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 346559 2019-04-22 15:09:47Z ian $");
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	&g_label_flashmap,
97#endif
98	NULL
99};
100
101void
102g_label_rtrim(char *label, size_t size)
103{
104	ptrdiff_t i;
105
106	for (i = size - 1; i >= 0; i--) {
107		if (label[i] == '\0')
108			continue;
109		else if (label[i] == ' ')
110			label[i] = '\0';
111		else
112			break;
113	}
114}
115
116static int
117g_label_destroy_geom(struct gctl_req *req __unused, struct g_class *mp,
118    struct g_geom *gp __unused)
119{
120
121	/*
122	 * XXX: Unloading a class which is using geom_slice:1.56 is currently
123	 * XXX: broken, so we deny unloading when we have geoms.
124	 */
125	return (EOPNOTSUPP);
126}
127
128static void
129g_label_orphan(struct g_consumer *cp)
130{
131
132	G_LABEL_DEBUG(1, "Label %s removed.",
133	    LIST_FIRST(&cp->geom->provider)->name);
134	g_slice_orphan(cp);
135}
136
137static void
138g_label_spoiled(struct g_consumer *cp)
139{
140
141	G_LABEL_DEBUG(1, "Label %s removed.",
142	    LIST_FIRST(&cp->geom->provider)->name);
143	g_slice_spoiled(cp);
144}
145
146static void
147g_label_resize(struct g_consumer *cp)
148{
149
150	G_LABEL_DEBUG(1, "Label %s resized.",
151	    LIST_FIRST(&cp->geom->provider)->name);
152
153	g_slice_config(cp->geom, 0, G_SLICE_CONFIG_FORCE, (off_t)0,
154	    cp->provider->mediasize, cp->provider->sectorsize, "notused");
155}
156
157static int
158g_label_is_name_ok(const char *label)
159{
160	const char *s;
161
162	/* Check if the label starts from ../ */
163	if (strncmp(label, "../", 3) == 0)
164		return (0);
165	/* Check if the label contains /../ */
166	if (strstr(label, "/../") != NULL)
167		return (0);
168	/* Check if the label ends at ../ */
169	if ((s = strstr(label, "/..")) != NULL && s[3] == '\0')
170		return (0);
171	return (1);
172}
173
174static void
175g_label_mangle_name(char *label, size_t size)
176{
177	struct sbuf *sb;
178	const u_char *c;
179
180	sb = sbuf_new(NULL, NULL, size, SBUF_FIXEDLEN);
181	for (c = label; *c != '\0'; c++) {
182		if (!isprint(*c) || isspace(*c) || *c =='"' || *c == '%')
183			sbuf_printf(sb, "%%%02X", *c);
184		else
185			sbuf_putc(sb, *c);
186	}
187	if (sbuf_finish(sb) != 0)
188		label[0] = '\0';
189	else
190		strlcpy(label, sbuf_data(sb), size);
191	sbuf_delete(sb);
192}
193
194static struct g_geom *
195g_label_create(struct gctl_req *req, struct g_class *mp, struct g_provider *pp,
196    const char *label, const char *dir, off_t mediasize)
197{
198	struct g_geom *gp;
199	struct g_provider *pp2;
200	struct g_consumer *cp;
201	char name[64];
202
203	g_topology_assert();
204
205	if (!g_label_is_name_ok(label)) {
206		G_LABEL_DEBUG(0, "%s contains suspicious label, skipping.",
207		    pp->name);
208		G_LABEL_DEBUG(1, "%s suspicious label is: %s", pp->name, label);
209		if (req != NULL)
210			gctl_error(req, "Label name %s is invalid.", label);
211		return (NULL);
212	}
213	gp = NULL;
214	cp = NULL;
215	snprintf(name, sizeof(name), "%s/%s", dir, label);
216	LIST_FOREACH(gp, &mp->geom, geom) {
217		pp2 = LIST_FIRST(&gp->provider);
218		if (pp2 == NULL)
219			continue;
220		if ((pp2->flags & G_PF_ORPHAN) != 0)
221			continue;
222		if (strcmp(pp2->name, name) == 0) {
223			G_LABEL_DEBUG(1, "Label %s(%s) already exists (%s).",
224			    label, name, pp->name);
225			if (req != NULL) {
226				gctl_error(req, "Provider %s already exists.",
227				    name);
228			}
229			return (NULL);
230		}
231	}
232	gp = g_slice_new(mp, 1, pp, &cp, NULL, 0, NULL);
233	if (gp == NULL) {
234		G_LABEL_DEBUG(0, "Cannot create slice %s.", label);
235		if (req != NULL)
236			gctl_error(req, "Cannot create slice %s.", label);
237		return (NULL);
238	}
239	gp->orphan = g_label_orphan;
240	gp->spoiled = g_label_spoiled;
241	gp->resize = g_label_resize;
242	g_access(cp, -1, 0, 0);
243	g_slice_config(gp, 0, G_SLICE_CONFIG_SET, (off_t)0, mediasize,
244	    pp->sectorsize, "%s", name);
245	G_LABEL_DEBUG(1, "Label for provider %s is %s.", pp->name, name);
246	return (gp);
247}
248
249static int
250g_label_destroy(struct g_geom *gp, boolean_t force)
251{
252	struct g_provider *pp;
253
254	g_topology_assert();
255	pp = LIST_FIRST(&gp->provider);
256	if (pp != NULL && (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)) {
257		if (force) {
258			G_LABEL_DEBUG(0, "Provider %s is still open, so it "
259			    "can't be definitely removed.", pp->name);
260		} else {
261			G_LABEL_DEBUG(1,
262			    "Provider %s is still open (r%dw%de%d).", pp->name,
263			    pp->acr, pp->acw, pp->ace);
264			return (EBUSY);
265		}
266	} else if (pp != NULL)
267		G_LABEL_DEBUG(1, "Label %s removed.", pp->name);
268	g_slice_spoiled(LIST_FIRST(&gp->consumer));
269	return (0);
270}
271
272static int
273g_label_read_metadata(struct g_consumer *cp, struct g_label_metadata *md)
274{
275	struct g_provider *pp;
276	u_char *buf;
277	int error;
278
279	g_topology_assert();
280
281	pp = cp->provider;
282	g_topology_unlock();
283	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
284	    &error);
285	g_topology_lock();
286	if (buf == NULL)
287		return (error);
288	/* Decode metadata. */
289	label_metadata_decode(buf, md);
290	g_free(buf);
291
292	return (0);
293}
294
295static void
296g_label_orphan_taste(struct g_consumer *cp __unused)
297{
298
299	KASSERT(1 == 0, ("%s called?", __func__));
300}
301
302static void
303g_label_start_taste(struct bio *bp __unused)
304{
305
306	KASSERT(1 == 0, ("%s called?", __func__));
307}
308
309static int
310g_label_access_taste(struct g_provider *pp __unused, int dr __unused,
311    int dw __unused, int de __unused)
312{
313
314	KASSERT(1 == 0, ("%s called", __func__));
315	return (EOPNOTSUPP);
316}
317
318static struct g_geom *
319g_label_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
320{
321	struct g_label_metadata md;
322	struct g_consumer *cp;
323	struct g_geom *gp;
324	int i;
325
326	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
327	g_topology_assert();
328
329	G_LABEL_DEBUG(2, "Tasting %s.", pp->name);
330
331	/* Skip providers that are already open for writing. */
332	if (pp->acw > 0)
333		return (NULL);
334
335	if (strcmp(pp->geom->class->name, mp->name) == 0)
336		return (NULL);
337
338	gp = g_new_geomf(mp, "label:taste");
339	gp->start = g_label_start_taste;
340	gp->access = g_label_access_taste;
341	gp->orphan = g_label_orphan_taste;
342	cp = g_new_consumer(gp);
343	g_attach(cp, pp);
344	if (g_access(cp, 1, 0, 0) != 0)
345		goto end;
346	do {
347		if (g_label_read_metadata(cp, &md) != 0)
348			break;
349		if (strcmp(md.md_magic, G_LABEL_MAGIC) != 0)
350			break;
351		if (md.md_version > G_LABEL_VERSION) {
352			printf("geom_label.ko module is too old to handle %s.\n",
353			    pp->name);
354			break;
355		}
356
357		/*
358		 * Backward compatibility:
359		 */
360		/*
361		 * There was no md_provsize field in earlier versions of
362		 * metadata.
363		 */
364		if (md.md_version < 2)
365			md.md_provsize = pp->mediasize;
366
367		if (md.md_provsize != pp->mediasize)
368			break;
369
370		g_label_create(NULL, mp, pp, md.md_label, G_LABEL_DIR,
371		    pp->mediasize - pp->sectorsize);
372	} while (0);
373	for (i = 0; g_labels[i] != NULL; i++) {
374		char label[128];
375
376		if (g_labels[i]->ld_enabled == 0)
377			continue;
378		g_topology_unlock();
379		g_labels[i]->ld_taste(cp, label, sizeof(label));
380		g_label_mangle_name(label, sizeof(label));
381		g_topology_lock();
382		if (label[0] == '\0')
383			continue;
384		g_label_create(NULL, mp, pp, label, g_labels[i]->ld_dir,
385		    pp->mediasize);
386	}
387	g_access(cp, -1, 0, 0);
388end:
389	g_detach(cp);
390	g_destroy_consumer(cp);
391	g_destroy_geom(gp);
392	return (NULL);
393}
394
395static void
396g_label_ctl_create(struct gctl_req *req, struct g_class *mp)
397{
398	struct g_provider *pp;
399	const char *name;
400	int *nargs;
401
402	g_topology_assert();
403
404	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
405	if (nargs == NULL) {
406		gctl_error(req, "No '%s' argument", "nargs");
407		return;
408	}
409	if (*nargs != 2) {
410		gctl_error(req, "Invalid number of arguments.");
411		return;
412	}
413	/*
414	 * arg1 is the name of provider.
415	 */
416	name = gctl_get_asciiparam(req, "arg1");
417	if (name == NULL) {
418		gctl_error(req, "No 'arg%d' argument", 1);
419		return;
420	}
421	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
422		name += strlen("/dev/");
423	pp = g_provider_by_name(name);
424	if (pp == NULL) {
425		G_LABEL_DEBUG(1, "Provider %s is invalid.", name);
426		gctl_error(req, "Provider %s is invalid.", name);
427		return;
428	}
429	/*
430	 * arg0 is the label.
431	 */
432	name = gctl_get_asciiparam(req, "arg0");
433	if (name == NULL) {
434		gctl_error(req, "No 'arg%d' argument", 0);
435		return;
436	}
437	g_label_create(req, mp, pp, name, G_LABEL_DIR, pp->mediasize);
438}
439
440static const char *
441g_label_skip_dir(const char *name)
442{
443	char path[64];
444	u_int i;
445
446	if (strncmp(name, "/dev/", strlen("/dev/")) == 0)
447		name += strlen("/dev/");
448	if (strncmp(name, G_LABEL_DIR "/", strlen(G_LABEL_DIR "/")) == 0)
449		name += strlen(G_LABEL_DIR "/");
450	for (i = 0; g_labels[i] != NULL; i++) {
451		snprintf(path, sizeof(path), "%s/", g_labels[i]->ld_dir);
452		if (strncmp(name, path, strlen(path)) == 0) {
453			name += strlen(path);
454			break;
455		}
456	}
457	return (name);
458}
459
460static struct g_geom *
461g_label_find_geom(struct g_class *mp, const char *name)
462{
463	struct g_geom *gp;
464	struct g_provider *pp;
465	const char *pname;
466
467	name = g_label_skip_dir(name);
468	LIST_FOREACH(gp, &mp->geom, geom) {
469		pp = LIST_FIRST(&gp->provider);
470		pname = g_label_skip_dir(pp->name);
471		if (strcmp(pname, name) == 0)
472			return (gp);
473	}
474	return (NULL);
475}
476
477static void
478g_label_ctl_destroy(struct gctl_req *req, struct g_class *mp)
479{
480	int *nargs, *force, error, i;
481	struct g_geom *gp;
482	const char *name;
483	char param[16];
484
485	g_topology_assert();
486
487	nargs = gctl_get_paraml(req, "nargs", sizeof(*nargs));
488	if (nargs == NULL) {
489		gctl_error(req, "No '%s' argument", "nargs");
490		return;
491	}
492	if (*nargs <= 0) {
493		gctl_error(req, "Missing device(s).");
494		return;
495	}
496	force = gctl_get_paraml(req, "force", sizeof(*force));
497	if (force == NULL) {
498		gctl_error(req, "No 'force' argument");
499		return;
500	}
501
502	for (i = 0; i < *nargs; i++) {
503		snprintf(param, sizeof(param), "arg%d", i);
504		name = gctl_get_asciiparam(req, param);
505		if (name == NULL) {
506			gctl_error(req, "No 'arg%d' argument", i);
507			return;
508		}
509		gp = g_label_find_geom(mp, name);
510		if (gp == NULL) {
511			G_LABEL_DEBUG(1, "Label %s is invalid.", name);
512			gctl_error(req, "Label %s is invalid.", name);
513			return;
514		}
515		error = g_label_destroy(gp, *force);
516		if (error != 0) {
517			gctl_error(req, "Cannot destroy label %s (error=%d).",
518			    LIST_FIRST(&gp->provider)->name, error);
519			return;
520		}
521	}
522}
523
524static void
525g_label_config(struct gctl_req *req, struct g_class *mp, const char *verb)
526{
527	uint32_t *version;
528
529	g_topology_assert();
530
531	version = gctl_get_paraml(req, "version", sizeof(*version));
532	if (version == NULL) {
533		gctl_error(req, "No '%s' argument.", "version");
534		return;
535	}
536	if (*version != G_LABEL_VERSION) {
537		gctl_error(req, "Userland and kernel parts are out of sync.");
538		return;
539	}
540
541	if (strcmp(verb, "create") == 0) {
542		g_label_ctl_create(req, mp);
543		return;
544	} else if (strcmp(verb, "destroy") == 0 ||
545	    strcmp(verb, "stop") == 0) {
546		g_label_ctl_destroy(req, mp);
547		return;
548	}
549
550	gctl_error(req, "Unknown verb.");
551}
552
553DECLARE_GEOM_CLASS(g_label_class, g_label);
554MODULE_VERSION(geom_label, 0);
555