xref: /openbsd-src/sbin/swapctl/swapctl.c (revision b2ea75c1b17e1a9a339660e7ed45cd24946b230e)
1 /*	$OpenBSD: swapctl.c,v 1.6 2001/06/04 14:59:50 mickey Exp $	*/
2 /*	$NetBSD: swapctl.c,v 1.9 1998/07/26 20:23:15 mycroft Exp $	*/
3 
4 /*
5  * Copyright (c) 1996, 1997 Matthew R. Green
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 /*
33  * swapctl command:
34  *	-A		add all devices listed as `sw' in /etc/fstab
35  *	-t [blk|noblk]	if -A, add either all block device or all non-block
36  *			devices
37  *	-a <dev>	add this device
38  *	-d <dev>	remove this swap device (not supported yet)
39  *	-l		list swap devices
40  *	-s		short listing of swap devices
41  *	-k		use kilobytes
42  *	-p <pri>	use this priority
43  *	-c		change priority
44  *
45  * or, if invoked as "swapon" (compatibility mode):
46  *
47  *	-a		all devices listed as `sw' in /etc/fstab
48  *	-t		same as -t above (feature not present in old
49  *			swapon(8) command)
50  *	<dev>		add this device
51  */
52 
53 #include <sys/param.h>
54 #include <sys/stat.h>
55 
56 #include <sys/swap.h>
57 
58 #include <unistd.h>
59 #include <err.h>
60 #include <errno.h>
61 #include <stdio.h>
62 #include <stdlib.h>
63 #include <string.h>
64 #include <fstab.h>
65 
66 #include "swapctl.h"
67 
68 int	command;
69 
70 /*
71  * Commands for swapctl(8).  These are mutually exclusive.
72  */
73 #define	CMD_A		0x01	/* process /etc/fstab */
74 #define	CMD_a		0x02	/* add a swap file/device */
75 #define	CMD_c		0x04	/* change priority of a swap file/device */
76 #define	CMD_d		0x08	/* delete a swap file/device */
77 #define	CMD_l		0x10	/* list swap files/devices */
78 #define	CMD_s		0x20	/* summary of swap files/devices */
79 
80 #define	SET_COMMAND(cmd) \
81 do { \
82 	if (command) \
83 		usage(); \
84 	command = (cmd); \
85 } while (0)
86 
87 /*
88  * Commands that require a "path" argument at the end of the command
89  * line, and the ones which require that none exist.
90  */
91 #define	REQUIRE_PATH	(CMD_a | CMD_c | CMD_d)
92 #define	REQUIRE_NOPATH	(CMD_A | CMD_l | CMD_s)
93 
94 /*
95  * Option flags, and the commands with which they are valid.
96  */
97 int	kflag;		/* display in 1K blocks */
98 #define	KFLAG_CMDS	(CMD_l | CMD_s)
99 
100 int	pflag;		/* priority was specified */
101 #define	PFLAG_CMDS	(CMD_A | CMD_a | CMD_c)
102 
103 char	*tflag;		/* swap device type (blk or noblk) */
104 #define	TFLAG_CMDS	(CMD_A)
105 
106 int	pri;		/* uses 0 as default pri */
107 
108 static	void change_priority __P((char *));
109 static	void add_swap __P((char *));
110 static	void del_swap __P((char *));
111 	int  main __P((int, char *[]));
112 static	void do_fstab __P((void));
113 static	void usage __P((void));
114 static	int  swapon_command __P((int, char **));
115 #if 0
116 static	void swapoff_command __P((int, char **));
117 #endif
118 
119 extern	char *__progname;	/* from crt0.o */
120 
121 int
122 main(argc, argv)
123 	int	argc;
124 	char	*argv[];
125 {
126 	int	c;
127 
128 	if (strcmp(__progname, "swapon") == 0)
129 		return swapon_command(argc, argv);
130 
131 #if 0
132 	if (strcmp(__progname, "swapoff") == 0) {
133 		swapoff_command(argc, argv);
134 		/* NOTREACHED */
135 	}
136 #endif
137 
138 	while ((c = getopt(argc, argv, "Aacdlkp:st:")) != -1) {
139 		switch (c) {
140 		case 'A':
141 			SET_COMMAND(CMD_A);
142 			break;
143 
144 		case 'a':
145 			SET_COMMAND(CMD_a);
146 			break;
147 
148 		case 'c':
149 			SET_COMMAND(CMD_c);
150 			break;
151 
152 		case 'd':
153 			SET_COMMAND(CMD_d);
154 			break;
155 
156 		case 'l':
157 			SET_COMMAND(CMD_l);
158 			break;
159 
160 		case 'k':
161 			kflag = 1;
162 			break;
163 
164 		case 'p':
165 			pflag = 1;
166 			/* XXX strtol() */
167 			pri = atoi(optarg);
168 			break;
169 
170 		case 's':
171 			SET_COMMAND(CMD_s);
172 			break;
173 
174 		case 't':
175 			if (tflag != NULL)
176 				usage();
177 			tflag = optarg;
178 			break;
179 
180 		default:
181 			usage();
182 			/* NOTREACHED */
183 		}
184 	}
185 
186 	/* Did the user specify a command? */
187 	if (command == 0)
188 		usage();
189 
190 	argv += optind;
191 	argc -= optind;
192 
193 	switch (argc) {
194 	case 0:
195 		if (command & REQUIRE_PATH)
196 			usage();
197 		break;
198 
199 	case 1:
200 		if (command & REQUIRE_NOPATH)
201 			usage();
202 		break;
203 
204 	default:
205 		usage();
206 	}
207 
208 	/* To change priority, you have to specify one. */
209 	if ((command == CMD_c) && pflag == 0)
210 		usage();
211 
212 	/* Sanity-check -t */
213 	if (tflag != NULL) {
214 		if (command != CMD_A)
215 			usage();
216 		if (strcmp(tflag, "blk") != 0 &&
217 		    strcmp(tflag, "noblk") != 0)
218 			usage();
219 	}
220 
221 	/* Dispatch the command. */
222 	switch (command) {
223 	case CMD_l:
224 		list_swap(pri, kflag, pflag, 0, 1);
225 		break;
226 
227 	case CMD_s:
228 		list_swap(pri, kflag, pflag, 0, 0);
229 		break;
230 
231 	case CMD_c:
232 		change_priority(argv[0]);
233 		break;
234 
235 	case CMD_a:
236 		add_swap(argv[0]);
237 		break;
238 
239 	case CMD_d:
240 		del_swap(argv[0]);
241 		break;
242 
243 	case CMD_A:
244 		do_fstab();
245 		break;
246 	}
247 
248 	return (0);
249 }
250 
251 /*
252  * swapon_command: emulate the old swapon(8) program.
253  */
254 int
255 swapon_command(argc, argv)
256 	int argc;
257 	char **argv;
258 {
259 	int ch, fiztab = 0;
260 
261 	while ((ch = getopt(argc, argv, "at:")) != -1) {
262 		switch (ch) {
263 		case 'a':
264 			fiztab = 1;
265 			break;
266 		case 't':
267 			if (tflag != NULL)
268 				usage();
269 			tflag = optarg;
270 			break;
271 		default:
272 			goto swapon_usage;
273 		}
274 	}
275 	argc -= optind;
276 	argv += optind;
277 
278 	if (fiztab) {
279 		if (argc)
280 			goto swapon_usage;
281 		/* Sanity-check -t */
282 		if (tflag != NULL) {
283 			if (strcmp(tflag, "blk") != 0 &&
284 			    strcmp(tflag, "noblk") != 0)
285 				usage();
286 		}
287 		do_fstab();
288 		return (0);
289 	} else if (argc == 0 || tflag != NULL)
290 		goto swapon_usage;
291 
292 	while (argc) {
293 		add_swap(argv[0]);
294 		argc--;
295 		argv++;
296 	}
297 	return (0);
298 
299  swapon_usage:
300 	fprintf(stderr, "usage: %s -a [-t blk|noblk]\n"
301 			"       %s <path> ...\n",
302 	    __progname, __progname);
303 	return (1);
304 }
305 
306 /*
307  * change_priority:  change the priority of a swap device.
308  */
309 void
310 change_priority(path)
311 	char	*path;
312 {
313 
314 	if (swapctl(SWAP_CTL, path, pri) < 0)
315 		warn("%s", path);
316 }
317 
318 /*
319  * add_swap:  add the pathname to the list of swap devices.
320  */
321 void
322 add_swap(path)
323 	char *path;
324 {
325 
326 	if (swapctl(SWAP_ON, path, pri) < 0)
327 		if (errno != EBUSY)
328 			err(1, "%s", path);
329 }
330 
331 /*
332  * del_swap:  remove the pathname to the list of swap devices.
333  */
334 void
335 del_swap(path)
336 	char *path;
337 {
338 
339 	if (swapctl(SWAP_OFF, path, pri) < 0)
340 		err(1, "%s", path);
341 }
342 
343 void
344 do_fstab()
345 {
346 	struct	fstab *fp;
347 	char	*s;
348 	long	priority;
349 	struct	stat st;
350 	mode_t	rejecttype;
351 	int	gotone = 0;
352 
353 	/*
354 	 * Select which mount point types to reject, depending on the
355 	 * value of the -t parameter.
356 	 */
357 	if (tflag != NULL) {
358 		if (strcmp(tflag, "blk") == 0)
359 			rejecttype = S_IFREG;
360 		else if (strcmp(tflag, "noblk") == 0)
361 			rejecttype = S_IFBLK;
362 	} else
363 		rejecttype = 0;
364 
365 #define PRIORITYEQ	"priority="
366 #define NFSMNTPT	"nfsmntpt="
367 #define PATH_MOUNT	"/sbin/mount_nfs"
368 	while ((fp = getfsent()) != NULL) {
369 		const char *spec;
370 
371 		if (strcmp(fp->fs_type, "sw") != 0)
372 			continue;
373 
374 		spec = fp->fs_spec;
375 
376 		if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
377 			s += sizeof(PRIORITYEQ) - 1;
378 			priority = atol(s);
379 		} else
380 			priority = pri;
381 
382 		if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
383 			char *t, cmd[strlen(PATH_MOUNT)+1+PATH_MAX+1+PATH_MAX+1];
384 
385 			/*
386 			 * Skip this song and dance if we're only
387 			 * doing block devices.
388 			 */
389 			if (rejecttype == S_IFREG)
390 				continue;
391 
392 			t = strpbrk(s, ",");
393 			if (t != 0)
394 				*t = '\0';
395 			spec = strdup(s + strlen(NFSMNTPT));
396 			if (t != 0)
397 				*t = ',';
398 
399 			if (spec == NULL)
400 				errx(1, "Out of memory");
401 
402 			if (strlen(spec) == 0) {
403 				warnx("empty mountpoint");
404 				free((char *)spec);
405 				continue;
406 			}
407 			snprintf(cmd, sizeof(cmd), "%s %s %s",
408 			    PATH_MOUNT, fp->fs_spec, spec);
409 			if (system(cmd) != 0) {
410 				warnx("%s: mount failed", fp->fs_spec);
411 				continue;
412 			}
413 		} else {
414 			/*
415 			 * Determine blk-ness.  Don't even consider a
416 			 * mountpoint outside /dev as a block device.
417 			 */
418 			if (rejecttype == S_IFREG) {
419 				if (strncmp("/dev/", spec, 5) != 0)
420 					continue;
421 			}
422 			if (stat(spec, &st) < 0) {
423 				warn("%s", spec);
424 				continue;
425 			}
426 			if ((st.st_mode & S_IFMT) == rejecttype)
427 				continue;
428 
429 			/*
430 			 * Do not allow fancy objects to be swap areas.
431 			 */
432 			if (!S_ISREG(st.st_mode) &&
433 			    !S_ISBLK(st.st_mode))
434 				continue;
435 		}
436 
437 		if (swapctl(SWAP_ON, spec, (int)priority) < 0) {
438 			if (errno != EBUSY)
439 				warn("%s", spec);
440 		} else {
441 			gotone = 1;
442 			printf("%s: adding %s as swap device at priority %d\n",
443 			    __progname, fp->fs_spec, (int)priority);
444 		}
445 
446 		if (spec != fp->fs_spec)
447 			free((char *)spec);
448 	}
449 	if (gotone == 0)
450 		exit(1);
451 }
452 
453 void
454 usage()
455 {
456 
457 	fprintf(stderr, "usage: %s -A [-p priority] [-t blk|noblk]\n",
458 	    __progname);
459 	fprintf(stderr, "       %s -a [-p priority] path\n", __progname);
460 	fprintf(stderr, "       %s -c -p priority path\n", __progname);
461 	fprintf(stderr, "       %s -d path\n", __progname);
462 	fprintf(stderr, "       %s -l | -s [-k]\n", __progname);
463 	exit(1);
464 }
465