xref: /trueos/usr.sbin/jail/command.c (revision f3fa4bdf8b98edb697d801e65b8b2bd542f15787)
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
next_command(struct cfjail * j)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 				break;
116 			case IP_MOUNT_PROCFS:
117 				if (!bool_param(j->intparams[IP_MOUNT_PROCFS]))
118 					continue;
119 				j->comstring = &dummystring;
120 				break;
121 			case IP__OP:
122 			case IP_STOP_TIMEOUT:
123 				j->comstring = &dummystring;
124 				break;
125 			default:
126 				if (j->intparams[comparam] == NULL)
127 					continue;
128 				j->comstring = create_failed || (stopping &&
129 				    (j->intparams[comparam]->flags & PF_REV))
130 				    ? TAILQ_LAST(&j->intparams[comparam]->val,
131 					cfstrings)
132 				    : TAILQ_FIRST(&j->intparams[comparam]->val);
133 			}
134 		} else {
135 			j->comstring = j->comstring == &dummystring ? NULL :
136 			    create_failed || (stopping &&
137 			    (j->intparams[comparam]->flags & PF_REV))
138 			    ? TAILQ_PREV(j->comstring, cfstrings, tq)
139 			    : TAILQ_NEXT(j->comstring, tq);
140 		}
141 		if (j->comstring == NULL || j->comstring->len == 0 ||
142 		    (create_failed && (comparam == IP_EXEC_PRESTART ||
143 		    comparam == IP_EXEC_START || comparam == IP_COMMAND ||
144 		    comparam == IP_EXEC_POSTSTART)))
145 			continue;
146 		switch (run_command(j)) {
147 		case -1:
148 			failed(j);
149 			/* FALLTHROUGH */
150 		case 1:
151 			return 1;
152 		}
153 	}
154 }
155 
156 /*
157  * Check command exit status
158  */
159 int
finish_command(struct cfjail * j)160 finish_command(struct cfjail *j)
161 {
162 	int error;
163 
164 	if (!(j->flags & JF_SLEEPQ))
165 		return 0;
166 	j->flags &= ~JF_SLEEPQ;
167 	if (*j->comparam == IP_STOP_TIMEOUT)
168 	{
169 		j->flags &= ~JF_TIMEOUT;
170 		j->pstatus = 0;
171 		return 0;
172 	}
173 	paralimit++;
174 	if (!TAILQ_EMPTY(&runnable))
175 		requeue(TAILQ_FIRST(&runnable), &ready);
176 	error = 0;
177 	if (j->flags & JF_TIMEOUT) {
178 		j->flags &= ~JF_TIMEOUT;
179 		if (*j->comparam != IP_STOP_TIMEOUT) {
180 			jail_warnx(j, "%s: timed out", j->comline);
181 			failed(j);
182 			error = -1;
183 		} else if (verbose > 0)
184 			jail_note(j, "timed out\n");
185 	} else if (j->pstatus != 0) {
186 		if (WIFSIGNALED(j->pstatus))
187 			jail_warnx(j, "%s: exited on signal %d",
188 			    j->comline, WTERMSIG(j->pstatus));
189 		else
190 			jail_warnx(j, "%s: failed", j->comline);
191 		j->pstatus = 0;
192 		failed(j);
193 		error = -1;
194 	}
195 	free(j->comline);
196 	j->comline = NULL;
197 	return error;
198 }
199 
200 /*
201  * Check for finished processes or timeouts.
202  */
203 struct cfjail *
next_proc(int nonblock)204 next_proc(int nonblock)
205 {
206 	struct kevent ke;
207 	struct timespec ts;
208 	struct timespec *tsp;
209 	struct cfjail *j;
210 
211 	if (!TAILQ_EMPTY(&sleeping)) {
212 	again:
213 		tsp = NULL;
214 		if ((j = TAILQ_FIRST(&sleeping)) && j->timeout.tv_sec) {
215 			clock_gettime(CLOCK_REALTIME, &ts);
216 			ts.tv_sec = j->timeout.tv_sec - ts.tv_sec;
217 			ts.tv_nsec = j->timeout.tv_nsec - ts.tv_nsec;
218 			if (ts.tv_nsec < 0) {
219 				ts.tv_sec--;
220 				ts.tv_nsec += 1000000000;
221 			}
222 			if (ts.tv_sec < 0 ||
223 			    (ts.tv_sec == 0 && ts.tv_nsec == 0)) {
224 				j->flags |= JF_TIMEOUT;
225 				clear_procs(j);
226 				return j;
227 			}
228 			tsp = &ts;
229 		}
230 		if (nonblock) {
231 			ts.tv_sec = 0;
232 			ts.tv_nsec = 0;
233 			tsp = &ts;
234 		}
235 		switch (kevent(kq, NULL, 0, &ke, 1, tsp)) {
236 		case -1:
237 			if (errno != EINTR)
238 				err(1, "kevent");
239 			goto again;
240 		case 0:
241 			if (!nonblock) {
242 				j = TAILQ_FIRST(&sleeping);
243 				j->flags |= JF_TIMEOUT;
244 				clear_procs(j);
245 				return j;
246 			}
247 			break;
248 		case 1:
249 			(void)waitpid(ke.ident, NULL, WNOHANG);
250 			if ((j = find_proc(ke.ident))) {
251 				j->pstatus = ke.data;
252 				return j;
253 			}
254 			goto again;
255 		}
256 	}
257 	return NULL;
258 }
259 
260 /*
261  * Run a single command for a jail, possible inside the jail.
262  */
263 static int
run_command(struct cfjail * j)264 run_command(struct cfjail *j)
265 {
266 	const struct passwd *pwd;
267 	const struct cfstring *comstring, *s;
268 	login_cap_t *lcap;
269 	char **argv;
270 	char *cs, *comcs, *devpath;
271 	const char *jidstr, *conslog, *path, *ruleset, *term, *username;
272 	enum intparam comparam;
273 	size_t comlen;
274 	pid_t pid;
275 	int argc, bg, clean, consfd, down, fib, i, injail, sjuser, timeout;
276 #if defined(INET) || defined(INET6)
277 	char *addr, *extrap, *p, *val;
278 #endif
279 
280 	static char *cleanenv;
281 
282 	/* Perform some operations that aren't actually commands */
283 	comparam = *j->comparam;
284 	down = j->flags & (JF_STOP | JF_FAILED);
285 	switch (comparam) {
286 	case IP_STOP_TIMEOUT:
287 		return term_procs(j);
288 
289 	case IP__OP:
290 		if (down) {
291 			if (jail_remove(j->jid) < 0 && errno == EPERM) {
292 				jail_warnx(j, "jail_remove: %s",
293 					   strerror(errno));
294 				return -1;
295 			}
296 			if (verbose > 0 || (verbose == 0 && (j->flags & JF_STOP
297 			    ? note_remove : j->name != NULL)))
298 			    jail_note(j, "removed\n");
299 			j->jid = -1;
300 			if (j->flags & JF_STOP)
301 				dep_done(j, DF_LIGHT);
302 			else
303 				j->flags &= ~JF_PERSIST;
304 		} else {
305 			if (create_jail(j) < 0)
306 				return -1;
307 			if (iflag)
308 				printf("%d\n", j->jid);
309 			if (verbose >= 0 && (j->name || verbose > 0))
310 				jail_note(j, "created\n");
311 			dep_done(j, DF_LIGHT);
312 		}
313 		return 0;
314 
315 	default: ;
316 	}
317 	/*
318 	 * Collect exec arguments.  Internal commands for network and
319 	 * mounting build their own argument lists.
320 	 */
321 	comstring = j->comstring;
322 	bg = 0;
323 	switch (comparam) {
324 #ifdef INET
325 	case IP__IP4_IFADDR:
326 		argc = 0;
327 		val = alloca(strlen(comstring->s) + 1);
328 		strcpy(val, comstring->s);
329 		cs = val;
330 		extrap = NULL;
331 		while ((p = strchr(cs, ' ')) != NULL && strlen(p) > 1) {
332 			if (extrap == NULL) {
333 				*p = '\0';
334 				extrap = p + 1;
335 			}
336 			cs = p + 1;
337 			argc++;
338 		}
339 
340 		argv = alloca((8 + argc) * sizeof(char *));
341 		*(const char **)&argv[0] = _PATH_IFCONFIG;
342 		if ((cs = strchr(val, '|'))) {
343 			argv[1] = alloca(cs - val + 1);
344 			strlcpy(argv[1], val, cs - val + 1);
345 			addr = cs + 1;
346 		} else {
347 			*(const char **)&argv[1] =
348 			    string_param(j->intparams[IP_INTERFACE]);
349 			addr = val;
350 		}
351 		*(const char **)&argv[2] = "inet";
352 		if (!(cs = strchr(addr, '/'))) {
353 			argv[3] = addr;
354 			*(const char **)&argv[4] = "netmask";
355 			*(const char **)&argv[5] = "255.255.255.255";
356 			argc = 6;
357 		} else if (strchr(cs + 1, '.')) {
358 			argv[3] = alloca(cs - addr + 1);
359 			strlcpy(argv[3], addr, cs - addr + 1);
360 			*(const char **)&argv[4] = "netmask";
361 			*(const char **)&argv[5] = cs + 1;
362 			argc = 6;
363 		} else {
364 			argv[3] = addr;
365 			argc = 4;
366 		}
367 
368 		if (!down) {
369 			for (cs = strtok(extrap, " "); cs; cs = strtok(NULL, " ")) {
370 				size_t len = strlen(cs) + 1;
371 				argv[argc] = alloca(len);
372 				strlcpy(argv[argc++], cs, len);
373 			}
374 		}
375 
376 		*(const char **)&argv[argc] = down ? "-alias" : "alias";
377 		argv[argc + 1] = NULL;
378 		break;
379 #endif
380 
381 #ifdef INET6
382 	case IP__IP6_IFADDR:
383 		argc = 0;
384 		val = alloca(strlen(comstring->s) + 1);
385 		strcpy(val, comstring->s);
386 		cs = val;
387 		extrap = NULL;
388 		while ((p = strchr(cs, ' ')) != NULL && strlen(p) > 1) {
389 			if (extrap == NULL) {
390 				*p = '\0';
391 				extrap = p + 1;
392 			}
393 			cs = p + 1;
394 			argc++;
395 		}
396 
397 		argv = alloca((8 + argc) * sizeof(char *));
398 		*(const char **)&argv[0] = _PATH_IFCONFIG;
399 		if ((cs = strchr(val, '|'))) {
400 			argv[1] = alloca(cs - val + 1);
401 			strlcpy(argv[1], val, cs - val + 1);
402 			addr = cs + 1;
403 		} else {
404 			*(const char **)&argv[1] =
405 			    string_param(j->intparams[IP_INTERFACE]);
406 			addr = val;
407 		}
408 		*(const char **)&argv[2] = "inet6";
409 		argv[3] = addr;
410 		if (!(cs = strchr(addr, '/'))) {
411 			*(const char **)&argv[4] = "prefixlen";
412 			*(const char **)&argv[5] = "128";
413 			argc = 6;
414 		} else
415 			argc = 4;
416 
417 		if (!down) {
418 			for (cs = strtok(extrap, " "); cs; cs = strtok(NULL, " ")) {
419 				size_t len = strlen(cs) + 1;
420 				argv[argc] = alloca(len);
421 				strlcpy(argv[argc++], cs, len);
422 			}
423 		}
424 
425 		*(const char **)&argv[argc] = down ? "-alias" : "alias";
426 		argv[argc + 1] = NULL;
427 		break;
428 #endif
429 
430 	case IP_VNET_INTERFACE:
431 		argv = alloca(5 * sizeof(char *));
432 		*(const char **)&argv[0] = _PATH_IFCONFIG;
433 		argv[1] = comstring->s;
434 		*(const char **)&argv[2] = down ? "-vnet" : "vnet";
435 		jidstr = string_param(j->intparams[KP_JID]);
436 		*(const char **)&argv[3] =
437 			jidstr ? jidstr : string_param(j->intparams[KP_NAME]);
438 		argv[4] = NULL;
439 		break;
440 
441 	case IP_MOUNT:
442 	case IP__MOUNT_FROM_FSTAB:
443 		argv = alloca(8 * sizeof(char *));
444 		comcs = alloca(comstring->len + 1);
445 		strcpy(comcs, comstring->s);
446 		argc = 0;
447 		for (cs = strtok(comcs, " \t\f\v\r\n"); cs && argc < 4;
448 		     cs = strtok(NULL, " \t\f\v\r\n"))
449 			argv[argc++] = cs;
450 		if (argc == 0)
451 			return 0;
452 		if (argc < 3) {
453 			jail_warnx(j, "%s: %s: missing information",
454 			    j->intparams[comparam]->name, comstring->s);
455 			return -1;
456 		}
457 		if (check_path(j, j->intparams[comparam]->name, argv[1], 0,
458 		    down ? argv[2] : NULL) < 0)
459 			return -1;
460 		if (down) {
461 			argv[4] = NULL;
462 			argv[3] = argv[1];
463 			*(const char **)&argv[0] = "/sbin/umount";
464 		} else {
465 			if (argc == 4) {
466 				argv[7] = NULL;
467 				argv[6] = argv[1];
468 				argv[5] = argv[0];
469 				argv[4] = argv[3];
470 				*(const char **)&argv[3] = "-o";
471 			} else {
472 				argv[5] = NULL;
473 				argv[4] = argv[1];
474 				argv[3] = argv[0];
475 			}
476 			*(const char **)&argv[0] = _PATH_MOUNT;
477 		}
478 		*(const char **)&argv[1] = "-t";
479 		break;
480 
481 	case IP_MOUNT_DEVFS:
482 		argv = alloca(7 * sizeof(char *));
483 		path = string_param(j->intparams[KP_PATH]);
484 		if (path == NULL) {
485 			jail_warnx(j, "mount.devfs: no path");
486 			return -1;
487 		}
488 		devpath = alloca(strlen(path) + 5);
489 		sprintf(devpath, "%s/dev", path);
490 		if (check_path(j, "mount.devfs", devpath, 0,
491 		    down ? "devfs" : NULL) < 0)
492 			return -1;
493 		if (down) {
494 			*(const char **)&argv[0] = "/sbin/umount";
495 			argv[1] = devpath;
496 			argv[2] = NULL;
497 		} else {
498 			*(const char **)&argv[0] = _PATH_MOUNT;
499 			*(const char **)&argv[1] = "-t";
500 			*(const char **)&argv[2] = "devfs";
501 			ruleset = string_param(j->intparams[KP_DEVFS_RULESET]);
502 			if (!ruleset)
503 			    ruleset = "4";	/* devfsrules_jail */
504 			argv[3] = alloca(11 + strlen(ruleset));
505 			sprintf(argv[3], "-oruleset=%s", ruleset);
506 			*(const char **)&argv[4] = ".";
507 			argv[5] = devpath;
508 			argv[6] = NULL;
509 		}
510 		break;
511 
512 	case IP_MOUNT_FDESCFS:
513 		argv = alloca(7 * sizeof(char *));
514 		path = string_param(j->intparams[KP_PATH]);
515 		if (path == NULL) {
516 			jail_warnx(j, "mount.fdescfs: no path");
517 			return -1;
518 		}
519 		devpath = alloca(strlen(path) + 8);
520 		sprintf(devpath, "%s/dev/fd", path);
521 		if (check_path(j, "mount.fdescfs", devpath, 0,
522 		    down ? "fdescfs" : NULL) < 0)
523 			return -1;
524 		if (down) {
525 			*(const char **)&argv[0] = "/sbin/umount";
526 			argv[1] = devpath;
527 			argv[2] = NULL;
528 		} else {
529 			*(const char **)&argv[0] = _PATH_MOUNT;
530 			*(const char **)&argv[1] = "-t";
531 			*(const char **)&argv[2] = "fdescfs";
532 			*(const char **)&argv[3] = ".";
533 			argv[4] = devpath;
534 			argv[5] = NULL;
535 		}
536 		break;
537 
538 	case IP_MOUNT_PROCFS:
539 		argv = alloca(7 * sizeof(char *));
540 		path = string_param(j->intparams[KP_PATH]);
541 		if (path == NULL) {
542 			jail_warnx(j, "mount.procfs: no path");
543 			return -1;
544 		}
545 		devpath = alloca(strlen(path) + 6);
546 		sprintf(devpath, "%s/proc", path);
547 		if (check_path(j, "mount.procfs", devpath, 0,
548 		    down ? "procfs" : NULL) < 0)
549 			return -1;
550 		if (down) {
551 			*(const char **)&argv[0] = "/sbin/umount";
552 			argv[1] = devpath;
553 			argv[2] = NULL;
554 		} else {
555 			*(const char **)&argv[0] = _PATH_MOUNT;
556 			*(const char **)&argv[1] = "-t";
557 			*(const char **)&argv[2] = "procfs";
558 			*(const char **)&argv[3] = ".";
559 			argv[4] = devpath;
560 			argv[5] = NULL;
561 		}
562 		break;
563 
564 	case IP_COMMAND:
565 		if (j->name != NULL)
566 			goto default_command;
567 		argc = 0;
568 		TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
569 			argc++;
570 		argv = alloca((argc + 1) * sizeof(char *));
571 		argc = 0;
572 		TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
573 			argv[argc++] = s->s;
574 		argv[argc] = NULL;
575 		j->comstring = &dummystring;
576 		break;
577 
578 	default:
579 	default_command:
580 		if ((cs = strpbrk(comstring->s, "!\"$&'()*;<>?[\\]`{|}~")) &&
581 		    !(cs[0] == '&' && cs[1] == '\0')) {
582 			argv = alloca(4 * sizeof(char *));
583 			*(const char **)&argv[0] = _PATH_BSHELL;
584 			*(const char **)&argv[1] = "-c";
585 			argv[2] = comstring->s;
586 			argv[3] = NULL;
587 		} else {
588 			if (cs) {
589 				*cs = 0;
590 				bg = 1;
591 			}
592 			comcs = alloca(comstring->len + 1);
593 			strcpy(comcs, comstring->s);
594 			argc = 0;
595 			for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
596 			     cs = strtok(NULL, " \t\f\v\r\n"))
597 				argc++;
598 			argv = alloca((argc + 1) * sizeof(char *));
599 			strcpy(comcs, comstring->s);
600 			argc = 0;
601 			for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
602 			     cs = strtok(NULL, " \t\f\v\r\n"))
603 				argv[argc++] = cs;
604 			argv[argc] = NULL;
605 		}
606 	}
607 	if (argv[0] == NULL)
608 		return 0;
609 
610 	if (int_param(j->intparams[IP_EXEC_TIMEOUT], &timeout) &&
611 	    timeout != 0) {
612 		clock_gettime(CLOCK_REALTIME, &j->timeout);
613 		j->timeout.tv_sec += timeout;
614 	} else
615 		j->timeout.tv_sec = 0;
616 
617 	injail = comparam == IP_EXEC_START || comparam == IP_COMMAND ||
618 	    comparam == IP_EXEC_STOP;
619 	clean = bool_param(j->intparams[IP_EXEC_CLEAN]);
620 	username = string_param(j->intparams[injail
621 	    ? IP_EXEC_JAIL_USER : IP_EXEC_SYSTEM_USER]);
622 	sjuser = bool_param(j->intparams[IP_EXEC_SYSTEM_JAIL_USER]);
623 
624 	consfd = 0;
625 	if (injail &&
626 	    (conslog = string_param(j->intparams[IP_EXEC_CONSOLELOG]))) {
627 		if (check_path(j, "exec.consolelog", conslog, 1, NULL) < 0)
628 			return -1;
629 		consfd =
630 		    open(conslog, O_WRONLY | O_CREAT | O_APPEND, DEFFILEMODE);
631 		if (consfd < 0) {
632 			jail_warnx(j, "open %s: %s", conslog, strerror(errno));
633 			return -1;
634 		}
635 	}
636 
637 	comlen = 0;
638 	for (i = 0; argv[i]; i++)
639 		comlen += strlen(argv[i]) + 1;
640 	j->comline = cs = emalloc(comlen);
641 	for (i = 0; argv[i]; i++) {
642 		strcpy(cs, argv[i]);
643 		if (argv[i + 1]) {
644 			cs += strlen(argv[i]) + 1;
645 			cs[-1] = ' ';
646 		}
647 	}
648 	if (verbose > 0)
649 		jail_note(j, "run command%s%s%s: %s\n",
650 		    injail ? " in jail" : "", username ? " as " : "",
651 		    username ? username : "", j->comline);
652 
653 	pid = fork();
654 	if (pid < 0)
655 		err(1, "fork");
656 	if (pid > 0) {
657 		if (bg || !add_proc(j, pid)) {
658 			free(j->comline);
659 			j->comline = NULL;
660 			return 0;
661 		} else {
662 			paralimit--;
663 			return 1;
664 		}
665 	}
666 	if (bg)
667 		setsid();
668 
669 	/* Set up the environment and run the command */
670 	pwd = NULL;
671 	lcap = NULL;
672 	if ((clean || username) && injail && sjuser &&
673 	    get_user_info(j, username, &pwd, &lcap) < 0)
674 		exit(1);
675 	if (injail) {
676 		/* jail_attach won't chdir along with its chroot. */
677 		path = string_param(j->intparams[KP_PATH]);
678 		if (path && chdir(path) < 0) {
679 			jail_warnx(j, "chdir %s: %s", path, strerror(errno));
680 			exit(1);
681 		}
682 		if (int_param(j->intparams[IP_EXEC_FIB], &fib) &&
683 		    setfib(fib) < 0) {
684 			jail_warnx(j, "setfib: %s", strerror(errno));
685 			exit(1);
686 		}
687 		if (jail_attach(j->jid) < 0) {
688 			jail_warnx(j, "jail_attach: %s", strerror(errno));
689 			exit(1);
690 		}
691 	}
692 	if (clean || username) {
693 		if (!(injail && sjuser) &&
694 		    get_user_info(j, username, &pwd, &lcap) < 0)
695 			exit(1);
696 		if (clean) {
697 			term = getenv("TERM");
698 			environ = &cleanenv;
699 			setenv("PATH", "/bin:/usr/bin", 0);
700 			if (term != NULL)
701 				setenv("TERM", term, 1);
702 		}
703 		if (setgid(pwd->pw_gid) < 0) {
704 			jail_warnx(j, "setgid %d: %s", pwd->pw_gid,
705 			    strerror(errno));
706 			exit(1);
707 		}
708 		if (setusercontext(lcap, pwd, pwd->pw_uid, username
709 		    ? LOGIN_SETALL & ~LOGIN_SETGROUP & ~LOGIN_SETLOGIN
710 		    : LOGIN_SETPATH | LOGIN_SETENV) < 0) {
711 			jail_warnx(j, "setusercontext %s: %s", pwd->pw_name,
712 			    strerror(errno));
713 			exit(1);
714 		}
715 		login_close(lcap);
716 		setenv("USER", pwd->pw_name, 1);
717 		setenv("HOME", pwd->pw_dir, 1);
718 		setenv("SHELL",
719 		    *pwd->pw_shell ? pwd->pw_shell : _PATH_BSHELL, 1);
720 		if (clean && chdir(pwd->pw_dir) < 0) {
721 			jail_warnx(j, "chdir %s: %s",
722 			    pwd->pw_dir, strerror(errno));
723 			exit(1);
724 		}
725 		endpwent();
726 	}
727 
728 	if (consfd != 0 && (dup2(consfd, 1) < 0 || dup2(consfd, 2) < 0)) {
729 		jail_warnx(j, "exec.consolelog: %s", strerror(errno));
730 		exit(1);
731 	}
732 	closefrom(3);
733 	execvp(argv[0], argv);
734 	jail_warnx(j, "exec %s: %s", argv[0], strerror(errno));
735 	exit(1);
736 }
737 
738 /*
739  * Add a process to the hash, tied to a jail.
740  */
741 static int
add_proc(struct cfjail * j,pid_t pid)742 add_proc(struct cfjail *j, pid_t pid)
743 {
744 	struct kevent ke;
745 	struct cfjail *tj;
746 	struct phash *ph;
747 
748 	if (!kq && (kq = kqueue()) < 0)
749 		err(1, "kqueue");
750 	EV_SET(&ke, pid, EVFILT_PROC, EV_ADD, NOTE_EXIT, 0, NULL);
751 	if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0) {
752 		if (errno == ESRCH)
753 			return 0;
754 		err(1, "kevent");
755 	}
756 	ph = emalloc(sizeof(struct phash));
757 	ph->j = j;
758 	ph->pid = pid;
759 	LIST_INSERT_HEAD(&phash[pid % PHASH_SIZE], ph, le);
760 	j->nprocs++;
761 	j->flags |= JF_SLEEPQ;
762 	if (j->timeout.tv_sec == 0)
763 		requeue(j, &sleeping);
764 	else {
765 		/* File the jail in the sleep queue acording to its timeout. */
766 		TAILQ_REMOVE(j->queue, j, tq);
767 		TAILQ_FOREACH(tj, &sleeping, tq) {
768 			if (!tj->timeout.tv_sec ||
769 			    j->timeout.tv_sec < tj->timeout.tv_sec ||
770 			    (j->timeout.tv_sec == tj->timeout.tv_sec &&
771 			    j->timeout.tv_nsec <= tj->timeout.tv_nsec)) {
772 				TAILQ_INSERT_BEFORE(tj, j, tq);
773 				break;
774 			}
775 		}
776 		if (tj == NULL)
777 			TAILQ_INSERT_TAIL(&sleeping, j, tq);
778 		j->queue = &sleeping;
779 	}
780 	return 1;
781 }
782 
783 /*
784  * Remove any processes from the hash that correspond to a jail.
785  */
786 static void
clear_procs(struct cfjail * j)787 clear_procs(struct cfjail *j)
788 {
789 	struct kevent ke;
790 	struct phash *ph, *tph;
791 	int i;
792 
793 	j->nprocs = 0;
794 	for (i = 0; i < PHASH_SIZE; i++)
795 		LIST_FOREACH_SAFE(ph, &phash[i], le, tph)
796 			if (ph->j == j) {
797 				EV_SET(&ke, ph->pid, EVFILT_PROC, EV_DELETE,
798 				    NOTE_EXIT, 0, NULL);
799 				(void)kevent(kq, &ke, 1, NULL, 0, NULL);
800 				LIST_REMOVE(ph, le);
801 				free(ph);
802 			}
803 }
804 
805 /*
806  * Find the jail that corresponds to an exited process.
807  */
808 static struct cfjail *
find_proc(pid_t pid)809 find_proc(pid_t pid)
810 {
811 	struct cfjail *j;
812 	struct phash *ph;
813 
814 	LIST_FOREACH(ph, &phash[pid % PHASH_SIZE], le)
815 		if (ph->pid == pid) {
816 			j = ph->j;
817 			LIST_REMOVE(ph, le);
818 			free(ph);
819 			return --j->nprocs ? NULL : j;
820 		}
821 	return NULL;
822 }
823 
824 /*
825  * Send SIGTERM to all processes in a jail and wait for them to die.
826  */
827 static int
term_procs(struct cfjail * j)828 term_procs(struct cfjail *j)
829 {
830 	struct kinfo_proc *ki;
831 	int i, noted, pcnt, timeout;
832 
833 	static kvm_t *kd;
834 
835 	if (!int_param(j->intparams[IP_STOP_TIMEOUT], &timeout))
836 		timeout = DEFAULT_STOP_TIMEOUT;
837 	else if (timeout == 0)
838 		return 0;
839 
840 	if (kd == NULL) {
841 		kd = kvm_open(NULL, NULL, NULL, O_RDONLY, NULL);
842 		if (kd == NULL)
843 			return 0;
844 	}
845 
846 	ki = kvm_getprocs(kd, KERN_PROC_PROC, 0, &pcnt);
847 	if (ki == NULL)
848 		return 0;
849 	noted = 0;
850 	for (i = 0; i < pcnt; i++)
851 		if (ki[i].ki_jid == j->jid &&
852 		    kill(ki[i].ki_pid, SIGTERM) == 0) {
853 			(void)add_proc(j, ki[i].ki_pid);
854 			if (verbose > 0) {
855 				if (!noted) {
856 					noted = 1;
857 					jail_note(j, "sent SIGTERM to:");
858 				}
859 				printf(" %d", ki[i].ki_pid);
860 			}
861 		}
862 	if (noted)
863 		printf("\n");
864 	if (j->nprocs > 0) {
865 		clock_gettime(CLOCK_REALTIME, &j->timeout);
866 		j->timeout.tv_sec += timeout;
867 		return 1;
868 	}
869 	return 0;
870 }
871 
872 /*
873  * Look up a user in the passwd and login.conf files.
874  */
875 static int
get_user_info(struct cfjail * j,const char * username,const struct passwd ** pwdp,login_cap_t ** lcapp)876 get_user_info(struct cfjail *j, const char *username,
877     const struct passwd **pwdp, login_cap_t **lcapp)
878 {
879 	const struct passwd *pwd;
880 
881 	*pwdp = pwd = username ? getpwnam(username) : getpwuid(getuid());
882 	if (pwd == NULL) {
883 		if (errno)
884 			jail_warnx(j, "getpwnam%s%s: %s", username ? " " : "",
885 			    username ? username : "", strerror(errno));
886 		else if (username)
887 			jail_warnx(j, "%s: no such user", username);
888 		else
889 			jail_warnx(j, "unknown uid %d", getuid());
890 		return -1;
891 	}
892 	*lcapp = login_getpwclass(pwd);
893 	if (*lcapp == NULL) {
894 		jail_warnx(j, "getpwclass %s: %s", pwd->pw_name,
895 		    strerror(errno));
896 		return -1;
897 	}
898 	/* Set the groups while the group file is still available */
899 	if (initgroups(pwd->pw_name, pwd->pw_gid) < 0) {
900 		jail_warnx(j, "initgroups %s: %s", pwd->pw_name,
901 		    strerror(errno));
902 		return -1;
903 	}
904 	return 0;
905 }
906 
907 /*
908  * Make sure a mount or consolelog path is a valid absolute pathname
909  * with no symlinks.
910  */
911 static int
check_path(struct cfjail * j,const char * pname,const char * path,int isfile,const char * umount_type)912 check_path(struct cfjail *j, const char *pname, const char *path, int isfile,
913     const char *umount_type)
914 {
915 	struct stat st, mpst;
916 	struct statfs stfs;
917 	char *tpath, *p;
918 	const char *jailpath;
919 	size_t jplen;
920 
921 	if (path[0] != '/') {
922 		jail_warnx(j, "%s: %s: not an absolute pathname",
923 		    pname, path);
924 		return -1;
925 	}
926 	/*
927 	 * Only check for symlinks in components below the jail's path,
928 	 * since that's where the security risk lies.
929 	 */
930 	jailpath = string_param(j->intparams[KP_PATH]);
931 	if (jailpath == NULL)
932 		jailpath = "";
933 	jplen = strlen(jailpath);
934 	if (!strncmp(path, jailpath, jplen) && path[jplen] == '/') {
935 		tpath = alloca(strlen(path) + 1);
936 		strcpy(tpath, path);
937 		for (p = tpath + jplen; p != NULL; ) {
938 			p = strchr(p + 1, '/');
939 			if (p)
940 				*p = '\0';
941 			if (lstat(tpath, &st) < 0) {
942 				if (errno == ENOENT && isfile && !p)
943 					break;
944 				jail_warnx(j, "%s: %s: %s", pname, tpath,
945 				    strerror(errno));
946 				return -1;
947 			}
948 			if (S_ISLNK(st.st_mode)) {
949 				jail_warnx(j, "%s: %s is a symbolic link",
950 				    pname, tpath);
951 				return -1;
952 			}
953 			if (p)
954 				*p = '/';
955 		}
956 	}
957 	if (umount_type != NULL) {
958 		if (stat(path, &st) < 0 || statfs(path, &stfs) < 0) {
959 			jail_warnx(j, "%s: %s: %s", pname, path,
960 			    strerror(errno));
961 			return -1;
962 		}
963 		if (stat(stfs.f_mntonname, &mpst) < 0) {
964 			jail_warnx(j, "%s: %s: %s", pname, stfs.f_mntonname,
965 			    strerror(errno));
966 			return -1;
967 		}
968 		if (st.st_ino != mpst.st_ino) {
969 			jail_warnx(j, "%s: %s: not a mount point",
970 			    pname, path);
971 			return -1;
972 		}
973 		if (strcmp(stfs.f_fstypename, umount_type)) {
974 			jail_warnx(j, "%s: %s: not a %s mount",
975 			    pname, path, umount_type);
976 			return -1;
977 		}
978 	}
979 	return 0;
980 }
981