1 /*	$NetBSD: gethostent.c,v 1.1.1.1 2009/04/12 15:33:39 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
5  * Copyright (c) 1996-1999 by Internet Software Consortium.
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
17  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #if !defined(LINT) && !defined(CODECENTER)
21 static const char rcsid[] = "Id: gethostent.c,v 1.8 2006/01/10 05:06:00 marka Exp";
22 #endif
23 
24 /* Imports */
25 
26 #include "port_before.h"
27 
28 #if !defined(__BIND_NOSTATIC)
29 
30 #include <sys/types.h>
31 #include <sys/param.h>
32 #include <sys/socket.h>
33 #include <sys/ioctl.h>
34 #include <netinet/in.h>
35 #include <net/if.h>
36 #include <arpa/inet.h>
37 #include <arpa/nameser.h>
38 
39 #include <ctype.h>
40 #include <errno.h>
41 #include <stdlib.h>
42 #include <netdb.h>
43 #include <resolv.h>
44 #include <stdio.h>
45 #include <string.h>
46 #include <unistd.h>
47 
48 #include <irs.h>
49 #include <isc/memcluster.h>
50 
51 #include "port_after.h"
52 
53 #include "irs_p.h"
54 #include "irs_data.h"
55 
56 /* Definitions */
57 
58 struct pvt {
59 	char *		aliases[1];
60 	char *		addrs[2];
61 	char		addr[NS_IN6ADDRSZ];
62 	char		name[NS_MAXDNAME + 1];
63 	struct hostent	host;
64 };
65 
66 /* Forward */
67 
68 static struct net_data *init(void);
69 static void		freepvt(struct net_data *);
70 static struct hostent  *fakeaddr(const char *, int, struct net_data *);
71 
72 
73 /* Public */
74 
75 struct hostent *
76 gethostbyname(const char *name) {
77 	struct net_data *net_data = init();
78 
79 	return (gethostbyname_p(name, net_data));
80 }
81 
82 struct hostent *
83 gethostbyname2(const char *name, int af) {
84 	struct net_data *net_data = init();
85 
86 	return (gethostbyname2_p(name, af, net_data));
87 }
88 
89 struct hostent *
90 gethostbyaddr(const char *addr, int len, int af) {
91 	struct net_data *net_data = init();
92 
93 	return (gethostbyaddr_p(addr, len, af, net_data));
94 }
95 
96 struct hostent *
97 gethostent() {
98 	struct net_data *net_data = init();
99 
100 	return (gethostent_p(net_data));
101 }
102 
103 void
104 sethostent(int stayopen) {
105 	struct net_data *net_data = init();
106 	sethostent_p(stayopen, net_data);
107 }
108 
109 
110 void
111 endhostent() {
112 	struct net_data *net_data = init();
113 	endhostent_p(net_data);
114 }
115 
116 /* Shared private. */
117 
118 struct hostent *
119 gethostbyname_p(const char *name, struct net_data *net_data) {
120 	struct hostent *hp;
121 
122 	if (!net_data)
123 		return (NULL);
124 
125 	if (net_data->res->options & RES_USE_INET6) {
126 		hp = gethostbyname2_p(name, AF_INET6, net_data);
127 		if (hp)
128 			return (hp);
129 	}
130 	return (gethostbyname2_p(name, AF_INET, net_data));
131 }
132 
133 struct hostent *
134 gethostbyname2_p(const char *name, int af, struct net_data *net_data) {
135 	struct irs_ho *ho;
136 	char tmp[NS_MAXDNAME];
137 	struct hostent *hp;
138 	const char *cp;
139 	char **hap;
140 
141 	if (!net_data || !(ho = net_data->ho))
142 		return (NULL);
143 	if (net_data->ho_stayopen && net_data->ho_last &&
144 	    net_data->ho_last->h_addrtype == af) {
145 		if (ns_samename(name, net_data->ho_last->h_name) == 1)
146 			return (net_data->ho_last);
147 		for (hap = net_data->ho_last->h_aliases; hap && *hap; hap++)
148 			if (ns_samename(name, *hap) == 1)
149 				return (net_data->ho_last);
150 	}
151 	if (!strchr(name, '.') && (cp = res_hostalias(net_data->res, name,
152 						      tmp, sizeof tmp)))
153 		name = cp;
154 	if ((hp = fakeaddr(name, af, net_data)) != NULL)
155 		return (hp);
156 	net_data->ho_last = (*ho->byname2)(ho, name, af);
157 	if (!net_data->ho_stayopen)
158 		endhostent();
159 	return (net_data->ho_last);
160 }
161 
162 struct hostent *
163 gethostbyaddr_p(const char *addr, int len, int af, struct net_data *net_data) {
164 	struct irs_ho *ho;
165 	char **hap;
166 
167 	if (!net_data || !(ho = net_data->ho))
168 		return (NULL);
169 	if (net_data->ho_stayopen && net_data->ho_last &&
170 	    net_data->ho_last->h_length == len)
171 		for (hap = net_data->ho_last->h_addr_list;
172 		     hap && *hap;
173 		     hap++)
174 			if (!memcmp(addr, *hap, len))
175 				return (net_data->ho_last);
176 	net_data->ho_last = (*ho->byaddr)(ho, addr, len, af);
177 	if (!net_data->ho_stayopen)
178 		endhostent();
179 	return (net_data->ho_last);
180 }
181 
182 
183 struct hostent *
184 gethostent_p(struct net_data *net_data) {
185 	struct irs_ho *ho;
186 	struct hostent *hp;
187 
188 	if (!net_data || !(ho = net_data->ho))
189 		return (NULL);
190 	while ((hp = (*ho->next)(ho)) != NULL &&
191 	       hp->h_addrtype == AF_INET6 &&
192 	       (net_data->res->options & RES_USE_INET6) == 0U)
193 		continue;
194 	net_data->ho_last = hp;
195 	return (net_data->ho_last);
196 }
197 
198 
199 void
200 sethostent_p(int stayopen, struct net_data *net_data) {
201 	struct irs_ho *ho;
202 
203 	if (!net_data || !(ho = net_data->ho))
204 		return;
205 	freepvt(net_data);
206 	(*ho->rewind)(ho);
207 	net_data->ho_stayopen = (stayopen != 0);
208 	if (stayopen == 0)
209 		net_data_minimize(net_data);
210 }
211 
212 void
213 endhostent_p(struct net_data *net_data) {
214 	struct irs_ho *ho;
215 
216 	if ((net_data != NULL) && ((ho = net_data->ho) != NULL))
217 		(*ho->minimize)(ho);
218 }
219 
220 #ifndef IN6_IS_ADDR_V4COMPAT
221 static const unsigned char in6addr_compat[12] = {
222 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
223 #define IN6_IS_ADDR_V4COMPAT(x) (!memcmp((x)->s6_addr, in6addr_compat, 12) && \
224 				 ((x)->s6_addr[12] != 0 || \
225 				  (x)->s6_addr[13] != 0 || \
226 				  (x)->s6_addr[14] != 0 || \
227 				   ((x)->s6_addr[15] != 0 && \
228 				    (x)->s6_addr[15] != 1)))
229 #endif
230 #ifndef IN6_IS_ADDR_V4MAPPED
231 #define IN6_IS_ADDR_V4MAPPED(x) (!memcmp((x)->s6_addr, in6addr_mapped, 12))
232 #endif
233 
234 static const unsigned char in6addr_mapped[12] = {
235 	0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0xff, 0xff };
236 
237 static int scan_interfaces(int *, int *);
238 static struct hostent *copyandmerge(struct hostent *, struct hostent *, int, int *);
239 
240 /*%
241  *	Public functions
242  */
243 
244 /*%
245  *	AI_V4MAPPED + AF_INET6
246  *	If no IPv6 address then a query for IPv4 and map returned values.
247  *
248  *	AI_ALL + AI_V4MAPPED + AF_INET6
249  *	Return IPv6 and IPv4 mapped.
250  *
251  *	AI_ADDRCONFIG
252  *	Only return IPv6 / IPv4 address if there is an interface of that
253  *	type active.
254  */
255 
256 struct hostent *
257 getipnodebyname(const char *name, int af, int flags, int *error_num) {
258 	int have_v4 = 1, have_v6 = 1;
259 	struct in_addr in4;
260 	struct in6_addr in6;
261 	struct hostent he, *he1 = NULL, *he2 = NULL, *he3;
262 	int v4 = 0, v6 = 0;
263 	struct net_data *net_data = init();
264 	u_long options;
265 	int tmp_err;
266 
267 	if (net_data == NULL) {
268 		*error_num = NO_RECOVERY;
269 		return (NULL);
270 	}
271 
272 	/* If we care about active interfaces then check. */
273 	if ((flags & AI_ADDRCONFIG) != 0)
274 		if (scan_interfaces(&have_v4, &have_v6) == -1) {
275 			*error_num = NO_RECOVERY;
276 			return (NULL);
277 		}
278 
279 	/* Check for literal address. */
280 	if ((v4 = inet_pton(AF_INET, name, &in4)) != 1)
281 		v6 = inet_pton(AF_INET6, name, &in6);
282 
283 	/* Impossible combination? */
284 
285 	if ((af == AF_INET6 && (flags & AI_V4MAPPED) == 0 && v4 == 1) ||
286 	    (af == AF_INET && v6 == 1) ||
287 	    (have_v4 == 0 && v4 == 1) ||
288 	    (have_v6 == 0 && v6 == 1) ||
289 	    (have_v4 == 0 && af == AF_INET) ||
290 	    (have_v6 == 0 && af == AF_INET6)) {
291 		*error_num = HOST_NOT_FOUND;
292 		return (NULL);
293 	}
294 
295 	/* Literal address? */
296 	if (v4 == 1 || v6 == 1) {
297 		char *addr_list[2];
298 		char *aliases[1];
299 
300 		DE_CONST(name, he.h_name);
301 		he.h_addr_list = addr_list;
302 		he.h_addr_list[0] = (v4 == 1) ? (char *)&in4 : (char *)&in6;
303 		he.h_addr_list[1] = NULL;
304 		he.h_aliases = aliases;
305 		he.h_aliases[0] = NULL;
306 		he.h_length = (v4 == 1) ? INADDRSZ : IN6ADDRSZ;
307 		he.h_addrtype = (v4 == 1) ? AF_INET : AF_INET6;
308 		return (copyandmerge(&he, NULL, af, error_num));
309 	}
310 
311 	options = net_data->res->options;
312 	net_data->res->options &= ~RES_USE_INET6;
313 
314 	tmp_err = NO_RECOVERY;
315 	if (have_v6 && af == AF_INET6) {
316 		he2 = gethostbyname2_p(name, AF_INET6, net_data);
317 		if (he2 != NULL) {
318 			he1 = copyandmerge(he2, NULL, af, error_num);
319 			if (he1 == NULL)
320 				return (NULL);
321 			he2 = NULL;
322 		} else {
323 			tmp_err = net_data->res->res_h_errno;
324 		}
325 	}
326 
327 	if (have_v4 &&
328 	    ((af == AF_INET) ||
329 	     (af == AF_INET6 && (flags & AI_V4MAPPED) != 0 &&
330 	      (he1 == NULL || (flags & AI_ALL) != 0)))) {
331 		he2 = gethostbyname2_p(name, AF_INET, net_data);
332 		if (he1 == NULL && he2 == NULL) {
333 			*error_num = net_data->res->res_h_errno;
334 			return (NULL);
335 		}
336 	} else
337 		*error_num = tmp_err;
338 
339 	net_data->res->options = options;
340 
341 	he3 = copyandmerge(he1, he2, af, error_num);
342 
343 	if (he1 != NULL)
344 		freehostent(he1);
345 	return (he3);
346 }
347 
348 struct hostent *
349 getipnodebyaddr(const void *src, size_t len, int af, int *error_num) {
350 	struct hostent *he1, *he2;
351 	struct net_data *net_data = init();
352 
353 	/* Sanity Checks. */
354 	if (src == NULL) {
355 		*error_num = NO_RECOVERY;
356 		return (NULL);
357 	}
358 
359 	switch (af) {
360 	case AF_INET:
361 		if (len != (size_t)INADDRSZ) {
362 			*error_num = NO_RECOVERY;
363 			return (NULL);
364 		}
365 		break;
366 	case AF_INET6:
367 		if (len != (size_t)IN6ADDRSZ) {
368 			*error_num = NO_RECOVERY;
369 			return (NULL);
370 		}
371 		break;
372 	default:
373 		*error_num = NO_RECOVERY;
374 		return (NULL);
375 	}
376 
377 	/*
378 	 * Lookup IPv4 and IPv4 mapped/compatible addresses
379 	 */
380 	if ((af == AF_INET6 &&
381 	     IN6_IS_ADDR_V4COMPAT((const struct in6_addr *)src)) ||
382 	    (af == AF_INET6 &&
383 	     IN6_IS_ADDR_V4MAPPED((const struct in6_addr *)src)) ||
384 	    (af == AF_INET)) {
385 		const char *cp = src;
386 
387 		if (af == AF_INET6)
388 			cp += 12;
389 		he1 = gethostbyaddr_p(cp, 4, AF_INET, net_data);
390 		if (he1 == NULL) {
391 			*error_num = net_data->res->res_h_errno;
392 			return (NULL);
393 		}
394 		he2 = copyandmerge(he1, NULL, af, error_num);
395 		if (he2 == NULL)
396 			return (NULL);
397 		/*
398 		 * Restore original address if mapped/compatible.
399 		 */
400 		if (af == AF_INET6)
401 			memcpy(he1->h_addr, src, len);
402 		return (he2);
403 	}
404 
405 	/*
406 	 * Lookup IPv6 address.
407 	 */
408 	if (memcmp((const struct in6_addr *)src, &in6addr_any, 16) == 0) {
409 		*error_num = HOST_NOT_FOUND;
410 		return (NULL);
411 	}
412 
413 	he1 = gethostbyaddr_p(src, 16, AF_INET6, net_data);
414 	if (he1 == NULL) {
415 		*error_num = net_data->res->res_h_errno;
416 		return (NULL);
417 	}
418 	return (copyandmerge(he1, NULL, af, error_num));
419 }
420 
421 void
422 freehostent(struct hostent *he) {
423 	char **cpp;
424 	int names = 1;
425 	int addresses = 1;
426 
427 	memput(he->h_name, strlen(he->h_name) + 1);
428 
429 	cpp = he->h_addr_list;
430 	while (*cpp != NULL) {
431 		memput(*cpp, (he->h_addrtype == AF_INET) ?
432 			     INADDRSZ : IN6ADDRSZ);
433 		*cpp = NULL;
434 		cpp++;
435 		addresses++;
436 	}
437 
438 	cpp = he->h_aliases;
439 	while (*cpp != NULL) {
440 		memput(*cpp, strlen(*cpp) + 1);
441 		cpp++;
442 		names++;
443 	}
444 
445 	memput(he->h_aliases, sizeof(char *) * (names));
446 	memput(he->h_addr_list, sizeof(char *) * (addresses));
447 	memput(he, sizeof *he);
448 }
449 
450 /*%
451  * Private
452  */
453 
454 /*%
455  * Scan the interface table and set have_v4 and have_v6 depending
456  * upon whether there are IPv4 and IPv6 interface addresses.
457  *
458  * Returns:
459  *	0 on success
460  *	-1 on failure.
461  */
462 
463 #if defined(SIOCGLIFCONF) && defined(SIOCGLIFADDR) && \
464     !defined(IRIX_EMUL_IOCTL_SIOCGIFCONF)
465 
466 #ifdef __hpux
467 #define lifc_len iflc_len
468 #define lifc_buf iflc_buf
469 #define lifc_req iflc_req
470 #define LIFCONF if_laddrconf
471 #else
472 #define SETFAMILYFLAGS
473 #define LIFCONF lifconf
474 #endif
475 
476 #ifdef __hpux
477 #define lifr_addr iflr_addr
478 #define lifr_name iflr_name
479 #define lifr_dstaddr iflr_dstaddr
480 #define lifr_flags iflr_flags
481 #define ss_family sa_family
482 #define LIFREQ if_laddrreq
483 #else
484 #define LIFREQ lifreq
485 #endif
486 
487 static void
488 scan_interfaces6(int *have_v4, int *have_v6) {
489 	struct LIFCONF lifc;
490 	struct LIFREQ lifreq;
491 	struct in_addr in4;
492 	struct in6_addr in6;
493 	char *buf = NULL, *cp, *cplim;
494 	static unsigned int bufsiz = 4095;
495 	int s, cpsize, n;
496 
497 	/* Get interface list from system. */
498 	if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) == -1)
499 		goto cleanup;
500 
501 	/*
502 	 * Grow buffer until large enough to contain all interface
503 	 * descriptions.
504 	 */
505 	for (;;) {
506 		buf = memget(bufsiz);
507 		if (buf == NULL)
508 			goto cleanup;
509 #ifdef SETFAMILYFLAGS
510 		lifc.lifc_family = AF_UNSPEC;	/*%< request all families */
511 		lifc.lifc_flags = 0;
512 #endif
513 		lifc.lifc_len = bufsiz;
514 		lifc.lifc_buf = buf;
515 		if ((n = ioctl(s, SIOCGLIFCONF, (char *)&lifc)) != -1) {
516 			/*
517 			 * Some OS's just return what will fit rather
518 			 * than set EINVAL if the buffer is too small
519 			 * to fit all the interfaces in.  If
520 			 * lifc.lifc_len is too near to the end of the
521 			 * buffer we will grow it just in case and
522 			 * retry.
523 			 */
524 			if (lifc.lifc_len + 2 * sizeof(lifreq) < bufsiz)
525 				break;
526 		}
527 		if ((n == -1) && errno != EINVAL)
528 			goto cleanup;
529 
530 		if (bufsiz > 1000000)
531 			goto cleanup;
532 
533 		memput(buf, bufsiz);
534 		bufsiz += 4096;
535 	}
536 
537 	/* Parse system's interface list. */
538 	cplim = buf + lifc.lifc_len;    /*%< skip over if's with big ifr_addr's */
539 	for (cp = buf;
540 	     (*have_v4 == 0 || *have_v6 == 0) && cp < cplim;
541 	     cp += cpsize) {
542 		memcpy(&lifreq, cp, sizeof lifreq);
543 #ifdef HAVE_SA_LEN
544 #ifdef FIX_ZERO_SA_LEN
545 		if (lifreq.lifr_addr.sa_len == 0)
546 			lifreq.lifr_addr.sa_len = 16;
547 #endif
548 #ifdef HAVE_MINIMUM_IFREQ
549 		cpsize = sizeof lifreq;
550 		if (lifreq.lifr_addr.sa_len > sizeof (struct sockaddr))
551 			cpsize += (int)lifreq.lifr_addr.sa_len -
552 				(int)(sizeof (struct sockaddr));
553 #else
554 		cpsize = sizeof lifreq.lifr_name + lifreq.lifr_addr.sa_len;
555 #endif /* HAVE_MINIMUM_IFREQ */
556 #elif defined SIOCGIFCONF_ADDR
557 		cpsize = sizeof lifreq;
558 #else
559 		cpsize = sizeof lifreq.lifr_name;
560 		/* XXX maybe this should be a hard error? */
561 		if (ioctl(s, SIOCGLIFADDR, (char *)&lifreq) < 0)
562 			continue;
563 #endif
564 		switch (lifreq.lifr_addr.ss_family) {
565 		case AF_INET:
566 			if (*have_v4 == 0) {
567 				memcpy(&in4,
568 				       &((struct sockaddr_in *)
569 				       &lifreq.lifr_addr)->sin_addr,
570 				       sizeof in4);
571 				if (in4.s_addr == INADDR_ANY)
572 					break;
573 				n = ioctl(s, SIOCGLIFFLAGS, (char *)&lifreq);
574 				if (n < 0)
575 					break;
576 				if ((lifreq.lifr_flags & IFF_UP) == 0)
577 					break;
578 				*have_v4 = 1;
579 			}
580 			break;
581 		case AF_INET6:
582 			if (*have_v6 == 0) {
583 				memcpy(&in6,
584 				       &((struct sockaddr_in6 *)
585 				       &lifreq.lifr_addr)->sin6_addr, sizeof in6);
586 				if (memcmp(&in6, &in6addr_any, sizeof in6) == 0)
587 					break;
588 				n = ioctl(s, SIOCGLIFFLAGS, (char *)&lifreq);
589 				if (n < 0)
590 					break;
591 				if ((lifreq.lifr_flags & IFF_UP) == 0)
592 					break;
593 				*have_v6 = 1;
594 			}
595 			break;
596 		}
597 	}
598 	if (buf != NULL)
599 		memput(buf, bufsiz);
600 	close(s);
601 	/* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
602 	return;
603  cleanup:
604 	if (buf != NULL)
605 		memput(buf, bufsiz);
606 	if (s != -1)
607 		close(s);
608 	/* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
609 	return;
610 }
611 #endif
612 
613 #if ( defined(__linux__) || defined(__linux) || defined(LINUX) )
614 #ifndef IF_NAMESIZE
615 # ifdef IFNAMSIZ
616 #  define IF_NAMESIZE  IFNAMSIZ
617 # else
618 #  define IF_NAMESIZE 16
619 # endif
620 #endif
621 static void
622 scan_linux6(int *have_v6) {
623 	FILE *proc = NULL;
624 	char address[33];
625 	char name[IF_NAMESIZE+1];
626 	int ifindex, prefix, flag3, flag4;
627 
628 	proc = fopen("/proc/net/if_inet6", "r");
629 	if (proc == NULL)
630 		return;
631 
632 	if (fscanf(proc, "%32[a-f0-9] %x %x %x %x %16s\n",
633 		   address, &ifindex, &prefix, &flag3, &flag4, name) == 6)
634 		*have_v6 = 1;
635 	fclose(proc);
636 	return;
637 }
638 #endif
639 
640 static int
641 scan_interfaces(int *have_v4, int *have_v6) {
642 	struct ifconf ifc;
643 	union {
644 		char _pad[256];		/*%< leave space for IPv6 addresses */
645 		struct ifreq ifreq;
646 	} u;
647 	struct in_addr in4;
648 	struct in6_addr in6;
649 	char *buf = NULL, *cp, *cplim;
650 	static unsigned int bufsiz = 4095;
651 	int s, n;
652 	size_t cpsize;
653 
654 	/* Set to zero.  Used as loop terminators below. */
655 	*have_v4 = *have_v6 = 0;
656 
657 #if defined(SIOCGLIFCONF) && defined(SIOCGLIFADDR) && \
658     !defined(IRIX_EMUL_IOCTL_SIOCGIFCONF)
659 	/*
660 	 * Try to scan the interfaces using IPv6 ioctls().
661 	 */
662 	scan_interfaces6(have_v4, have_v6);
663 	if (*have_v4 != 0 && *have_v6 != 0)
664 		return (0);
665 #endif
666 #ifdef __linux
667 	scan_linux6(have_v6);
668 #endif
669 
670 	/* Get interface list from system. */
671 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
672 		goto err_ret;
673 
674 	/*
675 	 * Grow buffer until large enough to contain all interface
676 	 * descriptions.
677 	 */
678 	for (;;) {
679 		buf = memget(bufsiz);
680 		if (buf == NULL)
681 			goto err_ret;
682 		ifc.ifc_len = bufsiz;
683 		ifc.ifc_buf = buf;
684 #ifdef IRIX_EMUL_IOCTL_SIOCGIFCONF
685 		/*
686 		 * This is a fix for IRIX OS in which the call to ioctl with
687 		 * the flag SIOCGIFCONF may not return an entry for all the
688 		 * interfaces like most flavors of Unix.
689 		 */
690 		if (emul_ioctl(&ifc) >= 0)
691 			break;
692 #else
693 		if ((n = ioctl(s, SIOCGIFCONF, (char *)&ifc)) != -1) {
694 			/*
695 			 * Some OS's just return what will fit rather
696 			 * than set EINVAL if the buffer is too small
697 			 * to fit all the interfaces in.  If
698 			 * ifc.ifc_len is too near to the end of the
699 			 * buffer we will grow it just in case and
700 			 * retry.
701 			 */
702 			if (ifc.ifc_len + 2 * sizeof(u.ifreq) < bufsiz)
703 				break;
704 		}
705 #endif
706 		if ((n == -1) && errno != EINVAL)
707 			goto err_ret;
708 
709 		if (bufsiz > 1000000)
710 			goto err_ret;
711 
712 		memput(buf, bufsiz);
713 		bufsiz += 4096;
714 	}
715 
716 	/* Parse system's interface list. */
717 	cplim = buf + ifc.ifc_len;    /*%< skip over if's with big ifr_addr's */
718 	for (cp = buf;
719 	     (*have_v4 == 0 || *have_v6 == 0) && cp < cplim;
720 	     cp += cpsize) {
721 		memcpy(&u.ifreq, cp, sizeof u.ifreq);
722 #ifdef HAVE_SA_LEN
723 #ifdef FIX_ZERO_SA_LEN
724 		if (u.ifreq.ifr_addr.sa_len == 0)
725 			u.ifreq.ifr_addr.sa_len = 16;
726 #endif
727 #ifdef HAVE_MINIMUM_IFREQ
728 		cpsize = sizeof u.ifreq;
729 		if (u.ifreq.ifr_addr.sa_len > sizeof (struct sockaddr))
730 			cpsize += (int)u.ifreq.ifr_addr.sa_len -
731 				(int)(sizeof (struct sockaddr));
732 #else
733 		cpsize = sizeof u.ifreq.ifr_name + u.ifreq.ifr_addr.sa_len;
734 #endif /* HAVE_MINIMUM_IFREQ */
735 		if (cpsize > sizeof u.ifreq && cpsize <= sizeof u)
736 			memcpy(&u.ifreq, cp, cpsize);
737 #elif defined SIOCGIFCONF_ADDR
738 		cpsize = sizeof u.ifreq;
739 #else
740 		cpsize = sizeof u.ifreq.ifr_name;
741 		/* XXX maybe this should be a hard error? */
742 		if (ioctl(s, SIOCGIFADDR, (char *)&u.ifreq) < 0)
743 			continue;
744 #endif
745 		switch (u.ifreq.ifr_addr.sa_family) {
746 		case AF_INET:
747 			if (*have_v4 == 0) {
748 				memcpy(&in4,
749 				       &((struct sockaddr_in *)
750 				       &u.ifreq.ifr_addr)->sin_addr,
751 				       sizeof in4);
752 				if (in4.s_addr == INADDR_ANY)
753 					break;
754 				n = ioctl(s, SIOCGIFFLAGS, (char *)&u.ifreq);
755 				if (n < 0)
756 					break;
757 				if ((u.ifreq.ifr_flags & IFF_UP) == 0)
758 					break;
759 				*have_v4 = 1;
760 			}
761 			break;
762 		case AF_INET6:
763 			if (*have_v6 == 0) {
764 				memcpy(&in6,
765 				       &((struct sockaddr_in6 *)
766 				       &u.ifreq.ifr_addr)->sin6_addr,
767 				       sizeof in6);
768 				if (memcmp(&in6, &in6addr_any, sizeof in6) == 0)
769 					break;
770 				n = ioctl(s, SIOCGIFFLAGS, (char *)&u.ifreq);
771 				if (n < 0)
772 					break;
773 				if ((u.ifreq.ifr_flags & IFF_UP) == 0)
774 					break;
775 				*have_v6 = 1;
776 			}
777 			break;
778 		}
779 	}
780 	if (buf != NULL)
781 		memput(buf, bufsiz);
782 	close(s);
783 	/* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
784 	return (0);
785  err_ret:
786 	if (buf != NULL)
787 		memput(buf, bufsiz);
788 	if (s != -1)
789 		close(s);
790 	/* printf("scan interface -> 4=%d 6=%d\n", *have_v4, *have_v6); */
791 	return (-1);
792 }
793 
794 static struct hostent *
795 copyandmerge(struct hostent *he1, struct hostent *he2, int af, int *error_num) {
796 	struct hostent *he = NULL;
797 	int addresses = 1;	/*%< NULL terminator */
798 	int names = 1;		/*%< NULL terminator */
799 	int len = 0;
800 	char **cpp, **npp;
801 
802 	/*
803 	 * Work out array sizes;
804 	 */
805 	if (he1 != NULL) {
806 		cpp = he1->h_addr_list;
807 		while (*cpp != NULL) {
808 			addresses++;
809 			cpp++;
810 		}
811 		cpp = he1->h_aliases;
812 		while (*cpp != NULL) {
813 			names++;
814 			cpp++;
815 		}
816 	}
817 
818 	if (he2 != NULL) {
819 		cpp = he2->h_addr_list;
820 		while (*cpp != NULL) {
821 			addresses++;
822 			cpp++;
823 		}
824 		if (he1 == NULL) {
825 			cpp = he2->h_aliases;
826 			while (*cpp != NULL) {
827 				names++;
828 				cpp++;
829 			}
830 		}
831 	}
832 
833 	if (addresses == 1) {
834 		*error_num = NO_ADDRESS;
835 		return (NULL);
836 	}
837 
838 	he = memget(sizeof *he);
839 	if (he == NULL)
840 		goto no_recovery;
841 
842 	he->h_addr_list = memget(sizeof(char *) * (addresses));
843 	if (he->h_addr_list == NULL)
844 		goto cleanup0;
845 	memset(he->h_addr_list, 0, sizeof(char *) * (addresses));
846 
847 	/* copy addresses */
848 	npp = he->h_addr_list;
849 	if (he1 != NULL) {
850 		cpp = he1->h_addr_list;
851 		while (*cpp != NULL) {
852 			*npp = memget((af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
853 			if (*npp == NULL)
854 				goto cleanup1;
855 			/* convert to mapped if required */
856 			if (af == AF_INET6 && he1->h_addrtype == AF_INET) {
857 				memcpy(*npp, in6addr_mapped,
858 				       sizeof in6addr_mapped);
859 				memcpy(*npp + sizeof in6addr_mapped, *cpp,
860 				       INADDRSZ);
861 			} else {
862 				memcpy(*npp, *cpp,
863 				       (af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
864 			}
865 			cpp++;
866 			npp++;
867 		}
868 	}
869 
870 	if (he2 != NULL) {
871 		cpp = he2->h_addr_list;
872 		while (*cpp != NULL) {
873 			*npp = memget((af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
874 			if (*npp == NULL)
875 				goto cleanup1;
876 			/* convert to mapped if required */
877 			if (af == AF_INET6 && he2->h_addrtype == AF_INET) {
878 				memcpy(*npp, in6addr_mapped,
879 				       sizeof in6addr_mapped);
880 				memcpy(*npp + sizeof in6addr_mapped, *cpp,
881 				       INADDRSZ);
882 			} else {
883 				memcpy(*npp, *cpp,
884 				       (af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
885 			}
886 			cpp++;
887 			npp++;
888 		}
889 	}
890 
891 	he->h_aliases = memget(sizeof(char *) * (names));
892 	if (he->h_aliases == NULL)
893 		goto cleanup1;
894 	memset(he->h_aliases, 0, sizeof(char *) * (names));
895 
896 	/* copy aliases */
897 	npp = he->h_aliases;
898 	cpp = (he1 != NULL) ? he1->h_aliases : he2->h_aliases;
899 	while (*cpp != NULL) {
900 		len = strlen (*cpp) + 1;
901 		*npp = memget(len);
902 		if (*npp == NULL)
903 			goto cleanup2;
904 		strcpy(*npp, *cpp);
905 		npp++;
906 		cpp++;
907 	}
908 
909 	/* copy hostname */
910 	he->h_name = memget(strlen((he1 != NULL) ?
911 			    he1->h_name : he2->h_name) + 1);
912 	if (he->h_name == NULL)
913 		goto cleanup2;
914 	strcpy(he->h_name, (he1 != NULL) ? he1->h_name : he2->h_name);
915 
916 	/* set address type and length */
917 	he->h_addrtype = af;
918 	he->h_length = (af == AF_INET) ? INADDRSZ : IN6ADDRSZ;
919 	return(he);
920 
921  cleanup2:
922 	cpp = he->h_aliases;
923 	while (*cpp != NULL) {
924 		memput(*cpp, strlen(*cpp) + 1);
925 		cpp++;
926 	}
927 	memput(he->h_aliases, sizeof(char *) * (names));
928 
929  cleanup1:
930 	cpp = he->h_addr_list;
931 	while (*cpp != NULL) {
932 		memput(*cpp, (af == AF_INET) ? INADDRSZ : IN6ADDRSZ);
933 		*cpp = NULL;
934 		cpp++;
935 	}
936 	memput(he->h_addr_list, sizeof(char *) * (addresses));
937 
938  cleanup0:
939 	memput(he, sizeof *he);
940 
941  no_recovery:
942 	*error_num = NO_RECOVERY;
943 	return (NULL);
944 }
945 
946 static struct net_data *
947 init() {
948 	struct net_data *net_data;
949 
950 	if (!(net_data = net_data_init(NULL)))
951 		goto error;
952 	if (!net_data->ho) {
953 		net_data->ho = (*net_data->irs->ho_map)(net_data->irs);
954 		if (!net_data->ho || !net_data->res) {
955   error:
956 			errno = EIO;
957 			if (net_data && net_data->res)
958 				RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
959 			return (NULL);
960 		}
961 
962 		(*net_data->ho->res_set)(net_data->ho, net_data->res, NULL);
963 	}
964 
965 	return (net_data);
966 }
967 
968 static void
969 freepvt(struct net_data *net_data) {
970 	if (net_data->ho_data) {
971 		free(net_data->ho_data);
972 		net_data->ho_data = NULL;
973 	}
974 }
975 
976 static struct hostent *
977 fakeaddr(const char *name, int af, struct net_data *net_data) {
978 	struct pvt *pvt;
979 
980 	freepvt(net_data);
981 	net_data->ho_data = malloc(sizeof (struct pvt));
982 	if (!net_data->ho_data) {
983 		errno = ENOMEM;
984 		RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
985 		return (NULL);
986 	}
987 	pvt = net_data->ho_data;
988 #ifndef __bsdi__
989 	/*
990 	 * Unlike its forebear(inet_aton), our friendly inet_pton() is strict
991 	 * in its interpretation of its input, and it will only return "1" if
992 	 * the input string is a formally valid(and thus unambiguous with
993 	 * respect to host names) internet address specification for this AF.
994 	 *
995 	 * This means "telnet 0xdeadbeef" and "telnet 127.1" are dead now.
996 	 */
997 	if (inet_pton(af, name, pvt->addr) != 1) {
998 #else
999 	/* BSDI XXX
1000 	 * We put this back to inet_aton -- we really want the old behavior
1001 	 * Long live 127.1...
1002 	 */
1003 	if ((af != AF_INET ||
1004 	    inet_aton(name, (struct in_addr *)pvt->addr) != 1) &&
1005 	    inet_pton(af, name, pvt->addr) != 1) {
1006 #endif
1007 		RES_SET_H_ERRNO(net_data->res, HOST_NOT_FOUND);
1008 		return (NULL);
1009 	}
1010 	strncpy(pvt->name, name, NS_MAXDNAME);
1011 	pvt->name[NS_MAXDNAME] = '\0';
1012 	if (af == AF_INET && (net_data->res->options & RES_USE_INET6) != 0U) {
1013 		map_v4v6_address(pvt->addr, pvt->addr);
1014 		af = AF_INET6;
1015 	}
1016 	pvt->host.h_addrtype = af;
1017 	switch(af) {
1018 	case AF_INET:
1019 		pvt->host.h_length = NS_INADDRSZ;
1020 		break;
1021 	case AF_INET6:
1022 		pvt->host.h_length = NS_IN6ADDRSZ;
1023 		break;
1024 	default:
1025 		errno = EAFNOSUPPORT;
1026 		RES_SET_H_ERRNO(net_data->res, NETDB_INTERNAL);
1027 		return (NULL);
1028 	}
1029 	pvt->host.h_name = pvt->name;
1030 	pvt->host.h_aliases = pvt->aliases;
1031 	pvt->aliases[0] = NULL;
1032 	pvt->addrs[0] = (char *)pvt->addr;
1033 	pvt->addrs[1] = NULL;
1034 	pvt->host.h_addr_list = pvt->addrs;
1035 	RES_SET_H_ERRNO(net_data->res, NETDB_SUCCESS);
1036 	return (&pvt->host);
1037 }
1038 
1039 #ifdef grot	/*%< for future use in gethostbyaddr(), for "SUNSECURITY" */
1040 	struct hostent *rhp;
1041 	char **haddr;
1042 	u_long old_options;
1043 	char hname2[MAXDNAME+1];
1044 
1045 	if (af == AF_INET) {
1046 	    /*
1047 	     * turn off search as the name should be absolute,
1048 	     * 'localhost' should be matched by defnames
1049 	     */
1050 	    strncpy(hname2, hp->h_name, MAXDNAME);
1051 	    hname2[MAXDNAME] = '\0';
1052 	    old_options = net_data->res->options;
1053 	    net_data->res->options &= ~RES_DNSRCH;
1054 	    net_data->res->options |= RES_DEFNAMES;
1055 	    if (!(rhp = gethostbyname(hname2))) {
1056 		net_data->res->options = old_options;
1057 		RES_SET_H_ERRNO(net_data->res, HOST_NOT_FOUND);
1058 		return (NULL);
1059 	    }
1060 	    net_data->res->options = old_options;
1061 	    for (haddr = rhp->h_addr_list; *haddr; haddr++)
1062 		if (!memcmp(*haddr, addr, INADDRSZ))
1063 			break;
1064 	    if (!*haddr) {
1065 		RES_SET_H_ERRNO(net_data->res, HOST_NOT_FOUND);
1066 		return (NULL);
1067 	    }
1068 	}
1069 #endif /* grot */
1070 #endif /*__BIND_NOSTATIC*/
1071 
1072 /*! \file */
1073