Home | History | Annotate | Line # | Download | only in swapctl
swapctl.c revision 1.14 
      1 /*	$NetBSD: swapctl.c,v 1.14 2000/04/13 08:29:56 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  *	-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 #include <sys/swap.h>
     58 
     59 #include <unistd.h>
     60 #include <err.h>
     61 #include <errno.h>
     62 #include <stdio.h>
     63 #include <stdlib.h>
     64 #include <string.h>
     65 #include <fstab.h>
     66 
     67 #include "swapctl.h"
     68 
     69 int	command;
     70 
     71 /*
     72  * Commands for swapctl(8).  These are mutually exclusive.
     73  */
     74 #define	CMD_A		0x01	/* process /etc/fstab for adding */
     75 #define	CMD_D		0x02	/* set dumpdev */
     76 #define	CMD_U		0x04	/* process /etc/fstab for removing */
     77 #define	CMD_a		0x08	/* add a swap file/device */
     78 #define	CMD_c		0x10	/* change priority of a swap file/device */
     79 #define	CMD_d		0x20	/* delete a swap file/device */
     80 #define	CMD_l		0x40	/* list swap files/devices */
     81 #define	CMD_s		0x80	/* summary of swap files/devices */
     82 
     83 #define	SET_COMMAND(cmd) \
     84 do { \
     85 	if (command) \
     86 		usage(); \
     87 	command = (cmd); \
     88 } while (0)
     89 
     90 /*
     91  * Commands that require a "path" argument at the end of the command
     92  * line, and the ones which require that none exist.
     93  */
     94 #define	REQUIRE_PATH	(CMD_D | CMD_a | CMD_c | CMD_d)
     95 #define	REQUIRE_NOPATH	(CMD_A | CMD_U | CMD_l | CMD_s)
     96 
     97 /*
     98  * Option flags, and the commands with which they are valid.
     99  */
    100 int	kflag;		/* display in 1K blocks */
    101 #define	KFLAG_CMDS	(CMD_l | CMD_s)
    102 
    103 int	pflag;		/* priority was specified */
    104 #define	PFLAG_CMDS	(CMD_A | CMD_a | CMD_c)
    105 
    106 char	*tflag;		/* swap device type (blk or noblk) */
    107 #define	TFLAG_CMDS	(CMD_A | CMD_U )
    108 
    109 int	pri;		/* uses 0 as default pri */
    110 
    111 static	void change_priority __P((const char *));
    112 static	int  add_swap __P((const char *, int));
    113 static	int  delete_swap __P((const char *));
    114 static	void set_dumpdev __P((const char *));
    115 	int  main __P((int, char *[]));
    116 static	void do_fstab __P((int));
    117 static	void usage __P((void));
    118 static	void swapon_command __P((int, char **));
    119 #if 0
    120 static	void swapoff_command __P((int, char **));
    121 #endif
    122 
    123 extern	char *__progname;	/* from crt0.o */
    124 
    125 int
    126 main(argc, argv)
    127 	int	argc;
    128 	char	*argv[];
    129 {
    130 	int	c;
    131 
    132 	if (strcmp(__progname, "swapon") == 0) {
    133 		swapon_command(argc, argv);
    134 		/* NOTREACHED */
    135 	}
    136 
    137 #if 0
    138 	if (strcmp(__progname, "swapoff") == 0) {
    139 		swapoff_command(argc, argv);
    140 		/* NOTREACHED */
    141 	}
    142 #endif
    143 
    144 	while ((c = getopt(argc, argv, "ADUacdlkp:st:")) != -1) {
    145 		switch (c) {
    146 		case 'A':
    147 			SET_COMMAND(CMD_A);
    148 			break;
    149 
    150 		case 'D':
    151 			SET_COMMAND(CMD_D);
    152 			break;
    153 
    154 		case 'U':
    155 			SET_COMMAND(CMD_U);
    156 			break;
    157 
    158 		case 'a':
    159 			SET_COMMAND(CMD_a);
    160 			break;
    161 
    162 		case 'c':
    163 			SET_COMMAND(CMD_c);
    164 			break;
    165 
    166 		case 'd':
    167 			SET_COMMAND(CMD_d);
    168 			break;
    169 
    170 		case 'l':
    171 			SET_COMMAND(CMD_l);
    172 			break;
    173 
    174 		case 'k':
    175 			kflag = 1;
    176 			break;
    177 
    178 		case 'p':
    179 			pflag = 1;
    180 			/* XXX strtol() */
    181 			pri = atoi(optarg);
    182 			break;
    183 
    184 		case 's':
    185 			SET_COMMAND(CMD_s);
    186 			break;
    187 
    188 		case 't':
    189 			if (tflag != NULL)
    190 				usage();
    191 			tflag = optarg;
    192 			break;
    193 
    194 		default:
    195 			usage();
    196 			/* NOTREACHED */
    197 		}
    198 	}
    199 
    200 	/* Did the user specify a command? */
    201 	if (command == 0)
    202 		usage();
    203 
    204 	argv += optind;
    205 	argc -= optind;
    206 
    207 	switch (argc) {
    208 	case 0:
    209 		if (command & REQUIRE_PATH)
    210 			usage();
    211 		break;
    212 
    213 	case 1:
    214 		if (command & REQUIRE_NOPATH)
    215 			usage();
    216 		break;
    217 
    218 	default:
    219 		usage();
    220 	}
    221 
    222 	/* To change priority, you have to specify one. */
    223 	if ((command == CMD_c) && pflag == 0)
    224 		usage();
    225 
    226 	/* Sanity-check -t */
    227 	if (tflag != NULL) {
    228 		if (command != CMD_A && command != CMD_U)
    229 			usage();
    230 		if (strcmp(tflag, "blk") != 0 &&
    231 		    strcmp(tflag, "noblk") != 0)
    232 			usage();
    233 	}
    234 
    235 	/* Dispatch the command. */
    236 	switch (command) {
    237 	case CMD_l:
    238 		list_swap(pri, kflag, pflag, 0, 1);
    239 		break;
    240 
    241 	case CMD_s:
    242 		list_swap(pri, kflag, pflag, 0, 0);
    243 		break;
    244 
    245 	case CMD_c:
    246 		change_priority(argv[0]);
    247 		break;
    248 
    249 	case CMD_a:
    250 		if (! add_swap(argv[0], pri))
    251 			exit(1);
    252 		break;
    253 
    254 	case CMD_d:
    255 		if (! delete_swap(argv[0]))
    256 			exit(1);
    257 		break;
    258 
    259 	case CMD_A:
    260 		do_fstab(1);
    261 		break;
    262 
    263 	case CMD_D:
    264 		set_dumpdev(argv[0]);
    265 		break;
    266 
    267 	case CMD_U:
    268 		do_fstab(0);
    269 		break;
    270 	}
    271 
    272 	exit(0);
    273 }
    274 
    275 /*
    276  * swapon_command: emulate the old swapon(8) program.
    277  */
    278 static void
    279 swapon_command(argc, argv)
    280 	int argc;
    281 	char **argv;
    282 {
    283 	int ch, fiztab = 0;
    284 
    285 	while ((ch = getopt(argc, argv, "at:")) != -1) {
    286 		switch (ch) {
    287 		case 'a':
    288 			fiztab = 1;
    289 			break;
    290 		case 't':
    291 			if (tflag != NULL)
    292 				usage();
    293 			tflag = optarg;
    294 			break;
    295 		default:
    296 			goto swapon_usage;
    297 		}
    298 	}
    299 	argc -= optind;
    300 	argv += optind;
    301 
    302 	if (fiztab) {
    303 		if (argc)
    304 			goto swapon_usage;
    305 		/* Sanity-check -t */
    306 		if (tflag != NULL) {
    307 			if (strcmp(tflag, "blk") != 0 &&
    308 			    strcmp(tflag, "noblk") != 0)
    309 				usage();
    310 		}
    311 		do_fstab(1);
    312 		exit(0);
    313 	} else if (argc == 0 || tflag != NULL)
    314 		goto swapon_usage;
    315 
    316 	while (argc) {
    317 		if (! add_swap(argv[0], pri))
    318 			exit(1);
    319 		argc--;
    320 		argv++;
    321 	}
    322 	exit(0);
    323 	/* NOTREACHED */
    324 
    325  swapon_usage:
    326 	fprintf(stderr, "usage: %s -a [-t blk|noblk]\n", __progname);
    327 	fprintf(stderr, "       %s <path> ...\n", __progname);
    328 	exit(1);
    329 }
    330 
    331 /*
    332  * change_priority:  change the priority of a swap device.
    333  */
    334 static void
    335 change_priority(path)
    336 	const char	*path;
    337 {
    338 
    339 	if (swapctl(SWAP_CTL, path, pri) < 0)
    340 		warn("%s", path);
    341 }
    342 
    343 /*
    344  * add_swap:  add the pathname to the list of swap devices.
    345  */
    346 static int
    347 add_swap(path, priority)
    348 	const char *path;
    349 	int priority;
    350 {
    351 	struct stat sb;
    352 
    353 	if (stat(path, &sb) < 0)
    354 		goto oops;
    355 
    356 	if (sb.st_mode & S_IROTH)
    357 		warnx("%s is readable by the world", path);
    358 	if (sb.st_mode & S_IWOTH)
    359 		warnx("%s is writable by the world", path);
    360 
    361 	if (swapctl(SWAP_ON, path, priority) < 0) {
    362 oops:
    363 		warn("%s", path);
    364 		return (0);
    365 	}
    366 	return (1);
    367 }
    368 
    369 /*
    370  * delete_swap:  remove the pathname to the list of swap devices.
    371  */
    372 static int
    373 delete_swap(path)
    374 	const char *path;
    375 {
    376 
    377 	if (swapctl(SWAP_OFF, path, pri) < 0) {
    378 		warn("%s", path);
    379 		return (0);
    380 	}
    381 	return (1);
    382 }
    383 
    384 static void
    385 set_dumpdev(path)
    386 	const char *path;
    387 {
    388 
    389 	if (swapctl(SWAP_DUMPDEV, path, NULL) == -1)
    390 		warn("could not set dump device to %s", path);
    391 	else
    392 		printf("%s: setting dump device to %s\n", __progname, path);
    393 }
    394 
    395 static void
    396 do_fstab(add)
    397 	int add;
    398 {
    399 	struct	fstab *fp;
    400 	char	*s;
    401 	long	priority;
    402 	struct	stat st;
    403 	int	isblk;
    404 	int	gotone = 0;
    405 #define PATH_MOUNT	"/sbin/mount_nfs"
    406 #define PATH_UMOUNT	"/sbin/umount"
    407 	char	cmd[2*PATH_MAX+sizeof(PATH_MOUNT)+2];
    408 
    409 #define PRIORITYEQ	"priority="
    410 #define NFSMNTPT	"nfsmntpt="
    411 	while ((fp = getfsent()) != NULL) {
    412 		const char *spec;
    413 
    414 		spec = fp->fs_spec;
    415 		cmd[0] = '\0';
    416 
    417 		if (strcmp(fp->fs_type, "dp") == 0 && add) {
    418 			set_dumpdev(spec);
    419 			continue;
    420 		}
    421 
    422 		if (strcmp(fp->fs_type, "sw") != 0)
    423 			continue;
    424 		isblk = 0;
    425 
    426 		if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
    427 			s += sizeof(PRIORITYEQ) - 1;
    428 			priority = atol(s);
    429 		} else
    430 			priority = pri;
    431 
    432 		if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
    433 			char *t;
    434 
    435 			/*
    436 			 * Skip this song and dance if we're only
    437 			 * doing block devices.
    438 			 */
    439 			if (tflag != NULL && strcmp(tflag, "blk") == 0)
    440 				continue;
    441 
    442 			t = strpbrk(s, ",");
    443 			if (t != 0)
    444 				*t = '\0';
    445 			spec = strdup(s + strlen(NFSMNTPT));
    446 			if (t != 0)
    447 				*t = ',';
    448 
    449 			if (spec == NULL)
    450 				errx(1, "Out of memory");
    451 
    452 			if (strlen(spec) == 0) {
    453 				warnx("empty mountpoint");
    454 				free((char *)spec);
    455 				continue;
    456 			}
    457 			if (add) {
    458 				snprintf(cmd, sizeof(cmd), "%s %s %s",
    459 					PATH_MOUNT, fp->fs_spec, spec);
    460 				if (system(cmd) != 0) {
    461 					warnx("%s: mount failed", fp->fs_spec);
    462 					continue;
    463 				}
    464 			} else {
    465 				snprintf(cmd, sizeof(cmd), "%s %s",
    466 					PATH_UMOUNT, fp->fs_spec);
    467 			}
    468 		} else {
    469 			/*
    470 			 * Determine blk-ness.
    471 			 */
    472 			if (stat(spec, &st) < 0) {
    473 				warn(spec);
    474 				continue;
    475 			}
    476 			if (S_ISBLK(st.st_mode))
    477 				isblk = 1;
    478 		}
    479 
    480 		/*
    481 		 * Skip this type if we're told to.
    482 		 */
    483 		if (tflag != NULL) {
    484 			if (strcmp(tflag, "blk") == 0 && isblk == 0)
    485 				continue;
    486 			if (strcmp(tflag, "noblk") == 0 && isblk == 1)
    487 				continue;
    488 		}
    489 
    490 		if (add) {
    491 			if (add_swap(spec, (int)priority)) {
    492 				gotone = 1;
    493 				printf(
    494 			    	"%s: adding %s as swap device at priority %d\n",
    495 				    __progname, fp->fs_spec, (int)priority);
    496 			}
    497 		} else {
    498 			if (delete_swap(spec)) {
    499 				gotone = 1;
    500 				printf(
    501 				    "%s: removing %s as swap device\n",
    502 				    __progname, fp->fs_spec);
    503 			}
    504 			if (cmd[0]) {
    505 				if (system(cmd) != 0) {
    506 					warnx("%s: umount failed", fp->fs_spec);
    507 					continue;
    508 				}
    509 			}
    510 		}
    511 
    512 		if (spec != fp->fs_spec)
    513 			free((char *)spec);
    514 	}
    515 	if (gotone == 0)
    516 		exit(1);
    517 }
    518 
    519 static void
    520 usage()
    521 {
    522 
    523 	fprintf(stderr, "usage: %s -A [-p priority] [-t blk|noblk]\n",
    524 	    __progname);
    525 	fprintf(stderr, "       %s -D dumppath\n", __progname);
    526 	fprintf(stderr, "       %s -U [-t blk|noblk]\n", __progname);
    527 	fprintf(stderr, "       %s -a [-p priority] path\n", __progname);
    528 	fprintf(stderr, "       %s -c -p priority path\n", __progname);
    529 	fprintf(stderr, "       %s -d path\n", __progname);
    530 	fprintf(stderr, "       %s -l | -s [-k]\n", __progname);
    531 	exit(1);
    532 }
    533