source/smbd/process.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    process incoming packets - main loop
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Volker Lendecke 2005-2007
   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
  23 extern struct auth_context *negprot_global_auth_context;
  24 extern int smb_echo_count;
  25
  26 const int total_buffer_size = (BUFFER_SIZE + LARGE_WRITEX_HDR_SIZE + SAFETY_MARGIN);
  27
  28 /*
  29  * Size of data we can send to client. Set
  30  *  by the client for all protocols above CORE.
  31  *  Set by us for CORE protocol.
  32  */
  33 int max_send = BUFFER_SIZE;
  34 /*
  35  * Size of the data we can receive. Set by us.
  36  * Can be modified by the max xmit parameter.
  37  */
  38 int max_recv = BUFFER_SIZE;
  39
  40 extern int last_message;
  41 extern int smb_read_error;
  42 SIG_ATOMIC_T reload_after_sighup = 0;
  43 SIG_ATOMIC_T got_sig_term = 0;
  44 extern BOOL global_machine_password_needs_changing;
  45 extern int max_send;
  46
  47 /*
  48  * Initialize a struct smb_request from an inbuf
  49  */
  50
  51 void init_smb_request(struct smb_request *req, const uint8 *inbuf)
  52 {
  53         size_t req_size = smb_len(inbuf) + 4;
  54         /* Ensure we have at least smb_size bytes. */
  55         if (req_size < smb_size) {
  56                 DEBUG(0,("init_smb_request: invalid request size %u\n",
  57                         (unsigned int)req_size ));
  58                 exit_server_cleanly("Invalid SMB request");
  59         }
  60         req->flags2 = SVAL(inbuf, smb_flg2);
  61         req->smbpid = SVAL(inbuf, smb_pid);
  62         req->mid    = SVAL(inbuf, smb_mid);
  63         req->vuid   = SVAL(inbuf, smb_uid);
  64         req->tid    = SVAL(inbuf, smb_tid);
  65         req->wct    = CVAL(inbuf, smb_wct);
  66         /* Ensure we have at least wct words and 2 bytes of bcc. */
  67         if (smb_size + req->wct*2 > req_size) {
  68                 DEBUG(0,("init_smb_request: invalid wct number %u (size %u)\n",
  69                         (unsigned int)req->wct,
  70                         (unsigned int)req_size));
  71                 exit_server_cleanly("Invalid SMB request");
  72         }
  73         /* Ensure bcc is correct. */
  74         if (((uint8 *)smb_buf(inbuf)) + smb_buflen(inbuf) > inbuf + req_size) {
  75                 DEBUG(0,("init_smb_request: invalid bcc number %u "
  76                         "(wct = %u, size %u)\n",
  77                         (unsigned int)smb_buflen(inbuf),
  78                         (unsigned int)req->wct,
  79                         (unsigned int)req_size));
  80                 exit_server_cleanly("Invalid SMB request");
  81         }
  82         req->inbuf  = inbuf;
  83         req->outbuf = NULL;
  84 }
  85
  86 /****************************************************************************
  87  structure to hold a linked list of queued messages.
  88  for processing.
  89 ****************************************************************************/
  90
  91 static struct pending_message_list *deferred_open_queue;
  92
  93 /****************************************************************************
  94  Function to push a message onto the tail of a linked list of smb messages ready
  95  for processing.
  96 ****************************************************************************/
  97
  98 static BOOL push_queued_message(struct smb_request *req,
  99                                 struct timeval request_time,
 100                                 struct timeval end_time,
 101                                 char *private_data, size_t private_len)
 102 {
 103         int msg_len = smb_len(req->inbuf) + 4;
 104         struct pending_message_list *msg;
 105
 106         msg = TALLOC_ZERO_P(NULL, struct pending_message_list);
 107
 108         if(msg == NULL) {
 109                 DEBUG(0,("push_message: malloc fail (1)\n"));
 110                 return False;
 111         }
 112
 113         msg->buf = data_blob_talloc(msg, req->inbuf, msg_len);
 114         if(msg->buf.data == NULL) {
 115                 DEBUG(0,("push_message: malloc fail (2)\n"));
 116                 TALLOC_FREE(msg);
 117                 return False;
 118         }
 119
 120         msg->request_time = request_time;
 121         msg->end_time = end_time;
 122
 123         if (private_data) {
 124                 msg->private_data = data_blob_talloc(msg, private_data,
 125                                                      private_len);
 126                 if (msg->private_data.data == NULL) {
 127                         DEBUG(0,("push_message: malloc fail (3)\n"));
 128                         TALLOC_FREE(msg);
 129                         return False;
 130                 }
 131         }
 132
 133         DLIST_ADD_END(deferred_open_queue, msg, struct pending_message_list *);
 134
 135         DEBUG(10,("push_message: pushed message length %u on "
 136                   "deferred_open_queue\n", (unsigned int)msg_len));
 137
 138         return True;
 139 }
 140
 141 /****************************************************************************
 142  Function to delete a sharing violation open message by mid.
 143 ****************************************************************************/
 144
 145 void remove_deferred_open_smb_message(uint16 mid)
 146 {
 147         struct pending_message_list *pml;
 148
 149         for (pml = deferred_open_queue; pml; pml = pml->next) {
 150                 if (mid == SVAL(pml->buf.data,smb_mid)) {
 151                         DEBUG(10,("remove_sharing_violation_open_smb_message: "
 152                                   "deleting mid %u len %u\n",
 153                                   (unsigned int)mid,
 154                                   (unsigned int)pml->buf.length ));
 155                         DLIST_REMOVE(deferred_open_queue, pml);
 156                         TALLOC_FREE(pml);
 157                         return;
 158                 }
 159         }
 160 }
 161
 162 /****************************************************************************
 163  Move a sharing violation open retry message to the front of the list and
 164  schedule it for immediate processing.
 165 ****************************************************************************/
 166
 167 void schedule_deferred_open_smb_message(uint16 mid)
 168 {
 169         struct pending_message_list *pml;
 170         int i = 0;
 171
 172         for (pml = deferred_open_queue; pml; pml = pml->next) {
 173                 uint16 msg_mid = SVAL(pml->buf.data,smb_mid);
 174                 DEBUG(10,("schedule_deferred_open_smb_message: [%d] msg_mid = %u\n", i++,
 175                         (unsigned int)msg_mid ));
 176                 if (mid == msg_mid) {
 177                         DEBUG(10,("schedule_deferred_open_smb_message: scheduling mid %u\n",
 178                                 mid ));
 179                         pml->end_time.tv_sec = 0;
 180                         pml->end_time.tv_usec = 0;
 181                         DLIST_PROMOTE(deferred_open_queue, pml);
 182                         return;
 183                 }
 184         }
 185
 186         DEBUG(10,("schedule_deferred_open_smb_message: failed to find message mid %u\n",
 187                 mid ));
 188 }
 189
 190 /****************************************************************************
 191  Return true if this mid is on the deferred queue.
 192 ****************************************************************************/
 193
 194 BOOL open_was_deferred(uint16 mid)
 195 {
 196         struct pending_message_list *pml;
 197
 198         for (pml = deferred_open_queue; pml; pml = pml->next) {
 199                 if (SVAL(pml->buf.data,smb_mid) == mid) {
 200                         return True;
 201                 }
 202         }
 203         return False;
 204 }
 205
 206 /****************************************************************************
 207  Return the message queued by this mid.
 208 ****************************************************************************/
 209
 210 struct pending_message_list *get_open_deferred_message(uint16 mid)
 211 {
 212         struct pending_message_list *pml;
 213
 214         for (pml = deferred_open_queue; pml; pml = pml->next) {
 215                 if (SVAL(pml->buf.data,smb_mid) == mid) {
 216                         return pml;
 217                 }
 218         }
 219         return NULL;
 220 }
 221
 222 /****************************************************************************
 223  Function to push a deferred open smb message onto a linked list of local smb
 224  messages ready for processing.
 225 ****************************************************************************/
 226
 227 BOOL push_deferred_smb_message(struct smb_request *req,
 228                                struct timeval request_time,
 229                                struct timeval timeout,
 230                                char *private_data, size_t priv_len)
 231 {
 232         struct timeval end_time;
 233
 234         end_time = timeval_sum(&request_time, &timeout);
 235
 236         DEBUG(10,("push_deferred_open_smb_message: pushing message len %u mid %u "
 237                   "timeout time [%u.%06u]\n",
 238                   (unsigned int) smb_len(req->inbuf)+4, (unsigned int)req->mid,
 239                   (unsigned int)end_time.tv_sec,
 240                   (unsigned int)end_time.tv_usec));
 241
 242         return push_queued_message(req, request_time, end_time,
 243                                    private_data, priv_len);
 244 }
 245
 246 struct idle_event {
 247         struct timed_event *te;
 248         struct timeval interval;
 249         char *name;
 250         BOOL (*handler)(const struct timeval *now, void *private_data);
 251         void *private_data;
 252 };
 253
 254 static void idle_event_handler(struct event_context *ctx,
 255                                struct timed_event *te,
 256                                const struct timeval *now,
 257                                void *private_data)
 258 {
 259         struct idle_event *event =
 260                 talloc_get_type_abort(private_data, struct idle_event);
 261
 262         TALLOC_FREE(event->te);
 263
 264         if (!event->handler(now, event->private_data)) {
 265                 /* Don't repeat, delete ourselves */
 266                 TALLOC_FREE(event);
 267                 return;
 268         }
 269
 270         event->te = event_add_timed(ctx, event,
 271                                     timeval_sum(now, &event->interval),
 272                                     event->name,
 273                                     idle_event_handler, event);
 274
 275         /* We can't do much but fail here. */
 276         SMB_ASSERT(event->te != NULL);
 277 }
 278
 279 struct idle_event *event_add_idle(struct event_context *event_ctx,
 280                                   TALLOC_CTX *mem_ctx,
 281                                   struct timeval interval,
 282                                   const char *name,
 283                                   BOOL (*handler)(const struct timeval *now,
 284                                                   void *private_data),
 285                                   void *private_data)
 286 {
 287         struct idle_event *result;
 288         struct timeval now = timeval_current();
 289
 290         result = TALLOC_P(mem_ctx, struct idle_event);
 291         if (result == NULL) {
 292                 DEBUG(0, ("talloc failed\n"));
 293                 return NULL;
 294         }
 295
 296         result->interval = interval;
 297         result->handler = handler;
 298         result->private_data = private_data;
 299
 300         if (!(result->name = talloc_asprintf(result, "idle_evt(%s)", name))) {
 301                 DEBUG(0, ("talloc failed\n"));
 302                 TALLOC_FREE(result);
 303                 return NULL;
 304         }
 305
 306         result->te = event_add_timed(event_ctx, result,
 307                                      timeval_sum(&now, &interval),
 308                                      result->name,
 309                                      idle_event_handler, result);
 310         if (result->te == NULL) {
 311                 DEBUG(0, ("event_add_timed failed\n"));
 312                 TALLOC_FREE(result);
 313                 return NULL;
 314         }
 315
 316         return result;
 317 }
 318
 319 /****************************************************************************
 320  Do all async processing in here. This includes kernel oplock messages, change
 321  notify events etc.
 322 ****************************************************************************/
 323
 324 static void async_processing(fd_set *pfds)
 325 {
 326         DEBUG(10,("async_processing: Doing async processing.\n"));
 327
 328         process_aio_queue();
 329
 330         process_kernel_oplocks(smbd_messaging_context(), pfds);
 331
 332         /* Do the aio check again after receive_local_message as it does a
 333            select and may have eaten our signal. */
 334         /* Is this till true? -- vl */
 335         process_aio_queue();
 336
 337         if (got_sig_term) {
 338                 exit_server_cleanly("termination signal");
 339         }
 340
 341         /* check for sighup processing */
 342         if (reload_after_sighup) {
 343                 change_to_root_user();
 344                 DEBUG(1,("Reloading services after SIGHUP\n"));
 345                 reload_services(False);
 346                 reload_after_sighup = 0;
 347         }
 348 }
 349
 350 /****************************************************************************
 351  Add a fd to the set we will be select(2)ing on.
 352 ****************************************************************************/
 353
 354 static int select_on_fd(int fd, int maxfd, fd_set *fds)
 355 {
 356         if (fd != -1) {
 357                 FD_SET(fd, fds);
 358                 maxfd = MAX(maxfd, fd);
 359         }
 360
 361         return maxfd;
 362 }
 363
 364 /****************************************************************************
 365   Do a select on an two fd's - with timeout.
 366
 367   If a local udp message has been pushed onto the
 368   queue (this can only happen during oplock break
 369   processing) call async_processing()
 370
 371   If a pending smb message has been pushed onto the
 372   queue (this can only happen during oplock break
 373   processing) return this next.
 374
 375   If the first smbfd is ready then read an smb from it.
 376   if the second (loopback UDP) fd is ready then read a message
 377   from it and setup the buffer header to identify the length
 378   and from address.
 379   Returns False on timeout or error.
 380   Else returns True.
 381
 382 The timeout is in milliseconds
 383 ****************************************************************************/
 384
 385 static BOOL receive_message_or_smb(TALLOC_CTX *mem_ctx, char **buffer,
 386                                    size_t *buffer_len, int timeout)
 387 {
 388         fd_set r_fds, w_fds;
 389         int selrtn;
 390         struct timeval to;
 391         int maxfd = 0;
 392         ssize_t len;
 393
 394         smb_read_error = 0;
 395
 396  again:
 397
 398         if (timeout >= 0) {
 399                 to.tv_sec = timeout / 1000;
 400                 to.tv_usec = (timeout % 1000) * 1000;
 401         } else {
 402                 to.tv_sec = SMBD_SELECT_TIMEOUT;
 403                 to.tv_usec = 0;
 404         }
 405
 406         /*
 407          * Note that this call must be before processing any SMB
 408          * messages as we need to synchronously process any messages
 409          * we may have sent to ourselves from the previous SMB.
 410          */
 411         message_dispatch(smbd_messaging_context());
 412
 413         /*
 414          * Check to see if we already have a message on the deferred open queue
 415          * and it's time to schedule.
 416          */
 417         if(deferred_open_queue != NULL) {
 418                 BOOL pop_message = False;
 419                 struct pending_message_list *msg = deferred_open_queue;
 420
 421                 if (timeval_is_zero(&msg->end_time)) {
 422                         pop_message = True;
 423                 } else {
 424                         struct timeval tv;
 425                         SMB_BIG_INT tdif;
 426
 427                         GetTimeOfDay(&tv);
 428                         tdif = usec_time_diff(&msg->end_time, &tv);
 429                         if (tdif <= 0) {
 430                                 /* Timed out. Schedule...*/
 431                                 pop_message = True;
 432                                 DEBUG(10,("receive_message_or_smb: queued message timed out.\n"));
 433                         } else {
 434                                 /* Make a more accurate select timeout. */
 435                                 to.tv_sec = tdif / 1000000;
 436                                 to.tv_usec = tdif % 1000000;
 437                                 DEBUG(10,("receive_message_or_smb: select with timeout of [%u.%06u]\n",
 438                                         (unsigned int)to.tv_sec, (unsigned int)to.tv_usec ));
 439                         }
 440                 }
 441
 442                 if (pop_message) {
 443
 444                         *buffer = (char *)talloc_memdup(mem_ctx, msg->buf.data,
 445                                                         msg->buf.length);
 446                         if (*buffer == NULL) {
 447                                 DEBUG(0, ("talloc failed\n"));
 448                                 smb_read_error = READ_ERROR;
 449                                 return False;
 450                         }
 451                         *buffer_len = msg->buf.length;
 452
 453                         /* We leave this message on the queue so the open code can
 454                            know this is a retry. */
 455                         DEBUG(5,("receive_message_or_smb: returning deferred open smb message.\n"));
 456                         return True;
 457                 }
 458         }
 459
 460         /*
 461          * Setup the select fd sets.
 462          */
 463
 464         FD_ZERO(&r_fds);
 465         FD_ZERO(&w_fds);
 466
 467         /*
 468          * Ensure we process oplock break messages by preference.
 469          * We have to do this before the select, after the select
 470          * and if the select returns EINTR. This is due to the fact
 471          * that the selects called from async_processing can eat an EINTR
 472          * caused by a signal (we can't take the break message there).
 473          * This is hideously complex - *MUST* be simplified for 3.0 ! JRA.
 474          */
 475
 476         if (oplock_message_waiting(&r_fds)) {
 477                 DEBUG(10,("receive_message_or_smb: oplock_message is waiting.\n"));
 478                 async_processing(&r_fds);
 479                 /*
 480                  * After async processing we must go and do the select again, as
 481                  * the state of the flag in fds for the server file descriptor is
 482                  * indeterminate - we may have done I/O on it in the oplock processing. JRA.
 483                  */
 484                 goto again;
 485         }
 486
 487         /*
 488          * Are there any timed events waiting ? If so, ensure we don't
 489          * select for longer than it would take to wait for them.
 490          */
 491
 492         {
 493                 struct timeval now;
 494                 GetTimeOfDay(&now);
 495
 496                 event_add_to_select_args(smbd_event_context(), &now,
 497                                          &r_fds, &w_fds, &to, &maxfd);
 498         }
 499
 500         if (timeval_is_zero(&to)) {
 501                 /* Process a timed event now... */
 502                 if (run_events(smbd_event_context(), 0, NULL, NULL)) {
 503                         goto again;
 504                 }
 505         }
 506
 507         {
 508                 int sav;
 509                 START_PROFILE(smbd_idle);
 510
 511                 maxfd = select_on_fd(smbd_server_fd(), maxfd, &r_fds);
 512                 maxfd = select_on_fd(oplock_notify_fd(), maxfd, &r_fds);
 513
 514                 selrtn = sys_select(maxfd+1,&r_fds,&w_fds,NULL,&to);
 515                 sav = errno;
 516
 517                 END_PROFILE(smbd_idle);
 518                 errno = sav;
 519         }
 520
 521         if (run_events(smbd_event_context(), selrtn, &r_fds, &w_fds)) {
 522                 goto again;
 523         }
 524
 525         /* if we get EINTR then maybe we have received an oplock
 526            signal - treat this as select returning 1. This is ugly, but
 527            is the best we can do until the oplock code knows more about
 528            signals */
 529         if (selrtn == -1 && errno == EINTR) {
 530                 async_processing(&r_fds);
 531                 /*
 532                  * After async processing we must go and do the select again, as
 533                  * the state of the flag in fds for the server file descriptor is
 534                  * indeterminate - we may have done I/O on it in the oplock processing. JRA.
 535                  */
 536                 goto again;
 537         }
 538
 539         /* Check if error */
 540         if (selrtn == -1) {
 541                 /* something is wrong. Maybe the socket is dead? */
 542                 smb_read_error = READ_ERROR;
 543                 return False;
 544         }
 545
 546         /* Did we timeout ? */
 547         if (selrtn == 0) {
 548                 smb_read_error = READ_TIMEOUT;
 549                 return False;
 550         }
 551
 552         /*
 553          * Ensure we process oplock break messages by preference.
 554          * This is IMPORTANT ! Otherwise we can starve other processes
 555          * sending us an oplock break message. JRA.
 556          */
 557
 558         if (oplock_message_waiting(&r_fds)) {
 559                 async_processing(&r_fds);
 560                 /*
 561                  * After async processing we must go and do the select again, as
 562                  * the state of the flag in fds for the server file descriptor is
 563                  * indeterminate - we may have done I/O on it in the oplock processing. JRA.
 564                  */
 565                 goto again;
 566         }
 567
 568         len = receive_smb_talloc(mem_ctx, smbd_server_fd(), buffer, 0);
 569
 570         if (len == -1) {
 571                 return False;
 572         }
 573
 574         *buffer_len = (size_t)len;
 575
 576         return True;
 577 }
 578
 579 /*
 580  * Only allow 5 outstanding trans requests. We're allocating memory, so
 581  * prevent a DoS.
 582  */
 583
 584 NTSTATUS allow_new_trans(struct trans_state *list, int mid)
 585 {
 586         int count = 0;
 587         for (; list != NULL; list = list->next) {
 588
 589                 if (list->mid == mid) {
 590                         return NT_STATUS_INVALID_PARAMETER;
 591                 }
 592
 593                 count += 1;
 594         }
 595         if (count > 5) {
 596                 return NT_STATUS_INSUFFICIENT_RESOURCES;
 597         }
 598
 599         return NT_STATUS_OK;
 600 }
 601
 602 /****************************************************************************
 603  We're terminating and have closed all our files/connections etc.
 604  If there are any pending local messages we need to respond to them
 605  before termination so that other smbds don't think we just died whilst
 606  holding oplocks.
 607 ****************************************************************************/
 608
 609 void respond_to_all_remaining_local_messages(void)
 610 {
 611         /*
 612          * Assert we have no exclusive open oplocks.
 613          */
 614
 615         if(get_number_of_exclusive_open_oplocks()) {
 616                 DEBUG(0,("respond_to_all_remaining_local_messages: PANIC : we have %d exclusive oplocks.\n",
 617                         get_number_of_exclusive_open_oplocks() ));
 618                 return;
 619         }
 620
 621         process_kernel_oplocks(smbd_messaging_context(), NULL);
 622
 623         return;
 624 }
 625
 626
 627 /*
 628 These flags determine some of the permissions required to do an operation
 629
 630 Note that I don't set NEED_WRITE on some write operations because they
 631 are used by some brain-dead clients when printing, and I don't want to
 632 force write permissions on print services.
 633 */
 634 #define AS_USER (1<<0)
 635 #define NEED_WRITE (1<<1) /* Must be paired with AS_USER */
 636 #define TIME_INIT (1<<2)
 637 #define CAN_IPC (1<<3) /* Must be paired with AS_USER */
 638 #define AS_GUEST (1<<5) /* Must *NOT* be paired with AS_USER */
 639 #define DO_CHDIR (1<<6)
 640
 641 /*
 642    define a list of possible SMB messages and their corresponding
 643    functions. Any message that has a NULL function is unimplemented -
 644    please feel free to contribute implementations!
 645 */
 646 static const struct smb_message_struct {
 647         const char *name;
 648         void (*fn_new)(connection_struct *conn, struct smb_request *req);
 649         int flags;
 650 } smb_messages[256] = {
 651
 652 /* 0x00 */ { "SMBmkdir",reply_mkdir,AS_USER | NEED_WRITE},
 653 /* 0x01 */ { "SMBrmdir",reply_rmdir,AS_USER | NEED_WRITE},
 654 /* 0x02 */ { "SMBopen",reply_open,AS_USER },
 655 /* 0x03 */ { "SMBcreate",reply_mknew,AS_USER},
 656 /* 0x04 */ { "SMBclose",reply_close,AS_USER | CAN_IPC },
 657 /* 0x05 */ { "SMBflush",reply_flush,AS_USER},
 658 /* 0x06 */ { "SMBunlink",reply_unlink,AS_USER | NEED_WRITE },
 659 /* 0x07 */ { "SMBmv",reply_mv,AS_USER | NEED_WRITE },
 660 /* 0x08 */ { "SMBgetatr",reply_getatr,AS_USER},
 661 /* 0x09 */ { "SMBsetatr",reply_setatr,AS_USER | NEED_WRITE},
 662 /* 0x0a */ { "SMBread",reply_read,AS_USER},
 663 /* 0x0b */ { "SMBwrite",reply_write,AS_USER | CAN_IPC },
 664 /* 0x0c */ { "SMBlock",reply_lock,AS_USER},
 665 /* 0x0d */ { "SMBunlock",reply_unlock,AS_USER},
 666 /* 0x0e */ { "SMBctemp",reply_ctemp,AS_USER },
 667 /* 0x0f */ { "SMBmknew",reply_mknew,AS_USER},
 668 /* 0x10 */ { "SMBcheckpath",reply_checkpath,AS_USER},
 669 /* 0x11 */ { "SMBexit",reply_exit,DO_CHDIR},
 670 /* 0x12 */ { "SMBlseek",reply_lseek,AS_USER},
 671 /* 0x13 */ { "SMBlockread",reply_lockread,AS_USER},
 672 /* 0x14 */ { "SMBwriteunlock",reply_writeunlock,AS_USER},
 673 /* 0x15 */ { NULL, NULL, 0 },
 674 /* 0x16 */ { NULL, NULL, 0 },
 675 /* 0x17 */ { NULL, NULL, 0 },
 676 /* 0x18 */ { NULL, NULL, 0 },
 677 /* 0x19 */ { NULL, NULL, 0 },
 678 /* 0x1a */ { "SMBreadbraw",reply_readbraw,AS_USER},
 679 /* 0x1b */ { "SMBreadBmpx",reply_readbmpx,AS_USER},
 680 /* 0x1c */ { "SMBreadBs",reply_readbs,AS_USER },
 681 /* 0x1d */ { "SMBwritebraw",reply_writebraw,AS_USER},
 682 /* 0x1e */ { "SMBwriteBmpx",reply_writebmpx,AS_USER},
 683 /* 0x1f */ { "SMBwriteBs",reply_writebs,AS_USER},
 684 /* 0x20 */ { "SMBwritec", NULL,0},
 685 /* 0x21 */ { NULL, NULL, 0 },
 686 /* 0x22 */ { "SMBsetattrE",reply_setattrE,AS_USER | NEED_WRITE },
 687 /* 0x23 */ { "SMBgetattrE",reply_getattrE,AS_USER },
 688 /* 0x24 */ { "SMBlockingX",reply_lockingX,AS_USER },
 689 /* 0x25 */ { "SMBtrans",reply_trans,AS_USER | CAN_IPC },
 690 /* 0x26 */ { "SMBtranss",reply_transs,AS_USER | CAN_IPC},
 691 /* 0x27 */ { "SMBioctl",reply_ioctl,0},
 692 /* 0x28 */ { "SMBioctls", NULL,AS_USER},
 693 /* 0x29 */ { "SMBcopy",reply_copy,AS_USER | NEED_WRITE },
 694 /* 0x2a */ { "SMBmove", NULL,AS_USER | NEED_WRITE },
 695 /* 0x2b */ { "SMBecho",reply_echo,0},
 696 /* 0x2c */ { "SMBwriteclose",reply_writeclose,AS_USER},
 697 /* 0x2d */ { "SMBopenX",reply_open_and_X,AS_USER | CAN_IPC },
 698 /* 0x2e */ { "SMBreadX",reply_read_and_X,AS_USER | CAN_IPC },
 699 /* 0x2f */ { "SMBwriteX",reply_write_and_X,AS_USER | CAN_IPC },
 700 /* 0x30 */ { NULL, NULL, 0 },
 701 /* 0x31 */ { NULL, NULL, 0 },
 702 /* 0x32 */ { "SMBtrans2",reply_trans2, AS_USER | CAN_IPC },
 703 /* 0x33 */ { "SMBtranss2",reply_transs2, AS_USER},
 704 /* 0x34 */ { "SMBfindclose",reply_findclose,AS_USER},
 705 /* 0x35 */ { "SMBfindnclose",reply_findnclose,AS_USER},
 706 /* 0x36 */ { NULL, NULL, 0 },
 707 /* 0x37 */ { NULL, NULL, 0 },
 708 /* 0x38 */ { NULL, NULL, 0 },
 709 /* 0x39 */ { NULL, NULL, 0 },
 710 /* 0x3a */ { NULL, NULL, 0 },
 711 /* 0x3b */ { NULL, NULL, 0 },
 712 /* 0x3c */ { NULL, NULL, 0 },
 713 /* 0x3d */ { NULL, NULL, 0 },
 714 /* 0x3e */ { NULL, NULL, 0 },
 715 /* 0x3f */ { NULL, NULL, 0 },
 716 /* 0x40 */ { NULL, NULL, 0 },
 717 /* 0x41 */ { NULL, NULL, 0 },
 718 /* 0x42 */ { NULL, NULL, 0 },
 719 /* 0x43 */ { NULL, NULL, 0 },
 720 /* 0x44 */ { NULL, NULL, 0 },
 721 /* 0x45 */ { NULL, NULL, 0 },
 722 /* 0x46 */ { NULL, NULL, 0 },
 723 /* 0x47 */ { NULL, NULL, 0 },
 724 /* 0x48 */ { NULL, NULL, 0 },
 725 /* 0x49 */ { NULL, NULL, 0 },
 726 /* 0x4a */ { NULL, NULL, 0 },
 727 /* 0x4b */ { NULL, NULL, 0 },
 728 /* 0x4c */ { NULL, NULL, 0 },
 729 /* 0x4d */ { NULL, NULL, 0 },
 730 /* 0x4e */ { NULL, NULL, 0 },
 731 /* 0x4f */ { NULL, NULL, 0 },
 732 /* 0x50 */ { NULL, NULL, 0 },
 733 /* 0x51 */ { NULL, NULL, 0 },
 734 /* 0x52 */ { NULL, NULL, 0 },
 735 /* 0x53 */ { NULL, NULL, 0 },
 736 /* 0x54 */ { NULL, NULL, 0 },
 737 /* 0x55 */ { NULL, NULL, 0 },
 738 /* 0x56 */ { NULL, NULL, 0 },
 739 /* 0x57 */ { NULL, NULL, 0 },
 740 /* 0x58 */ { NULL, NULL, 0 },
 741 /* 0x59 */ { NULL, NULL, 0 },
 742 /* 0x5a */ { NULL, NULL, 0 },
 743 /* 0x5b */ { NULL, NULL, 0 },
 744 /* 0x5c */ { NULL, NULL, 0 },
 745 /* 0x5d */ { NULL, NULL, 0 },
 746 /* 0x5e */ { NULL, NULL, 0 },
 747 /* 0x5f */ { NULL, NULL, 0 },
 748 /* 0x60 */ { NULL, NULL, 0 },
 749 /* 0x61 */ { NULL, NULL, 0 },
 750 /* 0x62 */ { NULL, NULL, 0 },
 751 /* 0x63 */ { NULL, NULL, 0 },
 752 /* 0x64 */ { NULL, NULL, 0 },
 753 /* 0x65 */ { NULL, NULL, 0 },
 754 /* 0x66 */ { NULL, NULL, 0 },
 755 /* 0x67 */ { NULL, NULL, 0 },
 756 /* 0x68 */ { NULL, NULL, 0 },
 757 /* 0x69 */ { NULL, NULL, 0 },
 758 /* 0x6a */ { NULL, NULL, 0 },
 759 /* 0x6b */ { NULL, NULL, 0 },
 760 /* 0x6c */ { NULL, NULL, 0 },
 761 /* 0x6d */ { NULL, NULL, 0 },
 762 /* 0x6e */ { NULL, NULL, 0 },
 763 /* 0x6f */ { NULL, NULL, 0 },
 764 /* 0x70 */ { "SMBtcon",reply_tcon,0},
 765 /* 0x71 */ { "SMBtdis",reply_tdis,DO_CHDIR},
 766 /* 0x72 */ { "SMBnegprot",reply_negprot,0},
 767 /* 0x73 */ { "SMBsesssetupX",reply_sesssetup_and_X,0},
 768 /* 0x74 */ { "SMBulogoffX",reply_ulogoffX, 0}, /* ulogoff doesn't give a valid TID */
 769 /* 0x75 */ { "SMBtconX",reply_tcon_and_X,0},
 770 /* 0x76 */ { NULL, NULL, 0 },
 771 /* 0x77 */ { NULL, NULL, 0 },
 772 /* 0x78 */ { NULL, NULL, 0 },
 773 /* 0x79 */ { NULL, NULL, 0 },
 774 /* 0x7a */ { NULL, NULL, 0 },
 775 /* 0x7b */ { NULL, NULL, 0 },
 776 /* 0x7c */ { NULL, NULL, 0 },
 777 /* 0x7d */ { NULL, NULL, 0 },
 778 /* 0x7e */ { NULL, NULL, 0 },
 779 /* 0x7f */ { NULL, NULL, 0 },
 780 /* 0x80 */ { "SMBdskattr",reply_dskattr,AS_USER},
 781 /* 0x81 */ { "SMBsearch",reply_search,AS_USER},
 782 /* 0x82 */ { "SMBffirst",reply_search,AS_USER},
 783 /* 0x83 */ { "SMBfunique",reply_search,AS_USER},
 784 /* 0x84 */ { "SMBfclose",reply_fclose,AS_USER},
 785 /* 0x85 */ { NULL, NULL, 0 },
 786 /* 0x86 */ { NULL, NULL, 0 },
 787 /* 0x87 */ { NULL, NULL, 0 },
 788 /* 0x88 */ { NULL, NULL, 0 },
 789 /* 0x89 */ { NULL, NULL, 0 },
 790 /* 0x8a */ { NULL, NULL, 0 },
 791 /* 0x8b */ { NULL, NULL, 0 },
 792 /* 0x8c */ { NULL, NULL, 0 },
 793 /* 0x8d */ { NULL, NULL, 0 },
 794 /* 0x8e */ { NULL, NULL, 0 },
 795 /* 0x8f */ { NULL, NULL, 0 },
 796 /* 0x90 */ { NULL, NULL, 0 },
 797 /* 0x91 */ { NULL, NULL, 0 },
 798 /* 0x92 */ { NULL, NULL, 0 },
 799 /* 0x93 */ { NULL, NULL, 0 },
 800 /* 0x94 */ { NULL, NULL, 0 },
 801 /* 0x95 */ { NULL, NULL, 0 },
 802 /* 0x96 */ { NULL, NULL, 0 },
 803 /* 0x97 */ { NULL, NULL, 0 },
 804 /* 0x98 */ { NULL, NULL, 0 },
 805 /* 0x99 */ { NULL, NULL, 0 },
 806 /* 0x9a */ { NULL, NULL, 0 },
 807 /* 0x9b */ { NULL, NULL, 0 },
 808 /* 0x9c */ { NULL, NULL, 0 },
 809 /* 0x9d */ { NULL, NULL, 0 },
 810 /* 0x9e */ { NULL, NULL, 0 },
 811 /* 0x9f */ { NULL, NULL, 0 },
 812 /* 0xa0 */ { "SMBnttrans",reply_nttrans, AS_USER | CAN_IPC },
 813 /* 0xa1 */ { "SMBnttranss",reply_nttranss, AS_USER | CAN_IPC },
 814 /* 0xa2 */ { "SMBntcreateX",reply_ntcreate_and_X, AS_USER | CAN_IPC },
 815 /* 0xa3 */ { NULL, NULL, 0 },
 816 /* 0xa4 */ { "SMBntcancel",reply_ntcancel, 0 },
 817 /* 0xa5 */ { "SMBntrename",reply_ntrename, AS_USER | NEED_WRITE },
 818 /* 0xa6 */ { NULL, NULL, 0 },
 819 /* 0xa7 */ { NULL, NULL, 0 },
 820 /* 0xa8 */ { NULL, NULL, 0 },
 821 /* 0xa9 */ { NULL, NULL, 0 },
 822 /* 0xaa */ { NULL, NULL, 0 },
 823 /* 0xab */ { NULL, NULL, 0 },
 824 /* 0xac */ { NULL, NULL, 0 },
 825 /* 0xad */ { NULL, NULL, 0 },
 826 /* 0xae */ { NULL, NULL, 0 },
 827 /* 0xaf */ { NULL, NULL, 0 },
 828 /* 0xb0 */ { NULL, NULL, 0 },
 829 /* 0xb1 */ { NULL, NULL, 0 },
 830 /* 0xb2 */ { NULL, NULL, 0 },
 831 /* 0xb3 */ { NULL, NULL, 0 },
 832 /* 0xb4 */ { NULL, NULL, 0 },
 833 /* 0xb5 */ { NULL, NULL, 0 },
 834 /* 0xb6 */ { NULL, NULL, 0 },
 835 /* 0xb7 */ { NULL, NULL, 0 },
 836 /* 0xb8 */ { NULL, NULL, 0 },
 837 /* 0xb9 */ { NULL, NULL, 0 },
 838 /* 0xba */ { NULL, NULL, 0 },
 839 /* 0xbb */ { NULL, NULL, 0 },
 840 /* 0xbc */ { NULL, NULL, 0 },
 841 /* 0xbd */ { NULL, NULL, 0 },
 842 /* 0xbe */ { NULL, NULL, 0 },
 843 /* 0xbf */ { NULL, NULL, 0 },
 844 /* 0xc0 */ { "SMBsplopen",reply_printopen,AS_USER},
 845 /* 0xc1 */ { "SMBsplwr",reply_printwrite,AS_USER},
 846 /* 0xc2 */ { "SMBsplclose",reply_printclose,AS_USER},
 847 /* 0xc3 */ { "SMBsplretq",reply_printqueue,AS_USER},
 848 /* 0xc4 */ { NULL, NULL, 0 },
 849 /* 0xc5 */ { NULL, NULL, 0 },
 850 /* 0xc6 */ { NULL, NULL, 0 },
 851 /* 0xc7 */ { NULL, NULL, 0 },
 852 /* 0xc8 */ { NULL, NULL, 0 },
 853 /* 0xc9 */ { NULL, NULL, 0 },
 854 /* 0xca */ { NULL, NULL, 0 },
 855 /* 0xcb */ { NULL, NULL, 0 },
 856 /* 0xcc */ { NULL, NULL, 0 },
 857 /* 0xcd */ { NULL, NULL, 0 },
 858 /* 0xce */ { NULL, NULL, 0 },
 859 /* 0xcf */ { NULL, NULL, 0 },
 860 /* 0xd0 */ { "SMBsends",reply_sends,AS_GUEST},
 861 /* 0xd1 */ { "SMBsendb", NULL,AS_GUEST},
 862 /* 0xd2 */ { "SMBfwdname", NULL,AS_GUEST},
 863 /* 0xd3 */ { "SMBcancelf", NULL,AS_GUEST},
 864 /* 0xd4 */ { "SMBgetmac", NULL,AS_GUEST},
 865 /* 0xd5 */ { "SMBsendstrt",reply_sendstrt,AS_GUEST},
 866 /* 0xd6 */ { "SMBsendend",reply_sendend,AS_GUEST},
 867 /* 0xd7 */ { "SMBsendtxt",reply_sendtxt,AS_GUEST},
 868 /* 0xd8 */ { NULL, NULL, 0 },
 869 /* 0xd9 */ { NULL, NULL, 0 },
 870 /* 0xda */ { NULL, NULL, 0 },
 871 /* 0xdb */ { NULL, NULL, 0 },
 872 /* 0xdc */ { NULL, NULL, 0 },
 873 /* 0xdd */ { NULL, NULL, 0 },
 874 /* 0xde */ { NULL, NULL, 0 },
 875 /* 0xdf */ { NULL, NULL, 0 },
 876 /* 0xe0 */ { NULL, NULL, 0 },
 877 /* 0xe1 */ { NULL, NULL, 0 },
 878 /* 0xe2 */ { NULL, NULL, 0 },
 879 /* 0xe3 */ { NULL, NULL, 0 },
 880 /* 0xe4 */ { NULL, NULL, 0 },
 881 /* 0xe5 */ { NULL, NULL, 0 },
 882 /* 0xe6 */ { NULL, NULL, 0 },
 883 /* 0xe7 */ { NULL, NULL, 0 },
 884 /* 0xe8 */ { NULL, NULL, 0 },
 885 /* 0xe9 */ { NULL, NULL, 0 },
 886 /* 0xea */ { NULL, NULL, 0 },
 887 /* 0xeb */ { NULL, NULL, 0 },
 888 /* 0xec */ { NULL, NULL, 0 },
 889 /* 0xed */ { NULL, NULL, 0 },
 890 /* 0xee */ { NULL, NULL, 0 },
 891 /* 0xef */ { NULL, NULL, 0 },
 892 /* 0xf0 */ { NULL, NULL, 0 },
 893 /* 0xf1 */ { NULL, NULL, 0 },
 894 /* 0xf2 */ { NULL, NULL, 0 },
 895 /* 0xf3 */ { NULL, NULL, 0 },
 896 /* 0xf4 */ { NULL, NULL, 0 },
 897 /* 0xf5 */ { NULL, NULL, 0 },
 898 /* 0xf6 */ { NULL, NULL, 0 },
 899 /* 0xf7 */ { NULL, NULL, 0 },
 900 /* 0xf8 */ { NULL, NULL, 0 },
 901 /* 0xf9 */ { NULL, NULL, 0 },
 902 /* 0xfa */ { NULL, NULL, 0 },
 903 /* 0xfb */ { NULL, NULL, 0 },
 904 /* 0xfc */ { NULL, NULL, 0 },
 905 /* 0xfd */ { NULL, NULL, 0 },
 906 /* 0xfe */ { NULL, NULL, 0 },
 907 /* 0xff */ { NULL, NULL, 0 }
 908
 909 };
 910
 911 /*******************************************************************
 912  allocate and initialize a reply packet
 913 ********************************************************************/
 914
 915 void reply_outbuf(struct smb_request *req, uint8 num_words, uint32 num_bytes)
 916 {
 917         /*
 918          * Protect against integer wrap
 919          */
 920         if ((num_bytes > 0xffffff)
 921             || ((num_bytes + smb_size + num_words*2) > 0xffffff)) {
 922                 char *msg;
 923                 asprintf(&msg, "num_bytes too large: %u",
 924                          (unsigned)num_bytes);
 925                 smb_panic(msg);
 926         }
 927
 928         if (!(req->outbuf = TALLOC_ARRAY(
 929                       req, uint8,
 930                       smb_size + num_words*2 + num_bytes))) {
 931                 smb_panic("could not allocate output buffer\n");
 932         }
 933
 934         construct_reply_common((char *)req->inbuf, (char *)req->outbuf);
 935         set_message((char *)req->outbuf, num_words, num_bytes, False);
 936         /*
 937          * Zero out the word area, the caller has to take care of the bcc area
 938          * himself
 939          */
 940         if (num_words != 0) {
 941                 memset(req->outbuf + smb_vwv0, 0, num_words*2);
 942         }
 943
 944         return;
 945 }
 946
 947
 948 /*******************************************************************
 949  Dump a packet to a file.
 950 ********************************************************************/
 951
 952 static void smb_dump(const char *name, int type, const char *data, ssize_t len)
 953 {
 954         int fd, i;
 955         pstring fname;
 956         if (DEBUGLEVEL < 50) return;
 957
 958         if (len < 4) len = smb_len(data)+4;
 959         for (i=1;i<100;i++) {
 960                 slprintf(fname,sizeof(fname)-1, "/tmp/%s.%d.%s", name, i,
 961                                 type ? "req" : "resp");
 962                 fd = open(fname, O_WRONLY|O_CREAT|O_EXCL, 0644);
 963                 if (fd != -1 || errno != EEXIST) break;
 964         }
 965         if (fd != -1) {
 966                 ssize_t ret = write(fd, data, len);
 967                 if (ret != len)
 968                         DEBUG(0,("smb_dump: problem: write returned %d\n", (int)ret ));
 969                 close(fd);
 970                 DEBUG(0,("created %s len %lu\n", fname, (unsigned long)len));
 971         }
 972 }
 973
 974 /****************************************************************************
 975  Prepare everything for calling the actual request function, and potentially
 976  call the request function via the "new" interface.
 977
 978  Return False if the "legacy" function needs to be called, everything is
 979  prepared.
 980
 981  Return True if we're done.
 982
 983  I know this API sucks, but it is the one with the least code change I could
 984  find.
 985 ****************************************************************************/
 986
 987 static void switch_message(uint8 type, struct smb_request *req, int size)
 988 {
 989         int flags;
 990         uint16 session_tag;
 991         connection_struct *conn;
 992
 993         static uint16 last_session_tag = UID_FIELD_INVALID;
 994
 995         errno = 0;
 996
 997         last_message = type;
 998
 999         /* Make sure this is an SMB packet. smb_size contains NetBIOS header
1000          * so subtract 4 from it. */
1001         if ((strncmp(smb_base(req->inbuf),"\377SMB",4) != 0)
1002             || (size < (smb_size - 4))) {
1003                 DEBUG(2,("Non-SMB packet of length %d. Terminating server\n",
1004                          smb_len(req->inbuf)));
1005                 exit_server_cleanly("Non-SMB packet");
1006         }
1007
1008         if (smb_messages[type].fn_new == NULL) {
1009                 DEBUG(0,("Unknown message type %d!\n",type));
1010                 smb_dump("Unknown", 1, (char *)req->inbuf, size);
1011                 reply_unknown_new(req, type);
1012                 return;
1013         }
1014
1015         flags = smb_messages[type].flags;
1016
1017         /* In share mode security we must ignore the vuid. */
1018         session_tag = (lp_security() == SEC_SHARE)
1019                 ? UID_FIELD_INVALID : req->vuid;
1020         conn = conn_find(req->tid);
1021
1022         DEBUG(3,("switch message %s (pid %d) conn 0x%lx\n", smb_fn_name(type),
1023                  (int)sys_getpid(), (unsigned long)conn));
1024
1025         smb_dump(smb_fn_name(type), 1, (char *)req->inbuf, size);
1026
1027         /* Ensure this value is replaced in the incoming packet. */
1028         SSVAL(req->inbuf,smb_uid,session_tag);
1029
1030         /*
1031          * Ensure the correct username is in current_user_info.  This is a
1032          * really ugly bugfix for problems with multiple session_setup_and_X's
1033          * being done and allowing %U and %G substitutions to work correctly.
1034          * There is a reason this code is done here, don't move it unless you
1035          * know what you're doing... :-).
1036          * JRA.
1037          */
1038
1039         if (session_tag != last_session_tag) {
1040                 user_struct *vuser = NULL;
1041
1042                 last_session_tag = session_tag;
1043                 if(session_tag != UID_FIELD_INVALID) {
1044                         vuser = get_valid_user_struct(session_tag);
1045                         if (vuser) {
1046                                 set_current_user_info(&vuser->user);
1047                         }
1048                 }
1049         }
1050
1051         /* Does this call need to be run as the connected user? */
1052         if (flags & AS_USER) {
1053
1054                 /* Does this call need a valid tree connection? */
1055                 if (!conn) {
1056                         /*
1057                          * Amazingly, the error code depends on the command
1058                          * (from Samba4).
1059                          */
1060                         if (type == SMBntcreateX) {
1061                                 reply_nterror(req, NT_STATUS_INVALID_HANDLE);
1062                         } else {
1063                                 reply_doserror(req, ERRSRV, ERRinvnid);
1064                         }
1065                         return;
1066                 }
1067
1068                 if (!change_to_user(conn,session_tag)) {
1069                         reply_nterror(req, NT_STATUS_DOS(ERRSRV, ERRbaduid));
1070                         return;
1071                 }
1072
1073                 /* All NEED_WRITE and CAN_IPC flags must also have AS_USER. */
1074
1075                 /* Does it need write permission? */
1076                 if ((flags & NEED_WRITE) && !CAN_WRITE(conn)) {
1077                         reply_nterror(req, NT_STATUS_MEDIA_WRITE_PROTECTED);
1078                         return;
1079                 }
1080
1081                 /* IPC services are limited */
1082                 if (IS_IPC(conn) && !(flags & CAN_IPC)) {
1083                         reply_doserror(req, ERRSRV,ERRaccess);
1084                         return;
1085                 }
1086         } else {
1087                 /* This call needs to be run as root */
1088                 change_to_root_user();
1089         }
1090
1091         /* load service specific parameters */
1092         if (conn) {
1093                 if (!set_current_service(conn,SVAL(req->inbuf,smb_flg),
1094                                          (flags & (AS_USER|DO_CHDIR)
1095                                           ?True:False))) {
1096                         reply_doserror(req, ERRSRV, ERRaccess);
1097                         return;
1098                 }
1099                 conn->num_smb_operations++;
1100         }
1101
1102         /* does this protocol need to be run as guest? */
1103         if ((flags & AS_GUEST)
1104             && (!change_to_guest() ||
1105                 !check_access(smbd_server_fd(), lp_hostsallow(-1),
1106                               lp_hostsdeny(-1)))) {
1107                 reply_doserror(req, ERRSRV, ERRaccess);
1108                 return;
1109         }
1110
1111         smb_messages[type].fn_new(conn, req);
1112 }
1113
1114 /****************************************************************************
1115  Construct a reply to the incoming packet.
1116 ****************************************************************************/
1117
1118 static void construct_reply(char *inbuf, int size)
1119 {
1120         uint8 type = CVAL(inbuf,smb_com);
1121         struct smb_request *req;
1122
1123         chain_size = 0;
1124         file_chain_reset();
1125         reset_chain_p();
1126
1127         if (!(req = talloc(talloc_tos(), struct smb_request))) {
1128                 smb_panic("could not allocate smb_request");
1129         }
1130         init_smb_request(req, (uint8 *)inbuf);
1131
1132         switch_message(type, req, size);
1133
1134         if (req->outbuf == NULL) {
1135                 return;
1136         }
1137
1138         if (CVAL(req->outbuf,0) == 0) {
1139                 show_msg((char *)req->outbuf);
1140         }
1141
1142         if (!send_smb(smbd_server_fd(), (char *)req->outbuf)) {
1143                 exit_server_cleanly("construct_reply: send_smb failed.");
1144         }
1145
1146         TALLOC_FREE(req);
1147
1148         return;
1149 }
1150
1151 /****************************************************************************
1152  Process an smb from the client
1153 ****************************************************************************/
1154
1155 static void process_smb(char *inbuf, size_t nread)
1156 {
1157         static int trans_num;
1158         int msg_type = CVAL(inbuf,0);
1159
1160         DO_PROFILE_INC(smb_count);
1161
1162         if (trans_num == 0) {
1163                 /* on the first packet, check the global hosts allow/ hosts
1164                 deny parameters before doing any parsing of the packet
1165                 passed to us by the client.  This prevents attacks on our
1166                 parsing code from hosts not in the hosts allow list */
1167                 if (!check_access(smbd_server_fd(), lp_hostsallow(-1),
1168                                   lp_hostsdeny(-1))) {
1169                         /* send a negative session response "not listening on calling name" */
1170                         static unsigned char buf[5] = {0x83, 0, 0, 1, 0x81};
1171                         DEBUG( 1, ( "Connection denied from %s\n", client_addr() ) );
1172                         (void)send_smb(smbd_server_fd(),(char *)buf);
1173                         exit_server_cleanly("connection denied");
1174                 }
1175         }
1176
1177         DEBUG( 6, ( "got message type 0x%x of len 0x%x\n", msg_type,
1178                     smb_len(inbuf) ) );
1179         DEBUG( 3, ( "Transaction %d of length %d\n", trans_num, (int)nread ) );
1180
1181         if (msg_type != 0) {
1182                 /*
1183                  * NetBIOS session request, keepalive, etc.
1184                  */
1185                 reply_special(inbuf);
1186                 return;
1187         }
1188
1189         show_msg(inbuf);
1190
1191         construct_reply(inbuf,nread);
1192
1193         trans_num++;
1194 }
1195
1196 /****************************************************************************
1197  Return a string containing the function name of a SMB command.
1198 ****************************************************************************/
1199
1200 const char *smb_fn_name(int type)
1201 {
1202         const char *unknown_name = "SMBunknown";
1203
1204         if (smb_messages[type].name == NULL)
1205                 return(unknown_name);
1206
1207         return(smb_messages[type].name);
1208 }
1209
1210 /****************************************************************************
1211  Helper functions for contruct_reply.
1212 ****************************************************************************/
1213
1214 static uint32 common_flags2 = FLAGS2_LONG_PATH_COMPONENTS|FLAGS2_32_BIT_ERROR_CODES;
1215
1216 void add_to_common_flags2(uint32 v)
1217 {
1218         common_flags2 |= v;
1219 }
1220
1221 void remove_from_common_flags2(uint32 v)
1222 {
1223         common_flags2 &= ~v;
1224 }
1225
1226 void construct_reply_common(const char *inbuf, char *outbuf)
1227 {
1228         set_message(outbuf,0,0,False);
1229
1230         SCVAL(outbuf,smb_com,CVAL(inbuf,smb_com));
1231         SIVAL(outbuf,smb_rcls,0);
1232         SCVAL(outbuf,smb_flg, FLAG_REPLY | (CVAL(inbuf,smb_flg) & FLAG_CASELESS_PATHNAMES));
1233         SSVAL(outbuf,smb_flg2,
1234                 (SVAL(inbuf,smb_flg2) & FLAGS2_UNICODE_STRINGS) |
1235                 common_flags2);
1236         memset(outbuf+smb_pidhigh,'\0',(smb_tid-smb_pidhigh));
1237
1238         SSVAL(outbuf,smb_tid,SVAL(inbuf,smb_tid));
1239         SSVAL(outbuf,smb_pid,SVAL(inbuf,smb_pid));
1240         SSVAL(outbuf,smb_uid,SVAL(inbuf,smb_uid));
1241         SSVAL(outbuf,smb_mid,SVAL(inbuf,smb_mid));
1242 }
1243
1244 /****************************************************************************
1245  Construct a chained reply and add it to the already made reply
1246 ****************************************************************************/
1247
1248 void chain_reply(struct smb_request *req)
1249 {
1250         static char *orig_inbuf;
1251
1252         /*
1253          * Dirty little const_discard: We mess with req->inbuf, which is
1254          * declared as const. If maybe at some point this routine gets
1255          * rewritten, this const_discard could go away.
1256          */
1257         char *inbuf = CONST_DISCARD(char *, req->inbuf);
1258         int size = smb_len(req->inbuf)+4;
1259
1260         int smb_com1, smb_com2 = CVAL(inbuf,smb_vwv0);
1261         unsigned smb_off2 = SVAL(inbuf,smb_vwv1);
1262         char *inbuf2;
1263         int outsize2;
1264         int new_size;
1265         char inbuf_saved[smb_wct];
1266         char *outbuf = (char *)req->outbuf;
1267         size_t outsize = smb_len(outbuf) + 4;
1268         size_t outsize_padded;
1269         size_t ofs, to_move;
1270
1271         struct smb_request *req2;
1272         size_t caller_outputlen;
1273         char *caller_output;
1274
1275         /* Maybe its not chained, or it's an error packet. */
1276         if (smb_com2 == 0xFF || SVAL(outbuf,smb_rcls) != 0) {
1277                 SCVAL(outbuf,smb_vwv0,0xFF);
1278                 return;
1279         }
1280
1281         if (chain_size == 0) {
1282                 /* this is the first part of the chain */
1283                 orig_inbuf = inbuf;
1284         }
1285
1286         /*
1287          * We need to save the output the caller added to the chain so that we
1288          * can splice it into the final output buffer later.
1289          */
1290
1291         caller_outputlen = outsize - smb_wct;
1292
1293         caller_output = (char *)memdup(outbuf + smb_wct, caller_outputlen);
1294
1295         if (caller_output == NULL) {
1296                 /* TODO: NT_STATUS_NO_MEMORY */
1297                 smb_panic("could not dup outbuf");
1298         }
1299
1300         /*
1301          * The original Win95 redirector dies on a reply to
1302          * a lockingX and read chain unless the chain reply is
1303          * 4 byte aligned. JRA.
1304          */
1305
1306         outsize_padded = (outsize + 3) & ~3;
1307
1308         /*
1309          * remember how much the caller added to the chain, only counting
1310          * stuff after the parameter words
1311          */
1312         chain_size += outsize_padded - smb_wct;
1313
1314         /*
1315          * work out pointers into the original packets. The
1316          * headers on these need to be filled in
1317          */
1318         inbuf2 = orig_inbuf + smb_off2 + 4 - smb_wct;
1319
1320         /* remember the original command type */
1321         smb_com1 = CVAL(orig_inbuf,smb_com);
1322
1323         /* save the data which will be overwritten by the new headers */
1324         memcpy(inbuf_saved,inbuf2,smb_wct);
1325
1326         /* give the new packet the same header as the last part of the SMB */
1327         memmove(inbuf2,inbuf,smb_wct);
1328
1329         /* create the in buffer */
1330         SCVAL(inbuf2,smb_com,smb_com2);
1331
1332         /* work out the new size for the in buffer. */
1333         new_size = size - (inbuf2 - inbuf);
1334         if (new_size < 0) {
1335                 DEBUG(0,("chain_reply: chain packet size incorrect "
1336                          "(orig size = %d, offset = %d)\n",
1337                          size, (int)(inbuf2 - inbuf) ));
1338                 exit_server_cleanly("Bad chained packet");
1339                 return;
1340         }
1341
1342         /* And set it in the header. */
1343         smb_setlen(inbuf2, new_size - 4);
1344
1345         DEBUG(3,("Chained message\n"));
1346         show_msg(inbuf2);
1347
1348         if (!(req2 = talloc(talloc_tos(), struct smb_request))) {
1349                 smb_panic("could not allocate smb_request");
1350         }
1351         init_smb_request(req2, (uint8 *)inbuf2);
1352
1353         /* process the request */
1354         switch_message(smb_com2, req2, new_size);
1355
1356         /*
1357          * We don't accept deferred operations in chained requests.
1358          */
1359         SMB_ASSERT(req2->outbuf != NULL);
1360         outsize2 = smb_len(req2->outbuf)+4;
1361
1362         /*
1363          * Move away the new command output so that caller_output fits in,
1364          * copy in the caller_output saved above.
1365          */
1366
1367         SMB_ASSERT(outsize_padded >= smb_wct);
1368
1369         /*
1370          * "ofs" is the space we need for caller_output. Equal to
1371          * caller_outputlen plus the padding.
1372          */
1373
1374         ofs = outsize_padded - smb_wct;
1375
1376         /*
1377          * "to_move" is the amount of bytes the secondary routine gave us
1378          */
1379
1380         to_move = outsize2 - smb_wct;
1381
1382         if (to_move + ofs + smb_wct + chain_size > max_send) {
1383                 smb_panic("replies too large -- would have to cut");
1384         }
1385
1386         /*
1387          * In the "new" API "outbuf" is allocated via reply_outbuf, just for
1388          * the first request in the chain. So we have to re-allocate it. In
1389          * the "old" API the only outbuf ever used is the global OutBuffer
1390          * which is always large enough.
1391          */
1392
1393         outbuf = TALLOC_REALLOC_ARRAY(NULL, outbuf, char,
1394                                       to_move + ofs + smb_wct);
1395         if (outbuf == NULL) {
1396                 smb_panic("could not realloc outbuf");
1397         }
1398
1399         req->outbuf = (uint8 *)outbuf;
1400
1401         memmove(outbuf + smb_wct + ofs, req2->outbuf + smb_wct, to_move);
1402         memcpy(outbuf + smb_wct, caller_output, caller_outputlen);
1403
1404         /*
1405          * copy the new reply header over the old one but preserve the smb_com
1406          * field
1407          */
1408         memmove(outbuf, req2->outbuf, smb_wct);
1409         SCVAL(outbuf, smb_com, smb_com1);
1410
1411         /*
1412          * We've just copied in the whole "wct" area from the secondary
1413          * function. Fix up the chaining: com2 and the offset need to be
1414          * readjusted.
1415          */
1416
1417         SCVAL(outbuf, smb_vwv0, smb_com2);
1418         SSVAL(outbuf, smb_vwv1, chain_size + smb_wct - 4);
1419
1420         if (outsize_padded > outsize) {
1421
1422                 /*
1423                  * Due to padding we have some uninitialized bytes after the
1424                  * caller's output
1425                  */
1426
1427                 memset(outbuf + outsize, 0, outsize_padded - outsize);
1428         }
1429
1430         smb_setlen(outbuf, outsize2 + chain_size - 4);
1431
1432         /*
1433          * restore the saved data, being careful not to overwrite any data
1434          * from the reply header
1435          */
1436         memcpy(inbuf2,inbuf_saved,smb_wct);
1437
1438         SAFE_FREE(caller_output);
1439         TALLOC_FREE(req2);
1440
1441         return;
1442 }
1443
1444 /****************************************************************************
1445  Setup the needed select timeout in milliseconds.
1446 ****************************************************************************/
1447
1448 static int setup_select_timeout(void)
1449 {
1450         int select_timeout;
1451
1452         select_timeout = SMBD_SELECT_TIMEOUT*1000;
1453
1454         if (print_notify_messages_pending()) {
1455                 select_timeout = MIN(select_timeout, 1000);
1456         }
1457
1458         return select_timeout;
1459 }
1460
1461 /****************************************************************************
1462  Check if services need reloading.
1463 ****************************************************************************/
1464
1465 void check_reload(time_t t)
1466 {
1467         static pid_t mypid = 0;
1468         static time_t last_smb_conf_reload_time = 0;
1469         static time_t last_printer_reload_time = 0;
1470         time_t printcap_cache_time = (time_t)lp_printcap_cache_time();
1471
1472         if(last_smb_conf_reload_time == 0) {
1473                 last_smb_conf_reload_time = t;
1474                 /* Our printing subsystem might not be ready at smbd start up.
1475                    Then no printer is available till the first printers check
1476                    is performed.  A lower initial interval circumvents this. */
1477                 if ( printcap_cache_time > 60 )
1478                         last_printer_reload_time = t - printcap_cache_time + 60;
1479                 else
1480                         last_printer_reload_time = t;
1481         }
1482
1483         if (mypid != getpid()) { /* First time or fork happened meanwhile */
1484                 /* randomize over 60 second the printcap reload to avoid all
1485                  * process hitting cupsd at the same time */
1486                 int time_range = 60;
1487
1488                 last_printer_reload_time += random() % time_range;
1489                 mypid = getpid();
1490         }
1491
1492         if (reload_after_sighup || (t >= last_smb_conf_reload_time+SMBD_RELOAD_CHECK)) {
1493                 reload_services(True);
1494                 reload_after_sighup = False;
1495                 last_smb_conf_reload_time = t;
1496         }
1497
1498         /* 'printcap cache time = 0' disable the feature */
1499
1500         if ( printcap_cache_time != 0 )
1501         {
1502                 /* see if it's time to reload or if the clock has been set back */
1503
1504                 if ( (t >= last_printer_reload_time+printcap_cache_time)
1505                         || (t-last_printer_reload_time  < 0) )
1506                 {
1507                         DEBUG( 3,( "Printcap cache time expired.\n"));
1508                         reload_printers();
1509                         last_printer_reload_time = t;
1510                 }
1511         }
1512 }
1513
1514 /****************************************************************************
1515  Process any timeout housekeeping. Return False if the caller should exit.
1516 ****************************************************************************/
1517
1518 static BOOL timeout_processing(int *select_timeout,
1519                                time_t *last_timeout_processing_time)
1520 {
1521         time_t t;
1522
1523         if (smb_read_error == READ_EOF) {
1524                 DEBUG(3,("timeout_processing: End of file from client (client has disconnected).\n"));
1525                 return False;
1526         }
1527
1528         if (smb_read_error == READ_ERROR) {
1529                 DEBUG(3,("timeout_processing: receive_smb error (%s) Exiting\n",
1530                         strerror(errno)));
1531                 return False;
1532         }
1533
1534         if (smb_read_error == READ_BAD_SIG) {
1535                 DEBUG(3,("timeout_processing: receive_smb error bad smb signature. Exiting\n"));
1536                 return False;
1537         }
1538
1539         *last_timeout_processing_time = t = time(NULL);
1540
1541         /* become root again if waiting */
1542         change_to_root_user();
1543
1544         /* check if we need to reload services */
1545         check_reload(t);
1546
1547         if(global_machine_password_needs_changing &&
1548                         /* for ADS we need to do a regular ADS password change, not a domain
1549                                         password change */
1550                         lp_security() == SEC_DOMAIN) {
1551
1552                 unsigned char trust_passwd_hash[16];
1553                 time_t lct;
1554
1555                 /*
1556                  * We're in domain level security, and the code that
1557                  * read the machine password flagged that the machine
1558                  * password needs changing.
1559                  */
1560
1561                 /*
1562                  * First, open the machine password file with an exclusive lock.
1563                  */
1564
1565                 if (secrets_lock_trust_account_password(lp_workgroup(), True) == False) {
1566                         DEBUG(0,("process: unable to lock the machine account password for \
1567 machine %s in domain %s.\n", global_myname(), lp_workgroup() ));
1568                         return True;
1569                 }
1570
1571                 if(!secrets_fetch_trust_account_password(lp_workgroup(), trust_passwd_hash, &lct, NULL)) {
1572                         DEBUG(0,("process: unable to read the machine account password for \
1573 machine %s in domain %s.\n", global_myname(), lp_workgroup()));
1574                         secrets_lock_trust_account_password(lp_workgroup(), False);
1575                         return True;
1576                 }
1577
1578                 /*
1579                  * Make sure someone else hasn't already done this.
1580                  */
1581
1582                 if(t < lct + lp_machine_password_timeout()) {
1583                         global_machine_password_needs_changing = False;
1584                         secrets_lock_trust_account_password(lp_workgroup(), False);
1585                         return True;
1586                 }
1587
1588                 /* always just contact the PDC here */
1589
1590                 change_trust_account_password( lp_workgroup(), NULL);
1591                 global_machine_password_needs_changing = False;
1592                 secrets_lock_trust_account_password(lp_workgroup(), False);
1593         }
1594
1595         /* update printer queue caches if necessary */
1596
1597         update_monitored_printq_cache();
1598
1599         /*
1600          * Now we are root, check if the log files need pruning.
1601          * Force a log file check.
1602          */
1603         force_check_log_size();
1604         check_log_size();
1605
1606         /* Send any queued printer notify message to interested smbd's. */
1607
1608         print_notify_send_messages(smbd_messaging_context(), 0);
1609
1610         /*
1611          * Modify the select timeout depending upon
1612          * what we have remaining in our queues.
1613          */
1614
1615         *select_timeout = setup_select_timeout();
1616
1617         return True;
1618 }
1619
1620 /****************************************************************************
1621  Process commands from the client
1622 ****************************************************************************/
1623
1624 void smbd_process(void)
1625 {
1626         time_t last_timeout_processing_time = time(NULL);
1627         unsigned int num_smbs = 0;
1628
1629         max_recv = MIN(lp_maxxmit(),BUFFER_SIZE);
1630
1631         while (True) {
1632                 int select_timeout = setup_select_timeout();
1633                 int num_echos;
1634                 char *inbuf;
1635                 size_t inbuf_len;
1636                 TALLOC_CTX *frame = talloc_stackframe();
1637
1638                 errno = 0;
1639
1640                 /* Did someone ask for immediate checks on things like blocking locks ? */
1641                 if (select_timeout == 0) {
1642                         if(!timeout_processing(&select_timeout,
1643                                                &last_timeout_processing_time))
1644                                 return;
1645                         num_smbs = 0; /* Reset smb counter. */
1646                 }
1647
1648                 run_events(smbd_event_context(), 0, NULL, NULL);
1649
1650                 while (!receive_message_or_smb(NULL, &inbuf, &inbuf_len,
1651                                                select_timeout)) {
1652                         if(!timeout_processing(&select_timeout,
1653                                                &last_timeout_processing_time))
1654                                 return;
1655                         num_smbs = 0; /* Reset smb counter. */
1656                 }
1657
1658
1659                 /*
1660                  * Ensure we do timeout processing if the SMB we just got was
1661                  * only an echo request. This allows us to set the select
1662                  * timeout in 'receive_message_or_smb()' to any value we like
1663                  * without worrying that the client will send echo requests
1664                  * faster than the select timeout, thus starving out the
1665                  * essential processing (change notify, blocking locks) that
1666                  * the timeout code does. JRA.
1667                  */
1668                 num_echos = smb_echo_count;
1669
1670                 process_smb(inbuf, inbuf_len);
1671
1672                 TALLOC_FREE(inbuf);
1673
1674                 if (smb_echo_count != num_echos) {
1675                         if(!timeout_processing( &select_timeout, &last_timeout_processing_time))
1676                                 return;
1677                         num_smbs = 0; /* Reset smb counter. */
1678                 }
1679
1680                 num_smbs++;
1681
1682                 /*
1683                  * If we are getting smb requests in a constant stream
1684                  * with no echos, make sure we attempt timeout processing
1685                  * every select_timeout milliseconds - but only check for this
1686                  * every 200 smb requests.
1687                  */
1688
1689                 if ((num_smbs % 200) == 0) {
1690                         time_t new_check_time = time(NULL);
1691                         if(new_check_time - last_timeout_processing_time >= (select_timeout/1000)) {
1692                                 if(!timeout_processing(
1693                                            &select_timeout,
1694                                            &last_timeout_processing_time))
1695                                         return;
1696                                 num_smbs = 0; /* Reset smb counter. */
1697                                 last_timeout_processing_time = new_check_time; /* Reset time. */
1698                         }
1699                 }
1700
1701                 /* The timeout_processing function isn't run nearly
1702                    often enough to implement 'max log size' without
1703                    overrunning the size of the file by many megabytes.
1704                    This is especially true if we are running at debug
1705                    level 10.  Checking every 50 SMBs is a nice
1706                    tradeoff of performance vs log file size overrun. */
1707
1708                 if ((num_smbs % 50) == 0 && need_to_check_log_size()) {
1709                         change_to_root_user();
1710                         check_log_size();
1711                 }
1712                 TALLOC_FREE(frame);
1713         }
1714 }