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->conn.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->conn.pending. So if nothing is pending anymore,
  60                  * we need to delete the socket read fde.
  61                  */
  62                 TALLOC_FREE(cli->conn.pending);
  63                 return;
  64         }
  65
  66         for (i=0; i<num_pending; i++) {
  67                 if (req == cli->conn.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->conn.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->conn.pending[i] = cli->conn.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->conn.pending = talloc_realloc(NULL, cli->conn.pending,
  92                                            struct tevent_req *,
  93                                            num_pending - 1);
  94         return;
  95 }
  96
  97 static int smb2cli_req_destructor(struct tevent_req *req)
  98 {
  99         smb2cli_req_unset_pending(req);
 100         return 0;
 101 }
 102
 103 static void smb2cli_inbuf_received(struct tevent_req *subreq);
 104
 105 static bool smb2cli_req_set_pending(struct tevent_req *req)
 106 {
 107         struct smb2cli_req_state *state =
 108                 tevent_req_data(req,
 109                 struct smb2cli_req_state);
 110         struct cli_state *cli;
 111         struct tevent_req **pending;
 112         int num_pending;
 113         struct tevent_req *subreq;
 114
 115         cli = state->cli;
 116         num_pending = talloc_array_length(cli->conn.pending);
 117
 118         pending = talloc_realloc(cli, cli->conn.pending, struct tevent_req *,
 119                                  num_pending+1);
 120         if (pending == NULL) {
 121                 return false;
 122         }
 123         pending[num_pending] = req;
 124         cli->conn.pending = pending;
 125         talloc_set_destructor(req, smb2cli_req_destructor);
 126
 127         if (num_pending > 0) {
 128                 return true;
 129         }
 130
 131         /*
 132          * We're the first ones, add the read_smb request that waits for the
 133          * answer from the server
 134          */
 135         subreq = read_smb_send(cli->conn.pending, state->ev, cli->fd);
 136         if (subreq == NULL) {
 137                 smb2cli_req_unset_pending(req);
 138                 return false;
 139         }
 140         tevent_req_set_callback(subreq, smb2cli_inbuf_received, cli);
 141         return true;
 142 }
 143
 144 static void smb2cli_notify_pending(struct cli_state *cli, NTSTATUS status)
 145 {
 146         if (cli->fd != -1) {
 147                 close(cli->fd);
 148                 cli->fd = -1;
 149         }
 150
 151         /*
 152          * Cancel all pending requests. We don't do a for-loop walking
 153          * cli->conn.pending because that array changes in
 154          * cli_smb_req_destructor().
 155          */
 156         while (talloc_array_length(cli->conn.pending) > 0) {
 157                 struct tevent_req *req;
 158                 struct smb2cli_req_state *state;
 159
 160                 req = cli->conn.pending[0];
 161                 state = tevent_req_data(req, struct smb2cli_req_state);
 162
 163                 smb2cli_req_unset_pending(req);
 164
 165                 /*
 166                  * we need to defer the callback, because we may notify more
 167                  * then one caller.
 168                  */
 169                 tevent_req_defer_callback(req, state->ev);
 170                 tevent_req_nterror(req, status);
 171         }
 172 }
 173
 174 struct tevent_req *smb2cli_req_create(TALLOC_CTX *mem_ctx,
 175                                       struct tevent_context *ev,
 176                                       struct cli_state *cli,
 177                                       uint16_t cmd,
 178                                       uint32_t flags,
 179                                       const uint8_t *fixed,
 180                                       uint16_t fixed_len,
 181                                       const uint8_t *dyn,
 182                                       uint16_t dyn_len)
 183 {
 184         struct tevent_req *req;
 185         struct smb2cli_req_state *state;
 186
 187         req = tevent_req_create(mem_ctx, &state,
 188                                 struct smb2cli_req_state);
 189         if (req == NULL) {
 190                 return NULL;
 191         }
 192         state->ev = ev;
 193         state->cli = cli;
 194
 195         state->recv_iov = talloc_zero_array(state, struct iovec, 3);
 196         if (state->recv_iov == NULL) {
 197                 TALLOC_FREE(req);
 198                 return NULL;
 199         }
 200
 201         state->fixed = fixed;
 202         state->fixed_len = fixed_len;
 203         state->dyn = dyn;
 204         state->dyn_len = dyn_len;
 205
 206         SIVAL(state->hdr, SMB2_HDR_PROTOCOL_ID, SMB2_MAGIC);
 207         SSVAL(state->hdr, SMB2_HDR_LENGTH,      SMB2_HDR_BODY);
 208         SSVAL(state->hdr, SMB2_HDR_EPOCH,       1);
 209         SIVAL(state->hdr, SMB2_HDR_STATUS,      NT_STATUS_V(NT_STATUS_OK));
 210         SSVAL(state->hdr, SMB2_HDR_OPCODE,      cmd);
 211         SSVAL(state->hdr, SMB2_HDR_CREDIT,      31);
 212         SIVAL(state->hdr, SMB2_HDR_FLAGS,       flags);
 213         SIVAL(state->hdr, SMB2_HDR_PID,         cli->smb2.pid);
 214         SIVAL(state->hdr, SMB2_HDR_TID,         cli->smb2.tid);
 215         SBVAL(state->hdr, SMB2_HDR_SESSION_ID,  cli->smb2.uid);
 216
 217         return req;
 218 }
 219
 220 static void smb2cli_writev_done(struct tevent_req *subreq);
 221
 222 NTSTATUS smb2cli_req_compound_submit(struct tevent_req **reqs,
 223                                      int num_reqs)
 224 {
 225         struct smb2cli_req_state *state;
 226         struct tevent_req *subreq;
 227         struct iovec *iov;
 228         int i, num_iov, nbt_len;
 229
 230         /*
 231          * 1 for the nbt length
 232          * per request: HDR, fixed, dyn, padding
 233          * -1 because the last one does not need padding
 234          */
 235
 236         iov = talloc_array(reqs[0], struct iovec, 1 + 4*num_reqs - 1);
 237         if (iov == NULL) {
 238                 return NT_STATUS_NO_MEMORY;
 239         }
 240
 241         num_iov = 1;
 242         nbt_len = 0;
 243
 244         for (i=0; i<num_reqs; i++) {
 245                 size_t reqlen;
 246                 bool ret;
 247
 248                 state = tevent_req_data(reqs[i], struct smb2cli_req_state);
 249
 250                 SBVAL(state->hdr, SMB2_HDR_MESSAGE_ID, state->cli->smb2.mid++);
 251
 252                 iov[num_iov].iov_base = state->hdr;
 253                 iov[num_iov].iov_len  = sizeof(state->hdr);
 254                 num_iov += 1;
 255
 256                 iov[num_iov].iov_base = discard_const(state->fixed);
 257                 iov[num_iov].iov_len  = state->fixed_len;
 258                 num_iov += 1;
 259
 260                 if (state->dyn != NULL) {
 261                         iov[num_iov].iov_base = discard_const(state->dyn);
 262                         iov[num_iov].iov_len  = state->dyn_len;
 263                         num_iov += 1;
 264                 }
 265
 266                 reqlen = sizeof(state->hdr) + state->fixed_len +
 267                         state->dyn_len;
 268
 269                 if (i < num_reqs-1) {
 270                         if ((reqlen % 8) > 0) {
 271                                 uint8_t pad = 8 - (reqlen % 8);
 272                                 iov[num_iov].iov_base = state->pad;
 273                                 iov[num_iov].iov_len = pad;
 274                                 num_iov += 1;
 275                                 reqlen += pad;
 276                         }
 277                         SIVAL(state->hdr, SMB2_HDR_NEXT_COMMAND, reqlen);
 278                 }
 279                 nbt_len += reqlen;
 280
 281                 ret = smb2cli_req_set_pending(reqs[i]);
 282                 if (!ret) {
 283                         return NT_STATUS_NO_MEMORY;
 284                 }
 285         }
 286
 287         /*
 288          * TODO: Do signing here
 289          */
 290
 291         state = tevent_req_data(reqs[0], struct smb2cli_req_state);
 292         _smb_setlen_large(state->nbt, nbt_len);
 293         iov[0].iov_base = state->nbt;
 294         iov[0].iov_len  = sizeof(state->nbt);
 295
 296         subreq = writev_send(state, state->ev, state->cli->conn.outgoing,
 297                              state->cli->fd, false, iov, num_iov);
 298         if (subreq == NULL) {
 299                 return NT_STATUS_NO_MEMORY;
 300         }
 301         tevent_req_set_callback(subreq, smb2cli_writev_done, reqs[0]);
 302         return NT_STATUS_OK;
 303 }
 304
 305 struct tevent_req *smb2cli_req_send(TALLOC_CTX *mem_ctx,
 306                                     struct tevent_context *ev,
 307                                     struct cli_state *cli,
 308                                     uint16_t cmd,
 309                                     uint32_t flags,
 310                                     const uint8_t *fixed,
 311                                     uint16_t fixed_len,
 312                                     const uint8_t *dyn,
 313                                     uint16_t dyn_len)
 314 {
 315         struct tevent_req *req;
 316         NTSTATUS status;
 317
 318         req = smb2cli_req_create(mem_ctx, ev, cli, cmd, flags,
 319                                  fixed, fixed_len, dyn, dyn_len);
 320         if (req == NULL) {
 321                 return NULL;
 322         }
 323         if (!tevent_req_is_in_progress(req)) {
 324                 return req;
 325         }
 326         status = smb2cli_req_compound_submit(&req, 1);
 327         if (tevent_req_nterror(req, status)) {
 328                 return tevent_req_post(req, ev);
 329         }
 330         return req;
 331 }
 332
 333 static void smb2cli_writev_done(struct tevent_req *subreq)
 334 {
 335         struct tevent_req *req =
 336                 tevent_req_callback_data(subreq,
 337                 struct tevent_req);
 338         struct smb2cli_req_state *state =
 339                 tevent_req_data(req,
 340                 struct smb2cli_req_state);
 341         ssize_t nwritten;
 342         int err;
 343
 344         nwritten = writev_recv(subreq, &err);
 345         TALLOC_FREE(subreq);
 346         if (nwritten == -1) {
 347                 /* here, we need to notify all pending requests */
 348                 smb2cli_notify_pending(state->cli, map_nt_error_from_unix(err));
 349                 return;
 350         }
 351 }
 352
 353 static NTSTATUS smb2cli_inbuf_parse_compound(uint8_t *buf, TALLOC_CTX *mem_ctx,
 354                                              struct iovec **piov, int *pnum_iov)
 355 {
 356         struct iovec *iov;
 357         int num_iov;
 358         size_t buflen;
 359         size_t taken;
 360
 361         num_iov = 1;
 362
 363         iov = talloc_array(mem_ctx, struct iovec, num_iov);
 364         if (iov == NULL) {
 365                 return NT_STATUS_NO_MEMORY;
 366         }
 367         iov[0].iov_base = buf;
 368         iov[0].iov_len = 4;
 369
 370         buflen = smb_len_large(buf) + 4;
 371         taken = 4;
 372
 373         while (taken < buflen) {
 374                 size_t len = buflen - taken;
 375                 uint8_t *hdr = buf + taken;
 376                 struct iovec *cur;
 377                 size_t full_size;
 378                 size_t next_command_ofs;
 379                 uint16_t body_size;
 380                 struct iovec *iov_tmp;
 381
 382                 /*
 383                  * We need the header plus the body length field
 384                  */
 385
 386                 if (len < SMB2_HDR_BODY + 2) {
 387                         DEBUG(10, ("%d bytes left, expected at least %d\n",
 388                                    (int)len, SMB2_HDR_BODY));
 389                         goto inval;
 390                 }
 391                 if (IVAL(hdr, 0) != SMB2_MAGIC) {
 392                         DEBUG(10, ("Got non-SMB2 PDU: %x\n",
 393                                    IVAL(hdr, 0)));
 394                         goto inval;
 395                 }
 396                 if (SVAL(hdr, 4) != SMB2_HDR_BODY) {
 397                         DEBUG(10, ("Got HDR len %d, expected %d\n",
 398                                    SVAL(hdr, 4), SMB2_HDR_BODY));
 399                         goto inval;
 400                 }
 401
 402                 full_size = len;
 403                 next_command_ofs = IVAL(hdr, SMB2_HDR_NEXT_COMMAND);
 404                 body_size = SVAL(hdr, SMB2_HDR_BODY);
 405
 406                 if (next_command_ofs != 0) {
 407                         if (next_command_ofs < (SMB2_HDR_BODY + 2)) {
 408                                 goto inval;
 409                         }
 410                         if (next_command_ofs > full_size) {
 411                                 goto inval;
 412                         }
 413                         full_size = next_command_ofs;
 414                 }
 415                 if (body_size < 2) {
 416                         goto inval;
 417                 }
 418                 body_size &= 0xfffe;
 419
 420                 if (body_size > (full_size - SMB2_HDR_BODY)) {
 421                         goto inval;
 422                 }
 423
 424                 iov_tmp = talloc_realloc(mem_ctx, iov, struct iovec,
 425                                          num_iov + 3);
 426                 if (iov_tmp == NULL) {
 427                         TALLOC_FREE(iov);
 428                         return NT_STATUS_NO_MEMORY;
 429                 }
 430                 iov = iov_tmp;
 431                 cur = &iov[num_iov];
 432                 num_iov += 3;
 433
 434                 cur[0].iov_base = hdr;
 435                 cur[0].iov_len  = SMB2_HDR_BODY;
 436                 cur[1].iov_base = hdr + SMB2_HDR_BODY;
 437                 cur[1].iov_len  = body_size;
 438                 cur[2].iov_base = hdr + SMB2_HDR_BODY + body_size;
 439                 cur[2].iov_len  = full_size - (SMB2_HDR_BODY + body_size);
 440
 441                 taken += full_size;
 442         }
 443
 444         *piov = iov;
 445         *pnum_iov = num_iov;
 446         return NT_STATUS_OK;
 447
 448 inval:
 449         TALLOC_FREE(iov);
 450         return NT_STATUS_INVALID_NETWORK_RESPONSE;
 451 }
 452
 453 static struct tevent_req *cli_smb2_find_pending(struct cli_state *cli,
 454                                                 uint64_t mid)
 455 {
 456         int num_pending = talloc_array_length(cli->conn.pending);
 457         int i;
 458
 459         for (i=0; i<num_pending; i++) {
 460                 struct tevent_req *req = cli->conn.pending[i];
 461                 struct smb2cli_req_state *state =
 462                         tevent_req_data(req,
 463                         struct smb2cli_req_state);
 464
 465                 if (mid == BVAL(state->hdr, SMB2_HDR_MESSAGE_ID)) {
 466                         return req;
 467                 }
 468         }
 469         return NULL;
 470 }
 471
 472 static void smb2cli_inbuf_received(struct tevent_req *subreq)
 473 {
 474         struct cli_state *cli =
 475                 tevent_req_callback_data(subreq,
 476                 struct cli_state);
 477         TALLOC_CTX *frame = talloc_stackframe();
 478         struct tevent_req *req;
 479         struct smb2cli_req_state *state;
 480         struct iovec *iov;
 481         int i, num_iov;
 482         NTSTATUS status;
 483         uint8_t *inbuf;
 484         ssize_t received;
 485         int err;
 486         size_t num_pending;
 487
 488         received = read_smb_recv(subreq, frame, &inbuf, &err);
 489         TALLOC_FREE(subreq);
 490         if (received == -1) {
 491                 /*
 492                  * We need to close the connection and notify
 493                  * all pending requests.
 494                  */
 495                 smb2cli_notify_pending(cli, map_nt_error_from_unix(err));
 496                 TALLOC_FREE(frame);
 497                 return;
 498         }
 499
 500         status = smb2cli_inbuf_parse_compound(inbuf, frame,
 501                                               &iov, &num_iov);
 502         if (!NT_STATUS_IS_OK(status)) {
 503                 /*
 504                  * if we cannot parse the incoming pdu,
 505                  * the connection becomes unusable.
 506                  *
 507                  * We need to close the connection and notify
 508                  * all pending requests.
 509                  */
 510                 smb2cli_notify_pending(cli, status);
 511                 TALLOC_FREE(frame);
 512                 return;
 513         }
 514
 515         for (i=1; i<num_iov; i+=3) {
 516                 uint8_t *inbuf_ref = NULL;
 517                 struct iovec *cur = &iov[i];
 518                 uint8_t *inhdr = (uint8_t *)cur[0].iov_base;
 519
 520                 req = cli_smb2_find_pending(
 521                         cli, BVAL(inhdr, SMB2_HDR_MESSAGE_ID));
 522                 if (req == NULL) {
 523                         /*
 524                          * TODO: handle oplock breaks and async responses
 525                          */
 526
 527                         /*
 528                          * We need to close the connection and notify
 529                          * all pending requests.
 530                          */
 531                         smb2cli_notify_pending(cli, status);
 532                         TALLOC_FREE(frame);
 533                         return;
 534                 }
 535                 smb2cli_req_unset_pending(req);
 536                 state = tevent_req_data(req, struct smb2cli_req_state);
 537
 538                 /*
 539                  * There might be more than one response
 540                  * we need to defer the notifications
 541                  */
 542                 tevent_req_defer_callback(req, state->ev);
 543
 544                 /*
 545                  * Note: here we use talloc_reference() in a way
 546                  *       that does not expose it to the caller.
 547                  */
 548                 inbuf_ref = talloc_reference(state->recv_iov, inbuf);
 549                 if (tevent_req_nomem(inbuf_ref, req)) {
 550                         continue;
 551                 }
 552
 553                 /* copy the related buffers */
 554                 state->recv_iov[0] = cur[0];
 555                 state->recv_iov[1] = cur[1];
 556                 state->recv_iov[2] = cur[2];
 557
 558                 tevent_req_done(req);
 559         }
 560
 561         TALLOC_FREE(frame);
 562
 563         num_pending = talloc_array_length(cli->conn.pending);
 564         if (num_pending == 0) {
 565                 /* no more pending requests, so we are done for now */
 566                 return;
 567         }
 568         req = cli->conn.pending[0];
 569         state = tevent_req_data(req, struct smb2cli_req_state);
 570
 571         /*
 572          * add the read_smb request that waits for the
 573          * next answer from the server
 574          */
 575         subreq = read_smb_send(cli->conn.pending, state->ev, cli->fd);
 576         if (subreq == NULL) {
 577                 smb2cli_notify_pending(cli, NT_STATUS_NO_MEMORY);
 578                 return;
 579         }
 580         tevent_req_set_callback(subreq, smb2cli_inbuf_received, cli);
 581 }
 582
 583 NTSTATUS smb2cli_req_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 584                           struct iovec **piov, int body_size)
 585 {
 586         struct smb2cli_req_state *state =
 587                 tevent_req_data(req,
 588                 struct smb2cli_req_state);
 589         NTSTATUS status;
 590
 591         if (tevent_req_is_nterror(req, &status)) {
 592                 return status;
 593         }
 594
 595         status = NT_STATUS(IVAL(state->recv_iov[0].iov_base, SMB2_HDR_STATUS));
 596
 597         if (body_size != 0) {
 598                 if (body_size != SVAL(state->recv_iov[1].iov_base, 0)) {
 599                         return NT_STATUS_INVALID_NETWORK_RESPONSE;
 600                 }
 601         }
 602         if (piov != NULL) {
 603                 *piov = talloc_move(mem_ctx, &state->recv_iov);
 604         }
 605
 606         return status;
 607 }