1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2012-2013 The FreeBSD Foundation
5 * All rights reserved.
6 *
7 * This software was developed by Pawel Jakub Dawidek under sponsorship from
8 * the FreeBSD Foundation.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD: stable/12/lib/libcasper/services/cap_dns/cap_dns.c 352189 2019-09-10 20:49:47Z oshogbo $");
34
35 #include <sys/dnv.h>
36 #include <sys/nv.h>
37 #include <netinet/in.h>
38
39 #include <assert.h>
40 #include <errno.h>
41 #include <netdb.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45
46 #include <libcasper.h>
47 #include <libcasper_service.h>
48
49 #include "cap_dns.h"
50
51 static struct hostent hent;
52
53 static void
hostent_free(struct hostent * hp)54 hostent_free(struct hostent *hp)
55 {
56 unsigned int ii;
57
58 free(hp->h_name);
59 hp->h_name = NULL;
60 if (hp->h_aliases != NULL) {
61 for (ii = 0; hp->h_aliases[ii] != NULL; ii++)
62 free(hp->h_aliases[ii]);
63 free(hp->h_aliases);
64 hp->h_aliases = NULL;
65 }
66 if (hp->h_addr_list != NULL) {
67 for (ii = 0; hp->h_addr_list[ii] != NULL; ii++)
68 free(hp->h_addr_list[ii]);
69 free(hp->h_addr_list);
70 hp->h_addr_list = NULL;
71 }
72 }
73
74 static struct hostent *
hostent_unpack(const nvlist_t * nvl,struct hostent * hp)75 hostent_unpack(const nvlist_t *nvl, struct hostent *hp)
76 {
77 unsigned int ii, nitems;
78 char nvlname[64];
79 int n;
80
81 hostent_free(hp);
82
83 hp->h_name = strdup(nvlist_get_string(nvl, "name"));
84 if (hp->h_name == NULL)
85 goto fail;
86 hp->h_addrtype = (int)nvlist_get_number(nvl, "addrtype");
87 hp->h_length = (int)nvlist_get_number(nvl, "length");
88
89 nitems = (unsigned int)nvlist_get_number(nvl, "naliases");
90 hp->h_aliases = calloc(sizeof(hp->h_aliases[0]), nitems + 1);
91 if (hp->h_aliases == NULL)
92 goto fail;
93 for (ii = 0; ii < nitems; ii++) {
94 n = snprintf(nvlname, sizeof(nvlname), "alias%u", ii);
95 assert(n > 0 && n < (int)sizeof(nvlname));
96 hp->h_aliases[ii] =
97 strdup(nvlist_get_string(nvl, nvlname));
98 if (hp->h_aliases[ii] == NULL)
99 goto fail;
100 }
101 hp->h_aliases[ii] = NULL;
102
103 nitems = (unsigned int)nvlist_get_number(nvl, "naddrs");
104 hp->h_addr_list = calloc(sizeof(hp->h_addr_list[0]), nitems + 1);
105 if (hp->h_addr_list == NULL)
106 goto fail;
107 for (ii = 0; ii < nitems; ii++) {
108 hp->h_addr_list[ii] = malloc(hp->h_length);
109 if (hp->h_addr_list[ii] == NULL)
110 goto fail;
111 n = snprintf(nvlname, sizeof(nvlname), "addr%u", ii);
112 assert(n > 0 && n < (int)sizeof(nvlname));
113 bcopy(nvlist_get_binary(nvl, nvlname, NULL),
114 hp->h_addr_list[ii], hp->h_length);
115 }
116 hp->h_addr_list[ii] = NULL;
117
118 return (hp);
119 fail:
120 hostent_free(hp);
121 h_errno = NO_RECOVERY;
122 return (NULL);
123 }
124
125 struct hostent *
cap_gethostbyname(cap_channel_t * chan,const char * name)126 cap_gethostbyname(cap_channel_t *chan, const char *name)
127 {
128
129 return (cap_gethostbyname2(chan, name, AF_INET));
130 }
131
132 struct hostent *
cap_gethostbyname2(cap_channel_t * chan,const char * name,int type)133 cap_gethostbyname2(cap_channel_t *chan, const char *name, int type)
134 {
135 struct hostent *hp;
136 nvlist_t *nvl;
137
138 nvl = nvlist_create(0);
139 nvlist_add_string(nvl, "cmd", "gethostbyname");
140 nvlist_add_number(nvl, "family", (uint64_t)type);
141 nvlist_add_string(nvl, "name", name);
142 nvl = cap_xfer_nvlist(chan, nvl);
143 if (nvl == NULL) {
144 h_errno = NO_RECOVERY;
145 return (NULL);
146 }
147 if (nvlist_get_number(nvl, "error") != 0) {
148 h_errno = (int)nvlist_get_number(nvl, "error");
149 nvlist_destroy(nvl);
150 return (NULL);
151 }
152
153 hp = hostent_unpack(nvl, &hent);
154 nvlist_destroy(nvl);
155 return (hp);
156 }
157
158 struct hostent *
cap_gethostbyaddr(cap_channel_t * chan,const void * addr,socklen_t len,int type)159 cap_gethostbyaddr(cap_channel_t *chan, const void *addr, socklen_t len,
160 int type)
161 {
162 struct hostent *hp;
163 nvlist_t *nvl;
164
165 nvl = nvlist_create(0);
166 nvlist_add_string(nvl, "cmd", "gethostbyaddr");
167 nvlist_add_binary(nvl, "addr", addr, (size_t)len);
168 nvlist_add_number(nvl, "family", (uint64_t)type);
169 nvl = cap_xfer_nvlist(chan, nvl);
170 if (nvl == NULL) {
171 h_errno = NO_RECOVERY;
172 return (NULL);
173 }
174 if (nvlist_get_number(nvl, "error") != 0) {
175 h_errno = (int)nvlist_get_number(nvl, "error");
176 nvlist_destroy(nvl);
177 return (NULL);
178 }
179 hp = hostent_unpack(nvl, &hent);
180 nvlist_destroy(nvl);
181 return (hp);
182 }
183
184 static struct addrinfo *
addrinfo_unpack(const nvlist_t * nvl)185 addrinfo_unpack(const nvlist_t *nvl)
186 {
187 struct addrinfo *ai;
188 const void *addr;
189 size_t addrlen;
190 const char *canonname;
191
192 addr = nvlist_get_binary(nvl, "ai_addr", &addrlen);
193 ai = malloc(sizeof(*ai) + addrlen);
194 if (ai == NULL)
195 return (NULL);
196 ai->ai_flags = (int)nvlist_get_number(nvl, "ai_flags");
197 ai->ai_family = (int)nvlist_get_number(nvl, "ai_family");
198 ai->ai_socktype = (int)nvlist_get_number(nvl, "ai_socktype");
199 ai->ai_protocol = (int)nvlist_get_number(nvl, "ai_protocol");
200 ai->ai_addrlen = (socklen_t)addrlen;
201 canonname = dnvlist_get_string(nvl, "ai_canonname", NULL);
202 if (canonname != NULL) {
203 ai->ai_canonname = strdup(canonname);
204 if (ai->ai_canonname == NULL) {
205 free(ai);
206 return (NULL);
207 }
208 } else {
209 ai->ai_canonname = NULL;
210 }
211 ai->ai_addr = (void *)(ai + 1);
212 bcopy(addr, ai->ai_addr, addrlen);
213 ai->ai_next = NULL;
214
215 return (ai);
216 }
217
218 int
cap_getaddrinfo(cap_channel_t * chan,const char * hostname,const char * servname,const struct addrinfo * hints,struct addrinfo ** res)219 cap_getaddrinfo(cap_channel_t *chan, const char *hostname, const char *servname,
220 const struct addrinfo *hints, struct addrinfo **res)
221 {
222 struct addrinfo *firstai, *prevai, *curai;
223 unsigned int ii;
224 const nvlist_t *nvlai;
225 char nvlname[64];
226 nvlist_t *nvl;
227 int error, n;
228
229 nvl = nvlist_create(0);
230 nvlist_add_string(nvl, "cmd", "getaddrinfo");
231 if (hostname != NULL)
232 nvlist_add_string(nvl, "hostname", hostname);
233 if (servname != NULL)
234 nvlist_add_string(nvl, "servname", servname);
235 if (hints != NULL) {
236 nvlist_add_number(nvl, "hints.ai_flags",
237 (uint64_t)hints->ai_flags);
238 nvlist_add_number(nvl, "hints.ai_family",
239 (uint64_t)hints->ai_family);
240 nvlist_add_number(nvl, "hints.ai_socktype",
241 (uint64_t)hints->ai_socktype);
242 nvlist_add_number(nvl, "hints.ai_protocol",
243 (uint64_t)hints->ai_protocol);
244 }
245 nvl = cap_xfer_nvlist(chan, nvl);
246 if (nvl == NULL)
247 return (EAI_MEMORY);
248 if (nvlist_get_number(nvl, "error") != 0) {
249 error = (int)nvlist_get_number(nvl, "error");
250 nvlist_destroy(nvl);
251 return (error);
252 }
253
254 nvlai = NULL;
255 firstai = prevai = curai = NULL;
256 for (ii = 0; ; ii++) {
257 n = snprintf(nvlname, sizeof(nvlname), "res%u", ii);
258 assert(n > 0 && n < (int)sizeof(nvlname));
259 if (!nvlist_exists_nvlist(nvl, nvlname))
260 break;
261 nvlai = nvlist_get_nvlist(nvl, nvlname);
262 curai = addrinfo_unpack(nvlai);
263 if (curai == NULL)
264 break;
265 if (prevai != NULL)
266 prevai->ai_next = curai;
267 else if (firstai == NULL)
268 firstai = curai;
269 prevai = curai;
270 }
271 nvlist_destroy(nvl);
272 if (curai == NULL && nvlai != NULL) {
273 if (firstai == NULL)
274 freeaddrinfo(firstai);
275 return (EAI_MEMORY);
276 }
277
278 *res = firstai;
279 return (0);
280 }
281
282 int
cap_getnameinfo(cap_channel_t * chan,const struct sockaddr * sa,socklen_t salen,char * host,size_t hostlen,char * serv,size_t servlen,int flags)283 cap_getnameinfo(cap_channel_t *chan, const struct sockaddr *sa, socklen_t salen,
284 char *host, size_t hostlen, char *serv, size_t servlen, int flags)
285 {
286 nvlist_t *nvl;
287 int error;
288
289 nvl = nvlist_create(0);
290 nvlist_add_string(nvl, "cmd", "getnameinfo");
291 nvlist_add_number(nvl, "hostlen", (uint64_t)hostlen);
292 nvlist_add_number(nvl, "servlen", (uint64_t)servlen);
293 nvlist_add_binary(nvl, "sa", sa, (size_t)salen);
294 nvlist_add_number(nvl, "flags", (uint64_t)flags);
295 nvl = cap_xfer_nvlist(chan, nvl);
296 if (nvl == NULL)
297 return (EAI_MEMORY);
298 if (nvlist_get_number(nvl, "error") != 0) {
299 error = (int)nvlist_get_number(nvl, "error");
300 nvlist_destroy(nvl);
301 return (error);
302 }
303
304 if (host != NULL && nvlist_exists_string(nvl, "host"))
305 strlcpy(host, nvlist_get_string(nvl, "host"), hostlen + 1);
306 if (serv != NULL && nvlist_exists_string(nvl, "serv"))
307 strlcpy(serv, nvlist_get_string(nvl, "serv"), servlen + 1);
308 nvlist_destroy(nvl);
309 return (0);
310 }
311
312 static void
limit_remove(nvlist_t * limits,const char * prefix)313 limit_remove(nvlist_t *limits, const char *prefix)
314 {
315 const char *name;
316 size_t prefixlen;
317 void *cookie;
318
319 prefixlen = strlen(prefix);
320 again:
321 cookie = NULL;
322 while ((name = nvlist_next(limits, NULL, &cookie)) != NULL) {
323 if (strncmp(name, prefix, prefixlen) == 0) {
324 nvlist_free(limits, name);
325 goto again;
326 }
327 }
328 }
329
330 int
cap_dns_type_limit(cap_channel_t * chan,const char * const * types,size_t ntypes)331 cap_dns_type_limit(cap_channel_t *chan, const char * const *types,
332 size_t ntypes)
333 {
334 nvlist_t *limits;
335 unsigned int i;
336 char nvlname[64];
337 int n;
338
339 if (cap_limit_get(chan, &limits) < 0)
340 return (-1);
341 if (limits == NULL)
342 limits = nvlist_create(0);
343 else
344 limit_remove(limits, "type");
345 for (i = 0; i < ntypes; i++) {
346 n = snprintf(nvlname, sizeof(nvlname), "type%u", i);
347 assert(n > 0 && n < (int)sizeof(nvlname));
348 nvlist_add_string(limits, nvlname, types[i]);
349 }
350 return (cap_limit_set(chan, limits));
351 }
352
353 int
cap_dns_family_limit(cap_channel_t * chan,const int * families,size_t nfamilies)354 cap_dns_family_limit(cap_channel_t *chan, const int *families,
355 size_t nfamilies)
356 {
357 nvlist_t *limits;
358 unsigned int i;
359 char nvlname[64];
360 int n;
361
362 if (cap_limit_get(chan, &limits) < 0)
363 return (-1);
364 if (limits == NULL)
365 limits = nvlist_create(0);
366 else
367 limit_remove(limits, "family");
368 for (i = 0; i < nfamilies; i++) {
369 n = snprintf(nvlname, sizeof(nvlname), "family%u", i);
370 assert(n > 0 && n < (int)sizeof(nvlname));
371 nvlist_add_number(limits, nvlname, (uint64_t)families[i]);
372 }
373 return (cap_limit_set(chan, limits));
374 }
375
376 /*
377 * Service functions.
378 */
379 static bool
dns_allowed_type(const nvlist_t * limits,const char * type)380 dns_allowed_type(const nvlist_t *limits, const char *type)
381 {
382 const char *name;
383 bool notypes;
384 void *cookie;
385
386 if (limits == NULL)
387 return (true);
388
389 notypes = true;
390 cookie = NULL;
391 while ((name = nvlist_next(limits, NULL, &cookie)) != NULL) {
392 if (strncmp(name, "type", sizeof("type") - 1) != 0)
393 continue;
394 notypes = false;
395 if (strcmp(nvlist_get_string(limits, name), type) == 0)
396 return (true);
397 }
398
399 /* If there are no types at all, allow any type. */
400 if (notypes)
401 return (true);
402
403 return (false);
404 }
405
406 static bool
dns_allowed_family(const nvlist_t * limits,int family)407 dns_allowed_family(const nvlist_t *limits, int family)
408 {
409 const char *name;
410 bool nofamilies;
411 void *cookie;
412
413 if (limits == NULL)
414 return (true);
415
416 nofamilies = true;
417 cookie = NULL;
418 while ((name = nvlist_next(limits, NULL, &cookie)) != NULL) {
419 if (strncmp(name, "family", sizeof("family") - 1) != 0)
420 continue;
421 nofamilies = false;
422 if (family == AF_UNSPEC)
423 continue;
424 if (nvlist_get_number(limits, name) == (uint64_t)family)
425 return (true);
426 }
427
428 /* If there are no families at all, allow any family. */
429 if (nofamilies)
430 return (true);
431
432 return (false);
433 }
434
435 static void
hostent_pack(const struct hostent * hp,nvlist_t * nvl)436 hostent_pack(const struct hostent *hp, nvlist_t *nvl)
437 {
438 unsigned int ii;
439 char nvlname[64];
440 int n;
441
442 nvlist_add_string(nvl, "name", hp->h_name);
443 nvlist_add_number(nvl, "addrtype", (uint64_t)hp->h_addrtype);
444 nvlist_add_number(nvl, "length", (uint64_t)hp->h_length);
445
446 if (hp->h_aliases == NULL) {
447 nvlist_add_number(nvl, "naliases", 0);
448 } else {
449 for (ii = 0; hp->h_aliases[ii] != NULL; ii++) {
450 n = snprintf(nvlname, sizeof(nvlname), "alias%u", ii);
451 assert(n > 0 && n < (int)sizeof(nvlname));
452 nvlist_add_string(nvl, nvlname, hp->h_aliases[ii]);
453 }
454 nvlist_add_number(nvl, "naliases", (uint64_t)ii);
455 }
456
457 if (hp->h_addr_list == NULL) {
458 nvlist_add_number(nvl, "naddrs", 0);
459 } else {
460 for (ii = 0; hp->h_addr_list[ii] != NULL; ii++) {
461 n = snprintf(nvlname, sizeof(nvlname), "addr%u", ii);
462 assert(n > 0 && n < (int)sizeof(nvlname));
463 nvlist_add_binary(nvl, nvlname, hp->h_addr_list[ii],
464 (size_t)hp->h_length);
465 }
466 nvlist_add_number(nvl, "naddrs", (uint64_t)ii);
467 }
468 }
469
470 static int
dns_gethostbyname(const nvlist_t * limits,const nvlist_t * nvlin,nvlist_t * nvlout)471 dns_gethostbyname(const nvlist_t *limits, const nvlist_t *nvlin,
472 nvlist_t *nvlout)
473 {
474 struct hostent *hp;
475 int family;
476
477 if (!dns_allowed_type(limits, "NAME2ADDR") &&
478 !dns_allowed_type(limits, "NAME"))
479 return (NO_RECOVERY);
480
481 family = (int)nvlist_get_number(nvlin, "family");
482
483 if (!dns_allowed_family(limits, family))
484 return (NO_RECOVERY);
485
486 hp = gethostbyname2(nvlist_get_string(nvlin, "name"), family);
487 if (hp == NULL)
488 return (h_errno);
489 hostent_pack(hp, nvlout);
490 return (0);
491 }
492
493 static int
dns_gethostbyaddr(const nvlist_t * limits,const nvlist_t * nvlin,nvlist_t * nvlout)494 dns_gethostbyaddr(const nvlist_t *limits, const nvlist_t *nvlin,
495 nvlist_t *nvlout)
496 {
497 struct hostent *hp;
498 const void *addr;
499 size_t addrsize;
500 int family;
501
502 if (!dns_allowed_type(limits, "ADDR2NAME") &&
503 !dns_allowed_type(limits, "ADDR"))
504 return (NO_RECOVERY);
505
506 family = (int)nvlist_get_number(nvlin, "family");
507
508 if (!dns_allowed_family(limits, family))
509 return (NO_RECOVERY);
510
511 addr = nvlist_get_binary(nvlin, "addr", &addrsize);
512 hp = gethostbyaddr(addr, (socklen_t)addrsize, family);
513 if (hp == NULL)
514 return (h_errno);
515 hostent_pack(hp, nvlout);
516 return (0);
517 }
518
519 static int
dns_getnameinfo(const nvlist_t * limits,const nvlist_t * nvlin,nvlist_t * nvlout)520 dns_getnameinfo(const nvlist_t *limits, const nvlist_t *nvlin, nvlist_t *nvlout)
521 {
522 struct sockaddr_storage sast;
523 const void *sabin;
524 char *host, *serv;
525 size_t sabinsize, hostlen, servlen;
526 socklen_t salen;
527 int error, flags;
528
529 if (!dns_allowed_type(limits, "ADDR2NAME") &&
530 !dns_allowed_type(limits, "ADDR"))
531 return (NO_RECOVERY);
532
533 error = 0;
534 host = serv = NULL;
535 memset(&sast, 0, sizeof(sast));
536
537 hostlen = (size_t)nvlist_get_number(nvlin, "hostlen");
538 servlen = (size_t)nvlist_get_number(nvlin, "servlen");
539
540 if (hostlen > 0) {
541 host = calloc(1, hostlen + 1);
542 if (host == NULL) {
543 error = EAI_MEMORY;
544 goto out;
545 }
546 }
547 if (servlen > 0) {
548 serv = calloc(1, servlen + 1);
549 if (serv == NULL) {
550 error = EAI_MEMORY;
551 goto out;
552 }
553 }
554
555 sabin = nvlist_get_binary(nvlin, "sa", &sabinsize);
556 if (sabinsize > sizeof(sast)) {
557 error = EAI_FAIL;
558 goto out;
559 }
560
561 memcpy(&sast, sabin, sabinsize);
562 salen = (socklen_t)sabinsize;
563
564 if ((sast.ss_family != AF_INET ||
565 salen != sizeof(struct sockaddr_in)) &&
566 (sast.ss_family != AF_INET6 ||
567 salen != sizeof(struct sockaddr_in6))) {
568 error = EAI_FAIL;
569 goto out;
570 }
571
572 if (!dns_allowed_family(limits, (int)sast.ss_family)) {
573 error = NO_RECOVERY;
574 goto out;
575 }
576
577 flags = (int)nvlist_get_number(nvlin, "flags");
578
579 error = getnameinfo((struct sockaddr *)&sast, salen, host, hostlen,
580 serv, servlen, flags);
581 if (error != 0)
582 goto out;
583
584 if (host != NULL)
585 nvlist_move_string(nvlout, "host", host);
586 if (serv != NULL)
587 nvlist_move_string(nvlout, "serv", serv);
588 out:
589 if (error != 0) {
590 free(host);
591 free(serv);
592 }
593 return (error);
594 }
595
596 static nvlist_t *
addrinfo_pack(const struct addrinfo * ai)597 addrinfo_pack(const struct addrinfo *ai)
598 {
599 nvlist_t *nvl;
600
601 nvl = nvlist_create(0);
602 nvlist_add_number(nvl, "ai_flags", (uint64_t)ai->ai_flags);
603 nvlist_add_number(nvl, "ai_family", (uint64_t)ai->ai_family);
604 nvlist_add_number(nvl, "ai_socktype", (uint64_t)ai->ai_socktype);
605 nvlist_add_number(nvl, "ai_protocol", (uint64_t)ai->ai_protocol);
606 nvlist_add_binary(nvl, "ai_addr", ai->ai_addr, (size_t)ai->ai_addrlen);
607 if (ai->ai_canonname != NULL)
608 nvlist_add_string(nvl, "ai_canonname", ai->ai_canonname);
609
610 return (nvl);
611 }
612
613 static int
dns_getaddrinfo(const nvlist_t * limits,const nvlist_t * nvlin,nvlist_t * nvlout)614 dns_getaddrinfo(const nvlist_t *limits, const nvlist_t *nvlin, nvlist_t *nvlout)
615 {
616 struct addrinfo hints, *hintsp, *res, *cur;
617 const char *hostname, *servname;
618 char nvlname[64];
619 nvlist_t *elem;
620 unsigned int ii;
621 int error, family, n;
622
623 if (!dns_allowed_type(limits, "NAME2ADDR") &&
624 !dns_allowed_type(limits, "NAME"))
625 return (NO_RECOVERY);
626
627 hostname = dnvlist_get_string(nvlin, "hostname", NULL);
628 servname = dnvlist_get_string(nvlin, "servname", NULL);
629 if (nvlist_exists_number(nvlin, "hints.ai_flags")) {
630 hints.ai_flags = (int)nvlist_get_number(nvlin,
631 "hints.ai_flags");
632 hints.ai_family = (int)nvlist_get_number(nvlin,
633 "hints.ai_family");
634 hints.ai_socktype = (int)nvlist_get_number(nvlin,
635 "hints.ai_socktype");
636 hints.ai_protocol = (int)nvlist_get_number(nvlin,
637 "hints.ai_protocol");
638 hints.ai_addrlen = 0;
639 hints.ai_addr = NULL;
640 hints.ai_canonname = NULL;
641 hints.ai_next = NULL;
642 hintsp = &hints;
643 family = hints.ai_family;
644 } else {
645 hintsp = NULL;
646 family = AF_UNSPEC;
647 }
648
649 if (!dns_allowed_family(limits, family))
650 return (NO_RECOVERY);
651
652 error = getaddrinfo(hostname, servname, hintsp, &res);
653 if (error != 0)
654 goto out;
655
656 for (cur = res, ii = 0; cur != NULL; cur = cur->ai_next, ii++) {
657 elem = addrinfo_pack(cur);
658 n = snprintf(nvlname, sizeof(nvlname), "res%u", ii);
659 assert(n > 0 && n < (int)sizeof(nvlname));
660 nvlist_move_nvlist(nvlout, nvlname, elem);
661 }
662
663 freeaddrinfo(res);
664 error = 0;
665 out:
666 return (error);
667 }
668
669 static bool
limit_has_entry(const nvlist_t * limits,const char * prefix)670 limit_has_entry(const nvlist_t *limits, const char *prefix)
671 {
672 const char *name;
673 size_t prefixlen;
674 void *cookie;
675
676 if (limits == NULL)
677 return (false);
678
679 prefixlen = strlen(prefix);
680
681 cookie = NULL;
682 while ((name = nvlist_next(limits, NULL, &cookie)) != NULL) {
683 if (strncmp(name, prefix, prefixlen) == 0)
684 return (true);
685 }
686
687 return (false);
688 }
689
690 static int
dns_limit(const nvlist_t * oldlimits,const nvlist_t * newlimits)691 dns_limit(const nvlist_t *oldlimits, const nvlist_t *newlimits)
692 {
693 const char *name;
694 void *cookie;
695 int nvtype;
696 bool hastype, hasfamily;
697
698 hastype = false;
699 hasfamily = false;
700
701 cookie = NULL;
702 while ((name = nvlist_next(newlimits, &nvtype, &cookie)) != NULL) {
703 if (nvtype == NV_TYPE_STRING) {
704 const char *type;
705
706 if (strncmp(name, "type", sizeof("type") - 1) != 0)
707 return (EINVAL);
708 type = nvlist_get_string(newlimits, name);
709 if (strcmp(type, "ADDR2NAME") != 0 &&
710 strcmp(type, "NAME2ADDR") != 0 &&
711 strcmp(type, "ADDR") != 0 &&
712 strcmp(type, "NAME") != 0) {
713 return (EINVAL);
714 }
715 if (!dns_allowed_type(oldlimits, type))
716 return (ENOTCAPABLE);
717 hastype = true;
718 } else if (nvtype == NV_TYPE_NUMBER) {
719 int family;
720
721 if (strncmp(name, "family", sizeof("family") - 1) != 0)
722 return (EINVAL);
723 family = (int)nvlist_get_number(newlimits, name);
724 if (!dns_allowed_family(oldlimits, family))
725 return (ENOTCAPABLE);
726 hasfamily = true;
727 } else {
728 return (EINVAL);
729 }
730 }
731
732 /*
733 * If the new limit doesn't mention type or family we have to
734 * check if the current limit does have those. Missing type or
735 * family in the limit means that all types or families are
736 * allowed.
737 */
738 if (!hastype) {
739 if (limit_has_entry(oldlimits, "type"))
740 return (ENOTCAPABLE);
741 }
742 if (!hasfamily) {
743 if (limit_has_entry(oldlimits, "family"))
744 return (ENOTCAPABLE);
745 }
746
747 return (0);
748 }
749
750 static int
dns_command(const char * cmd,const nvlist_t * limits,nvlist_t * nvlin,nvlist_t * nvlout)751 dns_command(const char *cmd, const nvlist_t *limits, nvlist_t *nvlin,
752 nvlist_t *nvlout)
753 {
754 int error;
755
756 if (strcmp(cmd, "gethostbyname") == 0)
757 error = dns_gethostbyname(limits, nvlin, nvlout);
758 else if (strcmp(cmd, "gethostbyaddr") == 0)
759 error = dns_gethostbyaddr(limits, nvlin, nvlout);
760 else if (strcmp(cmd, "getnameinfo") == 0)
761 error = dns_getnameinfo(limits, nvlin, nvlout);
762 else if (strcmp(cmd, "getaddrinfo") == 0)
763 error = dns_getaddrinfo(limits, nvlin, nvlout);
764 else
765 error = NO_RECOVERY;
766
767 return (error);
768 }
769
770 CREATE_SERVICE("system.dns", dns_limit, dns_command, 0);
771