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         const char *src_addr;
 157         int src_port;
 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                                  &src_addr, &src_port);
 177         if (!NT_STATUS_IS_OK(status)) {
 178                 talloc_free(tmp_ctx);
 179                 return;
 180         }
 181         talloc_steal(tmp_ctx, src_addr);
 182         blob.length = nread;
 183
 184         packet = talloc(tmp_ctx, struct nbt_name_packet);
 185         if (packet == NULL) {
 186                 talloc_free(tmp_ctx);
 187                 return;
 188         }
 189
 190         /* parse the request */
 191         status = ndr_pull_struct_blob(&blob, packet, packet,
 192                                       (ndr_pull_flags_fn_t)ndr_pull_nbt_name_packet);
 193         if (!NT_STATUS_IS_OK(status)) {
 194                 DEBUG(2,("Failed to parse incoming NBT name packet - %s\n",
 195                          nt_errstr(status)));
 196                 talloc_free(tmp_ctx);
 197                 return;
 198         }
 199
 200         if (DEBUGLVL(10)) {
 201                 DEBUG(10,("Received nbt packet of length %d from %s:%d\n",
 202                           (int)blob.length, src_addr, src_port));
 203                 NDR_PRINT_DEBUG(nbt_name_packet, packet);
 204         }
 205
 206         /* if its not a reply then pass it off to the incoming request
 207            handler, if any */
 208         if (!(packet->operation & NBT_FLAG_REPLY)) {
 209                 if (nbtsock->incoming.handler) {
 210                         nbtsock->incoming.handler(nbtsock, packet, src_addr, src_port);
 211                 }
 212                 talloc_free(tmp_ctx);
 213                 return;
 214         }
 215
 216         /* find the matching request */
 217         req = idr_find(nbtsock->idr, packet->name_trn_id);
 218         if (req == NULL) {
 219                 if (nbtsock->unexpected.handler) {
 220                         nbtsock->unexpected.handler(nbtsock, packet, src_addr, src_port);
 221                 } else {
 222                         DEBUG(2,("Failed to match request for incoming name packet id 0x%04x on %p\n",
 223                                  packet->name_trn_id, nbtsock));
 224                 }
 225                 talloc_free(tmp_ctx);
 226                 return;
 227         }
 228
 229         /* if this is a WACK response, this we need to go back to waiting,
 230            but perhaps increase the timeout */
 231         if ((packet->operation & NBT_OPCODE) == NBT_OPCODE_WACK) {
 232                 if (req->received_wack || packet->ancount < 1) {
 233                         nbt_name_request_destructor(req);
 234                         req->status = NT_STATUS_INVALID_NETWORK_RESPONSE;
 235                         req->state  = NBT_REQUEST_ERROR;
 236                         goto done;
 237                 }
 238                 talloc_free(req->te);
 239                 /* we know we won't need any more retries - the server
 240                    has received our request */
 241                 req->num_retries   = 0;
 242                 req->received_wack = True;
 243                 /* although there can be a timeout in the packet, w2k3 screws it up,
 244                    so better to set it ourselves */
 245                 req->timeout = lp_parm_int(-1, "nbt", "wack_timeout", 30);
 246                 req->te = event_add_timed(req->nbtsock->event_ctx, req,
 247                                           timeval_current_ofs(req->timeout, 0),
 248                                           nbt_name_socket_timeout, req);
 249                 talloc_free(tmp_ctx);
 250                 return;
 251         }
 252
 253
 254         req->replies = talloc_realloc(req, req->replies, struct nbt_name_reply, req->num_replies+1);
 255         if (req->replies == NULL) {
 256                 nbt_name_request_destructor(req);
 257                 req->state  = NBT_REQUEST_ERROR;
 258                 req->status = NT_STATUS_NO_MEMORY;
 259                 goto done;
 260         }
 261
 262         req->replies[req->num_replies].reply_addr = talloc_steal(req, src_addr);
 263         req->replies[req->num_replies].reply_port = src_port;
 264         req->replies[req->num_replies].packet     = talloc_steal(req, packet);
 265         req->num_replies++;
 266
 267         /* if we don't want multiple replies then we are done */
 268         if (req->allow_multiple_replies &&
 269             req->num_replies < NBT_MAX_REPLIES) {
 270                 talloc_free(tmp_ctx);
 271                 return;
 272         }
 273
 274         nbt_name_request_destructor(req);
 275         req->state  = NBT_REQUEST_DONE;
 276         req->status = NT_STATUS_OK;
 277
 278 done:
 279         talloc_free(tmp_ctx);
 280         if (req->async.fn) {
 281                 req->async.fn(req);
 282         }
 283 }
 284
 285 /*
 286   handle fd events on a nbt_name_socket
 287 */
 288 static void nbt_name_socket_handler(struct event_context *ev, struct fd_event *fde,
 289                                     uint16_t flags, void *private)
 290 {
 291         struct nbt_name_socket *nbtsock = talloc_get_type(private,
 292                                                           struct nbt_name_socket);
 293         if (flags & EVENT_FD_WRITE) {
 294                 nbt_name_socket_send(nbtsock);
 295         }
 296         if (flags & EVENT_FD_READ) {
 297                 nbt_name_socket_recv(nbtsock);
 298         }
 299 }
 300
 301
 302 /*
 303   initialise a nbt_name_socket. The event_ctx is optional, if provided
 304   then operations will use that event context
 305 */
 306 struct nbt_name_socket *nbt_name_socket_init(TALLOC_CTX *mem_ctx,
 307                                              struct event_context *event_ctx)
 308 {
 309         struct nbt_name_socket *nbtsock;
 310         NTSTATUS status;
 311
 312         nbtsock = talloc(mem_ctx, struct nbt_name_socket);
 313         if (nbtsock == NULL) goto failed;
 314
 315         if (event_ctx == NULL) {
 316                 nbtsock->event_ctx = event_context_init(nbtsock);
 317         } else {
 318                 nbtsock->event_ctx = talloc_reference(nbtsock, event_ctx);
 319         }
 320         if (nbtsock->event_ctx == NULL) goto failed;
 321
 322         status = socket_create("ip", SOCKET_TYPE_DGRAM, &nbtsock->sock, 0);
 323         if (!NT_STATUS_IS_OK(status)) goto failed;
 324
 325         socket_set_option(nbtsock->sock, "SO_BROADCAST", "1");
 326
 327         talloc_steal(nbtsock, nbtsock->sock);
 328
 329         nbtsock->idr = idr_init(nbtsock);
 330         if (nbtsock->idr == NULL) goto failed;
 331
 332         nbtsock->send_queue = NULL;
 333         nbtsock->num_pending = 0;
 334         nbtsock->incoming.handler = NULL;
 335         nbtsock->unexpected.handler = NULL;
 336
 337         nbtsock->fde = event_add_fd(nbtsock->event_ctx, nbtsock,
 338                                     socket_get_fd(nbtsock->sock), 0,
 339                                     nbt_name_socket_handler, nbtsock);
 340
 341         return nbtsock;
 342
 343 failed:
 344         talloc_free(nbtsock);
 345         return NULL;
 346 }
 347
 348 /*
 349   send off a nbt name request
 350 */
 351 struct nbt_name_request *nbt_name_request_send(struct nbt_name_socket *nbtsock,
 352                                                const char *dest_addr, int dest_port,
 353                                                struct nbt_name_packet *request,
 354                                                int timeout, int retries,
 355                                                BOOL allow_multiple_replies)
 356 {
 357         struct nbt_name_request *req;
 358         int id;
 359         NTSTATUS status;
 360
 361         req = talloc_zero(nbtsock, struct nbt_name_request);
 362         if (req == NULL) goto failed;
 363
 364         req->nbtsock                = nbtsock;
 365         req->dest_port              = dest_port;
 366         req->allow_multiple_replies = allow_multiple_replies;
 367         req->state                  = NBT_REQUEST_SEND;
 368         req->is_reply               = False;
 369         req->timeout                = timeout;
 370         req->num_retries            = retries;
 371         req->dest_addr              = talloc_strdup(req, dest_addr);
 372         if (req->dest_addr == NULL) goto failed;
 373
 374         /* we select a random transaction id unless the user supplied one */
 375         if (request->name_trn_id == 0) {
 376                 id = idr_get_new_random(req->nbtsock->idr, req, UINT16_MAX);
 377         } else {
 378                 if (idr_find(req->nbtsock->idr, request->name_trn_id)) goto failed;
 379                 id = idr_get_new_above(req->nbtsock->idr, req, request->name_trn_id,
 380                                        UINT16_MAX);
 381         }
 382         if (id == -1) goto failed;
 383
 384         request->name_trn_id = id;
 385         req->name_trn_id     = id;
 386
 387         req->te = event_add_timed(nbtsock->event_ctx, req,
 388                                   timeval_current_ofs(req->timeout, 0),
 389                                   nbt_name_socket_timeout, req);
 390
 391         talloc_set_destructor(req, nbt_name_request_destructor);
 392
 393         status = ndr_push_struct_blob(&req->encoded, req, request,
 394                                       (ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
 395         if (!NT_STATUS_IS_OK(status)) goto failed;
 396
 397         DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
 398
 399         if (DEBUGLVL(10)) {
 400                 DEBUG(10,("Queueing nbt packet to %s:%d\n",
 401                           req->dest_addr, req->dest_port));
 402                 NDR_PRINT_DEBUG(nbt_name_packet, request);
 403         }
 404
 405         EVENT_FD_WRITEABLE(nbtsock->fde);
 406
 407         return req;
 408
 409 failed:
 410         talloc_free(req);
 411         return NULL;
 412 }
 413
 414
 415 /*
 416   send off a nbt name reply
 417 */
 418 NTSTATUS nbt_name_reply_send(struct nbt_name_socket *nbtsock,
 419                              const char *dest_addr, int dest_port,
 420                              struct nbt_name_packet *request)
 421 {
 422         struct nbt_name_request *req;
 423         NTSTATUS status;
 424
 425         req = talloc_zero(nbtsock, struct nbt_name_request);
 426         NT_STATUS_HAVE_NO_MEMORY(req);
 427
 428         req->nbtsock   = nbtsock;
 429         req->dest_addr = talloc_strdup(req, dest_addr);
 430         if (req->dest_addr == NULL) goto failed;
 431         req->dest_port = dest_port;
 432         req->state     = NBT_REQUEST_SEND;
 433         req->is_reply = True;
 434
 435         talloc_set_destructor(req, nbt_name_request_destructor);
 436
 437         if (DEBUGLVL(10)) {
 438                 NDR_PRINT_DEBUG(nbt_name_packet, request);
 439         }
 440
 441         status = ndr_push_struct_blob(&req->encoded, req, request,
 442                                       (ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
 443         if (!NT_STATUS_IS_OK(status)) {
 444                 talloc_free(req);
 445                 return status;
 446         }
 447
 448         DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
 449
 450         EVENT_FD_WRITEABLE(nbtsock->fde);
 451
 452         return NT_STATUS_OK;
 453
 454 failed:
 455         talloc_free(req);
 456         return NT_STATUS_NO_MEMORY;
 457 }
 458
 459 /*
 460   wait for a nbt request to complete
 461 */
 462 NTSTATUS nbt_name_request_recv(struct nbt_name_request *req)
 463 {
 464         if (!req) return NT_STATUS_NO_MEMORY;
 465
 466         while (req->state < NBT_REQUEST_DONE) {
 467                 if (event_loop_once(req->nbtsock->event_ctx) != 0) {
 468                         req->state = NBT_REQUEST_ERROR;
 469                         req->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
 470                         if (req->async.fn) {
 471                                 req->async.fn(req);
 472                         }
 473                 }
 474         }
 475         return req->status;
 476 }
 477
 478
 479 /*
 480   setup a handler for incoming requests
 481 */
 482 NTSTATUS nbt_set_incoming_handler(struct nbt_name_socket *nbtsock,
 483                                   void (*handler)(struct nbt_name_socket *, struct nbt_name_packet *,
 484                                                   const char *, int ),
 485                                   void *private)
 486 {
 487         nbtsock->incoming.handler = handler;
 488         nbtsock->incoming.private = private;
 489         EVENT_FD_READABLE(nbtsock->fde);
 490         return NT_STATUS_OK;
 491 }
 492
 493
 494 /*
 495   turn a NBT rcode into a NTSTATUS
 496 */
 497 NTSTATUS nbt_rcode_to_ntstatus(uint8_t rcode)
 498 {
 499         int i;
 500         struct {
 501                 enum nbt_rcode rcode;
 502                 NTSTATUS status;
 503         } map[] = {
 504                 { NBT_RCODE_FMT, NT_STATUS_INVALID_PARAMETER },
 505                 { NBT_RCODE_SVR, NT_STATUS_SERVER_DISABLED },
 506                 { NBT_RCODE_NAM, NT_STATUS_OBJECT_NAME_NOT_FOUND },
 507                 { NBT_RCODE_IMP, NT_STATUS_NOT_SUPPORTED },
 508                 { NBT_RCODE_RFS, NT_STATUS_ACCESS_DENIED },
 509                 { NBT_RCODE_ACT, NT_STATUS_ADDRESS_ALREADY_EXISTS },
 510                 { NBT_RCODE_ACT, NT_STATUS_CONFLICTING_ADDRESSES }
 511         };
 512         for (i=0;i<ARRAY_SIZE(map);i++) {
 513                 if (map[i].rcode == rcode) {
 514                         return map[i].status;
 515                 }
 516         }
 517         return NT_STATUS_UNSUCCESSFUL;
 518 }