summaryrefslogtreecommitdiffstats
path: root/sbin/mdmfs/mdmfs.c
blob: 1ed069dd8180de38e42ac954652e82093778f296 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
/*
 * Copyright (c) 2001 Dima Dorfman.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * mdmfs (md/MFS) is a wrapper around mdconfig(8),
 * newfs(8), and mount(8) that mimics the command line option set of
 * the deprecated mount_mfs(8).
 */

#ifndef lint
static const char rcsid[] =
  "$FreeBSD$";
#endif /* not lint */

#include <sys/param.h>
#include <sys/mdioctl.h>
#include <sys/stat.h>
#include <sys/wait.h>

#include <assert.h>
#include <err.h>
#include <fcntl.h>
#include <grp.h>
#include <paths.h>
#include <pwd.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "pathnames.h"

typedef enum { false, true } bool;

struct mtpt_info {
	uid_t		 mi_uid;
	bool		 mi_have_uid;
	gid_t		 mi_gid;
	bool		 mi_have_gid;
	mode_t		 mi_mode;
	bool		 mi_have_mode;
};

static	bool compat;		/* Full compatibility with mount_mfs? */
static	bool debug;		/* Emit debugging information? */
static	bool loudsubs;		/* Suppress output from helper programs? */
static	bool norun;		/* Actually run the helper programs? */
static	int unit;      		/* The unit we're working with. */
static	const char *mdname;	/* Name of memory disk device (e.g., "md"). */
static	size_t mdnamelen;	/* Length of mdname. */

static void	 argappend(char **, const char *, ...) __printflike(2, 3);
static void	 debugprintf(const char *, ...) __printflike(1, 2);
static void	 do_mdconfig_attach(const char *, const enum md_types);
static void	 do_mdconfig_attach_au(const char *, const enum md_types);
static void	 do_mdconfig_detach(void);
static void	 do_mount(const char *, const char *);
static void	 do_mtptsetup(const char *, struct mtpt_info *);
static void	 do_newfs(const char *);
static void	 extract_ugid(const char *, struct mtpt_info *);
static int	 run(int *, const char *, ...) __printflike(2, 3);
static void	 usage(void);

int
main(int argc, char **argv)
{
	struct mtpt_info mi;		/* Mountpoint info. */
	char *mdconfig_arg, *newfs_arg,	/* Args to helper programs. */
	    *mount_arg;
	enum md_types mdtype;		/* The type of our memory disk. */
	bool have_mdtype;
	bool detach, softdep, autounit;
	char *mtpoint, *unitstr;
	char ch, *p;

	/* Misc. initialization. */
	(void)memset(&mi, '\0', sizeof(mi));
	detach = true;
	softdep = true;
	autounit = false;
	have_mdtype = false;
	mdname = MD_NAME;
	mdnamelen = strlen(mdname);
	/*
	 * Can't set these to NULL.  They may be passed to the
	 * respective programs without modification.  I.e., we may not
	 * receive any command-line options which will caused them to
	 * be modified.
	 */
	mdconfig_arg = strdup("");
	newfs_arg = strdup("");
	mount_arg = strdup("");

	/* If we were started as mount_mfs or mfs, imply -C. */
	if (strcmp(getprogname(), "mount_mfs") == 0 ||
	    strcmp(getprogname(), "mfs") == 0)
		compat = true;

	while ((ch = getopt(argc, argv,
	    "a:b:Cc:Dd:e:F:f:hi:LMm:Nn:O:o:p:Ss:t:Uw:X")) != -1)
		switch (ch) {
		case 'a':
			argappend(&newfs_arg, "-a %s", optarg);
			break;
		case 'b':
			argappend(&newfs_arg, "-b %s", optarg);
			break;
		case 'C':
			if (compat)
				usage();
			compat = true;
			break;
		case 'c':
			argappend(&newfs_arg, "-c %s", optarg);
			break;
		case 'D':
			if (compat)
				usage();
			detach = false;
			break;
		case 'd':
			argappend(&newfs_arg, "-d %s", optarg);
			break;
		case 'e':
			argappend(&newfs_arg, "-e %s", optarg);
			break;
		case 'F':
			if (have_mdtype)
				usage();
			mdtype = MD_VNODE;
			have_mdtype = true;
			argappend(&mdconfig_arg, "-f %s", optarg);
			break;
		case 'f':
			argappend(&newfs_arg, "-f %s", optarg);
			break;
		case 'h':
			usage();
			break;
		case 'i':
			argappend(&newfs_arg, "-i %s", optarg);
			break;
		case 'L':
			if (compat)
				usage();
			loudsubs = true;
			break;
		case 'M':
			if (have_mdtype)
				usage();
			mdtype = MD_MALLOC;
			have_mdtype = true;
			break;
		case 'm':
			argappend(&newfs_arg, "-m %s", optarg);
			break;
		case 'N':
			if (compat)
				usage();
			norun = true;
			break;
		case 'n':
			argappend(&newfs_arg, "-n %s", optarg);
			break;
		case 'O':
			argappend(&newfs_arg, "-o %s", optarg);
			break;
		case 'o':
			argappend(&mount_arg, "-o %s", optarg);
			break;
		case 'p':
			if (compat)
				usage();
			if (*optarg >= '0' && *optarg <= '7')
				mi.mi_mode = strtol(optarg, NULL, 8);
			if ((mi.mi_mode & ~07777) != 0)
				usage();
			mi.mi_have_mode = true;
			break;
		case 'S':
			if (compat)
				usage();
			softdep = false;
			break;
		case 's':
			argappend(&mdconfig_arg, "-s %s", optarg);
			break;
		case 'U':
			softdep = true;
			break;
		case 'w':
			if (compat)
				usage();
			extract_ugid(optarg, &mi);
			break;
		case 'X':
			if (compat)
				usage();
			debug = true;
			break;
		default:
			usage();
		}
	argc -= optind;
	argv += optind;
	if (argc < 2)
		usage();

	/* Make compatibility assumptions. */
	if (compat) {
		mi.mi_mode = 01777;
		mi.mi_have_mode = true;
	}

	/* Derive 'unit' (global). */
	unitstr = argv[0];
	if (strncmp(unitstr, "/dev/", 5) == 0)
		unitstr += 5;
	if (strncmp(unitstr, mdname, mdnamelen) == 0)
		unitstr += mdnamelen;
	if (*unitstr == '\0') {
		autounit = true;
		unit = -1;
	} else {
		unit = strtoul(unitstr, &p, 10);
		if ((unsigned)unit == ULONG_MAX || *p != '\0')
			errx(1, "bad device unit: %s", unitstr);
	}

	mtpoint = argv[1];
	if (!have_mdtype)
		mdtype = MD_SWAP;
	if (softdep)
		argappend(&newfs_arg, "-U");

	/* Do the work. */
	if (detach && !autounit)
		do_mdconfig_detach();
	if (autounit)
		do_mdconfig_attach_au(mdconfig_arg, mdtype);
	else
		do_mdconfig_attach(mdconfig_arg, mdtype);
	do_newfs(newfs_arg);
	do_mount(mount_arg, mtpoint);
	do_mtptsetup(mtpoint, &mi);

	return (0);
}

/*
 * Append the expansion of 'fmt' to the buffer pointed to by '*dstp';
 * reallocate as required.
 */
static void
argappend(char **dstp, const char *fmt, ...)
{
	char *old, *new;
	va_list ap;
	
	old = *dstp;
	assert(old != NULL);

	va_start(ap, fmt);
	if (vasprintf(&new, fmt,ap) == -1)
		errx(1, "vasprintf");
	va_end(ap);

	*dstp = new;
	if (asprintf(&new, "%s %s", old, new) == -1)
		errx(1, "asprintf");
	free(*dstp);
	free(old);

	*dstp = new;
}

/*
 * If run-time debugging is enabled, print the expansion of 'fmt'.
 * Otherwise, do nothing.
 */
static void
debugprintf(const char *fmt, ...)
{
	va_list ap;

	if (!debug)
		return;
	fprintf(stderr, "DEBUG: ");
	va_start(ap, fmt);
	vfprintf(stderr, fmt, ap);
	va_end(ap);
	fprintf(stderr, "\n");
	fflush(stderr);
}

/*
 * Attach a memory disk with a known unit.
 */
static void
do_mdconfig_attach(const char *args, const enum md_types mdtype)
{
	int rv;
	const char *ta;		/* Type arg. */

	switch (mdtype) {
	case MD_SWAP:
		ta = "-t swap";
		break;
	case MD_VNODE:
		ta = "-t vnode";
		break;
	case MD_MALLOC:
		ta = "-t malloc";
		break;
	default:
		abort();
	}
	rv = run(NULL, "%s -a %s%s -u %s%d", PATH_MDCONFIG, ta, args,
	    mdname, unit);
	if (rv)
		errx(1, "mdconfig (attach) exited with error code %d", rv);
}

/*
 * Attach a memory disk with an unknown unit; use autounit.
 */
static void
do_mdconfig_attach_au(const char *args, const enum md_types mdtype)
{
	const char *ta;		/* Type arg. */
	char *linep, *linebuf; 	/* Line pointer, line buffer. */
	int fd;			/* Standard output of mdconfig invocation. */
	FILE *sfd;
	int rv;
	char *p;
	size_t linelen;

	switch (mdtype) {
	case MD_SWAP:
		ta = "-t swap";
		break;
	case MD_VNODE:
		ta = "-t vnode";
		break;
	case MD_MALLOC:
		ta = "-t malloc";
		break;
	default:
		abort();
	}
	rv = run(&fd, "%s -a %s%s", PATH_MDCONFIG, ta, args);
	if (rv)
		errx(1, "mdconfig (attach) exited with error code %d", rv);

	/* Receive the unit number. */
	if (norun) {	/* Since we didn't run, we can't read.  Fake it. */
		unit = -1;
		return;
	}
	sfd = fdopen(fd, "r");
	if (sfd == NULL)
		err(1, "fdopen");
	linep = fgetln(sfd, &linelen);
	if (linep == NULL && linelen < mdnamelen + 1)
		errx(1, "unexpected output from mdconfig (attach)");
	/* If the output format changes, we want to know about it. */
	assert(strncmp(linep, mdname, mdnamelen) == 0);
	linebuf = malloc(linelen - mdnamelen + 1);
	assert(linebuf != NULL);
	/* Can't use strlcpy because linep is not NULL-terminated. */
	strncpy(linebuf, linep + mdnamelen, linelen);
	linebuf[linelen] = '\0';
	unit = strtoul(linebuf, &p, 10);
	if ((unsigned)unit == ULONG_MAX || *p != '\n')
		errx(1, "unexpected output from mdconfig (attach)");

	fclose(sfd);
	close(fd);
}

/*
 * Detach a memory disk.
 */
static void
do_mdconfig_detach(void)
{
	int rv;

	rv = run(NULL, "%s -d -u %s%d", PATH_MDCONFIG, mdname, unit);
	if (rv && debug)	/* This is allowed to fail. */
		warnx("mdconfig (detach) exited with error code %d (ignored)",
		      rv);
}

/*
 * Mount the configured memory disk.
 */
static void
do_mount(const char *args, const char *mtpoint)
{
	int rv;

	rv = run(NULL, "%s%s /dev/%s%d %s", PATH_MOUNT, args,
	    mdname, unit, mtpoint);
	if (rv)
		errx(1, "mount exited with error code %d", rv);
}

/*
 * Various configuration of the mountpoint.  Mostly, enact 'mip'.
 */
static void
do_mtptsetup(const char *mtpoint, struct mtpt_info *mip)
{

	if (mip->mi_have_mode) {
		debugprintf("changing mode of %s to %o.", mtpoint,
		    mip->mi_mode);
		if (!norun)
			if (chmod(mtpoint, mip->mi_mode) == -1)
				err(1, "chmod: %s", mtpoint);
	}
	/*
	 * We have to do these separately because the user may have
	 * only specified one of them.
	 */
	if (mip->mi_have_uid) {
		debugprintf("changing owner (user) or %s to %u.", mtpoint,
		    mip->mi_uid);
		if (!norun)
			if (chown(mtpoint, mip->mi_uid, -1) == -1)
				err(1, "chown %s to %u (user)", mtpoint,
				    mip->mi_uid);
	}
	if (mip->mi_have_gid) {
		debugprintf("changing owner (group) or %s to %u.", mtpoint,
		    mip->mi_gid);
		if (!norun)
			if (chown(mtpoint, -1, mip->mi_gid) == -1)
				err(1, "chown %s to %u (group)", mtpoint,
				    mip->mi_gid);
	}
}

/*
 * Put a file system on the memory disk.
 */
static void
do_newfs(const char *args)
{
	int rv;

	rv = run(NULL, "%s%s /dev/%s%d", PATH_NEWFS, args, mdname, unit);
	if (rv)
		errx(1, "newfs exited with error code %d", rv);
}

/*
 * 'str' should be a user and group name similar to the last argument
 * to chown(1); i.e., a user, followed by a colon, followed by a
 * group.  The user and group in 'str' may be either a [ug]id or a
 * name.  Upon return, the uid and gid fields in 'mip' will contain
 * the uid and gid of the user and group name in 'str', respectively.
 *
 * In other words, this derives a user and group id from a string
 * formatted like the last argument to chown(1).
 */
static void
extract_ugid(const char *str, struct mtpt_info *mip)
{
	char *ug;			/* Writable 'str'. */
	char *user, *group;		/* Result of extracton. */
	struct passwd *pw;
	struct group *gr;
	char *p;
	uid_t *uid;
	gid_t *gid;

	uid = &mip->mi_uid;
	gid = &mip->mi_gid;
	mip->mi_have_uid = mip->mi_have_gid = false;

	/* Extract the user and group from 'str'.  Format above. */
	ug = strdup(str);
	assert(ug != NULL);
	group = ug;
	user = strsep(&group, ":");
	if (user == NULL || group == NULL || *user == '\0' || *group == '\0')
		usage();

	/* Derive uid. */
	*uid = strtoul(user, &p, 10);
	if ((unsigned)*uid == ULONG_MAX)
		usage();
	if (*p != '\0') {
		pw = getpwnam(user);
		if (pw == NULL)
			errx(1, "invalid user: %s", user);
		*uid = pw->pw_uid;
		mip->mi_have_uid = true;
	}

	/* Derive gid. */
	*gid = strtoul(group, &p, 10);
	if ((unsigned)*gid == ULONG_MAX)
		usage();
	if (*p != '\0') {
		gr = getgrnam(group);
		if (gr == NULL)
			errx(1, "invalid group: %s", group);
		*gid = gr->gr_gid;
		mip->mi_have_gid = true;
	}

	free(ug);
	/*
	 * At this point we don't support only a username or only a
	 * group name.  do_mtptsetup already does, so when this
	 * feature is desired, this is the only routine that needs to
	 * be changed.
	 */
	assert(mip->mi_have_uid);
	assert(mip->mi_have_gid);
}

/*
 * Run a process with command name and arguments pointed to by the
 * formatted string 'cmdline'.  Since system(3) is not used, the first
 * space-delimited token of 'cmdline' must be the full pathname of the
 * program to run.  The return value is the return code of the process
 * spawned.  If 'ofd' is non-NULL, it is set to the standard output of
 * the program spawned (i.e., you can read from ofd and get the output
 * of the program).
 */
static int
run(int *ofd, const char *cmdline, ...)
{
	char **argv, **argvp;		/* Result of splitting 'cmd'. */
	int argc;
	char *cmd;			/* Expansion of 'cmdline'. */
	int pid, status;		/* Child info. */
	int pfd[2];			/* Pipe to the child. */
	int nfd;			/* Null (/dev/null) file descriptor. */
	bool dup2dn;			/* Dup /dev/null to stdout? */
	va_list ap;
	char *p;
	int rv, i;

	dup2dn = true;
	va_start(ap, cmdline);
	rv = vasprintf(&cmd, cmdline, ap);
	if (rv == -1)
		err(1, "vasprintf");
	va_end(ap);

	/* Split up 'cmd' into 'argv' for use with execve. */
	for (argc = 1, p = cmd; (p = strchr(p, ' ')) != NULL; p++)
		argc++;		/* 'argc' generation loop. */
	argv = (char **)malloc(sizeof(*argv) * (argc + 1));
	assert(argv != NULL);
	for (p = cmd, argvp = argv; (*argvp = strsep(&p, " ")) != NULL;)
		if (**argv != '\0')
			if (++argvp >= &argv[argc]) {
				*argvp = NULL;
				break;
			}
	assert(*argv);

	/* Make sure the above loop works as expected. */
	if (debug) {
		/*
		 * We can't, but should, use debugprintf here.  First,
		 * it appends a trailing newline to the output, and
		 * second it prepends "DEBUG: " to the output.  The
		 * former is a problem for this would-be first call,
		 * and the latter for the would-be call inside the
		 * loop.
		 */
		(void)fprintf(stderr, "DEBUG: running:");
		/* Should be equivilent to 'cmd' (before strsep, of course). */
		for (i = 0; argv[i] != NULL; i++)
			(void)fprintf(stderr, " %s", argv[i]);
		(void)fprintf(stderr, "\n");
	}

	/* Create a pipe if necessary and fork the helper program. */
	if (ofd != NULL) {
		if (pipe(&pfd[0]) == -1)
			err(1, "pipe");
		*ofd = pfd[0];
		dup2dn = false;
	}
	pid = fork();
	switch (pid) {
	case 0:
		/* XXX can we call err() in here? */
		if (norun)
			_exit(0);
		if (ofd != NULL)
			if (dup2(pfd[1], STDOUT_FILENO) < 0)
				err(1, "dup2");
		if (!loudsubs) {
			nfd = open(_PATH_DEVNULL, O_RDWR);
			if (nfd == -1)
				err(1, "open: %s", _PATH_DEVNULL);
			if (dup2(nfd, STDIN_FILENO) < 0)
				err(1, "dup2");
			if (dup2dn)
				if (dup2(nfd, STDOUT_FILENO) < 0)
				   err(1, "dup2");
			if (dup2(nfd, STDERR_FILENO) < 0)
				err(1, "dup2");
		}

		(void)execv(argv[0], argv);
		warn("exec: %s", argv[0]);
		_exit(-1);
	case -1:
		err(1, "fork");
	}

	free(cmd);
	free(argv);
	while (waitpid(pid, &status, 0) != pid)
		;
	return (WEXITSTATUS(status));
}

static void
usage(void)
{
	const char *name;

	if (compat)
		name = getprogname();
	else
		name = "mdmfs";
	if (!compat)
		fprintf(stderr,
"usage: %s [-DLMNSUX] [-a maxcontig [-b block-size] [-c cylinders]\n"
"\t[-d rotdelay] [-e maxbpg] [-F file] [-f frag-size] [-i bytes]\n"
"\t[-m percent-free] [-n rotational-positions] [-O optimization]\n"
"\t[-o mount-options] [-p permissions] [-s size] [-w user:group]\n"
"\tmd-device mount-point\n", name);
	fprintf(stderr,
"usage: %s -C [-NU] [-a maxcontig] [-b block-size] [-c cylinders]\n"
"\t[-d rotdelay] [-e maxbpg] [-F file] [-f frag-size] [-i bytes]\n"
"\t[-m percent-free] [-n rotational-positions] [-O optimization]\n"
"\t[-o mount-options] [-s size] md-device mount-point\n", name);
	exit(1);
}
OpenPOWER on IntegriCloud