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Jeff Layton23db65f2012-05-15 12:20:51 -04001/*
2 * SMB1 (CIFS) version specific operations
3 *
4 * Copyright (c) 2012, Jeff Layton <jlayton@redhat.com>
5 *
6 * This library is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License v2 as published
8 * by the Free Software Foundation.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public License
16 * along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#include "cifsglob.h"
Jeff Layton121b0462012-05-15 12:21:10 -040021#include "cifsproto.h"
22#include "cifs_debug.h"
Pavel Shilovsky106dc532012-02-28 14:23:34 +030023#include "cifspdu.h"
Jeff Layton121b0462012-05-15 12:21:10 -040024
25/*
26 * An NT cancel request header looks just like the original request except:
27 *
28 * The Command is SMB_COM_NT_CANCEL
29 * The WordCount is zeroed out
30 * The ByteCount is zeroed out
31 *
32 * This function mangles an existing request buffer into a
33 * SMB_COM_NT_CANCEL request and then sends it.
34 */
35static int
36send_nt_cancel(struct TCP_Server_Info *server, void *buf,
37 struct mid_q_entry *mid)
38{
39 int rc = 0;
40 struct smb_hdr *in_buf = (struct smb_hdr *)buf;
41
42 /* -4 for RFC1001 length and +2 for BCC field */
43 in_buf->smb_buf_length = cpu_to_be32(sizeof(struct smb_hdr) - 4 + 2);
44 in_buf->Command = SMB_COM_NT_CANCEL;
45 in_buf->WordCount = 0;
46 put_bcc(0, in_buf);
47
48 mutex_lock(&server->srv_mutex);
49 rc = cifs_sign_smb(in_buf, server, &mid->sequence_number);
50 if (rc) {
51 mutex_unlock(&server->srv_mutex);
52 return rc;
53 }
54 rc = smb_send(server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
55 mutex_unlock(&server->srv_mutex);
56
57 cFYI(1, "issued NT_CANCEL for mid %u, rc = %d",
58 in_buf->Mid, rc);
59
60 return rc;
61}
Jeff Layton23db65f2012-05-15 12:20:51 -040062
Pavel Shilovsky55157df2012-02-28 14:04:17 +030063static bool
64cifs_compare_fids(struct cifsFileInfo *ob1, struct cifsFileInfo *ob2)
65{
66 return ob1->netfid == ob2->netfid;
67}
68
Pavel Shilovskyeb378712012-05-17 13:02:51 +040069static unsigned int
70cifs_read_data_offset(char *buf)
71{
72 READ_RSP *rsp = (READ_RSP *)buf;
73 return le16_to_cpu(rsp->DataOffset);
74}
75
76static unsigned int
77cifs_read_data_length(char *buf)
78{
79 READ_RSP *rsp = (READ_RSP *)buf;
80 return (le16_to_cpu(rsp->DataLengthHigh) << 16) +
81 le16_to_cpu(rsp->DataLength);
82}
83
Pavel Shilovsky8aa26f32012-05-17 13:25:35 +040084static struct mid_q_entry *
85cifs_find_mid(struct TCP_Server_Info *server, char *buffer)
86{
87 struct smb_hdr *buf = (struct smb_hdr *)buffer;
88 struct mid_q_entry *mid;
89
90 spin_lock(&GlobalMid_Lock);
91 list_for_each_entry(mid, &server->pending_mid_q, qhead) {
92 if (mid->mid == buf->Mid &&
93 mid->mid_state == MID_REQUEST_SUBMITTED &&
94 le16_to_cpu(mid->command) == buf->Command) {
95 spin_unlock(&GlobalMid_Lock);
96 return mid;
97 }
98 }
99 spin_unlock(&GlobalMid_Lock);
100 return NULL;
101}
102
Pavel Shilovsky45275782012-05-17 17:53:29 +0400103static void
Pavel Shilovskya891f0f2012-05-23 16:14:34 +0400104cifs_add_credits(struct TCP_Server_Info *server, const unsigned int add,
105 const int optype)
Pavel Shilovsky45275782012-05-17 17:53:29 +0400106{
107 spin_lock(&server->req_lock);
108 server->credits += add;
109 server->in_flight--;
110 spin_unlock(&server->req_lock);
111 wake_up(&server->request_q);
112}
113
114static void
115cifs_set_credits(struct TCP_Server_Info *server, const int val)
116{
117 spin_lock(&server->req_lock);
118 server->credits = val;
119 server->oplocks = val > 1 ? enable_oplocks : false;
120 spin_unlock(&server->req_lock);
121}
122
123static int *
Pavel Shilovskya891f0f2012-05-23 16:14:34 +0400124cifs_get_credits_field(struct TCP_Server_Info *server, const int optype)
Pavel Shilovsky45275782012-05-17 17:53:29 +0400125{
126 return &server->credits;
127}
128
Pavel Shilovskya891f0f2012-05-23 16:14:34 +0400129static unsigned int
130cifs_get_credits(struct mid_q_entry *mid)
131{
132 return 1;
133}
134
Pavel Shilovsky88257362012-05-23 14:01:59 +0400135/*
136 * Find a free multiplex id (SMB mid). Otherwise there could be
137 * mid collisions which might cause problems, demultiplexing the
138 * wrong response to this request. Multiplex ids could collide if
139 * one of a series requests takes much longer than the others, or
140 * if a very large number of long lived requests (byte range
141 * locks or FindNotify requests) are pending. No more than
142 * 64K-1 requests can be outstanding at one time. If no
143 * mids are available, return zero. A future optimization
144 * could make the combination of mids and uid the key we use
145 * to demultiplex on (rather than mid alone).
146 * In addition to the above check, the cifs demultiplex
147 * code already used the command code as a secondary
148 * check of the frame and if signing is negotiated the
149 * response would be discarded if the mid were the same
150 * but the signature was wrong. Since the mid is not put in the
151 * pending queue until later (when it is about to be dispatched)
152 * we do have to limit the number of outstanding requests
153 * to somewhat less than 64K-1 although it is hard to imagine
154 * so many threads being in the vfs at one time.
155 */
156static __u64
157cifs_get_next_mid(struct TCP_Server_Info *server)
158{
159 __u64 mid = 0;
160 __u16 last_mid, cur_mid;
161 bool collision;
162
163 spin_lock(&GlobalMid_Lock);
164
165 /* mid is 16 bit only for CIFS/SMB */
166 cur_mid = (__u16)((server->CurrentMid) & 0xffff);
167 /* we do not want to loop forever */
168 last_mid = cur_mid;
169 cur_mid++;
170
171 /*
172 * This nested loop looks more expensive than it is.
173 * In practice the list of pending requests is short,
174 * fewer than 50, and the mids are likely to be unique
175 * on the first pass through the loop unless some request
176 * takes longer than the 64 thousand requests before it
177 * (and it would also have to have been a request that
178 * did not time out).
179 */
180 while (cur_mid != last_mid) {
181 struct mid_q_entry *mid_entry;
182 unsigned int num_mids;
183
184 collision = false;
185 if (cur_mid == 0)
186 cur_mid++;
187
188 num_mids = 0;
189 list_for_each_entry(mid_entry, &server->pending_mid_q, qhead) {
190 ++num_mids;
191 if (mid_entry->mid == cur_mid &&
192 mid_entry->mid_state == MID_REQUEST_SUBMITTED) {
193 /* This mid is in use, try a different one */
194 collision = true;
195 break;
196 }
197 }
198
199 /*
200 * if we have more than 32k mids in the list, then something
201 * is very wrong. Possibly a local user is trying to DoS the
202 * box by issuing long-running calls and SIGKILL'ing them. If
203 * we get to 2^16 mids then we're in big trouble as this
204 * function could loop forever.
205 *
206 * Go ahead and assign out the mid in this situation, but force
207 * an eventual reconnect to clean out the pending_mid_q.
208 */
209 if (num_mids > 32768)
210 server->tcpStatus = CifsNeedReconnect;
211
212 if (!collision) {
213 mid = (__u64)cur_mid;
214 server->CurrentMid = mid;
215 break;
216 }
217 cur_mid++;
218 }
219 spin_unlock(&GlobalMid_Lock);
220 return mid;
221}
222
Pavel Shilovsky316cf942012-05-23 14:31:03 +0400223/*
224 return codes:
225 0 not a transact2, or all data present
226 >0 transact2 with that much data missing
227 -EINVAL invalid transact2
228 */
229static int
230check2ndT2(char *buf)
231{
232 struct smb_hdr *pSMB = (struct smb_hdr *)buf;
233 struct smb_t2_rsp *pSMBt;
234 int remaining;
235 __u16 total_data_size, data_in_this_rsp;
236
237 if (pSMB->Command != SMB_COM_TRANSACTION2)
238 return 0;
239
240 /* check for plausible wct, bcc and t2 data and parm sizes */
241 /* check for parm and data offset going beyond end of smb */
242 if (pSMB->WordCount != 10) { /* coalesce_t2 depends on this */
243 cFYI(1, "invalid transact2 word count");
244 return -EINVAL;
245 }
246
247 pSMBt = (struct smb_t2_rsp *)pSMB;
248
249 total_data_size = get_unaligned_le16(&pSMBt->t2_rsp.TotalDataCount);
250 data_in_this_rsp = get_unaligned_le16(&pSMBt->t2_rsp.DataCount);
251
252 if (total_data_size == data_in_this_rsp)
253 return 0;
254 else if (total_data_size < data_in_this_rsp) {
255 cFYI(1, "total data %d smaller than data in frame %d",
256 total_data_size, data_in_this_rsp);
257 return -EINVAL;
258 }
259
260 remaining = total_data_size - data_in_this_rsp;
261
262 cFYI(1, "missing %d bytes from transact2, check next response",
263 remaining);
264 if (total_data_size > CIFSMaxBufSize) {
265 cERROR(1, "TotalDataSize %d is over maximum buffer %d",
266 total_data_size, CIFSMaxBufSize);
267 return -EINVAL;
268 }
269 return remaining;
270}
271
272static int
273coalesce_t2(char *second_buf, struct smb_hdr *target_hdr)
274{
275 struct smb_t2_rsp *pSMBs = (struct smb_t2_rsp *)second_buf;
276 struct smb_t2_rsp *pSMBt = (struct smb_t2_rsp *)target_hdr;
277 char *data_area_of_tgt;
278 char *data_area_of_src;
279 int remaining;
280 unsigned int byte_count, total_in_tgt;
281 __u16 tgt_total_cnt, src_total_cnt, total_in_src;
282
283 src_total_cnt = get_unaligned_le16(&pSMBs->t2_rsp.TotalDataCount);
284 tgt_total_cnt = get_unaligned_le16(&pSMBt->t2_rsp.TotalDataCount);
285
286 if (tgt_total_cnt != src_total_cnt)
287 cFYI(1, "total data count of primary and secondary t2 differ "
288 "source=%hu target=%hu", src_total_cnt, tgt_total_cnt);
289
290 total_in_tgt = get_unaligned_le16(&pSMBt->t2_rsp.DataCount);
291
292 remaining = tgt_total_cnt - total_in_tgt;
293
294 if (remaining < 0) {
295 cFYI(1, "Server sent too much data. tgt_total_cnt=%hu "
296 "total_in_tgt=%hu", tgt_total_cnt, total_in_tgt);
297 return -EPROTO;
298 }
299
300 if (remaining == 0) {
301 /* nothing to do, ignore */
302 cFYI(1, "no more data remains");
303 return 0;
304 }
305
306 total_in_src = get_unaligned_le16(&pSMBs->t2_rsp.DataCount);
307 if (remaining < total_in_src)
308 cFYI(1, "transact2 2nd response contains too much data");
309
310 /* find end of first SMB data area */
311 data_area_of_tgt = (char *)&pSMBt->hdr.Protocol +
312 get_unaligned_le16(&pSMBt->t2_rsp.DataOffset);
313
314 /* validate target area */
315 data_area_of_src = (char *)&pSMBs->hdr.Protocol +
316 get_unaligned_le16(&pSMBs->t2_rsp.DataOffset);
317
318 data_area_of_tgt += total_in_tgt;
319
320 total_in_tgt += total_in_src;
321 /* is the result too big for the field? */
322 if (total_in_tgt > USHRT_MAX) {
323 cFYI(1, "coalesced DataCount too large (%u)", total_in_tgt);
324 return -EPROTO;
325 }
326 put_unaligned_le16(total_in_tgt, &pSMBt->t2_rsp.DataCount);
327
328 /* fix up the BCC */
329 byte_count = get_bcc(target_hdr);
330 byte_count += total_in_src;
331 /* is the result too big for the field? */
332 if (byte_count > USHRT_MAX) {
333 cFYI(1, "coalesced BCC too large (%u)", byte_count);
334 return -EPROTO;
335 }
336 put_bcc(byte_count, target_hdr);
337
338 byte_count = be32_to_cpu(target_hdr->smb_buf_length);
339 byte_count += total_in_src;
340 /* don't allow buffer to overflow */
341 if (byte_count > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
342 cFYI(1, "coalesced BCC exceeds buffer size (%u)", byte_count);
343 return -ENOBUFS;
344 }
345 target_hdr->smb_buf_length = cpu_to_be32(byte_count);
346
347 /* copy second buffer into end of first buffer */
348 memcpy(data_area_of_tgt, data_area_of_src, total_in_src);
349
350 if (remaining != total_in_src) {
351 /* more responses to go */
352 cFYI(1, "waiting for more secondary responses");
353 return 1;
354 }
355
356 /* we are done */
357 cFYI(1, "found the last secondary response");
358 return 0;
359}
360
361static bool
362cifs_check_trans2(struct mid_q_entry *mid, struct TCP_Server_Info *server,
363 char *buf, int malformed)
364{
365 if (malformed)
366 return false;
367 if (check2ndT2(buf) <= 0)
368 return false;
369 mid->multiRsp = true;
370 if (mid->resp_buf) {
371 /* merge response - fix up 1st*/
372 malformed = coalesce_t2(buf, mid->resp_buf);
373 if (malformed > 0)
374 return true;
375 /* All parts received or packet is malformed. */
376 mid->multiEnd = true;
377 dequeue_mid(mid, malformed);
378 return true;
379 }
380 if (!server->large_buf) {
381 /*FIXME: switch to already allocated largebuf?*/
382 cERROR(1, "1st trans2 resp needs bigbuf");
383 } else {
384 /* Have first buffer */
385 mid->resp_buf = buf;
386 mid->large_buf = true;
387 server->bigbuf = NULL;
388 }
389 return true;
390}
391
Pavel Shilovsky286170a2012-05-25 10:43:58 +0400392static bool
393cifs_need_neg(struct TCP_Server_Info *server)
394{
395 return server->maxBuf == 0;
396}
397
398static int
399cifs_negotiate(const unsigned int xid, struct cifs_ses *ses)
400{
401 int rc;
402 rc = CIFSSMBNegotiate(xid, ses);
403 if (rc == -EAGAIN) {
404 /* retry only once on 1st time connection */
405 set_credits(ses->server, 1);
406 rc = CIFSSMBNegotiate(xid, ses);
407 if (rc == -EAGAIN)
408 rc = -EHOSTDOWN;
409 }
410 return rc;
411}
412
Jeff Layton23db65f2012-05-15 12:20:51 -0400413struct smb_version_operations smb1_operations = {
Jeff Layton121b0462012-05-15 12:21:10 -0400414 .send_cancel = send_nt_cancel,
Pavel Shilovsky55157df2012-02-28 14:04:17 +0300415 .compare_fids = cifs_compare_fids,
Pavel Shilovsky082d0642012-05-17 12:18:21 +0400416 .setup_request = cifs_setup_request,
417 .check_receive = cifs_check_receive,
Pavel Shilovsky45275782012-05-17 17:53:29 +0400418 .add_credits = cifs_add_credits,
419 .set_credits = cifs_set_credits,
420 .get_credits_field = cifs_get_credits_field,
Pavel Shilovskya891f0f2012-05-23 16:14:34 +0400421 .get_credits = cifs_get_credits,
Pavel Shilovsky88257362012-05-23 14:01:59 +0400422 .get_next_mid = cifs_get_next_mid,
Pavel Shilovskyeb378712012-05-17 13:02:51 +0400423 .read_data_offset = cifs_read_data_offset,
424 .read_data_length = cifs_read_data_length,
425 .map_error = map_smb_to_linux_error,
Pavel Shilovsky8aa26f32012-05-17 13:25:35 +0400426 .find_mid = cifs_find_mid,
427 .check_message = checkSMB,
428 .dump_detail = cifs_dump_detail,
429 .is_oplock_break = is_valid_oplock_break,
Pavel Shilovsky316cf942012-05-23 14:31:03 +0400430 .check_trans2 = cifs_check_trans2,
Pavel Shilovsky286170a2012-05-25 10:43:58 +0400431 .need_neg = cifs_need_neg,
432 .negotiate = cifs_negotiate,
Jeff Layton23db65f2012-05-15 12:20:51 -0400433};
434
435struct smb_version_values smb1_values = {
436 .version_string = SMB1_VERSION_STRING,
Pavel Shilovsky106dc532012-02-28 14:23:34 +0300437 .large_lock_type = LOCKING_ANDX_LARGE_FILES,
438 .exclusive_lock_type = 0,
439 .shared_lock_type = LOCKING_ANDX_SHARED_LOCK,
440 .unlock_lock_type = 0,
Pavel Shilovsky1887f602012-05-17 12:45:31 +0400441 .header_size = sizeof(struct smb_hdr),
442 .max_header_size = MAX_CIFS_HDR_SIZE,
Pavel Shilovskyeb378712012-05-17 13:02:51 +0400443 .read_rsp_size = sizeof(READ_RSP),
Jeff Layton23db65f2012-05-15 12:20:51 -0400444};