1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2009 James Gritton.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD: stable/12/lib/libjail/jail.c 356718 2020-01-14 02:41:52Z markj $");
31 
32 #include <sys/param.h>
33 #include <sys/types.h>
34 #include <sys/jail.h>
35 #include <sys/linker.h>
36 #include <sys/socket.h>
37 #include <sys/sysctl.h>
38 
39 #include <arpa/inet.h>
40 #include <netinet/in.h>
41 
42 #include <errno.h>
43 #include <inttypes.h>
44 #include <stdio.h>
45 #include <stdarg.h>
46 #include <stdlib.h>
47 #include <string.h>
48 
49 #include "jail.h"
50 
51 #define	SJPARAM		"security.jail.param"
52 
53 #define JPS_IN_ADDR	1
54 #define JPS_IN6_ADDR	2
55 
56 #define ARRAY_SANITY	5
57 #define ARRAY_SLOP	5
58 
59 
60 static int jailparam_import_enum(const char **values, int nvalues,
61     const char *valstr, size_t valsize, int *value);
62 static int jailparam_type(struct jailparam *jp);
63 static int kldload_param(const char *name);
64 static char *noname(const char *name);
65 static char *nononame(const char *name);
66 
67 char jail_errmsg[JAIL_ERRMSGLEN];
68 
69 static const char *bool_values[] = { "false", "true" };
70 static const char *jailsys_values[] = { "disable", "new", "inherit" };
71 
72 
73 /*
74  * Import a null-terminated parameter list and set a jail with the flags
75  * and parameters.
76  */
77 int
jail_setv(int flags,...)78 jail_setv(int flags, ...)
79 {
80 	va_list ap, tap;
81 	struct jailparam *jp;
82 	const char *name, *value;
83 	int njp, jid;
84 
85 	/* Create the parameter list and import the parameters. */
86 	va_start(ap, flags);
87 	va_copy(tap, ap);
88 	for (njp = 0; va_arg(tap, char *) != NULL; njp++)
89 		(void)va_arg(tap, char *);
90 	va_end(tap);
91 	jp = alloca(njp * sizeof(struct jailparam));
92 	for (njp = 0; (name = va_arg(ap, char *)) != NULL;) {
93 		value = va_arg(ap, char *);
94 		if (jailparam_init(jp + njp, name) < 0)
95 			goto error;
96 		if (jailparam_import(jp + njp++, value) < 0)
97 			goto error;
98 	}
99 	va_end(ap);
100 	jid = jailparam_set(jp, njp, flags);
101 	jailparam_free(jp, njp);
102 	return (jid);
103 
104  error:
105 	jailparam_free(jp, njp);
106 	va_end(ap);
107 	return (-1);
108 }
109 
110 /*
111  * Read a null-terminated parameter list, get the referenced jail, and export
112  * the parameters to the list.
113  */
114 int
jail_getv(int flags,...)115 jail_getv(int flags, ...)
116 {
117 	va_list ap, tap;
118 	struct jailparam *jp, *jp_lastjid, *jp_jid, *jp_name, *jp_key;
119 	char *valarg, *value;
120 	const char *name, *key_value, *lastjid_value, *jid_value, *name_value;
121 	int njp, i, jid;
122 
123 	/* Create the parameter list and find the key. */
124 	va_start(ap, flags);
125 	va_copy(tap, ap);
126 	for (njp = 0; va_arg(tap, char *) != NULL; njp++)
127 		(void)va_arg(tap, char *);
128 	va_end(tap);
129 
130 	jp = alloca(njp * sizeof(struct jailparam));
131 	va_copy(tap, ap);
132 	jp_lastjid = jp_jid = jp_name = NULL;
133 	lastjid_value = jid_value = name_value = NULL;
134 	for (njp = 0; (name = va_arg(tap, char *)) != NULL; njp++) {
135 		value = va_arg(tap, char *);
136 		if (jailparam_init(jp + njp, name) < 0) {
137 			va_end(tap);
138 			goto error;
139 		}
140 		if (!strcmp(jp[njp].jp_name, "lastjid")) {
141 			jp_lastjid = jp + njp;
142 			lastjid_value = value;
143 		} else if (!strcmp(jp[njp].jp_name, "jid")) {
144 			jp_jid = jp + njp;
145 			jid_value = value;
146 		} if (!strcmp(jp[njp].jp_name, "name")) {
147 			jp_name = jp + njp;
148 			name_value = value;
149 		}
150 	}
151 	va_end(tap);
152 	/* Import the key parameter. */
153 	if (jp_lastjid != NULL) {
154 		jp_key = jp_lastjid;
155 		key_value = lastjid_value;
156 	} else if (jp_jid != NULL && strtol(jid_value, NULL, 10) != 0) {
157 		jp_key = jp_jid;
158 		key_value = jid_value;
159 	} else if (jp_name != NULL) {
160 		jp_key = jp_name;
161 		key_value = name_value;
162 	} else {
163 		strlcpy(jail_errmsg, "no jail specified", JAIL_ERRMSGLEN);
164 		errno = ENOENT;
165 		goto error;
166 	}
167 	if (jailparam_import(jp_key, key_value) < 0)
168 		goto error;
169 	/* Get the jail and export the parameters. */
170 	jid = jailparam_get(jp, njp, flags);
171 	if (jid < 0)
172 		goto error;
173 	for (i = 0; i < njp; i++) {
174 		(void)va_arg(ap, char *);
175 		valarg = va_arg(ap, char *);
176 		if (jp + i != jp_key) {
177 			/* It's up to the caller to ensure there's room. */
178 			if ((jp[i].jp_ctltype & CTLTYPE) == CTLTYPE_STRING)
179 				strcpy(valarg, jp[i].jp_value);
180 			else {
181 				value = jailparam_export(jp + i);
182 				if (value == NULL)
183 					goto error;
184 				strcpy(valarg, value);
185 				free(value);
186 			}
187 		}
188 	}
189 	jailparam_free(jp, njp);
190 	va_end(ap);
191 	return (jid);
192 
193  error:
194 	jailparam_free(jp, njp);
195 	va_end(ap);
196 	return (-1);
197 }
198 
199 /*
200  * Return a list of all known parameters.
201  */
202 int
jailparam_all(struct jailparam ** jpp)203 jailparam_all(struct jailparam **jpp)
204 {
205 	struct jailparam *jp, *tjp;
206 	size_t mlen1, mlen2, buflen;
207 	unsigned njp, nlist;
208 	int mib1[CTL_MAXNAME], mib2[CTL_MAXNAME - 2];
209 	char buf[MAXPATHLEN];
210 
211 	njp = 0;
212 	nlist = 32;
213 	jp = malloc(nlist * sizeof(*jp));
214 	if (jp == NULL) {
215 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
216 		return (-1);
217 	}
218 	mib1[0] = 0;
219 	mib1[1] = 2;
220 	mlen1 = CTL_MAXNAME - 2;
221 	if (sysctlnametomib(SJPARAM, mib1 + 2, &mlen1) < 0) {
222 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
223 		    "sysctlnametomib(" SJPARAM "): %s", strerror(errno));
224 		goto error;
225 	}
226 	for (;; njp++) {
227 		/* Get the next parameter. */
228 		mlen2 = sizeof(mib2);
229 		if (sysctl(mib1, mlen1 + 2, mib2, &mlen2, NULL, 0) < 0) {
230 			if (errno == ENOENT) {
231 				/* No more entries. */
232 				break;
233 			}
234 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
235 			    "sysctl(0.2): %s", strerror(errno));
236 			goto error;
237 		}
238 		if (mib2[0] != mib1[2] ||
239 		    mib2[1] != mib1[3] ||
240 		    mib2[2] != mib1[4])
241 			break;
242 		/* Convert it to an ascii name. */
243 		memcpy(mib1 + 2, mib2, mlen2);
244 		mlen1 = mlen2 / sizeof(int);
245 		mib1[1] = 1;
246 		buflen = sizeof(buf);
247 		if (sysctl(mib1, mlen1 + 2, buf, &buflen, NULL, 0) < 0) {
248 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
249 			    "sysctl(0.1): %s", strerror(errno));
250 			goto error;
251 		}
252 		if (buf[buflen - 2] == '.')
253 			buf[buflen - 2] = '\0';
254 		/* Add the parameter to the list */
255 		if (njp >= nlist) {
256 			nlist *= 2;
257 			tjp = reallocarray(jp, nlist, sizeof(*jp));
258 			if (tjp == NULL)
259 				goto error;
260 			jp = tjp;
261 		}
262 		if (jailparam_init(jp + njp, buf + sizeof(SJPARAM)) < 0)
263 			goto error;
264 		mib1[1] = 2;
265 	}
266 	/* Just return the untrimmed buffer if reallocarray() somehow fails. */
267 	tjp = reallocarray(jp, njp, sizeof(*jp));
268 	if (tjp != NULL)
269 		jp = tjp;
270 	*jpp = jp;
271 	return (njp);
272 
273  error:
274 	jailparam_free(jp, njp);
275 	free(jp);
276 	return (-1);
277 }
278 
279 /*
280  * Clear a jail parameter and copy in its name.
281  */
282 int
jailparam_init(struct jailparam * jp,const char * name)283 jailparam_init(struct jailparam *jp, const char *name)
284 {
285 
286 	memset(jp, 0, sizeof(*jp));
287 	jp->jp_name = strdup(name);
288 	if (jp->jp_name == NULL) {
289 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
290 		return (-1);
291 	}
292 	if (jailparam_type(jp) < 0) {
293 		jailparam_free(jp, 1);
294 		jp->jp_name = NULL;
295 		jp->jp_value = NULL;
296 		return (-1);
297 	}
298 	return (0);
299 }
300 
301 /*
302  * Put a name and value into a jail parameter element, converting the value
303  * to internal form.
304  */
305 int
jailparam_import(struct jailparam * jp,const char * value)306 jailparam_import(struct jailparam *jp, const char *value)
307 {
308 	char *p, *ep, *tvalue;
309 	const char *avalue;
310 	int i, nval, fw;
311 
312 	if (value == NULL)
313 		return (0);
314 	if ((jp->jp_ctltype & CTLTYPE) == CTLTYPE_STRING) {
315 		jp->jp_value = strdup(value);
316 		if (jp->jp_value == NULL) {
317 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
318 			return (-1);
319 		}
320 		return (0);
321 	}
322 	nval = 1;
323 	if (jp->jp_elemlen) {
324 		if (value[0] == '\0' || (value[0] == '-' && value[1] == '\0')) {
325 			jp->jp_value = strdup("");
326 			if (jp->jp_value == NULL) {
327 				strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
328 				return (-1);
329 			}
330 			jp->jp_valuelen = 0;
331 			return (0);
332 		}
333 		for (p = strchr(value, ','); p; p = strchr(p + 1, ','))
334 			nval++;
335 		jp->jp_valuelen = jp->jp_elemlen * nval;
336 	}
337 	jp->jp_value = malloc(jp->jp_valuelen);
338 	if (jp->jp_value == NULL) {
339 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
340 		return (-1);
341 	}
342 	avalue = value;
343 	for (i = 0; i < nval; i++) {
344 		fw = nval == 1 ? strlen(avalue) : strcspn(avalue, ",");
345 		switch (jp->jp_ctltype & CTLTYPE) {
346 		case CTLTYPE_INT:
347 			if (jp->jp_flags & (JP_BOOL | JP_NOBOOL)) {
348 				if (!jailparam_import_enum(bool_values, 2,
349 				    avalue, fw, &((int *)jp->jp_value)[i])) {
350 					snprintf(jail_errmsg,
351 					    JAIL_ERRMSGLEN, "%s: "
352 					    "unknown boolean value \"%.*s\"",
353 					    jp->jp_name, fw, avalue);
354 					errno = EINVAL;
355 					goto error;
356 				}
357 				break;
358 			}
359 			if (jp->jp_flags & JP_JAILSYS) {
360 				/*
361 				 * Allow setting a jailsys parameter to "new"
362 				 * in a booleanesque fashion.
363 				 */
364 				if (value[0] == '\0')
365 					((int *)jp->jp_value)[i] = JAIL_SYS_NEW;
366 				else if (!jailparam_import_enum(jailsys_values,
367 				    sizeof(jailsys_values) /
368 				    sizeof(jailsys_values[0]), avalue, fw,
369 				    &((int *)jp->jp_value)[i])) {
370 					snprintf(jail_errmsg,
371 					    JAIL_ERRMSGLEN, "%s: "
372 					    "unknown jailsys value \"%.*s\"",
373 					    jp->jp_name, fw, avalue);
374 					errno = EINVAL;
375 					goto error;
376 				}
377 				break;
378 			}
379 			((int *)jp->jp_value)[i] = strtol(avalue, &ep, 10);
380 		integer_test:
381 			if (ep != avalue + fw) {
382 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
383 				    "%s: non-integer value \"%.*s\"",
384 				    jp->jp_name, fw, avalue);
385 				errno = EINVAL;
386 				goto error;
387 			}
388 			break;
389 		case CTLTYPE_UINT:
390 			((unsigned *)jp->jp_value)[i] =
391 			    strtoul(avalue, &ep, 10);
392 			goto integer_test;
393 		case CTLTYPE_LONG:
394 			((long *)jp->jp_value)[i] = strtol(avalue, &ep, 10);
395 			goto integer_test;
396 		case CTLTYPE_ULONG:
397 			((unsigned long *)jp->jp_value)[i] =
398 			    strtoul(avalue, &ep, 10);
399 			goto integer_test;
400 		case CTLTYPE_S64:
401 			((int64_t *)jp->jp_value)[i] =
402 			    strtoimax(avalue, &ep, 10);
403 			goto integer_test;
404 		case CTLTYPE_U64:
405 			((uint64_t *)jp->jp_value)[i] =
406 			    strtoumax(avalue, &ep, 10);
407 			goto integer_test;
408 		case CTLTYPE_STRUCT:
409 			tvalue = alloca(fw + 1);
410 			strlcpy(tvalue, avalue, fw + 1);
411 			switch (jp->jp_structtype) {
412 			case JPS_IN_ADDR:
413 				if (inet_pton(AF_INET, tvalue,
414 				    &((struct in_addr *)jp->jp_value)[i]) != 1)
415 				{
416 					snprintf(jail_errmsg,
417 					    JAIL_ERRMSGLEN,
418 					    "%s: not an IPv4 address: %s",
419 					    jp->jp_name, tvalue);
420 					errno = EINVAL;
421 					goto error;
422 				}
423 				break;
424 			case JPS_IN6_ADDR:
425 				if (inet_pton(AF_INET6, tvalue,
426 				    &((struct in6_addr *)jp->jp_value)[i]) != 1)
427 				{
428 					snprintf(jail_errmsg,
429 					    JAIL_ERRMSGLEN,
430 					    "%s: not an IPv6 address: %s",
431 					    jp->jp_name, tvalue);
432 					errno = EINVAL;
433 					goto error;
434 				}
435 				break;
436 			default:
437 				goto unknown_type;
438 			}
439 			break;
440 		default:
441 		unknown_type:
442 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
443 			    "unknown type for %s", jp->jp_name);
444 			errno = ENOENT;
445 			goto error;
446 		}
447 		avalue += fw + 1;
448 	}
449 	return (0);
450 
451  error:
452 	free(jp->jp_value);
453 	jp->jp_value = NULL;
454 	return (-1);
455 }
456 
457 static int
jailparam_import_enum(const char ** values,int nvalues,const char * valstr,size_t valsize,int * value)458 jailparam_import_enum(const char **values, int nvalues, const char *valstr,
459     size_t valsize, int *value)
460 {
461 	char *ep;
462 	int i;
463 
464 	for (i = 0; i < nvalues; i++)
465 		if (valsize == strlen(values[i]) &&
466 		    !strncasecmp(valstr, values[i], valsize)) {
467 			*value = i;
468 			return 1;
469 		}
470 	*value = strtol(valstr, &ep, 10);
471 	return (ep == valstr + valsize);
472 }
473 
474 /*
475  * Put a name and value into a jail parameter element, copying the value
476  * but not altering it.
477  */
478 int
jailparam_import_raw(struct jailparam * jp,void * value,size_t valuelen)479 jailparam_import_raw(struct jailparam *jp, void *value, size_t valuelen)
480 {
481 
482 	jp->jp_value = value;
483 	jp->jp_valuelen = valuelen;
484 	jp->jp_flags |= JP_RAWVALUE;
485 	return (0);
486 }
487 
488 /*
489  * Run the jail_set and jail_get system calls on a parameter list.
490  */
491 int
jailparam_set(struct jailparam * jp,unsigned njp,int flags)492 jailparam_set(struct jailparam *jp, unsigned njp, int flags)
493 {
494 	struct iovec *jiov;
495 	char *nname;
496 	int i, jid, bool0;
497 	unsigned j;
498 
499 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
500 	bool0 = 0;
501 	for (i = j = 0; j < njp; j++) {
502 		jiov[i].iov_base = jp[j].jp_name;
503 		jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
504 		i++;
505 		if (jp[j].jp_flags & (JP_BOOL | JP_NOBOOL)) {
506 			/*
507 			 * Set booleans without values.  If one has a value of
508 			 * zero, change it to (or from) its "no" counterpart.
509 			 */
510 			jiov[i].iov_base = NULL;
511 			jiov[i].iov_len = 0;
512 			if (jp[j].jp_value != NULL &&
513 			    jp[j].jp_valuelen == sizeof(int) &&
514 			    !*(int *)jp[j].jp_value) {
515 				bool0 = 1;
516 				nname = jp[j].jp_flags & JP_BOOL
517 				    ? noname(jp[j].jp_name)
518 				    : nononame(jp[j].jp_name);
519 				if (nname == NULL) {
520 					njp = j;
521 					jid = -1;
522 					goto done;
523 				}
524 				jiov[i - 1].iov_base = nname;
525 				jiov[i - 1].iov_len = strlen(nname) + 1;
526 
527 			}
528 		} else {
529 			/*
530 			 * Try to fill in missing values with an empty string.
531 			 */
532 			if (jp[j].jp_value == NULL && jp[j].jp_valuelen > 0 &&
533 			    jailparam_import(jp + j, "") < 0) {
534 				njp = j;
535 				jid = -1;
536 				goto done;
537 			}
538 			jiov[i].iov_base = jp[j].jp_value;
539 			jiov[i].iov_len =
540 			    (jp[j].jp_ctltype & CTLTYPE) == CTLTYPE_STRING
541 			    ? strlen(jp[j].jp_value) + 1
542 			    : jp[j].jp_valuelen;
543 		}
544 		i++;
545 	}
546 	jiov[i].iov_base = __DECONST(char *, "errmsg");
547 	jiov[i].iov_len = sizeof("errmsg");
548 	i++;
549 	jiov[i].iov_base = jail_errmsg;
550 	jiov[i].iov_len = JAIL_ERRMSGLEN;
551 	i++;
552 	jail_errmsg[0] = 0;
553 	jid = jail_set(jiov, i, flags);
554 	if (jid < 0 && !jail_errmsg[0])
555 		snprintf(jail_errmsg, sizeof(jail_errmsg), "jail_set: %s",
556 		    strerror(errno));
557  done:
558 	if (bool0)
559 		for (j = 0; j < njp; j++)
560 			if ((jp[j].jp_flags & (JP_BOOL | JP_NOBOOL)) &&
561 			    jp[j].jp_value != NULL &&
562 			    jp[j].jp_valuelen == sizeof(int) &&
563 			    !*(int *)jp[j].jp_value)
564 				free(jiov[j * 2].iov_base);
565 	return (jid);
566 }
567 
568 int
jailparam_get(struct jailparam * jp,unsigned njp,int flags)569 jailparam_get(struct jailparam *jp, unsigned njp, int flags)
570 {
571 	struct iovec *jiov;
572 	struct jailparam *jp_lastjid, *jp_jid, *jp_name, *jp_key;
573 	int i, ai, ki, jid, arrays, sanity;
574 	unsigned j;
575 
576 	/*
577 	 * Get the types for all parameters.
578 	 * Find the key and any array parameters.
579 	 */
580 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
581 	jp_lastjid = jp_jid = jp_name = NULL;
582 	arrays = 0;
583 	for (ai = j = 0; j < njp; j++) {
584 		if (!strcmp(jp[j].jp_name, "lastjid"))
585 			jp_lastjid = jp + j;
586 		else if (!strcmp(jp[j].jp_name, "jid"))
587 			jp_jid = jp + j;
588 		else if (!strcmp(jp[j].jp_name, "name"))
589 			jp_name = jp + j;
590 		else if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
591 			arrays = 1;
592 			jiov[ai].iov_base = jp[j].jp_name;
593 			jiov[ai].iov_len = strlen(jp[j].jp_name) + 1;
594 			ai++;
595 			jiov[ai].iov_base = NULL;
596 			jiov[ai].iov_len = 0;
597 			ai++;
598 		}
599 	}
600 	jp_key = jp_lastjid ? jp_lastjid :
601 	    jp_jid && jp_jid->jp_valuelen == sizeof(int) &&
602 	    jp_jid->jp_value && *(int *)jp_jid->jp_value ? jp_jid : jp_name;
603 	if (jp_key == NULL || jp_key->jp_value == NULL) {
604 		strlcpy(jail_errmsg, "no jail specified", JAIL_ERRMSGLEN);
605 		errno = ENOENT;
606 		return (-1);
607 	}
608 	ki = ai;
609 	jiov[ki].iov_base = jp_key->jp_name;
610 	jiov[ki].iov_len = strlen(jp_key->jp_name) + 1;
611 	ki++;
612 	jiov[ki].iov_base = jp_key->jp_value;
613 	jiov[ki].iov_len = (jp_key->jp_ctltype & CTLTYPE) == CTLTYPE_STRING
614 	    ? strlen(jp_key->jp_value) + 1 : jp_key->jp_valuelen;
615 	ki++;
616 	jiov[ki].iov_base = __DECONST(char *, "errmsg");
617 	jiov[ki].iov_len = sizeof("errmsg");
618 	ki++;
619 	jiov[ki].iov_base = jail_errmsg;
620 	jiov[ki].iov_len = JAIL_ERRMSGLEN;
621 	ki++;
622 	jail_errmsg[0] = 0;
623 	if (arrays && jail_get(jiov, ki, flags) < 0) {
624 		if (!jail_errmsg[0])
625 			snprintf(jail_errmsg, sizeof(jail_errmsg),
626 			    "jail_get: %s", strerror(errno));
627 		return (-1);
628 	}
629 	/* Allocate storage for all parameters. */
630 	for (ai = j = 0, i = ki; j < njp; j++) {
631 		if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
632 			ai++;
633 			jiov[ai].iov_len += jp[j].jp_elemlen * ARRAY_SLOP;
634 			if (jp[j].jp_valuelen >= jiov[ai].iov_len)
635 				jiov[ai].iov_len = jp[j].jp_valuelen;
636 			else {
637 				jp[j].jp_valuelen = jiov[ai].iov_len;
638 				if (jp[j].jp_value != NULL)
639 					free(jp[j].jp_value);
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[ai].iov_base = jp[j].jp_value;
648 			memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
649 			ai++;
650 		} else if (jp + j != jp_key) {
651 			jiov[i].iov_base = jp[j].jp_name;
652 			jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
653 			i++;
654 			if (jp[j].jp_value == NULL &&
655 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
656 				jp[j].jp_value = malloc(jp[j].jp_valuelen);
657 				if (jp[j].jp_value == NULL) {
658 					strerror_r(errno, jail_errmsg,
659 					    JAIL_ERRMSGLEN);
660 					return (-1);
661 				}
662 			}
663 			jiov[i].iov_base = jp[j].jp_value;
664 			jiov[i].iov_len = jp[j].jp_valuelen;
665 			memset(jiov[i].iov_base, 0, jiov[i].iov_len);
666 			i++;
667 		}
668 	}
669 	/*
670 	 * Get the prison.  If there are array elements, retry a few times
671 	 * in case their sizes changed from under us.
672 	 */
673 	for (sanity = 0;; sanity++) {
674 		jid = jail_get(jiov, i, flags);
675 		if (jid >= 0 || !arrays || sanity == ARRAY_SANITY ||
676 		    errno != EINVAL || jail_errmsg[0])
677 			break;
678 		for (ai = j = 0; j < njp; j++) {
679 			if (jp[j].jp_elemlen &&
680 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
681 				ai++;
682 				jiov[ai].iov_base = NULL;
683 				jiov[ai].iov_len = 0;
684 				ai++;
685 			}
686 		}
687 		if (jail_get(jiov, ki, flags) < 0)
688 			break;
689 		for (ai = j = 0; j < njp; j++) {
690 			if (jp[j].jp_elemlen &&
691 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
692 				ai++;
693 				jiov[ai].iov_len +=
694 				    jp[j].jp_elemlen * ARRAY_SLOP;
695 				if (jp[j].jp_valuelen >= jiov[ai].iov_len)
696 					jiov[ai].iov_len = jp[j].jp_valuelen;
697 				else {
698 					jp[j].jp_valuelen = jiov[ai].iov_len;
699 					if (jp[j].jp_value != NULL)
700 						free(jp[j].jp_value);
701 					jp[j].jp_value =
702 					    malloc(jiov[ai].iov_len);
703 					if (jp[j].jp_value == NULL) {
704 						strerror_r(errno, jail_errmsg,
705 						    JAIL_ERRMSGLEN);
706 						return (-1);
707 					}
708 				}
709 				jiov[ai].iov_base = jp[j].jp_value;
710 				memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
711 				ai++;
712 			}
713 		}
714 	}
715 	if (jid < 0 && !jail_errmsg[0])
716 		snprintf(jail_errmsg, sizeof(jail_errmsg),
717 		    "jail_get: %s", strerror(errno));
718 	for (ai = j = 0, i = ki; j < njp; j++) {
719 		if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
720 			ai++;
721 			jp[j].jp_valuelen = jiov[ai].iov_len;
722 			ai++;
723 		} else if (jp + j != jp_key) {
724 			i++;
725 			jp[j].jp_valuelen = jiov[i].iov_len;
726 			i++;
727 		}
728 	}
729 	return (jid);
730 }
731 
732 /*
733  * Convert a jail parameter's value to external form.
734  */
735 char *
jailparam_export(struct jailparam * jp)736 jailparam_export(struct jailparam *jp)
737 {
738 	size_t *valuelens;
739 	char *value, *tvalue, **values;
740 	size_t valuelen;
741 	int i, nval, ival;
742 	char valbuf[INET6_ADDRSTRLEN];
743 
744 	if ((jp->jp_ctltype & CTLTYPE) == CTLTYPE_STRING) {
745 		value = strdup(jp->jp_value);
746 		if (value == NULL)
747 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
748 		return (value);
749 	}
750 	nval = jp->jp_elemlen ? jp->jp_valuelen / jp->jp_elemlen : 1;
751 	if (nval == 0) {
752 		value = strdup("");
753 		if (value == NULL)
754 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
755 		return (value);
756 	}
757 	values = alloca(nval * sizeof(char *));
758 	valuelens = alloca(nval * sizeof(size_t));
759 	valuelen = 0;
760 	for (i = 0; i < nval; i++) {
761 		switch (jp->jp_ctltype & CTLTYPE) {
762 		case CTLTYPE_INT:
763 			ival = ((int *)jp->jp_value)[i];
764 			if ((jp->jp_flags & (JP_BOOL | JP_NOBOOL)) &&
765 			    (unsigned)ival < 2) {
766 				strlcpy(valbuf, bool_values[ival],
767 				    sizeof(valbuf));
768 				break;
769 			}
770 			if ((jp->jp_flags & JP_JAILSYS) &&
771 			    (unsigned)ival < sizeof(jailsys_values) /
772 			    sizeof(jailsys_values[0])) {
773 				strlcpy(valbuf, jailsys_values[ival],
774 				    sizeof(valbuf));
775 				break;
776 			}
777 			snprintf(valbuf, sizeof(valbuf), "%d", ival);
778 			break;
779 		case CTLTYPE_UINT:
780 			snprintf(valbuf, sizeof(valbuf), "%u",
781 			    ((unsigned *)jp->jp_value)[i]);
782 			break;
783 		case CTLTYPE_LONG:
784 			snprintf(valbuf, sizeof(valbuf), "%ld",
785 			    ((long *)jp->jp_value)[i]);
786 			break;
787 		case CTLTYPE_ULONG:
788 			snprintf(valbuf, sizeof(valbuf), "%lu",
789 			    ((unsigned long *)jp->jp_value)[i]);
790 			break;
791 		case CTLTYPE_S64:
792 			snprintf(valbuf, sizeof(valbuf), "%jd",
793 			    (intmax_t)((int64_t *)jp->jp_value)[i]);
794 			break;
795 		case CTLTYPE_U64:
796 			snprintf(valbuf, sizeof(valbuf), "%ju",
797 			    (uintmax_t)((uint64_t *)jp->jp_value)[i]);
798 			break;
799 		case CTLTYPE_STRUCT:
800 			switch (jp->jp_structtype) {
801 			case JPS_IN_ADDR:
802 				if (inet_ntop(AF_INET,
803 				    &((struct in_addr *)jp->jp_value)[i],
804 				    valbuf, sizeof(valbuf)) == NULL) {
805 					strerror_r(errno, jail_errmsg,
806 					    JAIL_ERRMSGLEN);
807 					return (NULL);
808 				}
809 				break;
810 			case JPS_IN6_ADDR:
811 				if (inet_ntop(AF_INET6,
812 				    &((struct in6_addr *)jp->jp_value)[i],
813 				    valbuf, sizeof(valbuf)) == NULL) {
814 					strerror_r(errno, jail_errmsg,
815 					    JAIL_ERRMSGLEN);
816 					return (NULL);
817 				}
818 				break;
819 			default:
820 				goto unknown_type;
821 			}
822 			break;
823 		default:
824 		unknown_type:
825 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
826 			    "unknown type for %s", jp->jp_name);
827 			errno = ENOENT;
828 			return (NULL);
829 		}
830 		valuelens[i] = strlen(valbuf) + 1;
831 		valuelen += valuelens[i];
832 		values[i] = alloca(valuelens[i]);
833 		strcpy(values[i], valbuf);
834 	}
835 	value = malloc(valuelen);
836 	if (value == NULL)
837 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
838 	else {
839 		tvalue = value;
840 		for (i = 0; i < nval; i++) {
841 			strcpy(tvalue, values[i]);
842 			if (i < nval - 1) {
843 				tvalue += valuelens[i];
844 				tvalue[-1] = ',';
845 			}
846 		}
847 	}
848 	return (value);
849 }
850 
851 /*
852  * Free the contents of a jail parameter list (but not the list itself).
853  */
854 void
jailparam_free(struct jailparam * jp,unsigned njp)855 jailparam_free(struct jailparam *jp, unsigned njp)
856 {
857 	unsigned j;
858 
859 	for (j = 0; j < njp; j++) {
860 		free(jp[j].jp_name);
861 		if (!(jp[j].jp_flags & JP_RAWVALUE))
862 			free(jp[j].jp_value);
863 	}
864 }
865 
866 /*
867  * Find a parameter's type and size from its MIB.
868  */
869 static int
jailparam_type(struct jailparam * jp)870 jailparam_type(struct jailparam *jp)
871 {
872 	char *p, *name, *nname;
873 	size_t miblen, desclen;
874 	int i, isarray;
875 	struct {
876 	    int i;
877 	    char s[MAXPATHLEN];
878 	} desc;
879 	int mib[CTL_MAXNAME];
880 
881 	/* The "lastjid" parameter isn't real. */
882 	name = jp->jp_name;
883 	if (!strcmp(name, "lastjid")) {
884 		jp->jp_valuelen = sizeof(int);
885 		jp->jp_ctltype = CTLTYPE_INT | CTLFLAG_WR;
886 		return (0);
887 	}
888 
889 	/* Find the sysctl that describes the parameter. */
890 	mib[0] = 0;
891 	mib[1] = 3;
892 	snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", name);
893 	miblen = sizeof(mib) - 2 * sizeof(int);
894 	if (sysctl(mib, 2, mib + 2, &miblen, desc.s, strlen(desc.s)) < 0) {
895 		if (errno != ENOENT) {
896 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
897 			    "sysctl(0.3.%s): %s", name, strerror(errno));
898 			return (-1);
899 		}
900 		if (kldload_param(name) >= 0 && sysctl(mib, 2, mib + 2, &miblen,
901 		    desc.s, strlen(desc.s)) >= 0)
902 			goto mib_desc;
903 		/*
904 		 * The parameter probably doesn't exist.  But it might be
905 		 * the "no" counterpart to a boolean.
906 		 */
907 		nname = nononame(name);
908 		if (nname == NULL) {
909 		unknown_parameter:
910 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
911 			    "unknown parameter: %s", jp->jp_name);
912 			errno = ENOENT;
913 			return (-1);
914 		}
915 		name = alloca(strlen(nname) + 1);
916 		strcpy(name, nname);
917 		free(nname);
918 		snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", name);
919 		miblen = sizeof(mib) - 2 * sizeof(int);
920 		if (sysctl(mib, 2, mib + 2, &miblen, desc.s,
921 		    strlen(desc.s)) < 0)
922 			goto unknown_parameter;
923 		jp->jp_flags |= JP_NOBOOL;
924 	}
925  mib_desc:
926 	mib[1] = 4;
927 	desclen = sizeof(desc);
928 	if (sysctl(mib, (miblen / sizeof(int)) + 2, &desc, &desclen,
929 	    NULL, 0) < 0) {
930 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
931 		    "sysctl(0.4.%s): %s", name, strerror(errno));
932 		return (-1);
933 	}
934 	jp->jp_ctltype = desc.i;
935 	/* If this came from removing a "no", it better be a boolean. */
936 	if (jp->jp_flags & JP_NOBOOL) {
937 		if ((desc.i & CTLTYPE) == CTLTYPE_INT && desc.s[0] == 'B') {
938 			jp->jp_valuelen = sizeof(int);
939 			return (0);
940 		}
941 		else if ((desc.i & CTLTYPE) != CTLTYPE_NODE)
942 			goto unknown_parameter;
943 	}
944 	/* See if this is an array type. */
945 	p = strchr(desc.s, '\0');
946 	isarray  = 0;
947 	if (p - 2 < desc.s || strcmp(p - 2, ",a"))
948 		isarray = 0;
949 	else {
950 		isarray = 1;
951 		p[-2] = 0;
952 	}
953 	/* Look for types we understand. */
954 	switch (desc.i & CTLTYPE) {
955 	case CTLTYPE_INT:
956 		if (desc.s[0] == 'B')
957 			jp->jp_flags |= JP_BOOL;
958 		else if (!strcmp(desc.s, "E,jailsys"))
959 			jp->jp_flags |= JP_JAILSYS;
960 	case CTLTYPE_UINT:
961 		jp->jp_valuelen = sizeof(int);
962 		break;
963 	case CTLTYPE_LONG:
964 	case CTLTYPE_ULONG:
965 		jp->jp_valuelen = sizeof(long);
966 		break;
967 	case CTLTYPE_S64:
968 	case CTLTYPE_U64:
969 		jp->jp_valuelen = sizeof(int64_t);
970 		break;
971 	case CTLTYPE_STRING:
972 		desc.s[0] = 0;
973 		desclen = sizeof(desc.s);
974 		if (sysctl(mib + 2, miblen / sizeof(int), desc.s, &desclen,
975 		    NULL, 0) < 0) {
976 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
977 			    "sysctl(" SJPARAM ".%s): %s", name,
978 			    strerror(errno));
979 			return (-1);
980 		}
981 		jp->jp_valuelen = strtoul(desc.s, NULL, 10);
982 		break;
983 	case CTLTYPE_STRUCT:
984 		if (!strcmp(desc.s, "S,in_addr")) {
985 			jp->jp_structtype = JPS_IN_ADDR;
986 			jp->jp_valuelen = sizeof(struct in_addr);
987 		} else if (!strcmp(desc.s, "S,in6_addr")) {
988 			jp->jp_structtype = JPS_IN6_ADDR;
989 			jp->jp_valuelen = sizeof(struct in6_addr);
990 		} else {
991 			desclen = 0;
992 			if (sysctl(mib + 2, miblen / sizeof(int),
993 			    NULL, &jp->jp_valuelen, NULL, 0) < 0) {
994 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
995 				    "sysctl(" SJPARAM ".%s): %s", name,
996 				    strerror(errno));
997 				return (-1);
998 			}
999 		}
1000 		break;
1001 	case CTLTYPE_NODE:
1002 		/*
1003 		 * A node might be described by an empty-named child,
1004 		 * which would be immediately before or after the node itself.
1005 		 */
1006 		mib[1] = 1;
1007 		miblen += sizeof(int);
1008 		for (i = -1; i <= 1; i += 2) {
1009 			mib[(miblen / sizeof(int)) + 1] =
1010 			    mib[(miblen / sizeof(int))] + i;
1011 			desclen = sizeof(desc.s);
1012 			if (sysctl(mib, (miblen / sizeof(int)) + 2, desc.s,
1013 			    &desclen, NULL, 0) < 0) {
1014 				if (errno == ENOENT)
1015 					continue;
1016 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
1017 				    "sysctl(0.1): %s", strerror(errno));
1018 				return (-1);
1019 			}
1020 			if (desclen == sizeof(SJPARAM) + strlen(name) + 2 &&
1021 			    memcmp(SJPARAM ".", desc.s, sizeof(SJPARAM)) == 0 &&
1022 			    memcmp(name, desc.s + sizeof(SJPARAM),
1023 			    desclen - sizeof(SJPARAM) - 2) == 0 &&
1024 			    desc.s[desclen - 2] == '.')
1025 				goto mib_desc;
1026 		}
1027 		goto unknown_parameter;
1028 	default:
1029 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
1030 		    "unknown type for %s", jp->jp_name);
1031 		errno = ENOENT;
1032 		return (-1);
1033 	}
1034 	if (isarray) {
1035 		jp->jp_elemlen = jp->jp_valuelen;
1036 		jp->jp_valuelen = 0;
1037 	}
1038 	return (0);
1039 }
1040 
1041 /*
1042  * Attempt to load a kernel module matching an otherwise nonexistent parameter.
1043  */
1044 static int
kldload_param(const char * name)1045 kldload_param(const char *name)
1046 {
1047 	int kl;
1048 
1049 	if (strcmp(name, "linux") == 0 || strncmp(name, "linux.", 6) == 0)
1050 		kl = kldload("linux");
1051 	else if (strcmp(name, "sysvmsg") == 0 || strcmp(name, "sysvsem") == 0 ||
1052 	    strcmp(name, "sysvshm") == 0)
1053 		kl = kldload(name);
1054 	else if (strncmp(name, "allow.mount.", 12) == 0) {
1055 		/* Load the matching filesystem */
1056 		const char *modname = name + 12;
1057 
1058 		kl = kldload(modname);
1059 		if (kl < 0 && errno == ENOENT &&
1060 		    strncmp(modname, "no", 2) == 0)
1061 			kl = kldload(modname + 2);
1062 	} else {
1063 		errno = ENOENT;
1064 		return (-1);
1065 	}
1066 	if (kl < 0 && errno == EEXIST) {
1067 		/*
1068 		 * In the module is already loaded, then it must not contain
1069 		 * the parameter.
1070 		 */
1071 		errno = ENOENT;
1072 	}
1073 	return kl;
1074 }
1075 
1076 /*
1077  * Change a boolean parameter name into its "no" counterpart or vice versa.
1078  */
1079 static char *
noname(const char * name)1080 noname(const char *name)
1081 {
1082 	char *nname, *p;
1083 
1084 	nname = malloc(strlen(name) + 3);
1085 	if (nname == NULL) {
1086 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
1087 		return (NULL);
1088 	}
1089 	p = strrchr(name, '.');
1090 	if (p != NULL)
1091 		sprintf(nname, "%.*s.no%s", (int)(p - name), name, p + 1);
1092 	else
1093 		sprintf(nname, "no%s", name);
1094 	return (nname);
1095 }
1096 
1097 static char *
nononame(const char * name)1098 nononame(const char *name)
1099 {
1100 	char *p, *nname;
1101 
1102 	p = strrchr(name, '.');
1103 	if (strncmp(p ? p + 1 : name, "no", 2)) {
1104 		snprintf(jail_errmsg, sizeof(jail_errmsg),
1105 		    "mismatched boolean: %s", name);
1106 		errno = EINVAL;
1107 		return (NULL);
1108 	}
1109 	nname = malloc(strlen(name) - 1);
1110 	if (nname == NULL) {
1111 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
1112 		return (NULL);
1113 	}
1114 	if (p != NULL)
1115 		sprintf(nname, "%.*s.%s", (int)(p - name), name, p + 3);
1116 	else
1117 		strcpy(nname, name + 2);
1118 	return (nname);
1119 }
1120