xref: /freebsd/usr.sbin/jail/command.c (revision b9f654b163bce26de79705e77b872427c9f2afa1)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2011 James Gritton
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/types.h>
33 #include <sys/event.h>
34 #include <sys/mount.h>
35 #include <sys/stat.h>
36 #include <sys/sysctl.h>
37 #include <sys/user.h>
38 #include <sys/wait.h>
39 
40 #include <err.h>
41 #include <errno.h>
42 #include <fcntl.h>
43 #include <kvm.h>
44 #include <login_cap.h>
45 #include <paths.h>
46 #include <pwd.h>
47 #include <signal.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <vis.h>
53 
54 #include "jailp.h"
55 
56 #define DEFAULT_STOP_TIMEOUT	10
57 #define PHASH_SIZE		256
58 
59 LIST_HEAD(phhead, phash);
60 
61 struct phash {
62 	LIST_ENTRY(phash)	le;
63 	struct cfjail		*j;
64 	pid_t			pid;
65 };
66 
67 int paralimit = -1;
68 
69 extern char **environ;
70 
71 static int run_command(struct cfjail *j);
72 static int add_proc(struct cfjail *j, pid_t pid);
73 static void clear_procs(struct cfjail *j);
74 static struct cfjail *find_proc(pid_t pid);
75 static int term_procs(struct cfjail *j);
76 static int get_user_info(struct cfjail *j, const char *username,
77     const struct passwd **pwdp, login_cap_t **lcapp);
78 static int check_path(struct cfjail *j, const char *pname, const char *path,
79     int isfile, const char *umount_type);
80 
81 static struct cfjails sleeping = TAILQ_HEAD_INITIALIZER(sleeping);
82 static struct cfjails runnable = TAILQ_HEAD_INITIALIZER(runnable);
83 static struct cfstring dummystring = { .len = 1 };
84 static struct phhead phash[PHASH_SIZE];
85 static int kq;
86 
87 /*
88  * Run the next command associated with a jail.
89  */
90 int
91 next_command(struct cfjail *j)
92 {
93 	enum intparam comparam;
94 	int create_failed, stopping;
95 
96 	if (paralimit == 0) {
97 		if (j->flags & JF_FROM_RUNQ)
98 			requeue_head(j, &runnable);
99 		else
100 			requeue(j, &runnable);
101 		return 1;
102 	}
103 	j->flags &= ~JF_FROM_RUNQ;
104 	create_failed = (j->flags & (JF_STOP | JF_FAILED)) == JF_FAILED;
105 	stopping = (j->flags & JF_STOP) != 0;
106 	comparam = *j->comparam;
107 	for (;;) {
108 		if (j->comstring == NULL) {
109 			j->comparam += create_failed ? -1 : 1;
110 			switch ((comparam = *j->comparam)) {
111 			case IP__NULL:
112 				return 0;
113 			case IP_MOUNT_DEVFS:
114 				if (!bool_param(j->intparams[IP_MOUNT_DEVFS]))
115 					continue;
116 				j->comstring = &dummystring;
117 				break;
118 			case IP_MOUNT_FDESCFS:
119 				if (!bool_param(j->intparams[IP_MOUNT_FDESCFS]))
120 					continue;
121 				j->comstring = &dummystring;
122 				break;
123 			case IP_MOUNT_PROCFS:
124 				if (!bool_param(j->intparams[IP_MOUNT_PROCFS]))
125 					continue;
126 				j->comstring = &dummystring;
127 				break;
128 			case IP__OP:
129 			case IP_STOP_TIMEOUT:
130 				j->comstring = &dummystring;
131 				break;
132 			default:
133 				if (j->intparams[comparam] == NULL)
134 					continue;
135 				j->comstring = create_failed || (stopping &&
136 				    (j->intparams[comparam]->flags & PF_REV))
137 				    ? TAILQ_LAST(&j->intparams[comparam]->val,
138 					cfstrings)
139 				    : TAILQ_FIRST(&j->intparams[comparam]->val);
140 			}
141 		} else {
142 			j->comstring = j->comstring == &dummystring ? NULL :
143 			    create_failed || (stopping &&
144 			    (j->intparams[comparam]->flags & PF_REV))
145 			    ? TAILQ_PREV(j->comstring, cfstrings, tq)
146 			    : TAILQ_NEXT(j->comstring, tq);
147 		}
148 		if (j->comstring == NULL || j->comstring->len == 0 ||
149 		    (create_failed && (comparam == IP_EXEC_PRESTART ||
150 		    comparam == IP_EXEC_CREATED || comparam == IP_EXEC_START ||
151 		    comparam == IP_COMMAND || comparam == IP_EXEC_POSTSTART)))
152 			continue;
153 		switch (run_command(j)) {
154 		case -1:
155 			failed(j);
156 			/* FALLTHROUGH */
157 		case 1:
158 			return 1;
159 		}
160 	}
161 }
162 
163 /*
164  * Check command exit status
165  */
166 int
167 finish_command(struct cfjail *j)
168 {
169 	struct cfjail *rj;
170 	int error;
171 
172 	if (!(j->flags & JF_SLEEPQ))
173 		return 0;
174 	j->flags &= ~JF_SLEEPQ;
175 	if (*j->comparam == IP_STOP_TIMEOUT) {
176 		j->flags &= ~JF_TIMEOUT;
177 		j->pstatus = 0;
178 		return 0;
179 	}
180 	paralimit++;
181 	if (!TAILQ_EMPTY(&runnable)) {
182 		rj = TAILQ_FIRST(&runnable);
183 		rj->flags |= JF_FROM_RUNQ;
184 		requeue(rj, &ready);
185 	}
186 	error = 0;
187 	if (j->flags & JF_TIMEOUT) {
188 		j->flags &= ~JF_TIMEOUT;
189 		if (*j->comparam != IP_STOP_TIMEOUT) {
190 			jail_warnx(j, "%s: timed out", j->comline);
191 			failed(j);
192 			error = -1;
193 		} else if (verbose > 0)
194 			jail_note(j, "timed out\n");
195 	} else if (j->pstatus != 0) {
196 		if (WIFSIGNALED(j->pstatus))
197 			jail_warnx(j, "%s: exited on signal %d",
198 			    j->comline, WTERMSIG(j->pstatus));
199 		else
200 			jail_warnx(j, "%s: failed", j->comline);
201 		j->pstatus = 0;
202 		failed(j);
203 		error = -1;
204 	}
205 	free(j->comline);
206 	j->comline = NULL;
207 	return error;
208 }
209 
210 /*
211  * Check for finished processes or timeouts.
212  */
213 struct cfjail *
214 next_proc(int nonblock)
215 {
216 	struct kevent ke;
217 	struct timespec ts;
218 	struct timespec *tsp;
219 	struct cfjail *j;
220 
221 	if (!TAILQ_EMPTY(&sleeping)) {
222 	again:
223 		tsp = NULL;
224 		if ((j = TAILQ_FIRST(&sleeping)) && j->timeout.tv_sec) {
225 			clock_gettime(CLOCK_REALTIME, &ts);
226 			ts.tv_sec = j->timeout.tv_sec - ts.tv_sec;
227 			ts.tv_nsec = j->timeout.tv_nsec - ts.tv_nsec;
228 			if (ts.tv_nsec < 0) {
229 				ts.tv_sec--;
230 				ts.tv_nsec += 1000000000;
231 			}
232 			if (ts.tv_sec < 0 ||
233 			    (ts.tv_sec == 0 && ts.tv_nsec == 0)) {
234 				j->flags |= JF_TIMEOUT;
235 				clear_procs(j);
236 				return j;
237 			}
238 			tsp = &ts;
239 		}
240 		if (nonblock) {
241 			ts.tv_sec = 0;
242 			ts.tv_nsec = 0;
243 			tsp = &ts;
244 		}
245 		switch (kevent(kq, NULL, 0, &ke, 1, tsp)) {
246 		case -1:
247 			if (errno != EINTR)
248 				err(1, "kevent");
249 			goto again;
250 		case 0:
251 			if (!nonblock) {
252 				j = TAILQ_FIRST(&sleeping);
253 				j->flags |= JF_TIMEOUT;
254 				clear_procs(j);
255 				return j;
256 			}
257 			break;
258 		case 1:
259 			(void)waitpid(ke.ident, NULL, WNOHANG);
260 			if ((j = find_proc(ke.ident))) {
261 				j->pstatus = ke.data;
262 				return j;
263 			}
264 			goto again;
265 		}
266 	}
267 	return NULL;
268 }
269 
270 /*
271  * Run a single command for a jail, possibly inside the jail.
272  */
273 static int
274 run_command(struct cfjail *j)
275 {
276 	const struct passwd *pwd;
277 	const struct cfstring *comstring, *s;
278 	login_cap_t *lcap;
279 	const char **argv;
280 	char *acs, *cs, *comcs, *devpath;
281 	const char *jidstr, *conslog, *path, *ruleset, *term, *username;
282 	enum intparam comparam;
283 	size_t comlen;
284 	pid_t pid;
285 	int argc, bg, clean, consfd, down, fib, i, injail, sjuser, timeout;
286 #if defined(INET) || defined(INET6)
287 	char *addr, *extrap, *p, *val;
288 #endif
289 
290 	static char *cleanenv;
291 
292 	/* Perform some operations that aren't actually commands */
293 	comparam = *j->comparam;
294 	down = j->flags & (JF_STOP | JF_FAILED);
295 	switch (comparam) {
296 	case IP_STOP_TIMEOUT:
297 		return term_procs(j);
298 
299 	case IP__OP:
300 		if (down) {
301 			if (jail_remove(j->jid) < 0 && errno == EPERM) {
302 				jail_warnx(j, "jail_remove: %s",
303 					   strerror(errno));
304 				return -1;
305 			}
306 			if (verbose > 0 || (verbose == 0 && (j->flags & JF_STOP
307 			    ? note_remove : j->name != NULL)))
308 			    jail_note(j, "removed\n");
309 			j->jid = -1;
310 			if (j->flags & JF_STOP)
311 				dep_done(j, DF_LIGHT);
312 			else
313 				j->flags &= ~JF_PERSIST;
314 		} else {
315 			if (create_jail(j) < 0)
316 				return -1;
317 			if (iflag)
318 				printf("%d\n", j->jid);
319 			if (verbose >= 0 && (j->name || verbose > 0))
320 				jail_note(j, "created\n");
321 			dep_done(j, DF_LIGHT);
322 		}
323 		return 0;
324 
325 	default: ;
326 	}
327 	/*
328 	 * Collect exec arguments.  Internal commands for network and
329 	 * mounting build their own argument lists.
330 	 */
331 	comstring = j->comstring;
332 	bg = 0;
333 	switch (comparam) {
334 #ifdef INET
335 	case IP__IP4_IFADDR:
336 		argc = 0;
337 		val = alloca(strlen(comstring->s) + 1);
338 		strcpy(val, comstring->s);
339 		cs = val;
340 		extrap = NULL;
341 		while ((p = strchr(cs, ' ')) != NULL && strlen(p) > 1) {
342 			if (extrap == NULL) {
343 				*p = '\0';
344 				extrap = p + 1;
345 			}
346 			cs = p + 1;
347 			argc++;
348 		}
349 
350 		argv = alloca((8 + argc) * sizeof(char *));
351 		argv[0] = _PATH_IFCONFIG;
352 		if ((cs = strchr(val, '|'))) {
353 			argv[1] = acs = alloca(cs - val + 1);
354 			strlcpy(acs, val, cs - val + 1);
355 			addr = cs + 1;
356 		} else {
357 			argv[1] = string_param(j->intparams[IP_INTERFACE]);
358 			addr = val;
359 		}
360 		argv[2] = "inet";
361 		if (!(cs = strchr(addr, '/'))) {
362 			argv[3] = addr;
363 			argv[4] = "netmask";
364 			argv[5] = "255.255.255.255";
365 			argc = 6;
366 		} else if (strchr(cs + 1, '.')) {
367 			argv[3] = acs = alloca(cs - addr + 1);
368 			strlcpy(acs, addr, cs - addr + 1);
369 			argv[4] = "netmask";
370 			argv[5] = cs + 1;
371 			argc = 6;
372 		} else {
373 			argv[3] = addr;
374 			argc = 4;
375 		}
376 
377 		if (!down && extrap != NULL) {
378 			for (cs = strtok(extrap, " "); cs;
379 			     cs = strtok(NULL, " ")) {
380 				size_t len = strlen(cs) + 1;
381 				argv[argc++] = acs = alloca(len);
382 				strlcpy(acs, cs, len);
383 			}
384 		}
385 
386 		argv[argc] = down ? "-alias" : "alias";
387 		argv[argc + 1] = NULL;
388 		break;
389 #endif
390 
391 #ifdef INET6
392 	case IP__IP6_IFADDR:
393 		argc = 0;
394 		val = alloca(strlen(comstring->s) + 1);
395 		strcpy(val, comstring->s);
396 		cs = val;
397 		extrap = NULL;
398 		while ((p = strchr(cs, ' ')) != NULL && strlen(p) > 1) {
399 			if (extrap == NULL) {
400 				*p = '\0';
401 				extrap = p + 1;
402 			}
403 			cs = p + 1;
404 			argc++;
405 		}
406 
407 		argv = alloca((8 + argc) * sizeof(char *));
408 		argv[0] = _PATH_IFCONFIG;
409 		if ((cs = strchr(val, '|'))) {
410 			argv[1] = acs = alloca(cs - val + 1);
411 			strlcpy(acs, val, cs - val + 1);
412 			addr = cs + 1;
413 		} else {
414 			argv[1] = string_param(j->intparams[IP_INTERFACE]);
415 			addr = val;
416 		}
417 		argv[2] = "inet6";
418 		argv[3] = addr;
419 		if (!(cs = strchr(addr, '/'))) {
420 			argv[4] = "prefixlen";
421 			argv[5] = "128";
422 			argc = 6;
423 		} else
424 			argc = 4;
425 
426 		if (!down) {
427 			for (cs = strtok(extrap, " "); cs;
428 			     cs = strtok(NULL, " ")) {
429 				size_t len = strlen(cs) + 1;
430 				argv[argc++] = acs = alloca(len);
431 				strlcpy(acs, cs, len);
432 			}
433 		}
434 
435 		argv[argc] = down ? "-alias" : "alias";
436 		argv[argc + 1] = NULL;
437 		break;
438 #endif
439 
440 	case IP_VNET_INTERFACE:
441 		argv = alloca(5 * sizeof(char *));
442 		argv[0] = _PATH_IFCONFIG;
443 		argv[1] = comstring->s;
444 		argv[2] = down ? "-vnet" : "vnet";
445 		jidstr = string_param(j->intparams[KP_JID]);
446 		argv[3] = jidstr ? jidstr : string_param(j->intparams[KP_NAME]);
447 		argv[4] = NULL;
448 		break;
449 
450 	case IP_MOUNT:
451 	case IP__MOUNT_FROM_FSTAB:
452 		argv = alloca(8 * sizeof(char *));
453 		comcs = alloca(comstring->len + 1);
454 		strcpy(comcs, comstring->s);
455 		argc = 0;
456 		for (cs = strtok(comcs, " \t\f\v\r\n"); cs && argc < 4;
457 		     cs = strtok(NULL, " \t\f\v\r\n")) {
458 			if (argc <= 1 && strunvis(cs, cs) < 0) {
459 				jail_warnx(j, "%s: %s: fstab parse error",
460 				    j->intparams[comparam]->name, comstring->s);
461 				return -1;
462 			}
463 			argv[argc++] = cs;
464 		}
465 		if (argc == 0)
466 			return 0;
467 		if (argc < 3) {
468 			jail_warnx(j, "%s: %s: missing information",
469 			    j->intparams[comparam]->name, comstring->s);
470 			return -1;
471 		}
472 		if (check_path(j, j->intparams[comparam]->name, argv[1], 0,
473 		    down ? argv[2] : NULL) < 0)
474 			return -1;
475 		if (down) {
476 			argv[4] = NULL;
477 			argv[3] = argv[1];
478 			argv[0] = "/sbin/umount";
479 		} else {
480 			if (argc == 4) {
481 				argv[7] = NULL;
482 				argv[6] = argv[1];
483 				argv[5] = argv[0];
484 				argv[4] = argv[3];
485 				argv[3] = "-o";
486 			} else {
487 				argv[5] = NULL;
488 				argv[4] = argv[1];
489 				argv[3] = argv[0];
490 			}
491 			argv[0] = _PATH_MOUNT;
492 		}
493 		argv[1] = "-t";
494 		break;
495 
496 	case IP_MOUNT_DEVFS:
497 		argv = alloca(7 * sizeof(char *));
498 		path = string_param(j->intparams[KP_PATH]);
499 		if (path == NULL) {
500 			jail_warnx(j, "mount.devfs: no jail root path defined");
501 			return -1;
502 		}
503 		devpath = alloca(strlen(path) + 5);
504 		sprintf(devpath, "%s/dev", path);
505 		if (check_path(j, "mount.devfs", devpath, 0,
506 		    down ? "devfs" : NULL) < 0)
507 			return -1;
508 		if (down) {
509 			argv[0] = "/sbin/umount";
510 			argv[1] = devpath;
511 			argv[2] = NULL;
512 		} else {
513 			argv[0] = _PATH_MOUNT;
514 			argv[1] = "-t";
515 			argv[2] = "devfs";
516 			ruleset = string_param(j->intparams[KP_DEVFS_RULESET]);
517 			if (!ruleset)
518 			    ruleset = "4";	/* devfsrules_jail */
519 			argv[3] = acs = alloca(11 + strlen(ruleset));
520 			sprintf(acs, "-oruleset=%s", ruleset);
521 			argv[4] = ".";
522 			argv[5] = devpath;
523 			argv[6] = NULL;
524 		}
525 		break;
526 
527 	case IP_MOUNT_FDESCFS:
528 		argv = alloca(7 * sizeof(char *));
529 		path = string_param(j->intparams[KP_PATH]);
530 		if (path == NULL) {
531 			jail_warnx(j, "mount.fdescfs: no jail root path defined");
532 			return -1;
533 		}
534 		devpath = alloca(strlen(path) + 8);
535 		sprintf(devpath, "%s/dev/fd", path);
536 		if (check_path(j, "mount.fdescfs", devpath, 0,
537 		    down ? "fdescfs" : NULL) < 0)
538 			return -1;
539 		if (down) {
540 			argv[0] = "/sbin/umount";
541 			argv[1] = devpath;
542 			argv[2] = NULL;
543 		} else {
544 			argv[0] = _PATH_MOUNT;
545 			argv[1] = "-t";
546 			argv[2] = "fdescfs";
547 			argv[3] = ".";
548 			argv[4] = devpath;
549 			argv[5] = NULL;
550 		}
551 		break;
552 
553 	case IP_MOUNT_PROCFS:
554 		argv = alloca(7 * sizeof(char *));
555 		path = string_param(j->intparams[KP_PATH]);
556 		if (path == NULL) {
557 			jail_warnx(j, "mount.procfs: no jail root path defined");
558 			return -1;
559 		}
560 		devpath = alloca(strlen(path) + 6);
561 		sprintf(devpath, "%s/proc", path);
562 		if (check_path(j, "mount.procfs", devpath, 0,
563 		    down ? "procfs" : NULL) < 0)
564 			return -1;
565 		if (down) {
566 			argv[0] = "/sbin/umount";
567 			argv[1] = devpath;
568 			argv[2] = NULL;
569 		} else {
570 			argv[0] = _PATH_MOUNT;
571 			argv[1] = "-t";
572 			argv[2] = "procfs";
573 			argv[3] = ".";
574 			argv[4] = devpath;
575 			argv[5] = NULL;
576 		}
577 		break;
578 
579 	case IP_COMMAND:
580 		if (j->name != NULL)
581 			goto default_command;
582 		argc = 0;
583 		TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
584 			argc++;
585 		argv = alloca((argc + 1) * sizeof(char *));
586 		argc = 0;
587 		TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
588 			argv[argc++] = s->s;
589 		argv[argc] = NULL;
590 		j->comstring = &dummystring;
591 		break;
592 
593 	default:
594 	default_command:
595 		if ((cs = strpbrk(comstring->s, "!\"$&'()*;<>?[\\]`{|}~")) &&
596 		    !(cs[0] == '&' && cs[1] == '\0')) {
597 			argv = alloca(4 * sizeof(char *));
598 			argv[0] = _PATH_BSHELL;
599 			argv[1] = "-c";
600 			argv[2] = comstring->s;
601 			argv[3] = NULL;
602 		} else {
603 			if (cs) {
604 				*cs = 0;
605 				bg = 1;
606 			}
607 			comcs = alloca(comstring->len + 1);
608 			strcpy(comcs, comstring->s);
609 			argc = 0;
610 			for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
611 			     cs = strtok(NULL, " \t\f\v\r\n"))
612 				argc++;
613 			argv = alloca((argc + 1) * sizeof(char *));
614 			strcpy(comcs, comstring->s);
615 			argc = 0;
616 			for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
617 			     cs = strtok(NULL, " \t\f\v\r\n"))
618 				argv[argc++] = cs;
619 			argv[argc] = NULL;
620 		}
621 	}
622 	if (argv[0] == NULL)
623 		return 0;
624 
625 	if (int_param(j->intparams[IP_EXEC_TIMEOUT], &timeout) &&
626 	    timeout != 0) {
627 		clock_gettime(CLOCK_REALTIME, &j->timeout);
628 		j->timeout.tv_sec += timeout;
629 	} else
630 		j->timeout.tv_sec = 0;
631 
632 	injail = comparam == IP_EXEC_START || comparam == IP_COMMAND ||
633 	    comparam == IP_EXEC_STOP;
634 	clean = bool_param(j->intparams[IP_EXEC_CLEAN]);
635 	username = string_param(j->intparams[injail
636 	    ? IP_EXEC_JAIL_USER : IP_EXEC_SYSTEM_USER]);
637 	sjuser = bool_param(j->intparams[IP_EXEC_SYSTEM_JAIL_USER]);
638 
639 	consfd = 0;
640 	if (injail &&
641 	    (conslog = string_param(j->intparams[IP_EXEC_CONSOLELOG]))) {
642 		if (check_path(j, "exec.consolelog", conslog, 1, NULL) < 0)
643 			return -1;
644 		consfd =
645 		    open(conslog, O_WRONLY | O_CREAT | O_APPEND, DEFFILEMODE);
646 		if (consfd < 0) {
647 			jail_warnx(j, "open %s: %s", conslog, strerror(errno));
648 			return -1;
649 		}
650 	}
651 
652 	comlen = 0;
653 	for (i = 0; argv[i]; i++)
654 		comlen += strlen(argv[i]) + 1;
655 	j->comline = cs = emalloc(comlen);
656 	for (i = 0; argv[i]; i++) {
657 		strcpy(cs, argv[i]);
658 		if (argv[i + 1]) {
659 			cs += strlen(argv[i]) + 1;
660 			cs[-1] = ' ';
661 		}
662 	}
663 	if (verbose > 0)
664 		jail_note(j, "run command%s%s%s: %s\n",
665 		    injail ? " in jail" : "", username ? " as " : "",
666 		    username ? username : "", j->comline);
667 
668 	pid = fork();
669 	if (pid < 0)
670 		err(1, "fork");
671 	if (pid > 0) {
672 		if (bg || !add_proc(j, pid)) {
673 			free(j->comline);
674 			j->comline = NULL;
675 			return 0;
676 		} else {
677 			paralimit--;
678 			return 1;
679 		}
680 	}
681 	if (bg)
682 		setsid();
683 
684 	/* Set up the environment and run the command */
685 	pwd = NULL;
686 	lcap = NULL;
687 	if ((clean || username) && injail && sjuser &&
688 	    get_user_info(j, username, &pwd, &lcap) < 0)
689 		exit(1);
690 	if (injail) {
691 		/* jail_attach won't chdir along with its chroot. */
692 		path = string_param(j->intparams[KP_PATH]);
693 		if (path && chdir(path) < 0) {
694 			jail_warnx(j, "chdir %s: %s", path, strerror(errno));
695 			exit(1);
696 		}
697 		if (int_param(j->intparams[IP_EXEC_FIB], &fib) &&
698 		    setfib(fib) < 0) {
699 			jail_warnx(j, "setfib: %s", strerror(errno));
700 			exit(1);
701 		}
702 		if (jail_attach(j->jid) < 0) {
703 			jail_warnx(j, "jail_attach: %s", strerror(errno));
704 			exit(1);
705 		}
706 	}
707 	if (clean || username) {
708 		if (!(injail && sjuser) &&
709 		    get_user_info(j, username, &pwd, &lcap) < 0)
710 			exit(1);
711 		if (clean) {
712 			term = getenv("TERM");
713 			environ = &cleanenv;
714 			setenv("PATH", "/bin:/usr/bin", 0);
715 			if (term != NULL)
716 				setenv("TERM", term, 1);
717 		}
718 		if (setgid(pwd->pw_gid) < 0) {
719 			jail_warnx(j, "setgid %d: %s", pwd->pw_gid,
720 			    strerror(errno));
721 			exit(1);
722 		}
723 		if (setusercontext(lcap, pwd, pwd->pw_uid, username
724 		    ? LOGIN_SETALL & ~LOGIN_SETGROUP & ~LOGIN_SETLOGIN
725 		    : LOGIN_SETPATH | LOGIN_SETENV) < 0) {
726 			jail_warnx(j, "setusercontext %s: %s", pwd->pw_name,
727 			    strerror(errno));
728 			exit(1);
729 		}
730 		login_close(lcap);
731 		setenv("USER", pwd->pw_name, 1);
732 		setenv("HOME", pwd->pw_dir, 1);
733 		setenv("SHELL",
734 		    *pwd->pw_shell ? pwd->pw_shell : _PATH_BSHELL, 1);
735 		if (clean && chdir(pwd->pw_dir) < 0) {
736 			jail_warnx(j, "chdir %s: %s",
737 			    pwd->pw_dir, strerror(errno));
738 			exit(1);
739 		}
740 		endpwent();
741 	}
742 
743 	if (consfd != 0 && (dup2(consfd, 1) < 0 || dup2(consfd, 2) < 0)) {
744 		jail_warnx(j, "exec.consolelog: %s", strerror(errno));
745 		exit(1);
746 	}
747 	closefrom(3);
748 	execvp(argv[0], __DECONST(char *const*, argv));
749 	jail_warnx(j, "exec %s: %s", argv[0], strerror(errno));
750 	exit(1);
751 }
752 
753 /*
754  * Add a process to the hash, tied to a jail.
755  */
756 static int
757 add_proc(struct cfjail *j, pid_t pid)
758 {
759 	struct kevent ke;
760 	struct cfjail *tj;
761 	struct phash *ph;
762 
763 	if (!kq && (kq = kqueue()) < 0)
764 		err(1, "kqueue");
765 	EV_SET(&ke, pid, EVFILT_PROC, EV_ADD, NOTE_EXIT, 0, NULL);
766 	if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0) {
767 		if (errno == ESRCH)
768 			return 0;
769 		err(1, "kevent");
770 	}
771 	ph = emalloc(sizeof(struct phash));
772 	ph->j = j;
773 	ph->pid = pid;
774 	LIST_INSERT_HEAD(&phash[pid % PHASH_SIZE], ph, le);
775 	j->nprocs++;
776 	j->flags |= JF_SLEEPQ;
777 	if (j->timeout.tv_sec == 0)
778 		requeue(j, &sleeping);
779 	else {
780 		/* File the jail in the sleep queue according to its timeout. */
781 		TAILQ_REMOVE(j->queue, j, tq);
782 		TAILQ_FOREACH(tj, &sleeping, tq) {
783 			if (!tj->timeout.tv_sec ||
784 			    j->timeout.tv_sec < tj->timeout.tv_sec ||
785 			    (j->timeout.tv_sec == tj->timeout.tv_sec &&
786 			    j->timeout.tv_nsec <= tj->timeout.tv_nsec)) {
787 				TAILQ_INSERT_BEFORE(tj, j, tq);
788 				break;
789 			}
790 		}
791 		if (tj == NULL)
792 			TAILQ_INSERT_TAIL(&sleeping, j, tq);
793 		j->queue = &sleeping;
794 	}
795 	return 1;
796 }
797 
798 /*
799  * Remove any processes from the hash that correspond to a jail.
800  */
801 static void
802 clear_procs(struct cfjail *j)
803 {
804 	struct kevent ke;
805 	struct phash *ph, *tph;
806 	int i;
807 
808 	j->nprocs = 0;
809 	for (i = 0; i < PHASH_SIZE; i++)
810 		LIST_FOREACH_SAFE(ph, &phash[i], le, tph)
811 			if (ph->j == j) {
812 				EV_SET(&ke, ph->pid, EVFILT_PROC, EV_DELETE,
813 				    NOTE_EXIT, 0, NULL);
814 				(void)kevent(kq, &ke, 1, NULL, 0, NULL);
815 				LIST_REMOVE(ph, le);
816 				free(ph);
817 			}
818 }
819 
820 /*
821  * Find the jail that corresponds to an exited process.
822  */
823 static struct cfjail *
824 find_proc(pid_t pid)
825 {
826 	struct cfjail *j;
827 	struct phash *ph;
828 
829 	LIST_FOREACH(ph, &phash[pid % PHASH_SIZE], le)
830 		if (ph->pid == pid) {
831 			j = ph->j;
832 			LIST_REMOVE(ph, le);
833 			free(ph);
834 			return --j->nprocs ? NULL : j;
835 		}
836 	return NULL;
837 }
838 
839 /*
840  * Send SIGTERM to all processes in a jail and wait for them to die.
841  */
842 static int
843 term_procs(struct cfjail *j)
844 {
845 	struct kinfo_proc *ki;
846 	int i, noted, pcnt, timeout;
847 
848 	static kvm_t *kd;
849 
850 	if (!int_param(j->intparams[IP_STOP_TIMEOUT], &timeout))
851 		timeout = DEFAULT_STOP_TIMEOUT;
852 	else if (timeout == 0)
853 		return 0;
854 
855 	if (kd == NULL) {
856 		kd = kvm_open(NULL, NULL, NULL, O_RDONLY, NULL);
857 		if (kd == NULL)
858 			return 0;
859 	}
860 
861 	ki = kvm_getprocs(kd, KERN_PROC_PROC, 0, &pcnt);
862 	if (ki == NULL)
863 		return 0;
864 	noted = 0;
865 	for (i = 0; i < pcnt; i++)
866 		if (ki[i].ki_jid == j->jid &&
867 		    kill(ki[i].ki_pid, SIGTERM) == 0) {
868 			(void)add_proc(j, ki[i].ki_pid);
869 			if (verbose > 0) {
870 				if (!noted) {
871 					noted = 1;
872 					jail_note(j, "sent SIGTERM to:");
873 				}
874 				printf(" %d", ki[i].ki_pid);
875 			}
876 		}
877 	if (noted)
878 		printf("\n");
879 	if (j->nprocs > 0) {
880 		clock_gettime(CLOCK_REALTIME, &j->timeout);
881 		j->timeout.tv_sec += timeout;
882 		return 1;
883 	}
884 	return 0;
885 }
886 
887 /*
888  * Look up a user in the passwd and login.conf files.
889  */
890 static int
891 get_user_info(struct cfjail *j, const char *username,
892     const struct passwd **pwdp, login_cap_t **lcapp)
893 {
894 	const struct passwd *pwd;
895 
896 	errno = 0;
897 	*pwdp = pwd = username ? getpwnam(username) : getpwuid(getuid());
898 	if (pwd == NULL) {
899 		if (errno)
900 			jail_warnx(j, "getpwnam%s%s: %s", username ? " " : "",
901 			    username ? username : "", strerror(errno));
902 		else if (username)
903 			jail_warnx(j, "%s: no such user", username);
904 		else
905 			jail_warnx(j, "unknown uid %d", getuid());
906 		return -1;
907 	}
908 	*lcapp = login_getpwclass(pwd);
909 	if (*lcapp == NULL) {
910 		jail_warnx(j, "getpwclass %s: %s", pwd->pw_name,
911 		    strerror(errno));
912 		return -1;
913 	}
914 	/* Set the groups while the group file is still available */
915 	if (initgroups(pwd->pw_name, pwd->pw_gid) < 0) {
916 		jail_warnx(j, "initgroups %s: %s", pwd->pw_name,
917 		    strerror(errno));
918 		return -1;
919 	}
920 	return 0;
921 }
922 
923 /*
924  * Make sure a mount or consolelog path is a valid absolute pathname
925  * with no symlinks.
926  */
927 static int
928 check_path(struct cfjail *j, const char *pname, const char *path, int isfile,
929     const char *umount_type)
930 {
931 	struct stat st, mpst;
932 	struct statfs stfs;
933 	char *tpath, *p;
934 	const char *jailpath;
935 	size_t jplen;
936 
937 	if (path[0] != '/') {
938 		jail_warnx(j, "%s: %s: not an absolute pathname",
939 		    pname, path);
940 		return -1;
941 	}
942 	/*
943 	 * Only check for symlinks in components below the jail's path,
944 	 * since that's where the security risk lies.
945 	 */
946 	jailpath = string_param(j->intparams[KP_PATH]);
947 	if (jailpath == NULL)
948 		jailpath = "";
949 	jplen = strlen(jailpath);
950 	if (!strncmp(path, jailpath, jplen) && path[jplen] == '/') {
951 		tpath = alloca(strlen(path) + 1);
952 		strcpy(tpath, path);
953 		for (p = tpath + jplen; p != NULL; ) {
954 			p = strchr(p + 1, '/');
955 			if (p)
956 				*p = '\0';
957 			if (lstat(tpath, &st) < 0) {
958 				if (errno == ENOENT && isfile && !p)
959 					break;
960 				jail_warnx(j, "%s: %s: %s", pname, tpath,
961 				    strerror(errno));
962 				return -1;
963 			}
964 			if (S_ISLNK(st.st_mode)) {
965 				jail_warnx(j, "%s: %s is a symbolic link",
966 				    pname, tpath);
967 				return -1;
968 			}
969 			if (p)
970 				*p = '/';
971 		}
972 	}
973 	if (umount_type != NULL) {
974 		if (stat(path, &st) < 0 || statfs(path, &stfs) < 0) {
975 			jail_warnx(j, "%s: %s: %s", pname, path,
976 			    strerror(errno));
977 			return -1;
978 		}
979 		if (stat(stfs.f_mntonname, &mpst) < 0) {
980 			jail_warnx(j, "%s: %s: %s", pname, stfs.f_mntonname,
981 			    strerror(errno));
982 			return -1;
983 		}
984 		if (st.st_ino != mpst.st_ino) {
985 			jail_warnx(j, "%s: %s: not a mount point",
986 			    pname, path);
987 			return -1;
988 		}
989 		if (strcmp(stfs.f_fstypename, umount_type)) {
990 			jail_warnx(j, "%s: %s: not a %s mount",
991 			    pname, path, umount_type);
992 			return -1;
993 		}
994 	}
995 	return 0;
996 }
997