xref: /freebsd/lib/libjail/jail.c (revision f5f47d5068fb97df18eb114a66ae8ef51a0b3c8c)
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; njp++) {
89 		value = va_arg(ap, char *);
90 		if (jailparam_init(jp + njp, name) < 0 ||
91 		    jailparam_import(jp + njp, value) < 0) {
92 			jailparam_free(jp, njp);
93 			va_end(ap);
94 			return (-1);
95 		}
96 	}
97 	va_end(ap);
98 	jid = jailparam_set(jp, njp, flags);
99 	jailparam_free(jp, njp);
100 	return (jid);
101 }
102 
103 /*
104  * Read a null-terminated parameter list, get the referenced jail, and export
105  * the parameters to the list.
106  */
107 int
108 jail_getv(int flags, ...)
109 {
110 	va_list ap, tap;
111 	struct jailparam *jp, *jp_lastjid, *jp_jid, *jp_name, *jp_key;
112 	char *valarg, *value;
113 	const char *name, *key_value, *lastjid_value, *jid_value, *name_value;
114 	int njp, i, jid;
115 
116 	/* Create the parameter list and find the key. */
117 	va_start(ap, flags);
118 	va_copy(tap, ap);
119 	for (njp = 0; va_arg(tap, char *) != NULL; njp++)
120 		(void)va_arg(tap, char *);
121 	va_end(tap);
122 
123 	jp = alloca(njp * sizeof(struct jailparam));
124 	va_copy(tap, ap);
125 	jp_lastjid = jp_jid = jp_name = NULL;
126 	lastjid_value = jid_value = name_value = NULL;
127 	for (njp = 0; (name = va_arg(tap, char *)) != NULL; njp++) {
128 		value = va_arg(tap, char *);
129 		if (jailparam_init(jp + njp, name) < 0) {
130 			va_end(tap);
131 			goto error;
132 		}
133 		if (!strcmp(jp[njp].jp_name, "lastjid")) {
134 			jp_lastjid = jp + njp;
135 			lastjid_value = value;
136 		} else if (!strcmp(jp[njp].jp_name, "jid")) {
137 			jp_jid = jp + njp;
138 			jid_value = value;
139 		} if (!strcmp(jp[njp].jp_name, "name")) {
140 			jp_name = jp + njp;
141 			name_value = value;
142 		}
143 	}
144 	va_end(tap);
145 	/* Import the key parameter. */
146 	if (jp_lastjid != NULL) {
147 		jp_key = jp_lastjid;
148 		key_value = lastjid_value;
149 	} else if (jp_jid != NULL && strtol(jid_value, NULL, 10) != 0) {
150 		jp_key = jp_jid;
151 		key_value = jid_value;
152 	} else if (jp_name != NULL) {
153 		jp_key = jp_name;
154 		key_value = name_value;
155 	} else {
156 		strlcpy(jail_errmsg, "no jail specified", JAIL_ERRMSGLEN);
157 		errno = ENOENT;
158 		goto error;
159 	}
160 	if (jailparam_import(jp_key, key_value) < 0)
161 		goto error;
162 	/* Get the jail and export the parameters. */
163 	jid = jailparam_get(jp, njp, flags);
164 	if (jid < 0)
165 		goto error;
166 	for (i = 0; i < njp; i++) {
167 		(void)va_arg(ap, char *);
168 		valarg = va_arg(ap, char *);
169 		if (jp + i != jp_key) {
170 			/* It's up to the caller to ensure there's room. */
171 			if ((jp[i].jp_ctltype & CTLTYPE) == CTLTYPE_STRING)
172 				strcpy(valarg, jp[i].jp_value);
173 			else {
174 				value = jailparam_export(jp + i);
175 				if (value == NULL)
176 					goto error;
177 				strcpy(valarg, value);
178 				free(value);
179 			}
180 		}
181 	}
182 	jailparam_free(jp, njp);
183 	va_end(ap);
184 	return (jid);
185 
186  error:
187 	jailparam_free(jp, njp);
188 	va_end(ap);
189 	return (-1);
190 }
191 
192 /*
193  * Return a list of all known parameters.
194  */
195 int
196 jailparam_all(struct jailparam **jpp)
197 {
198 	struct jailparam *jp;
199 	size_t mlen1, mlen2, buflen;
200 	int njp, nlist;
201 	int mib1[CTL_MAXNAME], mib2[CTL_MAXNAME - 2];
202 	char buf[MAXPATHLEN];
203 
204 	njp = 0;
205 	nlist = 32;
206 	jp = malloc(nlist * sizeof(*jp));
207 	if (jp == NULL) {
208 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
209 		return (-1);
210 	}
211 	mib1[0] = 0;
212 	mib1[1] = 2;
213 	mlen1 = CTL_MAXNAME - 2;
214 	if (sysctlnametomib(SJPARAM, mib1 + 2, &mlen1) < 0) {
215 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
216 		    "sysctlnametomib(" SJPARAM "): %s", strerror(errno));
217 		goto error;
218 	}
219 	for (;; njp++) {
220 		/* Get the next parameter. */
221 		mlen2 = sizeof(mib2);
222 		if (sysctl(mib1, mlen1 + 2, mib2, &mlen2, NULL, 0) < 0) {
223 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
224 			    "sysctl(0.2): %s", strerror(errno));
225 			goto error;
226 		}
227 		if (mib2[0] != mib1[2] || mib2[1] != mib1[3] ||
228 		    mib2[2] != mib1[4])
229 			break;
230 		/* Convert it to an ascii name. */
231 		memcpy(mib1 + 2, mib2, mlen2);
232 		mlen1 = mlen2 / sizeof(int);
233 		mib1[1] = 1;
234 		buflen = sizeof(buf);
235 		if (sysctl(mib1, mlen1 + 2, buf, &buflen, NULL, 0) < 0) {
236 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
237 			    "sysctl(0.1): %s", strerror(errno));
238 			goto error;
239 		}
240 		if (buf[buflen - 2] == '.')
241 			buf[buflen - 2] = '\0';
242 		/* Add the parameter to the list */
243 		if (njp >= nlist) {
244 			nlist *= 2;
245 			jp = realloc(jp, nlist * sizeof(*jp));
246 			if (jp == NULL) {
247 				jailparam_free(jp, njp);
248 				return (-1);
249 			}
250 		}
251 		if (jailparam_init(jp + njp, buf + sizeof(SJPARAM)) < 0)
252 			goto error;
253 		mib1[1] = 2;
254 	}
255 	jp = realloc(jp, njp * sizeof(*jp));
256 	*jpp = jp;
257 	return (njp);
258 
259  error:
260 	jailparam_free(jp, njp);
261 	free(jp);
262 	return (-1);
263 }
264 
265 /*
266  * Clear a jail parameter and copy in its name.
267  */
268 int
269 jailparam_init(struct jailparam *jp, const char *name)
270 {
271 
272 	memset(jp, 0, sizeof(*jp));
273 	jp->jp_name = strdup(name);
274 	if (jp->jp_name == NULL) {
275 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
276 		return (-1);
277 	}
278 	if (jailparam_type(jp) < 0) {
279 		jailparam_free(jp, 1);
280 		return (-1);
281 	}
282 	return (0);
283 }
284 
285 /*
286  * Put a name and value into a jail parameter element, converting the value
287  * to internal form.
288  */
289 int
290 jailparam_import(struct jailparam *jp, const char *value)
291 {
292 	char *p, *ep, *tvalue;
293 	const char *avalue;
294 	int i, nval, fw;
295 
296 	if (value == NULL)
297 		return (0);
298 	if ((jp->jp_ctltype & CTLTYPE) == CTLTYPE_STRING) {
299 		jp->jp_value = strdup(value);
300 		if (jp->jp_value == NULL) {
301 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
302 			return (-1);
303 		}
304 		return (0);
305 	}
306 	nval = 1;
307 	if (jp->jp_elemlen) {
308 		if (value[0] == '\0' || (value[0] == '-' && value[1] == '\0')) {
309 			jp->jp_value = strdup("");
310 			if (jp->jp_value == NULL) {
311 				strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
312 				return (-1);
313 			}
314 			jp->jp_valuelen = 0;
315 			return (0);
316 		}
317 		for (p = strchr(value, ','); p; p = strchr(p + 1, ','))
318 			nval++;
319 		jp->jp_valuelen = jp->jp_elemlen * nval;
320 	}
321 	jp->jp_value = malloc(jp->jp_valuelen);
322 	if (jp->jp_value == NULL) {
323 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
324 		return (-1);
325 	}
326 	avalue = value;
327 	for (i = 0; i < nval; i++) {
328 		fw = nval == 1 ? strlen(avalue) : strcspn(avalue, ",");
329 		switch (jp->jp_ctltype & CTLTYPE) {
330 		case CTLTYPE_INT:
331 			if (jp->jp_flags & (JP_BOOL | JP_NOBOOL)) {
332 				if (!jailparam_import_enum(bool_values, 2,
333 				    avalue, fw, &((int *)jp->jp_value)[i])) {
334 					snprintf(jail_errmsg,
335 					    JAIL_ERRMSGLEN, "%s: "
336 					    "unknown boolean value \"%.*s\"",
337 					    jp->jp_name, fw, avalue);
338 					errno = EINVAL;
339 					goto error;
340 				}
341 				break;
342 			}
343 			if (jp->jp_flags & JP_JAILSYS) {
344 				/*
345 				 * Allow setting a jailsys parameter to "new"
346 				 * in a booleanesque fashion.
347 				 */
348 				if (value[0] == '\0')
349 					((int *)jp->jp_value)[i] = JAIL_SYS_NEW;
350 				else if (!jailparam_import_enum(jailsys_values,
351 				    sizeof(jailsys_values) /
352 				    sizeof(jailsys_values[0]), avalue, fw,
353 				    &((int *)jp->jp_value)[i])) {
354 					snprintf(jail_errmsg,
355 					    JAIL_ERRMSGLEN, "%s: "
356 					    "unknown jailsys value \"%.*s\"",
357 					    jp->jp_name, fw, avalue);
358 					errno = EINVAL;
359 					goto error;
360 				}
361 				break;
362 			}
363 			((int *)jp->jp_value)[i] = strtol(avalue, &ep, 10);
364 		integer_test:
365 			if (ep != avalue + fw) {
366 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
367 				    "%s: non-integer value \"%.*s\"",
368 				    jp->jp_name, fw, avalue);
369 				errno = EINVAL;
370 				goto error;
371 			}
372 			break;
373 		case CTLTYPE_UINT:
374 			((unsigned *)jp->jp_value)[i] =
375 			    strtoul(avalue, &ep, 10);
376 			goto integer_test;
377 		case CTLTYPE_LONG:
378 			((long *)jp->jp_value)[i] = strtol(avalue, &ep, 10);
379 			goto integer_test;
380 		case CTLTYPE_ULONG:
381 			((unsigned long *)jp->jp_value)[i] =
382 			    strtoul(avalue, &ep, 10);
383 			goto integer_test;
384 		case CTLTYPE_S64:
385 			((int64_t *)jp->jp_value)[i] =
386 			    strtoimax(avalue, &ep, 10);
387 			goto integer_test;
388 		case CTLTYPE_U64:
389 			((uint64_t *)jp->jp_value)[i] =
390 			    strtoumax(avalue, &ep, 10);
391 			goto integer_test;
392 		case CTLTYPE_STRUCT:
393 			tvalue = alloca(fw + 1);
394 			strlcpy(tvalue, avalue, fw + 1);
395 			switch (jp->jp_structtype) {
396 			case JPS_IN_ADDR:
397 				if (inet_pton(AF_INET, tvalue,
398 				    &((struct in_addr *)jp->jp_value)[i]) != 1)
399 				{
400 					snprintf(jail_errmsg,
401 					    JAIL_ERRMSGLEN,
402 					    "%s: not an IPv4 address: %s",
403 					    jp->jp_name, tvalue);
404 					errno = EINVAL;
405 					goto error;
406 				}
407 				break;
408 			case JPS_IN6_ADDR:
409 				if (inet_pton(AF_INET6, tvalue,
410 				    &((struct in6_addr *)jp->jp_value)[i]) != 1)
411 				{
412 					snprintf(jail_errmsg,
413 					    JAIL_ERRMSGLEN,
414 					    "%s: not an IPv6 address: %s",
415 					    jp->jp_name, tvalue);
416 					errno = EINVAL;
417 					goto error;
418 				}
419 				break;
420 			default:
421 				goto unknown_type;
422 			}
423 			break;
424 		default:
425 		unknown_type:
426 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
427 			    "unknown type for %s", jp->jp_name);
428 			errno = ENOENT;
429 			goto error;
430 		}
431 		avalue += fw + 1;
432 	}
433 	return (0);
434 
435  error:
436 	free(jp->jp_value);
437 	jp->jp_value = NULL;
438 	return (-1);
439 }
440 
441 static int
442 jailparam_import_enum(const char **values, int nvalues, const char *valstr,
443     size_t valsize, int *value)
444 {
445 	char *ep;
446 	int i;
447 
448 	for (i = 0; i < nvalues; i++)
449 		if (valsize == strlen(values[i]) &&
450 		    !strncasecmp(valstr, values[i], valsize)) {
451 			*value = i;
452 			return 1;
453 		}
454 	*value = strtol(valstr, &ep, 10);
455 	return (ep == valstr + valsize);
456 }
457 
458 /*
459  * Put a name and value into a jail parameter element, copying the value
460  * but not altering it.
461  */
462 int
463 jailparam_import_raw(struct jailparam *jp, void *value, size_t valuelen)
464 {
465 
466 	jp->jp_value = value;
467 	jp->jp_valuelen = valuelen;
468 	jp->jp_flags |= JP_RAWVALUE;
469 	return (0);
470 }
471 
472 /*
473  * Run the jail_set and jail_get system calls on a parameter list.
474  */
475 int
476 jailparam_set(struct jailparam *jp, unsigned njp, int flags)
477 {
478 	struct iovec *jiov;
479 	char *nname;
480 	int i, jid, bool0;
481 	unsigned j;
482 
483 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
484 	bool0 = 0;
485 	for (i = j = 0; j < njp; j++) {
486 		jiov[i].iov_base = jp[j].jp_name;
487 		jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
488 		i++;
489 		if (jp[j].jp_flags & (JP_BOOL | JP_NOBOOL)) {
490 			/*
491 			 * Set booleans without values.  If one has a value of
492 			 * zero, change it to (or from) its "no" counterpart.
493 			 */
494 			jiov[i].iov_base = NULL;
495 			jiov[i].iov_len = 0;
496 			if (jp[j].jp_value != NULL &&
497 			    jp[j].jp_valuelen == sizeof(int) &&
498 			    !*(int *)jp[j].jp_value) {
499 				bool0 = 1;
500 				nname = jp[j].jp_flags & JP_BOOL
501 				    ? noname(jp[j].jp_name)
502 				    : nononame(jp[j].jp_name);
503 				if (nname == NULL) {
504 					njp = j;
505 					jid = -1;
506 					goto done;
507 				}
508 				jiov[i - 1].iov_base = nname;
509 				jiov[i - 1].iov_len = strlen(nname) + 1;
510 
511 			}
512 		} else {
513 			/*
514 			 * Try to fill in missing values with an empty string.
515 			 */
516 			if (jp[j].jp_value == NULL && jp[j].jp_valuelen > 0 &&
517 			    jailparam_import(jp + j, "") < 0) {
518 				njp = j;
519 				jid = -1;
520 				goto done;
521 			}
522 			jiov[i].iov_base = jp[j].jp_value;
523 			jiov[i].iov_len =
524 			    (jp[j].jp_ctltype & CTLTYPE) == CTLTYPE_STRING
525 			    ? strlen(jp[j].jp_value) + 1
526 			    : jp[j].jp_valuelen;
527 		}
528 		i++;
529 	}
530 	*(const void **)&jiov[i].iov_base = "errmsg";
531 	jiov[i].iov_len = sizeof("errmsg");
532 	i++;
533 	jiov[i].iov_base = jail_errmsg;
534 	jiov[i].iov_len = JAIL_ERRMSGLEN;
535 	i++;
536 	jail_errmsg[0] = 0;
537 	jid = jail_set(jiov, i, flags);
538 	if (jid < 0 && !jail_errmsg[0])
539 		snprintf(jail_errmsg, sizeof(jail_errmsg), "jail_set: %s",
540 		    strerror(errno));
541  done:
542 	if (bool0)
543 		for (j = 0; j < njp; j++)
544 			if ((jp[j].jp_flags & (JP_BOOL | JP_NOBOOL)) &&
545 			    jp[j].jp_value != NULL &&
546 			    jp[j].jp_valuelen == sizeof(int) &&
547 			    !*(int *)jp[j].jp_value)
548 				free(jiov[j * 2].iov_base);
549 	return (jid);
550 }
551 
552 int
553 jailparam_get(struct jailparam *jp, unsigned njp, int flags)
554 {
555 	struct iovec *jiov;
556 	struct jailparam *jp_lastjid, *jp_jid, *jp_name, *jp_key;
557 	int i, ai, ki, jid, arrays, sanity;
558 	unsigned j;
559 
560 	/*
561 	 * Get the types for all parameters.
562 	 * Find the key and any array parameters.
563 	 */
564 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
565 	jp_lastjid = jp_jid = jp_name = NULL;
566 	arrays = 0;
567 	for (ai = j = 0; j < njp; j++) {
568 		if (!strcmp(jp[j].jp_name, "lastjid"))
569 			jp_lastjid = jp + j;
570 		else if (!strcmp(jp[j].jp_name, "jid"))
571 			jp_jid = jp + j;
572 		else if (!strcmp(jp[j].jp_name, "name"))
573 			jp_name = jp + j;
574 		else if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
575 			arrays = 1;
576 			jiov[ai].iov_base = jp[j].jp_name;
577 			jiov[ai].iov_len = strlen(jp[j].jp_name) + 1;
578 			ai++;
579 			jiov[ai].iov_base = NULL;
580 			jiov[ai].iov_len = 0;
581 			ai++;
582 		}
583 	}
584 	jp_key = jp_lastjid ? jp_lastjid :
585 	    jp_jid && jp_jid->jp_valuelen == sizeof(int) &&
586 	    jp_jid->jp_value && *(int *)jp_jid->jp_value ? jp_jid : jp_name;
587 	if (jp_key == NULL || jp_key->jp_value == NULL) {
588 		strlcpy(jail_errmsg, "no jail specified", JAIL_ERRMSGLEN);
589 		errno = ENOENT;
590 		return (-1);
591 	}
592 	ki = ai;
593 	jiov[ki].iov_base = jp_key->jp_name;
594 	jiov[ki].iov_len = strlen(jp_key->jp_name) + 1;
595 	ki++;
596 	jiov[ki].iov_base = jp_key->jp_value;
597 	jiov[ki].iov_len = (jp_key->jp_ctltype & CTLTYPE) == CTLTYPE_STRING
598 	    ? strlen(jp_key->jp_value) + 1 : jp_key->jp_valuelen;
599 	ki++;
600 	*(const void **)&jiov[ki].iov_base = "errmsg";
601 	jiov[ki].iov_len = sizeof("errmsg");
602 	ki++;
603 	jiov[ki].iov_base = jail_errmsg;
604 	jiov[ki].iov_len = JAIL_ERRMSGLEN;
605 	ki++;
606 	jail_errmsg[0] = 0;
607 	if (arrays && jail_get(jiov, ki, flags) < 0) {
608 		if (!jail_errmsg[0])
609 			snprintf(jail_errmsg, sizeof(jail_errmsg),
610 			    "jail_get: %s", strerror(errno));
611 		return (-1);
612 	}
613 	/* Allocate storage for all parameters. */
614 	for (ai = j = 0, i = ki; j < njp; j++) {
615 		if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
616 			ai++;
617 			jiov[ai].iov_len += jp[j].jp_elemlen * ARRAY_SLOP;
618 			if (jp[j].jp_valuelen >= jiov[ai].iov_len)
619 				jiov[ai].iov_len = jp[j].jp_valuelen;
620 			else {
621 				jp[j].jp_valuelen = jiov[ai].iov_len;
622 				if (jp[j].jp_value != NULL)
623 					free(jp[j].jp_value);
624 				jp[j].jp_value = malloc(jp[j].jp_valuelen);
625 				if (jp[j].jp_value == NULL) {
626 					strerror_r(errno, jail_errmsg,
627 					    JAIL_ERRMSGLEN);
628 					return (-1);
629 				}
630 			}
631 			jiov[ai].iov_base = jp[j].jp_value;
632 			memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
633 			ai++;
634 		} else if (jp + j != jp_key) {
635 			jiov[i].iov_base = jp[j].jp_name;
636 			jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
637 			i++;
638 			if (jp[j].jp_value == NULL &&
639 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
640 				jp[j].jp_value = malloc(jp[j].jp_valuelen);
641 				if (jp[j].jp_value == NULL) {
642 					strerror_r(errno, jail_errmsg,
643 					    JAIL_ERRMSGLEN);
644 					return (-1);
645 				}
646 			}
647 			jiov[i].iov_base = jp[j].jp_value;
648 			jiov[i].iov_len = jp[j].jp_valuelen;
649 			memset(jiov[i].iov_base, 0, jiov[i].iov_len);
650 			i++;
651 		}
652 	}
653 	/*
654 	 * Get the prison.  If there are array elements, retry a few times
655 	 * in case their sizes changed from under us.
656 	 */
657 	for (sanity = 0;; sanity++) {
658 		jid = jail_get(jiov, i, flags);
659 		if (jid >= 0 || !arrays || sanity == ARRAY_SANITY ||
660 		    errno != EINVAL || jail_errmsg[0])
661 			break;
662 		for (ai = j = 0; j < njp; j++) {
663 			if (jp[j].jp_elemlen &&
664 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
665 				ai++;
666 				jiov[ai].iov_base = NULL;
667 				jiov[ai].iov_len = 0;
668 				ai++;
669 			}
670 		}
671 		if (jail_get(jiov, ki, flags) < 0)
672 			break;
673 		for (ai = j = 0; j < njp; j++) {
674 			if (jp[j].jp_elemlen &&
675 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
676 				ai++;
677 				jiov[ai].iov_len +=
678 				    jp[j].jp_elemlen * ARRAY_SLOP;
679 				if (jp[j].jp_valuelen >= jiov[ai].iov_len)
680 					jiov[ai].iov_len = jp[j].jp_valuelen;
681 				else {
682 					jp[j].jp_valuelen = jiov[ai].iov_len;
683 					if (jp[j].jp_value != NULL)
684 						free(jp[j].jp_value);
685 					jp[j].jp_value =
686 					    malloc(jiov[ai].iov_len);
687 					if (jp[j].jp_value == NULL) {
688 						strerror_r(errno, jail_errmsg,
689 						    JAIL_ERRMSGLEN);
690 						return (-1);
691 					}
692 				}
693 				jiov[ai].iov_base = jp[j].jp_value;
694 				memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
695 				ai++;
696 			}
697 		}
698 	}
699 	if (jid < 0 && !jail_errmsg[0])
700 		snprintf(jail_errmsg, sizeof(jail_errmsg),
701 		    "jail_get: %s", strerror(errno));
702 	for (ai = j = 0, i = ki; j < njp; j++) {
703 		if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
704 			ai++;
705 			jp[j].jp_valuelen = jiov[ai].iov_len;
706 			ai++;
707 		} else if (jp + j != jp_key) {
708 			i++;
709 			jp[j].jp_valuelen = jiov[i].iov_len;
710 			i++;
711 		}
712 	}
713 	return (jid);
714 }
715 
716 /*
717  * Convert a jail parameter's value to external form.
718  */
719 char *
720 jailparam_export(struct jailparam *jp)
721 {
722 	size_t *valuelens;
723 	char *value, *tvalue, **values;
724 	size_t valuelen;
725 	int i, nval, ival;
726 	char valbuf[INET6_ADDRSTRLEN];
727 
728 	if ((jp->jp_ctltype & CTLTYPE) == CTLTYPE_STRING) {
729 		value = strdup(jp->jp_value);
730 		if (value == NULL)
731 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
732 		return (value);
733 	}
734 	nval = jp->jp_elemlen ? jp->jp_valuelen / jp->jp_elemlen : 1;
735 	if (nval == 0) {
736 		value = strdup("");
737 		if (value == NULL)
738 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
739 		return (value);
740 	}
741 	values = alloca(nval * sizeof(char *));
742 	valuelens = alloca(nval * sizeof(size_t));
743 	valuelen = 0;
744 	for (i = 0; i < nval; i++) {
745 		switch (jp->jp_ctltype & CTLTYPE) {
746 		case CTLTYPE_INT:
747 			ival = ((int *)jp->jp_value)[i];
748 			if ((jp->jp_flags & (JP_BOOL | JP_NOBOOL)) &&
749 			    (unsigned)ival < 2) {
750 				strlcpy(valbuf, bool_values[ival],
751 				    sizeof(valbuf));
752 				break;
753 			}
754 			if ((jp->jp_flags & JP_JAILSYS) &&
755 			    (unsigned)ival < sizeof(jailsys_values) /
756 			    sizeof(jailsys_values[0])) {
757 				strlcpy(valbuf, jailsys_values[ival],
758 				    sizeof(valbuf));
759 				break;
760 			}
761 			snprintf(valbuf, sizeof(valbuf), "%d", ival);
762 			break;
763 		case CTLTYPE_UINT:
764 			snprintf(valbuf, sizeof(valbuf), "%u",
765 			    ((unsigned *)jp->jp_value)[i]);
766 			break;
767 		case CTLTYPE_LONG:
768 			snprintf(valbuf, sizeof(valbuf), "%ld",
769 			    ((long *)jp->jp_value)[i]);
770 			break;
771 		case CTLTYPE_ULONG:
772 			snprintf(valbuf, sizeof(valbuf), "%lu",
773 			    ((unsigned long *)jp->jp_value)[i]);
774 			break;
775 		case CTLTYPE_S64:
776 			snprintf(valbuf, sizeof(valbuf), "%jd",
777 			    (intmax_t)((int64_t *)jp->jp_value)[i]);
778 			break;
779 		case CTLTYPE_U64:
780 			snprintf(valbuf, sizeof(valbuf), "%ju",
781 			    (uintmax_t)((uint64_t *)jp->jp_value)[i]);
782 			break;
783 		case CTLTYPE_STRUCT:
784 			switch (jp->jp_structtype) {
785 			case JPS_IN_ADDR:
786 				if (inet_ntop(AF_INET,
787 				    &((struct in_addr *)jp->jp_value)[i],
788 				    valbuf, sizeof(valbuf)) == NULL) {
789 					strerror_r(errno, jail_errmsg,
790 					    JAIL_ERRMSGLEN);
791 					return (NULL);
792 				}
793 				break;
794 			case JPS_IN6_ADDR:
795 				if (inet_ntop(AF_INET6,
796 				    &((struct in6_addr *)jp->jp_value)[i],
797 				    valbuf, sizeof(valbuf)) == NULL) {
798 					strerror_r(errno, jail_errmsg,
799 					    JAIL_ERRMSGLEN);
800 					return (NULL);
801 				}
802 				break;
803 			default:
804 				goto unknown_type;
805 			}
806 			break;
807 		default:
808 		unknown_type:
809 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
810 			    "unknown type for %s", jp->jp_name);
811 			errno = ENOENT;
812 			return (NULL);
813 		}
814 		valuelens[i] = strlen(valbuf) + 1;
815 		valuelen += valuelens[i];
816 		values[i] = alloca(valuelens[i]);
817 		strcpy(values[i], valbuf);
818 	}
819 	value = malloc(valuelen);
820 	if (value == NULL)
821 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
822 	else {
823 		tvalue = value;
824 		for (i = 0; i < nval; i++) {
825 			strcpy(tvalue, values[i]);
826 			if (i < nval - 1) {
827 				tvalue += valuelens[i];
828 				tvalue[-1] = ',';
829 			}
830 		}
831 	}
832 	return (value);
833 }
834 
835 /*
836  * Free the contents of a jail parameter list (but not the list itself).
837  */
838 void
839 jailparam_free(struct jailparam *jp, unsigned njp)
840 {
841 	unsigned j;
842 
843 	for (j = 0; j < njp; j++) {
844 		free(jp[j].jp_name);
845 		if (!(jp[j].jp_flags & JP_RAWVALUE))
846 			free(jp[j].jp_value);
847 	}
848 }
849 
850 /*
851  * Find a parameter's type and size from its MIB.
852  */
853 static int
854 jailparam_type(struct jailparam *jp)
855 {
856 	char *p, *name, *nname;
857 	size_t miblen, desclen;
858 	int i, isarray;
859 	struct {
860 	    int i;
861 	    char s[MAXPATHLEN];
862 	} desc;
863 	int mib[CTL_MAXNAME];
864 
865 	/* The "lastjid" parameter isn't real. */
866 	name = jp->jp_name;
867 	if (!strcmp(name, "lastjid")) {
868 		jp->jp_valuelen = sizeof(int);
869 		jp->jp_ctltype = CTLTYPE_INT | CTLFLAG_WR;
870 		return (0);
871 	}
872 
873 	/* Find the sysctl that describes the parameter. */
874 	mib[0] = 0;
875 	mib[1] = 3;
876 	snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", name);
877 	miblen = sizeof(mib) - 2 * sizeof(int);
878 	if (sysctl(mib, 2, mib + 2, &miblen, desc.s, strlen(desc.s)) < 0) {
879 		if (errno != ENOENT) {
880 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
881 			    "sysctl(0.3.%s): %s", name, strerror(errno));
882 			return (-1);
883 		}
884 		/*
885 		 * The parameter probably doesn't exist.  But it might be
886 		 * the "no" counterpart to a boolean.
887 		 */
888 		nname = nononame(name);
889 		if (nname == NULL) {
890 		unknown_parameter:
891 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
892 			    "unknown parameter: %s", jp->jp_name);
893 			errno = ENOENT;
894 			return (-1);
895 		}
896 		name = alloca(strlen(nname) + 1);
897 		strcpy(name, nname);
898 		free(nname);
899 		snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", name);
900 		miblen = sizeof(mib) - 2 * sizeof(int);
901 		if (sysctl(mib, 2, mib + 2, &miblen, desc.s,
902 		    strlen(desc.s)) < 0)
903 			goto unknown_parameter;
904 		jp->jp_flags |= JP_NOBOOL;
905 	}
906  mib_desc:
907 	mib[1] = 4;
908 	desclen = sizeof(desc);
909 	if (sysctl(mib, (miblen / sizeof(int)) + 2, &desc, &desclen,
910 	    NULL, 0) < 0) {
911 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
912 		    "sysctl(0.4.%s): %s", name, strerror(errno));
913 		return (-1);
914 	}
915 	jp->jp_ctltype = desc.i;
916 	/* If this came from removing a "no", it better be a boolean. */
917 	if (jp->jp_flags & JP_NOBOOL) {
918 		if ((desc.i & CTLTYPE) == CTLTYPE_INT && desc.s[0] == 'B') {
919 			jp->jp_valuelen = sizeof(int);
920 			return (0);
921 		}
922 		else if ((desc.i & CTLTYPE) != CTLTYPE_NODE)
923 			goto unknown_parameter;
924 	}
925 	/* See if this is an array type. */
926 	p = strchr(desc.s, '\0');
927 	isarray  = 0;
928 	if (p - 2 < desc.s || strcmp(p - 2, ",a"))
929 		isarray = 0;
930 	else {
931 		isarray = 1;
932 		p[-2] = 0;
933 	}
934 	/* Look for types we understand. */
935 	switch (desc.i & CTLTYPE) {
936 	case CTLTYPE_INT:
937 		if (desc.s[0] == 'B')
938 			jp->jp_flags |= JP_BOOL;
939 		else if (!strcmp(desc.s, "E,jailsys"))
940 			jp->jp_flags |= JP_JAILSYS;
941 	case CTLTYPE_UINT:
942 		jp->jp_valuelen = sizeof(int);
943 		break;
944 	case CTLTYPE_LONG:
945 	case CTLTYPE_ULONG:
946 		jp->jp_valuelen = sizeof(long);
947 		break;
948 	case CTLTYPE_S64:
949 	case CTLTYPE_U64:
950 		jp->jp_valuelen = sizeof(int64_t);
951 		break;
952 	case CTLTYPE_STRING:
953 		desc.s[0] = 0;
954 		desclen = sizeof(desc.s);
955 		if (sysctl(mib + 2, miblen / sizeof(int), desc.s, &desclen,
956 		    NULL, 0) < 0) {
957 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
958 			    "sysctl(" SJPARAM ".%s): %s", name,
959 			    strerror(errno));
960 			return (-1);
961 		}
962 		jp->jp_valuelen = strtoul(desc.s, NULL, 10);
963 		break;
964 	case CTLTYPE_STRUCT:
965 		if (!strcmp(desc.s, "S,in_addr")) {
966 			jp->jp_structtype = JPS_IN_ADDR;
967 			jp->jp_valuelen = sizeof(struct in_addr);
968 		} else if (!strcmp(desc.s, "S,in6_addr")) {
969 			jp->jp_structtype = JPS_IN6_ADDR;
970 			jp->jp_valuelen = sizeof(struct in6_addr);
971 		} else {
972 			desclen = 0;
973 			if (sysctl(mib + 2, miblen / sizeof(int),
974 			    NULL, &jp->jp_valuelen, NULL, 0) < 0) {
975 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
976 				    "sysctl(" SJPARAM ".%s): %s", name,
977 				    strerror(errno));
978 				return (-1);
979 			}
980 		}
981 		break;
982 	case CTLTYPE_NODE:
983 		/*
984 		 * A node might be described by an empty-named child,
985 		 * which would be immediately before or after the node itself.
986 		 */
987 		mib[1] = 1;
988 		miblen += sizeof(int);
989 		for (i = -1; i <= 1; i += 2) {
990 			mib[(miblen / sizeof(int)) + 1] =
991 			    mib[(miblen / sizeof(int))] + i;
992 			desclen = sizeof(desc.s);
993 			if (sysctl(mib, (miblen / sizeof(int)) + 2, desc.s,
994 			    &desclen, NULL, 0) < 0) {
995 				if (errno == ENOENT)
996 					continue;
997 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
998 				    "sysctl(0.1): %s", strerror(errno));
999 				return (-1);
1000 			}
1001 			if (desclen == sizeof(SJPARAM) + strlen(name) + 2 &&
1002 			    memcmp(SJPARAM ".", desc.s, sizeof(SJPARAM)) == 0 &&
1003 			    memcmp(name, desc.s + sizeof(SJPARAM),
1004 			    desclen - sizeof(SJPARAM) - 2) == 0 &&
1005 			    desc.s[desclen - 2] == '.')
1006 				goto mib_desc;
1007 		}
1008 		goto unknown_parameter;
1009 	default:
1010 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
1011 		    "unknown type for %s", jp->jp_name);
1012 		errno = ENOENT;
1013 		return (-1);
1014 	}
1015 	if (isarray) {
1016 		jp->jp_elemlen = jp->jp_valuelen;
1017 		jp->jp_valuelen = 0;
1018 	}
1019 	return (0);
1020 }
1021 
1022 /*
1023  * Change a boolean parameter name into its "no" counterpart or vice versa.
1024  */
1025 static char *
1026 noname(const char *name)
1027 {
1028 	char *nname, *p;
1029 
1030 	nname = malloc(strlen(name) + 3);
1031 	if (nname == NULL) {
1032 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
1033 		return (NULL);
1034 	}
1035 	p = strrchr(name, '.');
1036 	if (p != NULL)
1037 		sprintf(nname, "%.*s.no%s", (int)(p - name), name, p + 1);
1038 	else
1039 		sprintf(nname, "no%s", name);
1040 	return (nname);
1041 }
1042 
1043 static char *
1044 nononame(const char *name)
1045 {
1046 	char *p, *nname;
1047 
1048 	p = strrchr(name, '.');
1049 	if (strncmp(p ? p + 1 : name, "no", 2)) {
1050 		snprintf(jail_errmsg, sizeof(jail_errmsg),
1051 		    "mismatched boolean: %s", name);
1052 		errno = EINVAL;
1053 		return (NULL);
1054 	}
1055 	nname = malloc(strlen(name) - 1);
1056 	if (nname == NULL) {
1057 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
1058 		return (NULL);
1059 	}
1060 	if (p != NULL)
1061 		sprintf(nname, "%.*s.%s", (int)(p - name), name, p + 3);
1062 	else
1063 		strcpy(nname, name + 2);
1064 	return (nname);
1065 }
1066