xref: /illumos-gate/usr/src/lib/libresolv2/common/irs/gethostent.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
1 /*
2  * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*
7  * Copyright (c) 1996-1999 by Internet Software Consortium.
8  *
9  * Permission to use, copy, modify, and distribute this software for any
10  * purpose with or without fee is hereby granted, provided that the above
11  * copyright notice and this permission notice appear in all copies.
12  *
13  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
14  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
15  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
16  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
17  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
18  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
19  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
20  * SOFTWARE.
21  */
22 
23 #pragma ident	"%Z%%M%	%I%	%E% SMI"
24 
25 #if !defined(LINT) && !defined(CODECENTER)
26 static const char rcsid[] = "$Id: gethostent.c,v 1.34 2003/05/29 00:05:18 marka Exp $";
27 #endif
28 
29 /* Imports */
30 
31 #include "port_before.h"
32 
33 #if !defined(__BIND_NOSTATIC)
34 
35 #include <sys/types.h>
36 #include <sys/param.h>
37 #include <sys/socket.h>
38 #include <sys/ioctl.h>
39 #include <netinet/in.h>
40 #include <net/if.h>
41 #include <arpa/inet.h>
42 #include <arpa/nameser.h>
43 
44 #include <ctype.h>
45 #include <errno.h>
46 #include <stdlib.h>
47 #include <netdb.h>
48 #include <resolv.h>
49 #include <stdio.h>
50 #include <string.h>
51 #include <unistd.h>
52 
53 #include <irs.h>
54 #include <isc/memcluster.h>
55 
56 #include "port_after.h"
57 
58 #include "irs_p.h"
59 #include "irs_data.h"
60 
61 /* Definitions */
62 
63 struct pvt {
64 	char *		aliases[1];
65 	char *		addrs[2];
66 	char		addr[NS_IN6ADDRSZ];
67 	char		name[NS_MAXDNAME + 1];
68 	struct hostent	host;
69 };
70 
71 /* Forward */
72 
73 static struct net_data *init(void);
74 static void		freepvt(struct net_data *);
75 static struct hostent  *fakeaddr(const char *, int, struct net_data *);
76 
77 #ifdef	SUNW_OVERRIDE_RETRY
78 extern int	__res_retry(int);
79 extern int	__res_retry_reset(void);
80 #endif	/* SUNW_OVERRIDE_RETRY */
81 
82 /* Public */
83 
84 struct hostent *
85 gethostbyname(const char *name) {
86 	struct net_data *net_data = init();
87 
88 	return (gethostbyname_p(name, net_data));
89 }
90 
91 struct hostent *
92 gethostbyname2(const char *name, int af) {
93 	struct net_data *net_data = init();
94 
95 	return (gethostbyname2_p(name, af, net_data));
96 }
97 
98 struct hostent *
99 #ifdef ORIGINAL_ISC_CODE
100 gethostbyaddr(const char *addr, int len, int af) {
101 #else
102 gethostbyaddr(const void *addr, socklen_t len, int af) {
103 #endif /* ORIGINAL_ISC_CODE */
104 	struct net_data *net_data = init();
105 
106 	return (gethostbyaddr_p(addr, len, af, net_data));
107 }
108 
109 struct hostent *
110 gethostent() {
111 	struct net_data *net_data = init();
112 
113 	return (gethostent_p(net_data));
114 }
115 
116 #ifdef	ORIGINAL_ISC_CODE
117 void
118 #else
119 int
120 #endif
121 sethostent(int stayopen) {
122 	struct net_data *net_data = init();
123 	sethostent_p(stayopen, net_data);
124 #ifdef	ORIGINAL_ISC_CODE
125 #else
126 	return (0);
127 #endif
128 }
129 
130 
131 #ifdef	ORIGINAL_ISC_CODE
132 void
133 #else
134 int
135 #endif
136 endhostent() {
137 	struct net_data *net_data = init();
138 	endhostent_p(net_data);
139 #ifdef	ORIGINAL_ISC_CODE
140 #else
141 	return (0);
142 #endif
143 }
144 
145 /* Shared private. */
146 
147 struct hostent *
148 gethostbyname_p(const char *name, struct net_data *net_data) {
149 	struct hostent *hp;
150 
151 	if (!net_data)
152 #ifdef	SUNW_SETHERRNO
153 	{
154 		/*
155 		*  Should set the context h_errno, but since net_data
156 		 * is NULL, we don't have a context.
157 		 */
158 		h_errno = NETDB_INTERNAL;
159 		return (NULL);
160 	}
161 #else
162 		return (NULL);
163 #endif	/* SUNW_SETHERRNO */
164 
165 	if (net_data->res->options & RES_USE_INET6) {
166 		hp = gethostbyname2_p(name, AF_INET6, net_data);
167 		if (hp)
168 			return (hp);
169 	}
170 	return (gethostbyname2_p(name, AF_INET, net_data));
171 }
172 
173 struct hostent *
174 gethostbyname2_p(const char *name, int af, struct net_data *net_data) {
175 	struct irs_ho *ho;
176 	char tmp[NS_MAXDNAME];
177 	struct hostent *hp;
178 	const char *cp;
179 	char **hap;
180 
181 	if (!net_data || !(ho = net_data->ho))
182 #ifdef	SUNW_SETHERRNO
183 	{
184 		h_errno = NETDB_INTERNAL;
185 		return (NULL);
186 	}
187 #else
188 		return (NULL);
189 #endif	/* SUNW_SETHERRNO */
190 	if (net_data->ho_stayopen && net_data->ho_last &&
191 	net_data->ho_last->h_addrtype == af) {
192 		if (ns_samename(name, net_data->ho_last->h_name) == 1)
193 			return (net_data->ho_last);
194 		for (hap = net_data->ho_last->h_aliases; hap && *hap; hap++)
195 			if (ns_samename(name, *hap) == 1)
196 				return (net_data->ho_last);
197 	}
198 	if (!strchr(name, '.') && (cp = res_hostalias(net_data->res, name,
199 						      tmp, sizeof tmp)))
200 		name = cp;
201 	if ((hp = fakeaddr(name, af, net_data)) != NULL)
202 		return (hp);
203 #ifdef	SUNW_OVERRIDE_RETRY
204 	net_data->res->retry = __res_retry(net_data->res->retry);
205 #endif	/* SUNW_OVERRIDE_RETRY */
206 	net_data->ho_last = (*ho->byname2)(ho, name, af);
207 #ifdef	SUNW_OVERRIDE_RETRY
208 	net_data->res->retry = __res_retry_reset();
209 #endif	/* SUNW_OVERRIDE_RETRY */
210 	if (!net_data->ho_stayopen)
211 		endhostent();
212 	return (net_data->ho_last);
213 }
214 
215 struct hostent *
216 gethostbyaddr_p(const char *addr, int len, int af, struct net_data *net_data) {
217 	struct irs_ho *ho;
218 	char **hap;
219 
220 	if (!net_data || !(ho = net_data->ho))
221 #ifdef	SUNW_SETHERRNO
222 	{
223 		h_errno = NETDB_INTERNAL;
224 		return (NULL);
225 	}
226 #else
227 		return (NULL);
228 #endif	/* SUNW_SETHERRNO */
229 	if (net_data->ho_stayopen && net_data->ho_last &&
230 	    net_data->ho_last->h_length == len)
231 		for (hap = net_data->ho_last->h_addr_list;
232 		     hap && *hap;
233 		     hap++)
234 			if (!memcmp(addr, *hap, len))
235 				return (net_data->ho_last);
236 	net_data->ho_last = (*ho->byaddr)(ho, addr, len, af);
237 	if (!net_data->ho_stayopen)
238 		endhostent();
239 	return (net_data->ho_last);
240 }
241 
242 
243 struct hostent *
244 gethostent_p(struct net_data *net_data) {
245 	struct irs_ho *ho;
246 	struct hostent *hp;
247 
248 	if (!net_data || !(ho = net_data->ho))
249 #ifdef	SUNW_SETHERRNO
250 	{
251 		h_errno = NETDB_INTERNAL;
252 		return (NULL);
253 	}
254 #else
255 		return (NULL);
256 #endif	/* SUNW_SETHERRNO */
257 	while ((hp = (*ho->next)(ho)) != NULL &&
258 	       hp->h_addrtype == AF_INET6 &&
259 	       (net_data->res->options & RES_USE_INET6) == 0)
260 		continue;
261 	net_data->ho_last = hp;
262 	return (net_data->ho_last);
263 }
264 
265 
266 void
267 sethostent_p(int stayopen, struct net_data *net_data) {
268 	struct irs_ho *ho;
269 
270 	if (!net_data || !(ho = net_data->ho))
271 		return;
272 	freepvt(net_data);
273 	(*ho->rewind)(ho);
274 	net_data->ho_stayopen = (stayopen != 0);
275 	if (stayopen == 0)
276 		net_data_minimize(net_data);
277 }
278 
279 void
280 endhostent_p(struct net_data *net_data) {
281 	struct irs_ho *ho;
282 
283 	if ((net_data != NULL) && ((ho = net_data->ho) != NULL))
284 		(*ho->minimize)(ho);
285 }
286 
287 #ifndef IN6_IS_ADDR_V4COMPAT
288 static const unsigned char in6addr_compat[12] = {
289 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
290 #define IN6_IS_ADDR_V4COMPAT(x) (!memcmp((x)->s6_addr, in6addr_compat, 12) && \
291 				 ((x)->s6_addr[12] != 0 || \
292 				  (x)->s6_addr[13] != 0 || \
293 				  (x)->s6_addr[14] != 0 || \
294 				   ((x)->s6_addr[15] != 0 && \
295 				    (x)->s6_addr[15] != 1)))
296 #endif
297 #ifndef IN6_IS_ADDR_V4MAPPED
298 #define IN6_IS_ADDR_V4MAPPED(x) (!memcmp((x)->s6_addr, in6addr_mapped, 12))
299 #endif
300 
301 static const unsigned char in6addr_mapped[12] = {
302 	0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0xff, 0xff };
303 
304 static int scan_interfaces(int *, int *);
305 static struct hostent *copyandmerge(struct hostent *, struct hostent *, int, int *);
306 
307 /*
308  *	Public functions
309  */
310 
311 /*
312  *	AI_V4MAPPED + AF_INET6
313  *	If no IPv6 address then a query for IPv4 and map returned values.
314  *
315  *	AI_ALL + AI_V4MAPPED + AF_INET6
316  *	Return IPv6 and IPv4 mapped.
317  *
318  *	AI_ADDRCONFIG
319  *	Only return IPv6 / IPv4 address if there is an interface of that
320  *	type active.
321  */
322 
323 struct hostent *
324 getipnodebyname(const char *name, int af, int flags, int *error_num) {
325 	int have_v4 = 1, have_v6 = 1;
326 	struct in_addr in4;
327 	struct in6_addr in6;
328 	struct hostent he, *he1 = NULL, *he2 = NULL, *he3;
329 	int v4 = 0, v6 = 0;
330 	struct net_data *net_data = init();
331 	u_long options;
332 	int tmp_err;
333 
334 	if (net_data == NULL) {
335 		*error_num = NO_RECOVERY;
336 		return (NULL);
337 	}
338 
339 	/* If we care about active interfaces then check. */
340 	if ((flags & AI_ADDRCONFIG) != 0)
341 		if (scan_interfaces(&have_v4, &have_v6) == -1) {
342 			*error_num = NO_RECOVERY;
343 			return (NULL);
344 		}
345 
346 	/* Check for literal address. */
347 	if ((v4 = inet_pton(AF_INET, name, &in4)) != 1)
348 		v6 = inet_pton(AF_INET6, name, &in6);
349 
350 	/* Impossible combination? */
351 
352 	if ((af == AF_INET6 && (flags & AI_V4MAPPED) == 0 && v4 == 1) ||
353 	    (af == AF_INET && v6 == 1) ||
354 	    (have_v4 == 0 && v4 == 1) ||
355 	    (have_v6 == 0 && v6 == 1) ||
356 	    (have_v4 == 0 && af == AF_INET) ||
357 	    (have_v6 == 0 && af == AF_INET6)) {
358 		*error_num = HOST_NOT_FOUND;
359 		return (NULL);
360 	}
361 
362 	/* Literal address? */
363 	if (v4 == 1 || v6 == 1) {
364 		char *addr_list[2];
365 		char *aliases[1];
366 
367 		DE_CONST(name, he.h_name);
368 		he.h_addr_list = addr_list;
369 		he.h_addr_list[0] = (v4 == 1) ? (char *)&in4 : (char *)&in6;
370 		he.h_addr_list[1] = NULL;
371 		he.h_aliases = aliases;
372 		he.h_aliases[0] = NULL;
373 		he.h_length = (v4 == 1) ? INADDRSZ : IN6ADDRSZ;
374 		he.h_addrtype = (v4 == 1) ? AF_INET : AF_INET6;
375 		return (copyandmerge(&he, NULL, af, error_num));
376 	}
377 
378 	options = net_data->res->options;
379 	net_data->res->options &= ~RES_USE_INET6;
380 
381 	tmp_err = NO_RECOVERY;
382 	if (have_v6 && af == AF_INET6) {
383 		he2 = gethostbyname2_p(name, AF_INET6, net_data);
384 		if (he2 != NULL) {
385 			he1 = copyandmerge(he2, NULL, af, error_num);
386 			if (he1 == NULL)
387 				return (NULL);
388 			he2 = NULL;
389 		} else {
390 			tmp_err = net_data->res->res_h_errno;
391 		}
392 	}
393 
394 	if (have_v4 &&
395 	    ((af == AF_INET) ||
396 	     (af == AF_INET6 && (flags & AI_V4MAPPED) != 0 &&
397 	      (he1 == NULL || (flags & AI_ALL) != 0)))) {
398 		he2 = gethostbyname2_p(name, AF_INET, net_data);
399 		if (he1 == NULL && he2 == NULL) {
400 			*error_num = net_data->res->res_h_errno;
401 			return (NULL);
402 		}
403 	} else
404 		*error_num = tmp_err;
405 
406 	net_data->res->options = options;
407 
408 	he3 = copyandmerge(he1, he2, af, error_num);
409 
410 	if (he1 != NULL)
411 		freehostent(he1);
412 	return (he3);
413 }
414 
415 struct hostent *
416 getipnodebyaddr(const void *src, size_t len, int af, int *error_num) {
417 	struct hostent *he1, *he2;
418 	struct net_data *net_data = init();
419 
420 	/* Sanity Checks. */
421 	if (src == NULL) {
422 		*error_num = NO_RECOVERY;
423 		return (NULL);
424 	}
425 
426 	switch (af) {
427 	case AF_INET:
428 		if (len != INADDRSZ) {
429 			*error_num = NO_RECOVERY;
430 			return (NULL);
431 		}
432 		break;
433 	case AF_INET6:
434 		if (len != IN6ADDRSZ) {
435 			*error_num = NO_RECOVERY;
436 			return (NULL);
437 		}
438 		break;
439 	default:
440 		*error_num = NO_RECOVERY;
441 		return (NULL);
442 	}
443 
444 	/*
445 	 * Lookup IPv4 and IPv4 mapped/compatible addresses
446 	 */
447 	if ((af == AF_INET6 &&
448 	     IN6_IS_ADDR_V4COMPAT((const struct in6_addr *)src)) ||
449 	    (af == AF_INET6 &&
450 	     IN6_IS_ADDR_V4MAPPED((const struct in6_addr *)src)) ||
451 	    (af == AF_INET)) {
452 		const char *cp = src;
453 
454 		if (af == AF_INET6)
455 			cp += 12;
456 		he1 = gethostbyaddr_p(cp, 4, AF_INET, net_data);
457 		if (he1 == NULL) {
458 			*error_num = net_data->res->res_h_errno;
459 			return (NULL);
460 		}
461 		he2 = copyandmerge(he1, NULL, af, error_num);
462 		if (he2 == NULL)
463 			return (NULL);
464 		/*
465 		 * Restore original address if mapped/compatible.
466 		 */
467 		if (af == AF_INET6)
468 			memcpy(he1->h_addr, src, len);
469 		return (he2);
470 	}
471 
472 	/*
473 	 * Lookup IPv6 address.
474 	 */
475 	if (memcmp((const struct in6_addr *)src, &in6addr_any, 16) == 0) {
476 		*error_num = HOST_NOT_FOUND;
477 		return (NULL);
478 	}
479 
480 	he1 = gethostbyaddr_p(src, 16, AF_INET6, net_data);
481 	if (he1 == NULL) {
482 		*error_num = net_data->res->res_h_errno;
483 		return (NULL);
484 	}
485 	return (copyandmerge(he1, NULL, af, error_num));
486 }
487 
488 void
489 freehostent(struct hostent *he) {
490 	char **cpp;
491 	int names = 1;
492 	int addresses = 1;
493 
494 	memput(he->h_name, strlen(he->h_name) + 1);
495 
496 	cpp = he->h_addr_list;
497 	while (*cpp != NULL) {
498 		memput(*cpp, (he->h_addrtype == AF_INET) ?
499 			     INADDRSZ : IN6ADDRSZ);
500 		*cpp = NULL;
501 		cpp++;
502 		addresses++;
503 	}
504 
505 	cpp = he->h_aliases;
506 	while (*cpp != NULL) {
507 		memput(*cpp, strlen(*cpp) + 1);
508 		cpp++;
509 		names++;
510 	}
511 
512 	memput(he->h_aliases, sizeof(char *) * (names));
513 	memput(he->h_addr_list, sizeof(char *) * (addresses));
514 	memput(he, sizeof *he);
515 }
516 
517 /*
518  * Private
519  */
520 
521 /*
522  * Scan the interface table and set have_v4 and have_v6 depending
523  * upon whether there are IPv4 and IPv6 interface addresses.
524  *
525  * Returns:
526  *	0 on success
527  *	-1 on failure.
528  */
529 
530 #if defined(SIOCGLIFCONF) && defined(SIOCGLIFADDR) && \
531     !defined(IRIX_EMUL_IOCTL_SIOCGIFCONF)
532 
533 #define SETFAMILYFLAGS
534 #define LIFCONF lifconf
535 #define LIFREQ lifreq
536 
537 static void
538 scan_interfaces6(int *have_v4, int *have_v6) {
539 	struct LIFCONF lifc;
540 	struct LIFREQ lifreq;
541 	struct in_addr in4;
542 	struct in6_addr in6;
543 	char *buf = NULL, *cp, *cplim;
544 	static unsigned int bufsiz = 4095;
545 	int s, cpsize, n;
546 
547 	/* Get interface list from system. */
548 	if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) == -1)
549 		goto cleanup;
550 
551 	/*
552 	 * Grow buffer until large enough to contain all interface
553 	 * descriptions.
554 	 */
555 	for (;;) {
556 		buf = memget(bufsiz);
557 		if (buf == NULL)
558 			goto cleanup;
559 #ifdef SETFAMILYFLAGS
560 		lifc.lifc_family = AF_UNSPEC;	/* request all families */
561 		lifc.lifc_flags = 0;
562 #endif
563 		lifc.lifc_len = bufsiz;
564 		lifc.lifc_buf = buf;
565 		if ((n = ioctl(s, SIOCGLIFCONF, (char *)&lifc)) != -1) {
566 			/*
567 			 * Some OS's just return what will fit rather
568 			 * than set EINVAL if the buffer is too small
569 			 * to fit all the interfaces in.  If
570 			 * lifc.lifc_len is too near to the end of the
571 			 * buffer we will grow it just in case and
572 			 * retry.
573 			 */
574 			if (lifc.lifc_len + 2 * sizeof(lifreq) < bufsiz)
575 				break;
576 		}
577 		if ((n == -1) && errno != EINVAL)
578 			goto cleanup;
579 
580 		if (bufsiz > 1000000)
581 			goto cleanup;
582 
583 		memput(buf, bufsiz);
584 		bufsiz += 4096;
585 	}
586 
587 	/* Parse system's interface list. */
588 	cplim = buf + lifc.lifc_len;    /* skip over if's with big ifr_addr's */
589 	for (cp = buf;
590 	     (*have_v4 == 0 || *have_v6 == 0) && cp < cplim;
591 	     cp += cpsize) {
592 		memcpy(&lifreq, cp, sizeof lifreq);
593 #ifdef HAVE_SA_LEN
594 #ifdef FIX_ZERO_SA_LEN
595 		if (lifreq.lifr_addr.sa_len == 0)
596 			lifreq.lifr_addr.sa_len = 16;
597 #endif
598 #ifdef HAVE_MINIMUM_IFREQ
599 		cpsize = sizeof lifreq;
600 		if (lifreq.lifr_addr.sa_len > sizeof (struct sockaddr))
601 			cpsize += (int)lifreq.lifr_addr.sa_len -
602 				(int)(sizeof (struct sockaddr));
603 #else
604 		cpsize = sizeof lifreq.lifr_name + lifreq.lifr_addr.sa_len;
605 #endif /* HAVE_MINIMUM_IFREQ */
606 #elif defined SIOCGIFCONF_ADDR
607 		cpsize = sizeof lifreq;
608 #else
609 		cpsize = sizeof lifreq.lifr_name;
610 		/* XXX maybe this should be a hard error? */
611 		if (ioctl(s, SIOCGLIFADDR, (char *)&lifreq) < 0)
612 			continue;
613 #endif
614 		switch (lifreq.lifr_addr.ss_family) {
615 		case AF_INET:
616 			if (*have_v4 == 0) {
617 				memcpy(&in4,
618 				       &((struct sockaddr_in *)
619 				       &lifreq.lifr_addr)->sin_addr,
620 				       sizeof in4);
621 				if (in4.s_addr == INADDR_ANY)
622 					break;
623 				n = ioctl(s, SIOCGLIFFLAGS, (char *)&lifreq);
624 				if (n < 0)
625 					break;
626 				if ((lifreq.lifr_flags & IFF_UP) == 0)
627 					break;
628 				*have_v4 = 1;
629 			}
630 			break;
631 		case AF_INET6:
632 			if (*have_v6 == 0) {
633 				memcpy(&in6,
634 				       &((struct sockaddr_in6 *)
635 				       &lifreq.lifr_addr)->sin6_addr, sizeof in6);
636 				if (memcmp(&in6, &in6addr_any, sizeof in6) == 0)
637 					break;
638 				n = ioctl(s, SIOCGLIFFLAGS, (char *)&lifreq);
639 				if (n < 0)
640 					break;
641 				if ((lifreq.lifr_flags & IFF_UP) == 0)
642 					break;
643 				*have_v6 = 1;
644 			}
645 			break;
646 		}
647 	}
648 	if (buf != NULL)
649 		memput(buf, bufsiz);
650 	close(s);
651 	/* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
652 	return;
653  cleanup:
654 	if (buf != NULL)
655 		memput(buf, bufsiz);
656 	if (s != -1)
657 		close(s);
658 	/* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
659 	return;
660 }
661 #endif
662 
663 static int
664 scan_interfaces(int *have_v4, int *have_v6) {
665 	struct ifconf ifc;
666 	union {
667 		char _pad[256];		/* leave space for IPv6 addresses */
668 		struct ifreq ifreq;
669 	} u;
670 	struct in_addr in4;
671 	struct in6_addr in6;
672 	char *buf = NULL, *cp, *cplim;
673 	static unsigned int bufsiz = 4095;
674 	int s, n;
675 	size_t cpsize;
676 
677 	/* Set to zero.  Used as loop terminators below. */
678 	*have_v4 = *have_v6 = 0;
679 
680 #if defined(SIOCGLIFCONF) && defined(SIOCGLIFADDR) && \
681     !defined(IRIX_EMUL_IOCTL_SIOCGIFCONF)
682 	/*
683 	 * Try to scan the interfaces using IPv6 ioctls().
684 	 */
685 	scan_interfaces6(have_v4, have_v6);
686 	if (*have_v4 != 0 && *have_v6 != 0)
687 		return (0);
688 #endif
689 
690 	/* Get interface list from system. */
691 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
692 		goto err_ret;
693 
694 	/*
695 	 * Grow buffer until large enough to contain all interface
696 	 * descriptions.
697 	 */
698 	for (;;) {
699 		buf = memget(bufsiz);
700 		if (buf == NULL)
701 			goto err_ret;
702 		ifc.ifc_len = bufsiz;
703 		ifc.ifc_buf = buf;
704 #ifdef IRIX_EMUL_IOCTL_SIOCGIFCONF
705 		/*
706 		 * This is a fix for IRIX OS in which the call to ioctl with
707 		 * the flag SIOCGIFCONF may not return an entry for all the
708 		 * interfaces like most flavors of Unix.
709 		 */
710 		if (emul_ioctl(&ifc) >= 0)
711 			break;
712 #else
713 		if ((n = ioctl(s, SIOCGIFCONF, (char *)&ifc)) != -1) {
714 			/*
715 			 * Some OS's just return what will fit rather
716 			 * than set EINVAL if the buffer is too small
717 			 * to fit all the interfaces in.  If
718 			 * ifc.ifc_len is too near to the end of the
719 			 * buffer we will grow it just in case and
720 			 * retry.
721 			 */
722 			if (ifc.ifc_len + 2 * sizeof(u.ifreq) < bufsiz)
723 				break;
724 		}
725 #endif
726 		if ((n == -1) && errno != EINVAL)
727 			goto err_ret;
728 
729 		if (bufsiz > 1000000)
730 			goto err_ret;
731 
732 		memput(buf, bufsiz);
733 		bufsiz += 4096;
734 	}
735 
736 	/* Parse system's interface list. */
737 	cplim = buf + ifc.ifc_len;    /* skip over if's with big ifr_addr's */
738 	for (cp = buf;
739 	     (*have_v4 == 0 || *have_v6 == 0) && cp < cplim;
740 	     cp += cpsize) {
741 		memcpy(&u.ifreq, cp, sizeof u.ifreq);
742 #ifdef HAVE_SA_LEN
743 #ifdef FIX_ZERO_SA_LEN
744 		if (u.ifreq.ifr_addr.sa_len == 0)
745 			u.ifreq.ifr_addr.sa_len = 16;
746 #endif
747 #ifdef HAVE_MINIMUM_IFREQ
748 		cpsize = sizeof u.ifreq;
749 		if (u.ifreq.ifr_addr.sa_len > sizeof (struct sockaddr))
750 			cpsize += (int)u.ifreq.ifr_addr.sa_len -
751 				(int)(sizeof (struct sockaddr));
752 #else
753 		cpsize = sizeof u.ifreq.ifr_name + u.ifreq.ifr_addr.sa_len;
754 #endif /* HAVE_MINIMUM_IFREQ */
755 		if (cpsize > sizeof u.ifreq && cpsize <= sizeof u)
756 			memcpy(&u.ifreq, cp, cpsize);
757 #elif defined SIOCGIFCONF_ADDR
758 		cpsize = sizeof u.ifreq;
759 #else
760 		cpsize = sizeof u.ifreq.ifr_name;
761 		/* XXX maybe this should be a hard error? */
762 		if (ioctl(s, SIOCGIFADDR, (char *)&u.ifreq) < 0)
763 			continue;
764 #endif
765 		switch (u.ifreq.ifr_addr.sa_family) {
766 		case AF_INET:
767 			if (*have_v4 == 0) {
768 				memcpy(&in4,
769 				       &((struct sockaddr_in *)
770 				       &u.ifreq.ifr_addr)->sin_addr,
771 				       sizeof in4);
772 				if (in4.s_addr == INADDR_ANY)
773 					break;
774 				n = ioctl(s, SIOCGIFFLAGS, (char *)&u.ifreq);
775 				if (n < 0)
776 					break;
777 				if ((u.ifreq.ifr_flags & IFF_UP) == 0)
778 					break;
779 				*have_v4 = 1;
780 			}
781 			break;
782 		case AF_INET6:
783 			if (*have_v6 == 0) {
784 				memcpy(&in6,
785 				       &((struct sockaddr_in6 *)
786 				       &u.ifreq.ifr_addr)->sin6_addr,
787 				       sizeof in6);
788 				if (memcmp(&in6, &in6addr_any, sizeof in6) == 0)
789 					break;
790 				n = ioctl(s, SIOCGIFFLAGS, (char *)&u.ifreq);
791 				if (n < 0)
792 					break;
793 				if ((u.ifreq.ifr_flags & IFF_UP) == 0)
794 					break;
795 				*have_v6 = 1;
796 			}
797 			break;
798 		}
799 	}
800 	if (buf != NULL)
801 		memput(buf, bufsiz);
802 	close(s);
803 	/* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
804 	return (0);
805  err_ret:
806 	if (buf != NULL)
807 		memput(buf, bufsiz);
808 	if (s != -1)
809 		close(s);
810 	/* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
811 	return (-1);
812 }
813 
814 static struct hostent *
815 copyandmerge(struct hostent *he1, struct hostent *he2, int af, int *error_num) {
816 	struct hostent *he = NULL;
817 	int addresses = 1;	/* NULL terminator */
818 	int names = 1;		/* NULL terminator */
819 	int len = 0;
820 	char **cpp, **npp;
821 
822 	/*
823 	 * Work out array sizes;
824 	 */
825 	if (he1 != NULL) {
826 		cpp = he1->h_addr_list;
827 		while (*cpp != NULL) {
828 			addresses++;
829 			cpp++;
830 		}
831 		cpp = he1->h_aliases;
832 		while (*cpp != NULL) {
833 			names++;
834 			cpp++;
835 		}
836 	}
837 
838 	if (he2 != NULL) {
839 		cpp = he2->h_addr_list;
840 		while (*cpp != NULL) {
841 			addresses++;
842 			cpp++;
843 		}
844 		if (he1 == NULL) {
845 			cpp = he2->h_aliases;
846 			while (*cpp != NULL) {
847 				names++;
848 				cpp++;
849 			}
850 		}
851 	}
852 
853 	if (addresses == 1) {
854 		*error_num = NO_ADDRESS;
855 		return (NULL);
856 	}
857 
858 	he = memget(sizeof *he);
859 	if (he == NULL)
860 		goto no_recovery;
861 
862 	he->h_addr_list = memget(sizeof(char *) * (addresses));
863 	if (he->h_addr_list == NULL)
864 		goto cleanup0;
865 	memset(he->h_addr_list, 0, sizeof(char *) * (addresses));
866 
867 	/* copy addresses */
868 	npp = he->h_addr_list;
869 	if (he1 != NULL) {
870 		cpp = he1->h_addr_list;
871 		while (*cpp != NULL) {
872 			*npp = memget((af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
873 			if (*npp == NULL)
874 				goto cleanup1;
875 			/* convert to mapped if required */
876 			if (af == AF_INET6 && he1->h_addrtype == AF_INET) {
877 				memcpy(*npp, in6addr_mapped,
878 				       sizeof in6addr_mapped);
879 				memcpy(*npp + sizeof in6addr_mapped, *cpp,
880 				       INADDRSZ);
881 			} else {
882 				memcpy(*npp, *cpp,
883 				       (af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
884 			}
885 			cpp++;
886 			npp++;
887 		}
888 	}
889 
890 	if (he2 != NULL) {
891 		cpp = he2->h_addr_list;
892 		while (*cpp != NULL) {
893 			*npp = memget((af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
894 			if (*npp == NULL)
895 				goto cleanup1;
896 			/* convert to mapped if required */
897 			if (af == AF_INET6 && he2->h_addrtype == AF_INET) {
898 				memcpy(*npp, in6addr_mapped,
899 				       sizeof in6addr_mapped);
900 				memcpy(*npp + sizeof in6addr_mapped, *cpp,
901 				       INADDRSZ);
902 			} else {
903 				memcpy(*npp, *cpp,
904 				       (af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
905 			}
906 			cpp++;
907 			npp++;
908 		}
909 	}
910 
911 	he->h_aliases = memget(sizeof(char *) * (names));
912 	if (he->h_aliases == NULL)
913 		goto cleanup1;
914 	memset(he->h_aliases, 0, sizeof(char *) * (names));
915 
916 	/* copy aliases */
917 	npp = he->h_aliases;
918 	cpp = (he1 != NULL) ? he1->h_aliases : he2->h_aliases;
919 	while (*cpp != NULL) {
920 		len = strlen (*cpp) + 1;
921 		*npp = memget(len);
922 		if (*npp == NULL)
923 			goto cleanup2;
924 		strcpy(*npp, *cpp);
925 		npp++;
926 		cpp++;
927 	}
928 
929 	/* copy hostname */
930 	he->h_name = memget(strlen((he1 != NULL) ?
931 			    he1->h_name : he2->h_name) + 1);
932 	if (he->h_name == NULL)
933 		goto cleanup2;
934 	strcpy(he->h_name, (he1 != NULL) ? he1->h_name : he2->h_name);
935 
936 	/* set address type and length */
937 	he->h_addrtype = af;
938 	he->h_length = (af == AF_INET) ? INADDRSZ : IN6ADDRSZ;
939 	return(he);
940 
941  cleanup2:
942 	cpp = he->h_aliases;
943 	while (*cpp != NULL) {
944 		memput(*cpp, strlen(*cpp) + 1);
945 		cpp++;
946 	}
947 	memput(he->h_aliases, sizeof(char *) * (names));
948 
949  cleanup1:
950 	cpp = he->h_addr_list;
951 	while (*cpp != NULL) {
952 		memput(*cpp, (af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
953 		*cpp = NULL;
954 		cpp++;
955 	}
956 	memput(he->h_addr_list, sizeof(char *) * (addresses));
957 
958  cleanup0:
959 	memput(he, sizeof *he);
960 
961  no_recovery:
962 	*error_num = NO_RECOVERY;
963 	return (NULL);
964 }
965 
966 static struct net_data *
967 init() {
968 	struct net_data *net_data;
969 
970 	if (!(net_data = net_data_init(NULL)))
971 		goto error;
972 	if (!net_data->ho) {
973 		net_data->ho = (*net_data->irs->ho_map)(net_data->irs);
974 		if (!net_data->ho || !net_data->res) {
975   error:
976 			errno = EIO;
977 			if (net_data && net_data->res)
978 				RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
979 			return (NULL);
980 		}
981 
982 		(*net_data->ho->res_set)(net_data->ho, net_data->res, NULL);
983 	}
984 
985 	return (net_data);
986 }
987 
988 static void
989 freepvt(struct net_data *net_data) {
990 	if (net_data->ho_data) {
991 		free(net_data->ho_data);
992 		net_data->ho_data = NULL;
993 	}
994 }
995 
996 static struct hostent *
997 fakeaddr(const char *name, int af, struct net_data *net_data) {
998 	struct pvt *pvt;
999 
1000 	freepvt(net_data);
1001 	net_data->ho_data = malloc(sizeof (struct pvt));
1002 	if (!net_data->ho_data) {
1003 		errno = ENOMEM;
1004 		RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
1005 		return (NULL);
1006 	}
1007 	pvt = net_data->ho_data;
1008 #ifndef __bsdi__
1009 	/*
1010 	 * Unlike its forebear(inet_aton), our friendly inet_pton() is strict
1011 	 * in its interpretation of its input, and it will only return "1" if
1012 	 * the input string is a formally valid(and thus unambiguous with
1013 	 * respect to host names) internet address specification for this AF.
1014 	 *
1015 	 * This means "telnet 0xdeadbeef" and "telnet 127.1" are dead now.
1016 	 */
1017 	if (inet_pton(af, name, pvt->addr) != 1) {
1018 #else
1019 	/* BSDI XXX
1020 	 * We put this back to inet_aton -- we really want the old behavior
1021 	 * Long live 127.1...
1022 	 */
1023 	if ((af != AF_INET ||
1024 	    inet_aton(name, (struct in_addr *)pvt->addr) != 1) &&
1025 	    inet_pton(af, name, pvt->addr) != 1) {
1026 #endif
1027 		RES_SET_H_ERRNO(net_data->res, HOST_NOT_FOUND);
1028 		return (NULL);
1029 	}
1030 	strncpy(pvt->name, name, NS_MAXDNAME);
1031 	pvt->name[NS_MAXDNAME] = '\0';
1032 	if (af == AF_INET && (net_data->res->options & RES_USE_INET6) != 0) {
1033 		map_v4v6_address(pvt->addr, pvt->addr);
1034 		af = AF_INET6;
1035 	}
1036 	pvt->host.h_addrtype = af;
1037 	switch(af) {
1038 	case AF_INET:
1039 		pvt->host.h_length = NS_INADDRSZ;
1040 		break;
1041 	case AF_INET6:
1042 		pvt->host.h_length = NS_IN6ADDRSZ;
1043 		break;
1044 	default:
1045 		errno = EAFNOSUPPORT;
1046 		RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
1047 		return (NULL);
1048 	}
1049 	pvt->host.h_name = pvt->name;
1050 	pvt->host.h_aliases = pvt->aliases;
1051 	pvt->aliases[0] = NULL;
1052 	pvt->addrs[0] = (char *)pvt->addr;
1053 	pvt->addrs[1] = NULL;
1054 	pvt->host.h_addr_list = pvt->addrs;
1055 	RES_SET_H_ERRNO(net_data->res, NETDB_SUCCESS);
1056 	return (&pvt->host);
1057 }
1058 
1059 #ifdef grot	/* for future use in gethostbyaddr(), for "SUNSECURITY" */
1060 	struct hostent *rhp;
1061 	char **haddr;
1062 	u_long old_options;
1063 	char hname2[MAXDNAME+1];
1064 
1065 	if (af == AF_INET) {
1066 	    /*
1067 	     * turn off search as the name should be absolute,
1068 	     * 'localhost' should be matched by defnames
1069 	     */
1070 	    strncpy(hname2, hp->h_name, MAXDNAME);
1071 	    hname2[MAXDNAME] = '\0';
1072 	    old_options = net_data->res->options;
1073 	    net_data->res->options &= ~RES_DNSRCH;
1074 	    net_data->res->options |= RES_DEFNAMES;
1075 	    if (!(rhp = gethostbyname(hname2))) {
1076 		net_data->res->options = old_options;
1077 		RES_SET_H_ERRNO(net_data->res, HOST_NOT_FOUND);
1078 		return (NULL);
1079 	    }
1080 	    net_data->res->options = old_options;
1081 	    for (haddr = rhp->h_addr_list; *haddr; haddr++)
1082 		if (!memcmp(*haddr, addr, INADDRSZ))
1083 			break;
1084 	    if (!*haddr) {
1085 		RES_SET_H_ERRNO(net_data->res, HOST_NOT_FOUND);
1086 		return (NULL);
1087 	    }
1088 	}
1089 #endif /* grot */
1090 
1091 #endif /*__BIND_NOSTATIC*/
1092