                       (ndr_pull_flags_fn_t)ndr_pull_nbt_name_packet);
 192         if (!NT_STATUS_IS_OK(status)) {
 193                 DEBUG(2,("Failed to parse incoming NBT name packet - %s\n",
 194                          nt_errstr(status)));
 195                 talloc_free(tmp_ctx);
 196                 return;
 197         }
 198
 199         if (DEBUGLVL(10)) {
 200                 DEBUG(10,("Received nbt packet of length %d from %s:%d\n",
 201                           (int)blob.length, src.addr, src.port));
 202                 NDR_PRINT_DEBUG(nbt_name_packet, packet);
 203         }
 204
 205         /* if its not a reply then pass it off to the incoming request
 206            handler, if any */
 207         if (!(packet->operation & NBT_FLAG_REPLY)) {
 208                 if (nbtsock->incoming.handler) {
 209                         nbtsock->incoming.handler(nbtsock, packet, &src);
 210                 }
 211                 talloc_free(tmp_ctx);
 212                 return;
 213         }
 214
 215         /* find the matching request */
 216         req = idr_find(nbtsock->idr, packet->name_trn_id);
 217         if (req == NULL) {
 218                 if (nbtsock->unexpected.handler) {
 219                         nbtsock->unexpected.handler(nbtsock, packet, &src);
 220                 } else {
 221                         DEBUG(2,("Failed to match request for incoming name packet id 0x%04x on %p\n",
 222                                  packet->name_trn_id, nbtsock));
 223                 }
 224                 talloc_free(tmp_ctx);
 225                 return;
 226         }
 227
 228         /* if this is a WACK response, this we need to go back to waiting,
 229            but perhaps increase the timeout */
 230         if ((packet->operation & NBT_OPCODE) == NBT_OPCODE_WACK) {
 231                 if (req->received_wack || packet->ancount < 1) {
 232                         nbt_name_request_destructor(req);
 233                         req->status = NT_STATUS_INVALID_NETWORK_RESPONSE;
 234                         req->state  = NBT_REQUEST_ERROR;
 235                         goto done;
 236                 }
 237                 talloc_free(req->te);
 238                 /* we know we won't need any more retries - the server
 239                    has received our request */
 240                 req->num_retries   = 0;
 241                 req->received_wack = True;
 242                 /* although there can be a timeout in the packet, w2k3 screws it up,
 243                    so better to set it ourselves */
 244                 req->timeout = lp_parm_int(-1, "nbt", "wack_timeout", 30);
 245                 req->te = event_add_timed(req->nbtsock->event_ctx, req,
 246                                           timeval_current_ofs(req->timeout, 0),
 247                                           nbt_name_socket_timeout, req);
 248                 talloc_free(tmp_ctx);
 249                 return;
 250         }
 251
 252
 253         req->replies = talloc_realloc(req, req->replies, struct nbt_name_reply, req->num_replies+1);
 254         if (req->replies == NULL) {
 255                 nbt_name_request_destructor(req);
 256                 req->state  = NBT_REQUEST_ERROR;
 257                 req->status = NT_STATUS_NO_MEMORY;
 258                 goto done;
 259         }
 260
 261         req->replies[req->num_replies].dest.addr = talloc_steal(req, src.addr);
 262         req->replies[req->num_replies].dest.port = src.port;
 263         req->replies[req->num_replies].packet     = talloc_steal(req, 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                                                const struct nbt_peer_socket *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.port              = dest->port;
 370         req->dest.addr              = talloc_strdup(req, dest->addr);
 371         if (req->dest.addr == NULL) goto failed;
 372
 373         /* we select a random transaction id unless the user supplied one */
 374         if (request->name_trn_id == 0) {
 375                 id = idr_get_new_random(req->nbtsock->idr, req, UINT16_MAX);
 376         } else {
 377                 if (idr_find(req->nbtsock->idr, request->name_trn_id)) goto failed;
 378                 id = idr_get_new_above(req->nbtsock->idr, req, request->name_trn_id,
 379                                        UINT16_MAX);
 380         }
 381         if (id == -1) goto failed;
 382
 383         request->name_trn_id = id;
 384         req->name_trn_id     = id;
 385
 386         req->te = event_add_timed(nbtsock->event_ctx, req,
 387                                   timeval_current_ofs(req->timeout, 0),
 388                                   nbt_name_socket_timeout, req);
 389
 390         talloc_set_destructor(req, nbt_name_request_destructor);
 391
 392         status = ndr_push_struct_blob(&req->encoded, req, request,
 393                                       (ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
 394         if (!NT_STATUS_IS_OK(status)) goto failed;
 395
 396         DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
 397
 398         if (DEBUGLVL(10)) {
 399                 DEBUG(10,("Queueing nbt packet to %s:%d\n",
 400                           req->dest.addr, req->dest.port));
 401                 NDR_PRINT_DEBUG(nbt_name_packet, request);
 402         }
 403
 404         EVENT_FD_WRITEABLE(nbtsock->fde);
 405
 406         return req;
 407
 408 failed:
 409         talloc_free(req);
 410         return NULL;
 411 }
 412
 413
 414 /*
 415   send off a nbt name reply
 416 */
 417 NTSTATUS nbt_name_reply_send(struct nbt_name_socket *nbtsock,
 418                              const struct nbt_peer_socket *dest,
 419                              struct nbt_name_packet *request)
 420 {
 421         struct nbt_name_request *req;
 422         NTSTATUS status;
 423
 424         req = talloc_zero(nbtsock, struct nbt_name_request);
 425         NT_STATUS_HAVE_NO_MEMORY(req);
 426
 427         req->nbtsock   = nbtsock;
 428         req->dest.port = dest->port;
 429         req->dest.addr = talloc_strdup(req, dest->addr);
 430         if (req->dest.addr == NULL) goto failed;
 431         req->state     = NBT_REQUEST_SEND;
 432         req->is_reply = True;
 433
 434         talloc_set_destructor(req, nbt_name_request_destructor);
 435
 436         if (DEBUGLVL(10)) {
 437                 NDR_PRINT_DEBUG(nbt_name_packet, request);
 438         }
 439
 440         status = ndr_push_struct_blob(&req->encoded, req, request,
 441                                       (ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
 442         if (!NT_STATUS_IS_OK(status)) {
 443                 talloc_free(req);
 444                 return status;
 445         }
 446
 447         DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
 448
 449         EVENT_FD_WRITEABLE(nbtsock->fde);
 450
 451         return NT_STATUS_OK;
 452
 453 failed:
 454         talloc_free(req);
 455         return NT_STATUS_NO_MEMORY;
 456 }
 457
 458 /*
 459   wait for a nbt request to complete
 460 */
 461 NTSTATUS nbt_name_request_recv(struct nbt_name_request *req)
 462 {
 463         if (!req) return NT_STATUS_NO_MEMORY;
 464
 465         while (req->state < NBT_REQUEST_DONE) {
 466                 if (event_loop_once(req->nbtsock->event_ctx) != 0) {
 467                         req->state = NBT_REQUEST_ERROR;
 468                         req->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
 469                         if (req->async.fn) {
 470                                 req->async.fn(req);
 471                         }
 472                 }
 473         }
 474         return req->status;
 475 }
 476
 477
 478 /*
 479   setup a handler for incoming requests
 480 */
 481 NTSTATUS nbt_set_incoming_handler(struct nbt_name_socket *nbtsock,
 482                                   void (*handler)(struct nbt_name_socket *, struct nbt_name_packet *,
 483                                                   const struct nbt_peer_socket *),
 484                                   void *private)
 485 {
 486         nbtsock->incoming.handler = handler;
 487         nbtsock->incoming.private = private;
 488         EVENT_FD_READABLE(nbtsock->fde);
 489         return NT_STATUS_OK;
 490 }
 491
 492
 493 /*
 494   turn a NBT rcode into a NTSTATUS
 495 */
 496 NTSTATUS nbt_rcode_to_ntstatus(uint8_t rcode)
 497 {
 498         int i;
 499         struct {
 500                 enum nbt_rcode rcode;
 501                 NTSTATUS status;
 502         } map[] = {
 503                 { NBT_RCODE_FMT, NT_STATUS_INVALID_PARAMETER },
 504                 { NBT_RCODE_SVR, NT_STATUS_SERVER_DISABLED },
 505                 { NBT_RCODE_NAM, NT_STATUS_OBJECT_NAME_NOT_FOUND },
 506                 { NBT_RCODE_IMP, NT_STATUS_NOT_SUPPORTED },
 507                 { NBT_RCODE_RFS, NT_STATUS_ACCESS_DENIED },
 508                 { NBT_RCODE_ACT, NT_STATUS_ADDRESS_ALREADY_EXISTS },
 509                 { NBT_RCODE_CFT, NT_STATUS_CONFLICTING_ADDRESSES }
 510         };
 511         for (i=0;i<ARRAY_SIZE(map);i++) {
 512                 if (map[i].rcode == rcode) {
 513                         return map[i].status;
 514                 }
 515         }
 516         return NT_STATUS_UNSUCCESSFUL;
 517 }