xref: /freebsd-11-stable/lib/libjail/jail.c (revision 98ac58d7f56bab7260cbd904a20bf5ce5f3ed3e8)
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/linker.h>
34 #include <sys/socket.h>
35 #include <sys/sysctl.h>
36 
37 #include <arpa/inet.h>
38 #include <netinet/in.h>
39 
40 #include <errno.h>
41 #include <inttypes.h>
42 #include <stdio.h>
43 #include <stdarg.h>
44 #include <stdlib.h>
45 #include <string.h>
46 
47 #include "jail.h"
48 
49 #define	SJPARAM		"security.jail.param"
50 
51 #define JPS_IN_ADDR	1
52 #define JPS_IN6_ADDR	2
53 
54 #define ARRAY_SANITY	5
55 #define ARRAY_SLOP	5
56 
57 
58 static int jailparam_import_enum(const char **values, int nvalues,
59     const char *valstr, size_t valsize, int *value);
60 static int jailparam_type(struct jailparam *jp);
61 static int kldload_param(const char *name);
62 static char *noname(const char *name);
63 static char *nononame(const char *name);
64 
65 char jail_errmsg[JAIL_ERRMSGLEN];
66 
67 static const char *bool_values[] = { "false", "true" };
68 static const char *jailsys_values[] = { "disable", "new", "inherit" };
69 
70 
71 /*
72  * Import a null-terminated parameter list and set a jail with the flags
73  * and parameters.
74  */
75 int
jail_setv(int flags,...)76 jail_setv(int flags, ...)
77 {
78 	va_list ap, tap;
79 	struct jailparam *jp;
80 	const char *name, *value;
81 	int njp, jid;
82 
83 	/* Create the parameter list and import the parameters. */
84 	va_start(ap, flags);
85 	va_copy(tap, ap);
86 	for (njp = 0; va_arg(tap, char *) != NULL; njp++)
87 		(void)va_arg(tap, char *);
88 	va_end(tap);
89 	jp = alloca(njp * sizeof(struct jailparam));
90 	for (njp = 0; (name = va_arg(ap, char *)) != NULL;) {
91 		value = va_arg(ap, char *);
92 		if (jailparam_init(jp + njp, name) < 0)
93 			goto error;
94 		if (jailparam_import(jp + njp++, value) < 0)
95 			goto error;
96 	}
97 	va_end(ap);
98 	jid = jailparam_set(jp, njp, flags);
99 	jailparam_free(jp, njp);
100 	return (jid);
101 
102  error:
103 	jailparam_free(jp, njp);
104 	va_end(ap);
105 	return (-1);
106 }
107 
108 /*
109  * Read a null-terminated parameter list, get the referenced jail, and export
110  * the parameters to the list.
111  */
112 int
jail_getv(int flags,...)113 jail_getv(int flags, ...)
114 {
115 	va_list ap, tap;
116 	struct jailparam *jp, *jp_lastjid, *jp_jid, *jp_name, *jp_key;
117 	char *valarg, *value;
118 	const char *name, *key_value, *lastjid_value, *jid_value, *name_value;
119 	int njp, i, jid;
120 
121 	/* Create the parameter list and find the key. */
122 	va_start(ap, flags);
123 	va_copy(tap, ap);
124 	for (njp = 0; va_arg(tap, char *) != NULL; njp++)
125 		(void)va_arg(tap, char *);
126 	va_end(tap);
127 
128 	jp = alloca(njp * sizeof(struct jailparam));
129 	va_copy(tap, ap);
130 	jp_lastjid = jp_jid = jp_name = NULL;
131 	lastjid_value = jid_value = name_value = NULL;
132 	for (njp = 0; (name = va_arg(tap, char *)) != NULL; njp++) {
133 		value = va_arg(tap, char *);
134 		if (jailparam_init(jp + njp, name) < 0) {
135 			va_end(tap);
136 			goto error;
137 		}
138 		if (!strcmp(jp[njp].jp_name, "lastjid")) {
139 			jp_lastjid = jp + njp;
140 			lastjid_value = value;
141 		} else if (!strcmp(jp[njp].jp_name, "jid")) {
142 			jp_jid = jp + njp;
143 			jid_value = value;
144 		} if (!strcmp(jp[njp].jp_name, "name")) {
145 			jp_name = jp + njp;
146 			name_value = value;
147 		}
148 	}
149 	va_end(tap);
150 	/* Import the key parameter. */
151 	if (jp_lastjid != NULL) {
152 		jp_key = jp_lastjid;
153 		key_value = lastjid_value;
154 	} else if (jp_jid != NULL && strtol(jid_value, NULL, 10) != 0) {
155 		jp_key = jp_jid;
156 		key_value = jid_value;
157 	} else if (jp_name != NULL) {
158 		jp_key = jp_name;
159 		key_value = name_value;
160 	} else {
161 		strlcpy(jail_errmsg, "no jail specified", JAIL_ERRMSGLEN);
162 		errno = ENOENT;
163 		goto error;
164 	}
165 	if (jailparam_import(jp_key, key_value) < 0)
166 		goto error;
167 	/* Get the jail and export the parameters. */
168 	jid = jailparam_get(jp, njp, flags);
169 	if (jid < 0)
170 		goto error;
171 	for (i = 0; i < njp; i++) {
172 		(void)va_arg(ap, char *);
173 		valarg = va_arg(ap, char *);
174 		if (jp + i != jp_key) {
175 			/* It's up to the caller to ensure there's room. */
176 			if ((jp[i].jp_ctltype & CTLTYPE) == CTLTYPE_STRING)
177 				strcpy(valarg, jp[i].jp_value);
178 			else {
179 				value = jailparam_export(jp + i);
180 				if (value == NULL)
181 					goto error;
182 				strcpy(valarg, value);
183 				free(value);
184 			}
185 		}
186 	}
187 	jailparam_free(jp, njp);
188 	va_end(ap);
189 	return (jid);
190 
191  error:
192 	jailparam_free(jp, njp);
193 	va_end(ap);
194 	return (-1);
195 }
196 
197 /*
198  * Return a list of all known parameters.
199  */
200 int
jailparam_all(struct jailparam ** jpp)201 jailparam_all(struct jailparam **jpp)
202 {
203 	struct jailparam *jp, *tjp;
204 	size_t mlen1, mlen2, buflen;
205 	unsigned njp, nlist;
206 	int mib1[CTL_MAXNAME], mib2[CTL_MAXNAME - 2];
207 	char buf[MAXPATHLEN];
208 
209 	njp = 0;
210 	nlist = 32;
211 	jp = malloc(nlist * sizeof(*jp));
212 	if (jp == NULL) {
213 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
214 		return (-1);
215 	}
216 	mib1[0] = 0;
217 	mib1[1] = 2;
218 	mlen1 = CTL_MAXNAME - 2;
219 	if (sysctlnametomib(SJPARAM, mib1 + 2, &mlen1) < 0) {
220 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
221 		    "sysctlnametomib(" SJPARAM "): %s", strerror(errno));
222 		goto error;
223 	}
224 	for (;; njp++) {
225 		/* Get the next parameter. */
226 		mlen2 = sizeof(mib2);
227 		if (sysctl(mib1, mlen1 + 2, mib2, &mlen2, NULL, 0) < 0) {
228 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
229 			    "sysctl(0.2): %s", strerror(errno));
230 			goto error;
231 		}
232 		if (mib2[0] != mib1[2] || mib2[1] != mib1[3] ||
233 		    mib2[2] != mib1[4])
234 			break;
235 		/* Convert it to an ascii name. */
236 		memcpy(mib1 + 2, mib2, mlen2);
237 		mlen1 = mlen2 / sizeof(int);
238 		mib1[1] = 1;
239 		buflen = sizeof(buf);
240 		if (sysctl(mib1, mlen1 + 2, buf, &buflen, NULL, 0) < 0) {
241 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
242 			    "sysctl(0.1): %s", strerror(errno));
243 			goto error;
244 		}
245 		if (buf[buflen - 2] == '.')
246 			buf[buflen - 2] = '\0';
247 		/* Add the parameter to the list */
248 		if (njp >= nlist) {
249 			nlist *= 2;
250 			tjp = reallocarray(jp, nlist, sizeof(*jp));
251 			if (tjp == NULL)
252 				goto error;
253 			jp = tjp;
254 		}
255 		if (jailparam_init(jp + njp, buf + sizeof(SJPARAM)) < 0)
256 			goto error;
257 		mib1[1] = 2;
258 	}
259 	jp = reallocarray(jp, njp, sizeof(*jp));
260 	*jpp = jp;
261 	return (njp);
262 
263  error:
264 	jailparam_free(jp, njp);
265 	free(jp);
266 	return (-1);
267 }
268 
269 /*
270  * Clear a jail parameter and copy in its name.
271  */
272 int
jailparam_init(struct jailparam * jp,const char * name)273 jailparam_init(struct jailparam *jp, const char *name)
274 {
275 
276 	memset(jp, 0, sizeof(*jp));
277 	jp->jp_name = strdup(name);
278 	if (jp->jp_name == NULL) {
279 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
280 		return (-1);
281 	}
282 	if (jailparam_type(jp) < 0) {
283 		jailparam_free(jp, 1);
284 		jp->jp_name = NULL;
285 		jp->jp_value = NULL;
286 		return (-1);
287 	}
288 	return (0);
289 }
290 
291 /*
292  * Put a name and value into a jail parameter element, converting the value
293  * to internal form.
294  */
295 int
jailparam_import(struct jailparam * jp,const char * value)296 jailparam_import(struct jailparam *jp, const char *value)
297 {
298 	char *p, *ep, *tvalue;
299 	const char *avalue;
300 	int i, nval, fw;
301 
302 	if (value == NULL)
303 		return (0);
304 	if ((jp->jp_ctltype & CTLTYPE) == CTLTYPE_STRING) {
305 		jp->jp_value = strdup(value);
306 		if (jp->jp_value == NULL) {
307 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
308 			return (-1);
309 		}
310 		return (0);
311 	}
312 	nval = 1;
313 	if (jp->jp_elemlen) {
314 		if (value[0] == '\0' || (value[0] == '-' && value[1] == '\0')) {
315 			jp->jp_value = strdup("");
316 			if (jp->jp_value == NULL) {
317 				strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
318 				return (-1);
319 			}
320 			jp->jp_valuelen = 0;
321 			return (0);
322 		}
323 		for (p = strchr(value, ','); p; p = strchr(p + 1, ','))
324 			nval++;
325 		jp->jp_valuelen = jp->jp_elemlen * nval;
326 	}
327 	jp->jp_value = malloc(jp->jp_valuelen);
328 	if (jp->jp_value == NULL) {
329 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
330 		return (-1);
331 	}
332 	avalue = value;
333 	for (i = 0; i < nval; i++) {
334 		fw = nval == 1 ? strlen(avalue) : strcspn(avalue, ",");
335 		switch (jp->jp_ctltype & CTLTYPE) {
336 		case CTLTYPE_INT:
337 			if (jp->jp_flags & (JP_BOOL | JP_NOBOOL)) {
338 				if (!jailparam_import_enum(bool_values, 2,
339 				    avalue, fw, &((int *)jp->jp_value)[i])) {
340 					snprintf(jail_errmsg,
341 					    JAIL_ERRMSGLEN, "%s: "
342 					    "unknown boolean value \"%.*s\"",
343 					    jp->jp_name, fw, avalue);
344 					errno = EINVAL;
345 					goto error;
346 				}
347 				break;
348 			}
349 			if (jp->jp_flags & JP_JAILSYS) {
350 				/*
351 				 * Allow setting a jailsys parameter to "new"
352 				 * in a booleanesque fashion.
353 				 */
354 				if (value[0] == '\0')
355 					((int *)jp->jp_value)[i] = JAIL_SYS_NEW;
356 				else if (!jailparam_import_enum(jailsys_values,
357 				    sizeof(jailsys_values) /
358 				    sizeof(jailsys_values[0]), avalue, fw,
359 				    &((int *)jp->jp_value)[i])) {
360 					snprintf(jail_errmsg,
361 					    JAIL_ERRMSGLEN, "%s: "
362 					    "unknown jailsys value \"%.*s\"",
363 					    jp->jp_name, fw, avalue);
364 					errno = EINVAL;
365 					goto error;
366 				}
367 				break;
368 			}
369 			((int *)jp->jp_value)[i] = strtol(avalue, &ep, 10);
370 		integer_test:
371 			if (ep != avalue + fw) {
372 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
373 				    "%s: non-integer value \"%.*s\"",
374 				    jp->jp_name, fw, avalue);
375 				errno = EINVAL;
376 				goto error;
377 			}
378 			break;
379 		case CTLTYPE_UINT:
380 			((unsigned *)jp->jp_value)[i] =
381 			    strtoul(avalue, &ep, 10);
382 			goto integer_test;
383 		case CTLTYPE_LONG:
384 			((long *)jp->jp_value)[i] = strtol(avalue, &ep, 10);
385 			goto integer_test;
386 		case CTLTYPE_ULONG:
387 			((unsigned long *)jp->jp_value)[i] =
388 			    strtoul(avalue, &ep, 10);
389 			goto integer_test;
390 		case CTLTYPE_S64:
391 			((int64_t *)jp->jp_value)[i] =
392 			    strtoimax(avalue, &ep, 10);
393 			goto integer_test;
394 		case CTLTYPE_U64:
395 			((uint64_t *)jp->jp_value)[i] =
396 			    strtoumax(avalue, &ep, 10);
397 			goto integer_test;
398 		case CTLTYPE_STRUCT:
399 			tvalue = alloca(fw + 1);
400 			strlcpy(tvalue, avalue, fw + 1);
401 			switch (jp->jp_structtype) {
402 			case JPS_IN_ADDR:
403 				if (inet_pton(AF_INET, tvalue,
404 				    &((struct in_addr *)jp->jp_value)[i]) != 1)
405 				{
406 					snprintf(jail_errmsg,
407 					    JAIL_ERRMSGLEN,
408 					    "%s: not an IPv4 address: %s",
409 					    jp->jp_name, tvalue);
410 					errno = EINVAL;
411 					goto error;
412 				}
413 				break;
414 			case JPS_IN6_ADDR:
415 				if (inet_pton(AF_INET6, tvalue,
416 				    &((struct in6_addr *)jp->jp_value)[i]) != 1)
417 				{
418 					snprintf(jail_errmsg,
419 					    JAIL_ERRMSGLEN,
420 					    "%s: not an IPv6 address: %s",
421 					    jp->jp_name, tvalue);
422 					errno = EINVAL;
423 					goto error;
424 				}
425 				break;
426 			default:
427 				goto unknown_type;
428 			}
429 			break;
430 		default:
431 		unknown_type:
432 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
433 			    "unknown type for %s", jp->jp_name);
434 			errno = ENOENT;
435 			goto error;
436 		}
437 		avalue += fw + 1;
438 	}
439 	return (0);
440 
441  error:
442 	free(jp->jp_value);
443 	jp->jp_value = NULL;
444 	return (-1);
445 }
446 
447 static int
jailparam_import_enum(const char ** values,int nvalues,const char * valstr,size_t valsize,int * value)448 jailparam_import_enum(const char **values, int nvalues, const char *valstr,
449     size_t valsize, int *value)
450 {
451 	char *ep;
452 	int i;
453 
454 	for (i = 0; i < nvalues; i++)
455 		if (valsize == strlen(values[i]) &&
456 		    !strncasecmp(valstr, values[i], valsize)) {
457 			*value = i;
458 			return 1;
459 		}
460 	*value = strtol(valstr, &ep, 10);
461 	return (ep == valstr + valsize);
462 }
463 
464 /*
465  * Put a name and value into a jail parameter element, copying the value
466  * but not altering it.
467  */
468 int
jailparam_import_raw(struct jailparam * jp,void * value,size_t valuelen)469 jailparam_import_raw(struct jailparam *jp, void *value, size_t valuelen)
470 {
471 
472 	jp->jp_value = value;
473 	jp->jp_valuelen = valuelen;
474 	jp->jp_flags |= JP_RAWVALUE;
475 	return (0);
476 }
477 
478 /*
479  * Run the jail_set and jail_get system calls on a parameter list.
480  */
481 int
jailparam_set(struct jailparam * jp,unsigned njp,int flags)482 jailparam_set(struct jailparam *jp, unsigned njp, int flags)
483 {
484 	struct iovec *jiov;
485 	char *nname;
486 	int i, jid, bool0;
487 	unsigned j;
488 
489 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
490 	bool0 = 0;
491 	for (i = j = 0; j < njp; j++) {
492 		jiov[i].iov_base = jp[j].jp_name;
493 		jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
494 		i++;
495 		if (jp[j].jp_flags & (JP_BOOL | JP_NOBOOL)) {
496 			/*
497 			 * Set booleans without values.  If one has a value of
498 			 * zero, change it to (or from) its "no" counterpart.
499 			 */
500 			jiov[i].iov_base = NULL;
501 			jiov[i].iov_len = 0;
502 			if (jp[j].jp_value != NULL &&
503 			    jp[j].jp_valuelen == sizeof(int) &&
504 			    !*(int *)jp[j].jp_value) {
505 				bool0 = 1;
506 				nname = jp[j].jp_flags & JP_BOOL
507 				    ? noname(jp[j].jp_name)
508 				    : nononame(jp[j].jp_name);
509 				if (nname == NULL) {
510 					njp = j;
511 					jid = -1;
512 					goto done;
513 				}
514 				jiov[i - 1].iov_base = nname;
515 				jiov[i - 1].iov_len = strlen(nname) + 1;
516 			}
517 			/*
518 			 * Load filesystem modules associated with allow.mount
519 			 * permissions.  Ignore failure, since the module may
520 			 * be static, and even a failure to load is not a jail
521 			 * error.
522 			 */
523 			if (strncmp(jp[j].jp_name, "allow.mount.", 12) == 0) {
524 				if (kldload(jp[j].jp_name + 12) < 0 &&
525 				    errno == ENOENT &&
526 				    strncmp(jp[j].jp_name + 12, "no", 2) == 0)
527 					(void)kldload(jp[j].jp_name + 14);
528 			}
529 		} else {
530 			/*
531 			 * Try to fill in missing values with an empty string.
532 			 */
533 			if (jp[j].jp_value == NULL && jp[j].jp_valuelen > 0 &&
534 			    jailparam_import(jp + j, "") < 0) {
535 				njp = j;
536 				jid = -1;
537 				goto done;
538 			}
539 			jiov[i].iov_base = jp[j].jp_value;
540 			jiov[i].iov_len =
541 			    (jp[j].jp_ctltype & CTLTYPE) == CTLTYPE_STRING
542 			    ? strlen(jp[j].jp_value) + 1
543 			    : jp[j].jp_valuelen;
544 		}
545 		i++;
546 	}
547 	jiov[i].iov_base = __DECONST(char *, "errmsg");
548 	jiov[i].iov_len = sizeof("errmsg");
549 	i++;
550 	jiov[i].iov_base = jail_errmsg;
551 	jiov[i].iov_len = JAIL_ERRMSGLEN;
552 	i++;
553 	jail_errmsg[0] = 0;
554 	jid = jail_set(jiov, i, flags);
555 	if (jid < 0 && !jail_errmsg[0])
556 		snprintf(jail_errmsg, sizeof(jail_errmsg), "jail_set: %s",
557 		    strerror(errno));
558  done:
559 	if (bool0)
560 		for (j = 0; j < njp; j++)
561 			if ((jp[j].jp_flags & (JP_BOOL | JP_NOBOOL)) &&
562 			    jp[j].jp_value != NULL &&
563 			    jp[j].jp_valuelen == sizeof(int) &&
564 			    !*(int *)jp[j].jp_value)
565 				free(jiov[j * 2].iov_base);
566 	return (jid);
567 }
568 
569 int
jailparam_get(struct jailparam * jp,unsigned njp,int flags)570 jailparam_get(struct jailparam *jp, unsigned njp, int flags)
571 {
572 	struct iovec *jiov;
573 	struct jailparam *jp_lastjid, *jp_jid, *jp_name, *jp_key;
574 	int i, ai, ki, jid, arrays, sanity;
575 	unsigned j;
576 
577 	/*
578 	 * Get the types for all parameters.
579 	 * Find the key and any array parameters.
580 	 */
581 	jiov = alloca(sizeof(struct iovec) * 2 * (njp + 1));
582 	jp_lastjid = jp_jid = jp_name = NULL;
583 	arrays = 0;
584 	for (ai = j = 0; j < njp; j++) {
585 		if (!strcmp(jp[j].jp_name, "lastjid"))
586 			jp_lastjid = jp + j;
587 		else if (!strcmp(jp[j].jp_name, "jid"))
588 			jp_jid = jp + j;
589 		else if (!strcmp(jp[j].jp_name, "name"))
590 			jp_name = jp + j;
591 		else if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
592 			arrays = 1;
593 			jiov[ai].iov_base = jp[j].jp_name;
594 			jiov[ai].iov_len = strlen(jp[j].jp_name) + 1;
595 			ai++;
596 			jiov[ai].iov_base = NULL;
597 			jiov[ai].iov_len = 0;
598 			ai++;
599 		}
600 	}
601 	jp_key = jp_lastjid ? jp_lastjid :
602 	    jp_jid && jp_jid->jp_valuelen == sizeof(int) &&
603 	    jp_jid->jp_value && *(int *)jp_jid->jp_value ? jp_jid : jp_name;
604 	if (jp_key == NULL || jp_key->jp_value == NULL) {
605 		strlcpy(jail_errmsg, "no jail specified", JAIL_ERRMSGLEN);
606 		errno = ENOENT;
607 		return (-1);
608 	}
609 	ki = ai;
610 	jiov[ki].iov_base = jp_key->jp_name;
611 	jiov[ki].iov_len = strlen(jp_key->jp_name) + 1;
612 	ki++;
613 	jiov[ki].iov_base = jp_key->jp_value;
614 	jiov[ki].iov_len = (jp_key->jp_ctltype & CTLTYPE) == CTLTYPE_STRING
615 	    ? strlen(jp_key->jp_value) + 1 : jp_key->jp_valuelen;
616 	ki++;
617 	jiov[ki].iov_base = __DECONST(char *, "errmsg");
618 	jiov[ki].iov_len = sizeof("errmsg");
619 	ki++;
620 	jiov[ki].iov_base = jail_errmsg;
621 	jiov[ki].iov_len = JAIL_ERRMSGLEN;
622 	ki++;
623 	jail_errmsg[0] = 0;
624 	if (arrays && jail_get(jiov, ki, flags) < 0) {
625 		if (!jail_errmsg[0])
626 			snprintf(jail_errmsg, sizeof(jail_errmsg),
627 			    "jail_get: %s", strerror(errno));
628 		return (-1);
629 	}
630 	/* Allocate storage for all parameters. */
631 	for (ai = j = 0, i = ki; j < njp; j++) {
632 		if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
633 			ai++;
634 			jiov[ai].iov_len += jp[j].jp_elemlen * ARRAY_SLOP;
635 			if (jp[j].jp_valuelen >= jiov[ai].iov_len)
636 				jiov[ai].iov_len = jp[j].jp_valuelen;
637 			else {
638 				jp[j].jp_valuelen = jiov[ai].iov_len;
639 				if (jp[j].jp_value != NULL)
640 					free(jp[j].jp_value);
641 				jp[j].jp_value = malloc(jp[j].jp_valuelen);
642 				if (jp[j].jp_value == NULL) {
643 					strerror_r(errno, jail_errmsg,
644 					    JAIL_ERRMSGLEN);
645 					return (-1);
646 				}
647 			}
648 			jiov[ai].iov_base = jp[j].jp_value;
649 			memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
650 			ai++;
651 		} else if (jp + j != jp_key) {
652 			jiov[i].iov_base = jp[j].jp_name;
653 			jiov[i].iov_len = strlen(jp[j].jp_name) + 1;
654 			i++;
655 			if (jp[j].jp_value == NULL &&
656 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
657 				jp[j].jp_value = malloc(jp[j].jp_valuelen);
658 				if (jp[j].jp_value == NULL) {
659 					strerror_r(errno, jail_errmsg,
660 					    JAIL_ERRMSGLEN);
661 					return (-1);
662 				}
663 			}
664 			jiov[i].iov_base = jp[j].jp_value;
665 			jiov[i].iov_len = jp[j].jp_valuelen;
666 			memset(jiov[i].iov_base, 0, jiov[i].iov_len);
667 			i++;
668 		}
669 	}
670 	/*
671 	 * Get the prison.  If there are array elements, retry a few times
672 	 * in case their sizes changed from under us.
673 	 */
674 	for (sanity = 0;; sanity++) {
675 		jid = jail_get(jiov, i, flags);
676 		if (jid >= 0 || !arrays || sanity == ARRAY_SANITY ||
677 		    errno != EINVAL || jail_errmsg[0])
678 			break;
679 		for (ai = j = 0; j < njp; j++) {
680 			if (jp[j].jp_elemlen &&
681 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
682 				ai++;
683 				jiov[ai].iov_base = NULL;
684 				jiov[ai].iov_len = 0;
685 				ai++;
686 			}
687 		}
688 		if (jail_get(jiov, ki, flags) < 0)
689 			break;
690 		for (ai = j = 0; j < njp; j++) {
691 			if (jp[j].jp_elemlen &&
692 			    !(jp[j].jp_flags & JP_RAWVALUE)) {
693 				ai++;
694 				jiov[ai].iov_len +=
695 				    jp[j].jp_elemlen * ARRAY_SLOP;
696 				if (jp[j].jp_valuelen >= jiov[ai].iov_len)
697 					jiov[ai].iov_len = jp[j].jp_valuelen;
698 				else {
699 					jp[j].jp_valuelen = jiov[ai].iov_len;
700 					if (jp[j].jp_value != NULL)
701 						free(jp[j].jp_value);
702 					jp[j].jp_value =
703 					    malloc(jiov[ai].iov_len);
704 					if (jp[j].jp_value == NULL) {
705 						strerror_r(errno, jail_errmsg,
706 						    JAIL_ERRMSGLEN);
707 						return (-1);
708 					}
709 				}
710 				jiov[ai].iov_base = jp[j].jp_value;
711 				memset(jiov[ai].iov_base, 0, jiov[ai].iov_len);
712 				ai++;
713 			}
714 		}
715 	}
716 	if (jid < 0 && !jail_errmsg[0])
717 		snprintf(jail_errmsg, sizeof(jail_errmsg),
718 		    "jail_get: %s", strerror(errno));
719 	for (ai = j = 0, i = ki; j < njp; j++) {
720 		if (jp[j].jp_elemlen && !(jp[j].jp_flags & JP_RAWVALUE)) {
721 			ai++;
722 			jp[j].jp_valuelen = jiov[ai].iov_len;
723 			ai++;
724 		} else if (jp + j != jp_key) {
725 			i++;
726 			jp[j].jp_valuelen = jiov[i].iov_len;
727 			i++;
728 		}
729 	}
730 	return (jid);
731 }
732 
733 /*
734  * Convert a jail parameter's value to external form.
735  */
736 char *
jailparam_export(struct jailparam * jp)737 jailparam_export(struct jailparam *jp)
738 {
739 	size_t *valuelens;
740 	char *value, *tvalue, **values;
741 	size_t valuelen;
742 	int i, nval, ival;
743 	char valbuf[INET6_ADDRSTRLEN];
744 
745 	if ((jp->jp_ctltype & CTLTYPE) == CTLTYPE_STRING) {
746 		value = strdup(jp->jp_value);
747 		if (value == NULL)
748 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
749 		return (value);
750 	}
751 	nval = jp->jp_elemlen ? jp->jp_valuelen / jp->jp_elemlen : 1;
752 	if (nval == 0) {
753 		value = strdup("");
754 		if (value == NULL)
755 			strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
756 		return (value);
757 	}
758 	values = alloca(nval * sizeof(char *));
759 	valuelens = alloca(nval * sizeof(size_t));
760 	valuelen = 0;
761 	for (i = 0; i < nval; i++) {
762 		switch (jp->jp_ctltype & CTLTYPE) {
763 		case CTLTYPE_INT:
764 			ival = ((int *)jp->jp_value)[i];
765 			if ((jp->jp_flags & (JP_BOOL | JP_NOBOOL)) &&
766 			    (unsigned)ival < 2) {
767 				strlcpy(valbuf, bool_values[ival],
768 				    sizeof(valbuf));
769 				break;
770 			}
771 			if ((jp->jp_flags & JP_JAILSYS) &&
772 			    (unsigned)ival < sizeof(jailsys_values) /
773 			    sizeof(jailsys_values[0])) {
774 				strlcpy(valbuf, jailsys_values[ival],
775 				    sizeof(valbuf));
776 				break;
777 			}
778 			snprintf(valbuf, sizeof(valbuf), "%d", ival);
779 			break;
780 		case CTLTYPE_UINT:
781 			snprintf(valbuf, sizeof(valbuf), "%u",
782 			    ((unsigned *)jp->jp_value)[i]);
783 			break;
784 		case CTLTYPE_LONG:
785 			snprintf(valbuf, sizeof(valbuf), "%ld",
786 			    ((long *)jp->jp_value)[i]);
787 			break;
788 		case CTLTYPE_ULONG:
789 			snprintf(valbuf, sizeof(valbuf), "%lu",
790 			    ((unsigned long *)jp->jp_value)[i]);
791 			break;
792 		case CTLTYPE_S64:
793 			snprintf(valbuf, sizeof(valbuf), "%jd",
794 			    (intmax_t)((int64_t *)jp->jp_value)[i]);
795 			break;
796 		case CTLTYPE_U64:
797 			snprintf(valbuf, sizeof(valbuf), "%ju",
798 			    (uintmax_t)((uint64_t *)jp->jp_value)[i]);
799 			break;
800 		case CTLTYPE_STRUCT:
801 			switch (jp->jp_structtype) {
802 			case JPS_IN_ADDR:
803 				if (inet_ntop(AF_INET,
804 				    &((struct in_addr *)jp->jp_value)[i],
805 				    valbuf, sizeof(valbuf)) == NULL) {
806 					strerror_r(errno, jail_errmsg,
807 					    JAIL_ERRMSGLEN);
808 					return (NULL);
809 				}
810 				break;
811 			case JPS_IN6_ADDR:
812 				if (inet_ntop(AF_INET6,
813 				    &((struct in6_addr *)jp->jp_value)[i],
814 				    valbuf, sizeof(valbuf)) == NULL) {
815 					strerror_r(errno, jail_errmsg,
816 					    JAIL_ERRMSGLEN);
817 					return (NULL);
818 				}
819 				break;
820 			default:
821 				goto unknown_type;
822 			}
823 			break;
824 		default:
825 		unknown_type:
826 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
827 			    "unknown type for %s", jp->jp_name);
828 			errno = ENOENT;
829 			return (NULL);
830 		}
831 		valuelens[i] = strlen(valbuf) + 1;
832 		valuelen += valuelens[i];
833 		values[i] = alloca(valuelens[i]);
834 		strcpy(values[i], valbuf);
835 	}
836 	value = malloc(valuelen);
837 	if (value == NULL)
838 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
839 	else {
840 		tvalue = value;
841 		for (i = 0; i < nval; i++) {
842 			strcpy(tvalue, values[i]);
843 			if (i < nval - 1) {
844 				tvalue += valuelens[i];
845 				tvalue[-1] = ',';
846 			}
847 		}
848 	}
849 	return (value);
850 }
851 
852 /*
853  * Free the contents of a jail parameter list (but not the list itself).
854  */
855 void
jailparam_free(struct jailparam * jp,unsigned njp)856 jailparam_free(struct jailparam *jp, unsigned njp)
857 {
858 	unsigned j;
859 
860 	for (j = 0; j < njp; j++) {
861 		free(jp[j].jp_name);
862 		if (!(jp[j].jp_flags & JP_RAWVALUE))
863 			free(jp[j].jp_value);
864 	}
865 }
866 
867 /*
868  * Find a parameter's type and size from its MIB.
869  */
870 static int
jailparam_type(struct jailparam * jp)871 jailparam_type(struct jailparam *jp)
872 {
873 	char *p, *name, *nname;
874 	size_t miblen, desclen;
875 	int i, isarray;
876 	struct {
877 	    int i;
878 	    char s[MAXPATHLEN];
879 	} desc;
880 	int mib[CTL_MAXNAME];
881 
882 	/* The "lastjid" parameter isn't real. */
883 	name = jp->jp_name;
884 	if (!strcmp(name, "lastjid")) {
885 		jp->jp_valuelen = sizeof(int);
886 		jp->jp_ctltype = CTLTYPE_INT | CTLFLAG_WR;
887 		return (0);
888 	}
889 
890 	/* Find the sysctl that describes the parameter. */
891 	mib[0] = 0;
892 	mib[1] = 3;
893 	snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", name);
894 	miblen = sizeof(mib) - 2 * sizeof(int);
895 	if (sysctl(mib, 2, mib + 2, &miblen, desc.s, strlen(desc.s)) < 0) {
896 		if (errno != ENOENT) {
897 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
898 			    "sysctl(0.3.%s): %s", name, strerror(errno));
899 			return (-1);
900 		}
901 		if (kldload_param(name) >= 0 && sysctl(mib, 2, mib + 2, &miblen,
902 		    desc.s, strlen(desc.s)) >= 0)
903 			goto mib_desc;
904 		/*
905 		 * The parameter probably doesn't exist.  But it might be
906 		 * the "no" counterpart to a boolean.
907 		 */
908 		nname = nononame(name);
909 		if (nname == NULL) {
910 		unknown_parameter:
911 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
912 			    "unknown parameter: %s", jp->jp_name);
913 			errno = ENOENT;
914 			return (-1);
915 		}
916 		name = alloca(strlen(nname) + 1);
917 		strcpy(name, nname);
918 		free(nname);
919 		snprintf(desc.s, sizeof(desc.s), SJPARAM ".%s", name);
920 		miblen = sizeof(mib) - 2 * sizeof(int);
921 		if (sysctl(mib, 2, mib + 2, &miblen, desc.s,
922 		    strlen(desc.s)) < 0)
923 			goto unknown_parameter;
924 		jp->jp_flags |= JP_NOBOOL;
925 	}
926  mib_desc:
927 	mib[1] = 4;
928 	desclen = sizeof(desc);
929 	if (sysctl(mib, (miblen / sizeof(int)) + 2, &desc, &desclen,
930 	    NULL, 0) < 0) {
931 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
932 		    "sysctl(0.4.%s): %s", name, strerror(errno));
933 		return (-1);
934 	}
935 	jp->jp_ctltype = desc.i;
936 	/* If this came from removing a "no", it better be a boolean. */
937 	if (jp->jp_flags & JP_NOBOOL) {
938 		if ((desc.i & CTLTYPE) == CTLTYPE_INT && desc.s[0] == 'B') {
939 			jp->jp_valuelen = sizeof(int);
940 			return (0);
941 		}
942 		else if ((desc.i & CTLTYPE) != CTLTYPE_NODE)
943 			goto unknown_parameter;
944 	}
945 	/* See if this is an array type. */
946 	p = strchr(desc.s, '\0');
947 	isarray  = 0;
948 	if (p - 2 < desc.s || strcmp(p - 2, ",a"))
949 		isarray = 0;
950 	else {
951 		isarray = 1;
952 		p[-2] = 0;
953 	}
954 	/* Look for types we understand. */
955 	switch (desc.i & CTLTYPE) {
956 	case CTLTYPE_INT:
957 		if (desc.s[0] == 'B')
958 			jp->jp_flags |= JP_BOOL;
959 		else if (!strcmp(desc.s, "E,jailsys"))
960 			jp->jp_flags |= JP_JAILSYS;
961 	case CTLTYPE_UINT:
962 		jp->jp_valuelen = sizeof(int);
963 		break;
964 	case CTLTYPE_LONG:
965 	case CTLTYPE_ULONG:
966 		jp->jp_valuelen = sizeof(long);
967 		break;
968 	case CTLTYPE_S64:
969 	case CTLTYPE_U64:
970 		jp->jp_valuelen = sizeof(int64_t);
971 		break;
972 	case CTLTYPE_STRING:
973 		desc.s[0] = 0;
974 		desclen = sizeof(desc.s);
975 		if (sysctl(mib + 2, miblen / sizeof(int), desc.s, &desclen,
976 		    NULL, 0) < 0) {
977 			snprintf(jail_errmsg, JAIL_ERRMSGLEN,
978 			    "sysctl(" SJPARAM ".%s): %s", name,
979 			    strerror(errno));
980 			return (-1);
981 		}
982 		jp->jp_valuelen = strtoul(desc.s, NULL, 10);
983 		break;
984 	case CTLTYPE_STRUCT:
985 		if (!strcmp(desc.s, "S,in_addr")) {
986 			jp->jp_structtype = JPS_IN_ADDR;
987 			jp->jp_valuelen = sizeof(struct in_addr);
988 		} else if (!strcmp(desc.s, "S,in6_addr")) {
989 			jp->jp_structtype = JPS_IN6_ADDR;
990 			jp->jp_valuelen = sizeof(struct in6_addr);
991 		} else {
992 			desclen = 0;
993 			if (sysctl(mib + 2, miblen / sizeof(int),
994 			    NULL, &jp->jp_valuelen, NULL, 0) < 0) {
995 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
996 				    "sysctl(" SJPARAM ".%s): %s", name,
997 				    strerror(errno));
998 				return (-1);
999 			}
1000 		}
1001 		break;
1002 	case CTLTYPE_NODE:
1003 		/*
1004 		 * A node might be described by an empty-named child,
1005 		 * which would be immediately before or after the node itself.
1006 		 */
1007 		mib[1] = 1;
1008 		miblen += sizeof(int);
1009 		for (i = -1; i <= 1; i += 2) {
1010 			mib[(miblen / sizeof(int)) + 1] =
1011 			    mib[(miblen / sizeof(int))] + i;
1012 			desclen = sizeof(desc.s);
1013 			if (sysctl(mib, (miblen / sizeof(int)) + 2, desc.s,
1014 			    &desclen, NULL, 0) < 0) {
1015 				if (errno == ENOENT)
1016 					continue;
1017 				snprintf(jail_errmsg, JAIL_ERRMSGLEN,
1018 				    "sysctl(0.1): %s", strerror(errno));
1019 				return (-1);
1020 			}
1021 			if (desclen == sizeof(SJPARAM) + strlen(name) + 2 &&
1022 			    memcmp(SJPARAM ".", desc.s, sizeof(SJPARAM)) == 0 &&
1023 			    memcmp(name, desc.s + sizeof(SJPARAM),
1024 			    desclen - sizeof(SJPARAM) - 2) == 0 &&
1025 			    desc.s[desclen - 2] == '.')
1026 				goto mib_desc;
1027 		}
1028 		goto unknown_parameter;
1029 	default:
1030 		snprintf(jail_errmsg, JAIL_ERRMSGLEN,
1031 		    "unknown type for %s", jp->jp_name);
1032 		errno = ENOENT;
1033 		return (-1);
1034 	}
1035 	if (isarray) {
1036 		jp->jp_elemlen = jp->jp_valuelen;
1037 		jp->jp_valuelen = 0;
1038 	}
1039 	return (0);
1040 }
1041 
1042 /*
1043  * Attempt to load a kernel module matching an otherwise nonexistent parameter.
1044  */
1045 static int
kldload_param(const char * name)1046 kldload_param(const char *name)
1047 {
1048 	int kl;
1049 
1050 	if (strcmp(name, "linux") == 0 || strncmp(name, "linux.", 6) == 0)
1051 		kl = kldload("linux");
1052 	else if (strcmp(name, "sysvmsg") == 0 || strcmp(name, "sysvsem") == 0 ||
1053 	    strcmp(name, "sysvshm") == 0)
1054 		kl = kldload(name);
1055 	else {
1056 		errno = ENOENT;
1057 		return (-1);
1058 	}
1059 	if (kl < 0 && errno == EEXIST) {
1060 		/*
1061 		 * In the module is already loaded, then it must not contain
1062 		 * the parameter.
1063 		 */
1064 		errno = ENOENT;
1065 	}
1066 	return kl;
1067 }
1068 
1069 /*
1070  * Change a boolean parameter name into its "no" counterpart or vice versa.
1071  */
1072 static char *
noname(const char * name)1073 noname(const char *name)
1074 {
1075 	char *nname, *p;
1076 
1077 	nname = malloc(strlen(name) + 3);
1078 	if (nname == NULL) {
1079 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
1080 		return (NULL);
1081 	}
1082 	p = strrchr(name, '.');
1083 	if (p != NULL)
1084 		sprintf(nname, "%.*s.no%s", (int)(p - name), name, p + 1);
1085 	else
1086 		sprintf(nname, "no%s", name);
1087 	return (nname);
1088 }
1089 
1090 static char *
nononame(const char * name)1091 nononame(const char *name)
1092 {
1093 	char *p, *nname;
1094 
1095 	p = strrchr(name, '.');
1096 	if (strncmp(p ? p + 1 : name, "no", 2)) {
1097 		snprintf(jail_errmsg, sizeof(jail_errmsg),
1098 		    "mismatched boolean: %s", name);
1099 		errno = EINVAL;
1100 		return (NULL);
1101 	}
1102 	nname = malloc(strlen(name) - 1);
1103 	if (nname == NULL) {
1104 		strerror_r(errno, jail_errmsg, JAIL_ERRMSGLEN);
1105 		return (NULL);
1106 	}
1107 	if (p != NULL)
1108 		sprintf(nname, "%.*s.%s", (int)(p - name), name, p + 3);
1109 	else
1110 		strcpy(nname, name + 2);
1111 	return (nname);
1112 }
1113