xref: /freebsd/sbin/geom/misc/subr.c (revision aa24f48b361effe51163877d84f1b70d32b77e04)
1 /*-
2  * Copyright (c) 2004-2010 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/disk.h>
32 #include <sys/endian.h>
33 #include <sys/uio.h>
34 #include <errno.h>
35 #include <fcntl.h>
36 #include <paths.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <limits.h>
40 #include <inttypes.h>
41 #include <stdarg.h>
42 #include <string.h>
43 #include <strings.h>
44 #include <unistd.h>
45 #include <assert.h>
46 #include <libgeom.h>
47 
48 #include "misc/subr.h"
49 
50 
51 struct std_metadata {
52 	char		md_magic[16];
53 	uint32_t	md_version;
54 };
55 
56 static void
57 std_metadata_decode(const unsigned char *data, struct std_metadata *md)
58 {
59 
60         bcopy(data, md->md_magic, sizeof(md->md_magic));
61         md->md_version = le32dec(data + 16);
62 }
63 
64 /*
65  * Greatest Common Divisor.
66  */
67 static unsigned int
68 gcd(unsigned int a, unsigned int b)
69 {
70 	unsigned int c;
71 
72 	while (b != 0) {
73 		c = a;
74 		a = b;
75 		b = (c % b);
76 	}
77 	return (a);
78 }
79 
80 /*
81  * Least Common Multiple.
82  */
83 unsigned int
84 g_lcm(unsigned int a, unsigned int b)
85 {
86 
87 	return ((a * b) / gcd(a, b));
88 }
89 
90 uint32_t
91 bitcount32(uint32_t x)
92 {
93 
94 	x = (x & 0x55555555) + ((x & 0xaaaaaaaa) >> 1);
95 	x = (x & 0x33333333) + ((x & 0xcccccccc) >> 2);
96 	x = (x & 0x0f0f0f0f) + ((x & 0xf0f0f0f0) >> 4);
97 	x = (x & 0x00ff00ff) + ((x & 0xff00ff00) >> 8);
98 	x = (x & 0x0000ffff) + ((x & 0xffff0000) >> 16);
99 	return (x);
100 }
101 
102 /*
103  * The size of a sector is context specific (i.e. determined by the
104  * media). But when users enter a value with a SI unit, they really
105  * mean the byte-size or byte-offset and not the size or offset in
106  * sectors. We should map the byte-oriented value into a sector-oriented
107  * value when we already know the sector size in bytes. At this time
108  * we can use g_parse_lba() function. It converts user specified
109  * value into sectors with following conditions:
110  * o  Sectors size taken as argument from caller.
111  * o  When no SI unit is specified the value is in sectors.
112  * o  With an SI unit the value is in bytes.
113  * o  The 'b' suffix forces byte interpretation and the 's'
114  *    suffix forces sector interpretation.
115  *
116  * Thus:
117  * o  2 and 2s mean 2 sectors, and 2b means 2 bytes.
118  * o  4k and 4kb mean 4096 bytes, and 4ks means 4096 sectors.
119  *
120  */
121 int
122 g_parse_lba(const char *lbastr, unsigned int sectorsize, off_t *sectors)
123 {
124 	off_t number, mult, unit;
125 	char *s;
126 
127 	assert(lbastr != NULL);
128 	assert(sectorsize > 0);
129 	assert(sectors != NULL);
130 
131 	number = (off_t)strtoimax(lbastr, &s, 0);
132 	if (s == lbastr || number < 0)
133 		return (EINVAL);
134 
135 	mult = 1;
136 	unit = sectorsize;
137 	if (*s == '\0')
138 		goto done;
139 	switch (*s) {
140 	case 'e': case 'E':
141 		mult *= 1024;
142 		/* FALLTHROUGH */
143 	case 'p': case 'P':
144 		mult *= 1024;
145 		/* FALLTHROUGH */
146 	case 't': case 'T':
147 		mult *= 1024;
148 		/* FALLTHROUGH */
149 	case 'g': case 'G':
150 		mult *= 1024;
151 		/* FALLTHROUGH */
152 	case 'm': case 'M':
153 		mult *= 1024;
154 		/* FALLTHROUGH */
155 	case 'k': case 'K':
156 		mult *= 1024;
157 		break;
158 	default:
159 		goto sfx;
160 	}
161 	unit = 1;	/* bytes */
162 	s++;
163 	if (*s == '\0')
164 		goto done;
165 sfx:
166 	switch (*s) {
167 	case 's': case 'S':
168 		unit = sectorsize;	/* sector */
169 		break;
170 	case 'b': case 'B':
171 		unit = 1;		/* bytes */
172 		break;
173 	default:
174 		return (EINVAL);
175 	}
176 	s++;
177 	if (*s != '\0')
178 		return (EINVAL);
179 done:
180 	if ((OFF_MAX / unit) < mult || (OFF_MAX / mult / unit) < number)
181 		return (ERANGE);
182 	number *= mult * unit;
183 	if (number % sectorsize)
184 		return (EINVAL);
185 	number /= sectorsize;
186 	*sectors = number;
187 	return (0);
188 }
189 
190 off_t
191 g_get_mediasize(const char *name)
192 {
193 	off_t mediasize;
194 	int fd;
195 
196 	fd = g_open(name, 0);
197 	if (fd == -1)
198 		return (0);
199 	mediasize = g_mediasize(fd);
200 	if (mediasize == -1)
201 		mediasize = 0;
202 	(void)g_close(fd);
203 	return (mediasize);
204 }
205 
206 unsigned int
207 g_get_sectorsize(const char *name)
208 {
209 	ssize_t sectorsize;
210 	int fd;
211 
212 	fd = g_open(name, 0);
213 	if (fd == -1)
214 		return (0);
215 	sectorsize = g_sectorsize(fd);
216 	if (sectorsize == -1)
217 		sectorsize = 0;
218 	(void)g_close(fd);
219 	return ((unsigned int)sectorsize);
220 }
221 
222 int
223 g_metadata_read(const char *name, unsigned char *md, size_t size,
224     const char *magic)
225 {
226 	struct std_metadata stdmd;
227 	unsigned char *sector;
228 	ssize_t sectorsize;
229 	off_t mediasize;
230 	int error, fd;
231 
232 	sector = NULL;
233 	error = 0;
234 
235 	fd = g_open(name, 0);
236 	if (fd == -1)
237 		return (errno);
238 	mediasize = g_mediasize(fd);
239 	if (mediasize == -1) {
240 		error = errno;
241 		goto out;
242 	}
243 	sectorsize = g_sectorsize(fd);
244 	if (sectorsize == -1) {
245 		error = errno;
246 		goto out;
247 	}
248 	assert(sectorsize >= (ssize_t)size);
249 	sector = malloc(sectorsize);
250 	if (sector == NULL) {
251 		error = ENOMEM;
252 		goto out;
253 	}
254 	if (pread(fd, sector, sectorsize, mediasize - sectorsize) !=
255 	    sectorsize) {
256 		error = errno;
257 		goto out;
258 	}
259 	if (magic != NULL) {
260 		std_metadata_decode(sector, &stdmd);
261 		if (strcmp(stdmd.md_magic, magic) != 0) {
262 			error = EINVAL;
263 			goto out;
264 		}
265 	}
266 	bcopy(sector, md, size);
267 out:
268 	if (sector != NULL)
269 		free(sector);
270 	g_close(fd);
271 	return (error);
272 }
273 
274 int
275 g_metadata_store(const char *name, const unsigned char *md, size_t size)
276 {
277 	unsigned char *sector;
278 	ssize_t sectorsize;
279 	off_t mediasize;
280 	int error, fd;
281 
282 	sector = NULL;
283 	error = 0;
284 
285 	fd = g_open(name, 1);
286 	if (fd == -1)
287 		return (errno);
288 	mediasize = g_mediasize(fd);
289 	if (mediasize == -1) {
290 		error = errno;
291 		goto out;
292 	}
293 	sectorsize = g_sectorsize(fd);
294 	if (sectorsize == -1) {
295 		error = errno;
296 		goto out;
297 	}
298 	assert(sectorsize >= (ssize_t)size);
299 	sector = malloc(sectorsize);
300 	if (sector == NULL) {
301 		error = ENOMEM;
302 		goto out;
303 	}
304 	bcopy(md, sector, size);
305 	if (pwrite(fd, sector, sectorsize, mediasize - sectorsize) !=
306 	    sectorsize) {
307 		error = errno;
308 		goto out;
309 	}
310 	(void)g_flush(fd);
311 out:
312 	if (sector != NULL)
313 		free(sector);
314 	(void)g_close(fd);
315 	return (error);
316 }
317 
318 int
319 g_metadata_clear(const char *name, const char *magic)
320 {
321 	struct std_metadata md;
322 	unsigned char *sector;
323 	ssize_t sectorsize;
324 	off_t mediasize;
325 	int error, fd;
326 
327 	sector = NULL;
328 	error = 0;
329 
330 	fd = g_open(name, 1);
331 	if (fd == -1)
332 		return (errno);
333 	mediasize = g_mediasize(fd);
334 	if (mediasize == 0) {
335 		error = errno;
336 		goto out;
337 	}
338 	sectorsize = g_sectorsize(fd);
339 	if (sectorsize <= 0) {
340 		error = errno;
341 		goto out;
342 	}
343 	sector = malloc(sectorsize);
344 	if (sector == NULL) {
345 		error = ENOMEM;
346 		goto out;
347 	}
348 	if (magic != NULL) {
349 		if (pread(fd, sector, sectorsize, mediasize - sectorsize) !=
350 		    sectorsize) {
351 			error = errno;
352 			goto out;
353 		}
354 		std_metadata_decode(sector, &md);
355 		if (strcmp(md.md_magic, magic) != 0) {
356 			error = EINVAL;
357 			goto out;
358 		}
359 	}
360 	bzero(sector, sectorsize);
361 	if (pwrite(fd, sector, sectorsize, mediasize - sectorsize) !=
362 	    sectorsize) {
363 		error = errno;
364 		goto out;
365 	}
366 	(void)g_flush(fd);
367 out:
368 	free(sector);
369 	g_close(fd);
370 	return (error);
371 }
372 
373 /*
374  * Set an error message, if one does not already exist.
375  */
376 void
377 gctl_error(struct gctl_req *req, const char *error, ...)
378 {
379 	va_list ap;
380 
381 	if (req != NULL && req->error != NULL)
382 		return;
383 	va_start(ap, error);
384 	if (req != NULL) {
385 		vasprintf(&req->error, error, ap);
386 	} else {
387 		vfprintf(stderr, error, ap);
388 		fprintf(stderr, "\n");
389 	}
390 	va_end(ap);
391 }
392 
393 static void *
394 gctl_get_param(struct gctl_req *req, size_t len, const char *pfmt, va_list ap)
395 {
396 	struct gctl_req_arg *argp;
397 	char param[256];
398 	unsigned int i;
399 	void *p;
400 
401 	vsnprintf(param, sizeof(param), pfmt, ap);
402 	for (i = 0; i < req->narg; i++) {
403 		argp = &req->arg[i];
404 		if (strcmp(param, argp->name))
405 			continue;
406 		if (!(argp->flag & GCTL_PARAM_RD))
407 			continue;
408 		p = argp->value;
409 		if (len == 0) {
410 			/* We are looking for a string. */
411 			if (argp->len < 1) {
412 				fprintf(stderr, "No length argument (%s).\n",
413 				    param);
414 				abort();
415 			}
416 			if (((char *)p)[argp->len - 1] != '\0') {
417 				fprintf(stderr, "Unterminated argument (%s).\n",
418 				    param);
419 				abort();
420 			}
421 		} else if ((int)len != argp->len) {
422 			fprintf(stderr, "Wrong length %s argument.\n", param);
423 			abort();
424 		}
425 		return (p);
426 	}
427 	fprintf(stderr, "No such argument (%s).\n", param);
428 	abort();
429 }
430 
431 int
432 gctl_get_int(struct gctl_req *req, const char *pfmt, ...)
433 {
434 	int *p;
435 	va_list ap;
436 
437 	va_start(ap, pfmt);
438 	p = gctl_get_param(req, sizeof(int), pfmt, ap);
439 	va_end(ap);
440 	return (*p);
441 }
442 
443 intmax_t
444 gctl_get_intmax(struct gctl_req *req, const char *pfmt, ...)
445 {
446 	intmax_t *p;
447 	va_list ap;
448 
449 	va_start(ap, pfmt);
450 	p = gctl_get_param(req, sizeof(intmax_t), pfmt, ap);
451 	va_end(ap);
452 	return (*p);
453 }
454 
455 const char *
456 gctl_get_ascii(struct gctl_req *req, const char *pfmt, ...)
457 {
458 	const char *p;
459 	va_list ap;
460 
461 	va_start(ap, pfmt);
462 	p = gctl_get_param(req, 0, pfmt, ap);
463 	va_end(ap);
464 	return (p);
465 }
466 
467 int
468 gctl_change_param(struct gctl_req *req, const char *name, int len,
469     const void *value)
470 {
471 	struct gctl_req_arg *ap;
472 	unsigned int i;
473 
474 	if (req == NULL || req->error != NULL)
475 		return (EDOOFUS);
476 	for (i = 0; i < req->narg; i++) {
477 		ap = &req->arg[i];
478 		if (strcmp(ap->name, name) != 0)
479 			continue;
480 		ap->value = __DECONST(void *, value);
481 		if (len >= 0) {
482 			ap->flag &= ~GCTL_PARAM_ASCII;
483 			ap->len = len;
484 		} else if (len < 0) {
485 			ap->flag |= GCTL_PARAM_ASCII;
486 			ap->len = strlen(value) + 1;
487 		}
488 		return (0);
489 	}
490 	return (ENOENT);
491 }
492 
493 int
494 gctl_delete_param(struct gctl_req *req, const char *name)
495 {
496 	struct gctl_req_arg *ap;
497 	unsigned int i;
498 
499 	if (req == NULL || req->error != NULL)
500 		return (EDOOFUS);
501 
502 	i = 0;
503 	while (i < req->narg) {
504 		ap = &req->arg[i];
505 		if (strcmp(ap->name, name) == 0)
506 			break;
507 		i++;
508 	}
509 	if (i == req->narg)
510 		return (ENOENT);
511 
512 	free(ap->name);
513 	req->narg--;
514 	while (i < req->narg) {
515 		req->arg[i] = req->arg[i + 1];
516 		i++;
517 	}
518 	return (0);
519 }
520 
521 int
522 gctl_has_param(struct gctl_req *req, const char *name)
523 {
524 	struct gctl_req_arg *ap;
525 	unsigned int i;
526 
527 	if (req == NULL || req->error != NULL)
528 		return (0);
529 
530 	for (i = 0; i < req->narg; i++) {
531 		ap = &req->arg[i];
532 		if (strcmp(ap->name, name) == 0)
533 			return (1);
534 	}
535 	return (0);
536 }
537