xref: /netbsd/sbin/swapctl/swapctl.c (revision c4a72b64) 
1 /*	$NetBSD: swapctl.c,v 1.21 2002/09/18 10:18:17 drochner Exp $	*/
2 
3 /*
4  * Copyright (c) 1996, 1997, 1999 Matthew R. Green
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. The name of the author may not be used to endorse or promote products
16  *    derived from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
23  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
25  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
26  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 /*
32  * swapctl command:
33  *	-A		add all devices listed as `sw' in /etc/fstab (also
34  *			(sets the dump device, if listed in fstab)
35  *	-D <dev>	set dumpdev to <dev>
36  *	-z		show dumpdev
37  *	-U		remove all devices listed as `sw' in /etc/fstab.
38  *	-t [blk|noblk]	if -A or -U , add (remove) either all block device
39  *			or all non-block devices
40  *	-a <dev>	add this device
41  *	-d <dev>	remove this swap device
42  *	-l		list swap devices
43  *	-s		short listing of swap devices
44  *	-k		use kilobytes
45  *	-p <pri>	use this priority
46  *	-c		change priority
47  *
48  * or, if invoked as "swapon" (compatibility mode):
49  *
50  *	-a		all devices listed as `sw' in /etc/fstab
51  *	-t		same as -t above (feature not present in old
52  *			swapon(8) command)
53  *	<dev>		add this device
54  */
55 
56 #include <sys/param.h>
57 #include <sys/stat.h>
58 #include <sys/swap.h>
59 
60 #include <unistd.h>
61 #include <err.h>
62 #include <errno.h>
63 #include <stdio.h>
64 #include <stdlib.h>
65 #include <string.h>
66 #include <fstab.h>
67 
68 #include "swapctl.h"
69 
70 int	command;
71 
72 /*
73  * Commands for swapctl(8).  These are mutually exclusive.
74  */
75 #define	CMD_A		0x01	/* process /etc/fstab for adding */
76 #define	CMD_D		0x02	/* set dumpdev */
77 #define	CMD_U		0x04	/* process /etc/fstab for removing */
78 #define	CMD_a		0x08	/* add a swap file/device */
79 #define	CMD_c		0x10	/* change priority of a swap file/device */
80 #define	CMD_d		0x20	/* delete a swap file/device */
81 #define	CMD_l		0x40	/* list swap files/devices */
82 #define	CMD_s		0x80	/* summary of swap files/devices */
83 #define	CMD_z		0x100	/* show dump device */
84 
85 #define	SET_COMMAND(cmd) \
86 do { \
87 	if (command) \
88 		usage(); \
89 	command = (cmd); \
90 } while (0)
91 
92 /*
93  * Commands that require a "path" argument at the end of the command
94  * line, and the ones which require that none exist.
95  */
96 #define	REQUIRE_PATH	(CMD_D | CMD_a | CMD_c | CMD_d)
97 #define	REQUIRE_NOPATH	(CMD_A | CMD_U | CMD_l | CMD_s | CMD_z)
98 
99 /*
100  * Option flags, and the commands with which they are valid.
101  */
102 int	kflag;		/* display in 1K blocks */
103 #define	KFLAG_CMDS	(CMD_l | CMD_s)
104 
105 int	pflag;		/* priority was specified */
106 #define	PFLAG_CMDS	(CMD_A | CMD_a | CMD_c)
107 
108 char	*tflag;		/* swap device type (blk or noblk) */
109 #define	TFLAG_CMDS	(CMD_A | CMD_U)
110 
111 int	pri;		/* uses 0 as default pri */
112 
113 static	void change_priority __P((const char *));
114 static	int  add_swap __P((const char *, int));
115 static	int  delete_swap __P((const char *));
116 static	void set_dumpdev __P((const char *));
117 static	void get_dumpdev __P((void));
118 	int  main __P((int, char *[]));
119 static	void do_fstab __P((int));
120 static	void usage __P((void));
121 static	void swapon_command __P((int, char **));
122 #if 0
123 static	void swapoff_command __P((int, char **));
124 #endif
125 
126 int
127 main(argc, argv)
128 	int	argc;
129 	char	*argv[];
130 {
131 	int	c;
132 
133 	if (strcmp(getprogname(), "swapon") == 0) {
134 		swapon_command(argc, argv);
135 		/* NOTREACHED */
136 	}
137 
138 #if 0
139 	if (strcmp(getprogname(), "swapoff") == 0) {
140 		swapoff_command(argc, argv);
141 		/* NOTREACHED */
142 	}
143 #endif
144 
145 	while ((c = getopt(argc, argv, "ADUacdlkp:st:z")) != -1) {
146 		switch (c) {
147 		case 'A':
148 			SET_COMMAND(CMD_A);
149 			break;
150 
151 		case 'D':
152 			SET_COMMAND(CMD_D);
153 			break;
154 
155 		case 'U':
156 			SET_COMMAND(CMD_U);
157 			break;
158 
159 		case 'a':
160 			SET_COMMAND(CMD_a);
161 			break;
162 
163 		case 'c':
164 			SET_COMMAND(CMD_c);
165 			break;
166 
167 		case 'd':
168 			SET_COMMAND(CMD_d);
169 			break;
170 
171 		case 'l':
172 			SET_COMMAND(CMD_l);
173 			break;
174 
175 		case 'k':
176 			kflag = 1;
177 			break;
178 
179 		case 'p':
180 			pflag = 1;
181 			/* XXX strtol() */
182 			pri = atoi(optarg);
183 			break;
184 
185 		case 's':
186 			SET_COMMAND(CMD_s);
187 			break;
188 
189 		case 't':
190 			if (tflag != NULL)
191 				usage();
192 			tflag = optarg;
193 			break;
194 
195 		case 'z':
196 			SET_COMMAND(CMD_z);
197 			break;
198 
199 		default:
200 			usage();
201 			/* NOTREACHED */
202 		}
203 	}
204 
205 	/* Did the user specify a command? */
206 	if (command == 0)
207 		usage();
208 
209 	argv += optind;
210 	argc -= optind;
211 
212 	switch (argc) {
213 	case 0:
214 		if (command & REQUIRE_PATH)
215 			usage();
216 		break;
217 
218 	case 1:
219 		if (command & REQUIRE_NOPATH)
220 			usage();
221 		break;
222 
223 	default:
224 		usage();
225 	}
226 
227 	/* To change priority, you have to specify one. */
228 	if ((command == CMD_c) && pflag == 0)
229 		usage();
230 
231 	/* Sanity-check -t */
232 	if (tflag != NULL) {
233 		if (command != CMD_A && command != CMD_U)
234 			usage();
235 		if (strcmp(tflag, "blk") != 0 &&
236 		    strcmp(tflag, "noblk") != 0)
237 			usage();
238 	}
239 
240 	/* Dispatch the command. */
241 	switch (command) {
242 	case CMD_l:
243 		list_swap(pri, kflag, pflag, 0, 1);
244 		break;
245 
246 	case CMD_s:
247 		list_swap(pri, kflag, pflag, 0, 0);
248 		break;
249 
250 	case CMD_c:
251 		change_priority(argv[0]);
252 		break;
253 
254 	case CMD_a:
255 		if (! add_swap(argv[0], pri))
256 			exit(1);
257 		break;
258 
259 	case CMD_d:
260 		if (! delete_swap(argv[0]))
261 			exit(1);
262 		break;
263 
264 	case CMD_A:
265 		do_fstab(1);
266 		break;
267 
268 	case CMD_D:
269 		set_dumpdev(argv[0]);
270 		break;
271 
272 	case CMD_z:
273 		get_dumpdev();
274 		break;
275 
276 	case CMD_U:
277 		do_fstab(0);
278 		break;
279 	}
280 
281 	exit(0);
282 }
283 
284 /*
285  * swapon_command: emulate the old swapon(8) program.
286  */
287 static void
288 swapon_command(argc, argv)
289 	int argc;
290 	char **argv;
291 {
292 	int ch, fiztab = 0;
293 
294 	while ((ch = getopt(argc, argv, "at:")) != -1) {
295 		switch (ch) {
296 		case 'a':
297 			fiztab = 1;
298 			break;
299 		case 't':
300 			if (tflag != NULL)
301 				usage();
302 			tflag = optarg;
303 			break;
304 		default:
305 			goto swapon_usage;
306 		}
307 	}
308 	argc -= optind;
309 	argv += optind;
310 
311 	if (fiztab) {
312 		if (argc)
313 			goto swapon_usage;
314 		/* Sanity-check -t */
315 		if (tflag != NULL) {
316 			if (strcmp(tflag, "blk") != 0 &&
317 			    strcmp(tflag, "noblk") != 0)
318 				usage();
319 		}
320 		do_fstab(1);
321 		exit(0);
322 	} else if (argc == 0 || tflag != NULL)
323 		goto swapon_usage;
324 
325 	while (argc) {
326 		if (! add_swap(argv[0], pri))
327 			exit(1);
328 		argc--;
329 		argv++;
330 	}
331 	exit(0);
332 	/* NOTREACHED */
333 
334  swapon_usage:
335 	fprintf(stderr, "usage: %s -a [-t blk|noblk]\n", getprogname());
336 	fprintf(stderr, "       %s <path> ...\n", getprogname());
337 	exit(1);
338 }
339 
340 /*
341  * change_priority:  change the priority of a swap device.
342  */
343 static void
344 change_priority(path)
345 	const char	*path;
346 {
347 
348 	if (swapctl(SWAP_CTL, path, pri) < 0)
349 		warn("%s", path);
350 }
351 
352 /*
353  * add_swap:  add the pathname to the list of swap devices.
354  */
355 static int
356 add_swap(path, priority)
357 	const char *path;
358 	int priority;
359 {
360 	struct stat sb;
361 
362 	if (stat(path, &sb) < 0)
363 		goto oops;
364 
365 	if (sb.st_mode & S_IROTH)
366 		warnx("WARNING: %s is readable by the world", path);
367 	if (sb.st_mode & S_IWOTH)
368 		warnx("WARNING: %s is writable by the world", path);
369 
370 	if (swapctl(SWAP_ON, path, priority) < 0) {
371 oops:
372 		warn("%s", path);
373 		return (0);
374 	}
375 	return (1);
376 }
377 
378 /*
379  * delete_swap:  remove the pathname to the list of swap devices.
380  */
381 static int
382 delete_swap(path)
383 	const char *path;
384 {
385 
386 	if (swapctl(SWAP_OFF, path, pri) < 0) {
387 		warn("%s", path);
388 		return (0);
389 	}
390 	return (1);
391 }
392 
393 static void
394 set_dumpdev(path)
395 	const char *path;
396 {
397 
398 	if (swapctl(SWAP_DUMPDEV, path, NULL) == -1)
399 		warn("could not set dump device to %s", path);
400 	else
401 		printf("%s: setting dump device to %s\n", getprogname(), path);
402 }
403 
404 static void
405 get_dumpdev()
406 {
407 	dev_t	dev;
408 	char 	*name;
409 
410 	if (swapctl(SWAP_GETDUMPDEV, &dev, NULL) == -1)
411 		warn("could not get dump device");
412 	else if (dev == NODEV)
413 		printf("no dump device set\n");
414 	else {
415 		name = devname(dev, S_IFBLK);
416 		printf("dump device is ");
417 		if (name)
418 			printf("%s\n", name);
419 		else
420 			printf("major %d minor %d\n", major(dev), minor(dev));
421 	}
422 }
423 
424 static void
425 do_fstab(add)
426 	int add;
427 {
428 	struct	fstab *fp;
429 	char	*s;
430 	long	priority;
431 	struct	stat st;
432 	int	isblk;
433 	int	gotone = 0;
434 #define PATH_MOUNT	"/sbin/mount_nfs"
435 #define PATH_UMOUNT	"/sbin/umount"
436 	char	cmd[2*PATH_MAX+sizeof(PATH_MOUNT)+2];
437 
438 #define PRIORITYEQ	"priority="
439 #define NFSMNTPT	"nfsmntpt="
440 	while ((fp = getfsent()) != NULL) {
441 		const char *spec;
442 
443 		spec = fp->fs_spec;
444 		cmd[0] = '\0';
445 
446 		if (strcmp(fp->fs_type, "dp") == 0 && add) {
447 			set_dumpdev(spec);
448 			continue;
449 		}
450 
451 		if (strcmp(fp->fs_type, "sw") != 0)
452 			continue;
453 
454 		/* handle dp as mnt option */
455 		if (strstr(fp->fs_mntops, "dp") && add)
456 			set_dumpdev(spec);
457 
458 		isblk = 0;
459 
460 		if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
461 			s += sizeof(PRIORITYEQ) - 1;
462 			priority = atol(s);
463 		} else
464 			priority = pri;
465 
466 		if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
467 			char *t;
468 
469 			/*
470 			 * Skip this song and dance if we're only
471 			 * doing block devices.
472 			 */
473 			if (tflag != NULL && strcmp(tflag, "blk") == 0)
474 				continue;
475 
476 			t = strpbrk(s, ",");
477 			if (t != 0)
478 				*t = '\0';
479 			spec = strdup(s + strlen(NFSMNTPT));
480 			if (t != 0)
481 				*t = ',';
482 
483 			if (spec == NULL)
484 				errx(1, "Out of memory");
485 
486 			if (strlen(spec) == 0) {
487 				warnx("empty mountpoint");
488 				free((char *)spec);
489 				continue;
490 			}
491 			if (add) {
492 				snprintf(cmd, sizeof(cmd), "%s %s %s",
493 					PATH_MOUNT, fp->fs_spec, spec);
494 				if (system(cmd) != 0) {
495 					warnx("%s: mount failed", fp->fs_spec);
496 					continue;
497 				}
498 			} else {
499 				snprintf(cmd, sizeof(cmd), "%s %s",
500 					PATH_UMOUNT, fp->fs_spec);
501 			}
502 		} else {
503 			/*
504 			 * Determine blk-ness.
505 			 */
506 			if (stat(spec, &st) < 0) {
507 				warn("%s", spec);
508 				continue;
509 			}
510 			if (S_ISBLK(st.st_mode))
511 				isblk = 1;
512 		}
513 
514 		/*
515 		 * Skip this type if we're told to.
516 		 */
517 		if (tflag != NULL) {
518 			if (strcmp(tflag, "blk") == 0 && isblk == 0)
519 				continue;
520 			if (strcmp(tflag, "noblk") == 0 && isblk == 1)
521 				continue;
522 		}
523 
524 		if (add) {
525 			if (add_swap(spec, (int)priority)) {
526 				gotone = 1;
527 				printf(
528 			    	"%s: adding %s as swap device at priority %d\n",
529 				    getprogname(), fp->fs_spec, (int)priority);
530 			}
531 		} else {
532 			if (delete_swap(spec)) {
533 				gotone = 1;
534 				printf(
535 				    "%s: removing %s as swap device\n",
536 				    getprogname(), fp->fs_spec);
537 			}
538 			if (cmd[0]) {
539 				if (system(cmd) != 0) {
540 					warnx("%s: umount failed", fp->fs_spec);
541 					continue;
542 				}
543 			}
544 		}
545 
546 		if (spec != fp->fs_spec)
547 			free((char *)spec);
548 	}
549 	if (gotone == 0)
550 		exit(1);
551 }
552 
553 static void
554 usage()
555 {
556 	const char *progname = getprogname();
557 
558 	fprintf(stderr, "usage: %s -A [-p priority] [-t blk|noblk]\n",
559 	    progname);
560 	fprintf(stderr, "       %s -D dumppath\n", progname);
561 	fprintf(stderr, "       %s -U [-t blk|noblk]\n", progname);
562 	fprintf(stderr, "       %s -a [-p priority] path\n", progname);
563 	fprintf(stderr, "       %s -c -p priority path\n", progname);
564 	fprintf(stderr, "       %s -d path\n", progname);
565 	fprintf(stderr, "       %s -l | -s [-k]\n", progname);
566 	exit(1);
567 }
568