source/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 3 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, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "lib/events/events.h"
  24 #include "lib/util/dlinklist.h"
  25 #include "libcli/nbt/libnbt.h"
  26 #include "lib/socket/socket.h"
  27 #include "librpc/gen_ndr/ndr_nbt.h"
  28 #include "param/param.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                 talloc_free(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,
  76                                        req->dest);
  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         } else if (req->is_reply) {
 107                 talloc_free(req);
 108         }
 109         return;
 110 }
 111
 112
 113 /*
 114   handle a request timeout
 115 */
 116 static void nbt_name_socket_timeout(struct event_context *ev, struct timed_event *te,
 117                                     struct timeval t, void *private)
 118 {
 119         struct nbt_name_request *req = talloc_get_type(private,
 120                                                        struct nbt_name_request);
 121
 122         if (req->num_retries != 0) {
 123                 req->num_retries--;
 124                 req->te = event_add_timed(req->nbtsock->event_ctx, req,
 125                                           timeval_add(&t, req->timeout, 0),
 126                                           nbt_name_socket_timeout, req);
 127                 if (req->state != NBT_REQUEST_SEND) {
 128                         req->state = NBT_REQUEST_SEND;
 129                         DLIST_ADD_END(req->nbtsock->send_queue, req,
 130                                       struct nbt_name_request *);
 131                 }
 132                 EVENT_FD_WRITEABLE(req->nbtsock->fde);
 133                 return;
 134         }
 135
 136         nbt_name_request_destructor(req);
 137         if (req->num_replies == 0) {
 138                 req->state = NBT_REQUEST_TIMEOUT;
 139                 req->status = NT_STATUS_IO_TIMEOUT;
 140         } else {
 141                 req->state = NBT_REQUEST_DONE;
 142                 req->status = NT_STATUS_OK;
 143         }
 144         if (req->async.fn) {
 145                 req->async.fn(req);
 146         } else if (req->is_reply) {
 147                 talloc_free(req);
 148         }
 149 }
 150
 151
 152
 153 /*
 154   handle recv events on a nbt name socket
 155 */
 156 static void nbt_name_socket_recv(struct nbt_name_socket *nbtsock)
 157 {
 158         TALLOC_CTX *tmp_ctx = talloc_new(nbtsock);
 159         NTSTATUS status;
 160         struct socket_address *src;
 161         DATA_BLOB blob;
 162         size_t nread, dsize;
 163         struct nbt_name_packet *packet;
 164         struct nbt_name_request *req;
 165
 166         status = socket_pending(nbtsock->sock, &dsize);
 167         if (!NT_STATUS_IS_OK(status)) {
 168                 talloc_free(tmp_ctx);
 169                 return;
 170         }
 171
 172         blob = data_blob_talloc(tmp_ctx, NULL, dsize);
 173         if (blob.data == NULL) {
 174                 talloc_free(tmp_ctx);
 175                 return;
 176         }
 177
 178         status = socket_recvfrom(nbtsock->sock, blob.data, blob.length, &nread,
 179                                  tmp_ctx, &src);
 180         if (!NT_STATUS_IS_OK(status)) {
 181                 talloc_free(tmp_ctx);
 182                 return;
 183         }
 184
 185         packet = talloc(tmp_ctx, struct nbt_name_packet);
 186         if (packet == NULL) {
 187                 talloc_free(tmp_ctx);
 188                 return;
 189         }
 190
 191         /* parse the request */
 192         status = ndr_pull_struct_blob(&blob, packet, packet,
 193                                       (ndr_pull_flags_fn_t)ndr_pull_nbt_name_packet);
 194         if (!NT_STATUS_IS_OK(status)) {
 195                 DEBUG(2,("Failed to parse incoming NBT name packet - %s\n",
 196                          nt_errstr(status)));
 197                 talloc_free(tmp_ctx);
 198                 return;
 199         }
 200
 201         if (DEBUGLVL(10)) {
 202                 DEBUG(10,("Received nbt packet of length %d from %s:%d\n",
 203                           (int)blob.length, src->addr, src->port));
 204                 NDR_PRINT_DEBUG(nbt_name_packet, packet);
 205         }
 206
 207         /* if its not a reply then pass it off to the incoming request
 208            handler, if any */
 209         if (!(packet->operation & NBT_FLAG_REPLY)) {
 210                 if (nbtsock->incoming.handler) {
 211                         nbtsock->incoming.handler(nbtsock, packet, src);
 212                 }
 213                 talloc_free(tmp_ctx);
 214                 return;
 215         }
 216
 217         /* find the matching request */
 218         req = (struct nbt_name_request *)idr_find(nbtsock->idr,
 219                                                   packet->name_trn_id);
 220         if (req == NULL) {
 221                 if (nbtsock->unexpected.handler) {
 222                         nbtsock->unexpected.handler(nbtsock, packet, src);
 223                 } else {
 224                         DEBUG(10,("Failed to match request for incoming name packet id 0x%04x on %p\n",
 225                                  packet->name_trn_id, nbtsock));
 226                 }
 227                 talloc_free(tmp_ctx);
 228                 return;
 229         }
 230
 231         /* if this is a WACK response, this we need to go back to waiting,
 232            but perhaps increase the timeout */
 233         if ((packet->operation & NBT_OPCODE) == NBT_OPCODE_WACK) {
 234                 if (req->received_wack || packet->ancount < 1) {
 235                         nbt_name_request_destructor(req);
 236                         req->status = NT_STATUS_INVALID_NETWORK_RESPONSE;
 237                         req->state  = NBT_REQUEST_ERROR;
 238                         goto done;
 239                 }
 240                 talloc_free(req->te);
 241                 /* we know we won't need any more retries - the server
 242                    has received our request */
 243                 req->num_retries   = 0;
 244                 req->received_wack = True;
 245                 /* although there can be a timeout in the packet, w2k3 screws it up,
 246                    so better to set it ourselves */
 247                 req->timeout = lp_parm_int(NULL, "nbt", "wack_timeout", 30);
 248                 req->te = event_add_timed(req->nbtsock->event_ctx, req,
 249                                           timeval_current_ofs(req->timeout, 0),
 250                                           nbt_name_socket_timeout, req);
 251                 talloc_free(tmp_ctx);
 252                 return;
 253         }
 254
 255
 256         req->replies = talloc_realloc(req, req->replies, struct nbt_name_reply, req->num_replies+1);
 257         if (req->replies == NULL) {
 258                 nbt_name_request_destructor(req);
 259                 req->state  = NBT_REQUEST_ERROR;
 260                 req->status = NT_STATUS_NO_MEMORY;
 261                 goto done;
 262         }
 263
 264         talloc_steal(req, src);
 265         req->replies[req->num_replies].dest   = src;
 266         talloc_steal(req, packet);
 267         req->replies[req->num_replies].packet = packet;
 268         req->num_replies++;
 269
 270         /* if we don't want multiple replies then we are done */
 271         if (req->allow_multiple_replies &&
 272             req->num_replies < NBT_MAX_REPLIES) {
 273                 talloc_free(tmp_ctx);
 274                 return;
 275         }
 276
 277         nbt_name_request_destructor(req);
 278         req->state  = NBT_REQUEST_DONE;
 279         req->status = NT_STATUS_OK;
 280
 281 done:
 282         talloc_free(tmp_ctx);
 283         if (req->async.fn) {
 284                 req->async.fn(req);
 285         }
 286 }
 287
 288 /*
 289   handle fd events on a nbt_name_socket
 290 */
 291 static void nbt_name_socket_handler(struct event_context *ev, struct fd_event *fde,
 292                                     uint16_t flags, void *private)
 293 {
 294         struct nbt_name_socket *nbtsock = talloc_get_type(private,
 295                                                           struct nbt_name_socket);
 296         if (flags & EVENT_FD_WRITE) {
 297                 nbt_name_socket_send(nbtsock);
 298         }
 299         if (flags & EVENT_FD_READ) {
 300                 nbt_name_socket_recv(nbtsock);
 301         }
 302 }
 303
 304
 305 /*
 306   initialise a nbt_name_socket. The event_ctx is optional, if provided
 307   then operations will use that event context
 308 */
 309 _PUBLIC_ struct nbt_name_socket *nbt_name_socket_init(TALLOC_CTX *mem_ctx,
 310                                              struct event_context *event_ctx)
 311 {
 312         struct nbt_name_socket *nbtsock;
 313         NTSTATUS status;
 314
 315         nbtsock = talloc(mem_ctx, struct nbt_name_socket);
 316         if (nbtsock == NULL) goto failed;
 317
 318         if (event_ctx == NULL) {
 319                 nbtsock->event_ctx = event_context_init(nbtsock);
 320         } else {
 321                 nbtsock->event_ctx = talloc_reference(nbtsock, event_ctx);
 322         }
 323         if (nbtsock->event_ctx == NULL) goto failed;
 324
 325         status = socket_create("ip", SOCKET_TYPE_DGRAM, &nbtsock->sock, 0);
 326         if (!NT_STATUS_IS_OK(status)) goto failed;
 327
 328         socket_set_option(nbtsock->sock, "SO_BROADCAST", "1");
 329
 330         talloc_steal(nbtsock, nbtsock->sock);
 331
 332         nbtsock->idr = idr_init(nbtsock);
 333         if (nbtsock->idr == NULL) goto failed;
 334
 335         nbtsock->send_queue = NULL;
 336         nbtsock->num_pending = 0;
 337         nbtsock->incoming.handler = NULL;
 338         nbtsock->unexpected.handler = NULL;
 339
 340         nbtsock->fde = event_add_fd(nbtsock->event_ctx, nbtsock,
 341                                     socket_get_fd(nbtsock->sock), 0,
 342                                     nbt_name_socket_handler, nbtsock);
 343
 344         return nbtsock;
 345
 346 failed:
 347         talloc_free(nbtsock);
 348         return NULL;
 349 }
 350
 351 /*
 352   send off a nbt name request
 353 */
 354 struct nbt_name_request *nbt_name_request_send(struct nbt_name_socket *nbtsock,
 355                                                struct socket_address *dest,
 356                                                struct nbt_name_packet *request,
 357                                                int timeout, int retries,
 358                                                BOOL allow_multiple_replies)
 359 {
 360         struct nbt_name_request *req;
 361         int id;
 362         NTSTATUS status;
 363
 364         req = talloc_zero(nbtsock, struct nbt_name_request);
 365         if (req == NULL) goto failed;
 366
 367         req->nbtsock                = nbtsock;
 368         req->allow_multiple_replies = allow_multiple_replies;
 369         req->state                  = NBT_REQUEST_SEND;
 370         req->is_reply               = False;
 371         req->timeout                = timeout;
 372         req->num_retries            = retries;
 373         req->dest                   = dest;
 374         if (talloc_reference(req, dest) == NULL) goto failed;
 375
 376         /* we select a random transaction id unless the user supplied one */
 377         if (request->name_trn_id == 0) {
 378                 id = idr_get_new_random(req->nbtsock->idr, req, UINT16_MAX);
 379         } else {
 380                 if (idr_find(req->nbtsock->idr, request->name_trn_id)) goto failed;
 381                 id = idr_get_new_above(req->nbtsock->idr, req, request->name_trn_id,
 382                                        UINT16_MAX);
 383         }
 384         if (id == -1) goto failed;
 385
 386         request->name_trn_id = id;
 387         req->name_trn_id     = id;
 388
 389         req->te = event_add_timed(nbtsock->event_ctx, req,
 390                                   timeval_current_ofs(req->timeout, 0),
 391                                   nbt_name_socket_timeout, req);
 392
 393         talloc_set_destructor(req, nbt_name_request_destructor);
 394
 395         status = ndr_push_struct_blob(&req->encoded, req, request,
 396                                       (ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
 397         if (!NT_STATUS_IS_OK(status)) goto failed;
 398
 399         DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
 400
 401         if (DEBUGLVL(10)) {
 402                 DEBUG(10,("Queueing nbt packet to %s:%d\n",
 403                           req->dest->addr, req->dest->port));
 404                 NDR_PRINT_DEBUG(nbt_name_packet, request);
 405         }
 406
 407         EVENT_FD_WRITEABLE(nbtsock->fde);
 408
 409         return req;
 410
 411 failed:
 412         talloc_free(req);
 413         return NULL;
 414 }
 415
 416
 417 /*
 418   send off a nbt name reply
 419 */
 420 NTSTATUS nbt_name_reply_send(struct nbt_name_socket *nbtsock,
 421                              struct socket_address *dest,
 422                              struct nbt_name_packet *request)
 423 {
 424         struct nbt_name_request *req;
 425         NTSTATUS status;
 426
 427         req = talloc_zero(nbtsock, struct nbt_name_request);
 428         NT_STATUS_HAVE_NO_MEMORY(req);
 429
 430         req->nbtsock   = nbtsock;
 431         req->dest = dest;
 432         if (talloc_reference(req, dest) == NULL) goto failed;
 433         req->state     = NBT_REQUEST_SEND;
 434         req->is_reply = True;
 435
 436         talloc_set_destructor(req, nbt_name_request_destructor);
 437
 438         if (DEBUGLVL(10)) {
 439                 NDR_PRINT_DEBUG(nbt_name_packet, request);
 440         }
 441
 442         status = ndr_push_struct_blob(&req->encoded, req, request,
 443                                       (ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
 444         if (!NT_STATUS_IS_OK(status)) {
 445                 talloc_free(req);
 446                 return status;
 447         }
 448
 449         DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
 450
 451         EVENT_FD_WRITEABLE(nbtsock->fde);
 452
 453         return NT_STATUS_OK;
 454
 455 failed:
 456         talloc_free(req);
 457         return NT_STATUS_NO_MEMORY;
 458 }
 459
 460 /*
 461   wait for a nbt request to complete
 462 */
 463 NTSTATUS nbt_name_request_recv(struct nbt_name_request *req)
 464 {
 465         if (!req) return NT_STATUS_NO_MEMORY;
 466
 467         while (req->state < NBT_REQUEST_DONE) {
 468                 if (event_loop_once(req->nbtsock->event_ctx) != 0) {
 469                         req->state = NBT_REQUEST_ERROR;
 470                         req->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
 471                         break;
 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                                                   struct socket_address *),
 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 }