1/*	$OpenBSD: swapctl.c,v 1.26 2020/02/11 18:16:38 jca 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 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
22 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
24 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30/*
31 * swapctl command:
32 *	-A		add all devices listed as `sw' in /etc/fstab
33 *	-t [blk|noblk]	if -A, add either all block device or all non-block
34 *			devices
35 *	-a <path>	add this device
36 *	-d <path>	remove this swap device
37 *	-l		list swap devices
38 *	-s		short listing of swap devices
39 *	-k		use kilobytes
40 *	-p <pri>	use this priority
41 *	-c <path>	change priority
42 *
43 * or, if invoked as "swapon" (compatibility mode):
44 *
45 *	-a		all devices listed as `sw' in /etc/fstab
46 *	-t		same as -t above (feature not present in old
47 *			swapon(8) command)
48 *	<dev>		add this device
49 */
50
51#include <sys/stat.h>
52#include <sys/swap.h>
53#include <sys/wait.h>
54
55#include <unistd.h>
56#include <err.h>
57#include <errno.h>
58#include <stdio.h>
59#include <stdlib.h>
60#include <limits.h>
61#include <string.h>
62#include <fstab.h>
63#include <util.h>
64
65#include "swapctl.h"
66
67int	command;
68
69/*
70 * Commands for swapctl(8).  These are mutually exclusive.
71 */
72#define	CMD_A		0x01	/* process /etc/fstab */
73#define	CMD_a		0x02	/* add a swap file/device */
74#define	CMD_c		0x04	/* change priority of a swap file/device */
75#define	CMD_d		0x08	/* delete a swap file/device */
76#define	CMD_l		0x10	/* list swap files/devices */
77#define	CMD_s		0x20	/* summary of swap files/devices */
78
79#define	SET_COMMAND(cmd) \
80do { \
81	if (command) \
82		usage(); \
83	command = (cmd); \
84} while (0)
85
86/*
87 * Commands that require a "path" argument at the end of the command
88 * line, and the ones which require that none exist.
89 */
90#define	REQUIRE_PATH	(CMD_a | CMD_c | CMD_d)
91#define	REQUIRE_NOPATH	(CMD_A | CMD_l | CMD_s)
92
93/*
94 * Option flags, and the commands with which they are valid.
95 */
96int	kflag;		/* display in 1K blocks */
97#define	KFLAG_CMDS	(CMD_l | CMD_s)
98
99int	pflag;		/* priority was specified */
100#define	PFLAG_CMDS	(CMD_A | CMD_a | CMD_c)
101
102char	*tflag;		/* swap device type (blk or noblk) */
103#define	TFLAG_CMDS	(CMD_A)
104
105int	pri;		/* uses 0 as default pri */
106
107static	void change_priority(char *);
108static	void add_swap(char *);
109static	void del_swap(char *);
110static	void do_fstab(void);
111static	void usage(void);
112static	int  swapon_command(int, char **);
113
114extern	char *__progname;	/* from crt0.o */
115
116int
117main(int argc, char *argv[])
118{
119	const char *errstr;
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			pri = strtonum(optarg, 0, INT_MAX, &errstr);
154			if (errstr)
155				errx(1, "-p %s: %s", errstr, 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	argv += optind;
175	argc -= optind;
176
177	/* Did the user specify a command? */
178	if (command == 0) {
179		if (argc == 0)
180			SET_COMMAND(CMD_l);
181		else
182			usage();
183	}
184
185	switch (argc) {
186	case 0:
187		if (command & REQUIRE_PATH)
188			usage();
189		break;
190
191	case 1:
192		if (command & REQUIRE_NOPATH)
193			usage();
194		break;
195
196	default:
197		usage();
198	}
199
200	/* To change priority, you have to specify one. */
201	if ((command == CMD_c) && pflag == 0)
202		usage();
203
204	/* Sanity-check -t */
205	if (tflag != NULL) {
206		if (command != CMD_A)
207			usage();
208		if (strcmp(tflag, "blk") != 0 &&
209		    strcmp(tflag, "noblk") != 0)
210			usage();
211	}
212
213	/* Dispatch the command. */
214	switch (command) {
215	case CMD_l:
216		list_swap(pri, kflag, pflag, 1);
217		break;
218
219	case CMD_s:
220		list_swap(pri, kflag, pflag, 0);
221		break;
222
223	case CMD_c:
224		change_priority(argv[0]);
225		break;
226
227	case CMD_a:
228		add_swap(argv[0]);
229		break;
230
231	case CMD_d:
232		del_swap(argv[0]);
233		break;
234
235	case CMD_A:
236		do_fstab();
237		break;
238	}
239
240	return (0);
241}
242
243/*
244 * swapon_command: emulate the old swapon(8) program.
245 */
246int
247swapon_command(int argc, char **argv)
248{
249	int ch, fiztab = 0;
250
251	while ((ch = getopt(argc, argv, "at:")) != -1) {
252		switch (ch) {
253		case 'a':
254			fiztab = 1;
255			break;
256		case 't':
257			if (tflag != NULL)
258				usage();
259			tflag = optarg;
260			break;
261		default:
262			goto swapon_usage;
263		}
264	}
265	argc -= optind;
266	argv += optind;
267
268	if (fiztab) {
269		if (argc)
270			goto swapon_usage;
271		/* Sanity-check -t */
272		if (tflag != NULL) {
273			if (strcmp(tflag, "blk") != 0 &&
274			    strcmp(tflag, "noblk") != 0)
275				usage();
276		}
277		do_fstab();
278		return (0);
279	} else if (argc == 0 || tflag != NULL)
280		goto swapon_usage;
281
282	while (argc) {
283		add_swap(argv[0]);
284		argc--;
285		argv++;
286	}
287	return (0);
288
289 swapon_usage:
290	fprintf(stderr, "usage: %s -a | path\n", __progname);
291	return (1);
292}
293
294/*
295 * change_priority:  change the priority of a swap device.
296 */
297void
298change_priority(char *path)
299{
300
301	if (swapctl(SWAP_CTL, path, pri) == -1)
302		warn("%s", path);
303}
304
305/*
306 * add_swap:  add the pathname to the list of swap devices.
307 */
308void
309add_swap(char *path)
310{
311
312	if (swapctl(SWAP_ON, path, pri) == -1)
313		if (errno != EBUSY)
314			err(1, "%s", path);
315}
316
317/*
318 * del_swap:  remove the pathname from the list of swap devices.
319 */
320void
321del_swap(char *path)
322{
323
324	if (swapctl(SWAP_OFF, path, pri) == -1)
325		err(1, "%s", path);
326}
327
328void
329do_fstab(void)
330{
331	struct	fstab *fp;
332	char	*s;
333	long	priority;
334	struct	stat st;
335	mode_t	rejecttype = 0;
336	int	gotone = 0;
337
338	/*
339	 * Select which mount point types to reject, depending on the
340	 * value of the -t parameter.
341	 */
342	if (tflag != NULL) {
343		if (strcmp(tflag, "blk") == 0)
344			rejecttype = S_IFREG;
345		else if (strcmp(tflag, "noblk") == 0)
346			rejecttype = S_IFBLK;
347	}
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;
368			pid_t pid;
369			int status;
370
371			/*
372			 * Skip this song and dance if we're only
373			 * doing block devices.
374			 */
375			if (rejecttype == S_IFREG)
376				continue;
377
378			t = strpbrk(s, ",");
379			if (t != 0)
380				*t = '\0';
381			spec = strdup(s + strlen(NFSMNTPT));
382			if (spec == NULL)
383				err(1, "strdup");
384
385			if (t != 0)
386				*t = ',';
387
388			if (strlen(spec) == 0) {
389				warnx("empty mountpoint");
390				free((char *)spec);
391				continue;
392			}
393
394			switch (pid = vfork()) {
395			case -1:	/* error */
396				err(1, "vfork");
397			case 0:
398				execl(PATH_MOUNT, PATH_MOUNT, fp->fs_spec, spec,
399				    (char *)NULL);
400				err(1, "execl");
401			}
402			while (waitpid(pid, &status, 0) == -1)
403				if (errno != EINTR)
404					err(1, "waitpid");
405			if (status != 0) {
406				warnx("%s: mount failed", fp->fs_spec);
407				free((char *)spec);
408				continue;
409			}
410		} else if (isduid(spec, 0)) {
411			if (rejecttype == S_IFBLK)
412				continue;
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) == -1) {
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) == -1) {
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
453void
454usage(void)
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