xref: /openbsd/sbin/swapctl/swapctl.c (revision cecf84d4) 
1 /*	$OpenBSD: swapctl.c,v 1.20 2015/04/18 18:28:37 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/stat.h>
54 #include <sys/swap.h>
55 
56 #include <unistd.h>
57 #include <err.h>
58 #include <errno.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <limits.h>
62 #include <string.h>
63 #include <fstab.h>
64 #include <util.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 	const char *errstr;
121 	int	c;
122 
123 	if (strcmp(__progname, "swapon") == 0)
124 		return swapon_command(argc, argv);
125 
126 	while ((c = getopt(argc, argv, "Aacdlkp:st:")) != -1) {
127 		switch (c) {
128 		case 'A':
129 			SET_COMMAND(CMD_A);
130 			break;
131 
132 		case 'a':
133 			SET_COMMAND(CMD_a);
134 			break;
135 
136 		case 'c':
137 			SET_COMMAND(CMD_c);
138 			break;
139 
140 		case 'd':
141 			SET_COMMAND(CMD_d);
142 			break;
143 
144 		case 'l':
145 			SET_COMMAND(CMD_l);
146 			break;
147 
148 		case 'k':
149 			kflag = 1;
150 			break;
151 
152 		case 'p':
153 			pflag = 1;
154 			pri = strtonum(optarg, 0, INT_MAX, &errstr);
155 			if (errstr)
156 				errx(1, "-p %s: %s", errstr, optarg);
157 			break;
158 
159 		case 's':
160 			SET_COMMAND(CMD_s);
161 			break;
162 
163 		case 't':
164 			if (tflag != NULL)
165 				usage();
166 			tflag = optarg;
167 			break;
168 
169 		default:
170 			usage();
171 			/* NOTREACHED */
172 		}
173 	}
174 
175 	argv += optind;
176 	argc -= optind;
177 
178 	/* Did the user specify a command? */
179 	if (command == 0) {
180 		if (argc == 0)
181 			SET_COMMAND(CMD_l);
182 		else
183 			usage();
184 	}
185 
186 	switch (argc) {
187 	case 0:
188 		if (command & REQUIRE_PATH)
189 			usage();
190 		break;
191 
192 	case 1:
193 		if (command & REQUIRE_NOPATH)
194 			usage();
195 		break;
196 
197 	default:
198 		usage();
199 	}
200 
201 	/* To change priority, you have to specify one. */
202 	if ((command == CMD_c) && pflag == 0)
203 		usage();
204 
205 	/* Sanity-check -t */
206 	if (tflag != NULL) {
207 		if (command != CMD_A)
208 			usage();
209 		if (strcmp(tflag, "blk") != 0 &&
210 		    strcmp(tflag, "noblk") != 0)
211 			usage();
212 	}
213 
214 	/* Dispatch the command. */
215 	switch (command) {
216 	case CMD_l:
217 		list_swap(pri, kflag, pflag, 1);
218 		break;
219 
220 	case CMD_s:
221 		list_swap(pri, kflag, pflag, 0);
222 		break;
223 
224 	case CMD_c:
225 		change_priority(argv[0]);
226 		break;
227 
228 	case CMD_a:
229 		add_swap(argv[0]);
230 		break;
231 
232 	case CMD_d:
233 		del_swap(argv[0]);
234 		break;
235 
236 	case CMD_A:
237 		do_fstab();
238 		break;
239 	}
240 
241 	return (0);
242 }
243 
244 /*
245  * swapon_command: emulate the old swapon(8) program.
246  */
247 int
248 swapon_command(int argc, char **argv)
249 {
250 	int ch, fiztab = 0;
251 
252 	while ((ch = getopt(argc, argv, "at:")) != -1) {
253 		switch (ch) {
254 		case 'a':
255 			fiztab = 1;
256 			break;
257 		case 't':
258 			if (tflag != NULL)
259 				usage();
260 			tflag = optarg;
261 			break;
262 		default:
263 			goto swapon_usage;
264 		}
265 	}
266 	argc -= optind;
267 	argv += optind;
268 
269 	if (fiztab) {
270 		if (argc)
271 			goto swapon_usage;
272 		/* Sanity-check -t */
273 		if (tflag != NULL) {
274 			if (strcmp(tflag, "blk") != 0 &&
275 			    strcmp(tflag, "noblk") != 0)
276 				usage();
277 		}
278 		do_fstab();
279 		return (0);
280 	} else if (argc == 0 || tflag != NULL)
281 		goto swapon_usage;
282 
283 	while (argc) {
284 		add_swap(argv[0]);
285 		argc--;
286 		argv++;
287 	}
288 	return (0);
289 
290  swapon_usage:
291 	fprintf(stderr, "usage: %s -a | path\n", __progname);
292 	return (1);
293 }
294 
295 /*
296  * change_priority:  change the priority of a swap device.
297  */
298 void
299 change_priority(char *path)
300 {
301 
302 	if (swapctl(SWAP_CTL, path, pri) < 0)
303 		warn("%s", path);
304 }
305 
306 /*
307  * add_swap:  add the pathname to the list of swap devices.
308  */
309 void
310 add_swap(char *path)
311 {
312 
313 	if (swapctl(SWAP_ON, path, pri) < 0)
314 		if (errno != EBUSY)
315 			err(1, "%s", path);
316 }
317 
318 /*
319  * del_swap:  remove the pathname from the list of swap devices.
320  */
321 void
322 del_swap(char *path)
323 {
324 
325 	if (swapctl(SWAP_OFF, path, pri) < 0)
326 		err(1, "%s", path);
327 }
328 
329 void
330 do_fstab(void)
331 {
332 	struct	fstab *fp;
333 	char	*s;
334 	long	priority;
335 	struct	stat st;
336 	mode_t	rejecttype;
337 	int	gotone = 0;
338 
339 	/*
340 	 * Select which mount point types to reject, depending on the
341 	 * value of the -t parameter.
342 	 */
343 	if (tflag != NULL) {
344 		if (strcmp(tflag, "blk") == 0)
345 			rejecttype = S_IFREG;
346 		else if (strcmp(tflag, "noblk") == 0)
347 			rejecttype = S_IFBLK;
348 	} else
349 		rejecttype = 0;
350 
351 #define PRIORITYEQ	"priority="
352 #define NFSMNTPT	"nfsmntpt="
353 #define PATH_MOUNT	"/sbin/mount_nfs"
354 	while ((fp = getfsent()) != NULL) {
355 		const char *spec;
356 
357 		if (strcmp(fp->fs_type, "sw") != 0)
358 			continue;
359 
360 		spec = fp->fs_spec;
361 
362 		if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
363 			s += sizeof(PRIORITYEQ) - 1;
364 			priority = atol(s);
365 		} else
366 			priority = pri;
367 
368 		if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
369 			char *t, cmd[sizeof(PATH_MOUNT)+PATH_MAX+1+PATH_MAX+1];
370 			int l;
371 
372 			/*
373 			 * Skip this song and dance if we're only
374 			 * doing block devices.
375 			 */
376 			if (rejecttype == S_IFREG)
377 				continue;
378 
379 			t = strpbrk(s, ",");
380 			if (t != 0)
381 				*t = '\0';
382 			spec = strdup(s + strlen(NFSMNTPT));
383 			if (spec == NULL)
384 				err(1, "strdup");
385 
386 			if (t != 0)
387 				*t = ',';
388 
389 			if (strlen(spec) == 0) {
390 				warnx("empty mountpoint");
391 				free((char *)spec);
392 				continue;
393 			}
394 			l = snprintf(cmd, sizeof(cmd), "%s %s %s",
395 			    PATH_MOUNT, fp->fs_spec, spec);
396 			if (l == -1 || l >= sizeof(cmd))
397 				errx(1, "path too long");
398 			if (system(cmd) != 0) {
399 				warnx("%s: mount failed", fp->fs_spec);
400 				free((char *)spec);
401 				continue;
402 			}
403 		} else if (isduid(spec, 0)) {
404 			if (rejecttype == S_IFBLK)
405 				continue;
406 		} else {
407 			/*
408 			 * Determine blk-ness.  Don't even consider a
409 			 * mountpoint outside /dev as a block device.
410 			 */
411 			if (rejecttype == S_IFREG) {
412 				if (strncmp("/dev/", spec, 5) != 0)
413 					continue;
414 			}
415 			if (stat(spec, &st) < 0) {
416 				warn("%s", spec);
417 				continue;
418 			}
419 			if ((st.st_mode & S_IFMT) == rejecttype)
420 				continue;
421 
422 			/*
423 			 * Do not allow fancy objects to be swap areas.
424 			 */
425 			if (!S_ISREG(st.st_mode) &&
426 			    !S_ISBLK(st.st_mode))
427 				continue;
428 		}
429 
430 		if (swapctl(SWAP_ON, spec, (int)priority) < 0) {
431 			if (errno != EBUSY)
432 				warn("%s", spec);
433 		} else {
434 			gotone = 1;
435 			printf("%s: adding %s as swap device at priority %d\n",
436 			    __progname, fp->fs_spec, (int)priority);
437 		}
438 
439 		if (spec != fp->fs_spec)
440 			free((char *)spec);
441 	}
442 	if (gotone == 0)
443 		exit(1);
444 }
445 
446 void
447 usage(void)
448 {
449 
450 	fprintf(stderr, "usage: %s -A [-p priority] [-t blk|noblk]\n",
451 	    __progname);
452 	fprintf(stderr, "       %s -a [-p priority] path\n", __progname);
453 	fprintf(stderr, "       %s -c -p priority path\n", __progname);
454 	fprintf(stderr, "       %s -d path\n", __progname);
455 	fprintf(stderr, "       %s [[-l] | -s] [-k]\n", __progname);
456 	exit(1);
457 }
458