command.c revision 276277
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: stable/10/usr.sbin/jail/command.c 276277 2014-12-27 02:17:35Z jamie $");
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
56LIST_HEAD(phhead, phash);
57
58struct phash {
59	LIST_ENTRY(phash)	le;
60	struct cfjail		*j;
61	pid_t			pid;
62};
63
64int paralimit = -1;
65
66extern char **environ;
67
68static int run_command(struct cfjail *j);
69static int add_proc(struct cfjail *j, pid_t pid);
70static void clear_procs(struct cfjail *j);
71static struct cfjail *find_proc(pid_t pid);
72static int term_procs(struct cfjail *j);
73static int get_user_info(struct cfjail *j, const char *username,
74    const struct passwd **pwdp, login_cap_t **lcapp);
75static int check_path(struct cfjail *j, const char *pname, const char *path,
76    int isfile, const char *umount_type);
77
78static struct cfjails sleeping = TAILQ_HEAD_INITIALIZER(sleeping);
79static struct cfjails runnable = TAILQ_HEAD_INITIALIZER(runnable);
80static struct cfstring dummystring = { .len = 1 };
81static struct phhead phash[PHASH_SIZE];
82static int kq;
83
84/*
85 * Run the next command associated with a jail.
86 */
87int
88next_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 */
153int
154finish_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 */
197struct cfjail *
198next_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 */
257static int
258run_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, *extrap, *p, *val;
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		argc = 0;
321		val = alloca(strlen(comstring->s) + 1);
322		strcpy(val, comstring->s);
323		cs = val;
324		extrap = NULL;
325		while ((p = strchr(cs, ' ')) != NULL && strlen(p) > 1) {
326			if (extrap == NULL) {
327				*p = '\0';
328				extrap = p + 1;
329			}
330			cs = p + 1;
331			argc++;
332		}
333
334		argv = alloca((8 + argc) * sizeof(char *));
335		*(const char **)&argv[0] = _PATH_IFCONFIG;
336		if ((cs = strchr(val, '|'))) {
337			argv[1] = alloca(cs - val + 1);
338			strlcpy(argv[1], val, cs - val + 1);
339			addr = cs + 1;
340		} else {
341			*(const char **)&argv[1] =
342			    string_param(j->intparams[IP_INTERFACE]);
343			addr = val;
344		}
345		*(const char **)&argv[2] = "inet";
346		if (!(cs = strchr(addr, '/'))) {
347			argv[3] = addr;
348			*(const char **)&argv[4] = "netmask";
349			*(const char **)&argv[5] = "255.255.255.255";
350			argc = 6;
351		} else if (strchr(cs + 1, '.')) {
352			argv[3] = alloca(cs - addr + 1);
353			strlcpy(argv[3], addr, cs - addr + 1);
354			*(const char **)&argv[4] = "netmask";
355			*(const char **)&argv[5] = cs + 1;
356			argc = 6;
357		} else {
358			argv[3] = addr;
359			argc = 4;
360		}
361
362		if (!down) {
363			for (cs = strtok(extrap, " "); cs; cs = strtok(NULL, " ")) {
364				size_t len = strlen(cs) + 1;
365				argv[argc] = alloca(len);
366				strlcpy(argv[argc++], cs, len);
367			}
368		}
369
370		*(const char **)&argv[argc] = down ? "-alias" : "alias";
371		argv[argc + 1] = NULL;
372		break;
373#endif
374
375#ifdef INET6
376	case IP__IP6_IFADDR:
377		argc = 0;
378		val = alloca(strlen(comstring->s) + 1);
379		strcpy(val, comstring->s);
380		cs = val;
381		extrap = NULL;
382		while ((p = strchr(cs, ' ')) != NULL && strlen(p) > 1) {
383			if (extrap == NULL) {
384				*p = '\0';
385				extrap = p + 1;
386			}
387			cs = p + 1;
388			argc++;
389		}
390
391		argv = alloca((8 + argc) * sizeof(char *));
392		*(const char **)&argv[0] = _PATH_IFCONFIG;
393		if ((cs = strchr(val, '|'))) {
394			argv[1] = alloca(cs - val + 1);
395			strlcpy(argv[1], val, cs - val + 1);
396			addr = cs + 1;
397		} else {
398			*(const char **)&argv[1] =
399			    string_param(j->intparams[IP_INTERFACE]);
400			addr = val;
401		}
402		*(const char **)&argv[2] = "inet6";
403		argv[3] = addr;
404		if (!(cs = strchr(addr, '/'))) {
405			*(const char **)&argv[4] = "prefixlen";
406			*(const char **)&argv[5] = "128";
407			argc = 6;
408		} else
409			argc = 4;
410
411		if (!down) {
412			for (cs = strtok(extrap, " "); cs; cs = strtok(NULL, " ")) {
413				size_t len = strlen(cs) + 1;
414				argv[argc] = alloca(len);
415				strlcpy(argv[argc++], cs, len);
416			}
417		}
418
419		*(const char **)&argv[argc] = down ? "-alias" : "alias";
420		argv[argc + 1] = NULL;
421		break;
422#endif
423
424	case IP_VNET_INTERFACE:
425		argv = alloca(5 * sizeof(char *));
426		*(const char **)&argv[0] = _PATH_IFCONFIG;
427		argv[1] = comstring->s;
428		*(const char **)&argv[2] = down ? "-vnet" : "vnet";
429		jidstr = string_param(j->intparams[KP_JID]);
430		*(const char **)&argv[3] =
431			jidstr ? jidstr : string_param(j->intparams[KP_NAME]);
432		argv[4] = NULL;
433		break;
434
435	case IP_MOUNT:
436	case IP__MOUNT_FROM_FSTAB:
437		argv = alloca(8 * sizeof(char *));
438		comcs = alloca(comstring->len + 1);
439		strcpy(comcs, comstring->s);
440		argc = 0;
441		for (cs = strtok(comcs, " \t\f\v\r\n"); cs && argc < 4;
442		     cs = strtok(NULL, " \t\f\v\r\n"))
443			argv[argc++] = cs;
444		if (argc == 0)
445			return 0;
446		if (argc < 3) {
447			jail_warnx(j, "%s: %s: missing information",
448			    j->intparams[comparam]->name, comstring->s);
449			return -1;
450		}
451		if (check_path(j, j->intparams[comparam]->name, argv[1], 0,
452		    down ? argv[2] : NULL) < 0)
453			return -1;
454		if (down) {
455			argv[4] = NULL;
456			argv[3] = argv[1];
457			*(const char **)&argv[0] = "/sbin/umount";
458		} else {
459			if (argc == 4) {
460				argv[7] = NULL;
461				argv[6] = argv[1];
462				argv[5] = argv[0];
463				argv[4] = argv[3];
464				*(const char **)&argv[3] = "-o";
465			} else {
466				argv[5] = NULL;
467				argv[4] = argv[1];
468				argv[3] = argv[0];
469			}
470			*(const char **)&argv[0] = _PATH_MOUNT;
471		}
472		*(const char **)&argv[1] = "-t";
473		break;
474
475	case IP_MOUNT_DEVFS:
476		argv = alloca(7 * sizeof(char *));
477		path = string_param(j->intparams[KP_PATH]);
478		if (path == NULL) {
479			jail_warnx(j, "mount.devfs: no path");
480			return -1;
481		}
482		devpath = alloca(strlen(path) + 5);
483		sprintf(devpath, "%s/dev", path);
484		if (check_path(j, "mount.devfs", devpath, 0,
485		    down ? "devfs" : NULL) < 0)
486			return -1;
487		if (down) {
488			*(const char **)&argv[0] = "/sbin/umount";
489			argv[1] = devpath;
490			argv[2] = NULL;
491		} else {
492			*(const char **)&argv[0] = _PATH_MOUNT;
493			*(const char **)&argv[1] = "-t";
494			*(const char **)&argv[2] = "devfs";
495			ruleset = string_param(j->intparams[KP_DEVFS_RULESET]);
496			if (!ruleset)
497			    ruleset = "4";	/* devfsrules_jail */
498			argv[3] = alloca(11 + strlen(ruleset));
499			sprintf(argv[3], "-oruleset=%s", ruleset);
500			*(const char **)&argv[4] = ".";
501			argv[5] = devpath;
502			argv[6] = NULL;
503		}
504		break;
505
506	case IP_MOUNT_FDESCFS:
507		argv = alloca(7 * sizeof(char *));
508		path = string_param(j->intparams[KP_PATH]);
509		if (path == NULL) {
510			jail_warnx(j, "mount.fdescfs: no path");
511			return -1;
512		}
513		devpath = alloca(strlen(path) + 8);
514		sprintf(devpath, "%s/dev/fd", path);
515		if (check_path(j, "mount.fdescfs", devpath, 0,
516		    down ? "fdescfs" : NULL) < 0)
517			return -1;
518		if (down) {
519			*(const char **)&argv[0] = "/sbin/umount";
520			argv[1] = devpath;
521			argv[2] = NULL;
522		} else {
523			*(const char **)&argv[0] = _PATH_MOUNT;
524			*(const char **)&argv[1] = "-t";
525			*(const char **)&argv[2] = "fdescfs";
526			*(const char **)&argv[3] = ".";
527			argv[4] = devpath;
528			argv[5] = NULL;
529		}
530		break;
531
532	case IP_COMMAND:
533		if (j->name != NULL)
534			goto default_command;
535		argc = 0;
536		TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
537			argc++;
538		argv = alloca((argc + 1) * sizeof(char *));
539		argc = 0;
540		TAILQ_FOREACH(s, &j->intparams[IP_COMMAND]->val, tq)
541			argv[argc++] = s->s;
542		argv[argc] = NULL;
543		j->comstring = &dummystring;
544		break;
545
546	default:
547	default_command:
548		if ((cs = strpbrk(comstring->s, "!\"$&'()*;<>?[\\]`{|}~")) &&
549		    !(cs[0] == '&' && cs[1] == '\0')) {
550			argv = alloca(4 * sizeof(char *));
551			*(const char **)&argv[0] = _PATH_BSHELL;
552			*(const char **)&argv[1] = "-c";
553			argv[2] = comstring->s;
554			argv[3] = NULL;
555		} else {
556			if (cs) {
557				*cs = 0;
558				bg = 1;
559			}
560			comcs = alloca(comstring->len + 1);
561			strcpy(comcs, comstring->s);
562			argc = 0;
563			for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
564			     cs = strtok(NULL, " \t\f\v\r\n"))
565				argc++;
566			argv = alloca((argc + 1) * sizeof(char *));
567			strcpy(comcs, comstring->s);
568			argc = 0;
569			for (cs = strtok(comcs, " \t\f\v\r\n"); cs;
570			     cs = strtok(NULL, " \t\f\v\r\n"))
571				argv[argc++] = cs;
572			argv[argc] = NULL;
573		}
574	}
575	if (argv[0] == NULL)
576		return 0;
577
578	if (int_param(j->intparams[IP_EXEC_TIMEOUT], &timeout) &&
579	    timeout != 0) {
580		clock_gettime(CLOCK_REALTIME, &j->timeout);
581		j->timeout.tv_sec += timeout;
582	} else
583		j->timeout.tv_sec = 0;
584
585	injail = comparam == IP_EXEC_START || comparam == IP_COMMAND ||
586	    comparam == IP_EXEC_STOP;
587	clean = bool_param(j->intparams[IP_EXEC_CLEAN]);
588	username = string_param(j->intparams[injail
589	    ? IP_EXEC_JAIL_USER : IP_EXEC_SYSTEM_USER]);
590	sjuser = bool_param(j->intparams[IP_EXEC_SYSTEM_JAIL_USER]);
591
592	consfd = 0;
593	if (injail &&
594	    (conslog = string_param(j->intparams[IP_EXEC_CONSOLELOG]))) {
595		if (check_path(j, "exec.consolelog", conslog, 1, NULL) < 0)
596			return -1;
597		consfd =
598		    open(conslog, O_WRONLY | O_CREAT | O_APPEND, DEFFILEMODE);
599		if (consfd < 0) {
600			jail_warnx(j, "open %s: %s", conslog, strerror(errno));
601			return -1;
602		}
603	}
604
605	comlen = 0;
606	for (i = 0; argv[i]; i++)
607		comlen += strlen(argv[i]) + 1;
608	j->comline = cs = emalloc(comlen);
609	for (i = 0; argv[i]; i++) {
610		strcpy(cs, argv[i]);
611		if (argv[i + 1]) {
612			cs += strlen(argv[i]) + 1;
613			cs[-1] = ' ';
614		}
615	}
616	if (verbose > 0)
617		jail_note(j, "run command%s%s%s: %s\n",
618		    injail ? " in jail" : "", username ? " as " : "",
619		    username ? username : "", j->comline);
620
621	pid = fork();
622	if (pid < 0)
623		err(1, "fork");
624	if (pid > 0) {
625		if (bg || !add_proc(j, pid)) {
626			free(j->comline);
627			j->comline = NULL;
628			return 0;
629		} else {
630			paralimit--;
631			return 1;
632		}
633	}
634	if (bg)
635		setsid();
636
637	/* Set up the environment and run the command */
638	pwd = NULL;
639	lcap = NULL;
640	if ((clean || username) && injail && sjuser &&
641	    get_user_info(j, username, &pwd, &lcap) < 0)
642		exit(1);
643	if (injail) {
644		/* jail_attach won't chdir along with its chroot. */
645		path = string_param(j->intparams[KP_PATH]);
646		if (path && chdir(path) < 0) {
647			jail_warnx(j, "chdir %s: %s", path, strerror(errno));
648			exit(1);
649		}
650		if (int_param(j->intparams[IP_EXEC_FIB], &fib) &&
651		    setfib(fib) < 0) {
652			jail_warnx(j, "setfib: %s", strerror(errno));
653			exit(1);
654		}
655		if (jail_attach(j->jid) < 0) {
656			jail_warnx(j, "jail_attach: %s", strerror(errno));
657			exit(1);
658		}
659	}
660	if (clean || username) {
661		if (!(injail && sjuser) &&
662		    get_user_info(j, username, &pwd, &lcap) < 0)
663			exit(1);
664		if (clean) {
665			term = getenv("TERM");
666			environ = &cleanenv;
667			setenv("PATH", "/bin:/usr/bin", 0);
668			if (term != NULL)
669				setenv("TERM", term, 1);
670		}
671		if (setgid(pwd->pw_gid) < 0) {
672			jail_warnx(j, "setgid %d: %s", pwd->pw_gid,
673			    strerror(errno));
674			exit(1);
675		}
676		if (setusercontext(lcap, pwd, pwd->pw_uid, username
677		    ? LOGIN_SETALL & ~LOGIN_SETGROUP & ~LOGIN_SETLOGIN
678		    : LOGIN_SETPATH | LOGIN_SETENV) < 0) {
679			jail_warnx(j, "setusercontext %s: %s", pwd->pw_name,
680			    strerror(errno));
681			exit(1);
682		}
683		login_close(lcap);
684		setenv("USER", pwd->pw_name, 1);
685		setenv("HOME", pwd->pw_dir, 1);
686		setenv("SHELL",
687		    *pwd->pw_shell ? pwd->pw_shell : _PATH_BSHELL, 1);
688		if (clean && chdir(pwd->pw_dir) < 0) {
689			jail_warnx(j, "chdir %s: %s",
690			    pwd->pw_dir, strerror(errno));
691			exit(1);
692		}
693		endpwent();
694	}
695
696	if (consfd != 0 && (dup2(consfd, 1) < 0 || dup2(consfd, 2) < 0)) {
697		jail_warnx(j, "exec.consolelog: %s", strerror(errno));
698		exit(1);
699	}
700	closefrom(3);
701	execvp(argv[0], argv);
702	jail_warnx(j, "exec %s: %s", argv[0], strerror(errno));
703	exit(1);
704}
705
706/*
707 * Add a process to the hash, tied to a jail.
708 */
709static int
710add_proc(struct cfjail *j, pid_t pid)
711{
712	struct kevent ke;
713	struct cfjail *tj;
714	struct phash *ph;
715
716	if (!kq && (kq = kqueue()) < 0)
717		err(1, "kqueue");
718	EV_SET(&ke, pid, EVFILT_PROC, EV_ADD, NOTE_EXIT, 0, NULL);
719	if (kevent(kq, &ke, 1, NULL, 0, NULL) < 0) {
720		if (errno == ESRCH)
721			return 0;
722		err(1, "kevent");
723	}
724	ph = emalloc(sizeof(struct phash));
725	ph->j = j;
726	ph->pid = pid;
727	LIST_INSERT_HEAD(&phash[pid % PHASH_SIZE], ph, le);
728	j->nprocs++;
729	j->flags |= JF_SLEEPQ;
730	if (j->timeout.tv_sec == 0)
731		requeue(j, &sleeping);
732	else {
733		/* File the jail in the sleep queue acording to its timeout. */
734		TAILQ_REMOVE(j->queue, j, tq);
735		TAILQ_FOREACH(tj, &sleeping, tq) {
736			if (!tj->timeout.tv_sec ||
737			    j->timeout.tv_sec < tj->timeout.tv_sec ||
738			    (j->timeout.tv_sec == tj->timeout.tv_sec &&
739			    j->timeout.tv_nsec <= tj->timeout.tv_nsec)) {
740				TAILQ_INSERT_BEFORE(tj, j, tq);
741				break;
742			}
743		}
744		if (tj == NULL)
745			TAILQ_INSERT_TAIL(&sleeping, j, tq);
746		j->queue = &sleeping;
747	}
748	return 1;
749}
750
751/*
752 * Remove any processes from the hash that correspond to a jail.
753 */
754static void
755clear_procs(struct cfjail *j)
756{
757	struct kevent ke;
758	struct phash *ph, *tph;
759	int i;
760
761	j->nprocs = 0;
762	for (i = 0; i < PHASH_SIZE; i++)
763		LIST_FOREACH_SAFE(ph, &phash[i], le, tph)
764			if (ph->j == j) {
765				EV_SET(&ke, ph->pid, EVFILT_PROC, EV_DELETE,
766				    NOTE_EXIT, 0, NULL);
767				(void)kevent(kq, &ke, 1, NULL, 0, NULL);
768				LIST_REMOVE(ph, le);
769				free(ph);
770			}
771}
772
773/*
774 * Find the jail that corresponds to an exited process.
775 */
776static struct cfjail *
777find_proc(pid_t pid)
778{
779	struct cfjail *j;
780	struct phash *ph;
781
782	LIST_FOREACH(ph, &phash[pid % PHASH_SIZE], le)
783		if (ph->pid == pid) {
784			j = ph->j;
785			LIST_REMOVE(ph, le);
786			free(ph);
787			return --j->nprocs ? NULL : j;
788		}
789	return NULL;
790}
791
792/*
793 * Send SIGTERM to all processes in a jail and wait for them to die.
794 */
795static int
796term_procs(struct cfjail *j)
797{
798	struct kinfo_proc *ki;
799	int i, noted, pcnt, timeout;
800
801	static kvm_t *kd;
802
803	if (!int_param(j->intparams[IP_STOP_TIMEOUT], &timeout))
804		timeout = DEFAULT_STOP_TIMEOUT;
805	else if (timeout == 0)
806		return 0;
807
808	if (kd == NULL) {
809		kd = kvm_open(NULL, NULL, NULL, O_RDONLY, NULL);
810		if (kd == NULL)
811			return 0;
812	}
813
814	ki = kvm_getprocs(kd, KERN_PROC_PROC, 0, &pcnt);
815	if (ki == NULL)
816		return 0;
817	noted = 0;
818	for (i = 0; i < pcnt; i++)
819		if (ki[i].ki_jid == j->jid &&
820		    kill(ki[i].ki_pid, SIGTERM) == 0) {
821			(void)add_proc(j, ki[i].ki_pid);
822			if (verbose > 0) {
823				if (!noted) {
824					noted = 1;
825					jail_note(j, "sent SIGTERM to:");
826				}
827				printf(" %d", ki[i].ki_pid);
828			}
829		}
830	if (noted)
831		printf("\n");
832	if (j->nprocs > 0) {
833		clock_gettime(CLOCK_REALTIME, &j->timeout);
834		j->timeout.tv_sec += timeout;
835		return 1;
836	}
837	return 0;
838}
839
840/*
841 * Look up a user in the passwd and login.conf files.
842 */
843static int
844get_user_info(struct cfjail *j, const char *username,
845    const struct passwd **pwdp, login_cap_t **lcapp)
846{
847	const struct passwd *pwd;
848
849	*pwdp = pwd = username ? getpwnam(username) : getpwuid(getuid());
850	if (pwd == NULL) {
851		if (errno)
852			jail_warnx(j, "getpwnam%s%s: %s", username ? " " : "",
853			    username ? username : "", strerror(errno));
854		else if (username)
855			jail_warnx(j, "%s: no such user", username);
856		else
857			jail_warnx(j, "unknown uid %d", getuid());
858		return -1;
859	}
860	*lcapp = login_getpwclass(pwd);
861	if (*lcapp == NULL) {
862		jail_warnx(j, "getpwclass %s: %s", pwd->pw_name,
863		    strerror(errno));
864		return -1;
865	}
866	/* Set the groups while the group file is still available */
867	if (initgroups(pwd->pw_name, pwd->pw_gid) < 0) {
868		jail_warnx(j, "initgroups %s: %s", pwd->pw_name,
869		    strerror(errno));
870		return -1;
871	}
872	return 0;
873}
874
875/*
876 * Make sure a mount or consolelog path is a valid absolute pathname
877 * with no symlinks.
878 */
879static int
880check_path(struct cfjail *j, const char *pname, const char *path, int isfile,
881    const char *umount_type)
882{
883	struct stat st, mpst;
884	struct statfs stfs;
885	char *tpath, *p;
886	const char *jailpath;
887	size_t jplen;
888
889	if (path[0] != '/') {
890		jail_warnx(j, "%s: %s: not an absolute pathname",
891		    pname, path);
892		return -1;
893	}
894	/*
895	 * Only check for symlinks in components below the jail's path,
896	 * since that's where the security risk lies.
897	 */
898	jailpath = string_param(j->intparams[KP_PATH]);
899	if (jailpath == NULL)
900		jailpath = "";
901	jplen = strlen(jailpath);
902	if (!strncmp(path, jailpath, jplen) && path[jplen] == '/') {
903		tpath = alloca(strlen(path) + 1);
904		strcpy(tpath, path);
905		for (p = tpath + jplen; p != NULL; ) {
906			p = strchr(p + 1, '/');
907			if (p)
908				*p = '\0';
909			if (lstat(tpath, &st) < 0) {
910				if (errno == ENOENT && isfile && !p)
911					break;
912				jail_warnx(j, "%s: %s: %s", pname, tpath,
913				    strerror(errno));
914				return -1;
915			}
916			if (S_ISLNK(st.st_mode)) {
917				jail_warnx(j, "%s: %s is a symbolic link",
918				    pname, tpath);
919				return -1;
920			}
921			if (p)
922				*p = '/';
923		}
924	}
925	if (umount_type != NULL) {
926		if (stat(path, &st) < 0 || statfs(path, &stfs) < 0) {
927			jail_warnx(j, "%s: %s: %s", pname, path,
928			    strerror(errno));
929			return -1;
930		}
931		if (stat(stfs.f_mntonname, &mpst) < 0) {
932			jail_warnx(j, "%s: %s: %s", pname, stfs.f_mntonname,
933			    strerror(errno));
934			return -1;
935		}
936		if (st.st_ino != mpst.st_ino) {
937			jail_warnx(j, "%s: %s: not a mount point",
938			    pname, path);
939			return -1;
940		}
941		if (strcmp(stfs.f_fstypename, umount_type)) {
942			jail_warnx(j, "%s: %s: not a %s mount",
943			    pname, path, umount_type);
944			return -1;
945		}
946	}
947	return 0;
948}
949