xref: /freebsd/lib/libjail/jail.c (revision 2a664c03e55254b0f3b32dcdfc78179c0a57a8d2)
1 /*-
2  * Copyright (c) 2009 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/param.h>
31 #include <sys/types.h>
32 #include <sys/jail.h>
33 #include <sys/socket.h>
34 #include <sys/sysctl.h>
35 
36 #include <arpa/inet.h>
37 #include <netinet/in.h>
38 
39 #include <errno.h>
40 #include <inttypes.h>
41 #include <stdio.h>
42 #include <stdarg.h>
43 #include <stdlib.h>
44 #include <string.h>
45 
46 #include "jail.h"
47 
48 #define	SJPARAM		"security.jail.param"
49 
50 #define JPS_IN_ADDR	1
51 #define JPS_IN6_ADDR	2
52 
53 #define ARRAY_SANITY	5
54 #define ARRAY_SLOP	5
55 
56 
57 static int jailparam_import_enum(const char **values, int nvalues,
58     const char *valstr, size_t valsize, int *value);
59 static int jailparam_type(struct jailparam *jp);
60 static char *noname(const char *name);
61 static char *nononame(const char *name);
62 
63 char jail_errmsg[JAIL_ERRMSGLEN];
64 
65 static const char *bool_values[] = { "false", "true" };
66 static const char *jailsys_values[] = { "disable", "new", "inherit" };
67 
68 
69 /*
70  * Import a null-terminated parameter list and set a jail with the flags
71  * and parameters.
72  */
73 int
74 jail_setv(int flags, ...)
75 {
76 	va_list ap, tap;
77 	struct jailparam *jp;
78 	const char *name, *value;
79 	int njp, jid;
80 
81 	/* Create the parameter list and import the parameters. */
82 	va_start(ap, flags);
83 	va_copy(tap, ap);
84 	for (njp = 0; va_arg(tap, char *) != NULL; njp++)
85 		(void)va_arg(tap, char *);
86 	va_end(tap);
87 	jp = alloca(njp * sizeof(struct jailparam));
88 	for (njp = 0; (name = va_arg(ap, char *)) != NULL;) {
89 		value = va_arg(ap, char *);
90 		if (jailparam_init(jp + njp, name) < 0)
91 			goto error;
92 		if (jailparam_import(jp + njp++, value) < 0)
93 			goto error;
94 	}
95 	va_end(ap);
96 	jid = jailparam_set(jp, njp, flags);
97 	jailparam_free(jp, njp);
98 	return (jid);
99 
100  error:
101 	jailparam_free(jp, njp);
102 	va_end(ap);
103 	return (-1);
104 }
105 
106 /*
107  * Read a null-terminated parameter list, get the referenced jail, and export
108  * the parameters to the list.
109  */
110 int
111 jail_getv(int flags, ...)
112 {
113 	va_list ap, tap;
114 	struct jailparam *jp, *jp_lastjid, *jp_jid, *jp_name, *jp_key;
115 	char *valarg, *value;
116 	const char *name, *key_value, *lastjid_value, *jid_value, *name_value;
117 	int njp, i, jid;
118 
119 	/* Create the parameter list and find the key. */
120 	va_start(ap, flags);
121 	va_copy(tap, ap);
122 	for (njp = 0; va_arg(tap, char *) != NULL; njp++)
123 		(void)va_arg(tap, char *);
124 	va_end(tap);
125 
126 	jp = alloca(njp * sizeof(struct jailparam));
127 	va_copy(tap, ap);
128 	jp_lastjid = jp_jid = jp_name = NULL;
129 	lastjid_value = jid_value = name_value = NULL;
130 	for (njp = 0; (name = va_arg(tap, char *)) != NULL; njp++) {
131 		value = va_arg(tap, char *);
132 		if (jailparam_init(jp + njp, name) < 0) {
133 			va_end(tap);
134 			goto error;
135 		}
136 		if (!strcmp(jp[njp].jp_name, "lastjid")) {
137 			jp_lastjid = jp + njp;
138 			lastjid_value = value;
139 		} else if (!strcmp(jp[njp].jp_name, "jid")) {
140 			jp_jid = jp + njp;
141 			jid_value = value;
142 		} if (!strcmp(jp[njp].jp_name, "name")) {
143 			jp_name = jp + njp;
144 			name_value = value;
145 		}
146 	}
147 	va_end(tap);
148 	/* Import the key parameter. */
149 	if (jp_lastjid != NULL) {
150 		jp_key = jp_lastjid;
151 		key_value = lastjid_value;
152 	} else if (jp_jid != NULL && strtol(jid_value, NULL, 10) != 0) {
153 		jp_key = jp_jid;
154 		key_value = jid_value;
155 	} else if (jp_name != NULL) {
156 		jp_key = jp_name;
157 		key_value = name_value;
158 	} else {
159 		strlcpy(jail_errmsg, "no jail specified", JAIL_ERRMSGLEN);
160 		errno = ENOENT;
161 		goto error;
162 	}
163 	if (jailparam_import(jp_key, key_value) < 0)
164 		goto error;
165 	/* Get the jail and export the parameters. */
166 	jid = jailparam_get(jp, njp, flags);
167 	if (jid < 0)
168 		goto error;
169 	for (i = 0; i < njp; i++) {
170 		(void)va_arg(ap, char *);
171 		valarg = va_arg(ap, char *);
172 		if (jp + i != jp_key) {
173 			/* It's up to the caller to ensure there's room. */
174 			if ((jp[i].jp_ctltype & CTLTYPE) == CTLTYPE_STRING)
175 				strcpy(valarg, jp[i].jp_value);
176 			else {
177 				value = jailparam_export(jp + i);
178 				if (value == NULL)
179 					goto error;
180 				strcpy(valarg, value);
181 				free(value);
182 			}
183 		}
184 	}
185 	jailparam_free(jp, njp);
186 	va_end(ap);
187 	return (jid);
188 
189  error:
190 	jailparam_free(jp, njp);
191 	va_end(ap);
192 	return (-1);
193 }
194 
195 /*
196  * Return a list of all known parameters.
197  */
198 int
199 jailparam_all(struct jailparam **jpp)
200 {
201 	struct jailparam *jp, *tjp;
202 	size_t mlen1, mlen2, buflen;
203 	int njp, nlist;
204 	int mib1[CTL_MAXNAME], mib2[CTL_MAXNAME - 2];
205 	char buf[MAXPATHLEN];
206 
207 	njp = 0;
208 	nlist = 32;
209 	jp = malloc(nlist * sizeof(*jp));
210 	if (jp == NULL) {
211 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
212 		return (-1);
213 	}
214 	mib1[0] = 0;
215 	mib1[1] = 2;
216 	mlen1 = CTL_MAXNAME - 2;
217 	if (sysctlnametomib(SJPARAM, mib1 + 2, &mlen1) < 0) {
218 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
219 		    "sysctlnametomib(" SJPARAM "): %s", strerror(errno));
220 		goto error;
221 	}
222 	for (;; njp++) {
223 		/* Get the next parameter. */
224 		mlen2 = sizeof(mib2);
225 		if (sysctl(mib1, mlen1 + 2, mib2, &mlen2, NULL, 0) < 0) {
226 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
227 			    "sysctl(0.2): %s", strerror(errno));
228 			goto error;
229 		}
230 		if (mib2[0] != mib1[2] || mib2[1] != mib1[3] ||
231 		    mib2[2] != mib1[4])
232 			break;
233 		/* Convert it to an ascii name. */
234 		memcpy(mib1 + 2, mib2, mlen2);
235 		mlen1 = mlen2 / sizeof(int);
236 		mib1[1] = 1;
237 		buflen = sizeof(buf);
238 		if (sysctl(mib1, mlen1 + 2, buf, &buflen, NULL, 0) < 0) {
239 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
240 			    "sysctl(0.1): %s", strerror(errno));
241 			goto error;
242 		}
243 		if (buf[buflen - 2] == '.')
244 			buf[buflen - 2] = '\0';
245 		/* Add the parameter to the list */
246 		if (njp >= nlist) {
247 			nlist *= 2;
248 			tjp = realloc(jp, nlist * sizeof(*jp));
249 			if (tjp == NULL)
250 				goto error;
251 			jp = tjp;
252 		}
253 		if (jailparam_init(jp + njp, buf + sizeof(SJPARAM)) < 0)
254 			goto error;
255 		mib1[1] = 2;
256 	}
257 	jp = realloc(jp, njp * sizeof(*jp));
258 	*jpp = jp;
259 	return (njp);
260 
261  error:
262 	jailparam_free(jp, njp);
263 	free(jp);
264 	return (-1);
265 }
266 
267 /*
268  * Clear a jail parameter and copy in its name.
269  */
270 int
271 jailparam_init(struct jailparam *jp, const char *name)
272 {
273 
274 	memset(jp, 0, sizeof(*jp));
275 	jp->jp_name = strdup(name);
276 	if (jp->jp_name == NULL) {
277 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
278 		return (-1);
279 	}
280 	if (jailparam_type(jp) < 0) {
281 		jailparam_free(jp, 1);
282 		jp->jp_name = NULL;
283 		jp->jp_value = NULL;
284 		return (-1);
285 	}
286 	return (0);
287 }
288 
289 /*
290  * Put a name and value into a jail parameter element, converting the value
291  * to internal form.
292  */
293 int
294 jailparam_import(struct jailparam *jp, const char *value)
295 {
296 	char *p, *ep, *tvalue;
297 	const char *avalue;
298 	int i, nval, fw;
299 
300 	if (value == NULL)
301 		return (0);
302 	if ((jp->jp_ctltype & CTLTYPE) == CTLTYPE_STRING) {
303 		jp->jp_value = strdup(value);
304 		if (jp->jp_value == NULL) {
305 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
306 			return (-1);
307 		}
308 		return (0);
309 	}
310 	nval = 1;
311 	if (jp->jp_elemlen) {
312 		if (value[0] == '\0' || (value[0] == '-' && value[1] == '\0')) {
313 			jp->jp_value = strdup("");
314 			if (jp->jp_value == NULL) {
315 				strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
316 				return (-1);
317 			}
318 			jp->jp_valuelen = 0;
319 			return (0);
320 		}
321 		for (p = strchr(value, ','); p; p = strchr(p + 1, ','))
322 			nval++;
323 		jp->jp_valuelen = jp->jp_elemlen * nval;
324 	}
325 	jp->jp_value = malloc(jp->jp_valuelen);
326 	if (jp->jp_value == NULL) {
327 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
328 		return (-1);
329 	}
330 	avalue = value;
331 	for (i = 0; i < nval; i++) {
332 		fw = nval == 1 ? strlen(avalue) : strcspn(avalue, ",");
333 		switch (jp->jp_ctltype & CTLTYPE) {
334 		case CTLTYPE_INT:
335 			if (jp->jp_flags & (JP_BOOL | JP_NOBOOL)) {
336 				if (!jailparam_import_enum(bool_values, 2,
337 				    avalue, fw, &((int *)jp->jp_value)[i])) {
338 					snprintf(jail_errmsg,
339 					    JAIL_ERRMSGLEN, "%s: "
340 					    "unknown boolean value \"%.*s\"",
341 					    jp->jp_name, fw, avalue);
342 					errno = EINVAL;
343 					goto error;
344 				}
345 				break;
346 			}
347 			if (jp->jp_flags & JP_JAILSYS) {
348 				/*
349 				 * Allow setting a jailsys parameter to "new"
350 				 * in a booleanesque fashion.
351 				 */
352 				if (value[0] == '\0')
353 					((int *)jp->jp_value)[i] = JAIL_SYS_NEW;
354 				else if (!jailparam_import_enum(jailsys_values,
355 				    sizeof(jailsys_values) /
356 				    sizeof(jailsys_values[0]), avalue, fw,
357 				    &((int *)jp->jp_value)[i])) {
358 					snprintf(jail_errmsg,
359 					    JAIL_ERRMSGLEN, "%s: "
360 					    "unknown jailsys value \"%.*s\"",
361 					    jp->jp_name, fw, avalue);
362 					errno = EINVAL;
363 					goto error;
364 				}
365 				break;
366 			}
367 			((int *)jp->jp_value)[i] = strtol(avalue, &ep, 10);
368 		integer_test:
369 			if (ep != avalue + fw) {
370 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
371 				    "%s: non-integer value \"%.*s\"",
372 				    jp->jp_name, fw, avalue);
373 				errno = EINVAL;
374 				goto error;
375 			}
376 			break;
377 		case CTLTYPE_UINT:
378 			((unsigned *)jp->jp_value)[i] =
379 			    strtoul(avalue, &ep, 10);
380 			goto integer_test;
381 		case CTLTYPE_LONG:
382 			((long *)jp->jp_value)[i] = strtol(avalue, &ep, 10);
383 			goto integer_test;
384 		case CTLTYPE_ULONG:
385 			((unsigned long *)jp->jp_value)[i] =
386 			    strtoul(avalue, &ep, 10);
387 			goto integer_test;
388 		case CTLTYPE_S64:
389 			((int64_t *)jp->jp_value)[i] =
390 			    strtoimax(avalue, &ep, 10);
391 			goto integer_test;
392 		case CTLTYPE_U64:
393 			((uint64_t *)jp->jp_value)[i] =
394 			    strtoumax(avalue, &ep, 10);
395 			goto integer_test;
396 		case CTLTYPE_STRUCT:
397 			tvalue = alloca(fw + 1);
398 			strlcpy(tvalue, avalue, fw + 1);
399 			switch (jp->jp_structtype) {
400 			case JPS_IN_ADDR:
401 				if (inet_pton(AF_INET, tvalue,
402 				    &((struct in_addr *)jp->jp_value)[i]) != 1)
403 				{
404 					snprintf(jail_errmsg,
405 					    JAIL_ERRMSGLEN,
406 					    "%s: not an IPv4 address: %s",
407 					    jp->jp_name, tvalue);
408 					errno = EINVAL;
409 					goto error;
410 				}
411 				break;
412 			case JPS_IN6_ADDR:
413 				if (inet_pton(AF_INET6, tvalue,
414 				    &((struct in6_addr *)jp->jp_value)[i]) != 1)
415 				{
416 					snprintf(jail_errmsg,
417 					    JAIL_ERRMSGLEN,
418 					    "%s: not an IPv6 address: %s",
419 					    jp->jp_name, tvalue);
420 					errno = EINVAL;
421 					goto error;
422 				}
423 				break;
424 			default:
425 				goto unknown_type;
426 			}
427 			break;
428 		default:
429 		unknown_type:
430 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
431 			    "unknown type for %s", jp->jp_name);
432 			errno = ENOENT;
433 			goto error;
434 		}
435 		avalue += fw + 1;
436 	}
437 	return (0);
438 
439  error:
440 	free(jp->jp_value);
441 	jp->jp_value = NULL;
442 	return (-1);
443 }
444 
445 static int
446 jailparam_import_enum(const char **values, int nvalues, const char *valstr,
447     size_t valsize, int *value)
448 {
449 	char *ep;
450 	int i;
451 
452 	for (i = 0; i < nvalues; i++)
453 		if (valsize == strlen(values[i]) &&
454 		    !strncasecmp(valstr, values[i], valsize)) {
455 			*value = i;
456 			return 1;
457 		}
458 	*value = strtol(valstr, &ep, 10);
459 	return (ep == valstr + valsize);
460 }
461 
462 /*
463  * Put a name and value into a jail parameter element, copying the value
464  * but not altering it.
465  */
466 int
467 jailparam_import_raw(struct jailparam *jp, void *value, size_t valuelen)
468 {
469 
470 	jp->jp_value = value;
471 	jp->jp_valuelen = valuelen;
472 	jp->jp_flags |= JP_RAWVALUE;
473 	return (0);
474 }
475 
476 /*
477  * Run the jail_set and jail_get system calls on a parameter list.
478  */
479 int
480 jailparam_set(struct jailparam *jp, unsigned njp, int flags)
481 {
482 	struct iovec *jiov;
483 	char *nname;
484 	int i, jid, bool0;
485 	unsigned j;
486 
487 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
488 	bool0 = 0;
489 	for (i = j = 0; j < njp; j++) {
490 		jiov[i].iov_base = jp[j].jp_name;
491 		jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
492 		i++;
493 		if (jp[j].jp_flags & (JP_BOOL | JP_NOBOOL)) {
494 			/*
495 			 * Set booleans without values.  If one has a value of
496 			 * zero, change it to (or from) its "no" counterpart.
497 			 */
498 			jiov[i].iov_base = NULL;
499 			jiov[i].iov_len = 0;
500 			if (jp[j].jp_value != NULL &&
501 			    jp[j].jp_valuelen == sizeof(int) &&
502 			    !*(int *)jp[j].jp_value) {
503 				bool0 = 1;
504 				nname = jp[j].jp_flags & JP_BOOL
505 				    ? noname(jp[j].jp_name)
506 				    : nononame(jp[j].jp_name);
507 				if (nname == NULL) {
508 					njp = j;
509 					jid = -1;
510 					goto done;
511 				}
512 				jiov[i - 1].iov_base = nname;
513 				jiov[i - 1].iov_len = strlen(nname) + 1;
514 
515 			}
516 		} else {
517 			/*
518 			 * Try to fill in missing values with an empty string.
519 			 */
520 			if (jp[j].jp_value == NULL && jp[j].jp_valuelen > 0 &&
521 			    jailparam_import(jp + j, "") < 0) {
522 				njp = j;
523 				jid = -1;
524 				goto done;
525 			}
526 			jiov[i].iov_base = jp[j].jp_value;
527 			jiov[i].iov_len =
528 			    (jp[j].jp_ctltype & CTLTYPE) == CTLTYPE_STRING
529 			    ? strlen(jp[j].jp_value) + 1
530 			    : jp[j].jp_valuelen;
531 		}
532 		i++;
533 	}
534 	*(const void **)&jiov[i].iov_base = "errmsg";
535 	jiov[i].iov_len = sizeof("errmsg");
536 	i++;
537 	jiov[i].iov_base = jail_errmsg;
538 	jiov[i].iov_len = JAIL_ERRMSGLEN;
539 	i++;
540 	jail_errmsg[0] = 0;
541 	jid = jail_set(jiov, i, flags);
542 	if (jid < 0 && !jail_errmsg[0])
543 		snprintf(jail_errmsg, sizeof(jail_errmsg), "jail_set: %s",
544 		    strerror(errno));
545  done:
546 	if (bool0)
547 		for (j = 0; j < njp; j++)
548 			if ((jp[j].jp_flags & (JP_BOOL | JP_NOBOOL)) &&
549 			    jp[j].jp_value != NULL &&
550 			    jp[j].jp_valuelen == sizeof(int) &&
551 			    !*(int *)jp[j].jp_value)
552 				free(jiov[j * 2].iov_base);
553 	return (jid);
554 }
555 
556 int
557 jailparam_get(struct jailparam *jp, unsigned njp, int flags)
558 {
559 	struct iovec *jiov;
560 	struct jailparam *jp_lastjid, *jp_jid, *jp_name, *jp_key;
561 	int i, ai, ki, jid, arrays, sanity;
562 	unsigned j;
563 
564 	/*
565 	 * Get the types for all parameters.
566 	 * Find the key and any array parameters.
567 	 */
568 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
569 	jp_lastjid = jp_jid = jp_name = NULL;
570 	arrays = 0;
571 	for (ai = j = 0; j < njp; j++) {
572 		if (!strcmp(jp[j].jp_name, "lastjid"))
573 			jp_lastjid = jp + j;
574 		else if (!strcmp(jp[j].jp_name, "jid"))
575 			jp_jid = jp + j;
576 		else if (!strcmp(jp[j].jp_name, "name"))
577 			jp_name = jp + j;
578 		else if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
579 			arrays = 1;
580 			jiov[ai].iov_base = jp[j].jp_name;
581 			jiov[ai].iov_len = strlen(jp[j].jp_name) + 1;
582 			ai++;
583 			jiov[ai].iov_base = NULL;
584 			jiov[ai].iov_len = 0;
585 			ai++;
586 		}
587 	}
588 	jp_key = jp_lastjid ? jp_lastjid :
589 	    jp_jid && jp_jid->jp_valuelen == sizeof(int) &&
590 	    jp_jid->jp_value && *(int *)jp_jid->jp_value ? jp_jid : jp_name;
591 	if (jp_key == NULL || jp_key->jp_value == NULL) {
592 		strlcpy(jail_errmsg, "no jail specified", JAIL_ERRMSGLEN);
593 		errno = ENOENT;
594 		return (-1);
595 	}
596 	ki = ai;
597 	jiov[ki].iov_base = jp_key->jp_name;
598 	jiov[ki].iov_len = strlen(jp_key->jp_name) + 1;
599 	ki++;
600 	jiov[ki].iov_base = jp_key->jp_value;
601 	jiov[ki].iov_len = (jp_key->jp_ctltype & CTLTYPE) == CTLTYPE_STRING
602 	    ? strlen(jp_key->jp_value) + 1 : jp_key->jp_valuelen;
603 	ki++;
604 	*(const void **)&jiov[ki].iov_base = "errmsg";
605 	jiov[ki].iov_len = sizeof("errmsg");
606 	ki++;
607 	jiov[ki].iov_base = jail_errmsg;
608 	jiov[ki].iov_len = JAIL_ERRMSGLEN;
609 	ki++;
610 	jail_errmsg[0] = 0;
611 	if (arrays && jail_get(jiov, ki, flags) < 0) {
612 		if (!jail_errmsg[0])
613 			snprintf(jail_errmsg, sizeof(jail_errmsg),
614 			    "jail_get: %s", strerror(errno));
615 		return (-1);
616 	}
617 	/* Allocate storage for all parameters. */
618 	for (ai = j = 0, i = ki; j < njp; j++) {
619 		if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
620 			ai++;
621 			jiov[ai].iov_len += jp[j].jp_elemlen * ARRAY_SLOP;
622 			if (jp[j].jp_valuelen >= jiov[ai].iov_len)
623 				jiov[ai].iov_len = jp[j].jp_valuelen;
624 			else {
625 				jp[j].jp_valuelen = jiov[ai].iov_len;
626 				if (jp[j].jp_value != NULL)
627 					free(jp[j].jp_value);
628 				jp[j].jp_value = malloc(jp[j].jp_valuelen);
629 				if (jp[j].jp_value == NULL) {
630 					strerror_r(errno, jail_errmsg,
631 					    JAIL_ERRMSGLEN);
632 					return (-1);
633 				}
634 			}
635 			jiov[ai].iov_base = jp[j].jp_value;
636 			memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
637 			ai++;
638 		} else if (jp + j != jp_key) {
639 			jiov[i].iov_base = jp[j].jp_name;
640 			jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
641 			i++;
642 			if (jp[j].jp_value == NULL &&
643 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
644 				jp[j].jp_value = malloc(jp[j].jp_valuelen);
645 				if (jp[j].jp_value == NULL) {
646 					strerror_r(errno, jail_errmsg,
647 					    JAIL_ERRMSGLEN);
648 					return (-1);
649 				}
650 			}
651 			jiov[i].iov_base = jp[j].jp_value;
652 			jiov[i].iov_len = jp[j].jp_valuelen;
653 			memset(jiov[i].iov_base, 0, jiov[i].iov_len);
654 			i++;
655 		}
656 	}
657 	/*
658 	 * Get the prison.  If there are array elements, retry a few times
659 	 * in case their sizes changed from under us.
660 	 */
661 	for (sanity = 0;; sanity++) {
662 		jid = jail_get(jiov, i, flags);
663 		if (jid >= 0 || !arrays || sanity == ARRAY_SANITY ||
664 		    errno != EINVAL || jail_errmsg[0])
665 			break;
666 		for (ai = j = 0; j < njp; j++) {
667 			if (jp[j].jp_elemlen &&
668 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
669 				ai++;
670 				jiov[ai].iov_base = NULL;
671 				jiov[ai].iov_len = 0;
672 				ai++;
673 			}
674 		}
675 		if (jail_get(jiov, ki, flags) < 0)
676 			break;
677 		for (ai = j = 0; j < njp; j++) {
678 			if (jp[j].jp_elemlen &&
679 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
680 				ai++;
681 				jiov[ai].iov_len +=
682 				    jp[j].jp_elemlen * ARRAY_SLOP;
683 				if (jp[j].jp_valuelen >= jiov[ai].iov_len)
684 					jiov[ai].iov_len = jp[j].jp_valuelen;
685 				else {
686 					jp[j].jp_valuelen = jiov[ai].iov_len;
687 					if (jp[j].jp_value != NULL)
688 						free(jp[j].jp_value);
689 					jp[j].jp_value =
690 					    malloc(jiov[ai].iov_len);
691 					if (jp[j].jp_value == NULL) {
692 						strerror_r(errno, jail_errmsg,
693 						    JAIL_ERRMSGLEN);
694 						return (-1);
695 					}
696 				}
697 				jiov[ai].iov_base = jp[j].jp_value;
698 				memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
699 				ai++;
700 			}
701 		}
702 	}
703 	if (jid < 0 && !jail_errmsg[0])
704 		snprintf(jail_errmsg, sizeof(jail_errmsg),
705 		    "jail_get: %s", strerror(errno));
706 	for (ai = j = 0, i = ki; j < njp; j++) {
707 		if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
708 			ai++;
709 			jp[j].jp_valuelen = jiov[ai].iov_len;
710 			ai++;
711 		} else if (jp + j != jp_key) {
712 			i++;
713 			jp[j].jp_valuelen = jiov[i].iov_len;
714 			i++;
715 		}
716 	}
717 	return (jid);
718 }
719 
720 /*
721  * Convert a jail parameter's value to external form.
722  */
723 char *
724 jailparam_export(struct jailparam *jp)
725 {
726 	size_t *valuelens;
727 	char *value, *tvalue, **values;
728 	size_t valuelen;
729 	int i, nval, ival;
730 	char valbuf[INET6_ADDRSTRLEN];
731 
732 	if ((jp->jp_ctltype & CTLTYPE) == CTLTYPE_STRING) {
733 		value = strdup(jp->jp_value);
734 		if (value == NULL)
735 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
736 		return (value);
737 	}
738 	nval = jp->jp_elemlen ? jp->jp_valuelen / jp->jp_elemlen : 1;
739 	if (nval == 0) {
740 		value = strdup("");
741 		if (value == NULL)
742 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
743 		return (value);
744 	}
745 	values = alloca(nval * sizeof(char *));
746 	valuelens = alloca(nval * sizeof(size_t));
747 	valuelen = 0;
748 	for (i = 0; i < nval; i++) {
749 		switch (jp->jp_ctltype & CTLTYPE) {
750 		case CTLTYPE_INT:
751 			ival = ((int *)jp->jp_value)[i];
752 			if ((jp->jp_flags & (JP_BOOL | JP_NOBOOL)) &&
753 			    (unsigned)ival < 2) {
754 				strlcpy(valbuf, bool_values[ival],
755 				    sizeof(valbuf));
756 				break;
757 			}
758 			if ((jp->jp_flags & JP_JAILSYS) &&
759 			    (unsigned)ival < sizeof(jailsys_values) /
760 			    sizeof(jailsys_values[0])) {
761 				strlcpy(valbuf, jailsys_values[ival],
762 				    sizeof(valbuf));
763 				break;
764 			}
765 			snprintf(valbuf, sizeof(valbuf), "%d", ival);
766 			break;
767 		case CTLTYPE_UINT:
768 			snprintf(valbuf, sizeof(valbuf), "%u",
769 			    ((unsigned *)jp->jp_value)[i]);
770 			break;
771 		case CTLTYPE_LONG:
772 			snprintf(valbuf, sizeof(valbuf), "%ld",
773 			    ((long *)jp->jp_value)[i]);
774 			break;
775 		case CTLTYPE_ULONG:
776 			snprintf(valbuf, sizeof(valbuf), "%lu",
777 			    ((unsigned long *)jp->jp_value)[i]);
778 			break;
779 		case CTLTYPE_S64:
780 			snprintf(valbuf, sizeof(valbuf), "%jd",
781 			    (intmax_t)((int64_t *)jp->jp_value)[i]);
782 			break;
783 		case CTLTYPE_U64:
784 			snprintf(valbuf, sizeof(valbuf), "%ju",
785 			    (uintmax_t)((uint64_t *)jp->jp_value)[i]);
786 			break;
787 		case CTLTYPE_STRUCT:
788 			switch (jp->jp_structtype) {
789 			case JPS_IN_ADDR:
790 				if (inet_ntop(AF_INET,
791 				    &((struct in_addr *)jp->jp_value)[i],
792 				    valbuf, sizeof(valbuf)) == NULL) {
793 					strerror_r(errno, jail_errmsg,
794 					    JAIL_ERRMSGLEN);
795 					return (NULL);
796 				}
797 				break;
798 			case JPS_IN6_ADDR:
799 				if (inet_ntop(AF_INET6,
800 				    &((struct in6_addr *)jp->jp_value)[i],
801 				    valbuf, sizeof(valbuf)) == NULL) {
802 					strerror_r(errno, jail_errmsg,
803 					    JAIL_ERRMSGLEN);
804 					return (NULL);
805 				}
806 				break;
807 			default:
808 				goto unknown_type;
809 			}
810 			break;
811 		default:
812 		unknown_type:
813 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
814 			    "unknown type for %s", jp->jp_name);
815 			errno = ENOENT;
816 			return (NULL);
817 		}
818 		valuelens[i] = strlen(valbuf) + 1;
819 		valuelen += valuelens[i];
820 		values[i] = alloca(valuelens[i]);
821 		strcpy(values[i], valbuf);
822 	}
823 	value = malloc(valuelen);
824 	if (value == NULL)
825 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
826 	else {
827 		tvalue = value;
828 		for (i = 0; i < nval; i++) {
829 			strcpy(tvalue, values[i]);
830 			if (i < nval - 1) {
831 				tvalue += valuelens[i];
832 				tvalue[-1] = ',';
833 			}
834 		}
835 	}
836 	return (value);
837 }
838 
839 /*
840  * Free the contents of a jail parameter list (but not the list itself).
841  */
842 void
843 jailparam_free(struct jailparam *jp, unsigned njp)
844 {
845 	unsigned j;
846 
847 	for (j = 0; j < njp; j++) {
848 		free(jp[j].jp_name);
849 		if (!(jp[j].jp_flags & JP_RAWVALUE))
850 			free(jp[j].jp_value);
851 	}
852 }
853 
854 /*
855  * Find a parameter's type and size from its MIB.
856  */
857 static int
858 jailparam_type(struct jailparam *jp)
859 {
860 	char *p, *name, *nname;
861 	size_t miblen, desclen;
862 	int i, isarray;
863 	struct {
864 	    int i;
865 	    char s[MAXPATHLEN];
866 	} desc;
867 	int mib[CTL_MAXNAME];
868 
869 	/* The "lastjid" parameter isn't real. */
870 	name = jp->jp_name;
871 	if (!strcmp(name, "lastjid")) {
872 		jp->jp_valuelen = sizeof(int);
873 		jp->jp_ctltype = CTLTYPE_INT | CTLFLAG_WR;
874 		return (0);
875 	}
876 
877 	/* Find the sysctl that describes the parameter. */
878 	mib[0] = 0;
879 	mib[1] = 3;
880 	snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", name);
881 	miblen = sizeof(mib) - 2 * sizeof(int);
882 	if (sysctl(mib, 2, mib + 2, &miblen, desc.s, strlen(desc.s)) < 0) {
883 		if (errno != ENOENT) {
884 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
885 			    "sysctl(0.3.%s): %s", name, strerror(errno));
886 			return (-1);
887 		}
888 		/*
889 		 * The parameter probably doesn't exist.  But it might be
890 		 * the "no" counterpart to a boolean.
891 		 */
892 		nname = nononame(name);
893 		if (nname == NULL) {
894 		unknown_parameter:
895 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
896 			    "unknown parameter: %s", jp->jp_name);
897 			errno = ENOENT;
898 			return (-1);
899 		}
900 		name = alloca(strlen(nname) + 1);
901 		strcpy(name, nname);
902 		free(nname);
903 		snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", name);
904 		miblen = sizeof(mib) - 2 * sizeof(int);
905 		if (sysctl(mib, 2, mib + 2, &miblen, desc.s,
906 		    strlen(desc.s)) < 0)
907 			goto unknown_parameter;
908 		jp->jp_flags |= JP_NOBOOL;
909 	}
910  mib_desc:
911 	mib[1] = 4;
912 	desclen = sizeof(desc);
913 	if (sysctl(mib, (miblen / sizeof(int)) + 2, &desc, &desclen,
914 	    NULL, 0) < 0) {
915 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
916 		    "sysctl(0.4.%s): %s", name, strerror(errno));
917 		return (-1);
918 	}
919 	jp->jp_ctltype = desc.i;
920 	/* If this came from removing a "no", it better be a boolean. */
921 	if (jp->jp_flags & JP_NOBOOL) {
922 		if ((desc.i & CTLTYPE) == CTLTYPE_INT && desc.s[0] == 'B') {
923 			jp->jp_valuelen = sizeof(int);
924 			return (0);
925 		}
926 		else if ((desc.i & CTLTYPE) != CTLTYPE_NODE)
927 			goto unknown_parameter;
928 	}
929 	/* See if this is an array type. */
930 	p = strchr(desc.s, '\0');
931 	isarray  = 0;
932 	if (p - 2 < desc.s || strcmp(p - 2, ",a"))
933 		isarray = 0;
934 	else {
935 		isarray = 1;
936 		p[-2] = 0;
937 	}
938 	/* Look for types we understand. */
939 	switch (desc.i & CTLTYPE) {
940 	case CTLTYPE_INT:
941 		if (desc.s[0] == 'B')
942 			jp->jp_flags |= JP_BOOL;
943 		else if (!strcmp(desc.s, "E,jailsys"))
944 			jp->jp_flags |= JP_JAILSYS;
945 	case CTLTYPE_UINT:
946 		jp->jp_valuelen = sizeof(int);
947 		break;
948 	case CTLTYPE_LONG:
949 	case CTLTYPE_ULONG:
950 		jp->jp_valuelen = sizeof(long);
951 		break;
952 	case CTLTYPE_S64:
953 	case CTLTYPE_U64:
954 		jp->jp_valuelen = sizeof(int64_t);
955 		break;
956 	case CTLTYPE_STRING:
957 		desc.s[0] = 0;
958 		desclen = sizeof(desc.s);
959 		if (sysctl(mib + 2, miblen / sizeof(int), desc.s, &desclen,
960 		    NULL, 0) < 0) {
961 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
962 			    "sysctl(" SJPARAM ".%s): %s", name,
963 			    strerror(errno));
964 			return (-1);
965 		}
966 		jp->jp_valuelen = strtoul(desc.s, NULL, 10);
967 		break;
968 	case CTLTYPE_STRUCT:
969 		if (!strcmp(desc.s, "S,in_addr")) {
970 			jp->jp_structtype = JPS_IN_ADDR;
971 			jp->jp_valuelen = sizeof(struct in_addr);
972 		} else if (!strcmp(desc.s, "S,in6_addr")) {
973 			jp->jp_structtype = JPS_IN6_ADDR;
974 			jp->jp_valuelen = sizeof(struct in6_addr);
975 		} else {
976 			desclen = 0;
977 			if (sysctl(mib + 2, miblen / sizeof(int),
978 			    NULL, &jp->jp_valuelen, NULL, 0) < 0) {
979 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
980 				    "sysctl(" SJPARAM ".%s): %s", name,
981 				    strerror(errno));
982 				return (-1);
983 			}
984 		}
985 		break;
986 	case CTLTYPE_NODE:
987 		/*
988 		 * A node might be described by an empty-named child,
989 		 * which would be immediately before or after the node itself.
990 		 */
991 		mib[1] = 1;
992 		miblen += sizeof(int);
993 		for (i = -1; i <= 1; i += 2) {
994 			mib[(miblen / sizeof(int)) + 1] =
995 			    mib[(miblen / sizeof(int))] + i;
996 			desclen = sizeof(desc.s);
997 			if (sysctl(mib, (miblen / sizeof(int)) + 2, desc.s,
998 			    &desclen, NULL, 0) < 0) {
999 				if (errno == ENOENT)
1000 					continue;
1001 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
1002 				    "sysctl(0.1): %s", strerror(errno));
1003 				return (-1);
1004 			}
1005 			if (desclen == sizeof(SJPARAM) + strlen(name) + 2 &&
1006 			    memcmp(SJPARAM ".", desc.s, sizeof(SJPARAM)) == 0 &&
1007 			    memcmp(name, desc.s + sizeof(SJPARAM),
1008 			    desclen - sizeof(SJPARAM) - 2) == 0 &&
1009 			    desc.s[desclen - 2] == '.')
1010 				goto mib_desc;
1011 		}
1012 		goto unknown_parameter;
1013 	default:
1014 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
1015 		    "unknown type for %s", jp->jp_name);
1016 		errno = ENOENT;
1017 		return (-1);
1018 	}
1019 	if (isarray) {
1020 		jp->jp_elemlen = jp->jp_valuelen;
1021 		jp->jp_valuelen = 0;
1022 	}
1023 	return (0);
1024 }
1025 
1026 /*
1027  * Change a boolean parameter name into its "no" counterpart or vice versa.
1028  */
1029 static char *
1030 noname(const char *name)
1031 {
1032 	char *nname, *p;
1033 
1034 	nname = malloc(strlen(name) + 3);
1035 	if (nname == NULL) {
1036 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
1037 		return (NULL);
1038 	}
1039 	p = strrchr(name, '.');
1040 	if (p != NULL)
1041 		sprintf(nname, "%.*s.no%s", (int)(p - name), name, p + 1);
1042 	else
1043 		sprintf(nname, "no%s", name);
1044 	return (nname);
1045 }
1046 
1047 static char *
1048 nononame(const char *name)
1049 {
1050 	char *p, *nname;
1051 
1052 	p = strrchr(name, '.');
1053 	if (strncmp(p ? p + 1 : name, "no", 2)) {
1054 		snprintf(jail_errmsg, sizeof(jail_errmsg),
1055 		    "mismatched boolean: %s", name);
1056 		errno = EINVAL;
1057 		return (NULL);
1058 	}
1059 	nname = malloc(strlen(name) - 1);
1060 	if (nname == NULL) {
1061 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
1062 		return (NULL);
1063 	}
1064 	if (p != NULL)
1065 		sprintf(nname, "%.*s.%s", (int)(p - name), name, p + 3);
1066 	else
1067 		strcpy(nname, name + 2);
1068 	return (nname);
1069 }
1070