summaryrefslogtreecommitdiffstats
path: root/drivers/scsi/scsi_ioctl.c
blob: 45d04b7b26439896b3caa4654222d77255994750 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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 <linux/uaccess.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_ioctl.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, sdev_printk(KERN_INFO, sdev,
				      "Trying ioctl with scsi command %d\n", *cmd));

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

	SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
				      "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
				sdev_printk(KERN_INFO, sdev,
					    "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)
				break;
			/* FALLTHROUGH */
		case UNIT_ATTENTION:
			if (sdev->removable) {
				sdev->changed = 1;
				result = 0;	/* This is no longer considered an error */
				break;
			}
			/* FALLTHROUGH -- for non-removable media */
		default:
			sdev_printk(KERN_INFO, sdev,
				    "ioctl_internal_command return code = %x\n",
				    result);
			scsi_print_sense_hdr(sdev, NULL, &sshdr);
			break;
		}
	}

	SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
				      "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);

/*
 * 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);
	const char *name;

        if (!dev)
		return -ENXIO;

	name = dev_name(dev);

	/* compatibility with old ioctl which only returned
	 * 20 characters */
        return copy_to_user(arg, name, min(strlen(name), (size_t)20))
		? -EFAULT: 0;
}


static int scsi_ioctl_common(struct scsi_device *sdev, int cmd, void __user *arg)
{
	char scsi_cmd[MAX_COMMAND_SIZE];
	struct scsi_sense_hdr sense_hdr;

	/* 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: {
		struct scsi_idlun v = {
			.dev_id = (sdev->id & 0xff)
				 + ((sdev->lun & 0xff) << 8)
				 + ((sdev->channel & 0xff) << 16)
				 + ((sdev->host->host_no & 0xff) << 24),
			.host_unique_id = sdev->host->unique_id
		};
		if (copy_to_user(arg, &v, sizeof(struct scsi_idlun)))
			return -EFAULT;
		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 sg_scsi_ioctl(sdev->request_queue, NULL, 0, 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, &sense_hdr);
	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);
	case SG_SCSI_RESET:
		return scsi_ioctl_reset(sdev, arg);
	}
	return -ENOIOCTLCMD;
}

/**
 * scsi_ioctl - Dispatch ioctl to scsi device
 * @sdev: scsi device receiving ioctl
 * @cmd: which ioctl is it
 * @arg: data associated with ioctl
 *
 * Description: 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 &struct scsi_device.
 */
int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
{
	int ret = scsi_ioctl_common(sdev, cmd, arg);

	if (ret != -ENOIOCTLCMD)
		return ret;

	if (sdev->host->hostt->ioctl)
		return sdev->host->hostt->ioctl(sdev, cmd, arg);

	return -EINVAL;
}
EXPORT_SYMBOL(scsi_ioctl);

#ifdef CONFIG_COMPAT
int scsi_compat_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
{
	int ret = scsi_ioctl_common(sdev, cmd, arg);

	if (ret != -ENOIOCTLCMD)
		return ret;

	if (sdev->host->hostt->compat_ioctl)
		return sdev->host->hostt->compat_ioctl(sdev, cmd, arg);

	return ret;
}
EXPORT_SYMBOL(scsi_compat_ioctl);
#endif

/*
 * We can process a reset even when a device isn't fully operable.
 */
int scsi_ioctl_block_when_processing_errors(struct scsi_device *sdev, int cmd,
		bool ndelay)
{
	if (cmd == SG_SCSI_RESET && ndelay) {
		if (scsi_host_in_recovery(sdev->host))
			return -EAGAIN;
	} else {
		if (!scsi_block_when_processing_errors(sdev))
			return -ENODEV;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(scsi_ioctl_block_when_processing_errors);