1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * RDMA Network Block Driver
4  *
5  * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
6  * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
7  * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
8  */
9 
10 #undef pr_fmt
11 #define pr_fmt(fmt) KBUILD_MODNAME " L" __stringify(__LINE__) ": " fmt
12 
13 #include <linux/types.h>
14 #include <linux/ctype.h>
15 #include <linux/parser.h>
16 #include <linux/module.h>
17 #include <linux/in6.h>
18 #include <linux/fs.h>
19 #include <linux/uaccess.h>
20 #include <linux/device.h>
21 #include <rdma/ib.h>
22 #include <rdma/rdma_cm.h>
23 
24 #include "rnbd-clt.h"
25 
26 static struct device *rnbd_dev;
27 static struct class *rnbd_dev_class;
28 static struct kobject *rnbd_devs_kobj;
29 
30 enum {
31 	RNBD_OPT_ERR		= 0,
32 	RNBD_OPT_DEST_PORT	= 1 << 0,
33 	RNBD_OPT_PATH		= 1 << 1,
34 	RNBD_OPT_DEV_PATH	= 1 << 2,
35 	RNBD_OPT_ACCESS_MODE	= 1 << 3,
36 	RNBD_OPT_SESSNAME	= 1 << 6,
37 };
38 
39 static const unsigned int rnbd_opt_mandatory[] = {
40 	RNBD_OPT_PATH,
41 	RNBD_OPT_DEV_PATH,
42 	RNBD_OPT_SESSNAME,
43 };
44 
45 static const match_table_t rnbd_opt_tokens = {
46 	{RNBD_OPT_PATH,		"path=%s"	},
47 	{RNBD_OPT_DEV_PATH,	"device_path=%s"},
48 	{RNBD_OPT_DEST_PORT,	"dest_port=%d"  },
49 	{RNBD_OPT_ACCESS_MODE,	"access_mode=%s"},
50 	{RNBD_OPT_SESSNAME,	"sessname=%s"	},
51 	{RNBD_OPT_ERR,		NULL		},
52 };
53 
54 struct rnbd_map_options {
55 	char *sessname;
56 	struct rtrs_addr *paths;
57 	size_t *path_cnt;
58 	char *pathname;
59 	u16 *dest_port;
60 	enum rnbd_access_mode *access_mode;
61 };
62 
63 static int rnbd_clt_parse_map_options(const char *buf, size_t max_path_cnt,
64 				       struct rnbd_map_options *opt)
65 {
66 	char *options, *sep_opt;
67 	char *p;
68 	substring_t args[MAX_OPT_ARGS];
69 	int opt_mask = 0;
70 	int token;
71 	int ret = -EINVAL;
72 	int i, dest_port;
73 	int p_cnt = 0;
74 
75 	options = kstrdup(buf, GFP_KERNEL);
76 	if (!options)
77 		return -ENOMEM;
78 
79 	sep_opt = strstrip(options);
80 	while ((p = strsep(&sep_opt, " ")) != NULL) {
81 		if (!*p)
82 			continue;
83 
84 		token = match_token(p, rnbd_opt_tokens, args);
85 		opt_mask |= token;
86 
87 		switch (token) {
88 		case RNBD_OPT_SESSNAME:
89 			p = match_strdup(args);
90 			if (!p) {
91 				ret = -ENOMEM;
92 				goto out;
93 			}
94 			if (strlen(p) > NAME_MAX) {
95 				pr_err("map_device: sessname too long\n");
96 				ret = -EINVAL;
97 				kfree(p);
98 				goto out;
99 			}
100 			strlcpy(opt->sessname, p, NAME_MAX);
101 			kfree(p);
102 			break;
103 
104 		case RNBD_OPT_PATH:
105 			if (p_cnt >= max_path_cnt) {
106 				pr_err("map_device: too many (> %zu) paths provided\n",
107 				       max_path_cnt);
108 				ret = -ENOMEM;
109 				goto out;
110 			}
111 			p = match_strdup(args);
112 			if (!p) {
113 				ret = -ENOMEM;
114 				goto out;
115 			}
116 
117 			ret = rtrs_addr_to_sockaddr(p, strlen(p),
118 						    *opt->dest_port,
119 						    &opt->paths[p_cnt]);
120 			if (ret) {
121 				pr_err("Can't parse path %s: %d\n", p, ret);
122 				kfree(p);
123 				goto out;
124 			}
125 
126 			p_cnt++;
127 
128 			kfree(p);
129 			break;
130 
131 		case RNBD_OPT_DEV_PATH:
132 			p = match_strdup(args);
133 			if (!p) {
134 				ret = -ENOMEM;
135 				goto out;
136 			}
137 			if (strlen(p) > NAME_MAX) {
138 				pr_err("map_device: Device path too long\n");
139 				ret = -EINVAL;
140 				kfree(p);
141 				goto out;
142 			}
143 			strlcpy(opt->pathname, p, NAME_MAX);
144 			kfree(p);
145 			break;
146 
147 		case RNBD_OPT_DEST_PORT:
148 			if (match_int(args, &dest_port) || dest_port < 0 ||
149 			    dest_port > 65535) {
150 				pr_err("bad destination port number parameter '%d'\n",
151 				       dest_port);
152 				ret = -EINVAL;
153 				goto out;
154 			}
155 			*opt->dest_port = dest_port;
156 			break;
157 
158 		case RNBD_OPT_ACCESS_MODE:
159 			p = match_strdup(args);
160 			if (!p) {
161 				ret = -ENOMEM;
162 				goto out;
163 			}
164 
165 			if (!strcmp(p, "ro")) {
166 				*opt->access_mode = RNBD_ACCESS_RO;
167 			} else if (!strcmp(p, "rw")) {
168 				*opt->access_mode = RNBD_ACCESS_RW;
169 			} else if (!strcmp(p, "migration")) {
170 				*opt->access_mode = RNBD_ACCESS_MIGRATION;
171 			} else {
172 				pr_err("map_device: Invalid access_mode: '%s'\n",
173 				       p);
174 				ret = -EINVAL;
175 				kfree(p);
176 				goto out;
177 			}
178 
179 			kfree(p);
180 			break;
181 
182 		default:
183 			pr_err("map_device: Unknown parameter or missing value '%s'\n",
184 			       p);
185 			ret = -EINVAL;
186 			goto out;
187 		}
188 	}
189 
190 	for (i = 0; i < ARRAY_SIZE(rnbd_opt_mandatory); i++) {
191 		if ((opt_mask & rnbd_opt_mandatory[i])) {
192 			ret = 0;
193 		} else {
194 			pr_err("map_device: Parameters missing\n");
195 			ret = -EINVAL;
196 			break;
197 		}
198 	}
199 
200 out:
201 	*opt->path_cnt = p_cnt;
202 	kfree(options);
203 	return ret;
204 }
205 
206 static ssize_t state_show(struct kobject *kobj,
207 			  struct kobj_attribute *attr, char *page)
208 {
209 	struct rnbd_clt_dev *dev;
210 
211 	dev = container_of(kobj, struct rnbd_clt_dev, kobj);
212 
213 	switch (dev->dev_state) {
214 	case DEV_STATE_INIT:
215 		return snprintf(page, PAGE_SIZE, "init\n");
216 	case DEV_STATE_MAPPED:
217 		/* TODO fix cli tool before changing to proper state */
218 		return snprintf(page, PAGE_SIZE, "open\n");
219 	case DEV_STATE_MAPPED_DISCONNECTED:
220 		/* TODO fix cli tool before changing to proper state */
221 		return snprintf(page, PAGE_SIZE, "closed\n");
222 	case DEV_STATE_UNMAPPED:
223 		return snprintf(page, PAGE_SIZE, "unmapped\n");
224 	default:
225 		return snprintf(page, PAGE_SIZE, "unknown\n");
226 	}
227 }
228 
229 static struct kobj_attribute rnbd_clt_state_attr = __ATTR_RO(state);
230 
231 static ssize_t mapping_path_show(struct kobject *kobj,
232 				 struct kobj_attribute *attr, char *page)
233 {
234 	struct rnbd_clt_dev *dev;
235 
236 	dev = container_of(kobj, struct rnbd_clt_dev, kobj);
237 
238 	return scnprintf(page, PAGE_SIZE, "%s\n", dev->pathname);
239 }
240 
241 static struct kobj_attribute rnbd_clt_mapping_path_attr =
242 	__ATTR_RO(mapping_path);
243 
244 static ssize_t access_mode_show(struct kobject *kobj,
245 				struct kobj_attribute *attr, char *page)
246 {
247 	struct rnbd_clt_dev *dev;
248 
249 	dev = container_of(kobj, struct rnbd_clt_dev, kobj);
250 
251 	return snprintf(page, PAGE_SIZE, "%s\n",
252 			rnbd_access_mode_str(dev->access_mode));
253 }
254 
255 static struct kobj_attribute rnbd_clt_access_mode =
256 	__ATTR_RO(access_mode);
257 
258 static ssize_t rnbd_clt_unmap_dev_show(struct kobject *kobj,
259 					struct kobj_attribute *attr, char *page)
260 {
261 	return scnprintf(page, PAGE_SIZE, "Usage: echo <normal|force> > %s\n",
262 			 attr->attr.name);
263 }
264 
265 static ssize_t rnbd_clt_unmap_dev_store(struct kobject *kobj,
266 					 struct kobj_attribute *attr,
267 					 const char *buf, size_t count)
268 {
269 	struct rnbd_clt_dev *dev;
270 	char *opt, *options;
271 	bool force;
272 	int err;
273 
274 	opt = kstrdup(buf, GFP_KERNEL);
275 	if (!opt)
276 		return -ENOMEM;
277 
278 	options = strstrip(opt);
279 	dev = container_of(kobj, struct rnbd_clt_dev, kobj);
280 	if (sysfs_streq(options, "normal")) {
281 		force = false;
282 	} else if (sysfs_streq(options, "force")) {
283 		force = true;
284 	} else {
285 		rnbd_clt_err(dev,
286 			      "unmap_device: Invalid value: %s\n",
287 			      options);
288 		err = -EINVAL;
289 		goto out;
290 	}
291 
292 	rnbd_clt_info(dev, "Unmapping device, option: %s.\n",
293 		       force ? "force" : "normal");
294 
295 	/*
296 	 * We take explicit module reference only for one reason: do not
297 	 * race with lockless rnbd_destroy_sessions().
298 	 */
299 	if (!try_module_get(THIS_MODULE)) {
300 		err = -ENODEV;
301 		goto out;
302 	}
303 	err = rnbd_clt_unmap_device(dev, force, &attr->attr);
304 	if (err) {
305 		if (err != -EALREADY)
306 			rnbd_clt_err(dev, "unmap_device: %d\n",  err);
307 		goto module_put;
308 	}
309 
310 	/*
311 	 * Here device can be vanished!
312 	 */
313 
314 	err = count;
315 
316 module_put:
317 	module_put(THIS_MODULE);
318 out:
319 	kfree(opt);
320 
321 	return err;
322 }
323 
324 static struct kobj_attribute rnbd_clt_unmap_device_attr =
325 	__ATTR(unmap_device, 0644, rnbd_clt_unmap_dev_show,
326 	       rnbd_clt_unmap_dev_store);
327 
328 static ssize_t rnbd_clt_resize_dev_show(struct kobject *kobj,
329 					 struct kobj_attribute *attr,
330 					 char *page)
331 {
332 	return scnprintf(page, PAGE_SIZE,
333 			 "Usage: echo <new size in sectors> > %s\n",
334 			 attr->attr.name);
335 }
336 
337 static ssize_t rnbd_clt_resize_dev_store(struct kobject *kobj,
338 					  struct kobj_attribute *attr,
339 					  const char *buf, size_t count)
340 {
341 	int ret;
342 	unsigned long sectors;
343 	struct rnbd_clt_dev *dev;
344 
345 	dev = container_of(kobj, struct rnbd_clt_dev, kobj);
346 
347 	ret = kstrtoul(buf, 0, &sectors);
348 	if (ret)
349 		return ret;
350 
351 	ret = rnbd_clt_resize_disk(dev, (size_t)sectors);
352 	if (ret)
353 		return ret;
354 
355 	return count;
356 }
357 
358 static struct kobj_attribute rnbd_clt_resize_dev_attr =
359 	__ATTR(resize, 0644, rnbd_clt_resize_dev_show,
360 	       rnbd_clt_resize_dev_store);
361 
362 static ssize_t rnbd_clt_remap_dev_show(struct kobject *kobj,
363 					struct kobj_attribute *attr, char *page)
364 {
365 	return scnprintf(page, PAGE_SIZE, "Usage: echo <1> > %s\n",
366 			 attr->attr.name);
367 }
368 
369 static ssize_t rnbd_clt_remap_dev_store(struct kobject *kobj,
370 					 struct kobj_attribute *attr,
371 					 const char *buf, size_t count)
372 {
373 	struct rnbd_clt_dev *dev;
374 	char *opt, *options;
375 	int err;
376 
377 	opt = kstrdup(buf, GFP_KERNEL);
378 	if (!opt)
379 		return -ENOMEM;
380 
381 	options = strstrip(opt);
382 	dev = container_of(kobj, struct rnbd_clt_dev, kobj);
383 	if (!sysfs_streq(options, "1")) {
384 		rnbd_clt_err(dev,
385 			      "remap_device: Invalid value: %s\n",
386 			      options);
387 		err = -EINVAL;
388 		goto out;
389 	}
390 	err = rnbd_clt_remap_device(dev);
391 	if (likely(!err))
392 		err = count;
393 
394 out:
395 	kfree(opt);
396 
397 	return err;
398 }
399 
400 static struct kobj_attribute rnbd_clt_remap_device_attr =
401 	__ATTR(remap_device, 0644, rnbd_clt_remap_dev_show,
402 	       rnbd_clt_remap_dev_store);
403 
404 static ssize_t session_show(struct kobject *kobj, struct kobj_attribute *attr,
405 			    char *page)
406 {
407 	struct rnbd_clt_dev *dev;
408 
409 	dev = container_of(kobj, struct rnbd_clt_dev, kobj);
410 
411 	return scnprintf(page, PAGE_SIZE, "%s\n", dev->sess->sessname);
412 }
413 
414 static struct kobj_attribute rnbd_clt_session_attr =
415 	__ATTR_RO(session);
416 
417 static struct attribute *rnbd_dev_attrs[] = {
418 	&rnbd_clt_unmap_device_attr.attr,
419 	&rnbd_clt_resize_dev_attr.attr,
420 	&rnbd_clt_remap_device_attr.attr,
421 	&rnbd_clt_mapping_path_attr.attr,
422 	&rnbd_clt_state_attr.attr,
423 	&rnbd_clt_session_attr.attr,
424 	&rnbd_clt_access_mode.attr,
425 	NULL,
426 };
427 
428 void rnbd_clt_remove_dev_symlink(struct rnbd_clt_dev *dev)
429 {
430 	/*
431 	 * The module unload rnbd_client_exit path is racing with unmapping of
432 	 * the last single device from the sysfs manually
433 	 * i.e. rnbd_clt_unmap_dev_store() leading to a sysfs warning because
434 	 * of sysfs link already was removed already.
435 	 */
436 	if (strlen(dev->blk_symlink_name) && try_module_get(THIS_MODULE)) {
437 		sysfs_remove_link(rnbd_devs_kobj, dev->blk_symlink_name);
438 		module_put(THIS_MODULE);
439 	}
440 }
441 
442 static struct kobj_type rnbd_dev_ktype = {
443 	.sysfs_ops      = &kobj_sysfs_ops,
444 	.default_attrs  = rnbd_dev_attrs,
445 };
446 
447 static int rnbd_clt_add_dev_kobj(struct rnbd_clt_dev *dev)
448 {
449 	int ret;
450 	struct kobject *gd_kobj = &disk_to_dev(dev->gd)->kobj;
451 
452 	ret = kobject_init_and_add(&dev->kobj, &rnbd_dev_ktype, gd_kobj, "%s",
453 				   "rnbd");
454 	if (ret)
455 		rnbd_clt_err(dev, "Failed to create device sysfs dir, err: %d\n",
456 			      ret);
457 
458 	return ret;
459 }
460 
461 static ssize_t rnbd_clt_map_device_show(struct kobject *kobj,
462 					 struct kobj_attribute *attr,
463 					 char *page)
464 {
465 	return scnprintf(page, PAGE_SIZE,
466 			 "Usage: echo \"[dest_port=server port number] sessname=<name of the rtrs session> path=<[srcaddr@]dstaddr> [path=<[srcaddr@]dstaddr>] device_path=<full path on remote side> [access_mode=<ro|rw|migration>]\" > %s\n\naddr ::= [ ip:<ipv4> | ip:<ipv6> | gid:<gid> ]\n",
467 			 attr->attr.name);
468 }
469 
470 static int rnbd_clt_get_path_name(struct rnbd_clt_dev *dev, char *buf,
471 				   size_t len)
472 {
473 	int ret;
474 	char pathname[NAME_MAX], *s;
475 
476 	strlcpy(pathname, dev->pathname, sizeof(pathname));
477 	while ((s = strchr(pathname, '/')))
478 		s[0] = '!';
479 
480 	ret = snprintf(buf, len, "%s", pathname);
481 	if (ret >= len)
482 		return -ENAMETOOLONG;
483 
484 	return 0;
485 }
486 
487 static int rnbd_clt_add_dev_symlink(struct rnbd_clt_dev *dev)
488 {
489 	struct kobject *gd_kobj = &disk_to_dev(dev->gd)->kobj;
490 	int ret;
491 
492 	ret = rnbd_clt_get_path_name(dev, dev->blk_symlink_name,
493 				      sizeof(dev->blk_symlink_name));
494 	if (ret) {
495 		rnbd_clt_err(dev, "Failed to get /sys/block symlink path, err: %d\n",
496 			      ret);
497 		goto out_err;
498 	}
499 
500 	ret = sysfs_create_link(rnbd_devs_kobj, gd_kobj,
501 				dev->blk_symlink_name);
502 	if (ret) {
503 		rnbd_clt_err(dev, "Creating /sys/block symlink failed, err: %d\n",
504 			      ret);
505 		goto out_err;
506 	}
507 
508 	return 0;
509 
510 out_err:
511 	dev->blk_symlink_name[0] = '\0';
512 	return ret;
513 }
514 
515 static ssize_t rnbd_clt_map_device_store(struct kobject *kobj,
516 					  struct kobj_attribute *attr,
517 					  const char *buf, size_t count)
518 {
519 	struct rnbd_clt_dev *dev;
520 	struct rnbd_map_options opt;
521 	int ret;
522 	char pathname[NAME_MAX];
523 	char sessname[NAME_MAX];
524 	enum rnbd_access_mode access_mode = RNBD_ACCESS_RW;
525 	u16 port_nr = RTRS_PORT;
526 
527 	struct sockaddr_storage *addrs;
528 	struct rtrs_addr paths[6];
529 	size_t path_cnt;
530 
531 	opt.sessname = sessname;
532 	opt.paths = paths;
533 	opt.path_cnt = &path_cnt;
534 	opt.pathname = pathname;
535 	opt.dest_port = &port_nr;
536 	opt.access_mode = &access_mode;
537 	addrs = kcalloc(ARRAY_SIZE(paths) * 2, sizeof(*addrs), GFP_KERNEL);
538 	if (!addrs)
539 		return -ENOMEM;
540 
541 	for (path_cnt = 0; path_cnt < ARRAY_SIZE(paths); path_cnt++) {
542 		paths[path_cnt].src = &addrs[path_cnt * 2];
543 		paths[path_cnt].dst = &addrs[path_cnt * 2 + 1];
544 	}
545 
546 	ret = rnbd_clt_parse_map_options(buf, ARRAY_SIZE(paths), &opt);
547 	if (ret)
548 		goto out;
549 
550 	pr_info("Mapping device %s on session %s, (access_mode: %s)\n",
551 		pathname, sessname,
552 		rnbd_access_mode_str(access_mode));
553 
554 	dev = rnbd_clt_map_device(sessname, paths, path_cnt, port_nr, pathname,
555 				  access_mode);
556 	if (IS_ERR(dev)) {
557 		ret = PTR_ERR(dev);
558 		goto out;
559 	}
560 
561 	ret = rnbd_clt_add_dev_kobj(dev);
562 	if (ret)
563 		goto unmap_dev;
564 
565 	ret = rnbd_clt_add_dev_symlink(dev);
566 	if (ret)
567 		goto unmap_dev;
568 
569 	kfree(addrs);
570 	return count;
571 
572 unmap_dev:
573 	rnbd_clt_unmap_device(dev, true, NULL);
574 out:
575 	kfree(addrs);
576 	return ret;
577 }
578 
579 static struct kobj_attribute rnbd_clt_map_device_attr =
580 	__ATTR(map_device, 0644,
581 	       rnbd_clt_map_device_show, rnbd_clt_map_device_store);
582 
583 static struct attribute *default_attrs[] = {
584 	&rnbd_clt_map_device_attr.attr,
585 	NULL,
586 };
587 
588 static struct attribute_group default_attr_group = {
589 	.attrs = default_attrs,
590 };
591 
592 static const struct attribute_group *default_attr_groups[] = {
593 	&default_attr_group,
594 	NULL,
595 };
596 
597 int rnbd_clt_create_sysfs_files(void)
598 {
599 	int err;
600 
601 	rnbd_dev_class = class_create(THIS_MODULE, "rnbd-client");
602 	if (IS_ERR(rnbd_dev_class))
603 		return PTR_ERR(rnbd_dev_class);
604 
605 	rnbd_dev = device_create_with_groups(rnbd_dev_class, NULL,
606 					      MKDEV(0, 0), NULL,
607 					      default_attr_groups, "ctl");
608 	if (IS_ERR(rnbd_dev)) {
609 		err = PTR_ERR(rnbd_dev);
610 		goto cls_destroy;
611 	}
612 	rnbd_devs_kobj = kobject_create_and_add("devices", &rnbd_dev->kobj);
613 	if (!rnbd_devs_kobj) {
614 		err = -ENOMEM;
615 		goto dev_destroy;
616 	}
617 
618 	return 0;
619 
620 dev_destroy:
621 	device_destroy(rnbd_dev_class, MKDEV(0, 0));
622 cls_destroy:
623 	class_destroy(rnbd_dev_class);
624 
625 	return err;
626 }
627 
628 void rnbd_clt_destroy_default_group(void)
629 {
630 	sysfs_remove_group(&rnbd_dev->kobj, &default_attr_group);
631 }
632 
633 void rnbd_clt_destroy_sysfs_files(void)
634 {
635 	kobject_del(rnbd_devs_kobj);
636 	kobject_put(rnbd_devs_kobj);
637 	device_destroy(rnbd_dev_class, MKDEV(0, 0));
638 	class_destroy(rnbd_dev_class);
639 }
640