xref: /titanic_44/usr/src/cmd/dumpadm/dconf.c (revision b7f45089ccbe01bab3d7c7377b49d80d2ae18a69)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 #include <sys/swap.h>
32 #include <sys/dumpadm.h>
33 #include <sys/utsname.h>
34 
35 #include <unistd.h>
36 #include <string.h>
37 #include <stdlib.h>
38 #include <stdio.h>
39 #include <fcntl.h>
40 #include <errno.h>
41 
42 #include "dconf.h"
43 #include "minfree.h"
44 #include "utils.h"
45 #include "swap.h"
46 
47 typedef struct dc_token {
48 	const char *tok_name;
49 	int (*tok_parse)(dumpconf_t *, char *);
50 	int (*tok_print)(const dumpconf_t *, FILE *);
51 } dc_token_t;
52 
53 static int print_device(const dumpconf_t *, FILE *);
54 static int print_savdir(const dumpconf_t *, FILE *);
55 static int print_content(const dumpconf_t *, FILE *);
56 static int print_enable(const dumpconf_t *, FILE *);
57 
58 static const dc_token_t tokens[] = {
59 	{ "DUMPADM_DEVICE", dconf_str2device, print_device },
60 	{ "DUMPADM_SAVDIR", dconf_str2savdir, print_savdir },
61 	{ "DUMPADM_CONTENT", dconf_str2content, print_content },
62 	{ "DUMPADM_ENABLE", dconf_str2enable, print_enable },
63 	{ NULL, NULL, NULL }
64 };
65 
66 static const char DC_STR_YES[] = "yes";		/* Enable on string */
67 static const char DC_STR_NO[] = "no";		/* Enable off string */
68 static const char DC_STR_SWAP[] = "swap";	/* Default dump device */
69 
70 /* The pages included in the dump */
71 static const char DC_STR_KERNEL[] = "kernel";	/* Kernel only */
72 static const char DC_STR_CURPROC[] = "curproc";	/* Kernel + current process */
73 static const char DC_STR_ALL[] = "all";		/* All pages */
74 
75 /*
76  * Permissions and ownership for the configuration file:
77  */
78 #define	DC_OWNER	0				/* Uid 0 (root) */
79 #define	DC_GROUP	1				/* Gid 1 (other) */
80 #define	DC_PERM	(S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)	/* Mode 0644 */
81 
82 static void
83 dconf_init(dumpconf_t *dcp, int dcmode)
84 {
85 	struct utsname ut;
86 
87 	/*
88 	 * Default device for dumps is 'swap' (appropriate swap device),
89 	 * and default savecore directory is /var/crash/`uname -n`,
90 	 * which is compatible with pre-dumpadm behavior.
91 	 */
92 	(void) strcpy(dcp->dc_device, DC_STR_SWAP);
93 	(void) strcpy(dcp->dc_savdir, "/var/crash");
94 
95 	if (uname(&ut) != -1) {
96 		(void) strcat(dcp->dc_savdir, "/");
97 		(void) strcat(dcp->dc_savdir, ut.nodename);
98 	}
99 
100 	/*
101 	 * Default is contents kernel, and savecore enabled on reboot.
102 	 */
103 	dcp->dc_cflags = DUMP_KERNEL;
104 	dcp->dc_enable = DC_ON;
105 
106 	dcp->dc_mode = dcmode;
107 	dcp->dc_conf_fp = NULL;
108 	dcp->dc_conf_fd = -1;
109 	dcp->dc_dump_fd = -1;
110 }
111 
112 int
113 dconf_open(dumpconf_t *dcp, const char *dpath, const char *fpath, int dcmode)
114 {
115 	char buf[BUFSIZ];
116 	int line;
117 
118 	dconf_init(dcp, dcmode);
119 
120 	if ((dcp->dc_dump_fd = open(dpath, O_RDWR)) == -1) {
121 		warn(gettext("failed to open %s"), dpath);
122 		return (-1);
123 	}
124 
125 	if ((dcp->dc_conf_fd = open(fpath, O_RDWR | O_CREAT, DC_PERM)) == -1) {
126 		warn(gettext("failed to open %s"), fpath);
127 		return (-1);
128 	}
129 
130 	if ((dcp->dc_conf_fp = fdopen(dcp->dc_conf_fd, "r+")) == NULL) {
131 		warn(gettext("failed to open stream for %s"), fpath);
132 		return (-1);
133 	}
134 
135 	/*
136 	 * If we're in override mode, the current kernel settings override the
137 	 * default settings and anything invalid in the configuration file.
138 	 */
139 	if (dcmode == DC_OVERRIDE)
140 		(void) dconf_getdev(dcp);
141 
142 	for (line = 1; fgets(buf, BUFSIZ, dcp->dc_conf_fp) != NULL; line++) {
143 
144 		char name[BUFSIZ], value[BUFSIZ];
145 		const dc_token_t *tokp;
146 		int len;
147 
148 		if (buf[0] == '#' || buf[0] == '\n')
149 			continue;
150 
151 		/*
152 		 * Look for "name=value", with optional whitespace on either
153 		 * side, terminated by a newline, and consuming the whole line.
154 		 */
155 		/* LINTED - unbounded string specifier */
156 		if (sscanf(buf, " %[^=]=%s \n%n", name, value, &len) == 2 &&
157 		    name[0] != '\0' && value[0] != '\0' && len == strlen(buf)) {
158 			/*
159 			 * Locate a matching token in the tokens[] table,
160 			 * and invoke its parsing function.
161 			 */
162 			for (tokp = tokens; tokp->tok_name != NULL; tokp++) {
163 				if (strcmp(name, tokp->tok_name) == 0) {
164 					if (tokp->tok_parse(dcp, value) == -1) {
165 						warn(gettext("\"%s\", line %d: "
166 						    "warning: invalid %s\n"),
167 						    fpath, line, name);
168 					}
169 					break;
170 				}
171 			}
172 
173 			/*
174 			 * If we hit the end of the tokens[] table,
175 			 * no matching token was found.
176 			 */
177 			if (tokp->tok_name == NULL) {
178 				warn(gettext("\"%s\", line %d: warning: "
179 				    "invalid token: %s\n"), fpath, line, name);
180 			}
181 
182 		} else {
183 			warn(gettext("\"%s\", line %d: syntax error\n"),
184 			    fpath, line);
185 		}
186 	}
187 
188 	/*
189 	 * If we're not in override mode, the current kernel settings
190 	 * override the settings read from the configuration file.
191 	 */
192 	if (dcmode == DC_CURRENT)
193 		return (dconf_getdev(dcp));
194 
195 	return (0);
196 }
197 
198 int
199 dconf_getdev(dumpconf_t *dcp)
200 {
201 	int status = 0;
202 
203 	if ((dcp->dc_cflags = ioctl(dcp->dc_dump_fd, DIOCGETCONF, 0)) == -1) {
204 		warn(gettext("failed to get kernel dump settings"));
205 		status = -1;
206 	}
207 
208 	if (ioctl(dcp->dc_dump_fd, DIOCGETDEV, dcp->dc_device) == -1) {
209 		if (errno != ENODEV) {
210 			warn(gettext("failed to get dump device"));
211 			status = -1;
212 		} else
213 			dcp->dc_device[0] = '\0';
214 	}
215 
216 	return (status);
217 }
218 
219 int
220 dconf_close(dumpconf_t *dcp)
221 {
222 	if (fclose(dcp->dc_conf_fp) == 0) {
223 		(void) close(dcp->dc_dump_fd);
224 		return (0);
225 	}
226 	return (-1);
227 }
228 
229 int
230 dconf_write(dumpconf_t *dcp)
231 {
232 	const dc_token_t *tokp;
233 
234 	if (fseeko(dcp->dc_conf_fp, (off_t)0, SEEK_SET) == -1) {
235 		warn(gettext("failed to seek config file"));
236 		return (-1);
237 	}
238 
239 	if (ftruncate(dcp->dc_conf_fd, (off_t)0) == -1) {
240 		warn(gettext("failed to truncate config file"));
241 		return (-1);
242 	}
243 
244 	(void) fputs("#\n# dumpadm.conf\n#\n"
245 	    "# Configuration parameters for system crash dump.\n"
246 	    "# Do NOT edit this file by hand -- use dumpadm(1m) instead.\n"
247 	    "#\n", dcp->dc_conf_fp);
248 
249 	for (tokp = tokens; tokp->tok_name != NULL; tokp++) {
250 		if (fprintf(dcp->dc_conf_fp, "%s=", tokp->tok_name) == -1 ||
251 		    tokp->tok_print(dcp, dcp->dc_conf_fp) == -1) {
252 			warn(gettext("failed to write token"));
253 			return (-1);
254 		}
255 	}
256 
257 	if (fflush(dcp->dc_conf_fp) != 0)
258 		warn(gettext("warning: failed to flush config file"));
259 
260 	if (fsync(dcp->dc_conf_fd) == -1)
261 		warn(gettext("warning: failed to sync config file to disk"));
262 
263 	if (fchmod(dcp->dc_conf_fd, DC_PERM) == -1)
264 		warn(gettext("warning: failed to reset mode on config file"));
265 
266 	if (fchown(dcp->dc_conf_fd, DC_OWNER, DC_GROUP) == -1)
267 		warn(gettext("warning: failed to reset owner on config file"));
268 
269 	return (0);
270 }
271 
272 static int
273 open_stat64(const char *path, struct stat64 *stp)
274 {
275 	int fd = open64(path, O_RDONLY);
276 
277 	if (fd >= 0) {
278 		int status = fstat64(fd, stp);
279 		(void) close(fd);
280 		return (status);
281 	}
282 
283 	return (-1);
284 }
285 
286 static int
287 dconf_swap_compare(const swapent_t *s1, const swapent_t *s2)
288 {
289 	struct stat64 st1, st2;
290 
291 	int prefer_s1 = -1;	/* Return value to move s1 left (s1 < s2) */
292 	int prefer_s2 = 1;	/* Return value to move s2 left (s1 > s2) */
293 
294 	/*
295 	 * First try: open and fstat each swap entry.  If either system
296 	 * call fails, arbitrarily prefer the other entry.
297 	 */
298 	if (open_stat64(s1->ste_path, &st1) == -1)
299 		return (prefer_s2);
300 
301 	if (open_stat64(s2->ste_path, &st2) == -1)
302 		return (prefer_s1);
303 
304 	/*
305 	 * Second try: if both entries are block devices, or if
306 	 * neither is a block device, prefer the larger.
307 	 */
308 	if (S_ISBLK(st1.st_mode) == S_ISBLK(st2.st_mode)) {
309 		if (st2.st_size > st1.st_size)
310 			return (prefer_s2);
311 		return (prefer_s1);
312 	}
313 
314 	/*
315 	 * Third try: prefer the entry that is a block device.
316 	 */
317 	if (S_ISBLK(st2.st_mode))
318 		return (prefer_s2);
319 	return (prefer_s1);
320 }
321 
322 static int
323 dconf_dev_ioctl(dumpconf_t *dcp, int cmd)
324 {
325 	if (ioctl(dcp->dc_dump_fd, cmd, dcp->dc_device) == 0)
326 		return (0);
327 
328 	switch (errno) {
329 	case ENOTSUP:
330 		warn(gettext("dumps not supported on %s\n"), dcp->dc_device);
331 		break;
332 	case EBUSY:
333 		warn(gettext("device %s is already in use\n"), dcp->dc_device);
334 		break;
335 	default:
336 		/*
337 		 * NOTE: The stmsboot(1M) command's boot-up script parses this
338 		 * error to get the dump device name. If you change the format
339 		 * of this message, make sure that stmsboot(1M) is in sync.
340 		 */
341 		warn(gettext("cannot use %s as dump device"), dcp->dc_device);
342 	}
343 	return (-1);
344 }
345 
346 int
347 dconf_update(dumpconf_t *dcp)
348 {
349 	int oconf;
350 
351 	/*
352 	 * Save the existing dump configuration in case something goes wrong.
353 	 */
354 	if ((oconf = ioctl(dcp->dc_dump_fd, DIOCGETCONF, 0)) == -1) {
355 		warn(gettext("failed to get kernel dump configuration"));
356 		return (-1);
357 	}
358 
359 	oconf &= DUMP_CONTENT;
360 	dcp->dc_cflags &= DUMP_CONTENT;
361 
362 	if (ioctl(dcp->dc_dump_fd, DIOCSETCONF, dcp->dc_cflags) == -1) {
363 		warn(gettext("failed to update kernel dump configuration"));
364 		return (-1);
365 	}
366 
367 	if (strcmp(dcp->dc_device, DC_STR_SWAP) == 0) {
368 		swaptbl_t *swt;
369 		int i;
370 
371 		if ((swt = swap_list()) == NULL)
372 			goto err;
373 
374 		if (swt->swt_n == 0) {
375 			warn(gettext("no swap devices are available\n"));
376 			free(swt);
377 			goto err;
378 		}
379 
380 		qsort(&swt->swt_ent[0], swt->swt_n, sizeof (swapent_t),
381 		    (int (*)(const void *, const void *))dconf_swap_compare);
382 
383 		/*
384 		 * Iterate through the prioritized list of swap entries,
385 		 * trying to configure one as the dump device.
386 		 */
387 		for (i = 0; i < swt->swt_n; i++) {
388 			if (ioctl(dcp->dc_dump_fd, DIOCSETDEV,
389 			    swt->swt_ent[i].ste_path) == 0) {
390 				(void) strcpy(dcp->dc_device,
391 				    swt->swt_ent[i].ste_path);
392 				break;
393 			}
394 		}
395 
396 		if (i == swt->swt_n) {
397 			warn(gettext("no swap devices could be configured "
398 			    "as the dump device\n"));
399 			free(swt);
400 			goto err;
401 		}
402 		free(swt);
403 
404 	} else if (dcp->dc_device[0] != '\0') {
405 		/*
406 		 * If we're not in forcible update mode, then fail the change
407 		 * if the selected device cannot be used as the dump device,
408 		 * or if it is not big enough to hold the dump.
409 		 */
410 		if (dcp->dc_mode == DC_CURRENT) {
411 			struct stat64 st;
412 			uint64_t d;
413 
414 			if (dconf_dev_ioctl(dcp, DIOCTRYDEV) == -1)
415 				goto err;
416 
417 			if (open_stat64(dcp->dc_device, &st) == -1) {
418 				warn(gettext("failed to access %s"),
419 				    dcp->dc_device);
420 				goto err;
421 			}
422 
423 			if (ioctl(dcp->dc_dump_fd, DIOCGETDUMPSIZE, &d) == -1) {
424 				warn(gettext("failed to get kernel dump size"));
425 				goto err;
426 			}
427 
428 			if (st.st_size < d) {
429 				warn(gettext("dump device %s is too small to "
430 				    "hold a system dump\ndump size %llu "
431 				    "bytes, device size %lld bytes\n"),
432 				    dcp->dc_device, d, st.st_size);
433 				goto err;
434 			}
435 		}
436 
437 		if (dconf_dev_ioctl(dcp, DIOCSETDEV) == -1)
438 			goto err;
439 	}
440 
441 	/*
442 	 * Now that we've updated the dump device, we need to issue another
443 	 * ioctl to re-read the config flags to determine whether we
444 	 * obtained DUMP_EXCL access on our dump device.
445 	 */
446 	if ((dcp->dc_cflags = ioctl(dcp->dc_dump_fd, DIOCGETCONF, 0)) == -1) {
447 		warn(gettext("failed to re-read kernel dump configuration"));
448 		return (-1);
449 	}
450 
451 	return (0);
452 
453 err:
454 	(void) ioctl(dcp->dc_dump_fd, DIOCSETCONF, oconf);
455 	return (-1);
456 }
457 
458 void
459 dconf_print(dumpconf_t *dcp, FILE *fp)
460 {
461 	u_longlong_t min;
462 	char *content;
463 
464 	if (dcp->dc_cflags & DUMP_ALL)
465 		content = gettext("all");
466 	else if (dcp->dc_cflags & DUMP_CURPROC)
467 		content = gettext("kernel and current process");
468 	else
469 		content = gettext("kernel");
470 
471 	(void) fprintf(fp, gettext("      Dump content: %s pages\n"), content);
472 
473 	if (dcp->dc_device[0] != '\0') {
474 		(void) fprintf(fp, gettext("       Dump device: %s (%s)\n"),
475 		    dcp->dc_device, (dcp->dc_cflags & DUMP_EXCL) ?
476 		    gettext("dedicated") : gettext("swap"));
477 	} else {
478 		(void) fprintf(fp, gettext("       Dump device: none "
479 		    "(dumps disabled)\n"));
480 	}
481 
482 	(void) fprintf(fp, gettext("Savecore directory: %s"), dcp->dc_savdir);
483 
484 	if (minfree_read(dcp->dc_savdir, &min) == 0) {
485 		if (min < 1024 || (min % 1024) != 0)
486 			(void) fprintf(fp, gettext(" (minfree = %lluKB)"), min);
487 		else
488 			(void) fprintf(fp, gettext(" (minfree = %lluMB)"),
489 			    min / 1024);
490 	}
491 
492 	(void) fprintf(fp, gettext("\n"));
493 
494 	(void) fprintf(fp, gettext("  Savecore enabled: %s\n"),
495 	    (dcp->dc_enable == DC_OFF) ? gettext("no") : gettext("yes"));
496 }
497 
498 int
499 dconf_str2device(dumpconf_t *dcp, char *buf)
500 {
501 	if (strcasecmp(buf, DC_STR_SWAP) == 0) {
502 		(void) strcpy(dcp->dc_device, DC_STR_SWAP);
503 		return (0);
504 	}
505 
506 	if (valid_abspath(buf)) {
507 		(void) strcpy(dcp->dc_device, buf);
508 		return (0);
509 	}
510 
511 	return (-1);
512 }
513 
514 int
515 dconf_str2savdir(dumpconf_t *dcp, char *buf)
516 {
517 	if (valid_abspath(buf)) {
518 		(void) strcpy(dcp->dc_savdir, buf);
519 		return (0);
520 	}
521 
522 	return (-1);
523 }
524 
525 int
526 dconf_str2content(dumpconf_t *dcp, char *buf)
527 {
528 	if (strcasecmp(buf, DC_STR_KERNEL) == 0) {
529 		dcp->dc_cflags = (dcp->dc_cflags & ~DUMP_CONTENT) | DUMP_KERNEL;
530 		return (0);
531 	}
532 
533 	if (strcasecmp(buf, DC_STR_CURPROC) == 0) {
534 		dcp->dc_cflags = (dcp->dc_cflags & ~DUMP_CONTENT) |
535 		    DUMP_CURPROC;
536 		return (0);
537 	}
538 
539 	if (strcasecmp(buf, DC_STR_ALL) == 0) {
540 		dcp->dc_cflags = (dcp->dc_cflags & ~DUMP_CONTENT) | DUMP_ALL;
541 		return (0);
542 	}
543 
544 	warn(gettext("invalid dump content type -- %s\n"), buf);
545 	return (-1);
546 }
547 
548 int
549 dconf_str2enable(dumpconf_t *dcp, char *buf)
550 {
551 	if (strcasecmp(buf, DC_STR_YES) == 0) {
552 		dcp->dc_enable = DC_ON;
553 		return (0);
554 	}
555 
556 	if (strcasecmp(buf, DC_STR_NO) == 0) {
557 		dcp->dc_enable = DC_OFF;
558 		return (0);
559 	}
560 
561 	warn(gettext("invalid enable value -- %s\n"), buf);
562 	return (-1);
563 }
564 
565 static int
566 print_content(const dumpconf_t *dcp, FILE *fp)
567 {
568 	const char *content;
569 
570 	if (dcp->dc_cflags & DUMP_ALL)
571 		content = DC_STR_ALL;
572 	else if (dcp->dc_cflags & DUMP_CURPROC)
573 		content = DC_STR_CURPROC;
574 	else
575 		content = DC_STR_KERNEL;
576 
577 	return (fprintf(fp, "%s\n", content));
578 }
579 
580 static int
581 print_device(const dumpconf_t *dcp, FILE *fp)
582 {
583 	return (fprintf(fp, "%s\n", (dcp->dc_device[0] != '\0') ?
584 	    dcp->dc_device : DC_STR_SWAP));
585 }
586 
587 static int
588 print_enable(const dumpconf_t *dcp, FILE *fp)
589 {
590 	return (fprintf(fp, "%s\n", (dcp->dc_enable == DC_OFF) ?
591 	    DC_STR_NO : DC_STR_YES));
592 }
593 
594 static int
595 print_savdir(const dumpconf_t *dcp, FILE *fp)
596 {
597 	return (fprintf(fp, "%s\n", dcp->dc_savdir));
598 }
599