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
67 int 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) \
80 do { \
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 */
96 int kflag; /* display in 1K blocks */
97 #define KFLAG_CMDS (CMD_l | CMD_s)
98
99 int pflag; /* priority was specified */
100 #define PFLAG_CMDS (CMD_A | CMD_a | CMD_c)
101
102 char *tflag; /* swap device type (blk or noblk) */
103 #define TFLAG_CMDS (CMD_A)
104
105 int pri; /* uses 0 as default pri */
106
107 static void change_priority(char *);
108 static void add_swap(char *);
109 static void del_swap(char *);
110 static void do_fstab(void);
111 static void usage(void);
112 static int swapon_command(int, char **);
113
114 extern char *__progname; /* from crt0.o */
115
116 int
main(int argc,char * argv[])117 main(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 */
246 int
swapon_command(int argc,char ** argv)247 swapon_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 */
297 void
change_priority(char * path)298 change_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 */
308 void
add_swap(char * path)309 add_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 */
320 void
del_swap(char * path)321 del_swap(char *path)
322 {
323
324 if (swapctl(SWAP_OFF, path, pri) == -1)
325 err(1, "%s", path);
326 }
327
328 void
do_fstab(void)329 do_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
453 void
usage(void)454 usage(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