xref: /illumos-gate/usr/src/lib/libdevinfo/devinfo_devperm.c (revision f00128d8e2d39a5be61357047531dc79fde48623)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 2011 Gary Mills
23  *
24  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
25  */
26 
27 #define	_POSIX_PTHREAD_SEMANTICS	/* for getgrnam_r */
28 #ifdef lint
29 #define	_REENTRANT			/* for strtok_r */
30 #endif
31 
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <ctype.h>
35 #include <string.h>
36 #include <unistd.h>
37 #include <dirent.h>
38 #include <errno.h>
39 #include <grp.h>
40 #include <pwd.h>
41 #include <nss_dbdefs.h>
42 #include <stdarg.h>
43 #include <syslog.h>
44 #include <sys/acl.h>
45 #include <sys/types.h>
46 #include <sys/stat.h>
47 #include <sys/ddi.h>
48 #include <sys/sunddi.h>
49 #include <sys/devinfo_impl.h>
50 #include <sys/hwconf.h>
51 #include <sys/modctl.h>
52 #include <libnvpair.h>
53 #include <device_info.h>
54 #include <regex.h>
55 #include <strings.h>
56 #include <libdevinfo.h>
57 #include <zone.h>
58 #include <fcntl.h>
59 #include <utmpx.h>
60 
61 extern int is_minor_node(const char *, const char **);
62 
63 static int is_login_user(uid_t);
64 static int logindevperm(const char *, uid_t, gid_t, void (*)());
65 static int dir_dev_acc(char *, char *, uid_t, gid_t, mode_t, char *line,
66 	void (*)());
67 static int setdevaccess(char *, uid_t, gid_t, mode_t, void (*)());
68 static void logerror(char *);
69 
70 static int is_blank(char *);
71 
72 #define	MAX_LINELEN	256
73 #define	LOGINDEVPERM	"/etc/logindevperm"
74 #define	DIRWILD		"/*"			/* directory wildcard */
75 #define	DIRWLDLEN	2			/* strlen(DIRWILD) */
76 
77 /*
78  * Revoke all access to a device node and make sure that there are
79  * no interposed streams devices attached.  Must be called before a
80  * device is actually opened.
81  * When fdetach is called, the underlying device node is revealed; it
82  * will have the previous owner and that owner can re-attach; so we
83  * retry until we win.
84  * Ignore non-existent devices.
85  */
86 static int
setdevaccess(char * dev,uid_t uid,gid_t gid,mode_t mode,void (* errmsg)(char *))87 setdevaccess(char *dev, uid_t uid, gid_t gid, mode_t mode,
88     void (*errmsg)(char *))
89 {
90 	int err = 0, local_errno;
91 	char errstring[MAX_LINELEN];
92 	struct stat st;
93 
94 	if (chown(dev, uid, gid) == -1) {
95 		if (errno == ENOENT)	/* no such file */
96 			return (0);
97 		err = -1;
98 		local_errno = errno;
99 	}
100 
101 	/*
102 	 * don't fdetach block devices, as it will unmount them
103 	 */
104 	if (!((stat(dev, &st) == 0) && ((st.st_mode & S_IFMT) == S_IFBLK))) {
105 		while (fdetach(dev) == 0) {
106 			if (chown(dev, uid, gid) == -1) {
107 				err = -1;
108 				local_errno = errno;
109 			}
110 		}
111 		if (err && errmsg) {
112 			(void) snprintf(errstring, MAX_LINELEN,
113 			    "failed to chown device %s: %s\n",
114 			    dev, strerror(local_errno));
115 			(*errmsg)(errstring);
116 		}
117 	}
118 
119 	/*
120 	 * strip_acl sets an acl and changes the files owner/group
121 	 */
122 	err = acl_strip(dev, uid, gid, mode);
123 
124 	if (err != 0) {
125 		/*
126 		 * If the file system returned ENOSYS, we know that it
127 		 * doesn't support ACLs, therefore, we must assume that
128 		 * there were no ACLs to remove in the first place.
129 		 */
130 		err = 0;
131 		if (errno != ENOSYS) {
132 			err = -1;
133 
134 			if (errmsg) {
135 				(void) snprintf(errstring, MAX_LINELEN,
136 				    "failed to set acl on device %s: %s\n",
137 				    dev, strerror(errno));
138 				(*errmsg)(errstring);
139 			}
140 		}
141 		if (chmod(dev, mode) == -1) {
142 			err = -1;
143 			if (errmsg) {
144 				(void) snprintf(errstring, MAX_LINELEN,
145 				    "failed to chmod device %s: %s\n",
146 				    dev, strerror(errno));
147 				(*errmsg)(errstring);
148 			}
149 		}
150 	}
151 
152 	return (err);
153 }
154 
155 /*
156  * logindevperm - change owner/group/permissions of devices
157  * list in /etc/logindevperm.
158  */
159 static int
logindevperm(const char * ttyn,uid_t uid,gid_t gid,void (* errmsg)(char *))160 logindevperm(const char *ttyn, uid_t uid, gid_t gid, void (*errmsg)(char *))
161 {
162 	int err = 0, lineno = 0;
163 	const char *field_delims = " \t\n";
164 	char line[MAX_LINELEN], errstring[MAX_LINELEN];
165 	char saveline[MAX_LINELEN];
166 	char *console;
167 	char *mode_str;
168 	char *dev_list;
169 	char *device;
170 	char *ptr;
171 	int mode;
172 	FILE *fp;
173 	char ttyn_path[PATH_MAX + 1];
174 	int n;
175 
176 	if ((fp = fopen(LOGINDEVPERM, "r")) == NULL) {
177 		if (errmsg) {
178 			(void) snprintf(errstring, MAX_LINELEN,
179 			    LOGINDEVPERM ": open failed: %s\n",
180 			    strerror(errno));
181 			(*errmsg)(errstring);
182 		}
183 		return (-1);
184 	}
185 
186 	if ((n = resolvepath(ttyn, ttyn_path, PATH_MAX)) == -1)
187 		return (-1);
188 	ttyn_path[n] = '\0';
189 
190 	while (fgets(line, MAX_LINELEN, fp) != NULL) {
191 		char *last;
192 		char tmp[PATH_MAX + 1];
193 
194 		lineno++;
195 
196 		if ((ptr = strchr(line, '#')) != NULL)
197 			*ptr = '\0';	/* handle comments */
198 
199 		(void) strcpy(saveline, line);
200 
201 		console = strtok_r(line, field_delims, &last);
202 		if (console == NULL)
203 			continue;	/* ignore blank lines */
204 
205 		if ((n = resolvepath(console, tmp, PATH_MAX)) == -1)
206 			continue;
207 		tmp[n] = '\0';
208 
209 		if (strcmp(ttyn_path, tmp) != 0)
210 			continue;
211 
212 		mode_str = strtok_r(last, field_delims, &last);
213 		if (mode_str == NULL) {
214 			err = -1;	/* invalid entry, skip */
215 			if (errmsg) {
216 				(void) snprintf(errstring, MAX_LINELEN,
217 				    LOGINDEVPERM
218 				    ": line %d, invalid entry -- %s\n",
219 				    lineno, line);
220 				(*errmsg)(errstring);
221 			}
222 			continue;
223 		}
224 
225 		/* convert string to octal value */
226 		mode = strtol(mode_str, &ptr, 8);
227 		if (mode < 0 || mode > 0777 || *ptr != '\0') {
228 			err = -1;	/* invalid mode, skip */
229 			if (errmsg) {
230 				(void) snprintf(errstring, MAX_LINELEN,
231 				    LOGINDEVPERM
232 				    ": line %d, invalid mode -- %s\n",
233 				    lineno, mode_str);
234 				(*errmsg)(errstring);
235 			}
236 			continue;
237 		}
238 
239 		dev_list = strtok_r(last, field_delims, &last);
240 		if (dev_list == NULL) {
241 			err = -1;	/* empty device list, skip */
242 			if (errmsg) {
243 				(void) snprintf(errstring, MAX_LINELEN,
244 				    LOGINDEVPERM
245 				    ": line %d, empty device list -- %s\n",
246 				    lineno, line);
247 				(*errmsg)(errstring);
248 			}
249 			continue;
250 		}
251 
252 		device = strtok_r(dev_list, ":", &last);
253 		while (device != NULL) {
254 			if ((device[0] != '/') || (strlen(device) <= 1))  {
255 				err = -1;
256 			} else if (dir_dev_acc("/", &device[1], uid, gid, mode,
257 			    saveline, errmsg)) {
258 				err = -1;
259 			}
260 			device = strtok_r(last, ":", &last);
261 		}
262 	}
263 	(void) fclose(fp);
264 	return (err);
265 }
266 
267 /*
268  * returns 0 if resolved, -1 otherwise.
269  * devpath: Absolute path to /dev link
270  * devfs_path: Returns malloced string: /devices path w/out "/devices"
271  */
272 int
devfs_resolve_link(char * devpath,char ** devfs_path)273 devfs_resolve_link(char *devpath, char **devfs_path)
274 {
275 	char contents[PATH_MAX + 1];
276 	char stage_link[PATH_MAX + 1];
277 	char *ptr;
278 	int linksize;
279 	char *slashdev = "/dev/";
280 
281 	if (devfs_path) {
282 		*devfs_path = NULL;
283 	}
284 
285 	linksize = readlink(devpath, contents, PATH_MAX);
286 
287 	if (linksize <= 0) {
288 		return (-1);
289 	} else {
290 		contents[linksize] = '\0';
291 	}
292 
293 	/*
294 	 * if the link contents is not a minor node assume
295 	 * that link contents is really a pointer to another
296 	 * link, and if so recurse and read its link contents.
297 	 */
298 	if (is_minor_node((const char *)contents, (const char **)&ptr) !=
299 	    1) {
300 		if (strncmp(contents, slashdev, strlen(slashdev)) == 0)  {
301 			/* absolute path, starting with /dev */
302 			(void) strcpy(stage_link, contents);
303 		} else {
304 			/* relative path, prefix devpath */
305 			if ((ptr = strrchr(devpath, '/')) == NULL) {
306 				/* invalid link */
307 				return (-1);
308 			}
309 			*ptr = '\0';
310 			(void) strcpy(stage_link, devpath);
311 			*ptr = '/';
312 			(void) strcat(stage_link, "/");
313 			(void) strcat(stage_link, contents);
314 
315 		}
316 		return (devfs_resolve_link(stage_link, devfs_path));
317 	}
318 
319 	if (devfs_path) {
320 		*devfs_path = strdup(ptr);
321 		if (*devfs_path == NULL) {
322 			return (-1);
323 		}
324 	}
325 
326 	return (0);
327 }
328 
329 /*
330  * check a logindevperm line for a driver list and match this against
331  * the driver of the minor node
332  * returns 0 if no drivers were specified or a driver match
333  */
334 static int
check_driver_match(char * path,char * line)335 check_driver_match(char *path, char *line)
336 {
337 	char *drv, *driver, *lasts;
338 	char *devfs_path = NULL;
339 	char saveline[MAX_LINELEN];
340 	char *p;
341 
342 	if (devfs_resolve_link(path, &devfs_path) == 0) {
343 		char *p;
344 		char pwd_buf[PATH_MAX];
345 		di_node_t node;
346 
347 		/* truncate on : so we can take a snapshot */
348 		(void) strcpy(pwd_buf, devfs_path);
349 		p = strrchr(pwd_buf, ':');
350 		*p = '\0';
351 
352 		node = di_init(pwd_buf, DINFOMINOR);
353 		free(devfs_path);
354 
355 		if (node) {
356 			drv = di_driver_name(node);
357 			di_fini(node);
358 		} else {
359 			return (0);
360 		}
361 	} else {
362 		return (0);
363 	}
364 
365 	(void) strcpy(saveline, line);
366 
367 	p = strstr(saveline, "driver");
368 	if (p == NULL) {
369 		return (0);
370 	}
371 
372 	driver = strtok_r(p, "=", &lasts);
373 	if (driver) {
374 		if (strcmp(driver, "driver") == 0) {
375 			driver = strtok_r(NULL, ", \t\n", &lasts);
376 			while (driver) {
377 				if (strcmp(driver, drv) == 0) {
378 					return (0);
379 				}
380 				driver = strtok_r(NULL, ", \t\n", &lasts);
381 			}
382 		}
383 	}
384 
385 	return (-1);
386 }
387 
388 /*
389  * Check whether the user has logged onto "/dev/console" or "/dev/vt/#".
390  */
391 static int
is_login_user(uid_t uid)392 is_login_user(uid_t uid)
393 {
394 	int changed = 0;
395 	struct passwd pwd, *ppwd;
396 	char pwd_buf[NSS_BUFLEN_PASSWD];
397 	struct utmpx *utx;
398 
399 	if ((getpwuid_r(uid, &pwd, pwd_buf, NSS_BUFLEN_PASSWD, &ppwd) != 0) ||
400 	    (ppwd == NULL)) {
401 		return (0);
402 	}
403 
404 	setutxent();
405 	while ((utx = getutxent()) != NULL) {
406 		if (utx->ut_type == USER_PROCESS &&
407 		    strncmp(utx->ut_user, ppwd->pw_name,
408 		    strlen(ppwd->pw_name)) == 0 && (strncmp(utx->ut_line,
409 		    "console", strlen("console")) == 0 || strncmp(utx->ut_line,
410 		    "vt", strlen("vt")) == 0)) {
411 
412 			changed = 1;
413 			break;
414 		}
415 	}
416 	endutxent();
417 
418 	return (changed);
419 }
420 
421 /*
422  * Apply owner/group/perms to all files (except "." and "..")
423  * in a directory.
424  * This function is recursive. We start with "/" and the rest of the pathname
425  * in left_to_do argument, and we walk the entire pathname which may contain
426  * regular expressions or '*' for each directory name or basename.
427  */
428 static int
dir_dev_acc(char * path,char * left_to_do,uid_t uid,gid_t gid,mode_t mode,char * line,void (* errmsg)(char *))429 dir_dev_acc(char *path, char *left_to_do, uid_t uid, gid_t gid, mode_t mode,
430     char *line, void (*errmsg)(char *))
431 {
432 	struct stat stat_buf;
433 	int err = 0;
434 	char errstring[MAX_LINELEN];
435 	char *p;
436 	regex_t regex;
437 	int alwaysmatch = 0;
438 	char *match;
439 	char *name, *newpath, *remainder_path;
440 	finddevhdl_t handle;
441 
442 	/*
443 	 * Determine if the search needs to be performed via finddev,
444 	 * which returns only persisted names in the global /dev, or
445 	 * readdir, for paths other than /dev and non-global zones.
446 	 * This use of finddev avoids triggering potential implicit
447 	 * reconfig for names managed by logindevperm but not present
448 	 * on the system.
449 	 */
450 	if (!device_exists(path)) {
451 		return (-1);
452 	}
453 	if (stat(path, &stat_buf) == -1) {
454 		/*
455 		 * ENOENT errors are expected errors when there are
456 		 * dangling /dev device links. Ignore them silently
457 		 */
458 		if (errno == ENOENT) {
459 			return (0);
460 		}
461 		if (errmsg) {
462 			(void) snprintf(errstring, MAX_LINELEN,
463 			    "failed to stat %s: %s\n", path,
464 			    strerror(errno));
465 			(*errmsg)(errstring);
466 		}
467 		return (-1);
468 	} else {
469 		if (!S_ISDIR(stat_buf.st_mode)) {
470 			if (strlen(left_to_do) == 0) {
471 				/* finally check the driver matches */
472 				if (check_driver_match(path, line) == 0) {
473 					/*
474 					 * if the owner of device has been
475 					 * login, the ownership and mode
476 					 * should be set already. in
477 					 * this case, do not set the
478 					 * permissions.
479 					 */
480 					if (is_login_user(stat_buf.st_uid)) {
481 
482 						return (0);
483 					}
484 					/* we are done, set the permissions */
485 					if (setdevaccess(path,
486 					    uid, gid, mode, errmsg)) {
487 
488 						return (-1);
489 					}
490 				}
491 			}
492 			return (0);
493 		}
494 	}
495 
496 	if (finddev_readdir(path, &handle) != 0)
497 		return (0);
498 
499 	p = strchr(left_to_do, '/');
500 	alwaysmatch = 0;
501 
502 	newpath = (char *)malloc(MAXPATHLEN);
503 	if (newpath == NULL) {
504 		finddev_close(handle);
505 		return (-1);
506 	}
507 	match = (char *)calloc(MAXPATHLEN + 2, 1);
508 	if (match == NULL) {
509 		finddev_close(handle);
510 		free(newpath);
511 		return (-1);
512 	}
513 
514 	/* transform pattern into ^pattern$ for exact match */
515 	if (snprintf(match, MAXPATHLEN + 2, "^%.*s$",
516 	    p ? (p - left_to_do) : strlen(left_to_do), left_to_do) >=
517 	    MAXPATHLEN + 2) {
518 		finddev_close(handle);
519 		free(newpath);
520 		free(match);
521 		return (-1);
522 	}
523 
524 	if (strcmp(match, "^*$") == 0) {
525 		alwaysmatch = 1;
526 	} else {
527 		if (regcomp(&regex, match, REG_EXTENDED) != 0) {
528 			free(newpath);
529 			free(match);
530 			finddev_close(handle);
531 			return (-1);
532 		}
533 	}
534 
535 	while ((name = (char *)finddev_next(handle)) != NULL) {
536 		if (alwaysmatch ||
537 		    regexec(&regex, name, 0, NULL, 0) == 0) {
538 			if (strcmp(path, "/") == 0) {
539 				(void) snprintf(newpath,
540 				    MAXPATHLEN, "%s%s", path, name);
541 			} else {
542 				(void) snprintf(newpath,
543 				    MAXPATHLEN, "%s/%s", path, name);
544 			}
545 
546 			/*
547 			 * recurse but adjust what is still left to do
548 			 */
549 			remainder_path = (p ?
550 			    left_to_do + (p - left_to_do) + 1 :
551 			    &left_to_do[strlen(left_to_do)]);
552 			if (dir_dev_acc(newpath, remainder_path,
553 			    uid, gid, mode, line, errmsg)) {
554 				err = -1;
555 			}
556 		}
557 	}
558 
559 	finddev_close(handle);
560 	free(newpath);
561 	free(match);
562 	if (!alwaysmatch) {
563 		regfree(&regex);
564 	}
565 
566 	return (err);
567 }
568 
569 /*
570  * di_devperm_login - modify access of devices in /etc/logindevperm
571  * by changing owner/group/permissions to that of ttyn.
572  */
573 int
di_devperm_login(const char * ttyn,uid_t uid,gid_t gid,void (* errmsg)(char *))574 di_devperm_login(const char *ttyn, uid_t uid, gid_t gid,
575     void (*errmsg)(char *))
576 {
577 	int err;
578 	struct group grp, *grpp;
579 	gid_t tty_gid;
580 	char grbuf[NSS_BUFLEN_GROUP];
581 
582 	if (errmsg == NULL)
583 		errmsg = logerror;
584 
585 	if (ttyn == NULL) {
586 		(*errmsg)("di_devperm_login: NULL tty device\n");
587 		return (-1);
588 	}
589 
590 	if (getgrnam_r("tty", &grp, grbuf, NSS_BUFLEN_GROUP, &grpp) != 0) {
591 		tty_gid = grpp->gr_gid;
592 	} else {
593 		/*
594 		 * this should never happen, but if it does set
595 		 * group to tty's traditional value.
596 		 */
597 		tty_gid = 7;
598 	}
599 
600 	/* set the login console device permission */
601 	err = setdevaccess((char *)ttyn, uid, tty_gid,
602 	    S_IRUSR|S_IWUSR|S_IWGRP, errmsg);
603 	if (err) {
604 		return (err);
605 	}
606 
607 	/* set the device permissions */
608 	return (logindevperm(ttyn, uid, gid, errmsg));
609 }
610 
611 /*
612  * di_devperm_logout - clean up access of devices in /etc/logindevperm
613  * by resetting owner/group/permissions.
614  */
615 int
di_devperm_logout(const char * ttyn)616 di_devperm_logout(const char *ttyn)
617 {
618 	struct passwd *pwd;
619 	uid_t root_uid;
620 	gid_t root_gid;
621 
622 	if (ttyn == NULL)
623 		return (-1);
624 
625 	pwd = getpwnam("root");
626 	if (pwd != NULL) {
627 		root_uid = pwd->pw_uid;
628 		root_gid = pwd->pw_gid;
629 	} else {
630 		/*
631 		 * this should never happen, but if it does set user
632 		 * and group to root's traditional values.
633 		 */
634 		root_uid = 0;
635 		root_gid = 0;
636 	}
637 
638 	return (logindevperm(ttyn, root_uid, root_gid, NULL));
639 }
640 
641 static void
logerror(char * errstring)642 logerror(char *errstring)
643 {
644 	syslog(LOG_AUTH | LOG_CRIT, "%s", errstring);
645 }
646 
647 
648 /*
649  * Tokens are separated by ' ', '\t', ':', '=', '&', '|', ';', '\n', or '\0'
650  */
651 static int
getnexttoken(char * next,char ** nextp,char ** tokenpp,char * tchar)652 getnexttoken(char *next, char **nextp, char **tokenpp, char *tchar)
653 {
654 	char *cp;
655 	char *cp1;
656 	char *tokenp;
657 
658 	cp = next;
659 	while (*cp == ' ' || *cp == '\t') {
660 		cp++;			/* skip leading spaces */
661 	}
662 	tokenp = cp;			/* start of token */
663 	while (*cp != '\0' && *cp != '\n' && *cp != ' ' && *cp != '\t' &&
664 	    *cp != ':' && *cp != '=' && *cp != '&' &&
665 	    *cp != '|' && *cp != ';') {
666 		cp++;			/* point to next character */
667 	}
668 	/*
669 	 * If terminating character is a space or tab, look ahead to see if
670 	 * there's another terminator that's not a space or a tab.
671 	 * (This code handles trailing spaces.)
672 	 */
673 	if (*cp == ' ' || *cp == '\t') {
674 		cp1 = cp;
675 		while (*++cp1 == ' ' || *cp1 == '\t')
676 			;
677 		if (*cp1 == '=' || *cp1 == ':' || *cp1 == '&' || *cp1 == '|' ||
678 		    *cp1 == ';' || *cp1 == '\n' || *cp1 == '\0') {
679 			*cp = '\0';	/* terminate token */
680 			cp = cp1;
681 		}
682 	}
683 	if (tchar != NULL) {
684 		*tchar = *cp;		/* save terminating character */
685 		if (*tchar == '\0') {
686 			*tchar = '\n';
687 		}
688 	}
689 	*cp++ = '\0';			/* terminate token, point to next */
690 	*nextp = cp;			/* set pointer to next character */
691 	if (cp - tokenp - 1 == 0) {
692 		return (0);
693 	}
694 	*tokenpp = tokenp;
695 	return (1);
696 }
697 
698 /*
699  * get a decimal octal or hex number. Handle '~' for one's complement.
700  */
701 static int
getvalue(char * token,int * valuep)702 getvalue(char *token, int *valuep)
703 {
704 	int radix;
705 	int retval = 0;
706 	int onescompl = 0;
707 	int negate = 0;
708 	char c;
709 
710 	if (*token == '~') {
711 		onescompl++; /* perform one's complement on result */
712 		token++;
713 	} else if (*token == '-') {
714 		negate++;
715 		token++;
716 	}
717 	if (*token == '0') {
718 		token++;
719 		c = *token;
720 
721 		if (c == '\0') {
722 			*valuep = 0;	/* value is 0 */
723 			return (0);
724 		}
725 
726 		if (c == 'x' || c == 'X') {
727 			radix = 16;
728 			token++;
729 		} else {
730 			radix = 8;
731 		}
732 	} else
733 		radix = 10;
734 
735 	while ((c = *token++)) {
736 		switch (radix) {
737 		case 8:
738 			if (c >= '0' && c <= '7') {
739 				c -= '0';
740 			} else {
741 				/* invalid number */
742 				return (0);
743 			}
744 			retval = (retval << 3) + c;
745 			break;
746 		case 10:
747 			if (c >= '0' && c <= '9') {
748 				c -= '0';
749 			} else {
750 				/* invalid number */
751 				return (0);
752 			}
753 			retval = (retval * 10) + c;
754 			break;
755 		case 16:
756 			if (c >= 'a' && c <= 'f') {
757 				c = c - 'a' + 10;
758 			} else if (c >= 'A' && c <= 'F') {
759 				c = c - 'A' + 10;
760 			} else if (c >= '0' && c <= '9') {
761 				c -= '0';
762 			} else {
763 				/* invalid number */
764 				return (0);
765 			}
766 			retval = (retval << 4) + c;
767 			break;
768 		}
769 	}
770 	if (onescompl) {
771 		retval = ~retval;
772 	}
773 	if (negate) {
774 		retval = -retval;
775 	}
776 	*valuep = retval;
777 	return (1);
778 }
779 
780 /*
781  * Read /etc/minor_perm, return mperm list of entries
782  */
783 struct mperm *
i_devfs_read_minor_perm(char * drvname,void (* errcb)(minorperm_err_t,int))784 i_devfs_read_minor_perm(char *drvname, void (*errcb)(minorperm_err_t, int))
785 {
786 	FILE *pfd;
787 	struct mperm *mp;
788 	char line[MAX_MINOR_PERM_LINE];
789 	char *cp, *p, t;
790 	struct mperm *minor_perms = NULL;
791 	struct mperm *mptail = NULL;
792 	struct passwd *pw;
793 	struct group *gp;
794 	uid_t root_uid;
795 	gid_t sys_gid;
796 	int ln = 0;
797 
798 	/*
799 	 * Get root/sys ids, these being the most common
800 	 */
801 	if ((pw = getpwnam(DEFAULT_DEV_USER)) != NULL) {
802 		root_uid = pw->pw_uid;
803 	} else {
804 		(*errcb)(MP_CANT_FIND_USER_ERR, 0);
805 		root_uid = (uid_t)0;	/* assume 0 is root */
806 	}
807 	if ((gp = getgrnam(DEFAULT_DEV_GROUP)) != NULL) {
808 		sys_gid = gp->gr_gid;
809 	} else {
810 		(*errcb)(MP_CANT_FIND_GROUP_ERR, 0);
811 		sys_gid = (gid_t)3;	/* assume 3 is sys */
812 	}
813 
814 	if ((pfd = fopen(MINOR_PERM_FILE, "r")) == NULL) {
815 		(*errcb)(MP_FOPEN_ERR, errno);
816 		return (NULL);
817 	}
818 	while (fgets(line, MAX_MINOR_PERM_LINE, pfd) != NULL) {
819 		ln++;
820 		/* cut off comments starting with '#' */
821 		if ((cp = strchr(line, '#')) != NULL)
822 			*cp = '\0';
823 		/* ignore comment or blank lines */
824 		if (is_blank(line))
825 			continue;
826 		mp = (struct mperm *)calloc(1, sizeof (struct mperm));
827 		if (mp == NULL) {
828 			(*errcb)(MP_ALLOC_ERR, sizeof (struct mperm));
829 			continue;
830 		}
831 		cp = line;
832 		/* sanity-check */
833 		if (getnexttoken(cp, &cp, &p, &t) == 0) {
834 			(*errcb)(MP_IGNORING_LINE_ERR, ln);
835 			devfs_free_minor_perm(mp);
836 			continue;
837 		}
838 		mp->mp_drvname = strdup(p);
839 		if (mp->mp_drvname == NULL) {
840 			(*errcb)(MP_ALLOC_ERR, strlen(p)+1);
841 			devfs_free_minor_perm(mp);
842 			continue;
843 		} else if (t == '\n' || t == '\0') {
844 			(*errcb)(MP_IGNORING_LINE_ERR, ln);
845 			devfs_free_minor_perm(mp);
846 			continue;
847 		}
848 		if (t == ':') {
849 			if (getnexttoken(cp, &cp, &p, &t) == 0) {
850 				(*errcb)(MP_IGNORING_LINE_ERR, ln);
851 				devfs_free_minor_perm(mp);
852 			}
853 			mp->mp_minorname = strdup(p);
854 			if (mp->mp_minorname == NULL) {
855 				(*errcb)(MP_ALLOC_ERR, strlen(p)+1);
856 				devfs_free_minor_perm(mp);
857 				continue;
858 			}
859 		} else {
860 			mp->mp_minorname = NULL;
861 		}
862 
863 		if (t == '\n' || t == '\0') {
864 			devfs_free_minor_perm(mp);
865 			(*errcb)(MP_IGNORING_LINE_ERR, ln);
866 			continue;
867 		}
868 		if (getnexttoken(cp, &cp, &p, &t) == 0) {
869 			goto link;
870 		}
871 		if (getvalue(p, (int *)&mp->mp_mode) == 0) {
872 			goto link;
873 		}
874 		if (t == '\n' || t == '\0') {	/* no owner or group */
875 			goto link;
876 		}
877 		if (getnexttoken(cp, &cp, &p, &t) == 0) {
878 			goto link;
879 		}
880 		mp->mp_owner = strdup(p);
881 		if (mp->mp_owner == NULL) {
882 			(*errcb)(MP_ALLOC_ERR, strlen(p)+1);
883 			devfs_free_minor_perm(mp);
884 			continue;
885 		} else if (t == '\n' || t == '\0') {	/* no group */
886 			goto link;
887 		}
888 		if (getnexttoken(cp, &cp, &p, 0) == 0) {
889 			goto link;
890 		}
891 		mp->mp_group = strdup(p);
892 		if (mp->mp_group == NULL) {
893 			(*errcb)(MP_ALLOC_ERR, strlen(p)+1);
894 			devfs_free_minor_perm(mp);
895 			continue;
896 		}
897 link:
898 		if (drvname != NULL) {
899 			/*
900 			 * We only want the minor perm entry for a
901 			 * the named driver.  The driver name is the
902 			 * minor in the clone case.
903 			 */
904 			if (strcmp(mp->mp_drvname, "clone") == 0) {
905 				if (mp->mp_minorname == NULL ||
906 				    strcmp(drvname, mp->mp_minorname) != 0) {
907 					devfs_free_minor_perm(mp);
908 					continue;
909 				}
910 			} else {
911 				if (strcmp(drvname, mp->mp_drvname) != 0) {
912 					devfs_free_minor_perm(mp);
913 					continue;
914 				}
915 			}
916 		}
917 		if (minor_perms == NULL) {
918 			minor_perms = mp;
919 		} else {
920 			mptail->mp_next = mp;
921 		}
922 		mptail = mp;
923 
924 		/*
925 		 * Compute the uid's and gid's here - there are
926 		 * fewer lines in the /etc/minor_perm file than there
927 		 * are devices to be stat(2)ed.  And almost every
928 		 * device is 'root sys'.  See 1135520.
929 		 */
930 		if (mp->mp_owner == NULL ||
931 		    strcmp(mp->mp_owner, DEFAULT_DEV_USER) == 0 ||
932 		    (pw = getpwnam(mp->mp_owner)) == NULL) {
933 			mp->mp_uid = root_uid;
934 		} else {
935 			mp->mp_uid = pw->pw_uid;
936 		}
937 
938 		if (mp->mp_group == NULL ||
939 		    strcmp(mp->mp_group, DEFAULT_DEV_GROUP) == 0 ||
940 		    (gp = getgrnam(mp->mp_group)) == NULL) {
941 			mp->mp_gid = sys_gid;
942 		} else {
943 			mp->mp_gid = gp->gr_gid;
944 		}
945 	}
946 
947 	if (fclose(pfd) == EOF) {
948 		(*errcb)(MP_FCLOSE_ERR, errno);
949 	}
950 
951 	return (minor_perms);
952 }
953 
954 struct mperm *
devfs_read_minor_perm(void (* errcb)(minorperm_err_t,int))955 devfs_read_minor_perm(void (*errcb)(minorperm_err_t, int))
956 {
957 	return (i_devfs_read_minor_perm(NULL, errcb));
958 }
959 
960 static struct mperm *
i_devfs_read_minor_perm_by_driver(char * drvname,void (* errcb)(minorperm_err_t mp_err,int key))961 i_devfs_read_minor_perm_by_driver(char *drvname,
962     void (*errcb)(minorperm_err_t mp_err, int key))
963 {
964 	return (i_devfs_read_minor_perm(drvname, errcb));
965 }
966 
967 /*
968  * Free mperm list of entries
969  */
970 void
devfs_free_minor_perm(struct mperm * mplist)971 devfs_free_minor_perm(struct mperm *mplist)
972 {
973 	struct mperm *mp, *next;
974 
975 	for (mp = mplist; mp != NULL; mp = next) {
976 		next = mp->mp_next;
977 
978 		if (mp->mp_drvname)
979 			free(mp->mp_drvname);
980 		if (mp->mp_minorname)
981 			free(mp->mp_minorname);
982 		if (mp->mp_owner)
983 			free(mp->mp_owner);
984 		if (mp->mp_group)
985 			free(mp->mp_group);
986 		free(mp);
987 	}
988 }
989 
990 static int
i_devfs_add_perm_entry(nvlist_t * nvl,struct mperm * mp)991 i_devfs_add_perm_entry(nvlist_t *nvl, struct mperm *mp)
992 {
993 	int err;
994 
995 	err = nvlist_add_string(nvl, mp->mp_drvname, mp->mp_minorname);
996 	if (err != 0)
997 		return (err);
998 
999 	err = nvlist_add_int32(nvl, "mode", (int32_t)mp->mp_mode);
1000 	if (err != 0)
1001 		return (err);
1002 
1003 	err = nvlist_add_uint32(nvl, "uid", mp->mp_uid);
1004 	if (err != 0)
1005 		return (err);
1006 
1007 	err = nvlist_add_uint32(nvl, "gid", mp->mp_gid);
1008 	return (err);
1009 }
1010 
1011 static nvlist_t *
i_devfs_minor_perm_nvlist(struct mperm * mplist,void (* errcb)(minorperm_err_t,int))1012 i_devfs_minor_perm_nvlist(struct mperm *mplist,
1013     void (*errcb)(minorperm_err_t, int))
1014 {
1015 	int err;
1016 	struct mperm *mp;
1017 	nvlist_t *nvl = NULL;
1018 
1019 	if ((err = nvlist_alloc(&nvl, 0, 0)) != 0) {
1020 		(*errcb)(MP_NVLIST_ERR, err);
1021 		return (NULL);
1022 	}
1023 
1024 	for (mp = mplist; mp != NULL; mp = mp->mp_next) {
1025 		if ((err = i_devfs_add_perm_entry(nvl, mp)) != 0) {
1026 			(*errcb)(MP_NVLIST_ERR, err);
1027 			nvlist_free(nvl);
1028 			return (NULL);
1029 		}
1030 	}
1031 
1032 	return (nvl);
1033 }
1034 
1035 /*
1036  * Load all minor perm entries into the kernel
1037  * Done at boot time via devfsadm
1038  */
1039 int
devfs_load_minor_perm(struct mperm * mplist,void (* errcb)(minorperm_err_t,int))1040 devfs_load_minor_perm(struct mperm *mplist, void (*errcb)(minorperm_err_t, int))
1041 {
1042 	int err;
1043 	char *buf = NULL;
1044 	size_t buflen;
1045 	nvlist_t *nvl;
1046 
1047 	nvl = i_devfs_minor_perm_nvlist(mplist, errcb);
1048 	if (nvl == NULL)
1049 		return (-1);
1050 
1051 	if (nvlist_pack(nvl, &buf, &buflen, NV_ENCODE_NATIVE, 0) != 0) {
1052 		nvlist_free(nvl);
1053 		return (-1);
1054 	}
1055 
1056 	err = modctl(MODLOADMINORPERM, buf, buflen);
1057 	nvlist_free(nvl);
1058 	free(buf);
1059 
1060 	return (err);
1061 }
1062 
1063 /*
1064  * Add/remove minor perm entry for a driver
1065  */
1066 static int
i_devfs_update_minor_perm(char * drv,int ctl,void (* errcb)(minorperm_err_t,int))1067 i_devfs_update_minor_perm(char *drv, int ctl,
1068     void (*errcb)(minorperm_err_t, int))
1069 {
1070 	int err;
1071 	char *buf;
1072 	size_t buflen;
1073 	nvlist_t *nvl;
1074 	struct mperm *mplist;
1075 
1076 	mplist = i_devfs_read_minor_perm_by_driver(drv, errcb);
1077 
1078 	nvl = i_devfs_minor_perm_nvlist(mplist, errcb);
1079 	if (nvl == NULL)
1080 		return (-1);
1081 
1082 	buf = NULL;
1083 	if (nvlist_pack(nvl, &buf, &buflen, NV_ENCODE_NATIVE, 0) != 0) {
1084 		nvlist_free(nvl);
1085 		return (-1);
1086 	}
1087 
1088 	err = modctl(ctl, buf, buflen);
1089 	nvlist_free(nvl);
1090 	devfs_free_minor_perm(mplist);
1091 	free(buf);
1092 
1093 	return (err);
1094 }
1095 
1096 int
devfs_add_minor_perm(char * drv,void (* errcb)(minorperm_err_t,int))1097 devfs_add_minor_perm(char *drv, void (*errcb)(minorperm_err_t, int))
1098 {
1099 	return (i_devfs_update_minor_perm(drv, MODADDMINORPERM, errcb));
1100 }
1101 
1102 int
devfs_rm_minor_perm(char * drv,void (* errcb)(minorperm_err_t,int))1103 devfs_rm_minor_perm(char *drv, void (*errcb)(minorperm_err_t, int))
1104 {
1105 	return (i_devfs_update_minor_perm(drv, MODREMMINORPERM, errcb));
1106 }
1107 
1108 /*
1109  * is_blank() returns 1 (true) if a line specified is composed of
1110  * whitespace characters only. otherwise, it returns 0 (false).
1111  *
1112  * Note. the argument (line) must be null-terminated.
1113  */
1114 static int
is_blank(char * line)1115 is_blank(char *line)
1116 {
1117 	for (/* nothing */; *line != '\0'; line++)
1118 		if (!isspace(*line))
1119 			return (0);
1120 	return (1);
1121 }
1122