aboutsummaryrefslogtreecommitdiff
path: root/drivers/scsi/scsi_ioctl.c
blob: 6a3f6aae8a976c8ef1011dafc6bd5c8806952109 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
/*
 * Changes:
 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 08/23/2000
 * - get rid of some verify_areas and use __copy*user and __get/put_user
 *   for the ones that remain
 */
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <asm/uaccess.h>

#include <scsi/scsi.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/scsi_request.h>
#include <scsi/sg.h>
#include <scsi/scsi_dbg.h>

#include "scsi_logging.h"

#define NORMAL_RETRIES			5
#define IOCTL_NORMAL_TIMEOUT			(10 * HZ)

#define MAX_BUF PAGE_SIZE

/**
 * ioctl_probe  --  return host identification
 * @host:	host to identify
 * @buffer:	userspace buffer for identification
 *
 * Return an identifying string at @buffer, if @buffer is non-NULL, filling
 * to the length stored at * (int *) @buffer.
 */
static int ioctl_probe(struct Scsi_Host *host, void __user *buffer)
{
	unsigned int len, slen;
	const char *string;

	if (buffer) {
		if (get_user(len, (unsigned int __user *) buffer))
			return -EFAULT;

		if (host->hostt->info)
			string = host->hostt->info(host);
		else
			string = host->hostt->name;
		if (string) {
			slen = strlen(string);
			if (len > slen)
				len = slen + 1;
			if (copy_to_user(buffer, string, len))
				return -EFAULT;
		}
	}
	return 1;
}

/*

 * The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host.
 * The IOCTL_NORMAL_TIMEOUT and NORMAL_RETRIES  variables are used.  
 * 
 * dev is the SCSI device struct ptr, *(int *) arg is the length of the
 * input data, if any, not including the command string & counts, 
 * *((int *)arg + 1) is the output buffer size in bytes.
 * 
 * *(char *) ((int *) arg)[2] the actual command byte.   
 * 
 * Note that if more than MAX_BUF bytes are requested to be transferred,
 * the ioctl will fail with error EINVAL.
 * 
 * This size *does not* include the initial lengths that were passed.
 * 
 * The SCSI command is read from the memory location immediately after the
 * length words, and the input data is right after the command.  The SCSI
 * routines know the command size based on the opcode decode.  
 * 
 * The output area is then filled in starting from the command byte. 
 */

static int ioctl_internal_command(struct scsi_device *sdev, char *cmd,
				  int timeout, int retries)
{
	int result;
	struct scsi_sense_hdr sshdr;

	SCSI_LOG_IOCTL(1, printk("Trying ioctl with scsi command %d\n", *cmd));

	result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0,
				  &sshdr, timeout, retries);

	SCSI_LOG_IOCTL(2, printk("Ioctl returned  0x%x\n", result));

	if ((driver_byte(result) & DRIVER_SENSE) &&
	    (scsi_sense_valid(&sshdr))) {
		switch (sshdr.sense_key) {
		case ILLEGAL_REQUEST:
			if (cmd[0] == ALLOW_MEDIUM_REMOVAL)
				sdev->lockable = 0;
			else
				printk(KERN_INFO "ioctl_internal_command: "
				       "ILLEGAL REQUEST asc=0x%x ascq=0x%x\n",
				       sshdr.asc, sshdr.ascq);
			break;
		case NOT_READY:	/* This happens if there is no disc in drive */
			if (sdev->removable && (cmd[0] != TEST_UNIT_READY)) {
				printk(KERN_INFO "Device not ready. Make sure"
				       " there is a disc in the drive.\n");
				break;
			}
		case UNIT_ATTENTION:
			if (sdev->removable) {
				sdev->changed = 1;
				result = 0;	/* This is no longer considered an error */
				break;
			}
		default:	/* Fall through for non-removable media */
			printk(KERN_INFO "ioctl_internal_command: <%d %d %d "
			       "%d> return code = %x\n",
			       sdev->host->host_no,
			       sdev->channel,
			       sdev->id,
			       sdev->lun,
			       result);
			scsi_print_sense_hdr("   ", &sshdr);
			break;
		}
	}

	SCSI_LOG_IOCTL(2, printk("IOCTL Releasing command\n"));
	return result;
}

int scsi_set_medium_removal(struct scsi_device *sdev, char state)
{
	char scsi_cmd[MAX_COMMAND_SIZE];
	int ret;

	if (!sdev->removable || !sdev->lockable)
	       return 0;

	scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
	scsi_cmd[1] = 0;
	scsi_cmd[2] = 0;
	scsi_cmd[3] = 0;
	scsi_cmd[4] = state;
	scsi_cmd[5] = 0;

	ret = ioctl_internal_command(sdev, scsi_cmd,
			IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
	if (ret == 0)
		sdev->locked = (state == SCSI_REMOVAL_PREVENT);
	return ret;
}
EXPORT_SYMBOL(scsi_set_medium_removal);

/*
 * This interface is deprecated - users should use the scsi generic (sg)
 * interface instead, as this is a more flexible approach to performing
 * generic SCSI commands on a device.
 *
 * The structure that we are passed should look like:
 *
 * struct sdata {
 *  unsigned int inlen;      [i] Length of data to be written to device 
 *  unsigned int outlen;     [i] Length of data to be read from device 
 *  unsigned char cmd[x];    [i] SCSI command (6 <= x <= 12).
 *                           [o] Data read from device starts here.
 *                           [o] On error, sense buffer starts here.
 *  unsigned char wdata[y];  [i] Data written to device starts here.
 * };
 * Notes:
 *   -  The SCSI command length is determined by examining the 1st byte
 *      of the given command. There is no way to override this.
 *   -  Data transfers are limited to PAGE_SIZE (4K on i386, 8K on alpha).
 *   -  The length (x + y) must be at least OMAX_SB_LEN bytes long to
 *      accommodate the sense buffer when an error occurs.
 *      The sense buffer is truncated to OMAX_SB_LEN (16) bytes so that
 *      old code will not be surprised.
 *   -  If a Unix error occurs (e.g. ENOMEM) then the user will receive
 *      a negative return and the Unix error code in 'errno'. 
 *      If the SCSI command succeeds then 0 is returned.
 *      Positive numbers returned are the compacted SCSI error codes (4 
 *      bytes in one int) where the lowest byte is the SCSI status.
 *      See the drivers/scsi/scsi.h file for more information on this.
 *
 */
#define OMAX_SB_LEN 16		/* Old sense buffer length */

int scsi_ioctl_send_command(struct scsi_device *sdev,
			    struct scsi_ioctl_command __user *sic)
{
	char *buf;
	unsigned char cmd[MAX_COMMAND_SIZE];
	unsigned char sense[SCSI_SENSE_BUFFERSIZE];
	char __user *cmd_in;
	unsigned char opcode;
	unsigned int inlen, outlen, cmdlen;
	unsigned int needed, buf_needed;
	int timeout, retries, result;
	int data_direction;
	gfp_t gfp_mask = GFP_KERNEL;

	if (!sic)
		return -EINVAL;

	if (sdev->host->unchecked_isa_dma)
		gfp_mask |= GFP_DMA;

	/*
	 * Verify that we can read at least this much.
	 */
	if (!access_ok(VERIFY_READ, sic, sizeof(Scsi_Ioctl_Command)))
		return -EFAULT;

	if(__get_user(inlen, &sic->inlen))
		return -EFAULT;
		
	if(__get_user(outlen, &sic->outlen))
		return -EFAULT;

	/*
	 * We do not transfer more than MAX_BUF with this interface.
	 * If the user needs to transfer more data than this, they
	 * should use scsi_generics (sg) instead.
	 */
	if (inlen > MAX_BUF)
		return -EINVAL;
	if (outlen > MAX_BUF)
		return -EINVAL;

	cmd_in = sic->data;
	if(get_user(opcode, cmd_in))
		return -EFAULT;

	needed = buf_needed = (inlen > outlen ? inlen : outlen);
	if (buf_needed) {
		buf_needed = (buf_needed + 511) & ~511;
		if (buf_needed > MAX_BUF)
			buf_needed = MAX_BUF;
		buf = kmalloc(buf_needed, gfp_mask);
		if (!buf)
			return -ENOMEM;
		memset(buf, 0, buf_needed);
		if (inlen == 0) {
			data_direction = DMA_FROM_DEVICE;
		} else if (outlen == 0 ) {
			data_direction = DMA_TO_DEVICE;
		} else {
			/*
			 * Can this ever happen?
			 */
			data_direction = DMA_BIDIRECTIONAL;
		}

	} else {
		buf = NULL;
		data_direction = DMA_NONE;
	}

	/*
	 * Obtain the command from the user's address space.
	 */
	cmdlen = COMMAND_SIZE(opcode);
	
	result = -EFAULT;

	if (!access_ok(VERIFY_READ, cmd_in, cmdlen + inlen))
		goto error;

	if(__copy_from_user(cmd, cmd_in, cmdlen))
		goto error;

	/*
	 * Obtain the data to be sent to the device (if any).
	 */

	if(copy_from_user(buf, cmd_in + cmdlen, inlen))
		goto error;

	switch (opcode) {
	case SEND_DIAGNOSTIC:
	case FORMAT_UNIT:
		timeout = FORMAT_UNIT_TIMEOUT;
		retries = 1;
		break;
	case START_STOP:
		timeout = START_STOP_TIMEOUT;
		retries = NORMAL_RETRIES;
		break;
	case MOVE_MEDIUM:
		timeout = MOVE_MEDIUM_TIMEOUT;
		retries = NORMAL_RETRIES;
		break;
	case READ_ELEMENT_STATUS:
		timeout = READ_ELEMENT_STATUS_TIMEOUT;
		retries = NORMAL_RETRIES;
		break;
	case READ_DEFECT_DATA:
		timeout = READ_DEFECT_DATA_TIMEOUT;
		retries = 1;
		break;
	default:
		timeout = IOCTL_NORMAL_TIMEOUT;
		retries = NORMAL_RETRIES;
		break;
	}

	result = scsi_execute(sdev, cmd, data_direction, buf, needed,
			      sense, timeout, retries, 0);

	/* 
	 * If there was an error condition, pass the info back to the user. 
	 */
	if (result) {
		int sb_len = sizeof(*sense);

		sb_len = (sb_len > OMAX_SB_LEN) ? OMAX_SB_LEN : sb_len;
		if (copy_to_user(cmd_in, sense, sb_len))
			result = -EFAULT;
	} else {
		if (copy_to_user(cmd_in, buf, outlen))
			result = -EFAULT;
	}	

error:
	kfree(buf);
	return result;
}
EXPORT_SYMBOL(scsi_ioctl_send_command);

/*
 * The scsi_ioctl_get_pci() function places into arg the value
 * pci_dev::slot_name (8 characters) for the PCI device (if any).
 * Returns: 0 on success
 *          -ENXIO if there isn't a PCI device pointer
 *                 (could be because the SCSI driver hasn't been
 *                  updated yet, or because it isn't a SCSI
 *                  device)
 *          any copy_to_user() error on failure there
 */
static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
{
	struct device *dev = scsi_get_device(sdev->host);

        if (!dev)
		return -ENXIO;
        return copy_to_user(arg, dev->bus_id, sizeof(dev->bus_id))? -EFAULT: 0;
}


/*
 * the scsi_ioctl() function differs from most ioctls in that it does
 * not take a major/minor number as the dev field.  Rather, it takes
 * a pointer to a scsi_devices[] element, a structure. 
 */
int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
{
	char scsi_cmd[MAX_COMMAND_SIZE];

	/* No idea how this happens.... */
	if (!sdev)
		return -ENXIO;

	/*
	 * If we are in the middle of error recovery, don't let anyone
	 * else try and use this device.  Also, if error recovery fails, it
	 * may try and take the device offline, in which case all further
	 * access to the device is prohibited.
	 */
	if (!scsi_block_when_processing_errors(sdev))
		return -ENODEV;

	/* Check for deprecated ioctls ... all the ioctls which don't
	 * follow the new unique numbering scheme are deprecated */
	switch (cmd) {
	case SCSI_IOCTL_SEND_COMMAND:
	case SCSI_IOCTL_TEST_UNIT_READY:
	case SCSI_IOCTL_BENCHMARK_COMMAND:
	case SCSI_IOCTL_SYNC:
	case SCSI_IOCTL_START_UNIT:
	case SCSI_IOCTL_STOP_UNIT:
		printk(KERN_WARNING "program %s is using a deprecated SCSI "
		       "ioctl, please convert it to SG_IO\n", current->comm);
		break;
	default:
		break;
	}

	switch (cmd) {
	case SCSI_IOCTL_GET_IDLUN:
		if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun)))
			return -EFAULT;

		__put_user((sdev->id & 0xff)
			 + ((sdev->lun & 0xff) << 8)
			 + ((sdev->channel & 0xff) << 16)
			 + ((sdev->host->host_no & 0xff) << 24),
			 &((struct scsi_idlun __user *)arg)->dev_id);
		__put_user(sdev->host->unique_id,
			 &((struct scsi_idlun __user *)arg)->host_unique_id);
		return 0;
	case SCSI_IOCTL_GET_BUS_NUMBER:
		return put_user(sdev->host->host_no, (int __user *)arg);
	case SCSI_IOCTL_PROBE_HOST:
		return ioctl_probe(sdev->host, arg);
	case SCSI_IOCTL_SEND_COMMAND:
		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
			return -EACCES;
		return scsi_ioctl_send_command(sdev, arg);
	case SCSI_IOCTL_DOORLOCK:
		return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
	case SCSI_IOCTL_DOORUNLOCK:
		return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
	case SCSI_IOCTL_TEST_UNIT_READY:
		return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
					    NORMAL_RETRIES);
	case SCSI_IOCTL_START_UNIT:
		scsi_cmd[0] = START_STOP;
		scsi_cmd[1] = 0;
		scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
		scsi_cmd[4] = 1;
		return ioctl_internal_command(sdev, scsi_cmd,
				     START_STOP_TIMEOUT, NORMAL_RETRIES);
	case SCSI_IOCTL_STOP_UNIT:
		scsi_cmd[0] = START_STOP;
		scsi_cmd[1] = 0;
		scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
		scsi_cmd[4] = 0;
		return ioctl_internal_command(sdev, scsi_cmd,
				     START_STOP_TIMEOUT, NORMAL_RETRIES);
        case SCSI_IOCTL_GET_PCI:
                return scsi_ioctl_get_pci(sdev, arg);
	default:
		if (sdev->host->hostt->ioctl)
			return sdev->host->hostt->ioctl(sdev, cmd, arg);
	}
	return -EINVAL;
}
EXPORT_SYMBOL(scsi_ioctl);

/*
 * the scsi_nonblock_ioctl() function is designed for ioctls which may
 * be executed even if the device is in recovery.
 */
int scsi_nonblockable_ioctl(struct scsi_device *sdev, int cmd,
			    void __user *arg, struct file *filp)
{
	int val, result;

	/* The first set of iocts may be executed even if we're doing
	 * error processing, as long as the device was opened
	 * non-blocking */
	if (filp && filp->f_flags & O_NONBLOCK) {
		if (scsi_host_in_recovery(sdev->host))
			return -ENODEV;
	} else if (!scsi_block_when_processing_errors(sdev))
		return -ENODEV;

	switch (cmd) {
	case SG_SCSI_RESET:
		result = get_user(val, (int __user *)arg);
		if (result)
			return result;
		if (val == SG_SCSI_RESET_NOTHING)
			return 0;
		switch (val) {
		case SG_SCSI_RESET_DEVICE:
			val = SCSI_TRY_RESET_DEVICE;
			break;
		case SG_SCSI_RESET_BUS:
			val = SCSI_TRY_RESET_BUS;
			break;
		case SG_SCSI_RESET_HOST:
			val = SCSI_TRY_RESET_HOST;
			break;
		default:
			return -EINVAL;
		}
		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
			return -EACCES;
		return (scsi_reset_provider(sdev, val) ==
			SUCCESS) ? 0 : -EIO;
	}
	return -ENODEV;
}
EXPORT_SYMBOL(scsi_nonblockable_ioctl);