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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/bvec.h>
32#include <linux/highmem.h>
33#include <linux/uaccess.h>
34#include <asm/processor.h>
35#include <linux/mempool.h>
36#include "cifspdu.h"
37#include "cifsglob.h"
38#include "cifsproto.h"
39#include "cifs_debug.h"
40#include "smb2proto.h"
41#include "smbdirect.h"
42
43/* Max number of iovectors we can use off the stack when sending requests. */
44#define CIFS_MAX_IOV_SIZE 8
45
46void
47cifs_wake_up_task(struct mid_q_entry *mid)
48{
49 wake_up_process(mid->callback_data);
50}
51
52struct mid_q_entry *
53AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
54{
55 struct mid_q_entry *temp;
56
57 if (server == NULL) {
58 cifs_dbg(VFS, "Null TCP session in AllocMidQEntry\n");
59 return NULL;
60 }
61
62 temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
63 memset(temp, 0, sizeof(struct mid_q_entry));
64 temp->mid = get_mid(smb_buffer);
65 temp->pid = current->pid;
66 temp->command = cpu_to_le16(smb_buffer->Command);
67 cifs_dbg(FYI, "For smb_command %d\n", smb_buffer->Command);
68 /* do_gettimeofday(&temp->when_sent);*/ /* easier to use jiffies */
69 /* when mid allocated can be before when sent */
70 temp->when_alloc = jiffies;
71 temp->server = server;
72
73 /*
74 * The default is for the mid to be synchronous, so the
75 * default callback just wakes up the current task.
76 */
77 temp->callback = cifs_wake_up_task;
78 temp->callback_data = current;
79
80 atomic_inc(&midCount);
81 temp->mid_state = MID_REQUEST_ALLOCATED;
82 return temp;
83}
84
85void
86DeleteMidQEntry(struct mid_q_entry *midEntry)
87{
88#ifdef CONFIG_CIFS_STATS2
89 __le16 command = midEntry->server->vals->lock_cmd;
90 unsigned long now;
91#endif
92 midEntry->mid_state = MID_FREE;
93 atomic_dec(&midCount);
94 if (midEntry->large_buf)
95 cifs_buf_release(midEntry->resp_buf);
96 else
97 cifs_small_buf_release(midEntry->resp_buf);
98#ifdef CONFIG_CIFS_STATS2
99 now = jiffies;
100 /* commands taking longer than one second are indications that
101 something is wrong, unless it is quite a slow link or server */
102 if (time_after(now, midEntry->when_alloc + HZ)) {
103 if ((cifsFYI & CIFS_TIMER) && (midEntry->command != command)) {
104 pr_debug(" CIFS slow rsp: cmd %d mid %llu",
105 midEntry->command, midEntry->mid);
106 pr_info(" A: 0x%lx S: 0x%lx R: 0x%lx\n",
107 now - midEntry->when_alloc,
108 now - midEntry->when_sent,
109 now - midEntry->when_received);
110 }
111 }
112#endif
113 mempool_free(midEntry, cifs_mid_poolp);
114}
115
116void
117cifs_delete_mid(struct mid_q_entry *mid)
118{
119 spin_lock(&GlobalMid_Lock);
120 list_del(&mid->qhead);
121 spin_unlock(&GlobalMid_Lock);
122
123 DeleteMidQEntry(mid);
124}
125
126/*
127 * smb_send_kvec - send an array of kvecs to the server
128 * @server: Server to send the data to
129 * @smb_msg: Message to send
130 * @sent: amount of data sent on socket is stored here
131 *
132 * Our basic "send data to server" function. Should be called with srv_mutex
133 * held. The caller is responsible for handling the results.
134 */
135static int
136smb_send_kvec(struct TCP_Server_Info *server, struct msghdr *smb_msg,
137 size_t *sent)
138{
139 int rc = 0;
140 int retries = 0;
141 struct socket *ssocket = server->ssocket;
142
143 *sent = 0;
144
145 smb_msg->msg_name = (struct sockaddr *) &server->dstaddr;
146 smb_msg->msg_namelen = sizeof(struct sockaddr);
147 smb_msg->msg_control = NULL;
148 smb_msg->msg_controllen = 0;
149 if (server->noblocksnd)
150 smb_msg->msg_flags = MSG_DONTWAIT + MSG_NOSIGNAL;
151 else
152 smb_msg->msg_flags = MSG_NOSIGNAL;
153
154 while (msg_data_left(smb_msg)) {
155 /*
156 * If blocking send, we try 3 times, since each can block
157 * for 5 seconds. For nonblocking we have to try more
158 * but wait increasing amounts of time allowing time for
159 * socket to clear. The overall time we wait in either
160 * case to send on the socket is about 15 seconds.
161 * Similarly we wait for 15 seconds for a response from
162 * the server in SendReceive[2] for the server to send
163 * a response back for most types of requests (except
164 * SMB Write past end of file which can be slow, and
165 * blocking lock operations). NFS waits slightly longer
166 * than CIFS, but this can make it take longer for
167 * nonresponsive servers to be detected and 15 seconds
168 * is more than enough time for modern networks to
169 * send a packet. In most cases if we fail to send
170 * after the retries we will kill the socket and
171 * reconnect which may clear the network problem.
172 */
173 rc = sock_sendmsg(ssocket, smb_msg);
174 if (rc == -EAGAIN) {
175 retries++;
176 if (retries >= 14 ||
177 (!server->noblocksnd && (retries > 2))) {
178 cifs_dbg(VFS, "sends on sock %p stuck for 15 seconds\n",
179 ssocket);
180 return -EAGAIN;
181 }
182 msleep(1 << retries);
183 continue;
184 }
185
186 if (rc < 0)
187 return rc;
188
189 if (rc == 0) {
190 /* should never happen, letting socket clear before
191 retrying is our only obvious option here */
192 cifs_dbg(VFS, "tcp sent no data\n");
193 msleep(500);
194 continue;
195 }
196
197 /* send was at least partially successful */
198 *sent += rc;
199 retries = 0; /* in case we get ENOSPC on the next send */
200 }
201 return 0;
202}
203
204static unsigned long
205rqst_len(struct smb_rqst *rqst)
206{
207 unsigned int i;
208 struct kvec *iov = rqst->rq_iov;
209 unsigned long buflen = 0;
210
211 /* total up iov array first */
212 for (i = 0; i < rqst->rq_nvec; i++)
213 buflen += iov[i].iov_len;
214
215 /* add in the page array if there is one */
216 if (rqst->rq_npages) {
217 buflen += rqst->rq_pagesz * (rqst->rq_npages - 1);
218 buflen += rqst->rq_tailsz;
219 }
220
221 return buflen;
222}
223
224static int
225__smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst)
226{
227 int rc;
228 struct kvec *iov = rqst->rq_iov;
229 int n_vec = rqst->rq_nvec;
230 unsigned int smb_buf_length = get_rfc1002_length(iov[0].iov_base);
231 unsigned long send_length;
232 unsigned int i;
233 size_t total_len = 0, sent, size;
234 struct socket *ssocket = server->ssocket;
235 struct msghdr smb_msg;
236 int val = 1;
237 if (cifs_rdma_enabled(server) && server->smbd_conn) {
238 rc = smbd_send(server->smbd_conn, rqst);
239 goto smbd_done;
240 }
241 if (ssocket == NULL)
242 return -ENOTSOCK;
243
244 /* sanity check send length */
245 send_length = rqst_len(rqst);
246 if (send_length != smb_buf_length + 4) {
247 WARN(1, "Send length mismatch(send_length=%lu smb_buf_length=%u)\n",
248 send_length, smb_buf_length);
249 return -EIO;
250 }
251
252 if (n_vec < 2)
253 return -EIO;
254
255 cifs_dbg(FYI, "Sending smb: smb_len=%u\n", smb_buf_length);
256 dump_smb(iov[0].iov_base, iov[0].iov_len);
257 dump_smb(iov[1].iov_base, iov[1].iov_len);
258
259 /* cork the socket */
260 kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
261 (char *)&val, sizeof(val));
262
263 size = 0;
264 for (i = 0; i < n_vec; i++)
265 size += iov[i].iov_len;
266
267 iov_iter_kvec(&smb_msg.msg_iter, WRITE | ITER_KVEC, iov, n_vec, size);
268
269 rc = smb_send_kvec(server, &smb_msg, &sent);
270 if (rc < 0)
271 goto uncork;
272
273 total_len += sent;
274
275 /* now walk the page array and send each page in it */
276 for (i = 0; i < rqst->rq_npages; i++) {
277 size_t len = i == rqst->rq_npages - 1
278 ? rqst->rq_tailsz
279 : rqst->rq_pagesz;
280 struct bio_vec bvec = {
281 .bv_page = rqst->rq_pages[i],
282 .bv_len = len
283 };
284 iov_iter_bvec(&smb_msg.msg_iter, WRITE | ITER_BVEC,
285 &bvec, 1, len);
286 rc = smb_send_kvec(server, &smb_msg, &sent);
287 if (rc < 0)
288 break;
289
290 total_len += sent;
291 }
292
293uncork:
294 /* uncork it */
295 val = 0;
296 kernel_setsockopt(ssocket, SOL_TCP, TCP_CORK,
297 (char *)&val, sizeof(val));
298
299 if ((total_len > 0) && (total_len != smb_buf_length + 4)) {
300 cifs_dbg(FYI, "partial send (wanted=%u sent=%zu): terminating session\n",
301 smb_buf_length + 4, total_len);
302 /*
303 * If we have only sent part of an SMB then the next SMB could
304 * be taken as the remainder of this one. We need to kill the
305 * socket so the server throws away the partial SMB
306 */
307 server->tcpStatus = CifsNeedReconnect;
308 }
309smbd_done:
310 if (rc < 0 && rc != -EINTR)
311 cifs_dbg(VFS, "Error %d sending data on socket to server\n",
312 rc);
313 else
314 rc = 0;
315
316 return rc;
317}
318
319static int
320smb_send_rqst(struct TCP_Server_Info *server, struct smb_rqst *rqst, int flags)
321{
322 struct smb_rqst cur_rqst;
323 int rc;
324
325 if (!(flags & CIFS_TRANSFORM_REQ))
326 return __smb_send_rqst(server, rqst);
327
328 if (!server->ops->init_transform_rq ||
329 !server->ops->free_transform_rq) {
330 cifs_dbg(VFS, "Encryption requested but transform callbacks are missed\n");
331 return -EIO;
332 }
333
334 rc = server->ops->init_transform_rq(server, &cur_rqst, rqst);
335 if (rc)
336 return rc;
337
338 rc = __smb_send_rqst(server, &cur_rqst);
339 server->ops->free_transform_rq(&cur_rqst);
340 return rc;
341}
342
343int
344smb_send(struct TCP_Server_Info *server, struct smb_hdr *smb_buffer,
345 unsigned int smb_buf_length)
346{
347 struct kvec iov[2];
348 struct smb_rqst rqst = { .rq_iov = iov,
349 .rq_nvec = 2 };
350
351 iov[0].iov_base = smb_buffer;
352 iov[0].iov_len = 4;
353 iov[1].iov_base = (char *)smb_buffer + 4;
354 iov[1].iov_len = smb_buf_length;
355
356 return __smb_send_rqst(server, &rqst);
357}
358
359static int
360wait_for_free_credits(struct TCP_Server_Info *server, const int timeout,
361 int *credits)
362{
363 int rc;
364
365 spin_lock(&server->req_lock);
366 if (timeout == CIFS_ASYNC_OP) {
367 /* oplock breaks must not be held up */
368 server->in_flight++;
369 *credits -= 1;
370 spin_unlock(&server->req_lock);
371 return 0;
372 }
373
374 while (1) {
375 if (*credits <= 0) {
376 spin_unlock(&server->req_lock);
377 cifs_num_waiters_inc(server);
378 rc = wait_event_killable(server->request_q,
379 has_credits(server, credits));
380 cifs_num_waiters_dec(server);
381 if (rc)
382 return rc;
383 spin_lock(&server->req_lock);
384 } else {
385 if (server->tcpStatus == CifsExiting) {
386 spin_unlock(&server->req_lock);
387 return -ENOENT;
388 }
389
390 /*
391 * Can not count locking commands against total
392 * as they are allowed to block on server.
393 */
394
395 /* update # of requests on the wire to server */
396 if (timeout != CIFS_BLOCKING_OP) {
397 *credits -= 1;
398 server->in_flight++;
399 }
400 spin_unlock(&server->req_lock);
401 break;
402 }
403 }
404 return 0;
405}
406
407static int
408wait_for_free_request(struct TCP_Server_Info *server, const int timeout,
409 const int optype)
410{
411 int *val;
412
413 val = server->ops->get_credits_field(server, optype);
414 /* Since an echo is already inflight, no need to wait to send another */
415 if (*val <= 0 && optype == CIFS_ECHO_OP)
416 return -EAGAIN;
417 return wait_for_free_credits(server, timeout, val);
418}
419
420int
421cifs_wait_mtu_credits(struct TCP_Server_Info *server, unsigned int size,
422 unsigned int *num, unsigned int *credits)
423{
424 *num = size;
425 *credits = 0;
426 return 0;
427}
428
429static int allocate_mid(struct cifs_ses *ses, struct smb_hdr *in_buf,
430 struct mid_q_entry **ppmidQ)
431{
432 if (ses->server->tcpStatus == CifsExiting) {
433 return -ENOENT;
434 }
435
436 if (ses->server->tcpStatus == CifsNeedReconnect) {
437 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
438 return -EAGAIN;
439 }
440
441 if (ses->status == CifsNew) {
442 if ((in_buf->Command != SMB_COM_SESSION_SETUP_ANDX) &&
443 (in_buf->Command != SMB_COM_NEGOTIATE))
444 return -EAGAIN;
445 /* else ok - we are setting up session */
446 }
447
448 if (ses->status == CifsExiting) {
449 /* check if SMB session is bad because we are setting it up */
450 if (in_buf->Command != SMB_COM_LOGOFF_ANDX)
451 return -EAGAIN;
452 /* else ok - we are shutting down session */
453 }
454
455 *ppmidQ = AllocMidQEntry(in_buf, ses->server);
456 if (*ppmidQ == NULL)
457 return -ENOMEM;
458 spin_lock(&GlobalMid_Lock);
459 list_add_tail(&(*ppmidQ)->qhead, &ses->server->pending_mid_q);
460 spin_unlock(&GlobalMid_Lock);
461 return 0;
462}
463
464static int
465wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
466{
467 int error;
468
469 error = wait_event_freezekillable_unsafe(server->response_q,
470 midQ->mid_state != MID_REQUEST_SUBMITTED);
471 if (error < 0)
472 return -ERESTARTSYS;
473
474 return 0;
475}
476
477struct mid_q_entry *
478cifs_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
479{
480 int rc;
481 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
482 struct mid_q_entry *mid;
483
484 if (rqst->rq_iov[0].iov_len != 4 ||
485 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
486 return ERR_PTR(-EIO);
487
488 /* enable signing if server requires it */
489 if (server->sign)
490 hdr->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
491
492 mid = AllocMidQEntry(hdr, server);
493 if (mid == NULL)
494 return ERR_PTR(-ENOMEM);
495
496 rc = cifs_sign_rqst(rqst, server, &mid->sequence_number);
497 if (rc) {
498 DeleteMidQEntry(mid);
499 return ERR_PTR(rc);
500 }
501
502 return mid;
503}
504
505/*
506 * Send a SMB request and set the callback function in the mid to handle
507 * the result. Caller is responsible for dealing with timeouts.
508 */
509int
510cifs_call_async(struct TCP_Server_Info *server, struct smb_rqst *rqst,
511 mid_receive_t *receive, mid_callback_t *callback,
512 mid_handle_t *handle, void *cbdata, const int flags)
513{
514 int rc, timeout, optype;
515 struct mid_q_entry *mid;
516 unsigned int credits = 0;
517
518 timeout = flags & CIFS_TIMEOUT_MASK;
519 optype = flags & CIFS_OP_MASK;
520
521 if ((flags & CIFS_HAS_CREDITS) == 0) {
522 rc = wait_for_free_request(server, timeout, optype);
523 if (rc)
524 return rc;
525 credits = 1;
526 }
527
528 mutex_lock(&server->srv_mutex);
529 mid = server->ops->setup_async_request(server, rqst);
530 if (IS_ERR(mid)) {
531 mutex_unlock(&server->srv_mutex);
532 add_credits_and_wake_if(server, credits, optype);
533 return PTR_ERR(mid);
534 }
535
536 mid->receive = receive;
537 mid->callback = callback;
538 mid->callback_data = cbdata;
539 mid->handle = handle;
540 mid->mid_state = MID_REQUEST_SUBMITTED;
541
542 /* put it on the pending_mid_q */
543 spin_lock(&GlobalMid_Lock);
544 list_add_tail(&mid->qhead, &server->pending_mid_q);
545 spin_unlock(&GlobalMid_Lock);
546
547 /*
548 * Need to store the time in mid before calling I/O. For call_async,
549 * I/O response may come back and free the mid entry on another thread.
550 */
551 cifs_save_when_sent(mid);
552 cifs_in_send_inc(server);
553 rc = smb_send_rqst(server, rqst, flags);
554 cifs_in_send_dec(server);
555
556 if (rc < 0) {
557 server->sequence_number -= 2;
558 cifs_delete_mid(mid);
559 }
560
561 mutex_unlock(&server->srv_mutex);
562
563 if (rc == 0)
564 return 0;
565
566 add_credits_and_wake_if(server, credits, optype);
567 return rc;
568}
569
570/*
571 *
572 * Send an SMB Request. No response info (other than return code)
573 * needs to be parsed.
574 *
575 * flags indicate the type of request buffer and how long to wait
576 * and whether to log NT STATUS code (error) before mapping it to POSIX error
577 *
578 */
579int
580SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
581 char *in_buf, int flags)
582{
583 int rc;
584 struct kvec iov[1];
585 struct kvec rsp_iov;
586 int resp_buf_type;
587
588 iov[0].iov_base = in_buf;
589 iov[0].iov_len = get_rfc1002_length(in_buf) + 4;
590 flags |= CIFS_NO_RESP;
591 rc = SendReceive2(xid, ses, iov, 1, &resp_buf_type, flags, &rsp_iov);
592 cifs_dbg(NOISY, "SendRcvNoRsp flags %d rc %d\n", flags, rc);
593
594 return rc;
595}
596
597static int
598cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
599{
600 int rc = 0;
601
602 cifs_dbg(FYI, "%s: cmd=%d mid=%llu state=%d\n",
603 __func__, le16_to_cpu(mid->command), mid->mid, mid->mid_state);
604
605 spin_lock(&GlobalMid_Lock);
606 switch (mid->mid_state) {
607 case MID_RESPONSE_RECEIVED:
608 spin_unlock(&GlobalMid_Lock);
609 return rc;
610 case MID_RETRY_NEEDED:
611 rc = -EAGAIN;
612 break;
613 case MID_RESPONSE_MALFORMED:
614 rc = -EIO;
615 break;
616 case MID_SHUTDOWN:
617 rc = -EHOSTDOWN;
618 break;
619 default:
620 list_del_init(&mid->qhead);
621 cifs_dbg(VFS, "%s: invalid mid state mid=%llu state=%d\n",
622 __func__, mid->mid, mid->mid_state);
623 rc = -EIO;
624 }
625 spin_unlock(&GlobalMid_Lock);
626
627 DeleteMidQEntry(mid);
628 return rc;
629}
630
631static inline int
632send_cancel(struct TCP_Server_Info *server, struct smb_rqst *rqst,
633 struct mid_q_entry *mid)
634{
635 return server->ops->send_cancel ?
636 server->ops->send_cancel(server, rqst, mid) : 0;
637}
638
639int
640cifs_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
641 bool log_error)
642{
643 unsigned int len = get_rfc1002_length(mid->resp_buf) + 4;
644
645 dump_smb(mid->resp_buf, min_t(u32, 92, len));
646
647 /* convert the length into a more usable form */
648 if (server->sign) {
649 struct kvec iov[2];
650 int rc = 0;
651 struct smb_rqst rqst = { .rq_iov = iov,
652 .rq_nvec = 2 };
653
654 iov[0].iov_base = mid->resp_buf;
655 iov[0].iov_len = 4;
656 iov[1].iov_base = (char *)mid->resp_buf + 4;
657 iov[1].iov_len = len - 4;
658 /* FIXME: add code to kill session */
659 rc = cifs_verify_signature(&rqst, server,
660 mid->sequence_number);
661 if (rc)
662 cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
663 rc);
664 }
665
666 /* BB special case reconnect tid and uid here? */
667 return map_smb_to_linux_error(mid->resp_buf, log_error);
668}
669
670struct mid_q_entry *
671cifs_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
672{
673 int rc;
674 struct smb_hdr *hdr = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
675 struct mid_q_entry *mid;
676
677 if (rqst->rq_iov[0].iov_len != 4 ||
678 rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
679 return ERR_PTR(-EIO);
680
681 rc = allocate_mid(ses, hdr, &mid);
682 if (rc)
683 return ERR_PTR(rc);
684 rc = cifs_sign_rqst(rqst, ses->server, &mid->sequence_number);
685 if (rc) {
686 cifs_delete_mid(mid);
687 return ERR_PTR(rc);
688 }
689 return mid;
690}
691
692int
693cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
694 struct smb_rqst *rqst, int *resp_buf_type, const int flags,
695 struct kvec *resp_iov)
696{
697 int rc = 0;
698 int timeout, optype;
699 struct mid_q_entry *midQ;
700 unsigned int credits = 1;
701 char *buf;
702
703 timeout = flags & CIFS_TIMEOUT_MASK;
704 optype = flags & CIFS_OP_MASK;
705
706 *resp_buf_type = CIFS_NO_BUFFER; /* no response buf yet */
707
708 if ((ses == NULL) || (ses->server == NULL)) {
709 cifs_dbg(VFS, "Null session\n");
710 return -EIO;
711 }
712
713 if (ses->server->tcpStatus == CifsExiting)
714 return -ENOENT;
715
716 /*
717 * Ensure that we do not send more than 50 overlapping requests
718 * to the same server. We may make this configurable later or
719 * use ses->maxReq.
720 */
721
722 rc = wait_for_free_request(ses->server, timeout, optype);
723 if (rc)
724 return rc;
725
726 /*
727 * Make sure that we sign in the same order that we send on this socket
728 * and avoid races inside tcp sendmsg code that could cause corruption
729 * of smb data.
730 */
731
732 mutex_lock(&ses->server->srv_mutex);
733
734 midQ = ses->server->ops->setup_request(ses, rqst);
735 if (IS_ERR(midQ)) {
736 mutex_unlock(&ses->server->srv_mutex);
737 /* Update # of requests on wire to server */
738 add_credits(ses->server, 1, optype);
739 return PTR_ERR(midQ);
740 }
741
742 midQ->mid_state = MID_REQUEST_SUBMITTED;
743 cifs_in_send_inc(ses->server);
744 rc = smb_send_rqst(ses->server, rqst, flags);
745 cifs_in_send_dec(ses->server);
746 cifs_save_when_sent(midQ);
747
748 if (rc < 0)
749 ses->server->sequence_number -= 2;
750 mutex_unlock(&ses->server->srv_mutex);
751
752 if (rc < 0)
753 goto out;
754
755#ifdef CONFIG_CIFS_SMB311
756 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP))
757 smb311_update_preauth_hash(ses, rqst->rq_iov+1,
758 rqst->rq_nvec-1);
759#endif
760
761 if (timeout == CIFS_ASYNC_OP)
762 goto out;
763
764 rc = wait_for_response(ses->server, midQ);
765 if (rc != 0) {
766 cifs_dbg(FYI, "Cancelling wait for mid %llu\n", midQ->mid);
767 send_cancel(ses->server, rqst, midQ);
768 spin_lock(&GlobalMid_Lock);
769 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
770 midQ->mid_flags |= MID_WAIT_CANCELLED;
771 midQ->callback = DeleteMidQEntry;
772 spin_unlock(&GlobalMid_Lock);
773 add_credits(ses->server, 1, optype);
774 return rc;
775 }
776 spin_unlock(&GlobalMid_Lock);
777 }
778
779 rc = cifs_sync_mid_result(midQ, ses->server);
780 if (rc != 0) {
781 add_credits(ses->server, 1, optype);
782 return rc;
783 }
784
785 if (!midQ->resp_buf || midQ->mid_state != MID_RESPONSE_RECEIVED) {
786 rc = -EIO;
787 cifs_dbg(FYI, "Bad MID state?\n");
788 goto out;
789 }
790
791 buf = (char *)midQ->resp_buf;
792 resp_iov->iov_base = buf;
793 resp_iov->iov_len = midQ->resp_buf_size +
794 ses->server->vals->header_preamble_size;
795 if (midQ->large_buf)
796 *resp_buf_type = CIFS_LARGE_BUFFER;
797 else
798 *resp_buf_type = CIFS_SMALL_BUFFER;
799
800#ifdef CONFIG_CIFS_SMB311
801 if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP)) {
802 struct kvec iov = {
803 .iov_base = buf + 4,
804 .iov_len = get_rfc1002_length(buf)
805 };
806 smb311_update_preauth_hash(ses, &iov, 1);
807 }
808#endif
809
810 credits = ses->server->ops->get_credits(midQ);
811
812 rc = ses->server->ops->check_receive(midQ, ses->server,
813 flags & CIFS_LOG_ERROR);
814
815 /* mark it so buf will not be freed by cifs_delete_mid */
816 if ((flags & CIFS_NO_RESP) == 0)
817 midQ->resp_buf = NULL;
818out:
819 cifs_delete_mid(midQ);
820 add_credits(ses->server, credits, optype);
821
822 return rc;
823}
824
825int
826SendReceive2(const unsigned int xid, struct cifs_ses *ses,
827 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
828 const int flags, struct kvec *resp_iov)
829{
830 struct smb_rqst rqst;
831 struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
832 int rc;
833
834 if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
835 new_iov = kmalloc(sizeof(struct kvec) * (n_vec + 1),
836 GFP_KERNEL);
837 if (!new_iov) {
838 /* otherwise cifs_send_recv below sets resp_buf_type */
839 *resp_buf_type = CIFS_NO_BUFFER;
840 return -ENOMEM;
841 }
842 } else
843 new_iov = s_iov;
844
845 /* 1st iov is a RFC1001 length followed by the rest of the packet */
846 memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
847
848 new_iov[0].iov_base = new_iov[1].iov_base;
849 new_iov[0].iov_len = 4;
850 new_iov[1].iov_base += 4;
851 new_iov[1].iov_len -= 4;
852
853 memset(&rqst, 0, sizeof(struct smb_rqst));
854 rqst.rq_iov = new_iov;
855 rqst.rq_nvec = n_vec + 1;
856
857 rc = cifs_send_recv(xid, ses, &rqst, resp_buf_type, flags, resp_iov);
858 if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
859 kfree(new_iov);
860 return rc;
861}
862
863/* Like SendReceive2 but iov[0] does not contain an rfc1002 header */
864int
865smb2_send_recv(const unsigned int xid, struct cifs_ses *ses,
866 struct kvec *iov, int n_vec, int *resp_buf_type /* ret */,
867 const int flags, struct kvec *resp_iov)
868{
869 struct smb_rqst rqst;
870 struct kvec s_iov[CIFS_MAX_IOV_SIZE], *new_iov;
871 int rc;
872 int i;
873 __u32 count;
874 __be32 rfc1002_marker;
875
876 if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
877 new_iov = kmalloc(sizeof(struct kvec) * (n_vec + 1),
878 GFP_KERNEL);
879 if (!new_iov)
880 return -ENOMEM;
881 } else
882 new_iov = s_iov;
883
884 /* 1st iov is an RFC1002 Session Message length */
885 memcpy(new_iov + 1, iov, (sizeof(struct kvec) * n_vec));
886
887 count = 0;
888 for (i = 1; i < n_vec + 1; i++)
889 count += new_iov[i].iov_len;
890
891 rfc1002_marker = cpu_to_be32(count);
892
893 new_iov[0].iov_base = &rfc1002_marker;
894 new_iov[0].iov_len = 4;
895
896 memset(&rqst, 0, sizeof(struct smb_rqst));
897 rqst.rq_iov = new_iov;
898 rqst.rq_nvec = n_vec + 1;
899
900 rc = cifs_send_recv(xid, ses, &rqst, resp_buf_type, flags, resp_iov);
901 if (n_vec + 1 > CIFS_MAX_IOV_SIZE)
902 kfree(new_iov);
903 return rc;
904}
905
906int
907SendReceive(const unsigned int xid, struct cifs_ses *ses,
908 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
909 int *pbytes_returned, const int timeout)
910{
911 int rc = 0;
912 struct mid_q_entry *midQ;
913 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
914 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
915 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
916
917 if (ses == NULL) {
918 cifs_dbg(VFS, "Null smb session\n");
919 return -EIO;
920 }
921 if (ses->server == NULL) {
922 cifs_dbg(VFS, "Null tcp session\n");
923 return -EIO;
924 }
925
926 if (ses->server->tcpStatus == CifsExiting)
927 return -ENOENT;
928
929 /* Ensure that we do not send more than 50 overlapping requests
930 to the same server. We may make this configurable later or
931 use ses->maxReq */
932
933 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
934 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
935 len);
936 return -EIO;
937 }
938
939 rc = wait_for_free_request(ses->server, timeout, 0);
940 if (rc)
941 return rc;
942
943 /* make sure that we sign in the same order that we send on this socket
944 and avoid races inside tcp sendmsg code that could cause corruption
945 of smb data */
946
947 mutex_lock(&ses->server->srv_mutex);
948
949 rc = allocate_mid(ses, in_buf, &midQ);
950 if (rc) {
951 mutex_unlock(&ses->server->srv_mutex);
952 /* Update # of requests on wire to server */
953 add_credits(ses->server, 1, 0);
954 return rc;
955 }
956
957 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
958 if (rc) {
959 mutex_unlock(&ses->server->srv_mutex);
960 goto out;
961 }
962
963 midQ->mid_state = MID_REQUEST_SUBMITTED;
964
965 cifs_in_send_inc(ses->server);
966 rc = smb_send(ses->server, in_buf, len);
967 cifs_in_send_dec(ses->server);
968 cifs_save_when_sent(midQ);
969
970 if (rc < 0)
971 ses->server->sequence_number -= 2;
972
973 mutex_unlock(&ses->server->srv_mutex);
974
975 if (rc < 0)
976 goto out;
977
978 if (timeout == CIFS_ASYNC_OP)
979 goto out;
980
981 rc = wait_for_response(ses->server, midQ);
982 if (rc != 0) {
983 send_cancel(ses->server, &rqst, midQ);
984 spin_lock(&GlobalMid_Lock);
985 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
986 /* no longer considered to be "in-flight" */
987 midQ->callback = DeleteMidQEntry;
988 spin_unlock(&GlobalMid_Lock);
989 add_credits(ses->server, 1, 0);
990 return rc;
991 }
992 spin_unlock(&GlobalMid_Lock);
993 }
994
995 rc = cifs_sync_mid_result(midQ, ses->server);
996 if (rc != 0) {
997 add_credits(ses->server, 1, 0);
998 return rc;
999 }
1000
1001 if (!midQ->resp_buf || !out_buf ||
1002 midQ->mid_state != MID_RESPONSE_RECEIVED) {
1003 rc = -EIO;
1004 cifs_dbg(VFS, "Bad MID state?\n");
1005 goto out;
1006 }
1007
1008 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1009 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1010 rc = cifs_check_receive(midQ, ses->server, 0);
1011out:
1012 cifs_delete_mid(midQ);
1013 add_credits(ses->server, 1, 0);
1014
1015 return rc;
1016}
1017
1018/* We send a LOCKINGX_CANCEL_LOCK to cause the Windows
1019 blocking lock to return. */
1020
1021static int
1022send_lock_cancel(const unsigned int xid, struct cifs_tcon *tcon,
1023 struct smb_hdr *in_buf,
1024 struct smb_hdr *out_buf)
1025{
1026 int bytes_returned;
1027 struct cifs_ses *ses = tcon->ses;
1028 LOCK_REQ *pSMB = (LOCK_REQ *)in_buf;
1029
1030 /* We just modify the current in_buf to change
1031 the type of lock from LOCKING_ANDX_SHARED_LOCK
1032 or LOCKING_ANDX_EXCLUSIVE_LOCK to
1033 LOCKING_ANDX_CANCEL_LOCK. */
1034
1035 pSMB->LockType = LOCKING_ANDX_CANCEL_LOCK|LOCKING_ANDX_LARGE_FILES;
1036 pSMB->Timeout = 0;
1037 pSMB->hdr.Mid = get_next_mid(ses->server);
1038
1039 return SendReceive(xid, ses, in_buf, out_buf,
1040 &bytes_returned, 0);
1041}
1042
1043int
1044SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
1045 struct smb_hdr *in_buf, struct smb_hdr *out_buf,
1046 int *pbytes_returned)
1047{
1048 int rc = 0;
1049 int rstart = 0;
1050 struct mid_q_entry *midQ;
1051 struct cifs_ses *ses;
1052 unsigned int len = be32_to_cpu(in_buf->smb_buf_length);
1053 struct kvec iov = { .iov_base = in_buf, .iov_len = len };
1054 struct smb_rqst rqst = { .rq_iov = &iov, .rq_nvec = 1 };
1055
1056 if (tcon == NULL || tcon->ses == NULL) {
1057 cifs_dbg(VFS, "Null smb session\n");
1058 return -EIO;
1059 }
1060 ses = tcon->ses;
1061
1062 if (ses->server == NULL) {
1063 cifs_dbg(VFS, "Null tcp session\n");
1064 return -EIO;
1065 }
1066
1067 if (ses->server->tcpStatus == CifsExiting)
1068 return -ENOENT;
1069
1070 /* Ensure that we do not send more than 50 overlapping requests
1071 to the same server. We may make this configurable later or
1072 use ses->maxReq */
1073
1074 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
1075 cifs_dbg(VFS, "Illegal length, greater than maximum frame, %d\n",
1076 len);
1077 return -EIO;
1078 }
1079
1080 rc = wait_for_free_request(ses->server, CIFS_BLOCKING_OP, 0);
1081 if (rc)
1082 return rc;
1083
1084 /* make sure that we sign in the same order that we send on this socket
1085 and avoid races inside tcp sendmsg code that could cause corruption
1086 of smb data */
1087
1088 mutex_lock(&ses->server->srv_mutex);
1089
1090 rc = allocate_mid(ses, in_buf, &midQ);
1091 if (rc) {
1092 mutex_unlock(&ses->server->srv_mutex);
1093 return rc;
1094 }
1095
1096 rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number);
1097 if (rc) {
1098 cifs_delete_mid(midQ);
1099 mutex_unlock(&ses->server->srv_mutex);
1100 return rc;
1101 }
1102
1103 midQ->mid_state = MID_REQUEST_SUBMITTED;
1104 cifs_in_send_inc(ses->server);
1105 rc = smb_send(ses->server, in_buf, len);
1106 cifs_in_send_dec(ses->server);
1107 cifs_save_when_sent(midQ);
1108
1109 if (rc < 0)
1110 ses->server->sequence_number -= 2;
1111
1112 mutex_unlock(&ses->server->srv_mutex);
1113
1114 if (rc < 0) {
1115 cifs_delete_mid(midQ);
1116 return rc;
1117 }
1118
1119 /* Wait for a reply - allow signals to interrupt. */
1120 rc = wait_event_interruptible(ses->server->response_q,
1121 (!(midQ->mid_state == MID_REQUEST_SUBMITTED)) ||
1122 ((ses->server->tcpStatus != CifsGood) &&
1123 (ses->server->tcpStatus != CifsNew)));
1124
1125 /* Were we interrupted by a signal ? */
1126 if ((rc == -ERESTARTSYS) &&
1127 (midQ->mid_state == MID_REQUEST_SUBMITTED) &&
1128 ((ses->server->tcpStatus == CifsGood) ||
1129 (ses->server->tcpStatus == CifsNew))) {
1130
1131 if (in_buf->Command == SMB_COM_TRANSACTION2) {
1132 /* POSIX lock. We send a NT_CANCEL SMB to cause the
1133 blocking lock to return. */
1134 rc = send_cancel(ses->server, &rqst, midQ);
1135 if (rc) {
1136 cifs_delete_mid(midQ);
1137 return rc;
1138 }
1139 } else {
1140 /* Windows lock. We send a LOCKINGX_CANCEL_LOCK
1141 to cause the blocking lock to return. */
1142
1143 rc = send_lock_cancel(xid, tcon, in_buf, out_buf);
1144
1145 /* If we get -ENOLCK back the lock may have
1146 already been removed. Don't exit in this case. */
1147 if (rc && rc != -ENOLCK) {
1148 cifs_delete_mid(midQ);
1149 return rc;
1150 }
1151 }
1152
1153 rc = wait_for_response(ses->server, midQ);
1154 if (rc) {
1155 send_cancel(ses->server, &rqst, midQ);
1156 spin_lock(&GlobalMid_Lock);
1157 if (midQ->mid_state == MID_REQUEST_SUBMITTED) {
1158 /* no longer considered to be "in-flight" */
1159 midQ->callback = DeleteMidQEntry;
1160 spin_unlock(&GlobalMid_Lock);
1161 return rc;
1162 }
1163 spin_unlock(&GlobalMid_Lock);
1164 }
1165
1166 /* We got the response - restart system call. */
1167 rstart = 1;
1168 }
1169
1170 rc = cifs_sync_mid_result(midQ, ses->server);
1171 if (rc != 0)
1172 return rc;
1173
1174 /* rcvd frame is ok */
1175 if (out_buf == NULL || midQ->mid_state != MID_RESPONSE_RECEIVED) {
1176 rc = -EIO;
1177 cifs_dbg(VFS, "Bad MID state?\n");
1178 goto out;
1179 }
1180
1181 *pbytes_returned = get_rfc1002_length(midQ->resp_buf);
1182 memcpy(out_buf, midQ->resp_buf, *pbytes_returned + 4);
1183 rc = cifs_check_receive(midQ, ses->server, 0);
1184out:
1185 cifs_delete_mid(midQ);
1186 if (rstart && rc == -EACCES)
1187 return -ERESTARTSYS;
1188 return rc;
1189}