xref: /freebsd/sys/geom/label/g_label.c (revision 9e5787d2284e187abb5b654d924394a65772e004)
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 
207 	sb = sbuf_new(NULL, NULL, size, SBUF_FIXEDLEN);
208 	for (c = label; *c != '\0'; c++) {
209 		/* Trim leading whitespace. */
210 		if (isspace(*c) && sbuf_len(sb) == 0)
211 			continue;
212 		if (!isprint(*c) || isspace(*c) || *c =='"' || *c == '%')
213 			sbuf_printf(sb, "%%%02X", *c);
214 		else
215 			sbuf_putc(sb, *c);
216 	}
217 	if (sbuf_finish(sb) != 0)
218 		label[0] = '\0';
219 	else
220 		strlcpy(label, sbuf_data(sb), size);
221 	sbuf_delete(sb);
222 }
223 
224 static struct g_geom *
225 g_label_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
226     const char *label, const char *dirprefix, off_t mediasize)
227 {
228 	struct g_geom *gp;
229 	struct g_provider *pp2;
230 	struct g_consumer *cp;
231 	char name[64];
232 
233 	g_topology_assert();
234 
235 	if (!g_label_is_name_ok(label)) {
236 		G_LABEL_DEBUG(0, "%s contains suspicious label, skipping.",
237 		    pp->name);
238 		G_LABEL_DEBUG(1, "%s suspicious label is: %s", pp->name, label);
239 		if (req != NULL)
240 			gctl_error(req, "Label name %s is invalid.", label);
241 		return (NULL);
242 	}
243 	gp = NULL;
244 	cp = NULL;
245 	if (snprintf(name, sizeof(name), "%s%s", dirprefix, label) >= sizeof(name)) {
246 		if (req != NULL)
247 			gctl_error(req, "Label name %s is too long.", label);
248 		return (NULL);
249 	}
250 	LIST_FOREACH(gp, &mp->geom, geom) {
251 		pp2 = LIST_FIRST(&gp->provider);
252 		if (pp2 == NULL)
253 			continue;
254 		if ((pp2->flags & G_PF_ORPHAN) != 0)
255 			continue;
256 		if (strcmp(pp2->name, name) == 0) {
257 			G_LABEL_DEBUG(1, "Label %s(%s) already exists (%s).",
258 			    label, name, pp->name);
259 			if (req != NULL) {
260 				gctl_error(req, "Provider %s already exists.",
261 				    name);
262 			}
263 			return (NULL);
264 		}
265 	}
266 	gp = g_slice_new(mp, 1, pp, &cp, NULL, 0, NULL);
267 	if (gp == NULL) {
268 		G_LABEL_DEBUG(0, "Cannot create slice %s.", label);
269 		if (req != NULL)
270 			gctl_error(req, "Cannot create slice %s.", label);
271 		return (NULL);
272 	}
273 	gp->orphan = g_label_orphan;
274 	gp->spoiled = g_label_spoiled;
275 	gp->resize = g_label_resize;
276 	g_access(cp, -1, 0, 0);
277 	g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t)0, mediasize,
278 	    pp->sectorsize, "%s", name);
279 	G_LABEL_DEBUG(1, "Label for provider %s is %s.", pp->name, name);
280 	return (gp);
281 }
282 
283 static int
284 g_label_destroy(struct g_geom *gp, boolean_t force)
285 {
286 	struct g_provider *pp;
287 
288 	g_topology_assert();
289 	pp = LIST_FIRST(&gp->provider);
290 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
291 		if (force) {
292 			G_LABEL_DEBUG(0, "Provider %s is still open, so it "
293 			    "can't be definitely removed.", pp->name);
294 		} else {
295 			G_LABEL_DEBUG(1,
296 			    "Provider %s is still open (r%dw%de%d).", pp->name,
297 			    pp->acr, pp->acw, pp->ace);
298 			return (EBUSY);
299 		}
300 	} else if (pp != NULL)
301 		G_LABEL_DEBUG(1, "Label %s removed.", pp->name);
302 	g_slice_spoiled(LIST_FIRST(&gp->consumer));
303 	return (0);
304 }
305 
306 static int
307 g_label_read_metadata(struct g_consumer *cp, struct g_label_metadata *md)
308 {
309 	struct g_provider *pp;
310 	u_char *buf;
311 	int error;
312 
313 	pp = cp->provider;
314 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
315 	    &error);
316 	if (buf == NULL)
317 		return (error);
318 	/* Decode metadata. */
319 	label_metadata_decode(buf, md);
320 	g_free(buf);
321 
322 	return (0);
323 }
324 
325 static void
326 g_label_orphan_taste(struct g_consumer *cp __unused)
327 {
328 
329 	KASSERT(1 == 0, ("%s called?", __func__));
330 }
331 
332 static void
333 g_label_start_taste(struct bio *bp __unused)
334 {
335 
336 	KASSERT(1 == 0, ("%s called?", __func__));
337 }
338 
339 static int
340 g_label_access_taste(struct g_provider *pp __unused, int dr __unused,
341     int dw __unused, int de __unused)
342 {
343 
344 	KASSERT(1 == 0, ("%s called", __func__));
345 	return (EOPNOTSUPP);
346 }
347 
348 static void
349 g_label_generic_taste(struct g_consumer *cp, char *label, size_t size)
350 {
351 	struct g_provider *pp;
352 	struct g_label_metadata md;
353 
354 	g_topology_assert_not();
355 	label[0] = '\0';
356 	pp = cp->provider;
357 
358 	if (g_label_read_metadata(cp, &md) != 0)
359 		return;
360 
361 	if (strcmp(md.md_magic, G_LABEL_MAGIC) != 0)
362 		return;
363 
364 	if (md.md_version > G_LABEL_VERSION) {
365 		printf("geom_label.ko module is too old to handle %s.\n",
366 			pp->name);
367 		return;
368 	}
369 	/*
370 	 * Backward compatibility: there was no md_provsize field in
371 	 * earlier versions of metadata, so only check if we have it.
372 	 */
373 	if (md.md_version >= 2 && md.md_provsize != pp->mediasize)
374 		return;
375 
376 	strlcpy(label, md.md_label, size);
377 }
378 
379 static struct g_geom *
380 g_label_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
381 {
382 	struct g_consumer *cp;
383 	struct g_geom *gp;
384 	off_t mediasize;
385 	int i;
386 
387 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
388 	g_topology_assert();
389 
390 	G_LABEL_DEBUG(2, "Tasting %s.", pp->name);
391 
392 	/* Skip providers that are already open for writing. */
393 	if (pp->acw > 0)
394 		return (NULL);
395 
396 	if (strcmp(pp->geom->class->name, mp->name) == 0)
397 		return (NULL);
398 
399 	gp = g_new_geomf(mp, "label:taste");
400 	gp->start = g_label_start_taste;
401 	gp->access = g_label_access_taste;
402 	gp->orphan = g_label_orphan_taste;
403 	cp = g_new_consumer(gp);
404 	g_attach(cp, pp);
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 	g_destroy_consumer(cp);
430 	g_destroy_geom(gp);
431 	return (NULL);
432 }
433 
434 static void
435 g_label_ctl_create(struct gctl_req *req, struct g_class *mp)
436 {
437 	struct g_provider *pp;
438 	const char *name;
439 	int *nargs;
440 
441 	g_topology_assert();
442 
443 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
444 	if (nargs == NULL) {
445 		gctl_error(req, "No '%s' argument", "nargs");
446 		return;
447 	}
448 	if (*nargs != 2) {
449 		gctl_error(req, "Invalid number of arguments.");
450 		return;
451 	}
452 	/*
453 	 * arg1 is the name of provider.
454 	 */
455 	pp = gctl_get_provider(req, "arg1");
456 	if (pp == NULL)
457 		return;
458 	/*
459 	 * arg0 is the label.
460 	 */
461 	name = gctl_get_asciiparam(req, "arg0");
462 	if (name == NULL) {
463 		gctl_error(req, "No 'arg%d' argument", 0);
464 		return;
465 	}
466 	g_label_create(req, mp, pp, name, G_LABEL_DIRPREFIX, pp->mediasize);
467 }
468 
469 static const char *
470 g_label_skip_dir(const char *name)
471 {
472 	u_int i;
473 
474 	if (strncmp(name, _PATH_DEV, strlen(_PATH_DEV)) == 0)
475 		name += strlen(_PATH_DEV);
476 	for (i = 0; g_labels[i] != NULL; i++) {
477 		if (strncmp(name, g_labels[i]->ld_dirprefix,
478 		    strlen(g_labels[i]->ld_dirprefix)) == 0) {
479 			name += strlen(g_labels[i]->ld_dirprefix);
480 			break;
481 		}
482 	}
483 	return (name);
484 }
485 
486 static struct g_geom *
487 g_label_find_geom(struct g_class *mp, const char *name)
488 {
489 	struct g_geom *gp;
490 	struct g_provider *pp;
491 	const char *pname;
492 
493 	name = g_label_skip_dir(name);
494 	LIST_FOREACH(gp, &mp->geom, geom) {
495 		pp = LIST_FIRST(&gp->provider);
496 		pname = g_label_skip_dir(pp->name);
497 		if (strcmp(pname, name) == 0)
498 			return (gp);
499 	}
500 	return (NULL);
501 }
502 
503 static void
504 g_label_ctl_destroy(struct gctl_req *req, struct g_class *mp)
505 {
506 	int *nargs, *force, error, i;
507 	struct g_geom *gp;
508 	const char *name;
509 	char param[16];
510 
511 	g_topology_assert();
512 
513 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
514 	if (nargs == NULL) {
515 		gctl_error(req, "No '%s' argument", "nargs");
516 		return;
517 	}
518 	if (*nargs <= 0) {
519 		gctl_error(req, "Missing device(s).");
520 		return;
521 	}
522 	force = gctl_get_paraml(req, "force", sizeof(*force));
523 	if (force == NULL) {
524 		gctl_error(req, "No 'force' argument");
525 		return;
526 	}
527 
528 	for (i = 0; i < *nargs; i++) {
529 		snprintf(param, sizeof(param), "arg%d", i);
530 		name = gctl_get_asciiparam(req, param);
531 		if (name == NULL) {
532 			gctl_error(req, "No 'arg%d' argument", i);
533 			return;
534 		}
535 		gp = g_label_find_geom(mp, name);
536 		if (gp == NULL) {
537 			G_LABEL_DEBUG(1, "Label %s is invalid.", name);
538 			gctl_error(req, "Label %s is invalid.", name);
539 			return;
540 		}
541 		error = g_label_destroy(gp, *force);
542 		if (error != 0) {
543 			gctl_error(req, "Cannot destroy label %s (error=%d).",
544 			    LIST_FIRST(&gp->provider)->name, error);
545 			return;
546 		}
547 	}
548 }
549 
550 static void
551 g_label_config(struct gctl_req *req, struct g_class *mp, const char *verb)
552 {
553 	uint32_t *version;
554 
555 	g_topology_assert();
556 
557 	version = gctl_get_paraml(req, "version", sizeof(*version));
558 	if (version == NULL) {
559 		gctl_error(req, "No '%s' argument.", "version");
560 		return;
561 	}
562 	if (*version != G_LABEL_VERSION) {
563 		gctl_error(req, "Userland and kernel parts are out of sync.");
564 		return;
565 	}
566 
567 	if (strcmp(verb, "create") == 0) {
568 		g_label_ctl_create(req, mp);
569 		return;
570 	} else if (strcmp(verb, "destroy") == 0 ||
571 	    strcmp(verb, "stop") == 0) {
572 		g_label_ctl_destroy(req, mp);
573 		return;
574 	}
575 
576 	gctl_error(req, "Unknown verb.");
577 }
578 
579 DECLARE_GEOM_CLASS(g_label_class, g_label);
580 MODULE_VERSION(geom_label, 0);
581