xref: /openbsd/sbin/swapctl/swapctl.c (revision 404b540a) 
1 /*	$OpenBSD: swapctl.c,v 1.17 2007/11/26 13:36:33 deraadt 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 <path>	add this device
38  *	-d <path>	remove this swap device
39  *	-l		list swap devices
40  *	-s		short listing of swap devices
41  *	-k		use kilobytes
42  *	-p <pri>	use this priority
43  *	-c <path>	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(char *);
109 static	void add_swap(char *);
110 static	void del_swap(char *);
111 static	void do_fstab(void);
112 static	void usage(void);
113 static	int  swapon_command(int, char **);
114 
115 extern	char *__progname;	/* from crt0.o */
116 
117 int
118 main(int argc, char *argv[])
119 {
120 	int	c;
121 
122 	if (strcmp(__progname, "swapon") == 0)
123 		return swapon_command(argc, argv);
124 
125 	while ((c = getopt(argc, argv, "Aacdlkp:st:")) != -1) {
126 		switch (c) {
127 		case 'A':
128 			SET_COMMAND(CMD_A);
129 			break;
130 
131 		case 'a':
132 			SET_COMMAND(CMD_a);
133 			break;
134 
135 		case 'c':
136 			SET_COMMAND(CMD_c);
137 			break;
138 
139 		case 'd':
140 			SET_COMMAND(CMD_d);
141 			break;
142 
143 		case 'l':
144 			SET_COMMAND(CMD_l);
145 			break;
146 
147 		case 'k':
148 			kflag = 1;
149 			break;
150 
151 		case 'p':
152 			pflag = 1;
153 			/* XXX strtol() */
154 			pri = atoi(optarg);
155 			break;
156 
157 		case 's':
158 			SET_COMMAND(CMD_s);
159 			break;
160 
161 		case 't':
162 			if (tflag != NULL)
163 				usage();
164 			tflag = optarg;
165 			break;
166 
167 		default:
168 			usage();
169 			/* NOTREACHED */
170 		}
171 	}
172 
173 	argv += optind;
174 	argc -= optind;
175 
176 	/* Did the user specify a command? */
177 	if (command == 0) {
178 		if (argc == 0)
179 			SET_COMMAND(CMD_l);
180 		else
181 			usage();
182 	}
183 
184 	switch (argc) {
185 	case 0:
186 		if (command & REQUIRE_PATH)
187 			usage();
188 		break;
189 
190 	case 1:
191 		if (command & REQUIRE_NOPATH)
192 			usage();
193 		break;
194 
195 	default:
196 		usage();
197 	}
198 
199 	/* To change priority, you have to specify one. */
200 	if ((command == CMD_c) && pflag == 0)
201 		usage();
202 
203 	/* Sanity-check -t */
204 	if (tflag != NULL) {
205 		if (command != CMD_A)
206 			usage();
207 		if (strcmp(tflag, "blk") != 0 &&
208 		    strcmp(tflag, "noblk") != 0)
209 			usage();
210 	}
211 
212 	/* Dispatch the command. */
213 	switch (command) {
214 	case CMD_l:
215 		list_swap(pri, kflag, pflag, 1);
216 		break;
217 
218 	case CMD_s:
219 		list_swap(pri, kflag, pflag, 0);
220 		break;
221 
222 	case CMD_c:
223 		change_priority(argv[0]);
224 		break;
225 
226 	case CMD_a:
227 		add_swap(argv[0]);
228 		break;
229 
230 	case CMD_d:
231 		del_swap(argv[0]);
232 		break;
233 
234 	case CMD_A:
235 		do_fstab();
236 		break;
237 	}
238 
239 	return (0);
240 }
241 
242 /*
243  * swapon_command: emulate the old swapon(8) program.
244  */
245 int
246 swapon_command(int argc, char **argv)
247 {
248 	int ch, fiztab = 0;
249 
250 	while ((ch = getopt(argc, argv, "at:")) != -1) {
251 		switch (ch) {
252 		case 'a':
253 			fiztab = 1;
254 			break;
255 		case 't':
256 			if (tflag != NULL)
257 				usage();
258 			tflag = optarg;
259 			break;
260 		default:
261 			goto swapon_usage;
262 		}
263 	}
264 	argc -= optind;
265 	argv += optind;
266 
267 	if (fiztab) {
268 		if (argc)
269 			goto swapon_usage;
270 		/* Sanity-check -t */
271 		if (tflag != NULL) {
272 			if (strcmp(tflag, "blk") != 0 &&
273 			    strcmp(tflag, "noblk") != 0)
274 				usage();
275 		}
276 		do_fstab();
277 		return (0);
278 	} else if (argc == 0 || tflag != NULL)
279 		goto swapon_usage;
280 
281 	while (argc) {
282 		add_swap(argv[0]);
283 		argc--;
284 		argv++;
285 	}
286 	return (0);
287 
288  swapon_usage:
289 	fprintf(stderr, "usage: %s -a | path\n", __progname);
290 	return (1);
291 }
292 
293 /*
294  * change_priority:  change the priority of a swap device.
295  */
296 void
297 change_priority(char *path)
298 {
299 
300 	if (swapctl(SWAP_CTL, path, pri) < 0)
301 		warn("%s", path);
302 }
303 
304 /*
305  * add_swap:  add the pathname to the list of swap devices.
306  */
307 void
308 add_swap(char *path)
309 {
310 
311 	if (swapctl(SWAP_ON, path, pri) < 0)
312 		if (errno != EBUSY)
313 			err(1, "%s", path);
314 }
315 
316 /*
317  * del_swap:  remove the pathname from the list of swap devices.
318  */
319 void
320 del_swap(char *path)
321 {
322 
323 	if (swapctl(SWAP_OFF, path, pri) < 0)
324 		err(1, "%s", path);
325 }
326 
327 void
328 do_fstab(void)
329 {
330 	struct	fstab *fp;
331 	char	*s;
332 	long	priority;
333 	struct	stat st;
334 	mode_t	rejecttype;
335 	int	gotone = 0;
336 
337 	/*
338 	 * Select which mount point types to reject, depending on the
339 	 * value of the -t parameter.
340 	 */
341 	if (tflag != NULL) {
342 		if (strcmp(tflag, "blk") == 0)
343 			rejecttype = S_IFREG;
344 		else if (strcmp(tflag, "noblk") == 0)
345 			rejecttype = S_IFBLK;
346 	} else
347 		rejecttype = 0;
348 
349 #define PRIORITYEQ	"priority="
350 #define NFSMNTPT	"nfsmntpt="
351 #define PATH_MOUNT	"/sbin/mount_nfs"
352 	while ((fp = getfsent()) != NULL) {
353 		const char *spec;
354 
355 		if (strcmp(fp->fs_type, "sw") != 0)
356 			continue;
357 
358 		spec = fp->fs_spec;
359 
360 		if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
361 			s += sizeof(PRIORITYEQ) - 1;
362 			priority = atol(s);
363 		} else
364 			priority = pri;
365 
366 		if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
367 			char *t, cmd[sizeof(PATH_MOUNT)+PATH_MAX+1+PATH_MAX+1];
368 			int l;
369 
370 			/*
371 			 * Skip this song and dance if we're only
372 			 * doing block devices.
373 			 */
374 			if (rejecttype == S_IFREG)
375 				continue;
376 
377 			t = strpbrk(s, ",");
378 			if (t != 0)
379 				*t = '\0';
380 			spec = strdup(s + strlen(NFSMNTPT));
381 			if (spec == NULL)
382 				err(1, "strdup");
383 
384 			if (t != 0)
385 				*t = ',';
386 
387 			if (strlen(spec) == 0) {
388 				warnx("empty mountpoint");
389 				free((char *)spec);
390 				continue;
391 			}
392 			l = snprintf(cmd, sizeof(cmd), "%s %s %s",
393 			    PATH_MOUNT, fp->fs_spec, spec);
394 			if (l == -1 || l >= sizeof(cmd))
395 				errx(1, "path too long");
396 			if (system(cmd) != 0) {
397 				warnx("%s: mount failed", fp->fs_spec);
398 				continue;
399 			}
400 		} else {
401 			/*
402 			 * Determine blk-ness.  Don't even consider a
403 			 * mountpoint outside /dev as a block device.
404 			 */
405 			if (rejecttype == S_IFREG) {
406 				if (strncmp("/dev/", spec, 5) != 0)
407 					continue;
408 			}
409 			if (stat(spec, &st) < 0) {
410 				warn("%s", spec);
411 				continue;
412 			}
413 			if ((st.st_mode & S_IFMT) == rejecttype)
414 				continue;
415 
416 			/*
417 			 * Do not allow fancy objects to be swap areas.
418 			 */
419 			if (!S_ISREG(st.st_mode) &&
420 			    !S_ISBLK(st.st_mode))
421 				continue;
422 		}
423 
424 		if (swapctl(SWAP_ON, spec, (int)priority) < 0) {
425 			if (errno != EBUSY)
426 				warn("%s", spec);
427 		} else {
428 			gotone = 1;
429 			printf("%s: adding %s as swap device at priority %d\n",
430 			    __progname, fp->fs_spec, (int)priority);
431 		}
432 
433 		if (spec != fp->fs_spec)
434 			free((char *)spec);
435 	}
436 	if (gotone == 0)
437 		exit(1);
438 }
439 
440 void
441 usage(void)
442 {
443 
444 	fprintf(stderr, "usage: %s -A [-p priority] [-t blk|noblk]\n",
445 	    __progname);
446 	fprintf(stderr, "       %s -a [-p priority] path\n", __progname);
447 	fprintf(stderr, "       %s -c -p priority path\n", __progname);
448 	fprintf(stderr, "       %s -d path\n", __progname);
449 	fprintf(stderr, "       %s [[-l] | -s] [-k]\n", __progname);
450 	exit(1);
451 }
452