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 <linux/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 /* FALLTHROUGH */
120 case UNIT_ATTENTION:
121 if (sdev->removable) {
122 sdev->changed = 1;
123 result = 0; /* This is no longer considered an error */
124 break;
125 }
126 /* FALLTHROUGH -- for non-removable media */
127 default:
128 sdev_printk(KERN_INFO, sdev,
129 "ioctl_internal_command return code = %x\n",
130 result);
131 scsi_print_sense_hdr(sdev, NULL, &sshdr);
132 break;
133 }
134 }
135
136 SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
137 "IOCTL Releasing command\n"));
138 return result;
139}
140
141int scsi_set_medium_removal(struct scsi_device *sdev, char state)
142{
143 char scsi_cmd[MAX_COMMAND_SIZE];
144 int ret;
145
146 if (!sdev->removable || !sdev->lockable)
147 return 0;
148
149 scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
150 scsi_cmd[1] = 0;
151 scsi_cmd[2] = 0;
152 scsi_cmd[3] = 0;
153 scsi_cmd[4] = state;
154 scsi_cmd[5] = 0;
155
156 ret = ioctl_internal_command(sdev, scsi_cmd,
157 IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
158 if (ret == 0)
159 sdev->locked = (state == SCSI_REMOVAL_PREVENT);
160 return ret;
161}
162EXPORT_SYMBOL(scsi_set_medium_removal);
163
164/*
165 * The scsi_ioctl_get_pci() function places into arg the value
166 * pci_dev::slot_name (8 characters) for the PCI device (if any).
167 * Returns: 0 on success
168 * -ENXIO if there isn't a PCI device pointer
169 * (could be because the SCSI driver hasn't been
170 * updated yet, or because it isn't a SCSI
171 * device)
172 * any copy_to_user() error on failure there
173 */
174static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
175{
176 struct device *dev = scsi_get_device(sdev->host);
177 const char *name;
178
179 if (!dev)
180 return -ENXIO;
181
182 name = dev_name(dev);
183
184 /* compatibility with old ioctl which only returned
185 * 20 characters */
186 return copy_to_user(arg, name, min(strlen(name), (size_t)20))
187 ? -EFAULT: 0;
188}
189
190
191/**
192 * scsi_ioctl - Dispatch ioctl to scsi device
193 * @sdev: scsi device receiving ioctl
194 * @cmd: which ioctl is it
195 * @arg: data associated with ioctl
196 *
197 * Description: The scsi_ioctl() function differs from most ioctls in that it
198 * does not take a major/minor number as the dev field. Rather, it takes
199 * a pointer to a &struct scsi_device.
200 */
201int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
202{
203 char scsi_cmd[MAX_COMMAND_SIZE];
204 struct scsi_sense_hdr sense_hdr;
205
206 /* Check for deprecated ioctls ... all the ioctls which don't
207 * follow the new unique numbering scheme are deprecated */
208 switch (cmd) {
209 case SCSI_IOCTL_SEND_COMMAND:
210 case SCSI_IOCTL_TEST_UNIT_READY:
211 case SCSI_IOCTL_BENCHMARK_COMMAND:
212 case SCSI_IOCTL_SYNC:
213 case SCSI_IOCTL_START_UNIT:
214 case SCSI_IOCTL_STOP_UNIT:
215 printk(KERN_WARNING "program %s is using a deprecated SCSI "
216 "ioctl, please convert it to SG_IO\n", current->comm);
217 break;
218 default:
219 break;
220 }
221
222 switch (cmd) {
223 case SCSI_IOCTL_GET_IDLUN:
224 if (!access_ok(arg, sizeof(struct scsi_idlun)))
225 return -EFAULT;
226
227 __put_user((sdev->id & 0xff)
228 + ((sdev->lun & 0xff) << 8)
229 + ((sdev->channel & 0xff) << 16)
230 + ((sdev->host->host_no & 0xff) << 24),
231 &((struct scsi_idlun __user *)arg)->dev_id);
232 __put_user(sdev->host->unique_id,
233 &((struct scsi_idlun __user *)arg)->host_unique_id);
234 return 0;
235 case SCSI_IOCTL_GET_BUS_NUMBER:
236 return put_user(sdev->host->host_no, (int __user *)arg);
237 case SCSI_IOCTL_PROBE_HOST:
238 return ioctl_probe(sdev->host, arg);
239 case SCSI_IOCTL_SEND_COMMAND:
240 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
241 return -EACCES;
242 return sg_scsi_ioctl(sdev->request_queue, NULL, 0, arg);
243 case SCSI_IOCTL_DOORLOCK:
244 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
245 case SCSI_IOCTL_DOORUNLOCK:
246 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
247 case SCSI_IOCTL_TEST_UNIT_READY:
248 return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
249 NORMAL_RETRIES, &sense_hdr);
250 case SCSI_IOCTL_START_UNIT:
251 scsi_cmd[0] = START_STOP;
252 scsi_cmd[1] = 0;
253 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
254 scsi_cmd[4] = 1;
255 return ioctl_internal_command(sdev, scsi_cmd,
256 START_STOP_TIMEOUT, NORMAL_RETRIES);
257 case SCSI_IOCTL_STOP_UNIT:
258 scsi_cmd[0] = START_STOP;
259 scsi_cmd[1] = 0;
260 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
261 scsi_cmd[4] = 0;
262 return ioctl_internal_command(sdev, scsi_cmd,
263 START_STOP_TIMEOUT, NORMAL_RETRIES);
264 case SCSI_IOCTL_GET_PCI:
265 return scsi_ioctl_get_pci(sdev, arg);
266 case SG_SCSI_RESET:
267 return scsi_ioctl_reset(sdev, arg);
268 default:
269 if (sdev->host->hostt->ioctl)
270 return sdev->host->hostt->ioctl(sdev, cmd, arg);
271 }
272 return -EINVAL;
273}
274EXPORT_SYMBOL(scsi_ioctl);
275
276/*
277 * We can process a reset even when a device isn't fully operable.
278 */
279int scsi_ioctl_block_when_processing_errors(struct scsi_device *sdev, int cmd,
280 bool ndelay)
281{
282 if (cmd == SG_SCSI_RESET && ndelay) {
283 if (scsi_host_in_recovery(sdev->host))
284 return -EAGAIN;
285 } else {
286 if (!scsi_block_when_processing_errors(sdev))
287 return -ENODEV;
288 }
289
290 return 0;
291}
292EXPORT_SYMBOL_GPL(scsi_ioctl_block_when_processing_errors);
293