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swapctl.c revision 1.20 
      1 /*	$NetBSD: swapctl.c,v 1.20 2002/06/21 09:04:16 jdolecek 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 {
    413 		name = devname(dev, S_IFBLK);
    414 		printf("dump device is ");
    415 		if (name)
    416 			printf("%s\n", name);
    417 		else
    418 			printf("major %d minor %d\n", major(dev), minor(dev));
    419 	}
    420 }
    421 
    422 static void
    423 do_fstab(add)
    424 	int add;
    425 {
    426 	struct	fstab *fp;
    427 	char	*s;
    428 	long	priority;
    429 	struct	stat st;
    430 	int	isblk;
    431 	int	gotone = 0;
    432 #define PATH_MOUNT	"/sbin/mount_nfs"
    433 #define PATH_UMOUNT	"/sbin/umount"
    434 	char	cmd[2*PATH_MAX+sizeof(PATH_MOUNT)+2];
    435 
    436 #define PRIORITYEQ	"priority="
    437 #define NFSMNTPT	"nfsmntpt="
    438 	while ((fp = getfsent()) != NULL) {
    439 		const char *spec;
    440 
    441 		spec = fp->fs_spec;
    442 		cmd[0] = '\0';
    443 
    444 		if (strcmp(fp->fs_type, "dp") == 0 && add) {
    445 			set_dumpdev(spec);
    446 			continue;
    447 		}
    448 
    449 		if (strcmp(fp->fs_type, "sw") != 0)
    450 			continue;
    451 
    452 		/* handle dp as mnt option */
    453 		if (strstr(fp->fs_mntops, "dp") && add)
    454 			set_dumpdev(spec);
    455 
    456 		isblk = 0;
    457 
    458 		if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
    459 			s += sizeof(PRIORITYEQ) - 1;
    460 			priority = atol(s);
    461 		} else
    462 			priority = pri;
    463 
    464 		if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
    465 			char *t;
    466 
    467 			/*
    468 			 * Skip this song and dance if we're only
    469 			 * doing block devices.
    470 			 */
    471 			if (tflag != NULL && strcmp(tflag, "blk") == 0)
    472 				continue;
    473 
    474 			t = strpbrk(s, ",");
    475 			if (t != 0)
    476 				*t = '\0';
    477 			spec = strdup(s + strlen(NFSMNTPT));
    478 			if (t != 0)
    479 				*t = ',';
    480 
    481 			if (spec == NULL)
    482 				errx(1, "Out of memory");
    483 
    484 			if (strlen(spec) == 0) {
    485 				warnx("empty mountpoint");
    486 				free((char *)spec);
    487 				continue;
    488 			}
    489 			if (add) {
    490 				snprintf(cmd, sizeof(cmd), "%s %s %s",
    491 					PATH_MOUNT, fp->fs_spec, spec);
    492 				if (system(cmd) != 0) {
    493 					warnx("%s: mount failed", fp->fs_spec);
    494 					continue;
    495 				}
    496 			} else {
    497 				snprintf(cmd, sizeof(cmd), "%s %s",
    498 					PATH_UMOUNT, fp->fs_spec);
    499 			}
    500 		} else {
    501 			/*
    502 			 * Determine blk-ness.
    503 			 */
    504 			if (stat(spec, &st) < 0) {
    505 				warn("%s", spec);
    506 				continue;
    507 			}
    508 			if (S_ISBLK(st.st_mode))
    509 				isblk = 1;
    510 		}
    511 
    512 		/*
    513 		 * Skip this type if we're told to.
    514 		 */
    515 		if (tflag != NULL) {
    516 			if (strcmp(tflag, "blk") == 0 && isblk == 0)
    517 				continue;
    518 			if (strcmp(tflag, "noblk") == 0 && isblk == 1)
    519 				continue;
    520 		}
    521 
    522 		if (add) {
    523 			if (add_swap(spec, (int)priority)) {
    524 				gotone = 1;
    525 				printf(
    526 			    	"%s: adding %s as swap device at priority %d\n",
    527 				    getprogname(), fp->fs_spec, (int)priority);
    528 			}
    529 		} else {
    530 			if (delete_swap(spec)) {
    531 				gotone = 1;
    532 				printf(
    533 				    "%s: removing %s as swap device\n",
    534 				    getprogname(), fp->fs_spec);
    535 			}
    536 			if (cmd[0]) {
    537 				if (system(cmd) != 0) {
    538 					warnx("%s: umount failed", fp->fs_spec);
    539 					continue;
    540 				}
    541 			}
    542 		}
    543 
    544 		if (spec != fp->fs_spec)
    545 			free((char *)spec);
    546 	}
    547 	if (gotone == 0)
    548 		exit(1);
    549 }
    550 
    551 static void
    552 usage()
    553 {
    554 	const char *progname = getprogname();
    555 
    556 	fprintf(stderr, "usage: %s -A [-p priority] [-t blk|noblk]\n",
    557 	    progname);
    558 	fprintf(stderr, "       %s -D dumppath\n", progname);
    559 	fprintf(stderr, "       %s -U [-t blk|noblk]\n", progname);
    560 	fprintf(stderr, "       %s -a [-p priority] path\n", progname);
    561 	fprintf(stderr, "       %s -c -p priority path\n", progname);
    562 	fprintf(stderr, "       %s -d path\n", progname);
    563 	fprintf(stderr, "       %s -l | -s [-k]\n", progname);
    564 	exit(1);
    565 }
    566