2 * SMB1 (CIFS) version specific operations
4 * Copyright (c) 2012, Jeff Layton <jlayton@redhat.com>
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.
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.
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
21 #include "cifsproto.h"
22 #include "cifs_debug.h"
26 * An NT cancel request header looks just like the original request except:
28 * The Command is SMB_COM_NT_CANCEL
29 * The WordCount is zeroed out
30 * The ByteCount is zeroed out
32 * This function mangles an existing request buffer into a
33 * SMB_COM_NT_CANCEL request and then sends it.
36 send_nt_cancel(struct TCP_Server_Info *server, void *buf,
37 struct mid_q_entry *mid)
40 struct smb_hdr *in_buf = (struct smb_hdr *)buf;
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;
48 mutex_lock(&server->srv_mutex);
49 rc = cifs_sign_smb(in_buf, server, &mid->sequence_number);
51 mutex_unlock(&server->srv_mutex);
54 rc = smb_send(server, in_buf, be32_to_cpu(in_buf->smb_buf_length));
55 mutex_unlock(&server->srv_mutex);
57 cFYI(1, "issued NT_CANCEL for mid %u, rc = %d",
64 cifs_compare_fids(struct cifsFileInfo *ob1, struct cifsFileInfo *ob2)
66 return ob1->netfid == ob2->netfid;
70 cifs_read_data_offset(char *buf)
72 READ_RSP *rsp = (READ_RSP *)buf;
73 return le16_to_cpu(rsp->DataOffset);
77 cifs_read_data_length(char *buf)
79 READ_RSP *rsp = (READ_RSP *)buf;
80 return (le16_to_cpu(rsp->DataLengthHigh) << 16) +
81 le16_to_cpu(rsp->DataLength);
84 static struct mid_q_entry *
85 cifs_find_mid(struct TCP_Server_Info *server, char *buffer)
87 struct smb_hdr *buf = (struct smb_hdr *)buffer;
88 struct mid_q_entry *mid;
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);
99 spin_unlock(&GlobalMid_Lock);
104 cifs_add_credits(struct TCP_Server_Info *server, const unsigned int add)
106 spin_lock(&server->req_lock);
107 server->credits += add;
109 spin_unlock(&server->req_lock);
110 wake_up(&server->request_q);
114 cifs_set_credits(struct TCP_Server_Info *server, const int val)
116 spin_lock(&server->req_lock);
117 server->credits = val;
118 server->oplocks = val > 1 ? enable_oplocks : false;
119 spin_unlock(&server->req_lock);
123 cifs_get_credits_field(struct TCP_Server_Info *server)
125 return &server->credits;
129 * Find a free multiplex id (SMB mid). Otherwise there could be
130 * mid collisions which might cause problems, demultiplexing the
131 * wrong response to this request. Multiplex ids could collide if
132 * one of a series requests takes much longer than the others, or
133 * if a very large number of long lived requests (byte range
134 * locks or FindNotify requests) are pending. No more than
135 * 64K-1 requests can be outstanding at one time. If no
136 * mids are available, return zero. A future optimization
137 * could make the combination of mids and uid the key we use
138 * to demultiplex on (rather than mid alone).
139 * In addition to the above check, the cifs demultiplex
140 * code already used the command code as a secondary
141 * check of the frame and if signing is negotiated the
142 * response would be discarded if the mid were the same
143 * but the signature was wrong. Since the mid is not put in the
144 * pending queue until later (when it is about to be dispatched)
145 * we do have to limit the number of outstanding requests
146 * to somewhat less than 64K-1 although it is hard to imagine
147 * so many threads being in the vfs at one time.
150 cifs_get_next_mid(struct TCP_Server_Info *server)
153 __u16 last_mid, cur_mid;
156 spin_lock(&GlobalMid_Lock);
158 /* mid is 16 bit only for CIFS/SMB */
159 cur_mid = (__u16)((server->CurrentMid) & 0xffff);
160 /* we do not want to loop forever */
165 * This nested loop looks more expensive than it is.
166 * In practice the list of pending requests is short,
167 * fewer than 50, and the mids are likely to be unique
168 * on the first pass through the loop unless some request
169 * takes longer than the 64 thousand requests before it
170 * (and it would also have to have been a request that
173 while (cur_mid != last_mid) {
174 struct mid_q_entry *mid_entry;
175 unsigned int num_mids;
182 list_for_each_entry(mid_entry, &server->pending_mid_q, qhead) {
184 if (mid_entry->mid == cur_mid &&
185 mid_entry->mid_state == MID_REQUEST_SUBMITTED) {
186 /* This mid is in use, try a different one */
193 * if we have more than 32k mids in the list, then something
194 * is very wrong. Possibly a local user is trying to DoS the
195 * box by issuing long-running calls and SIGKILL'ing them. If
196 * we get to 2^16 mids then we're in big trouble as this
197 * function could loop forever.
199 * Go ahead and assign out the mid in this situation, but force
200 * an eventual reconnect to clean out the pending_mid_q.
202 if (num_mids > 32768)
203 server->tcpStatus = CifsNeedReconnect;
206 mid = (__u64)cur_mid;
207 server->CurrentMid = mid;
212 spin_unlock(&GlobalMid_Lock);
218 0 not a transact2, or all data present
219 >0 transact2 with that much data missing
220 -EINVAL invalid transact2
223 check2ndT2(char *buf)
225 struct smb_hdr *pSMB = (struct smb_hdr *)buf;
226 struct smb_t2_rsp *pSMBt;
228 __u16 total_data_size, data_in_this_rsp;
230 if (pSMB->Command != SMB_COM_TRANSACTION2)
233 /* check for plausible wct, bcc and t2 data and parm sizes */
234 /* check for parm and data offset going beyond end of smb */
235 if (pSMB->WordCount != 10) { /* coalesce_t2 depends on this */
236 cFYI(1, "invalid transact2 word count");
240 pSMBt = (struct smb_t2_rsp *)pSMB;
242 total_data_size = get_unaligned_le16(&pSMBt->t2_rsp.TotalDataCount);
243 data_in_this_rsp = get_unaligned_le16(&pSMBt->t2_rsp.DataCount);
245 if (total_data_size == data_in_this_rsp)
247 else if (total_data_size < data_in_this_rsp) {
248 cFYI(1, "total data %d smaller than data in frame %d",
249 total_data_size, data_in_this_rsp);
253 remaining = total_data_size - data_in_this_rsp;
255 cFYI(1, "missing %d bytes from transact2, check next response",
257 if (total_data_size > CIFSMaxBufSize) {
258 cERROR(1, "TotalDataSize %d is over maximum buffer %d",
259 total_data_size, CIFSMaxBufSize);
266 coalesce_t2(char *second_buf, struct smb_hdr *target_hdr)
268 struct smb_t2_rsp *pSMBs = (struct smb_t2_rsp *)second_buf;
269 struct smb_t2_rsp *pSMBt = (struct smb_t2_rsp *)target_hdr;
270 char *data_area_of_tgt;
271 char *data_area_of_src;
273 unsigned int byte_count, total_in_tgt;
274 __u16 tgt_total_cnt, src_total_cnt, total_in_src;
276 src_total_cnt = get_unaligned_le16(&pSMBs->t2_rsp.TotalDataCount);
277 tgt_total_cnt = get_unaligned_le16(&pSMBt->t2_rsp.TotalDataCount);
279 if (tgt_total_cnt != src_total_cnt)
280 cFYI(1, "total data count of primary and secondary t2 differ "
281 "source=%hu target=%hu", src_total_cnt, tgt_total_cnt);
283 total_in_tgt = get_unaligned_le16(&pSMBt->t2_rsp.DataCount);
285 remaining = tgt_total_cnt - total_in_tgt;
288 cFYI(1, "Server sent too much data. tgt_total_cnt=%hu "
289 "total_in_tgt=%hu", tgt_total_cnt, total_in_tgt);
293 if (remaining == 0) {
294 /* nothing to do, ignore */
295 cFYI(1, "no more data remains");
299 total_in_src = get_unaligned_le16(&pSMBs->t2_rsp.DataCount);
300 if (remaining < total_in_src)
301 cFYI(1, "transact2 2nd response contains too much data");
303 /* find end of first SMB data area */
304 data_area_of_tgt = (char *)&pSMBt->hdr.Protocol +
305 get_unaligned_le16(&pSMBt->t2_rsp.DataOffset);
307 /* validate target area */
308 data_area_of_src = (char *)&pSMBs->hdr.Protocol +
309 get_unaligned_le16(&pSMBs->t2_rsp.DataOffset);
311 data_area_of_tgt += total_in_tgt;
313 total_in_tgt += total_in_src;
314 /* is the result too big for the field? */
315 if (total_in_tgt > USHRT_MAX) {
316 cFYI(1, "coalesced DataCount too large (%u)", total_in_tgt);
319 put_unaligned_le16(total_in_tgt, &pSMBt->t2_rsp.DataCount);
322 byte_count = get_bcc(target_hdr);
323 byte_count += total_in_src;
324 /* is the result too big for the field? */
325 if (byte_count > USHRT_MAX) {
326 cFYI(1, "coalesced BCC too large (%u)", byte_count);
329 put_bcc(byte_count, target_hdr);
331 byte_count = be32_to_cpu(target_hdr->smb_buf_length);
332 byte_count += total_in_src;
333 /* don't allow buffer to overflow */
334 if (byte_count > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
335 cFYI(1, "coalesced BCC exceeds buffer size (%u)", byte_count);
338 target_hdr->smb_buf_length = cpu_to_be32(byte_count);
340 /* copy second buffer into end of first buffer */
341 memcpy(data_area_of_tgt, data_area_of_src, total_in_src);
343 if (remaining != total_in_src) {
344 /* more responses to go */
345 cFYI(1, "waiting for more secondary responses");
350 cFYI(1, "found the last secondary response");
355 cifs_check_trans2(struct mid_q_entry *mid, struct TCP_Server_Info *server,
356 char *buf, int malformed)
360 if (check2ndT2(buf) <= 0)
362 mid->multiRsp = true;
364 /* merge response - fix up 1st*/
365 malformed = coalesce_t2(buf, mid->resp_buf);
368 /* All parts received or packet is malformed. */
369 mid->multiEnd = true;
370 dequeue_mid(mid, malformed);
373 if (!server->large_buf) {
374 /*FIXME: switch to already allocated largebuf?*/
375 cERROR(1, "1st trans2 resp needs bigbuf");
377 /* Have first buffer */
379 mid->large_buf = true;
380 server->bigbuf = NULL;
385 struct smb_version_operations smb1_operations = {
386 .send_cancel = send_nt_cancel,
387 .compare_fids = cifs_compare_fids,
388 .setup_request = cifs_setup_request,
389 .check_receive = cifs_check_receive,
390 .add_credits = cifs_add_credits,
391 .set_credits = cifs_set_credits,
392 .get_credits_field = cifs_get_credits_field,
393 .get_next_mid = cifs_get_next_mid,
394 .read_data_offset = cifs_read_data_offset,
395 .read_data_length = cifs_read_data_length,
396 .map_error = map_smb_to_linux_error,
397 .find_mid = cifs_find_mid,
398 .check_message = checkSMB,
399 .dump_detail = cifs_dump_detail,
400 .is_oplock_break = is_valid_oplock_break,
401 .check_trans2 = cifs_check_trans2,
404 struct smb_version_values smb1_values = {
405 .version_string = SMB1_VERSION_STRING,
406 .large_lock_type = LOCKING_ANDX_LARGE_FILES,
407 .exclusive_lock_type = 0,
408 .shared_lock_type = LOCKING_ANDX_SHARED_LOCK,
409 .unlock_lock_type = 0,
410 .header_size = sizeof(struct smb_hdr),
411 .max_header_size = MAX_CIFS_HDR_SIZE,
412 .read_rsp_size = sizeof(READ_RSP),