fs/smbfs/request.c

   1 /*
   2  *  request.c
   3  *
   4  *  Copyright (C) 2001 by Urban Widmark
   5  *
   6  *  Please add a note about your changes to smbfs in the ChangeLog file.
   7  */
   8
   9 #include <linux/types.h>
  10 #include <linux/fs.h>
  11 #include <linux/slab.h>
  12 #include <linux/net.h>
  13
  14 #include <linux/smb_fs.h>
  15 #include <linux/smbno.h>
  16 #include <linux/smb_mount.h>
  17
  18 #include "smb_debug.h"
  19 #include "request.h"
  20 #include "proto.h"
  21
  22 /* #define SMB_SLAB_DEBUG       (SLAB_RED_ZONE | SLAB_POISON) */
  23 #define SMB_SLAB_DEBUG  0
  24
  25 #define ROUND_UP(x) (((x)+3) & ~3)
  26
  27 /* cache for request structures */
  28 static kmem_cache_t *req_cachep;
  29
  30 static int smb_request_send_req(struct smb_request *req);
  31
  32 /*
  33   /proc/slabinfo:
  34   name, active, num, objsize, active_slabs, num_slaps, #pages
  35 */
  36
  37
  38 int smb_init_request_cache(void)
  39 {
  40         req_cachep = kmem_cache_create("smb_request",
  41                                        sizeof(struct smb_request), 0,
  42                                        SMB_SLAB_DEBUG | SLAB_HWCACHE_ALIGN,
  43                                        NULL, NULL);
  44         if (req_cachep == NULL)
  45                 return -ENOMEM;
  46
  47         return 0;
  48 }
  49
  50 void smb_destroy_request_cache(void)
  51 {
  52         if (kmem_cache_destroy(req_cachep))
  53                 printk(KERN_INFO "smb_destroy_request_cache: not all structures were freed\n");
  54 }
  55
  56 /*
  57  * Allocate and initialise a request structure
  58  */
  59 static struct smb_request *smb_do_alloc_request(struct smb_sb_info *server,
  60                                                 int bufsize)
  61 {
  62         struct smb_request *req;
  63         unsigned char *buf = NULL;
  64
  65         req = kmem_cache_alloc(req_cachep, SLAB_KERNEL);
  66         VERBOSE("allocating request: %p\n", req);
  67         if (!req)
  68                 goto out;
  69
  70         if (bufsize > 0) {
  71                 buf = smb_kmalloc(bufsize, GFP_NOFS);
  72                 if (!buf) {
  73                         kmem_cache_free(req_cachep, req);
  74                         return NULL;
  75                 }
  76         }
  77
  78         memset(req, 0, sizeof(struct smb_request));
  79         req->rq_buffer = buf;
  80         req->rq_bufsize = bufsize;
  81         req->rq_server = server;
  82         init_waitqueue_head(&req->rq_wait);
  83         INIT_LIST_HEAD(&req->rq_queue);
  84         atomic_set(&req->rq_count, 1);
  85
  86 out:
  87         return req;
  88 }
  89
  90 struct smb_request *smb_alloc_request(struct smb_sb_info *server, int bufsize)
  91 {
  92         struct smb_request *req = NULL;
  93
  94         for (;;) {
  95                 atomic_inc(&server->nr_requests);
  96                 if (atomic_read(&server->nr_requests) <= MAX_REQUEST_HARD) {
  97                         req = smb_do_alloc_request(server, bufsize);
  98                         if (req != NULL)
  99                                 break;
 100                 }
 101
 102 #if 0
 103                 /*
 104                  * Try to free up at least one request in order to stay
 105                  * below the hard limit
 106                  */
 107                 if (nfs_try_to_free_pages(server))
 108                         continue;
 109
 110                 if (signalled() && (server->flags & NFS_MOUNT_INTR))
 111                         return ERR_PTR(-ERESTARTSYS);
 112                 current->policy = SCHED_YIELD;
 113                 schedule();
 114 #else
 115                 /* FIXME: we want something like nfs does above, but that
 116                    requires changes to all callers and can wait. */
 117                 break;
 118 #endif
 119         }
 120         return req;
 121 }
 122
 123 static void smb_free_request(struct smb_request *req)
 124 {
 125         atomic_dec(&req->rq_server->nr_requests);
 126         if (req->rq_buffer && !(req->rq_flags & SMB_REQ_STATIC))
 127                 smb_kfree(req->rq_buffer);
 128         if (req->rq_trans2buffer)
 129                 smb_kfree(req->rq_trans2buffer);
 130         kmem_cache_free(req_cachep, req);
 131 }
 132
 133 /*
 134  * What prevents a rget to race with a rput? The count must never drop to zero
 135  * while it is in use. Only rput if it is ok that it is free'd.
 136  */
 137 static void smb_rget(struct smb_request *req)
 138 {
 139         atomic_inc(&req->rq_count);
 140 }
 141 void smb_rput(struct smb_request *req)
 142 {
 143         if (atomic_dec_and_test(&req->rq_count)) {
 144                 list_del_init(&req->rq_queue);
 145                 smb_free_request(req);
 146         }
 147 }
 148
 149 /* setup to receive the data part of the SMB */
 150 static int smb_setup_bcc(struct smb_request *req)
 151 {
 152         int result = 0;
 153         req->rq_rlen = smb_len(req->rq_header) + 4 - req->rq_bytes_recvd;
 154
 155         if (req->rq_rlen > req->rq_bufsize) {
 156                 PARANOIA("Packet too large %d > %d\n",
 157                          req->rq_rlen, req->rq_bufsize);
 158                 return -ENOBUFS;
 159         }
 160
 161         req->rq_iov[0].iov_base = req->rq_buffer;
 162         req->rq_iov[0].iov_len  = req->rq_rlen;
 163         req->rq_iovlen = 1;
 164
 165         return result;
 166 }
 167
 168 /*
 169  * Prepare a "normal" request structure.
 170  */
 171 static int smb_setup_request(struct smb_request *req)
 172 {
 173         int len = smb_len(req->rq_header) + 4;
 174         req->rq_slen = len;
 175
 176         /* if we expect a data part in the reply we set the iov's to read it */
 177         if (req->rq_resp_bcc)
 178                 req->rq_setup_read = smb_setup_bcc;
 179
 180         /* This tries to support re-using the same request */
 181         req->rq_bytes_sent = 0;
 182         req->rq_rcls = 0;
 183         req->rq_err = 0;
 184         req->rq_errno = 0;
 185         req->rq_fragment = 0;
 186         if (req->rq_trans2buffer)
 187                 smb_kfree(req->rq_trans2buffer);
 188
 189         return 0;
 190 }
 191
 192 /*
 193  * Prepare a transaction2 request structure
 194  */
 195 static int smb_setup_trans2request(struct smb_request *req)
 196 {
 197         struct smb_sb_info *server = req->rq_server;
 198         int mparam, mdata;
 199         static unsigned char padding[4];
 200
 201         /* I know the following is very ugly, but I want to build the
 202            smb packet as efficiently as possible. */
 203
 204         const int smb_parameters = 15;
 205         const int header = SMB_HEADER_LEN + 2 * smb_parameters + 2;
 206         const int oparam = ROUND_UP(header + 3);
 207         const int odata  = ROUND_UP(oparam + req->rq_lparm);
 208         const int bcc = (req->rq_data ? odata + req->rq_ldata :
 209                                         oparam + req->rq_lparm) - header;
 210
 211         if ((bcc + oparam) > server->opt.max_xmit)
 212                 return -ENOMEM;
 213         smb_setup_header(req, SMBtrans2, smb_parameters, bcc);
 214
 215         /*
 216          * max parameters + max data + max setup == bufsize to make NT4 happy
 217          * and not abort the transfer or split into multiple responses. It also
 218          * makes smbfs happy as handling packets larger than the buffer size
 219          * is extra work.
 220          *
 221          * OS/2 is probably going to hate me for this ...
 222          */
 223         mparam = SMB_TRANS2_MAX_PARAM;
 224         mdata = req->rq_bufsize - mparam;
 225
 226         mdata = server->opt.max_xmit - mparam - 100;
 227         if (mdata < 1024) {
 228                 mdata = 1024;
 229                 mparam = 20;
 230         }
 231
 232 #if 0
 233         /* NT/win2k has ~4k max_xmit, so with this we request more than it wants
 234            to return as one SMB. Useful for testing the fragmented trans2
 235            handling. */
 236         mdata = 8192;
 237 #endif
 238
 239         WSET(req->rq_header, smb_tpscnt, req->rq_lparm);
 240         WSET(req->rq_header, smb_tdscnt, req->rq_ldata);
 241         WSET(req->rq_header, smb_mprcnt, mparam);
 242         WSET(req->rq_header, smb_mdrcnt, mdata);
 243         WSET(req->rq_header, smb_msrcnt, 0);    /* max setup always 0 ? */
 244         WSET(req->rq_header, smb_flags, 0);
 245         DSET(req->rq_header, smb_timeout, 0);
 246         WSET(req->rq_header, smb_pscnt, req->rq_lparm);
 247         WSET(req->rq_header, smb_psoff, oparam - 4);
 248         WSET(req->rq_header, smb_dscnt, req->rq_ldata);
 249         WSET(req->rq_header, smb_dsoff, req->rq_data ? odata - 4 : 0);
 250         *(req->rq_header + smb_suwcnt) = 0x01;          /* setup count */
 251         *(req->rq_header + smb_suwcnt + 1) = 0x00;      /* reserved */
 252         WSET(req->rq_header, smb_setup0, req->rq_trans2_command);
 253
 254         req->rq_iovlen = 2;
 255         req->rq_iov[0].iov_base = (void *) req->rq_header;
 256         req->rq_iov[0].iov_len = oparam;
 257         req->rq_iov[1].iov_base = (req->rq_parm==NULL) ? padding : req->rq_parm;
 258         req->rq_iov[1].iov_len = req->rq_lparm;
 259         req->rq_slen = oparam + req->rq_lparm;
 260
 261         if (req->rq_data) {
 262                 req->rq_iovlen += 2;
 263                 req->rq_iov[2].iov_base = padding;
 264                 req->rq_iov[2].iov_len = odata - oparam - req->rq_lparm;
 265                 req->rq_iov[3].iov_base = req->rq_data;
 266                 req->rq_iov[3].iov_len = req->rq_ldata;
 267                 req->rq_slen = odata + req->rq_ldata;
 268         }
 269
 270         /* always a data part for trans2 replies */
 271         req->rq_setup_read = smb_setup_bcc;
 272
 273         return 0;
 274 }
 275
 276 /*
 277  * Add a request and tell smbiod to process it
 278  */
 279 int smb_add_request(struct smb_request *req)
 280 {
 281         long timeleft;
 282         struct smb_sb_info *server = req->rq_server;
 283         int result = 0;
 284
 285         smb_setup_request(req);
 286         if (req->rq_trans2_command) {
 287                 if (req->rq_buffer == NULL) {
 288                         PARANOIA("trans2 attempted without response buffer!\n");
 289                         return -EIO;
 290                 }
 291                 result = smb_setup_trans2request(req);
 292         }
 293         if (result < 0)
 294                 return result;
 295
 296 #ifdef SMB_DEBUG_PACKET_SIZE
 297         add_xmit_stats(req);
 298 #endif
 299
 300         /* add 'req' to the queue of requests */
 301         if (smb_lock_server_interruptible(server))
 302                 return -EINTR;
 303
 304         /*
 305          * Try to send the request as the process. If that fails we queue the
 306          * request and let smbiod send it later.
 307          */
 308
 309         /* FIXME: each server has a number on the maximum number of parallel
 310            requests. 10, 50 or so. We should not allow more requests to be
 311            active. */
 312         if (server->mid > 0xf000)
 313                 server->mid = 0;
 314         req->rq_mid = server->mid++;
 315         WSET(req->rq_header, smb_mid, req->rq_mid);
 316
 317         result = 0;
 318         if (server->state == CONN_VALID) {
 319                 if (list_empty(&server->xmitq))
 320                         result = smb_request_send_req(req);
 321                 if (result < 0) {
 322                         /* Connection lost? */
 323                         server->conn_error = result;
 324                         server->state = CONN_INVALID;
 325                 }
 326         }
 327         if (result != 1)
 328                 list_add_tail(&req->rq_queue, &server->xmitq);
 329         smb_rget(req);
 330
 331         if (server->state != CONN_VALID)
 332                 smbiod_retry(server);
 333
 334         smb_unlock_server(server);
 335
 336         smbiod_wake_up();
 337
 338         timeleft = wait_event_interruptible_timeout(req->rq_wait,
 339                                     req->rq_flags & SMB_REQ_RECEIVED, 30*HZ);
 340         if (!timeleft || signal_pending(current)) {
 341                 /*
 342                  * On timeout or on interrupt we want to try and remove the
 343                  * request from the recvq/xmitq.
 344                  */
 345                 smb_lock_server(server);
 346                 if (!(req->rq_flags & SMB_REQ_RECEIVED)) {
 347                         list_del_init(&req->rq_queue);
 348                         smb_rput(req);
 349                 }
 350                 smb_unlock_server(server);
 351         }
 352
 353         if (!timeleft) {
 354                 PARANOIA("request [%p, mid=%d] timed out!\n",
 355                          req, req->rq_mid);
 356                 VERBOSE("smb_com:  %02x\n", *(req->rq_header + smb_com));
 357                 VERBOSE("smb_rcls: %02x\n", *(req->rq_header + smb_rcls));
 358                 VERBOSE("smb_flg:  %02x\n", *(req->rq_header + smb_flg));
 359                 VERBOSE("smb_tid:  %04x\n", WVAL(req->rq_header, smb_tid));
 360                 VERBOSE("smb_pid:  %04x\n", WVAL(req->rq_header, smb_pid));
 361                 VERBOSE("smb_uid:  %04x\n", WVAL(req->rq_header, smb_uid));
 362                 VERBOSE("smb_mid:  %04x\n", WVAL(req->rq_header, smb_mid));
 363                 VERBOSE("smb_wct:  %02x\n", *(req->rq_header + smb_wct));
 364
 365                 req->rq_rcls = ERRSRV;
 366                 req->rq_err  = ERRtimeout;
 367
 368                 /* Just in case it was "stuck" */
 369                 smbiod_wake_up();
 370         }
 371         VERBOSE("woke up, rcls=%d\n", req->rq_rcls);
 372
 373         if (req->rq_rcls != 0)
 374                 req->rq_errno = smb_errno(req);
 375         if (signal_pending(current))
 376                 req->rq_errno = -ERESTARTSYS;
 377         return req->rq_errno;
 378 }
 379
 380 /*
 381  * Send a request and place it on the recvq if successfully sent.
 382  * Must be called with the server lock held.
 383  */
 384 static int smb_request_send_req(struct smb_request *req)
 385 {
 386         struct smb_sb_info *server = req->rq_server;
 387         int result;
 388
 389         if (req->rq_bytes_sent == 0) {
 390                 WSET(req->rq_header, smb_tid, server->opt.tid);
 391                 WSET(req->rq_header, smb_pid, 1);
 392                 WSET(req->rq_header, smb_uid, server->opt.server_uid);
 393         }
 394
 395         result = smb_send_request(req);
 396         if (result < 0 && result != -EAGAIN)
 397                 goto out;
 398
 399         result = 0;
 400         if (!(req->rq_flags & SMB_REQ_TRANSMITTED))
 401                 goto out;
 402
 403         list_del_init(&req->rq_queue);
 404         list_add_tail(&req->rq_queue, &server->recvq);
 405         result = 1;
 406 out:
 407         return result;
 408 }
 409
 410 /*
 411  * Sends one request for this server. (smbiod)
 412  * Must be called with the server lock held.
 413  * Returns: <0 on error
 414  *           0 if no request could be completely sent
 415  *           1 if all data for one request was sent
 416  */
 417 int smb_request_send_server(struct smb_sb_info *server)
 418 {
 419         struct list_head *head;
 420         struct smb_request *req;
 421         int result;
 422
 423         if (server->state != CONN_VALID)
 424                 return 0;
 425
 426         /* dequeue first request, if any */
 427         req = NULL;
 428         head = server->xmitq.next;
 429         if (head != &server->xmitq) {
 430                 req = list_entry(head, struct smb_request, rq_queue);
 431         }
 432         if (!req)
 433                 return 0;
 434
 435         result = smb_request_send_req(req);
 436         if (result < 0) {
 437                 server->conn_error = result;
 438                 list_del_init(&req->rq_queue);
 439                 list_add(&req->rq_queue, &server->xmitq);
 440                 result = -EIO;
 441                 goto out;
 442         }
 443
 444 out:
 445         return result;
 446 }
 447
 448 /*
 449  * Try to find a request matching this "mid". Typically the first entry will
 450  * be the matching one.
 451  */
 452 static struct smb_request *find_request(struct smb_sb_info *server, int mid)
 453 {
 454         struct list_head *tmp;
 455         struct smb_request *req = NULL;
 456
 457         list_for_each(tmp, &server->recvq) {
 458                 req = list_entry(tmp, struct smb_request, rq_queue);
 459                 if (req->rq_mid == mid) {
 460                         break;
 461                 }
 462                 req = NULL;
 463         }
 464
 465         if (!req) {
 466                 VERBOSE("received reply with mid %d but no request!\n",
 467                         WVAL(server->header, smb_mid));
 468                 server->rstate = SMB_RECV_DROP;
 469         }
 470
 471         return req;
 472 }
 473
 474 /*
 475  * Called when we have read the smb header and believe this is a response.
 476  */
 477 static int smb_init_request(struct smb_sb_info *server, struct smb_request *req)
 478 {
 479         int hdrlen, wct;
 480
 481         memcpy(req->rq_header, server->header, SMB_HEADER_LEN);
 482
 483         wct = *(req->rq_header + smb_wct);
 484         if (wct > 20) {
 485                 PARANOIA("wct too large, %d > 20\n", wct);
 486                 server->rstate = SMB_RECV_DROP;
 487                 return 0;
 488         }
 489
 490         req->rq_resp_wct = wct;
 491         hdrlen = SMB_HEADER_LEN + wct*2 + 2;
 492         VERBOSE("header length: %d   smb_wct: %2d\n", hdrlen, wct);
 493
 494         req->rq_bytes_recvd = SMB_HEADER_LEN;
 495         req->rq_rlen = hdrlen;
 496         req->rq_iov[0].iov_base = req->rq_header;
 497         req->rq_iov[0].iov_len  = hdrlen;
 498         req->rq_iovlen = 1;
 499         server->rstate = SMB_RECV_PARAM;
 500
 501 #ifdef SMB_DEBUG_PACKET_SIZE
 502         add_recv_stats(smb_len(server->header));
 503 #endif
 504         return 0;
 505 }
 506
 507 /*
 508  * Reads the SMB parameters
 509  */
 510 static int smb_recv_param(struct smb_sb_info *server, struct smb_request *req)
 511 {
 512         int result;
 513
 514         result = smb_receive(server, req);
 515         if (result < 0)
 516                 return result;
 517         if (req->rq_bytes_recvd < req->rq_rlen)
 518                 return 0;
 519
 520         VERBOSE("result: %d   smb_bcc:  %04x\n", result,
 521                 WVAL(req->rq_header, SMB_HEADER_LEN +
 522                      (*(req->rq_header + smb_wct) * 2)));
 523
 524         result = 0;
 525         req->rq_iov[0].iov_base = NULL;
 526         req->rq_rlen = 0;
 527         if (req->rq_callback)
 528                 req->rq_callback(req);
 529         else if (req->rq_setup_read)
 530                 result = req->rq_setup_read(req);
 531         if (result < 0) {
 532                 server->rstate = SMB_RECV_DROP;
 533                 return result;
 534         }
 535
 536         server->rstate = req->rq_rlen > 0 ? SMB_RECV_DATA : SMB_RECV_END;
 537
 538         req->rq_bytes_recvd = 0;        // recvd out of the iov
 539
 540         VERBOSE("rlen: %d\n", req->rq_rlen);
 541         if (req->rq_rlen < 0) {
 542                 PARANOIA("Parameters read beyond end of packet!\n");
 543                 server->rstate = SMB_RECV_END;
 544                 return -EIO;
 545         }
 546         return 0;
 547 }
 548
 549 /*
 550  * Reads the SMB data
 551  */
 552 static int smb_recv_data(struct smb_sb_info *server, struct smb_request *req)
 553 {
 554         int result;
 555
 556         result = smb_receive(server, req);
 557         if (result < 0)
 558                 goto out;
 559         if (req->rq_bytes_recvd < req->rq_rlen)
 560                 goto out;
 561         server->rstate = SMB_RECV_END;
 562 out:
 563         VERBOSE("result: %d\n", result);
 564         return result;
 565 }
 566
 567 /*
 568  * Receive a transaction2 response
 569  * Return: 0 if the response has been fully read
 570  *         1 if there are further "fragments" to read
 571  *        <0 if there is an error
 572  */
 573 static int smb_recv_trans2(struct smb_sb_info *server, struct smb_request *req)
 574 {
 575         unsigned char *inbuf;
 576         unsigned int parm_disp, parm_offset, parm_count, parm_tot;
 577         unsigned int data_disp, data_offset, data_count, data_tot;
 578         int hdrlen = SMB_HEADER_LEN + req->rq_resp_wct*2 - 2;
 579
 580         VERBOSE("handling trans2\n");
 581
 582         inbuf = req->rq_header;
 583         data_tot    = WVAL(inbuf, smb_tdrcnt);
 584         parm_tot    = WVAL(inbuf, smb_tprcnt);
 585         parm_disp   = WVAL(inbuf, smb_prdisp);
 586         parm_offset = WVAL(inbuf, smb_proff);
 587         parm_count  = WVAL(inbuf, smb_prcnt);
 588         data_disp   = WVAL(inbuf, smb_drdisp);
 589         data_offset = WVAL(inbuf, smb_droff);
 590         data_count  = WVAL(inbuf, smb_drcnt);
 591
 592         /* Modify offset for the split header/buffer we use */
 593         if (data_count || data_offset) {
 594                 if (unlikely(data_offset < hdrlen))
 595                         goto out_bad_data;
 596                 else
 597                         data_offset -= hdrlen;
 598         }
 599         if (parm_count || parm_offset) {
 600                 if (unlikely(parm_offset < hdrlen))
 601                         goto out_bad_parm;
 602                 else
 603                         parm_offset -= hdrlen;
 604         }
 605
 606         if (parm_count == parm_tot && data_count == data_tot) {
 607                 /*
 608                  * This packet has all the trans2 data.
 609                  *
 610                  * We setup the request so that this will be the common
 611                  * case. It may be a server error to not return a
 612                  * response that fits.
 613                  */
 614                 VERBOSE("single trans2 response  "
 615                         "dcnt=%u, pcnt=%u, doff=%u, poff=%u\n",
 616                         data_count, parm_count,
 617                         data_offset, parm_offset);
 618                 req->rq_ldata = data_count;
 619                 req->rq_lparm = parm_count;
 620                 req->rq_data = req->rq_buffer + data_offset;
 621                 req->rq_parm = req->rq_buffer + parm_offset;
 622                 if (unlikely(parm_offset + parm_count > req->rq_rlen))
 623                         goto out_bad_parm;
 624                 if (unlikely(data_offset + data_count > req->rq_rlen))
 625                         goto out_bad_data;
 626                 return 0;
 627         }
 628
 629         VERBOSE("multi trans2 response  "
 630                 "frag=%d, dcnt=%u, pcnt=%u, doff=%u, poff=%u\n",
 631                 req->rq_fragment,
 632                 data_count, parm_count,
 633                 data_offset, parm_offset);
 634
 635         if (!req->rq_fragment) {
 636                 int buf_len;
 637
 638                 /* We got the first trans2 fragment */
 639                 req->rq_fragment = 1;
 640                 req->rq_total_data = data_tot;
 641                 req->rq_total_parm = parm_tot;
 642                 req->rq_ldata = 0;
 643                 req->rq_lparm = 0;
 644
 645                 buf_len = data_tot + parm_tot;
 646                 if (buf_len > SMB_MAX_PACKET_SIZE)
 647                         goto out_too_long;
 648
 649                 req->rq_trans2bufsize = buf_len;
 650                 req->rq_trans2buffer = smb_kmalloc(buf_len, GFP_NOFS);
 651                 if (!req->rq_trans2buffer)
 652                         goto out_no_mem;
 653                 memset(req->rq_trans2buffer, 0, buf_len);
 654
 655                 req->rq_parm = req->rq_trans2buffer;
 656                 req->rq_data = req->rq_trans2buffer + parm_tot;
 657         } else if (unlikely(req->rq_total_data < data_tot ||
 658                             req->rq_total_parm < parm_tot))
 659                 goto out_data_grew;
 660
 661         if (unlikely(parm_disp + parm_count > req->rq_total_parm ||
 662                      parm_offset + parm_count > req->rq_rlen))
 663                 goto out_bad_parm;
 664         if (unlikely(data_disp + data_count > req->rq_total_data ||
 665                      data_offset + data_count > req->rq_rlen))
 666                 goto out_bad_data;
 667
 668         inbuf = req->rq_buffer;
 669         memcpy(req->rq_parm + parm_disp, inbuf + parm_offset, parm_count);
 670         memcpy(req->rq_data + data_disp, inbuf + data_offset, data_count);
 671
 672         req->rq_ldata += data_count;
 673         req->rq_lparm += parm_count;
 674
 675         /*
 676          * Check whether we've received all of the data. Note that
 677          * we use the packet totals -- total lengths might shrink!
 678          */
 679         if (req->rq_ldata >= data_tot && req->rq_lparm >= parm_tot) {
 680                 req->rq_ldata = data_tot;
 681                 req->rq_lparm = parm_tot;
 682                 return 0;
 683         }
 684         return 1;
 685
 686 out_too_long:
 687         printk(KERN_ERR "smb_trans2: data/param too long, data=%u, parm=%u\n",
 688                 data_tot, parm_tot);
 689         goto out_EIO;
 690 out_no_mem:
 691         printk(KERN_ERR "smb_trans2: couldn't allocate data area of %d bytes\n",
 692                req->rq_trans2bufsize);
 693         req->rq_errno = -ENOMEM;
 694         goto out;
 695 out_data_grew:
 696         printk(KERN_ERR "smb_trans2: data/params grew!\n");
 697         goto out_EIO;
 698 out_bad_parm:
 699         printk(KERN_ERR "smb_trans2: invalid parms, disp=%u, cnt=%u, tot=%u, ofs=%u\n",
 700                parm_disp, parm_count, parm_tot, parm_offset);
 701         goto out_EIO;
 702 out_bad_data:
 703         printk(KERN_ERR "smb_trans2: invalid data, disp=%u, cnt=%u, tot=%u, ofs=%u\n",
 704                data_disp, data_count, data_tot, data_offset);
 705 out_EIO:
 706         req->rq_errno = -EIO;
 707 out:
 708         return req->rq_errno;
 709 }
 710
 711 /*
 712  * State machine for receiving responses. We handle the fact that we can't
 713  * read the full response in one try by having states telling us how much we
 714  * have read.
 715  *
 716  * Must be called with the server lock held (only called from smbiod).
 717  *
 718  * Return: <0 on error
 719  */
 720 int smb_request_recv(struct smb_sb_info *server)
 721 {
 722         struct smb_request *req = NULL;
 723         int result = 0;
 724
 725         if (smb_recv_available(server) <= 0)
 726                 return 0;
 727
 728         VERBOSE("state: %d\n", server->rstate);
 729         switch (server->rstate) {
 730         case SMB_RECV_DROP:
 731                 result = smb_receive_drop(server);
 732                 if (result < 0)
 733                         break;
 734                 if (server->rstate == SMB_RECV_DROP)
 735                         break;
 736                 server->rstate = SMB_RECV_START;
 737                 /* fallthrough */
 738         case SMB_RECV_START:
 739                 server->smb_read = 0;
 740                 server->rstate = SMB_RECV_HEADER;
 741                 /* fallthrough */
 742         case SMB_RECV_HEADER:
 743                 result = smb_receive_header(server);
 744                 if (result < 0)
 745                         break;
 746                 if (server->rstate == SMB_RECV_HEADER)
 747                         break;
 748                 if (! (*(server->header + smb_flg) & SMB_FLAGS_REPLY) ) {
 749                         server->rstate = SMB_RECV_REQUEST;
 750                         break;
 751                 }
 752                 if (server->rstate != SMB_RECV_HCOMPLETE)
 753                         break;
 754                 /* fallthrough */
 755         case SMB_RECV_HCOMPLETE:
 756                 req = find_request(server, WVAL(server->header, smb_mid));
 757                 if (!req)
 758                         break;
 759                 smb_init_request(server, req);
 760                 req->rq_rcls = *(req->rq_header + smb_rcls);
 761                 req->rq_err  = WVAL(req->rq_header, smb_err);
 762                 if (server->rstate != SMB_RECV_PARAM)
 763                         break;
 764                 /* fallthrough */
 765         case SMB_RECV_PARAM:
 766                 if (!req)
 767                         req = find_request(server,WVAL(server->header,smb_mid));
 768                 if (!req)
 769                         break;
 770                 result = smb_recv_param(server, req);
 771                 if (result < 0)
 772                         break;
 773                 if (server->rstate != SMB_RECV_DATA)
 774                         break;
 775                 /* fallthrough */
 776         case SMB_RECV_DATA:
 777                 if (!req)
 778                         req = find_request(server,WVAL(server->header,smb_mid));
 779                 if (!req)
 780                         break;
 781                 result = smb_recv_data(server, req);
 782                 if (result < 0)
 783                         break;
 784                 break;
 785
 786                 /* We should never be called with any of these states */
 787         case SMB_RECV_END:
 788         case SMB_RECV_REQUEST:
 789                 BUG();
 790         }
 791
 792         if (result < 0) {
 793                 /* We saw an error */
 794                 return result;
 795         }
 796
 797         if (server->rstate != SMB_RECV_END)
 798                 return 0;
 799
 800         result = 0;
 801         if (req->rq_trans2_command && req->rq_rcls == SUCCESS)
 802                 result = smb_recv_trans2(server, req);
 803
 804         /*
 805          * Response completely read. Drop any extra bytes sent by the server.
 806          * (Yes, servers sometimes add extra bytes to responses)
 807          */
 808         VERBOSE("smb_len: %d   smb_read: %d\n",
 809                 server->smb_len, server->smb_read);
 810         if (server->smb_read < server->smb_len)
 811                 smb_receive_drop(server);
 812
 813         server->rstate = SMB_RECV_START;
 814
 815         if (!result) {
 816                 list_del_init(&req->rq_queue);
 817                 req->rq_flags |= SMB_REQ_RECEIVED;
 818                 smb_rput(req);
 819                 wake_up_interruptible(&req->rq_wait);
 820         }
 821         return 0;
 822 }