1/*
2 * Changes:
3 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 08/23/2000
4 * - get rid of some verify_areas and use __copy*user and __get/put_user
5 *   for the ones that remain
6 */
7#include <linux/module.h>
8#include <linux/blkdev.h>
9#include <linux/interrupt.h>
10#include <linux/errno.h>
11#include <linux/kernel.h>
12#include <linux/sched.h>
13#include <linux/mm.h>
14#include <linux/string.h>
15#include <asm/uaccess.h>
16
17#include <scsi/scsi.h>
18#include <scsi/scsi_cmnd.h>
19#include <scsi/scsi_device.h>
20#include <scsi/scsi_eh.h>
21#include <scsi/scsi_host.h>
22#include <scsi/scsi_ioctl.h>
23#include <scsi/sg.h>
24#include <scsi/scsi_dbg.h>
25
26#include "scsi_logging.h"
27
28#define NORMAL_RETRIES			5
29#define IOCTL_NORMAL_TIMEOUT			(10 * HZ)
30
31#define MAX_BUF PAGE_SIZE
32
33/**
34 * ioctl_probe  --  return host identification
35 * @host:	host to identify
36 * @buffer:	userspace buffer for identification
37 *
38 * Return an identifying string at @buffer, if @buffer is non-NULL, filling
39 * to the length stored at * (int *) @buffer.
40 */
41static int ioctl_probe(struct Scsi_Host *host, void __user *buffer)
42{
43	unsigned int len, slen;
44	const char *string;
45
46	if (buffer) {
47		if (get_user(len, (unsigned int __user *) buffer))
48			return -EFAULT;
49
50		if (host->hostt->info)
51			string = host->hostt->info(host);
52		else
53			string = host->hostt->name;
54		if (string) {
55			slen = strlen(string);
56			if (len > slen)
57				len = slen + 1;
58			if (copy_to_user(buffer, string, len))
59				return -EFAULT;
60		}
61	}
62	return 1;
63}
64
65/*
66
67 * The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host.
68 * The IOCTL_NORMAL_TIMEOUT and NORMAL_RETRIES  variables are used.
69 *
70 * dev is the SCSI device struct ptr, *(int *) arg is the length of the
71 * input data, if any, not including the command string & counts,
72 * *((int *)arg + 1) is the output buffer size in bytes.
73 *
74 * *(char *) ((int *) arg)[2] the actual command byte.
75 *
76 * Note that if more than MAX_BUF bytes are requested to be transferred,
77 * the ioctl will fail with error EINVAL.
78 *
79 * This size *does not* include the initial lengths that were passed.
80 *
81 * The SCSI command is read from the memory location immediately after the
82 * length words, and the input data is right after the command.  The SCSI
83 * routines know the command size based on the opcode decode.
84 *
85 * The output area is then filled in starting from the command byte.
86 */
87
88static int ioctl_internal_command(struct scsi_device *sdev, char *cmd,
89				  int timeout, int retries)
90{
91	int result;
92	struct scsi_sense_hdr sshdr;
93
94	SCSI_LOG_IOCTL(1, sdev_printk(KERN_INFO, sdev,
95				      "Trying ioctl with scsi command %d\n", *cmd));
96
97	result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0,
98				  &sshdr, timeout, retries, NULL);
99
100	SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
101				      "Ioctl returned  0x%x\n", result));
102
103	if ((driver_byte(result) & DRIVER_SENSE) &&
104	    (scsi_sense_valid(&sshdr))) {
105		switch (sshdr.sense_key) {
106		case ILLEGAL_REQUEST:
107			if (cmd[0] == ALLOW_MEDIUM_REMOVAL)
108				sdev->lockable = 0;
109			else
110				sdev_printk(KERN_INFO, sdev,
111					    "ioctl_internal_command: "
112					    "ILLEGAL REQUEST "
113					    "asc=0x%x ascq=0x%x\n",
114					    sshdr.asc, sshdr.ascq);
115			break;
116		case NOT_READY:	/* This happens if there is no disc in drive */
117			if (sdev->removable)
118				break;
119		case UNIT_ATTENTION:
120			if (sdev->removable) {
121				sdev->changed = 1;
122				result = 0;	/* This is no longer considered an error */
123				break;
124			}
125		default:	/* Fall through for non-removable media */
126			sdev_printk(KERN_INFO, sdev,
127				    "ioctl_internal_command return code = %x\n",
128				    result);
129			scsi_print_sense_hdr(sdev, NULL, &sshdr);
130			break;
131		}
132	}
133
134	SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
135				      "IOCTL Releasing command\n"));
136	return result;
137}
138
139int scsi_set_medium_removal(struct scsi_device *sdev, char state)
140{
141	char scsi_cmd[MAX_COMMAND_SIZE];
142	int ret;
143
144	if (!sdev->removable || !sdev->lockable)
145	       return 0;
146
147	scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
148	scsi_cmd[1] = 0;
149	scsi_cmd[2] = 0;
150	scsi_cmd[3] = 0;
151	scsi_cmd[4] = state;
152	scsi_cmd[5] = 0;
153
154	ret = ioctl_internal_command(sdev, scsi_cmd,
155			IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
156	if (ret == 0)
157		sdev->locked = (state == SCSI_REMOVAL_PREVENT);
158	return ret;
159}
160EXPORT_SYMBOL(scsi_set_medium_removal);
161
162/*
163 * The scsi_ioctl_get_pci() function places into arg the value
164 * pci_dev::slot_name (8 characters) for the PCI device (if any).
165 * Returns: 0 on success
166 *          -ENXIO if there isn't a PCI device pointer
167 *                 (could be because the SCSI driver hasn't been
168 *                  updated yet, or because it isn't a SCSI
169 *                  device)
170 *          any copy_to_user() error on failure there
171 */
172static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
173{
174	struct device *dev = scsi_get_device(sdev->host);
175	const char *name;
176
177        if (!dev)
178		return -ENXIO;
179
180	name = dev_name(dev);
181
182	/* compatibility with old ioctl which only returned
183	 * 20 characters */
184        return copy_to_user(arg, name, min(strlen(name), (size_t)20))
185		? -EFAULT: 0;
186}
187
188
189/**
190 * scsi_ioctl - Dispatch ioctl to scsi device
191 * @sdev: scsi device receiving ioctl
192 * @cmd: which ioctl is it
193 * @arg: data associated with ioctl
194 *
195 * Description: The scsi_ioctl() function differs from most ioctls in that it
196 * does not take a major/minor number as the dev field.  Rather, it takes
197 * a pointer to a &struct scsi_device.
198 */
199int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
200{
201	char scsi_cmd[MAX_COMMAND_SIZE];
202
203	/* Check for deprecated ioctls ... all the ioctls which don't
204	 * follow the new unique numbering scheme are deprecated */
205	switch (cmd) {
206	case SCSI_IOCTL_SEND_COMMAND:
207	case SCSI_IOCTL_TEST_UNIT_READY:
208	case SCSI_IOCTL_BENCHMARK_COMMAND:
209	case SCSI_IOCTL_SYNC:
210	case SCSI_IOCTL_START_UNIT:
211	case SCSI_IOCTL_STOP_UNIT:
212		printk(KERN_WARNING "program %s is using a deprecated SCSI "
213		       "ioctl, please convert it to SG_IO\n", current->comm);
214		break;
215	default:
216		break;
217	}
218
219	switch (cmd) {
220	case SCSI_IOCTL_GET_IDLUN:
221		if (!access_ok(VERIFY_WRITE, arg, sizeof(struct scsi_idlun)))
222			return -EFAULT;
223
224		__put_user((sdev->id & 0xff)
225			 + ((sdev->lun & 0xff) << 8)
226			 + ((sdev->channel & 0xff) << 16)
227			 + ((sdev->host->host_no & 0xff) << 24),
228			 &((struct scsi_idlun __user *)arg)->dev_id);
229		__put_user(sdev->host->unique_id,
230			 &((struct scsi_idlun __user *)arg)->host_unique_id);
231		return 0;
232	case SCSI_IOCTL_GET_BUS_NUMBER:
233		return put_user(sdev->host->host_no, (int __user *)arg);
234	case SCSI_IOCTL_PROBE_HOST:
235		return ioctl_probe(sdev->host, arg);
236	case SCSI_IOCTL_SEND_COMMAND:
237		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
238			return -EACCES;
239		return sg_scsi_ioctl(sdev->request_queue, NULL, 0, arg);
240	case SCSI_IOCTL_DOORLOCK:
241		return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
242	case SCSI_IOCTL_DOORUNLOCK:
243		return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
244	case SCSI_IOCTL_TEST_UNIT_READY:
245		return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
246					    NORMAL_RETRIES, NULL);
247	case SCSI_IOCTL_START_UNIT:
248		scsi_cmd[0] = START_STOP;
249		scsi_cmd[1] = 0;
250		scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
251		scsi_cmd[4] = 1;
252		return ioctl_internal_command(sdev, scsi_cmd,
253				     START_STOP_TIMEOUT, NORMAL_RETRIES);
254	case SCSI_IOCTL_STOP_UNIT:
255		scsi_cmd[0] = START_STOP;
256		scsi_cmd[1] = 0;
257		scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
258		scsi_cmd[4] = 0;
259		return ioctl_internal_command(sdev, scsi_cmd,
260				     START_STOP_TIMEOUT, NORMAL_RETRIES);
261        case SCSI_IOCTL_GET_PCI:
262                return scsi_ioctl_get_pci(sdev, arg);
263	case SG_SCSI_RESET:
264		return scsi_ioctl_reset(sdev, arg);
265	default:
266		if (sdev->host->hostt->ioctl)
267			return sdev->host->hostt->ioctl(sdev, cmd, arg);
268	}
269	return -EINVAL;
270}
271EXPORT_SYMBOL(scsi_ioctl);
272
273/*
274 * We can process a reset even when a device isn't fully operable.
275 */
276int scsi_ioctl_block_when_processing_errors(struct scsi_device *sdev, int cmd,
277		bool ndelay)
278{
279	if (cmd == SG_SCSI_RESET && ndelay) {
280		if (scsi_host_in_recovery(sdev->host))
281			return -EAGAIN;
282	} else {
283		if (!scsi_block_when_processing_errors(sdev))
284			return -ENODEV;
285	}
286
287	return 0;
288}
289EXPORT_SYMBOL_GPL(scsi_ioctl_block_when_processing_errors);
290