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swapctl.c revision 1.29 
      1 /*	$NetBSD: swapctl.c,v 1.29 2005/06/12 16:24:20 christos 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  *	-g		use gigabytes
     43  *	-h		use humanize_number(3) for listing
     44  *	-l		list swap devices
     45  *	-m		use megabytes
     46  *	-s		short listing of swap devices
     47  *	-k		use kilobytes
     48  *	-p <pri>	use this priority
     49  *	-c		change priority
     50  *
     51  * or, if invoked as "swapon" (compatibility mode):
     52  *
     53  *	-a		all devices listed as `sw' in /etc/fstab
     54  *	-t		same as -t above (feature not present in old
     55  *			swapon(8) command)
     56  *	<dev>		add this device
     57  */
     58 #include <sys/cdefs.h>
     59 
     60 #ifndef lint
     61 __RCSID("$NetBSD: swapctl.c,v 1.29 2005/06/12 16:24:20 christos Exp $");
     62 #endif
     63 
     64 
     65 #include <sys/param.h>
     66 #include <sys/stat.h>
     67 #include <sys/swap.h>
     68 
     69 #include <unistd.h>
     70 #include <err.h>
     71 #include <errno.h>
     72 #include <stdio.h>
     73 #include <stdlib.h>
     74 #include <string.h>
     75 #include <fstab.h>
     76 
     77 #include "swapctl.h"
     78 
     79 int	command;
     80 
     81 /*
     82  * Commands for swapctl(8).  These are mutually exclusive.
     83  */
     84 #define	CMD_A		0x01	/* process /etc/fstab for adding */
     85 #define	CMD_D		0x02	/* set dumpdev */
     86 #define	CMD_U		0x04	/* process /etc/fstab for removing */
     87 #define	CMD_a		0x08	/* add a swap file/device */
     88 #define	CMD_c		0x10	/* change priority of a swap file/device */
     89 #define	CMD_d		0x20	/* delete a swap file/device */
     90 #define	CMD_l		0x40	/* list swap files/devices */
     91 #define	CMD_s		0x80	/* summary of swap files/devices */
     92 #define	CMD_z		0x100	/* show dump device */
     93 
     94 #define	SET_COMMAND(cmd) \
     95 do { \
     96 	if (command) \
     97 		usage(); \
     98 	command = (cmd); \
     99 } while (0)
    100 
    101 /*
    102  * Commands that require a "path" argument at the end of the command
    103  * line, and the ones which require that none exist.
    104  */
    105 #define	REQUIRE_PATH	(CMD_D | CMD_a | CMD_c | CMD_d)
    106 #define	REQUIRE_NOPATH	(CMD_A | CMD_U | CMD_l | CMD_s | CMD_z)
    107 
    108 /*
    109  * Option flags, and the commands with which they are valid.
    110  */
    111 int	kflag;		/* display in 1K^x blocks */
    112 #define	KFLAG_CMDS	(CMD_l | CMD_s)
    113 #define MFLAG_CMDS	(CMD_l | CMD_s)
    114 #define GFLAG_CMDS	(CMD_l | CMD_s)
    115 
    116 int	hflag;		/* display with humanize_number */
    117 #define HFLAG_CMDS	(CMD_l | CMD_s)
    118 
    119 int	pflag;		/* priority was specified */
    120 #define	PFLAG_CMDS	(CMD_A | CMD_a | CMD_c)
    121 
    122 char	*tflag;		/* swap device type (blk or noblk) */
    123 #define	TFLAG_CMDS	(CMD_A | CMD_U)
    124 
    125 int	pri;		/* uses 0 as default pri */
    126 
    127 static	void change_priority(char *);
    128 static	int  add_swap(char *, int);
    129 static	int  delete_swap(char *);
    130 static	void set_dumpdev(char *);
    131 static	void get_dumpdev(void);
    132 static	void do_fstab(int);
    133 static	void usage(void);
    134 static	void swapon_command(int, char **);
    135 #if 0
    136 static	void swapoff_command(int, char **);
    137 #endif
    138 
    139 int
    140 main(int argc, char *argv[])
    141 {
    142 	int	c;
    143 
    144 	if (strcmp(getprogname(), "swapon") == 0) {
    145 		swapon_command(argc, argv);
    146 		/* NOTREACHED */
    147 	}
    148 
    149 #if 0
    150 	if (strcmp(getprogname(), "swapoff") == 0) {
    151 		swapoff_command(argc, argv);
    152 		/* NOTREACHED */
    153 	}
    154 #endif
    155 
    156 	while ((c = getopt(argc, argv, "ADUacdghklmp:st:z")) != -1) {
    157 		switch (c) {
    158 		case 'A':
    159 			SET_COMMAND(CMD_A);
    160 			break;
    161 
    162 		case 'D':
    163 			SET_COMMAND(CMD_D);
    164 			break;
    165 
    166 		case 'U':
    167 			SET_COMMAND(CMD_U);
    168 			break;
    169 
    170 		case 'a':
    171 			SET_COMMAND(CMD_a);
    172 			break;
    173 
    174 		case 'c':
    175 			SET_COMMAND(CMD_c);
    176 			break;
    177 
    178 		case 'd':
    179 			SET_COMMAND(CMD_d);
    180 			break;
    181 
    182 		case 'g':
    183 			kflag = 3; /* 1k ^ 3 */
    184 			break;
    185 
    186 		case 'h':
    187 			hflag = 1;
    188 			break;
    189 
    190 		case 'k':
    191 			kflag = 1;
    192 			break;
    193 
    194 		case 'l':
    195 			SET_COMMAND(CMD_l);
    196 			break;
    197 
    198 		case 'm':
    199 			kflag = 2; /* 1k ^ 2 */
    200 			break;
    201 
    202 		case 'p':
    203 			pflag = 1;
    204 			/* XXX strtol() */
    205 			pri = atoi(optarg);
    206 			break;
    207 
    208 		case 's':
    209 			SET_COMMAND(CMD_s);
    210 			break;
    211 
    212 		case 't':
    213 			if (tflag != NULL)
    214 				usage();
    215 			tflag = optarg;
    216 			break;
    217 
    218 		case 'z':
    219 			SET_COMMAND(CMD_z);
    220 			break;
    221 
    222 		default:
    223 			usage();
    224 			/* NOTREACHED */
    225 		}
    226 	}
    227 
    228 	/* Did the user specify a command? */
    229 	if (command == 0)
    230 		usage();
    231 
    232 	argv += optind;
    233 	argc -= optind;
    234 
    235 	switch (argc) {
    236 	case 0:
    237 		if (command & REQUIRE_PATH)
    238 			usage();
    239 		break;
    240 
    241 	case 1:
    242 		if (command & REQUIRE_NOPATH)
    243 			usage();
    244 		break;
    245 
    246 	default:
    247 		usage();
    248 	}
    249 
    250 	/* To change priority, you have to specify one. */
    251 	if ((command == CMD_c) && pflag == 0)
    252 		usage();
    253 
    254 	/* Sanity-check -t */
    255 	if (tflag != NULL) {
    256 		if (command != CMD_A && command != CMD_U)
    257 			usage();
    258 		if (strcmp(tflag, "blk") != 0 &&
    259 		    strcmp(tflag, "noblk") != 0)
    260 			usage();
    261 	}
    262 
    263 	/* Dispatch the command. */
    264 	switch (command) {
    265 	case CMD_l:
    266 		list_swap(pri, kflag, pflag, 0, 1, hflag);
    267 		break;
    268 
    269 	case CMD_s:
    270 		list_swap(pri, kflag, pflag, 0, 0, hflag);
    271 		break;
    272 
    273 	case CMD_c:
    274 		change_priority(argv[0]);
    275 		break;
    276 
    277 	case CMD_a:
    278 		if (! add_swap(argv[0], pri))
    279 			exit(1);
    280 		break;
    281 
    282 	case CMD_d:
    283 		if (! delete_swap(argv[0]))
    284 			exit(1);
    285 		break;
    286 
    287 	case CMD_A:
    288 		do_fstab(1);
    289 		break;
    290 
    291 	case CMD_D:
    292 		set_dumpdev(argv[0]);
    293 		break;
    294 
    295 	case CMD_z:
    296 		get_dumpdev();
    297 		break;
    298 
    299 	case CMD_U:
    300 		do_fstab(0);
    301 		break;
    302 	}
    303 
    304 	exit(0);
    305 }
    306 
    307 /*
    308  * swapon_command: emulate the old swapon(8) program.
    309  */
    310 static void
    311 swapon_command(int argc, char **argv)
    312 {
    313 	int ch, fiztab = 0;
    314 
    315 	while ((ch = getopt(argc, argv, "at:")) != -1) {
    316 		switch (ch) {
    317 		case 'a':
    318 			fiztab = 1;
    319 			break;
    320 		case 't':
    321 			if (tflag != NULL)
    322 				usage();
    323 			tflag = optarg;
    324 			break;
    325 		default:
    326 			goto swapon_usage;
    327 		}
    328 	}
    329 	argc -= optind;
    330 	argv += optind;
    331 
    332 	if (fiztab) {
    333 		if (argc)
    334 			goto swapon_usage;
    335 		/* Sanity-check -t */
    336 		if (tflag != NULL) {
    337 			if (strcmp(tflag, "blk") != 0 &&
    338 			    strcmp(tflag, "noblk") != 0)
    339 				usage();
    340 		}
    341 		do_fstab(1);
    342 		exit(0);
    343 	} else if (argc == 0 || tflag != NULL)
    344 		goto swapon_usage;
    345 
    346 	while (argc) {
    347 		if (! add_swap(argv[0], pri))
    348 			exit(1);
    349 		argc--;
    350 		argv++;
    351 	}
    352 	exit(0);
    353 	/* NOTREACHED */
    354 
    355  swapon_usage:
    356 	fprintf(stderr, "usage: %s -a [-t blk|noblk]\n", getprogname());
    357 	fprintf(stderr, "       %s <path> ...\n", getprogname());
    358 	exit(1);
    359 }
    360 
    361 /*
    362  * change_priority:  change the priority of a swap device.
    363  */
    364 static void
    365 change_priority(char *path)
    366 {
    367 
    368 	if (swapctl(SWAP_CTL, path, pri) < 0)
    369 		warn("%s", path);
    370 }
    371 
    372 /*
    373  * add_swap:  add the pathname to the list of swap devices.
    374  */
    375 static int
    376 add_swap(char *path, int priority)
    377 {
    378 	struct stat sb;
    379 
    380 	if (stat(path, &sb) < 0)
    381 		goto oops;
    382 
    383 	if (sb.st_mode & S_IROTH)
    384 		warnx("WARNING: %s is readable by the world", path);
    385 	if (sb.st_mode & S_IWOTH)
    386 		warnx("WARNING: %s is writable by the world", path);
    387 
    388 	if (swapctl(SWAP_ON, path, priority) < 0) {
    389 oops:
    390 		warn("%s", path);
    391 		return (0);
    392 	}
    393 	return (1);
    394 }
    395 
    396 /*
    397  * delete_swap:  remove the pathname to the list of swap devices.
    398  */
    399 static int
    400 delete_swap(char *path)
    401 {
    402 
    403 	if (swapctl(SWAP_OFF, path, pri) < 0) {
    404 		warn("%s", path);
    405 		return (0);
    406 	}
    407 	return (1);
    408 }
    409 
    410 static void
    411 set_dumpdev(char *path)
    412 {
    413 
    414 	if (swapctl(SWAP_DUMPDEV, path, 0) == -1)
    415 		warn("could not set dump device to %s", path);
    416 	else
    417 		printf("%s: setting dump device to %s\n", getprogname(), path);
    418 }
    419 
    420 static void
    421 get_dumpdev(void)
    422 {
    423 	dev_t	dev;
    424 	char 	*name;
    425 
    426 	if (swapctl(SWAP_GETDUMPDEV, &dev, 0) == -1)
    427 		warn("could not get dump device");
    428 	else if (dev == NODEV)
    429 		printf("no dump device set\n");
    430 	else {
    431 		name = devname(dev, S_IFBLK);
    432 		printf("dump device is ");
    433 		if (name)
    434 			printf("%s\n", name);
    435 		else
    436 			printf("major %d minor %d\n", major(dev), minor(dev));
    437 	}
    438 }
    439 
    440 static void
    441 do_fstab(int add)
    442 {
    443 	struct	fstab *fp;
    444 	char	*s;
    445 	long	priority;
    446 	struct	stat st;
    447 	int	isblk;
    448 	int	gotone = 0;
    449 
    450 #ifdef RESCUEDIR
    451 #define PATH_MOUNT	RESCUEDIR "/mount_nfs"
    452 #define PATH_UMOUNT	RESCUEDIR "/umount"
    453 #else
    454 #define PATH_MOUNT	"/sbin/mount_nfs"
    455 #define PATH_UMOUNT	"/sbin/umount"
    456 #endif
    457 
    458 	char	cmd[2*PATH_MAX+sizeof(PATH_MOUNT)+2];
    459 
    460 #define PRIORITYEQ	"priority="
    461 #define NFSMNTPT	"nfsmntpt="
    462 	while ((fp = getfsent()) != NULL) {
    463 		char *spec;
    464 
    465 		spec = fp->fs_spec;
    466 		cmd[0] = '\0';
    467 
    468 		if (strcmp(fp->fs_type, "dp") == 0 && add) {
    469 			set_dumpdev(spec);
    470 			continue;
    471 		}
    472 
    473 		if (strcmp(fp->fs_type, "sw") != 0)
    474 			continue;
    475 
    476 		/* handle dp as mnt option */
    477 		if (strstr(fp->fs_mntops, "dp") && add)
    478 			set_dumpdev(spec);
    479 
    480 		isblk = 0;
    481 
    482 		if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
    483 			s += sizeof(PRIORITYEQ) - 1;
    484 			priority = atol(s);
    485 		} else
    486 			priority = pri;
    487 
    488 		if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
    489 			char *t;
    490 
    491 			/*
    492 			 * Skip this song and dance if we're only
    493 			 * doing block devices.
    494 			 */
    495 			if (tflag != NULL && strcmp(tflag, "blk") == 0)
    496 				continue;
    497 
    498 			t = strpbrk(s, ",");
    499 			if (t != 0)
    500 				*t = '\0';
    501 			spec = strdup(s + strlen(NFSMNTPT));
    502 			if (t != 0)
    503 				*t = ',';
    504 
    505 			if (spec == NULL)
    506 				errx(1, "Out of memory");
    507 
    508 			if (strlen(spec) == 0) {
    509 				warnx("empty mountpoint");
    510 				free(spec);
    511 				continue;
    512 			}
    513 			if (add) {
    514 				snprintf(cmd, sizeof(cmd), "%s %s %s",
    515 					PATH_MOUNT, fp->fs_spec, spec);
    516 				if (system(cmd) != 0) {
    517 					warnx("%s: mount failed", fp->fs_spec);
    518 					continue;
    519 				}
    520 			} else {
    521 				snprintf(cmd, sizeof(cmd), "%s %s",
    522 					PATH_UMOUNT, fp->fs_spec);
    523 			}
    524 		} else {
    525 			/*
    526 			 * Determine blk-ness.
    527 			 */
    528 			if (stat(spec, &st) < 0) {
    529 				warn("%s", spec);
    530 				continue;
    531 			}
    532 			if (S_ISBLK(st.st_mode))
    533 				isblk = 1;
    534 		}
    535 
    536 		/*
    537 		 * Skip this type if we're told to.
    538 		 */
    539 		if (tflag != NULL) {
    540 			if (strcmp(tflag, "blk") == 0 && isblk == 0)
    541 				continue;
    542 			if (strcmp(tflag, "noblk") == 0 && isblk == 1)
    543 				continue;
    544 		}
    545 
    546 		if (add) {
    547 			if (add_swap(spec, (int)priority)) {
    548 				gotone = 1;
    549 				printf(
    550 			    	"%s: adding %s as swap device at priority %d\n",
    551 				    getprogname(), fp->fs_spec, (int)priority);
    552 			}
    553 		} else {
    554 			if (delete_swap(spec)) {
    555 				gotone = 1;
    556 				printf(
    557 				    "%s: removing %s as swap device\n",
    558 				    getprogname(), fp->fs_spec);
    559 			}
    560 			if (cmd[0]) {
    561 				if (system(cmd) != 0) {
    562 					warnx("%s: umount failed", fp->fs_spec);
    563 					continue;
    564 				}
    565 			}
    566 		}
    567 
    568 		if (spec != fp->fs_spec)
    569 			free(spec);
    570 	}
    571 	if (gotone == 0)
    572 		exit(1);
    573 }
    574 
    575 static void
    576 usage(void)
    577 {
    578 	const char *progname = getprogname();
    579 
    580 	fprintf(stderr, "usage: %s -A [-p priority] [-t blk|noblk]\n",
    581 	    progname);
    582 	fprintf(stderr, "       %s -D dumppath\n", progname);
    583 	fprintf(stderr, "       %s -U [-t blk|noblk]\n", progname);
    584 	fprintf(stderr, "       %s -a [-p priority] path\n", progname);
    585 	fprintf(stderr, "       %s -c -p priority path\n", progname);
    586 	fprintf(stderr, "       %s -d path\n", progname);
    587 	fprintf(stderr, "       %s -l | -s [-k|-m|-g|-h]\n", progname);
    588 	fprintf(stderr, "       %s -z\n", progname);
    589 	exit(1);
    590 }
    591