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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 <linux/freezer.h>
30#include <asm/uaccess.h>
31#include <asm/processor.h>
32#include <linux/mempool.h>
33#include "cifspdu.h"
34#include "cifsglob.h"
35#include "cifsproto.h"
36#include "cifs_debug.h"
37
38extern mempool_t *cifs_mid_poolp;
39
40static void
41wake_up_task(struct mid_q_entry *mid)
42{
43 wake_up_process(mid->callback_data);
44}
45
46struct mid_q_entry *
47AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
48{
49 struct mid_q_entry *temp;
50
51 if (server == NULL) {
52 cERROR(1, "Null TCP session in AllocMidQEntry");
53 return NULL;
54 }
55
56 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
57 if (temp == NULL)
58 return temp;
59 else {
60 memset(temp, 0, sizeof(struct mid_q_entry));
61 temp->mid = smb_buffer->Mid; /* always LE */
62 temp->pid = current->pid;
63 temp->command = cpu_to_le16(smb_buffer->Command);
64 cFYI(1, "For smb_command %d", smb_buffer->Command);
65 /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
66 /* when mid allocated can be before when sent */
67 temp->when_alloc = jiffies;
68
69 /*
70 * The default is for the mid to be synchronous, so the
71 * default callback just wakes up the current task.
72 */
73 temp->callback = wake_up_task;
74 temp->callback_data = current;
75 }
76
77 atomic_inc(&midCount);
78 temp->mid_state = MID_REQUEST_ALLOCATED;
79 return temp;
80}
81
82void
83DeleteMidQEntry(struct mid_q_entry *midEntry)
84{
85#ifdef CONFIG_CIFS_STATS2
86 unsigned long now;
87#endif
88 midEntry->mid_state = MID_FREE;
89 atomic_dec(&midCount);
90 if (midEntry->large_buf)
91 cifs_buf_release(midEntry->resp_buf);
92 else
93 cifs_small_buf_release(midEntry->resp_buf);
94#ifdef CONFIG_CIFS_STATS2
95 now = jiffies;
96 /* commands taking longer than one second are indications that
97 something is wrong, unless it is quite a slow link or server */
98 if ((now - midEntry->when_alloc) > HZ) {
99 if ((cifsFYI & CIFS_TIMER) &&
100 (midEntry->command != cpu_to_le16(SMB_COM_LOCKING_ANDX))) {
101 printk(KERN_DEBUG " CIFS slow rsp: cmd %d mid %llu",
102 midEntry->command, midEntry->mid);
103 printk(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
104 now - midEntry->when_alloc,
105 now - midEntry->when_sent,
106 now - midEntry->when_received);
107 }
108 }
109#endif
110 mempool_free(midEntry, cifs_mid_poolp);
111}
112
113static void
114delete_mid(struct mid_q_entry *mid)
115{
116 spin_lock(&GlobalMid_Lock);
117 list_del(&mid->qhead);
118 spin_unlock(&GlobalMid_Lock);
119
120 DeleteMidQEntry(mid);
121}
122
123static int
124smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
125{
126 int rc = 0;
127 int i = 0;
128 struct msghdr smb_msg;
129 __be32 *buf_len = (__be32 *)(iov[0].iov_base);
130 unsigned int len = iov[0].iov_len;
131 unsigned int total_len;
132 int first_vec = 0;
133 unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
134 struct socket *ssocket = server->ssocket;
135
136 if (ssocket == NULL)
137 return -ENOTSOCK; /* BB eventually add reconnect code here */
138
139 smb_msg.msg_name = (struct sockaddr *) &server->dstaddr;
140 smb_msg.msg_namelen = sizeof(struct sockaddr);
141 smb_msg.msg_control = NULL;
142 smb_msg.msg_controllen = 0;
143 if (server->noblocksnd)
144 smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
145 else
146 smb_msg.msg_flags = MSG_NOSIGNAL;
147
148 total_len = 0;
149 for (i = 0; i < n_vec; i++)
150 total_len += iov[i].iov_len;
151
152 cFYI(1, "Sending smb: total_len %d", total_len);
153 dump_smb(iov[0].iov_base, len);
154
155 i = 0;
156 while (total_len) {
157 rc = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec],
158 n_vec - first_vec, total_len);
159 if ((rc == -ENOSPC) || (rc == -EAGAIN)) {
160 i++;
161 /*
162 * If blocking send we try 3 times, since each can block
163 * for 5 seconds. For nonblocking we have to try more
164 * but wait increasing amounts of time allowing time for
165 * socket to clear. The overall time we wait in either
166 * case to send on the socket is about 15 seconds.
167 * Similarly we wait for 15 seconds for a response from
168 * the server in SendReceive[2] for the server to send
169 * a response back for most types of requests (except
170 * SMB Write past end of file which can be slow, and
171 * blocking lock operations). NFS waits slightly longer
172 * than CIFS, but this can make it take longer for
173 * nonresponsive servers to be detected and 15 seconds
174 * is more than enough time for modern networks to
175 * send a packet. In most cases if we fail to send
176 * after the retries we will kill the socket and
177 * reconnect which may clear the network problem.
178 */
179 if ((i >= 14) || (!server->noblocksnd && (i > 2))) {
180 cERROR(1, "sends on sock %p stuck for 15 seconds",
181 ssocket);
182 rc = -EAGAIN;
183 break;
184 }
185 msleep(1 << i);
186 continue;
187 }
188 if (rc < 0)
189 break;
190
191 if (rc == total_len) {
192 total_len = 0;
193 break;
194 } else if (rc > total_len) {
195 cERROR(1, "sent %d requested %d", rc, total_len);
196 break;
197 }
198 if (rc == 0) {
199 /* should never happen, letting socket clear before
200 retrying is our only obvious option here */
201 cERROR(1, "tcp sent no data");
202 msleep(500);
203 continue;
204 }
205 total_len -= rc;
206 /* the line below resets i */
207 for (i = first_vec; i < n_vec; i++) {
208 if (iov[i].iov_len) {
209 if (rc > iov[i].iov_len) {
210 rc -= iov[i].iov_len;
211 iov[i].iov_len = 0;
212 } else {
213 iov[i].iov_base += rc;
214 iov[i].iov_len -= rc;
215 first_vec = i;
216 break;
217 }
218 }
219 }
220 i = 0; /* in case we get ENOSPC on the next send */
221 }
222
223 if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
224 cFYI(1, "partial send (%d remaining), terminating session",
225 total_len);
226 /* If we have only sent part of an SMB then the next SMB
227 could be taken as the remainder of this one. We need
228 to kill the socket so the server throws away the partial
229 SMB */
230 server->tcpStatus = CifsNeedReconnect;
231 }
232
233 if (rc < 0 && rc != -EINTR)
234 cERROR(1, "Error %d sending data on socket to server", rc);
235 else
236 rc = 0;
237
238 /* Don't want to modify the buffer as a side effect of this call. */
239 *buf_len = cpu_to_be32(smb_buf_length);
240
241 return rc;
242}
243
244int
245smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
246 unsigned int smb_buf_length)
247{
248 struct kvec iov;
249
250 iov.iov_base = smb_buffer;
251 iov.iov_len = smb_buf_length + 4;
252
253 return smb_sendv(server, &iov, 1);
254}
255
256static int
257wait_for_free_credits(struct TCP_Server_Info *server, const int optype,
258 int *credits)
259{
260 int rc;
261
262 spin_lock(&server->req_lock);
263 if (optype == CIFS_ASYNC_OP) {
264 /* oplock breaks must not be held up */
265 server->in_flight++;
266 *credits -= 1;
267 spin_unlock(&server->req_lock);
268 return 0;
269 }
270
271 while (1) {
272 if (*credits <= 0) {
273 spin_unlock(&server->req_lock);
274 cifs_num_waiters_inc(server);
275 rc = wait_event_killable(server->request_q,
276 has_credits(server, credits));
277 cifs_num_waiters_dec(server);
278 if (rc)
279 return rc;
280 spin_lock(&server->req_lock);
281 } else {
282 if (server->tcpStatus == CifsExiting) {
283 spin_unlock(&server->req_lock);
284 return -ENOENT;
285 }
286
287 /*
288 * Can not count locking commands against total
289 * as they are allowed to block on server.
290 */
291
292 /* update # of requests on the wire to server */
293 if (optype != CIFS_BLOCKING_OP) {
294 *credits -= 1;
295 server->in_flight++;
296 }
297 spin_unlock(&server->req_lock);
298 break;
299 }
300 }
301 return 0;
302}
303
304static int
305wait_for_free_request(struct TCP_Server_Info *server, const int optype)
306{
307 return wait_for_free_credits(server, optype,
308 server->ops->get_credits_field(server));
309}
310
311static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
312 struct mid_q_entry **ppmidQ)
313{
314 if (ses->server->tcpStatus == CifsExiting) {
315 return -ENOENT;
316 }
317
318 if (ses->server->tcpStatus == CifsNeedReconnect) {
319 cFYI(1, "tcp session dead - return to caller to retry");
320 return -EAGAIN;
321 }
322
323 if (ses->status != CifsGood) {
324 /* check if SMB session is bad because we are setting it up */
325 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
326 (in_buf->Command != SMB_COM_NEGOTIATE))
327 return -EAGAIN;
328 /* else ok - we are setting up session */
329 }
330 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
331 if (*ppmidQ == NULL)
332 return -ENOMEM;
333 spin_lock(&GlobalMid_Lock);
334 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
335 spin_unlock(&GlobalMid_Lock);
336 return 0;
337}
338
339static int
340wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
341{
342 int error;
343
344 error = wait_event_freezekillable(server->response_q,
345 midQ->mid_state != MID_REQUEST_SUBMITTED);
346 if (error < 0)
347 return -ERESTARTSYS;
348
349 return 0;
350}
351
352static int
353cifs_setup_async_request(struct TCP_Server_Info *server, struct kvec *iov,
354 unsigned int nvec, struct mid_q_entry **ret_mid)
355{
356 int rc;
357 struct smb_hdr *hdr = (struct smb_hdr *)iov[0].iov_base;
358 struct mid_q_entry *mid;
359
360 /* enable signing if server requires it */
361 if (server->sec_mode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
362 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
363
364 mid = AllocMidQEntry(hdr, server);
365 if (mid == NULL)
366 return -ENOMEM;
367
368 rc = cifs_sign_smb2(iov, nvec, server, &mid->sequence_number);
369 if (rc) {
370 DeleteMidQEntry(mid);
371 return rc;
372 }
373
374 *ret_mid = mid;
375 return 0;
376}
377
378/*
379 * Send a SMB request and set the callback function in the mid to handle
380 * the result. Caller is responsible for dealing with timeouts.
381 */
382int
383cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
384 unsigned int nvec, mid_receive_t *receive,
385 mid_callback_t *callback, void *cbdata, bool ignore_pend)
386{
387 int rc;
388 struct mid_q_entry *mid;
389
390 rc = wait_for_free_request(server, ignore_pend ? CIFS_ASYNC_OP : 0);
391 if (rc)
392 return rc;
393
394 mutex_lock(&server->srv_mutex);
395 rc = cifs_setup_async_request(server, iov, nvec, &mid);
396 if (rc) {
397 mutex_unlock(&server->srv_mutex);
398 add_credits(server, 1);
399 wake_up(&server->request_q);
400 return rc;
401 }
402
403 mid->receive = receive;
404 mid->callback = callback;
405 mid->callback_data = cbdata;
406 mid->mid_state = MID_REQUEST_SUBMITTED;
407
408 /* put it on the pending_mid_q */
409 spin_lock(&GlobalMid_Lock);
410 list_add_tail(&mid->qhead, &server->pending_mid_q);
411 spin_unlock(&GlobalMid_Lock);
412
413
414 cifs_in_send_inc(server);
415 rc = smb_sendv(server, iov, nvec);
416 cifs_in_send_dec(server);
417 cifs_save_when_sent(mid);
418 mutex_unlock(&server->srv_mutex);
419
420 if (rc == 0)
421 return 0;
422
423 delete_mid(mid);
424 add_credits(server, 1);
425 wake_up(&server->request_q);
426 return rc;
427}
428
429/*
430 *
431 * Send an SMB Request. No response info (other than return code)
432 * needs to be parsed.
433 *
434 * flags indicate the type of request buffer and how long to wait
435 * and whether to log NT STATUS code (error) before mapping it to POSIX error
436 *
437 */
438int
439SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
440 char *in_buf, int flags)
441{
442 int rc;
443 struct kvec iov[1];
444 int resp_buf_type;
445
446 iov[0].iov_base = in_buf;
447 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
448 flags |= CIFS_NO_RESP;
449 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags);
450 cFYI(DBG2, "SendRcvNoRsp flags %d rc %d", flags, rc);
451
452 return rc;
453}
454
455static int
456cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
457{
458 int rc = 0;
459
460 cFYI(1, "%s: cmd=%d mid=%llu state=%d", __func__,
461 le16_to_cpu(mid->command), mid->mid, mid->mid_state);
462
463 spin_lock(&GlobalMid_Lock);
464 switch (mid->mid_state) {
465 case MID_RESPONSE_RECEIVED:
466 spin_unlock(&GlobalMid_Lock);
467 return rc;
468 case MID_RETRY_NEEDED:
469 rc = -EAGAIN;
470 break;
471 case MID_RESPONSE_MALFORMED:
472 rc = -EIO;
473 break;
474 case MID_SHUTDOWN:
475 rc = -EHOSTDOWN;
476 break;
477 default:
478 list_del_init(&mid->qhead);
479 cERROR(1, "%s: invalid mid state mid=%llu state=%d", __func__,
480 mid->mid, mid->mid_state);
481 rc = -EIO;
482 }
483 spin_unlock(&GlobalMid_Lock);
484
485 DeleteMidQEntry(mid);
486 return rc;
487}
488
489static inline int
490send_cancel(struct TCP_Server_Info *server, void *buf, struct mid_q_entry *mid)
491{
492 return server->ops->send_cancel ?
493 server->ops->send_cancel(server, buf, mid) : 0;
494}
495
496int
497cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
498 bool log_error)
499{
500 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
501
502 dump_smb(mid->resp_buf, min_t(u32, 92, len));
503
504 /* convert the length into a more usable form */
505 if (server->sec_mode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
506 struct kvec iov;
507
508 iov.iov_base = mid->resp_buf;
509 iov.iov_len = len;
510 /* FIXME: add code to kill session */
511 if (cifs_verify_signature(&iov, 1, server,
512 mid->sequence_number + 1) != 0)
513 cERROR(1, "Unexpected SMB signature");
514 }
515
516 /* BB special case reconnect tid and uid here? */
517 return map_smb_to_linux_error(mid->resp_buf, log_error);
518}
519
520int
521cifs_setup_request(struct cifs_ses *ses, struct kvec *iov,
522 unsigned int nvec, struct mid_q_entry **ret_mid)
523{
524 int rc;
525 struct smb_hdr *hdr = (struct smb_hdr *)iov[0].iov_base;
526 struct mid_q_entry *mid;
527
528 rc = allocate_mid(ses, hdr, &mid);
529 if (rc)
530 return rc;
531 rc = cifs_sign_smb2(iov, nvec, ses->server, &mid->sequence_number);
532 if (rc)
533 delete_mid(mid);
534 *ret_mid = mid;
535 return rc;
536}
537
538int
539SendReceive2(const unsigned int xid, struct cifs_ses *ses,
540 struct kvec *iov, int n_vec, int *pRespBufType /* ret */,
541 const int flags)
542{
543 int rc = 0;
544 int long_op;
545 struct mid_q_entry *midQ;
546 char *buf = iov[0].iov_base;
547
548 long_op = flags & CIFS_TIMEOUT_MASK;
549
550 *pRespBufType = CIFS_NO_BUFFER; /* no response buf yet */
551
552 if ((ses == NULL) || (ses->server == NULL)) {
553 cifs_small_buf_release(buf);
554 cERROR(1, "Null session");
555 return -EIO;
556 }
557
558 if (ses->server->tcpStatus == CifsExiting) {
559 cifs_small_buf_release(buf);
560 return -ENOENT;
561 }
562
563 /*
564 * Ensure that we do not send more than 50 overlapping requests
565 * to the same server. We may make this configurable later or
566 * use ses->maxReq.
567 */
568
569 rc = wait_for_free_request(ses->server, long_op);
570 if (rc) {
571 cifs_small_buf_release(buf);
572 return rc;
573 }
574
575 /*
576 * Make sure that we sign in the same order that we send on this socket
577 * and avoid races inside tcp sendmsg code that could cause corruption
578 * of smb data.
579 */
580
581 mutex_lock(&ses->server->srv_mutex);
582
583 rc = ses->server->ops->setup_request(ses, iov, n_vec, &midQ);
584 if (rc) {
585 mutex_unlock(&ses->server->srv_mutex);
586 cifs_small_buf_release(buf);
587 /* Update # of requests on wire to server */
588 add_credits(ses->server, 1);
589 return rc;
590 }
591
592 midQ->mid_state = MID_REQUEST_SUBMITTED;
593 cifs_in_send_inc(ses->server);
594 rc = smb_sendv(ses->server, iov, n_vec);
595 cifs_in_send_dec(ses->server);
596 cifs_save_when_sent(midQ);
597
598 mutex_unlock(&ses->server->srv_mutex);
599
600 if (rc < 0) {
601 cifs_small_buf_release(buf);
602 goto out;
603 }
604
605 if (long_op == CIFS_ASYNC_OP) {
606 cifs_small_buf_release(buf);
607 goto out;
608 }
609
610 rc = wait_for_response(ses->server, midQ);
611 if (rc != 0) {
612 send_cancel(ses->server, buf, midQ);
613 spin_lock(&GlobalMid_Lock);
614 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
615 midQ->callback = DeleteMidQEntry;
616 spin_unlock(&GlobalMid_Lock);
617 cifs_small_buf_release(buf);
618 add_credits(ses->server, 1);
619 return rc;
620 }
621 spin_unlock(&GlobalMid_Lock);
622 }
623
624 cifs_small_buf_release(buf);
625
626 rc = cifs_sync_mid_result(midQ, ses->server);
627 if (rc != 0) {
628 add_credits(ses->server, 1);
629 return rc;
630 }
631
632 if (!midQ->resp_buf || midQ->mid_state != MID_RESPONSE_RECEIVED) {
633 rc = -EIO;
634 cFYI(1, "Bad MID state?");
635 goto out;
636 }
637
638 buf = (char *)midQ->resp_buf;
639 iov[0].iov_base = buf;
640 iov[0].iov_len = get_rfc1002_length(buf) + 4;
641 if (midQ->large_buf)
642 *pRespBufType = CIFS_LARGE_BUFFER;
643 else
644 *pRespBufType = CIFS_SMALL_BUFFER;
645
646 rc = ses->server->ops->check_receive(midQ, ses->server,
647 flags & CIFS_LOG_ERROR);
648
649 /* mark it so buf will not be freed by delete_mid */
650 if ((flags & CIFS_NO_RESP) == 0)
651 midQ->resp_buf = NULL;
652out:
653 delete_mid(midQ);
654 add_credits(ses->server, 1);
655
656 return rc;
657}
658
659int
660SendReceive(const unsigned int xid, struct cifs_ses *ses,
661 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
662 int *pbytes_returned, const int long_op)
663{
664 int rc = 0;
665 struct mid_q_entry *midQ;
666
667 if (ses == NULL) {
668 cERROR(1, "Null smb session");
669 return -EIO;
670 }
671 if (ses->server == NULL) {
672 cERROR(1, "Null tcp session");
673 return -EIO;
674 }
675
676 if (ses->server->tcpStatus == CifsExiting)
677 return -ENOENT;
678
679 /* Ensure that we do not send more than 50 overlapping requests
680 to the same server. We may make this configurable later or
681 use ses->maxReq */
682
683 if (be32_to_cpu(in_buf->smb_buf_length) > CIFSMaxBufSize +
684 MAX_CIFS_HDR_SIZE - 4) {
685 cERROR(1, "Illegal length, greater than maximum frame, %d",
686 be32_to_cpu(in_buf->smb_buf_length));
687 return -EIO;
688 }
689
690 rc = wait_for_free_request(ses->server, long_op);
691 if (rc)
692 return rc;
693
694 /* make sure that we sign in the same order that we send on this socket
695 and avoid races inside tcp sendmsg code that could cause corruption
696 of smb data */
697
698 mutex_lock(&ses->server->srv_mutex);
699
700 rc = allocate_mid(ses, in_buf, &midQ);
701 if (rc) {
702 mutex_unlock(&ses->server->srv_mutex);
703 /* Update # of requests on wire to server */
704 add_credits(ses->server, 1);
705 return rc;
706 }
707
708 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
709 if (rc) {
710 mutex_unlock(&ses->server->srv_mutex);
711 goto out;
712 }
713
714 midQ->mid_state = MID_REQUEST_SUBMITTED;
715
716 cifs_in_send_inc(ses->server);
717 rc = smb_send(ses->server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
718 cifs_in_send_dec(ses->server);
719 cifs_save_when_sent(midQ);
720 mutex_unlock(&ses->server->srv_mutex);
721
722 if (rc < 0)
723 goto out;
724
725 if (long_op == CIFS_ASYNC_OP)
726 goto out;
727
728 rc = wait_for_response(ses->server, midQ);
729 if (rc != 0) {
730 send_cancel(ses->server, in_buf, midQ);
731 spin_lock(&GlobalMid_Lock);
732 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
733 /* no longer considered to be "in-flight" */
734 midQ->callback = DeleteMidQEntry;
735 spin_unlock(&GlobalMid_Lock);
736 add_credits(ses->server, 1);
737 return rc;
738 }
739 spin_unlock(&GlobalMid_Lock);
740 }
741
742 rc = cifs_sync_mid_result(midQ, ses->server);
743 if (rc != 0) {
744 add_credits(ses->server, 1);
745 return rc;
746 }
747
748 if (!midQ->resp_buf || !out_buf ||
749 midQ->mid_state != MID_RESPONSE_RECEIVED) {
750 rc = -EIO;
751 cERROR(1, "Bad MID state?");
752 goto out;
753 }
754
755 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
756 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
757 rc = cifs_check_receive(midQ, ses->server, 0);
758out:
759 delete_mid(midQ);
760 add_credits(ses->server, 1);
761
762 return rc;
763}
764
765/* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
766 blocking lock to return. */
767
768static int
769send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
770 struct smb_hdr *in_buf,
771 struct smb_hdr *out_buf)
772{
773 int bytes_returned;
774 struct cifs_ses *ses = tcon->ses;
775 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
776
777 /* We just modify the current in_buf to change
778 the type of lock from LOCKING_ANDX_SHARED_LOCK
779 or LOCKING_ANDX_EXCLUSIVE_LOCK to
780 LOCKING_ANDX_CANCEL_LOCK. */
781
782 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
783 pSMB->Timeout = 0;
784 pSMB->hdr.Mid = get_next_mid(ses->server);
785
786 return SendReceive(xid, ses, in_buf, out_buf,
787 &bytes_returned, 0);
788}
789
790int
791SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
792 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
793 int *pbytes_returned)
794{
795 int rc = 0;
796 int rstart = 0;
797 struct mid_q_entry *midQ;
798 struct cifs_ses *ses;
799
800 if (tcon == NULL || tcon->ses == NULL) {
801 cERROR(1, "Null smb session");
802 return -EIO;
803 }
804 ses = tcon->ses;
805
806 if (ses->server == NULL) {
807 cERROR(1, "Null tcp session");
808 return -EIO;
809 }
810
811 if (ses->server->tcpStatus == CifsExiting)
812 return -ENOENT;
813
814 /* Ensure that we do not send more than 50 overlapping requests
815 to the same server. We may make this configurable later or
816 use ses->maxReq */
817
818 if (be32_to_cpu(in_buf->smb_buf_length) > CIFSMaxBufSize +
819 MAX_CIFS_HDR_SIZE - 4) {
820 cERROR(1, "Illegal length, greater than maximum frame, %d",
821 be32_to_cpu(in_buf->smb_buf_length));
822 return -EIO;
823 }
824
825 rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP);
826 if (rc)
827 return rc;
828
829 /* make sure that we sign in the same order that we send on this socket
830 and avoid races inside tcp sendmsg code that could cause corruption
831 of smb data */
832
833 mutex_lock(&ses->server->srv_mutex);
834
835 rc = allocate_mid(ses, in_buf, &midQ);
836 if (rc) {
837 mutex_unlock(&ses->server->srv_mutex);
838 return rc;
839 }
840
841 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
842 if (rc) {
843 delete_mid(midQ);
844 mutex_unlock(&ses->server->srv_mutex);
845 return rc;
846 }
847
848 midQ->mid_state = MID_REQUEST_SUBMITTED;
849 cifs_in_send_inc(ses->server);
850 rc = smb_send(ses->server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
851 cifs_in_send_dec(ses->server);
852 cifs_save_when_sent(midQ);
853 mutex_unlock(&ses->server->srv_mutex);
854
855 if (rc < 0) {
856 delete_mid(midQ);
857 return rc;
858 }
859
860 /* Wait for a reply - allow signals to interrupt. */
861 rc = wait_event_interruptible(ses->server->response_q,
862 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
863 ((ses->server->tcpStatus != CifsGood) &&
864 (ses->server->tcpStatus != CifsNew)));
865
866 /* Were we interrupted by a signal ? */
867 if ((rc == -ERESTARTSYS) &&
868 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
869 ((ses->server->tcpStatus == CifsGood) ||
870 (ses->server->tcpStatus == CifsNew))) {
871
872 if (in_buf->Command == SMB_COM_TRANSACTION2) {
873 /* POSIX lock. We send a NT_CANCEL SMB to cause the
874 blocking lock to return. */
875 rc = send_cancel(ses->server, in_buf, midQ);
876 if (rc) {
877 delete_mid(midQ);
878 return rc;
879 }
880 } else {
881 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
882 to cause the blocking lock to return. */
883
884 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
885
886 /* If we get -ENOLCK back the lock may have
887 already been removed. Don't exit in this case. */
888 if (rc && rc != -ENOLCK) {
889 delete_mid(midQ);
890 return rc;
891 }
892 }
893
894 rc = wait_for_response(ses->server, midQ);
895 if (rc) {
896 send_cancel(ses->server, in_buf, midQ);
897 spin_lock(&GlobalMid_Lock);
898 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
899 /* no longer considered to be "in-flight" */
900 midQ->callback = DeleteMidQEntry;
901 spin_unlock(&GlobalMid_Lock);
902 return rc;
903 }
904 spin_unlock(&GlobalMid_Lock);
905 }
906
907 /* We got the response - restart system call. */
908 rstart = 1;
909 }
910
911 rc = cifs_sync_mid_result(midQ, ses->server);
912 if (rc != 0)
913 return rc;
914
915 /* rcvd frame is ok */
916 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
917 rc = -EIO;
918 cERROR(1, "Bad MID state?");
919 goto out;
920 }
921
922 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
923 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
924 rc = cifs_check_receive(midQ, ses->server, 0);
925out:
926 delete_mid(midQ);
927 if (rstart && rc == -EACCES)
928 return -ERESTARTSYS;
929 return rc;
930}
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 <linux/freezer.h>
30#include <linux/tcp.h>
31#include <linux/highmem.h>
32#include <asm/uaccess.h>
33#include <asm/processor.h>
34#include <linux/mempool.h>
35#include "cifspdu.h"
36#include "cifsglob.h"
37#include "cifsproto.h"
38#include "cifs_debug.h"
39
40void
41cifs_wake_up_task(struct mid_q_entry *mid)
42{
43 wake_up_process(mid->callback_data);
44}
45
46struct mid_q_entry *
47AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
48{
49 struct mid_q_entry *temp;
50
51 if (server == NULL) {
52 cifs_dbg(VFS, "Null TCP session in AllocMidQEntry\n");
53 return NULL;
54 }
55
56 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
57 if (temp == NULL)
58 return temp;
59 else {
60 memset(temp, 0, sizeof(struct mid_q_entry));
61 temp->mid = get_mid(smb_buffer);
62 temp->pid = current->pid;
63 temp->command = cpu_to_le16(smb_buffer->Command);
64 cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
65 /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
66 /* when mid allocated can be before when sent */
67 temp->when_alloc = jiffies;
68 temp->server = server;
69
70 /*
71 * The default is for the mid to be synchronous, so the
72 * default callback just wakes up the current task.
73 */
74 temp->callback = cifs_wake_up_task;
75 temp->callback_data = current;
76 }
77
78 atomic_inc(&midCount);
79 temp->mid_state = MID_REQUEST_ALLOCATED;
80 return temp;
81}
82
83void
84DeleteMidQEntry(struct mid_q_entry *midEntry)
85{
86#ifdef CONFIG_CIFS_STATS2
87 __le16 command = midEntry->server->vals->lock_cmd;
88 unsigned long now;
89#endif
90 midEntry->mid_state = MID_FREE;
91 atomic_dec(&midCount);
92 if (midEntry->large_buf)
93 cifs_buf_release(midEntry->resp_buf);
94 else
95 cifs_small_buf_release(midEntry->resp_buf);
96#ifdef CONFIG_CIFS_STATS2
97 now = jiffies;
98 /* commands taking longer than one second are indications that
99 something is wrong, unless it is quite a slow link or server */
100 if ((now - midEntry->when_alloc) > HZ) {
101 if ((cifsFYI & CIFS_TIMER) && (midEntry->command != command)) {
102 pr_debug(" CIFS slow rsp: cmd %d mid %llu",
103 midEntry->command, midEntry->mid);
104 pr_info(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
105 now - midEntry->when_alloc,
106 now - midEntry->when_sent,
107 now - midEntry->when_received);
108 }
109 }
110#endif
111 mempool_free(midEntry, cifs_mid_poolp);
112}
113
114void
115cifs_delete_mid(struct mid_q_entry *mid)
116{
117 spin_lock(&GlobalMid_Lock);
118 list_del(&mid->qhead);
119 spin_unlock(&GlobalMid_Lock);
120
121 DeleteMidQEntry(mid);
122}
123
124/*
125 * smb_send_kvec - send an array of kvecs to the server
126 * @server: Server to send the data to
127 * @iov: Pointer to array of kvecs
128 * @n_vec: length of kvec array
129 * @sent: amount of data sent on socket is stored here
130 *
131 * Our basic "send data to server" function. Should be called with srv_mutex
132 * held. The caller is responsible for handling the results.
133 */
134static int
135smb_send_kvec(struct TCP_Server_Info *server, struct kvec *iov, size_t n_vec,
136 size_t *sent)
137{
138 int rc = 0;
139 int i = 0;
140 struct msghdr smb_msg;
141 unsigned int remaining;
142 size_t first_vec = 0;
143 struct socket *ssocket = server->ssocket;
144
145 *sent = 0;
146
147 smb_msg.msg_name = (struct sockaddr *) &server->dstaddr;
148 smb_msg.msg_namelen = sizeof(struct sockaddr);
149 smb_msg.msg_control = NULL;
150 smb_msg.msg_controllen = 0;
151 if (server->noblocksnd)
152 smb_msg.msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
153 else
154 smb_msg.msg_flags = MSG_NOSIGNAL;
155
156 remaining = 0;
157 for (i = 0; i < n_vec; i++)
158 remaining += iov[i].iov_len;
159
160 i = 0;
161 while (remaining) {
162 /*
163 * If blocking send, we try 3 times, since each can block
164 * for 5 seconds. For nonblocking we have to try more
165 * but wait increasing amounts of time allowing time for
166 * socket to clear. The overall time we wait in either
167 * case to send on the socket is about 15 seconds.
168 * Similarly we wait for 15 seconds for a response from
169 * the server in SendReceive[2] for the server to send
170 * a response back for most types of requests (except
171 * SMB Write past end of file which can be slow, and
172 * blocking lock operations). NFS waits slightly longer
173 * than CIFS, but this can make it take longer for
174 * nonresponsive servers to be detected and 15 seconds
175 * is more than enough time for modern networks to
176 * send a packet. In most cases if we fail to send
177 * after the retries we will kill the socket and
178 * reconnect which may clear the network problem.
179 */
180 rc = kernel_sendmsg(ssocket, &smb_msg, &iov[first_vec],
181 n_vec - first_vec, remaining);
182 if (rc == -EAGAIN) {
183 i++;
184 if (i >= 14 || (!server->noblocksnd && (i > 2))) {
185 cifs_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
186 ssocket);
187 rc = -EAGAIN;
188 break;
189 }
190 msleep(1 << i);
191 continue;
192 }
193
194 if (rc < 0)
195 break;
196
197 /* send was at least partially successful */
198 *sent += rc;
199
200 if (rc == remaining) {
201 remaining = 0;
202 break;
203 }
204
205 if (rc > remaining) {
206 cifs_dbg(VFS, "sent %d requested %d\n", rc, remaining);
207 break;
208 }
209
210 if (rc == 0) {
211 /* should never happen, letting socket clear before
212 retrying is our only obvious option here */
213 cifs_dbg(VFS, "tcp sent no data\n");
214 msleep(500);
215 continue;
216 }
217
218 remaining -= rc;
219
220 /* the line below resets i */
221 for (i = first_vec; i < n_vec; i++) {
222 if (iov[i].iov_len) {
223 if (rc > iov[i].iov_len) {
224 rc -= iov[i].iov_len;
225 iov[i].iov_len = 0;
226 } else {
227 iov[i].iov_base += rc;
228 iov[i].iov_len -= rc;
229 first_vec = i;
230 break;
231 }
232 }
233 }
234
235 i = 0; /* in case we get ENOSPC on the next send */
236 rc = 0;
237 }
238 return rc;
239}
240
241/**
242 * rqst_page_to_kvec - Turn a slot in the smb_rqst page array into a kvec
243 * @rqst: pointer to smb_rqst
244 * @idx: index into the array of the page
245 * @iov: pointer to struct kvec that will hold the result
246 *
247 * Helper function to convert a slot in the rqst->rq_pages array into a kvec.
248 * The page will be kmapped and the address placed into iov_base. The length
249 * will then be adjusted according to the ptailoff.
250 */
251void
252cifs_rqst_page_to_kvec(struct smb_rqst *rqst, unsigned int idx,
253 struct kvec *iov)
254{
255 /*
256 * FIXME: We could avoid this kmap altogether if we used
257 * kernel_sendpage instead of kernel_sendmsg. That will only
258 * work if signing is disabled though as sendpage inlines the
259 * page directly into the fraglist. If userspace modifies the
260 * page after we calculate the signature, then the server will
261 * reject it and may break the connection. kernel_sendmsg does
262 * an extra copy of the data and avoids that issue.
263 */
264 iov->iov_base = kmap(rqst->rq_pages[idx]);
265
266 /* if last page, don't send beyond this offset into page */
267 if (idx == (rqst->rq_npages - 1))
268 iov->iov_len = rqst->rq_tailsz;
269 else
270 iov->iov_len = rqst->rq_pagesz;
271}
272
273static unsigned long
274rqst_len(struct smb_rqst *rqst)
275{
276 unsigned int i;
277 struct kvec *iov = rqst->rq_iov;
278 unsigned long buflen = 0;
279
280 /* total up iov array first */
281 for (i = 0; i < rqst->rq_nvec; i++)
282 buflen += iov[i].iov_len;
283
284 /* add in the page array if there is one */
285 if (rqst->rq_npages) {
286 buflen += rqst->rq_pagesz * (rqst->rq_npages - 1);
287 buflen += rqst->rq_tailsz;
288 }
289
290 return buflen;
291}
292
293static int
294smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
295{
296 int rc;
297 struct kvec *iov = rqst->rq_iov;
298 int n_vec = rqst->rq_nvec;
299 unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
300 unsigned long send_length;
301 unsigned int i;
302 size_t total_len = 0, sent;
303 struct socket *ssocket = server->ssocket;
304 int val = 1;
305
306 if (ssocket == NULL)
307 return -ENOTSOCK;
308
309 /* sanity check send length */
310 send_length = rqst_len(rqst);
311 if (send_length != smb_buf_length + 4) {
312 WARN(1, "Send length mismatch(send_length=%lu smb_buf_length=%u)\n",
313 send_length, smb_buf_length);
314 return -EIO;
315 }
316
317 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", smb_buf_length);
318 dump_smb(iov[0].iov_base, iov[0].iov_len);
319
320 /* cork the socket */
321 kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
322 (char *)&val, sizeof(val));
323
324 rc = smb_send_kvec(server, iov, n_vec, &sent);
325 if (rc < 0)
326 goto uncork;
327
328 total_len += sent;
329
330 /* now walk the page array and send each page in it */
331 for (i = 0; i < rqst->rq_npages; i++) {
332 struct kvec p_iov;
333
334 cifs_rqst_page_to_kvec(rqst, i, &p_iov);
335 rc = smb_send_kvec(server, &p_iov, 1, &sent);
336 kunmap(rqst->rq_pages[i]);
337 if (rc < 0)
338 break;
339
340 total_len += sent;
341 }
342
343uncork:
344 /* uncork it */
345 val = 0;
346 kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
347 (char *)&val, sizeof(val));
348
349 if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
350 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
351 smb_buf_length + 4, total_len);
352 /*
353 * If we have only sent part of an SMB then the next SMB could
354 * be taken as the remainder of this one. We need to kill the
355 * socket so the server throws away the partial SMB
356 */
357 server->tcpStatus = CifsNeedReconnect;
358 }
359
360 if (rc < 0 && rc != -EINTR)
361 cifs_dbg(VFS, "Error %d sending data on socket to server\n",
362 rc);
363 else
364 rc = 0;
365
366 return rc;
367}
368
369static int
370smb_sendv(struct TCP_Server_Info *server, struct kvec *iov, int n_vec)
371{
372 struct smb_rqst rqst = { .rq_iov = iov,
373 .rq_nvec = n_vec };
374
375 return smb_send_rqst(server, &rqst);
376}
377
378int
379smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
380 unsigned int smb_buf_length)
381{
382 struct kvec iov;
383
384 iov.iov_base = smb_buffer;
385 iov.iov_len = smb_buf_length + 4;
386
387 return smb_sendv(server, &iov, 1);
388}
389
390static int
391wait_for_free_credits(struct TCP_Server_Info *server, const int timeout,
392 int *credits)
393{
394 int rc;
395
396 spin_lock(&server->req_lock);
397 if (timeout == CIFS_ASYNC_OP) {
398 /* oplock breaks must not be held up */
399 server->in_flight++;
400 *credits -= 1;
401 spin_unlock(&server->req_lock);
402 return 0;
403 }
404
405 while (1) {
406 if (*credits <= 0) {
407 spin_unlock(&server->req_lock);
408 cifs_num_waiters_inc(server);
409 rc = wait_event_killable(server->request_q,
410 has_credits(server, credits));
411 cifs_num_waiters_dec(server);
412 if (rc)
413 return rc;
414 spin_lock(&server->req_lock);
415 } else {
416 if (server->tcpStatus == CifsExiting) {
417 spin_unlock(&server->req_lock);
418 return -ENOENT;
419 }
420
421 /*
422 * Can not count locking commands against total
423 * as they are allowed to block on server.
424 */
425
426 /* update # of requests on the wire to server */
427 if (timeout != CIFS_BLOCKING_OP) {
428 *credits -= 1;
429 server->in_flight++;
430 }
431 spin_unlock(&server->req_lock);
432 break;
433 }
434 }
435 return 0;
436}
437
438static int
439wait_for_free_request(struct TCP_Server_Info *server, const int timeout,
440 const int optype)
441{
442 int *val;
443
444 val = server->ops->get_credits_field(server, optype);
445 /* Since an echo is already inflight, no need to wait to send another */
446 if (*val <= 0 && optype == CIFS_ECHO_OP)
447 return -EAGAIN;
448 return wait_for_free_credits(server, timeout, val);
449}
450
451int
452cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
453 unsigned int *num, unsigned int *credits)
454{
455 *num = size;
456 *credits = 0;
457 return 0;
458}
459
460static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
461 struct mid_q_entry **ppmidQ)
462{
463 if (ses->server->tcpStatus == CifsExiting) {
464 return -ENOENT;
465 }
466
467 if (ses->server->tcpStatus == CifsNeedReconnect) {
468 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
469 return -EAGAIN;
470 }
471
472 if (ses->status == CifsNew) {
473 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
474 (in_buf->Command != SMB_COM_NEGOTIATE))
475 return -EAGAIN;
476 /* else ok - we are setting up session */
477 }
478
479 if (ses->status == CifsExiting) {
480 /* check if SMB session is bad because we are setting it up */
481 if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
482 return -EAGAIN;
483 /* else ok - we are shutting down session */
484 }
485
486 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
487 if (*ppmidQ == NULL)
488 return -ENOMEM;
489 spin_lock(&GlobalMid_Lock);
490 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
491 spin_unlock(&GlobalMid_Lock);
492 return 0;
493}
494
495static int
496wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
497{
498 int error;
499
500 error = wait_event_freezekillable_unsafe(server->response_q,
501 midQ->mid_state != MID_REQUEST_SUBMITTED);
502 if (error < 0)
503 return -ERESTARTSYS;
504
505 return 0;
506}
507
508struct mid_q_entry *
509cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
510{
511 int rc;
512 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
513 struct mid_q_entry *mid;
514
515 /* enable signing if server requires it */
516 if (server->sign)
517 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
518
519 mid = AllocMidQEntry(hdr, server);
520 if (mid == NULL)
521 return ERR_PTR(-ENOMEM);
522
523 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
524 if (rc) {
525 DeleteMidQEntry(mid);
526 return ERR_PTR(rc);
527 }
528
529 return mid;
530}
531
532/*
533 * Send a SMB request and set the callback function in the mid to handle
534 * the result. Caller is responsible for dealing with timeouts.
535 */
536int
537cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
538 mid_receive_t *receive, mid_callback_t *callback,
539 void *cbdata, const int flags)
540{
541 int rc, timeout, optype;
542 struct mid_q_entry *mid;
543 unsigned int credits = 0;
544
545 timeout = flags & CIFS_TIMEOUT_MASK;
546 optype = flags & CIFS_OP_MASK;
547
548 if ((flags & CIFS_HAS_CREDITS) == 0) {
549 rc = wait_for_free_request(server, timeout, optype);
550 if (rc)
551 return rc;
552 credits = 1;
553 }
554
555 mutex_lock(&server->srv_mutex);
556 mid = server->ops->setup_async_request(server, rqst);
557 if (IS_ERR(mid)) {
558 mutex_unlock(&server->srv_mutex);
559 add_credits_and_wake_if(server, credits, optype);
560 return PTR_ERR(mid);
561 }
562
563 mid->receive = receive;
564 mid->callback = callback;
565 mid->callback_data = cbdata;
566 mid->mid_state = MID_REQUEST_SUBMITTED;
567
568 /* put it on the pending_mid_q */
569 spin_lock(&GlobalMid_Lock);
570 list_add_tail(&mid->qhead, &server->pending_mid_q);
571 spin_unlock(&GlobalMid_Lock);
572
573
574 cifs_in_send_inc(server);
575 rc = smb_send_rqst(server, rqst);
576 cifs_in_send_dec(server);
577 cifs_save_when_sent(mid);
578
579 if (rc < 0) {
580 server->sequence_number -= 2;
581 cifs_delete_mid(mid);
582 }
583
584 mutex_unlock(&server->srv_mutex);
585
586 if (rc == 0)
587 return 0;
588
589 add_credits_and_wake_if(server, credits, optype);
590 return rc;
591}
592
593/*
594 *
595 * Send an SMB Request. No response info (other than return code)
596 * needs to be parsed.
597 *
598 * flags indicate the type of request buffer and how long to wait
599 * and whether to log NT STATUS code (error) before mapping it to POSIX error
600 *
601 */
602int
603SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
604 char *in_buf, int flags)
605{
606 int rc;
607 struct kvec iov[1];
608 int resp_buf_type;
609
610 iov[0].iov_base = in_buf;
611 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
612 flags |= CIFS_NO_RESP;
613 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags);
614 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
615
616 return rc;
617}
618
619static int
620cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
621{
622 int rc = 0;
623
624 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
625 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
626
627 spin_lock(&GlobalMid_Lock);
628 switch (mid->mid_state) {
629 case MID_RESPONSE_RECEIVED:
630 spin_unlock(&GlobalMid_Lock);
631 return rc;
632 case MID_RETRY_NEEDED:
633 rc = -EAGAIN;
634 break;
635 case MID_RESPONSE_MALFORMED:
636 rc = -EIO;
637 break;
638 case MID_SHUTDOWN:
639 rc = -EHOSTDOWN;
640 break;
641 default:
642 list_del_init(&mid->qhead);
643 cifs_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
644 __func__, mid->mid, mid->mid_state);
645 rc = -EIO;
646 }
647 spin_unlock(&GlobalMid_Lock);
648
649 mutex_lock(&server->srv_mutex);
650 DeleteMidQEntry(mid);
651 mutex_unlock(&server->srv_mutex);
652 return rc;
653}
654
655static inline int
656send_cancel(struct TCP_Server_Info *server, void *buf, struct mid_q_entry *mid)
657{
658 return server->ops->send_cancel ?
659 server->ops->send_cancel(server, buf, mid) : 0;
660}
661
662int
663cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
664 bool log_error)
665{
666 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
667
668 dump_smb(mid->resp_buf, min_t(u32, 92, len));
669
670 /* convert the length into a more usable form */
671 if (server->sign) {
672 struct kvec iov;
673 int rc = 0;
674 struct smb_rqst rqst = { .rq_iov = &iov,
675 .rq_nvec = 1 };
676
677 iov.iov_base = mid->resp_buf;
678 iov.iov_len = len;
679 /* FIXME: add code to kill session */
680 rc = cifs_verify_signature(&rqst, server,
681 mid->sequence_number);
682 if (rc)
683 cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
684 rc);
685 }
686
687 /* BB special case reconnect tid and uid here? */
688 return map_smb_to_linux_error(mid->resp_buf, log_error);
689}
690
691struct mid_q_entry *
692cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
693{
694 int rc;
695 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
696 struct mid_q_entry *mid;
697
698 rc = allocate_mid(ses, hdr, &mid);
699 if (rc)
700 return ERR_PTR(rc);
701 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
702 if (rc) {
703 cifs_delete_mid(mid);
704 return ERR_PTR(rc);
705 }
706 return mid;
707}
708
709int
710SendReceive2(const unsigned int xid, struct cifs_ses *ses,
711 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
712 const int flags)
713{
714 int rc = 0;
715 int timeout, optype;
716 struct mid_q_entry *midQ;
717 char *buf = iov[0].iov_base;
718 unsigned int credits = 1;
719 struct smb_rqst rqst = { .rq_iov = iov,
720 .rq_nvec = n_vec };
721
722 timeout = flags & CIFS_TIMEOUT_MASK;
723 optype = flags & CIFS_OP_MASK;
724
725 *resp_buf_type = CIFS_NO_BUFFER; /* no response buf yet */
726
727 if ((ses == NULL) || (ses->server == NULL)) {
728 cifs_small_buf_release(buf);
729 cifs_dbg(VFS, "Null session\n");
730 return -EIO;
731 }
732
733 if (ses->server->tcpStatus == CifsExiting) {
734 cifs_small_buf_release(buf);
735 return -ENOENT;
736 }
737
738 /*
739 * Ensure that we do not send more than 50 overlapping requests
740 * to the same server. We may make this configurable later or
741 * use ses->maxReq.
742 */
743
744 rc = wait_for_free_request(ses->server, timeout, optype);
745 if (rc) {
746 cifs_small_buf_release(buf);
747 return rc;
748 }
749
750 /*
751 * Make sure that we sign in the same order that we send on this socket
752 * and avoid races inside tcp sendmsg code that could cause corruption
753 * of smb data.
754 */
755
756 mutex_lock(&ses->server->srv_mutex);
757
758 midQ = ses->server->ops->setup_request(ses, &rqst);
759 if (IS_ERR(midQ)) {
760 mutex_unlock(&ses->server->srv_mutex);
761 cifs_small_buf_release(buf);
762 /* Update # of requests on wire to server */
763 add_credits(ses->server, 1, optype);
764 return PTR_ERR(midQ);
765 }
766
767 midQ->mid_state = MID_REQUEST_SUBMITTED;
768 cifs_in_send_inc(ses->server);
769 rc = smb_sendv(ses->server, iov, n_vec);
770 cifs_in_send_dec(ses->server);
771 cifs_save_when_sent(midQ);
772
773 if (rc < 0)
774 ses->server->sequence_number -= 2;
775 mutex_unlock(&ses->server->srv_mutex);
776
777 if (rc < 0) {
778 cifs_small_buf_release(buf);
779 goto out;
780 }
781
782 if (timeout == CIFS_ASYNC_OP) {
783 cifs_small_buf_release(buf);
784 goto out;
785 }
786
787 rc = wait_for_response(ses->server, midQ);
788 if (rc != 0) {
789 send_cancel(ses->server, buf, midQ);
790 spin_lock(&GlobalMid_Lock);
791 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
792 midQ->callback = DeleteMidQEntry;
793 spin_unlock(&GlobalMid_Lock);
794 cifs_small_buf_release(buf);
795 add_credits(ses->server, 1, optype);
796 return rc;
797 }
798 spin_unlock(&GlobalMid_Lock);
799 }
800
801 cifs_small_buf_release(buf);
802
803 rc = cifs_sync_mid_result(midQ, ses->server);
804 if (rc != 0) {
805 add_credits(ses->server, 1, optype);
806 return rc;
807 }
808
809 if (!midQ->resp_buf || midQ->mid_state != MID_RESPONSE_RECEIVED) {
810 rc = -EIO;
811 cifs_dbg(FYI, "Bad MID state?\n");
812 goto out;
813 }
814
815 buf = (char *)midQ->resp_buf;
816 iov[0].iov_base = buf;
817 iov[0].iov_len = get_rfc1002_length(buf) + 4;
818 if (midQ->large_buf)
819 *resp_buf_type = CIFS_LARGE_BUFFER;
820 else
821 *resp_buf_type = CIFS_SMALL_BUFFER;
822
823 credits = ses->server->ops->get_credits(midQ);
824
825 rc = ses->server->ops->check_receive(midQ, ses->server,
826 flags & CIFS_LOG_ERROR);
827
828 /* mark it so buf will not be freed by cifs_delete_mid */
829 if ((flags & CIFS_NO_RESP) == 0)
830 midQ->resp_buf = NULL;
831out:
832 cifs_delete_mid(midQ);
833 add_credits(ses->server, credits, optype);
834
835 return rc;
836}
837
838int
839SendReceive(const unsigned int xid, struct cifs_ses *ses,
840 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
841 int *pbytes_returned, const int timeout)
842{
843 int rc = 0;
844 struct mid_q_entry *midQ;
845
846 if (ses == NULL) {
847 cifs_dbg(VFS, "Null smb session\n");
848 return -EIO;
849 }
850 if (ses->server == NULL) {
851 cifs_dbg(VFS, "Null tcp session\n");
852 return -EIO;
853 }
854
855 if (ses->server->tcpStatus == CifsExiting)
856 return -ENOENT;
857
858 /* Ensure that we do not send more than 50 overlapping requests
859 to the same server. We may make this configurable later or
860 use ses->maxReq */
861
862 if (be32_to_cpu(in_buf->smb_buf_length) > CIFSMaxBufSize +
863 MAX_CIFS_HDR_SIZE - 4) {
864 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
865 be32_to_cpu(in_buf->smb_buf_length));
866 return -EIO;
867 }
868
869 rc = wait_for_free_request(ses->server, timeout, 0);
870 if (rc)
871 return rc;
872
873 /* make sure that we sign in the same order that we send on this socket
874 and avoid races inside tcp sendmsg code that could cause corruption
875 of smb data */
876
877 mutex_lock(&ses->server->srv_mutex);
878
879 rc = allocate_mid(ses, in_buf, &midQ);
880 if (rc) {
881 mutex_unlock(&ses->server->srv_mutex);
882 /* Update # of requests on wire to server */
883 add_credits(ses->server, 1, 0);
884 return rc;
885 }
886
887 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
888 if (rc) {
889 mutex_unlock(&ses->server->srv_mutex);
890 goto out;
891 }
892
893 midQ->mid_state = MID_REQUEST_SUBMITTED;
894
895 cifs_in_send_inc(ses->server);
896 rc = smb_send(ses->server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
897 cifs_in_send_dec(ses->server);
898 cifs_save_when_sent(midQ);
899
900 if (rc < 0)
901 ses->server->sequence_number -= 2;
902
903 mutex_unlock(&ses->server->srv_mutex);
904
905 if (rc < 0)
906 goto out;
907
908 if (timeout == CIFS_ASYNC_OP)
909 goto out;
910
911 rc = wait_for_response(ses->server, midQ);
912 if (rc != 0) {
913 send_cancel(ses->server, in_buf, midQ);
914 spin_lock(&GlobalMid_Lock);
915 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
916 /* no longer considered to be "in-flight" */
917 midQ->callback = DeleteMidQEntry;
918 spin_unlock(&GlobalMid_Lock);
919 add_credits(ses->server, 1, 0);
920 return rc;
921 }
922 spin_unlock(&GlobalMid_Lock);
923 }
924
925 rc = cifs_sync_mid_result(midQ, ses->server);
926 if (rc != 0) {
927 add_credits(ses->server, 1, 0);
928 return rc;
929 }
930
931 if (!midQ->resp_buf || !out_buf ||
932 midQ->mid_state != MID_RESPONSE_RECEIVED) {
933 rc = -EIO;
934 cifs_dbg(VFS, "Bad MID state?\n");
935 goto out;
936 }
937
938 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
939 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
940 rc = cifs_check_receive(midQ, ses->server, 0);
941out:
942 cifs_delete_mid(midQ);
943 add_credits(ses->server, 1, 0);
944
945 return rc;
946}
947
948/* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
949 blocking lock to return. */
950
951static int
952send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
953 struct smb_hdr *in_buf,
954 struct smb_hdr *out_buf)
955{
956 int bytes_returned;
957 struct cifs_ses *ses = tcon->ses;
958 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
959
960 /* We just modify the current in_buf to change
961 the type of lock from LOCKING_ANDX_SHARED_LOCK
962 or LOCKING_ANDX_EXCLUSIVE_LOCK to
963 LOCKING_ANDX_CANCEL_LOCK. */
964
965 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
966 pSMB->Timeout = 0;
967 pSMB->hdr.Mid = get_next_mid(ses->server);
968
969 return SendReceive(xid, ses, in_buf, out_buf,
970 &bytes_returned, 0);
971}
972
973int
974SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
975 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
976 int *pbytes_returned)
977{
978 int rc = 0;
979 int rstart = 0;
980 struct mid_q_entry *midQ;
981 struct cifs_ses *ses;
982
983 if (tcon == NULL || tcon->ses == NULL) {
984 cifs_dbg(VFS, "Null smb session\n");
985 return -EIO;
986 }
987 ses = tcon->ses;
988
989 if (ses->server == NULL) {
990 cifs_dbg(VFS, "Null tcp session\n");
991 return -EIO;
992 }
993
994 if (ses->server->tcpStatus == CifsExiting)
995 return -ENOENT;
996
997 /* Ensure that we do not send more than 50 overlapping requests
998 to the same server. We may make this configurable later or
999 use ses->maxReq */
1000
1001 if (be32_to_cpu(in_buf->smb_buf_length) > CIFSMaxBufSize +
1002 MAX_CIFS_HDR_SIZE - 4) {
1003 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
1004 be32_to_cpu(in_buf->smb_buf_length));
1005 return -EIO;
1006 }
1007
1008 rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP, 0);
1009 if (rc)
1010 return rc;
1011
1012 /* make sure that we sign in the same order that we send on this socket
1013 and avoid races inside tcp sendmsg code that could cause corruption
1014 of smb data */
1015
1016 mutex_lock(&ses->server->srv_mutex);
1017
1018 rc = allocate_mid(ses, in_buf, &midQ);
1019 if (rc) {
1020 mutex_unlock(&ses->server->srv_mutex);
1021 return rc;
1022 }
1023
1024 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
1025 if (rc) {
1026 cifs_delete_mid(midQ);
1027 mutex_unlock(&ses->server->srv_mutex);
1028 return rc;
1029 }
1030
1031 midQ->mid_state = MID_REQUEST_SUBMITTED;
1032 cifs_in_send_inc(ses->server);
1033 rc = smb_send(ses->server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
1034 cifs_in_send_dec(ses->server);
1035 cifs_save_when_sent(midQ);
1036
1037 if (rc < 0)
1038 ses->server->sequence_number -= 2;
1039
1040 mutex_unlock(&ses->server->srv_mutex);
1041
1042 if (rc < 0) {
1043 cifs_delete_mid(midQ);
1044 return rc;
1045 }
1046
1047 /* Wait for a reply - allow signals to interrupt. */
1048 rc = wait_event_interruptible(ses->server->response_q,
1049 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
1050 ((ses->server->tcpStatus != CifsGood) &&
1051 (ses->server->tcpStatus != CifsNew)));
1052
1053 /* Were we interrupted by a signal ? */
1054 if ((rc == -ERESTARTSYS) &&
1055 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
1056 ((ses->server->tcpStatus == CifsGood) ||
1057 (ses->server->tcpStatus == CifsNew))) {
1058
1059 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1060 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1061 blocking lock to return. */
1062 rc = send_cancel(ses->server, in_buf, midQ);
1063 if (rc) {
1064 cifs_delete_mid(midQ);
1065 return rc;
1066 }
1067 } else {
1068 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1069 to cause the blocking lock to return. */
1070
1071 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1072
1073 /* If we get -ENOLCK back the lock may have
1074 already been removed. Don't exit in this case. */
1075 if (rc && rc != -ENOLCK) {
1076 cifs_delete_mid(midQ);
1077 return rc;
1078 }
1079 }
1080
1081 rc = wait_for_response(ses->server, midQ);
1082 if (rc) {
1083 send_cancel(ses->server, in_buf, midQ);
1084 spin_lock(&GlobalMid_Lock);
1085 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1086 /* no longer considered to be "in-flight" */
1087 midQ->callback = DeleteMidQEntry;
1088 spin_unlock(&GlobalMid_Lock);
1089 return rc;
1090 }
1091 spin_unlock(&GlobalMid_Lock);
1092 }
1093
1094 /* We got the response - restart system call. */
1095 rstart = 1;
1096 }
1097
1098 rc = cifs_sync_mid_result(midQ, ses->server);
1099 if (rc != 0)
1100 return rc;
1101
1102 /* rcvd frame is ok */
1103 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1104 rc = -EIO;
1105 cifs_dbg(VFS, "Bad MID state?\n");
1106 goto out;
1107 }
1108
1109 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1110 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1111 rc = cifs_check_receive(midQ, ses->server, 0);
1112out:
1113 cifs_delete_mid(midQ);
1114 if (rstart && rc == -EACCES)
1115 return -ERESTARTSYS;
1116 return rc;
1117}