xref: /freebsd/usr.sbin/jail/command.c (revision ab0b9f6b3073e6c4d1dfbf07444d7db67a189a96)
1 /*-
2  * Copyright (c) 2011 James Gritton
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/types.h>
31 #include <sys/event.h>
32 #include <sys/mount.h>
33 #include <sys/stat.h>
34 #include <sys/sysctl.h>
35 #include <sys/user.h>
36 #include <sys/wait.h>
37 
38 #include <err.h>
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <kvm.h>
42 #include <login_cap.h>
43 #include <paths.h>
44 #include <pwd.h>
45 #include <signal.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 
51 #include "jailp.h"
52 
53 #define DEFAULT_STOP_TIMEOUT	10
54 #define PHASH_SIZE		256
55 
56 LIST_HEAD(phhead, phash);
57 
58 struct phash {
59 	LIST_ENTRY(phash)	le;
60 	struct cfjail		*j;
61 	pid_t			pid;
62 };
63 
64 int paralimit = -1;
65 
66 extern char **environ;
67 
68 static int run_command(struct cfjail *j);
69 static int add_proc(struct cfjail *j, pid_t pid);
70 static void clear_procs(struct cfjail *j);
71 static struct cfjail *find_proc(pid_t pid);
72 static int term_procs(struct cfjail *j);
73 static int get_user_info(struct cfjail *j, const char *username,
74     const struct passwd **pwdp, login_cap_t **lcapp);
75 static int check_path(struct cfjail *j, const char *pname, const char *path,
76     int isfile, const char *umount_type);
77 
78 static struct cfjails sleeping = TAILQ_HEAD_INITIALIZER(sleeping);
79 static struct cfjails runnable = TAILQ_HEAD_INITIALIZER(runnable);
80 static struct cfstring dummystring = { .len = 1 };
81 static struct phhead phash[PHASH_SIZE];
82 static int kq;
83 
84 /*
85  * Run the next command associated with a jail.
86  */
87 int
88 next_command(struct cfjail *j)
89 {
90 	enum intparam comparam;
91 	int create_failed, stopping;
92 
93 	if (paralimit == 0) {
94 		requeue(j, &runnable);
95 		return 1;
96 	}
97 	create_failed = (j->flags & (JF_STOP | JF_FAILED)) == JF_FAILED;
98 	stopping = (j->flags & JF_STOP) != 0;
99 	comparam = *j->comparam;
100 	for (;;) {
101 		if (j->comstring == NULL) {
102 			j->comparam += create_failed ? -1 : 1;
103 			switch ((comparam = *j->comparam)) {
104 			case IP__NULL:
105 				return 0;
106 			case IP_MOUNT_DEVFS:
107 				if (!bool_param(j->intparams[IP_MOUNT_DEVFS]))
108 					continue;
109 				j->comstring = &dummystring;
110 				break;
111 			case IP_MOUNT_FDESCFS:
112 				if (!bool_param(j->intparams[IP_MOUNT_FDESCFS]))
113 					continue;
114 				j->comstring = &dummystring;
115 			case IP__OP:
116 			case IP_STOP_TIMEOUT:
117 				j->comstring = &dummystring;
118 				break;
119 			default:
120 				if (j->intparams[comparam] == NULL)
121 					continue;
122 				j->comstring = create_failed || (stopping &&
123 				    (j->intparams[comparam]->flags & PF_REV))
124 				    ? TAILQ_LAST(&j->intparams[comparam]->val,
125 					cfstrings)
126 				    : TAILQ_FIRST(&j->intparams[comparam]->val);
127 			}
128 		} else {
129 			j->comstring = j->comstring == &dummystring ? NULL :
130 			    create_failed || (stopping &&
131 			    (j->intparams[comparam]->flags & PF_REV))
132 			    ? TAILQ_PREV(j->comstring, cfstrings, tq)
133 			    : TAILQ_NEXT(j->comstring, tq);
134 		}
135 		if (j->comstring == NULL || j->comstring->len == 0 ||
136 		    (create_failed && (comparam == IP_EXEC_PRESTART ||
137 		    comparam == IP_EXEC_START || comparam == IP_COMMAND ||
138 		    comparam == IP_EXEC_POSTSTART)))
139 			continue;
140 		switch (run_command(j)) {
141 		case -1:
142 			failed(j);
143 			/* FALLTHROUGH */
144 		case 1:
145 			return 1;
146 		}
147 	}
148 }
149 
150 /*
151  * Check command exit status
152  */
153 int
154 finish_command(struct cfjail *j)
155 {
156 	int error;
157 
158 	if (!(j->flags & JF_SLEEPQ))
159 		return 0;
160 	j->flags &= ~JF_SLEEPQ;
161 	if (*j->comparam == IP_STOP_TIMEOUT)
162 	{
163 		j->flags &= ~JF_TIMEOUT;
164 		j->pstatus = 0;
165 		return 0;
166 	}
167 	paralimit++;
168 	if (!TAILQ_EMPTY(&runnable))
169 		requeue(TAILQ_FIRST(&runnable), &ready);
170 	error = 0;
171 	if (j->flags & JF_TIMEOUT) {
172 		j->flags &= ~JF_TIMEOUT;
173 		if (*j->comparam != IP_STOP_TIMEOUT) {
174 			jail_warnx(j, "%s: timed out", j->comline);
175 			failed(j);
176 			error = -1;
177 		} else if (verbose > 0)
178 			jail_note(j, "timed out\n");
179 	} else if (j->pstatus != 0) {
180 		if (WIFSIGNALED(j->pstatus))
181 			jail_warnx(j, "%s: exited on signal %d",
182 			    j->comline, WTERMSIG(j->pstatus));
183 		else
184 			jail_warnx(j, "%s: failed", j->comline);
185 		j->pstatus = 0;
186 		failed(j);
187 		error = -1;
188 	}
189 	free(j->comline);
190 	j->comline = NULL;
191 	return error;
192 }
193 
194 /*
195  * Check for finished processes or timeouts.
196  */
197 struct cfjail *
198 next_proc(int nonblock)
199 {
200 	struct kevent ke;
201 	struct timespec ts;
202 	struct timespec *tsp;
203 	struct cfjail *j;
204 
205 	if (!TAILQ_EMPTY(&sleeping)) {
206 	again:
207 		tsp = NULL;
208 		if ((j = TAILQ_FIRST(&sleeping)) && j->timeout.tv_sec) {
209 			clock_gettime(CLOCK_REALTIME, &ts);
210 			ts.tv_sec = j->timeout.tv_sec - ts.tv_sec;
211 			ts.tv_nsec = j->timeout.tv_nsec - ts.tv_nsec;
212 			if (ts.tv_nsec < 0) {
213 				ts.tv_sec--;
214 				ts.tv_nsec += 1000000000;
215 			}
216 			if (ts.tv_sec < 0 ||
217 			    (ts.tv_sec == 0 && ts.tv_nsec == 0)) {
218 				j->flags |= JF_TIMEOUT;
219 				clear_procs(j);
220 				return j;
221 			}
222 			tsp = &ts;
223 		}
224 		if (nonblock) {
225 			ts.tv_sec = 0;
226 			ts.tv_nsec = 0;
227 			tsp = &ts;
228 		}
229 		switch (kevent(kq, NULL, 0, &ke, 1, tsp)) {
230 		case -1:
231 			if (errno != EINTR)
232 				err(1, "kevent");
233 			goto again;
234 		case 0:
235 			if (!nonblock) {
236 				j = TAILQ_FIRST(&sleeping);
237 				j->flags |= JF_TIMEOUT;
238 				clear_procs(j);
239 				return j;
240 			}
241 			break;
242 		case 1:
243 			(void)waitpid(ke.ident, NULL, WNOHANG);
244 			if ((j = find_proc(ke.ident))) {
245 				j->pstatus = ke.data;
246 				return j;
247 			}
248 			goto again;
249 		}
250 	}
251 	return NULL;
252 }
253 
254 /*
255  * Run a single command for a jail, possible inside the jail.
256  */
257 static int
258 run_command(struct cfjail *j)
259 {
260 	const struct passwd *pwd;
261 	const struct cfstring *comstring, *s;
262 	login_cap_t *lcap;
263 	char **argv;
264 	char *cs, *comcs, *devpath;
265 	const char *jidstr, *conslog, *path, *ruleset, *term, *username;
266 	enum intparam comparam;
267 	size_t comlen;
268 	pid_t pid;
269 	int argc, bg, clean, consfd, down, fib, i, injail, sjuser, timeout;
270 #if defined(INET) || defined(INET6)
271 	char *addr;
272 #endif
273 
274 	static char *cleanenv;
275 
276 	/* Perform some operations that aren't actually commands */
277 	comparam = *j->comparam;
278 	down = j->flags & (JF_STOP | JF_FAILED);
279 	switch (comparam) {
280 	case IP_STOP_TIMEOUT:
281 		return term_procs(j);
282 
283 	case IP__OP:
284 		if (down) {
285 			if (jail_remove(j->jid) < 0 && errno == EPERM) {
286 				jail_warnx(j, "jail_remove: %s",
287 					   strerror(errno));
288 				return -1;
289 			}
290 			if (verbose > 0 || (verbose == 0 && (j->flags & JF_STOP
291 			    ? note_remove : j->name != NULL)))
292 			    jail_note(j, "removed\n");
293 			j->jid = -1;
294 			if (j->flags & JF_STOP)
295 				dep_done(j, DF_LIGHT);
296 			else
297 				j->flags &= ~JF_PERSIST;
298 		} else {
299 			if (create_jail(j) < 0)
300 				return -1;
301 			if (iflag)
302 				printf("%d\n", j->jid);
303 			if (verbose >= 0 && (j->name || verbose > 0))
304 				jail_note(j, "created\n");
305 			dep_done(j, DF_LIGHT);
306 		}
307 		return 0;
308 
309 	default: ;
310 	}
311 	/*
312 	 * Collect exec arguments.  Internal commands for network and
313 	 * mounting build their own argument lists.
314 	 */
315 	comstring = j->comstring;
316 	bg = 0;
317 	switch (comparam) {
318 #ifdef INET
319 	case IP__IP4_IFADDR:
320 		argv = alloca(8 * sizeof(char *));
321 		*(const char **)&argv[0] = _PATH_IFCONFIG;
322 		if ((cs = strchr(comstring->s, '|'))) {
323 			argv[1] = alloca(cs - comstring->s + 1);
324 			strlcpy(argv[1], comstring->s, cs - comstring->s + 1);
325 			addr = cs + 1;
326 		} else {
327 			*(const char **)&argv[1] =
328 			    string_param(j->intparams[IP_INTERFACE]);
329 			addr = comstring->s;
330 		}
331 		*(const char **)&argv[2] = "inet";
332 		if (!(cs = strchr(addr, '/'))) {
333 			argv[3] = addr;
334 			*(const char **)&argv[4] = "netmask";
335 			*(const char **)&argv[5] = "255.255.255.255";
336 			argc = 6;
337 		} else if (strchr(cs + 1, '.')) {
338 			argv[3] = alloca(cs - addr + 1);
339 			strlcpy(argv[3], addr, cs - addr + 1);
340 			*(const char **)&argv[4] = "netmask";
341 			*(const char **)&argv[5] = cs + 1;
342 			argc = 6;
343 		} else {
344 			argv[3] = addr;
345 			argc = 4;
346 		}
347 		*(const char **)&argv[argc] = down ? "-alias" : "alias";
348 		argv[argc + 1] = NULL;
349 		break;
350 #endif
351 
352 #ifdef INET6
353 	case IP__IP6_IFADDR:
354 		argv = alloca(8 * sizeof(char *));
355 		*(const char **)&argv[0] = _PATH_IFCONFIG;
356 		if ((cs = strchr(comstring->s, '|'))) {
357 			argv[1] = alloca(cs - comstring->s + 1);
358 			strlcpy(argv[1], comstring->s, cs - comstring->s + 1);
359 			addr = cs + 1;
360 		} else {
361 			*(const char **)&argv[1] =
362 			    string_param(j->intparams[IP_INTERFACE]);
363 			addr = comstring->s;
364 		}
365 		*(const char **)&argv[2] = "inet6";
366 		argv[3] = addr;
367 		if (!(cs = strchr(addr, '/'))) {
368 			*(const char **)&argv[4] = "prefixlen";
369 			*(const char **)&argv[5] = "128";
370 			argc = 6;
371 		} else
372 			argc = 4;
373 		*(const char **)&argv[argc] = down ? "-alias" : "alias";
374 		argv[argc + 1] = NULL;
375 		break;
376 #endif
377 
378 	case IP_VNET_INTERFACE:
379 		argv = alloca(5 * sizeof(char *));
380 		*(const char **)&argv[0] = _PATH_IFCONFIG;
381 		argv[1] = comstring->s;
382 		*(const char **)&argv[2] = down ? "-vnet" : "vnet";
383 		jidstr = string_param(j->intparams[KP_JID]);
384 		*(const char **)&argv[3] =
385 			jidstr ? jidstr : string_param(j->intparams[KP_NAME]);
386 		argv[4] = NULL;
387 		break;
388 
389 	case IP_MOUNT:
390 	case IP__MOUNT_FROM_FSTAB:
391 		argv = alloca(8 * sizeof(char *));
392 		comcs = alloca(comstring->len + 1);
393 		strcpy(comcs, comstring->s);
394 		argc = 0;
395 		for (cs = strtok(comcs, " \t\f\v\r\n"); cs && argc < 4;
396 		     cs = strtok(NULL, " \t\f\v\r\n"))
397 			argv[argc++] = cs;
398 		if (argc == 0)
399 			return 0;
400 		if (argc < 3) {
401 			jail_warnx(j, "%s: %s: missing information",
402 			    j->intparams[comparam]->name, comstring->s);
403 			return -1;
404 		}
405 		if (check_path(j, j->intparams[comparam]->name, argv[1], 0,
406 		    down ? argv[2] : NULL) < 0)
407 			return -1;
408 		if (down) {
409 			argv[4] = NULL;
410 			argv[3] = argv[1];
411 			*(const char **)&argv[0] = "/sbin/umount";
412 		} else {
413 			if (argc == 4) {
414 				argv[7] = NULL;
415 				argv[6] = argv[1];
416 				argv[5] = argv[0];
417 				argv[4] = argv[3];
418 				*(const char **)&argv[3] = "-o";
419 			} else {
420 				argv[5] = NULL;
421 				argv[4] = argv[1];
422 				argv[3] = argv[0];
423 			}
424 			*(const char **)&argv[0] = _PATH_MOUNT;
425 		}
426 		*(const char **)&argv[1] = "-t";
427 		break;
428 
429 	case IP_MOUNT_DEVFS:
430 		argv = alloca(7 * sizeof(char *));
431 		path = string_param(j->intparams[KP_PATH]);
432 		if (path == NULL) {
433 			jail_warnx(j, "mount.devfs: no path");
434 			return -1;
435 		}
436 		devpath = alloca(strlen(path) + 5);
437 		sprintf(devpath, "%s/dev", path);
438 		if (check_path(j, "mount.devfs", devpath, 0,
439 		    down ? "devfs" : NULL) < 0)
440 			return -1;
441 		if (down) {
442 			*(const char **)&argv[0] = "/sbin/umount";
443 			argv[1] = devpath;
444 			argv[2] = NULL;
445 		} else {
446 			*(const char **)&argv[0] = _PATH_MOUNT;
447 			*(const char **)&argv[1] = "-t";
448 			*(const char **)&argv[2] = "devfs";
449 			ruleset = string_param(j->intparams[KP_DEVFS_RULESET]);
450 			if (!ruleset)
451 			    ruleset = "4";	/* devfsrules_jail */
452 			argv[3] = alloca(11 + strlen(ruleset));
453 			sprintf(argv[3], "-oruleset=%s", ruleset);
454 			*(const char **)&argv[4] = ".";
455 			argv[5] = devpath;
456 			argv[6] = NULL;
457 		}
458 		break;
459 
460 	case IP_MOUNT_FDESCFS:
461 		argv = alloca(7 * sizeof(char *));
462 		path = string_param(j->intparams[KP_PATH]);
463 		if (path == NULL) {
464 			jail_warnx(j, "mount.fdescfs: no path");
465 			return -1;
466 		}
467 		devpath = alloca(strlen(path) + 8);
468 		sprintf(devpath, "%s/dev/fd", path);
469 		if (check_path(j, "mount.fdescfs", devpath, 0,
470 		    down ? "fdescfs" : NULL) < 0)
471 			return -1;
472 		if (down) {
473 			*(const char **)&argv[0] = "/sbin/umount";
474 			argv[1] = devpath;
475 			argv[2] = NULL;
476 		} else {
477 			*(const char **)&argv[0] = _PATH_MOUNT;
478 			*(const char **)&argv[1] = "-t";
479 			*(const char **)&argv[2] = "fdescfs";
480 			*(const char **)&argv[3] = ".";
481 			argv[4] = devpath;
482 			argv[5] = NULL;
483 		}
484 		break;
485 
486 	case IP_COMMAND:
487 		if (j->name != NULL)
488 			goto default_command;
489 		argc = 0;
490 		TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
491 			argc++;
492 		argv = alloca((argc + 1) * sizeof(char *));
493 		argc = 0;
494 		TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
495 			argv[argc++] = s->s;
496 		argv[argc] = NULL;
497 		j->comstring = &dummystring;
498 		break;
499 
500 	default:
501 	default_command:
502 		if ((cs = strpbrk(comstring->s, "!\"$&'()*;<>?[\\]`{|}~")) &&
503 		    !(cs[0] == '&' && cs[1] == '\0')) {
504 			argv = alloca(4 * sizeof(char *));
505 			*(const char **)&argv[0] = _PATH_BSHELL;
506 			*(const char **)&argv[1] = "-c";
507 			argv[2] = comstring->s;
508 			argv[3] = NULL;
509 		} else {
510 			if (cs) {
511 				*cs = 0;
512 				bg = 1;
513 			}
514 			comcs = alloca(comstring->len + 1);
515 			strcpy(comcs, comstring->s);
516 			argc = 0;
517 			for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
518 			     cs = strtok(NULL, " \t\f\v\r\n"))
519 				argc++;
520 			argv = alloca((argc + 1) * sizeof(char *));
521 			strcpy(comcs, comstring->s);
522 			argc = 0;
523 			for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
524 			     cs = strtok(NULL, " \t\f\v\r\n"))
525 				argv[argc++] = cs;
526 			argv[argc] = NULL;
527 		}
528 	}
529 	if (argv[0] == NULL)
530 		return 0;
531 
532 	if (int_param(j->intparams[IP_EXEC_TIMEOUT], &timeout) &&
533 	    timeout != 0) {
534 		clock_gettime(CLOCK_REALTIME, &j->timeout);
535 		j->timeout.tv_sec += timeout;
536 	} else
537 		j->timeout.tv_sec = 0;
538 
539 	injail = comparam == IP_EXEC_START || comparam == IP_COMMAND ||
540 	    comparam == IP_EXEC_STOP;
541 	clean = bool_param(j->intparams[IP_EXEC_CLEAN]);
542 	username = string_param(j->intparams[injail
543 	    ? IP_EXEC_JAIL_USER : IP_EXEC_SYSTEM_USER]);
544 	sjuser = bool_param(j->intparams[IP_EXEC_SYSTEM_JAIL_USER]);
545 
546 	consfd = 0;
547 	if (injail &&
548 	    (conslog = string_param(j->intparams[IP_EXEC_CONSOLELOG]))) {
549 		if (check_path(j, "exec.consolelog", conslog, 1, NULL) < 0)
550 			return -1;
551 		consfd =
552 		    open(conslog, O_WRONLY | O_CREAT | O_APPEND, DEFFILEMODE);
553 		if (consfd < 0) {
554 			jail_warnx(j, "open %s: %s", conslog, strerror(errno));
555 			return -1;
556 		}
557 	}
558 
559 	comlen = 0;
560 	for (i = 0; argv[i]; i++)
561 		comlen += strlen(argv[i]) + 1;
562 	j->comline = cs = emalloc(comlen);
563 	for (i = 0; argv[i]; i++) {
564 		strcpy(cs, argv[i]);
565 		if (argv[i + 1]) {
566 			cs += strlen(argv[i]) + 1;
567 			cs[-1] = ' ';
568 		}
569 	}
570 	if (verbose > 0)
571 		jail_note(j, "run command%s%s%s: %s\n",
572 		    injail ? " in jail" : "", username ? " as " : "",
573 		    username ? username : "", j->comline);
574 
575 	pid = fork();
576 	if (pid < 0)
577 		err(1, "fork");
578 	if (pid > 0) {
579 		if (bg || !add_proc(j, pid)) {
580 			free(j->comline);
581 			j->comline = NULL;
582 			return 0;
583 		} else {
584 			paralimit--;
585 			return 1;
586 		}
587 	}
588 	if (bg)
589 		setsid();
590 
591 	/* Set up the environment and run the command */
592 	pwd = NULL;
593 	lcap = NULL;
594 	if ((clean || username) && injail && sjuser &&
595 	    get_user_info(j, username, &pwd, &lcap) < 0)
596 		exit(1);
597 	if (injail) {
598 		/* jail_attach won't chdir along with its chroot. */
599 		path = string_param(j->intparams[KP_PATH]);
600 		if (path && chdir(path) < 0) {
601 			jail_warnx(j, "chdir %s: %s", path, strerror(errno));
602 			exit(1);
603 		}
604 		if (int_param(j->intparams[IP_EXEC_FIB], &fib) &&
605 		    setfib(fib) < 0) {
606 			jail_warnx(j, "setfib: %s", strerror(errno));
607 			exit(1);
608 		}
609 		if (jail_attach(j->jid) < 0) {
610 			jail_warnx(j, "jail_attach: %s", strerror(errno));
611 			exit(1);
612 		}
613 	}
614 	if (clean || username) {
615 		if (!(injail && sjuser) &&
616 		    get_user_info(j, username, &pwd, &lcap) < 0)
617 			exit(1);
618 		if (clean) {
619 			term = getenv("TERM");
620 			environ = &cleanenv;
621 			setenv("PATH", "/bin:/usr/bin", 0);
622 			if (term != NULL)
623 				setenv("TERM", term, 1);
624 		}
625 		if (setusercontext(lcap, pwd, pwd->pw_uid, username
626 		    ? LOGIN_SETALL & ~LOGIN_SETGROUP & ~LOGIN_SETLOGIN
627 		    : LOGIN_SETPATH | LOGIN_SETENV) < 0) {
628 			jail_warnx(j, "setusercontext %s: %s", pwd->pw_name,
629 			    strerror(errno));
630 			exit(1);
631 		}
632 		login_close(lcap);
633 		setenv("USER", pwd->pw_name, 1);
634 		setenv("HOME", pwd->pw_dir, 1);
635 		setenv("SHELL",
636 		    *pwd->pw_shell ? pwd->pw_shell : _PATH_BSHELL, 1);
637 		if (clean && chdir(pwd->pw_dir) < 0) {
638 			jail_warnx(j, "chdir %s: %s",
639 			    pwd->pw_dir, strerror(errno));
640 			exit(1);
641 		}
642 		endpwent();
643 	}
644 
645 	if (consfd != 0 && (dup2(consfd, 1) < 0 || dup2(consfd, 2) < 0)) {
646 		jail_warnx(j, "exec.consolelog: %s", strerror(errno));
647 		exit(1);
648 	}
649 	closefrom(3);
650 	execvp(argv[0], argv);
651 	jail_warnx(j, "exec %s: %s", argv[0], strerror(errno));
652 	exit(1);
653 }
654 
655 /*
656  * Add a process to the hash, tied to a jail.
657  */
658 static int
659 add_proc(struct cfjail *j, pid_t pid)
660 {
661 	struct kevent ke;
662 	struct cfjail *tj;
663 	struct phash *ph;
664 
665 	if (!kq && (kq = kqueue()) < 0)
666 		err(1, "kqueue");
667 	EV_SET(&ke, pid, EVFILT_PROC, EV_ADD, NOTE_EXIT, 0, NULL);
668 	if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0) {
669 		if (errno == ESRCH)
670 			return 0;
671 		err(1, "kevent");
672 	}
673 	ph = emalloc(sizeof(struct phash));
674 	ph->j = j;
675 	ph->pid = pid;
676 	LIST_INSERT_HEAD(&phash[pid % PHASH_SIZE], ph, le);
677 	j->nprocs++;
678 	j->flags |= JF_SLEEPQ;
679 	if (j->timeout.tv_sec == 0)
680 		requeue(j, &sleeping);
681 	else {
682 		/* File the jail in the sleep queue acording to its timeout. */
683 		TAILQ_REMOVE(j->queue, j, tq);
684 		TAILQ_FOREACH(tj, &sleeping, tq) {
685 			if (!tj->timeout.tv_sec ||
686 			    j->timeout.tv_sec < tj->timeout.tv_sec ||
687 			    (j->timeout.tv_sec == tj->timeout.tv_sec &&
688 			    j->timeout.tv_nsec <= tj->timeout.tv_nsec)) {
689 				TAILQ_INSERT_BEFORE(tj, j, tq);
690 				break;
691 			}
692 		}
693 		if (tj == NULL)
694 			TAILQ_INSERT_TAIL(&sleeping, j, tq);
695 		j->queue = &sleeping;
696 	}
697 	return 1;
698 }
699 
700 /*
701  * Remove any processes from the hash that correspond to a jail.
702  */
703 static void
704 clear_procs(struct cfjail *j)
705 {
706 	struct kevent ke;
707 	struct phash *ph, *tph;
708 	int i;
709 
710 	j->nprocs = 0;
711 	for (i = 0; i < PHASH_SIZE; i++)
712 		LIST_FOREACH_SAFE(ph, &phash[i], le, tph)
713 			if (ph->j == j) {
714 				EV_SET(&ke, ph->pid, EVFILT_PROC, EV_DELETE,
715 				    NOTE_EXIT, 0, NULL);
716 				(void)kevent(kq, &ke, 1, NULL, 0, NULL);
717 				LIST_REMOVE(ph, le);
718 				free(ph);
719 			}
720 }
721 
722 /*
723  * Find the jail that corresponds to an exited process.
724  */
725 static struct cfjail *
726 find_proc(pid_t pid)
727 {
728 	struct cfjail *j;
729 	struct phash *ph;
730 
731 	LIST_FOREACH(ph, &phash[pid % PHASH_SIZE], le)
732 		if (ph->pid == pid) {
733 			j = ph->j;
734 			LIST_REMOVE(ph, le);
735 			free(ph);
736 			return --j->nprocs ? NULL : j;
737 		}
738 	return NULL;
739 }
740 
741 /*
742  * Send SIGTERM to all processes in a jail and wait for them to die.
743  */
744 static int
745 term_procs(struct cfjail *j)
746 {
747 	struct kinfo_proc *ki;
748 	int i, noted, pcnt, timeout;
749 
750 	static kvm_t *kd;
751 
752 	if (!int_param(j->intparams[IP_STOP_TIMEOUT], &timeout))
753 		timeout = DEFAULT_STOP_TIMEOUT;
754 	else if (timeout == 0)
755 		return 0;
756 
757 	if (kd == NULL) {
758 		kd = kvm_open(NULL, NULL, NULL, O_RDONLY, NULL);
759 		if (kd == NULL)
760 			return 0;
761 	}
762 
763 	ki = kvm_getprocs(kd, KERN_PROC_PROC, 0, &pcnt);
764 	if (ki == NULL)
765 		return 0;
766 	noted = 0;
767 	for (i = 0; i < pcnt; i++)
768 		if (ki[i].ki_jid == j->jid &&
769 		    kill(ki[i].ki_pid, SIGTERM) == 0) {
770 			(void)add_proc(j, ki[i].ki_pid);
771 			if (verbose > 0) {
772 				if (!noted) {
773 					noted = 1;
774 					jail_note(j, "sent SIGTERM to:");
775 				}
776 				printf(" %d", ki[i].ki_pid);
777 			}
778 		}
779 	if (noted)
780 		printf("\n");
781 	if (j->nprocs > 0) {
782 		clock_gettime(CLOCK_REALTIME, &j->timeout);
783 		j->timeout.tv_sec += timeout;
784 		return 1;
785 	}
786 	return 0;
787 }
788 
789 /*
790  * Look up a user in the passwd and login.conf files.
791  */
792 static int
793 get_user_info(struct cfjail *j, const char *username,
794     const struct passwd **pwdp, login_cap_t **lcapp)
795 {
796 	const struct passwd *pwd;
797 
798 	*pwdp = pwd = username ? getpwnam(username) : getpwuid(getuid());
799 	if (pwd == NULL) {
800 		if (errno)
801 			jail_warnx(j, "getpwnam%s%s: %s", username ? " " : "",
802 			    username ? username : "", strerror(errno));
803 		else if (username)
804 			jail_warnx(j, "%s: no such user", username);
805 		else
806 			jail_warnx(j, "unknown uid %d", getuid());
807 		return -1;
808 	}
809 	*lcapp = login_getpwclass(pwd);
810 	if (*lcapp == NULL) {
811 		jail_warnx(j, "getpwclass %s: %s", pwd->pw_name,
812 		    strerror(errno));
813 		return -1;
814 	}
815 	/* Set the groups while the group file is still available */
816 	if (initgroups(pwd->pw_name, pwd->pw_gid) < 0) {
817 		jail_warnx(j, "initgroups %s: %s", pwd->pw_name,
818 		    strerror(errno));
819 		return -1;
820 	}
821 	return 0;
822 }
823 
824 /*
825  * Make sure a mount or consolelog path is a valid absolute pathname
826  * with no symlinks.
827  */
828 static int
829 check_path(struct cfjail *j, const char *pname, const char *path, int isfile,
830     const char *umount_type)
831 {
832 	struct stat st, mpst;
833 	struct statfs stfs;
834 	char *tpath, *p;
835 	const char *jailpath;
836 	size_t jplen;
837 
838 	if (path[0] != '/') {
839 		jail_warnx(j, "%s: %s: not an absolute pathname",
840 		    pname, path);
841 		return -1;
842 	}
843 	/*
844 	 * Only check for symlinks in components below the jail's path,
845 	 * since that's where the security risk lies.
846 	 */
847 	jailpath = string_param(j->intparams[KP_PATH]);
848 	if (jailpath == NULL)
849 		jailpath = "";
850 	jplen = strlen(jailpath);
851 	if (!strncmp(path, jailpath, jplen) && path[jplen] == '/') {
852 		tpath = alloca(strlen(path) + 1);
853 		strcpy(tpath, path);
854 		for (p = tpath + jplen; p != NULL; ) {
855 			p = strchr(p + 1, '/');
856 			if (p)
857 				*p = '\0';
858 			if (lstat(tpath, &st) < 0) {
859 				if (errno == ENOENT && isfile && !p)
860 					break;
861 				jail_warnx(j, "%s: %s: %s", pname, tpath,
862 				    strerror(errno));
863 				return -1;
864 			}
865 			if (S_ISLNK(st.st_mode)) {
866 				jail_warnx(j, "%s: %s is a symbolic link",
867 				    pname, tpath);
868 				return -1;
869 			}
870 			if (p)
871 				*p = '/';
872 		}
873 	}
874 	if (umount_type != NULL) {
875 		if (stat(path, &st) < 0 || statfs(path, &stfs) < 0) {
876 			jail_warnx(j, "%s: %s: %s", pname, path,
877 			    strerror(errno));
878 			return -1;
879 		}
880 		if (stat(stfs.f_mntonname, &mpst) < 0) {
881 			jail_warnx(j, "%s: %s: %s", pname, stfs.f_mntonname,
882 			    strerror(errno));
883 			return -1;
884 		}
885 		if (st.st_ino != mpst.st_ino) {
886 			jail_warnx(j, "%s: %s: not a mount point",
887 			    pname, path);
888 			return -1;
889 		}
890 		if (strcmp(stfs.f_fstypename, umount_type)) {
891 			jail_warnx(j, "%s: %s: not a %s mount",
892 			    pname, path, umount_type);
893 			return -1;
894 		}
895 	}
896 	return 0;
897 }
898