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swapctl.c revision 1.26 
      1 /*	$NetBSD: swapctl.c,v 1.26 2004/06/08 08:13:16 cjep 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  *	-g		use gigabytes
     43  *	-h		use humanize_number(3) for listing
     44  *	-l		list swap devices
     45  *	-m		use megabytes
     46  *	-s		short listing of swap devices
     47  *	-k		use kilobytes
     48  *	-p <pri>	use this priority
     49  *	-c		change priority
     50  *
     51  * or, if invoked as "swapon" (compatibility mode):
     52  *
     53  *	-a		all devices listed as `sw' in /etc/fstab
     54  *	-t		same as -t above (feature not present in old
     55  *			swapon(8) command)
     56  *	<dev>		add this device
     57  */
     58 #include <sys/cdefs.h>
     59 
     60 #ifndef lint
     61 __RCSID("$NetBSD: swapctl.c,v 1.26 2004/06/08 08:13:16 cjep Exp $");
     62 #endif
     63 
     64 
     65 #include <sys/param.h>
     66 #include <sys/stat.h>
     67 #include <sys/swap.h>
     68 
     69 #include <unistd.h>
     70 #include <err.h>
     71 #include <errno.h>
     72 #include <stdio.h>
     73 #include <stdlib.h>
     74 #include <string.h>
     75 #include <fstab.h>
     76 
     77 #include "swapctl.h"
     78 
     79 int	command;
     80 
     81 /*
     82  * Commands for swapctl(8).  These are mutually exclusive.
     83  */
     84 #define	CMD_A		0x01	/* process /etc/fstab for adding */
     85 #define	CMD_D		0x02	/* set dumpdev */
     86 #define	CMD_U		0x04	/* process /etc/fstab for removing */
     87 #define	CMD_a		0x08	/* add a swap file/device */
     88 #define	CMD_c		0x10	/* change priority of a swap file/device */
     89 #define	CMD_d		0x20	/* delete a swap file/device */
     90 #define	CMD_l		0x40	/* list swap files/devices */
     91 #define	CMD_s		0x80	/* summary of swap files/devices */
     92 #define	CMD_z		0x100	/* show dump device */
     93 
     94 #define	SET_COMMAND(cmd) \
     95 do { \
     96 	if (command) \
     97 		usage(); \
     98 	command = (cmd); \
     99 } while (0)
    100 
    101 /*
    102  * Commands that require a "path" argument at the end of the command
    103  * line, and the ones which require that none exist.
    104  */
    105 #define	REQUIRE_PATH	(CMD_D | CMD_a | CMD_c | CMD_d)
    106 #define	REQUIRE_NOPATH	(CMD_A | CMD_U | CMD_l | CMD_s | CMD_z)
    107 
    108 /*
    109  * Option flags, and the commands with which they are valid.
    110  */
    111 int	kflag;		/* display in 1K^x blocks */
    112 #define	KFLAG_CMDS	(CMD_l | CMD_s)
    113 #define MFLAG_CMDS	(CMD_l | CMD_s)
    114 #define GFLAG_CMDS	(CMD_l | CMD_s)
    115 
    116 int	hflag;		/* display with humanize_number */
    117 #define HFLAG_CMDS	(CMD_l | CMD_s)
    118 
    119 int	pflag;		/* priority was specified */
    120 #define	PFLAG_CMDS	(CMD_A | CMD_a | CMD_c)
    121 
    122 char	*tflag;		/* swap device type (blk or noblk) */
    123 #define	TFLAG_CMDS	(CMD_A | CMD_U)
    124 
    125 int	pri;		/* uses 0 as default pri */
    126 
    127 static	void change_priority __P((const char *));
    128 static	int  add_swap __P((const char *, int));
    129 static	int  delete_swap __P((const char *));
    130 static	void set_dumpdev __P((const char *));
    131 static	void get_dumpdev __P((void));
    132 	int  main __P((int, char *[]));
    133 static	void do_fstab __P((int));
    134 static	void usage __P((void));
    135 static	void swapon_command __P((int, char **));
    136 #if 0
    137 static	void swapoff_command __P((int, char **));
    138 #endif
    139 
    140 int
    141 main(argc, argv)
    142 	int	argc;
    143 	char	*argv[];
    144 {
    145 	int	c;
    146 
    147 	if (strcmp(getprogname(), "swapon") == 0) {
    148 		swapon_command(argc, argv);
    149 		/* NOTREACHED */
    150 	}
    151 
    152 #if 0
    153 	if (strcmp(getprogname(), "swapoff") == 0) {
    154 		swapoff_command(argc, argv);
    155 		/* NOTREACHED */
    156 	}
    157 #endif
    158 
    159 	while ((c = getopt(argc, argv, "ADUacdghklmp:st:z")) != -1) {
    160 		switch (c) {
    161 		case 'A':
    162 			SET_COMMAND(CMD_A);
    163 			break;
    164 
    165 		case 'D':
    166 			SET_COMMAND(CMD_D);
    167 			break;
    168 
    169 		case 'U':
    170 			SET_COMMAND(CMD_U);
    171 			break;
    172 
    173 		case 'a':
    174 			SET_COMMAND(CMD_a);
    175 			break;
    176 
    177 		case 'c':
    178 			SET_COMMAND(CMD_c);
    179 			break;
    180 
    181 		case 'd':
    182 			SET_COMMAND(CMD_d);
    183 			break;
    184 
    185 		case 'g':
    186 			kflag = 3; /* 1k ^ 3 */
    187 			break;
    188 
    189 		case 'h':
    190 			hflag = 1;
    191 			break;
    192 
    193 		case 'k':
    194 			kflag = 1;
    195 			break;
    196 
    197 		case 'l':
    198 			SET_COMMAND(CMD_l);
    199 			break;
    200 
    201 		case 'm':
    202 			kflag = 2; /* 1k ^ 2 */
    203 			break;
    204 
    205 		case 'p':
    206 			pflag = 1;
    207 			/* XXX strtol() */
    208 			pri = atoi(optarg);
    209 			break;
    210 
    211 		case 's':
    212 			SET_COMMAND(CMD_s);
    213 			break;
    214 
    215 		case 't':
    216 			if (tflag != NULL)
    217 				usage();
    218 			tflag = optarg;
    219 			break;
    220 
    221 		case 'z':
    222 			SET_COMMAND(CMD_z);
    223 			break;
    224 
    225 		default:
    226 			usage();
    227 			/* NOTREACHED */
    228 		}
    229 	}
    230 
    231 	/* Did the user specify a command? */
    232 	if (command == 0)
    233 		usage();
    234 
    235 	argv += optind;
    236 	argc -= optind;
    237 
    238 	switch (argc) {
    239 	case 0:
    240 		if (command & REQUIRE_PATH)
    241 			usage();
    242 		break;
    243 
    244 	case 1:
    245 		if (command & REQUIRE_NOPATH)
    246 			usage();
    247 		break;
    248 
    249 	default:
    250 		usage();
    251 	}
    252 
    253 	/* To change priority, you have to specify one. */
    254 	if ((command == CMD_c) && pflag == 0)
    255 		usage();
    256 
    257 	/* Sanity-check -t */
    258 	if (tflag != NULL) {
    259 		if (command != CMD_A && command != CMD_U)
    260 			usage();
    261 		if (strcmp(tflag, "blk") != 0 &&
    262 		    strcmp(tflag, "noblk") != 0)
    263 			usage();
    264 	}
    265 
    266 	/* Dispatch the command. */
    267 	switch (command) {
    268 	case CMD_l:
    269 		list_swap(pri, kflag, pflag, 0, 1, hflag);
    270 		break;
    271 
    272 	case CMD_s:
    273 		list_swap(pri, kflag, pflag, 0, 0, hflag);
    274 		break;
    275 
    276 	case CMD_c:
    277 		change_priority(argv[0]);
    278 		break;
    279 
    280 	case CMD_a:
    281 		if (! add_swap(argv[0], pri))
    282 			exit(1);
    283 		break;
    284 
    285 	case CMD_d:
    286 		if (! delete_swap(argv[0]))
    287 			exit(1);
    288 		break;
    289 
    290 	case CMD_A:
    291 		do_fstab(1);
    292 		break;
    293 
    294 	case CMD_D:
    295 		set_dumpdev(argv[0]);
    296 		break;
    297 
    298 	case CMD_z:
    299 		get_dumpdev();
    300 		break;
    301 
    302 	case CMD_U:
    303 		do_fstab(0);
    304 		break;
    305 	}
    306 
    307 	exit(0);
    308 }
    309 
    310 /*
    311  * swapon_command: emulate the old swapon(8) program.
    312  */
    313 static void
    314 swapon_command(argc, argv)
    315 	int argc;
    316 	char **argv;
    317 {
    318 	int ch, fiztab = 0;
    319 
    320 	while ((ch = getopt(argc, argv, "at:")) != -1) {
    321 		switch (ch) {
    322 		case 'a':
    323 			fiztab = 1;
    324 			break;
    325 		case 't':
    326 			if (tflag != NULL)
    327 				usage();
    328 			tflag = optarg;
    329 			break;
    330 		default:
    331 			goto swapon_usage;
    332 		}
    333 	}
    334 	argc -= optind;
    335 	argv += optind;
    336 
    337 	if (fiztab) {
    338 		if (argc)
    339 			goto swapon_usage;
    340 		/* Sanity-check -t */
    341 		if (tflag != NULL) {
    342 			if (strcmp(tflag, "blk") != 0 &&
    343 			    strcmp(tflag, "noblk") != 0)
    344 				usage();
    345 		}
    346 		do_fstab(1);
    347 		exit(0);
    348 	} else if (argc == 0 || tflag != NULL)
    349 		goto swapon_usage;
    350 
    351 	while (argc) {
    352 		if (! add_swap(argv[0], pri))
    353 			exit(1);
    354 		argc--;
    355 		argv++;
    356 	}
    357 	exit(0);
    358 	/* NOTREACHED */
    359 
    360  swapon_usage:
    361 	fprintf(stderr, "usage: %s -a [-t blk|noblk]\n", getprogname());
    362 	fprintf(stderr, "       %s <path> ...\n", getprogname());
    363 	exit(1);
    364 }
    365 
    366 /*
    367  * change_priority:  change the priority of a swap device.
    368  */
    369 static void
    370 change_priority(path)
    371 	const char	*path;
    372 {
    373 
    374 	if (swapctl(SWAP_CTL, path, pri) < 0)
    375 		warn("%s", path);
    376 }
    377 
    378 /*
    379  * add_swap:  add the pathname to the list of swap devices.
    380  */
    381 static int
    382 add_swap(path, priority)
    383 	const char *path;
    384 	int priority;
    385 {
    386 	struct stat sb;
    387 
    388 	if (stat(path, &sb) < 0)
    389 		goto oops;
    390 
    391 	if (sb.st_mode & S_IROTH)
    392 		warnx("WARNING: %s is readable by the world", path);
    393 	if (sb.st_mode & S_IWOTH)
    394 		warnx("WARNING: %s is writable by the world", path);
    395 
    396 	if (swapctl(SWAP_ON, path, priority) < 0) {
    397 oops:
    398 		warn("%s", path);
    399 		return (0);
    400 	}
    401 	return (1);
    402 }
    403 
    404 /*
    405  * delete_swap:  remove the pathname to the list of swap devices.
    406  */
    407 static int
    408 delete_swap(path)
    409 	const char *path;
    410 {
    411 
    412 	if (swapctl(SWAP_OFF, path, pri) < 0) {
    413 		warn("%s", path);
    414 		return (0);
    415 	}
    416 	return (1);
    417 }
    418 
    419 static void
    420 set_dumpdev(path)
    421 	const char *path;
    422 {
    423 
    424 	if (swapctl(SWAP_DUMPDEV, path, 0) == -1)
    425 		warn("could not set dump device to %s", path);
    426 	else
    427 		printf("%s: setting dump device to %s\n", getprogname(), path);
    428 }
    429 
    430 static void
    431 get_dumpdev()
    432 {
    433 	dev_t	dev;
    434 	char 	*name;
    435 
    436 	if (swapctl(SWAP_GETDUMPDEV, &dev, 0) == -1)
    437 		warn("could not get dump device");
    438 	else if (dev == NODEV)
    439 		printf("no dump device set\n");
    440 	else {
    441 		name = devname(dev, S_IFBLK);
    442 		printf("dump device is ");
    443 		if (name)
    444 			printf("%s\n", name);
    445 		else
    446 			printf("major %d minor %d\n", major(dev), minor(dev));
    447 	}
    448 }
    449 
    450 static void
    451 do_fstab(add)
    452 	int add;
    453 {
    454 	struct	fstab *fp;
    455 	char	*s;
    456 	long	priority;
    457 	struct	stat st;
    458 	int	isblk;
    459 	int	gotone = 0;
    460 #define PATH_MOUNT	"/sbin/mount_nfs"
    461 #define PATH_UMOUNT	"/sbin/umount"
    462 	char	cmd[2*PATH_MAX+sizeof(PATH_MOUNT)+2];
    463 
    464 #define PRIORITYEQ	"priority="
    465 #define NFSMNTPT	"nfsmntpt="
    466 	while ((fp = getfsent()) != NULL) {
    467 		const char *spec;
    468 
    469 		spec = fp->fs_spec;
    470 		cmd[0] = '\0';
    471 
    472 		if (strcmp(fp->fs_type, "dp") == 0 && add) {
    473 			set_dumpdev(spec);
    474 			continue;
    475 		}
    476 
    477 		if (strcmp(fp->fs_type, "sw") != 0)
    478 			continue;
    479 
    480 		/* handle dp as mnt option */
    481 		if (strstr(fp->fs_mntops, "dp") && add)
    482 			set_dumpdev(spec);
    483 
    484 		isblk = 0;
    485 
    486 		if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
    487 			s += sizeof(PRIORITYEQ) - 1;
    488 			priority = atol(s);
    489 		} else
    490 			priority = pri;
    491 
    492 		if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
    493 			char *t;
    494 
    495 			/*
    496 			 * Skip this song and dance if we're only
    497 			 * doing block devices.
    498 			 */
    499 			if (tflag != NULL && strcmp(tflag, "blk") == 0)
    500 				continue;
    501 
    502 			t = strpbrk(s, ",");
    503 			if (t != 0)
    504 				*t = '\0';
    505 			spec = strdup(s + strlen(NFSMNTPT));
    506 			if (t != 0)
    507 				*t = ',';
    508 
    509 			if (spec == NULL)
    510 				errx(1, "Out of memory");
    511 
    512 			if (strlen(spec) == 0) {
    513 				warnx("empty mountpoint");
    514 				free((char *)spec);
    515 				continue;
    516 			}
    517 			if (add) {
    518 				snprintf(cmd, sizeof(cmd), "%s %s %s",
    519 					PATH_MOUNT, fp->fs_spec, spec);
    520 				if (system(cmd) != 0) {
    521 					warnx("%s: mount failed", fp->fs_spec);
    522 					continue;
    523 				}
    524 			} else {
    525 				snprintf(cmd, sizeof(cmd), "%s %s",
    526 					PATH_UMOUNT, fp->fs_spec);
    527 			}
    528 		} else {
    529 			/*
    530 			 * Determine blk-ness.
    531 			 */
    532 			if (stat(spec, &st) < 0) {
    533 				warn("%s", spec);
    534 				continue;
    535 			}
    536 			if (S_ISBLK(st.st_mode))
    537 				isblk = 1;
    538 		}
    539 
    540 		/*
    541 		 * Skip this type if we're told to.
    542 		 */
    543 		if (tflag != NULL) {
    544 			if (strcmp(tflag, "blk") == 0 && isblk == 0)
    545 				continue;
    546 			if (strcmp(tflag, "noblk") == 0 && isblk == 1)
    547 				continue;
    548 		}
    549 
    550 		if (add) {
    551 			if (add_swap(spec, (int)priority)) {
    552 				gotone = 1;
    553 				printf(
    554 			    	"%s: adding %s as swap device at priority %d\n",
    555 				    getprogname(), fp->fs_spec, (int)priority);
    556 			}
    557 		} else {
    558 			if (delete_swap(spec)) {
    559 				gotone = 1;
    560 				printf(
    561 				    "%s: removing %s as swap device\n",
    562 				    getprogname(), fp->fs_spec);
    563 			}
    564 			if (cmd[0]) {
    565 				if (system(cmd) != 0) {
    566 					warnx("%s: umount failed", fp->fs_spec);
    567 					continue;
    568 				}
    569 			}
    570 		}
    571 
    572 		if (spec != fp->fs_spec)
    573 			free((char *)spec);
    574 	}
    575 	if (gotone == 0)
    576 		exit(1);
    577 }
    578 
    579 static void
    580 usage()
    581 {
    582 	const char *progname = getprogname();
    583 
    584 	fprintf(stderr, "usage: %s -A [-p priority] [-t blk|noblk]\n",
    585 	    progname);
    586 	fprintf(stderr, "       %s -D dumppath\n", progname);
    587 	fprintf(stderr, "       %s -U [-t blk|noblk]\n", progname);
    588 	fprintf(stderr, "       %s -a [-p priority] path\n", progname);
    589 	fprintf(stderr, "       %s -c -p priority path\n", progname);
    590 	fprintf(stderr, "       %s -d path\n", progname);
    591 	fprintf(stderr, "       %s -l | -s [-k|-m|-g|-h]\n", progname);
    592 	fprintf(stderr, "       %s -z\n", progname);
    593 	exit(1);
    594 }
    595