1 /* $NetBSD: getaddrinfo.c,v 1.7 2014/12/10 04:37:59 christos Exp $ */
2
3 /*
4 * Copyright (C) 2009, 2012-2014 Internet Systems Consortium, Inc. ("ISC")
5 *
6 * Permission to use, copy, modify, and/or distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
11 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
12 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
13 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
14 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
15 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
16 * PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 /* Id: getaddrinfo.c,v 1.3 2009/09/02 23:48:02 tbox Exp */
20
21 /*! \file */
22
23 /**
24 * getaddrinfo() is used to get a list of IP addresses and port
25 * numbers for host hostname and service servname as defined in RFC3493.
26 * hostname and servname are pointers to null-terminated strings
27 * or NULL. hostname is either a host name or a numeric host address
28 * string: a dotted decimal IPv4 address or an IPv6 address. servname is
29 * either a decimal port number or a service name as listed in
30 * /etc/services.
31 *
32 * If the operating system does not provide a struct addrinfo, the
33 * following structure is used:
34 *
35 * \code
36 * struct addrinfo {
37 * int ai_flags; // AI_PASSIVE, AI_CANONNAME
38 * int ai_family; // PF_xxx
39 * int ai_socktype; // SOCK_xxx
40 * int ai_protocol; // 0 or IPPROTO_xxx for IPv4 and IPv6
41 * size_t ai_addrlen; // length of ai_addr
42 * char *ai_canonname; // canonical name for hostname
43 * struct sockaddr *ai_addr; // binary address
44 * struct addrinfo *ai_next; // next structure in linked list
45 * };
46 * \endcode
47 *
48 *
49 * hints is an optional pointer to a struct addrinfo. This structure can
50 * be used to provide hints concerning the type of socket that the caller
51 * supports or wishes to use. The caller can supply the following
52 * structure elements in *hints:
53 *
54 * <ul>
55 * <li>ai_family:
56 * The protocol family that should be used. When ai_family is set
57 * to PF_UNSPEC, it means the caller will accept any protocol
58 * family supported by the operating system.</li>
59 *
60 * <li>ai_socktype:
61 * denotes the type of socket -- SOCK_STREAM, SOCK_DGRAM or
62 * SOCK_RAW -- that is wanted. When ai_socktype is zero the caller
63 * will accept any socket type.</li>
64 *
65 * <li>ai_protocol:
66 * indicates which transport protocol is wanted: IPPROTO_UDP or
67 * IPPROTO_TCP. If ai_protocol is zero the caller will accept any
68 * protocol.</li>
69 *
70 * <li>ai_flags:
71 * Flag bits. If the AI_CANONNAME bit is set, a successful call to
72 * getaddrinfo() will return a null-terminated string
73 * containing the canonical name of the specified hostname in
74 * ai_canonname of the first addrinfo structure returned. Setting
75 * the AI_PASSIVE bit indicates that the returned socket address
76 * structure is intended for used in a call to bind(2). In this
77 * case, if the hostname argument is a NULL pointer, then the IP
78 * address portion of the socket address structure will be set to
79 * INADDR_ANY for an IPv4 address or IN6ADDR_ANY_INIT for an IPv6
80 * address.<br /><br />
81 *
82 * When ai_flags does not set the AI_PASSIVE bit, the returned
83 * socket address structure will be ready for use in a call to
84 * connect(2) for a connection-oriented protocol or connect(2),
85 * sendto(2), or sendmsg(2) if a connectionless protocol was
86 * chosen. The IP address portion of the socket address structure
87 * will be set to the loopback address if hostname is a NULL
88 * pointer and AI_PASSIVE is not set in ai_flags.<br /><br />
89 *
90 * If ai_flags is set to AI_NUMERICHOST it indicates that hostname
91 * should be treated as a numeric string defining an IPv4 or IPv6
92 * address and no name resolution should be attempted.
93 * </li></ul>
94 *
95 * All other elements of the struct addrinfo passed via hints must be
96 * zero.
97 *
98 * A hints of NULL is treated as if the caller provided a struct addrinfo
99 * initialized to zero with ai_familyset to PF_UNSPEC.
100 *
101 * After a successful call to getaddrinfo(), *res is a pointer to a
102 * linked list of one or more addrinfo structures. Each struct addrinfo
103 * in this list cn be processed by following the ai_next pointer, until a
104 * NULL pointer is encountered. The three members ai_family, ai_socktype,
105 * and ai_protocol in each returned addrinfo structure contain the
106 * corresponding arguments for a call to socket(2). For each addrinfo
107 * structure in the list, the ai_addr member points to a filled-in socket
108 * address structure of length ai_addrlen.
109 *
110 * All of the information returned by getaddrinfo() is dynamically
111 * allocated: the addrinfo structures, and the socket address structures
112 * and canonical host name strings pointed to by the addrinfostructures.
113 * Memory allocated for the dynamically allocated structures created by a
114 * successful call to getaddrinfo() is released by freeaddrinfo().
115 * ai is a pointer to a struct addrinfo created by a call to getaddrinfo().
116 *
117 * \section irsreturn RETURN VALUES
118 *
119 * getaddrinfo() returns zero on success or one of the error codes
120 * listed in gai_strerror() if an error occurs. If both hostname and
121 * servname are NULL getaddrinfo() returns #EAI_NONAME.
122 *
123 * \section irssee SEE ALSO
124 *
125 * getaddrinfo(), freeaddrinfo(),
126 * gai_strerror(), RFC3493, getservbyname(3), connect(2),
127 * sendto(2), sendmsg(2), socket(2).
128 */
129
130 #include <config.h>
131
132 #include <stdlib.h>
133 #include <string.h>
134 #include <errno.h>
135
136 #include <isc/app.h>
137 #include <isc/buffer.h>
138 #include <isc/lib.h>
139 #include <isc/mem.h>
140 #include <isc/sockaddr.h>
141 #include <isc/string.h>
142 #include <isc/util.h>
143
144 #include <dns/client.h>
145 #include <dns/fixedname.h>
146 #include <dns/name.h>
147 #include <dns/rdata.h>
148 #include <dns/rdataset.h>
149 #include <dns/rdatastruct.h>
150 #include <dns/rdatatype.h>
151 #include <dns/result.h>
152
153 #include <irs/context.h>
154 #include <irs/netdb.h>
155 #include <irs/resconf.h>
156
157 #define SA(addr) ((struct sockaddr *)(addr))
158 #define SIN(addr) ((struct sockaddr_in *)(addr))
159 #define SIN6(addr) ((struct sockaddr_in6 *)(addr))
160 #define SLOCAL(addr) ((struct sockaddr_un *)(addr))
161
162 /*! \struct addrinfo
163 */
164 static struct addrinfo
165 *ai_concat(struct addrinfo *ai1, struct addrinfo *ai2),
166 *ai_reverse(struct addrinfo *oai),
167 *ai_clone(struct addrinfo *oai, int family),
168 *ai_alloc(int family, int addrlen);
169 #ifdef AF_LOCAL
170 static int get_local(const char *name, int socktype, struct addrinfo **res);
171 #endif
172
173 static int
174 resolve_name(int family, const char *hostname, int flags,
175 struct addrinfo **aip, int socktype, int port);
176
177 static int add_ipv4(const char *hostname, int flags, struct addrinfo **aip,
178 int socktype, int port);
179 static int add_ipv6(const char *hostname, int flags, struct addrinfo **aip,
180 int socktype, int port);
181 static void set_order(int, int (**)(const char *, int, struct addrinfo **,
182 int, int));
183 static void _freeaddrinfo(struct addrinfo *ai);
184
185 #define FOUND_IPV4 0x1
186 #define FOUND_IPV6 0x2
187 #define FOUND_MAX 2
188
189 #define ISC_AI_MASK (AI_PASSIVE|AI_CANONNAME|AI_NUMERICHOST)
190 /*%
191 * Get a list of IP addresses and port numbers for host hostname and
192 * service servname.
193 */
194 int
getaddrinfo(const char * hostname,const char * servname,const struct addrinfo * hints,struct addrinfo ** res)195 getaddrinfo(const char *hostname, const char *servname,
196 const struct addrinfo *hints, struct addrinfo **res)
197 {
198 struct servent *sp;
199 const char *proto;
200 int family, socktype, flags, protocol;
201 struct addrinfo *ai, *ai_list;
202 int err = 0;
203 int port, i;
204 int (*net_order[FOUND_MAX+1])(const char *, int, struct addrinfo **,
205 int, int);
206
207 if (hostname == NULL && servname == NULL)
208 return (EAI_NONAME);
209
210 proto = NULL;
211 if (hints != NULL) {
212 if ((hints->ai_flags & ~(ISC_AI_MASK)) != 0)
213 return (EAI_BADFLAGS);
214 if (hints->ai_addrlen || hints->ai_canonname ||
215 hints->ai_addr || hints->ai_next) {
216 errno = EINVAL;
217 return (EAI_SYSTEM);
218 }
219 family = hints->ai_family;
220 socktype = hints->ai_socktype;
221 protocol = hints->ai_protocol;
222 flags = hints->ai_flags;
223 switch (family) {
224 case AF_UNSPEC:
225 switch (hints->ai_socktype) {
226 case SOCK_STREAM:
227 proto = "tcp";
228 break;
229 case SOCK_DGRAM:
230 proto = "udp";
231 break;
232 }
233 break;
234 case AF_INET:
235 case AF_INET6:
236 switch (hints->ai_socktype) {
237 case 0:
238 break;
239 case SOCK_STREAM:
240 proto = "tcp";
241 break;
242 case SOCK_DGRAM:
243 proto = "udp";
244 break;
245 case SOCK_RAW:
246 break;
247 default:
248 return (EAI_SOCKTYPE);
249 }
250 break;
251 #ifdef AF_LOCAL
252 case AF_LOCAL:
253 switch (hints->ai_socktype) {
254 case 0:
255 break;
256 case SOCK_STREAM:
257 break;
258 case SOCK_DGRAM:
259 break;
260 default:
261 return (EAI_SOCKTYPE);
262 }
263 break;
264 #endif
265 default:
266 return (EAI_FAMILY);
267 }
268 } else {
269 protocol = 0;
270 family = 0;
271 socktype = 0;
272 flags = 0;
273 }
274
275 #ifdef AF_LOCAL
276 /*!
277 * First, deal with AF_LOCAL. If the family was not set,
278 * then assume AF_LOCAL if the first character of the
279 * hostname/servname is '/'.
280 */
281
282 if (hostname != NULL &&
283 (family == AF_LOCAL || (family == 0 && *hostname == '/')))
284 return (get_local(hostname, socktype, res));
285
286 if (servname != NULL &&
287 (family == AF_LOCAL || (family == 0 && *servname == '/')))
288 return (get_local(servname, socktype, res));
289 #endif
290
291 /*
292 * Ok, only AF_INET and AF_INET6 left.
293 */
294 ai_list = NULL;
295
296 /*
297 * First, look up the service name (port) if it was
298 * requested. If the socket type wasn't specified, then
299 * try and figure it out.
300 */
301 if (servname != NULL) {
302 char *e;
303
304 port = strtol(servname, &e, 10);
305 if (*e == '\0') {
306 if (socktype == 0)
307 return (EAI_SOCKTYPE);
308 if (port < 0 || port > 65535)
309 return (EAI_SERVICE);
310 port = htons((unsigned short) port);
311 } else {
312 sp = getservbyname(servname, proto);
313 if (sp == NULL)
314 return (EAI_SERVICE);
315 port = sp->s_port;
316 if (socktype == 0) {
317 if (strcmp(sp->s_proto, "tcp") == 0)
318 socktype = SOCK_STREAM;
319 else if (strcmp(sp->s_proto, "udp") == 0)
320 socktype = SOCK_DGRAM;
321 }
322 }
323 } else
324 port = 0;
325
326 /*
327 * Next, deal with just a service name, and no hostname.
328 * (we verified that one of them was non-null up above).
329 */
330 if (hostname == NULL && (flags & AI_PASSIVE) != 0) {
331 if (family == AF_INET || family == 0) {
332 ai = ai_alloc(AF_INET, sizeof(struct sockaddr_in));
333 if (ai == NULL)
334 return (EAI_MEMORY);
335 ai->ai_socktype = socktype;
336 ai->ai_protocol = protocol;
337 SIN(ai->ai_addr)->sin_port = port;
338 ai->ai_next = ai_list;
339 ai_list = ai;
340 }
341
342 if (family == AF_INET6 || family == 0) {
343 ai = ai_alloc(AF_INET6, sizeof(struct sockaddr_in6));
344 if (ai == NULL) {
345 _freeaddrinfo(ai_list);
346 return (EAI_MEMORY);
347 }
348 ai->ai_socktype = socktype;
349 ai->ai_protocol = protocol;
350 SIN6(ai->ai_addr)->sin6_port = port;
351 ai->ai_next = ai_list;
352 ai_list = ai;
353 }
354
355 *res = ai_list;
356 return (0);
357 }
358
359 /*
360 * If the family isn't specified or AI_NUMERICHOST specified, check
361 * first to see if it is a numeric address.
362 * Though the gethostbyname2() routine will recognize numeric addresses,
363 * it will only recognize the format that it is being called for. Thus,
364 * a numeric AF_INET address will be treated by the AF_INET6 call as
365 * a domain name, and vice versa. Checking for both numerics here
366 * avoids that.
367 */
368 if (hostname != NULL &&
369 (family == 0 || (flags & AI_NUMERICHOST) != 0)) {
370 char abuf[sizeof(struct in6_addr)];
371 char nbuf[NI_MAXHOST];
372 int addrsize, addroff;
373 #ifdef IRS_HAVE_SIN6_SCOPE_ID
374 char *p, *ep;
375 char ntmp[NI_MAXHOST];
376 isc_uint32_t scopeid;
377 #endif
378
379 #ifdef IRS_HAVE_SIN6_SCOPE_ID
380 /*
381 * Scope identifier portion.
382 */
383 ntmp[0] = '\0';
384 if (strchr(hostname, '%') != NULL) {
385 strncpy(ntmp, hostname, sizeof(ntmp) - 1);
386 ntmp[sizeof(ntmp) - 1] = '\0';
387 p = strchr(ntmp, '%');
388 ep = NULL;
389
390 /*
391 * Vendors may want to support non-numeric
392 * scopeid around here.
393 */
394
395 if (p != NULL)
396 scopeid = (isc_uint32_t)strtoul(p + 1,
397 &ep, 10);
398 if (p != NULL && ep != NULL && ep[0] == '\0')
399 *p = '\0';
400 else {
401 ntmp[0] = '\0';
402 scopeid = 0;
403 }
404 } else
405 scopeid = 0;
406 #endif
407
408 if (inet_pton(AF_INET, hostname, (struct in_addr *)abuf)
409 == 1) {
410 if (family == AF_INET6) {
411 /*
412 * Convert to a V4 mapped address.
413 */
414 struct in6_addr *a6 = (struct in6_addr *)abuf;
415 memmove(&a6->s6_addr[12], &a6->s6_addr[0], 4);
416 memset(&a6->s6_addr[10], 0xff, 2);
417 memset(&a6->s6_addr[0], 0, 10);
418 goto inet6_addr;
419 }
420 addrsize = sizeof(struct in_addr);
421 addroff = (char *)(&SIN(0)->sin_addr) - (char *)0;
422 family = AF_INET;
423 goto common;
424 #ifdef IRS_HAVE_SIN6_SCOPE_ID
425 } else if (ntmp[0] != '\0' &&
426 inet_pton(AF_INET6, ntmp, abuf) == 1) {
427 if (family && family != AF_INET6)
428 return (EAI_NONAME);
429 addrsize = sizeof(struct in6_addr);
430 addroff = (char *)(&SIN6(0)->sin6_addr) - (char *)0;
431 family = AF_INET6;
432 goto common;
433 #endif
434 } else if (inet_pton(AF_INET6, hostname, abuf) == 1) {
435 if (family != 0 && family != AF_INET6)
436 return (EAI_NONAME);
437 inet6_addr:
438 addrsize = sizeof(struct in6_addr);
439 addroff = (char *)(&SIN6(0)->sin6_addr) - (char *)0;
440 family = AF_INET6;
441
442 common:
443 ai = ai_alloc(family,
444 ((family == AF_INET6) ?
445 sizeof(struct sockaddr_in6) :
446 sizeof(struct sockaddr_in)));
447 if (ai == NULL)
448 return (EAI_MEMORY);
449 ai_list = ai;
450 ai->ai_socktype = socktype;
451 SIN(ai->ai_addr)->sin_port = port;
452 memmove((char *)ai->ai_addr + addroff, abuf, addrsize);
453 if ((flags & AI_CANONNAME) != 0) {
454 #ifdef IRS_HAVE_SIN6_SCOPE_ID
455 if (ai->ai_family == AF_INET6)
456 SIN6(ai->ai_addr)->sin6_scope_id =
457 scopeid;
458 #endif
459 if (getnameinfo(ai->ai_addr,
460 (socklen_t)ai->ai_addrlen,
461 nbuf, sizeof(nbuf), NULL, 0,
462 NI_NUMERICHOST) == 0) {
463 ai->ai_canonname = strdup(nbuf);
464 if (ai->ai_canonname == NULL) {
465 _freeaddrinfo(ai);
466 return (EAI_MEMORY);
467 }
468 } else {
469 /* XXX raise error? */
470 ai->ai_canonname = NULL;
471 }
472 }
473 goto done;
474 } else if ((flags & AI_NUMERICHOST) != 0) {
475 return (EAI_NONAME);
476 }
477 }
478
479 if (hostname == NULL && (flags & AI_PASSIVE) == 0) {
480 set_order(family, net_order);
481 for (i = 0; i < FOUND_MAX; i++) {
482 if (net_order[i] == NULL)
483 break;
484 err = (net_order[i])(hostname, flags, &ai_list,
485 socktype, port);
486 if (err != 0) {
487 if (ai_list != NULL) {
488 _freeaddrinfo(ai_list);
489 ai_list = NULL;
490 }
491 break;
492 }
493 }
494 } else
495 err = resolve_name(family, hostname, flags, &ai_list,
496 socktype, port);
497
498 if (ai_list == NULL) {
499 if (err == 0)
500 err = EAI_NONAME;
501 return (err);
502 }
503
504 done:
505 ai_list = ai_reverse(ai_list);
506
507 *res = ai_list;
508 return (0);
509 }
510
511 typedef struct gai_restrans {
512 dns_clientrestrans_t *xid;
513 isc_boolean_t is_inprogress;
514 int error;
515 struct addrinfo ai_sentinel;
516 struct gai_resstate *resstate;
517 } gai_restrans_t;
518
519 typedef struct gai_resstate {
520 isc_mem_t *mctx;
521 struct gai_statehead *head;
522 dns_fixedname_t fixedname;
523 dns_name_t *qname;
524 gai_restrans_t *trans4;
525 gai_restrans_t *trans6;
526 ISC_LINK(struct gai_resstate) link;
527 } gai_resstate_t;
528
529 typedef struct gai_statehead {
530 int ai_family;
531 int ai_flags;
532 int ai_socktype;
533 int ai_port;
534 isc_appctx_t *actx;
535 dns_client_t *dnsclient;
536 ISC_LIST(struct gai_resstate) resstates;
537 unsigned int activestates;
538 } gai_statehead_t;
539
540 static isc_result_t
make_resstate(isc_mem_t * mctx,gai_statehead_t * head,const char * hostname,const char * domain,gai_resstate_t ** statep)541 make_resstate(isc_mem_t *mctx, gai_statehead_t *head, const char *hostname,
542 const char *domain, gai_resstate_t **statep)
543 {
544 isc_result_t result;
545 gai_resstate_t *state;
546 dns_fixedname_t fixeddomain;
547 dns_name_t *qdomain;
548 unsigned int namelen;
549 isc_buffer_t b;
550 isc_boolean_t need_v4 = ISC_FALSE;
551 isc_boolean_t need_v6 = ISC_FALSE;
552
553 state = isc_mem_get(mctx, sizeof(*state));
554 if (state == NULL)
555 return (ISC_R_NOMEMORY);
556
557 /* Construct base domain name */
558 namelen = strlen(domain);
559 isc_buffer_constinit(&b, domain, namelen);
560 isc_buffer_add(&b, namelen);
561 dns_fixedname_init(&fixeddomain);
562 qdomain = dns_fixedname_name(&fixeddomain);
563 result = dns_name_fromtext(qdomain, &b, dns_rootname, 0, NULL);
564 if (result != ISC_R_SUCCESS) {
565 isc_mem_put(mctx, state, sizeof(*state));
566 return (result);
567 }
568
569 /* Construct query name */
570 namelen = strlen(hostname);
571 isc_buffer_constinit(&b, hostname, namelen);
572 isc_buffer_add(&b, namelen);
573 dns_fixedname_init(&state->fixedname);
574 state->qname = dns_fixedname_name(&state->fixedname);
575 result = dns_name_fromtext(state->qname, &b, qdomain, 0, NULL);
576 if (result != ISC_R_SUCCESS) {
577 isc_mem_put(mctx, state, sizeof(*state));
578 return (result);
579 }
580
581 if (head->ai_family == AF_UNSPEC || head->ai_family == AF_INET)
582 need_v4 = ISC_TRUE;
583 if (head->ai_family == AF_UNSPEC || head->ai_family == AF_INET6)
584 need_v6 = ISC_TRUE;
585
586 state->trans6 = NULL;
587 state->trans4 = NULL;
588 if (need_v4) {
589 state->trans4 = isc_mem_get(mctx, sizeof(gai_restrans_t));
590 if (state->trans4 == NULL) {
591 isc_mem_put(mctx, state, sizeof(*state));
592 return (ISC_R_NOMEMORY);
593 }
594 state->trans4->error = 0;
595 state->trans4->xid = NULL;
596 state->trans4->resstate = state;
597 state->trans4->is_inprogress = ISC_TRUE;
598 state->trans4->ai_sentinel.ai_next = NULL;
599 }
600 if (need_v6) {
601 state->trans6 = isc_mem_get(mctx, sizeof(gai_restrans_t));
602 if (state->trans6 == NULL) {
603 if (state->trans4 != NULL)
604 isc_mem_put(mctx, state->trans4,
605 sizeof(*state->trans4));
606 isc_mem_put(mctx, state, sizeof(*state));
607 return (ISC_R_NOMEMORY);
608 }
609 state->trans6->error = 0;
610 state->trans6->xid = NULL;
611 state->trans6->resstate = state;
612 state->trans6->is_inprogress = ISC_TRUE;
613 state->trans6->ai_sentinel.ai_next = NULL;
614 }
615
616 state->mctx = mctx;
617 state->head = head;
618 ISC_LINK_INIT(state, link);
619
620 *statep = state;
621
622 return (ISC_R_SUCCESS);
623 }
624
625 static isc_result_t
make_resstates(isc_mem_t * mctx,const char * hostname,gai_statehead_t * head,irs_resconf_t * resconf)626 make_resstates(isc_mem_t *mctx, const char *hostname, gai_statehead_t *head,
627 irs_resconf_t *resconf)
628 {
629 isc_result_t result;
630 irs_resconf_searchlist_t *searchlist;
631 irs_resconf_search_t *searchent;
632 gai_resstate_t *resstate, *resstate0;
633
634 resstate0 = NULL;
635 result = make_resstate(mctx, head, hostname, ".", &resstate0);
636 if (result != ISC_R_SUCCESS)
637 return (result);
638
639 searchlist = irs_resconf_getsearchlist(resconf);
640 for (searchent = ISC_LIST_HEAD(*searchlist); searchent != NULL;
641 searchent = ISC_LIST_NEXT(searchent, link)) {
642 resstate = NULL;
643 result = make_resstate(mctx, head, hostname,
644 (const char *)searchent->domain,
645 &resstate);
646 if (result != ISC_R_SUCCESS)
647 break;
648
649 ISC_LIST_APPEND(head->resstates, resstate, link);
650 head->activestates++;
651 }
652
653 /*
654 * Insert the original hostname either at the head or the tail of the
655 * state list, depending on the number of labels contained in the
656 * original name and the 'ndots' configuration parameter.
657 */
658 if (dns_name_countlabels(resstate0->qname) >
659 irs_resconf_getndots(resconf) + 1) {
660 ISC_LIST_PREPEND(head->resstates, resstate0, link);
661 } else
662 ISC_LIST_APPEND(head->resstates, resstate0, link);
663 head->activestates++;
664
665 if (result != ISC_R_SUCCESS) {
666 while ((resstate = ISC_LIST_HEAD(head->resstates)) != NULL) {
667 ISC_LIST_UNLINK(head->resstates, resstate, link);
668 if (resstate->trans4 != NULL) {
669 isc_mem_put(mctx, resstate->trans4,
670 sizeof(*resstate->trans4));
671 }
672 if (resstate->trans6 != NULL) {
673 isc_mem_put(mctx, resstate->trans6,
674 sizeof(*resstate->trans6));
675 }
676
677 isc_mem_put(mctx, resstate, sizeof(*resstate));
678 }
679 }
680
681 return (result);
682 }
683
684 static void
process_answer(isc_task_t * task,isc_event_t * event)685 process_answer(isc_task_t *task, isc_event_t *event) {
686 int error = 0, family;
687 gai_restrans_t *trans = event->ev_arg;
688 gai_resstate_t *resstate;
689 dns_clientresevent_t *rev = (dns_clientresevent_t *)event;
690 dns_rdatatype_t qtype;
691 dns_name_t *name;
692
693 REQUIRE(trans != NULL);
694 resstate = trans->resstate;
695 REQUIRE(resstate != NULL);
696 REQUIRE(task != NULL);
697
698 if (trans == resstate->trans4) {
699 family = AF_INET;
700 qtype = dns_rdatatype_a;
701 } else {
702 INSIST(trans == resstate->trans6);
703 family = AF_INET6;
704 qtype = dns_rdatatype_aaaa;
705 }
706
707 INSIST(trans->is_inprogress);
708 trans->is_inprogress = ISC_FALSE;
709
710 switch (rev->result) {
711 case ISC_R_SUCCESS:
712 case DNS_R_NCACHENXDOMAIN: /* treat this as a fatal error? */
713 case DNS_R_NCACHENXRRSET:
714 break;
715 default:
716 switch (rev->vresult) {
717 case DNS_R_SIGINVALID:
718 case DNS_R_SIGEXPIRED:
719 case DNS_R_SIGFUTURE:
720 case DNS_R_KEYUNAUTHORIZED:
721 case DNS_R_MUSTBESECURE:
722 case DNS_R_COVERINGNSEC:
723 case DNS_R_NOTAUTHORITATIVE:
724 case DNS_R_NOVALIDKEY:
725 case DNS_R_NOVALIDDS:
726 case DNS_R_NOVALIDSIG:
727 error = EAI_INSECUREDATA;
728 break;
729 default:
730 error = EAI_FAIL;
731 }
732 goto done;
733 }
734
735 /* Parse the response and construct the addrinfo chain */
736 for (name = ISC_LIST_HEAD(rev->answerlist); name != NULL;
737 name = ISC_LIST_NEXT(name, link)) {
738 isc_result_t result;
739 dns_rdataset_t *rdataset;
740 isc_buffer_t b;
741 isc_region_t r;
742 char t[1024];
743
744 for (rdataset = ISC_LIST_HEAD(name->list);
745 rdataset != NULL;
746 rdataset = ISC_LIST_NEXT(rdataset, link)) {
747 if (!dns_rdataset_isassociated(rdataset))
748 continue;
749 if (rdataset->type != qtype)
750 continue;
751
752 if ((resstate->head->ai_flags & AI_CANONNAME) != 0) {
753 isc_buffer_init(&b, t, sizeof(t));
754 result = dns_name_totext(name, ISC_TRUE, &b);
755 if (result != ISC_R_SUCCESS) {
756 error = EAI_FAIL;
757 goto done;
758 }
759 isc_buffer_putuint8(&b, '\0');
760 isc_buffer_usedregion(&b, &r);
761 }
762
763 for (result = dns_rdataset_first(rdataset);
764 result == ISC_R_SUCCESS;
765 result = dns_rdataset_next(rdataset)) {
766 struct addrinfo *ai;
767 dns_rdata_t rdata;
768 dns_rdata_in_a_t rdata_a;
769 dns_rdata_in_aaaa_t rdata_aaaa;
770
771 ai = ai_alloc(family,
772 ((family == AF_INET6) ?
773 sizeof(struct sockaddr_in6) :
774 sizeof(struct sockaddr_in)));
775 if (ai == NULL) {
776 error = EAI_MEMORY;
777 goto done;
778 }
779 ai->ai_socktype = resstate->head->ai_socktype;
780 ai->ai_next = trans->ai_sentinel.ai_next;
781 trans->ai_sentinel.ai_next = ai;
782
783 /*
784 * Set AF-specific parameters
785 * (IPv4/v6 address/port)
786 */
787 dns_rdata_init(&rdata);
788 switch (family) {
789 case AF_INET:
790 dns_rdataset_current(rdataset, &rdata);
791 result = dns_rdata_tostruct(&rdata, &rdata_a,
792 NULL);
793 RUNTIME_CHECK(result == ISC_R_SUCCESS);
794 SIN(ai->ai_addr)->sin_port =
795 resstate->head->ai_port;
796 memmove(&SIN(ai->ai_addr)->sin_addr,
797 &rdata_a.in_addr, 4);
798 dns_rdata_freestruct(&rdata_a);
799 break;
800 case AF_INET6:
801 dns_rdataset_current(rdataset, &rdata);
802 result = dns_rdata_tostruct(&rdata, &rdata_aaaa,
803 NULL);
804 RUNTIME_CHECK(result == ISC_R_SUCCESS);
805 SIN6(ai->ai_addr)->sin6_port =
806 resstate->head->ai_port;
807 memmove(&SIN6(ai->ai_addr)->sin6_addr,
808 &rdata_aaaa.in6_addr, 16);
809 dns_rdata_freestruct(&rdata_aaaa);
810 break;
811 }
812
813 if ((resstate->head->ai_flags & AI_CANONNAME)
814 != 0) {
815 ai->ai_canonname =
816 strdup((const char *)r.base);
817 if (ai->ai_canonname == NULL) {
818 error = EAI_MEMORY;
819 goto done;
820 }
821 }
822 }
823 }
824 }
825
826 done:
827 dns_client_freeresanswer(resstate->head->dnsclient, &rev->answerlist);
828 dns_client_destroyrestrans(&trans->xid);
829
830 isc_event_free(&event);
831
832 /* Make sure that error == 0 iff we have a non-empty list */
833 if (error == 0) {
834 if (trans->ai_sentinel.ai_next == NULL)
835 error = EAI_NONAME;
836 } else {
837 if (trans->ai_sentinel.ai_next != NULL) {
838 _freeaddrinfo(trans->ai_sentinel.ai_next);
839 trans->ai_sentinel.ai_next = NULL;
840 }
841 }
842 trans->error = error;
843
844 /* Check whether we are done */
845 if ((resstate->trans4 == NULL || !resstate->trans4->is_inprogress) &&
846 (resstate->trans6 == NULL || !resstate->trans6->is_inprogress)) {
847 /*
848 * We're done for this state. If there is no other outstanding
849 * state, we can exit.
850 */
851 resstate->head->activestates--;
852 if (resstate->head->activestates == 0) {
853 isc_app_ctxsuspend(resstate->head->actx);
854 return;
855 }
856
857 /*
858 * There are outstanding states, but if we are at the head
859 * of the state list (i.e., at the highest search priority)
860 * and have any answer, we can stop now by canceling the
861 * others.
862 */
863 if (resstate == ISC_LIST_HEAD(resstate->head->resstates)) {
864 if ((resstate->trans4 != NULL &&
865 resstate->trans4->ai_sentinel.ai_next != NULL) ||
866 (resstate->trans6 != NULL &&
867 resstate->trans6->ai_sentinel.ai_next != NULL)) {
868 gai_resstate_t *rest;
869
870 for (rest = ISC_LIST_NEXT(resstate, link);
871 rest != NULL;
872 rest = ISC_LIST_NEXT(rest, link)) {
873 if (rest->trans4 != NULL &&
874 rest->trans4->xid != NULL)
875 dns_client_cancelresolve(
876 rest->trans4->xid);
877 if (rest->trans6 != NULL &&
878 rest->trans6->xid != NULL)
879 dns_client_cancelresolve(
880 rest->trans6->xid);
881 }
882 } else {
883 /*
884 * This search fails, so we move to the tail
885 * of the list so that the next entry will
886 * have the highest priority.
887 */
888 ISC_LIST_UNLINK(resstate->head->resstates,
889 resstate, link);
890 ISC_LIST_APPEND(resstate->head->resstates,
891 resstate, link);
892 }
893 }
894 }
895 }
896
897 static int
resolve_name(int family,const char * hostname,int flags,struct addrinfo ** aip,int socktype,int port)898 resolve_name(int family, const char *hostname, int flags,
899 struct addrinfo **aip, int socktype, int port)
900 {
901 isc_result_t result;
902 irs_context_t *irsctx;
903 irs_resconf_t *conf;
904 isc_mem_t *mctx;
905 isc_appctx_t *actx;
906 isc_task_t *task;
907 int terror = 0;
908 int error = 0;
909 dns_client_t *client;
910 gai_resstate_t *resstate;
911 gai_statehead_t head;
912 isc_boolean_t all_fail = ISC_TRUE;
913
914 /* get IRS context and the associated parameters */
915 irsctx = NULL;
916 result = irs_context_get(&irsctx);
917 if (result != ISC_R_SUCCESS)
918 return (EAI_FAIL);
919 actx = irs_context_getappctx(irsctx);
920
921 mctx = irs_context_getmctx(irsctx);
922 task = irs_context_gettask(irsctx);
923 conf = irs_context_getresconf(irsctx);
924 client = irs_context_getdnsclient(irsctx);
925
926 /* construct resolution states */
927 head.activestates = 0;
928 head.ai_family = family;
929 head.ai_socktype = socktype;
930 head.ai_flags = flags;
931 head.ai_port = port;
932 head.actx = actx;
933 head.dnsclient = client;
934 ISC_LIST_INIT(head.resstates);
935 result = make_resstates(mctx, hostname, &head, conf);
936 if (result != ISC_R_SUCCESS)
937 return (EAI_FAIL);
938
939 for (resstate = ISC_LIST_HEAD(head.resstates);
940 resstate != NULL; resstate = ISC_LIST_NEXT(resstate, link)) {
941 if (resstate->trans4 != NULL) {
942 result = dns_client_startresolve(client,
943 resstate->qname,
944 dns_rdataclass_in,
945 dns_rdatatype_a,
946 0, task,
947 process_answer,
948 resstate->trans4,
949 &resstate->trans4->xid);
950 if (result == ISC_R_SUCCESS) {
951 resstate->trans4->is_inprogress = ISC_TRUE;
952 all_fail = ISC_FALSE;
953 } else
954 resstate->trans4->is_inprogress = ISC_FALSE;
955 }
956 if (resstate->trans6 != NULL) {
957 result = dns_client_startresolve(client,
958 resstate->qname,
959 dns_rdataclass_in,
960 dns_rdatatype_aaaa,
961 0, task,
962 process_answer,
963 resstate->trans6,
964 &resstate->trans6->xid);
965 if (result == ISC_R_SUCCESS) {
966 resstate->trans6->is_inprogress = ISC_TRUE;
967 all_fail = ISC_FALSE;
968 } else
969 resstate->trans6->is_inprogress= ISC_FALSE;
970 }
971 }
972 if (!all_fail) {
973 /* Start all the events */
974 isc_app_ctxrun(actx);
975 } else
976 error = EAI_FAIL;
977
978 /* Cleanup */
979 while ((resstate = ISC_LIST_HEAD(head.resstates)) != NULL) {
980 int terror4 = 0, terror6 = 0;
981
982 ISC_LIST_UNLINK(head.resstates, resstate, link);
983
984 if (*aip == NULL) {
985 struct addrinfo *sentinel4 = NULL;
986 struct addrinfo *sentinel6 = NULL;
987
988 if (resstate->trans4 != NULL) {
989 sentinel4 =
990 resstate->trans4->ai_sentinel.ai_next;
991 resstate->trans4->ai_sentinel.ai_next = NULL;
992 }
993 if (resstate->trans6 != NULL) {
994 sentinel6 =
995 resstate->trans6->ai_sentinel.ai_next;
996 resstate->trans6->ai_sentinel.ai_next = NULL;
997 }
998 *aip = ai_concat(sentinel4, sentinel6);
999 }
1000
1001 if (resstate->trans4 != NULL) {
1002 INSIST(resstate->trans4->xid == NULL);
1003 terror4 = resstate->trans4->error;
1004 isc_mem_put(mctx, resstate->trans4,
1005 sizeof(*resstate->trans4));
1006 }
1007 if (resstate->trans6 != NULL) {
1008 INSIST(resstate->trans6->xid == NULL);
1009 terror6 = resstate->trans6->error;
1010 isc_mem_put(mctx, resstate->trans6,
1011 sizeof(*resstate->trans6));
1012 }
1013
1014 /*
1015 * If the entire lookup fails, we need to choose an appropriate
1016 * error code from individual codes. We'll try to provide as
1017 * specific a code as possible. In general, we are going to
1018 * find an error code other than EAI_NONAME (which is too
1019 * generic and may actually not be problematic in some cases).
1020 * EAI_NONAME will be set below if no better code is found.
1021 */
1022 if (terror == 0 || terror == EAI_NONAME) {
1023 if (terror4 != 0 && terror4 != EAI_NONAME)
1024 terror = terror4;
1025 else if (terror6 != 0 && terror6 != EAI_NONAME)
1026 terror = terror6;
1027 }
1028
1029 isc_mem_put(mctx, resstate, sizeof(*resstate));
1030 }
1031
1032 if (*aip == NULL) {
1033 error = terror;
1034 if (error == 0)
1035 error = EAI_NONAME;
1036 }
1037
1038 #if 1 /* XXX: enabled for finding leaks. should be cleaned up later. */
1039 isc_app_ctxfinish(actx);
1040 irs_context_destroy(&irsctx);
1041 #endif
1042
1043 return (error);
1044 }
1045
1046 static char *
irs_strsep(char ** stringp,const char * delim)1047 irs_strsep(char **stringp, const char *delim) {
1048 char *string = *stringp;
1049 char *s;
1050 const char *d;
1051 char sc, dc;
1052
1053 if (string == NULL)
1054 return (NULL);
1055
1056 for (s = string; *s != '\0'; s++) {
1057 sc = *s;
1058 for (d = delim; (dc = *d) != '\0'; d++)
1059 if (sc == dc) {
1060 *s++ = '\0';
1061 *stringp = s;
1062 return (string);
1063 }
1064 }
1065 *stringp = NULL;
1066 return (string);
1067 }
1068
1069 static void
set_order(int family,int (** net_order)(const char *,int,struct addrinfo **,int,int))1070 set_order(int family, int (**net_order)(const char *, int, struct addrinfo **,
1071 int, int))
1072 {
1073 char *order, *tok;
1074 int found;
1075
1076 if (family) {
1077 switch (family) {
1078 case AF_INET:
1079 *net_order++ = add_ipv4;
1080 break;
1081 case AF_INET6:
1082 *net_order++ = add_ipv6;
1083 break;
1084 }
1085 } else {
1086 order = getenv("NET_ORDER");
1087 found = 0;
1088 while (order != NULL) {
1089 /*
1090 * We ignore any unknown names.
1091 */
1092 tok = irs_strsep(&order, ":");
1093 if (strcasecmp(tok, "inet6") == 0) {
1094 if ((found & FOUND_IPV6) == 0)
1095 *net_order++ = add_ipv6;
1096 found |= FOUND_IPV6;
1097 } else if (strcasecmp(tok, "inet") == 0 ||
1098 strcasecmp(tok, "inet4") == 0) {
1099 if ((found & FOUND_IPV4) == 0)
1100 *net_order++ = add_ipv4;
1101 found |= FOUND_IPV4;
1102 }
1103 }
1104
1105 /*
1106 * Add in anything that we didn't find.
1107 */
1108 if ((found & FOUND_IPV4) == 0)
1109 *net_order++ = add_ipv4;
1110 if ((found & FOUND_IPV6) == 0)
1111 *net_order++ = add_ipv6;
1112 }
1113 *net_order = NULL;
1114 return;
1115 }
1116
1117 static char v4_loop[4] = { 127, 0, 0, 1 };
1118
1119 static int
add_ipv4(const char * hostname,int flags,struct addrinfo ** aip,int socktype,int port)1120 add_ipv4(const char *hostname, int flags, struct addrinfo **aip,
1121 int socktype, int port)
1122 {
1123 struct addrinfo *ai;
1124
1125 UNUSED(hostname);
1126 UNUSED(flags);
1127
1128 ai = ai_clone(*aip, AF_INET); /* don't use ai_clone() */
1129 if (ai == NULL) {
1130 _freeaddrinfo(*aip);
1131 return (EAI_MEMORY);
1132 }
1133
1134 *aip = ai;
1135 ai->ai_socktype = socktype;
1136 SIN(ai->ai_addr)->sin_port = port;
1137 memmove(&SIN(ai->ai_addr)->sin_addr, v4_loop, 4);
1138
1139 return (0);
1140 }
1141
1142 static char v6_loop[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 };
1143
1144 static int
add_ipv6(const char * hostname,int flags,struct addrinfo ** aip,int socktype,int port)1145 add_ipv6(const char *hostname, int flags, struct addrinfo **aip,
1146 int socktype, int port)
1147 {
1148 struct addrinfo *ai;
1149
1150 UNUSED(hostname);
1151 UNUSED(flags);
1152
1153 ai = ai_clone(*aip, AF_INET6); /* don't use ai_clone() */
1154 if (ai == NULL)
1155 return (EAI_MEMORY);
1156
1157 *aip = ai;
1158 ai->ai_socktype = socktype;
1159 SIN6(ai->ai_addr)->sin6_port = port;
1160 memmove(&SIN6(ai->ai_addr)->sin6_addr, v6_loop, 16);
1161
1162 return (0);
1163 }
1164
1165 /*% Free address info. */
1166 void
freeaddrinfo(struct addrinfo * ai)1167 freeaddrinfo(struct addrinfo *ai) {
1168 _freeaddrinfo(ai);
1169 }
1170
1171 static void
_freeaddrinfo(struct addrinfo * ai)1172 _freeaddrinfo(struct addrinfo *ai) {
1173 struct addrinfo *ai_next;
1174
1175 while (ai != NULL) {
1176 ai_next = ai->ai_next;
1177 if (ai->ai_addr != NULL)
1178 free(ai->ai_addr);
1179 if (ai->ai_canonname)
1180 free(ai->ai_canonname);
1181 free(ai);
1182 ai = ai_next;
1183 }
1184 }
1185
1186 #ifdef AF_LOCAL
1187 static int
get_local(const char * name,int socktype,struct addrinfo ** res)1188 get_local(const char *name, int socktype, struct addrinfo **res) {
1189 struct addrinfo *ai;
1190 struct sockaddr_un *slocal;
1191
1192 if (socktype == 0)
1193 return (EAI_SOCKTYPE);
1194
1195 ai = ai_alloc(AF_LOCAL, sizeof(*slocal));
1196 if (ai == NULL)
1197 return (EAI_MEMORY);
1198
1199 slocal = SLOCAL(ai->ai_addr);
1200 strlcpy(slocal->sun_path, name, sizeof(slocal->sun_path));
1201
1202 ai->ai_socktype = socktype;
1203 /*
1204 * ai->ai_flags, ai->ai_protocol, ai->ai_canonname,
1205 * and ai->ai_next were initialized to zero.
1206 */
1207
1208 *res = ai;
1209 return (0);
1210 }
1211 #endif
1212
1213 /*!
1214 * Allocate an addrinfo structure, and a sockaddr structure
1215 * of the specificed length. We initialize:
1216 * ai_addrlen
1217 * ai_family
1218 * ai_addr
1219 * ai_addr->sa_family
1220 * ai_addr->sa_len (IRS_PLATFORM_HAVESALEN)
1221 * and everything else is initialized to zero.
1222 */
1223 static struct addrinfo *
ai_alloc(int family,int addrlen)1224 ai_alloc(int family, int addrlen) {
1225 struct addrinfo *ai;
1226
1227 ai = (struct addrinfo *)calloc(1, sizeof(*ai));
1228 if (ai == NULL)
1229 return (NULL);
1230
1231 ai->ai_addr = SA(calloc(1, addrlen));
1232 if (ai->ai_addr == NULL) {
1233 free(ai);
1234 return (NULL);
1235 }
1236 ai->ai_addrlen = addrlen;
1237 ai->ai_family = family;
1238 ai->ai_addr->sa_family = family;
1239 #ifdef IRS_PLATFORM_HAVESALEN
1240 ai->ai_addr->sa_len = addrlen;
1241 #endif
1242 return (ai);
1243 }
1244
1245 static struct addrinfo *
ai_clone(struct addrinfo * oai,int family)1246 ai_clone(struct addrinfo *oai, int family) {
1247 struct addrinfo *ai;
1248
1249 ai = ai_alloc(family, ((family == AF_INET6) ?
1250 sizeof(struct sockaddr_in6) : sizeof(struct sockaddr_in)));
1251
1252 if (ai == NULL) {
1253 if (oai != NULL)
1254 freeaddrinfo(oai);
1255 return (NULL);
1256 }
1257 if (oai == NULL)
1258 return (ai);
1259
1260 ai->ai_flags = oai->ai_flags;
1261 ai->ai_socktype = oai->ai_socktype;
1262 ai->ai_protocol = oai->ai_protocol;
1263 ai->ai_canonname = NULL;
1264 ai->ai_next = oai;
1265 return (ai);
1266 }
1267
1268 static struct addrinfo *
ai_reverse(struct addrinfo * oai)1269 ai_reverse(struct addrinfo *oai) {
1270 struct addrinfo *nai, *tai;
1271
1272 nai = NULL;
1273
1274 while (oai != NULL) {
1275 /*
1276 * Grab one off the old list.
1277 */
1278 tai = oai;
1279 oai = oai->ai_next;
1280 /*
1281 * Put it on the front of the new list.
1282 */
1283 tai->ai_next = nai;
1284 nai = tai;
1285 }
1286 return (nai);
1287 }
1288
1289
1290 static struct addrinfo *
ai_concat(struct addrinfo * ai1,struct addrinfo * ai2)1291 ai_concat(struct addrinfo *ai1, struct addrinfo *ai2) {
1292 struct addrinfo *ai_tmp;
1293
1294 if (ai1 == NULL)
1295 return (ai2);
1296 else if (ai2 == NULL)
1297 return (ai1);
1298
1299 for (ai_tmp = ai1; ai_tmp != NULL && ai_tmp->ai_next != NULL;
1300 ai_tmp = ai_tmp->ai_next)
1301 ;
1302
1303 ai_tmp->ai_next = ai2;
1304
1305 return (ai1);
1306 }
1307