1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/drivers/scsi/scsi_proc.c
4 *
5 * The functions in this file provide an interface between
6 * the PROC file system and the SCSI device drivers
7 * It is mainly used for debugging, statistics and to pass
8 * information directly to the lowlevel driver.
9 *
10 * (c) 1995 Michael Neuffer neuffer@goofy.zdv.uni-mainz.de
11 * Version: 0.99.8 last change: 95/09/13
12 *
13 * generic command parser provided by:
14 * Andreas Heilwagen <crashcar@informatik.uni-koblenz.de>
15 *
16 * generic_proc_info() support of xxxx_info() by:
17 * Michael A. Griffith <grif@acm.org>
18 */
19
20#include <linux/module.h>
21#include <linux/init.h>
22#include <linux/string.h>
23#include <linux/mm.h>
24#include <linux/proc_fs.h>
25#include <linux/errno.h>
26#include <linux/blkdev.h>
27#include <linux/seq_file.h>
28#include <linux/mutex.h>
29#include <linux/gfp.h>
30#include <linux/uaccess.h>
31
32#include <scsi/scsi.h>
33#include <scsi/scsi_device.h>
34#include <scsi/scsi_host.h>
35#include <scsi/scsi_transport.h>
36
37#include "scsi_priv.h"
38#include "scsi_logging.h"
39
40
41/* 4K page size, but our output routines, use some slack for overruns */
42#define PROC_BLOCK_SIZE (3*1024)
43
44static struct proc_dir_entry *proc_scsi;
45
46/* Protects scsi_proc_list */
47static DEFINE_MUTEX(global_host_template_mutex);
48static LIST_HEAD(scsi_proc_list);
49
50/**
51 * struct scsi_proc_entry - (host template, SCSI proc dir) association
52 * @entry: entry in scsi_proc_list.
53 * @sht: SCSI host template associated with the procfs directory.
54 * @proc_dir: procfs directory associated with the SCSI host template.
55 * @present: Number of SCSI hosts instantiated for @sht.
56 */
57struct scsi_proc_entry {
58 struct list_head entry;
59 const struct scsi_host_template *sht;
60 struct proc_dir_entry *proc_dir;
61 unsigned int present;
62};
63
64static ssize_t proc_scsi_host_write(struct file *file, const char __user *buf,
65 size_t count, loff_t *ppos)
66{
67 struct Scsi_Host *shost = pde_data(inode: file_inode(f: file));
68 ssize_t ret = -ENOMEM;
69 char *page;
70
71 if (count > PROC_BLOCK_SIZE)
72 return -EOVERFLOW;
73
74 if (!shost->hostt->write_info)
75 return -EINVAL;
76
77 page = (char *)__get_free_page(GFP_KERNEL);
78 if (page) {
79 ret = -EFAULT;
80 if (copy_from_user(to: page, from: buf, n: count))
81 goto out;
82 ret = shost->hostt->write_info(shost, page, count);
83 }
84out:
85 free_page((unsigned long)page);
86 return ret;
87}
88
89static int proc_scsi_show(struct seq_file *m, void *v)
90{
91 struct Scsi_Host *shost = m->private;
92 return shost->hostt->show_info(m, shost);
93}
94
95static int proc_scsi_host_open(struct inode *inode, struct file *file)
96{
97 return single_open_size(file, proc_scsi_show, pde_data(inode),
98 4 * PAGE_SIZE);
99}
100
101static struct scsi_proc_entry *
102__scsi_lookup_proc_entry(const struct scsi_host_template *sht)
103{
104 struct scsi_proc_entry *e;
105
106 lockdep_assert_held(&global_host_template_mutex);
107
108 list_for_each_entry(e, &scsi_proc_list, entry)
109 if (e->sht == sht)
110 return e;
111
112 return NULL;
113}
114
115static struct scsi_proc_entry *
116scsi_lookup_proc_entry(const struct scsi_host_template *sht)
117{
118 struct scsi_proc_entry *e;
119
120 mutex_lock(lock: &global_host_template_mutex);
121 e = __scsi_lookup_proc_entry(sht);
122 mutex_unlock(lock: &global_host_template_mutex);
123
124 return e;
125}
126
127/**
128 * scsi_template_proc_dir() - returns the procfs dir for a SCSI host template
129 * @sht: SCSI host template pointer.
130 */
131struct proc_dir_entry *
132scsi_template_proc_dir(const struct scsi_host_template *sht)
133{
134 struct scsi_proc_entry *e = scsi_lookup_proc_entry(sht);
135
136 return e ? e->proc_dir : NULL;
137}
138EXPORT_SYMBOL_GPL(scsi_template_proc_dir);
139
140static const struct proc_ops proc_scsi_ops = {
141 .proc_open = proc_scsi_host_open,
142 .proc_release = single_release,
143 .proc_read = seq_read,
144 .proc_lseek = seq_lseek,
145 .proc_write = proc_scsi_host_write
146};
147
148/**
149 * scsi_proc_hostdir_add - Create directory in /proc for a scsi host
150 * @sht: owner of this directory
151 *
152 * Sets sht->proc_dir to the new directory.
153 */
154int scsi_proc_hostdir_add(const struct scsi_host_template *sht)
155{
156 struct scsi_proc_entry *e;
157 int ret;
158
159 if (!sht->show_info)
160 return 0;
161
162 mutex_lock(lock: &global_host_template_mutex);
163 e = __scsi_lookup_proc_entry(sht);
164 if (!e) {
165 e = kzalloc(sizeof(*e), GFP_KERNEL);
166 if (!e) {
167 ret = -ENOMEM;
168 goto unlock;
169 }
170 }
171 if (e->present++)
172 goto success;
173 e->proc_dir = proc_mkdir(sht->proc_name, proc_scsi);
174 if (!e->proc_dir) {
175 printk(KERN_ERR "%s: proc_mkdir failed for %s\n", __func__,
176 sht->proc_name);
177 ret = -ENOMEM;
178 goto unlock;
179 }
180 e->sht = sht;
181 list_add_tail(new: &e->entry, head: &scsi_proc_list);
182success:
183 e = NULL;
184 ret = 0;
185unlock:
186 mutex_unlock(lock: &global_host_template_mutex);
187
188 kfree(objp: e);
189 return ret;
190}
191
192/**
193 * scsi_proc_hostdir_rm - remove directory in /proc for a scsi host
194 * @sht: owner of directory
195 */
196void scsi_proc_hostdir_rm(const struct scsi_host_template *sht)
197{
198 struct scsi_proc_entry *e;
199
200 if (!sht->show_info)
201 return;
202
203 mutex_lock(lock: &global_host_template_mutex);
204 e = __scsi_lookup_proc_entry(sht);
205 if (e && !--e->present) {
206 remove_proc_entry(sht->proc_name, proc_scsi);
207 list_del(entry: &e->entry);
208 kfree(objp: e);
209 }
210 mutex_unlock(lock: &global_host_template_mutex);
211}
212
213
214/**
215 * scsi_proc_host_add - Add entry for this host to appropriate /proc dir
216 * @shost: host to add
217 */
218void scsi_proc_host_add(struct Scsi_Host *shost)
219{
220 const struct scsi_host_template *sht = shost->hostt;
221 struct scsi_proc_entry *e;
222 struct proc_dir_entry *p;
223 char name[10];
224
225 if (!sht->show_info)
226 return;
227
228 e = scsi_lookup_proc_entry(sht);
229 if (!e)
230 goto err;
231
232 sprintf(buf: name,fmt: "%d", shost->host_no);
233 p = proc_create_data(name, S_IRUGO | S_IWUSR, e->proc_dir,
234 &proc_scsi_ops, shost);
235 if (!p)
236 goto err;
237 return;
238
239err:
240 shost_printk(KERN_ERR, shost,
241 "%s: Failed to register host (%s failed)\n", __func__,
242 e ? "proc_create_data()" : "scsi_proc_hostdir_add()");
243}
244
245/**
246 * scsi_proc_host_rm - remove this host's entry from /proc
247 * @shost: which host
248 */
249void scsi_proc_host_rm(struct Scsi_Host *shost)
250{
251 const struct scsi_host_template *sht = shost->hostt;
252 struct scsi_proc_entry *e;
253 char name[10];
254
255 if (!sht->show_info)
256 return;
257
258 e = scsi_lookup_proc_entry(sht);
259 if (!e)
260 return;
261
262 sprintf(buf: name,fmt: "%d", shost->host_no);
263 remove_proc_entry(name, e->proc_dir);
264}
265/**
266 * proc_print_scsidevice - return data about this host
267 * @dev: A scsi device
268 * @data: &struct seq_file to output to.
269 *
270 * Description: prints Host, Channel, Id, Lun, Vendor, Model, Rev, Type,
271 * and revision.
272 */
273static int proc_print_scsidevice(struct device *dev, void *data)
274{
275 struct scsi_device *sdev;
276 struct seq_file *s = data;
277 int i;
278
279 if (!scsi_is_sdev_device(dev))
280 goto out;
281
282 sdev = to_scsi_device(dev);
283 seq_printf(m: s,
284 fmt: "Host: scsi%d Channel: %02d Id: %02d Lun: %02llu\n Vendor: ",
285 sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
286 for (i = 0; i < 8; i++) {
287 if (sdev->vendor[i] >= 0x20)
288 seq_putc(m: s, c: sdev->vendor[i]);
289 else
290 seq_putc(m: s, c: ' ');
291 }
292
293 seq_puts(m: s, s: " Model: ");
294 for (i = 0; i < 16; i++) {
295 if (sdev->model[i] >= 0x20)
296 seq_putc(m: s, c: sdev->model[i]);
297 else
298 seq_putc(m: s, c: ' ');
299 }
300
301 seq_puts(m: s, s: " Rev: ");
302 for (i = 0; i < 4; i++) {
303 if (sdev->rev[i] >= 0x20)
304 seq_putc(m: s, c: sdev->rev[i]);
305 else
306 seq_putc(m: s, c: ' ');
307 }
308
309 seq_putc(m: s, c: '\n');
310
311 seq_printf(m: s, fmt: " Type: %s ", scsi_device_type(type: sdev->type));
312 seq_printf(m: s, fmt: " ANSI SCSI revision: %02x",
313 sdev->scsi_level - (sdev->scsi_level > 1));
314 if (sdev->scsi_level == 2)
315 seq_puts(m: s, s: " CCS\n");
316 else
317 seq_putc(m: s, c: '\n');
318
319out:
320 return 0;
321}
322
323/**
324 * scsi_add_single_device - Respond to user request to probe for/add device
325 * @host: user-supplied decimal integer
326 * @channel: user-supplied decimal integer
327 * @id: user-supplied decimal integer
328 * @lun: user-supplied decimal integer
329 *
330 * Description: called by writing "scsi add-single-device" to /proc/scsi/scsi.
331 *
332 * does scsi_host_lookup() and either user_scan() if that transport
333 * type supports it, or else scsi_scan_host_selected()
334 *
335 * Note: this seems to be aimed exclusively at SCSI parallel busses.
336 */
337
338static int scsi_add_single_device(uint host, uint channel, uint id, uint lun)
339{
340 struct Scsi_Host *shost;
341 int error = -ENXIO;
342
343 shost = scsi_host_lookup(hostnum: host);
344 if (!shost)
345 return error;
346
347 if (shost->transportt->user_scan)
348 error = shost->transportt->user_scan(shost, channel, id, lun);
349 else
350 error = scsi_scan_host_selected(shost, channel, id, lun,
351 SCSI_SCAN_MANUAL);
352 scsi_host_put(t: shost);
353 return error;
354}
355
356/**
357 * scsi_remove_single_device - Respond to user request to remove a device
358 * @host: user-supplied decimal integer
359 * @channel: user-supplied decimal integer
360 * @id: user-supplied decimal integer
361 * @lun: user-supplied decimal integer
362 *
363 * Description: called by writing "scsi remove-single-device" to
364 * /proc/scsi/scsi. Does a scsi_device_lookup() and scsi_remove_device()
365 */
366static int scsi_remove_single_device(uint host, uint channel, uint id, uint lun)
367{
368 struct scsi_device *sdev;
369 struct Scsi_Host *shost;
370 int error = -ENXIO;
371
372 shost = scsi_host_lookup(hostnum: host);
373 if (!shost)
374 return error;
375 sdev = scsi_device_lookup(shost, channel, id, lun);
376 if (sdev) {
377 scsi_remove_device(sdev);
378 scsi_device_put(sdev);
379 error = 0;
380 }
381
382 scsi_host_put(t: shost);
383 return error;
384}
385
386/**
387 * proc_scsi_write - handle writes to /proc/scsi/scsi
388 * @file: not used
389 * @buf: buffer to write
390 * @length: length of buf, at most PAGE_SIZE
391 * @ppos: not used
392 *
393 * Description: this provides a legacy mechanism to add or remove devices by
394 * Host, Channel, ID, and Lun. To use,
395 * "echo 'scsi add-single-device 0 1 2 3' > /proc/scsi/scsi" or
396 * "echo 'scsi remove-single-device 0 1 2 3' > /proc/scsi/scsi" with
397 * "0 1 2 3" replaced by the Host, Channel, Id, and Lun.
398 *
399 * Note: this seems to be aimed at parallel SCSI. Most modern busses (USB,
400 * SATA, Firewire, Fibre Channel, etc) dynamically assign these values to
401 * provide a unique identifier and nothing more.
402 */
403
404
405static ssize_t proc_scsi_write(struct file *file, const char __user *buf,
406 size_t length, loff_t *ppos)
407{
408 int host, channel, id, lun;
409 char *buffer, *end, *p;
410 int err;
411
412 if (!buf || length > PAGE_SIZE)
413 return -EINVAL;
414
415 buffer = (char *)__get_free_page(GFP_KERNEL);
416 if (!buffer)
417 return -ENOMEM;
418
419 err = -EFAULT;
420 if (copy_from_user(to: buffer, from: buf, n: length))
421 goto out;
422
423 err = -EINVAL;
424 if (length < PAGE_SIZE) {
425 end = buffer + length;
426 *end = '\0';
427 } else {
428 end = buffer + PAGE_SIZE - 1;
429 if (*end)
430 goto out;
431 }
432
433 /*
434 * Usage: echo "scsi add-single-device 0 1 2 3" >/proc/scsi/scsi
435 * with "0 1 2 3" replaced by your "Host Channel Id Lun".
436 */
437 if (!strncmp("scsi add-single-device", buffer, 22)) {
438 p = buffer + 23;
439
440 host = (p < end) ? simple_strtoul(p, &p, 0) : 0;
441 channel = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
442 id = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
443 lun = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
444
445 err = scsi_add_single_device(host, channel, id, lun);
446
447 /*
448 * Usage: echo "scsi remove-single-device 0 1 2 3" >/proc/scsi/scsi
449 * with "0 1 2 3" replaced by your "Host Channel Id Lun".
450 */
451 } else if (!strncmp("scsi remove-single-device", buffer, 25)) {
452 p = buffer + 26;
453
454 host = (p < end) ? simple_strtoul(p, &p, 0) : 0;
455 channel = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
456 id = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
457 lun = (p + 1 < end) ? simple_strtoul(p + 1, &p, 0) : 0;
458
459 err = scsi_remove_single_device(host, channel, id, lun);
460 }
461
462 /*
463 * convert success returns so that we return the
464 * number of bytes consumed.
465 */
466 if (!err)
467 err = length;
468
469 out:
470 free_page((unsigned long)buffer);
471 return err;
472}
473
474static inline struct device *next_scsi_device(struct device *start)
475{
476 struct device *next = bus_find_next_device(bus: &scsi_bus_type, cur: start);
477
478 put_device(dev: start);
479 return next;
480}
481
482static void *scsi_seq_start(struct seq_file *sfile, loff_t *pos)
483{
484 struct device *dev = NULL;
485 loff_t n = *pos;
486
487 while ((dev = next_scsi_device(start: dev))) {
488 if (!n--)
489 break;
490 sfile->private++;
491 }
492 return dev;
493}
494
495static void *scsi_seq_next(struct seq_file *sfile, void *v, loff_t *pos)
496{
497 (*pos)++;
498 sfile->private++;
499 return next_scsi_device(start: v);
500}
501
502static void scsi_seq_stop(struct seq_file *sfile, void *v)
503{
504 put_device(dev: v);
505}
506
507static int scsi_seq_show(struct seq_file *sfile, void *dev)
508{
509 if (!sfile->private)
510 seq_puts(m: sfile, s: "Attached devices:\n");
511
512 return proc_print_scsidevice(dev, data: sfile);
513}
514
515static const struct seq_operations scsi_seq_ops = {
516 .start = scsi_seq_start,
517 .next = scsi_seq_next,
518 .stop = scsi_seq_stop,
519 .show = scsi_seq_show
520};
521
522/**
523 * proc_scsi_open - glue function
524 * @inode: not used
525 * @file: passed to single_open()
526 *
527 * Associates proc_scsi_show with this file
528 */
529static int proc_scsi_open(struct inode *inode, struct file *file)
530{
531 /*
532 * We don't really need this for the write case but it doesn't
533 * harm either.
534 */
535 return seq_open(file, &scsi_seq_ops);
536}
537
538static const struct proc_ops scsi_scsi_proc_ops = {
539 .proc_open = proc_scsi_open,
540 .proc_read = seq_read,
541 .proc_write = proc_scsi_write,
542 .proc_lseek = seq_lseek,
543 .proc_release = seq_release,
544};
545
546/**
547 * scsi_init_procfs - create scsi and scsi/scsi in procfs
548 */
549int __init scsi_init_procfs(void)
550{
551 struct proc_dir_entry *pde;
552
553 proc_scsi = proc_mkdir("scsi", NULL);
554 if (!proc_scsi)
555 goto err1;
556
557 pde = proc_create(name: "scsi/scsi", mode: 0, NULL, proc_ops: &scsi_scsi_proc_ops);
558 if (!pde)
559 goto err2;
560
561 return 0;
562
563err2:
564 remove_proc_entry("scsi", NULL);
565err1:
566 return -ENOMEM;
567}
568
569/**
570 * scsi_exit_procfs - Remove scsi/scsi and scsi from procfs
571 */
572void scsi_exit_procfs(void)
573{
574 remove_proc_entry("scsi/scsi", NULL);
575 remove_proc_entry("scsi", NULL);
576}
577