source3/libsmb/smb2cli_base.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    smb2 lib
   4    Copyright (C) Volker Lendecke 2011
   5    Copyright (C) Stefan Metzmacher 2011
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "client.h"
  23 #include "read_smb.h"
  24 #include "smb2cli_base.h"
  25 #include "lib/async_req/async_sock.h"
  26 #include "lib/util/tevent_ntstatus.h"
  27
  28 struct smb2cli_req_state {
  29         struct tevent_context *ev;
  30         struct cli_state *cli;
  31
  32         const uint8_t *fixed;
  33         uint16_t fixed_len;
  34         const uint8_t *dyn;
  35         uint16_t dyn_len;
  36
  37         uint8_t nbt[4];
  38         uint8_t hdr[64];
  39         uint8_t pad[7]; /* padding space for compounding */
  40
  41         /* always an array of 3 talloc elements */
  42         struct iovec *recv_iov;
  43 };
  44
  45 static void smb2cli_req_unset_pending(struct tevent_req *req)
  46 {
  47         struct smb2cli_req_state *state =
  48                 tevent_req_data(req,
  49                 struct smb2cli_req_state);
  50         struct cli_state *cli = state->cli;
  51         int num_pending = talloc_array_length(cli->pending);
  52         int i;
  53
  54         talloc_set_destructor(req, NULL);
  55
  56         if (num_pending == 1) {
  57                 /*
  58                  * The pending read_smb tevent_req is a child of
  59                  * cli->pending. So if nothing is pending anymore, we need to
  60                  * delete the socket read fde.
  61                  */
  62                 TALLOC_FREE(cli->pending);
  63                 return;
  64         }
  65
  66         for (i=0; i<num_pending; i++) {
  67                 if (req == cli->pending[i]) {
  68                         break;
  69                 }
  70         }
  71         if (i == num_pending) {
  72                 /*
  73                  * Something's seriously broken. Just returning here is the
  74                  * right thing nevertheless, the point of this routine is to
  75                  * remove ourselves from cli->pending.
  76                  */
  77                 return;
  78         }
  79
  80         /*
  81          * Remove ourselves from the cli->pending array
  82          */
  83         for (; i < (num_pending - 1); i++) {
  84                 cli->pending[i] = cli->pending[i+1];
  85         }
  86
  87         /*
  88          * No NULL check here, we're shrinking by sizeof(void *), and
  89          * talloc_realloc just adjusts the size for this.
  90          */
  91         cli->pending = talloc_realloc(NULL, cli->pending, struct tevent_req *,
  92                                       num_pending - 1);
  93         return;
  94 }
  95
  96 static int smb2cli_req_destructor(struct tevent_req *req)
  97 {
  98         smb2cli_req_unset_pending(req);
  99         return 0;
 100 }
 101
 102 static void smb2cli_inbuf_received(struct tevent_req *subreq);
 103
 104 static bool smb2cli_req_set_pending(struct tevent_req *req)
 105 {
 106         struct smb2cli_req_state *state =
 107                 tevent_req_data(req,
 108                 struct smb2cli_req_state);
 109         struct cli_state *cli;
 110         struct tevent_req **pending;
 111         int num_pending;
 112         struct tevent_req *subreq;
 113
 114         cli = state->cli;
 115         num_pending = talloc_array_length(cli->pending);
 116
 117         pending = talloc_realloc(cli, cli->pending, struct tevent_req *,
 118                                  num_pending+1);
 119         if (pending == NULL) {
 120                 return false;
 121         }
 122         pending[num_pending] = req;
 123         cli->pending = pending;
 124         talloc_set_destructor(req, smb2cli_req_destructor);
 125
 126         if (num_pending > 0) {
 127                 return true;
 128         }
 129
 130         /*
 131          * We're the first ones, add the read_smb request that waits for the
 132          * answer from the server
 133          */
 134         subreq = read_smb_send(cli->pending, state->ev, cli->fd);
 135         if (subreq == NULL) {
 136                 smb2cli_req_unset_pending(req);
 137                 return false;
 138         }
 139         tevent_req_set_callback(subreq, smb2cli_inbuf_received, cli);
 140         return true;
 141 }
 142
 143 static void smb2cli_notify_pending(struct cli_state *cli, NTSTATUS status)
 144 {
 145         if (cli->fd != -1) {
 146                 close(cli->fd);
 147                 cli->fd = -1;
 148         }
 149
 150         /*
 151          * Cancel all pending requests. We don't do a for-loop walking
 152          * cli->pending because that array changes in
 153          * cli_smb_req_destructor().
 154          */
 155         while (talloc_array_length(cli->pending) > 0) {
 156                 struct tevent_req *req;
 157                 struct smb2cli_req_state *state;
 158
 159                 req = cli->pending[0];
 160                 state = tevent_req_data(req, struct smb2cli_req_state);
 161
 162                 smb2cli_req_unset_pending(req);
 163
 164                 /*
 165                  * we need to defer the callback, because we may notify more
 166                  * then one caller.
 167                  */
 168                 tevent_req_defer_callback(req, state->ev);
 169                 tevent_req_nterror(req, status);
 170         }
 171 }
 172
 173 struct tevent_req *smb2cli_req_create(TALLOC_CTX *mem_ctx,
 174                                       struct tevent_context *ev,
 175                                       struct cli_state *cli,
 176                                       uint16_t cmd,
 177                                       uint32_t flags,
 178                                       const uint8_t *fixed,
 179                                       uint16_t fixed_len,
 180                                       const uint8_t *dyn,
 181                                       uint16_t dyn_len)
 182 {
 183         struct tevent_req *req;
 184         struct smb2cli_req_state *state;
 185
 186         req = tevent_req_create(mem_ctx, &state,
 187                                 struct smb2cli_req_state);
 188         if (req == NULL) {
 189                 return NULL;
 190         }
 191         state->ev = ev;
 192         state->cli = cli;
 193
 194         state->recv_iov = talloc_zero_array(state, struct iovec, 3);
 195         if (state->recv_iov == NULL) {
 196                 TALLOC_FREE(req);
 197                 return NULL;
 198         }
 199
 200         state->fixed = fixed;
 201         state->fixed_len = fixed_len;
 202         state->dyn = dyn;
 203         state->dyn_len = dyn_len;
 204
 205         SIVAL(state->hdr, SMB2_HDR_PROTOCOL_ID, SMB2_MAGIC);
 206         SSVAL(state->hdr, SMB2_HDR_LENGTH,      SMB2_HDR_BODY);
 207         SSVAL(state->hdr, SMB2_HDR_EPOCH,       1);
 208         SIVAL(state->hdr, SMB2_HDR_STATUS,      NT_STATUS_V(NT_STATUS_OK));
 209         SSVAL(state->hdr, SMB2_HDR_OPCODE,      cmd);
 210         SSVAL(state->hdr, SMB2_HDR_CREDIT,      31);
 211         SIVAL(state->hdr, SMB2_HDR_FLAGS,       flags);
 212         SIVAL(state->hdr, SMB2_HDR_PID,         cli->smb2.pid);
 213         SIVAL(state->hdr, SMB2_HDR_TID,         cli->smb2.tid);
 214         SBVAL(state->hdr, SMB2_HDR_SESSION_ID,  cli->smb2.uid);
 215
 216         return req;
 217 }
 218
 219 static void smb2cli_writev_done(struct tevent_req *subreq);
 220
 221 NTSTATUS smb2cli_req_compound_submit(struct tevent_req **reqs,
 222                                      int num_reqs)
 223 {
 224         struct smb2cli_req_state *state;
 225         struct tevent_req *subreq;
 226         struct iovec *iov;
 227         int i, num_iov, nbt_len;
 228
 229         /*
 230          * 1 for the nbt length
 231          * per request: HDR, fixed, dyn, padding
 232          * -1 because the last one does not need padding
 233          */
 234
 235         iov = talloc_array(reqs[0], struct iovec, 1 + 4*num_reqs - 1);
 236         if (iov == NULL) {
 237                 return NT_STATUS_NO_MEMORY;
 238         }
 239
 240         num_iov = 1;
 241         nbt_len = 0;
 242
 243         for (i=0; i<num_reqs; i++) {
 244                 size_t reqlen;
 245                 bool ret;
 246
 247                 state = tevent_req_data(reqs[i], struct smb2cli_req_state);
 248
 249                 SBVAL(state->hdr, SMB2_HDR_MESSAGE_ID, state->cli->smb2.mid++);
 250
 251                 iov[num_iov].iov_base = state->hdr;
 252                 iov[num_iov].iov_len  = sizeof(state->hdr);
 253                 num_iov += 1;
 254
 255                 iov[num_iov].iov_base = discard_const(state->fixed);
 256                 iov[num_iov].iov_len  = state->fixed_len;
 257                 num_iov += 1;
 258
 259                 if (state->dyn != NULL) {
 260                         iov[num_iov].iov_base = discard_const(state->dyn);
 261                         iov[num_iov].iov_len  = state->dyn_len;
 262                         num_iov += 1;
 263                 }
 264
 265                 reqlen = sizeof(state->hdr) + state->fixed_len +
 266                         state->dyn_len;
 267
 268                 if (i < num_reqs-1) {
 269                         if ((reqlen % 8) > 0) {
 270                                 uint8_t pad = 8 - (reqlen % 8);
 271                                 iov[num_iov].iov_base = state->pad;
 272                                 iov[num_iov].iov_len = pad;
 273                                 num_iov += 1;
 274                                 reqlen += pad;
 275                         }
 276                         SIVAL(state->hdr, SMB2_HDR_NEXT_COMMAND, reqlen);
 277                 }
 278                 nbt_len += reqlen;
 279
 280                 ret = smb2cli_req_set_pending(reqs[i]);
 281                 if (!ret) {
 282                         return NT_STATUS_NO_MEMORY;
 283                 }
 284         }
 285
 286         /*
 287          * TODO: Do signing here
 288          */
 289
 290         state = tevent_req_data(reqs[0], struct smb2cli_req_state);
 291         _smb_setlen_large(state->nbt, nbt_len);
 292         iov[0].iov_base = state->nbt;
 293         iov[0].iov_len  = sizeof(state->nbt);
 294
 295         subreq = writev_send(state, state->ev, state->cli->outgoing,
 296                              state->cli->fd, false, iov, num_iov);
 297         if (subreq == NULL) {
 298                 return NT_STATUS_NO_MEMORY;
 299         }
 300         tevent_req_set_callback(subreq, smb2cli_writev_done, reqs[0]);
 301         return NT_STATUS_OK;
 302 }
 303
 304 struct tevent_req *smb2cli_req_send(TALLOC_CTX *mem_ctx,
 305                                     struct tevent_context *ev,
 306                                     struct cli_state *cli,
 307                                     uint16_t cmd,
 308                                     uint32_t flags,
 309                                     const uint8_t *fixed,
 310                                     uint16_t fixed_len,
 311                                     const uint8_t *dyn,
 312                                     uint16_t dyn_len)
 313 {
 314         struct tevent_req *req;
 315         NTSTATUS status;
 316
 317         req = smb2cli_req_create(mem_ctx, ev, cli, cmd, flags,
 318                                  fixed, fixed_len, dyn, dyn_len);
 319         if (req == NULL) {
 320                 return NULL;
 321         }
 322         if (!tevent_req_is_in_progress(req)) {
 323                 return req;
 324         }
 325         status = smb2cli_req_compound_submit(&req, 1);
 326         if (tevent_req_nterror(req, status)) {
 327                 return tevent_req_post(req, ev);
 328         }
 329         return req;
 330 }
 331
 332 static void smb2cli_writev_done(struct tevent_req *subreq)
 333 {
 334         struct tevent_req *req =
 335                 tevent_req_callback_data(subreq,
 336                 struct tevent_req);
 337         struct smb2cli_req_state *state =
 338                 tevent_req_data(req,
 339                 struct smb2cli_req_state);
 340         ssize_t nwritten;
 341         int err;
 342
 343         nwritten = writev_recv(subreq, &err);
 344         TALLOC_FREE(subreq);
 345         if (nwritten == -1) {
 346                 /* here, we need to notify all pending requests */
 347                 smb2cli_notify_pending(state->cli, map_nt_error_from_unix(err));
 348                 return;
 349         }
 350 }
 351
 352 static NTSTATUS smb2cli_inbuf_parse_compound(uint8_t *buf, TALLOC_CTX *mem_ctx,
 353                                              struct iovec **piov, int *pnum_iov)
 354 {
 355         struct iovec *iov;
 356         int num_iov;
 357         size_t buflen;
 358         size_t taken;
 359
 360         num_iov = 1;
 361
 362         iov = talloc_array(mem_ctx, struct iovec, num_iov);
 363         if (iov == NULL) {
 364                 return NT_STATUS_NO_MEMORY;
 365         }
 366         iov[0].iov_base = buf;
 367         iov[0].iov_len = 4;
 368
 369         buflen = smb_len_large(buf) + 4;
 370         taken = 4;
 371
 372         while (taken < buflen) {
 373                 size_t len = buflen - taken;
 374                 uint8_t *hdr = buf + taken;
 375                 struct iovec *cur;
 376                 size_t full_size;
 377                 size_t next_command_ofs;
 378                 uint16_t body_size;
 379                 struct iovec *iov_tmp;
 380
 381                 /*
 382                  * We need the header plus the body length field
 383                  */
 384
 385                 if (len < SMB2_HDR_BODY + 2) {
 386                         DEBUG(10, ("%d bytes left, expected at least %d\n",
 387                                    (int)len, SMB2_HDR_BODY));
 388                         goto inval;
 389                 }
 390                 if (IVAL(hdr, 0) != SMB2_MAGIC) {
 391                         DEBUG(10, ("Got non-SMB2 PDU: %x\n",
 392                                    IVAL(hdr, 0)));
 393                         goto inval;
 394                 }
 395                 if (SVAL(hdr, 4) != SMB2_HDR_BODY) {
 396                         DEBUG(10, ("Got HDR len %d, expected %d\n",
 397                                    SVAL(hdr, 4), SMB2_HDR_BODY));
 398                         goto inval;
 399                 }
 400
 401                 full_size = len;
 402                 next_command_ofs = IVAL(hdr, SMB2_HDR_NEXT_COMMAND);
 403                 body_size = SVAL(hdr, SMB2_HDR_BODY);
 404
 405                 if (next_command_ofs != 0) {
 406                         if (next_command_ofs < (SMB2_HDR_BODY + 2)) {
 407                                 goto inval;
 408                         }
 409                         if (next_command_ofs > full_size) {
 410                                 goto inval;
 411                         }
 412                         full_size = next_command_ofs;
 413                 }
 414                 if (body_size < 2) {
 415                         goto inval;
 416                 }
 417                 body_size &= 0xfffe;
 418
 419                 if (body_size > (full_size - SMB2_HDR_BODY)) {
 420                         goto inval;
 421                 }
 422
 423                 iov_tmp = talloc_realloc(mem_ctx, iov, struct iovec,
 424                                          num_iov + 3);
 425                 if (iov_tmp == NULL) {
 426                         TALLOC_FREE(iov);
 427                         return NT_STATUS_NO_MEMORY;
 428                 }
 429                 iov = iov_tmp;
 430                 cur = &iov[num_iov];
 431                 num_iov += 3;
 432
 433                 cur[0].iov_base = hdr;
 434                 cur[0].iov_len  = SMB2_HDR_BODY;
 435                 cur[1].iov_base = hdr + SMB2_HDR_BODY;
 436                 cur[1].iov_len  = body_size;
 437                 cur[2].iov_base = hdr + SMB2_HDR_BODY + body_size;
 438                 cur[2].iov_len  = full_size - (SMB2_HDR_BODY + body_size);
 439
 440                 taken += full_size;
 441         }
 442
 443         *piov = iov;
 444         *pnum_iov = num_iov;
 445         return NT_STATUS_OK;
 446
 447 inval:
 448         TALLOC_FREE(iov);
 449         return NT_STATUS_INVALID_NETWORK_RESPONSE;
 450 }
 451
 452 static struct tevent_req *cli_smb2_find_pending(struct cli_state *cli,
 453                                                 uint64_t mid)
 454 {
 455         int num_pending = talloc_array_length(cli->pending);
 456         int i;
 457
 458         for (i=0; i<num_pending; i++) {
 459                 struct tevent_req *req = cli->pending[i];
 460                 struct smb2cli_req_state *state =
 461                         tevent_req_data(req,
 462                         struct smb2cli_req_state);
 463
 464                 if (mid == BVAL(state->hdr, SMB2_HDR_MESSAGE_ID)) {
 465                         return req;
 466                 }
 467         }
 468         return NULL;
 469 }
 470
 471 static void smb2cli_inbuf_received(struct tevent_req *subreq)
 472 {
 473         struct cli_state *cli =
 474                 tevent_req_callback_data(subreq,
 475                 struct cli_state);
 476         TALLOC_CTX *frame = talloc_stackframe();
 477         struct tevent_req *req;
 478         struct smb2cli_req_state *state;
 479         struct iovec *iov;
 480         int i, num_iov;
 481         NTSTATUS status;
 482         uint8_t *inbuf;
 483         ssize_t received;
 484         int err;
 485         size_t num_pending;
 486
 487         received = read_smb_recv(subreq, frame, &inbuf, &err);
 488         TALLOC_FREE(subreq);
 489         if (received == -1) {
 490                 /*
 491                  * We need to close the connection and notify
 492                  * all pending requests.
 493                  */
 494                 smb2cli_notify_pending(cli, map_nt_error_from_unix(err));
 495                 TALLOC_FREE(frame);
 496                 return;
 497         }
 498
 499         status = smb2cli_inbuf_parse_compound(inbuf, frame,
 500                                               &iov, &num_iov);
 501         if (!NT_STATUS_IS_OK(status)) {
 502                 /*
 503                  * if we cannot parse the incoming pdu,
 504                  * the connection becomes unusable.
 505                  *
 506                  * We need to close the connection and notify
 507                  * all pending requests.
 508                  */
 509                 smb2cli_notify_pending(cli, status);
 510                 TALLOC_FREE(frame);
 511                 return;
 512         }
 513
 514         for (i=1; i<num_iov; i+=3) {
 515                 uint8_t *inbuf_ref = NULL;
 516                 struct iovec *cur = &iov[i];
 517                 uint8_t *inhdr = (uint8_t *)cur[0].iov_base;
 518
 519                 req = cli_smb2_find_pending(
 520                         cli, BVAL(inhdr, SMB2_HDR_MESSAGE_ID));
 521                 if (req == NULL) {
 522                         /*
 523                          * TODO: handle oplock breaks and async responses
 524                          */
 525
 526                         /*
 527                          * We need to close the connection and notify
 528                          * all pending requests.
 529                          */
 530                         smb2cli_notify_pending(cli, status);
 531                         TALLOC_FREE(frame);
 532                         return;
 533                 }
 534                 smb2cli_req_unset_pending(req);
 535                 state = tevent_req_data(req, struct smb2cli_req_state);
 536
 537                 /*
 538                  * There might be more than one response
 539                  * we need to defer the notifications
 540                  */
 541                 tevent_req_defer_callback(req, state->ev);
 542
 543                 /*
 544                  * Note: here we use talloc_reference() in a way
 545                  *       that does not expose it to the caller.
 546                  */
 547                 inbuf_ref = talloc_reference(state->recv_iov, inbuf);
 548                 if (tevent_req_nomem(inbuf_ref, req)) {
 549                         continue;
 550                 }
 551
 552                 /* copy the related buffers */
 553                 state->recv_iov[0] = cur[0];
 554                 state->recv_iov[1] = cur[1];
 555                 state->recv_iov[2] = cur[2];
 556
 557                 tevent_req_done(req);
 558         }
 559
 560         TALLOC_FREE(frame);
 561
 562         num_pending = talloc_array_length(cli->pending);
 563         if (num_pending == 0) {
 564                 /* no more pending requests, so we are done for now */
 565                 return;
 566         }
 567         req = cli->pending[0];
 568         state = tevent_req_data(req, struct smb2cli_req_state);
 569
 570         /*
 571          * add the read_smb request that waits for the
 572          * next answer from the server
 573          */
 574         subreq = read_smb_send(cli->pending, state->ev, cli->fd);
 575         if (subreq == NULL) {
 576                 smb2cli_notify_pending(cli, NT_STATUS_NO_MEMORY);
 577                 return;
 578         }
 579         tevent_req_set_callback(subreq, smb2cli_inbuf_received, cli);
 580 }
 581
 582 NTSTATUS smb2cli_req_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 583                           struct iovec **piov, int body_size)
 584 {
 585         struct smb2cli_req_state *state =
 586                 tevent_req_data(req,
 587                 struct smb2cli_req_state);
 588         NTSTATUS status;
 589
 590         if (tevent_req_is_nterror(req, &status)) {
 591                 return status;
 592         }
 593
 594         status = NT_STATUS(IVAL(state->recv_iov[0].iov_base, SMB2_HDR_STATUS));
 595
 596         if (body_size != 0) {
 597                 if (body_size != SVAL(state->recv_iov[1].iov_base, 0)) {
 598                         return NT_STATUS_INVALID_NETWORK_RESPONSE;
 599                 }
 600         }
 601         if (piov != NULL) {
 602                 *piov = talloc_move(mem_ctx, &state->recv_iov);
 603         }
 604
 605         return status;
 606 }