xref: /freebsd/sys/geom/label/g_label.c (revision a0b9e2e854027e6ff61fb075a1309dbc71c42b54)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2004-2005 Pawel Jakub Dawidek <pjd@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include "opt_geom.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38 #include <sys/lock.h>
39 #include <sys/mutex.h>
40 #include <sys/bio.h>
41 #include <sys/ctype.h>
42 #include <sys/malloc.h>
43 #include <sys/libkern.h>
44 #include <sys/sbuf.h>
45 #include <sys/stddef.h>
46 #include <sys/sysctl.h>
47 #include <geom/geom.h>
48 #include <geom/geom_dbg.h>
49 #include <geom/geom_slice.h>
50 #include <geom/label/g_label.h>
51 
52 FEATURE(geom_label, "GEOM labeling support");
53 
54 SYSCTL_DECL(_kern_geom);
55 SYSCTL_NODE(_kern_geom, OID_AUTO, label, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
56     "GEOM_LABEL stuff");
57 u_int g_label_debug = 0;
58 SYSCTL_UINT(_kern_geom_label, OID_AUTO, debug, CTLFLAG_RWTUN, &g_label_debug, 0,
59     "Debug level");
60 
61 static int g_label_destroy_geom(struct gctl_req *req, struct g_class *mp,
62     struct g_geom *gp);
63 static int g_label_destroy(struct g_geom *gp, boolean_t force);
64 static struct g_geom *g_label_taste(struct g_class *mp, struct g_provider *pp,
65     int flags __unused);
66 static void g_label_generic_taste(struct g_consumer *, char *, size_t);
67 static void g_label_config(struct gctl_req *req, struct g_class *mp,
68     const char *verb);
69 
70 #define	G_LABEL_DIRPREFIX	"label/"
71 
72 struct g_class g_label_class = {
73 	.name = G_LABEL_CLASS_NAME,
74 	.version = G_VERSION,
75 	.ctlreq = g_label_config,
76 	.taste = g_label_taste,
77 	.destroy_geom = g_label_destroy_geom
78 };
79 
80 static struct g_label_desc g_label_generic = {
81         .ld_taste = g_label_generic_taste,
82         .ld_dirprefix = G_LABEL_DIRPREFIX,
83         .ld_enabled = 1
84 };
85 
86 /*
87  * To add a new file system where you want to look for volume labels,
88  * you have to:
89  * 1. Add a file g_label_<file system>.c which implements labels recognition.
90  * 2. Add an 'extern const struct g_label_desc g_label_<file system>;' into
91  *    g_label.h file.
92  * 3. Add an element to the table below '&g_label_<file system>,'.
93  * 4. Add your file to sys/conf/files.
94  * 5. Add your file to sys/modules/geom/geom_label/Makefile.
95  * 6. Add your file system to manual page sbin/geom/class/label/glabel.8.
96  */
97 const struct g_label_desc *g_labels[] = {
98 	&g_label_gpt,
99 	&g_label_gpt_uuid,
100 #ifdef GEOM_LABEL
101 	&g_label_ufs_id,
102 	&g_label_ufs_volume,
103 	&g_label_iso9660,
104 	&g_label_msdosfs,
105 	&g_label_ext2fs,
106 	&g_label_reiserfs,
107 	&g_label_ntfs,
108 	&g_label_disk_ident,
109 	&g_label_flashmap,
110 #endif
111 	&g_label_generic,
112 	NULL
113 };
114 
115 void
116 g_label_rtrim(char *label, size_t size)
117 {
118 	ptrdiff_t i;
119 
120 	for (i = size - 1; i >= 0; i--) {
121 		if (label[i] == '\0')
122 			continue;
123 		else if (label[i] == ' ')
124 			label[i] = '\0';
125 		else
126 			break;
127 	}
128 }
129 
130 static int
131 g_label_destroy_geom(struct gctl_req *req __unused, struct g_class *mp,
132     struct g_geom *gp __unused)
133 {
134 
135 	/*
136 	 * XXX: Unloading a class which is using geom_slice:1.56 is currently
137 	 * XXX: broken, so we deny unloading when we have geoms.
138 	 */
139 	return (EOPNOTSUPP);
140 }
141 
142 static void
143 g_label_orphan(struct g_consumer *cp)
144 {
145 
146 	G_LABEL_DEBUG(1, "Label %s removed.",
147 	    LIST_FIRST(&cp->geom->provider)->name);
148 	g_slice_orphan(cp);
149 }
150 
151 static void
152 g_label_spoiled(struct g_consumer *cp)
153 {
154 
155 	G_LABEL_DEBUG(1, "Label %s removed.",
156 	    LIST_FIRST(&cp->geom->provider)->name);
157 	g_slice_spoiled(cp);
158 }
159 
160 static void
161 g_label_resize(struct g_consumer *cp)
162 {
163 
164 	G_LABEL_DEBUG(1, "Label %s resized.",
165 	    LIST_FIRST(&cp->geom->provider)->name);
166 
167 	g_slice_config(cp->geom, 0, G_SLICE_CONFIG_FORCE, (off_t)0,
168 	    cp->provider->mediasize, cp->provider->sectorsize, "notused");
169 }
170 
171 static int
172 g_label_is_name_ok(const char *label)
173 {
174 	const char *s;
175 
176 	/* Check if the label starts from ../ */
177 	if (strncmp(label, "../", 3) == 0)
178 		return (0);
179 	/* Check if the label contains /../ */
180 	if (strstr(label, "/../") != NULL)
181 		return (0);
182 	/* Check if the label ends at ../ */
183 	if ((s = strstr(label, "/..")) != NULL && s[3] == '\0')
184 		return (0);
185 	return (1);
186 }
187 
188 static void
189 g_label_mangle_name(char *label, size_t size)
190 {
191 	struct sbuf *sb;
192 	const u_char *c;
193 	size_t len, i;
194 
195 	/* Trim trailing whitespace. */
196 	len = strlen(label);
197 	for (i = len; i > 0; i--) {
198 		if (isspace(label[i - 1]))
199 			label[i - 1] = '\0';
200 		else
201 			break;
202 	}
203 	if (*label == '\0')
204 		return;
205 
206 	sb = sbuf_new(NULL, NULL, size, SBUF_FIXEDLEN);
207 	for (c = label; *c != '\0'; c++) {
208 		/* Trim leading whitespace. */
209 		if (isspace(*c) && sbuf_len(sb) == 0)
210 			continue;
211 		if (!isprint(*c) || isspace(*c) || *c =='"' || *c == '%')
212 			sbuf_printf(sb, "%%%02X", *c);
213 		else
214 			sbuf_putc(sb, *c);
215 	}
216 	if (sbuf_finish(sb) != 0)
217 		label[0] = '\0';
218 	else
219 		strlcpy(label, sbuf_data(sb), size);
220 	sbuf_delete(sb);
221 }
222 
223 static struct g_geom *
224 g_label_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
225     const char *label, const char *dirprefix, off_t mediasize)
226 {
227 	struct g_geom *gp;
228 	struct g_provider *pp2;
229 	struct g_consumer *cp;
230 	char name[64];
231 
232 	g_topology_assert();
233 
234 	if (!g_label_is_name_ok(label)) {
235 		G_LABEL_DEBUG(0, "%s contains suspicious label, skipping.",
236 		    pp->name);
237 		G_LABEL_DEBUG(1, "%s suspicious label is: %s", pp->name, label);
238 		if (req != NULL)
239 			gctl_error(req, "Label name %s is invalid.", label);
240 		return (NULL);
241 	}
242 	gp = NULL;
243 	cp = NULL;
244 	if (snprintf(name, sizeof(name), "%s%s", dirprefix, label) >= sizeof(name)) {
245 		if (req != NULL)
246 			gctl_error(req, "Label name %s is too long.", label);
247 		return (NULL);
248 	}
249 	LIST_FOREACH(gp, &mp->geom, geom) {
250 		pp2 = LIST_FIRST(&gp->provider);
251 		if (pp2 == NULL)
252 			continue;
253 		if ((pp2->flags & G_PF_ORPHAN) != 0)
254 			continue;
255 		if (strcmp(pp2->name, name) == 0) {
256 			G_LABEL_DEBUG(1, "Label %s(%s) already exists (%s).",
257 			    label, name, pp->name);
258 			if (req != NULL) {
259 				gctl_error(req, "Provider %s already exists.",
260 				    name);
261 			}
262 			return (NULL);
263 		}
264 	}
265 	gp = g_slice_new(mp, 1, pp, &cp, NULL, 0, NULL);
266 	if (gp == NULL) {
267 		G_LABEL_DEBUG(0, "Cannot create slice %s.", label);
268 		if (req != NULL)
269 			gctl_error(req, "Cannot create slice %s.", label);
270 		return (NULL);
271 	}
272 	gp->orphan = g_label_orphan;
273 	gp->spoiled = g_label_spoiled;
274 	gp->resize = g_label_resize;
275 	g_access(cp, -1, 0, 0);
276 	g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t)0, mediasize,
277 	    pp->sectorsize, "%s", name);
278 	G_LABEL_DEBUG(1, "Label for provider %s is %s.", pp->name, name);
279 	return (gp);
280 }
281 
282 static int
283 g_label_destroy(struct g_geom *gp, boolean_t force)
284 {
285 	struct g_provider *pp;
286 
287 	g_topology_assert();
288 	pp = LIST_FIRST(&gp->provider);
289 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
290 		if (force) {
291 			G_LABEL_DEBUG(0, "Provider %s is still open, so it "
292 			    "can't be definitely removed.", pp->name);
293 		} else {
294 			G_LABEL_DEBUG(1,
295 			    "Provider %s is still open (r%dw%de%d).", pp->name,
296 			    pp->acr, pp->acw, pp->ace);
297 			return (EBUSY);
298 		}
299 	} else if (pp != NULL)
300 		G_LABEL_DEBUG(1, "Label %s removed.", pp->name);
301 	g_slice_spoiled(LIST_FIRST(&gp->consumer));
302 	return (0);
303 }
304 
305 static int
306 g_label_read_metadata(struct g_consumer *cp, struct g_label_metadata *md)
307 {
308 	struct g_provider *pp;
309 	u_char *buf;
310 	int error;
311 
312 	pp = cp->provider;
313 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
314 	    &error);
315 	if (buf == NULL)
316 		return (error);
317 	/* Decode metadata. */
318 	label_metadata_decode(buf, md);
319 	g_free(buf);
320 
321 	return (0);
322 }
323 
324 static void
325 g_label_orphan_taste(struct g_consumer *cp __unused)
326 {
327 
328 	KASSERT(1 == 0, ("%s called?", __func__));
329 }
330 
331 static void
332 g_label_start_taste(struct bio *bp __unused)
333 {
334 
335 	KASSERT(1 == 0, ("%s called?", __func__));
336 }
337 
338 static int
339 g_label_access_taste(struct g_provider *pp __unused, int dr __unused,
340     int dw __unused, int de __unused)
341 {
342 
343 	KASSERT(1 == 0, ("%s called", __func__));
344 	return (EOPNOTSUPP);
345 }
346 
347 static void
348 g_label_generic_taste(struct g_consumer *cp, char *label, size_t size)
349 {
350 	struct g_provider *pp;
351 	struct g_label_metadata md;
352 
353 	g_topology_assert_not();
354 	label[0] = '\0';
355 	pp = cp->provider;
356 
357 	if (g_label_read_metadata(cp, &md) != 0)
358 		return;
359 
360 	if (strcmp(md.md_magic, G_LABEL_MAGIC) != 0)
361 		return;
362 
363 	if (md.md_version > G_LABEL_VERSION) {
364 		printf("geom_label.ko module is too old to handle %s.\n",
365 			pp->name);
366 		return;
367 	}
368 	/*
369 	 * Backward compatibility: there was no md_provsize field in
370 	 * earlier versions of metadata, so only check if we have it.
371 	 */
372 	if (md.md_version >= 2 && md.md_provsize != pp->mediasize)
373 		return;
374 
375 	strlcpy(label, md.md_label, size);
376 }
377 
378 static struct g_geom *
379 g_label_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
380 {
381 	struct g_consumer *cp;
382 	struct g_geom *gp;
383 	off_t mediasize;
384 	int i;
385 
386 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
387 	g_topology_assert();
388 
389 	G_LABEL_DEBUG(2, "Tasting %s.", pp->name);
390 
391 	/* Skip providers that are already open for writing. */
392 	if (pp->acw > 0)
393 		return (NULL);
394 
395 	if (strcmp(pp->geom->class->name, mp->name) == 0)
396 		return (NULL);
397 
398 	gp = g_new_geomf(mp, "label:taste");
399 	gp->start = g_label_start_taste;
400 	gp->access = g_label_access_taste;
401 	gp->orphan = g_label_orphan_taste;
402 	cp = g_new_consumer(gp);
403 	if (g_attach(cp, pp) != 0)
404 		goto end2;
405 	if (g_access(cp, 1, 0, 0) != 0)
406 		goto end;
407 	for (i = 0; g_labels[i] != NULL; i++) {
408 		char label[128];
409 
410 		if (g_labels[i]->ld_enabled == 0)
411 			continue;
412 		g_topology_unlock();
413 		g_labels[i]->ld_taste(cp, label, sizeof(label));
414 		g_label_mangle_name(label, sizeof(label));
415 		g_topology_lock();
416 		if (label[0] == '\0')
417 			continue;
418 		if (g_labels[i] != &g_label_generic) {
419 			mediasize = pp->mediasize;
420 		} else {
421 			mediasize = pp->mediasize - pp->sectorsize;
422 		}
423 		g_label_create(NULL, mp, pp, label,
424 		    g_labels[i]->ld_dirprefix, mediasize);
425 	}
426 	g_access(cp, -1, 0, 0);
427 end:
428 	g_detach(cp);
429 end2:
430 	g_destroy_consumer(cp);
431 	g_destroy_geom(gp);
432 	return (NULL);
433 }
434 
435 static void
436 g_label_ctl_create(struct gctl_req *req, struct g_class *mp)
437 {
438 	struct g_provider *pp;
439 	const char *name;
440 	int *nargs;
441 
442 	g_topology_assert();
443 
444 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
445 	if (nargs == NULL) {
446 		gctl_error(req, "No '%s' argument", "nargs");
447 		return;
448 	}
449 	if (*nargs != 2) {
450 		gctl_error(req, "Invalid number of arguments.");
451 		return;
452 	}
453 	/*
454 	 * arg1 is the name of provider.
455 	 */
456 	pp = gctl_get_provider(req, "arg1");
457 	if (pp == NULL)
458 		return;
459 	/*
460 	 * arg0 is the label.
461 	 */
462 	name = gctl_get_asciiparam(req, "arg0");
463 	if (name == NULL) {
464 		gctl_error(req, "No 'arg%d' argument", 0);
465 		return;
466 	}
467 	g_label_create(req, mp, pp, name, G_LABEL_DIRPREFIX, pp->mediasize);
468 }
469 
470 static const char *
471 g_label_skip_dir(const char *name)
472 {
473 	u_int i;
474 
475 	if (strncmp(name, _PATH_DEV, strlen(_PATH_DEV)) == 0)
476 		name += strlen(_PATH_DEV);
477 	for (i = 0; g_labels[i] != NULL; i++) {
478 		if (strncmp(name, g_labels[i]->ld_dirprefix,
479 		    strlen(g_labels[i]->ld_dirprefix)) == 0) {
480 			name += strlen(g_labels[i]->ld_dirprefix);
481 			break;
482 		}
483 	}
484 	return (name);
485 }
486 
487 static struct g_geom *
488 g_label_find_geom(struct g_class *mp, const char *name)
489 {
490 	struct g_geom *gp;
491 	struct g_provider *pp;
492 	const char *pname;
493 
494 	name = g_label_skip_dir(name);
495 	LIST_FOREACH(gp, &mp->geom, geom) {
496 		pp = LIST_FIRST(&gp->provider);
497 		pname = g_label_skip_dir(pp->name);
498 		if (strcmp(pname, name) == 0)
499 			return (gp);
500 	}
501 	return (NULL);
502 }
503 
504 static void
505 g_label_ctl_destroy(struct gctl_req *req, struct g_class *mp)
506 {
507 	int *nargs, *force, error, i;
508 	struct g_geom *gp;
509 	const char *name;
510 	char param[16];
511 
512 	g_topology_assert();
513 
514 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
515 	if (nargs == NULL) {
516 		gctl_error(req, "No '%s' argument", "nargs");
517 		return;
518 	}
519 	if (*nargs <= 0) {
520 		gctl_error(req, "Missing device(s).");
521 		return;
522 	}
523 	force = gctl_get_paraml(req, "force", sizeof(*force));
524 	if (force == NULL) {
525 		gctl_error(req, "No 'force' argument");
526 		return;
527 	}
528 
529 	for (i = 0; i < *nargs; i++) {
530 		snprintf(param, sizeof(param), "arg%d", i);
531 		name = gctl_get_asciiparam(req, param);
532 		if (name == NULL) {
533 			gctl_error(req, "No 'arg%d' argument", i);
534 			return;
535 		}
536 		gp = g_label_find_geom(mp, name);
537 		if (gp == NULL) {
538 			G_LABEL_DEBUG(1, "Label %s is invalid.", name);
539 			gctl_error(req, "Label %s is invalid.", name);
540 			return;
541 		}
542 		error = g_label_destroy(gp, *force);
543 		if (error != 0) {
544 			gctl_error(req, "Cannot destroy label %s (error=%d).",
545 			    LIST_FIRST(&gp->provider)->name, error);
546 			return;
547 		}
548 	}
549 }
550 
551 static void
552 g_label_config(struct gctl_req *req, struct g_class *mp, const char *verb)
553 {
554 	uint32_t *version;
555 
556 	g_topology_assert();
557 
558 	version = gctl_get_paraml(req, "version", sizeof(*version));
559 	if (version == NULL) {
560 		gctl_error(req, "No '%s' argument.", "version");
561 		return;
562 	}
563 	if (*version != G_LABEL_VERSION) {
564 		gctl_error(req, "Userland and kernel parts are out of sync.");
565 		return;
566 	}
567 
568 	if (strcmp(verb, "create") == 0) {
569 		g_label_ctl_create(req, mp);
570 		return;
571 	} else if (strcmp(verb, "destroy") == 0 ||
572 	    strcmp(verb, "stop") == 0) {
573 		g_label_ctl_destroy(req, mp);
574 		return;
575 	}
576 
577 	gctl_error(req, "Unknown verb.");
578 }
579 
580 DECLARE_GEOM_CLASS(g_label_class, g_label);
581 MODULE_VERSION(geom_label, 0);
582