swapctl.c revision 1.10 
1/*	$OpenBSD: swapctl.c,v 1.10 2002/07/03 22:32:33 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 <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
68int	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) \
81do { \
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 */
97int	kflag;		/* display in 1K blocks */
98#define	KFLAG_CMDS	(CMD_l | CMD_s)
99
100int	pflag;		/* priority was specified */
101#define	PFLAG_CMDS	(CMD_A | CMD_a | CMD_c)
102
103char	*tflag;		/* swap device type (blk or noblk) */
104#define	TFLAG_CMDS	(CMD_A)
105
106int	pri;		/* uses 0 as default pri */
107
108static	void change_priority(char *);
109static	void add_swap(char *);
110static	void del_swap(char *);
111	int  main(int, char *[]);
112static	void do_fstab(void);
113static	void usage(void);
114static	int  swapon_command(int, char **);
115
116extern	char *__progname;	/* from crt0.o */
117
118int
119main(int argc, char *argv[])
120{
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			/* XXX strtol() */
155			pri = atoi(optarg);
156			break;
157
158		case 's':
159			SET_COMMAND(CMD_s);
160			break;
161
162		case 't':
163			if (tflag != NULL)
164				usage();
165			tflag = optarg;
166			break;
167
168		default:
169			usage();
170			/* NOTREACHED */
171		}
172	}
173
174	/* Did the user specify a command? */
175	if (command == 0)
176		usage();
177
178	argv += optind;
179	argc -= optind;
180
181	switch (argc) {
182	case 0:
183		if (command & REQUIRE_PATH)
184			usage();
185		break;
186
187	case 1:
188		if (command & REQUIRE_NOPATH)
189			usage();
190		break;
191
192	default:
193		usage();
194	}
195
196	/* To change priority, you have to specify one. */
197	if ((command == CMD_c) && pflag == 0)
198		usage();
199
200	/* Sanity-check -t */
201	if (tflag != NULL) {
202		if (command != CMD_A)
203			usage();
204		if (strcmp(tflag, "blk") != 0 &&
205		    strcmp(tflag, "noblk") != 0)
206			usage();
207	}
208
209	/* Dispatch the command. */
210	switch (command) {
211	case CMD_l:
212		list_swap(pri, kflag, pflag, 0, 1);
213		break;
214
215	case CMD_s:
216		list_swap(pri, kflag, pflag, 0, 0);
217		break;
218
219	case CMD_c:
220		change_priority(argv[0]);
221		break;
222
223	case CMD_a:
224		add_swap(argv[0]);
225		break;
226
227	case CMD_d:
228		del_swap(argv[0]);
229		break;
230
231	case CMD_A:
232		do_fstab();
233		break;
234	}
235
236	return (0);
237}
238
239/*
240 * swapon_command: emulate the old swapon(8) program.
241 */
242int
243swapon_command(int argc, char **argv)
244{
245	int ch, fiztab = 0;
246
247	while ((ch = getopt(argc, argv, "at:")) != -1) {
248		switch (ch) {
249		case 'a':
250			fiztab = 1;
251			break;
252		case 't':
253			if (tflag != NULL)
254				usage();
255			tflag = optarg;
256			break;
257		default:
258			goto swapon_usage;
259		}
260	}
261	argc -= optind;
262	argv += optind;
263
264	if (fiztab) {
265		if (argc)
266			goto swapon_usage;
267		/* Sanity-check -t */
268		if (tflag != NULL) {
269			if (strcmp(tflag, "blk") != 0 &&
270			    strcmp(tflag, "noblk") != 0)
271				usage();
272		}
273		do_fstab();
274		return (0);
275	} else if (argc == 0 || tflag != NULL)
276		goto swapon_usage;
277
278	while (argc) {
279		add_swap(argv[0]);
280		argc--;
281		argv++;
282	}
283	return (0);
284
285 swapon_usage:
286	fprintf(stderr, "usage: %s -a [-t blk|noblk]\n"
287			"       %s <path> ...\n",
288	    __progname, __progname);
289	return (1);
290}
291
292/*
293 * change_priority:  change the priority of a swap device.
294 */
295void
296change_priority(char *path)
297{
298
299	if (swapctl(SWAP_CTL, path, pri) < 0)
300		warn("%s", path);
301}
302
303/*
304 * add_swap:  add the pathname to the list of swap devices.
305 */
306void
307add_swap(char *path)
308{
309
310	if (swapctl(SWAP_ON, path, pri) < 0)
311		if (errno != EBUSY)
312			err(1, "%s", path);
313}
314
315/*
316 * del_swap:  remove the pathname from the list of swap devices.
317 */
318void
319del_swap(char *path)
320{
321
322	if (swapctl(SWAP_OFF, path, pri) < 0)
323		err(1, "%s", path);
324}
325
326void
327do_fstab(void)
328{
329	struct	fstab *fp;
330	char	*s;
331	long	priority;
332	struct	stat st;
333	mode_t	rejecttype;
334	int	gotone = 0;
335
336	/*
337	 * Select which mount point types to reject, depending on the
338	 * value of the -t parameter.
339	 */
340	if (tflag != NULL) {
341		if (strcmp(tflag, "blk") == 0)
342			rejecttype = S_IFREG;
343		else if (strcmp(tflag, "noblk") == 0)
344			rejecttype = S_IFBLK;
345	} else
346		rejecttype = 0;
347
348#define PRIORITYEQ	"priority="
349#define NFSMNTPT	"nfsmntpt="
350#define PATH_MOUNT	"/sbin/mount_nfs"
351	while ((fp = getfsent()) != NULL) {
352		const char *spec;
353
354		if (strcmp(fp->fs_type, "sw") != 0)
355			continue;
356
357		spec = fp->fs_spec;
358
359		if ((s = strstr(fp->fs_mntops, PRIORITYEQ)) != NULL) {
360			s += sizeof(PRIORITYEQ) - 1;
361			priority = atol(s);
362		} else
363			priority = pri;
364
365		if ((s = strstr(fp->fs_mntops, NFSMNTPT)) != NULL) {
366			char *t, cmd[strlen(PATH_MOUNT)+1+PATH_MAX+1+PATH_MAX+1];
367
368			/*
369			 * Skip this song and dance if we're only
370			 * doing block devices.
371			 */
372			if (rejecttype == S_IFREG)
373				continue;
374
375			t = strpbrk(s, ",");
376			if (t != 0)
377				*t = '\0';
378			spec = strdup(s + strlen(NFSMNTPT));
379			if (t != 0)
380				*t = ',';
381
382			if (spec == NULL)
383				errx(1, "Out of memory");
384
385			if (strlen(spec) == 0) {
386				warnx("empty mountpoint");
387				free((char *)spec);
388				continue;
389			}
390			snprintf(cmd, sizeof(cmd), "%s %s %s",
391			    PATH_MOUNT, fp->fs_spec, spec);
392			if (system(cmd) != 0) {
393				warnx("%s: mount failed", fp->fs_spec);
394				continue;
395			}
396		} else {
397			/*
398			 * Determine blk-ness.  Don't even consider a
399			 * mountpoint outside /dev as a block device.
400			 */
401			if (rejecttype == S_IFREG) {
402				if (strncmp("/dev/", spec, 5) != 0)
403					continue;
404			}
405			if (stat(spec, &st) < 0) {
406				warn("%s", spec);
407				continue;
408			}
409			if ((st.st_mode & S_IFMT) == rejecttype)
410				continue;
411
412			/*
413			 * Do not allow fancy objects to be swap areas.
414			 */
415			if (!S_ISREG(st.st_mode) &&
416			    !S_ISBLK(st.st_mode))
417				continue;
418		}
419
420		if (swapctl(SWAP_ON, spec, (int)priority) < 0) {
421			if (errno != EBUSY)
422				warn("%s", spec);
423		} else {
424			gotone = 1;
425			printf("%s: adding %s as swap device at priority %d\n",
426			    __progname, fp->fs_spec, (int)priority);
427		}
428
429		if (spec != fp->fs_spec)
430			free((char *)spec);
431	}
432	if (gotone == 0)
433		exit(1);
434}
435
436void
437usage(void)
438{
439
440	fprintf(stderr, "usage: %s -A [-p priority] [-t blk|noblk]\n",
441	    __progname);
442	fprintf(stderr, "       %s -a [-p priority] path\n", __progname);
443	fprintf(stderr, "       %s -c -p priority path\n", __progname);
444	fprintf(stderr, "       %s -d path\n", __progname);
445	fprintf(stderr, "       %s -l | -s [-k]\n", __progname);
446	exit(1);
447}
448