xref: /freebsd/sys/geom/label/g_label.c (revision 955c8cbb4960e6cf3602de144b1b9154a5092968)
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 	NULL
93 };
94 
95 
96 static int
97 g_label_destroy_geom(struct gctl_req *req __unused, struct g_class *mp,
98     struct g_geom *gp __unused)
99 {
100 
101 	/*
102 	 * XXX: Unloading a class which is using geom_slice:1.56 is currently
103 	 * XXX: broken, so we deny unloading when we have geoms.
104 	 */
105 	return (EOPNOTSUPP);
106 }
107 
108 static void
109 g_label_orphan(struct g_consumer *cp)
110 {
111 
112 	G_LABEL_DEBUG(1, "Label %s removed.",
113 	    LIST_FIRST(&cp->geom->provider)->name);
114 	g_slice_orphan(cp);
115 }
116 
117 static void
118 g_label_spoiled(struct g_consumer *cp)
119 {
120 
121 	G_LABEL_DEBUG(1, "Label %s removed.",
122 	    LIST_FIRST(&cp->geom->provider)->name);
123 	g_slice_spoiled(cp);
124 }
125 
126 static int
127 g_label_is_name_ok(const char *label)
128 {
129 	const char *s;
130 
131 	/* Check if the label starts from ../ */
132 	if (strncmp(label, "../", 3) == 0)
133 		return (0);
134 	/* Check if the label contains /../ */
135 	if (strstr(label, "/../") != NULL)
136 		return (0);
137 	/* Check if the label ends at ../ */
138 	if ((s = strstr(label, "/..")) != NULL && s[3] == '\0')
139 		return (0);
140 	return (1);
141 }
142 
143 static void
144 g_label_mangle_name(char *label, size_t size)
145 {
146 	struct sbuf *sb;
147 	const u_char *c;
148 
149 	sb = sbuf_new(NULL, NULL, size, SBUF_FIXEDLEN);
150 	for (c = label; *c != '\0'; c++) {
151 		if (!isprint(*c) || isspace(*c) || *c =='"' || *c == '%')
152 			sbuf_printf(sb, "%%%02X", *c);
153 		else
154 			sbuf_putc(sb, *c);
155 	}
156 	if (sbuf_finish(sb) != 0)
157 		label[0] = '\0';
158 	else
159 		strlcpy(label, sbuf_data(sb), size);
160 	sbuf_delete(sb);
161 }
162 
163 static struct g_geom *
164 g_label_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
165     const char *label, const char *dir, off_t mediasize)
166 {
167 	struct g_geom *gp;
168 	struct g_provider *pp2;
169 	struct g_consumer *cp;
170 	char name[64];
171 
172 	g_topology_assert();
173 
174 	if (!g_label_is_name_ok(label)) {
175 		G_LABEL_DEBUG(0, "%s contains suspicious label, skipping.",
176 		    pp->name);
177 		G_LABEL_DEBUG(1, "%s suspicious label is: %s", pp->name, label);
178 		if (req != NULL)
179 			gctl_error(req, "Label name %s is invalid.", label);
180 		return (NULL);
181 	}
182 	gp = NULL;
183 	cp = NULL;
184 	snprintf(name, sizeof(name), "%s/%s", dir, label);
185 	LIST_FOREACH(gp, &mp->geom, geom) {
186 		pp2 = LIST_FIRST(&gp->provider);
187 		if (pp2 == NULL)
188 			continue;
189 		if ((pp2->flags & G_PF_ORPHAN) != 0)
190 			continue;
191 		if (strcmp(pp2->name, name) == 0) {
192 			G_LABEL_DEBUG(1, "Label %s(%s) already exists (%s).",
193 			    label, name, pp->name);
194 			if (req != NULL) {
195 				gctl_error(req, "Provider %s already exists.",
196 				    name);
197 			}
198 			return (NULL);
199 		}
200 	}
201 	gp = g_slice_new(mp, 1, pp, &cp, NULL, 0, NULL);
202 	if (gp == NULL) {
203 		G_LABEL_DEBUG(0, "Cannot create slice %s.", label);
204 		if (req != NULL)
205 			gctl_error(req, "Cannot create slice %s.", label);
206 		return (NULL);
207 	}
208 	gp->orphan = g_label_orphan;
209 	gp->spoiled = g_label_spoiled;
210 	g_access(cp, -1, 0, 0);
211 	g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t)0, mediasize,
212 	    pp->sectorsize, "%s", name);
213 	G_LABEL_DEBUG(1, "Label for provider %s is %s.", pp->name, name);
214 	return (gp);
215 }
216 
217 static int
218 g_label_destroy(struct g_geom *gp, boolean_t force)
219 {
220 	struct g_provider *pp;
221 
222 	g_topology_assert();
223 	pp = LIST_FIRST(&gp->provider);
224 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
225 		if (force) {
226 			G_LABEL_DEBUG(0, "Provider %s is still open, so it "
227 			    "can't be definitely removed.", pp->name);
228 		} else {
229 			G_LABEL_DEBUG(1,
230 			    "Provider %s is still open (r%dw%de%d).", pp->name,
231 			    pp->acr, pp->acw, pp->ace);
232 			return (EBUSY);
233 		}
234 	} else if (pp != NULL)
235 		G_LABEL_DEBUG(1, "Label %s removed.", pp->name);
236 	g_slice_spoiled(LIST_FIRST(&gp->consumer));
237 	return (0);
238 }
239 
240 static int
241 g_label_read_metadata(struct g_consumer *cp, struct g_label_metadata *md)
242 {
243 	struct g_provider *pp;
244 	u_char *buf;
245 	int error;
246 
247 	g_topology_assert();
248 
249 	pp = cp->provider;
250 	g_topology_unlock();
251 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
252 	    &error);
253 	g_topology_lock();
254 	if (buf == NULL)
255 		return (error);
256 	/* Decode metadata. */
257 	label_metadata_decode(buf, md);
258 	g_free(buf);
259 
260 	return (0);
261 }
262 
263 static void
264 g_label_orphan_taste(struct g_consumer *cp __unused)
265 {
266 
267 	KASSERT(1 == 0, ("%s called?", __func__));
268 }
269 
270 static void
271 g_label_start_taste(struct bio *bp __unused)
272 {
273 
274 	KASSERT(1 == 0, ("%s called?", __func__));
275 }
276 
277 static int
278 g_label_access_taste(struct g_provider *pp __unused, int dr __unused,
279     int dw __unused, int de __unused)
280 {
281 
282 	KASSERT(1 == 0, ("%s called", __func__));
283 	return (EOPNOTSUPP);
284 }
285 
286 static struct g_geom *
287 g_label_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
288 {
289 	struct g_label_metadata md;
290 	struct g_consumer *cp;
291 	struct g_geom *gp;
292 	int i;
293 
294 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
295 	g_topology_assert();
296 
297 	G_LABEL_DEBUG(2, "Tasting %s.", pp->name);
298 
299 	/* Skip providers that are already open for writing. */
300 	if (pp->acw > 0)
301 		return (NULL);
302 
303 	if (strcmp(pp->geom->class->name, mp->name) == 0)
304 		return (NULL);
305 
306 	gp = g_new_geomf(mp, "label:taste");
307 	gp->start = g_label_start_taste;
308 	gp->access = g_label_access_taste;
309 	gp->orphan = g_label_orphan_taste;
310 	cp = g_new_consumer(gp);
311 	g_attach(cp, pp);
312 	if (g_access(cp, 1, 0, 0) != 0)
313 		goto end;
314 	do {
315 		if (g_label_read_metadata(cp, &md) != 0)
316 			break;
317 		if (strcmp(md.md_magic, G_LABEL_MAGIC) != 0)
318 			break;
319 		if (md.md_version > G_LABEL_VERSION) {
320 			printf("geom_label.ko module is too old to handle %s.\n",
321 			    pp->name);
322 			break;
323 		}
324 
325 		/*
326 		 * Backward compatibility:
327 		 */
328 		/*
329 		 * There was no md_provsize field in earlier versions of
330 		 * metadata.
331 		 */
332 		if (md.md_version < 2)
333 			md.md_provsize = pp->mediasize;
334 
335 		if (md.md_provsize != pp->mediasize)
336 			break;
337 
338 		g_label_create(NULL, mp, pp, md.md_label, G_LABEL_DIR,
339 		    pp->mediasize - pp->sectorsize);
340 	} while (0);
341 	for (i = 0; g_labels[i] != NULL; i++) {
342 		char label[64];
343 
344 		if (g_labels[i]->ld_enabled == 0)
345 			continue;
346 		g_topology_unlock();
347 		g_labels[i]->ld_taste(cp, label, sizeof(label));
348 		g_label_mangle_name(label, sizeof(label));
349 		g_topology_lock();
350 		if (label[0] == '\0')
351 			continue;
352 		g_label_create(NULL, mp, pp, label, g_labels[i]->ld_dir,
353 		    pp->mediasize);
354 	}
355 	g_access(cp, -1, 0, 0);
356 end:
357 	g_detach(cp);
358 	g_destroy_consumer(cp);
359 	g_destroy_geom(gp);
360 	return (NULL);
361 }
362 
363 static void
364 g_label_ctl_create(struct gctl_req *req, struct g_class *mp)
365 {
366 	struct g_provider *pp;
367 	const char *name;
368 	int *nargs;
369 
370 	g_topology_assert();
371 
372 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
373 	if (nargs == NULL) {
374 		gctl_error(req, "No '%s' argument", "nargs");
375 		return;
376 	}
377 	if (*nargs != 2) {
378 		gctl_error(req, "Invalid number of arguments.");
379 		return;
380 	}
381 	/*
382 	 * arg1 is the name of provider.
383 	 */
384 	name = gctl_get_asciiparam(req, "arg1");
385 	if (name == NULL) {
386 		gctl_error(req, "No 'arg%d' argument", 1);
387 		return;
388 	}
389 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
390 		name += strlen("/dev/");
391 	pp = g_provider_by_name(name);
392 	if (pp == NULL) {
393 		G_LABEL_DEBUG(1, "Provider %s is invalid.", name);
394 		gctl_error(req, "Provider %s is invalid.", name);
395 		return;
396 	}
397 	/*
398 	 * arg0 is the label.
399 	 */
400 	name = gctl_get_asciiparam(req, "arg0");
401 	if (name == NULL) {
402 		gctl_error(req, "No 'arg%d' argument", 0);
403 		return;
404 	}
405 	g_label_create(req, mp, pp, name, G_LABEL_DIR, pp->mediasize);
406 }
407 
408 static const char *
409 g_label_skip_dir(const char *name)
410 {
411 	char path[64];
412 	u_int i;
413 
414 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
415 		name += strlen("/dev/");
416 	if (strncmp(name, G_LABEL_DIR "/", strlen(G_LABEL_DIR "/")) == 0)
417 		name += strlen(G_LABEL_DIR "/");
418 	for (i = 0; g_labels[i] != NULL; i++) {
419 		snprintf(path, sizeof(path), "%s/", g_labels[i]->ld_dir);
420 		if (strncmp(name, path, strlen(path)) == 0) {
421 			name += strlen(path);
422 			break;
423 		}
424 	}
425 	return (name);
426 }
427 
428 static struct g_geom *
429 g_label_find_geom(struct g_class *mp, const char *name)
430 {
431 	struct g_geom *gp;
432 	struct g_provider *pp;
433 	const char *pname;
434 
435 	name = g_label_skip_dir(name);
436 	LIST_FOREACH(gp, &mp->geom, geom) {
437 		pp = LIST_FIRST(&gp->provider);
438 		pname = g_label_skip_dir(pp->name);
439 		if (strcmp(pname, name) == 0)
440 			return (gp);
441 	}
442 	return (NULL);
443 }
444 
445 static void
446 g_label_ctl_destroy(struct gctl_req *req, struct g_class *mp)
447 {
448 	int *nargs, *force, error, i;
449 	struct g_geom *gp;
450 	const char *name;
451 	char param[16];
452 
453 	g_topology_assert();
454 
455 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
456 	if (nargs == NULL) {
457 		gctl_error(req, "No '%s' argument", "nargs");
458 		return;
459 	}
460 	if (*nargs <= 0) {
461 		gctl_error(req, "Missing device(s).");
462 		return;
463 	}
464 	force = gctl_get_paraml(req, "force", sizeof(*force));
465 	if (force == NULL) {
466 		gctl_error(req, "No 'force' argument");
467 		return;
468 	}
469 
470 	for (i = 0; i < *nargs; i++) {
471 		snprintf(param, sizeof(param), "arg%d", i);
472 		name = gctl_get_asciiparam(req, param);
473 		if (name == NULL) {
474 			gctl_error(req, "No 'arg%d' argument", i);
475 			return;
476 		}
477 		gp = g_label_find_geom(mp, name);
478 		if (gp == NULL) {
479 			G_LABEL_DEBUG(1, "Label %s is invalid.", name);
480 			gctl_error(req, "Label %s is invalid.", name);
481 			return;
482 		}
483 		error = g_label_destroy(gp, *force);
484 		if (error != 0) {
485 			gctl_error(req, "Cannot destroy label %s (error=%d).",
486 			    LIST_FIRST(&gp->provider)->name, error);
487 			return;
488 		}
489 	}
490 }
491 
492 static void
493 g_label_config(struct gctl_req *req, struct g_class *mp, const char *verb)
494 {
495 	uint32_t *version;
496 
497 	g_topology_assert();
498 
499 	version = gctl_get_paraml(req, "version", sizeof(*version));
500 	if (version == NULL) {
501 		gctl_error(req, "No '%s' argument.", "version");
502 		return;
503 	}
504 	if (*version != G_LABEL_VERSION) {
505 		gctl_error(req, "Userland and kernel parts are out of sync.");
506 		return;
507 	}
508 
509 	if (strcmp(verb, "create") == 0) {
510 		g_label_ctl_create(req, mp);
511 		return;
512 	} else if (strcmp(verb, "destroy") == 0 ||
513 	    strcmp(verb, "stop") == 0) {
514 		g_label_ctl_destroy(req, mp);
515 		return;
516 	}
517 
518 	gctl_error(req, "Unknown verb.");
519 }
520 
521 DECLARE_GEOM_CLASS(g_label_class, g_label);
522