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         enum ndr_err_code ndr_err;
 161         struct socket_address *src;
 162         DATA_BLOB blob;
 163         size_t nread, dsize;
 164         struct nbt_name_packet *packet;
 165         struct nbt_name_request *req;
 166
 167         status = socket_pending(nbtsock->sock, &dsize);
 168         if (!NT_STATUS_IS_OK(status)) {
 169                 talloc_free(tmp_ctx);
 170                 return;
 171         }
 172
 173         blob = data_blob_talloc(tmp_ctx, NULL, dsize);
 174         if (blob.data == NULL) {
 175                 talloc_free(tmp_ctx);
 176                 return;
 177         }
 178
 179         status = socket_recvfrom(nbtsock->sock, blob.data, blob.length, &nread,
 180                                  tmp_ctx, &src);
 181         if (!NT_STATUS_IS_OK(status)) {
 182                 talloc_free(tmp_ctx);
 183                 return;
 184         }
 185
 186         packet = talloc(tmp_ctx, struct nbt_name_packet);
 187         if (packet == NULL) {
 188                 talloc_free(tmp_ctx);
 189                 return;
 190         }
 191
 192         /* parse the request */
 193         ndr_err = ndr_pull_struct_blob(&blob, packet, nbtsock->iconv_convenience, packet,
 194                                        (ndr_pull_flags_fn_t)ndr_pull_nbt_name_packet);
 195         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 196                 status = ndr_map_error2ntstatus(ndr_err);
 197                 DEBUG(2,("Failed to parse incoming NBT name packet - %s\n",
 198                          nt_errstr(status)));
 199                 talloc_free(tmp_ctx);
 200                 return;
 201         }
 202
 203         if (DEBUGLVL(10)) {
 204                 DEBUG(10,("Received nbt packet of length %d from %s:%d\n",
 205                           (int)blob.length, src->addr, src->port));
 206                 NDR_PRINT_DEBUG(nbt_name_packet, packet);
 207         }
 208
 209         /* if its not a reply then pass it off to the incoming request
 210            handler, if any */
 211         if (!(packet->operation & NBT_FLAG_REPLY)) {
 212                 if (nbtsock->incoming.handler) {
 213                         nbtsock->incoming.handler(nbtsock, packet, src);
 214                 }
 215                 talloc_free(tmp_ctx);
 216                 return;
 217         }
 218
 219         /* find the matching request */
 220         req = (struct nbt_name_request *)idr_find(nbtsock->idr,
 221                                                   packet->name_trn_id);
 222         if (req == NULL) {
 223                 if (nbtsock->unexpected.handler) {
 224                         nbtsock->unexpected.handler(nbtsock, packet, src);
 225                 } else {
 226                         DEBUG(10,("Failed to match request for incoming name packet id 0x%04x on %p\n",
 227                                  packet->name_trn_id, nbtsock));
 228                 }
 229                 talloc_free(tmp_ctx);
 230                 return;
 231         }
 232
 233         /* if this is a WACK response, this we need to go back to waiting,
 234            but perhaps increase the timeout */
 235         if ((packet->operation & NBT_OPCODE) == NBT_OPCODE_WACK) {
 236                 if (req->received_wack || packet->ancount < 1) {
 237                         nbt_name_request_destructor(req);
 238                         req->status = NT_STATUS_INVALID_NETWORK_RESPONSE;
 239                         req->state  = NBT_REQUEST_ERROR;
 240                         goto done;
 241                 }
 242                 talloc_free(req->te);
 243                 /* we know we won't need any more retries - the server
 244                    has received our request */
 245                 req->num_retries   = 0;
 246                 req->received_wack = true;
 247                 /* although there can be a timeout in the packet, w2k3 screws it up,
 248                    so better to set it ourselves */
 249                 req->timeout = lp_parm_int(global_loadparm, NULL, "nbt", "wack_timeout", 30);
 250                 req->te = event_add_timed(req->nbtsock->event_ctx, req,
 251                                           timeval_current_ofs(req->timeout, 0),
 252                                           nbt_name_socket_timeout, req);
 253                 talloc_free(tmp_ctx);
 254                 return;
 255         }
 256
 257
 258         req->replies = talloc_realloc(req, req->replies, struct nbt_name_reply, req->num_replies+1);
 259         if (req->replies == NULL) {
 260                 nbt_name_request_destructor(req);
 261                 req->state  = NBT_REQUEST_ERROR;
 262                 req->status = NT_STATUS_NO_MEMORY;
 263                 goto done;
 264         }
 265
 266         talloc_steal(req, src);
 267         req->replies[req->num_replies].dest   = src;
 268         talloc_steal(req, packet);
 269         req->replies[req->num_replies].packet = packet;
 270         req->num_replies++;
 271
 272         /* if we don't want multiple replies then we are done */
 273         if (req->allow_multiple_replies &&
 274             req->num_replies < NBT_MAX_REPLIES) {
 275                 talloc_free(tmp_ctx);
 276                 return;
 277         }
 278
 279         nbt_name_request_destructor(req);
 280         req->state  = NBT_REQUEST_DONE;
 281         req->status = NT_STATUS_OK;
 282
 283 done:
 284         talloc_free(tmp_ctx);
 285         if (req->async.fn) {
 286                 req->async.fn(req);
 287         }
 288 }
 289
 290 /*
 291   handle fd events on a nbt_name_socket
 292 */
 293 static void nbt_name_socket_handler(struct event_context *ev, struct fd_event *fde,
 294                                     uint16_t flags, void *private)
 295 {
 296         struct nbt_name_socket *nbtsock = talloc_get_type(private,
 297                                                           struct nbt_name_socket);
 298         if (flags & EVENT_FD_WRITE) {
 299                 nbt_name_socket_send(nbtsock);
 300         }
 301         if (flags & EVENT_FD_READ) {
 302                 nbt_name_socket_recv(nbtsock);
 303         }
 304 }
 305
 306
 307 /*
 308   initialise a nbt_name_socket. The event_ctx is optional, if provided
 309   then operations will use that event context
 310 */
 311 _PUBLIC_ struct nbt_name_socket *nbt_name_socket_init(TALLOC_CTX *mem_ctx,
 312                                              struct event_context *event_ctx,
 313                                              struct smb_iconv_convenience *iconv_convenience)
 314 {
 315         struct nbt_name_socket *nbtsock;
 316         NTSTATUS status;
 317
 318         nbtsock = talloc(mem_ctx, struct nbt_name_socket);
 319         if (nbtsock == NULL) goto failed;
 320
 321         nbtsock->event_ctx = talloc_reference(nbtsock, event_ctx);
 322         if (nbtsock->event_ctx == NULL) goto failed;
 323
 324         status = socket_create("ip", SOCKET_TYPE_DGRAM, &nbtsock->sock, 0);
 325         if (!NT_STATUS_IS_OK(status)) goto failed;
 326
 327         socket_set_option(nbtsock->sock, "SO_BROADCAST", "1");
 328
 329         talloc_steal(nbtsock, nbtsock->sock);
 330
 331         nbtsock->idr = idr_init(nbtsock);
 332         if (nbtsock->idr == NULL) goto failed;
 333
 334         nbtsock->send_queue = NULL;
 335         nbtsock->num_pending = 0;
 336         nbtsock->incoming.handler = NULL;
 337         nbtsock->unexpected.handler = NULL;
 338         nbtsock->iconv_convenience = iconv_convenience;
 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         enum ndr_err_code ndr_err;
 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         ndr_err = ndr_push_struct_blob(&req->encoded, req,
 396                                        req->nbtsock->iconv_convenience,
 397                                        request,
 398                                        (ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
 399         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) goto failed;
 400
 401         DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
 402
 403         if (DEBUGLVL(10)) {
 404                 DEBUG(10,("Queueing nbt packet to %s:%d\n",
 405                           req->dest->addr, req->dest->port));
 406                 NDR_PRINT_DEBUG(nbt_name_packet, request);
 407         }
 408
 409         EVENT_FD_WRITEABLE(nbtsock->fde);
 410
 411         return req;
 412
 413 failed:
 414         talloc_free(req);
 415         return NULL;
 416 }
 417
 418
 419 /*
 420   send off a nbt name reply
 421 */
 422 _PUBLIC_ NTSTATUS nbt_name_reply_send(struct nbt_name_socket *nbtsock,
 423                              struct socket_address *dest,
 424                              struct nbt_name_packet *request)
 425 {
 426         struct nbt_name_request *req;
 427         enum ndr_err_code ndr_err;
 428
 429         req = talloc_zero(nbtsock, struct nbt_name_request);
 430         NT_STATUS_HAVE_NO_MEMORY(req);
 431
 432         req->nbtsock   = nbtsock;
 433         req->dest = dest;
 434         if (talloc_reference(req, dest) == NULL) goto failed;
 435         req->state     = NBT_REQUEST_SEND;
 436         req->is_reply = true;
 437
 438         talloc_set_destructor(req, nbt_name_request_destructor);
 439
 440         if (DEBUGLVL(10)) {
 441                 NDR_PRINT_DEBUG(nbt_name_packet, request);
 442         }
 443
 444         ndr_err = ndr_push_struct_blob(&req->encoded, req,
 445                                        req->nbtsock->iconv_convenience,
 446                                        request,
 447                                        (ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
 448         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 449                 talloc_free(req);
 450                 return ndr_map_error2ntstatus(ndr_err);
 451         }
 452
 453         DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
 454
 455         EVENT_FD_WRITEABLE(nbtsock->fde);
 456
 457         return NT_STATUS_OK;
 458
 459 failed:
 460         talloc_free(req);
 461         return NT_STATUS_NO_MEMORY;
 462 }
 463
 464 /*
 465   wait for a nbt request to complete
 466 */
 467 NTSTATUS nbt_name_request_recv(struct nbt_name_request *req)
 468 {
 469         if (!req) return NT_STATUS_NO_MEMORY;
 470
 471         while (req->state < NBT_REQUEST_DONE) {
 472                 if (event_loop_once(req->nbtsock->event_ctx) != 0) {
 473                         req->state = NBT_REQUEST_ERROR;
 474                         req->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
 475                         break;
 476                 }
 477         }
 478         return req->status;
 479 }
 480
 481
 482 /*
 483   setup a handler for incoming requests
 484 */
 485 _PUBLIC_ NTSTATUS nbt_set_incoming_handler(struct nbt_name_socket *nbtsock,
 486                                   void (*handler)(struct nbt_name_socket *, struct nbt_name_packet *,
 487                                                   struct socket_address *),
 488                                   void *private)
 489 {
 490         nbtsock->incoming.handler = handler;
 491         nbtsock->incoming.private_data = private;
 492         EVENT_FD_READABLE(nbtsock->fde);
 493         return NT_STATUS_OK;
 494 }
 495
 496
 497 /*
 498   turn a NBT rcode into a NTSTATUS
 499 */
 500 _PUBLIC_ NTSTATUS nbt_rcode_to_ntstatus(uint8_t rcode)
 501 {
 502         int i;
 503         struct {
 504                 enum nbt_rcode rcode;
 505                 NTSTATUS status;
 506         } map[] = {
 507                 { NBT_RCODE_FMT, NT_STATUS_INVALID_PARAMETER },
 508                 { NBT_RCODE_SVR, NT_STATUS_SERVER_DISABLED },
 509                 { NBT_RCODE_NAM, NT_STATUS_OBJECT_NAME_NOT_FOUND },
 510                 { NBT_RCODE_IMP, NT_STATUS_NOT_SUPPORTED },
 511                 { NBT_RCODE_RFS, NT_STATUS_ACCESS_DENIED },
 512                 { NBT_RCODE_ACT, NT_STATUS_ADDRESS_ALREADY_EXISTS },
 513                 { NBT_RCODE_CFT, NT_STATUS_CONFLICTING_ADDRESSES }
 514         };
 515         for (i=0;i<ARRAY_SIZE(map);i++) {
 516                 if (map[i].rcode == rcode) {
 517                         return map[i].status;
 518                 }
 519         }
 520         return NT_STATUS_UNSUCCESSFUL;
 521 }