1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Changes:
4 * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 08/23/2000
5 * - get rid of some verify_areas and use __copy*user and __get/put_user
6 * for the ones that remain
7 */
8 #include <linux/module.h>
9 #include <linux/blkdev.h>
10 #include <linux/interrupt.h>
11 #include <linux/errno.h>
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <linux/mm.h>
15 #include <linux/string.h>
16 #include <linux/uaccess.h>
17
18 #include <scsi/scsi.h>
19 #include <scsi/scsi_cmnd.h>
20 #include <scsi/scsi_device.h>
21 #include <scsi/scsi_eh.h>
22 #include <scsi/scsi_host.h>
23 #include <scsi/scsi_ioctl.h>
24 #include <scsi/sg.h>
25 #include <scsi/scsi_dbg.h>
26
27 #include "scsi_logging.h"
28
29 #define NORMAL_RETRIES 5
30 #define IOCTL_NORMAL_TIMEOUT (10 * HZ)
31
32 #define MAX_BUF PAGE_SIZE
33
34 /**
35 * ioctl_probe -- return host identification
36 * @host: host to identify
37 * @buffer: userspace buffer for identification
38 *
39 * Return an identifying string at @buffer, if @buffer is non-NULL, filling
40 * to the length stored at * (int *) @buffer.
41 */
ioctl_probe(struct Scsi_Host * host,void __user * buffer)42 static int ioctl_probe(struct Scsi_Host *host, void __user *buffer)
43 {
44 unsigned int len, slen;
45 const char *string;
46
47 if (buffer) {
48 if (get_user(len, (unsigned int __user *) buffer))
49 return -EFAULT;
50
51 if (host->hostt->info)
52 string = host->hostt->info(host);
53 else
54 string = host->hostt->name;
55 if (string) {
56 slen = strlen(string);
57 if (len > slen)
58 len = slen + 1;
59 if (copy_to_user(buffer, string, len))
60 return -EFAULT;
61 }
62 }
63 return 1;
64 }
65
66 /*
67
68 * The SCSI_IOCTL_SEND_COMMAND ioctl sends a command out to the SCSI host.
69 * The IOCTL_NORMAL_TIMEOUT and NORMAL_RETRIES variables are used.
70 *
71 * dev is the SCSI device struct ptr, *(int *) arg is the length of the
72 * input data, if any, not including the command string & counts,
73 * *((int *)arg + 1) is the output buffer size in bytes.
74 *
75 * *(char *) ((int *) arg)[2] the actual command byte.
76 *
77 * Note that if more than MAX_BUF bytes are requested to be transferred,
78 * the ioctl will fail with error EINVAL.
79 *
80 * This size *does not* include the initial lengths that were passed.
81 *
82 * The SCSI command is read from the memory location immediately after the
83 * length words, and the input data is right after the command. The SCSI
84 * routines know the command size based on the opcode decode.
85 *
86 * The output area is then filled in starting from the command byte.
87 */
88
ioctl_internal_command(struct scsi_device * sdev,char * cmd,int timeout,int retries)89 static int ioctl_internal_command(struct scsi_device *sdev, char *cmd,
90 int timeout, int retries)
91 {
92 int result;
93 struct scsi_sense_hdr sshdr;
94
95 SCSI_LOG_IOCTL(1, sdev_printk(KERN_INFO, sdev,
96 "Trying ioctl with scsi command %d\n", *cmd));
97
98 result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0,
99 &sshdr, timeout, retries, NULL);
100
101 SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
102 "Ioctl returned 0x%x\n", result));
103
104 if (driver_byte(result) == DRIVER_SENSE &&
105 scsi_sense_valid(&sshdr)) {
106 switch (sshdr.sense_key) {
107 case ILLEGAL_REQUEST:
108 if (cmd[0] == ALLOW_MEDIUM_REMOVAL)
109 sdev->lockable = 0;
110 else
111 sdev_printk(KERN_INFO, sdev,
112 "ioctl_internal_command: "
113 "ILLEGAL REQUEST "
114 "asc=0x%x ascq=0x%x\n",
115 sshdr.asc, sshdr.ascq);
116 break;
117 case NOT_READY: /* This happens if there is no disc in drive */
118 if (sdev->removable)
119 break;
120 fallthrough;
121 case UNIT_ATTENTION:
122 if (sdev->removable) {
123 sdev->changed = 1;
124 result = 0; /* This is no longer considered an error */
125 break;
126 }
127 fallthrough; /* for non-removable media */
128 default:
129 sdev_printk(KERN_INFO, sdev,
130 "ioctl_internal_command return code = %x\n",
131 result);
132 scsi_print_sense_hdr(sdev, NULL, &sshdr);
133 break;
134 }
135 }
136
137 SCSI_LOG_IOCTL(2, sdev_printk(KERN_INFO, sdev,
138 "IOCTL Releasing command\n"));
139 return result;
140 }
141
scsi_set_medium_removal(struct scsi_device * sdev,char state)142 int scsi_set_medium_removal(struct scsi_device *sdev, char state)
143 {
144 char scsi_cmd[MAX_COMMAND_SIZE];
145 int ret;
146
147 if (!sdev->removable || !sdev->lockable)
148 return 0;
149
150 scsi_cmd[0] = ALLOW_MEDIUM_REMOVAL;
151 scsi_cmd[1] = 0;
152 scsi_cmd[2] = 0;
153 scsi_cmd[3] = 0;
154 scsi_cmd[4] = state;
155 scsi_cmd[5] = 0;
156
157 ret = ioctl_internal_command(sdev, scsi_cmd,
158 IOCTL_NORMAL_TIMEOUT, NORMAL_RETRIES);
159 if (ret == 0)
160 sdev->locked = (state == SCSI_REMOVAL_PREVENT);
161 return ret;
162 }
163 EXPORT_SYMBOL(scsi_set_medium_removal);
164
165 /*
166 * The scsi_ioctl_get_pci() function places into arg the value
167 * pci_dev::slot_name (8 characters) for the PCI device (if any).
168 * Returns: 0 on success
169 * -ENXIO if there isn't a PCI device pointer
170 * (could be because the SCSI driver hasn't been
171 * updated yet, or because it isn't a SCSI
172 * device)
173 * any copy_to_user() error on failure there
174 */
scsi_ioctl_get_pci(struct scsi_device * sdev,void __user * arg)175 static int scsi_ioctl_get_pci(struct scsi_device *sdev, void __user *arg)
176 {
177 struct device *dev = scsi_get_device(sdev->host);
178 const char *name;
179
180 if (!dev)
181 return -ENXIO;
182
183 name = dev_name(dev);
184
185 /* compatibility with old ioctl which only returned
186 * 20 characters */
187 return copy_to_user(arg, name, min(strlen(name), (size_t)20))
188 ? -EFAULT: 0;
189 }
190
191
scsi_ioctl_common(struct scsi_device * sdev,int cmd,void __user * arg)192 static int scsi_ioctl_common(struct scsi_device *sdev, int cmd, void __user *arg)
193 {
194 char scsi_cmd[MAX_COMMAND_SIZE];
195 struct scsi_sense_hdr sense_hdr;
196
197 /* Check for deprecated ioctls ... all the ioctls which don't
198 * follow the new unique numbering scheme are deprecated */
199 switch (cmd) {
200 case SCSI_IOCTL_SEND_COMMAND:
201 case SCSI_IOCTL_TEST_UNIT_READY:
202 case SCSI_IOCTL_BENCHMARK_COMMAND:
203 case SCSI_IOCTL_SYNC:
204 case SCSI_IOCTL_START_UNIT:
205 case SCSI_IOCTL_STOP_UNIT:
206 printk(KERN_WARNING "program %s is using a deprecated SCSI "
207 "ioctl, please convert it to SG_IO\n", current->comm);
208 break;
209 default:
210 break;
211 }
212
213 switch (cmd) {
214 case SCSI_IOCTL_GET_IDLUN: {
215 struct scsi_idlun v = {
216 .dev_id = (sdev->id & 0xff)
217 + ((sdev->lun & 0xff) << 8)
218 + ((sdev->channel & 0xff) << 16)
219 + ((sdev->host->host_no & 0xff) << 24),
220 .host_unique_id = sdev->host->unique_id
221 };
222 if (copy_to_user(arg, &v, sizeof(struct scsi_idlun)))
223 return -EFAULT;
224 return 0;
225 }
226 case SCSI_IOCTL_GET_BUS_NUMBER:
227 return put_user(sdev->host->host_no, (int __user *)arg);
228 case SCSI_IOCTL_PROBE_HOST:
229 return ioctl_probe(sdev->host, arg);
230 case SCSI_IOCTL_SEND_COMMAND:
231 if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
232 return -EACCES;
233 return sg_scsi_ioctl(sdev->request_queue, NULL, 0, arg);
234 case SCSI_IOCTL_DOORLOCK:
235 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_PREVENT);
236 case SCSI_IOCTL_DOORUNLOCK:
237 return scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
238 case SCSI_IOCTL_TEST_UNIT_READY:
239 return scsi_test_unit_ready(sdev, IOCTL_NORMAL_TIMEOUT,
240 NORMAL_RETRIES, &sense_hdr);
241 case SCSI_IOCTL_START_UNIT:
242 scsi_cmd[0] = START_STOP;
243 scsi_cmd[1] = 0;
244 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
245 scsi_cmd[4] = 1;
246 return ioctl_internal_command(sdev, scsi_cmd,
247 START_STOP_TIMEOUT, NORMAL_RETRIES);
248 case SCSI_IOCTL_STOP_UNIT:
249 scsi_cmd[0] = START_STOP;
250 scsi_cmd[1] = 0;
251 scsi_cmd[2] = scsi_cmd[3] = scsi_cmd[5] = 0;
252 scsi_cmd[4] = 0;
253 return ioctl_internal_command(sdev, scsi_cmd,
254 START_STOP_TIMEOUT, NORMAL_RETRIES);
255 case SCSI_IOCTL_GET_PCI:
256 return scsi_ioctl_get_pci(sdev, arg);
257 case SG_SCSI_RESET:
258 return scsi_ioctl_reset(sdev, arg);
259 }
260 return -ENOIOCTLCMD;
261 }
262
263 /**
264 * scsi_ioctl - Dispatch ioctl to scsi device
265 * @sdev: scsi device receiving ioctl
266 * @cmd: which ioctl is it
267 * @arg: data associated with ioctl
268 *
269 * Description: The scsi_ioctl() function differs from most ioctls in that it
270 * does not take a major/minor number as the dev field. Rather, it takes
271 * a pointer to a &struct scsi_device.
272 */
scsi_ioctl(struct scsi_device * sdev,int cmd,void __user * arg)273 int scsi_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
274 {
275 int ret = scsi_ioctl_common(sdev, cmd, arg);
276
277 if (ret != -ENOIOCTLCMD)
278 return ret;
279
280 if (sdev->host->hostt->ioctl)
281 return sdev->host->hostt->ioctl(sdev, cmd, arg);
282
283 return -EINVAL;
284 }
285 EXPORT_SYMBOL(scsi_ioctl);
286
287 #ifdef CONFIG_COMPAT
scsi_compat_ioctl(struct scsi_device * sdev,int cmd,void __user * arg)288 int scsi_compat_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
289 {
290 int ret = scsi_ioctl_common(sdev, cmd, arg);
291
292 if (ret != -ENOIOCTLCMD)
293 return ret;
294
295 if (sdev->host->hostt->compat_ioctl)
296 return sdev->host->hostt->compat_ioctl(sdev, cmd, arg);
297
298 return ret;
299 }
300 EXPORT_SYMBOL(scsi_compat_ioctl);
301 #endif
302
303 /*
304 * We can process a reset even when a device isn't fully operable.
305 */
scsi_ioctl_block_when_processing_errors(struct scsi_device * sdev,int cmd,bool ndelay)306 int scsi_ioctl_block_when_processing_errors(struct scsi_device *sdev, int cmd,
307 bool ndelay)
308 {
309 if (cmd == SG_SCSI_RESET && ndelay) {
310 if (scsi_host_in_recovery(sdev->host))
311 return -EAGAIN;
312 } else {
313 if (!scsi_block_when_processing_errors(sdev))
314 return -ENODEV;
315 }
316
317 return 0;
318 }
319 EXPORT_SYMBOL_GPL(scsi_ioctl_block_when_processing_errors);
320