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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 <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}
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}