g_label.c revision 332640 
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: stable/11/sys/geom/label/g_label.c 332640 2018-04-17 02:18:04Z kevans $");
29
30#include "opt_geom.h"
31
32#include <sys/param.h>
33#include <sys/systm.h>
34#include <sys/kernel.h>
35#include <sys/module.h>
36#include <sys/lock.h>
37#include <sys/mutex.h>
38#include <sys/bio.h>
39#include <sys/ctype.h>
40#include <sys/malloc.h>
41#include <sys/libkern.h>
42#include <sys/sbuf.h>
43#include <sys/stddef.h>
44#include <sys/sysctl.h>
45#include <geom/geom.h>
46#include <geom/geom_slice.h>
47#include <geom/label/g_label.h>
48
49FEATURE(geom_label, "GEOM labeling support");
50
51SYSCTL_DECL(_kern_geom);
52SYSCTL_NODE(_kern_geom, OID_AUTO, label, CTLFLAG_RW, 0, "GEOM_LABEL stuff");
53u_int g_label_debug = 0;
54SYSCTL_UINT(_kern_geom_label, OID_AUTO, debug, CTLFLAG_RWTUN, &g_label_debug, 0,
55    "Debug level");
56
57static int g_label_destroy_geom(struct gctl_req *req, struct g_class *mp,
58    struct g_geom *gp);
59static int g_label_destroy(struct g_geom *gp, boolean_t force);
60static struct g_geom *g_label_taste(struct g_class *mp, struct g_provider *pp,
61    int flags __unused);
62static void g_label_config(struct gctl_req *req, struct g_class *mp,
63    const char *verb);
64
65struct g_class g_label_class = {
66	.name = G_LABEL_CLASS_NAME,
67	.version = G_VERSION,
68	.ctlreq = g_label_config,
69	.taste = g_label_taste,
70	.destroy_geom = g_label_destroy_geom
71};
72
73/*
74 * To add a new file system where you want to look for volume labels,
75 * you have to:
76 * 1. Add a file g_label_<file system>.c which implements labels recognition.
77 * 2. Add an 'extern const struct g_label_desc g_label_<file system>;' into
78 *    g_label.h file.
79 * 3. Add an element to the table below '&g_label_<file system>,'.
80 * 4. Add your file to sys/conf/files.
81 * 5. Add your file to sys/modules/geom/geom_label/Makefile.
82 * 6. Add your file system to manual page sbin/geom/class/label/glabel.8.
83 */
84const struct g_label_desc *g_labels[] = {
85	&g_label_gpt,
86	&g_label_gpt_uuid,
87#ifdef GEOM_LABEL
88	&g_label_ufs_id,
89	&g_label_ufs_volume,
90	&g_label_iso9660,
91	&g_label_msdosfs,
92	&g_label_ext2fs,
93	&g_label_reiserfs,
94	&g_label_ntfs,
95	&g_label_disk_ident,
96#endif
97	NULL
98};
99
100void
101g_label_rtrim(char *label, size_t size)
102{
103	ptrdiff_t i;
104
105	for (i = size - 1; i >= 0; i--) {
106		if (label[i] == '\0')
107			continue;
108		else if (label[i] == ' ')
109			label[i] = '\0';
110		else
111			break;
112	}
113}
114
115static int
116g_label_destroy_geom(struct gctl_req *req __unused, struct g_class *mp,
117    struct g_geom *gp __unused)
118{
119
120	/*
121	 * XXX: Unloading a class which is using geom_slice:1.56 is currently
122	 * XXX: broken, so we deny unloading when we have geoms.
123	 */
124	return (EOPNOTSUPP);
125}
126
127static void
128g_label_orphan(struct g_consumer *cp)
129{
130
131	G_LABEL_DEBUG(1, "Label %s removed.",
132	    LIST_FIRST(&cp->geom->provider)->name);
133	g_slice_orphan(cp);
134}
135
136static void
137g_label_spoiled(struct g_consumer *cp)
138{
139
140	G_LABEL_DEBUG(1, "Label %s removed.",
141	    LIST_FIRST(&cp->geom->provider)->name);
142	g_slice_spoiled(cp);
143}
144
145static void
146g_label_resize(struct g_consumer *cp)
147{
148
149	G_LABEL_DEBUG(1, "Label %s resized.",
150	    LIST_FIRST(&cp->geom->provider)->name);
151
152	g_slice_config(cp->geom, 0, G_SLICE_CONFIG_FORCE, (off_t)0,
153	    cp->provider->mediasize, cp->provider->sectorsize, "notused");
154}
155
156static int
157g_label_is_name_ok(const char *label)
158{
159	const char *s;
160
161	/* Check if the label starts from ../ */
162	if (strncmp(label, "../", 3) == 0)
163		return (0);
164	/* Check if the label contains /../ */
165	if (strstr(label, "/../") != NULL)
166		return (0);
167	/* Check if the label ends at ../ */
168	if ((s = strstr(label, "/..")) != NULL && s[3] == '\0')
169		return (0);
170	return (1);
171}
172
173static void
174g_label_mangle_name(char *label, size_t size)
175{
176	struct sbuf *sb;
177	const u_char *c;
178
179	sb = sbuf_new(NULL, NULL, size, SBUF_FIXEDLEN);
180	for (c = label; *c != '\0'; c++) {
181		if (!isprint(*c) || isspace(*c) || *c =='"' || *c == '%')
182			sbuf_printf(sb, "%%%02X", *c);
183		else
184			sbuf_putc(sb, *c);
185	}
186	if (sbuf_finish(sb) != 0)
187		label[0] = '\0';
188	else
189		strlcpy(label, sbuf_data(sb), size);
190	sbuf_delete(sb);
191}
192
193static struct g_geom *
194g_label_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
195    const char *label, const char *dir, off_t mediasize)
196{
197	struct g_geom *gp;
198	struct g_provider *pp2;
199	struct g_consumer *cp;
200	char name[64];
201
202	g_topology_assert();
203
204	if (!g_label_is_name_ok(label)) {
205		G_LABEL_DEBUG(0, "%s contains suspicious label, skipping.",
206		    pp->name);
207		G_LABEL_DEBUG(1, "%s suspicious label is: %s", pp->name, label);
208		if (req != NULL)
209			gctl_error(req, "Label name %s is invalid.", label);
210		return (NULL);
211	}
212	gp = NULL;
213	cp = NULL;
214	snprintf(name, sizeof(name), "%s/%s", dir, label);
215	LIST_FOREACH(gp, &mp->geom, geom) {
216		pp2 = LIST_FIRST(&gp->provider);
217		if (pp2 == NULL)
218			continue;
219		if ((pp2->flags & G_PF_ORPHAN) != 0)
220			continue;
221		if (strcmp(pp2->name, name) == 0) {
222			G_LABEL_DEBUG(1, "Label %s(%s) already exists (%s).",
223			    label, name, pp->name);
224			if (req != NULL) {
225				gctl_error(req, "Provider %s already exists.",
226				    name);
227			}
228			return (NULL);
229		}
230	}
231	gp = g_slice_new(mp, 1, pp, &cp, NULL, 0, NULL);
232	if (gp == NULL) {
233		G_LABEL_DEBUG(0, "Cannot create slice %s.", label);
234		if (req != NULL)
235			gctl_error(req, "Cannot create slice %s.", label);
236		return (NULL);
237	}
238	gp->orphan = g_label_orphan;
239	gp->spoiled = g_label_spoiled;
240	gp->resize = g_label_resize;
241	g_access(cp, -1, 0, 0);
242	g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t)0, mediasize,
243	    pp->sectorsize, "%s", name);
244	G_LABEL_DEBUG(1, "Label for provider %s is %s.", pp->name, name);
245	return (gp);
246}
247
248static int
249g_label_destroy(struct g_geom *gp, boolean_t force)
250{
251	struct g_provider *pp;
252
253	g_topology_assert();
254	pp = LIST_FIRST(&gp->provider);
255	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
256		if (force) {
257			G_LABEL_DEBUG(0, "Provider %s is still open, so it "
258			    "can't be definitely removed.", pp->name);
259		} else {
260			G_LABEL_DEBUG(1,
261			    "Provider %s is still open (r%dw%de%d).", pp->name,
262			    pp->acr, pp->acw, pp->ace);
263			return (EBUSY);
264		}
265	} else if (pp != NULL)
266		G_LABEL_DEBUG(1, "Label %s removed.", pp->name);
267	g_slice_spoiled(LIST_FIRST(&gp->consumer));
268	return (0);
269}
270
271static int
272g_label_read_metadata(struct g_consumer *cp, struct g_label_metadata *md)
273{
274	struct g_provider *pp;
275	u_char *buf;
276	int error;
277
278	g_topology_assert();
279
280	pp = cp->provider;
281	g_topology_unlock();
282	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
283	    &error);
284	g_topology_lock();
285	if (buf == NULL)
286		return (error);
287	/* Decode metadata. */
288	label_metadata_decode(buf, md);
289	g_free(buf);
290
291	return (0);
292}
293
294static void
295g_label_orphan_taste(struct g_consumer *cp __unused)
296{
297
298	KASSERT(1 == 0, ("%s called?", __func__));
299}
300
301static void
302g_label_start_taste(struct bio *bp __unused)
303{
304
305	KASSERT(1 == 0, ("%s called?", __func__));
306}
307
308static int
309g_label_access_taste(struct g_provider *pp __unused, int dr __unused,
310    int dw __unused, int de __unused)
311{
312
313	KASSERT(1 == 0, ("%s called", __func__));
314	return (EOPNOTSUPP);
315}
316
317static struct g_geom *
318g_label_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
319{
320	struct g_label_metadata md;
321	struct g_consumer *cp;
322	struct g_geom *gp;
323	int i;
324
325	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
326	g_topology_assert();
327
328	G_LABEL_DEBUG(2, "Tasting %s.", pp->name);
329
330	/* Skip providers that are already open for writing. */
331	if (pp->acw > 0)
332		return (NULL);
333
334	if (strcmp(pp->geom->class->name, mp->name) == 0)
335		return (NULL);
336
337	gp = g_new_geomf(mp, "label:taste");
338	gp->start = g_label_start_taste;
339	gp->access = g_label_access_taste;
340	gp->orphan = g_label_orphan_taste;
341	cp = g_new_consumer(gp);
342	g_attach(cp, pp);
343	if (g_access(cp, 1, 0, 0) != 0)
344		goto end;
345	do {
346		if (g_label_read_metadata(cp, &md) != 0)
347			break;
348		if (strcmp(md.md_magic, G_LABEL_MAGIC) != 0)
349			break;
350		if (md.md_version > G_LABEL_VERSION) {
351			printf("geom_label.ko module is too old to handle %s.\n",
352			    pp->name);
353			break;
354		}
355
356		/*
357		 * Backward compatibility:
358		 */
359		/*
360		 * There was no md_provsize field in earlier versions of
361		 * metadata.
362		 */
363		if (md.md_version < 2)
364			md.md_provsize = pp->mediasize;
365
366		if (md.md_provsize != pp->mediasize)
367			break;
368
369		g_label_create(NULL, mp, pp, md.md_label, G_LABEL_DIR,
370		    pp->mediasize - pp->sectorsize);
371	} while (0);
372	for (i = 0; g_labels[i] != NULL; i++) {
373		char label[128];
374
375		if (g_labels[i]->ld_enabled == 0)
376			continue;
377		g_topology_unlock();
378		g_labels[i]->ld_taste(cp, label, sizeof(label));
379		g_label_mangle_name(label, sizeof(label));
380		g_topology_lock();
381		if (label[0] == '\0')
382			continue;
383		g_label_create(NULL, mp, pp, label, g_labels[i]->ld_dir,
384		    pp->mediasize);
385	}
386	g_access(cp, -1, 0, 0);
387end:
388	g_detach(cp);
389	g_destroy_consumer(cp);
390	g_destroy_geom(gp);
391	return (NULL);
392}
393
394static void
395g_label_ctl_create(struct gctl_req *req, struct g_class *mp)
396{
397	struct g_provider *pp;
398	const char *name;
399	int *nargs;
400
401	g_topology_assert();
402
403	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
404	if (nargs == NULL) {
405		gctl_error(req, "No '%s' argument", "nargs");
406		return;
407	}
408	if (*nargs != 2) {
409		gctl_error(req, "Invalid number of arguments.");
410		return;
411	}
412	/*
413	 * arg1 is the name of provider.
414	 */
415	name = gctl_get_asciiparam(req, "arg1");
416	if (name == NULL) {
417		gctl_error(req, "No 'arg%d' argument", 1);
418		return;
419	}
420	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
421		name += strlen("/dev/");
422	pp = g_provider_by_name(name);
423	if (pp == NULL) {
424		G_LABEL_DEBUG(1, "Provider %s is invalid.", name);
425		gctl_error(req, "Provider %s is invalid.", name);
426		return;
427	}
428	/*
429	 * arg0 is the label.
430	 */
431	name = gctl_get_asciiparam(req, "arg0");
432	if (name == NULL) {
433		gctl_error(req, "No 'arg%d' argument", 0);
434		return;
435	}
436	g_label_create(req, mp, pp, name, G_LABEL_DIR, pp->mediasize);
437}
438
439static const char *
440g_label_skip_dir(const char *name)
441{
442	char path[64];
443	u_int i;
444
445	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
446		name += strlen("/dev/");
447	if (strncmp(name, G_LABEL_DIR "/", strlen(G_LABEL_DIR "/")) == 0)
448		name += strlen(G_LABEL_DIR "/");
449	for (i = 0; g_labels[i] != NULL; i++) {
450		snprintf(path, sizeof(path), "%s/", g_labels[i]->ld_dir);
451		if (strncmp(name, path, strlen(path)) == 0) {
452			name += strlen(path);
453			break;
454		}
455	}
456	return (name);
457}
458
459static struct g_geom *
460g_label_find_geom(struct g_class *mp, const char *name)
461{
462	struct g_geom *gp;
463	struct g_provider *pp;
464	const char *pname;
465
466	name = g_label_skip_dir(name);
467	LIST_FOREACH(gp, &mp->geom, geom) {
468		pp = LIST_FIRST(&gp->provider);
469		pname = g_label_skip_dir(pp->name);
470		if (strcmp(pname, name) == 0)
471			return (gp);
472	}
473	return (NULL);
474}
475
476static void
477g_label_ctl_destroy(struct gctl_req *req, struct g_class *mp)
478{
479	int *nargs, *force, error, i;
480	struct g_geom *gp;
481	const char *name;
482	char param[16];
483
484	g_topology_assert();
485
486	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
487	if (nargs == NULL) {
488		gctl_error(req, "No '%s' argument", "nargs");
489		return;
490	}
491	if (*nargs <= 0) {
492		gctl_error(req, "Missing device(s).");
493		return;
494	}
495	force = gctl_get_paraml(req, "force", sizeof(*force));
496	if (force == NULL) {
497		gctl_error(req, "No 'force' argument");
498		return;
499	}
500
501	for (i = 0; i < *nargs; i++) {
502		snprintf(param, sizeof(param), "arg%d", i);
503		name = gctl_get_asciiparam(req, param);
504		if (name == NULL) {
505			gctl_error(req, "No 'arg%d' argument", i);
506			return;
507		}
508		gp = g_label_find_geom(mp, name);
509		if (gp == NULL) {
510			G_LABEL_DEBUG(1, "Label %s is invalid.", name);
511			gctl_error(req, "Label %s is invalid.", name);
512			return;
513		}
514		error = g_label_destroy(gp, *force);
515		if (error != 0) {
516			gctl_error(req, "Cannot destroy label %s (error=%d).",
517			    LIST_FIRST(&gp->provider)->name, error);
518			return;
519		}
520	}
521}
522
523static void
524g_label_config(struct gctl_req *req, struct g_class *mp, const char *verb)
525{
526	uint32_t *version;
527
528	g_topology_assert();
529
530	version = gctl_get_paraml(req, "version", sizeof(*version));
531	if (version == NULL) {
532		gctl_error(req, "No '%s' argument.", "version");
533		return;
534	}
535	if (*version != G_LABEL_VERSION) {
536		gctl_error(req, "Userland and kernel parts are out of sync.");
537		return;
538	}
539
540	if (strcmp(verb, "create") == 0) {
541		g_label_ctl_create(req, mp);
542		return;
543	} else if (strcmp(verb, "destroy") == 0 ||
544	    strcmp(verb, "stop") == 0) {
545		g_label_ctl_destroy(req, mp);
546		return;
547	}
548
549	gctl_error(req, "Unknown verb.");
550}
551
552DECLARE_GEOM_CLASS(g_label_class, g_label);
553MODULE_VERSION(geom_label, 0);
554