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 && rc != -EINTR)
 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         /* enable signing if server requires it */
 363         if (server->secMode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
 364                 in_buf->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
 365
 366         mutex_lock(&server->srv_mutex);
 367         mid = AllocMidQEntry(in_buf, server);
 368         if (mid == NULL) {
 369                 mutex_unlock(&server->srv_mutex);
 370                 return -ENOMEM;
 371         }
 372
 373         /* put it on the pending_mid_q */
 374         spin_lock(&GlobalMid_Lock);
 375         list_add_tail(&mid->qhead, &server->pending_mid_q);
 376         spin_unlock(&GlobalMid_Lock);
 377
 378         rc = cifs_sign_smb(in_buf, server, &mid->sequence_number);
 379         if (rc) {
 380                 mutex_unlock(&server->srv_mutex);
 381                 goto out_err;
 382         }
 383
 384         mid->callback = callback;
 385         mid->callback_data = cbdata;
 386         mid->midState = MID_REQUEST_SUBMITTED;
 387 #ifdef CONFIG_CIFS_STATS2
 388         atomic_inc(&server->inSend);
 389 #endif
 390         rc = smb_send(server, in_buf, in_buf->smb_buf_length);
 391 #ifdef CONFIG_CIFS_STATS2
 392         atomic_dec(&server->inSend);
 393         mid->when_sent = jiffies;
 394 #endif
 395         mutex_unlock(&server->srv_mutex);
 396         if (rc)
 397                 goto out_err;
 398
 399         return rc;
 400 out_err:
 401         delete_mid(mid);
 402         atomic_dec(&server->inFlight);
 403         wake_up(&server->request_q);
 404         return rc;
 405 }
 406
 407 /*
 408  *
 409  * Send an SMB Request.  No response info (other than return code)
 410  * needs to be parsed.
 411  *
 412  * flags indicate the type of request buffer and how long to wait
 413  * and whether to log NT STATUS code (error) before mapping it to POSIX error
 414  *
 415  */
 416 int
 417 SendReceiveNoRsp(const unsigned int xid, struct cifsSesInfo *ses,
 418                 struct smb_hdr *in_buf, int flags)
 419 {
 420         int rc;
 421         struct kvec iov[1];
 422         int resp_buf_type;
 423
 424         iov[0].iov_base = (char *)in_buf;
 425         iov[0].iov_len = in_buf->smb_buf_length + 4;
 426         flags |= CIFS_NO_RESP;
 427         rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags);
 428         cFYI(DBG2, "SendRcvNoRsp flags %d rc %d", flags, rc);
 429
 430         return rc;
 431 }
 432
 433 static int
 434 sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
 435 {
 436         int rc = 0;
 437
 438         cFYI(1, "%s: cmd=%d mid=%d state=%d", __func__, mid->command,
 439                 mid->mid, mid->midState);
 440
 441         spin_lock(&GlobalMid_Lock);
 442         /* ensure that it's no longer on the pending_mid_q */
 443         list_del_init(&mid->qhead);
 444
 445         switch (mid->midState) {
 446         case MID_RESPONSE_RECEIVED:
 447                 spin_unlock(&GlobalMid_Lock);
 448                 return rc;
 449         case MID_REQUEST_SUBMITTED:
 450                 /* socket is going down, reject all calls */
 451                 if (server->tcpStatus == CifsExiting) {
 452                         cERROR(1, "%s: canceling mid=%d cmd=0x%x state=%d",
 453                                __func__, mid->mid, mid->command, mid->midState);
 454                         rc = -EHOSTDOWN;
 455                         break;
 456                 }
 457         case MID_RETRY_NEEDED:
 458                 rc = -EAGAIN;
 459                 break;
 460         default:
 461                 cERROR(1, "%s: invalid mid state mid=%d state=%d", __func__,
 462                         mid->mid, mid->midState);
 463                 rc = -EIO;
 464         }
 465         spin_unlock(&GlobalMid_Lock);
 466
 467         DeleteMidQEntry(mid);
 468         return rc;
 469 }
 470
 471 /*
 472  * An NT cancel request header looks just like the original request except:
 473  *
 474  * The Command is SMB_COM_NT_CANCEL
 475  * The WordCount is zeroed out
 476  * The ByteCount is zeroed out
 477  *
 478  * This function mangles an existing request buffer into a
 479  * SMB_COM_NT_CANCEL request and then sends it.
 480  */
 481 static int
 482 send_nt_cancel(struct TCP_Server_Info *server, struct smb_hdr *in_buf,
 483                 struct mid_q_entry *mid)
 484 {
 485         int rc = 0;
 486
 487         /* -4 for RFC1001 length and +2 for BCC field */
 488         in_buf->smb_buf_length = sizeof(struct smb_hdr) - 4  + 2;
 489         in_buf->Command = SMB_COM_NT_CANCEL;
 490         in_buf->WordCount = 0;
 491         put_bcc_le(0, in_buf);
 492
 493         mutex_lock(&server->srv_mutex);
 494         rc = cifs_sign_smb(in_buf, server, &mid->sequence_number);
 495         if (rc) {
 496                 mutex_unlock(&server->srv_mutex);
 497                 return rc;
 498         }
 499         rc = smb_send(server, in_buf, in_buf->smb_buf_length);
 500         mutex_unlock(&server->srv_mutex);
 501
 502         cFYI(1, "issued NT_CANCEL for mid %u, rc = %d",
 503                 in_buf->Mid, rc);
 504
 505         return rc;
 506 }
 507
 508 int
 509 SendReceive2(const unsigned int xid, struct cifsSesInfo *ses,
 510              struct kvec *iov, int n_vec, int *pRespBufType /* ret */,
 511              const int flags)
 512 {
 513         int rc = 0;
 514         int long_op;
 515         unsigned int receive_len;
 516         struct mid_q_entry *midQ;
 517         struct smb_hdr *in_buf = iov[0].iov_base;
 518
 519         long_op = flags & CIFS_TIMEOUT_MASK;
 520
 521         *pRespBufType = CIFS_NO_BUFFER;  /* no response buf yet */
 522
 523         if ((ses == NULL) || (ses->server == NULL)) {
 524                 cifs_small_buf_release(in_buf);
 525                 cERROR(1, "Null session");
 526                 return -EIO;
 527         }
 528
 529         if (ses->server->tcpStatus == CifsExiting) {
 530                 cifs_small_buf_release(in_buf);
 531                 return -ENOENT;
 532         }
 533
 534         /* Ensure that we do not send more than 50 overlapping requests
 535            to the same server. We may make this configurable later or
 536            use ses->maxReq */
 537
 538         rc = wait_for_free_request(ses->server, long_op);
 539         if (rc) {
 540                 cifs_small_buf_release(in_buf);
 541                 return rc;
 542         }
 543
 544         /* make sure that we sign in the same order that we send on this socket
 545            and avoid races inside tcp sendmsg code that could cause corruption
 546            of smb data */
 547
 548         mutex_lock(&ses->server->srv_mutex);
 549
 550         rc = allocate_mid(ses, in_buf, &midQ);
 551         if (rc) {
 552                 mutex_unlock(&ses->server->srv_mutex);
 553                 cifs_small_buf_release(in_buf);
 554                 /* Update # of requests on wire to server */
 555                 atomic_dec(&ses->server->inFlight);
 556                 wake_up(&ses->server->request_q);
 557                 return rc;
 558         }
 559         rc = cifs_sign_smb2(iov, n_vec, ses->server, &midQ->sequence_number);
 560         if (rc) {
 561                 mutex_unlock(&ses->server->srv_mutex);
 562                 cifs_small_buf_release(in_buf);
 563                 goto out;
 564         }
 565
 566         midQ->midState = MID_REQUEST_SUBMITTED;
 567 #ifdef CONFIG_CIFS_STATS2
 568         atomic_inc(&ses->server->inSend);
 569 #endif
 570         rc = smb_sendv(ses->server, iov, n_vec);
 571 #ifdef CONFIG_CIFS_STATS2
 572         atomic_dec(&ses->server->inSend);
 573         midQ->when_sent = jiffies;
 574 #endif
 575
 576         mutex_unlock(&ses->server->srv_mutex);
 577
 578         if (rc < 0) {
 579                 cifs_small_buf_release(in_buf);
 580                 goto out;
 581         }
 582
 583         if (long_op == CIFS_ASYNC_OP) {
 584                 cifs_small_buf_release(in_buf);
 585                 goto out;
 586         }
 587
 588         rc = wait_for_response(ses->server, midQ);
 589         if (rc != 0) {
 590                 send_nt_cancel(ses->server, in_buf, midQ);
 591                 spin_lock(&GlobalMid_Lock);
 592                 if (midQ->midState == MID_REQUEST_SUBMITTED) {
 593                         midQ->callback = DeleteMidQEntry;
 594                         spin_unlock(&GlobalMid_Lock);
 595                         cifs_small_buf_release(in_buf);
 596                         atomic_dec(&ses->server->inFlight);
 597                         wake_up(&ses->server->request_q);
 598                         return rc;
 599                 }
 600                 spin_unlock(&GlobalMid_Lock);
 601         }
 602
 603         cifs_small_buf_release(in_buf);
 604
 605         rc = sync_mid_result(midQ, ses->server);
 606         if (rc != 0) {
 607                 atomic_dec(&ses->server->inFlight);
 608                 wake_up(&ses->server->request_q);
 609                 return rc;
 610         }
 611
 612         receive_len = midQ->resp_buf->smb_buf_length;
 613
 614         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 615                 cERROR(1, "Frame too large received.  Length: %d  Xid: %d",
 616                         receive_len, xid);
 617                 rc = -EIO;
 618                 goto out;
 619         }
 620
 621         /* rcvd frame is ok */
 622
 623         if (midQ->resp_buf &&
 624             (midQ->midState == MID_RESPONSE_RECEIVED)) {
 625
 626                 iov[0].iov_base = (char *)midQ->resp_buf;
 627                 if (midQ->largeBuf)
 628                         *pRespBufType = CIFS_LARGE_BUFFER;
 629                 else
 630                         *pRespBufType = CIFS_SMALL_BUFFER;
 631                 iov[0].iov_len = receive_len + 4;
 632
 633                 dump_smb(midQ->resp_buf, 80);
 634                 /* convert the length into a more usable form */
 635                 if ((receive_len > 24) &&
 636                     (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 637                                              SECMODE_SIGN_ENABLED))) {
 638                         rc = cifs_verify_signature(midQ->resp_buf,
 639                                                 ses->server,
 640                                                 midQ->sequence_number+1);
 641                         if (rc) {
 642                                 cERROR(1, "Unexpected SMB signature");
 643                                 /* BB FIXME add code to kill session */
 644                         }
 645                 }
 646
 647                 /* BB special case reconnect tid and uid here? */
 648                 rc = map_smb_to_linux_error(midQ->resp_buf,
 649                                             flags & CIFS_LOG_ERROR);
 650
 651                 /* convert ByteCount if necessary */
 652                 if (receive_len >= sizeof(struct smb_hdr) - 4
 653                     /* do not count RFC1001 header */  +
 654                     (2 * midQ->resp_buf->WordCount) + 2 /* bcc */ )
 655                         put_bcc(get_bcc_le(midQ->resp_buf), midQ->resp_buf);
 656                 if ((flags & CIFS_NO_RESP) == 0)
 657                         midQ->resp_buf = NULL;  /* mark it so buf will
 658                                                    not be freed by
 659                                                    delete_mid */
 660         } else {
 661                 rc = -EIO;
 662                 cFYI(1, "Bad MID state?");
 663         }
 664
 665 out:
 666         delete_mid(midQ);
 667         atomic_dec(&ses->server->inFlight);
 668         wake_up(&ses->server->request_q);
 669
 670         return rc;
 671 }
 672
 673 int
 674 SendReceive(const unsigned int xid, struct cifsSesInfo *ses,
 675             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 676             int *pbytes_returned, const int long_op)
 677 {
 678         int rc = 0;
 679         unsigned int receive_len;
 680         struct mid_q_entry *midQ;
 681
 682         if (ses == NULL) {
 683                 cERROR(1, "Null smb session");
 684                 return -EIO;
 685         }
 686         if (ses->server == NULL) {
 687                 cERROR(1, "Null tcp session");
 688                 return -EIO;
 689         }
 690
 691         if (ses->server->tcpStatus == CifsExiting)
 692                 return -ENOENT;
 693
 694         /* Ensure that we do not send more than 50 overlapping requests
 695            to the same server. We may make this configurable later or
 696            use ses->maxReq */
 697
 698         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 699                 cERROR(1, "Illegal length, greater than maximum frame, %d",
 700                            in_buf->smb_buf_length);
 701                 return -EIO;
 702         }
 703
 704         rc = wait_for_free_request(ses->server, long_op);
 705         if (rc)
 706                 return rc;
 707
 708         /* make sure that we sign in the same order that we send on this socket
 709            and avoid races inside tcp sendmsg code that could cause corruption
 710            of smb data */
 711
 712         mutex_lock(&ses->server->srv_mutex);
 713
 714         rc = allocate_mid(ses, in_buf, &midQ);
 715         if (rc) {
 716                 mutex_unlock(&ses->server->srv_mutex);
 717                 /* Update # of requests on wire to server */
 718                 atomic_dec(&ses->server->inFlight);
 719                 wake_up(&ses->server->request_q);
 720                 return rc;
 721         }
 722
 723         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 724         if (rc) {
 725                 mutex_unlock(&ses->server->srv_mutex);
 726                 goto out;
 727         }
 728
 729         midQ->midState = MID_REQUEST_SUBMITTED;
 730 #ifdef CONFIG_CIFS_STATS2
 731         atomic_inc(&ses->server->inSend);
 732 #endif
 733         rc = smb_send(ses->server, in_buf, in_buf->smb_buf_length);
 734 #ifdef CONFIG_CIFS_STATS2
 735         atomic_dec(&ses->server->inSend);
 736         midQ->when_sent = jiffies;
 737 #endif
 738         mutex_unlock(&ses->server->srv_mutex);
 739
 740         if (rc < 0)
 741                 goto out;
 742
 743         if (long_op == CIFS_ASYNC_OP)
 744                 goto out;
 745
 746         rc = wait_for_response(ses->server, midQ);
 747         if (rc != 0) {
 748                 send_nt_cancel(ses->server, in_buf, midQ);
 749                 spin_lock(&GlobalMid_Lock);
 750                 if (midQ->midState == MID_REQUEST_SUBMITTED) {
 751                         /* no longer considered to be "in-flight" */
 752                         midQ->callback = DeleteMidQEntry;
 753                         spin_unlock(&GlobalMid_Lock);
 754                         atomic_dec(&ses->server->inFlight);
 755                         wake_up(&ses->server->request_q);
 756                         return rc;
 757                 }
 758                 spin_unlock(&GlobalMid_Lock);
 759         }
 760
 761         rc = sync_mid_result(midQ, ses->server);
 762         if (rc != 0) {
 763                 atomic_dec(&ses->server->inFlight);
 764                 wake_up(&ses->server->request_q);
 765                 return rc;
 766         }
 767
 768         receive_len = midQ->resp_buf->smb_buf_length;
 769
 770         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 771                 cERROR(1, "Frame too large received.  Length: %d  Xid: %d",
 772                         receive_len, xid);
 773                 rc = -EIO;
 774                 goto out;
 775         }
 776
 777         /* rcvd frame is ok */
 778
 779         if (midQ->resp_buf && out_buf
 780             && (midQ->midState == MID_RESPONSE_RECEIVED)) {
 781                 out_buf->smb_buf_length = receive_len;
 782                 memcpy((char *)out_buf + 4,
 783                        (char *)midQ->resp_buf + 4,
 784                        receive_len);
 785
 786                 dump_smb(out_buf, 92);
 787                 /* convert the length into a more usable form */
 788                 if ((receive_len > 24) &&
 789                     (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 790                                              SECMODE_SIGN_ENABLED))) {
 791                         rc = cifs_verify_signature(out_buf,
 792                                                 ses->server,
 793                                                 midQ->sequence_number+1);
 794                         if (rc) {
 795                                 cERROR(1, "Unexpected SMB signature");
 796                                 /* BB FIXME add code to kill session */
 797                         }
 798                 }
 799
 800                 *pbytes_returned = out_buf->smb_buf_length;
 801
 802                 /* BB special case reconnect tid and uid here? */
 803                 rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );
 804
 805                 /* convert ByteCount if necessary */
 806                 if (receive_len >= sizeof(struct smb_hdr) - 4
 807                     /* do not count RFC1001 header */  +
 808                     (2 * out_buf->WordCount) + 2 /* bcc */ )
 809                         put_bcc(get_bcc_le(midQ->resp_buf), midQ->resp_buf);
 810         } else {
 811                 rc = -EIO;
 812                 cERROR(1, "Bad MID state?");
 813         }
 814
 815 out:
 816         delete_mid(midQ);
 817         atomic_dec(&ses->server->inFlight);
 818         wake_up(&ses->server->request_q);
 819
 820         return rc;
 821 }
 822
 823 /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
 824    blocking lock to return. */
 825
 826 static int
 827 send_lock_cancel(const unsigned int xid, struct cifsTconInfo *tcon,
 828                         struct smb_hdr *in_buf,
 829                         struct smb_hdr *out_buf)
 830 {
 831         int bytes_returned;
 832         struct cifsSesInfo *ses = tcon->ses;
 833         LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
 834
 835         /* We just modify the current in_buf to change
 836            the type of lock from LOCKING_ANDX_SHARED_LOCK
 837            or LOCKING_ANDX_EXCLUSIVE_LOCK to
 838            LOCKING_ANDX_CANCEL_LOCK. */
 839
 840         pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
 841         pSMB->Timeout = 0;
 842         pSMB->hdr.Mid = GetNextMid(ses->server);
 843
 844         return SendReceive(xid, ses, in_buf, out_buf,
 845                         &bytes_returned, 0);
 846 }
 847
 848 int
 849 SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon,
 850             struct smb_hdr *in_buf, struct smb_hdr *out_buf,
 851             int *pbytes_returned)
 852 {
 853         int rc = 0;
 854         int rstart = 0;
 855         unsigned int receive_len;
 856         struct mid_q_entry *midQ;
 857         struct cifsSesInfo *ses;
 858
 859         if (tcon == NULL || tcon->ses == NULL) {
 860                 cERROR(1, "Null smb session");
 861                 return -EIO;
 862         }
 863         ses = tcon->ses;
 864
 865         if (ses->server == NULL) {
 866                 cERROR(1, "Null tcp session");
 867                 return -EIO;
 868         }
 869
 870         if (ses->server->tcpStatus == CifsExiting)
 871                 return -ENOENT;
 872
 873         /* Ensure that we do not send more than 50 overlapping requests
 874            to the same server. We may make this configurable later or
 875            use ses->maxReq */
 876
 877         if (in_buf->smb_buf_length > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
 878                 cERROR(1, "Illegal length, greater than maximum frame, %d",
 879                            in_buf->smb_buf_length);
 880                 return -EIO;
 881         }
 882
 883         rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP);
 884         if (rc)
 885                 return rc;
 886
 887         /* make sure that we sign in the same order that we send on this socket
 888            and avoid races inside tcp sendmsg code that could cause corruption
 889            of smb data */
 890
 891         mutex_lock(&ses->server->srv_mutex);
 892
 893         rc = allocate_mid(ses, in_buf, &midQ);
 894         if (rc) {
 895                 mutex_unlock(&ses->server->srv_mutex);
 896                 return rc;
 897         }
 898
 899         rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
 900         if (rc) {
 901                 delete_mid(midQ);
 902                 mutex_unlock(&ses->server->srv_mutex);
 903                 return rc;
 904         }
 905
 906         midQ->midState = MID_REQUEST_SUBMITTED;
 907 #ifdef CONFIG_CIFS_STATS2
 908         atomic_inc(&ses->server->inSend);
 909 #endif
 910         rc = smb_send(ses->server, in_buf, in_buf->smb_buf_length);
 911 #ifdef CONFIG_CIFS_STATS2
 912         atomic_dec(&ses->server->inSend);
 913         midQ->when_sent = jiffies;
 914 #endif
 915         mutex_unlock(&ses->server->srv_mutex);
 916
 917         if (rc < 0) {
 918                 delete_mid(midQ);
 919                 return rc;
 920         }
 921
 922         /* Wait for a reply - allow signals to interrupt. */
 923         rc = wait_event_interruptible(ses->server->response_q,
 924                 (!(midQ->midState == MID_REQUEST_SUBMITTED)) ||
 925                 ((ses->server->tcpStatus != CifsGood) &&
 926                  (ses->server->tcpStatus != CifsNew)));
 927
 928         /* Were we interrupted by a signal ? */
 929         if ((rc == -ERESTARTSYS) &&
 930                 (midQ->midState == MID_REQUEST_SUBMITTED) &&
 931                 ((ses->server->tcpStatus == CifsGood) ||
 932                  (ses->server->tcpStatus == CifsNew))) {
 933
 934                 if (in_buf->Command == SMB_COM_TRANSACTION2) {
 935                         /* POSIX lock. We send a NT_CANCEL SMB to cause the
 936                            blocking lock to return. */
 937                         rc = send_nt_cancel(ses->server, in_buf, midQ);
 938                         if (rc) {
 939                                 delete_mid(midQ);
 940                                 return rc;
 941                         }
 942                 } else {
 943                         /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
 944                            to cause the blocking lock to return. */
 945
 946                         rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
 947
 948                         /* If we get -ENOLCK back the lock may have
 949                            already been removed. Don't exit in this case. */
 950                         if (rc && rc != -ENOLCK) {
 951                                 delete_mid(midQ);
 952                                 return rc;
 953                         }
 954                 }
 955
 956                 rc = wait_for_response(ses->server, midQ);
 957                 if (rc) {
 958                         send_nt_cancel(ses->server, in_buf, midQ);
 959                         spin_lock(&GlobalMid_Lock);
 960                         if (midQ->midState == MID_REQUEST_SUBMITTED) {
 961                                 /* no longer considered to be "in-flight" */
 962                                 midQ->callback = DeleteMidQEntry;
 963                                 spin_unlock(&GlobalMid_Lock);
 964                                 return rc;
 965                         }
 966                         spin_unlock(&GlobalMid_Lock);
 967                 }
 968
 969                 /* We got the response - restart system call. */
 970                 rstart = 1;
 971         }
 972
 973         rc = sync_mid_result(midQ, ses->server);
 974         if (rc != 0)
 975                 return rc;
 976
 977         receive_len = midQ->resp_buf->smb_buf_length;
 978         if (receive_len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE) {
 979                 cERROR(1, "Frame too large received.  Length: %d  Xid: %d",
 980                         receive_len, xid);
 981                 rc = -EIO;
 982                 goto out;
 983         }
 984
 985         /* rcvd frame is ok */
 986
 987         if ((out_buf == NULL) || (midQ->midState != MID_RESPONSE_RECEIVED)) {
 988                 rc = -EIO;
 989                 cERROR(1, "Bad MID state?");
 990                 goto out;
 991         }
 992
 993         out_buf->smb_buf_length = receive_len;
 994         memcpy((char *)out_buf + 4,
 995                (char *)midQ->resp_buf + 4,
 996                receive_len);
 997
 998         dump_smb(out_buf, 92);
 999         /* convert the length into a more usable form */
1000         if ((receive_len > 24) &&
1001             (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
1002                                      SECMODE_SIGN_ENABLED))) {
1003                 rc = cifs_verify_signature(out_buf,
1004                                            ses->server,
1005                                            midQ->sequence_number+1);
1006                 if (rc) {
1007                         cERROR(1, "Unexpected SMB signature");
1008                         /* BB FIXME add code to kill session */
1009                 }
1010         }
1011
1012         *pbytes_returned = out_buf->smb_buf_length;
1013
1014         /* BB special case reconnect tid and uid here? */
1015         rc = map_smb_to_linux_error(out_buf, 0 /* no log */ );
1016
1017         /* convert ByteCount if necessary */
1018         if (receive_len >= sizeof(struct smb_hdr) - 4
1019             /* do not count RFC1001 header */  +
1020             (2 * out_buf->WordCount) + 2 /* bcc */ )
1021                 put_bcc(get_bcc_le(out_buf), out_buf);
1022
1023 out:
1024         delete_mid(midQ);
1025         if (rstart && rc == -EACCES)
1026                 return -ERESTARTSYS;
1027         return rc;
1028 }