xref: /freebsd/sbin/mdmfs/mdmfs.c (revision 4b2eaea43fec8e8792be611dea204071a10b655a)
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 #ifndef lint
34 static const char rcsid[] =
35   "$FreeBSD$";
36 #endif /* not lint */
37 
38 #include <sys/param.h>
39 #include <sys/mdioctl.h>
40 #include <sys/stat.h>
41 #include <sys/wait.h>
42 
43 #include <assert.h>
44 #include <err.h>
45 #include <fcntl.h>
46 #include <grp.h>
47 #include <paths.h>
48 #include <pwd.h>
49 #include <stdarg.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 
55 #include "pathnames.h"
56 
57 typedef enum { false, true } bool;
58 
59 struct mtpt_info {
60 	uid_t		 mi_uid;
61 	bool		 mi_have_uid;
62 	gid_t		 mi_gid;
63 	bool		 mi_have_gid;
64 	mode_t		 mi_mode;
65 	bool		 mi_have_mode;
66 };
67 
68 static	bool compat;		/* Full compatibility with mount_mfs? */
69 static	bool debug;		/* Emit debugging information? */
70 static	bool loudsubs;		/* Suppress output from helper programs? */
71 static	bool norun;		/* Actually run the helper programs? */
72 static	int unit;      		/* The unit we're working with. */
73 static	const char *mdname;	/* Name of memory disk device (e.g., "md"). */
74 static	size_t mdnamelen;	/* Length of mdname. */
75 
76 static void	 argappend(char **, const char *, ...) __printflike(2, 3);
77 static void	 debugprintf(const char *, ...) __printflike(1, 2);
78 static void	 do_mdconfig_attach(const char *, const enum md_types);
79 static void	 do_mdconfig_attach_au(const char *, const enum md_types);
80 static void	 do_mdconfig_detach(void);
81 static void	 do_mount(const char *, const char *);
82 static void	 do_mtptsetup(const char *, struct mtpt_info *);
83 static void	 do_newfs(const char *);
84 static void	 extract_ugid(const char *, struct mtpt_info *);
85 static int	 run(int *, const char *, ...) __printflike(2, 3);
86 static void	 usage(void);
87 
88 int
89 main(int argc, char **argv)
90 {
91 	struct mtpt_info mi;		/* Mountpoint info. */
92 	char *mdconfig_arg, *newfs_arg,	/* Args to helper programs. */
93 	    *mount_arg;
94 	enum md_types mdtype;		/* The type of our memory disk. */
95 	bool have_mdtype;
96 	bool detach, softdep, autounit;
97 	char *mtpoint, *unitstr;
98 	char ch, *p;
99 
100 	/* Misc. initialization. */
101 	(void)memset(&mi, '\0', sizeof(mi));
102 	detach = true;
103 	softdep = true;
104 	autounit = false;
105 	have_mdtype = false;
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:LMm: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 'M':
173 			if (have_mdtype)
174 				usage();
175 			mdtype = MD_MALLOC;
176 			have_mdtype = true;
177 			break;
178 		case 'm':
179 			argappend(&newfs_arg, "-m %s", optarg);
180 			break;
181 		case 'N':
182 			if (compat)
183 				usage();
184 			norun = true;
185 			break;
186 		case 'n':
187 			argappend(&newfs_arg, "-n %s", optarg);
188 			break;
189 		case 'O':
190 			argappend(&newfs_arg, "-o %s", optarg);
191 			break;
192 		case 'o':
193 			argappend(&mount_arg, "-o %s", optarg);
194 			break;
195 		case 'p':
196 			if (compat)
197 				usage();
198 			if (*optarg >= '0' && *optarg <= '7')
199 				mi.mi_mode = strtol(optarg, NULL, 8);
200 			if ((mi.mi_mode & ~07777) != 0)
201 				usage();
202 			mi.mi_have_mode = true;
203 			break;
204 		case 'S':
205 			if (compat)
206 				usage();
207 			softdep = false;
208 			break;
209 		case 's':
210 			argappend(&mdconfig_arg, "-s %s", optarg);
211 			break;
212 		case 'U':
213 			softdep = true;
214 			break;
215 		case 'v':
216 			argappend(&newfs_arg, "-O %s", optarg);
217 			break;
218 		case 'w':
219 			if (compat)
220 				usage();
221 			extract_ugid(optarg, &mi);
222 			break;
223 		case 'X':
224 			if (compat)
225 				usage();
226 			debug = true;
227 			break;
228 		default:
229 			usage();
230 		}
231 	argc -= optind;
232 	argv += optind;
233 	if (argc < 2)
234 		usage();
235 
236 	/* Make compatibility assumptions. */
237 	if (compat) {
238 		mi.mi_mode = 01777;
239 		mi.mi_have_mode = true;
240 	}
241 
242 	/* Derive 'unit' (global). */
243 	unitstr = argv[0];
244 	if (strncmp(unitstr, "/dev/", 5) == 0)
245 		unitstr += 5;
246 	if (strncmp(unitstr, mdname, mdnamelen) == 0)
247 		unitstr += mdnamelen;
248 	if (*unitstr == '\0') {
249 		autounit = true;
250 		unit = -1;
251 	} else {
252 		unit = strtoul(unitstr, &p, 10);
253 		if ((unsigned)unit == ULONG_MAX || *p != '\0')
254 			errx(1, "bad device unit: %s", unitstr);
255 	}
256 
257 	mtpoint = argv[1];
258 	if (!have_mdtype)
259 		mdtype = MD_SWAP;
260 	if (softdep)
261 		argappend(&newfs_arg, "-U");
262 
263 	/* Do the work. */
264 	if (detach && !autounit)
265 		do_mdconfig_detach();
266 	if (autounit)
267 		do_mdconfig_attach_au(mdconfig_arg, mdtype);
268 	else
269 		do_mdconfig_attach(mdconfig_arg, mdtype);
270 	do_newfs(newfs_arg);
271 	do_mount(mount_arg, mtpoint);
272 	do_mtptsetup(mtpoint, &mi);
273 
274 	return (0);
275 }
276 
277 /*
278  * Append the expansion of 'fmt' to the buffer pointed to by '*dstp';
279  * reallocate as required.
280  */
281 static void
282 argappend(char **dstp, const char *fmt, ...)
283 {
284 	char *old, *new;
285 	va_list ap;
286 
287 	old = *dstp;
288 	assert(old != NULL);
289 
290 	va_start(ap, fmt);
291 	if (vasprintf(&new, fmt,ap) == -1)
292 		errx(1, "vasprintf");
293 	va_end(ap);
294 
295 	*dstp = new;
296 	if (asprintf(&new, "%s %s", old, new) == -1)
297 		errx(1, "asprintf");
298 	free(*dstp);
299 	free(old);
300 
301 	*dstp = new;
302 }
303 
304 /*
305  * If run-time debugging is enabled, print the expansion of 'fmt'.
306  * Otherwise, do nothing.
307  */
308 static void
309 debugprintf(const char *fmt, ...)
310 {
311 	va_list ap;
312 
313 	if (!debug)
314 		return;
315 	fprintf(stderr, "DEBUG: ");
316 	va_start(ap, fmt);
317 	vfprintf(stderr, fmt, ap);
318 	va_end(ap);
319 	fprintf(stderr, "\n");
320 	fflush(stderr);
321 }
322 
323 /*
324  * Attach a memory disk with a known unit.
325  */
326 static void
327 do_mdconfig_attach(const char *args, const enum md_types mdtype)
328 {
329 	int rv;
330 	const char *ta;		/* Type arg. */
331 
332 	switch (mdtype) {
333 	case MD_SWAP:
334 		ta = "-t swap";
335 		break;
336 	case MD_VNODE:
337 		ta = "-t vnode";
338 		break;
339 	case MD_MALLOC:
340 		ta = "-t malloc";
341 		break;
342 	default:
343 		abort();
344 	}
345 	rv = run(NULL, "%s -a %s%s -u %s%d", PATH_MDCONFIG, ta, args,
346 	    mdname, unit);
347 	if (rv)
348 		errx(1, "mdconfig (attach) exited with error code %d", rv);
349 }
350 
351 /*
352  * Attach a memory disk with an unknown unit; use autounit.
353  */
354 static void
355 do_mdconfig_attach_au(const char *args, const enum md_types mdtype)
356 {
357 	const char *ta;		/* Type arg. */
358 	char *linep, *linebuf; 	/* Line pointer, line buffer. */
359 	int fd;			/* Standard output of mdconfig invocation. */
360 	FILE *sfd;
361 	int rv;
362 	char *p;
363 	size_t linelen;
364 
365 	switch (mdtype) {
366 	case MD_SWAP:
367 		ta = "-t swap";
368 		break;
369 	case MD_VNODE:
370 		ta = "-t vnode";
371 		break;
372 	case MD_MALLOC:
373 		ta = "-t malloc";
374 		break;
375 	default:
376 		abort();
377 	}
378 	rv = run(&fd, "%s -a %s%s", PATH_MDCONFIG, ta, args);
379 	if (rv)
380 		errx(1, "mdconfig (attach) exited with error code %d", rv);
381 
382 	/* Receive the unit number. */
383 	if (norun) {	/* Since we didn't run, we can't read.  Fake it. */
384 		unit = -1;
385 		return;
386 	}
387 	sfd = fdopen(fd, "r");
388 	if (sfd == NULL)
389 		err(1, "fdopen");
390 	linep = fgetln(sfd, &linelen);
391 	if (linep == NULL && linelen < mdnamelen + 1)
392 		errx(1, "unexpected output from mdconfig (attach)");
393 	/* If the output format changes, we want to know about it. */
394 	assert(strncmp(linep, mdname, mdnamelen) == 0);
395 	linebuf = malloc(linelen - mdnamelen + 1);
396 	assert(linebuf != NULL);
397 	/* Can't use strlcpy because linep is not NULL-terminated. */
398 	strncpy(linebuf, linep + mdnamelen, linelen);
399 	linebuf[linelen] = '\0';
400 	unit = strtoul(linebuf, &p, 10);
401 	if ((unsigned)unit == ULONG_MAX || *p != '\n')
402 		errx(1, "unexpected output from mdconfig (attach)");
403 
404 	fclose(sfd);
405 	close(fd);
406 }
407 
408 /*
409  * Detach a memory disk.
410  */
411 static void
412 do_mdconfig_detach(void)
413 {
414 	int rv;
415 
416 	rv = run(NULL, "%s -d -u %s%d", PATH_MDCONFIG, mdname, unit);
417 	if (rv && debug)	/* This is allowed to fail. */
418 		warnx("mdconfig (detach) exited with error code %d (ignored)",
419 		      rv);
420 }
421 
422 /*
423  * Mount the configured memory disk.
424  */
425 static void
426 do_mount(const char *args, const char *mtpoint)
427 {
428 	int rv;
429 
430 	rv = run(NULL, "%s%s /dev/%s%d %s", PATH_MOUNT, args,
431 	    mdname, unit, mtpoint);
432 	if (rv)
433 		errx(1, "mount exited with error code %d", rv);
434 }
435 
436 /*
437  * Various configuration of the mountpoint.  Mostly, enact 'mip'.
438  */
439 static void
440 do_mtptsetup(const char *mtpoint, struct mtpt_info *mip)
441 {
442 
443 	if (mip->mi_have_mode) {
444 		debugprintf("changing mode of %s to %o.", mtpoint,
445 		    mip->mi_mode);
446 		if (!norun)
447 			if (chmod(mtpoint, mip->mi_mode) == -1)
448 				err(1, "chmod: %s", mtpoint);
449 	}
450 	/*
451 	 * We have to do these separately because the user may have
452 	 * only specified one of them.
453 	 */
454 	if (mip->mi_have_uid) {
455 		debugprintf("changing owner (user) or %s to %u.", mtpoint,
456 		    mip->mi_uid);
457 		if (!norun)
458 			if (chown(mtpoint, mip->mi_uid, -1) == -1)
459 				err(1, "chown %s to %u (user)", mtpoint,
460 				    mip->mi_uid);
461 	}
462 	if (mip->mi_have_gid) {
463 		debugprintf("changing owner (group) or %s to %u.", mtpoint,
464 		    mip->mi_gid);
465 		if (!norun)
466 			if (chown(mtpoint, -1, mip->mi_gid) == -1)
467 				err(1, "chown %s to %u (group)", mtpoint,
468 				    mip->mi_gid);
469 	}
470 }
471 
472 /*
473  * Put a file system on the memory disk.
474  */
475 static void
476 do_newfs(const char *args)
477 {
478 	int rv;
479 
480 	rv = run(NULL, "%s%s /dev/%s%d", PATH_NEWFS, args, mdname, unit);
481 	if (rv)
482 		errx(1, "newfs exited with error code %d", rv);
483 }
484 
485 /*
486  * 'str' should be a user and group name similar to the last argument
487  * to chown(1); i.e., a user, followed by a colon, followed by a
488  * group.  The user and group in 'str' may be either a [ug]id or a
489  * name.  Upon return, the uid and gid fields in 'mip' will contain
490  * the uid and gid of the user and group name in 'str', respectively.
491  *
492  * In other words, this derives a user and group id from a string
493  * formatted like the last argument to chown(1).
494  */
495 static void
496 extract_ugid(const char *str, struct mtpt_info *mip)
497 {
498 	char *ug;			/* Writable 'str'. */
499 	char *user, *group;		/* Result of extracton. */
500 	struct passwd *pw;
501 	struct group *gr;
502 	char *p;
503 	uid_t *uid;
504 	gid_t *gid;
505 
506 	uid = &mip->mi_uid;
507 	gid = &mip->mi_gid;
508 	mip->mi_have_uid = mip->mi_have_gid = false;
509 
510 	/* Extract the user and group from 'str'.  Format above. */
511 	ug = strdup(str);
512 	assert(ug != NULL);
513 	group = ug;
514 	user = strsep(&group, ":");
515 	if (user == NULL || group == NULL || *user == '\0' || *group == '\0')
516 		usage();
517 
518 	/* Derive uid. */
519 	*uid = strtoul(user, &p, 10);
520 	if ((unsigned)*uid == ULONG_MAX)
521 		usage();
522 	if (*p != '\0') {
523 		pw = getpwnam(user);
524 		if (pw == NULL)
525 			errx(1, "invalid user: %s", user);
526 		*uid = pw->pw_uid;
527 		mip->mi_have_uid = true;
528 	}
529 
530 	/* Derive gid. */
531 	*gid = strtoul(group, &p, 10);
532 	if ((unsigned)*gid == ULONG_MAX)
533 		usage();
534 	if (*p != '\0') {
535 		gr = getgrnam(group);
536 		if (gr == NULL)
537 			errx(1, "invalid group: %s", group);
538 		*gid = gr->gr_gid;
539 		mip->mi_have_gid = true;
540 	}
541 
542 	free(ug);
543 	/*
544 	 * At this point we don't support only a username or only a
545 	 * group name.  do_mtptsetup already does, so when this
546 	 * feature is desired, this is the only routine that needs to
547 	 * be changed.
548 	 */
549 	assert(mip->mi_have_uid);
550 	assert(mip->mi_have_gid);
551 }
552 
553 /*
554  * Run a process with command name and arguments pointed to by the
555  * formatted string 'cmdline'.  Since system(3) is not used, the first
556  * space-delimited token of 'cmdline' must be the full pathname of the
557  * program to run.  The return value is the return code of the process
558  * spawned.  If 'ofd' is non-NULL, it is set to the standard output of
559  * the program spawned (i.e., you can read from ofd and get the output
560  * of the program).
561  */
562 static int
563 run(int *ofd, const char *cmdline, ...)
564 {
565 	char **argv, **argvp;		/* Result of splitting 'cmd'. */
566 	int argc;
567 	char *cmd;			/* Expansion of 'cmdline'. */
568 	int pid, status;		/* Child info. */
569 	int pfd[2];			/* Pipe to the child. */
570 	int nfd;			/* Null (/dev/null) file descriptor. */
571 	bool dup2dn;			/* Dup /dev/null to stdout? */
572 	va_list ap;
573 	char *p;
574 	int rv, i;
575 
576 	dup2dn = true;
577 	va_start(ap, cmdline);
578 	rv = vasprintf(&cmd, cmdline, ap);
579 	if (rv == -1)
580 		err(1, "vasprintf");
581 	va_end(ap);
582 
583 	/* Split up 'cmd' into 'argv' for use with execve. */
584 	for (argc = 1, p = cmd; (p = strchr(p, ' ')) != NULL; p++)
585 		argc++;		/* 'argc' generation loop. */
586 	argv = (char **)malloc(sizeof(*argv) * (argc + 1));
587 	assert(argv != NULL);
588 	for (p = cmd, argvp = argv; (*argvp = strsep(&p, " ")) != NULL;)
589 		if (**argv != '\0')
590 			if (++argvp >= &argv[argc]) {
591 				*argvp = NULL;
592 				break;
593 			}
594 	assert(*argv);
595 
596 	/* Make sure the above loop works as expected. */
597 	if (debug) {
598 		/*
599 		 * We can't, but should, use debugprintf here.  First,
600 		 * it appends a trailing newline to the output, and
601 		 * second it prepends "DEBUG: " to the output.  The
602 		 * former is a problem for this would-be first call,
603 		 * and the latter for the would-be call inside the
604 		 * loop.
605 		 */
606 		(void)fprintf(stderr, "DEBUG: running:");
607 		/* Should be equivilent to 'cmd' (before strsep, of course). */
608 		for (i = 0; argv[i] != NULL; i++)
609 			(void)fprintf(stderr, " %s", argv[i]);
610 		(void)fprintf(stderr, "\n");
611 	}
612 
613 	/* Create a pipe if necessary and fork the helper program. */
614 	if (ofd != NULL) {
615 		if (pipe(&pfd[0]) == -1)
616 			err(1, "pipe");
617 		*ofd = pfd[0];
618 		dup2dn = false;
619 	}
620 	pid = fork();
621 	switch (pid) {
622 	case 0:
623 		/* XXX can we call err() in here? */
624 		if (norun)
625 			_exit(0);
626 		if (ofd != NULL)
627 			if (dup2(pfd[1], STDOUT_FILENO) < 0)
628 				err(1, "dup2");
629 		if (!loudsubs) {
630 			nfd = open(_PATH_DEVNULL, O_RDWR);
631 			if (nfd == -1)
632 				err(1, "open: %s", _PATH_DEVNULL);
633 			if (dup2(nfd, STDIN_FILENO) < 0)
634 				err(1, "dup2");
635 			if (dup2dn)
636 				if (dup2(nfd, STDOUT_FILENO) < 0)
637 				   err(1, "dup2");
638 			if (dup2(nfd, STDERR_FILENO) < 0)
639 				err(1, "dup2");
640 		}
641 
642 		(void)execv(argv[0], argv);
643 		warn("exec: %s", argv[0]);
644 		_exit(-1);
645 	case -1:
646 		err(1, "fork");
647 	}
648 
649 	free(cmd);
650 	free(argv);
651 	while (waitpid(pid, &status, 0) != pid)
652 		;
653 	return (WEXITSTATUS(status));
654 }
655 
656 static void
657 usage(void)
658 {
659 	const char *name;
660 
661 	if (compat)
662 		name = getprogname();
663 	else
664 		name = "mdmfs";
665 	if (!compat)
666 		fprintf(stderr,
667 "usage: %s [-DLMNSUX] [-a maxcontig [-b block-size] [-c cylinders]\n"
668 "\t[-d rotdelay] [-e maxbpg] [-F file] [-f frag-size] [-i bytes]\n"
669 "\t[-m percent-free] [-n rotational-positions] [-O optimization]\n"
670 "\t[-o mount-options] [-p permissions] [-s size] [-w user:group]\n"
671 "\tmd-device mount-point\n", name);
672 	fprintf(stderr,
673 "usage: %s -C [-NU] [-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] [-s size] md-device mount-point\n", name);
677 	exit(1);
678 }
679