xref: /freebsd/sys/geom/label/g_label.c (revision d4ae33f0721c1b170fe37d97e395228ffcfb3f80)
1 /*-
2  * Copyright (c) 2004-2005 Pawel Jakub Dawidek <pjd@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #include <sys/module.h>
34 #include <sys/lock.h>
35 #include <sys/mutex.h>
36 #include <sys/bio.h>
37 #include <sys/ctype.h>
38 #include <sys/malloc.h>
39 #include <sys/libkern.h>
40 #include <sys/sbuf.h>
41 #include <sys/sysctl.h>
42 #include <geom/geom.h>
43 #include <geom/geom_slice.h>
44 #include <geom/label/g_label.h>
45 
46 FEATURE(geom_label, "GEOM labeling support");
47 
48 SYSCTL_DECL(_kern_geom);
49 SYSCTL_NODE(_kern_geom, OID_AUTO, label, CTLFLAG_RW, 0, "GEOM_LABEL stuff");
50 u_int g_label_debug = 0;
51 TUNABLE_INT("kern.geom.label.debug", &g_label_debug);
52 SYSCTL_UINT(_kern_geom_label, OID_AUTO, debug, CTLFLAG_RW, &g_label_debug, 0,
53     "Debug level");
54 
55 static int g_label_destroy_geom(struct gctl_req *req, struct g_class *mp,
56     struct g_geom *gp);
57 static int g_label_destroy(struct g_geom *gp, boolean_t force);
58 static struct g_geom *g_label_taste(struct g_class *mp, struct g_provider *pp,
59     int flags __unused);
60 static void g_label_config(struct gctl_req *req, struct g_class *mp,
61     const char *verb);
62 
63 struct g_class g_label_class = {
64 	.name = G_LABEL_CLASS_NAME,
65 	.version = G_VERSION,
66 	.ctlreq = g_label_config,
67 	.taste = g_label_taste,
68 	.destroy_geom = g_label_destroy_geom
69 };
70 
71 /*
72  * To add a new file system where you want to look for volume labels,
73  * you have to:
74  * 1. Add a file g_label_<file system>.c which implements labels recognition.
75  * 2. Add an 'extern const struct g_label_desc g_label_<file system>;' into
76  *    g_label.h file.
77  * 3. Add an element to the table below '&g_label_<file system>,'.
78  * 4. Add your file to sys/conf/files.
79  * 5. Add your file to sys/modules/geom/geom_label/Makefile.
80  * 6. Add your file system to manual page sbin/geom/class/label/glabel.8.
81  */
82 const struct g_label_desc *g_labels[] = {
83 	&g_label_ufs_id,
84 	&g_label_ufs_volume,
85 	&g_label_iso9660,
86 	&g_label_msdosfs,
87 	&g_label_ext2fs,
88 	&g_label_reiserfs,
89 	&g_label_ntfs,
90 	&g_label_gpt,
91 	&g_label_gpt_uuid,
92 	&g_label_disk_ident,
93 	NULL
94 };
95 
96 
97 static int
98 g_label_destroy_geom(struct gctl_req *req __unused, struct g_class *mp,
99     struct g_geom *gp __unused)
100 {
101 
102 	/*
103 	 * XXX: Unloading a class which is using geom_slice:1.56 is currently
104 	 * XXX: broken, so we deny unloading when we have geoms.
105 	 */
106 	return (EOPNOTSUPP);
107 }
108 
109 static void
110 g_label_orphan(struct g_consumer *cp)
111 {
112 
113 	G_LABEL_DEBUG(1, "Label %s removed.",
114 	    LIST_FIRST(&cp->geom->provider)->name);
115 	g_slice_orphan(cp);
116 }
117 
118 static void
119 g_label_spoiled(struct g_consumer *cp)
120 {
121 
122 	G_LABEL_DEBUG(1, "Label %s removed.",
123 	    LIST_FIRST(&cp->geom->provider)->name);
124 	g_slice_spoiled(cp);
125 }
126 
127 static void
128 g_label_resize(struct g_consumer *cp)
129 {
130 
131 	G_LABEL_DEBUG(1, "Label %s resized.",
132 	    LIST_FIRST(&cp->geom->provider)->name);
133 
134 	g_slice_config(cp->geom, 0, G_SLICE_CONFIG_FORCE, (off_t)0,
135 	    cp->provider->mediasize, cp->provider->sectorsize, "notused");
136 }
137 
138 static int
139 g_label_is_name_ok(const char *label)
140 {
141 	const char *s;
142 
143 	/* Check if the label starts from ../ */
144 	if (strncmp(label, "../", 3) == 0)
145 		return (0);
146 	/* Check if the label contains /../ */
147 	if (strstr(label, "/../") != NULL)
148 		return (0);
149 	/* Check if the label ends at ../ */
150 	if ((s = strstr(label, "/..")) != NULL && s[3] == '\0')
151 		return (0);
152 	return (1);
153 }
154 
155 static void
156 g_label_mangle_name(char *label, size_t size)
157 {
158 	struct sbuf *sb;
159 	const u_char *c;
160 
161 	sb = sbuf_new(NULL, NULL, size, SBUF_FIXEDLEN);
162 	for (c = label; *c != '\0'; c++) {
163 		if (!isprint(*c) || isspace(*c) || *c =='"' || *c == '%')
164 			sbuf_printf(sb, "%%%02X", *c);
165 		else
166 			sbuf_putc(sb, *c);
167 	}
168 	if (sbuf_finish(sb) != 0)
169 		label[0] = '\0';
170 	else
171 		strlcpy(label, sbuf_data(sb), size);
172 	sbuf_delete(sb);
173 }
174 
175 static struct g_geom *
176 g_label_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
177     const char *label, const char *dir, off_t mediasize)
178 {
179 	struct g_geom *gp;
180 	struct g_provider *pp2;
181 	struct g_consumer *cp;
182 	char name[64];
183 
184 	g_topology_assert();
185 
186 	if (!g_label_is_name_ok(label)) {
187 		G_LABEL_DEBUG(0, "%s contains suspicious label, skipping.",
188 		    pp->name);
189 		G_LABEL_DEBUG(1, "%s suspicious label is: %s", pp->name, label);
190 		if (req != NULL)
191 			gctl_error(req, "Label name %s is invalid.", label);
192 		return (NULL);
193 	}
194 	gp = NULL;
195 	cp = NULL;
196 	snprintf(name, sizeof(name), "%s/%s", dir, label);
197 	LIST_FOREACH(gp, &mp->geom, geom) {
198 		pp2 = LIST_FIRST(&gp->provider);
199 		if (pp2 == NULL)
200 			continue;
201 		if ((pp2->flags & G_PF_ORPHAN) != 0)
202 			continue;
203 		if (strcmp(pp2->name, name) == 0) {
204 			G_LABEL_DEBUG(1, "Label %s(%s) already exists (%s).",
205 			    label, name, pp->name);
206 			if (req != NULL) {
207 				gctl_error(req, "Provider %s already exists.",
208 				    name);
209 			}
210 			return (NULL);
211 		}
212 	}
213 	gp = g_slice_new(mp, 1, pp, &cp, NULL, 0, NULL);
214 	if (gp == NULL) {
215 		G_LABEL_DEBUG(0, "Cannot create slice %s.", label);
216 		if (req != NULL)
217 			gctl_error(req, "Cannot create slice %s.", label);
218 		return (NULL);
219 	}
220 	gp->orphan = g_label_orphan;
221 	gp->spoiled = g_label_spoiled;
222 	gp->resize = g_label_resize;
223 	g_access(cp, -1, 0, 0);
224 	g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t)0, mediasize,
225 	    pp->sectorsize, "%s", name);
226 	G_LABEL_DEBUG(1, "Label for provider %s is %s.", pp->name, name);
227 	return (gp);
228 }
229 
230 static int
231 g_label_destroy(struct g_geom *gp, boolean_t force)
232 {
233 	struct g_provider *pp;
234 
235 	g_topology_assert();
236 	pp = LIST_FIRST(&gp->provider);
237 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
238 		if (force) {
239 			G_LABEL_DEBUG(0, "Provider %s is still open, so it "
240 			    "can't be definitely removed.", pp->name);
241 		} else {
242 			G_LABEL_DEBUG(1,
243 			    "Provider %s is still open (r%dw%de%d).", pp->name,
244 			    pp->acr, pp->acw, pp->ace);
245 			return (EBUSY);
246 		}
247 	} else if (pp != NULL)
248 		G_LABEL_DEBUG(1, "Label %s removed.", pp->name);
249 	g_slice_spoiled(LIST_FIRST(&gp->consumer));
250 	return (0);
251 }
252 
253 static int
254 g_label_read_metadata(struct g_consumer *cp, struct g_label_metadata *md)
255 {
256 	struct g_provider *pp;
257 	u_char *buf;
258 	int error;
259 
260 	g_topology_assert();
261 
262 	pp = cp->provider;
263 	g_topology_unlock();
264 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
265 	    &error);
266 	g_topology_lock();
267 	if (buf == NULL)
268 		return (error);
269 	/* Decode metadata. */
270 	label_metadata_decode(buf, md);
271 	g_free(buf);
272 
273 	return (0);
274 }
275 
276 static void
277 g_label_orphan_taste(struct g_consumer *cp __unused)
278 {
279 
280 	KASSERT(1 == 0, ("%s called?", __func__));
281 }
282 
283 static void
284 g_label_start_taste(struct bio *bp __unused)
285 {
286 
287 	KASSERT(1 == 0, ("%s called?", __func__));
288 }
289 
290 static int
291 g_label_access_taste(struct g_provider *pp __unused, int dr __unused,
292     int dw __unused, int de __unused)
293 {
294 
295 	KASSERT(1 == 0, ("%s called", __func__));
296 	return (EOPNOTSUPP);
297 }
298 
299 static struct g_geom *
300 g_label_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
301 {
302 	struct g_label_metadata md;
303 	struct g_consumer *cp;
304 	struct g_geom *gp;
305 	int i;
306 
307 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
308 	g_topology_assert();
309 
310 	G_LABEL_DEBUG(2, "Tasting %s.", pp->name);
311 
312 	/* Skip providers that are already open for writing. */
313 	if (pp->acw > 0)
314 		return (NULL);
315 
316 	if (strcmp(pp->geom->class->name, mp->name) == 0)
317 		return (NULL);
318 
319 	gp = g_new_geomf(mp, "label:taste");
320 	gp->start = g_label_start_taste;
321 	gp->access = g_label_access_taste;
322 	gp->orphan = g_label_orphan_taste;
323 	cp = g_new_consumer(gp);
324 	g_attach(cp, pp);
325 	if (g_access(cp, 1, 0, 0) != 0)
326 		goto end;
327 	do {
328 		if (g_label_read_metadata(cp, &md) != 0)
329 			break;
330 		if (strcmp(md.md_magic, G_LABEL_MAGIC) != 0)
331 			break;
332 		if (md.md_version > G_LABEL_VERSION) {
333 			printf("geom_label.ko module is too old to handle %s.\n",
334 			    pp->name);
335 			break;
336 		}
337 
338 		/*
339 		 * Backward compatibility:
340 		 */
341 		/*
342 		 * There was no md_provsize field in earlier versions of
343 		 * metadata.
344 		 */
345 		if (md.md_version < 2)
346 			md.md_provsize = pp->mediasize;
347 
348 		if (md.md_provsize != pp->mediasize)
349 			break;
350 
351 		g_label_create(NULL, mp, pp, md.md_label, G_LABEL_DIR,
352 		    pp->mediasize - pp->sectorsize);
353 	} while (0);
354 	for (i = 0; g_labels[i] != NULL; i++) {
355 		char label[128];
356 
357 		if (g_labels[i]->ld_enabled == 0)
358 			continue;
359 		g_topology_unlock();
360 		g_labels[i]->ld_taste(cp, label, sizeof(label));
361 		g_label_mangle_name(label, sizeof(label));
362 		g_topology_lock();
363 		if (label[0] == '\0')
364 			continue;
365 		g_label_create(NULL, mp, pp, label, g_labels[i]->ld_dir,
366 		    pp->mediasize);
367 	}
368 	g_access(cp, -1, 0, 0);
369 end:
370 	g_detach(cp);
371 	g_destroy_consumer(cp);
372 	g_destroy_geom(gp);
373 	return (NULL);
374 }
375 
376 static void
377 g_label_ctl_create(struct gctl_req *req, struct g_class *mp)
378 {
379 	struct g_provider *pp;
380 	const char *name;
381 	int *nargs;
382 
383 	g_topology_assert();
384 
385 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
386 	if (nargs == NULL) {
387 		gctl_error(req, "No '%s' argument", "nargs");
388 		return;
389 	}
390 	if (*nargs != 2) {
391 		gctl_error(req, "Invalid number of arguments.");
392 		return;
393 	}
394 	/*
395 	 * arg1 is the name of provider.
396 	 */
397 	name = gctl_get_asciiparam(req, "arg1");
398 	if (name == NULL) {
399 		gctl_error(req, "No 'arg%d' argument", 1);
400 		return;
401 	}
402 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
403 		name += strlen("/dev/");
404 	pp = g_provider_by_name(name);
405 	if (pp == NULL) {
406 		G_LABEL_DEBUG(1, "Provider %s is invalid.", name);
407 		gctl_error(req, "Provider %s is invalid.", name);
408 		return;
409 	}
410 	/*
411 	 * arg0 is the label.
412 	 */
413 	name = gctl_get_asciiparam(req, "arg0");
414 	if (name == NULL) {
415 		gctl_error(req, "No 'arg%d' argument", 0);
416 		return;
417 	}
418 	g_label_create(req, mp, pp, name, G_LABEL_DIR, pp->mediasize);
419 }
420 
421 static const char *
422 g_label_skip_dir(const char *name)
423 {
424 	char path[64];
425 	u_int i;
426 
427 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
428 		name += strlen("/dev/");
429 	if (strncmp(name, G_LABEL_DIR "/", strlen(G_LABEL_DIR "/")) == 0)
430 		name += strlen(G_LABEL_DIR "/");
431 	for (i = 0; g_labels[i] != NULL; i++) {
432 		snprintf(path, sizeof(path), "%s/", g_labels[i]->ld_dir);
433 		if (strncmp(name, path, strlen(path)) == 0) {
434 			name += strlen(path);
435 			break;
436 		}
437 	}
438 	return (name);
439 }
440 
441 static struct g_geom *
442 g_label_find_geom(struct g_class *mp, const char *name)
443 {
444 	struct g_geom *gp;
445 	struct g_provider *pp;
446 	const char *pname;
447 
448 	name = g_label_skip_dir(name);
449 	LIST_FOREACH(gp, &mp->geom, geom) {
450 		pp = LIST_FIRST(&gp->provider);
451 		pname = g_label_skip_dir(pp->name);
452 		if (strcmp(pname, name) == 0)
453 			return (gp);
454 	}
455 	return (NULL);
456 }
457 
458 static void
459 g_label_ctl_destroy(struct gctl_req *req, struct g_class *mp)
460 {
461 	int *nargs, *force, error, i;
462 	struct g_geom *gp;
463 	const char *name;
464 	char param[16];
465 
466 	g_topology_assert();
467 
468 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
469 	if (nargs == NULL) {
470 		gctl_error(req, "No '%s' argument", "nargs");
471 		return;
472 	}
473 	if (*nargs <= 0) {
474 		gctl_error(req, "Missing device(s).");
475 		return;
476 	}
477 	force = gctl_get_paraml(req, "force", sizeof(*force));
478 	if (force == NULL) {
479 		gctl_error(req, "No 'force' argument");
480 		return;
481 	}
482 
483 	for (i = 0; i < *nargs; i++) {
484 		snprintf(param, sizeof(param), "arg%d", i);
485 		name = gctl_get_asciiparam(req, param);
486 		if (name == NULL) {
487 			gctl_error(req, "No 'arg%d' argument", i);
488 			return;
489 		}
490 		gp = g_label_find_geom(mp, name);
491 		if (gp == NULL) {
492 			G_LABEL_DEBUG(1, "Label %s is invalid.", name);
493 			gctl_error(req, "Label %s is invalid.", name);
494 			return;
495 		}
496 		error = g_label_destroy(gp, *force);
497 		if (error != 0) {
498 			gctl_error(req, "Cannot destroy label %s (error=%d).",
499 			    LIST_FIRST(&gp->provider)->name, error);
500 			return;
501 		}
502 	}
503 }
504 
505 static void
506 g_label_config(struct gctl_req *req, struct g_class *mp, const char *verb)
507 {
508 	uint32_t *version;
509 
510 	g_topology_assert();
511 
512 	version = gctl_get_paraml(req, "version", sizeof(*version));
513 	if (version == NULL) {
514 		gctl_error(req, "No '%s' argument.", "version");
515 		return;
516 	}
517 	if (*version != G_LABEL_VERSION) {
518 		gctl_error(req, "Userland and kernel parts are out of sync.");
519 		return;
520 	}
521 
522 	if (strcmp(verb, "create") == 0) {
523 		g_label_ctl_create(req, mp);
524 		return;
525 	} else if (strcmp(verb, "destroy") == 0 ||
526 	    strcmp(verb, "stop") == 0) {
527 		g_label_ctl_destroy(req, mp);
528 		return;
529 	}
530 
531 	gctl_error(req, "Unknown verb.");
532 }
533 
534 DECLARE_GEOM_CLASS(g_label_class, g_label);
535