source3/libsmb/async_smb.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Infrastructure for async SMB client requests
   4    Copyright (C) Volker Lendecke 2008
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "libsmb/libsmb.h"
  22 #include "../lib/async_req/async_sock.h"
  23 #include "../lib/util/tevent_ntstatus.h"
  24 #include "../lib/util/tevent_unix.h"
  25 #include "async_smb.h"
  26 #include "../libcli/smb/smb_seal.h"
  27 #include "libsmb/nmblib.h"
  28 #include "../libcli/smb/read_smb.h"
  29
  30 static NTSTATUS cli_pull_raw_error(const uint8_t *buf)
  31 {
  32         const uint8_t *hdr = buf + NBT_HDR_SIZE;
  33         uint32_t flags2 = SVAL(hdr, HDR_FLG2);
  34         NTSTATUS status = NT_STATUS(IVAL(hdr, HDR_RCLS));
  35
  36         if (NT_STATUS_IS_OK(status)) {
  37                 return NT_STATUS_OK;
  38         }
  39
  40         if (flags2 & FLAGS2_32_BIT_ERROR_CODES) {
  41                 return status;
  42         }
  43
  44         return NT_STATUS_DOS(CVAL(hdr, HDR_RCLS), SVAL(hdr, HDR_ERR));
  45 }
  46
  47 /**
  48  * Figure out if there is an andx command behind the current one
  49  * @param[in] buf       The smb buffer to look at
  50  * @param[in] ofs       The offset to the wct field that is followed by the cmd
  51  * @retval Is there a command following?
  52  */
  53
  54 static bool have_andx_command(const char *buf, uint16_t ofs)
  55 {
  56         uint8_t wct;
  57         size_t buflen = talloc_get_size(buf);
  58
  59         if ((ofs == buflen-1) || (ofs == buflen)) {
  60                 return false;
  61         }
  62
  63         wct = CVAL(buf, ofs);
  64         if (wct < 2) {
  65                 /*
  66                  * Not enough space for the command and a following pointer
  67                  */
  68                 return false;
  69         }
  70         return (CVAL(buf, ofs+1) != 0xff);
  71 }
  72
  73 #define MAX_SMB_IOV 5
  74
  75 struct cli_smb_state {
  76         struct tevent_context *ev;
  77         struct cli_state *cli;
  78         uint8_t header[smb_wct+1]; /* Space for the header including the wct */
  79
  80         /*
  81          * For normal requests, cli_smb_req_send chooses a mid. Secondary
  82          * trans requests need to use the mid of the primary request, so we
  83          * need a place to store it. Assume it's set if != 0.
  84          */
  85         uint16_t mid;
  86
  87         uint16_t *vwv;
  88         uint8_t bytecount_buf[2];
  89
  90         struct iovec iov[MAX_SMB_IOV+3];
  91         int iov_count;
  92
  93         uint8_t *inbuf;
  94         uint32_t seqnum;
  95         int chain_num;
  96         int chain_length;
  97         struct tevent_req **chained_requests;
  98
  99         bool one_way;
 100 };
 101
 102 static uint16_t cli_alloc_mid(struct cli_state *cli)
 103 {
 104         int num_pending = talloc_array_length(cli->conn.pending);
 105         uint16_t result;
 106
 107         while (true) {
 108                 int i;
 109
 110                 result = cli->conn.smb1.mid++;
 111                 if ((result == 0) || (result == 0xffff)) {
 112                         continue;
 113                 }
 114
 115                 for (i=0; i<num_pending; i++) {
 116                         if (result == cli_smb_req_mid(cli->conn.pending[i])) {
 117                                 break;
 118                         }
 119                 }
 120
 121                 if (i == num_pending) {
 122                         return result;
 123                 }
 124         }
 125 }
 126
 127 void cli_smb_req_unset_pending(struct tevent_req *req)
 128 {
 129         struct cli_smb_state *state = tevent_req_data(
 130                 req, struct cli_smb_state);
 131         struct cli_state *cli = state->cli;
 132         int num_pending = talloc_array_length(cli->conn.pending);
 133         int i;
 134
 135         if (state->mid != 0) {
 136                 /*
 137                  * This is a [nt]trans[2] request which waits
 138                  * for more than one reply.
 139                  */
 140                 return;
 141         }
 142
 143         talloc_set_destructor(req, NULL);
 144
 145         if (num_pending == 1) {
 146                 /*
 147                  * The pending read_smb tevent_req is a child of
 148                  * cli->pending. So if nothing is pending anymore, we need to
 149                  * delete the socket read fde.
 150                  */
 151                 TALLOC_FREE(cli->conn.pending);
 152                 cli->conn.read_smb_req = NULL;
 153                 return;
 154         }
 155
 156         for (i=0; i<num_pending; i++) {
 157                 if (req == cli->conn.pending[i]) {
 158                         break;
 159                 }
 160         }
 161         if (i == num_pending) {
 162                 /*
 163                  * Something's seriously broken. Just returning here is the
 164                  * right thing nevertheless, the point of this routine is to
 165                  * remove ourselves from cli->conn.pending.
 166                  */
 167                 return;
 168         }
 169
 170         /*
 171          * Remove ourselves from the cli->conn.pending array
 172          */
 173         for (; i < (num_pending - 1); i++) {
 174                 cli->conn.pending[i] = cli->conn.pending[i+1];
 175         }
 176
 177         /*
 178          * No NULL check here, we're shrinking by sizeof(void *), and
 179          * talloc_realloc just adjusts the size for this.
 180          */
 181         cli->conn.pending = talloc_realloc(NULL, cli->conn.pending,
 182                                            struct tevent_req *,
 183                                            num_pending - 1);
 184         return;
 185 }
 186
 187 static int cli_smb_req_destructor(struct tevent_req *req)
 188 {
 189         struct cli_smb_state *state = tevent_req_data(
 190                 req, struct cli_smb_state);
 191         /*
 192          * Make sure we really remove it from
 193          * the pending array on destruction.
 194          */
 195         state->mid = 0;
 196         cli_smb_req_unset_pending(req);
 197         return 0;
 198 }
 199
 200 static bool cli_state_receive_next(struct cli_state *cli);
 201 static void cli_state_notify_pending(struct cli_state *cli, NTSTATUS status);
 202
 203 bool cli_smb_req_set_pending(struct tevent_req *req)
 204 {
 205         struct cli_smb_state *state = tevent_req_data(
 206                 req, struct cli_smb_state);
 207         struct cli_state *cli;
 208         struct tevent_req **pending;
 209         int num_pending;
 210
 211         cli = state->cli;
 212         num_pending = talloc_array_length(cli->conn.pending);
 213
 214         pending = talloc_realloc(cli, cli->conn.pending, struct tevent_req *,
 215                                  num_pending+1);
 216         if (pending == NULL) {
 217                 return false;
 218         }
 219         pending[num_pending] = req;
 220         cli->conn.pending = pending;
 221         talloc_set_destructor(req, cli_smb_req_destructor);
 222
 223         if (!cli_state_receive_next(cli)) {
 224                 /*
 225                  * the caller should notify the current request
 226                  *
 227                  * And all other pending requests get notified
 228                  * by cli_state_notify_pending().
 229                  */
 230                 cli_smb_req_unset_pending(req);
 231                 cli_state_notify_pending(cli, NT_STATUS_NO_MEMORY);
 232                 return false;
 233         }
 234
 235         return true;
 236 }
 237
 238 static void cli_smb_received(struct tevent_req *subreq);
 239 static NTSTATUS cli_state_dispatch_smb1(struct cli_state *cli,
 240                                         TALLOC_CTX *frame,
 241                                         uint8_t *inbuf);
 242
 243 static bool cli_state_receive_next(struct cli_state *cli)
 244 {
 245         size_t num_pending = talloc_array_length(cli->conn.pending);
 246         struct tevent_req *req;
 247         struct cli_smb_state *state;
 248
 249         if (cli->conn.read_smb_req != NULL) {
 250                 return true;
 251         }
 252
 253         if (num_pending == 0) {
 254                 return true;
 255         }
 256
 257         req = cli->conn.pending[0];
 258         state = tevent_req_data(req, struct cli_smb_state);
 259
 260         cli->conn.dispatch_incoming = cli_state_dispatch_smb1;
 261
 262         /*
 263          * We're the first ones, add the read_smb request that waits for the
 264          * answer from the server
 265          */
 266         cli->conn.read_smb_req = read_smb_send(cli->conn.pending, state->ev,
 267                                                cli->conn.fd);
 268         if (cli->conn.read_smb_req == NULL) {
 269                 return false;
 270         }
 271         tevent_req_set_callback(cli->conn.read_smb_req, cli_smb_received, cli);
 272         return true;
 273 }
 274
 275 static void cli_state_notify_pending(struct cli_state *cli, NTSTATUS status)
 276 {
 277         cli_state_disconnect(cli);
 278
 279         /*
 280          * Cancel all pending requests. We do not do a for-loop walking
 281          * cli->conn.pending because that array changes in
 282          * cli_smb_req_destructor().
 283          */
 284         while (talloc_array_length(cli->conn.pending) > 0) {
 285                 struct tevent_req *req;
 286                 struct cli_smb_state *state;
 287
 288                 req = cli->conn.pending[0];
 289                 state = tevent_req_data(req, struct cli_smb_state);
 290
 291                 /*
 292                  * We're dead. No point waiting for trans2
 293                  * replies.
 294                  */
 295                 state->mid = 0;
 296
 297                 cli_smb_req_unset_pending(req);
 298
 299                 /*
 300                  * we need to defer the callback, because we may notify more
 301                  * then one caller.
 302                  */
 303                 tevent_req_defer_callback(req, state->ev);
 304                 tevent_req_nterror(req, status);
 305         }
 306 }
 307
 308 /*
 309  * Fetch a smb request's mid. Only valid after the request has been sent by
 310  * cli_smb_req_send().
 311  */
 312 uint16_t cli_smb_req_mid(struct tevent_req *req)
 313 {
 314         struct cli_smb_state *state = tevent_req_data(
 315                 req, struct cli_smb_state);
 316
 317         if (state->mid != 0) {
 318                 return state->mid;
 319         }
 320
 321         return SVAL(state->header, smb_mid);
 322 }
 323
 324 void cli_smb_req_set_mid(struct tevent_req *req, uint16_t mid)
 325 {
 326         struct cli_smb_state *state = tevent_req_data(
 327                 req, struct cli_smb_state);
 328         state->mid = mid;
 329 }
 330
 331 uint32_t cli_smb_req_seqnum(struct tevent_req *req)
 332 {
 333         struct cli_smb_state *state = tevent_req_data(
 334                 req, struct cli_smb_state);
 335         return state->seqnum;
 336 }
 337
 338 void cli_smb_req_set_seqnum(struct tevent_req *req, uint32_t seqnum)
 339 {
 340         struct cli_smb_state *state = tevent_req_data(
 341                 req, struct cli_smb_state);
 342         state->seqnum = seqnum;
 343 }
 344
 345 static size_t iov_len(const struct iovec *iov, int count)
 346 {
 347         size_t result = 0;
 348         int i;
 349         for (i=0; i<count; i++) {
 350                 result += iov[i].iov_len;
 351         }
 352         return result;
 353 }
 354
 355 static uint8_t *iov_concat(TALLOC_CTX *mem_ctx, const struct iovec *iov,
 356                            int count)
 357 {
 358         size_t len = iov_len(iov, count);
 359         size_t copied;
 360         uint8_t *buf;
 361         int i;
 362
 363         buf = talloc_array(mem_ctx, uint8_t, len);
 364         if (buf == NULL) {
 365                 return NULL;
 366         }
 367         copied = 0;
 368         for (i=0; i<count; i++) {
 369                 memcpy(buf+copied, iov[i].iov_base, iov[i].iov_len);
 370                 copied += iov[i].iov_len;
 371         }
 372         return buf;
 373 }
 374
 375 struct tevent_req *cli_smb_req_create(TALLOC_CTX *mem_ctx,
 376                                       struct tevent_context *ev,
 377                                       struct cli_state *cli,
 378                                       uint8_t smb_command,
 379                                       uint8_t additional_flags,
 380                                       uint8_t wct, uint16_t *vwv,
 381                                       int iov_count,
 382                                       struct iovec *bytes_iov)
 383 {
 384         struct tevent_req *result;
 385         struct cli_smb_state *state;
 386         struct timeval endtime;
 387
 388         if (iov_count > MAX_SMB_IOV) {
 389                 /*
 390                  * Should not happen :-)
 391                  */
 392                 return NULL;
 393         }
 394
 395         result = tevent_req_create(mem_ctx, &state, struct cli_smb_state);
 396         if (result == NULL) {
 397                 return NULL;
 398         }
 399         state->ev = ev;
 400         state->cli = cli;
 401         state->mid = 0;         /* Set to auto-choose in cli_smb_req_send */
 402         state->chain_num = 0;
 403         state->chained_requests = NULL;
 404
 405         cli_setup_packet_buf(cli, (char *)state->header);
 406         SCVAL(state->header, smb_com, smb_command);
 407         SSVAL(state->header, smb_tid, cli->smb1.tid);
 408         SCVAL(state->header, smb_wct, wct);
 409
 410         state->vwv = vwv;
 411
 412         SSVAL(state->bytecount_buf, 0, iov_len(bytes_iov, iov_count));
 413
 414         state->iov[0].iov_base = (void *)state->header;
 415         state->iov[0].iov_len  = sizeof(state->header);
 416         state->iov[1].iov_base = (void *)state->vwv;
 417         state->iov[1].iov_len  = wct * sizeof(uint16_t);
 418         state->iov[2].iov_base = (void *)state->bytecount_buf;
 419         state->iov[2].iov_len  = sizeof(uint16_t);
 420
 421         if (iov_count != 0) {
 422                 memcpy(&state->iov[3], bytes_iov,
 423                        iov_count * sizeof(*bytes_iov));
 424         }
 425         state->iov_count = iov_count + 3;
 426
 427         if (cli->timeout) {
 428                 endtime = timeval_current_ofs_msec(cli->timeout);
 429                 if (!tevent_req_set_endtime(result, ev, endtime)) {
 430                         return result;
 431                 }
 432         }
 433
 434         switch (smb_command) {
 435         case SMBtranss:
 436         case SMBtranss2:
 437         case SMBnttranss:
 438         case SMBntcancel:
 439                 state->one_way = true;
 440                 break;
 441         case SMBlockingX:
 442                 if ((wct == 8) &&
 443                     (CVAL(vwv+3, 0) == LOCKING_ANDX_OPLOCK_RELEASE)) {
 444                         state->one_way = true;
 445                 }
 446                 break;
 447         }
 448
 449         return result;
 450 }
 451
 452 static NTSTATUS cli_signv(struct cli_state *cli, struct iovec *iov, int count,
 453                           uint32_t *seqnum)
 454 {
 455         uint8_t *buf;
 456
 457         /*
 458          * Obvious optimization: Make cli_calculate_sign_mac work with struct
 459          * iovec directly. MD5Update would do that just fine.
 460          */
 461
 462         if ((count <= 0) || (iov[0].iov_len < smb_wct)) {
 463                 return NT_STATUS_INVALID_PARAMETER;
 464         }
 465
 466         buf = iov_concat(talloc_tos(), iov, count);
 467         if (buf == NULL) {
 468                 return NT_STATUS_NO_MEMORY;
 469         }
 470
 471         cli_calculate_sign_mac(cli, (char *)buf, seqnum);
 472         memcpy(iov[0].iov_base, buf, iov[0].iov_len);
 473
 474         TALLOC_FREE(buf);
 475         return NT_STATUS_OK;
 476 }
 477
 478 static void cli_smb_sent(struct tevent_req *subreq);
 479
 480 static NTSTATUS cli_smb_req_iov_send(struct tevent_req *req,
 481                                      struct cli_smb_state *state,
 482                                      struct iovec *iov, int iov_count)
 483 {
 484         struct tevent_req *subreq;
 485         NTSTATUS status;
 486
 487         if (!cli_state_is_connected(state->cli)) {
 488                 return NT_STATUS_CONNECTION_DISCONNECTED;
 489         }
 490
 491         if (iov[0].iov_len < smb_wct) {
 492                 return NT_STATUS_INVALID_PARAMETER;
 493         }
 494
 495         if (state->mid != 0) {
 496                 SSVAL(iov[0].iov_base, smb_mid, state->mid);
 497         } else {
 498                 uint16_t mid = cli_alloc_mid(state->cli);
 499                 SSVAL(iov[0].iov_base, smb_mid, mid);
 500         }
 501
 502         smb_setlen_nbt((char *)iov[0].iov_base, iov_len(iov, iov_count) - 4);
 503
 504         status = cli_signv(state->cli, iov, iov_count, &state->seqnum);
 505
 506         if (!NT_STATUS_IS_OK(status)) {
 507                 return status;
 508         }
 509
 510         if (cli_state_encryption_on(state->cli)) {
 511                 char *buf, *enc_buf;
 512
 513                 buf = (char *)iov_concat(talloc_tos(), iov, iov_count);
 514                 if (buf == NULL) {
 515                         return NT_STATUS_NO_MEMORY;
 516                 }
 517                 status = common_encrypt_buffer(state->cli->trans_enc_state,
 518                                                (char *)buf, &enc_buf);
 519                 TALLOC_FREE(buf);
 520                 if (!NT_STATUS_IS_OK(status)) {
 521                         DEBUG(0, ("Error in encrypting client message: %s\n",
 522                                   nt_errstr(status)));
 523                         return status;
 524                 }
 525                 buf = (char *)talloc_memdup(state, enc_buf,
 526                                             smb_len_nbt(enc_buf)+4);
 527                 SAFE_FREE(enc_buf);
 528                 if (buf == NULL) {
 529                         return NT_STATUS_NO_MEMORY;
 530                 }
 531                 iov[0].iov_base = (void *)buf;
 532                 iov[0].iov_len = talloc_get_size(buf);
 533                 iov_count = 1;
 534         }
 535         subreq = writev_send(state, state->ev, state->cli->conn.outgoing,
 536                              state->cli->conn.fd, false, iov, iov_count);
 537         if (subreq == NULL) {
 538                 return NT_STATUS_NO_MEMORY;
 539         }
 540         tevent_req_set_callback(subreq, cli_smb_sent, req);
 541         return NT_STATUS_OK;
 542 }
 543
 544 NTSTATUS cli_smb_req_send(struct tevent_req *req)
 545 {
 546         struct cli_smb_state *state = tevent_req_data(
 547                 req, struct cli_smb_state);
 548
 549         if (!tevent_req_is_in_progress(req)) {
 550                 return NT_STATUS_INTERNAL_ERROR;
 551         }
 552
 553         return cli_smb_req_iov_send(req, state, state->iov, state->iov_count);
 554 }
 555
 556 struct tevent_req *cli_smb_send(TALLOC_CTX *mem_ctx,
 557                                 struct tevent_context *ev,
 558                                 struct cli_state *cli,
 559                                 uint8_t smb_command,
 560                                 uint8_t additional_flags,
 561                                 uint8_t wct, uint16_t *vwv,
 562                                 uint32_t num_bytes,
 563                                 const uint8_t *bytes)
 564 {
 565         struct tevent_req *req;
 566         struct iovec iov;
 567         NTSTATUS status;
 568
 569         iov.iov_base = discard_const_p(void, bytes);
 570         iov.iov_len = num_bytes;
 571
 572         req = cli_smb_req_create(mem_ctx, ev, cli, smb_command,
 573                                  additional_flags, wct, vwv, 1, &iov);
 574         if (req == NULL) {
 575                 return NULL;
 576         }
 577         if (!tevent_req_is_in_progress(req)) {
 578                 return tevent_req_post(req, ev);
 579         }
 580         status = cli_smb_req_send(req);
 581         if (!NT_STATUS_IS_OK(status)) {
 582                 tevent_req_nterror(req, status);
 583                 return tevent_req_post(req, ev);
 584         }
 585         return req;
 586 }
 587
 588 static void cli_smb_sent(struct tevent_req *subreq)
 589 {
 590         struct tevent_req *req = tevent_req_callback_data(
 591                 subreq, struct tevent_req);
 592         struct cli_smb_state *state = tevent_req_data(
 593                 req, struct cli_smb_state);
 594         ssize_t nwritten;
 595         int err;
 596
 597         nwritten = writev_recv(subreq, &err);
 598         TALLOC_FREE(subreq);
 599         if (nwritten == -1) {
 600                 NTSTATUS status = map_nt_error_from_unix_common(err);
 601                 cli_state_notify_pending(state->cli, status);
 602                 return;
 603         }
 604
 605         if (state->one_way) {
 606                 state->inbuf = NULL;
 607                 tevent_req_done(req);
 608                 return;
 609         }
 610
 611         if (!cli_smb_req_set_pending(req)) {
 612                 tevent_req_nterror(req, NT_STATUS_NO_MEMORY);
 613                 return;
 614         }
 615 }
 616
 617 static void cli_smb_received(struct tevent_req *subreq)
 618 {
 619         struct cli_state *cli = tevent_req_callback_data(
 620                 subreq, struct cli_state);
 621         TALLOC_CTX *frame = talloc_stackframe();
 622         NTSTATUS status;
 623         uint8_t *inbuf;
 624         ssize_t received;
 625         int err;
 626
 627         if (subreq != cli->conn.read_smb_req) {
 628                 DEBUG(1, ("Internal error: cli_smb_received called with "
 629                           "unexpected subreq\n"));
 630                 status = NT_STATUS_INTERNAL_ERROR;
 631                 cli_state_notify_pending(cli, status);
 632                 TALLOC_FREE(frame);
 633                 return;
 634         }
 635
 636         received = read_smb_recv(subreq, frame, &inbuf, &err);
 637         TALLOC_FREE(subreq);
 638         cli->conn.read_smb_req = NULL;
 639         if (received == -1) {
 640                 status = map_nt_error_from_unix_common(err);
 641                 cli_state_notify_pending(cli, status);
 642                 TALLOC_FREE(frame);
 643                 return;
 644         }
 645
 646         status = cli->conn.dispatch_incoming(cli, frame, inbuf);
 647         TALLOC_FREE(frame);
 648         if (NT_STATUS_IS_OK(status)) {
 649                 /*
 650                  * We should not do any more processing
 651                  * as the dispatch function called
 652                  * tevent_req_done().
 653                  */
 654                 return;
 655         } else if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
 656                 /*
 657                  * We got an error, so notify all pending requests
 658                  */
 659                 cli_state_notify_pending(cli, status);
 660                 return;
 661         }
 662
 663         /*
 664          * We got NT_STATUS_RETRY, so we may ask for a
 665          * next incoming pdu.
 666          */
 667         if (!cli_state_receive_next(cli)) {
 668                 cli_state_notify_pending(cli, NT_STATUS_NO_MEMORY);
 669         }
 670 }
 671
 672 static NTSTATUS cli_state_dispatch_smb1(struct cli_state *cli,
 673                                         TALLOC_CTX *frame,
 674                                         uint8_t *inbuf)
 675 {
 676         struct tevent_req *req;
 677         struct cli_smb_state *state;
 678         NTSTATUS status;
 679         int num_pending;
 680         int i;
 681         uint16_t mid;
 682         bool oplock_break;
 683         const uint8_t *inhdr = inbuf + NBT_HDR_SIZE;
 684
 685         if ((IVAL(inhdr, 0) != SMB_MAGIC) /* 0xFF"SMB" */
 686             && (SVAL(inhdr, 0) != 0x45ff)) /* 0xFF"E" */ {
 687                 DEBUG(10, ("Got non-SMB PDU\n"));
 688                 return NT_STATUS_INVALID_NETWORK_RESPONSE;
 689         }
 690
 691         if (cli_state_encryption_on(cli) && (CVAL(inbuf, 0) == 0)) {
 692                 uint16_t enc_ctx_num;
 693
 694                 status = get_enc_ctx_num(inbuf, &enc_ctx_num);
 695                 if (!NT_STATUS_IS_OK(status)) {
 696                         DEBUG(10, ("get_enc_ctx_num returned %s\n",
 697                                    nt_errstr(status)));
 698                         return status;
 699                 }
 700
 701                 if (enc_ctx_num != cli->trans_enc_state->enc_ctx_num) {
 702                         DEBUG(10, ("wrong enc_ctx %d, expected %d\n",
 703                                    enc_ctx_num,
 704                                    cli->trans_enc_state->enc_ctx_num));
 705                         return NT_STATUS_INVALID_HANDLE;
 706                 }
 707
 708                 status = common_decrypt_buffer(cli->trans_enc_state,
 709                                                (char *)inbuf);
 710                 if (!NT_STATUS_IS_OK(status)) {
 711                         DEBUG(10, ("common_decrypt_buffer returned %s\n",
 712                                    nt_errstr(status)));
 713                         return status;
 714                 }
 715         }
 716
 717         mid = SVAL(inhdr, HDR_MID);
 718         num_pending = talloc_array_length(cli->conn.pending);
 719
 720         for (i=0; i<num_pending; i++) {
 721                 if (mid == cli_smb_req_mid(cli->conn.pending[i])) {
 722                         break;
 723                 }
 724         }
 725         if (i == num_pending) {
 726                 /* Dump unexpected reply */
 727                 return NT_STATUS_RETRY;
 728         }
 729
 730         oplock_break = false;
 731
 732         if (mid == 0xffff) {
 733                 /*
 734                  * Paranoia checks that this is really an oplock break request.
 735                  */
 736                 oplock_break = (smb_len_nbt(inbuf) == 51); /* hdr + 8 words */
 737                 oplock_break &= ((CVAL(inhdr, HDR_FLG) & FLAG_REPLY) == 0);
 738                 oplock_break &= (CVAL(inhdr, HDR_COM) == SMBlockingX);
 739                 oplock_break &= (SVAL(inhdr, HDR_VWV+VWV(6)) == 0);
 740                 oplock_break &= (SVAL(inhdr, HDR_VWV+VWV(7)) == 0);
 741
 742                 if (!oplock_break) {
 743                         /* Dump unexpected reply */
 744                         return NT_STATUS_RETRY;
 745                 }
 746         }
 747
 748         req = cli->conn.pending[i];
 749         state = tevent_req_data(req, struct cli_smb_state);
 750
 751         if (!oplock_break /* oplock breaks are not signed */
 752             && !cli_check_sign_mac(cli, (char *)inbuf, state->seqnum+1)) {
 753                 DEBUG(10, ("cli_check_sign_mac failed\n"));
 754                 return NT_STATUS_ACCESS_DENIED;
 755         }
 756
 757         if (state->chained_requests != NULL) {
 758                 struct tevent_req **chain = talloc_move(frame,
 759                                             &state->chained_requests);
 760                 int num_chained = talloc_array_length(chain);
 761
 762                 /*
 763                  * We steal the inbuf to the chain,
 764                  * so that it will stay until all
 765                  * requests of the chain are finished.
 766                  *
 767                  * Each requests in the chain will
 768                  * hold a talloc reference to the chain.
 769                  * This way we do not expose the talloc_reference()
 770                  * behavior to the callers.
 771                  */
 772                 talloc_steal(chain, inbuf);
 773
 774                 for (i=0; i<num_chained; i++) {
 775                         struct tevent_req **ref;
 776
 777                         req = chain[i];
 778                         state = tevent_req_data(req, struct cli_smb_state);
 779
 780                         cli_smb_req_unset_pending(req);
 781
 782                         /*
 783                          * as we finish multiple requests here
 784                          * we need to defer the callbacks as
 785                          * they could destroy our current stack state.
 786                          */
 787                         tevent_req_defer_callback(req, state->ev);
 788
 789                         ref = talloc_reference(state, chain);
 790                         if (tevent_req_nomem(ref, req)) {
 791                                 continue;
 792                         }
 793
 794                         state->inbuf = inbuf;
 795                         state->chain_num = i;
 796                         state->chain_length = num_chained;
 797
 798                         tevent_req_done(req);
 799                 }
 800
 801                 return NT_STATUS_RETRY;
 802         }
 803
 804         cli_smb_req_unset_pending(req);
 805
 806         state->inbuf = talloc_move(state, &inbuf);
 807         state->chain_num = 0;
 808         state->chain_length = 1;
 809
 810         if (talloc_array_length(cli->conn.pending) == 0) {
 811                 tevent_req_done(req);
 812                 return NT_STATUS_OK;
 813         }
 814
 815         tevent_req_defer_callback(req, state->ev);
 816         tevent_req_done(req);
 817         return NT_STATUS_RETRY;
 818 }
 819
 820 NTSTATUS cli_smb_recv(struct tevent_req *req,
 821                       TALLOC_CTX *mem_ctx, uint8_t **pinbuf,
 822                       uint8_t min_wct, uint8_t *pwct, uint16_t **pvwv,
 823                       uint32_t *pnum_bytes, uint8_t **pbytes)
 824 {
 825         struct cli_smb_state *state = tevent_req_data(
 826                 req, struct cli_smb_state);
 827         NTSTATUS status = NT_STATUS_OK;
 828         uint8_t cmd, wct;
 829         uint16_t num_bytes;
 830         size_t wct_ofs, bytes_offset;
 831         int i;
 832
 833         if (tevent_req_is_nterror(req, &status)) {
 834                 return status;
 835         }
 836
 837         if (state->inbuf == NULL) {
 838                 if (min_wct != 0) {
 839                         return NT_STATUS_INVALID_NETWORK_RESPONSE;
 840                 }
 841                 if (pinbuf) {
 842                         *pinbuf = NULL;
 843                 }
 844                 if (pwct) {
 845                         *pwct = 0;
 846                 }
 847                 if (pvwv) {
 848                         *pvwv = NULL;
 849                 }
 850                 if (pnum_bytes) {
 851                         *pnum_bytes = 0;
 852                 }
 853                 if (pbytes) {
 854                         *pbytes = NULL;
 855                 }
 856                 /* This was a request without a reply */
 857                 return NT_STATUS_OK;
 858         }
 859
 860         wct_ofs = smb_wct;
 861         cmd = CVAL(state->inbuf, smb_com);
 862
 863         for (i=0; i<state->chain_num; i++) {
 864                 if (i < state->chain_num-1) {
 865                         if (cmd == 0xff) {
 866                                 return NT_STATUS_REQUEST_ABORTED;
 867                         }
 868                         if (!is_andx_req(cmd)) {
 869                                 return NT_STATUS_INVALID_NETWORK_RESPONSE;
 870                         }
 871                 }
 872
 873                 if (!have_andx_command((char *)state->inbuf, wct_ofs)) {
 874                         /*
 875                          * This request was not completed because a previous
 876                          * request in the chain had received an error.
 877                          */
 878                         return NT_STATUS_REQUEST_ABORTED;
 879                 }
 880
 881                 wct_ofs = SVAL(state->inbuf, wct_ofs + 3);
 882
 883                 /*
 884                  * Skip the all-present length field. No overflow, we've just
 885                  * put a 16-bit value into a size_t.
 886                  */
 887                 wct_ofs += 4;
 888
 889                 if (wct_ofs+2 > talloc_get_size(state->inbuf)) {
 890                         return NT_STATUS_INVALID_NETWORK_RESPONSE;
 891                 }
 892
 893                 cmd = CVAL(state->inbuf, wct_ofs + 1);
 894         }
 895
 896         state->cli->raw_status = cli_pull_raw_error(state->inbuf);
 897         if (NT_STATUS_IS_DOS(state->cli->raw_status)) {
 898                 uint8_t eclass = NT_STATUS_DOS_CLASS(state->cli->raw_status);
 899                 uint16_t ecode = NT_STATUS_DOS_CODE(state->cli->raw_status);
 900                 /*
 901                  * TODO: is it really a good idea to do a mapping here?
 902                  *
 903                  * The old cli_pull_error() also does it, so I do not change
 904                  * the behavior yet.
 905                  */
 906                 status = dos_to_ntstatus(eclass, ecode);
 907         } else {
 908                 status = state->cli->raw_status;
 909         }
 910
 911         if (!have_andx_command((char *)state->inbuf, wct_ofs)) {
 912
 913                 if ((cmd == SMBsesssetupX)
 914                     && NT_STATUS_EQUAL(
 915                             status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 916                         /*
 917                          * NT_STATUS_MORE_PROCESSING_REQUIRED is a
 918                          * valid return code for session setup
 919                          */
 920                         goto no_err;
 921                 }
 922
 923                 if (NT_STATUS_IS_ERR(status)) {
 924                         /*
 925                          * The last command takes the error code. All
 926                          * further commands down the requested chain
 927                          * will get a NT_STATUS_REQUEST_ABORTED.
 928                          */
 929                         return status;
 930                 }
 931         }
 932
 933 no_err:
 934
 935         wct = CVAL(state->inbuf, wct_ofs);
 936         bytes_offset = wct_ofs + 1 + wct * sizeof(uint16_t);
 937         num_bytes = SVAL(state->inbuf, bytes_offset);
 938
 939         if (wct < min_wct) {
 940                 return NT_STATUS_INVALID_NETWORK_RESPONSE;
 941         }
 942
 943         /*
 944          * wct_ofs is a 16-bit value plus 4, wct is a 8-bit value, num_bytes
 945          * is a 16-bit value. So bytes_offset being size_t should be far from
 946          * wrapping.
 947          */
 948         if ((bytes_offset + 2 > talloc_get_size(state->inbuf))
 949             || (bytes_offset > 0xffff)) {
 950                 return NT_STATUS_INVALID_NETWORK_RESPONSE;
 951         }
 952
 953         if (pwct != NULL) {
 954                 *pwct = wct;
 955         }
 956         if (pvwv != NULL) {
 957                 *pvwv = (uint16_t *)(state->inbuf + wct_ofs + 1);
 958         }
 959         if (pnum_bytes != NULL) {
 960                 *pnum_bytes = num_bytes;
 961         }
 962         if (pbytes != NULL) {
 963                 *pbytes = (uint8_t *)state->inbuf + bytes_offset + 2;
 964         }
 965         if ((mem_ctx != NULL) && (pinbuf != NULL)) {
 966                 if (state->chain_num == state->chain_length-1) {
 967                         *pinbuf = talloc_move(mem_ctx, &state->inbuf);
 968                 } else {
 969                         *pinbuf = state->inbuf;
 970                 }
 971         }
 972
 973         return status;
 974 }
 975
 976 size_t cli_smb_wct_ofs(struct tevent_req **reqs, int num_reqs)
 977 {
 978         size_t wct_ofs;
 979         int i;
 980
 981         wct_ofs = smb_wct - 4;
 982
 983         for (i=0; i<num_reqs; i++) {
 984                 struct cli_smb_state *state;
 985                 state = tevent_req_data(reqs[i], struct cli_smb_state);
 986                 wct_ofs += iov_len(state->iov+1, state->iov_count-1);
 987                 wct_ofs = (wct_ofs + 3) & ~3;
 988         }
 989         return wct_ofs;
 990 }
 991
 992 NTSTATUS cli_smb_chain_send(struct tevent_req **reqs, int num_reqs)
 993 {
 994         struct cli_smb_state *first_state = tevent_req_data(
 995                 reqs[0], struct cli_smb_state);
 996         struct cli_smb_state *last_state = tevent_req_data(
 997                 reqs[num_reqs-1], struct cli_smb_state);
 998         struct cli_smb_state *state;
 999         size_t wct_offset;
1000         size_t chain_padding = 0;
1001         int i, iovlen;
1002         struct iovec *iov = NULL;
1003         struct iovec *this_iov;
1004         NTSTATUS status;
1005
1006         iovlen = 0;
1007         for (i=0; i<num_reqs; i++) {
1008                 if (!tevent_req_is_in_progress(reqs[i])) {
1009                         return NT_STATUS_INTERNAL_ERROR;
1010                 }
1011
1012                 state = tevent_req_data(reqs[i], struct cli_smb_state);
1013                 iovlen += state->iov_count;
1014         }
1015
1016         iov = talloc_array(last_state, struct iovec, iovlen);
1017         if (iov == NULL) {
1018                 return NT_STATUS_NO_MEMORY;
1019         }
1020
1021         first_state->chained_requests = (struct tevent_req **)talloc_memdup(
1022                 last_state, reqs, sizeof(*reqs) * num_reqs);
1023         if (first_state->chained_requests == NULL) {
1024                 TALLOC_FREE(iov);
1025                 return NT_STATUS_NO_MEMORY;
1026         }
1027
1028         wct_offset = smb_wct - 4;
1029         this_iov = iov;
1030
1031         for (i=0; i<num_reqs; i++) {
1032                 size_t next_padding = 0;
1033                 uint16_t *vwv;
1034
1035                 state = tevent_req_data(reqs[i], struct cli_smb_state);
1036
1037                 if (i < num_reqs-1) {
1038                         if (!is_andx_req(CVAL(state->header, smb_com))
1039                             || CVAL(state->header, smb_wct) < 2) {
1040                                 TALLOC_FREE(iov);
1041                                 TALLOC_FREE(first_state->chained_requests);
1042                                 return NT_STATUS_INVALID_PARAMETER;
1043                         }
1044                 }
1045
1046                 wct_offset += iov_len(state->iov+1, state->iov_count-1) + 1;
1047                 if ((wct_offset % 4) != 0) {
1048                         next_padding = 4 - (wct_offset % 4);
1049                 }
1050                 wct_offset += next_padding;
1051                 vwv = state->vwv;
1052
1053                 if (i < num_reqs-1) {
1054                         struct cli_smb_state *next_state = tevent_req_data(
1055                                 reqs[i+1], struct cli_smb_state);
1056                         SCVAL(vwv+0, 0, CVAL(next_state->header, smb_com));
1057                         SCVAL(vwv+0, 1, 0);
1058                         SSVAL(vwv+1, 0, wct_offset);
1059                 } else if (is_andx_req(CVAL(state->header, smb_com))) {
1060                         /* properly end the chain */
1061                         SCVAL(vwv+0, 0, 0xff);
1062                         SCVAL(vwv+0, 1, 0xff);
1063                         SSVAL(vwv+1, 0, 0);
1064                 }
1065
1066                 if (i == 0) {
1067                         this_iov[0] = state->iov[0];
1068                 } else {
1069                         /*
1070                          * This one is a bit subtle. We have to add
1071                          * chain_padding bytes between the requests, and we
1072                          * have to also include the wct field of the
1073                          * subsequent requests. We use the subsequent header
1074                          * for the padding, it contains the wct field in its
1075                          * last byte.
1076                          */
1077                         this_iov[0].iov_len = chain_padding+1;
1078                         this_iov[0].iov_base = (void *)&state->header[
1079                                 sizeof(state->header) - this_iov[0].iov_len];
1080                         memset(this_iov[0].iov_base, 0, this_iov[0].iov_len-1);
1081                 }
1082                 memcpy(this_iov+1, state->iov+1,
1083                        sizeof(struct iovec) * (state->iov_count-1));
1084                 this_iov += state->iov_count;
1085                 chain_padding = next_padding;
1086         }
1087
1088         status = cli_smb_req_iov_send(reqs[0], last_state, iov, iovlen);
1089         if (!NT_STATUS_IS_OK(status)) {
1090                 TALLOC_FREE(iov);
1091                 TALLOC_FREE(first_state->chained_requests);
1092                 return status;
1093         }
1094
1095         return NT_STATUS_OK;
1096 }
1097
1098 bool cli_has_async_calls(struct cli_state *cli)
1099 {
1100         return ((tevent_queue_length(cli->conn.outgoing) != 0)
1101                 || (talloc_array_length(cli->conn.pending) != 0));
1102 }