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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 <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, 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 	if (copy_from_user(rq->cmd, hdr->cmdp, hdr->cmd_len))
234 		return -EFAULT;
235 	if (blk_verify_command(rq->cmd, mode & FMODE_WRITE))
236 		return -EPERM;
237 
238 	/*
239 	 * fill in request structure
240 	 */
241 	rq->cmd_len = hdr->cmd_len;
242 
243 	rq->timeout = msecs_to_jiffies(hdr->timeout);
244 	if (!rq->timeout)
245 		rq->timeout = q->sg_timeout;
246 	if (!rq->timeout)
247 		rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
248 	if (rq->timeout < BLK_MIN_SG_TIMEOUT)
249 		rq->timeout = BLK_MIN_SG_TIMEOUT;
250 
251 	return 0;
252 }
253 
blk_complete_sghdr_rq(struct request * rq,struct sg_io_hdr * hdr,struct bio * bio)254 static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
255 				 struct bio *bio)
256 {
257 	int r, ret = 0;
258 
259 	/*
260 	 * fill in all the output members
261 	 */
262 	hdr->status = rq->errors & 0xff;
263 	hdr->masked_status = status_byte(rq->errors);
264 	hdr->msg_status = msg_byte(rq->errors);
265 	hdr->host_status = host_byte(rq->errors);
266 	hdr->driver_status = driver_byte(rq->errors);
267 	hdr->info = 0;
268 	if (hdr->masked_status || hdr->host_status || hdr->driver_status)
269 		hdr->info |= SG_INFO_CHECK;
270 	hdr->resid = rq->resid_len;
271 	hdr->sb_len_wr = 0;
272 
273 	if (rq->sense_len && hdr->sbp) {
274 		int len = min((unsigned int) hdr->mx_sb_len, rq->sense_len);
275 
276 		if (!copy_to_user(hdr->sbp, rq->sense, len))
277 			hdr->sb_len_wr = len;
278 		else
279 			ret = -EFAULT;
280 	}
281 
282 	r = blk_rq_unmap_user(bio);
283 	if (!ret)
284 		ret = r;
285 
286 	return ret;
287 }
288 
sg_io(struct request_queue * q,struct gendisk * bd_disk,struct sg_io_hdr * hdr,fmode_t mode)289 static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
290 		struct sg_io_hdr *hdr, fmode_t mode)
291 {
292 	unsigned long start_time;
293 	ssize_t ret = 0;
294 	int writing = 0;
295 	int at_head = 0;
296 	struct request *rq;
297 	char sense[SCSI_SENSE_BUFFERSIZE];
298 	struct bio *bio;
299 
300 	if (hdr->interface_id != 'S')
301 		return -EINVAL;
302 
303 	if (hdr->dxfer_len > (queue_max_hw_sectors(q) << 9))
304 		return -EIO;
305 
306 	if (hdr->dxfer_len)
307 		switch (hdr->dxfer_direction) {
308 		default:
309 			return -EINVAL;
310 		case SG_DXFER_TO_DEV:
311 			writing = 1;
312 			break;
313 		case SG_DXFER_TO_FROM_DEV:
314 		case SG_DXFER_FROM_DEV:
315 			break;
316 		}
317 	if (hdr->flags & SG_FLAG_Q_AT_HEAD)
318 		at_head = 1;
319 
320 	ret = -ENOMEM;
321 	rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);
322 	if (IS_ERR(rq))
323 		return PTR_ERR(rq);
324 	blk_rq_set_block_pc(rq);
325 
326 	if (hdr->cmd_len > BLK_MAX_CDB) {
327 		rq->cmd = kzalloc(hdr->cmd_len, GFP_KERNEL);
328 		if (!rq->cmd)
329 			goto out_put_request;
330 	}
331 
332 	ret = -EFAULT;
333 	if (blk_fill_sghdr_rq(q, rq, hdr, mode))
334 		goto out_free_cdb;
335 
336 	ret = 0;
337 	if (hdr->iovec_count) {
338 		size_t iov_data_len;
339 		struct iovec *iov = NULL;
340 
341 		ret = rw_copy_check_uvector(-1, hdr->dxferp, hdr->iovec_count,
342 					    0, NULL, &iov);
343 		if (ret < 0) {
344 			kfree(iov);
345 			goto out_free_cdb;
346 		}
347 
348 		iov_data_len = ret;
349 		ret = 0;
350 
351 		/* SG_IO howto says that the shorter of the two wins */
352 		if (hdr->dxfer_len < iov_data_len) {
353 			hdr->iovec_count = iov_shorten(iov,
354 						       hdr->iovec_count,
355 						       hdr->dxfer_len);
356 			iov_data_len = hdr->dxfer_len;
357 		}
358 
359 		ret = blk_rq_map_user_iov(q, rq, NULL, (struct sg_iovec *) iov,
360 					  hdr->iovec_count,
361 					  iov_data_len, GFP_KERNEL);
362 		kfree(iov);
363 	} else if (hdr->dxfer_len)
364 		ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len,
365 				      GFP_KERNEL);
366 
367 	if (ret)
368 		goto out_free_cdb;
369 
370 	bio = rq->bio;
371 	memset(sense, 0, sizeof(sense));
372 	rq->sense = sense;
373 	rq->sense_len = 0;
374 	rq->retries = 0;
375 
376 	start_time = jiffies;
377 
378 	/* ignore return value. All information is passed back to caller
379 	 * (if he doesn't check that is his problem).
380 	 * N.B. a non-zero SCSI status is _not_ necessarily an error.
381 	 */
382 	blk_execute_rq(q, bd_disk, rq, at_head);
383 
384 	hdr->duration = jiffies_to_msecs(jiffies - start_time);
385 
386 	ret = blk_complete_sghdr_rq(rq, hdr, bio);
387 
388 out_free_cdb:
389 	if (rq->cmd != rq->__cmd)
390 		kfree(rq->cmd);
391 out_put_request:
392 	blk_put_request(rq);
393 	return ret;
394 }
395 
396 /**
397  * sg_scsi_ioctl  --  handle deprecated SCSI_IOCTL_SEND_COMMAND ioctl
398  * @file:	file this ioctl operates on (optional)
399  * @q:		request queue to send scsi commands down
400  * @disk:	gendisk to operate on (option)
401  * @sic:	userspace structure describing the command to perform
402  *
403  * Send down the scsi command described by @sic to the device below
404  * the request queue @q.  If @file is non-NULL it's used to perform
405  * fine-grained permission checks that allow users to send down
406  * non-destructive SCSI commands.  If the caller has a struct gendisk
407  * available it should be passed in as @disk to allow the low level
408  * driver to use the information contained in it.  A non-NULL @disk
409  * is only allowed if the caller knows that the low level driver doesn't
410  * need it (e.g. in the scsi subsystem).
411  *
412  * Notes:
413  *   -  This interface is deprecated - users should use the SG_IO
414  *      interface instead, as this is a more flexible approach to
415  *      performing SCSI commands on a device.
416  *   -  The SCSI command length is determined by examining the 1st byte
417  *      of the given command. There is no way to override this.
418  *   -  Data transfers are limited to PAGE_SIZE
419  *   -  The length (x + y) must be at least OMAX_SB_LEN bytes long to
420  *      accommodate the sense buffer when an error occurs.
421  *      The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
422  *      old code will not be surprised.
423  *   -  If a Unix error occurs (e.g. ENOMEM) then the user will receive
424  *      a negative return and the Unix error code in 'errno'.
425  *      If the SCSI command succeeds then 0 is returned.
426  *      Positive numbers returned are the compacted SCSI error codes (4
427  *      bytes in one int) where the lowest byte is the SCSI status.
428  */
429 #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)430 int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
431 		struct scsi_ioctl_command __user *sic)
432 {
433 	struct request *rq;
434 	int err;
435 	unsigned int in_len, out_len, bytes, opcode, cmdlen;
436 	char *buffer = NULL, sense[SCSI_SENSE_BUFFERSIZE];
437 
438 	if (!sic)
439 		return -EINVAL;
440 
441 	/*
442 	 * get in an out lengths, verify they don't exceed a page worth of data
443 	 */
444 	if (get_user(in_len, &sic->inlen))
445 		return -EFAULT;
446 	if (get_user(out_len, &sic->outlen))
447 		return -EFAULT;
448 	if (in_len > PAGE_SIZE || out_len > PAGE_SIZE)
449 		return -EINVAL;
450 	if (get_user(opcode, sic->data))
451 		return -EFAULT;
452 
453 	bytes = max(in_len, out_len);
454 	if (bytes) {
455 		buffer = kzalloc(bytes, q->bounce_gfp | GFP_USER| __GFP_NOWARN);
456 		if (!buffer)
457 			return -ENOMEM;
458 
459 	}
460 
461 	rq = blk_get_request(q, in_len ? WRITE : READ, __GFP_WAIT);
462 	if (IS_ERR(rq)) {
463 		err = PTR_ERR(rq);
464 		goto error_free_buffer;
465 	}
466 	blk_rq_set_block_pc(rq);
467 
468 	cmdlen = COMMAND_SIZE(opcode);
469 
470 	/*
471 	 * get command and data to send to device, if any
472 	 */
473 	err = -EFAULT;
474 	rq->cmd_len = cmdlen;
475 	if (copy_from_user(rq->cmd, sic->data, cmdlen))
476 		goto error;
477 
478 	if (in_len && copy_from_user(buffer, sic->data + cmdlen, in_len))
479 		goto error;
480 
481 	err = blk_verify_command(rq->cmd, mode & FMODE_WRITE);
482 	if (err)
483 		goto error;
484 
485 	/* default.  possible overriden later */
486 	rq->retries = 5;
487 
488 	switch (opcode) {
489 	case SEND_DIAGNOSTIC:
490 	case FORMAT_UNIT:
491 		rq->timeout = FORMAT_UNIT_TIMEOUT;
492 		rq->retries = 1;
493 		break;
494 	case START_STOP:
495 		rq->timeout = START_STOP_TIMEOUT;
496 		break;
497 	case MOVE_MEDIUM:
498 		rq->timeout = MOVE_MEDIUM_TIMEOUT;
499 		break;
500 	case READ_ELEMENT_STATUS:
501 		rq->timeout = READ_ELEMENT_STATUS_TIMEOUT;
502 		break;
503 	case READ_DEFECT_DATA:
504 		rq->timeout = READ_DEFECT_DATA_TIMEOUT;
505 		rq->retries = 1;
506 		break;
507 	default:
508 		rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
509 		break;
510 	}
511 
512 	if (bytes && blk_rq_map_kern(q, rq, buffer, bytes, __GFP_WAIT)) {
513 		err = DRIVER_ERROR << 24;
514 		goto error;
515 	}
516 
517 	memset(sense, 0, sizeof(sense));
518 	rq->sense = sense;
519 	rq->sense_len = 0;
520 
521 	blk_execute_rq(q, disk, rq, 0);
522 
523 	err = rq->errors & 0xff;	/* only 8 bit SCSI status */
524 	if (err) {
525 		if (rq->sense_len && rq->sense) {
526 			bytes = (OMAX_SB_LEN > rq->sense_len) ?
527 				rq->sense_len : OMAX_SB_LEN;
528 			if (copy_to_user(sic->data, rq->sense, bytes))
529 				err = -EFAULT;
530 		}
531 	} else {
532 		if (copy_to_user(sic->data, buffer, out_len))
533 			err = -EFAULT;
534 	}
535 
536 error:
537 	blk_put_request(rq);
538 
539 error_free_buffer:
540 	kfree(buffer);
541 
542 	return err;
543 }
544 EXPORT_SYMBOL_GPL(sg_scsi_ioctl);
545 
546 /* Send basic block requests */
__blk_send_generic(struct request_queue * q,struct gendisk * bd_disk,int cmd,int data)547 static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
548 			      int cmd, int data)
549 {
550 	struct request *rq;
551 	int err;
552 
553 	rq = blk_get_request(q, WRITE, __GFP_WAIT);
554 	if (IS_ERR(rq))
555 		return PTR_ERR(rq);
556 	blk_rq_set_block_pc(rq);
557 	rq->timeout = BLK_DEFAULT_SG_TIMEOUT;
558 	rq->cmd[0] = cmd;
559 	rq->cmd[4] = data;
560 	rq->cmd_len = 6;
561 	err = blk_execute_rq(q, bd_disk, rq, 0);
562 	blk_put_request(rq);
563 
564 	return err;
565 }
566 
blk_send_start_stop(struct request_queue * q,struct gendisk * bd_disk,int data)567 static inline int blk_send_start_stop(struct request_queue *q,
568 				      struct gendisk *bd_disk, int data)
569 {
570 	return __blk_send_generic(q, bd_disk, GPCMD_START_STOP_UNIT, data);
571 }
572 
scsi_cmd_ioctl(struct request_queue * q,struct gendisk * bd_disk,fmode_t mode,unsigned int cmd,void __user * arg)573 int scsi_cmd_ioctl(struct request_queue *q, struct gendisk *bd_disk, fmode_t mode,
574 		   unsigned int cmd, void __user *arg)
575 {
576 	int err;
577 
578 	if (!q)
579 		return -ENXIO;
580 
581 	switch (cmd) {
582 		/*
583 		 * new sgv3 interface
584 		 */
585 		case SG_GET_VERSION_NUM:
586 			err = sg_get_version(arg);
587 			break;
588 		case SCSI_IOCTL_GET_IDLUN:
589 			err = scsi_get_idlun(q, arg);
590 			break;
591 		case SCSI_IOCTL_GET_BUS_NUMBER:
592 			err = scsi_get_bus(q, arg);
593 			break;
594 		case SG_SET_TIMEOUT:
595 			err = sg_set_timeout(q, arg);
596 			break;
597 		case SG_GET_TIMEOUT:
598 			err = sg_get_timeout(q);
599 			break;
600 		case SG_GET_RESERVED_SIZE:
601 			err = sg_get_reserved_size(q, arg);
602 			break;
603 		case SG_SET_RESERVED_SIZE:
604 			err = sg_set_reserved_size(q, arg);
605 			break;
606 		case SG_EMULATED_HOST:
607 			err = sg_emulated_host(q, arg);
608 			break;
609 		case SG_IO: {
610 			struct sg_io_hdr hdr;
611 
612 			err = -EFAULT;
613 			if (copy_from_user(&hdr, arg, sizeof(hdr)))
614 				break;
615 			err = sg_io(q, bd_disk, &hdr, mode);
616 			if (err == -EFAULT)
617 				break;
618 
619 			if (copy_to_user(arg, &hdr, sizeof(hdr)))
620 				err = -EFAULT;
621 			break;
622 		}
623 		case CDROM_SEND_PACKET: {
624 			struct cdrom_generic_command cgc;
625 			struct sg_io_hdr hdr;
626 
627 			err = -EFAULT;
628 			if (copy_from_user(&cgc, arg, sizeof(cgc)))
629 				break;
630 			cgc.timeout = clock_t_to_jiffies(cgc.timeout);
631 			memset(&hdr, 0, sizeof(hdr));
632 			hdr.interface_id = 'S';
633 			hdr.cmd_len = sizeof(cgc.cmd);
634 			hdr.dxfer_len = cgc.buflen;
635 			err = 0;
636 			switch (cgc.data_direction) {
637 				case CGC_DATA_UNKNOWN:
638 					hdr.dxfer_direction = SG_DXFER_UNKNOWN;
639 					break;
640 				case CGC_DATA_WRITE:
641 					hdr.dxfer_direction = SG_DXFER_TO_DEV;
642 					break;
643 				case CGC_DATA_READ:
644 					hdr.dxfer_direction = SG_DXFER_FROM_DEV;
645 					break;
646 				case CGC_DATA_NONE:
647 					hdr.dxfer_direction = SG_DXFER_NONE;
648 					break;
649 				default:
650 					err = -EINVAL;
651 			}
652 			if (err)
653 				break;
654 
655 			hdr.dxferp = cgc.buffer;
656 			hdr.sbp = cgc.sense;
657 			if (hdr.sbp)
658 				hdr.mx_sb_len = sizeof(struct request_sense);
659 			hdr.timeout = jiffies_to_msecs(cgc.timeout);
660 			hdr.cmdp = ((struct cdrom_generic_command __user*) arg)->cmd;
661 			hdr.cmd_len = sizeof(cgc.cmd);
662 
663 			err = sg_io(q, bd_disk, &hdr, mode);
664 			if (err == -EFAULT)
665 				break;
666 
667 			if (hdr.status)
668 				err = -EIO;
669 
670 			cgc.stat = err;
671 			cgc.buflen = hdr.resid;
672 			if (copy_to_user(arg, &cgc, sizeof(cgc)))
673 				err = -EFAULT;
674 
675 			break;
676 		}
677 
678 		/*
679 		 * old junk scsi send command ioctl
680 		 */
681 		case SCSI_IOCTL_SEND_COMMAND:
682 			printk(KERN_WARNING "program %s is using a deprecated SCSI ioctl, please convert it to SG_IO\n", current->comm);
683 			err = -EINVAL;
684 			if (!arg)
685 				break;
686 
687 			err = sg_scsi_ioctl(q, bd_disk, mode, arg);
688 			break;
689 		case CDROMCLOSETRAY:
690 			err = blk_send_start_stop(q, bd_disk, 0x03);
691 			break;
692 		case CDROMEJECT:
693 			err = blk_send_start_stop(q, bd_disk, 0x02);
694 			break;
695 		default:
696 			err = -ENOTTY;
697 	}
698 
699 	return err;
700 }
701 EXPORT_SYMBOL(scsi_cmd_ioctl);
702 
scsi_verify_blk_ioctl(struct block_device * bd,unsigned int cmd)703 int scsi_verify_blk_ioctl(struct block_device *bd, unsigned int cmd)
704 {
705 	if (bd && bd == bd->bd_contains)
706 		return 0;
707 
708 	/* Actually none of these is particularly useful on a partition,
709 	 * but they are safe.
710 	 */
711 	switch (cmd) {
712 	case SCSI_IOCTL_GET_IDLUN:
713 	case SCSI_IOCTL_GET_BUS_NUMBER:
714 	case SCSI_IOCTL_GET_PCI:
715 	case SCSI_IOCTL_PROBE_HOST:
716 	case SG_GET_VERSION_NUM:
717 	case SG_SET_TIMEOUT:
718 	case SG_GET_TIMEOUT:
719 	case SG_GET_RESERVED_SIZE:
720 	case SG_SET_RESERVED_SIZE:
721 	case SG_EMULATED_HOST:
722 		return 0;
723 	case CDROM_GET_CAPABILITY:
724 		/* Keep this until we remove the printk below.  udev sends it
725 		 * and we do not want to spam dmesg about it.   CD-ROMs do
726 		 * not have partitions, so we get here only for disks.
727 		 */
728 		return -ENOIOCTLCMD;
729 	default:
730 		break;
731 	}
732 
733 	if (capable(CAP_SYS_RAWIO))
734 		return 0;
735 
736 	/* In particular, rule out all resets and host-specific ioctls.  */
737 	printk_ratelimited(KERN_WARNING
738 			   "%s: sending ioctl %x to a partition!\n", current->comm, cmd);
739 
740 	return -ENOIOCTLCMD;
741 }
742 EXPORT_SYMBOL(scsi_verify_blk_ioctl);
743 
scsi_cmd_blk_ioctl(struct block_device * bd,fmode_t mode,unsigned int cmd,void __user * arg)744 int scsi_cmd_blk_ioctl(struct block_device *bd, fmode_t mode,
745 		       unsigned int cmd, void __user *arg)
746 {
747 	int ret;
748 
749 	ret = scsi_verify_blk_ioctl(bd, cmd);
750 	if (ret < 0)
751 		return ret;
752 
753 	return scsi_cmd_ioctl(bd->bd_disk->queue, bd->bd_disk, mode, cmd, arg);
754 }
755 EXPORT_SYMBOL(scsi_cmd_blk_ioctl);
756 
blk_scsi_ioctl_init(void)757 static int __init blk_scsi_ioctl_init(void)
758 {
759 	blk_set_cmd_filter_defaults(&blk_default_cmd_filter);
760 	return 0;
761 }
762 fs_initcall(blk_scsi_ioctl_init);
763