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1 /*
2  * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  *
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public Licens
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
17  *
18  */
19 #include <linux/kernel.h>
20 #include <linux/errno.h>
21 #include <linux/string.h>
22 #include <linux/module.h>
23 #include <linux/blkdev.h>
24 #include <linux/capability.h>
25 #include <linux/completion.h>
26 #include <linux/cdrom.h>
27 #include <linux/ratelimit.h>
28 #include <linux/slab.h>
29 #include <linux/times.h>
30 #include <linux/uio.h>
31 #include <linux/uaccess.h>
32 
33 #include <scsi/scsi.h>
34 #include <scsi/scsi_ioctl.h>
35 #include <scsi/scsi_cmnd.h>
36 
37 struct blk_cmd_filter {
38 	unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
39 	unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
40 };
41 
42 static struct blk_cmd_filter blk_default_cmd_filter;
43 
44 /* Command group 3 is reserved and should never be used.  */
45 const unsigned char scsi_command_size_tbl[8] =
46 {
47 	6, 10, 10, 12,
48 	16, 12, 10, 10
49 };
50 EXPORT_SYMBOL(scsi_command_size_tbl);
51 
52 #include <scsi/sg.h>
53 
sg_get_version(int __user * p)54 static int sg_get_version(int __user *p)
55 {
56 	static const int sg_version_num = 30527;
57 	return put_user(sg_version_num, p);
58 }
59 
scsi_get_idlun(struct request_queue * q,int __user * p)60 static int scsi_get_idlun(struct request_queue *q, int __user *p)
61 {
62 	return put_user(0, p);
63 }
64 
scsi_get_bus(struct request_queue * q,int __user * p)65 static int scsi_get_bus(struct request_queue *q, int __user *p)
66 {
67 	return put_user(0, p);
68 }
69 
sg_get_timeout(struct request_queue * q)70 static int sg_get_timeout(struct request_queue *q)
71 {
72 	return jiffies_to_clock_t(q->sg_timeout);
73 }
74 
sg_set_timeout(struct request_queue * q,int __user * p)75 static int sg_set_timeout(struct request_queue *q, int __user *p)
76 {
77 	int timeout, err = get_user(timeout, p);
78 
79 	if (!err)
80 		q->sg_timeout = clock_t_to_jiffies(timeout);
81 
82 	return err;
83 }
84 
max_sectors_bytes(struct request_queue * q)85 static int max_sectors_bytes(struct request_queue *q)
86 {
87 	unsigned int max_sectors = queue_max_sectors(q);
88 
89 	max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
90 
91 	return max_sectors << 9;
92 }
93 
sg_get_reserved_size(struct request_queue * q,int __user * p)94 static int sg_get_reserved_size(struct request_queue *q, int __user *p)
95 {
96 	int val = min_t(int, q->sg_reserved_size, max_sectors_bytes(q));
97 
98 	return put_user(val, p);
99 }
100 
sg_set_reserved_size(struct request_queue * q,int __user * p)101 static int sg_set_reserved_size(struct request_queue *q, int __user *p)
102 {
103 	int size, err = get_user(size, p);
104 
105 	if (err)
106 		return err;
107 
108 	if (size < 0)
109 		return -EINVAL;
110 
111 	q->sg_reserved_size = min(size, max_sectors_bytes(q));
112 	return 0;
113 }
114 
115 /*
116  * will always return that we are ATAPI even for a real SCSI drive, I'm not
117  * so sure this is worth doing anything about (why would you care??)
118  */
sg_emulated_host(struct request_queue * q,int __user * p)119 static int sg_emulated_host(struct request_queue *q, int __user *p)
120 {
121 	return put_user(1, p);
122 }
123 
blk_set_cmd_filter_defaults(struct blk_cmd_filter * filter)124 static void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter)
125 {
126 	/* Basic read-only commands */
127 	__set_bit(TEST_UNIT_READY, filter->read_ok);
128 	__set_bit(REQUEST_SENSE, filter->read_ok);
129 	__set_bit(READ_6, filter->read_ok);
130 	__set_bit(READ_10, filter->read_ok);
131 	__set_bit(READ_12, filter->read_ok);
132 	__set_bit(READ_16, filter->read_ok);
133 	__set_bit(READ_BUFFER, filter->read_ok);
134 	__set_bit(READ_DEFECT_DATA, filter->read_ok);
135 	__set_bit(READ_CAPACITY, filter->read_ok);
136 	__set_bit(READ_LONG, filter->read_ok);
137 	__set_bit(INQUIRY, filter->read_ok);
138 	__set_bit(MODE_SENSE, filter->read_ok);
139 	__set_bit(MODE_SENSE_10, filter->read_ok);
140 	__set_bit(LOG_SENSE, filter->read_ok);
141 	__set_bit(START_STOP, filter->read_ok);
142 	__set_bit(GPCMD_VERIFY_10, filter->read_ok);
143 	__set_bit(VERIFY_16, filter->read_ok);
144 	__set_bit(REPORT_LUNS, filter->read_ok);
145 	__set_bit(SERVICE_ACTION_IN_16, filter->read_ok);
146 	__set_bit(RECEIVE_DIAGNOSTIC, filter->read_ok);
147 	__set_bit(MAINTENANCE_IN, filter->read_ok);
148 	__set_bit(GPCMD_READ_BUFFER_CAPACITY, filter->read_ok);
149 
150 	/* Audio CD commands */
151 	__set_bit(GPCMD_PLAY_CD, filter->read_ok);
152 	__set_bit(GPCMD_PLAY_AUDIO_10, filter->read_ok);
153 	__set_bit(GPCMD_PLAY_AUDIO_MSF, filter->read_ok);
154 	__set_bit(GPCMD_PLAY_AUDIO_TI, filter->read_ok);
155 	__set_bit(GPCMD_PAUSE_RESUME, filter->read_ok);
156 
157 	/* CD/DVD data reading */
158 	__set_bit(GPCMD_READ_CD, filter->read_ok);
159 	__set_bit(GPCMD_READ_CD_MSF, filter->read_ok);
160 	__set_bit(GPCMD_READ_DISC_INFO, filter->read_ok);
161 	__set_bit(GPCMD_READ_CDVD_CAPACITY, filter->read_ok);
162 	__set_bit(GPCMD_READ_DVD_STRUCTURE, filter->read_ok);
163 	__set_bit(GPCMD_READ_HEADER, filter->read_ok);
164 	__set_bit(GPCMD_READ_TRACK_RZONE_INFO, filter->read_ok);
165 	__set_bit(GPCMD_READ_SUBCHANNEL, filter->read_ok);
166 	__set_bit(GPCMD_READ_TOC_PMA_ATIP, filter->read_ok);
167 	__set_bit(GPCMD_REPORT_KEY, filter->read_ok);
168 	__set_bit(GPCMD_SCAN, filter->read_ok);
169 	__set_bit(GPCMD_GET_CONFIGURATION, filter->read_ok);
170 	__set_bit(GPCMD_READ_FORMAT_CAPACITIES, filter->read_ok);
171 	__set_bit(GPCMD_GET_EVENT_STATUS_NOTIFICATION, filter->read_ok);
172 	__set_bit(GPCMD_GET_PERFORMANCE, filter->read_ok);
173 	__set_bit(GPCMD_SEEK, filter->read_ok);
174 	__set_bit(GPCMD_STOP_PLAY_SCAN, filter->read_ok);
175 
176 	/* Basic writing commands */
177 	__set_bit(WRITE_6, filter->write_ok);
178 	__set_bit(WRITE_10, filter->write_ok);
179 	__set_bit(WRITE_VERIFY, filter->write_ok);
180 	__set_bit(WRITE_12, filter->write_ok);
181 	__set_bit(WRITE_VERIFY_12, filter->write_ok);
182 	__set_bit(WRITE_16, filter->write_ok);
183 	__set_bit(WRITE_LONG, filter->write_ok);
184 	__set_bit(WRITE_LONG_2, filter->write_ok);
185 	__set_bit(WRITE_SAME, filter->write_ok);
186 	__set_bit(WRITE_SAME_16, filter->write_ok);
187 	__set_bit(WRITE_SAME_32, filter->write_ok);
188 	__set_bit(ERASE, filter->write_ok);
189 	__set_bit(GPCMD_MODE_SELECT_10, filter->write_ok);
190 	__set_bit(MODE_SELECT, filter->write_ok);
191 	__set_bit(LOG_SELECT, filter->write_ok);
192 	__set_bit(GPCMD_BLANK, filter->write_ok);
193 	__set_bit(GPCMD_CLOSE_TRACK, filter->write_ok);
194 	__set_bit(GPCMD_FLUSH_CACHE, filter->write_ok);
195 	__set_bit(GPCMD_FORMAT_UNIT, filter->write_ok);
196 	__set_bit(GPCMD_REPAIR_RZONE_TRACK, filter->write_ok);
197 	__set_bit(GPCMD_RESERVE_RZONE_TRACK, filter->write_ok);
198 	__set_bit(GPCMD_SEND_DVD_STRUCTURE, filter->write_ok);
199 	__set_bit(GPCMD_SEND_EVENT, filter->write_ok);
200 	__set_bit(GPCMD_SEND_KEY, filter->write_ok);
201 	__set_bit(GPCMD_SEND_OPC, filter->write_ok);
202 	__set_bit(GPCMD_SEND_CUE_SHEET, filter->write_ok);
203 	__set_bit(GPCMD_SET_SPEED, filter->write_ok);
204 	__set_bit(GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL, filter->write_ok);
205 	__set_bit(GPCMD_LOAD_UNLOAD, filter->write_ok);
206 	__set_bit(GPCMD_SET_STREAMING, filter->write_ok);
207 	__set_bit(GPCMD_SET_READ_AHEAD, filter->write_ok);
208 }
209 
blk_verify_command(unsigned char * cmd,fmode_t has_write_perm)210 int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm)
211 {
212 	struct blk_cmd_filter *filter = &blk_default_cmd_filter;
213 
214 	/* root can do any command. */
215 	if (capable(CAP_SYS_RAWIO))
216 		return 0;
217 
218 	/* Anybody who can open the device can do a read-safe command */
219 	if (test_bit(cmd[0], filter->read_ok))
220 		return 0;
221 
222 	/* Write-safe commands require a writable open */
223 	if (test_bit(cmd[0], filter->write_ok) && has_write_perm)
224 		return 0;
225 
226 	return -EPERM;
227 }
228 EXPORT_SYMBOL(blk_verify_command);
229 
blk_fill_sghdr_rq(struct request_queue * q,struct request * rq,struct sg_io_hdr * hdr,fmode_t mode)230 static int blk_fill_sghdr_rq(struct request_queue *q, struct request *rq,
231 			     struct sg_io_hdr *hdr, fmode_t mode)
232 {
233 	struct scsi_request *req = scsi_req(rq);
234 
235 	if (copy_from_user(req->cmd, hdr->cmdp, hdr->cmd_len))
236 		return -EFAULT;
237 	if (blk_verify_command(req->cmd, mode & FMODE_WRITE))
238 		return -EPERM;
239 
240 	/*
241 	 * fill in request structure
242 	 */
243 	req->cmd_len = hdr->cmd_len;
244 
245 	rq->timeout = msecs_to_jiffies(hdr->timeout);
246 	if (!rq->timeout)
247 		rq->timeout = q->sg_timeout;
248 	if (!rq->timeout)
249 		rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
250 	if (rq->timeout < BLK_MIN_SG_TIMEOUT)
251 		rq->timeout = BLK_MIN_SG_TIMEOUT;
252 
253 	return 0;
254 }
255 
blk_complete_sghdr_rq(struct request * rq,struct sg_io_hdr * hdr,struct bio * bio)256 static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
257 				 struct bio *bio)
258 {
259 	struct scsi_request *req = scsi_req(rq);
260 	int r, ret = 0;
261 
262 	/*
263 	 * fill in all the output members
264 	 */
265 	hdr->status = req->result & 0xff;
266 	hdr->masked_status = status_byte(req->result);
267 	hdr->msg_status = msg_byte(req->result);
268 	hdr->host_status = host_byte(req->result);
269 	hdr->driver_status = driver_byte(req->result);
270 	hdr->info = 0;
271 	if (hdr->masked_status || hdr->host_status || hdr->driver_status)
272 		hdr->info |= SG_INFO_CHECK;
273 	hdr->resid = req->resid_len;
274 	hdr->sb_len_wr = 0;
275 
276 	if (req->sense_len && hdr->sbp) {
277 		int len = min((unsigned int) hdr->mx_sb_len, req->sense_len);
278 
279 		if (!copy_to_user(hdr->sbp, req->sense, len))
280 			hdr->sb_len_wr = len;
281 		else
282 			ret = -EFAULT;
283 	}
284 
285 	r = blk_rq_unmap_user(bio);
286 	if (!ret)
287 		ret = r;
288 
289 	return ret;
290 }
291 
sg_io(struct request_queue * q,struct gendisk * bd_disk,struct sg_io_hdr * hdr,fmode_t mode)292 static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
293 		struct sg_io_hdr *hdr, fmode_t mode)
294 {
295 	unsigned long start_time;
296 	ssize_t ret = 0;
297 	int writing = 0;
298 	int at_head = 0;
299 	struct request *rq;
300 	struct scsi_request *req;
301 	struct bio *bio;
302 
303 	if (hdr->interface_id != 'S')
304 		return -EINVAL;
305 
306 	if (hdr->dxfer_len > (queue_max_hw_sectors(q) << 9))
307 		return -EIO;
308 
309 	if (hdr->dxfer_len)
310 		switch (hdr->dxfer_direction) {
311 		default:
312 			return -EINVAL;
313 		case SG_DXFER_TO_DEV:
314 			writing = 1;
315 			break;
316 		case SG_DXFER_TO_FROM_DEV:
317 		case SG_DXFER_FROM_DEV:
318 			break;
319 		}
320 	if (hdr->flags & SG_FLAG_Q_AT_HEAD)
321 		at_head = 1;
322 
323 	ret = -ENOMEM;
324 	rq = blk_get_request(q, writing ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
325 			GFP_KERNEL);
326 	if (IS_ERR(rq))
327 		return PTR_ERR(rq);
328 	req = scsi_req(rq);
329 
330 	if (hdr->cmd_len > BLK_MAX_CDB) {
331 		req->cmd = kzalloc(hdr->cmd_len, GFP_KERNEL);
332 		if (!req->cmd)
333 			goto out_put_request;
334 	}
335 
336 	ret = blk_fill_sghdr_rq(q, rq, hdr, mode);
337 	if (ret < 0)
338 		goto out_free_cdb;
339 
340 	ret = 0;
341 	if (hdr->iovec_count) {
342 		struct iov_iter i;
343 		struct iovec *iov = NULL;
344 
345 		ret = import_iovec(rq_data_dir(rq),
346 				   hdr->dxferp, hdr->iovec_count,
347 				   0, &iov, &i);
348 		if (ret < 0)
349 			goto out_free_cdb;
350 
351 		/* SG_IO howto says that the shorter of the two wins */
352 		iov_iter_truncate(&i, hdr->dxfer_len);
353 
354 		ret = blk_rq_map_user_iov(q, rq, NULL, &i, GFP_KERNEL);
355 		kfree(iov);
356 	} else if (hdr->dxfer_len)
357 		ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len,
358 				      GFP_KERNEL);
359 
360 	if (ret)
361 		goto out_free_cdb;
362 
363 	bio = rq->bio;
364 	req->retries = 0;
365 
366 	start_time = jiffies;
367 
368 	/* ignore return value. All information is passed back to caller
369 	 * (if he doesn't check that is his problem).
370 	 * N.B. a non-zero SCSI status is _not_ necessarily an error.
371 	 */
372 	blk_execute_rq(q, bd_disk, rq, at_head);
373 
374 	hdr->duration = jiffies_to_msecs(jiffies - start_time);
375 
376 	ret = blk_complete_sghdr_rq(rq, hdr, bio);
377 
378 out_free_cdb:
379 	scsi_req_free_cmd(req);
380 out_put_request:
381 	blk_put_request(rq);
382 	return ret;
383 }
384 
385 /**
386  * sg_scsi_ioctl  --  handle deprecated SCSI_IOCTL_SEND_COMMAND ioctl
387  * @file:	file this ioctl operates on (optional)
388  * @q:		request queue to send scsi commands down
389  * @disk:	gendisk to operate on (option)
390  * @sic:	userspace structure describing the command to perform
391  *
392  * Send down the scsi command described by @sic to the device below
393  * the request queue @q.  If @file is non-NULL it's used to perform
394  * fine-grained permission checks that allow users to send down
395  * non-destructive SCSI commands.  If the caller has a struct gendisk
396  * available it should be passed in as @disk to allow the low level
397  * driver to use the information contained in it.  A non-NULL @disk
398  * is only allowed if the caller knows that the low level driver doesn't
399  * need it (e.g. in the scsi subsystem).
400  *
401  * Notes:
402  *   -  This interface is deprecated - users should use the SG_IO
403  *      interface instead, as this is a more flexible approach to
404  *      performing SCSI commands on a device.
405  *   -  The SCSI command length is determined by examining the 1st byte
406  *      of the given command. There is no way to override this.
407  *   -  Data transfers are limited to PAGE_SIZE
408  *   -  The length (x + y) must be at least OMAX_SB_LEN bytes long to
409  *      accommodate the sense buffer when an error occurs.
410  *      The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
411  *      old code will not be surprised.
412  *   -  If a Unix error occurs (e.g. ENOMEM) then the user will receive
413  *      a negative return and the Unix error code in 'errno'.
414  *      If the SCSI command succeeds then 0 is returned.
415  *      Positive numbers returned are the compacted SCSI error codes (4
416  *      bytes in one int) where the lowest byte is the SCSI status.
417  */
418 #define OMAX_SB_LEN 16          /* For backward compatibility */
sg_scsi_ioctl(struct request_queue * q,struct gendisk * disk,fmode_t mode,struct scsi_ioctl_command __user * sic)419 int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
420 		struct scsi_ioctl_command __user *sic)
421 {
422 	struct request *rq;
423 	struct scsi_request *req;
424 	int err;
425 	unsigned int in_len, out_len, bytes, opcode, cmdlen;
426 	char *buffer = NULL;
427 
428 	if (!sic)
429 		return -EINVAL;
430 
431 	/*
432 	 * get in an out lengths, verify they don't exceed a page worth of data
433 	 */
434 	if (get_user(in_len, &sic->inlen))
435 		return -EFAULT;
436 	if (get_user(out_len, &sic->outlen))
437 		return -EFAULT;
438 	if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
439 		return -EINVAL;
440 	if (get_user(opcode, sic->data))
441 		return -EFAULT;
442 
443 	bytes = max(in_len, out_len);
444 	if (bytes) {
445 		buffer = kzalloc(bytes, q->bounce_gfp | GFP_USER| __GFP_NOWARN);
446 		if (!buffer)
447 			return -ENOMEM;
448 
449 	}
450 
451 	rq = blk_get_request(q, in_len ? REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN,
452 			__GFP_RECLAIM);
453 	if (IS_ERR(rq)) {
454 		err = PTR_ERR(rq);
455 		goto error_free_buffer;
456 	}
457 	req = scsi_req(rq);
458 
459 	cmdlen = COMMAND_SIZE(opcode);
460 
461 	/*
462 	 * get command and data to send to device, if any
463 	 */
464 	err = -EFAULT;
465 	req->cmd_len = cmdlen;
466 	if (copy_from_user(req->cmd, sic->data, cmdlen))
467 		goto error;
468 
469 	if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
470 		goto error;
471 
472 	err = blk_verify_command(req->cmd, mode & FMODE_WRITE);
473 	if (err)
474 		goto error;
475 
476 	/* default.  possible overriden later */
477 	req->retries = 5;
478 
479 	switch (opcode) {
480 	case SEND_DIAGNOSTIC:
481 	case FORMAT_UNIT:
482 		rq->timeout = FORMAT_UNIT_TIMEOUT;
483 		req->retries = 1;
484 		break;
485 	case START_STOP:
486 		rq->timeout = START_STOP_TIMEOUT;
487 		break;
488 	case MOVE_MEDIUM:
489 		rq->timeout = MOVE_MEDIUM_TIMEOUT;
490 		break;
491 	case READ_ELEMENT_STATUS:
492 		rq->timeout = READ_ELEMENT_STATUS_TIMEOUT;
493 		break;
494 	case READ_DEFECT_DATA:
495 		rq->timeout = READ_DEFECT_DATA_TIMEOUT;
496 		req->retries = 1;
497 		break;
498 	default:
499 		rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
500 		break;
501 	}
502 
503 	if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, __GFP_RECLAIM)) {
504 		err = DRIVER_ERROR << 24;
505 		goto error;
506 	}
507 
508 	blk_execute_rq(q, disk, rq, 0);
509 
510 	err = req->result & 0xff;	/* only 8 bit SCSI status */
511 	if (err) {
512 		if (req->sense_len && req->sense) {
513 			bytes = (OMAX_SB_LEN > req->sense_len) ?
514 				req->sense_len : OMAX_SB_LEN;
515 			if (copy_to_user(sic->data, req->sense, bytes))
516 				err = -EFAULT;
517 		}
518 	} else {
519 		if (copy_to_user(sic->data, buffer, out_len))
520 			err = -EFAULT;
521 	}
522 
523 error:
524 	blk_put_request(rq);
525 
526 error_free_buffer:
527 	kfree(buffer);
528 
529 	return err;
530 }
531 EXPORT_SYMBOL_GPL(sg_scsi_ioctl);
532 
533 /* Send basic block requests */
__blk_send_generic(struct request_queue * q,struct gendisk * bd_disk,int cmd,int data)534 static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
535 			      int cmd, int data)
536 {
537 	struct request *rq;
538 	int err;
539 
540 	rq = blk_get_request(q, REQ_OP_SCSI_OUT, __GFP_RECLAIM);
541 	if (IS_ERR(rq))
542 		return PTR_ERR(rq);
543 	rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
544 	scsi_req(rq)->cmd[0] = cmd;
545 	scsi_req(rq)->cmd[4] = data;
546 	scsi_req(rq)->cmd_len = 6;
547 	blk_execute_rq(q, bd_disk, rq, 0);
548 	err = scsi_req(rq)->result ? -EIO : 0;
549 	blk_put_request(rq);
550 
551 	return err;
552 }
553 
blk_send_start_stop(struct request_queue * q,struct gendisk * bd_disk,int data)554 static inline int blk_send_start_stop(struct request_queue *q,
555 				      struct gendisk *bd_disk, int data)
556 {
557 	return __blk_send_generic(q, bd_disk, GPCMD_START_STOP_UNIT, data);
558 }
559 
scsi_cmd_ioctl(struct request_queue * q,struct gendisk * bd_disk,fmode_t mode,unsigned int cmd,void __user * arg)560 int scsi_cmd_ioctl(struct request_queue *q, struct gendisk *bd_disk, fmode_t mode,
561 		   unsigned int cmd, void __user *arg)
562 {
563 	int err;
564 
565 	if (!q)
566 		return -ENXIO;
567 
568 	switch (cmd) {
569 		/*
570 		 * new sgv3 interface
571 		 */
572 		case SG_GET_VERSION_NUM:
573 			err = sg_get_version(arg);
574 			break;
575 		case SCSI_IOCTL_GET_IDLUN:
576 			err = scsi_get_idlun(q, arg);
577 			break;
578 		case SCSI_IOCTL_GET_BUS_NUMBER:
579 			err = scsi_get_bus(q, arg);
580 			break;
581 		case SG_SET_TIMEOUT:
582 			err = sg_set_timeout(q, arg);
583 			break;
584 		case SG_GET_TIMEOUT:
585 			err = sg_get_timeout(q);
586 			break;
587 		case SG_GET_RESERVED_SIZE:
588 			err = sg_get_reserved_size(q, arg);
589 			break;
590 		case SG_SET_RESERVED_SIZE:
591 			err = sg_set_reserved_size(q, arg);
592 			break;
593 		case SG_EMULATED_HOST:
594 			err = sg_emulated_host(q, arg);
595 			break;
596 		case SG_IO: {
597 			struct sg_io_hdr hdr;
598 
599 			err = -EFAULT;
600 			if (copy_from_user(&hdr, arg, sizeof(hdr)))
601 				break;
602 			err = sg_io(q, bd_disk, &hdr, mode);
603 			if (err == -EFAULT)
604 				break;
605 
606 			if (copy_to_user(arg, &hdr, sizeof(hdr)))
607 				err = -EFAULT;
608 			break;
609 		}
610 		case CDROM_SEND_PACKET: {
611 			struct cdrom_generic_command cgc;
612 			struct sg_io_hdr hdr;
613 
614 			err = -EFAULT;
615 			if (copy_from_user(&cgc, arg, sizeof(cgc)))
616 				break;
617 			cgc.timeout = clock_t_to_jiffies(cgc.timeout);
618 			memset(&hdr, 0, sizeof(hdr));
619 			hdr.interface_id = 'S';
620 			hdr.cmd_len = sizeof(cgc.cmd);
621 			hdr.dxfer_len = cgc.buflen;
622 			err = 0;
623 			switch (cgc.data_direction) {
624 				case CGC_DATA_UNKNOWN:
625 					hdr.dxfer_direction = SG_DXFER_UNKNOWN;
626 					break;
627 				case CGC_DATA_WRITE:
628 					hdr.dxfer_direction = SG_DXFER_TO_DEV;
629 					break;
630 				case CGC_DATA_READ:
631 					hdr.dxfer_direction = SG_DXFER_FROM_DEV;
632 					break;
633 				case CGC_DATA_NONE:
634 					hdr.dxfer_direction = SG_DXFER_NONE;
635 					break;
636 				default:
637 					err = -EINVAL;
638 			}
639 			if (err)
640 				break;
641 
642 			hdr.dxferp = cgc.buffer;
643 			hdr.sbp = cgc.sense;
644 			if (hdr.sbp)
645 				hdr.mx_sb_len = sizeof(struct request_sense);
646 			hdr.timeout = jiffies_to_msecs(cgc.timeout);
647 			hdr.cmdp = ((struct cdrom_generic_command __user*) arg)->cmd;
648 			hdr.cmd_len = sizeof(cgc.cmd);
649 
650 			err = sg_io(q, bd_disk, &hdr, mode);
651 			if (err == -EFAULT)
652 				break;
653 
654 			if (hdr.status)
655 				err = -EIO;
656 
657 			cgc.stat = err;
658 			cgc.buflen = hdr.resid;
659 			if (copy_to_user(arg, &cgc, sizeof(cgc)))
660 				err = -EFAULT;
661 
662 			break;
663 		}
664 
665 		/*
666 		 * old junk scsi send command ioctl
667 		 */
668 		case SCSI_IOCTL_SEND_COMMAND:
669 			printk(KERN_WARNING "program %s is using a deprecated SCSI ioctl, please convert it to SG_IO\n", current->comm);
670 			err = -EINVAL;
671 			if (!arg)
672 				break;
673 
674 			err = sg_scsi_ioctl(q, bd_disk, mode, arg);
675 			break;
676 		case CDROMCLOSETRAY:
677 			err = blk_send_start_stop(q, bd_disk, 0x03);
678 			break;
679 		case CDROMEJECT:
680 			err = blk_send_start_stop(q, bd_disk, 0x02);
681 			break;
682 		default:
683 			err = -ENOTTY;
684 	}
685 
686 	return err;
687 }
688 EXPORT_SYMBOL(scsi_cmd_ioctl);
689 
scsi_verify_blk_ioctl(struct block_device * bd,unsigned int cmd)690 int scsi_verify_blk_ioctl(struct block_device *bd, unsigned int cmd)
691 {
692 	if (bd && bd == bd->bd_contains)
693 		return 0;
694 
695 	/* Actually none of these is particularly useful on a partition,
696 	 * but they are safe.
697 	 */
698 	switch (cmd) {
699 	case SCSI_IOCTL_GET_IDLUN:
700 	case SCSI_IOCTL_GET_BUS_NUMBER:
701 	case SCSI_IOCTL_GET_PCI:
702 	case SCSI_IOCTL_PROBE_HOST:
703 	case SG_GET_VERSION_NUM:
704 	case SG_SET_TIMEOUT:
705 	case SG_GET_TIMEOUT:
706 	case SG_GET_RESERVED_SIZE:
707 	case SG_SET_RESERVED_SIZE:
708 	case SG_EMULATED_HOST:
709 		return 0;
710 	case CDROM_GET_CAPABILITY:
711 		/* Keep this until we remove the printk below.  udev sends it
712 		 * and we do not want to spam dmesg about it.   CD-ROMs do
713 		 * not have partitions, so we get here only for disks.
714 		 */
715 		return -ENOIOCTLCMD;
716 	default:
717 		break;
718 	}
719 
720 	if (capable(CAP_SYS_RAWIO))
721 		return 0;
722 
723 	/* In particular, rule out all resets and host-specific ioctls.  */
724 	printk_ratelimited(KERN_WARNING
725 			   "%s: sending ioctl %x to a partition!\n", current->comm, cmd);
726 
727 	return -ENOIOCTLCMD;
728 }
729 EXPORT_SYMBOL(scsi_verify_blk_ioctl);
730 
scsi_cmd_blk_ioctl(struct block_device * bd,fmode_t mode,unsigned int cmd,void __user * arg)731 int scsi_cmd_blk_ioctl(struct block_device *bd, fmode_t mode,
732 		       unsigned int cmd, void __user *arg)
733 {
734 	int ret;
735 
736 	ret = scsi_verify_blk_ioctl(bd, cmd);
737 	if (ret < 0)
738 		return ret;
739 
740 	return scsi_cmd_ioctl(bd->bd_disk->queue, bd->bd_disk, mode, cmd, arg);
741 }
742 EXPORT_SYMBOL(scsi_cmd_blk_ioctl);
743 
744 /**
745  * scsi_req_init - initialize certain fields of a scsi_request structure
746  * @req: Pointer to a scsi_request structure.
747  * Initializes .__cmd[], .cmd, .cmd_len and .sense_len but no other members
748  * of struct scsi_request.
749  */
scsi_req_init(struct scsi_request * req)750 void scsi_req_init(struct scsi_request *req)
751 {
752 	memset(req->__cmd, 0, sizeof(req->__cmd));
753 	req->cmd = req->__cmd;
754 	req->cmd_len = BLK_MAX_CDB;
755 	req->sense_len = 0;
756 }
757 EXPORT_SYMBOL(scsi_req_init);
758 
blk_scsi_ioctl_init(void)759 static int __init blk_scsi_ioctl_init(void)
760 {
761 	blk_set_cmd_filter_defaults(&blk_default_cmd_filter);
762 	return 0;
763 }
764 fs_initcall(blk_scsi_ioctl_init);
765