xref: /freebsd/sbin/mdmfs/mdmfs.c (revision 6af83ee0d2941d18880b6aaa2b4facd1d30c6106)
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 *p;
95 	int ch;
96 	void *set;
97 	unsigned long ul;
98 
99 	/* Misc. initialization. */
100 	(void)memset(&mi, '\0', sizeof(mi));
101 	detach = true;
102 	softdep = true;
103 	autounit = false;
104 	have_mdtype = false;
105 	mdtype = MD_SWAP;
106 	mdname = MD_NAME;
107 	mdnamelen = strlen(mdname);
108 	/*
109 	 * Can't set these to NULL.  They may be passed to the
110 	 * respective programs without modification.  I.e., we may not
111 	 * receive any command-line options which will caused them to
112 	 * be modified.
113 	 */
114 	mdconfig_arg = strdup("");
115 	newfs_arg = strdup("");
116 	mount_arg = strdup("");
117 
118 	/* If we were started as mount_mfs or mfs, imply -C. */
119 	if (strcmp(getprogname(), "mount_mfs") == 0 ||
120 	    strcmp(getprogname(), "mfs") == 0)
121 		compat = true;
122 
123 	while ((ch = getopt(argc, argv,
124 	    "a:b:Cc:Dd:e:F:f:hi:LlMm:Nn:O:o:p:Ss:t:Uv:w:X")) != -1)
125 		switch (ch) {
126 		case 'a':
127 			argappend(&newfs_arg, "-a %s", optarg);
128 			break;
129 		case 'b':
130 			argappend(&newfs_arg, "-b %s", optarg);
131 			break;
132 		case 'C':
133 			if (compat)
134 				usage();
135 			compat = true;
136 			break;
137 		case 'c':
138 			argappend(&newfs_arg, "-c %s", optarg);
139 			break;
140 		case 'D':
141 			if (compat)
142 				usage();
143 			detach = false;
144 			break;
145 		case 'd':
146 			argappend(&newfs_arg, "-d %s", optarg);
147 			break;
148 		case 'e':
149 			argappend(&newfs_arg, "-e %s", optarg);
150 			break;
151 		case 'F':
152 			if (have_mdtype)
153 				usage();
154 			mdtype = MD_VNODE;
155 			have_mdtype = true;
156 			argappend(&mdconfig_arg, "-f %s", optarg);
157 			break;
158 		case 'f':
159 			argappend(&newfs_arg, "-f %s", optarg);
160 			break;
161 		case 'h':
162 			usage();
163 			break;
164 		case 'i':
165 			argappend(&newfs_arg, "-i %s", optarg);
166 			break;
167 		case 'L':
168 			if (compat)
169 				usage();
170 			loudsubs = true;
171 			break;
172 		case 'l':
173 			argappend(&newfs_arg, "-l");
174 			break;
175 		case 'M':
176 			if (have_mdtype)
177 				usage();
178 			mdtype = MD_MALLOC;
179 			have_mdtype = true;
180 			break;
181 		case 'm':
182 			argappend(&newfs_arg, "-m %s", optarg);
183 			break;
184 		case 'N':
185 			if (compat)
186 				usage();
187 			norun = true;
188 			break;
189 		case 'n':
190 			argappend(&newfs_arg, "-n %s", optarg);
191 			break;
192 		case 'O':
193 			argappend(&newfs_arg, "-o %s", optarg);
194 			break;
195 		case 'o':
196 			argappend(&mount_arg, "-o %s", optarg);
197 			break;
198 		case 'p':
199 			if (compat)
200 				usage();
201 			if ((set = setmode(optarg)) == NULL)
202 				usage();
203 			mi.mi_mode = getmode(set, S_IRWXU | S_IRWXG | S_IRWXO);
204 			mi.mi_have_mode = true;
205 			free(set);
206 			break;
207 		case 'S':
208 			if (compat)
209 				usage();
210 			softdep = false;
211 			break;
212 		case 's':
213 			argappend(&mdconfig_arg, "-s %s", optarg);
214 			break;
215 		case 'U':
216 			softdep = true;
217 			break;
218 		case 'v':
219 			argappend(&newfs_arg, "-O %s", optarg);
220 			break;
221 		case 'w':
222 			if (compat)
223 				usage();
224 			extract_ugid(optarg, &mi);
225 			break;
226 		case 'X':
227 			if (compat)
228 				usage();
229 			debug = true;
230 			break;
231 		default:
232 			usage();
233 		}
234 	argc -= optind;
235 	argv += optind;
236 	if (argc < 2)
237 		usage();
238 
239 	/* Make compatibility assumptions. */
240 	if (compat) {
241 		mi.mi_mode = 01777;
242 		mi.mi_have_mode = true;
243 	}
244 
245 	/* Derive 'unit' (global). */
246 	unitstr = argv[0];
247 	if (strncmp(unitstr, "/dev/", 5) == 0)
248 		unitstr += 5;
249 	if (strncmp(unitstr, mdname, mdnamelen) == 0)
250 		unitstr += mdnamelen;
251 	if (*unitstr == '\0') {
252 		autounit = true;
253 		unit = -1;
254 	} else {
255 		ul = strtoul(unitstr, &p, 10);
256 		if (ul == ULONG_MAX || *p != '\0')
257 			errx(1, "bad device unit: %s", unitstr);
258 		unit = ul;
259 	}
260 
261 	mtpoint = argv[1];
262 	if (!have_mdtype)
263 		mdtype = MD_SWAP;
264 	if (softdep)
265 		argappend(&newfs_arg, "-U");
266 
267 	/* Do the work. */
268 	if (detach && !autounit)
269 		do_mdconfig_detach();
270 	if (autounit)
271 		do_mdconfig_attach_au(mdconfig_arg, mdtype);
272 	else
273 		do_mdconfig_attach(mdconfig_arg, mdtype);
274 	do_newfs(newfs_arg);
275 	do_mount(mount_arg, mtpoint);
276 	do_mtptsetup(mtpoint, &mi);
277 
278 	return (0);
279 }
280 
281 /*
282  * Append the expansion of 'fmt' to the buffer pointed to by '*dstp';
283  * reallocate as required.
284  */
285 static void
286 argappend(char **dstp, const char *fmt, ...)
287 {
288 	char *old, *new;
289 	va_list ap;
290 
291 	old = *dstp;
292 	assert(old != NULL);
293 
294 	va_start(ap, fmt);
295 	if (vasprintf(&new, fmt,ap) == -1)
296 		errx(1, "vasprintf");
297 	va_end(ap);
298 
299 	*dstp = new;
300 	if (asprintf(&new, "%s %s", old, new) == -1)
301 		errx(1, "asprintf");
302 	free(*dstp);
303 	free(old);
304 
305 	*dstp = new;
306 }
307 
308 /*
309  * If run-time debugging is enabled, print the expansion of 'fmt'.
310  * Otherwise, do nothing.
311  */
312 static void
313 debugprintf(const char *fmt, ...)
314 {
315 	va_list ap;
316 
317 	if (!debug)
318 		return;
319 	fprintf(stderr, "DEBUG: ");
320 	va_start(ap, fmt);
321 	vfprintf(stderr, fmt, ap);
322 	va_end(ap);
323 	fprintf(stderr, "\n");
324 	fflush(stderr);
325 }
326 
327 /*
328  * Attach a memory disk with a known unit.
329  */
330 static void
331 do_mdconfig_attach(const char *args, const enum md_types mdtype)
332 {
333 	int rv;
334 	const char *ta;		/* Type arg. */
335 
336 	switch (mdtype) {
337 	case MD_SWAP:
338 		ta = "-t swap";
339 		break;
340 	case MD_VNODE:
341 		ta = "-t vnode";
342 		break;
343 	case MD_MALLOC:
344 		ta = "-t malloc";
345 		break;
346 	default:
347 		abort();
348 	}
349 	rv = run(NULL, "%s -a %s%s -u %s%d", _PATH_MDCONFIG, ta, args,
350 	    mdname, unit);
351 	if (rv)
352 		errx(1, "mdconfig (attach) exited with error code %d", rv);
353 }
354 
355 /*
356  * Attach a memory disk with an unknown unit; use autounit.
357  */
358 static void
359 do_mdconfig_attach_au(const char *args, const enum md_types mdtype)
360 {
361 	const char *ta;		/* Type arg. */
362 	char *linep, *linebuf; 	/* Line pointer, line buffer. */
363 	int fd;			/* Standard output of mdconfig invocation. */
364 	FILE *sfd;
365 	int rv;
366 	char *p;
367 	size_t linelen;
368 	unsigned long ul;
369 
370 	switch (mdtype) {
371 	case MD_SWAP:
372 		ta = "-t swap";
373 		break;
374 	case MD_VNODE:
375 		ta = "-t vnode";
376 		break;
377 	case MD_MALLOC:
378 		ta = "-t malloc";
379 		break;
380 	default:
381 		abort();
382 	}
383 	rv = run(&fd, "%s -a %s%s", _PATH_MDCONFIG, ta, args);
384 	if (rv)
385 		errx(1, "mdconfig (attach) exited with error code %d", rv);
386 
387 	/* Receive the unit number. */
388 	if (norun) {	/* Since we didn't run, we can't read.  Fake it. */
389 		unit = -1;
390 		return;
391 	}
392 	sfd = fdopen(fd, "r");
393 	if (sfd == NULL)
394 		err(1, "fdopen");
395 	linep = fgetln(sfd, &linelen);
396 	if (linep == NULL && linelen < mdnamelen + 1)
397 		errx(1, "unexpected output from mdconfig (attach)");
398 	/* If the output format changes, we want to know about it. */
399 	assert(strncmp(linep, mdname, mdnamelen) == 0);
400 	linebuf = malloc(linelen - mdnamelen + 1);
401 	assert(linebuf != NULL);
402 	/* Can't use strlcpy because linep is not NULL-terminated. */
403 	strncpy(linebuf, linep + mdnamelen, linelen);
404 	linebuf[linelen] = '\0';
405 	ul = strtoul(linebuf, &p, 10);
406 	if (ul == ULONG_MAX || *p != '\n')
407 		errx(1, "unexpected output from mdconfig (attach)");
408 	unit = ul;
409 
410 	fclose(sfd);
411 	close(fd);
412 }
413 
414 /*
415  * Detach a memory disk.
416  */
417 static void
418 do_mdconfig_detach(void)
419 {
420 	int rv;
421 
422 	rv = run(NULL, "%s -d -u %s%d", _PATH_MDCONFIG, mdname, unit);
423 	if (rv && debug)	/* This is allowed to fail. */
424 		warnx("mdconfig (detach) exited with error code %d (ignored)",
425 		      rv);
426 }
427 
428 /*
429  * Mount the configured memory disk.
430  */
431 static void
432 do_mount(const char *args, const char *mtpoint)
433 {
434 	int rv;
435 
436 	rv = run(NULL, "%s%s /dev/%s%d %s", _PATH_MOUNT, args,
437 	    mdname, unit, mtpoint);
438 	if (rv)
439 		errx(1, "mount exited with error code %d", rv);
440 }
441 
442 /*
443  * Various configuration of the mountpoint.  Mostly, enact 'mip'.
444  */
445 static void
446 do_mtptsetup(const char *mtpoint, struct mtpt_info *mip)
447 {
448 
449 	if (mip->mi_have_mode) {
450 		debugprintf("changing mode of %s to %o.", mtpoint,
451 		    mip->mi_mode);
452 		if (!norun)
453 			if (chmod(mtpoint, mip->mi_mode) == -1)
454 				err(1, "chmod: %s", mtpoint);
455 	}
456 	/*
457 	 * We have to do these separately because the user may have
458 	 * only specified one of them.
459 	 */
460 	if (mip->mi_have_uid) {
461 		debugprintf("changing owner (user) or %s to %u.", mtpoint,
462 		    mip->mi_uid);
463 		if (!norun)
464 			if (chown(mtpoint, mip->mi_uid, -1) == -1)
465 				err(1, "chown %s to %u (user)", mtpoint,
466 				    mip->mi_uid);
467 	}
468 	if (mip->mi_have_gid) {
469 		debugprintf("changing owner (group) or %s to %u.", mtpoint,
470 		    mip->mi_gid);
471 		if (!norun)
472 			if (chown(mtpoint, -1, mip->mi_gid) == -1)
473 				err(1, "chown %s to %u (group)", mtpoint,
474 				    mip->mi_gid);
475 	}
476 }
477 
478 /*
479  * Put a file system on the memory disk.
480  */
481 static void
482 do_newfs(const char *args)
483 {
484 	int rv;
485 
486 	rv = run(NULL, "%s%s /dev/%s%d", _PATH_NEWFS, args, mdname, unit);
487 	if (rv)
488 		errx(1, "newfs exited with error code %d", rv);
489 }
490 
491 /*
492  * 'str' should be a user and group name similar to the last argument
493  * to chown(1); i.e., a user, followed by a colon, followed by a
494  * group.  The user and group in 'str' may be either a [ug]id or a
495  * name.  Upon return, the uid and gid fields in 'mip' will contain
496  * the uid and gid of the user and group name in 'str', respectively.
497  *
498  * In other words, this derives a user and group id from a string
499  * formatted like the last argument to chown(1).
500  */
501 static void
502 extract_ugid(const char *str, struct mtpt_info *mip)
503 {
504 	char *ug;			/* Writable 'str'. */
505 	char *user, *group;		/* Result of extracton. */
506 	struct passwd *pw;
507 	struct group *gr;
508 	char *p;
509 	uid_t *uid;
510 	gid_t *gid;
511 
512 	uid = &mip->mi_uid;
513 	gid = &mip->mi_gid;
514 	mip->mi_have_uid = mip->mi_have_gid = false;
515 
516 	/* Extract the user and group from 'str'.  Format above. */
517 	ug = strdup(str);
518 	assert(ug != NULL);
519 	group = ug;
520 	user = strsep(&group, ":");
521 	if (user == NULL || group == NULL || *user == '\0' || *group == '\0')
522 		usage();
523 
524 	/* Derive uid. */
525 	*uid = strtoul(user, &p, 10);
526 	if (*uid == (uid_t)ULONG_MAX)
527 		usage();
528 	if (*p != '\0') {
529 		pw = getpwnam(user);
530 		if (pw == NULL)
531 			errx(1, "invalid user: %s", user);
532 		*uid = pw->pw_uid;
533 		mip->mi_have_uid = true;
534 	}
535 
536 	/* Derive gid. */
537 	*gid = strtoul(group, &p, 10);
538 	if (*gid == (gid_t)ULONG_MAX)
539 		usage();
540 	if (*p != '\0') {
541 		gr = getgrnam(group);
542 		if (gr == NULL)
543 			errx(1, "invalid group: %s", group);
544 		*gid = gr->gr_gid;
545 		mip->mi_have_gid = true;
546 	}
547 
548 	free(ug);
549 	/*
550 	 * At this point we don't support only a username or only a
551 	 * group name.  do_mtptsetup already does, so when this
552 	 * feature is desired, this is the only routine that needs to
553 	 * be changed.
554 	 */
555 	assert(mip->mi_have_uid);
556 	assert(mip->mi_have_gid);
557 }
558 
559 /*
560  * Run a process with command name and arguments pointed to by the
561  * formatted string 'cmdline'.  Since system(3) is not used, the first
562  * space-delimited token of 'cmdline' must be the full pathname of the
563  * program to run.  The return value is the return code of the process
564  * spawned.  If 'ofd' is non-NULL, it is set to the standard output of
565  * the program spawned (i.e., you can read from ofd and get the output
566  * of the program).
567  */
568 static int
569 run(int *ofd, const char *cmdline, ...)
570 {
571 	char **argv, **argvp;		/* Result of splitting 'cmd'. */
572 	int argc;
573 	char *cmd;			/* Expansion of 'cmdline'. */
574 	int pid, status;		/* Child info. */
575 	int pfd[2];			/* Pipe to the child. */
576 	int nfd;			/* Null (/dev/null) file descriptor. */
577 	bool dup2dn;			/* Dup /dev/null to stdout? */
578 	va_list ap;
579 	char *p;
580 	int rv, i;
581 
582 	dup2dn = true;
583 	va_start(ap, cmdline);
584 	rv = vasprintf(&cmd, cmdline, ap);
585 	if (rv == -1)
586 		err(1, "vasprintf");
587 	va_end(ap);
588 
589 	/* Split up 'cmd' into 'argv' for use with execve. */
590 	for (argc = 1, p = cmd; (p = strchr(p, ' ')) != NULL; p++)
591 		argc++;		/* 'argc' generation loop. */
592 	argv = (char **)malloc(sizeof(*argv) * (argc + 1));
593 	assert(argv != NULL);
594 	for (p = cmd, argvp = argv; (*argvp = strsep(&p, " ")) != NULL;)
595 		if (**argv != '\0')
596 			if (++argvp >= &argv[argc]) {
597 				*argvp = NULL;
598 				break;
599 			}
600 	assert(*argv);
601 
602 	/* Make sure the above loop works as expected. */
603 	if (debug) {
604 		/*
605 		 * We can't, but should, use debugprintf here.  First,
606 		 * it appends a trailing newline to the output, and
607 		 * second it prepends "DEBUG: " to the output.  The
608 		 * former is a problem for this would-be first call,
609 		 * and the latter for the would-be call inside the
610 		 * loop.
611 		 */
612 		(void)fprintf(stderr, "DEBUG: running:");
613 		/* Should be equivilent to 'cmd' (before strsep, of course). */
614 		for (i = 0; argv[i] != NULL; i++)
615 			(void)fprintf(stderr, " %s", argv[i]);
616 		(void)fprintf(stderr, "\n");
617 	}
618 
619 	/* Create a pipe if necessary and fork the helper program. */
620 	if (ofd != NULL) {
621 		if (pipe(&pfd[0]) == -1)
622 			err(1, "pipe");
623 		*ofd = pfd[0];
624 		dup2dn = false;
625 	}
626 	pid = fork();
627 	switch (pid) {
628 	case 0:
629 		/* XXX can we call err() in here? */
630 		if (norun)
631 			_exit(0);
632 		if (ofd != NULL)
633 			if (dup2(pfd[1], STDOUT_FILENO) < 0)
634 				err(1, "dup2");
635 		if (!loudsubs) {
636 			nfd = open(_PATH_DEVNULL, O_RDWR);
637 			if (nfd == -1)
638 				err(1, "open: %s", _PATH_DEVNULL);
639 			if (dup2(nfd, STDIN_FILENO) < 0)
640 				err(1, "dup2");
641 			if (dup2dn)
642 				if (dup2(nfd, STDOUT_FILENO) < 0)
643 				   err(1, "dup2");
644 			if (dup2(nfd, STDERR_FILENO) < 0)
645 				err(1, "dup2");
646 		}
647 
648 		(void)execv(argv[0], argv);
649 		warn("exec: %s", argv[0]);
650 		_exit(-1);
651 	case -1:
652 		err(1, "fork");
653 	}
654 
655 	free(cmd);
656 	free(argv);
657 	while (waitpid(pid, &status, 0) != pid)
658 		;
659 	return (WEXITSTATUS(status));
660 }
661 
662 static void
663 usage(void)
664 {
665 	const char *name;
666 
667 	if (compat)
668 		name = getprogname();
669 	else
670 		name = "mdmfs";
671 	if (!compat)
672 		fprintf(stderr,
673 "usage: %s [-DLlMNSUX] [-a maxcontig] [-b block-size] [-c cylinders]\n"
674 "\t[-d rotdelay] [-e maxbpg] [-F file] [-f frag-size] [-i bytes]\n"
675 "\t[-m percent-free] [-n rotational-positions] [-O optimization]\n"
676 "\t[-o mount-options] [-p permissions] [-s size] [-v version]\n"
677 "\t[-w user:group] md-device mount-point\n", name);
678 	fprintf(stderr,
679 "usage: %s -C [-lNU] [-a maxcontig] [-b block-size] [-c cylinders]\n"
680 "\t[-d rotdelay] [-e maxbpg] [-F file] [-f frag-size] [-i bytes]\n"
681 "\t[-m percent-free] [-n rotational-positions] [-O optimization]\n"
682 "\t[-o mount-options] [-s size] [-v version] md-device mount-point\n", name);
683 	exit(1);
684 }
685