source: trunk/server/source3/smbd/smb2_read.c

Last change on this file was 751, checked in by Silvan Scherrer, 13 years ago

Samba Server: updated trunk to 3.6.9
File size: 16.2 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3 Core SMB2 server
4
5 Copyright (C) Stefan Metzmacher 2009
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>.
19*/
20
21#include "includes.h"
22#include "system/filesys.h"
23#include "smbd/smbd.h"
24#include "smbd/globals.h"
25#include "../libcli/smb/smb_common.h"
26#include "libcli/security/security.h"
27#include "../lib/util/tevent_ntstatus.h"
28#include "rpc_server/srv_pipe_hnd.h"
29
30static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
31 struct tevent_context *ev,
32 struct smbd_smb2_request *smb2req,
33 struct files_struct *in_fsp,
34 uint32_t in_smbpid,
35 uint32_t in_length,
36 uint64_t in_offset,
37 uint32_t in_minimum,
38 uint32_t in_remaining);
39static NTSTATUS smbd_smb2_read_recv(struct tevent_req *req,
40 TALLOC_CTX *mem_ctx,
41 DATA_BLOB *out_data,
42 uint32_t *out_remaining);
43
44static void smbd_smb2_request_read_done(struct tevent_req *subreq);
45NTSTATUS smbd_smb2_request_process_read(struct smbd_smb2_request *req)
46{
47 NTSTATUS status;
48 const uint8_t *inhdr;
49 const uint8_t *inbody;
50 int i = req->current_idx;
51 uint32_t in_smbpid;
52 uint32_t in_length;
53 uint64_t in_offset;
54 uint64_t in_file_id_persistent;
55 uint64_t in_file_id_volatile;
56 struct files_struct *in_fsp;
57 uint32_t in_minimum_count;
58 uint32_t in_remaining_bytes;
59 struct tevent_req *subreq;
60
61 status = smbd_smb2_request_verify_sizes(req, 0x31);
62 if (!NT_STATUS_IS_OK(status)) {
63 return smbd_smb2_request_error(req, status);
64 }
65 inhdr = (const uint8_t *)req->in.vector[i+0].iov_base;
66 inbody = (const uint8_t *)req->in.vector[i+1].iov_base;
67
68 in_smbpid = IVAL(inhdr, SMB2_HDR_PID);
69
70 in_length = IVAL(inbody, 0x04);
71 in_offset = BVAL(inbody, 0x08);
72 in_file_id_persistent = BVAL(inbody, 0x10);
73 in_file_id_volatile = BVAL(inbody, 0x18);
74 in_minimum_count = IVAL(inbody, 0x20);
75 in_remaining_bytes = IVAL(inbody, 0x28);
76
77 /* check the max read size */
78 if (in_length > req->sconn->smb2.max_read) {
79 DEBUG(0,("here:%s: 0x%08X: 0x%08X\n",
80 __location__, in_length, req->sconn->smb2.max_read));
81 return smbd_smb2_request_error(req, NT_STATUS_INVALID_PARAMETER);
82 }
83
84 in_fsp = file_fsp_smb2(req, in_file_id_persistent, in_file_id_volatile);
85 if (in_fsp == NULL) {
86 return smbd_smb2_request_error(req, NT_STATUS_FILE_CLOSED);
87 }
88
89 subreq = smbd_smb2_read_send(req, req->sconn->smb2.event_ctx,
90 req, in_fsp,
91 in_smbpid,
92 in_length,
93 in_offset,
94 in_minimum_count,
95 in_remaining_bytes);
96 if (subreq == NULL) {
97 return smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
98 }
99 tevent_req_set_callback(subreq, smbd_smb2_request_read_done, req);
100
101 return smbd_smb2_request_pending_queue(req, subreq);
102}
103
104static void smbd_smb2_request_read_done(struct tevent_req *subreq)
105{
106 struct smbd_smb2_request *req = tevent_req_callback_data(subreq,
107 struct smbd_smb2_request);
108 int i = req->current_idx;
109 uint8_t *outhdr;
110 DATA_BLOB outbody;
111 DATA_BLOB outdyn;
112 uint8_t out_data_offset;
113 DATA_BLOB out_data_buffer = data_blob_null;
114 uint32_t out_data_remaining = 0;
115 NTSTATUS status;
116 NTSTATUS error; /* transport error */
117
118 status = smbd_smb2_read_recv(subreq,
119 req,
120 &out_data_buffer,
121 &out_data_remaining);
122 TALLOC_FREE(subreq);
123 if (!NT_STATUS_IS_OK(status)) {
124 error = smbd_smb2_request_error(req, status);
125 if (!NT_STATUS_IS_OK(error)) {
126 smbd_server_connection_terminate(req->sconn,
127 nt_errstr(error));
128 return;
129 }
130 return;
131 }
132
133 out_data_offset = SMB2_HDR_BODY + 0x10;
134
135 outhdr = (uint8_t *)req->out.vector[i].iov_base;
136
137 outbody = data_blob_talloc(req->out.vector, NULL, 0x10);
138 if (outbody.data == NULL) {
139 error = smbd_smb2_request_error(req, NT_STATUS_NO_MEMORY);
140 if (!NT_STATUS_IS_OK(error)) {
141 smbd_server_connection_terminate(req->sconn,
142 nt_errstr(error));
143 return;
144 }
145 return;
146 }
147
148 SSVAL(outbody.data, 0x00, 0x10 + 1); /* struct size */
149 SCVAL(outbody.data, 0x02,
150 out_data_offset); /* data offset */
151 SCVAL(outbody.data, 0x03, 0); /* reserved */
152 SIVAL(outbody.data, 0x04,
153 out_data_buffer.length); /* data length */
154 SIVAL(outbody.data, 0x08,
155 out_data_remaining); /* data remaining */
156 SIVAL(outbody.data, 0x0C, 0); /* reserved */
157
158 outdyn = out_data_buffer;
159
160 error = smbd_smb2_request_done(req, outbody, &outdyn);
161 if (!NT_STATUS_IS_OK(error)) {
162 smbd_server_connection_terminate(req->sconn,
163 nt_errstr(error));
164 return;
165 }
166}
167
168struct smbd_smb2_read_state {
169 struct smbd_smb2_request *smb2req;
170 files_struct *fsp;
171 uint32_t in_length;
172 uint64_t in_offset;
173 uint32_t in_minimum;
174 DATA_BLOB out_data;
175 uint32_t out_remaining;
176};
177
178/* struct smbd_smb2_read_state destructor. Send the SMB2_READ data. */
179static int smb2_sendfile_send_data(struct smbd_smb2_read_state *state)
180{
181 struct lock_struct lock;
182 uint32_t in_length = state->in_length;
183 uint64_t in_offset = state->in_offset;
184 files_struct *fsp = state->fsp;
185 ssize_t nread;
186
187 nread = SMB_VFS_SENDFILE(fsp->conn->sconn->sock,
188 fsp,
189 NULL,
190 in_offset,
191 in_length);
192 DEBUG(10,("smb2_sendfile_send_data: SMB_VFS_SENDFILE returned %d on file %s\n",
193 (int)nread,
194 fsp_str_dbg(fsp) ));
195
196 if (nread == -1) {
197 if (errno == ENOSYS || errno == EINTR) {
198 /*
199 * Special hack for broken systems with no working
200 * sendfile. Fake this up by doing read/write calls.
201 */
202 set_use_sendfile(SNUM(fsp->conn), false);
203 nread = fake_sendfile(fsp, in_offset, in_length);
204 if (nread == -1) {
205 DEBUG(0,("smb2_sendfile_send_data: "
206 "fake_sendfile failed for "
207 "file %s (%s).\n",
208 fsp_str_dbg(fsp),
209 strerror(errno)));
210 exit_server_cleanly("smb2_sendfile_send_data: "
211 "fake_sendfile failed");
212 }
213 goto out;
214 }
215
216 DEBUG(0,("smb2_sendfile_send_data: sendfile failed for file "
217 "%s (%s). Terminating\n",
218 fsp_str_dbg(fsp),
219 strerror(errno)));
220 exit_server_cleanly("smb2_sendfile_send_data: sendfile failed");
221 } else if (nread == 0) {
222 /*
223 * Some sendfile implementations return 0 to indicate
224 * that there was a short read, but nothing was
225 * actually written to the socket. In this case,
226 * fallback to the normal read path so the header gets
227 * the correct byte count.
228 */
229 DEBUG(3, ("send_file_readX: sendfile sent zero bytes "
230 "falling back to the normal read: %s\n",
231 fsp_str_dbg(fsp)));
232
233 nread = fake_sendfile(fsp, in_offset, in_length);
234 if (nread == -1) {
235 DEBUG(0,("smb2_sendfile_send_data: "
236 "fake_sendfile failed for file "
237 "%s (%s). Terminating\n",
238 fsp_str_dbg(fsp),
239 strerror(errno)));
240 exit_server_cleanly("smb2_sendfile_send_data: "
241 "fake_sendfile failed");
242 }
243 }
244
245 out:
246
247 if (nread < in_length) {
248 sendfile_short_send(fsp, nread, 0, in_length);
249 }
250
251 init_strict_lock_struct(fsp,
252 fsp->fnum,
253 in_offset,
254 in_length,
255 READ_LOCK,
256 &lock);
257
258 SMB_VFS_STRICT_UNLOCK(fsp->conn, fsp, &lock);
259 return 0;
260}
261
262static NTSTATUS schedule_smb2_sendfile_read(struct smbd_smb2_request *smb2req,
263 struct smbd_smb2_read_state *state)
264{
265 struct smbd_smb2_read_state *state_copy = NULL;
266 files_struct *fsp = state->fsp;
267
268 /*
269 * We cannot use sendfile if...
270 * We were not configured to do so OR
271 * Signing is active OR
272 * This is a compound SMB2 operation OR
273 * fsp is a STREAM file OR
274 * We're using a write cache OR
275 * It's not a regular file OR
276 * Requested offset is greater than file size OR
277 * there's not enough data in the file.
278 * Phew :-). Luckily this means most
279 * reads on most normal files. JRA.
280 */
281
282 if (!_lp_use_sendfile(SNUM(fsp->conn)) ||
283 smb2req->do_signing ||
284 smb2req->in.vector_count != 4 ||
285 (fsp->base_fsp != NULL) ||
286 (fsp->wcp != NULL) ||
287 (!S_ISREG(fsp->fsp_name->st.st_ex_mode)) ||
288 (state->in_offset >= fsp->fsp_name->st.st_ex_size) ||
289 (fsp->fsp_name->st.st_ex_size < state->in_offset +
290 state->in_length)) {
291 return NT_STATUS_RETRY;
292 }
293
294 /* We've already checked there's this amount of data
295 to read. */
296 state->out_data.length = state->in_length;
297 state->out_remaining = 0;
298
299 /* Make a copy of state attached to the smb2req. Attach
300 the destructor here as this will trigger the sendfile
301 call when the request is destroyed. */
302 state_copy = TALLOC_P(smb2req, struct smbd_smb2_read_state);
303 if (!state_copy) {
304 return NT_STATUS_NO_MEMORY;
305 }
306 *state_copy = *state;
307 talloc_set_destructor(state_copy, smb2_sendfile_send_data);
308 return NT_STATUS_OK;
309}
310
311static void smbd_smb2_read_pipe_done(struct tevent_req *subreq);
312
313/*******************************************************************
314 Common read complete processing function for both synchronous and
315 asynchronous reads.
316*******************************************************************/
317
318NTSTATUS smb2_read_complete(struct tevent_req *req, ssize_t nread, int err)
319{
320 struct smbd_smb2_read_state *state = tevent_req_data(req,
321 struct smbd_smb2_read_state);
322 files_struct *fsp = state->fsp;
323
324 if (nread < 0) {
325 NTSTATUS status = map_nt_error_from_unix(err);
326
327 DEBUG( 3,( "smb2_read_complete: file %s nread = %d. "
328 "Error = %s (NTSTATUS %s)\n",
329 fsp_str_dbg(fsp),
330 (int)nread,
331 strerror(err),
332 nt_errstr(status)));
333
334 return status;
335 }
336 if (nread == 0 && state->in_length != 0) {
337 DEBUG(5,("smb2_read_complete: read_file[%s] end of file\n",
338 fsp_str_dbg(fsp)));
339 return NT_STATUS_END_OF_FILE;
340 }
341
342 if (nread < state->in_minimum) {
343 DEBUG(5,("smb2_read_complete: read_file[%s] read less %d than "
344 "minimum requested %u. Returning end of file\n",
345 fsp_str_dbg(fsp),
346 (int)nread,
347 (unsigned int)state->in_minimum));
348 return NT_STATUS_END_OF_FILE;
349 }
350
351 DEBUG(3,("smbd_smb2_read: fnum=[%d/%s] length=%lu offset=%lu read=%lu\n",
352 fsp->fnum,
353 fsp_str_dbg(fsp),
354 (unsigned long)state->in_length,
355 (unsigned long)state->in_offset,
356 (unsigned long)nread));
357
358 state->out_data.length = nread;
359 state->out_remaining = 0;
360
361 return NT_STATUS_OK;
362}
363
364static struct tevent_req *smbd_smb2_read_send(TALLOC_CTX *mem_ctx,
365 struct tevent_context *ev,
366 struct smbd_smb2_request *smb2req,
367 struct files_struct *fsp,
368 uint32_t in_smbpid,
369 uint32_t in_length,
370 uint64_t in_offset,
371 uint32_t in_minimum,
372 uint32_t in_remaining)
373{
374 NTSTATUS status;
375 struct tevent_req *req = NULL;
376 struct smbd_smb2_read_state *state = NULL;
377 struct smb_request *smbreq = NULL;
378 connection_struct *conn = smb2req->tcon->compat_conn;
379 ssize_t nread = -1;
380 struct lock_struct lock;
381 int saved_errno;
382
383 req = tevent_req_create(mem_ctx, &state,
384 struct smbd_smb2_read_state);
385 if (req == NULL) {
386 return NULL;
387 }
388 state->smb2req = smb2req;
389 state->in_length = in_length;
390 state->in_offset = in_offset;
391 state->in_minimum = in_minimum;
392 state->out_data = data_blob_null;
393 state->out_remaining = 0;
394
395 DEBUG(10,("smbd_smb2_read: %s - fnum[%d]\n",
396 fsp_str_dbg(fsp), fsp->fnum));
397
398 smbreq = smbd_smb2_fake_smb_request(smb2req);
399 if (tevent_req_nomem(smbreq, req)) {
400 return tevent_req_post(req, ev);
401 }
402
403 if (fsp->is_directory) {
404 tevent_req_nterror(req, NT_STATUS_INVALID_DEVICE_REQUEST);
405 return tevent_req_post(req, ev);
406 }
407
408 state->fsp = fsp;
409
410 if (IS_IPC(smbreq->conn)) {
411 struct tevent_req *subreq = NULL;
412
413 state->out_data = data_blob_talloc(state, NULL, in_length);
414 if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
415 return tevent_req_post(req, ev);
416 }
417
418 if (!fsp_is_np(fsp)) {
419 tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
420 return tevent_req_post(req, ev);
421 }
422
423 subreq = np_read_send(state, smbd_event_context(),
424 fsp->fake_file_handle,
425 state->out_data.data,
426 state->out_data.length);
427 if (tevent_req_nomem(subreq, req)) {
428 return tevent_req_post(req, ev);
429 }
430 tevent_req_set_callback(subreq,
431 smbd_smb2_read_pipe_done,
432 req);
433 return req;
434 }
435
436 if (!CHECK_READ(fsp, smbreq)) {
437 tevent_req_nterror(req, NT_STATUS_ACCESS_DENIED);
438 return tevent_req_post(req, ev);
439 }
440
441 status = schedule_smb2_aio_read(fsp->conn,
442 smbreq,
443 fsp,
444 state,
445 &state->out_data,
446 (SMB_OFF_T)in_offset,
447 (size_t)in_length);
448
449 if (NT_STATUS_IS_OK(status)) {
450 /*
451 * Doing an async read. Don't
452 * send a "gone async" message
453 * as we expect this to be less
454 * than the client timeout period.
455 * JRA. FIXME for offline files..
456 * FIXME. Add cancel code..
457 */
458 smb2req->async = true;
459 return req;
460 }
461
462 if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
463 /* Real error in setting up aio. Fail. */
464 tevent_req_nterror(req, NT_STATUS_FILE_CLOSED);
465 return tevent_req_post(req, ev);
466 }
467
468 /* Fallback to synchronous. */
469
470 init_strict_lock_struct(fsp,
471 fsp->fnum,
472 in_offset,
473 in_length,
474 READ_LOCK,
475 &lock);
476
477 if (!SMB_VFS_STRICT_LOCK(conn, fsp, &lock)) {
478 tevent_req_nterror(req, NT_STATUS_FILE_LOCK_CONFLICT);
479 return tevent_req_post(req, ev);
480 }
481
482 /* Try sendfile in preference. */
483 status = schedule_smb2_sendfile_read(smb2req, state);
484 if (NT_STATUS_IS_OK(status)) {
485 tevent_req_done(req);
486 return tevent_req_post(req, ev);
487 } else {
488 if (!NT_STATUS_EQUAL(status, NT_STATUS_RETRY)) {
489 SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
490 tevent_req_nterror(req, status);
491 return tevent_req_post(req, ev);
492 }
493 }
494
495 /* Ok, read into memory. Allocate the out buffer. */
496 state->out_data = data_blob_talloc(state, NULL, in_length);
497 if (in_length > 0 && tevent_req_nomem(state->out_data.data, req)) {
498 SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
499 return tevent_req_post(req, ev);
500 }
501
502 nread = read_file(fsp,
503 (char *)state->out_data.data,
504 in_offset,
505 in_length);
506
507 saved_errno = errno;
508
509 SMB_VFS_STRICT_UNLOCK(conn, fsp, &lock);
510
511 DEBUG(10,("smbd_smb2_read: file %s fnum[%d] offset=%llu "
512 "len=%llu returned %lld\n",
513 fsp_str_dbg(fsp),
514 fsp->fnum,
515 (unsigned long long)in_offset,
516 (unsigned long long)in_length,
517 (long long)nread));
518
519 status = smb2_read_complete(req, nread, saved_errno);
520 if (!NT_STATUS_IS_OK(status)) {
521 tevent_req_nterror(req, status);
522 } else {
523 /* Success. */
524 tevent_req_done(req);
525 }
526 return tevent_req_post(req, ev);
527}
528
529static void smbd_smb2_read_pipe_done(struct tevent_req *subreq)
530{
531 struct tevent_req *req = tevent_req_callback_data(subreq,
532 struct tevent_req);
533 struct smbd_smb2_read_state *state = tevent_req_data(req,
534 struct smbd_smb2_read_state);
535 NTSTATUS status;
536 ssize_t nread = -1;
537 bool is_data_outstanding;
538
539 status = np_read_recv(subreq, &nread, &is_data_outstanding);
540 TALLOC_FREE(subreq);
541 if (!NT_STATUS_IS_OK(status)) {
542 tevent_req_nterror(req, status);
543 return;
544 }
545
546 if (nread == 0 && state->out_data.length != 0) {
547 tevent_req_nterror(req, NT_STATUS_END_OF_FILE);
548 return;
549 }
550
551 state->out_data.length = nread;
552 state->out_remaining = 0;
553
554 /*
555 * TODO: add STATUS_BUFFER_OVERFLOW handling, once we also
556 * handle it in SMB1 pipe_read_andx_done().
557 */
558
559 tevent_req_done(req);
560}
561
562static NTSTATUS smbd_smb2_read_recv(struct tevent_req *req,
563 TALLOC_CTX *mem_ctx,
564 DATA_BLOB *out_data,
565 uint32_t *out_remaining)
566{
567 NTSTATUS status;
568 struct smbd_smb2_read_state *state = tevent_req_data(req,
569 struct smbd_smb2_read_state);
570
571 if (tevent_req_is_nterror(req, &status)) {
572 tevent_req_received(req);
573 return status;
574 }
575
576 *out_data = state->out_data;
577 talloc_steal(mem_ctx, out_data->data);
578 *out_remaining = state->out_remaining;
579
580 tevent_req_received(req);
581 return NT_STATUS_OK;
582}
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