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 <asm/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(ERASE, filter->write_ok);
186 	__set_bit(GPCMD_MODE_SELECT_10, filter->write_ok);
187 	__set_bit(MODE_SELECT, filter->write_ok);
188 	__set_bit(LOG_SELECT, filter->write_ok);
189 	__set_bit(GPCMD_BLANK, filter->write_ok);
190 	__set_bit(GPCMD_CLOSE_TRACK, filter->write_ok);
191 	__set_bit(GPCMD_FLUSH_CACHE, filter->write_ok);
192 	__set_bit(GPCMD_FORMAT_UNIT, filter->write_ok);
193 	__set_bit(GPCMD_REPAIR_RZONE_TRACK, filter->write_ok);
194 	__set_bit(GPCMD_RESERVE_RZONE_TRACK, filter->write_ok);
195 	__set_bit(GPCMD_SEND_DVD_STRUCTURE, filter->write_ok);
196 	__set_bit(GPCMD_SEND_EVENT, filter->write_ok);
197 	__set_bit(GPCMD_SEND_KEY, filter->write_ok);
198 	__set_bit(GPCMD_SEND_OPC, filter->write_ok);
199 	__set_bit(GPCMD_SEND_CUE_SHEET, filter->write_ok);
200 	__set_bit(GPCMD_SET_SPEED, filter->write_ok);
201 	__set_bit(GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL, filter->write_ok);
202 	__set_bit(GPCMD_LOAD_UNLOAD, filter->write_ok);
203 	__set_bit(GPCMD_SET_STREAMING, filter->write_ok);
204 	__set_bit(GPCMD_SET_READ_AHEAD, filter->write_ok);
205 }
206 
blk_verify_command(unsigned char * cmd,fmode_t has_write_perm)207 int blk_verify_command(unsigned char *cmd, fmode_t has_write_perm)
208 {
209 	struct blk_cmd_filter *filter = &blk_default_cmd_filter;
210 
211 	/* root can do any command. */
212 	if (capable(CAP_SYS_RAWIO))
213 		return 0;
214 
215 	/* Anybody who can open the device can do a read-safe command */
216 	if (test_bit(cmd[0], filter->read_ok))
217 		return 0;
218 
219 	/* Write-safe commands require a writable open */
220 	if (test_bit(cmd[0], filter->write_ok) && has_write_perm)
221 		return 0;
222 
223 	return -EPERM;
224 }
225 EXPORT_SYMBOL(blk_verify_command);
226 
blk_fill_sghdr_rq(struct request_queue * q,struct request * rq,struct sg_io_hdr * hdr,fmode_t mode)227 static int blk_fill_sghdr_rq(struct request_queue *q, struct request *rq,
228 			     struct sg_io_hdr *hdr, fmode_t mode)
229 {
230 	if (copy_from_user(rq->cmd, hdr->cmdp, hdr->cmd_len))
231 		return -EFAULT;
232 	if (blk_verify_command(rq->cmd, mode & FMODE_WRITE))
233 		return -EPERM;
234 
235 	/*
236 	 * fill in request structure
237 	 */
238 	rq->cmd_len = hdr->cmd_len;
239 
240 	rq->timeout = msecs_to_jiffies(hdr->timeout);
241 	if (!rq->timeout)
242 		rq->timeout = q->sg_timeout;
243 	if (!rq->timeout)
244 		rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
245 	if (rq->timeout < BLK_MIN_SG_TIMEOUT)
246 		rq->timeout = BLK_MIN_SG_TIMEOUT;
247 
248 	return 0;
249 }
250 
blk_complete_sghdr_rq(struct request * rq,struct sg_io_hdr * hdr,struct bio * bio)251 static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
252 				 struct bio *bio)
253 {
254 	int r, ret = 0;
255 
256 	/*
257 	 * fill in all the output members
258 	 */
259 	hdr->status = rq->errors & 0xff;
260 	hdr->masked_status = status_byte(rq->errors);
261 	hdr->msg_status = msg_byte(rq->errors);
262 	hdr->host_status = host_byte(rq->errors);
263 	hdr->driver_status = driver_byte(rq->errors);
264 	hdr->info = 0;
265 	if (hdr->masked_status || hdr->host_status || hdr->driver_status)
266 		hdr->info |= SG_INFO_CHECK;
267 	hdr->resid = rq->resid_len;
268 	hdr->sb_len_wr = 0;
269 
270 	if (rq->sense_len && hdr->sbp) {
271 		int len = min((unsigned int) hdr->mx_sb_len, rq->sense_len);
272 
273 		if (!copy_to_user(hdr->sbp, rq->sense, len))
274 			hdr->sb_len_wr = len;
275 		else
276 			ret = -EFAULT;
277 	}
278 
279 	r = blk_rq_unmap_user(bio);
280 	if (!ret)
281 		ret = r;
282 
283 	return ret;
284 }
285 
sg_io(struct request_queue * q,struct gendisk * bd_disk,struct sg_io_hdr * hdr,fmode_t mode)286 static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
287 		struct sg_io_hdr *hdr, fmode_t mode)
288 {
289 	unsigned long start_time;
290 	ssize_t ret = 0;
291 	int writing = 0;
292 	int at_head = 0;
293 	struct request *rq;
294 	char sense[SCSI_SENSE_BUFFERSIZE];
295 	struct bio *bio;
296 
297 	if (hdr->interface_id != 'S')
298 		return -EINVAL;
299 
300 	if (hdr->dxfer_len > (queue_max_hw_sectors(q) << 9))
301 		return -EIO;
302 
303 	if (hdr->dxfer_len)
304 		switch (hdr->dxfer_direction) {
305 		default:
306 			return -EINVAL;
307 		case SG_DXFER_TO_DEV:
308 			writing = 1;
309 			break;
310 		case SG_DXFER_TO_FROM_DEV:
311 		case SG_DXFER_FROM_DEV:
312 			break;
313 		}
314 	if (hdr->flags & SG_FLAG_Q_AT_HEAD)
315 		at_head = 1;
316 
317 	ret = -ENOMEM;
318 	rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);
319 	if (IS_ERR(rq))
320 		return PTR_ERR(rq);
321 	blk_rq_set_block_pc(rq);
322 
323 	if (hdr->cmd_len > BLK_MAX_CDB) {
324 		rq->cmd = kzalloc(hdr->cmd_len, GFP_KERNEL);
325 		if (!rq->cmd)
326 			goto out_put_request;
327 	}
328 
329 	ret = -EFAULT;
330 	if (blk_fill_sghdr_rq(q, rq, hdr, mode))
331 		goto out_free_cdb;
332 
333 	ret = 0;
334 	if (hdr->iovec_count) {
335 		struct iov_iter i;
336 		struct iovec *iov = NULL;
337 
338 		ret = import_iovec(rq_data_dir(rq),
339 				   hdr->dxferp, hdr->iovec_count,
340 				   0, &iov, &i);
341 		if (ret < 0)
342 			goto out_free_cdb;
343 
344 		/* SG_IO howto says that the shorter of the two wins */
345 		iov_iter_truncate(&i, hdr->dxfer_len);
346 
347 		ret = blk_rq_map_user_iov(q, rq, NULL, &i, GFP_KERNEL);
348 		kfree(iov);
349 	} else if (hdr->dxfer_len)
350 		ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len,
351 				      GFP_KERNEL);
352 
353 	if (ret)
354 		goto out_free_cdb;
355 
356 	bio = rq->bio;
357 	memset(sense, 0, sizeof(sense));
358 	rq->sense = sense;
359 	rq->sense_len = 0;
360 	rq->retries = 0;
361 
362 	start_time = jiffies;
363 
364 	/* ignore return value. All information is passed back to caller
365 	 * (if he doesn't check that is his problem).
366 	 * N.B. a non-zero SCSI status is _not_ necessarily an error.
367 	 */
368 	blk_execute_rq(q, bd_disk, rq, at_head);
369 
370 	hdr->duration = jiffies_to_msecs(jiffies - start_time);
371 
372 	ret = blk_complete_sghdr_rq(rq, hdr, bio);
373 
374 out_free_cdb:
375 	if (rq->cmd != rq->__cmd)
376 		kfree(rq->cmd);
377 out_put_request:
378 	blk_put_request(rq);
379 	return ret;
380 }
381 
382 /**
383  * sg_scsi_ioctl  --  handle deprecated SCSI_IOCTL_SEND_COMMAND ioctl
384  * @file:	file this ioctl operates on (optional)
385  * @q:		request queue to send scsi commands down
386  * @disk:	gendisk to operate on (option)
387  * @sic:	userspace structure describing the command to perform
388  *
389  * Send down the scsi command described by @sic to the device below
390  * the request queue @q.  If @file is non-NULL it's used to perform
391  * fine-grained permission checks that allow users to send down
392  * non-destructive SCSI commands.  If the caller has a struct gendisk
393  * available it should be passed in as @disk to allow the low level
394  * driver to use the information contained in it.  A non-NULL @disk
395  * is only allowed if the caller knows that the low level driver doesn't
396  * need it (e.g. in the scsi subsystem).
397  *
398  * Notes:
399  *   -  This interface is deprecated - users should use the SG_IO
400  *      interface instead, as this is a more flexible approach to
401  *      performing SCSI commands on a device.
402  *   -  The SCSI command length is determined by examining the 1st byte
403  *      of the given command. There is no way to override this.
404  *   -  Data transfers are limited to PAGE_SIZE
405  *   -  The length (x + y) must be at least OMAX_SB_LEN bytes long to
406  *      accommodate the sense buffer when an error occurs.
407  *      The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
408  *      old code will not be surprised.
409  *   -  If a Unix error occurs (e.g. ENOMEM) then the user will receive
410  *      a negative return and the Unix error code in 'errno'.
411  *      If the SCSI command succeeds then 0 is returned.
412  *      Positive numbers returned are the compacted SCSI error codes (4
413  *      bytes in one int) where the lowest byte is the SCSI status.
414  */
415 #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)416 int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
417 		struct scsi_ioctl_command __user *sic)
418 {
419 	struct request *rq;
420 	int err;
421 	unsigned int in_len, out_len, bytes, opcode, cmdlen;
422 	char *buffer = NULL, sense[SCSI_SENSE_BUFFERSIZE];
423 
424 	if (!sic)
425 		return -EINVAL;
426 
427 	/*
428 	 * get in an out lengths, verify they don't exceed a page worth of data
429 	 */
430 	if (get_user(in_len, &sic->inlen))
431 		return -EFAULT;
432 	if (get_user(out_len, &sic->outlen))
433 		return -EFAULT;
434 	if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
435 		return -EINVAL;
436 	if (get_user(opcode, sic->data))
437 		return -EFAULT;
438 
439 	bytes = max(in_len, out_len);
440 	if (bytes) {
441 		buffer = kzalloc(bytes, q->bounce_gfp | GFP_USER| __GFP_NOWARN);
442 		if (!buffer)
443 			return -ENOMEM;
444 
445 	}
446 
447 	rq = blk_get_request(q, in_len ? WRITE : READ, __GFP_WAIT);
448 	if (IS_ERR(rq)) {
449 		err = PTR_ERR(rq);
450 		goto error_free_buffer;
451 	}
452 	blk_rq_set_block_pc(rq);
453 
454 	cmdlen = COMMAND_SIZE(opcode);
455 
456 	/*
457 	 * get command and data to send to device, if any
458 	 */
459 	err = -EFAULT;
460 	rq->cmd_len = cmdlen;
461 	if (copy_from_user(rq->cmd, sic->data, cmdlen))
462 		goto error;
463 
464 	if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
465 		goto error;
466 
467 	err = blk_verify_command(rq->cmd, mode & FMODE_WRITE);
468 	if (err)
469 		goto error;
470 
471 	/* default.  possible overriden later */
472 	rq->retries = 5;
473 
474 	switch (opcode) {
475 	case SEND_DIAGNOSTIC:
476 	case FORMAT_UNIT:
477 		rq->timeout = FORMAT_UNIT_TIMEOUT;
478 		rq->retries = 1;
479 		break;
480 	case START_STOP:
481 		rq->timeout = START_STOP_TIMEOUT;
482 		break;
483 	case MOVE_MEDIUM:
484 		rq->timeout = MOVE_MEDIUM_TIMEOUT;
485 		break;
486 	case READ_ELEMENT_STATUS:
487 		rq->timeout = READ_ELEMENT_STATUS_TIMEOUT;
488 		break;
489 	case READ_DEFECT_DATA:
490 		rq->timeout = READ_DEFECT_DATA_TIMEOUT;
491 		rq->retries = 1;
492 		break;
493 	default:
494 		rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
495 		break;
496 	}
497 
498 	if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, __GFP_WAIT)) {
499 		err = DRIVER_ERROR << 24;
500 		goto error;
501 	}
502 
503 	memset(sense, 0, sizeof(sense));
504 	rq->sense = sense;
505 	rq->sense_len = 0;
506 
507 	blk_execute_rq(q, disk, rq, 0);
508 
509 	err = rq->errors & 0xff;	/* only 8 bit SCSI status */
510 	if (err) {
511 		if (rq->sense_len && rq->sense) {
512 			bytes = (OMAX_SB_LEN > rq->sense_len) ?
513 				rq->sense_len : OMAX_SB_LEN;
514 			if (copy_to_user(sic->data, rq->sense, bytes))
515 				err = -EFAULT;
516 		}
517 	} else {
518 		if (copy_to_user(sic->data, buffer, out_len))
519 			err = -EFAULT;
520 	}
521 
522 error:
523 	blk_put_request(rq);
524 
525 error_free_buffer:
526 	kfree(buffer);
527 
528 	return err;
529 }
530 EXPORT_SYMBOL_GPL(sg_scsi_ioctl);
531 
532 /* Send basic block requests */
__blk_send_generic(struct request_queue * q,struct gendisk * bd_disk,int cmd,int data)533 static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
534 			      int cmd, int data)
535 {
536 	struct request *rq;
537 	int err;
538 
539 	rq = blk_get_request(q, WRITE, __GFP_WAIT);
540 	if (IS_ERR(rq))
541 		return PTR_ERR(rq);
542 	blk_rq_set_block_pc(rq);
543 	rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
544 	rq->cmd[0] = cmd;
545 	rq->cmd[4] = data;
546 	rq->cmd_len = 6;
547 	err = blk_execute_rq(q, bd_disk, rq, 0);
548 	blk_put_request(rq);
549 
550 	return err;
551 }
552 
blk_send_start_stop(struct request_queue * q,struct gendisk * bd_disk,int data)553 static inline int blk_send_start_stop(struct request_queue *q,
554 				      struct gendisk *bd_disk, int data)
555 {
556 	return __blk_send_generic(q, bd_disk, GPCMD_START_STOP_UNIT, data);
557 }
558 
scsi_cmd_ioctl(struct request_queue * q,struct gendisk * bd_disk,fmode_t mode,unsigned int cmd,void __user * arg)559 int scsi_cmd_ioctl(struct request_queue *q, struct gendisk *bd_disk, fmode_t mode,
560 		   unsigned int cmd, void __user *arg)
561 {
562 	int err;
563 
564 	if (!q)
565 		return -ENXIO;
566 
567 	switch (cmd) {
568 		/*
569 		 * new sgv3 interface
570 		 */
571 		case SG_GET_VERSION_NUM:
572 			err = sg_get_version(arg);
573 			break;
574 		case SCSI_IOCTL_GET_IDLUN:
575 			err = scsi_get_idlun(q, arg);
576 			break;
577 		case SCSI_IOCTL_GET_BUS_NUMBER:
578 			err = scsi_get_bus(q, arg);
579 			break;
580 		case SG_SET_TIMEOUT:
581 			err = sg_set_timeout(q, arg);
582 			break;
583 		case SG_GET_TIMEOUT:
584 			err = sg_get_timeout(q);
585 			break;
586 		case SG_GET_RESERVED_SIZE:
587 			err = sg_get_reserved_size(q, arg);
588 			break;
589 		case SG_SET_RESERVED_SIZE:
590 			err = sg_set_reserved_size(q, arg);
591 			break;
592 		case SG_EMULATED_HOST:
593 			err = sg_emulated_host(q, arg);
594 			break;
595 		case SG_IO: {
596 			struct sg_io_hdr hdr;
597 
598 			err = -EFAULT;
599 			if (copy_from_user(&hdr, arg, sizeof(hdr)))
600 				break;
601 			err = sg_io(q, bd_disk, &hdr, mode);
602 			if (err == -EFAULT)
603 				break;
604 
605 			if (copy_to_user(arg, &hdr, sizeof(hdr)))
606 				err = -EFAULT;
607 			break;
608 		}
609 		case CDROM_SEND_PACKET: {
610 			struct cdrom_generic_command cgc;
611 			struct sg_io_hdr hdr;
612 
613 			err = -EFAULT;
614 			if (copy_from_user(&cgc, arg, sizeof(cgc)))
615 				break;
616 			cgc.timeout = clock_t_to_jiffies(cgc.timeout);
617 			memset(&hdr, 0, sizeof(hdr));
618 			hdr.interface_id = 'S';
619 			hdr.cmd_len = sizeof(cgc.cmd);
620 			hdr.dxfer_len = cgc.buflen;
621 			err = 0;
622 			switch (cgc.data_direction) {
623 				case CGC_DATA_UNKNOWN:
624 					hdr.dxfer_direction = SG_DXFER_UNKNOWN;
625 					break;
626 				case CGC_DATA_WRITE:
627 					hdr.dxfer_direction = SG_DXFER_TO_DEV;
628 					break;
629 				case CGC_DATA_READ:
630 					hdr.dxfer_direction = SG_DXFER_FROM_DEV;
631 					break;
632 				case CGC_DATA_NONE:
633 					hdr.dxfer_direction = SG_DXFER_NONE;
634 					break;
635 				default:
636 					err = -EINVAL;
637 			}
638 			if (err)
639 				break;
640 
641 			hdr.dxferp = cgc.buffer;
642 			hdr.sbp = cgc.sense;
643 			if (hdr.sbp)
644 				hdr.mx_sb_len = sizeof(struct request_sense);
645 			hdr.timeout = jiffies_to_msecs(cgc.timeout);
646 			hdr.cmdp = ((struct cdrom_generic_command __user*) arg)->cmd;
647 			hdr.cmd_len = sizeof(cgc.cmd);
648 
649 			err = sg_io(q, bd_disk, &hdr, mode);
650 			if (err == -EFAULT)
651 				break;
652 
653 			if (hdr.status)
654 				err = -EIO;
655 
656 			cgc.stat = err;
657 			cgc.buflen = hdr.resid;
658 			if (copy_to_user(arg, &cgc, sizeof(cgc)))
659 				err = -EFAULT;
660 
661 			break;
662 		}
663 
664 		/*
665 		 * old junk scsi send command ioctl
666 		 */
667 		case SCSI_IOCTL_SEND_COMMAND:
668 			printk(KERN_WARNING "program %s is using a deprecated SCSI ioctl, please convert it to SG_IO\n", current->comm);
669 			err = -EINVAL;
670 			if (!arg)
671 				break;
672 
673 			err = sg_scsi_ioctl(q, bd_disk, mode, arg);
674 			break;
675 		case CDROMCLOSETRAY:
676 			err = blk_send_start_stop(q, bd_disk, 0x03);
677 			break;
678 		case CDROMEJECT:
679 			err = blk_send_start_stop(q, bd_disk, 0x02);
680 			break;
681 		default:
682 			err = -ENOTTY;
683 	}
684 
685 	return err;
686 }
687 EXPORT_SYMBOL(scsi_cmd_ioctl);
688 
scsi_verify_blk_ioctl(struct block_device * bd,unsigned int cmd)689 int scsi_verify_blk_ioctl(struct block_device *bd, unsigned int cmd)
690 {
691 	if (bd && bd == bd->bd_contains)
692 		return 0;
693 
694 	/* Actually none of these is particularly useful on a partition,
695 	 * but they are safe.
696 	 */
697 	switch (cmd) {
698 	case SCSI_IOCTL_GET_IDLUN:
699 	case SCSI_IOCTL_GET_BUS_NUMBER:
700 	case SCSI_IOCTL_GET_PCI:
701 	case SCSI_IOCTL_PROBE_HOST:
702 	case SG_GET_VERSION_NUM:
703 	case SG_SET_TIMEOUT:
704 	case SG_GET_TIMEOUT:
705 	case SG_GET_RESERVED_SIZE:
706 	case SG_SET_RESERVED_SIZE:
707 	case SG_EMULATED_HOST:
708 		return 0;
709 	case CDROM_GET_CAPABILITY:
710 		/* Keep this until we remove the printk below.  udev sends it
711 		 * and we do not want to spam dmesg about it.   CD-ROMs do
712 		 * not have partitions, so we get here only for disks.
713 		 */
714 		return -ENOIOCTLCMD;
715 	default:
716 		break;
717 	}
718 
719 	if (capable(CAP_SYS_RAWIO))
720 		return 0;
721 
722 	/* In particular, rule out all resets and host-specific ioctls.  */
723 	printk_ratelimited(KERN_WARNING
724 			   "%s: sending ioctl %x to a partition!\n", current->comm, cmd);
725 
726 	return -ENOIOCTLCMD;
727 }
728 EXPORT_SYMBOL(scsi_verify_blk_ioctl);
729 
scsi_cmd_blk_ioctl(struct block_device * bd,fmode_t mode,unsigned int cmd,void __user * arg)730 int scsi_cmd_blk_ioctl(struct block_device *bd, fmode_t mode,
731 		       unsigned int cmd, void __user *arg)
732 {
733 	int ret;
734 
735 	ret = scsi_verify_blk_ioctl(bd, cmd);
736 	if (ret < 0)
737 		return ret;
738 
739 	return scsi_cmd_ioctl(bd->bd_disk->queue, bd->bd_disk, mode, cmd, arg);
740 }
741 EXPORT_SYMBOL(scsi_cmd_blk_ioctl);
742 
blk_scsi_ioctl_init(void)743 static int __init blk_scsi_ioctl_init(void)
744 {
745 	blk_set_cmd_filter_defaults(&blk_default_cmd_filter);
746 	return 0;
747 }
748 fs_initcall(blk_scsi_ioctl_init);
749