xref: /freebsd/sbin/mdmfs/mdmfs.c (revision 3d238d9e981227b3bf739a51281e5d200bff3f8c)
1 /*
2  * Copyright (c) 2001 Dima Dorfman.
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 AUTHOR 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 AUTHOR 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 /*
28  * mdmfs (md/MFS) is a wrapper around mdconfig(8),
29  * newfs(8), and mount(8) that mimics the command line option set of
30  * the deprecated mount_mfs(8).
31  */
32 
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #include <sys/param.h>
37 #include <sys/mdioctl.h>
38 #include <sys/stat.h>
39 #include <sys/wait.h>
40 
41 #include <assert.h>
42 #include <err.h>
43 #include <fcntl.h>
44 #include <grp.h>
45 #include <paths.h>
46 #include <pwd.h>
47 #include <stdarg.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 
53 typedef enum { false, true } bool;
54 
55 struct mtpt_info {
56 	uid_t		 mi_uid;
57 	bool		 mi_have_uid;
58 	gid_t		 mi_gid;
59 	bool		 mi_have_gid;
60 	mode_t		 mi_mode;
61 	bool		 mi_have_mode;
62 };
63 
64 static	bool compat;		/* Full compatibility with mount_mfs? */
65 static	bool debug;		/* Emit debugging information? */
66 static	bool loudsubs;		/* Suppress output from helper programs? */
67 static	bool norun;		/* Actually run the helper programs? */
68 static	int unit;      		/* The unit we're working with. */
69 static	const char *mdname;	/* Name of memory disk device (e.g., "md"). */
70 static	size_t mdnamelen;	/* Length of mdname. */
71 
72 static void	 argappend(char **, const char *, ...) __printflike(2, 3);
73 static void	 debugprintf(const char *, ...) __printflike(1, 2);
74 static void	 do_mdconfig_attach(const char *, const enum md_types);
75 static void	 do_mdconfig_attach_au(const char *, const enum md_types);
76 static void	 do_mdconfig_detach(void);
77 static void	 do_mount(const char *, const char *);
78 static void	 do_mtptsetup(const char *, struct mtpt_info *);
79 static void	 do_newfs(const char *);
80 static void	 extract_ugid(const char *, struct mtpt_info *);
81 static int	 run(int *, const char *, ...) __printflike(2, 3);
82 static void	 usage(void);
83 
84 int
85 main(int argc, char **argv)
86 {
87 	struct mtpt_info mi;		/* Mountpoint info. */
88 	char *mdconfig_arg, *newfs_arg,	/* Args to helper programs. */
89 	    *mount_arg;
90 	enum md_types mdtype;		/* The type of our memory disk. */
91 	bool have_mdtype;
92 	bool detach, softdep, autounit;
93 	char *mtpoint, *unitstr;
94 	char ch, *p;
95 
96 	/* Misc. initialization. */
97 	(void)memset(&mi, '\0', sizeof(mi));
98 	detach = true;
99 	softdep = true;
100 	autounit = false;
101 	have_mdtype = false;
102 	mdname = MD_NAME;
103 	mdnamelen = strlen(mdname);
104 	/*
105 	 * Can't set these to NULL.  They may be passed to the
106 	 * respective programs without modification.  I.e., we may not
107 	 * receive any command-line options which will caused them to
108 	 * be modified.
109 	 */
110 	mdconfig_arg = strdup("");
111 	newfs_arg = strdup("");
112 	mount_arg = strdup("");
113 
114 	/* If we were started as mount_mfs or mfs, imply -C. */
115 	if (strcmp(getprogname(), "mount_mfs") == 0 ||
116 	    strcmp(getprogname(), "mfs") == 0)
117 		compat = true;
118 
119 	while ((ch = getopt(argc, argv,
120 	    "a:b:Cc:Dd:e:F:f:hi:LMm:Nn:O:o:p:Ss:t:Uv:w:X")) != -1)
121 		switch (ch) {
122 		case 'a':
123 			argappend(&newfs_arg, "-a %s", optarg);
124 			break;
125 		case 'b':
126 			argappend(&newfs_arg, "-b %s", optarg);
127 			break;
128 		case 'C':
129 			if (compat)
130 				usage();
131 			compat = true;
132 			break;
133 		case 'c':
134 			argappend(&newfs_arg, "-c %s", optarg);
135 			break;
136 		case 'D':
137 			if (compat)
138 				usage();
139 			detach = false;
140 			break;
141 		case 'd':
142 			argappend(&newfs_arg, "-d %s", optarg);
143 			break;
144 		case 'e':
145 			argappend(&newfs_arg, "-e %s", optarg);
146 			break;
147 		case 'F':
148 			if (have_mdtype)
149 				usage();
150 			mdtype = MD_VNODE;
151 			have_mdtype = true;
152 			argappend(&mdconfig_arg, "-f %s", optarg);
153 			break;
154 		case 'f':
155 			argappend(&newfs_arg, "-f %s", optarg);
156 			break;
157 		case 'h':
158 			usage();
159 			break;
160 		case 'i':
161 			argappend(&newfs_arg, "-i %s", optarg);
162 			break;
163 		case 'L':
164 			if (compat)
165 				usage();
166 			loudsubs = true;
167 			break;
168 		case 'M':
169 			if (have_mdtype)
170 				usage();
171 			mdtype = MD_MALLOC;
172 			have_mdtype = true;
173 			break;
174 		case 'm':
175 			argappend(&newfs_arg, "-m %s", optarg);
176 			break;
177 		case 'N':
178 			if (compat)
179 				usage();
180 			norun = true;
181 			break;
182 		case 'n':
183 			argappend(&newfs_arg, "-n %s", optarg);
184 			break;
185 		case 'O':
186 			argappend(&newfs_arg, "-o %s", optarg);
187 			break;
188 		case 'o':
189 			argappend(&mount_arg, "-o %s", optarg);
190 			break;
191 		case 'p':
192 			if (compat)
193 				usage();
194 			if (*optarg >= '0' && *optarg <= '7')
195 				mi.mi_mode = strtol(optarg, NULL, 8);
196 			if ((mi.mi_mode & ~07777) != 0)
197 				usage();
198 			mi.mi_have_mode = true;
199 			break;
200 		case 'S':
201 			if (compat)
202 				usage();
203 			softdep = false;
204 			break;
205 		case 's':
206 			argappend(&mdconfig_arg, "-s %s", optarg);
207 			break;
208 		case 'U':
209 			softdep = true;
210 			break;
211 		case 'v':
212 			argappend(&newfs_arg, "-O %s", optarg);
213 			break;
214 		case 'w':
215 			if (compat)
216 				usage();
217 			extract_ugid(optarg, &mi);
218 			break;
219 		case 'X':
220 			if (compat)
221 				usage();
222 			debug = true;
223 			break;
224 		default:
225 			usage();
226 		}
227 	argc -= optind;
228 	argv += optind;
229 	if (argc < 2)
230 		usage();
231 
232 	/* Make compatibility assumptions. */
233 	if (compat) {
234 		mi.mi_mode = 01777;
235 		mi.mi_have_mode = true;
236 	}
237 
238 	/* Derive 'unit' (global). */
239 	unitstr = argv[0];
240 	if (strncmp(unitstr, "/dev/", 5) == 0)
241 		unitstr += 5;
242 	if (strncmp(unitstr, mdname, mdnamelen) == 0)
243 		unitstr += mdnamelen;
244 	if (*unitstr == '\0') {
245 		autounit = true;
246 		unit = -1;
247 	} else {
248 		unit = strtoul(unitstr, &p, 10);
249 		if ((unsigned)unit == ULONG_MAX || *p != '\0')
250 			errx(1, "bad device unit: %s", unitstr);
251 	}
252 
253 	mtpoint = argv[1];
254 	if (!have_mdtype)
255 		mdtype = MD_SWAP;
256 	if (softdep)
257 		argappend(&newfs_arg, "-U");
258 
259 	/* Do the work. */
260 	if (detach && !autounit)
261 		do_mdconfig_detach();
262 	if (autounit)
263 		do_mdconfig_attach_au(mdconfig_arg, mdtype);
264 	else
265 		do_mdconfig_attach(mdconfig_arg, mdtype);
266 	do_newfs(newfs_arg);
267 	do_mount(mount_arg, mtpoint);
268 	do_mtptsetup(mtpoint, &mi);
269 
270 	return (0);
271 }
272 
273 /*
274  * Append the expansion of 'fmt' to the buffer pointed to by '*dstp';
275  * reallocate as required.
276  */
277 static void
278 argappend(char **dstp, const char *fmt, ...)
279 {
280 	char *old, *new;
281 	va_list ap;
282 
283 	old = *dstp;
284 	assert(old != NULL);
285 
286 	va_start(ap, fmt);
287 	if (vasprintf(&new, fmt,ap) == -1)
288 		errx(1, "vasprintf");
289 	va_end(ap);
290 
291 	*dstp = new;
292 	if (asprintf(&new, "%s %s", old, new) == -1)
293 		errx(1, "asprintf");
294 	free(*dstp);
295 	free(old);
296 
297 	*dstp = new;
298 }
299 
300 /*
301  * If run-time debugging is enabled, print the expansion of 'fmt'.
302  * Otherwise, do nothing.
303  */
304 static void
305 debugprintf(const char *fmt, ...)
306 {
307 	va_list ap;
308 
309 	if (!debug)
310 		return;
311 	fprintf(stderr, "DEBUG: ");
312 	va_start(ap, fmt);
313 	vfprintf(stderr, fmt, ap);
314 	va_end(ap);
315 	fprintf(stderr, "\n");
316 	fflush(stderr);
317 }
318 
319 /*
320  * Attach a memory disk with a known unit.
321  */
322 static void
323 do_mdconfig_attach(const char *args, const enum md_types mdtype)
324 {
325 	int rv;
326 	const char *ta;		/* Type arg. */
327 
328 	switch (mdtype) {
329 	case MD_SWAP:
330 		ta = "-t swap";
331 		break;
332 	case MD_VNODE:
333 		ta = "-t vnode";
334 		break;
335 	case MD_MALLOC:
336 		ta = "-t malloc";
337 		break;
338 	default:
339 		abort();
340 	}
341 	rv = run(NULL, "%s -a %s%s -u %s%d", _PATH_MDCONFIG, ta, args,
342 	    mdname, unit);
343 	if (rv)
344 		errx(1, "mdconfig (attach) exited with error code %d", rv);
345 }
346 
347 /*
348  * Attach a memory disk with an unknown unit; use autounit.
349  */
350 static void
351 do_mdconfig_attach_au(const char *args, const enum md_types mdtype)
352 {
353 	const char *ta;		/* Type arg. */
354 	char *linep, *linebuf; 	/* Line pointer, line buffer. */
355 	int fd;			/* Standard output of mdconfig invocation. */
356 	FILE *sfd;
357 	int rv;
358 	char *p;
359 	size_t linelen;
360 
361 	switch (mdtype) {
362 	case MD_SWAP:
363 		ta = "-t swap";
364 		break;
365 	case MD_VNODE:
366 		ta = "-t vnode";
367 		break;
368 	case MD_MALLOC:
369 		ta = "-t malloc";
370 		break;
371 	default:
372 		abort();
373 	}
374 	rv = run(&fd, "%s -a %s%s", _PATH_MDCONFIG, ta, args);
375 	if (rv)
376 		errx(1, "mdconfig (attach) exited with error code %d", rv);
377 
378 	/* Receive the unit number. */
379 	if (norun) {	/* Since we didn't run, we can't read.  Fake it. */
380 		unit = -1;
381 		return;
382 	}
383 	sfd = fdopen(fd, "r");
384 	if (sfd == NULL)
385 		err(1, "fdopen");
386 	linep = fgetln(sfd, &linelen);
387 	if (linep == NULL && linelen < mdnamelen + 1)
388 		errx(1, "unexpected output from mdconfig (attach)");
389 	/* If the output format changes, we want to know about it. */
390 	assert(strncmp(linep, mdname, mdnamelen) == 0);
391 	linebuf = malloc(linelen - mdnamelen + 1);
392 	assert(linebuf != NULL);
393 	/* Can't use strlcpy because linep is not NULL-terminated. */
394 	strncpy(linebuf, linep + mdnamelen, linelen);
395 	linebuf[linelen] = '\0';
396 	unit = strtoul(linebuf, &p, 10);
397 	if ((unsigned)unit == ULONG_MAX || *p != '\n')
398 		errx(1, "unexpected output from mdconfig (attach)");
399 
400 	fclose(sfd);
401 	close(fd);
402 }
403 
404 /*
405  * Detach a memory disk.
406  */
407 static void
408 do_mdconfig_detach(void)
409 {
410 	int rv;
411 
412 	rv = run(NULL, "%s -d -u %s%d", _PATH_MDCONFIG, mdname, unit);
413 	if (rv && debug)	/* This is allowed to fail. */
414 		warnx("mdconfig (detach) exited with error code %d (ignored)",
415 		      rv);
416 }
417 
418 /*
419  * Mount the configured memory disk.
420  */
421 static void
422 do_mount(const char *args, const char *mtpoint)
423 {
424 	int rv;
425 
426 	rv = run(NULL, "%s%s /dev/%s%d %s", _PATH_MOUNT, args,
427 	    mdname, unit, mtpoint);
428 	if (rv)
429 		errx(1, "mount exited with error code %d", rv);
430 }
431 
432 /*
433  * Various configuration of the mountpoint.  Mostly, enact 'mip'.
434  */
435 static void
436 do_mtptsetup(const char *mtpoint, struct mtpt_info *mip)
437 {
438 
439 	if (mip->mi_have_mode) {
440 		debugprintf("changing mode of %s to %o.", mtpoint,
441 		    mip->mi_mode);
442 		if (!norun)
443 			if (chmod(mtpoint, mip->mi_mode) == -1)
444 				err(1, "chmod: %s", mtpoint);
445 	}
446 	/*
447 	 * We have to do these separately because the user may have
448 	 * only specified one of them.
449 	 */
450 	if (mip->mi_have_uid) {
451 		debugprintf("changing owner (user) or %s to %u.", mtpoint,
452 		    mip->mi_uid);
453 		if (!norun)
454 			if (chown(mtpoint, mip->mi_uid, -1) == -1)
455 				err(1, "chown %s to %u (user)", mtpoint,
456 				    mip->mi_uid);
457 	}
458 	if (mip->mi_have_gid) {
459 		debugprintf("changing owner (group) or %s to %u.", mtpoint,
460 		    mip->mi_gid);
461 		if (!norun)
462 			if (chown(mtpoint, -1, mip->mi_gid) == -1)
463 				err(1, "chown %s to %u (group)", mtpoint,
464 				    mip->mi_gid);
465 	}
466 }
467 
468 /*
469  * Put a file system on the memory disk.
470  */
471 static void
472 do_newfs(const char *args)
473 {
474 	int rv;
475 
476 	rv = run(NULL, "%s%s /dev/%s%d", _PATH_NEWFS, args, mdname, unit);
477 	if (rv)
478 		errx(1, "newfs exited with error code %d", rv);
479 }
480 
481 /*
482  * 'str' should be a user and group name similar to the last argument
483  * to chown(1); i.e., a user, followed by a colon, followed by a
484  * group.  The user and group in 'str' may be either a [ug]id or a
485  * name.  Upon return, the uid and gid fields in 'mip' will contain
486  * the uid and gid of the user and group name in 'str', respectively.
487  *
488  * In other words, this derives a user and group id from a string
489  * formatted like the last argument to chown(1).
490  */
491 static void
492 extract_ugid(const char *str, struct mtpt_info *mip)
493 {
494 	char *ug;			/* Writable 'str'. */
495 	char *user, *group;		/* Result of extracton. */
496 	struct passwd *pw;
497 	struct group *gr;
498 	char *p;
499 	uid_t *uid;
500 	gid_t *gid;
501 
502 	uid = &mip->mi_uid;
503 	gid = &mip->mi_gid;
504 	mip->mi_have_uid = mip->mi_have_gid = false;
505 
506 	/* Extract the user and group from 'str'.  Format above. */
507 	ug = strdup(str);
508 	assert(ug != NULL);
509 	group = ug;
510 	user = strsep(&group, ":");
511 	if (user == NULL || group == NULL || *user == '\0' || *group == '\0')
512 		usage();
513 
514 	/* Derive uid. */
515 	*uid = strtoul(user, &p, 10);
516 	if ((unsigned)*uid == ULONG_MAX)
517 		usage();
518 	if (*p != '\0') {
519 		pw = getpwnam(user);
520 		if (pw == NULL)
521 			errx(1, "invalid user: %s", user);
522 		*uid = pw->pw_uid;
523 		mip->mi_have_uid = true;
524 	}
525 
526 	/* Derive gid. */
527 	*gid = strtoul(group, &p, 10);
528 	if ((unsigned)*gid == ULONG_MAX)
529 		usage();
530 	if (*p != '\0') {
531 		gr = getgrnam(group);
532 		if (gr == NULL)
533 			errx(1, "invalid group: %s", group);
534 		*gid = gr->gr_gid;
535 		mip->mi_have_gid = true;
536 	}
537 
538 	free(ug);
539 	/*
540 	 * At this point we don't support only a username or only a
541 	 * group name.  do_mtptsetup already does, so when this
542 	 * feature is desired, this is the only routine that needs to
543 	 * be changed.
544 	 */
545 	assert(mip->mi_have_uid);
546 	assert(mip->mi_have_gid);
547 }
548 
549 /*
550  * Run a process with command name and arguments pointed to by the
551  * formatted string 'cmdline'.  Since system(3) is not used, the first
552  * space-delimited token of 'cmdline' must be the full pathname of the
553  * program to run.  The return value is the return code of the process
554  * spawned.  If 'ofd' is non-NULL, it is set to the standard output of
555  * the program spawned (i.e., you can read from ofd and get the output
556  * of the program).
557  */
558 static int
559 run(int *ofd, const char *cmdline, ...)
560 {
561 	char **argv, **argvp;		/* Result of splitting 'cmd'. */
562 	int argc;
563 	char *cmd;			/* Expansion of 'cmdline'. */
564 	int pid, status;		/* Child info. */
565 	int pfd[2];			/* Pipe to the child. */
566 	int nfd;			/* Null (/dev/null) file descriptor. */
567 	bool dup2dn;			/* Dup /dev/null to stdout? */
568 	va_list ap;
569 	char *p;
570 	int rv, i;
571 
572 	dup2dn = true;
573 	va_start(ap, cmdline);
574 	rv = vasprintf(&cmd, cmdline, ap);
575 	if (rv == -1)
576 		err(1, "vasprintf");
577 	va_end(ap);
578 
579 	/* Split up 'cmd' into 'argv' for use with execve. */
580 	for (argc = 1, p = cmd; (p = strchr(p, ' ')) != NULL; p++)
581 		argc++;		/* 'argc' generation loop. */
582 	argv = (char **)malloc(sizeof(*argv) * (argc + 1));
583 	assert(argv != NULL);
584 	for (p = cmd, argvp = argv; (*argvp = strsep(&p, " ")) != NULL;)
585 		if (**argv != '\0')
586 			if (++argvp >= &argv[argc]) {
587 				*argvp = NULL;
588 				break;
589 			}
590 	assert(*argv);
591 
592 	/* Make sure the above loop works as expected. */
593 	if (debug) {
594 		/*
595 		 * We can't, but should, use debugprintf here.  First,
596 		 * it appends a trailing newline to the output, and
597 		 * second it prepends "DEBUG: " to the output.  The
598 		 * former is a problem for this would-be first call,
599 		 * and the latter for the would-be call inside the
600 		 * loop.
601 		 */
602 		(void)fprintf(stderr, "DEBUG: running:");
603 		/* Should be equivilent to 'cmd' (before strsep, of course). */
604 		for (i = 0; argv[i] != NULL; i++)
605 			(void)fprintf(stderr, " %s", argv[i]);
606 		(void)fprintf(stderr, "\n");
607 	}
608 
609 	/* Create a pipe if necessary and fork the helper program. */
610 	if (ofd != NULL) {
611 		if (pipe(&pfd[0]) == -1)
612 			err(1, "pipe");
613 		*ofd = pfd[0];
614 		dup2dn = false;
615 	}
616 	pid = fork();
617 	switch (pid) {
618 	case 0:
619 		/* XXX can we call err() in here? */
620 		if (norun)
621 			_exit(0);
622 		if (ofd != NULL)
623 			if (dup2(pfd[1], STDOUT_FILENO) < 0)
624 				err(1, "dup2");
625 		if (!loudsubs) {
626 			nfd = open(_PATH_DEVNULL, O_RDWR);
627 			if (nfd == -1)
628 				err(1, "open: %s", _PATH_DEVNULL);
629 			if (dup2(nfd, STDIN_FILENO) < 0)
630 				err(1, "dup2");
631 			if (dup2dn)
632 				if (dup2(nfd, STDOUT_FILENO) < 0)
633 				   err(1, "dup2");
634 			if (dup2(nfd, STDERR_FILENO) < 0)
635 				err(1, "dup2");
636 		}
637 
638 		(void)execv(argv[0], argv);
639 		warn("exec: %s", argv[0]);
640 		_exit(-1);
641 	case -1:
642 		err(1, "fork");
643 	}
644 
645 	free(cmd);
646 	free(argv);
647 	while (waitpid(pid, &status, 0) != pid)
648 		;
649 	return (WEXITSTATUS(status));
650 }
651 
652 static void
653 usage(void)
654 {
655 	const char *name;
656 
657 	if (compat)
658 		name = getprogname();
659 	else
660 		name = "mdmfs";
661 	if (!compat)
662 		fprintf(stderr,
663 "usage: %s [-DLMNSUX] [-a maxcontig [-b block-size] [-c cylinders]\n"
664 "\t[-d rotdelay] [-e maxbpg] [-F file] [-f frag-size] [-i bytes]\n"
665 "\t[-m percent-free] [-n rotational-positions] [-O optimization]\n"
666 "\t[-o mount-options] [-p permissions] [-s size] [-w user:group]\n"
667 "\tmd-device mount-point\n", name);
668 	fprintf(stderr,
669 "usage: %s -C [-NU] [-a maxcontig] [-b block-size] [-c cylinders]\n"
670 "\t[-d rotdelay] [-e maxbpg] [-F file] [-f frag-size] [-i bytes]\n"
671 "\t[-m percent-free] [-n rotational-positions] [-O optimization]\n"
672 "\t[-o mount-options] [-s size] md-device mount-point\n", name);
673 	exit(1);
674 }
675