xref: /freebsd/lib/libjail/jail.c (revision ef36b3f75658d201edb495068db5e1be49593de5)
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 	unsigned 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 			if (errno == ENOENT) {
227 				/* No more entries. */
228 				break;
229 			}
230 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
231 			    "sysctl(0.2): %s", strerror(errno));
232 			goto error;
233 		}
234 		if (mib2[0] != mib1[2] ||
235 		    mib2[1] != mib1[3] ||
236 		    mib2[2] != mib1[4])
237 			break;
238 		/* Convert it to an ascii name. */
239 		memcpy(mib1 + 2, mib2, mlen2);
240 		mlen1 = mlen2 / sizeof(int);
241 		mib1[1] = 1;
242 		buflen = sizeof(buf);
243 		if (sysctl(mib1, mlen1 + 2, buf, &buflen, NULL, 0) < 0) {
244 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
245 			    "sysctl(0.1): %s", strerror(errno));
246 			goto error;
247 		}
248 		if (buf[buflen - 2] == '.')
249 			buf[buflen - 2] = '\0';
250 		/* Add the parameter to the list */
251 		if (njp >= nlist) {
252 			nlist *= 2;
253 			tjp = reallocarray(jp, nlist, sizeof(*jp));
254 			if (tjp == NULL)
255 				goto error;
256 			jp = tjp;
257 		}
258 		if (jailparam_init(jp + njp, buf + sizeof(SJPARAM)) < 0)
259 			goto error;
260 		mib1[1] = 2;
261 	}
262 	jp = reallocarray(jp, njp, sizeof(*jp));
263 	*jpp = jp;
264 	return (njp);
265 
266  error:
267 	jailparam_free(jp, njp);
268 	free(jp);
269 	return (-1);
270 }
271 
272 /*
273  * Clear a jail parameter and copy in its name.
274  */
275 int
276 jailparam_init(struct jailparam *jp, const char *name)
277 {
278 
279 	memset(jp, 0, sizeof(*jp));
280 	jp->jp_name = strdup(name);
281 	if (jp->jp_name == NULL) {
282 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
283 		return (-1);
284 	}
285 	if (jailparam_type(jp) < 0) {
286 		jailparam_free(jp, 1);
287 		jp->jp_name = NULL;
288 		jp->jp_value = NULL;
289 		return (-1);
290 	}
291 	return (0);
292 }
293 
294 /*
295  * Put a name and value into a jail parameter element, converting the value
296  * to internal form.
297  */
298 int
299 jailparam_import(struct jailparam *jp, const char *value)
300 {
301 	char *p, *ep, *tvalue;
302 	const char *avalue;
303 	int i, nval, fw;
304 
305 	if (value == NULL)
306 		return (0);
307 	if ((jp->jp_ctltype & CTLTYPE) == CTLTYPE_STRING) {
308 		jp->jp_value = strdup(value);
309 		if (jp->jp_value == NULL) {
310 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
311 			return (-1);
312 		}
313 		return (0);
314 	}
315 	nval = 1;
316 	if (jp->jp_elemlen) {
317 		if (value[0] == '\0' || (value[0] == '-' && value[1] == '\0')) {
318 			jp->jp_value = strdup("");
319 			if (jp->jp_value == NULL) {
320 				strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
321 				return (-1);
322 			}
323 			jp->jp_valuelen = 0;
324 			return (0);
325 		}
326 		for (p = strchr(value, ','); p; p = strchr(p + 1, ','))
327 			nval++;
328 		jp->jp_valuelen = jp->jp_elemlen * nval;
329 	}
330 	jp->jp_value = malloc(jp->jp_valuelen);
331 	if (jp->jp_value == NULL) {
332 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
333 		return (-1);
334 	}
335 	avalue = value;
336 	for (i = 0; i < nval; i++) {
337 		fw = nval == 1 ? strlen(avalue) : strcspn(avalue, ",");
338 		switch (jp->jp_ctltype & CTLTYPE) {
339 		case CTLTYPE_INT:
340 			if (jp->jp_flags & (JP_BOOL | JP_NOBOOL)) {
341 				if (!jailparam_import_enum(bool_values, 2,
342 				    avalue, fw, &((int *)jp->jp_value)[i])) {
343 					snprintf(jail_errmsg,
344 					    JAIL_ERRMSGLEN, "%s: "
345 					    "unknown boolean value \"%.*s\"",
346 					    jp->jp_name, fw, avalue);
347 					errno = EINVAL;
348 					goto error;
349 				}
350 				break;
351 			}
352 			if (jp->jp_flags & JP_JAILSYS) {
353 				/*
354 				 * Allow setting a jailsys parameter to "new"
355 				 * in a booleanesque fashion.
356 				 */
357 				if (value[0] == '\0')
358 					((int *)jp->jp_value)[i] = JAIL_SYS_NEW;
359 				else if (!jailparam_import_enum(jailsys_values,
360 				    sizeof(jailsys_values) /
361 				    sizeof(jailsys_values[0]), avalue, fw,
362 				    &((int *)jp->jp_value)[i])) {
363 					snprintf(jail_errmsg,
364 					    JAIL_ERRMSGLEN, "%s: "
365 					    "unknown jailsys value \"%.*s\"",
366 					    jp->jp_name, fw, avalue);
367 					errno = EINVAL;
368 					goto error;
369 				}
370 				break;
371 			}
372 			((int *)jp->jp_value)[i] = strtol(avalue, &ep, 10);
373 		integer_test:
374 			if (ep != avalue + fw) {
375 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
376 				    "%s: non-integer value \"%.*s\"",
377 				    jp->jp_name, fw, avalue);
378 				errno = EINVAL;
379 				goto error;
380 			}
381 			break;
382 		case CTLTYPE_UINT:
383 			((unsigned *)jp->jp_value)[i] =
384 			    strtoul(avalue, &ep, 10);
385 			goto integer_test;
386 		case CTLTYPE_LONG:
387 			((long *)jp->jp_value)[i] = strtol(avalue, &ep, 10);
388 			goto integer_test;
389 		case CTLTYPE_ULONG:
390 			((unsigned long *)jp->jp_value)[i] =
391 			    strtoul(avalue, &ep, 10);
392 			goto integer_test;
393 		case CTLTYPE_S64:
394 			((int64_t *)jp->jp_value)[i] =
395 			    strtoimax(avalue, &ep, 10);
396 			goto integer_test;
397 		case CTLTYPE_U64:
398 			((uint64_t *)jp->jp_value)[i] =
399 			    strtoumax(avalue, &ep, 10);
400 			goto integer_test;
401 		case CTLTYPE_STRUCT:
402 			tvalue = alloca(fw + 1);
403 			strlcpy(tvalue, avalue, fw + 1);
404 			switch (jp->jp_structtype) {
405 			case JPS_IN_ADDR:
406 				if (inet_pton(AF_INET, tvalue,
407 				    &((struct in_addr *)jp->jp_value)[i]) != 1)
408 				{
409 					snprintf(jail_errmsg,
410 					    JAIL_ERRMSGLEN,
411 					    "%s: not an IPv4 address: %s",
412 					    jp->jp_name, tvalue);
413 					errno = EINVAL;
414 					goto error;
415 				}
416 				break;
417 			case JPS_IN6_ADDR:
418 				if (inet_pton(AF_INET6, tvalue,
419 				    &((struct in6_addr *)jp->jp_value)[i]) != 1)
420 				{
421 					snprintf(jail_errmsg,
422 					    JAIL_ERRMSGLEN,
423 					    "%s: not an IPv6 address: %s",
424 					    jp->jp_name, tvalue);
425 					errno = EINVAL;
426 					goto error;
427 				}
428 				break;
429 			default:
430 				goto unknown_type;
431 			}
432 			break;
433 		default:
434 		unknown_type:
435 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
436 			    "unknown type for %s", jp->jp_name);
437 			errno = ENOENT;
438 			goto error;
439 		}
440 		avalue += fw + 1;
441 	}
442 	return (0);
443 
444  error:
445 	free(jp->jp_value);
446 	jp->jp_value = NULL;
447 	return (-1);
448 }
449 
450 static int
451 jailparam_import_enum(const char **values, int nvalues, const char *valstr,
452     size_t valsize, int *value)
453 {
454 	char *ep;
455 	int i;
456 
457 	for (i = 0; i < nvalues; i++)
458 		if (valsize == strlen(values[i]) &&
459 		    !strncasecmp(valstr, values[i], valsize)) {
460 			*value = i;
461 			return 1;
462 		}
463 	*value = strtol(valstr, &ep, 10);
464 	return (ep == valstr + valsize);
465 }
466 
467 /*
468  * Put a name and value into a jail parameter element, copying the value
469  * but not altering it.
470  */
471 int
472 jailparam_import_raw(struct jailparam *jp, void *value, size_t valuelen)
473 {
474 
475 	jp->jp_value = value;
476 	jp->jp_valuelen = valuelen;
477 	jp->jp_flags |= JP_RAWVALUE;
478 	return (0);
479 }
480 
481 /*
482  * Run the jail_set and jail_get system calls on a parameter list.
483  */
484 int
485 jailparam_set(struct jailparam *jp, unsigned njp, int flags)
486 {
487 	struct iovec *jiov;
488 	char *nname;
489 	int i, jid, bool0;
490 	unsigned j;
491 
492 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
493 	bool0 = 0;
494 	for (i = j = 0; j < njp; j++) {
495 		jiov[i].iov_base = jp[j].jp_name;
496 		jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
497 		i++;
498 		if (jp[j].jp_flags & (JP_BOOL | JP_NOBOOL)) {
499 			/*
500 			 * Set booleans without values.  If one has a value of
501 			 * zero, change it to (or from) its "no" counterpart.
502 			 */
503 			jiov[i].iov_base = NULL;
504 			jiov[i].iov_len = 0;
505 			if (jp[j].jp_value != NULL &&
506 			    jp[j].jp_valuelen == sizeof(int) &&
507 			    !*(int *)jp[j].jp_value) {
508 				bool0 = 1;
509 				nname = jp[j].jp_flags & JP_BOOL
510 				    ? noname(jp[j].jp_name)
511 				    : nononame(jp[j].jp_name);
512 				if (nname == NULL) {
513 					njp = j;
514 					jid = -1;
515 					goto done;
516 				}
517 				jiov[i - 1].iov_base = nname;
518 				jiov[i - 1].iov_len = strlen(nname) + 1;
519 
520 			}
521 		} else {
522 			/*
523 			 * Try to fill in missing values with an empty string.
524 			 */
525 			if (jp[j].jp_value == NULL && jp[j].jp_valuelen > 0 &&
526 			    jailparam_import(jp + j, "") < 0) {
527 				njp = j;
528 				jid = -1;
529 				goto done;
530 			}
531 			jiov[i].iov_base = jp[j].jp_value;
532 			jiov[i].iov_len =
533 			    (jp[j].jp_ctltype & CTLTYPE) == CTLTYPE_STRING
534 			    ? strlen(jp[j].jp_value) + 1
535 			    : jp[j].jp_valuelen;
536 		}
537 		i++;
538 	}
539 	jiov[i].iov_base = __DECONST(char *, "errmsg");
540 	jiov[i].iov_len = sizeof("errmsg");
541 	i++;
542 	jiov[i].iov_base = jail_errmsg;
543 	jiov[i].iov_len = JAIL_ERRMSGLEN;
544 	i++;
545 	jail_errmsg[0] = 0;
546 	jid = jail_set(jiov, i, flags);
547 	if (jid < 0 && !jail_errmsg[0])
548 		snprintf(jail_errmsg, sizeof(jail_errmsg), "jail_set: %s",
549 		    strerror(errno));
550  done:
551 	if (bool0)
552 		for (j = 0; j < njp; j++)
553 			if ((jp[j].jp_flags & (JP_BOOL | JP_NOBOOL)) &&
554 			    jp[j].jp_value != NULL &&
555 			    jp[j].jp_valuelen == sizeof(int) &&
556 			    !*(int *)jp[j].jp_value)
557 				free(jiov[j * 2].iov_base);
558 	return (jid);
559 }
560 
561 int
562 jailparam_get(struct jailparam *jp, unsigned njp, int flags)
563 {
564 	struct iovec *jiov;
565 	struct jailparam *jp_lastjid, *jp_jid, *jp_name, *jp_key;
566 	int i, ai, ki, jid, arrays, sanity;
567 	unsigned j;
568 
569 	/*
570 	 * Get the types for all parameters.
571 	 * Find the key and any array parameters.
572 	 */
573 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
574 	jp_lastjid = jp_jid = jp_name = NULL;
575 	arrays = 0;
576 	for (ai = j = 0; j < njp; j++) {
577 		if (!strcmp(jp[j].jp_name, "lastjid"))
578 			jp_lastjid = jp + j;
579 		else if (!strcmp(jp[j].jp_name, "jid"))
580 			jp_jid = jp + j;
581 		else if (!strcmp(jp[j].jp_name, "name"))
582 			jp_name = jp + j;
583 		else if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
584 			arrays = 1;
585 			jiov[ai].iov_base = jp[j].jp_name;
586 			jiov[ai].iov_len = strlen(jp[j].jp_name) + 1;
587 			ai++;
588 			jiov[ai].iov_base = NULL;
589 			jiov[ai].iov_len = 0;
590 			ai++;
591 		}
592 	}
593 	jp_key = jp_lastjid ? jp_lastjid :
594 	    jp_jid && jp_jid->jp_valuelen == sizeof(int) &&
595 	    jp_jid->jp_value && *(int *)jp_jid->jp_value ? jp_jid : jp_name;
596 	if (jp_key == NULL || jp_key->jp_value == NULL) {
597 		strlcpy(jail_errmsg, "no jail specified", JAIL_ERRMSGLEN);
598 		errno = ENOENT;
599 		return (-1);
600 	}
601 	ki = ai;
602 	jiov[ki].iov_base = jp_key->jp_name;
603 	jiov[ki].iov_len = strlen(jp_key->jp_name) + 1;
604 	ki++;
605 	jiov[ki].iov_base = jp_key->jp_value;
606 	jiov[ki].iov_len = (jp_key->jp_ctltype & CTLTYPE) == CTLTYPE_STRING
607 	    ? strlen(jp_key->jp_value) + 1 : jp_key->jp_valuelen;
608 	ki++;
609 	jiov[ki].iov_base = __DECONST(char *, "errmsg");
610 	jiov[ki].iov_len = sizeof("errmsg");
611 	ki++;
612 	jiov[ki].iov_base = jail_errmsg;
613 	jiov[ki].iov_len = JAIL_ERRMSGLEN;
614 	ki++;
615 	jail_errmsg[0] = 0;
616 	if (arrays && jail_get(jiov, ki, flags) < 0) {
617 		if (!jail_errmsg[0])
618 			snprintf(jail_errmsg, sizeof(jail_errmsg),
619 			    "jail_get: %s", strerror(errno));
620 		return (-1);
621 	}
622 	/* Allocate storage for all parameters. */
623 	for (ai = j = 0, i = ki; j < njp; j++) {
624 		if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
625 			ai++;
626 			jiov[ai].iov_len += jp[j].jp_elemlen * ARRAY_SLOP;
627 			if (jp[j].jp_valuelen >= jiov[ai].iov_len)
628 				jiov[ai].iov_len = jp[j].jp_valuelen;
629 			else {
630 				jp[j].jp_valuelen = jiov[ai].iov_len;
631 				if (jp[j].jp_value != NULL)
632 					free(jp[j].jp_value);
633 				jp[j].jp_value = malloc(jp[j].jp_valuelen);
634 				if (jp[j].jp_value == NULL) {
635 					strerror_r(errno, jail_errmsg,
636 					    JAIL_ERRMSGLEN);
637 					return (-1);
638 				}
639 			}
640 			jiov[ai].iov_base = jp[j].jp_value;
641 			memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
642 			ai++;
643 		} else if (jp + j != jp_key) {
644 			jiov[i].iov_base = jp[j].jp_name;
645 			jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
646 			i++;
647 			if (jp[j].jp_value == NULL &&
648 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
649 				jp[j].jp_value = malloc(jp[j].jp_valuelen);
650 				if (jp[j].jp_value == NULL) {
651 					strerror_r(errno, jail_errmsg,
652 					    JAIL_ERRMSGLEN);
653 					return (-1);
654 				}
655 			}
656 			jiov[i].iov_base = jp[j].jp_value;
657 			jiov[i].iov_len = jp[j].jp_valuelen;
658 			memset(jiov[i].iov_base, 0, jiov[i].iov_len);
659 			i++;
660 		}
661 	}
662 	/*
663 	 * Get the prison.  If there are array elements, retry a few times
664 	 * in case their sizes changed from under us.
665 	 */
666 	for (sanity = 0;; sanity++) {
667 		jid = jail_get(jiov, i, flags);
668 		if (jid >= 0 || !arrays || sanity == ARRAY_SANITY ||
669 		    errno != EINVAL || jail_errmsg[0])
670 			break;
671 		for (ai = j = 0; j < njp; j++) {
672 			if (jp[j].jp_elemlen &&
673 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
674 				ai++;
675 				jiov[ai].iov_base = NULL;
676 				jiov[ai].iov_len = 0;
677 				ai++;
678 			}
679 		}
680 		if (jail_get(jiov, ki, flags) < 0)
681 			break;
682 		for (ai = j = 0; j < njp; j++) {
683 			if (jp[j].jp_elemlen &&
684 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
685 				ai++;
686 				jiov[ai].iov_len +=
687 				    jp[j].jp_elemlen * ARRAY_SLOP;
688 				if (jp[j].jp_valuelen >= jiov[ai].iov_len)
689 					jiov[ai].iov_len = jp[j].jp_valuelen;
690 				else {
691 					jp[j].jp_valuelen = jiov[ai].iov_len;
692 					if (jp[j].jp_value != NULL)
693 						free(jp[j].jp_value);
694 					jp[j].jp_value =
695 					    malloc(jiov[ai].iov_len);
696 					if (jp[j].jp_value == NULL) {
697 						strerror_r(errno, jail_errmsg,
698 						    JAIL_ERRMSGLEN);
699 						return (-1);
700 					}
701 				}
702 				jiov[ai].iov_base = jp[j].jp_value;
703 				memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
704 				ai++;
705 			}
706 		}
707 	}
708 	if (jid < 0 && !jail_errmsg[0])
709 		snprintf(jail_errmsg, sizeof(jail_errmsg),
710 		    "jail_get: %s", strerror(errno));
711 	for (ai = j = 0, i = ki; j < njp; j++) {
712 		if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
713 			ai++;
714 			jp[j].jp_valuelen = jiov[ai].iov_len;
715 			ai++;
716 		} else if (jp + j != jp_key) {
717 			i++;
718 			jp[j].jp_valuelen = jiov[i].iov_len;
719 			i++;
720 		}
721 	}
722 	return (jid);
723 }
724 
725 /*
726  * Convert a jail parameter's value to external form.
727  */
728 char *
729 jailparam_export(struct jailparam *jp)
730 {
731 	size_t *valuelens;
732 	char *value, *tvalue, **values;
733 	size_t valuelen;
734 	int i, nval, ival;
735 	char valbuf[INET6_ADDRSTRLEN];
736 
737 	if ((jp->jp_ctltype & CTLTYPE) == CTLTYPE_STRING) {
738 		value = strdup(jp->jp_value);
739 		if (value == NULL)
740 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
741 		return (value);
742 	}
743 	nval = jp->jp_elemlen ? jp->jp_valuelen / jp->jp_elemlen : 1;
744 	if (nval == 0) {
745 		value = strdup("");
746 		if (value == NULL)
747 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
748 		return (value);
749 	}
750 	values = alloca(nval * sizeof(char *));
751 	valuelens = alloca(nval * sizeof(size_t));
752 	valuelen = 0;
753 	for (i = 0; i < nval; i++) {
754 		switch (jp->jp_ctltype & CTLTYPE) {
755 		case CTLTYPE_INT:
756 			ival = ((int *)jp->jp_value)[i];
757 			if ((jp->jp_flags & (JP_BOOL | JP_NOBOOL)) &&
758 			    (unsigned)ival < 2) {
759 				strlcpy(valbuf, bool_values[ival],
760 				    sizeof(valbuf));
761 				break;
762 			}
763 			if ((jp->jp_flags & JP_JAILSYS) &&
764 			    (unsigned)ival < sizeof(jailsys_values) /
765 			    sizeof(jailsys_values[0])) {
766 				strlcpy(valbuf, jailsys_values[ival],
767 				    sizeof(valbuf));
768 				break;
769 			}
770 			snprintf(valbuf, sizeof(valbuf), "%d", ival);
771 			break;
772 		case CTLTYPE_UINT:
773 			snprintf(valbuf, sizeof(valbuf), "%u",
774 			    ((unsigned *)jp->jp_value)[i]);
775 			break;
776 		case CTLTYPE_LONG:
777 			snprintf(valbuf, sizeof(valbuf), "%ld",
778 			    ((long *)jp->jp_value)[i]);
779 			break;
780 		case CTLTYPE_ULONG:
781 			snprintf(valbuf, sizeof(valbuf), "%lu",
782 			    ((unsigned long *)jp->jp_value)[i]);
783 			break;
784 		case CTLTYPE_S64:
785 			snprintf(valbuf, sizeof(valbuf), "%jd",
786 			    (intmax_t)((int64_t *)jp->jp_value)[i]);
787 			break;
788 		case CTLTYPE_U64:
789 			snprintf(valbuf, sizeof(valbuf), "%ju",
790 			    (uintmax_t)((uint64_t *)jp->jp_value)[i]);
791 			break;
792 		case CTLTYPE_STRUCT:
793 			switch (jp->jp_structtype) {
794 			case JPS_IN_ADDR:
795 				if (inet_ntop(AF_INET,
796 				    &((struct in_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 			case JPS_IN6_ADDR:
804 				if (inet_ntop(AF_INET6,
805 				    &((struct in6_addr *)jp->jp_value)[i],
806 				    valbuf, sizeof(valbuf)) == NULL) {
807 					strerror_r(errno, jail_errmsg,
808 					    JAIL_ERRMSGLEN);
809 					return (NULL);
810 				}
811 				break;
812 			default:
813 				goto unknown_type;
814 			}
815 			break;
816 		default:
817 		unknown_type:
818 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
819 			    "unknown type for %s", jp->jp_name);
820 			errno = ENOENT;
821 			return (NULL);
822 		}
823 		valuelens[i] = strlen(valbuf) + 1;
824 		valuelen += valuelens[i];
825 		values[i] = alloca(valuelens[i]);
826 		strcpy(values[i], valbuf);
827 	}
828 	value = malloc(valuelen);
829 	if (value == NULL)
830 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
831 	else {
832 		tvalue = value;
833 		for (i = 0; i < nval; i++) {
834 			strcpy(tvalue, values[i]);
835 			if (i < nval - 1) {
836 				tvalue += valuelens[i];
837 				tvalue[-1] = ',';
838 			}
839 		}
840 	}
841 	return (value);
842 }
843 
844 /*
845  * Free the contents of a jail parameter list (but not the list itself).
846  */
847 void
848 jailparam_free(struct jailparam *jp, unsigned njp)
849 {
850 	unsigned j;
851 
852 	for (j = 0; j < njp; j++) {
853 		free(jp[j].jp_name);
854 		if (!(jp[j].jp_flags & JP_RAWVALUE))
855 			free(jp[j].jp_value);
856 	}
857 }
858 
859 /*
860  * Find a parameter's type and size from its MIB.
861  */
862 static int
863 jailparam_type(struct jailparam *jp)
864 {
865 	char *p, *name, *nname;
866 	size_t miblen, desclen;
867 	int i, isarray;
868 	struct {
869 	    int i;
870 	    char s[MAXPATHLEN];
871 	} desc;
872 	int mib[CTL_MAXNAME];
873 
874 	/* The "lastjid" parameter isn't real. */
875 	name = jp->jp_name;
876 	if (!strcmp(name, "lastjid")) {
877 		jp->jp_valuelen = sizeof(int);
878 		jp->jp_ctltype = CTLTYPE_INT | CTLFLAG_WR;
879 		return (0);
880 	}
881 
882 	/* Find the sysctl that describes the parameter. */
883 	mib[0] = 0;
884 	mib[1] = 3;
885 	snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", name);
886 	miblen = sizeof(mib) - 2 * sizeof(int);
887 	if (sysctl(mib, 2, mib + 2, &miblen, desc.s, strlen(desc.s)) < 0) {
888 		if (errno != ENOENT) {
889 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
890 			    "sysctl(0.3.%s): %s", name, strerror(errno));
891 			return (-1);
892 		}
893 		/*
894 		 * The parameter probably doesn't exist.  But it might be
895 		 * the "no" counterpart to a boolean.
896 		 */
897 		nname = nononame(name);
898 		if (nname == NULL) {
899 		unknown_parameter:
900 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
901 			    "unknown parameter: %s", jp->jp_name);
902 			errno = ENOENT;
903 			return (-1);
904 		}
905 		name = alloca(strlen(nname) + 1);
906 		strcpy(name, nname);
907 		free(nname);
908 		snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", name);
909 		miblen = sizeof(mib) - 2 * sizeof(int);
910 		if (sysctl(mib, 2, mib + 2, &miblen, desc.s,
911 		    strlen(desc.s)) < 0)
912 			goto unknown_parameter;
913 		jp->jp_flags |= JP_NOBOOL;
914 	}
915  mib_desc:
916 	mib[1] = 4;
917 	desclen = sizeof(desc);
918 	if (sysctl(mib, (miblen / sizeof(int)) + 2, &desc, &desclen,
919 	    NULL, 0) < 0) {
920 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
921 		    "sysctl(0.4.%s): %s", name, strerror(errno));
922 		return (-1);
923 	}
924 	jp->jp_ctltype = desc.i;
925 	/* If this came from removing a "no", it better be a boolean. */
926 	if (jp->jp_flags & JP_NOBOOL) {
927 		if ((desc.i & CTLTYPE) == CTLTYPE_INT && desc.s[0] == 'B') {
928 			jp->jp_valuelen = sizeof(int);
929 			return (0);
930 		}
931 		else if ((desc.i & CTLTYPE) != CTLTYPE_NODE)
932 			goto unknown_parameter;
933 	}
934 	/* See if this is an array type. */
935 	p = strchr(desc.s, '\0');
936 	isarray  = 0;
937 	if (p - 2 < desc.s || strcmp(p - 2, ",a"))
938 		isarray = 0;
939 	else {
940 		isarray = 1;
941 		p[-2] = 0;
942 	}
943 	/* Look for types we understand. */
944 	switch (desc.i & CTLTYPE) {
945 	case CTLTYPE_INT:
946 		if (desc.s[0] == 'B')
947 			jp->jp_flags |= JP_BOOL;
948 		else if (!strcmp(desc.s, "E,jailsys"))
949 			jp->jp_flags |= JP_JAILSYS;
950 	case CTLTYPE_UINT:
951 		jp->jp_valuelen = sizeof(int);
952 		break;
953 	case CTLTYPE_LONG:
954 	case CTLTYPE_ULONG:
955 		jp->jp_valuelen = sizeof(long);
956 		break;
957 	case CTLTYPE_S64:
958 	case CTLTYPE_U64:
959 		jp->jp_valuelen = sizeof(int64_t);
960 		break;
961 	case CTLTYPE_STRING:
962 		desc.s[0] = 0;
963 		desclen = sizeof(desc.s);
964 		if (sysctl(mib + 2, miblen / sizeof(int), desc.s, &desclen,
965 		    NULL, 0) < 0) {
966 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
967 			    "sysctl(" SJPARAM ".%s): %s", name,
968 			    strerror(errno));
969 			return (-1);
970 		}
971 		jp->jp_valuelen = strtoul(desc.s, NULL, 10);
972 		break;
973 	case CTLTYPE_STRUCT:
974 		if (!strcmp(desc.s, "S,in_addr")) {
975 			jp->jp_structtype = JPS_IN_ADDR;
976 			jp->jp_valuelen = sizeof(struct in_addr);
977 		} else if (!strcmp(desc.s, "S,in6_addr")) {
978 			jp->jp_structtype = JPS_IN6_ADDR;
979 			jp->jp_valuelen = sizeof(struct in6_addr);
980 		} else {
981 			desclen = 0;
982 			if (sysctl(mib + 2, miblen / sizeof(int),
983 			    NULL, &jp->jp_valuelen, NULL, 0) < 0) {
984 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
985 				    "sysctl(" SJPARAM ".%s): %s", name,
986 				    strerror(errno));
987 				return (-1);
988 			}
989 		}
990 		break;
991 	case CTLTYPE_NODE:
992 		/*
993 		 * A node might be described by an empty-named child,
994 		 * which would be immediately before or after the node itself.
995 		 */
996 		mib[1] = 1;
997 		miblen += sizeof(int);
998 		for (i = -1; i <= 1; i += 2) {
999 			mib[(miblen / sizeof(int)) + 1] =
1000 			    mib[(miblen / sizeof(int))] + i;
1001 			desclen = sizeof(desc.s);
1002 			if (sysctl(mib, (miblen / sizeof(int)) + 2, desc.s,
1003 			    &desclen, NULL, 0) < 0) {
1004 				if (errno == ENOENT)
1005 					continue;
1006 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
1007 				    "sysctl(0.1): %s", strerror(errno));
1008 				return (-1);
1009 			}
1010 			if (desclen == sizeof(SJPARAM) + strlen(name) + 2 &&
1011 			    memcmp(SJPARAM ".", desc.s, sizeof(SJPARAM)) == 0 &&
1012 			    memcmp(name, desc.s + sizeof(SJPARAM),
1013 			    desclen - sizeof(SJPARAM) - 2) == 0 &&
1014 			    desc.s[desclen - 2] == '.')
1015 				goto mib_desc;
1016 		}
1017 		goto unknown_parameter;
1018 	default:
1019 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
1020 		    "unknown type for %s", jp->jp_name);
1021 		errno = ENOENT;
1022 		return (-1);
1023 	}
1024 	if (isarray) {
1025 		jp->jp_elemlen = jp->jp_valuelen;
1026 		jp->jp_valuelen = 0;
1027 	}
1028 	return (0);
1029 }
1030 
1031 /*
1032  * Change a boolean parameter name into its "no" counterpart or vice versa.
1033  */
1034 static char *
1035 noname(const char *name)
1036 {
1037 	char *nname, *p;
1038 
1039 	nname = malloc(strlen(name) + 3);
1040 	if (nname == NULL) {
1041 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
1042 		return (NULL);
1043 	}
1044 	p = strrchr(name, '.');
1045 	if (p != NULL)
1046 		sprintf(nname, "%.*s.no%s", (int)(p - name), name, p + 1);
1047 	else
1048 		sprintf(nname, "no%s", name);
1049 	return (nname);
1050 }
1051 
1052 static char *
1053 nononame(const char *name)
1054 {
1055 	char *p, *nname;
1056 
1057 	p = strrchr(name, '.');
1058 	if (strncmp(p ? p + 1 : name, "no", 2)) {
1059 		snprintf(jail_errmsg, sizeof(jail_errmsg),
1060 		    "mismatched boolean: %s", name);
1061 		errno = EINVAL;
1062 		return (NULL);
1063 	}
1064 	nname = malloc(strlen(name) - 1);
1065 	if (nname == NULL) {
1066 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
1067 		return (NULL);
1068 	}
1069 	if (p != NULL)
1070 		sprintf(nname, "%.*s.%s", (int)(p - name), name, p + 3);
1071 	else
1072 		strcpy(nname, name + 2);
1073 	return (nname);
1074 }
1075