fs/cifs/transport.c

   1 /*
   2  *   fs/cifs/transport.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2008
   5  *   Author(s): Steve French (sfrench@us.ibm.com)
   6  *   Jeremy Allison (jra@samba.org) 2006.
   7  *
   8  *   This library is free software; you can redistribute it and/or modify
   9  *   it under the terms of the GNU Lesser General Public License as published
  10  *   by the Free Software Foundation; either version 2.1 of the License, or
  11  *   (at your option) any later version.
  12  *
  13  *   This library is distributed in the hope that it will be useful,
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  16  *   the GNU Lesser General Public License for more details.
  17  *
  18  *   You should have received a copy of the GNU Lesser General Public License
  19  *   along with this library; if not, write to the Free Software
  20  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  21  */
  22
  23 #include <linux/fs.h>
  24 #include <linux/list.h>
  25 #include <linux/gfp.h>
  26 #include <linux/wait.h>
  27 #include <linux/net.h>
  28 #include <linux/delay.h>
  29 #include <asm/uaccess.h>
  30 #include <asm/processor.h>
  31 #include <linux/mempool.h>
  32 #include "cifspdu.h"
  33 #include "cifsglob.h"
  34 #include "cifsproto.h"
  35 #include "cifs_debug.h"
  36
  37 extern mempool_t *cifs_mid_poolp;
  38
  39 static void
  40 wake_up_task(struct mid_q_entry *mid)
  41 {
  42         wake_up_process(mid->callback_data);
  43 }
  44
  45 struct mid_q_entry *
  46 AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
  47 {
  48         struct mid_q_entry *temp;
  49
  50         if (server == NULL) {
  51                 cERROR(1, "Null TCP session in AllocMidQEntry");
  52                 return NULL;
  53         }
  54
  55         temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
  56         if (temp == NULL)
  57                 return temp;
  58         else {
  59                 memset(temp, 0, sizeof(struct mid_q_entry));
  60                 temp->mid = smb_buffer->Mid;    /* always LE */
  61                 temp->pid = current->pid;
  62                 temp->command = smb_buffer->Command;
  63                 cFYI(1, "For smb_command %d", temp->command);
  64         /*      do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
  65                 /* when mid allocated can be before when sent */
  66                 temp->when_alloc = jiffies;
  67
  68                 /*
  69                  * The default is for the mid to be synchronous, so the
  70                  * default callback just wakes up the current task.
  71                  */
  72                 temp->callback = wake_up_task;
  73                 temp->callback_data = current;
  74         }
  75
  76         atomic_inc(&midCount);
  77         temp->midState = MID_REQUEST_ALLOCATED;
  78         return temp;
  79 }
  80
  81 void
  82 DeleteMidQEntry(struct mid_q_entry *midEntry)
  83 {
  84 #ifdef CONFIG_CIFS_STATS2
  85         unsigned long now;
  86 #endif
  87         midEntry->midState = MID_FREE;
  88         atomic_dec(&midCount);
  89         if (midEntry->largeBuf)
  90                 cifs_buf_release(midEntry->resp_buf);
  91         else
  92                 cifs_small_buf_release(midEntry->resp_buf);
  93 #ifdef CONFIG_CIFS_STATS2
  94         now = jiffies;
  95         /* commands taking longer than one second are indications that
  96            something is wrong, unless it is quite a slow link or server */
  97         if ((now - midEntry->when_alloc) > HZ) {
  98                 if ((cifsFYI & CIFS_TIMER) &&
  99                    (midEntry->command != SMB_COM_LOCKING_ANDX)) {
 100                         printk(KERN_DEBUG " CIFS slow rsp: cmd %d mid %d",
 101                                midEntry->command, midEntry->mid);
 102                         printk(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
 103                                now - midEntry->when_alloc,
 104                                now - midEntry->when_sent,
 105                                now - midEntry->when_received);
 106                 }
 107         }
 108 #endif
 109         mempool_free(midEntry, cifs_mid_poolp);
 110 }
 111
 112 static void
 113 delete_mid(struct mid_q_entry *mid)
 114 {
 115         spin_lock(&GlobalMid_Lock);
 116         list_del(&mid->qhead);
 117         spin_unlock(&GlobalMid_Lock);
 118
 119         DeleteMidQEntry(mid);
 120 }
 121
 122 static int
 123 smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
 124 {
 125         int rc = 0;
 126         int i = 0;
 127         struct msghdr smb_msg;
 128         struct smb_hdr *smb_buffer = iov[0].iov_base;
 129         unsigned int len = iov[0].iov_len;
 130         unsigned int total_len;
 131         int first_vec = 0;
 132         unsigned int smb_buf_length = smb_buffer->smb_buf_length;
 133         struct socket *ssocket = server->ssocket;
 134
 135         if (ssocket == NULL)
 136                 return -ENOTSOCK; /* BB eventually add reconnect code here */
 137
 138         smb_msg.msg_name = (struct sockaddr *) &server->dstaddr;
 139         smb_msg.msg_namelen = sizeof(struct sockaddr);
 140         smb_msg.msg_control = NULL;
 141         smb_msg.msg_controllen = 0;
 142         if (server->noblocksnd)
 143                 smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
 144         else
 145                 smb_msg.msg_flags = MSG_NOSIGNAL;
 146
 147         /* smb header is converted in header_assemble. bcc and rest of SMB word
 148            area, and byte area if necessary, is converted to littleendian in
 149            cifssmb.c and RFC1001 len is converted to bigendian in smb_send
 150            Flags2 is converted in SendReceive */
 151
 152
 153         total_len = 0;
 154         for (i = 0; i < n_vec; i++)
 155                 total_len += iov[i].iov_len;
 156
 157         smb_buffer->smb_buf_length = cpu_to_be32(smb_buffer->smb_buf_length);
 158         cFYI(1, "Sending smb:  total_len %d", total_len);
 159         dump_smb(smb_buffer, len);
 160
 161         i = 0;
 162         while (total_len) {
 163                 rc = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec],
 164                                     n_vec - first_vec, total_len);
 165                 if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
 166                         i++;
 167                         /* if blocking send we try 3 times, since each can block
 168                            for 5 seconds. For nonblocking  we have to try more
 169                            but wait increasing amounts of time allowing time for
 170                            socket to clear.  The overall time we wait in either
 171                            case to send on the socket is about 15 seconds.
 172                            Similarly we wait for 15 seconds for
 173                            a response from the server in SendReceive[2]
 174                            for the server to send a response back for
 175                            most types of requests (except SMB Write
 176                            past end of file which can be slow, and
 177                            blocking lock operations). NFS waits slightly longer
 178                            than CIFS, but this can make it take longer for
 179                            nonresponsive servers to be detected and 15 seconds
 180                            is more than enough time for modern networks to
 181                            send a packet.  In most cases if we fail to send
 182                            after the retries we will kill the socket and
 183                            reconnect which may clear the network problem.
 184                         */
 185                         if ((i >= 14) || (!server->noblocksnd && (i > 2))) {
 186                                 cERROR(1, "sends on sock %p stuck for 15 seconds",
 187                                     ssocket);
 188                                 rc = -EAGAIN;
 189                                 break;
 190                         }
 191                         msleep(1 << i);
 192                         continue;
 193                 }
 194                 if (rc < 0)
 195                         break;
 196
 197                 if (rc == total_len) {
 198                         total_len = 0;
 199                         break;
 200                 } else if (rc > total_len) {
 201                         cERROR(1, "sent %d requested %d", rc, total_len);
 202                         break;
 203                 }
 204                 if (rc == 0) {
 205                         /* should never happen, letting socket clear before
 206                            retrying is our only obvious option here */
 207                         cERROR(1, "tcp sent no data");
 208                         msleep(500);
 209                         continue;
 210                 }
 211                 total_len -= rc;
 212                 /* the line below resets i */
 213                 for (i = first_vec; i < n_vec; i++) {
 214                         if (iov[i].iov_len) {
 215                                 if (rc > iov[i].iov_len) {
 216                                         rc -= iov[i].iov_len;
 217                                         iov[i].iov_len = 0;
 218                                 } else {
 219                                         iov[i].iov_base += rc;
 220                                         iov[i].iov_len -= rc;
 221                                         first_vec = i;
 222                                         break;
 223                                 }
 224                         }
 225                 }
 226                 i = 0; /* in case we get ENOSPC on the next send */
 227         }
 228
 229         if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
 230                 cFYI(1, "partial send (%d remaining), terminating session",
 231                         total_len);
 232                 /* If we have only sent part of an SMB then the next SMB
 233                    could be taken as the remainder of this one.  We need
 234                    to kill the socket so the server throws away the partial
 235                    SMB */
 236                 server->tcpStatus = CifsNeedReconnect;
 237         }
 238
 239         if (rc < 0) {
 240                 cERROR(1, "Error %d sending data on socket to server", rc);
 241         } else
 242                 rc = 0;
 243
 244         /* Don't want to modify the buffer as a
 245            side effect of this call. */
 246         smb_buffer->smb_buf_length = smb_buf_length;
 247
 248         return rc;
 249 }
 250
 251 int
 252 smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
 253          unsigned int smb_buf_length)
 254 {
 255         struct kvec iov;
 256
 257         iov.iov_base = smb_buffer;
 258         iov.iov_len = smb_buf_length + 4;
 259
 260         return smb_sendv(server, &iov, 1);
 261 }
 262
 263 static int wait_for_free_request(struct TCP_Server_Info *server,
 264                                  const int long_op)
 265 {
 266         if (long_op == CIFS_ASYNC_OP) {
 267                 /* oplock breaks must not be held up */
 268                 atomic_inc(&server->inFlight);
 269                 return 0;
 270         }
 271
 272         spin_lock(&GlobalMid_Lock);
 273         while (1) {
 274                 if (atomic_read(&server->inFlight) >= cifs_max_pending) {
 275                         spin_unlock(&GlobalMid_Lock);
 276 #ifdef CONFIG_CIFS_STATS2
 277                         atomic_inc(&server->num_waiters);
 278 #endif
 279                         wait_event(server->request_q,
 280                                    atomic_read(&server->inFlight)
 281                                      < cifs_max_pending);
 282 #ifdef CONFIG_CIFS_STATS2
 283                         atomic_dec(&server->num_waiters);
 284 #endif
 285                         spin_lock(&GlobalMid_Lock);
 286                 } else {
 287                         if (server->tcpStatus == CifsExiting) {
 288                                 spin_unlock(&GlobalMid_Lock);
 289                                 return -ENOENT;
 290                         }
 291
 292                         /* can not count locking commands against total
 293                            as they are allowed to block on server */
 294
 295                         /* update # of requests on the wire to server */
 296                         if (long_op != CIFS_BLOCKING_OP)
 297                                 atomic_inc(&server->inFlight);
 298                         spin_unlock(&GlobalMid_Lock);
 299                         break;
 300                 }
 301         }
 302         return 0;
 303 }
 304
 305 static int allocate_mid(struct cifsSesInfo *ses, struct smb_hdr *in_buf,
 306                         struct mid_q_entry **ppmidQ)
 307 {
 308         if (ses->server->tcpStatus == CifsExiting) {
 309                 return -ENOENT;
 310         }
 311
 312         if (ses->server->tcpStatus == CifsNeedReconnect) {
 313                 cFYI(1, "tcp session dead - return to caller to retry");
 314                 return -EAGAIN;
 315         }
 316
 317         if (ses->status != CifsGood) {
 318                 /* check if SMB session is bad because we are setting it up */
 319                 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
 320                         (in_buf->Command != SMB_COM_NEGOTIATE))
 321                         return -EAGAIN;
 322                 /* else ok - we are setting up session */
 323         }
 324         *ppmidQ = AllocMidQEntry(in_buf, ses->server);
 325         if (*ppmidQ == NULL)
 326                 return -ENOMEM;
 327         spin_lock(&GlobalMid_Lock);
 328         list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
 329         spin_unlock(&GlobalMid_Lock);
 330         return 0;
 331 }
 332
 333 static int
 334 wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
 335 {
 336         int error;
 337
 338         error = wait_event_killable(server->response_q,
 339                                     midQ->midState != MID_REQUEST_SUBMITTED);
 340         if (error < 0)
 341                 return -ERESTARTSYS;
 342
 343         return 0;
 344 }
 345
 346
 347 /*
 348  * Send a SMB request and set the callback function in the mid to handle
 349  * the result. Caller is responsible for dealing with timeouts.
 350  */
 351 int
 352 cifs_call_async(struct TCP_Server_Info *server, struct smb_hdr *in_buf,
 353                 mid_callback_t *callback, void *cbdata)
 354 {
 355         int rc;
 356         struct mid_q_entry *mid;
 357
 358         rc = wait_for_free_request(server, CIFS_ASYNC_OP);
 359         if (rc)
 360                 return rc;
 361
 362         mutex_lock(&server->srv_mutex);
 363         mid = AllocMidQEntry(in_buf, server);
 364         if (mid == NULL) {
 365                 mutex_unlock(&server->srv_mutex);
 366                 return -ENOMEM;
 367         }
 368
 369         /* put it on the pending_mid_q */
 370         spin_lock(&GlobalMid_Lock);
 371         list_add_tail(&mid->qhead, &server->pending_mid_q);
 372         spin_unlock(&GlobalMid_Lock);
 373
 374         rc = cifs_sign_smb(in_buf, server, &mid->sequence_number);
 375         if (rc) {
 376                 mutex_unlock(&server->srv_mutex);
 377                 goto out_err;
 378         }
 379
 380         mid->callback = callback;
 381         mid->callback_data = cbdata;
 382         mid->midState = MID_REQUEST_SUBMITTED;
 383 #ifdef CONFIG_CIFS_STATS2
 384         atomic_inc(&server->inSend);
 385 #endif
 386         rc = smb_send(server, in_buf, in_buf->smb_buf_length);
 387 #ifdef CONFIG_CIFS_STATS2
 388         atomic_dec(&server->inSend);
 389         mid->when_sent = jiffies;
 390 #endif
 391         mutex_unlock(&server->srv_mutex);
 392         if (rc)
 393                 goto out_err;
 394
 395         return rc;
 396 out_err:
 397         delete_mid(mid);
 398         atomic_dec(&server->inFlight);
 399         wake_up(&server->request_q);
 400         return rc;
 401 }
 402
 403 /*
 404  *
 405  * Send an SMB Request.  No response info (other than return code)
 406  * needs to be parsed.
 407  *
 408  * flags indicate the type of request buffer and how long to wait
 409  * and whether to log NT STATUS code (error) before mapping it to POSIX error
 410  *
 411  */
 412 int
 413 SendReceiveNoRsp(const unsigned int xid, struct cifsSesInfo *ses,
 414                 struct smb_hdr *in_buf, int flags)
 415 {
 416         int rc;
 417         struct kvec iov[1];
 418         int resp_buf_type;
 419
 420         iov[0].iov_base = (char *)in_buf;
 421         iov[0].iov_len = in_buf->smb_buf_length + 4;
 422         flags |= CIFS_NO_RESP;
 423         rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags);
 424         cFYI(DBG2, "SendRcvNoRsp flags %d rc %d", flags, rc);
 425
 426         return rc;
 427 }
 428
 429 static int
 430 sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
 431 {
 432         int rc = 0;
 433
 434         cFYI(1, "%s: cmd=%d mid=%d state=%d", __func__, mid->command,
 435                 mid->mid, mid->midState);
 436
 437         spin_lock(&GlobalMid_Lock);
 438         /* ensure that it's no longer on the pending_mid_q */
 439         list_del_init(&mid->qhead);
 440
 441         switch (mid->midState) {
 442         case MID_RESPONSE_RECEIVED:
 443                 spin_unlock(&GlobalMid_Lock);
 444                 return rc;
 445         case MID_REQUEST_SUBMITTED:
 446                 /* socket is going down, reject all calls */
 447                 if (server->tcpStatus == CifsExiting) {
 448                         cERROR(1, "%s: canceling mid=%d cmd=0x%x state=%d",
 449                                __func__, mid->mid, mid->command, mid->midState);
 450                         rc = -EHOSTDOWN;
 451                         break;
 452                 }
 453         case MID_RETRY_NEEDED:
 454                 rc = -EAGAIN;
 455                 break;
 456         default:
 457                 cERROR(1, "%s: invalid mid state mid=%d state=%d", __func__,
 458                         mid->mid, mid->midState);
 459                 rc = -EIO;
 460         }
 461         spin_unlock(&GlobalMid_Lock);
 462
 463         DeleteMidQEntry(mid);
 464         return rc;
 465 }
 466
 467 /*
 468  * An NT cancel request header looks just like the original request except:
 469  *
 470  * The Command is SMB_COM_NT_CANCEL
 471  * The WordCount is zeroed out
 472  * The ByteCount is zeroed out
 473  *
 474  * This function mangles an existing request buffer into a
 475  * SMB_COM_NT_CANCEL request and then sends it.
 476  */
 477 static int
 478 send_nt_cancel(struct TCP_Server_Info *server, struct smb_hdr *in_buf,
 479                 struct mid_q_entry *mid)
 480 {
 481         int rc = 0;
 482
 483         /* -4 for RFC1001 length and +2 for BCC field */
 484         in_buf->smb_buf_length = sizeof(struct smb_hdr) - 4  + 2;
 485         in_buf->Command = SMB_COM_NT_CANCEL;
 486         in_buf->WordCount = 0;
 487         BCC_LE(in_buf) = 0;
 488
 489         mutex_lock(&server->srv_mutex);
 490         rc = cifs_sign_smb(in_buf, server, &mid->sequence_number);
 491         if (rc) {
 492                 mutex_unlock(&server->srv_mutex);
 493                 return rc;
 494         }
 495         rc = smb_send(server, in_buf, in_buf->smb_buf_length);
 496         mutex_unlock(&server->srv_mutex);
 497
 498         cFYI(1, "issued NT_CANCEL for mid %u, rc = %d",
 499                 in_buf->Mid, rc);
 500
 501         return rc;
 502 }
 503
 504 int
 505 SendReceive2(const unsigned int xid, struct cifsSesInfo *ses,
 506              struct kvec *iov, int n_vec, int *pRespBufType /* ret */,
 507              const int flags)
 508 {
 509         int rc = 0;
 510         int long_op;
 511         unsigned int receive_len;
 512         struct mid_q_entry *midQ;
 513         struct smb_hdr *in_buf = iov[0].iov_base;
 514
 515         long_op = flags & CIFS_TIMEOUT_MASK;
 516
 517         *pRespBufType = CIFS_NO_BUFFER;  /* no response buf yet */
 518
 519         if ((ses == NULL) || (ses->server == NULL)) {
 520                 cifs_small_buf_release(in_buf);
 521                 cERROR(1, "Null session");
 522                 return -EIO;
 523         }
 524
 525         if (ses->server->tcpStatus == CifsExiting) {
 526                 cifs_small_buf_release(in_buf);
 527                 return -ENOENT;
 528         }
 529
 530         /* Ensure that we do not send more than 50 overlapping requests
 531            to the same server. We may make this configurable later or
 532            use ses->maxReq */
 533
 534         rc = wait_for_free_request(ses->server, long_op);
 535         if (rc) {
 536                 cifs_small_buf_release(in_buf);
 537                 return rc;
 538         }
 539
 540         /* make sure that we sign in the same order that we send on this socket
 541            and avoid races inside tcp sendmsg code that could cause corruption
 542            of smb data */
 543
 544         mutex_lock(&ses->server->srv_mutex);
 545
 546         rc = allocate_mid(ses, in_buf, &midQ);
 547         if (rc) {
 548                 mutex_unlock(&ses->server->srv_mutex);
 549                 cifs_small_buf_release(in_buf);
 550                 /* Update # of requests on wire to server */
 551                 atomic_dec(&ses->server->inFlight);
 552                 wake_up(&ses->server->request_q);
 553                 return rc;
 554         }
 555         rc = cifs_sign_smb2(iov, n_vec, ses->server, &midQ->sequence_number);
 556         if (rc) {
 557                 mutex_unlock(&ses->server->srv_mutex);
 558                 cifs_small_buf_release(in_buf);
 559                 goto out;
 560         }
 561
 562         midQ->midState = MID_REQUEST_SUBMITTED;
 563 #ifdef CONFIG_CIFS_STATS2
 564         atomic_inc(&ses->server->inSend);
 565 #endif
 566         rc = smb_sendv(ses->server, iov, n_vec);
 567 #ifdef CONFIG_CIFS_STATS2
 568         atomic_dec(&ses->server->inSend);
 569         midQ->when_sent = jiffies;
 570 #endif
 571
 572         mutex_unlock(&ses->server->srv_mutex);
 573         cifs_small_buf_release(in_buf);
 574
 575         if (rc < 0)
 576                 goto out;
 577
 578         if (long_op == CIFS_ASYNC_OP)
 579                 goto out;
 580
 581         rc = wait_for_response(ses->server, midQ);
 582         if (rc != 0)
 583                 goto out;
 584
 585         rc = sync_mid_result(midQ, ses->server);
 586         if (rc != 0) {
 587                 atomic_dec(&ses->server->inFlight);
 588                 wake_up(&ses->server->request_q);
 589                 return rc;
 590         }
 591
 592         receive_len = midQ->resp_buf->smb_buf_length;
 593
 594         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 595                 cERROR(1, "Frame too large received.  Length: %d  Xid: %d",
 596                         receive_len, xid);
 597                 rc = -EIO;
 598                 goto out;
 599         }
 600
 601         /* rcvd frame is ok */
 602
 603         if (midQ->resp_buf &&
 604             (midQ->midState == MID_RESPONSE_RECEIVED)) {
 605
 606                 iov[0].iov_base = (char *)midQ->resp_buf;
 607                 if (midQ->largeBuf)
 608                         *pRespBufType = CIFS_LARGE_BUFFER;
 609                 else
 610                         *pRespBufType = CIFS_SMALL_BUFFER;
 611                 iov[0].iov_len = receive_len + 4;
 612
 613                 dump_smb(midQ->resp_buf, 80);
 614                 /* convert the length into a more usable form */
 615                 if ((receive_len > 24) &&
 616                     (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 617                                              SECMODE_SIGN_ENABLED))) {
 618                         rc = cifs_verify_signature(midQ->resp_buf,
 619                                                 ses->server,
 620                                                 midQ->sequence_number+1);
 621                         if (rc) {
 622                                 cERROR(1, "Unexpected SMB signature");
 623                                 /* BB FIXME add code to kill session */
 624                         }
 625                 }
 626
 627                 /* BB special case reconnect tid and uid here? */
 628                 rc = map_smb_to_linux_error(midQ->resp_buf,
 629                                             flags & CIFS_LOG_ERROR);
 630
 631                 /* convert ByteCount if necessary */
 632                 if (receive_len >= sizeof(struct smb_hdr) - 4
 633                     /* do not count RFC1001 header */  +
 634                     (2 * midQ->resp_buf->WordCount) + 2 /* bcc */ )
 635                         BCC(midQ->resp_buf) =
 636                                 le16_to_cpu(BCC_LE(midQ->resp_buf));
 637                 if ((flags & CIFS_NO_RESP) == 0)
 638                         midQ->resp_buf = NULL;  /* mark it so buf will
 639                                                    not be freed by
 640                                                    delete_mid */
 641         } else {
 642                 rc = -EIO;
 643                 cFYI(1, "Bad MID state?");
 644         }
 645
 646 out:
 647         delete_mid(midQ);
 648         atomic_dec(&ses->server->inFlight);
 649         wake_up(&ses->server->request_q);
 650
 651         return rc;
 652 }
 653
 654 int
 655 SendReceive(const unsigned int xid, struct cifsSesInfo *ses,
 656             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 657             int *pbytes_returned, const int long_op)
 658 {
 659         int rc = 0;
 660         unsigned int receive_len;
 661         struct mid_q_entry *midQ;
 662
 663         if (ses == NULL) {
 664                 cERROR(1, "Null smb session");
 665                 return -EIO;
 666         }
 667         if (ses->server == NULL) {
 668                 cERROR(1, "Null tcp session");
 669                 return -EIO;
 670         }
 671
 672         if (ses->server->tcpStatus == CifsExiting)
 673                 return -ENOENT;
 674
 675         /* Ensure that we do not send more than 50 overlapping requests
 676            to the same server. We may make this configurable later or
 677            use ses->maxReq */
 678
 679         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 680                 cERROR(1, "Illegal length, greater than maximum frame, %d",
 681                            in_buf->smb_buf_length);
 682                 return -EIO;
 683         }
 684
 685         rc = wait_for_free_request(ses->server, long_op);
 686         if (rc)
 687                 return rc;
 688
 689         /* make sure that we sign in the same order that we send on this socket
 690            and avoid races inside tcp sendmsg code that could cause corruption
 691            of smb data */
 692
 693         mutex_lock(&ses->server->srv_mutex);
 694
 695         rc = allocate_mid(ses, in_buf, &midQ);
 696         if (rc) {
 697                 mutex_unlock(&ses->server->srv_mutex);
 698                 /* Update # of requests on wire to server */
 699                 atomic_dec(&ses->server->inFlight);
 700                 wake_up(&ses->server->request_q);
 701                 return rc;
 702         }
 703
 704         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 705         if (rc) {
 706                 mutex_unlock(&ses->server->srv_mutex);
 707                 goto out;
 708         }
 709
 710         midQ->midState = MID_REQUEST_SUBMITTED;
 711 #ifdef CONFIG_CIFS_STATS2
 712         atomic_inc(&ses->server->inSend);
 713 #endif
 714         rc = smb_send(ses->server, in_buf, in_buf->smb_buf_length);
 715 #ifdef CONFIG_CIFS_STATS2
 716         atomic_dec(&ses->server->inSend);
 717         midQ->when_sent = jiffies;
 718 #endif
 719         mutex_unlock(&ses->server->srv_mutex);
 720
 721         if (rc < 0)
 722                 goto out;
 723
 724         if (long_op == CIFS_ASYNC_OP)
 725                 goto out;
 726
 727         rc = wait_for_response(ses->server, midQ);
 728         if (rc != 0)
 729                 goto out;
 730
 731         rc = sync_mid_result(midQ, ses->server);
 732         if (rc != 0) {
 733                 atomic_dec(&ses->server->inFlight);
 734                 wake_up(&ses->server->request_q);
 735                 return rc;
 736         }
 737
 738         receive_len = midQ->resp_buf->smb_buf_length;
 739
 740         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 741                 cERROR(1, "Frame too large received.  Length: %d  Xid: %d",
 742                         receive_len, xid);
 743                 rc = -EIO;
 744                 goto out;
 745         }
 746
 747         /* rcvd frame is ok */
 748
 749         if (midQ->resp_buf && out_buf
 750             && (midQ->midState == MID_RESPONSE_RECEIVED)) {
 751                 out_buf->smb_buf_length = receive_len;
 752                 memcpy((char *)out_buf + 4,
 753                        (char *)midQ->resp_buf + 4,
 754                        receive_len);
 755
 756                 dump_smb(out_buf, 92);
 757                 /* convert the length into a more usable form */
 758                 if ((receive_len > 24) &&
 759                     (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 760                                              SECMODE_SIGN_ENABLED))) {
 761                         rc = cifs_verify_signature(out_buf,
 762                                                 ses->server,
 763                                                 midQ->sequence_number+1);
 764                         if (rc) {
 765                                 cERROR(1, "Unexpected SMB signature");
 766                                 /* BB FIXME add code to kill session */
 767                         }
 768                 }
 769
 770                 *pbytes_returned = out_buf->smb_buf_length;
 771
 772                 /* BB special case reconnect tid and uid here? */
 773                 rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );
 774
 775                 /* convert ByteCount if necessary */
 776                 if (receive_len >= sizeof(struct smb_hdr) - 4
 777                     /* do not count RFC1001 header */  +
 778                     (2 * out_buf->WordCount) + 2 /* bcc */ )
 779                         BCC(out_buf) = le16_to_cpu(BCC_LE(out_buf));
 780         } else {
 781                 rc = -EIO;
 782                 cERROR(1, "Bad MID state?");
 783         }
 784
 785 out:
 786         delete_mid(midQ);
 787         atomic_dec(&ses->server->inFlight);
 788         wake_up(&ses->server->request_q);
 789
 790         return rc;
 791 }
 792
 793 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
 794    blocking lock to return. */
 795
 796 static int
 797 send_lock_cancel(const unsigned int xid, struct cifsTconInfo *tcon,
 798                         struct smb_hdr *in_buf,
 799                         struct smb_hdr *out_buf)
 800 {
 801         int bytes_returned;
 802         struct cifsSesInfo *ses = tcon->ses;
 803         LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
 804
 805         /* We just modify the current in_buf to change
 806            the type of lock from LOCKING_ANDX_SHARED_LOCK
 807            or LOCKING_ANDX_EXCLUSIVE_LOCK to
 808            LOCKING_ANDX_CANCEL_LOCK. */
 809
 810         pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
 811         pSMB->Timeout = 0;
 812         pSMB->hdr.Mid = GetNextMid(ses->server);
 813
 814         return SendReceive(xid, ses, in_buf, out_buf,
 815                         &bytes_returned, 0);
 816 }
 817
 818 int
 819 SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon,
 820             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 821             int *pbytes_returned)
 822 {
 823         int rc = 0;
 824         int rstart = 0;
 825         unsigned int receive_len;
 826         struct mid_q_entry *midQ;
 827         struct cifsSesInfo *ses;
 828
 829         if (tcon == NULL || tcon->ses == NULL) {
 830                 cERROR(1, "Null smb session");
 831                 return -EIO;
 832         }
 833         ses = tcon->ses;
 834
 835         if (ses->server == NULL) {
 836                 cERROR(1, "Null tcp session");
 837                 return -EIO;
 838         }
 839
 840         if (ses->server->tcpStatus == CifsExiting)
 841                 return -ENOENT;
 842
 843         /* Ensure that we do not send more than 50 overlapping requests
 844            to the same server. We may make this configurable later or
 845            use ses->maxReq */
 846
 847         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 848                 cERROR(1, "Illegal length, greater than maximum frame, %d",
 849                            in_buf->smb_buf_length);
 850                 return -EIO;
 851         }
 852
 853         rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP);
 854         if (rc)
 855                 return rc;
 856
 857         /* make sure that we sign in the same order that we send on this socket
 858            and avoid races inside tcp sendmsg code that could cause corruption
 859            of smb data */
 860
 861         mutex_lock(&ses->server->srv_mutex);
 862
 863         rc = allocate_mid(ses, in_buf, &midQ);
 864         if (rc) {
 865                 mutex_unlock(&ses->server->srv_mutex);
 866                 return rc;
 867         }
 868
 869         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 870         if (rc) {
 871                 delete_mid(midQ);
 872                 mutex_unlock(&ses->server->srv_mutex);
 873                 return rc;
 874         }
 875
 876         midQ->midState = MID_REQUEST_SUBMITTED;
 877 #ifdef CONFIG_CIFS_STATS2
 878         atomic_inc(&ses->server->inSend);
 879 #endif
 880         rc = smb_send(ses->server, in_buf, in_buf->smb_buf_length);
 881 #ifdef CONFIG_CIFS_STATS2
 882         atomic_dec(&ses->server->inSend);
 883         midQ->when_sent = jiffies;
 884 #endif
 885         mutex_unlock(&ses->server->srv_mutex);
 886
 887         if (rc < 0) {
 888                 delete_mid(midQ);
 889                 return rc;
 890         }
 891
 892         /* Wait for a reply - allow signals to interrupt. */
 893         rc = wait_event_interruptible(ses->server->response_q,
 894                 (!(midQ->midState == MID_REQUEST_SUBMITTED)) ||
 895                 ((ses->server->tcpStatus != CifsGood) &&
 896                  (ses->server->tcpStatus != CifsNew)));
 897
 898         /* Were we interrupted by a signal ? */
 899         if ((rc == -ERESTARTSYS) &&
 900                 (midQ->midState == MID_REQUEST_SUBMITTED) &&
 901                 ((ses->server->tcpStatus == CifsGood) ||
 902                  (ses->server->tcpStatus == CifsNew))) {
 903
 904                 if (in_buf->Command == SMB_COM_TRANSACTION2) {
 905                         /* POSIX lock. We send a NT_CANCEL SMB to cause the
 906                            blocking lock to return. */
 907                         rc = send_nt_cancel(ses->server, in_buf, midQ);
 908                         if (rc) {
 909                                 delete_mid(midQ);
 910                                 return rc;
 911                         }
 912                 } else {
 913                         /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
 914                            to cause the blocking lock to return. */
 915
 916                         rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
 917
 918                         /* If we get -ENOLCK back the lock may have
 919                            already been removed. Don't exit in this case. */
 920                         if (rc && rc != -ENOLCK) {
 921                                 delete_mid(midQ);
 922                                 return rc;
 923                         }
 924                 }
 925
 926                 if (wait_for_response(ses->server, midQ) == 0) {
 927                         /* We got the response - restart system call. */
 928                         rstart = 1;
 929                 }
 930         }
 931
 932         rc = sync_mid_result(midQ, ses->server);
 933         if (rc != 0)
 934                 return rc;
 935
 936         receive_len = midQ->resp_buf->smb_buf_length;
 937         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 938                 cERROR(1, "Frame too large received.  Length: %d  Xid: %d",
 939                         receive_len, xid);
 940                 rc = -EIO;
 941                 goto out;
 942         }
 943
 944         /* rcvd frame is ok */
 945
 946         if ((out_buf == NULL) || (midQ->midState != MID_RESPONSE_RECEIVED)) {
 947                 rc = -EIO;
 948                 cERROR(1, "Bad MID state?");
 949                 goto out;
 950         }
 951
 952         out_buf->smb_buf_length = receive_len;
 953         memcpy((char *)out_buf + 4,
 954                (char *)midQ->resp_buf + 4,
 955                receive_len);
 956
 957         dump_smb(out_buf, 92);
 958         /* convert the length into a more usable form */
 959         if ((receive_len > 24) &&
 960             (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 961                                      SECMODE_SIGN_ENABLED))) {
 962                 rc = cifs_verify_signature(out_buf,
 963                                            ses->server,
 964                                            midQ->sequence_number+1);
 965                 if (rc) {
 966                         cERROR(1, "Unexpected SMB signature");
 967                         /* BB FIXME add code to kill session */
 968                 }
 969         }
 970
 971         *pbytes_returned = out_buf->smb_buf_length;
 972
 973         /* BB special case reconnect tid and uid here? */
 974         rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );
 975
 976         /* convert ByteCount if necessary */
 977         if (receive_len >= sizeof(struct smb_hdr) - 4
 978             /* do not count RFC1001 header */  +
 979             (2 * out_buf->WordCount) + 2 /* bcc */ )
 980                 BCC(out_buf) = le16_to_cpu(BCC_LE(out_buf));
 981
 982 out:
 983         delete_mid(midQ);
 984         if (rstart && rc == -EACCES)
 985                 return -ERESTARTSYS;
 986         return rc;
 987 }