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swapctl.c revision 1.16 
      1 /*	$NetBSD: swapctl.c,v 1.16 2000/11/17 11:43:41 mrg 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 (not supported yet)
     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 extern	char *__progname;	/* from crt0.o */
    127 
    128 int
    129 main(argc, argv)
    130 	int	argc;
    131 	char	*argv[];
    132 {
    133 	int	c;
    134 
    135 	if (strcmp(__progname, "swapon") == 0) {
    136 		swapon_command(argc, argv);
    137 		/* NOTREACHED */
    138 	}
    139 
    140 #if 0
    141 	if (strcmp(__progname, "swapoff") == 0) {
    142 		swapoff_command(argc, argv);
    143 		/* NOTREACHED */
    144 	}
    145 #endif
    146 
    147 	while ((c = getopt(argc, argv, "ADUacdlkp:st:z")) != -1) {
    148 		switch (c) {
    149 		case 'A':
    150 			SET_COMMAND(CMD_A);
    151 			break;
    152 
    153 		case 'D':
    154 			SET_COMMAND(CMD_D);
    155 			break;
    156 
    157 		case 'U':
    158 			SET_COMMAND(CMD_U);
    159 			break;
    160 
    161 		case 'a':
    162 			SET_COMMAND(CMD_a);
    163 			break;
    164 
    165 		case 'c':
    166 			SET_COMMAND(CMD_c);
    167 			break;
    168 
    169 		case 'd':
    170 			SET_COMMAND(CMD_d);
    171 			break;
    172 
    173 		case 'l':
    174 			SET_COMMAND(CMD_l);
    175 			break;
    176 
    177 		case 'k':
    178 			kflag = 1;
    179 			break;
    180 
    181 		case 'p':
    182 			pflag = 1;
    183 			/* XXX strtol() */
    184 			pri = atoi(optarg);
    185 			break;
    186 
    187 		case 's':
    188 			SET_COMMAND(CMD_s);
    189 			break;
    190 
    191 		case 't':
    192 			if (tflag != NULL)
    193 				usage();
    194 			tflag = optarg;
    195 			break;
    196 
    197 		case 'z':
    198 			SET_COMMAND(CMD_z);
    199 			break;
    200 
    201 		default:
    202 			usage();
    203 			/* NOTREACHED */
    204 		}
    205 	}
    206 
    207 	/* Did the user specify a command? */
    208 	if (command == 0)
    209 		usage();
    210 
    211 	argv += optind;
    212 	argc -= optind;
    213 
    214 	switch (argc) {
    215 	case 0:
    216 		if (command & REQUIRE_PATH)
    217 			usage();
    218 		break;
    219 
    220 	case 1:
    221 		if (command & REQUIRE_NOPATH)
    222 			usage();
    223 		break;
    224 
    225 	default:
    226 		usage();
    227 	}
    228 
    229 	/* To change priority, you have to specify one. */
    230 	if ((command == CMD_c) && pflag == 0)
    231 		usage();
    232 
    233 	/* Sanity-check -t */
    234 	if (tflag != NULL) {
    235 		if (command != CMD_A && command != CMD_U)
    236 			usage();
    237 		if (strcmp(tflag, "blk") != 0 &&
    238 		    strcmp(tflag, "noblk") != 0)
    239 			usage();
    240 	}
    241 
    242 	/* Dispatch the command. */
    243 	switch (command) {
    244 	case CMD_l:
    245 		list_swap(pri, kflag, pflag, 0, 1);
    246 		break;
    247 
    248 	case CMD_s:
    249 		list_swap(pri, kflag, pflag, 0, 0);
    250 		break;
    251 
    252 	case CMD_c:
    253 		change_priority(argv[0]);
    254 		break;
    255 
    256 	case CMD_a:
    257 		if (! add_swap(argv[0], pri))
    258 			exit(1);
    259 		break;
    260 
    261 	case CMD_d:
    262 		if (! delete_swap(argv[0]))
    263 			exit(1);
    264 		break;
    265 
    266 	case CMD_A:
    267 		do_fstab(1);
    268 		break;
    269 
    270 	case CMD_D:
    271 		set_dumpdev(argv[0]);
    272 		break;
    273 
    274 	case CMD_z:
    275 		get_dumpdev();
    276 		break;
    277 
    278 	case CMD_U:
    279 		do_fstab(0);
    280 		break;
    281 	}
    282 
    283 	exit(0);
    284 }
    285 
    286 /*
    287  * swapon_command: emulate the old swapon(8) program.
    288  */
    289 static void
    290 swapon_command(argc, argv)
    291 	int argc;
    292 	char **argv;
    293 {
    294 	int ch, fiztab = 0;
    295 
    296 	while ((ch = getopt(argc, argv, "at:")) != -1) {
    297 		switch (ch) {
    298 		case 'a':
    299 			fiztab = 1;
    300 			break;
    301 		case 't':
    302 			if (tflag != NULL)
    303 				usage();
    304 			tflag = optarg;
    305 			break;
    306 		default:
    307 			goto swapon_usage;
    308 		}
    309 	}
    310 	argc -= optind;
    311 	argv += optind;
    312 
    313 	if (fiztab) {
    314 		if (argc)
    315 			goto swapon_usage;
    316 		/* Sanity-check -t */
    317 		if (tflag != NULL) {
    318 			if (strcmp(tflag, "blk") != 0 &&
    319 			    strcmp(tflag, "noblk") != 0)
    320 				usage();
    321 		}
    322 		do_fstab(1);
    323 		exit(0);
    324 	} else if (argc == 0 || tflag != NULL)
    325 		goto swapon_usage;
    326 
    327 	while (argc) {
    328 		if (! add_swap(argv[0], pri))
    329 			exit(1);
    330 		argc--;
    331 		argv++;
    332 	}
    333 	exit(0);
    334 	/* NOTREACHED */
    335 
    336  swapon_usage:
    337 	fprintf(stderr, "usage: %s -a [-t blk|noblk]\n", __progname);
    338 	fprintf(stderr, "       %s <path> ...\n", __progname);
    339 	exit(1);
    340 }
    341 
    342 /*
    343  * change_priority:  change the priority of a swap device.
    344  */
    345 static void
    346 change_priority(path)
    347 	const char	*path;
    348 {
    349 
    350 	if (swapctl(SWAP_CTL, path, pri) < 0)
    351 		warn("%s", path);
    352 }
    353 
    354 /*
    355  * add_swap:  add the pathname to the list of swap devices.
    356  */
    357 static int
    358 add_swap(path, priority)
    359 	const char *path;
    360 	int priority;
    361 {
    362 	struct stat sb;
    363 
    364 	if (stat(path, &sb) < 0)
    365 		goto oops;
    366 
    367 	if (sb.st_mode & S_IROTH)
    368 		warnx("%s is readable by the world", path);
    369 	if (sb.st_mode & S_IWOTH)
    370 		warnx("%s is writable by the world", path);
    371 
    372 	if (swapctl(SWAP_ON, path, priority) < 0) {
    373 oops:
    374 		warn("%s", path);
    375 		return (0);
    376 	}
    377 	return (1);
    378 }
    379 
    380 /*
    381  * delete_swap:  remove the pathname to the list of swap devices.
    382  */
    383 static int
    384 delete_swap(path)
    385 	const char *path;
    386 {
    387 
    388 	if (swapctl(SWAP_OFF, path, pri) < 0) {
    389 		warn("%s", path);
    390 		return (0);
    391 	}
    392 	return (1);
    393 }
    394 
    395 static void
    396 set_dumpdev(path)
    397 	const char *path;
    398 {
    399 
    400 	if (swapctl(SWAP_DUMPDEV, path, NULL) == -1)
    401 		warn("could not set dump device to %s", path);
    402 	else
    403 		printf("%s: setting dump device to %s\n", __progname, path);
    404 }
    405 
    406 static void
    407 get_dumpdev()
    408 {
    409 	dev_t	dev;
    410 	char 	*name;
    411 
    412 	if (swapctl(SWAP_GETDUMPDEV, &dev, NULL) == -1)
    413 		warn("could not get dump device");
    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 		isblk = 0;
    454 
    455 		if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
    456 			s += sizeof(PRIORITYEQ) - 1;
    457 			priority = atol(s);
    458 		} else
    459 			priority = pri;
    460 
    461 		if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
    462 			char *t;
    463 
    464 			/*
    465 			 * Skip this song and dance if we're only
    466 			 * doing block devices.
    467 			 */
    468 			if (tflag != NULL && strcmp(tflag, "blk") == 0)
    469 				continue;
    470 
    471 			t = strpbrk(s, ",");
    472 			if (t != 0)
    473 				*t = '\0';
    474 			spec = strdup(s + strlen(NFSMNTPT));
    475 			if (t != 0)
    476 				*t = ',';
    477 
    478 			if (spec == NULL)
    479 				errx(1, "Out of memory");
    480 
    481 			if (strlen(spec) == 0) {
    482 				warnx("empty mountpoint");
    483 				free((char *)spec);
    484 				continue;
    485 			}
    486 			if (add) {
    487 				snprintf(cmd, sizeof(cmd), "%s %s %s",
    488 					PATH_MOUNT, fp->fs_spec, spec);
    489 				if (system(cmd) != 0) {
    490 					warnx("%s: mount failed", fp->fs_spec);
    491 					continue;
    492 				}
    493 			} else {
    494 				snprintf(cmd, sizeof(cmd), "%s %s",
    495 					PATH_UMOUNT, fp->fs_spec);
    496 			}
    497 		} else {
    498 			/*
    499 			 * Determine blk-ness.
    500 			 */
    501 			if (stat(spec, &st) < 0) {
    502 				warn("%s", spec);
    503 				continue;
    504 			}
    505 			if (S_ISBLK(st.st_mode))
    506 				isblk = 1;
    507 		}
    508 
    509 		/*
    510 		 * Skip this type if we're told to.
    511 		 */
    512 		if (tflag != NULL) {
    513 			if (strcmp(tflag, "blk") == 0 && isblk == 0)
    514 				continue;
    515 			if (strcmp(tflag, "noblk") == 0 && isblk == 1)
    516 				continue;
    517 		}
    518 
    519 		if (add) {
    520 			if (add_swap(spec, (int)priority)) {
    521 				gotone = 1;
    522 				printf(
    523 			    	"%s: adding %s as swap device at priority %d\n",
    524 				    __progname, fp->fs_spec, (int)priority);
    525 			}
    526 		} else {
    527 			if (delete_swap(spec)) {
    528 				gotone = 1;
    529 				printf(
    530 				    "%s: removing %s as swap device\n",
    531 				    __progname, fp->fs_spec);
    532 			}
    533 			if (cmd[0]) {
    534 				if (system(cmd) != 0) {
    535 					warnx("%s: umount failed", fp->fs_spec);
    536 					continue;
    537 				}
    538 			}
    539 		}
    540 
    541 		if (spec != fp->fs_spec)
    542 			free((char *)spec);
    543 	}
    544 	if (gotone == 0)
    545 		exit(1);
    546 }
    547 
    548 static void
    549 usage()
    550 {
    551 
    552 	fprintf(stderr, "usage: %s -A [-p priority] [-t blk|noblk]\n",
    553 	    __progname);
    554 	fprintf(stderr, "       %s -D dumppath\n", __progname);
    555 	fprintf(stderr, "       %s -U [-t blk|noblk]\n", __progname);
    556 	fprintf(stderr, "       %s -a [-p priority] path\n", __progname);
    557 	fprintf(stderr, "       %s -c -p priority path\n", __progname);
    558 	fprintf(stderr, "       %s -d path\n", __progname);
    559 	fprintf(stderr, "       %s -l | -s [-k]\n", __progname);
    560 	exit(1);
    561 }
    562