xref: /freebsd/lib/libjail/jail.c (revision d91f8db5f1822c43cd256f19aae1d059e4b25a26)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2009 James Gritton.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/jail.h>
34 #include <sys/linker.h>
35 #include <sys/socket.h>
36 #include <sys/sysctl.h>
37 
38 #include <arpa/inet.h>
39 #include <netinet/in.h>
40 
41 #include <errno.h>
42 #include <inttypes.h>
43 #include <stdio.h>
44 #include <stdarg.h>
45 #include <stdlib.h>
46 #include <string.h>
47 
48 #include "jail.h"
49 
50 #define	SJPARAM		"security.jail.param"
51 
52 #define JPS_IN_ADDR	1
53 #define JPS_IN6_ADDR	2
54 
55 #define ARRAY_SANITY	5
56 #define ARRAY_SLOP	5
57 
58 
59 static int jailparam_import_enum(const char **values, int nvalues,
60     const char *valstr, size_t valsize, int *value);
61 static int jailparam_type(struct jailparam *jp);
62 static int kldload_param(const char *name);
63 static char *noname(const char *name);
64 static char *nononame(const char *name);
65 
66 char jail_errmsg[JAIL_ERRMSGLEN];
67 
68 static const char *bool_values[] = { "false", "true" };
69 static const char *jailsys_values[] = { "disable", "new", "inherit" };
70 
71 
72 /*
73  * Import a null-terminated parameter list and set a jail with the flags
74  * and parameters.
75  */
76 int
77 jail_setv(int flags, ...)
78 {
79 	va_list ap, tap;
80 	struct jailparam *jp;
81 	const char *name, *value;
82 	int njp, jid;
83 
84 	/* Create the parameter list and import the parameters. */
85 	va_start(ap, flags);
86 	va_copy(tap, ap);
87 	for (njp = 0; va_arg(tap, char *) != NULL; njp++)
88 		(void)va_arg(tap, char *);
89 	va_end(tap);
90 	jp = alloca(njp * sizeof(struct jailparam));
91 	for (njp = 0; (name = va_arg(ap, char *)) != NULL;) {
92 		value = va_arg(ap, char *);
93 		if (jailparam_init(jp + njp, name) < 0)
94 			goto error;
95 		if (jailparam_import(jp + njp++, value) < 0)
96 			goto error;
97 	}
98 	va_end(ap);
99 	jid = jailparam_set(jp, njp, flags);
100 	jailparam_free(jp, njp);
101 	return (jid);
102 
103  error:
104 	jailparam_free(jp, njp);
105 	va_end(ap);
106 	return (-1);
107 }
108 
109 /*
110  * Read a null-terminated parameter list, get the referenced jail, and export
111  * the parameters to the list.
112  */
113 int
114 jail_getv(int flags, ...)
115 {
116 	va_list ap, tap;
117 	struct jailparam *jp, *jp_lastjid, *jp_jid, *jp_name, *jp_key;
118 	char *valarg, *value;
119 	const char *name, *key_value, *lastjid_value, *jid_value, *name_value;
120 	int njp, i, jid;
121 
122 	/* Create the parameter list and find the key. */
123 	va_start(ap, flags);
124 	va_copy(tap, ap);
125 	for (njp = 0; va_arg(tap, char *) != NULL; njp++)
126 		(void)va_arg(tap, char *);
127 	va_end(tap);
128 
129 	jp = alloca(njp * sizeof(struct jailparam));
130 	va_copy(tap, ap);
131 	jp_lastjid = jp_jid = jp_name = NULL;
132 	lastjid_value = jid_value = name_value = NULL;
133 	for (njp = 0; (name = va_arg(tap, char *)) != NULL; njp++) {
134 		value = va_arg(tap, char *);
135 		if (jailparam_init(jp + njp, name) < 0) {
136 			va_end(tap);
137 			goto error;
138 		}
139 		if (!strcmp(jp[njp].jp_name, "lastjid")) {
140 			jp_lastjid = jp + njp;
141 			lastjid_value = value;
142 		} else if (!strcmp(jp[njp].jp_name, "jid")) {
143 			jp_jid = jp + njp;
144 			jid_value = value;
145 		} if (!strcmp(jp[njp].jp_name, "name")) {
146 			jp_name = jp + njp;
147 			name_value = value;
148 		}
149 	}
150 	va_end(tap);
151 	/* Import the key parameter. */
152 	if (jp_lastjid != NULL) {
153 		jp_key = jp_lastjid;
154 		key_value = lastjid_value;
155 	} else if (jp_jid != NULL && strtol(jid_value, NULL, 10) != 0) {
156 		jp_key = jp_jid;
157 		key_value = jid_value;
158 	} else if (jp_name != NULL) {
159 		jp_key = jp_name;
160 		key_value = name_value;
161 	} else {
162 		strlcpy(jail_errmsg, "no jail specified", JAIL_ERRMSGLEN);
163 		errno = ENOENT;
164 		goto error;
165 	}
166 	if (jailparam_import(jp_key, key_value) < 0)
167 		goto error;
168 	/* Get the jail and export the parameters. */
169 	jid = jailparam_get(jp, njp, flags);
170 	if (jid < 0)
171 		goto error;
172 	for (i = 0; i < njp; i++) {
173 		(void)va_arg(ap, char *);
174 		valarg = va_arg(ap, char *);
175 		if (jp + i != jp_key) {
176 			/* It's up to the caller to ensure there's room. */
177 			if ((jp[i].jp_ctltype & CTLTYPE) == CTLTYPE_STRING)
178 				strcpy(valarg, jp[i].jp_value);
179 			else {
180 				value = jailparam_export(jp + i);
181 				if (value == NULL)
182 					goto error;
183 				strcpy(valarg, value);
184 				free(value);
185 			}
186 		}
187 	}
188 	jailparam_free(jp, njp);
189 	va_end(ap);
190 	return (jid);
191 
192  error:
193 	jailparam_free(jp, njp);
194 	va_end(ap);
195 	return (-1);
196 }
197 
198 /*
199  * Return a list of all known parameters.
200  */
201 int
202 jailparam_all(struct jailparam **jpp)
203 {
204 	struct jailparam *jp, *tjp;
205 	size_t mlen1, mlen2, buflen;
206 	unsigned njp, nlist;
207 	int mib1[CTL_MAXNAME], mib2[CTL_MAXNAME - 2];
208 	char buf[MAXPATHLEN];
209 
210 	njp = 0;
211 	nlist = 32;
212 	jp = malloc(nlist * sizeof(*jp));
213 	if (jp == NULL) {
214 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
215 		return (-1);
216 	}
217 	mib1[0] = 0;
218 	mib1[1] = 2;
219 	mlen1 = CTL_MAXNAME - 2;
220 	if (sysctlnametomib(SJPARAM, mib1 + 2, &mlen1) < 0) {
221 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
222 		    "sysctlnametomib(" SJPARAM "): %s", strerror(errno));
223 		goto error;
224 	}
225 	for (;; njp++) {
226 		/* Get the next parameter. */
227 		mlen2 = sizeof(mib2);
228 		if (sysctl(mib1, mlen1 + 2, mib2, &mlen2, NULL, 0) < 0) {
229 			if (errno == ENOENT) {
230 				/* No more entries. */
231 				break;
232 			}
233 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
234 			    "sysctl(0.2): %s", strerror(errno));
235 			goto error;
236 		}
237 		if (mib2[0] != mib1[2] ||
238 		    mib2[1] != mib1[3] ||
239 		    mib2[2] != mib1[4])
240 			break;
241 		/* Convert it to an ascii name. */
242 		memcpy(mib1 + 2, mib2, mlen2);
243 		mlen1 = mlen2 / sizeof(int);
244 		mib1[1] = 1;
245 		buflen = sizeof(buf);
246 		if (sysctl(mib1, mlen1 + 2, buf, &buflen, NULL, 0) < 0) {
247 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
248 			    "sysctl(0.1): %s", strerror(errno));
249 			goto error;
250 		}
251 		if (buf[buflen - 2] == '.')
252 			buf[buflen - 2] = '\0';
253 		/* Add the parameter to the list */
254 		if (njp >= nlist) {
255 			nlist *= 2;
256 			tjp = reallocarray(jp, nlist, sizeof(*jp));
257 			if (tjp == NULL)
258 				goto error;
259 			jp = tjp;
260 		}
261 		if (jailparam_init(jp + njp, buf + sizeof(SJPARAM)) < 0)
262 			goto error;
263 		mib1[1] = 2;
264 	}
265 	/* Just return the untrimmed buffer if reallocarray() somehow fails. */
266 	tjp = reallocarray(jp, njp, sizeof(*jp));
267 	if (tjp != NULL)
268 		jp = tjp;
269 	*jpp = jp;
270 	return (njp);
271 
272  error:
273 	jailparam_free(jp, njp);
274 	free(jp);
275 	return (-1);
276 }
277 
278 /*
279  * Clear a jail parameter and copy in its name.
280  */
281 int
282 jailparam_init(struct jailparam *jp, const char *name)
283 {
284 
285 	memset(jp, 0, sizeof(*jp));
286 	jp->jp_name = strdup(name);
287 	if (jp->jp_name == NULL) {
288 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
289 		return (-1);
290 	}
291 	if (jailparam_type(jp) < 0) {
292 		jailparam_free(jp, 1);
293 		jp->jp_name = NULL;
294 		jp->jp_value = NULL;
295 		return (-1);
296 	}
297 	return (0);
298 }
299 
300 /*
301  * Put a name and value into a jail parameter element, converting the value
302  * to internal form.
303  */
304 int
305 jailparam_import(struct jailparam *jp, const char *value)
306 {
307 	char *p, *ep, *tvalue;
308 	const char *avalue;
309 	int i, nval, fw;
310 
311 	if (value == NULL)
312 		return (0);
313 	if ((jp->jp_ctltype & CTLTYPE) == CTLTYPE_STRING) {
314 		jp->jp_value = strdup(value);
315 		if (jp->jp_value == NULL) {
316 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
317 			return (-1);
318 		}
319 		return (0);
320 	}
321 	nval = 1;
322 	if (jp->jp_elemlen) {
323 		if (value[0] == '\0' || (value[0] == '-' && value[1] == '\0')) {
324 			jp->jp_value = strdup("");
325 			if (jp->jp_value == NULL) {
326 				strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
327 				return (-1);
328 			}
329 			jp->jp_valuelen = 0;
330 			return (0);
331 		}
332 		for (p = strchr(value, ','); p; p = strchr(p + 1, ','))
333 			nval++;
334 		jp->jp_valuelen = jp->jp_elemlen * nval;
335 	}
336 	jp->jp_value = malloc(jp->jp_valuelen);
337 	if (jp->jp_value == NULL) {
338 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
339 		return (-1);
340 	}
341 	avalue = value;
342 	for (i = 0; i < nval; i++) {
343 		fw = nval == 1 ? strlen(avalue) : strcspn(avalue, ",");
344 		switch (jp->jp_ctltype & CTLTYPE) {
345 		case CTLTYPE_INT:
346 			if (jp->jp_flags & (JP_BOOL | JP_NOBOOL)) {
347 				if (!jailparam_import_enum(bool_values, 2,
348 				    avalue, fw, &((int *)jp->jp_value)[i])) {
349 					snprintf(jail_errmsg,
350 					    JAIL_ERRMSGLEN, "%s: "
351 					    "unknown boolean value \"%.*s\"",
352 					    jp->jp_name, fw, avalue);
353 					errno = EINVAL;
354 					goto error;
355 				}
356 				break;
357 			}
358 			if (jp->jp_flags & JP_JAILSYS) {
359 				/*
360 				 * Allow setting a jailsys parameter to "new"
361 				 * in a booleanesque fashion.
362 				 */
363 				if (value[0] == '\0')
364 					((int *)jp->jp_value)[i] = JAIL_SYS_NEW;
365 				else if (!jailparam_import_enum(jailsys_values,
366 				    sizeof(jailsys_values) /
367 				    sizeof(jailsys_values[0]), avalue, fw,
368 				    &((int *)jp->jp_value)[i])) {
369 					snprintf(jail_errmsg,
370 					    JAIL_ERRMSGLEN, "%s: "
371 					    "unknown jailsys value \"%.*s\"",
372 					    jp->jp_name, fw, avalue);
373 					errno = EINVAL;
374 					goto error;
375 				}
376 				break;
377 			}
378 			((int *)jp->jp_value)[i] = strtol(avalue, &ep, 10);
379 		integer_test:
380 			if (ep != avalue + fw) {
381 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
382 				    "%s: non-integer value \"%.*s\"",
383 				    jp->jp_name, fw, avalue);
384 				errno = EINVAL;
385 				goto error;
386 			}
387 			break;
388 		case CTLTYPE_UINT:
389 			((unsigned *)jp->jp_value)[i] =
390 			    strtoul(avalue, &ep, 10);
391 			goto integer_test;
392 		case CTLTYPE_LONG:
393 			((long *)jp->jp_value)[i] = strtol(avalue, &ep, 10);
394 			goto integer_test;
395 		case CTLTYPE_ULONG:
396 			((unsigned long *)jp->jp_value)[i] =
397 			    strtoul(avalue, &ep, 10);
398 			goto integer_test;
399 		case CTLTYPE_S64:
400 			((int64_t *)jp->jp_value)[i] =
401 			    strtoimax(avalue, &ep, 10);
402 			goto integer_test;
403 		case CTLTYPE_U64:
404 			((uint64_t *)jp->jp_value)[i] =
405 			    strtoumax(avalue, &ep, 10);
406 			goto integer_test;
407 		case CTLTYPE_STRUCT:
408 			tvalue = alloca(fw + 1);
409 			strlcpy(tvalue, avalue, fw + 1);
410 			switch (jp->jp_structtype) {
411 			case JPS_IN_ADDR:
412 				if (inet_pton(AF_INET, tvalue,
413 				    &((struct in_addr *)jp->jp_value)[i]) != 1)
414 				{
415 					snprintf(jail_errmsg,
416 					    JAIL_ERRMSGLEN,
417 					    "%s: not an IPv4 address: %s",
418 					    jp->jp_name, tvalue);
419 					errno = EINVAL;
420 					goto error;
421 				}
422 				break;
423 			case JPS_IN6_ADDR:
424 				if (inet_pton(AF_INET6, tvalue,
425 				    &((struct in6_addr *)jp->jp_value)[i]) != 1)
426 				{
427 					snprintf(jail_errmsg,
428 					    JAIL_ERRMSGLEN,
429 					    "%s: not an IPv6 address: %s",
430 					    jp->jp_name, tvalue);
431 					errno = EINVAL;
432 					goto error;
433 				}
434 				break;
435 			default:
436 				goto unknown_type;
437 			}
438 			break;
439 		default:
440 		unknown_type:
441 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
442 			    "unknown type for %s", jp->jp_name);
443 			errno = ENOENT;
444 			goto error;
445 		}
446 		avalue += fw + 1;
447 	}
448 	return (0);
449 
450  error:
451 	free(jp->jp_value);
452 	jp->jp_value = NULL;
453 	return (-1);
454 }
455 
456 static int
457 jailparam_import_enum(const char **values, int nvalues, const char *valstr,
458     size_t valsize, int *value)
459 {
460 	char *ep;
461 	int i;
462 
463 	for (i = 0; i < nvalues; i++)
464 		if (valsize == strlen(values[i]) &&
465 		    !strncasecmp(valstr, values[i], valsize)) {
466 			*value = i;
467 			return 1;
468 		}
469 	*value = strtol(valstr, &ep, 10);
470 	return (ep == valstr + valsize);
471 }
472 
473 /*
474  * Put a name and value into a jail parameter element, copying the value
475  * but not altering it.
476  */
477 int
478 jailparam_import_raw(struct jailparam *jp, void *value, size_t valuelen)
479 {
480 
481 	jp->jp_value = value;
482 	jp->jp_valuelen = valuelen;
483 	jp->jp_flags |= JP_RAWVALUE;
484 	return (0);
485 }
486 
487 /*
488  * Run the jail_set and jail_get system calls on a parameter list.
489  */
490 int
491 jailparam_set(struct jailparam *jp, unsigned njp, int flags)
492 {
493 	struct iovec *jiov;
494 	char *nname;
495 	int i, jid, bool0;
496 	unsigned j;
497 
498 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
499 	bool0 = 0;
500 	for (i = j = 0; j < njp; j++) {
501 		jiov[i].iov_base = jp[j].jp_name;
502 		jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
503 		i++;
504 		if (jp[j].jp_flags & (JP_BOOL | JP_NOBOOL)) {
505 			/*
506 			 * Set booleans without values.  If one has a value of
507 			 * zero, change it to (or from) its "no" counterpart.
508 			 */
509 			jiov[i].iov_base = NULL;
510 			jiov[i].iov_len = 0;
511 			if (jp[j].jp_value != NULL &&
512 			    jp[j].jp_valuelen == sizeof(int) &&
513 			    !*(int *)jp[j].jp_value) {
514 				bool0 = 1;
515 				nname = jp[j].jp_flags & JP_BOOL
516 				    ? noname(jp[j].jp_name)
517 				    : nononame(jp[j].jp_name);
518 				if (nname == NULL) {
519 					njp = j;
520 					jid = -1;
521 					goto done;
522 				}
523 				jiov[i - 1].iov_base = nname;
524 				jiov[i - 1].iov_len = strlen(nname) + 1;
525 
526 			}
527 		} else {
528 			/*
529 			 * Try to fill in missing values with an empty string.
530 			 */
531 			if (jp[j].jp_value == NULL && jp[j].jp_valuelen > 0 &&
532 			    jailparam_import(jp + j, "") < 0) {
533 				njp = j;
534 				jid = -1;
535 				goto done;
536 			}
537 			jiov[i].iov_base = jp[j].jp_value;
538 			jiov[i].iov_len =
539 			    (jp[j].jp_ctltype & CTLTYPE) == CTLTYPE_STRING
540 			    ? strlen(jp[j].jp_value) + 1
541 			    : jp[j].jp_valuelen;
542 		}
543 		i++;
544 	}
545 	jiov[i].iov_base = __DECONST(char *, "errmsg");
546 	jiov[i].iov_len = sizeof("errmsg");
547 	i++;
548 	jiov[i].iov_base = jail_errmsg;
549 	jiov[i].iov_len = JAIL_ERRMSGLEN;
550 	i++;
551 	jail_errmsg[0] = 0;
552 	jid = jail_set(jiov, i, flags);
553 	if (jid < 0 && !jail_errmsg[0])
554 		snprintf(jail_errmsg, sizeof(jail_errmsg), "jail_set: %s",
555 		    strerror(errno));
556  done:
557 	if (bool0)
558 		for (j = 0; j < njp; j++)
559 			if ((jp[j].jp_flags & (JP_BOOL | JP_NOBOOL)) &&
560 			    jp[j].jp_value != NULL &&
561 			    jp[j].jp_valuelen == sizeof(int) &&
562 			    !*(int *)jp[j].jp_value)
563 				free(jiov[j * 2].iov_base);
564 	return (jid);
565 }
566 
567 int
568 jailparam_get(struct jailparam *jp, unsigned njp, int flags)
569 {
570 	struct iovec *jiov;
571 	struct jailparam *jp_lastjid, *jp_jid, *jp_name, *jp_key;
572 	int i, ai, ki, jid, arrays, sanity;
573 	unsigned j;
574 
575 	/*
576 	 * Get the types for all parameters.
577 	 * Find the key and any array parameters.
578 	 */
579 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
580 	jp_lastjid = jp_jid = jp_name = NULL;
581 	arrays = 0;
582 	for (ai = j = 0; j < njp; j++) {
583 		if (!strcmp(jp[j].jp_name, "lastjid"))
584 			jp_lastjid = jp + j;
585 		else if (!strcmp(jp[j].jp_name, "jid"))
586 			jp_jid = jp + j;
587 		else if (!strcmp(jp[j].jp_name, "name"))
588 			jp_name = jp + j;
589 		else if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
590 			arrays = 1;
591 			jiov[ai].iov_base = jp[j].jp_name;
592 			jiov[ai].iov_len = strlen(jp[j].jp_name) + 1;
593 			ai++;
594 			jiov[ai].iov_base = NULL;
595 			jiov[ai].iov_len = 0;
596 			ai++;
597 		}
598 	}
599 	jp_key = jp_lastjid ? jp_lastjid :
600 	    jp_jid && jp_jid->jp_valuelen == sizeof(int) &&
601 	    jp_jid->jp_value && *(int *)jp_jid->jp_value ? jp_jid : jp_name;
602 	if (jp_key == NULL || jp_key->jp_value == NULL) {
603 		strlcpy(jail_errmsg, "no jail specified", JAIL_ERRMSGLEN);
604 		errno = ENOENT;
605 		return (-1);
606 	}
607 	ki = ai;
608 	jiov[ki].iov_base = jp_key->jp_name;
609 	jiov[ki].iov_len = strlen(jp_key->jp_name) + 1;
610 	ki++;
611 	jiov[ki].iov_base = jp_key->jp_value;
612 	jiov[ki].iov_len = (jp_key->jp_ctltype & CTLTYPE) == CTLTYPE_STRING
613 	    ? strlen(jp_key->jp_value) + 1 : jp_key->jp_valuelen;
614 	ki++;
615 	jiov[ki].iov_base = __DECONST(char *, "errmsg");
616 	jiov[ki].iov_len = sizeof("errmsg");
617 	ki++;
618 	jiov[ki].iov_base = jail_errmsg;
619 	jiov[ki].iov_len = JAIL_ERRMSGLEN;
620 	ki++;
621 	jail_errmsg[0] = 0;
622 	if (arrays && jail_get(jiov, ki, flags) < 0) {
623 		if (!jail_errmsg[0])
624 			snprintf(jail_errmsg, sizeof(jail_errmsg),
625 			    "jail_get: %s", strerror(errno));
626 		return (-1);
627 	}
628 	/* Allocate storage for all parameters. */
629 	for (ai = j = 0, i = ki; j < njp; j++) {
630 		if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
631 			ai++;
632 			jiov[ai].iov_len += jp[j].jp_elemlen * ARRAY_SLOP;
633 			if (jp[j].jp_valuelen >= jiov[ai].iov_len)
634 				jiov[ai].iov_len = jp[j].jp_valuelen;
635 			else {
636 				jp[j].jp_valuelen = jiov[ai].iov_len;
637 				if (jp[j].jp_value != NULL)
638 					free(jp[j].jp_value);
639 				jp[j].jp_value = malloc(jp[j].jp_valuelen);
640 				if (jp[j].jp_value == NULL) {
641 					strerror_r(errno, jail_errmsg,
642 					    JAIL_ERRMSGLEN);
643 					return (-1);
644 				}
645 			}
646 			jiov[ai].iov_base = jp[j].jp_value;
647 			memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
648 			ai++;
649 		} else if (jp + j != jp_key) {
650 			jiov[i].iov_base = jp[j].jp_name;
651 			jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
652 			i++;
653 			if (jp[j].jp_value == NULL &&
654 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
655 				jp[j].jp_value = malloc(jp[j].jp_valuelen);
656 				if (jp[j].jp_value == NULL) {
657 					strerror_r(errno, jail_errmsg,
658 					    JAIL_ERRMSGLEN);
659 					return (-1);
660 				}
661 			}
662 			jiov[i].iov_base = jp[j].jp_value;
663 			jiov[i].iov_len = jp[j].jp_valuelen;
664 			memset(jiov[i].iov_base, 0, jiov[i].iov_len);
665 			i++;
666 		}
667 	}
668 	/*
669 	 * Get the prison.  If there are array elements, retry a few times
670 	 * in case their sizes changed from under us.
671 	 */
672 	for (sanity = 0;; sanity++) {
673 		jid = jail_get(jiov, i, flags);
674 		if (jid >= 0 || !arrays || sanity == ARRAY_SANITY ||
675 		    errno != EINVAL || jail_errmsg[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_base = NULL;
682 				jiov[ai].iov_len = 0;
683 				ai++;
684 			}
685 		}
686 		if (jail_get(jiov, ki, flags) < 0)
687 			break;
688 		for (ai = j = 0; j < njp; j++) {
689 			if (jp[j].jp_elemlen &&
690 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
691 				ai++;
692 				jiov[ai].iov_len +=
693 				    jp[j].jp_elemlen * ARRAY_SLOP;
694 				if (jp[j].jp_valuelen >= jiov[ai].iov_len)
695 					jiov[ai].iov_len = jp[j].jp_valuelen;
696 				else {
697 					jp[j].jp_valuelen = jiov[ai].iov_len;
698 					if (jp[j].jp_value != NULL)
699 						free(jp[j].jp_value);
700 					jp[j].jp_value =
701 					    malloc(jiov[ai].iov_len);
702 					if (jp[j].jp_value == NULL) {
703 						strerror_r(errno, jail_errmsg,
704 						    JAIL_ERRMSGLEN);
705 						return (-1);
706 					}
707 				}
708 				jiov[ai].iov_base = jp[j].jp_value;
709 				memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
710 				ai++;
711 			}
712 		}
713 	}
714 	if (jid < 0 && !jail_errmsg[0])
715 		snprintf(jail_errmsg, sizeof(jail_errmsg),
716 		    "jail_get: %s", strerror(errno));
717 	for (ai = j = 0, i = ki; j < njp; j++) {
718 		if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
719 			ai++;
720 			jp[j].jp_valuelen = jiov[ai].iov_len;
721 			ai++;
722 		} else if (jp + j != jp_key) {
723 			i++;
724 			jp[j].jp_valuelen = jiov[i].iov_len;
725 			i++;
726 		}
727 	}
728 	return (jid);
729 }
730 
731 /*
732  * Convert a jail parameter's value to external form.
733  */
734 char *
735 jailparam_export(struct jailparam *jp)
736 {
737 	size_t *valuelens;
738 	char *value, *tvalue, **values;
739 	size_t valuelen;
740 	int i, nval, ival;
741 	char valbuf[INET6_ADDRSTRLEN];
742 
743 	if ((jp->jp_ctltype & CTLTYPE) == CTLTYPE_STRING) {
744 		value = strdup(jp->jp_value);
745 		if (value == NULL)
746 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
747 		return (value);
748 	}
749 	nval = jp->jp_elemlen ? jp->jp_valuelen / jp->jp_elemlen : 1;
750 	if (nval == 0) {
751 		value = strdup("");
752 		if (value == NULL)
753 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
754 		return (value);
755 	}
756 	values = alloca(nval * sizeof(char *));
757 	valuelens = alloca(nval * sizeof(size_t));
758 	valuelen = 0;
759 	for (i = 0; i < nval; i++) {
760 		switch (jp->jp_ctltype & CTLTYPE) {
761 		case CTLTYPE_INT:
762 			ival = ((int *)jp->jp_value)[i];
763 			if ((jp->jp_flags & (JP_BOOL | JP_NOBOOL)) &&
764 			    (unsigned)ival < 2) {
765 				strlcpy(valbuf, bool_values[ival],
766 				    sizeof(valbuf));
767 				break;
768 			}
769 			if ((jp->jp_flags & JP_JAILSYS) &&
770 			    (unsigned)ival < sizeof(jailsys_values) /
771 			    sizeof(jailsys_values[0])) {
772 				strlcpy(valbuf, jailsys_values[ival],
773 				    sizeof(valbuf));
774 				break;
775 			}
776 			snprintf(valbuf, sizeof(valbuf), "%d", ival);
777 			break;
778 		case CTLTYPE_UINT:
779 			snprintf(valbuf, sizeof(valbuf), "%u",
780 			    ((unsigned *)jp->jp_value)[i]);
781 			break;
782 		case CTLTYPE_LONG:
783 			snprintf(valbuf, sizeof(valbuf), "%ld",
784 			    ((long *)jp->jp_value)[i]);
785 			break;
786 		case CTLTYPE_ULONG:
787 			snprintf(valbuf, sizeof(valbuf), "%lu",
788 			    ((unsigned long *)jp->jp_value)[i]);
789 			break;
790 		case CTLTYPE_S64:
791 			snprintf(valbuf, sizeof(valbuf), "%jd",
792 			    (intmax_t)((int64_t *)jp->jp_value)[i]);
793 			break;
794 		case CTLTYPE_U64:
795 			snprintf(valbuf, sizeof(valbuf), "%ju",
796 			    (uintmax_t)((uint64_t *)jp->jp_value)[i]);
797 			break;
798 		case CTLTYPE_STRUCT:
799 			switch (jp->jp_structtype) {
800 			case JPS_IN_ADDR:
801 				if (inet_ntop(AF_INET,
802 				    &((struct in_addr *)jp->jp_value)[i],
803 				    valbuf, sizeof(valbuf)) == NULL) {
804 					strerror_r(errno, jail_errmsg,
805 					    JAIL_ERRMSGLEN);
806 					return (NULL);
807 				}
808 				break;
809 			case JPS_IN6_ADDR:
810 				if (inet_ntop(AF_INET6,
811 				    &((struct in6_addr *)jp->jp_value)[i],
812 				    valbuf, sizeof(valbuf)) == NULL) {
813 					strerror_r(errno, jail_errmsg,
814 					    JAIL_ERRMSGLEN);
815 					return (NULL);
816 				}
817 				break;
818 			default:
819 				goto unknown_type;
820 			}
821 			break;
822 		default:
823 		unknown_type:
824 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
825 			    "unknown type for %s", jp->jp_name);
826 			errno = ENOENT;
827 			return (NULL);
828 		}
829 		valuelens[i] = strlen(valbuf) + 1;
830 		valuelen += valuelens[i];
831 		values[i] = alloca(valuelens[i]);
832 		strcpy(values[i], valbuf);
833 	}
834 	value = malloc(valuelen);
835 	if (value == NULL)
836 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
837 	else {
838 		tvalue = value;
839 		for (i = 0; i < nval; i++) {
840 			strcpy(tvalue, values[i]);
841 			if (i < nval - 1) {
842 				tvalue += valuelens[i];
843 				tvalue[-1] = ',';
844 			}
845 		}
846 	}
847 	return (value);
848 }
849 
850 /*
851  * Free the contents of a jail parameter list (but not the list itself).
852  */
853 void
854 jailparam_free(struct jailparam *jp, unsigned njp)
855 {
856 	unsigned j;
857 
858 	for (j = 0; j < njp; j++) {
859 		free(jp[j].jp_name);
860 		if (!(jp[j].jp_flags & JP_RAWVALUE))
861 			free(jp[j].jp_value);
862 	}
863 }
864 
865 /*
866  * Find a parameter's type and size from its MIB.
867  */
868 static int
869 jailparam_type(struct jailparam *jp)
870 {
871 	char *p, *name, *nname;
872 	size_t miblen, desclen;
873 	int i, isarray;
874 	struct {
875 	    int i;
876 	    char s[MAXPATHLEN];
877 	} desc;
878 	int mib[CTL_MAXNAME];
879 
880 	/* The "lastjid" parameter isn't real. */
881 	name = jp->jp_name;
882 	if (!strcmp(name, "lastjid")) {
883 		jp->jp_valuelen = sizeof(int);
884 		jp->jp_ctltype = CTLTYPE_INT | CTLFLAG_WR;
885 		return (0);
886 	}
887 
888 	/* Find the sysctl that describes the parameter. */
889 	mib[0] = 0;
890 	mib[1] = 3;
891 	snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", name);
892 	miblen = sizeof(mib) - 2 * sizeof(int);
893 	if (sysctl(mib, 2, mib + 2, &miblen, desc.s, strlen(desc.s)) < 0) {
894 		if (errno != ENOENT) {
895 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
896 			    "sysctl(0.3.%s): %s", name, strerror(errno));
897 			return (-1);
898 		}
899 		if (kldload_param(name) >= 0 && sysctl(mib, 2, mib + 2, &miblen,
900 		    desc.s, strlen(desc.s)) >= 0)
901 			goto mib_desc;
902 		/*
903 		 * The parameter probably doesn't exist.  But it might be
904 		 * the "no" counterpart to a boolean.
905 		 */
906 		nname = nononame(name);
907 		if (nname == NULL) {
908 		unknown_parameter:
909 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
910 			    "unknown parameter: %s", jp->jp_name);
911 			errno = ENOENT;
912 			return (-1);
913 		}
914 		name = alloca(strlen(nname) + 1);
915 		strcpy(name, nname);
916 		free(nname);
917 		snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", name);
918 		miblen = sizeof(mib) - 2 * sizeof(int);
919 		if (sysctl(mib, 2, mib + 2, &miblen, desc.s,
920 		    strlen(desc.s)) < 0)
921 			goto unknown_parameter;
922 		jp->jp_flags |= JP_NOBOOL;
923 	}
924  mib_desc:
925 	mib[1] = 4;
926 	desclen = sizeof(desc);
927 	if (sysctl(mib, (miblen / sizeof(int)) + 2, &desc, &desclen,
928 	    NULL, 0) < 0) {
929 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
930 		    "sysctl(0.4.%s): %s", name, strerror(errno));
931 		return (-1);
932 	}
933 	jp->jp_ctltype = desc.i;
934 	/* If this came from removing a "no", it better be a boolean. */
935 	if (jp->jp_flags & JP_NOBOOL) {
936 		if ((desc.i & CTLTYPE) == CTLTYPE_INT && desc.s[0] == 'B') {
937 			jp->jp_valuelen = sizeof(int);
938 			return (0);
939 		}
940 		else if ((desc.i & CTLTYPE) != CTLTYPE_NODE)
941 			goto unknown_parameter;
942 	}
943 	/* See if this is an array type. */
944 	p = strchr(desc.s, '\0');
945 	isarray  = 0;
946 	if (p - 2 < desc.s || strcmp(p - 2, ",a"))
947 		isarray = 0;
948 	else {
949 		isarray = 1;
950 		p[-2] = 0;
951 	}
952 	/* Look for types we understand. */
953 	switch (desc.i & CTLTYPE) {
954 	case CTLTYPE_INT:
955 		if (desc.s[0] == 'B')
956 			jp->jp_flags |= JP_BOOL;
957 		else if (!strcmp(desc.s, "E,jailsys"))
958 			jp->jp_flags |= JP_JAILSYS;
959 	case CTLTYPE_UINT:
960 		jp->jp_valuelen = sizeof(int);
961 		break;
962 	case CTLTYPE_LONG:
963 	case CTLTYPE_ULONG:
964 		jp->jp_valuelen = sizeof(long);
965 		break;
966 	case CTLTYPE_S64:
967 	case CTLTYPE_U64:
968 		jp->jp_valuelen = sizeof(int64_t);
969 		break;
970 	case CTLTYPE_STRING:
971 		desc.s[0] = 0;
972 		desclen = sizeof(desc.s);
973 		if (sysctl(mib + 2, miblen / sizeof(int), desc.s, &desclen,
974 		    NULL, 0) < 0) {
975 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
976 			    "sysctl(" SJPARAM ".%s): %s", name,
977 			    strerror(errno));
978 			return (-1);
979 		}
980 		jp->jp_valuelen = strtoul(desc.s, NULL, 10);
981 		break;
982 	case CTLTYPE_STRUCT:
983 		if (!strcmp(desc.s, "S,in_addr")) {
984 			jp->jp_structtype = JPS_IN_ADDR;
985 			jp->jp_valuelen = sizeof(struct in_addr);
986 		} else if (!strcmp(desc.s, "S,in6_addr")) {
987 			jp->jp_structtype = JPS_IN6_ADDR;
988 			jp->jp_valuelen = sizeof(struct in6_addr);
989 		} else {
990 			desclen = 0;
991 			if (sysctl(mib + 2, miblen / sizeof(int),
992 			    NULL, &jp->jp_valuelen, NULL, 0) < 0) {
993 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
994 				    "sysctl(" SJPARAM ".%s): %s", name,
995 				    strerror(errno));
996 				return (-1);
997 			}
998 		}
999 		break;
1000 	case CTLTYPE_NODE:
1001 		/*
1002 		 * A node might be described by an empty-named child,
1003 		 * which would be immediately before or after the node itself.
1004 		 */
1005 		mib[1] = 1;
1006 		miblen += sizeof(int);
1007 		for (i = -1; i <= 1; i += 2) {
1008 			mib[(miblen / sizeof(int)) + 1] =
1009 			    mib[(miblen / sizeof(int))] + i;
1010 			desclen = sizeof(desc.s);
1011 			if (sysctl(mib, (miblen / sizeof(int)) + 2, desc.s,
1012 			    &desclen, NULL, 0) < 0) {
1013 				if (errno == ENOENT)
1014 					continue;
1015 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
1016 				    "sysctl(0.1): %s", strerror(errno));
1017 				return (-1);
1018 			}
1019 			if (desclen == sizeof(SJPARAM) + strlen(name) + 2 &&
1020 			    memcmp(SJPARAM ".", desc.s, sizeof(SJPARAM)) == 0 &&
1021 			    memcmp(name, desc.s + sizeof(SJPARAM),
1022 			    desclen - sizeof(SJPARAM) - 2) == 0 &&
1023 			    desc.s[desclen - 2] == '.')
1024 				goto mib_desc;
1025 		}
1026 		goto unknown_parameter;
1027 	default:
1028 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
1029 		    "unknown type for %s", jp->jp_name);
1030 		errno = ENOENT;
1031 		return (-1);
1032 	}
1033 	if (isarray) {
1034 		jp->jp_elemlen = jp->jp_valuelen;
1035 		jp->jp_valuelen = 0;
1036 	}
1037 	return (0);
1038 }
1039 
1040 /*
1041  * Attempt to load a kernel module matching an otherwise nonexistent parameter.
1042  */
1043 static int
1044 kldload_param(const char *name)
1045 {
1046 	int kl;
1047 
1048 	if (strcmp(name, "linux") == 0 || strncmp(name, "linux.", 6) == 0)
1049 		kl = kldload("linux");
1050 	else if (strcmp(name, "sysvmsg") == 0 || strcmp(name, "sysvsem") == 0 ||
1051 	    strcmp(name, "sysvshm") == 0)
1052 		kl = kldload(name);
1053 	else if (strncmp(name, "allow.mount.", 12) == 0) {
1054 		/* Load the matching filesystem */
1055 		const char *modname = name + 12;
1056 
1057 		kl = kldload(modname);
1058 		if (kl < 0 && errno == ENOENT &&
1059 		    strncmp(modname, "no", 2) == 0)
1060 			kl = kldload(modname + 2);
1061 	} else {
1062 		errno = ENOENT;
1063 		return (-1);
1064 	}
1065 	if (kl < 0 && errno == EEXIST) {
1066 		/*
1067 		 * In the module is already loaded, then it must not contain
1068 		 * the parameter.
1069 		 */
1070 		errno = ENOENT;
1071 	}
1072 	return kl;
1073 }
1074 
1075 /*
1076  * Change a boolean parameter name into its "no" counterpart or vice versa.
1077  */
1078 static char *
1079 noname(const char *name)
1080 {
1081 	char *nname, *p;
1082 
1083 	nname = malloc(strlen(name) + 3);
1084 	if (nname == NULL) {
1085 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
1086 		return (NULL);
1087 	}
1088 	p = strrchr(name, '.');
1089 	if (p != NULL)
1090 		sprintf(nname, "%.*s.no%s", (int)(p - name), name, p + 1);
1091 	else
1092 		sprintf(nname, "no%s", name);
1093 	return (nname);
1094 }
1095 
1096 static char *
1097 nononame(const char *name)
1098 {
1099 	char *p, *nname;
1100 
1101 	p = strrchr(name, '.');
1102 	if (strncmp(p ? p + 1 : name, "no", 2)) {
1103 		snprintf(jail_errmsg, sizeof(jail_errmsg),
1104 		    "mismatched boolean: %s", name);
1105 		errno = EINVAL;
1106 		return (NULL);
1107 	}
1108 	nname = malloc(strlen(name) - 1);
1109 	if (nname == NULL) {
1110 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
1111 		return (NULL);
1112 	}
1113 	if (p != NULL)
1114 		sprintf(nname, "%.*s.%s", (int)(p - name), name, p + 3);
1115 	else
1116 		strcpy(nname, name + 2);
1117 	return (nname);
1118 }
1119