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swapctl.c revision 1.13 
      1 /*	$NetBSD: swapctl.c,v 1.13 2000/03/13 22:59:22 soren 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  *	-U		remove all devices listed as `sw' in /etc/fstab.
     37  *	-t [blk|noblk]	if -A or -U , add (remove) either all block device
     38  *			or all non-block devices
     39  *	-a <dev>	add this device
     40  *	-d <dev>	remove this swap device (not supported yet)
     41  *	-l		list swap devices
     42  *	-s		short listing of swap devices
     43  *	-k		use kilobytes
     44  *	-p <pri>	use this priority
     45  *	-c		change priority
     46  *
     47  * or, if invoked as "swapon" (compatibility mode):
     48  *
     49  *	-a		all devices listed as `sw' in /etc/fstab
     50  *	-t		same as -t above (feature not present in old
     51  *			swapon(8) command)
     52  *	<dev>		add this device
     53  */
     54 
     55 #include <sys/param.h>
     56 #include <sys/stat.h>
     57 
     58 #include <vm/vm_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 
     84 #define	SET_COMMAND(cmd) \
     85 do { \
     86 	if (command) \
     87 		usage(); \
     88 	command = (cmd); \
     89 } while (0)
     90 
     91 /*
     92  * Commands that require a "path" argument at the end of the command
     93  * line, and the ones which require that none exist.
     94  */
     95 #define	REQUIRE_PATH	(CMD_D | CMD_a | CMD_c | CMD_d)
     96 #define	REQUIRE_NOPATH	(CMD_A | CMD_U | CMD_l | CMD_s)
     97 
     98 /*
     99  * Option flags, and the commands with which they are valid.
    100  */
    101 int	kflag;		/* display in 1K blocks */
    102 #define	KFLAG_CMDS	(CMD_l | CMD_s)
    103 
    104 int	pflag;		/* priority was specified */
    105 #define	PFLAG_CMDS	(CMD_A | CMD_a | CMD_c)
    106 
    107 char	*tflag;		/* swap device type (blk or noblk) */
    108 #define	TFLAG_CMDS	(CMD_A | CMD_U )
    109 
    110 int	pri;		/* uses 0 as default pri */
    111 
    112 static	void change_priority __P((const char *));
    113 static	int  add_swap __P((const char *, int));
    114 static	int  delete_swap __P((const char *));
    115 static	void set_dumpdev __P((const char *));
    116 	int  main __P((int, char *[]));
    117 static	void do_fstab __P((int));
    118 static	void usage __P((void));
    119 static	void swapon_command __P((int, char **));
    120 #if 0
    121 static	void swapoff_command __P((int, char **));
    122 #endif
    123 
    124 extern	char *__progname;	/* from crt0.o */
    125 
    126 int
    127 main(argc, argv)
    128 	int	argc;
    129 	char	*argv[];
    130 {
    131 	int	c;
    132 
    133 	if (strcmp(__progname, "swapon") == 0) {
    134 		swapon_command(argc, argv);
    135 		/* NOTREACHED */
    136 	}
    137 
    138 #if 0
    139 	if (strcmp(__progname, "swapoff") == 0) {
    140 		swapoff_command(argc, argv);
    141 		/* NOTREACHED */
    142 	}
    143 #endif
    144 
    145 	while ((c = getopt(argc, argv, "ADUacdlkp:st:")) != -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 		default:
    196 			usage();
    197 			/* NOTREACHED */
    198 		}
    199 	}
    200 
    201 	/* Did the user specify a command? */
    202 	if (command == 0)
    203 		usage();
    204 
    205 	argv += optind;
    206 	argc -= optind;
    207 
    208 	switch (argc) {
    209 	case 0:
    210 		if (command & REQUIRE_PATH)
    211 			usage();
    212 		break;
    213 
    214 	case 1:
    215 		if (command & REQUIRE_NOPATH)
    216 			usage();
    217 		break;
    218 
    219 	default:
    220 		usage();
    221 	}
    222 
    223 	/* To change priority, you have to specify one. */
    224 	if ((command == CMD_c) && pflag == 0)
    225 		usage();
    226 
    227 	/* Sanity-check -t */
    228 	if (tflag != NULL) {
    229 		if (command != CMD_A && command != CMD_U)
    230 			usage();
    231 		if (strcmp(tflag, "blk") != 0 &&
    232 		    strcmp(tflag, "noblk") != 0)
    233 			usage();
    234 	}
    235 
    236 	/* Dispatch the command. */
    237 	switch (command) {
    238 	case CMD_l:
    239 		list_swap(pri, kflag, pflag, 0, 1);
    240 		break;
    241 
    242 	case CMD_s:
    243 		list_swap(pri, kflag, pflag, 0, 0);
    244 		break;
    245 
    246 	case CMD_c:
    247 		change_priority(argv[0]);
    248 		break;
    249 
    250 	case CMD_a:
    251 		if (! add_swap(argv[0], pri))
    252 			exit(1);
    253 		break;
    254 
    255 	case CMD_d:
    256 		if (! delete_swap(argv[0]))
    257 			exit(1);
    258 		break;
    259 
    260 	case CMD_A:
    261 		do_fstab(1);
    262 		break;
    263 
    264 	case CMD_D:
    265 		set_dumpdev(argv[0]);
    266 		break;
    267 
    268 	case CMD_U:
    269 		do_fstab(0);
    270 		break;
    271 	}
    272 
    273 	exit(0);
    274 }
    275 
    276 /*
    277  * swapon_command: emulate the old swapon(8) program.
    278  */
    279 static void
    280 swapon_command(argc, argv)
    281 	int argc;
    282 	char **argv;
    283 {
    284 	int ch, fiztab = 0;
    285 
    286 	while ((ch = getopt(argc, argv, "at:")) != -1) {
    287 		switch (ch) {
    288 		case 'a':
    289 			fiztab = 1;
    290 			break;
    291 		case 't':
    292 			if (tflag != NULL)
    293 				usage();
    294 			tflag = optarg;
    295 			break;
    296 		default:
    297 			goto swapon_usage;
    298 		}
    299 	}
    300 	argc -= optind;
    301 	argv += optind;
    302 
    303 	if (fiztab) {
    304 		if (argc)
    305 			goto swapon_usage;
    306 		/* Sanity-check -t */
    307 		if (tflag != NULL) {
    308 			if (strcmp(tflag, "blk") != 0 &&
    309 			    strcmp(tflag, "noblk") != 0)
    310 				usage();
    311 		}
    312 		do_fstab(1);
    313 		exit(0);
    314 	} else if (argc == 0 || tflag != NULL)
    315 		goto swapon_usage;
    316 
    317 	while (argc) {
    318 		if (! add_swap(argv[0], pri))
    319 			exit(1);
    320 		argc--;
    321 		argv++;
    322 	}
    323 	exit(0);
    324 	/* NOTREACHED */
    325 
    326  swapon_usage:
    327 	fprintf(stderr, "usage: %s -a [-t blk|noblk]\n", __progname);
    328 	fprintf(stderr, "       %s <path> ...\n", __progname);
    329 	exit(1);
    330 }
    331 
    332 /*
    333  * change_priority:  change the priority of a swap device.
    334  */
    335 static void
    336 change_priority(path)
    337 	const char	*path;
    338 {
    339 
    340 	if (swapctl(SWAP_CTL, path, pri) < 0)
    341 		warn("%s", path);
    342 }
    343 
    344 /*
    345  * add_swap:  add the pathname to the list of swap devices.
    346  */
    347 static int
    348 add_swap(path, priority)
    349 	const char *path;
    350 	int priority;
    351 {
    352 	struct stat sb;
    353 
    354 	if (stat(path, &sb) < 0)
    355 		goto oops;
    356 
    357 	if (sb.st_mode & S_IROTH)
    358 		warnx("%s is readable by the world", path);
    359 	if (sb.st_mode & S_IWOTH)
    360 		warnx("%s is writable by the world", path);
    361 
    362 	if (swapctl(SWAP_ON, path, priority) < 0) {
    363 oops:
    364 		warn("%s", path);
    365 		return (0);
    366 	}
    367 	return (1);
    368 }
    369 
    370 /*
    371  * delete_swap:  remove the pathname to the list of swap devices.
    372  */
    373 static int
    374 delete_swap(path)
    375 	const char *path;
    376 {
    377 
    378 	if (swapctl(SWAP_OFF, path, pri) < 0) {
    379 		warn("%s", path);
    380 		return (0);
    381 	}
    382 	return (1);
    383 }
    384 
    385 static void
    386 set_dumpdev(path)
    387 	const char *path;
    388 {
    389 
    390 	if (swapctl(SWAP_DUMPDEV, path, NULL) == -1)
    391 		warn("could not set dump device to %s", path);
    392 	else
    393 		printf("%s: setting dump device to %s\n", __progname, path);
    394 }
    395 
    396 static void
    397 do_fstab(add)
    398 	int add;
    399 {
    400 	struct	fstab *fp;
    401 	char	*s;
    402 	long	priority;
    403 	struct	stat st;
    404 	int	isblk;
    405 	int	gotone = 0;
    406 #define PATH_MOUNT	"/sbin/mount_nfs"
    407 #define PATH_UMOUNT	"/sbin/umount"
    408 	char	cmd[2*PATH_MAX+sizeof(PATH_MOUNT)+2];
    409 
    410 #define PRIORITYEQ	"priority="
    411 #define NFSMNTPT	"nfsmntpt="
    412 	while ((fp = getfsent()) != NULL) {
    413 		const char *spec;
    414 
    415 		spec = fp->fs_spec;
    416 		cmd[0] = '\0';
    417 
    418 		if (strcmp(fp->fs_type, "dp") == 0 && add) {
    419 			set_dumpdev(spec);
    420 			continue;
    421 		}
    422 
    423 		if (strcmp(fp->fs_type, "sw") != 0)
    424 			continue;
    425 		isblk = 0;
    426 
    427 		if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
    428 			s += sizeof(PRIORITYEQ) - 1;
    429 			priority = atol(s);
    430 		} else
    431 			priority = pri;
    432 
    433 		if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
    434 			char *t;
    435 
    436 			/*
    437 			 * Skip this song and dance if we're only
    438 			 * doing block devices.
    439 			 */
    440 			if (tflag != NULL && strcmp(tflag, "blk") == 0)
    441 				continue;
    442 
    443 			t = strpbrk(s, ",");
    444 			if (t != 0)
    445 				*t = '\0';
    446 			spec = strdup(s + strlen(NFSMNTPT));
    447 			if (t != 0)
    448 				*t = ',';
    449 
    450 			if (spec == NULL)
    451 				errx(1, "Out of memory");
    452 
    453 			if (strlen(spec) == 0) {
    454 				warnx("empty mountpoint");
    455 				free((char *)spec);
    456 				continue;
    457 			}
    458 			if (add) {
    459 				snprintf(cmd, sizeof(cmd), "%s %s %s",
    460 					PATH_MOUNT, fp->fs_spec, spec);
    461 				if (system(cmd) != 0) {
    462 					warnx("%s: mount failed", fp->fs_spec);
    463 					continue;
    464 				}
    465 			} else {
    466 				snprintf(cmd, sizeof(cmd), "%s %s",
    467 					PATH_UMOUNT, fp->fs_spec);
    468 			}
    469 		} else {
    470 			/*
    471 			 * Determine blk-ness.
    472 			 */
    473 			if (stat(spec, &st) < 0) {
    474 				warn(spec);
    475 				continue;
    476 			}
    477 			if (S_ISBLK(st.st_mode))
    478 				isblk = 1;
    479 		}
    480 
    481 		/*
    482 		 * Skip this type if we're told to.
    483 		 */
    484 		if (tflag != NULL) {
    485 			if (strcmp(tflag, "blk") == 0 && isblk == 0)
    486 				continue;
    487 			if (strcmp(tflag, "noblk") == 0 && isblk == 1)
    488 				continue;
    489 		}
    490 
    491 		if (add) {
    492 			if (add_swap(spec, (int)priority)) {
    493 				gotone = 1;
    494 				printf(
    495 			    	"%s: adding %s as swap device at priority %d\n",
    496 				    __progname, fp->fs_spec, (int)priority);
    497 			}
    498 		} else {
    499 			if (delete_swap(spec)) {
    500 				gotone = 1;
    501 				printf(
    502 				    "%s: removing %s as swap device\n",
    503 				    __progname, fp->fs_spec);
    504 			}
    505 			if (cmd[0]) {
    506 				if (system(cmd) != 0) {
    507 					warnx("%s: umount failed", fp->fs_spec);
    508 					continue;
    509 				}
    510 			}
    511 		}
    512 
    513 		if (spec != fp->fs_spec)
    514 			free((char *)spec);
    515 	}
    516 	if (gotone == 0)
    517 		exit(1);
    518 }
    519 
    520 static void
    521 usage()
    522 {
    523 
    524 	fprintf(stderr, "usage: %s -A [-p priority] [-t blk|noblk]\n",
    525 	    __progname);
    526 	fprintf(stderr, "       %s -D dumppath\n", __progname);
    527 	fprintf(stderr, "       %s -U [-t blk|noblk]\n", __progname);
    528 	fprintf(stderr, "       %s -a [-p priority] path\n", __progname);
    529 	fprintf(stderr, "       %s -c -p priority path\n", __progname);
    530 	fprintf(stderr, "       %s -d path\n", __progname);
    531 	fprintf(stderr, "       %s -l | -s [-k]\n", __progname);
    532 	exit(1);
    533 }
    534