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swapctl.c revision 1.23 
      1 /*	$NetBSD: swapctl.c,v 1.23 2003/10/21 02:32:54 fvdl 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 #include <sys/cdefs.h>
     56 
     57 #ifndef lint
     58 __RCSID("$NetBSD: swapctl.c,v 1.23 2003/10/21 02:32:54 fvdl Exp $");
     59 #endif
     60 
     61 
     62 #include <sys/param.h>
     63 #include <sys/stat.h>
     64 #include <sys/swap.h>
     65 
     66 #include <unistd.h>
     67 #include <err.h>
     68 #include <errno.h>
     69 #include <stdio.h>
     70 #include <stdlib.h>
     71 #include <string.h>
     72 #include <fstab.h>
     73 
     74 #include "swapctl.h"
     75 
     76 int	command;
     77 
     78 /*
     79  * Commands for swapctl(8).  These are mutually exclusive.
     80  */
     81 #define	CMD_A		0x01	/* process /etc/fstab for adding */
     82 #define	CMD_D		0x02	/* set dumpdev */
     83 #define	CMD_U		0x04	/* process /etc/fstab for removing */
     84 #define	CMD_a		0x08	/* add a swap file/device */
     85 #define	CMD_c		0x10	/* change priority of a swap file/device */
     86 #define	CMD_d		0x20	/* delete a swap file/device */
     87 #define	CMD_l		0x40	/* list swap files/devices */
     88 #define	CMD_s		0x80	/* summary of swap files/devices */
     89 #define	CMD_z		0x100	/* show dump device */
     90 
     91 #define	SET_COMMAND(cmd) \
     92 do { \
     93 	if (command) \
     94 		usage(); \
     95 	command = (cmd); \
     96 } while (0)
     97 
     98 /*
     99  * Commands that require a "path" argument at the end of the command
    100  * line, and the ones which require that none exist.
    101  */
    102 #define	REQUIRE_PATH	(CMD_D | CMD_a | CMD_c | CMD_d)
    103 #define	REQUIRE_NOPATH	(CMD_A | CMD_U | CMD_l | CMD_s | CMD_z)
    104 
    105 /*
    106  * Option flags, and the commands with which they are valid.
    107  */
    108 int	kflag;		/* display in 1K blocks */
    109 #define	KFLAG_CMDS	(CMD_l | CMD_s)
    110 
    111 int	pflag;		/* priority was specified */
    112 #define	PFLAG_CMDS	(CMD_A | CMD_a | CMD_c)
    113 
    114 char	*tflag;		/* swap device type (blk or noblk) */
    115 #define	TFLAG_CMDS	(CMD_A | CMD_U)
    116 
    117 int	pri;		/* uses 0 as default pri */
    118 
    119 static	void change_priority __P((const char *));
    120 static	int  add_swap __P((const char *, int));
    121 static	int  delete_swap __P((const char *));
    122 static	void set_dumpdev __P((const char *));
    123 static	void get_dumpdev __P((void));
    124 	int  main __P((int, char *[]));
    125 static	void do_fstab __P((int));
    126 static	void usage __P((void));
    127 static	void swapon_command __P((int, char **));
    128 #if 0
    129 static	void swapoff_command __P((int, char **));
    130 #endif
    131 
    132 int
    133 main(argc, argv)
    134 	int	argc;
    135 	char	*argv[];
    136 {
    137 	int	c;
    138 
    139 	if (strcmp(getprogname(), "swapon") == 0) {
    140 		swapon_command(argc, argv);
    141 		/* NOTREACHED */
    142 	}
    143 
    144 #if 0
    145 	if (strcmp(getprogname(), "swapoff") == 0) {
    146 		swapoff_command(argc, argv);
    147 		/* NOTREACHED */
    148 	}
    149 #endif
    150 
    151 	while ((c = getopt(argc, argv, "ADUacdlkp:st:z")) != -1) {
    152 		switch (c) {
    153 		case 'A':
    154 			SET_COMMAND(CMD_A);
    155 			break;
    156 
    157 		case 'D':
    158 			SET_COMMAND(CMD_D);
    159 			break;
    160 
    161 		case 'U':
    162 			SET_COMMAND(CMD_U);
    163 			break;
    164 
    165 		case 'a':
    166 			SET_COMMAND(CMD_a);
    167 			break;
    168 
    169 		case 'c':
    170 			SET_COMMAND(CMD_c);
    171 			break;
    172 
    173 		case 'd':
    174 			SET_COMMAND(CMD_d);
    175 			break;
    176 
    177 		case 'l':
    178 			SET_COMMAND(CMD_l);
    179 			break;
    180 
    181 		case 'k':
    182 			kflag = 1;
    183 			break;
    184 
    185 		case 'p':
    186 			pflag = 1;
    187 			/* XXX strtol() */
    188 			pri = atoi(optarg);
    189 			break;
    190 
    191 		case 's':
    192 			SET_COMMAND(CMD_s);
    193 			break;
    194 
    195 		case 't':
    196 			if (tflag != NULL)
    197 				usage();
    198 			tflag = optarg;
    199 			break;
    200 
    201 		case 'z':
    202 			SET_COMMAND(CMD_z);
    203 			break;
    204 
    205 		default:
    206 			usage();
    207 			/* NOTREACHED */
    208 		}
    209 	}
    210 
    211 	/* Did the user specify a command? */
    212 	if (command == 0)
    213 		usage();
    214 
    215 	argv += optind;
    216 	argc -= optind;
    217 
    218 	switch (argc) {
    219 	case 0:
    220 		if (command & REQUIRE_PATH)
    221 			usage();
    222 		break;
    223 
    224 	case 1:
    225 		if (command & REQUIRE_NOPATH)
    226 			usage();
    227 		break;
    228 
    229 	default:
    230 		usage();
    231 	}
    232 
    233 	/* To change priority, you have to specify one. */
    234 	if ((command == CMD_c) && pflag == 0)
    235 		usage();
    236 
    237 	/* Sanity-check -t */
    238 	if (tflag != NULL) {
    239 		if (command != CMD_A && command != CMD_U)
    240 			usage();
    241 		if (strcmp(tflag, "blk") != 0 &&
    242 		    strcmp(tflag, "noblk") != 0)
    243 			usage();
    244 	}
    245 
    246 	/* Dispatch the command. */
    247 	switch (command) {
    248 	case CMD_l:
    249 		list_swap(pri, kflag, pflag, 0, 1);
    250 		break;
    251 
    252 	case CMD_s:
    253 		list_swap(pri, kflag, pflag, 0, 0);
    254 		break;
    255 
    256 	case CMD_c:
    257 		change_priority(argv[0]);
    258 		break;
    259 
    260 	case CMD_a:
    261 		if (! add_swap(argv[0], pri))
    262 			exit(1);
    263 		break;
    264 
    265 	case CMD_d:
    266 		if (! delete_swap(argv[0]))
    267 			exit(1);
    268 		break;
    269 
    270 	case CMD_A:
    271 		do_fstab(1);
    272 		break;
    273 
    274 	case CMD_D:
    275 		set_dumpdev(argv[0]);
    276 		break;
    277 
    278 	case CMD_z:
    279 		get_dumpdev();
    280 		break;
    281 
    282 	case CMD_U:
    283 		do_fstab(0);
    284 		break;
    285 	}
    286 
    287 	exit(0);
    288 }
    289 
    290 /*
    291  * swapon_command: emulate the old swapon(8) program.
    292  */
    293 static void
    294 swapon_command(argc, argv)
    295 	int argc;
    296 	char **argv;
    297 {
    298 	int ch, fiztab = 0;
    299 
    300 	while ((ch = getopt(argc, argv, "at:")) != -1) {
    301 		switch (ch) {
    302 		case 'a':
    303 			fiztab = 1;
    304 			break;
    305 		case 't':
    306 			if (tflag != NULL)
    307 				usage();
    308 			tflag = optarg;
    309 			break;
    310 		default:
    311 			goto swapon_usage;
    312 		}
    313 	}
    314 	argc -= optind;
    315 	argv += optind;
    316 
    317 	if (fiztab) {
    318 		if (argc)
    319 			goto swapon_usage;
    320 		/* Sanity-check -t */
    321 		if (tflag != NULL) {
    322 			if (strcmp(tflag, "blk") != 0 &&
    323 			    strcmp(tflag, "noblk") != 0)
    324 				usage();
    325 		}
    326 		do_fstab(1);
    327 		exit(0);
    328 	} else if (argc == 0 || tflag != NULL)
    329 		goto swapon_usage;
    330 
    331 	while (argc) {
    332 		if (! add_swap(argv[0], pri))
    333 			exit(1);
    334 		argc--;
    335 		argv++;
    336 	}
    337 	exit(0);
    338 	/* NOTREACHED */
    339 
    340  swapon_usage:
    341 	fprintf(stderr, "usage: %s -a [-t blk|noblk]\n", getprogname());
    342 	fprintf(stderr, "       %s <path> ...\n", getprogname());
    343 	exit(1);
    344 }
    345 
    346 /*
    347  * change_priority:  change the priority of a swap device.
    348  */
    349 static void
    350 change_priority(path)
    351 	const char	*path;
    352 {
    353 
    354 	if (swapctl(SWAP_CTL, path, pri) < 0)
    355 		warn("%s", path);
    356 }
    357 
    358 /*
    359  * add_swap:  add the pathname to the list of swap devices.
    360  */
    361 static int
    362 add_swap(path, priority)
    363 	const char *path;
    364 	int priority;
    365 {
    366 	struct stat sb;
    367 
    368 	if (stat(path, &sb) < 0)
    369 		goto oops;
    370 
    371 	if (sb.st_mode & S_IROTH)
    372 		warnx("WARNING: %s is readable by the world", path);
    373 	if (sb.st_mode & S_IWOTH)
    374 		warnx("WARNING: %s is writable by the world", path);
    375 
    376 	if (swapctl(SWAP_ON, path, priority) < 0) {
    377 oops:
    378 		warn("%s", path);
    379 		return (0);
    380 	}
    381 	return (1);
    382 }
    383 
    384 /*
    385  * delete_swap:  remove the pathname to the list of swap devices.
    386  */
    387 static int
    388 delete_swap(path)
    389 	const char *path;
    390 {
    391 
    392 	if (swapctl(SWAP_OFF, path, pri) < 0) {
    393 		warn("%s", path);
    394 		return (0);
    395 	}
    396 	return (1);
    397 }
    398 
    399 static void
    400 set_dumpdev(path)
    401 	const char *path;
    402 {
    403 
    404 	if (swapctl(SWAP_DUMPDEV, path, 0) == -1)
    405 		warn("could not set dump device to %s", path);
    406 	else
    407 		printf("%s: setting dump device to %s\n", getprogname(), path);
    408 }
    409 
    410 static void
    411 get_dumpdev()
    412 {
    413 	dev_t	dev;
    414 	char 	*name;
    415 
    416 	if (swapctl(SWAP_GETDUMPDEV, &dev, 0) == -1)
    417 		warn("could not get dump device");
    418 	else if (dev == NODEV)
    419 		printf("no dump device set\n");
    420 	else {
    421 		name = devname(dev, S_IFBLK);
    422 		printf("dump device is ");
    423 		if (name)
    424 			printf("%s\n", name);
    425 		else
    426 			printf("major %d minor %d\n", major(dev), minor(dev));
    427 	}
    428 }
    429 
    430 static void
    431 do_fstab(add)
    432 	int add;
    433 {
    434 	struct	fstab *fp;
    435 	char	*s;
    436 	long	priority;
    437 	struct	stat st;
    438 	int	isblk;
    439 	int	gotone = 0;
    440 #define PATH_MOUNT	"/sbin/mount_nfs"
    441 #define PATH_UMOUNT	"/sbin/umount"
    442 	char	cmd[2*PATH_MAX+sizeof(PATH_MOUNT)+2];
    443 
    444 #define PRIORITYEQ	"priority="
    445 #define NFSMNTPT	"nfsmntpt="
    446 	while ((fp = getfsent()) != NULL) {
    447 		const char *spec;
    448 
    449 		spec = fp->fs_spec;
    450 		cmd[0] = '\0';
    451 
    452 		if (strcmp(fp->fs_type, "dp") == 0 && add) {
    453 			set_dumpdev(spec);
    454 			continue;
    455 		}
    456 
    457 		if (strcmp(fp->fs_type, "sw") != 0)
    458 			continue;
    459 
    460 		/* handle dp as mnt option */
    461 		if (strstr(fp->fs_mntops, "dp") && add)
    462 			set_dumpdev(spec);
    463 
    464 		isblk = 0;
    465 
    466 		if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
    467 			s += sizeof(PRIORITYEQ) - 1;
    468 			priority = atol(s);
    469 		} else
    470 			priority = pri;
    471 
    472 		if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
    473 			char *t;
    474 
    475 			/*
    476 			 * Skip this song and dance if we're only
    477 			 * doing block devices.
    478 			 */
    479 			if (tflag != NULL && strcmp(tflag, "blk") == 0)
    480 				continue;
    481 
    482 			t = strpbrk(s, ",");
    483 			if (t != 0)
    484 				*t = '\0';
    485 			spec = strdup(s + strlen(NFSMNTPT));
    486 			if (t != 0)
    487 				*t = ',';
    488 
    489 			if (spec == NULL)
    490 				errx(1, "Out of memory");
    491 
    492 			if (strlen(spec) == 0) {
    493 				warnx("empty mountpoint");
    494 				free((char *)spec);
    495 				continue;
    496 			}
    497 			if (add) {
    498 				snprintf(cmd, sizeof(cmd), "%s %s %s",
    499 					PATH_MOUNT, fp->fs_spec, spec);
    500 				if (system(cmd) != 0) {
    501 					warnx("%s: mount failed", fp->fs_spec);
    502 					continue;
    503 				}
    504 			} else {
    505 				snprintf(cmd, sizeof(cmd), "%s %s",
    506 					PATH_UMOUNT, fp->fs_spec);
    507 			}
    508 		} else {
    509 			/*
    510 			 * Determine blk-ness.
    511 			 */
    512 			if (stat(spec, &st) < 0) {
    513 				warn("%s", spec);
    514 				continue;
    515 			}
    516 			if (S_ISBLK(st.st_mode))
    517 				isblk = 1;
    518 		}
    519 
    520 		/*
    521 		 * Skip this type if we're told to.
    522 		 */
    523 		if (tflag != NULL) {
    524 			if (strcmp(tflag, "blk") == 0 && isblk == 0)
    525 				continue;
    526 			if (strcmp(tflag, "noblk") == 0 && isblk == 1)
    527 				continue;
    528 		}
    529 
    530 		if (add) {
    531 			if (add_swap(spec, (int)priority)) {
    532 				gotone = 1;
    533 				printf(
    534 			    	"%s: adding %s as swap device at priority %d\n",
    535 				    getprogname(), fp->fs_spec, (int)priority);
    536 			}
    537 		} else {
    538 			if (delete_swap(spec)) {
    539 				gotone = 1;
    540 				printf(
    541 				    "%s: removing %s as swap device\n",
    542 				    getprogname(), fp->fs_spec);
    543 			}
    544 			if (cmd[0]) {
    545 				if (system(cmd) != 0) {
    546 					warnx("%s: umount failed", fp->fs_spec);
    547 					continue;
    548 				}
    549 			}
    550 		}
    551 
    552 		if (spec != fp->fs_spec)
    553 			free((char *)spec);
    554 	}
    555 	if (gotone == 0)
    556 		exit(1);
    557 }
    558 
    559 static void
    560 usage()
    561 {
    562 	const char *progname = getprogname();
    563 
    564 	fprintf(stderr, "usage: %s -A [-p priority] [-t blk|noblk]\n",
    565 	    progname);
    566 	fprintf(stderr, "       %s -D dumppath\n", progname);
    567 	fprintf(stderr, "       %s -U [-t blk|noblk]\n", progname);
    568 	fprintf(stderr, "       %s -a [-p priority] path\n", progname);
    569 	fprintf(stderr, "       %s -c -p priority path\n", progname);
    570 	fprintf(stderr, "       %s -d path\n", progname);
    571 	fprintf(stderr, "       %s -l | -s [-k]\n", progname);
    572 	exit(1);
    573 }
    574