xref: /freebsd/sys/geom/label/g_label.c (revision e14ddd1f16e7e5788392c50de21ea7c927e0690c)
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 int
128 g_label_is_name_ok(const char *label)
129 {
130 	const char *s;
131 
132 	/* Check if the label starts from ../ */
133 	if (strncmp(label, "../", 3) == 0)
134 		return (0);
135 	/* Check if the label contains /../ */
136 	if (strstr(label, "/../") != NULL)
137 		return (0);
138 	/* Check if the label ends at ../ */
139 	if ((s = strstr(label, "/..")) != NULL && s[3] == '\0')
140 		return (0);
141 	return (1);
142 }
143 
144 static void
145 g_label_mangle_name(char *label, size_t size)
146 {
147 	struct sbuf *sb;
148 	const u_char *c;
149 
150 	sb = sbuf_new(NULL, NULL, size, SBUF_FIXEDLEN);
151 	for (c = label; *c != '\0'; c++) {
152 		if (!isprint(*c) || isspace(*c) || *c =='"' || *c == '%')
153 			sbuf_printf(sb, "%%%02X", *c);
154 		else
155 			sbuf_putc(sb, *c);
156 	}
157 	if (sbuf_finish(sb) != 0)
158 		label[0] = '\0';
159 	else
160 		strlcpy(label, sbuf_data(sb), size);
161 	sbuf_delete(sb);
162 }
163 
164 static struct g_geom *
165 g_label_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
166     const char *label, const char *dir, off_t mediasize)
167 {
168 	struct g_geom *gp;
169 	struct g_provider *pp2;
170 	struct g_consumer *cp;
171 	char name[64];
172 
173 	g_topology_assert();
174 
175 	if (!g_label_is_name_ok(label)) {
176 		G_LABEL_DEBUG(0, "%s contains suspicious label, skipping.",
177 		    pp->name);
178 		G_LABEL_DEBUG(1, "%s suspicious label is: %s", pp->name, label);
179 		if (req != NULL)
180 			gctl_error(req, "Label name %s is invalid.", label);
181 		return (NULL);
182 	}
183 	gp = NULL;
184 	cp = NULL;
185 	snprintf(name, sizeof(name), "%s/%s", dir, label);
186 	LIST_FOREACH(gp, &mp->geom, geom) {
187 		pp2 = LIST_FIRST(&gp->provider);
188 		if (pp2 == NULL)
189 			continue;
190 		if ((pp2->flags & G_PF_ORPHAN) != 0)
191 			continue;
192 		if (strcmp(pp2->name, name) == 0) {
193 			G_LABEL_DEBUG(1, "Label %s(%s) already exists (%s).",
194 			    label, name, pp->name);
195 			if (req != NULL) {
196 				gctl_error(req, "Provider %s already exists.",
197 				    name);
198 			}
199 			return (NULL);
200 		}
201 	}
202 	gp = g_slice_new(mp, 1, pp, &cp, NULL, 0, NULL);
203 	if (gp == NULL) {
204 		G_LABEL_DEBUG(0, "Cannot create slice %s.", label);
205 		if (req != NULL)
206 			gctl_error(req, "Cannot create slice %s.", label);
207 		return (NULL);
208 	}
209 	gp->orphan = g_label_orphan;
210 	gp->spoiled = g_label_spoiled;
211 	g_access(cp, -1, 0, 0);
212 	g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t)0, mediasize,
213 	    pp->sectorsize, "%s", name);
214 	G_LABEL_DEBUG(1, "Label for provider %s is %s.", pp->name, name);
215 	return (gp);
216 }
217 
218 static int
219 g_label_destroy(struct g_geom *gp, boolean_t force)
220 {
221 	struct g_provider *pp;
222 
223 	g_topology_assert();
224 	pp = LIST_FIRST(&gp->provider);
225 	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
226 		if (force) {
227 			G_LABEL_DEBUG(0, "Provider %s is still open, so it "
228 			    "can't be definitely removed.", pp->name);
229 		} else {
230 			G_LABEL_DEBUG(1,
231 			    "Provider %s is still open (r%dw%de%d).", pp->name,
232 			    pp->acr, pp->acw, pp->ace);
233 			return (EBUSY);
234 		}
235 	} else if (pp != NULL)
236 		G_LABEL_DEBUG(1, "Label %s removed.", pp->name);
237 	g_slice_spoiled(LIST_FIRST(&gp->consumer));
238 	return (0);
239 }
240 
241 static int
242 g_label_read_metadata(struct g_consumer *cp, struct g_label_metadata *md)
243 {
244 	struct g_provider *pp;
245 	u_char *buf;
246 	int error;
247 
248 	g_topology_assert();
249 
250 	pp = cp->provider;
251 	g_topology_unlock();
252 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
253 	    &error);
254 	g_topology_lock();
255 	if (buf == NULL)
256 		return (error);
257 	/* Decode metadata. */
258 	label_metadata_decode(buf, md);
259 	g_free(buf);
260 
261 	return (0);
262 }
263 
264 static void
265 g_label_orphan_taste(struct g_consumer *cp __unused)
266 {
267 
268 	KASSERT(1 == 0, ("%s called?", __func__));
269 }
270 
271 static void
272 g_label_start_taste(struct bio *bp __unused)
273 {
274 
275 	KASSERT(1 == 0, ("%s called?", __func__));
276 }
277 
278 static int
279 g_label_access_taste(struct g_provider *pp __unused, int dr __unused,
280     int dw __unused, int de __unused)
281 {
282 
283 	KASSERT(1 == 0, ("%s called", __func__));
284 	return (EOPNOTSUPP);
285 }
286 
287 static struct g_geom *
288 g_label_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
289 {
290 	struct g_label_metadata md;
291 	struct g_consumer *cp;
292 	struct g_geom *gp;
293 	int i;
294 
295 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
296 	g_topology_assert();
297 
298 	G_LABEL_DEBUG(2, "Tasting %s.", pp->name);
299 
300 	/* Skip providers that are already open for writing. */
301 	if (pp->acw > 0)
302 		return (NULL);
303 
304 	if (strcmp(pp->geom->class->name, mp->name) == 0)
305 		return (NULL);
306 
307 	gp = g_new_geomf(mp, "label:taste");
308 	gp->start = g_label_start_taste;
309 	gp->access = g_label_access_taste;
310 	gp->orphan = g_label_orphan_taste;
311 	cp = g_new_consumer(gp);
312 	g_attach(cp, pp);
313 	if (g_access(cp, 1, 0, 0) != 0)
314 		goto end;
315 	do {
316 		if (g_label_read_metadata(cp, &md) != 0)
317 			break;
318 		if (strcmp(md.md_magic, G_LABEL_MAGIC) != 0)
319 			break;
320 		if (md.md_version > G_LABEL_VERSION) {
321 			printf("geom_label.ko module is too old to handle %s.\n",
322 			    pp->name);
323 			break;
324 		}
325 
326 		/*
327 		 * Backward compatibility:
328 		 */
329 		/*
330 		 * There was no md_provsize field in earlier versions of
331 		 * metadata.
332 		 */
333 		if (md.md_version < 2)
334 			md.md_provsize = pp->mediasize;
335 
336 		if (md.md_provsize != pp->mediasize)
337 			break;
338 
339 		g_label_create(NULL, mp, pp, md.md_label, G_LABEL_DIR,
340 		    pp->mediasize - pp->sectorsize);
341 	} while (0);
342 	for (i = 0; g_labels[i] != NULL; i++) {
343 		char label[128];
344 
345 		if (g_labels[i]->ld_enabled == 0)
346 			continue;
347 		g_topology_unlock();
348 		g_labels[i]->ld_taste(cp, label, sizeof(label));
349 		g_label_mangle_name(label, sizeof(label));
350 		g_topology_lock();
351 		if (label[0] == '\0')
352 			continue;
353 		g_label_create(NULL, mp, pp, label, g_labels[i]->ld_dir,
354 		    pp->mediasize);
355 	}
356 	g_access(cp, -1, 0, 0);
357 end:
358 	g_detach(cp);
359 	g_destroy_consumer(cp);
360 	g_destroy_geom(gp);
361 	return (NULL);
362 }
363 
364 static void
365 g_label_ctl_create(struct gctl_req *req, struct g_class *mp)
366 {
367 	struct g_provider *pp;
368 	const char *name;
369 	int *nargs;
370 
371 	g_topology_assert();
372 
373 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
374 	if (nargs == NULL) {
375 		gctl_error(req, "No '%s' argument", "nargs");
376 		return;
377 	}
378 	if (*nargs != 2) {
379 		gctl_error(req, "Invalid number of arguments.");
380 		return;
381 	}
382 	/*
383 	 * arg1 is the name of provider.
384 	 */
385 	name = gctl_get_asciiparam(req, "arg1");
386 	if (name == NULL) {
387 		gctl_error(req, "No 'arg%d' argument", 1);
388 		return;
389 	}
390 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
391 		name += strlen("/dev/");
392 	pp = g_provider_by_name(name);
393 	if (pp == NULL) {
394 		G_LABEL_DEBUG(1, "Provider %s is invalid.", name);
395 		gctl_error(req, "Provider %s is invalid.", name);
396 		return;
397 	}
398 	/*
399 	 * arg0 is the label.
400 	 */
401 	name = gctl_get_asciiparam(req, "arg0");
402 	if (name == NULL) {
403 		gctl_error(req, "No 'arg%d' argument", 0);
404 		return;
405 	}
406 	g_label_create(req, mp, pp, name, G_LABEL_DIR, pp->mediasize);
407 }
408 
409 static const char *
410 g_label_skip_dir(const char *name)
411 {
412 	char path[64];
413 	u_int i;
414 
415 	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
416 		name += strlen("/dev/");
417 	if (strncmp(name, G_LABEL_DIR "/", strlen(G_LABEL_DIR "/")) == 0)
418 		name += strlen(G_LABEL_DIR "/");
419 	for (i = 0; g_labels[i] != NULL; i++) {
420 		snprintf(path, sizeof(path), "%s/", g_labels[i]->ld_dir);
421 		if (strncmp(name, path, strlen(path)) == 0) {
422 			name += strlen(path);
423 			break;
424 		}
425 	}
426 	return (name);
427 }
428 
429 static struct g_geom *
430 g_label_find_geom(struct g_class *mp, const char *name)
431 {
432 	struct g_geom *gp;
433 	struct g_provider *pp;
434 	const char *pname;
435 
436 	name = g_label_skip_dir(name);
437 	LIST_FOREACH(gp, &mp->geom, geom) {
438 		pp = LIST_FIRST(&gp->provider);
439 		pname = g_label_skip_dir(pp->name);
440 		if (strcmp(pname, name) == 0)
441 			return (gp);
442 	}
443 	return (NULL);
444 }
445 
446 static void
447 g_label_ctl_destroy(struct gctl_req *req, struct g_class *mp)
448 {
449 	int *nargs, *force, error, i;
450 	struct g_geom *gp;
451 	const char *name;
452 	char param[16];
453 
454 	g_topology_assert();
455 
456 	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
457 	if (nargs == NULL) {
458 		gctl_error(req, "No '%s' argument", "nargs");
459 		return;
460 	}
461 	if (*nargs <= 0) {
462 		gctl_error(req, "Missing device(s).");
463 		return;
464 	}
465 	force = gctl_get_paraml(req, "force", sizeof(*force));
466 	if (force == NULL) {
467 		gctl_error(req, "No 'force' argument");
468 		return;
469 	}
470 
471 	for (i = 0; i < *nargs; i++) {
472 		snprintf(param, sizeof(param), "arg%d", i);
473 		name = gctl_get_asciiparam(req, param);
474 		if (name == NULL) {
475 			gctl_error(req, "No 'arg%d' argument", i);
476 			return;
477 		}
478 		gp = g_label_find_geom(mp, name);
479 		if (gp == NULL) {
480 			G_LABEL_DEBUG(1, "Label %s is invalid.", name);
481 			gctl_error(req, "Label %s is invalid.", name);
482 			return;
483 		}
484 		error = g_label_destroy(gp, *force);
485 		if (error != 0) {
486 			gctl_error(req, "Cannot destroy label %s (error=%d).",
487 			    LIST_FIRST(&gp->provider)->name, error);
488 			return;
489 		}
490 	}
491 }
492 
493 static void
494 g_label_config(struct gctl_req *req, struct g_class *mp, const char *verb)
495 {
496 	uint32_t *version;
497 
498 	g_topology_assert();
499 
500 	version = gctl_get_paraml(req, "version", sizeof(*version));
501 	if (version == NULL) {
502 		gctl_error(req, "No '%s' argument.", "version");
503 		return;
504 	}
505 	if (*version != G_LABEL_VERSION) {
506 		gctl_error(req, "Userland and kernel parts are out of sync.");
507 		return;
508 	}
509 
510 	if (strcmp(verb, "create") == 0) {
511 		g_label_ctl_create(req, mp);
512 		return;
513 	} else if (strcmp(verb, "destroy") == 0 ||
514 	    strcmp(verb, "stop") == 0) {
515 		g_label_ctl_destroy(req, mp);
516 		return;
517 	}
518 
519 	gctl_error(req, "Unknown verb.");
520 }
521 
522 DECLARE_GEOM_CLASS(g_label_class, g_label);
523