xref: /freebsd/lib/libjail/jail.c (revision 0bf48626aaa33768078f5872b922b1487b3a9296)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2009 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/param.h>
33 #include <sys/jail.h>
34 #include <sys/linker.h>
35 #include <sys/socket.h>
36 #include <sys/sysctl.h>
37 
38 #include <arpa/inet.h>
39 #include <netinet/in.h>
40 
41 #include <errno.h>
42 #include <inttypes.h>
43 #include <stdio.h>
44 #include <stdarg.h>
45 #include <stdlib.h>
46 #include <string.h>
47 
48 #include "jail.h"
49 
50 #define	SJPARAM		"security.jail.param"
51 
52 #define JPS_IN_ADDR	1
53 #define JPS_IN6_ADDR	2
54 
55 #define ARRAY_SANITY	5
56 #define ARRAY_SLOP	5
57 
58 
59 static int jailparam_import_enum(const char **values, int nvalues,
60     const char *valstr, size_t valsize, int *value);
61 static int jailparam_type(struct jailparam *jp);
62 static int kldload_param(const char *name);
63 static char *noname(const char *name);
64 static char *nononame(const char *name);
65 
66 char jail_errmsg[JAIL_ERRMSGLEN];
67 
68 static const char *bool_values[] = { "false", "true" };
69 static const char *jailsys_values[] = { "disable", "new", "inherit" };
70 
71 
72 /*
73  * Import a null-terminated parameter list and set a jail with the flags
74  * and parameters.
75  */
76 int
77 jail_setv(int flags, ...)
78 {
79 	va_list ap, tap;
80 	struct jailparam *jp;
81 	const char *name, *value;
82 	int njp, jid;
83 
84 	/* Create the parameter list and import the parameters. */
85 	va_start(ap, flags);
86 	va_copy(tap, ap);
87 	for (njp = 0; va_arg(tap, char *) != NULL; njp++)
88 		(void)va_arg(tap, char *);
89 	va_end(tap);
90 	jp = alloca(njp * sizeof(struct jailparam));
91 	for (njp = 0; (name = va_arg(ap, char *)) != NULL;) {
92 		value = va_arg(ap, char *);
93 		if (jailparam_init(jp + njp, name) < 0)
94 			goto error;
95 		if (jailparam_import(jp + njp++, value) < 0)
96 			goto error;
97 	}
98 	va_end(ap);
99 	jid = jailparam_set(jp, njp, flags);
100 	jailparam_free(jp, njp);
101 	return (jid);
102 
103  error:
104 	jailparam_free(jp, njp);
105 	va_end(ap);
106 	return (-1);
107 }
108 
109 /*
110  * Read a null-terminated parameter list, get the referenced jail, and export
111  * the parameters to the list.
112  */
113 int
114 jail_getv(int flags, ...)
115 {
116 	va_list ap, tap;
117 	struct jailparam *jp, *jp_lastjid, *jp_jid, *jp_name, *jp_key;
118 	char *valarg, *value;
119 	const char *name, *key_value, *lastjid_value, *jid_value, *name_value;
120 	int njp, i, jid;
121 
122 	/* Create the parameter list and find the key. */
123 	va_start(ap, flags);
124 	va_copy(tap, ap);
125 	for (njp = 0; va_arg(tap, char *) != NULL; njp++)
126 		(void)va_arg(tap, char *);
127 	va_end(tap);
128 
129 	jp = alloca(njp * sizeof(struct jailparam));
130 	va_copy(tap, ap);
131 	jp_lastjid = jp_jid = jp_name = NULL;
132 	lastjid_value = jid_value = name_value = NULL;
133 	for (njp = 0; (name = va_arg(tap, char *)) != NULL; njp++) {
134 		value = va_arg(tap, char *);
135 		if (jailparam_init(jp + njp, name) < 0) {
136 			va_end(tap);
137 			goto error;
138 		}
139 		if (!strcmp(jp[njp].jp_name, "lastjid")) {
140 			jp_lastjid = jp + njp;
141 			lastjid_value = value;
142 		} else if (!strcmp(jp[njp].jp_name, "jid")) {
143 			jp_jid = jp + njp;
144 			jid_value = value;
145 		} if (!strcmp(jp[njp].jp_name, "name")) {
146 			jp_name = jp + njp;
147 			name_value = value;
148 		}
149 	}
150 	va_end(tap);
151 	/* Import the key parameter. */
152 	if (jp_lastjid != NULL) {
153 		jp_key = jp_lastjid;
154 		key_value = lastjid_value;
155 	} else if (jp_jid != NULL && strtol(jid_value, NULL, 10) != 0) {
156 		jp_key = jp_jid;
157 		key_value = jid_value;
158 	} else if (jp_name != NULL) {
159 		jp_key = jp_name;
160 		key_value = name_value;
161 	} else {
162 		strlcpy(jail_errmsg, "no jail specified", JAIL_ERRMSGLEN);
163 		errno = ENOENT;
164 		goto error;
165 	}
166 	if (jailparam_import(jp_key, key_value) < 0)
167 		goto error;
168 	/* Get the jail and export the parameters. */
169 	jid = jailparam_get(jp, njp, flags);
170 	if (jid < 0)
171 		goto error;
172 	for (i = 0; i < njp; i++) {
173 		(void)va_arg(ap, char *);
174 		valarg = va_arg(ap, char *);
175 		if (jp + i != jp_key) {
176 			/* It's up to the caller to ensure there's room. */
177 			if ((jp[i].jp_ctltype & CTLTYPE) == CTLTYPE_STRING)
178 				strcpy(valarg, jp[i].jp_value);
179 			else {
180 				value = jailparam_export(jp + i);
181 				if (value == NULL)
182 					goto error;
183 				strcpy(valarg, value);
184 				free(value);
185 			}
186 		}
187 	}
188 	jailparam_free(jp, njp);
189 	va_end(ap);
190 	return (jid);
191 
192  error:
193 	jailparam_free(jp, njp);
194 	va_end(ap);
195 	return (-1);
196 }
197 
198 /*
199  * Return a list of all known parameters.
200  */
201 int
202 jailparam_all(struct jailparam **jpp)
203 {
204 	struct jailparam *jp, *tjp;
205 	size_t mlen1, mlen2, buflen;
206 	unsigned njp, nlist;
207 	int mib1[CTL_MAXNAME], mib2[CTL_MAXNAME - 2];
208 	char buf[MAXPATHLEN];
209 
210 	njp = 0;
211 	nlist = 32;
212 	jp = malloc(nlist * sizeof(*jp));
213 	if (jp == NULL) {
214 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
215 		return (-1);
216 	}
217 	mib1[0] = 0;
218 	mib1[1] = 2;
219 	mlen1 = CTL_MAXNAME - 2;
220 	if (sysctlnametomib(SJPARAM, mib1 + 2, &mlen1) < 0) {
221 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
222 		    "sysctlnametomib(" SJPARAM "): %s", strerror(errno));
223 		goto error;
224 	}
225 	for (;; njp++) {
226 		/* Get the next parameter. */
227 		mlen2 = sizeof(mib2);
228 		if (sysctl(mib1, mlen1 + 2, mib2, &mlen2, NULL, 0) < 0) {
229 			if (errno == ENOENT) {
230 				/* No more entries. */
231 				break;
232 			}
233 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
234 			    "sysctl(0.2): %s", strerror(errno));
235 			goto error;
236 		}
237 		if (mib2[0] != mib1[2] ||
238 		    mib2[1] != mib1[3] ||
239 		    mib2[2] != mib1[4])
240 			break;
241 		/* Convert it to an ascii name. */
242 		memcpy(mib1 + 2, mib2, mlen2);
243 		mlen1 = mlen2 / sizeof(int);
244 		mib1[1] = 1;
245 		buflen = sizeof(buf);
246 		if (sysctl(mib1, mlen1 + 2, buf, &buflen, NULL, 0) < 0) {
247 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
248 			    "sysctl(0.1): %s", strerror(errno));
249 			goto error;
250 		}
251 		if (buf[buflen - 2] == '.')
252 			buf[buflen - 2] = '\0';
253 		/* Add the parameter to the list */
254 		if (njp >= nlist) {
255 			nlist *= 2;
256 			tjp = reallocarray(jp, nlist, sizeof(*jp));
257 			if (tjp == NULL)
258 				goto error;
259 			jp = tjp;
260 		}
261 		if (jailparam_init(jp + njp, buf + sizeof(SJPARAM)) < 0)
262 			goto error;
263 		mib1[1] = 2;
264 	}
265 	jp = reallocarray(jp, njp, sizeof(*jp));
266 	*jpp = jp;
267 	return (njp);
268 
269  error:
270 	jailparam_free(jp, njp);
271 	free(jp);
272 	return (-1);
273 }
274 
275 /*
276  * Clear a jail parameter and copy in its name.
277  */
278 int
279 jailparam_init(struct jailparam *jp, const char *name)
280 {
281 
282 	memset(jp, 0, sizeof(*jp));
283 	jp->jp_name = strdup(name);
284 	if (jp->jp_name == NULL) {
285 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
286 		return (-1);
287 	}
288 	if (jailparam_type(jp) < 0) {
289 		jailparam_free(jp, 1);
290 		jp->jp_name = NULL;
291 		jp->jp_value = NULL;
292 		return (-1);
293 	}
294 	return (0);
295 }
296 
297 /*
298  * Put a name and value into a jail parameter element, converting the value
299  * to internal form.
300  */
301 int
302 jailparam_import(struct jailparam *jp, const char *value)
303 {
304 	char *p, *ep, *tvalue;
305 	const char *avalue;
306 	int i, nval, fw;
307 
308 	if (value == NULL)
309 		return (0);
310 	if ((jp->jp_ctltype & CTLTYPE) == CTLTYPE_STRING) {
311 		jp->jp_value = strdup(value);
312 		if (jp->jp_value == NULL) {
313 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
314 			return (-1);
315 		}
316 		return (0);
317 	}
318 	nval = 1;
319 	if (jp->jp_elemlen) {
320 		if (value[0] == '\0' || (value[0] == '-' && value[1] == '\0')) {
321 			jp->jp_value = strdup("");
322 			if (jp->jp_value == NULL) {
323 				strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
324 				return (-1);
325 			}
326 			jp->jp_valuelen = 0;
327 			return (0);
328 		}
329 		for (p = strchr(value, ','); p; p = strchr(p + 1, ','))
330 			nval++;
331 		jp->jp_valuelen = jp->jp_elemlen * nval;
332 	}
333 	jp->jp_value = malloc(jp->jp_valuelen);
334 	if (jp->jp_value == NULL) {
335 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
336 		return (-1);
337 	}
338 	avalue = value;
339 	for (i = 0; i < nval; i++) {
340 		fw = nval == 1 ? strlen(avalue) : strcspn(avalue, ",");
341 		switch (jp->jp_ctltype & CTLTYPE) {
342 		case CTLTYPE_INT:
343 			if (jp->jp_flags & (JP_BOOL | JP_NOBOOL)) {
344 				if (!jailparam_import_enum(bool_values, 2,
345 				    avalue, fw, &((int *)jp->jp_value)[i])) {
346 					snprintf(jail_errmsg,
347 					    JAIL_ERRMSGLEN, "%s: "
348 					    "unknown boolean value \"%.*s\"",
349 					    jp->jp_name, fw, avalue);
350 					errno = EINVAL;
351 					goto error;
352 				}
353 				break;
354 			}
355 			if (jp->jp_flags & JP_JAILSYS) {
356 				/*
357 				 * Allow setting a jailsys parameter to "new"
358 				 * in a booleanesque fashion.
359 				 */
360 				if (value[0] == '\0')
361 					((int *)jp->jp_value)[i] = JAIL_SYS_NEW;
362 				else if (!jailparam_import_enum(jailsys_values,
363 				    sizeof(jailsys_values) /
364 				    sizeof(jailsys_values[0]), avalue, fw,
365 				    &((int *)jp->jp_value)[i])) {
366 					snprintf(jail_errmsg,
367 					    JAIL_ERRMSGLEN, "%s: "
368 					    "unknown jailsys value \"%.*s\"",
369 					    jp->jp_name, fw, avalue);
370 					errno = EINVAL;
371 					goto error;
372 				}
373 				break;
374 			}
375 			((int *)jp->jp_value)[i] = strtol(avalue, &ep, 10);
376 		integer_test:
377 			if (ep != avalue + fw) {
378 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
379 				    "%s: non-integer value \"%.*s\"",
380 				    jp->jp_name, fw, avalue);
381 				errno = EINVAL;
382 				goto error;
383 			}
384 			break;
385 		case CTLTYPE_UINT:
386 			((unsigned *)jp->jp_value)[i] =
387 			    strtoul(avalue, &ep, 10);
388 			goto integer_test;
389 		case CTLTYPE_LONG:
390 			((long *)jp->jp_value)[i] = strtol(avalue, &ep, 10);
391 			goto integer_test;
392 		case CTLTYPE_ULONG:
393 			((unsigned long *)jp->jp_value)[i] =
394 			    strtoul(avalue, &ep, 10);
395 			goto integer_test;
396 		case CTLTYPE_S64:
397 			((int64_t *)jp->jp_value)[i] =
398 			    strtoimax(avalue, &ep, 10);
399 			goto integer_test;
400 		case CTLTYPE_U64:
401 			((uint64_t *)jp->jp_value)[i] =
402 			    strtoumax(avalue, &ep, 10);
403 			goto integer_test;
404 		case CTLTYPE_STRUCT:
405 			tvalue = alloca(fw + 1);
406 			strlcpy(tvalue, avalue, fw + 1);
407 			switch (jp->jp_structtype) {
408 			case JPS_IN_ADDR:
409 				if (inet_pton(AF_INET, tvalue,
410 				    &((struct in_addr *)jp->jp_value)[i]) != 1)
411 				{
412 					snprintf(jail_errmsg,
413 					    JAIL_ERRMSGLEN,
414 					    "%s: not an IPv4 address: %s",
415 					    jp->jp_name, tvalue);
416 					errno = EINVAL;
417 					goto error;
418 				}
419 				break;
420 			case JPS_IN6_ADDR:
421 				if (inet_pton(AF_INET6, tvalue,
422 				    &((struct in6_addr *)jp->jp_value)[i]) != 1)
423 				{
424 					snprintf(jail_errmsg,
425 					    JAIL_ERRMSGLEN,
426 					    "%s: not an IPv6 address: %s",
427 					    jp->jp_name, tvalue);
428 					errno = EINVAL;
429 					goto error;
430 				}
431 				break;
432 			default:
433 				goto unknown_type;
434 			}
435 			break;
436 		default:
437 		unknown_type:
438 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
439 			    "unknown type for %s", jp->jp_name);
440 			errno = ENOENT;
441 			goto error;
442 		}
443 		avalue += fw + 1;
444 	}
445 	return (0);
446 
447  error:
448 	free(jp->jp_value);
449 	jp->jp_value = NULL;
450 	return (-1);
451 }
452 
453 static int
454 jailparam_import_enum(const char **values, int nvalues, const char *valstr,
455     size_t valsize, int *value)
456 {
457 	char *ep;
458 	int i;
459 
460 	for (i = 0; i < nvalues; i++)
461 		if (valsize == strlen(values[i]) &&
462 		    !strncasecmp(valstr, values[i], valsize)) {
463 			*value = i;
464 			return 1;
465 		}
466 	*value = strtol(valstr, &ep, 10);
467 	return (ep == valstr + valsize);
468 }
469 
470 /*
471  * Put a name and value into a jail parameter element, copying the value
472  * but not altering it.
473  */
474 int
475 jailparam_import_raw(struct jailparam *jp, void *value, size_t valuelen)
476 {
477 
478 	jp->jp_value = value;
479 	jp->jp_valuelen = valuelen;
480 	jp->jp_flags |= JP_RAWVALUE;
481 	return (0);
482 }
483 
484 /*
485  * Run the jail_set and jail_get system calls on a parameter list.
486  */
487 int
488 jailparam_set(struct jailparam *jp, unsigned njp, int flags)
489 {
490 	struct iovec *jiov;
491 	char *nname;
492 	int i, jid, bool0;
493 	unsigned j;
494 
495 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
496 	bool0 = 0;
497 	for (i = j = 0; j < njp; j++) {
498 		jiov[i].iov_base = jp[j].jp_name;
499 		jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
500 		i++;
501 		if (jp[j].jp_flags & (JP_BOOL | JP_NOBOOL)) {
502 			/*
503 			 * Set booleans without values.  If one has a value of
504 			 * zero, change it to (or from) its "no" counterpart.
505 			 */
506 			jiov[i].iov_base = NULL;
507 			jiov[i].iov_len = 0;
508 			if (jp[j].jp_value != NULL &&
509 			    jp[j].jp_valuelen == sizeof(int) &&
510 			    !*(int *)jp[j].jp_value) {
511 				bool0 = 1;
512 				nname = jp[j].jp_flags & JP_BOOL
513 				    ? noname(jp[j].jp_name)
514 				    : nononame(jp[j].jp_name);
515 				if (nname == NULL) {
516 					njp = j;
517 					jid = -1;
518 					goto done;
519 				}
520 				jiov[i - 1].iov_base = nname;
521 				jiov[i - 1].iov_len = strlen(nname) + 1;
522 
523 			}
524 		} else {
525 			/*
526 			 * Try to fill in missing values with an empty string.
527 			 */
528 			if (jp[j].jp_value == NULL && jp[j].jp_valuelen > 0 &&
529 			    jailparam_import(jp + j, "") < 0) {
530 				njp = j;
531 				jid = -1;
532 				goto done;
533 			}
534 			jiov[i].iov_base = jp[j].jp_value;
535 			jiov[i].iov_len =
536 			    (jp[j].jp_ctltype & CTLTYPE) == CTLTYPE_STRING
537 			    ? strlen(jp[j].jp_value) + 1
538 			    : jp[j].jp_valuelen;
539 		}
540 		i++;
541 	}
542 	jiov[i].iov_base = __DECONST(char *, "errmsg");
543 	jiov[i].iov_len = sizeof("errmsg");
544 	i++;
545 	jiov[i].iov_base = jail_errmsg;
546 	jiov[i].iov_len = JAIL_ERRMSGLEN;
547 	i++;
548 	jail_errmsg[0] = 0;
549 	jid = jail_set(jiov, i, flags);
550 	if (jid < 0 && !jail_errmsg[0])
551 		snprintf(jail_errmsg, sizeof(jail_errmsg), "jail_set: %s",
552 		    strerror(errno));
553  done:
554 	if (bool0)
555 		for (j = 0; j < njp; j++)
556 			if ((jp[j].jp_flags & (JP_BOOL | JP_NOBOOL)) &&
557 			    jp[j].jp_value != NULL &&
558 			    jp[j].jp_valuelen == sizeof(int) &&
559 			    !*(int *)jp[j].jp_value)
560 				free(jiov[j * 2].iov_base);
561 	return (jid);
562 }
563 
564 int
565 jailparam_get(struct jailparam *jp, unsigned njp, int flags)
566 {
567 	struct iovec *jiov;
568 	struct jailparam *jp_lastjid, *jp_jid, *jp_name, *jp_key;
569 	int i, ai, ki, jid, arrays, sanity;
570 	unsigned j;
571 
572 	/*
573 	 * Get the types for all parameters.
574 	 * Find the key and any array parameters.
575 	 */
576 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
577 	jp_lastjid = jp_jid = jp_name = NULL;
578 	arrays = 0;
579 	for (ai = j = 0; j < njp; j++) {
580 		if (!strcmp(jp[j].jp_name, "lastjid"))
581 			jp_lastjid = jp + j;
582 		else if (!strcmp(jp[j].jp_name, "jid"))
583 			jp_jid = jp + j;
584 		else if (!strcmp(jp[j].jp_name, "name"))
585 			jp_name = jp + j;
586 		else if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
587 			arrays = 1;
588 			jiov[ai].iov_base = jp[j].jp_name;
589 			jiov[ai].iov_len = strlen(jp[j].jp_name) + 1;
590 			ai++;
591 			jiov[ai].iov_base = NULL;
592 			jiov[ai].iov_len = 0;
593 			ai++;
594 		}
595 	}
596 	jp_key = jp_lastjid ? jp_lastjid :
597 	    jp_jid && jp_jid->jp_valuelen == sizeof(int) &&
598 	    jp_jid->jp_value && *(int *)jp_jid->jp_value ? jp_jid : jp_name;
599 	if (jp_key == NULL || jp_key->jp_value == NULL) {
600 		strlcpy(jail_errmsg, "no jail specified", JAIL_ERRMSGLEN);
601 		errno = ENOENT;
602 		return (-1);
603 	}
604 	ki = ai;
605 	jiov[ki].iov_base = jp_key->jp_name;
606 	jiov[ki].iov_len = strlen(jp_key->jp_name) + 1;
607 	ki++;
608 	jiov[ki].iov_base = jp_key->jp_value;
609 	jiov[ki].iov_len = (jp_key->jp_ctltype & CTLTYPE) == CTLTYPE_STRING
610 	    ? strlen(jp_key->jp_value) + 1 : jp_key->jp_valuelen;
611 	ki++;
612 	jiov[ki].iov_base = __DECONST(char *, "errmsg");
613 	jiov[ki].iov_len = sizeof("errmsg");
614 	ki++;
615 	jiov[ki].iov_base = jail_errmsg;
616 	jiov[ki].iov_len = JAIL_ERRMSGLEN;
617 	ki++;
618 	jail_errmsg[0] = 0;
619 	if (arrays && jail_get(jiov, ki, flags) < 0) {
620 		if (!jail_errmsg[0])
621 			snprintf(jail_errmsg, sizeof(jail_errmsg),
622 			    "jail_get: %s", strerror(errno));
623 		return (-1);
624 	}
625 	/* Allocate storage for all parameters. */
626 	for (ai = j = 0, i = ki; j < njp; j++) {
627 		if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
628 			ai++;
629 			jiov[ai].iov_len += jp[j].jp_elemlen * ARRAY_SLOP;
630 			if (jp[j].jp_valuelen >= jiov[ai].iov_len)
631 				jiov[ai].iov_len = jp[j].jp_valuelen;
632 			else {
633 				jp[j].jp_valuelen = jiov[ai].iov_len;
634 				if (jp[j].jp_value != NULL)
635 					free(jp[j].jp_value);
636 				jp[j].jp_value = malloc(jp[j].jp_valuelen);
637 				if (jp[j].jp_value == NULL) {
638 					strerror_r(errno, jail_errmsg,
639 					    JAIL_ERRMSGLEN);
640 					return (-1);
641 				}
642 			}
643 			jiov[ai].iov_base = jp[j].jp_value;
644 			memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
645 			ai++;
646 		} else if (jp + j != jp_key) {
647 			jiov[i].iov_base = jp[j].jp_name;
648 			jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
649 			i++;
650 			if (jp[j].jp_value == NULL &&
651 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
652 				jp[j].jp_value = malloc(jp[j].jp_valuelen);
653 				if (jp[j].jp_value == NULL) {
654 					strerror_r(errno, jail_errmsg,
655 					    JAIL_ERRMSGLEN);
656 					return (-1);
657 				}
658 			}
659 			jiov[i].iov_base = jp[j].jp_value;
660 			jiov[i].iov_len = jp[j].jp_valuelen;
661 			memset(jiov[i].iov_base, 0, jiov[i].iov_len);
662 			i++;
663 		}
664 	}
665 	/*
666 	 * Get the prison.  If there are array elements, retry a few times
667 	 * in case their sizes changed from under us.
668 	 */
669 	for (sanity = 0;; sanity++) {
670 		jid = jail_get(jiov, i, flags);
671 		if (jid >= 0 || !arrays || sanity == ARRAY_SANITY ||
672 		    errno != EINVAL || jail_errmsg[0])
673 			break;
674 		for (ai = j = 0; j < njp; j++) {
675 			if (jp[j].jp_elemlen &&
676 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
677 				ai++;
678 				jiov[ai].iov_base = NULL;
679 				jiov[ai].iov_len = 0;
680 				ai++;
681 			}
682 		}
683 		if (jail_get(jiov, ki, flags) < 0)
684 			break;
685 		for (ai = j = 0; j < njp; j++) {
686 			if (jp[j].jp_elemlen &&
687 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
688 				ai++;
689 				jiov[ai].iov_len +=
690 				    jp[j].jp_elemlen * ARRAY_SLOP;
691 				if (jp[j].jp_valuelen >= jiov[ai].iov_len)
692 					jiov[ai].iov_len = jp[j].jp_valuelen;
693 				else {
694 					jp[j].jp_valuelen = jiov[ai].iov_len;
695 					if (jp[j].jp_value != NULL)
696 						free(jp[j].jp_value);
697 					jp[j].jp_value =
698 					    malloc(jiov[ai].iov_len);
699 					if (jp[j].jp_value == NULL) {
700 						strerror_r(errno, jail_errmsg,
701 						    JAIL_ERRMSGLEN);
702 						return (-1);
703 					}
704 				}
705 				jiov[ai].iov_base = jp[j].jp_value;
706 				memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
707 				ai++;
708 			}
709 		}
710 	}
711 	if (jid < 0 && !jail_errmsg[0])
712 		snprintf(jail_errmsg, sizeof(jail_errmsg),
713 		    "jail_get: %s", strerror(errno));
714 	for (ai = j = 0, i = ki; j < njp; j++) {
715 		if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
716 			ai++;
717 			jp[j].jp_valuelen = jiov[ai].iov_len;
718 			ai++;
719 		} else if (jp + j != jp_key) {
720 			i++;
721 			jp[j].jp_valuelen = jiov[i].iov_len;
722 			i++;
723 		}
724 	}
725 	return (jid);
726 }
727 
728 /*
729  * Convert a jail parameter's value to external form.
730  */
731 char *
732 jailparam_export(struct jailparam *jp)
733 {
734 	size_t *valuelens;
735 	char *value, *tvalue, **values;
736 	size_t valuelen;
737 	int i, nval, ival;
738 	char valbuf[INET6_ADDRSTRLEN];
739 
740 	if ((jp->jp_ctltype & CTLTYPE) == CTLTYPE_STRING) {
741 		value = strdup(jp->jp_value);
742 		if (value == NULL)
743 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
744 		return (value);
745 	}
746 	nval = jp->jp_elemlen ? jp->jp_valuelen / jp->jp_elemlen : 1;
747 	if (nval == 0) {
748 		value = strdup("");
749 		if (value == NULL)
750 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
751 		return (value);
752 	}
753 	values = alloca(nval * sizeof(char *));
754 	valuelens = alloca(nval * sizeof(size_t));
755 	valuelen = 0;
756 	for (i = 0; i < nval; i++) {
757 		switch (jp->jp_ctltype & CTLTYPE) {
758 		case CTLTYPE_INT:
759 			ival = ((int *)jp->jp_value)[i];
760 			if ((jp->jp_flags & (JP_BOOL | JP_NOBOOL)) &&
761 			    (unsigned)ival < 2) {
762 				strlcpy(valbuf, bool_values[ival],
763 				    sizeof(valbuf));
764 				break;
765 			}
766 			if ((jp->jp_flags & JP_JAILSYS) &&
767 			    (unsigned)ival < sizeof(jailsys_values) /
768 			    sizeof(jailsys_values[0])) {
769 				strlcpy(valbuf, jailsys_values[ival],
770 				    sizeof(valbuf));
771 				break;
772 			}
773 			snprintf(valbuf, sizeof(valbuf), "%d", ival);
774 			break;
775 		case CTLTYPE_UINT:
776 			snprintf(valbuf, sizeof(valbuf), "%u",
777 			    ((unsigned *)jp->jp_value)[i]);
778 			break;
779 		case CTLTYPE_LONG:
780 			snprintf(valbuf, sizeof(valbuf), "%ld",
781 			    ((long *)jp->jp_value)[i]);
782 			break;
783 		case CTLTYPE_ULONG:
784 			snprintf(valbuf, sizeof(valbuf), "%lu",
785 			    ((unsigned long *)jp->jp_value)[i]);
786 			break;
787 		case CTLTYPE_S64:
788 			snprintf(valbuf, sizeof(valbuf), "%jd",
789 			    (intmax_t)((int64_t *)jp->jp_value)[i]);
790 			break;
791 		case CTLTYPE_U64:
792 			snprintf(valbuf, sizeof(valbuf), "%ju",
793 			    (uintmax_t)((uint64_t *)jp->jp_value)[i]);
794 			break;
795 		case CTLTYPE_STRUCT:
796 			switch (jp->jp_structtype) {
797 			case JPS_IN_ADDR:
798 				if (inet_ntop(AF_INET,
799 				    &((struct in_addr *)jp->jp_value)[i],
800 				    valbuf, sizeof(valbuf)) == NULL) {
801 					strerror_r(errno, jail_errmsg,
802 					    JAIL_ERRMSGLEN);
803 					return (NULL);
804 				}
805 				break;
806 			case JPS_IN6_ADDR:
807 				if (inet_ntop(AF_INET6,
808 				    &((struct in6_addr *)jp->jp_value)[i],
809 				    valbuf, sizeof(valbuf)) == NULL) {
810 					strerror_r(errno, jail_errmsg,
811 					    JAIL_ERRMSGLEN);
812 					return (NULL);
813 				}
814 				break;
815 			default:
816 				goto unknown_type;
817 			}
818 			break;
819 		default:
820 		unknown_type:
821 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
822 			    "unknown type for %s", jp->jp_name);
823 			errno = ENOENT;
824 			return (NULL);
825 		}
826 		valuelens[i] = strlen(valbuf) + 1;
827 		valuelen += valuelens[i];
828 		values[i] = alloca(valuelens[i]);
829 		strcpy(values[i], valbuf);
830 	}
831 	value = malloc(valuelen);
832 	if (value == NULL)
833 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
834 	else {
835 		tvalue = value;
836 		for (i = 0; i < nval; i++) {
837 			strcpy(tvalue, values[i]);
838 			if (i < nval - 1) {
839 				tvalue += valuelens[i];
840 				tvalue[-1] = ',';
841 			}
842 		}
843 	}
844 	return (value);
845 }
846 
847 /*
848  * Free the contents of a jail parameter list (but not the list itself).
849  */
850 void
851 jailparam_free(struct jailparam *jp, unsigned njp)
852 {
853 	unsigned j;
854 
855 	for (j = 0; j < njp; j++) {
856 		free(jp[j].jp_name);
857 		if (!(jp[j].jp_flags & JP_RAWVALUE))
858 			free(jp[j].jp_value);
859 	}
860 }
861 
862 /*
863  * Find a parameter's type and size from its MIB.
864  */
865 static int
866 jailparam_type(struct jailparam *jp)
867 {
868 	char *p, *name, *nname;
869 	size_t miblen, desclen;
870 	int i, isarray;
871 	struct {
872 	    int i;
873 	    char s[MAXPATHLEN];
874 	} desc;
875 	int mib[CTL_MAXNAME];
876 
877 	/* The "lastjid" parameter isn't real. */
878 	name = jp->jp_name;
879 	if (!strcmp(name, "lastjid")) {
880 		jp->jp_valuelen = sizeof(int);
881 		jp->jp_ctltype = CTLTYPE_INT | CTLFLAG_WR;
882 		return (0);
883 	}
884 
885 	/* Find the sysctl that describes the parameter. */
886 	mib[0] = 0;
887 	mib[1] = 3;
888 	snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", name);
889 	miblen = sizeof(mib) - 2 * sizeof(int);
890 	if (sysctl(mib, 2, mib + 2, &miblen, desc.s, strlen(desc.s)) < 0) {
891 		if (errno != ENOENT) {
892 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
893 			    "sysctl(0.3.%s): %s", name, strerror(errno));
894 			return (-1);
895 		}
896 		if (kldload_param(name) >= 0 && sysctl(mib, 2, mib + 2, &miblen,
897 		    desc.s, strlen(desc.s)) >= 0)
898 			goto mib_desc;
899 		/*
900 		 * The parameter probably doesn't exist.  But it might be
901 		 * the "no" counterpart to a boolean.
902 		 */
903 		nname = nononame(name);
904 		if (nname == NULL) {
905 		unknown_parameter:
906 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
907 			    "unknown parameter: %s", jp->jp_name);
908 			errno = ENOENT;
909 			return (-1);
910 		}
911 		name = alloca(strlen(nname) + 1);
912 		strcpy(name, nname);
913 		free(nname);
914 		snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", name);
915 		miblen = sizeof(mib) - 2 * sizeof(int);
916 		if (sysctl(mib, 2, mib + 2, &miblen, desc.s,
917 		    strlen(desc.s)) < 0)
918 			goto unknown_parameter;
919 		jp->jp_flags |= JP_NOBOOL;
920 	}
921  mib_desc:
922 	mib[1] = 4;
923 	desclen = sizeof(desc);
924 	if (sysctl(mib, (miblen / sizeof(int)) + 2, &desc, &desclen,
925 	    NULL, 0) < 0) {
926 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
927 		    "sysctl(0.4.%s): %s", name, strerror(errno));
928 		return (-1);
929 	}
930 	jp->jp_ctltype = desc.i;
931 	/* If this came from removing a "no", it better be a boolean. */
932 	if (jp->jp_flags & JP_NOBOOL) {
933 		if ((desc.i & CTLTYPE) == CTLTYPE_INT && desc.s[0] == 'B') {
934 			jp->jp_valuelen = sizeof(int);
935 			return (0);
936 		}
937 		else if ((desc.i & CTLTYPE) != CTLTYPE_NODE)
938 			goto unknown_parameter;
939 	}
940 	/* See if this is an array type. */
941 	p = strchr(desc.s, '\0');
942 	isarray  = 0;
943 	if (p - 2 < desc.s || strcmp(p - 2, ",a"))
944 		isarray = 0;
945 	else {
946 		isarray = 1;
947 		p[-2] = 0;
948 	}
949 	/* Look for types we understand. */
950 	switch (desc.i & CTLTYPE) {
951 	case CTLTYPE_INT:
952 		if (desc.s[0] == 'B')
953 			jp->jp_flags |= JP_BOOL;
954 		else if (!strcmp(desc.s, "E,jailsys"))
955 			jp->jp_flags |= JP_JAILSYS;
956 	case CTLTYPE_UINT:
957 		jp->jp_valuelen = sizeof(int);
958 		break;
959 	case CTLTYPE_LONG:
960 	case CTLTYPE_ULONG:
961 		jp->jp_valuelen = sizeof(long);
962 		break;
963 	case CTLTYPE_S64:
964 	case CTLTYPE_U64:
965 		jp->jp_valuelen = sizeof(int64_t);
966 		break;
967 	case CTLTYPE_STRING:
968 		desc.s[0] = 0;
969 		desclen = sizeof(desc.s);
970 		if (sysctl(mib + 2, miblen / sizeof(int), desc.s, &desclen,
971 		    NULL, 0) < 0) {
972 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
973 			    "sysctl(" SJPARAM ".%s): %s", name,
974 			    strerror(errno));
975 			return (-1);
976 		}
977 		jp->jp_valuelen = strtoul(desc.s, NULL, 10);
978 		break;
979 	case CTLTYPE_STRUCT:
980 		if (!strcmp(desc.s, "S,in_addr")) {
981 			jp->jp_structtype = JPS_IN_ADDR;
982 			jp->jp_valuelen = sizeof(struct in_addr);
983 		} else if (!strcmp(desc.s, "S,in6_addr")) {
984 			jp->jp_structtype = JPS_IN6_ADDR;
985 			jp->jp_valuelen = sizeof(struct in6_addr);
986 		} else {
987 			desclen = 0;
988 			if (sysctl(mib + 2, miblen / sizeof(int),
989 			    NULL, &jp->jp_valuelen, NULL, 0) < 0) {
990 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
991 				    "sysctl(" SJPARAM ".%s): %s", name,
992 				    strerror(errno));
993 				return (-1);
994 			}
995 		}
996 		break;
997 	case CTLTYPE_NODE:
998 		/*
999 		 * A node might be described by an empty-named child,
1000 		 * which would be immediately before or after the node itself.
1001 		 */
1002 		mib[1] = 1;
1003 		miblen += sizeof(int);
1004 		for (i = -1; i <= 1; i += 2) {
1005 			mib[(miblen / sizeof(int)) + 1] =
1006 			    mib[(miblen / sizeof(int))] + i;
1007 			desclen = sizeof(desc.s);
1008 			if (sysctl(mib, (miblen / sizeof(int)) + 2, desc.s,
1009 			    &desclen, NULL, 0) < 0) {
1010 				if (errno == ENOENT)
1011 					continue;
1012 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
1013 				    "sysctl(0.1): %s", strerror(errno));
1014 				return (-1);
1015 			}
1016 			if (desclen == sizeof(SJPARAM) + strlen(name) + 2 &&
1017 			    memcmp(SJPARAM ".", desc.s, sizeof(SJPARAM)) == 0 &&
1018 			    memcmp(name, desc.s + sizeof(SJPARAM),
1019 			    desclen - sizeof(SJPARAM) - 2) == 0 &&
1020 			    desc.s[desclen - 2] == '.')
1021 				goto mib_desc;
1022 		}
1023 		goto unknown_parameter;
1024 	default:
1025 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
1026 		    "unknown type for %s", jp->jp_name);
1027 		errno = ENOENT;
1028 		return (-1);
1029 	}
1030 	if (isarray) {
1031 		jp->jp_elemlen = jp->jp_valuelen;
1032 		jp->jp_valuelen = 0;
1033 	}
1034 	return (0);
1035 }
1036 
1037 /*
1038  * Attempt to load a kernel module matching an otherwise nonexistent parameter.
1039  */
1040 static int
1041 kldload_param(const char *name)
1042 {
1043 	int kl;
1044 
1045 	if (strcmp(name, "linux") == 0 || strncmp(name, "linux.", 6) == 0)
1046 		kl = kldload("linux");
1047 	else if (strcmp(name, "sysvmsg") == 0 || strcmp(name, "sysvsem") == 0 ||
1048 	    strcmp(name, "sysvshm") == 0)
1049 		kl = kldload(name);
1050 	else if (strncmp(name, "allow.mount.", 12) == 0) {
1051 		/* Load the matching filesystem */
1052 		const char *modname = name + 12;
1053 
1054 		kl = kldload(modname);
1055 		if (kl < 0 && errno == ENOENT &&
1056 		    strncmp(modname, "no", 2) == 0)
1057 			kl = kldload(modname + 2);
1058 	} else {
1059 		errno = ENOENT;
1060 		return (-1);
1061 	}
1062 	if (kl < 0 && errno == EEXIST) {
1063 		/*
1064 		 * In the module is already loaded, then it must not contain
1065 		 * the parameter.
1066 		 */
1067 		errno = ENOENT;
1068 	}
1069 	return kl;
1070 }
1071 
1072 /*
1073  * Change a boolean parameter name into its "no" counterpart or vice versa.
1074  */
1075 static char *
1076 noname(const char *name)
1077 {
1078 	char *nname, *p;
1079 
1080 	nname = malloc(strlen(name) + 3);
1081 	if (nname == NULL) {
1082 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
1083 		return (NULL);
1084 	}
1085 	p = strrchr(name, '.');
1086 	if (p != NULL)
1087 		sprintf(nname, "%.*s.no%s", (int)(p - name), name, p + 1);
1088 	else
1089 		sprintf(nname, "no%s", name);
1090 	return (nname);
1091 }
1092 
1093 static char *
1094 nononame(const char *name)
1095 {
1096 	char *p, *nname;
1097 
1098 	p = strrchr(name, '.');
1099 	if (strncmp(p ? p + 1 : name, "no", 2)) {
1100 		snprintf(jail_errmsg, sizeof(jail_errmsg),
1101 		    "mismatched boolean: %s", name);
1102 		errno = EINVAL;
1103 		return (NULL);
1104 	}
1105 	nname = malloc(strlen(name) - 1);
1106 	if (nname == NULL) {
1107 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
1108 		return (NULL);
1109 	}
1110 	if (p != NULL)
1111 		sprintf(nname, "%.*s.%s", (int)(p - name), name, p + 3);
1112 	else
1113 		strcpy(nname, name + 2);
1114 	return (nname);
1115 }
1116