1/*	$NetBSD: gethnamaddr.c,v 1.91 2014/06/19 15:08:18 christos Exp $	*/
2
3/*
4 * ++Copyright++ 1985, 1988, 1993
5 * -
6 * Copyright (c) 1985, 1988, 1993
7 *    The Regents of the University of California.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 * -
33 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
34 *
35 * Permission to use, copy, modify, and distribute this software for any
36 * purpose with or without fee is hereby granted, provided that the above
37 * copyright notice and this permission notice appear in all copies, and that
38 * the name of Digital Equipment Corporation not be used in advertising or
39 * publicity pertaining to distribution of the document or software without
40 * specific, written prior permission.
41 *
42 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
43 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
44 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
45 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
46 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
47 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
48 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
49 * SOFTWARE.
50 * -
51 * --Copyright--
52 */
53
54#include <sys/cdefs.h>
55#include <sys/types.h>
56
57#include <sys/param.h>
58#include <sys/socket.h>
59#include <sys/un.h>
60#include <netinet/in.h>
61#include <arpa/inet.h>
62#include <arpa/nameser.h>
63#include "NetdClientDispatch.h"
64#include "resolv_netid.h"
65#include "resolv_private.h"
66#include "resolv_cache.h"
67#include <assert.h>
68#include <ctype.h>
69#include <errno.h>
70#include <netdb.h>
71#include <stdarg.h>
72#include <stdbool.h>
73#include <stdio.h>
74#include <strings.h>
75#include <syslog.h>
76#include <unistd.h>
77
78#define ALIGNBYTES (sizeof(uintptr_t) - 1)
79#define ALIGN(p) (((uintptr_t)(p) + ALIGNBYTES) &~ ALIGNBYTES)
80
81#ifndef LOG_AUTH
82# define LOG_AUTH 0
83#endif
84
85#define MULTI_PTRS_ARE_ALIASES 1	/* XXX - experimental */
86
87#include "nsswitch.h"
88#include <stdlib.h>
89#include <string.h>
90
91#include "hostent.h"
92
93#define maybe_ok(res, nm, ok) (((res)->options & RES_NOCHECKNAME) != 0U || \
94                               (ok)(nm) != 0)
95#define maybe_hnok(res, hn) maybe_ok((res), (hn), res_hnok)
96#define maybe_dnok(res, dn) maybe_ok((res), (dn), res_dnok)
97
98#define addalias(d, s, arr, siz) do {			\
99	if (d >= &arr[siz]) {				\
100		char **xptr = realloc(arr, (siz + 10) * sizeof(*arr)); \
101		if (xptr == NULL)			\
102			goto nospc;			\
103		d = xptr + (d - arr);			\
104		arr = xptr;				\
105		siz += 10;				\
106	}						\
107	*d++ = s;					\
108} while (/*CONSTCOND*/0)
109
110#define setup(arr, siz) do {				\
111	arr = malloc((siz = 10) * sizeof(*arr)); 	\
112	if (arr == NULL)				\
113		goto nospc;				\
114} while (/*CONSTCOND*/0)
115
116// This should be synchronized to ResponseCode.h
117static const int DnsProxyQueryResult = 222;
118
119static const char AskedForGot[] =
120			  "gethostby*.getanswer: asked for \"%s\", got \"%s\"";
121
122#define	MAXPACKET	(64*1024)
123
124typedef union {
125    HEADER hdr;
126    u_char buf[MAXPACKET];
127} querybuf;
128
129typedef union {
130    int32_t al;
131    char ac;
132} align;
133
134#ifdef DEBUG
135static void debugprintf(const char *, res_state, ...)
136	__attribute__((__format__(__printf__, 1, 3)));
137#endif
138static struct hostent *getanswer(const querybuf *, int, const char *, int,
139    res_state, struct hostent *, char *, size_t, int *);
140static void map_v4v6_address(const char *, char *);
141static void map_v4v6_hostent(struct hostent *, char **, char *);
142static void addrsort(char **, int, res_state);
143
144void ht_sethostent(int);
145void ht_endhostent(void);
146struct hostent *ht_gethostbyname(char *);
147struct hostent *ht_gethostbyaddr(const char *, int, int);
148void dns_service(void);
149#undef dn_skipname
150int dn_skipname(const u_char *, const u_char *);
151static int _dns_gethtbyaddr(void *, void *, va_list);
152static int _dns_gethtbyname(void *, void *, va_list);
153
154static struct hostent *gethostbyname_internal(const char *, int, res_state,
155    struct hostent *, char *, size_t, int *, unsigned, unsigned);
156static struct hostent* android_gethostbyaddrfornet_proxy_internal(const void*, socklen_t,
157    int, struct hostent *, char *, size_t, int *, unsigned, unsigned);
158
159static const ns_src default_dns_files[] = {
160	{ NSSRC_FILES, 	NS_SUCCESS },
161	{ NSSRC_DNS, 	NS_SUCCESS },
162	{ 0, 0 }
163};
164
165
166#ifdef DEBUG
167static void
168debugprintf(const char *msg, res_state res, ...)
169{
170	_DIAGASSERT(msg != NULL);
171
172	if (res->options & RES_DEBUG) {
173		int save = errno;
174		va_list ap;
175
176		va_start (ap, res);
177		vprintf(msg, ap);
178		va_end (ap);
179
180		errno = save;
181	}
182}
183#else
184# define debugprintf(msg, res, num) /*nada*/
185#endif
186
187#define BOUNDED_INCR(x) \
188	do { \
189		cp += (x); \
190		if (cp > eom) \
191			goto no_recovery; \
192	} while (/*CONSTCOND*/0)
193
194#define BOUNDS_CHECK(ptr, count) \
195	do { \
196		if ((ptr) + (count) > eom) \
197			goto no_recovery; \
198	} while (/*CONSTCOND*/0)
199
200static struct hostent *
201getanswer(const querybuf *answer, int anslen, const char *qname, int qtype,
202    res_state res, struct hostent *hent, char *buf, size_t buflen, int *he)
203{
204	const HEADER *hp;
205	const u_char *cp;
206	int n;
207	size_t qlen;
208	const u_char *eom, *erdata;
209	char *bp, **ap, **hap, *ep;
210	int type, class, ancount, qdcount;
211	int haveanswer, had_error;
212	int toobig = 0;
213	char tbuf[MAXDNAME];
214	char **aliases;
215	size_t maxaliases;
216	char *addr_ptrs[MAXADDRS];
217	const char *tname;
218	int (*name_ok)(const char *);
219
220	_DIAGASSERT(answer != NULL);
221	_DIAGASSERT(qname != NULL);
222
223	tname = qname;
224	hent->h_name = NULL;
225	eom = answer->buf + anslen;
226	switch (qtype) {
227	case T_A:
228	case T_AAAA:
229		name_ok = res_hnok;
230		break;
231	case T_PTR:
232		name_ok = res_dnok;
233		break;
234	default:
235	  *he = NO_RECOVERY;
236		return NULL;	/* XXX should be abort(); */
237	}
238
239	setup(aliases, maxaliases);
240	/*
241	 * find first satisfactory answer
242	 */
243	hp = &answer->hdr;
244	ancount = ntohs(hp->ancount);
245	qdcount = ntohs(hp->qdcount);
246	bp = buf;
247	ep = buf + buflen;
248	cp = answer->buf;
249	BOUNDED_INCR(HFIXEDSZ);
250	if (qdcount != 1)
251		goto no_recovery;
252
253	n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
254	if ((n < 0) || !maybe_ok(res, bp, name_ok))
255		goto no_recovery;
256
257	BOUNDED_INCR(n + QFIXEDSZ);
258	if (qtype == T_A || qtype == T_AAAA) {
259		/* res_send() has already verified that the query name is the
260		 * same as the one we sent; this just gets the expanded name
261		 * (i.e., with the succeeding search-domain tacked on).
262		 */
263		n = (int)strlen(bp) + 1;		/* for the \0 */
264		if (n >= MAXHOSTNAMELEN)
265			goto no_recovery;
266		hent->h_name = bp;
267		bp += n;
268		/* The qname can be abbreviated, but h_name is now absolute. */
269		qname = hent->h_name;
270	}
271	hent->h_aliases = ap = aliases;
272	hent->h_addr_list = hap = addr_ptrs;
273	*ap = NULL;
274	*hap = NULL;
275	haveanswer = 0;
276	had_error = 0;
277	while (ancount-- > 0 && cp < eom && !had_error) {
278		n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
279		if ((n < 0) || !maybe_ok(res, bp, name_ok)) {
280			had_error++;
281			continue;
282		}
283		cp += n;			/* name */
284		BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ);
285		type = _getshort(cp);
286 		cp += INT16SZ;			/* type */
287		class = _getshort(cp);
288 		cp += INT16SZ + INT32SZ;	/* class, TTL */
289		n = _getshort(cp);
290		cp += INT16SZ;			/* len */
291		BOUNDS_CHECK(cp, n);
292		erdata = cp + n;
293		if (class != C_IN) {
294			/* XXX - debug? syslog? */
295			cp += n;
296			continue;		/* XXX - had_error++ ? */
297		}
298		if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) {
299			n = dn_expand(answer->buf, eom, cp, tbuf,
300			    (int)sizeof tbuf);
301			if ((n < 0) || !maybe_ok(res, tbuf, name_ok)) {
302				had_error++;
303				continue;
304			}
305			cp += n;
306			if (cp != erdata)
307				goto no_recovery;
308			/* Store alias. */
309			addalias(ap, bp, aliases, maxaliases);
310			n = (int)strlen(bp) + 1;	/* for the \0 */
311			if (n >= MAXHOSTNAMELEN) {
312				had_error++;
313				continue;
314			}
315			bp += n;
316			/* Get canonical name. */
317			n = (int)strlen(tbuf) + 1;	/* for the \0 */
318			if (n > ep - bp || n >= MAXHOSTNAMELEN) {
319				had_error++;
320				continue;
321			}
322			strlcpy(bp, tbuf, (size_t)(ep - bp));
323			hent->h_name = bp;
324			bp += n;
325			continue;
326		}
327		if (qtype == T_PTR && type == T_CNAME) {
328			n = dn_expand(answer->buf, eom, cp, tbuf,
329			    (int)sizeof tbuf);
330			if (n < 0 || !maybe_dnok(res, tbuf)) {
331				had_error++;
332				continue;
333			}
334			cp += n;
335			if (cp != erdata)
336				goto no_recovery;
337			/* Get canonical name. */
338			n = (int)strlen(tbuf) + 1;	/* for the \0 */
339			if (n > ep - bp || n >= MAXHOSTNAMELEN) {
340				had_error++;
341				continue;
342			}
343			strlcpy(bp, tbuf, (size_t)(ep - bp));
344			tname = bp;
345			bp += n;
346			continue;
347		}
348		if (type != qtype) {
349			if (type != T_KEY && type != T_SIG)
350				syslog(LOG_NOTICE|LOG_AUTH,
351	       "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
352				       qname, p_class(C_IN), p_type(qtype),
353				       p_type(type));
354			cp += n;
355			continue;		/* XXX - had_error++ ? */
356		}
357		switch (type) {
358		case T_PTR:
359			if (strcasecmp(tname, bp) != 0) {
360				syslog(LOG_NOTICE|LOG_AUTH,
361				       AskedForGot, qname, bp);
362				cp += n;
363				continue;	/* XXX - had_error++ ? */
364			}
365			n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
366			if ((n < 0) || !maybe_hnok(res, bp)) {
367				had_error++;
368				break;
369			}
370#if MULTI_PTRS_ARE_ALIASES
371			cp += n;
372			if (cp != erdata)
373				goto no_recovery;
374			if (!haveanswer)
375				hent->h_name = bp;
376			else
377				addalias(ap, bp, aliases, maxaliases);
378			if (n != -1) {
379				n = (int)strlen(bp) + 1;	/* for the \0 */
380				if (n >= MAXHOSTNAMELEN) {
381					had_error++;
382					break;
383				}
384				bp += n;
385			}
386			break;
387#else
388			hent->h_name = bp;
389			if (res->options & RES_USE_INET6) {
390				n = strlen(bp) + 1;	/* for the \0 */
391				if (n >= MAXHOSTNAMELEN) {
392					had_error++;
393					break;
394				}
395				bp += n;
396				map_v4v6_hostent(hent, &bp, ep);
397			}
398			goto success;
399#endif
400		case T_A:
401		case T_AAAA:
402			if (strcasecmp(hent->h_name, bp) != 0) {
403				syslog(LOG_NOTICE|LOG_AUTH,
404				       AskedForGot, hent->h_name, bp);
405				cp += n;
406				continue;	/* XXX - had_error++ ? */
407			}
408			if (n != hent->h_length) {
409				cp += n;
410				continue;
411			}
412			if (type == T_AAAA) {
413				struct in6_addr in6;
414				memcpy(&in6, cp, NS_IN6ADDRSZ);
415				if (IN6_IS_ADDR_V4MAPPED(&in6)) {
416					cp += n;
417					continue;
418				}
419			}
420			if (!haveanswer) {
421				int nn;
422
423				hent->h_name = bp;
424				nn = (int)strlen(bp) + 1;	/* for the \0 */
425				bp += nn;
426			}
427
428			bp += sizeof(align) -
429			    (size_t)((u_long)bp % sizeof(align));
430
431			if (bp + n >= ep) {
432				debugprintf("size (%d) too big\n", res, n);
433				had_error++;
434				continue;
435			}
436			if (hap >= &addr_ptrs[MAXADDRS - 1]) {
437				if (!toobig++) {
438					debugprintf("Too many addresses (%d)\n",
439						res, MAXADDRS);
440				}
441				cp += n;
442				continue;
443			}
444			(void)memcpy(*hap++ = bp, cp, (size_t)n);
445			bp += n;
446			cp += n;
447			if (cp != erdata)
448				goto no_recovery;
449			break;
450		default:
451			abort();
452		}
453		if (!had_error)
454			haveanswer++;
455	}
456	if (haveanswer) {
457		*ap = NULL;
458		*hap = NULL;
459		/*
460		 * Note: we sort even if host can take only one address
461		 * in its return structures - should give it the "best"
462		 * address in that case, not some random one
463		 */
464		if (res->nsort && haveanswer > 1 && qtype == T_A)
465			addrsort(addr_ptrs, haveanswer, res);
466		if (!hent->h_name) {
467			n = (int)strlen(qname) + 1;	/* for the \0 */
468			if (n > ep - bp || n >= MAXHOSTNAMELEN)
469				goto no_recovery;
470			strlcpy(bp, qname, (size_t)(ep - bp));
471			hent->h_name = bp;
472			bp += n;
473		}
474		if (res->options & RES_USE_INET6)
475			map_v4v6_hostent(hent, &bp, ep);
476	  goto success;
477	}
478no_recovery:
479	free(aliases);
480	*he = NO_RECOVERY;
481	return NULL;
482success:
483	bp = (char *)ALIGN(bp);
484	n = (int)(ap - aliases);
485	qlen = (n + 1) * sizeof(*hent->h_aliases);
486	if ((size_t)(ep - bp) < qlen)
487		goto nospc;
488	hent->h_aliases = (void *)bp;
489	memcpy(bp, aliases, qlen);
490	free(aliases);
491	aliases = NULL;
492
493	bp += qlen;
494	n = (int)(hap - addr_ptrs);
495	qlen = (n + 1) * sizeof(*hent->h_addr_list);
496	if ((size_t)(ep - bp) < qlen)
497		goto nospc;
498	hent->h_addr_list = (void *)bp;
499	memcpy(bp, addr_ptrs, qlen);
500	*he = NETDB_SUCCESS;
501	return hent;
502nospc:
503	free(aliases);
504	errno = ENOSPC;
505	*he = NETDB_INTERNAL;
506	return NULL;
507}
508
509/* The prototype of gethostbyname_r is from glibc, not that in netbsd. */
510int
511gethostbyname_r(const char *name, struct hostent *hp, char *buf, size_t buflen,
512    struct hostent **result, int *errorp)
513{
514	res_state res = __res_get_state();
515
516	if (res == NULL) {
517	  *result = NULL;
518		*errorp = NETDB_INTERNAL;
519		return -1;
520	}
521
522	_DIAGASSERT(name != NULL);
523
524	if (res->options & RES_USE_INET6) {
525		*result = gethostbyname_internal(name, AF_INET6, res, hp, buf, buflen, errorp, NETID_UNSET,
526		                                 MARK_UNSET);
527		if (*result) {
528			__res_put_state(res);
529			return 0;
530		}
531	}
532	*result = gethostbyname_internal(name, AF_INET, res, hp, buf, buflen, errorp, NETID_UNSET,
533	                                 MARK_UNSET);
534	__res_put_state(res);
535	if (!*result && errno == ENOSPC) {
536	  errno = ERANGE;
537	  return ERANGE; /* Return error as in linux manual page. */
538	}
539	return (*result) ? 0 : -1;
540}
541
542/* The prototype of gethostbyname2_r is from glibc, not that in netbsd. */
543int
544gethostbyname2_r(const char *name, int af, struct hostent *hp, char *buf,
545    size_t buflen, struct hostent **result, int *errorp)
546{
547	res_state res = __res_get_state();
548
549	if (res == NULL) {
550		*result = NULL;
551		*errorp = NETDB_INTERNAL;
552		return -1;
553	}
554	*result = gethostbyname_internal(name, af, res, hp, buf, buflen, errorp, NETID_UNSET,
555	                                 MARK_UNSET);
556	__res_put_state(res);
557	if (!*result && errno == ENOSPC) {
558		errno = ERANGE;
559		return ERANGE;
560	}
561	return (*result) ? 0 : -1;
562}
563
564__LIBC_HIDDEN__ FILE* android_open_proxy() {
565	const char* cache_mode = getenv("ANDROID_DNS_MODE");
566	bool use_proxy = (cache_mode == NULL || strcmp(cache_mode, "local") != 0);
567	if (!use_proxy) {
568		return NULL;
569	}
570
571	int s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0);
572	if (s == -1) {
573		return NULL;
574	}
575
576	const int one = 1;
577	setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
578
579	struct sockaddr_un proxy_addr;
580	memset(&proxy_addr, 0, sizeof(proxy_addr));
581	proxy_addr.sun_family = AF_UNIX;
582	strlcpy(proxy_addr.sun_path, "/dev/socket/dnsproxyd", sizeof(proxy_addr.sun_path));
583
584	if (TEMP_FAILURE_RETRY(connect(s, (const struct sockaddr*) &proxy_addr, sizeof(proxy_addr))) != 0) {
585		close(s);
586		return NULL;
587	}
588
589	return fdopen(s, "r+");
590}
591
592static struct hostent *
593android_read_hostent(FILE* proxy, struct hostent* hp, char* hbuf, size_t hbuflen, int *he)
594{
595	uint32_t size;
596	char buf[4];
597	if (fread(buf, 1, sizeof(buf), proxy) != sizeof(buf)) return NULL;
598
599	// This is reading serialized data from system/netd/server/DnsProxyListener.cpp
600	// and changes here need to be matched there.
601	int result_code = strtol(buf, NULL, 10);
602	if (result_code != DnsProxyQueryResult) {
603		fread(&size, 1, sizeof(size), proxy);
604		*he = HOST_NOT_FOUND;
605		return NULL;
606	}
607
608	if (fread(&size, 1, sizeof(size), proxy) != sizeof(size)) return NULL;
609	size = ntohl(size);
610
611	memset(hp, 0, sizeof(*hp));
612	char *ptr = hbuf;
613	char *hbuf_end = hbuf + hbuflen;
614
615	if (ptr + size > hbuf_end) {
616		goto nospc;
617	}
618	if (fread(ptr, 1, size, proxy) != size) return NULL;
619	hp->h_name = ptr;
620	ptr += size;
621
622	char *aliases_ptrs[MAXALIASES];
623	char **aliases = &aliases_ptrs[0];
624
625	while (1) {
626		if (fread(&size, 1, sizeof(size), proxy) != sizeof(size)) return NULL;
627		size = ntohl(size);
628
629		if (size == 0) {
630			*aliases = NULL;
631			break;
632		}
633		if (ptr + size > hbuf_end) {
634		  goto nospc;
635		}
636		if (fread(ptr, 1, size, proxy) != size) return NULL;
637		if (aliases < &aliases_ptrs[MAXALIASES - 1]) {
638		  *aliases++ = ptr;
639		}
640		ptr += size;
641	}
642
643	// Fix alignment after variable-length data.
644	ptr = (char*)ALIGN(ptr);
645
646	int aliases_len = ((int)(aliases - aliases_ptrs) + 1) * sizeof(*hp->h_aliases);
647	if (ptr + aliases_len > hbuf_end) {
648		goto nospc;
649	}
650	hp->h_aliases = (void*)ptr;
651	memcpy(ptr, aliases_ptrs, aliases_len);
652	ptr += aliases_len;
653
654	if (fread(&size, 1, sizeof(size), proxy) != sizeof(size)) return NULL;
655	hp->h_addrtype = ntohl(size);
656
657	if (fread(&size, 1, sizeof(size), proxy) != sizeof(size)) return NULL;
658	hp->h_length = ntohl(size);
659
660	char *addr_ptrs[MAXADDRS];
661	char **addr_p = &addr_ptrs[0];
662
663	while (1) {
664		if (fread(&size, 1, sizeof(size), proxy) != sizeof(size)) return NULL;
665		size = ntohl(size);
666		if (size == 0) {
667			*addr_p = NULL;
668			break;
669		}
670		if (ptr + size > hbuf_end) {
671		  goto nospc;
672		}
673		if (fread(ptr, 1, size, proxy) != size) return NULL;
674		if (addr_p < &addr_ptrs[MAXADDRS - 1]) {
675		  *addr_p++ = ptr;
676		}
677		ptr += size;
678	}
679
680	// Fix alignment after variable-length data.
681	ptr = (char*)ALIGN(ptr);
682
683	int addrs_len = ((int)(addr_p - addr_ptrs) + 1) * sizeof(*hp->h_addr_list);
684	if (ptr + addrs_len > hbuf_end) {
685		goto nospc;
686	}
687	hp->h_addr_list = (void*)ptr;
688	memcpy(ptr, addr_ptrs, addrs_len);
689	*he = NETDB_SUCCESS;
690	return hp;
691
692nospc:
693	*he = NETDB_INTERNAL;
694	errno = ENOSPC;
695	return NULL;
696}
697
698static struct hostent *
699gethostbyname_internal_real(const char *name, int af, res_state res, struct hostent *hp, char *buf,
700                            size_t buflen, int *he)
701{
702	const char *cp;
703	struct getnamaddr info;
704	char hbuf[MAXHOSTNAMELEN];
705	size_t size;
706	static const ns_dtab dtab[] = {
707		NS_FILES_CB(_hf_gethtbyname, NULL)
708		{ NSSRC_DNS, _dns_gethtbyname, NULL },	/* force -DHESIOD */
709		NS_NIS_CB(_yp_gethtbyname, NULL)
710		NS_NULL_CB
711	};
712
713	_DIAGASSERT(name != NULL);
714
715	switch (af) {
716	case AF_INET:
717		size = NS_INADDRSZ;
718		break;
719	case AF_INET6:
720		size = NS_IN6ADDRSZ;
721		break;
722	default:
723		*he = NETDB_INTERNAL;
724		errno = EAFNOSUPPORT;
725		return NULL;
726	}
727	if (buflen < size)
728		goto nospc;
729
730	hp->h_addrtype = af;
731	hp->h_length = (int)size;
732
733	/*
734	 * if there aren't any dots, it could be a user-level alias.
735	 * this is also done in res_nquery() since we are not the only
736	 * function that looks up host names.
737	 */
738	if (!strchr(name, '.') && (cp = res_hostalias(res, name,
739	    hbuf, sizeof(hbuf))))
740		name = cp;
741
742	/*
743	 * disallow names consisting only of digits/dots, unless
744	 * they end in a dot.
745	 */
746	if (isdigit((u_char) name[0]))
747		for (cp = name;; ++cp) {
748			if (!*cp) {
749				if (*--cp == '.')
750					break;
751				/*
752				 * All-numeric, no dot at the end.
753				 * Fake up a hostent as if we'd actually
754				 * done a lookup.
755				 */
756				goto fake;
757			}
758			if (!isdigit((u_char) *cp) && *cp != '.')
759				break;
760		}
761	if ((isxdigit((u_char) name[0]) && strchr(name, ':') != NULL) ||
762	    name[0] == ':')
763		for (cp = name;; ++cp) {
764			if (!*cp) {
765				if (*--cp == '.')
766					break;
767				/*
768				 * All-IPv6-legal, no dot at the end.
769				 * Fake up a hostent as if we'd actually
770				 * done a lookup.
771				 */
772				goto fake;
773			}
774			if (!isxdigit((u_char) *cp) && *cp != ':' && *cp != '.')
775				break;
776		}
777
778	*he = NETDB_INTERNAL;
779	info.hp = hp;
780	info.buf = buf;
781	info.buflen = buflen;
782	info.he = he;
783	if (nsdispatch(&info, dtab, NSDB_HOSTS, "gethostbyname",
784	    default_dns_files, name, strlen(name), af) != NS_SUCCESS)
785		return NULL;
786	*he = NETDB_SUCCESS;
787	return hp;
788nospc:
789	*he = NETDB_INTERNAL;
790	errno = ENOSPC;
791	return NULL;
792fake:
793	HENT_ARRAY(hp->h_addr_list, 1, buf, buflen);
794	HENT_ARRAY(hp->h_aliases, 0, buf, buflen);
795
796	hp->h_aliases[0] = NULL;
797	if (size > buflen)
798		goto nospc;
799
800	if (inet_pton(af, name, buf) <= 0) {
801		*he = HOST_NOT_FOUND;
802		return NULL;
803	}
804	hp->h_addr_list[0] = buf;
805	hp->h_addr_list[1] = NULL;
806	buf += size;
807	buflen -= size;
808	HENT_SCOPY(hp->h_name, name, buf, buflen);
809	if (res->options & RES_USE_INET6)
810		map_v4v6_hostent(hp, &buf, buf + buflen);
811	*he = NETDB_SUCCESS;
812	return hp;
813}
814
815// very similar in proxy-ness to android_getaddrinfo_proxy
816static struct hostent *
817gethostbyname_internal(const char *name, int af, res_state res, struct hostent *hp, char *hbuf,
818                       size_t hbuflen, int *errorp, unsigned netid, unsigned mark)
819{
820	FILE* proxy = android_open_proxy();
821	if (proxy == NULL) {
822		// Either we're not supposed to be using the proxy or the proxy is unavailable.
823		res_setnetid(res, netid);
824		res_setmark(res, mark);
825		return gethostbyname_internal_real(name, af, res, hp, hbuf, hbuflen, errorp);
826	}
827
828	netid = __netdClientDispatch.netIdForResolv(netid);
829
830	// This is writing to system/netd/server/DnsProxyListener.cpp and changes
831	// here need to be matched there.
832	if (fprintf(proxy, "gethostbyname %u %s %d",
833			netid,
834			name == NULL ? "^" : name,
835			af) < 0) {
836		fclose(proxy);
837		return NULL;
838	}
839
840	if (fputc(0, proxy) == EOF || fflush(proxy) != 0) {
841		fclose(proxy);
842		return NULL;
843	}
844
845	struct hostent* result = android_read_hostent(proxy, hp, hbuf, hbuflen, errorp);
846	fclose(proxy);
847	return result;
848}
849
850/* The prototype of gethostbyaddr_r is from glibc, not that in netbsd. */
851int gethostbyaddr_r(const void *addr, socklen_t len, int af, struct hostent *hp, char *buf,
852                    size_t buflen, struct hostent **result, int *h_errnop)
853{
854	*result = android_gethostbyaddrfornet_proxy_internal(addr, len, af, hp, buf, buflen, h_errnop,
855                                                       NETID_UNSET, MARK_UNSET);
856	if (!*result && errno == ENOSPC) {
857		errno = ERANGE;
858		return ERANGE;
859	}
860	return (*result) ? 0 : -1;
861}
862
863static struct hostent *
864android_gethostbyaddrfornet_real(const void *addr, socklen_t len, int af, struct hostent *hp,
865                                 char *buf, size_t buflen, int *he, unsigned netid, unsigned mark)
866{
867	const u_char *uaddr = (const u_char *)addr;
868	socklen_t size;
869	struct getnamaddr info;
870	static const ns_dtab dtab[] = {
871		NS_FILES_CB(_hf_gethtbyaddr, NULL)
872		{ NSSRC_DNS, _dns_gethtbyaddr, NULL },	/* force -DHESIOD */
873		NS_NIS_CB(_yp_gethtbyaddr, NULL)
874		NS_NULL_CB
875	};
876
877	_DIAGASSERT(addr != NULL);
878
879	if (af == AF_INET6 && len == NS_IN6ADDRSZ &&
880	    (IN6_IS_ADDR_LINKLOCAL((const struct in6_addr *)addr) ||
881	     IN6_IS_ADDR_SITELOCAL((const struct in6_addr *)addr))) {
882		*he = HOST_NOT_FOUND;
883		return NULL;
884	}
885	if (af == AF_INET6 && len == NS_IN6ADDRSZ &&
886	    (IN6_IS_ADDR_V4MAPPED((const struct in6_addr *)addr) ||
887	     IN6_IS_ADDR_V4COMPAT((const struct in6_addr *)addr))) {
888		/* Unmap. */
889		uaddr += NS_IN6ADDRSZ - NS_INADDRSZ;
890		addr = uaddr;
891		af = AF_INET;
892		len = NS_INADDRSZ;
893	}
894	switch (af) {
895	case AF_INET:
896		size = NS_INADDRSZ;
897		break;
898	case AF_INET6:
899		size = NS_IN6ADDRSZ;
900		break;
901	default:
902		errno = EAFNOSUPPORT;
903		*he = NETDB_INTERNAL;
904		return NULL;
905	}
906	if (size != len) {
907		errno = EINVAL;
908		*he = NETDB_INTERNAL;
909		return NULL;
910	}
911	info.hp = hp;
912	info.buf = buf;
913	info.buflen = buflen;
914	info.he = he;
915	*he = NETDB_INTERNAL;
916	if (nsdispatch(&info, dtab, NSDB_HOSTS, "gethostbyaddr",
917	    default_dns_files, uaddr, len, af, netid, mark) != NS_SUCCESS)
918		return NULL;
919	*he = NETDB_SUCCESS;
920	return hp;
921}
922
923static struct hostent*
924android_gethostbyaddrfornet_proxy_internal(const void* addr, socklen_t len, int af,
925                             struct hostent *hp, char *hbuf, size_t hbuflen, int *he,
926                             unsigned netid, unsigned mark)
927{
928	FILE* proxy = android_open_proxy();
929	if (proxy == NULL) {
930		// Either we're not supposed to be using the proxy or the proxy is unavailable.
931		return android_gethostbyaddrfornet_real(addr,len, af, hp, hbuf, hbuflen, he, netid, mark);
932	}
933
934	char buf[INET6_ADDRSTRLEN];  //big enough for IPv4 and IPv6
935	const char * addrStr = inet_ntop(af, addr, buf, sizeof(buf));
936	if (addrStr == NULL) {
937		fclose(proxy);
938		return NULL;
939	}
940
941	netid = __netdClientDispatch.netIdForResolv(netid);
942
943	if (fprintf(proxy, "gethostbyaddr %s %d %d %u",
944			addrStr, len, af, netid) < 0) {
945		fclose(proxy);
946		return NULL;
947	}
948
949	if (fputc(0, proxy) == EOF || fflush(proxy) != 0) {
950		fclose(proxy);
951		return NULL;
952	}
953
954	struct hostent *result = android_read_hostent(proxy, hp, hbuf, hbuflen, he);
955	fclose(proxy);
956	return result;
957}
958
959struct hostent*
960netbsd_gethostent_r(FILE *hf, struct hostent *hent, char *buf, size_t buflen, int *he)
961{
962	char *p, *name;
963	char *cp, **q;
964	int af, len;
965	size_t anum;
966	char **aliases;
967	size_t maxaliases;
968	struct in6_addr host_addr;
969
970	if (hf == NULL) {
971		*he = NETDB_INTERNAL;
972		errno = EINVAL;
973		return NULL;
974	}
975	p = NULL;
976	setup(aliases, maxaliases);
977
978	/* Allocate a new space to read file lines like upstream does.
979	 * To keep reentrancy we cannot use __res_get_static()->hostbuf here,
980	 * as the buffer may be used to store content for a previous hostent
981	 * returned by non-reentrant functions like gethostbyname().
982	 */
983	const size_t line_buf_size = sizeof(__res_get_static()->hostbuf);
984	if ((p = malloc(line_buf_size)) == NULL) {
985	  goto nospc;
986	}
987	for (;;) {
988		if (!fgets(p, line_buf_size, hf)) {
989			free(p);
990			free(aliases);
991			*he = HOST_NOT_FOUND;
992			return NULL;
993    		}
994		if (*p == '#') {
995			continue;
996		}
997		if (!(cp = strpbrk(p, "#\n"))) {
998			continue;
999		}
1000		*cp = '\0';
1001		if (!(cp = strpbrk(p, " \t")))
1002			continue;
1003		*cp++ = '\0';
1004		if (inet_pton(AF_INET6, p, &host_addr) > 0) {
1005			af = AF_INET6;
1006			len = NS_IN6ADDRSZ;
1007		} else {
1008			if (inet_pton(AF_INET, p, &host_addr) <= 0)
1009				continue;
1010
1011			res_state res = __res_get_state();
1012			if (res == NULL)
1013				goto nospc;
1014			if (res->options & RES_USE_INET6) {
1015				map_v4v6_address(buf, buf);
1016				af = AF_INET6;
1017				len = NS_IN6ADDRSZ;
1018			} else {
1019				af = AF_INET;
1020				len = NS_INADDRSZ;
1021			}
1022			__res_put_state(res);
1023		}
1024
1025		/* if this is not something we're looking for, skip it. */
1026		if (hent->h_addrtype != 0 && hent->h_addrtype != af)
1027			continue;
1028		if (hent->h_length != 0 && hent->h_length != len)
1029			continue;
1030
1031		while (*cp == ' ' || *cp == '\t')
1032			cp++;
1033		if ((cp = strpbrk(name = cp, " \t")) != NULL)
1034			*cp++ = '\0';
1035		q = aliases;
1036		while (cp && *cp) {
1037			if (*cp == ' ' || *cp == '\t') {
1038				cp++;
1039				continue;
1040			}
1041			addalias(q, cp, aliases, maxaliases);
1042			if ((cp = strpbrk(cp, " \t")) != NULL)
1043				*cp++ = '\0';
1044		}
1045		break;
1046	}
1047	hent->h_length = len;
1048	hent->h_addrtype = af;
1049	HENT_ARRAY(hent->h_addr_list, 1, buf, buflen);
1050	anum = (size_t)(q - aliases);
1051	HENT_ARRAY(hent->h_aliases, anum, buf, buflen);
1052	HENT_COPY(hent->h_addr_list[0], &host_addr, hent->h_length, buf,
1053	    buflen);
1054	hent->h_addr_list[1] = NULL;
1055
1056	HENT_SCOPY(hent->h_name, name, buf, buflen);
1057	for (size_t i = 0; i < anum; i++)
1058		HENT_SCOPY(hent->h_aliases[i], aliases[i], buf, buflen);
1059	hent->h_aliases[anum] = NULL;
1060
1061	*he = NETDB_SUCCESS;
1062	free(p);
1063	free(aliases);
1064	return hent;
1065nospc:
1066	free(p);
1067	free(aliases);
1068	errno = ENOSPC;
1069	*he = NETDB_INTERNAL;
1070	return NULL;
1071}
1072
1073static void
1074map_v4v6_address(const char *src, char *dst)
1075{
1076	u_char *p = (u_char *)dst;
1077	char tmp[NS_INADDRSZ];
1078	int i;
1079
1080	_DIAGASSERT(src != NULL);
1081	_DIAGASSERT(dst != NULL);
1082
1083	/* Stash a temporary copy so our caller can update in place. */
1084	(void)memcpy(tmp, src, NS_INADDRSZ);
1085	/* Mark this ipv6 addr as a mapped ipv4. */
1086	for (i = 0; i < 10; i++)
1087		*p++ = 0x00;
1088	*p++ = 0xff;
1089	*p++ = 0xff;
1090	/* Retrieve the saved copy and we're done. */
1091	(void)memcpy(p, tmp, NS_INADDRSZ);
1092}
1093
1094static void
1095map_v4v6_hostent(struct hostent *hp, char **bpp, char *ep)
1096{
1097	char **ap;
1098
1099	_DIAGASSERT(hp != NULL);
1100	_DIAGASSERT(bpp != NULL);
1101	_DIAGASSERT(ep != NULL);
1102
1103	if (hp->h_addrtype != AF_INET || hp->h_length != NS_INADDRSZ)
1104		return;
1105	hp->h_addrtype = AF_INET6;
1106	hp->h_length = NS_IN6ADDRSZ;
1107	for (ap = hp->h_addr_list; *ap; ap++) {
1108		int i = (int)(sizeof(align) -
1109		    (size_t)((u_long)*bpp % sizeof(align)));
1110
1111		if (ep - *bpp < (i + NS_IN6ADDRSZ)) {
1112			/* Out of memory.  Truncate address list here.  XXX */
1113			*ap = NULL;
1114			return;
1115		}
1116		*bpp += i;
1117		map_v4v6_address(*ap, *bpp);
1118		*ap = *bpp;
1119		*bpp += NS_IN6ADDRSZ;
1120	}
1121}
1122
1123static void
1124addrsort(char **ap, int num, res_state res)
1125{
1126	int i, j;
1127	char **p;
1128	short aval[MAXADDRS];
1129	int needsort = 0;
1130
1131	_DIAGASSERT(ap != NULL);
1132
1133	p = ap;
1134	for (i = 0; i < num; i++, p++) {
1135	    for (j = 0 ; (unsigned)j < res->nsort; j++)
1136		if (res->sort_list[j].addr.s_addr ==
1137		    (((struct in_addr *)(void *)(*p))->s_addr &
1138		    res->sort_list[j].mask))
1139			break;
1140	    aval[i] = j;
1141	    if (needsort == 0 && i > 0 && j < aval[i-1])
1142		needsort = i;
1143	}
1144	if (!needsort)
1145	    return;
1146
1147	while (needsort < num) {
1148	    for (j = needsort - 1; j >= 0; j--) {
1149		if (aval[j] > aval[j+1]) {
1150		    char *hp;
1151
1152		    i = aval[j];
1153		    aval[j] = aval[j+1];
1154		    aval[j+1] = i;
1155
1156		    hp = ap[j];
1157		    ap[j] = ap[j+1];
1158		    ap[j+1] = hp;
1159		} else
1160		    break;
1161	    }
1162	    needsort++;
1163	}
1164}
1165
1166/*ARGSUSED*/
1167static int
1168_dns_gethtbyname(void *rv, void *cb_data, va_list ap)
1169{
1170	querybuf *buf;
1171	int n, type;
1172	struct hostent *hp;
1173	const char *name;
1174	res_state res;
1175	struct getnamaddr *info = rv;
1176
1177	_DIAGASSERT(rv != NULL);
1178
1179	name = va_arg(ap, char *);
1180	/* NOSTRICT skip string len */(void)va_arg(ap, int);
1181	info->hp->h_addrtype = va_arg(ap, int);
1182
1183	switch (info->hp->h_addrtype) {
1184	case AF_INET:
1185		info->hp->h_length = NS_INADDRSZ;
1186		type = T_A;
1187		break;
1188	case AF_INET6:
1189		info->hp->h_length = NS_IN6ADDRSZ;
1190		type = T_AAAA;
1191		break;
1192	default:
1193		return NS_UNAVAIL;
1194	}
1195	buf = malloc(sizeof(*buf));
1196	if (buf == NULL) {
1197		*info->he = NETDB_INTERNAL;
1198		return NS_NOTFOUND;
1199	}
1200	res = __res_get_state();
1201	if (res == NULL) {
1202		free(buf);
1203		return NS_NOTFOUND;
1204	}
1205	n = res_nsearch(res, name, C_IN, type, buf->buf, (int)sizeof(buf->buf));
1206	if (n < 0) {
1207		free(buf);
1208		debugprintf("res_nsearch failed (%d)\n", res, n);
1209		__res_put_state(res);
1210		return NS_NOTFOUND;
1211	}
1212	hp = getanswer(buf, n, name, type, res, info->hp, info->buf,
1213	    info->buflen, info->he);
1214	free(buf);
1215	__res_put_state(res);
1216	if (hp == NULL)
1217		switch (*info->he) {
1218		case HOST_NOT_FOUND:
1219			return NS_NOTFOUND;
1220		case TRY_AGAIN:
1221			return NS_TRYAGAIN;
1222		default:
1223			return NS_UNAVAIL;
1224		}
1225	return NS_SUCCESS;
1226}
1227
1228/*ARGSUSED*/
1229static int
1230_dns_gethtbyaddr(void *rv, void	*cb_data, va_list ap)
1231{
1232	char qbuf[MAXDNAME + 1], *qp, *ep;
1233	int n;
1234	querybuf *buf;
1235	struct hostent *hp;
1236	const unsigned char *uaddr;
1237	int advance;
1238	res_state res;
1239	char *bf;
1240	size_t blen;
1241	struct getnamaddr *info = rv;
1242	unsigned netid, mark;
1243
1244	_DIAGASSERT(rv != NULL);
1245
1246	uaddr = va_arg(ap, unsigned char *);
1247	info->hp->h_length = va_arg(ap, int);
1248	info->hp->h_addrtype = va_arg(ap, int);
1249	netid = va_arg(ap, unsigned);
1250	mark = va_arg(ap, unsigned);
1251
1252	switch (info->hp->h_addrtype) {
1253	case AF_INET:
1254		(void)snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u.in-addr.arpa",
1255		    (uaddr[3] & 0xff), (uaddr[2] & 0xff),
1256		    (uaddr[1] & 0xff), (uaddr[0] & 0xff));
1257		break;
1258
1259	case AF_INET6:
1260		qp = qbuf;
1261		ep = qbuf + sizeof(qbuf) - 1;
1262		for (n = NS_IN6ADDRSZ - 1; n >= 0; n--) {
1263			advance = snprintf(qp, (size_t)(ep - qp), "%x.%x.",
1264			    uaddr[n] & 0xf,
1265			    ((unsigned int)uaddr[n] >> 4) & 0xf);
1266			if (advance > 0 && qp + advance < ep)
1267				qp += advance;
1268			else {
1269				*info->he = NETDB_INTERNAL;
1270				return NS_NOTFOUND;
1271			}
1272		}
1273		if (strlcat(qbuf, "ip6.arpa", sizeof(qbuf)) >= sizeof(qbuf)) {
1274			*info->he = NETDB_INTERNAL;
1275			return NS_NOTFOUND;
1276		}
1277		break;
1278	default:
1279		return NS_UNAVAIL;
1280	}
1281
1282	buf = malloc(sizeof(*buf));
1283	if (buf == NULL) {
1284		*info->he = NETDB_INTERNAL;
1285		return NS_NOTFOUND;
1286	}
1287	res = __res_get_state();
1288	if (res == NULL) {
1289		free(buf);
1290		return NS_NOTFOUND;
1291	}
1292	res_setnetid(res, netid);
1293	res_setmark(res, mark);
1294	n = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf, (int)sizeof(buf->buf));
1295	if (n < 0) {
1296		free(buf);
1297		debugprintf("res_nquery failed (%d)\n", res, n);
1298		__res_put_state(res);
1299		return NS_NOTFOUND;
1300	}
1301	hp = getanswer(buf, n, qbuf, T_PTR, res, info->hp, info->buf,
1302	    info->buflen, info->he);
1303	free(buf);
1304	if (hp == NULL) {
1305		__res_put_state(res);
1306		switch (*info->he) {
1307		case HOST_NOT_FOUND:
1308			return NS_NOTFOUND;
1309		case TRY_AGAIN:
1310			return NS_TRYAGAIN;
1311		default:
1312			return NS_UNAVAIL;
1313		}
1314	}
1315
1316	bf = (void *)(hp->h_addr_list + 2);
1317	blen = (size_t)(bf - info->buf);
1318	if (blen + info->hp->h_length > info->buflen)
1319		goto nospc;
1320	hp->h_addr_list[0] = bf;
1321	hp->h_addr_list[1] = NULL;
1322	(void)memcpy(bf, uaddr, (size_t)info->hp->h_length);
1323	if (info->hp->h_addrtype == AF_INET && (res->options & RES_USE_INET6)) {
1324		if (blen + NS_IN6ADDRSZ > info->buflen)
1325			goto nospc;
1326		map_v4v6_address(bf, bf);
1327		hp->h_addrtype = AF_INET6;
1328		hp->h_length = NS_IN6ADDRSZ;
1329	}
1330
1331	__res_put_state(res);
1332	*info->he = NETDB_SUCCESS;
1333	return NS_SUCCESS;
1334nospc:
1335	errno = ENOSPC;
1336	*info->he = NETDB_INTERNAL;
1337	return NS_UNAVAIL;
1338}
1339
1340#ifdef YP
1341/*ARGSUSED*/
1342static struct hostent *
1343_yp_hostent(char *line, int af, struct getnamaddr *info)
1344{
1345	struct in6_addr host_addrs[MAXADDRS];
1346	char **aliases;
1347	size_t maxaliases;
1348	char *p = line;
1349	char *cp, **q, *ptr;
1350	size_t len, anum, i;
1351	int addrok;
1352	int more;
1353	size_t naddrs;
1354	struct hostent *hp = info->hp;
1355
1356	_DIAGASSERT(line != NULL);
1357
1358	hp->h_name = NULL;
1359	hp->h_addrtype = af;
1360	switch (af) {
1361	case AF_INET:
1362		hp->h_length = NS_INADDRSZ;
1363		break;
1364	case AF_INET6:
1365		hp->h_length = NS_IN6ADDRSZ;
1366		break;
1367	default:
1368		return NULL;
1369	}
1370	setup(aliases, maxaliases);
1371	naddrs = 0;
1372	q = aliases;
1373
1374nextline:
1375	/* check for host_addrs overflow */
1376	if (naddrs >= __arraycount(host_addrs))
1377		goto done;
1378
1379	more = 0;
1380	cp = strpbrk(p, " \t");
1381	if (cp == NULL)
1382		goto done;
1383	*cp++ = '\0';
1384
1385	/* p has should have an address */
1386	addrok = inet_pton(af, p, &host_addrs[naddrs]);
1387	if (addrok != 1) {
1388		/* skip to the next line */
1389		while (cp && *cp) {
1390			if (*cp == '\n') {
1391				cp++;
1392				goto nextline;
1393			}
1394			cp++;
1395		}
1396		goto done;
1397	}
1398	naddrs++;
1399
1400	while (*cp == ' ' || *cp == '\t')
1401		cp++;
1402	p = cp;
1403	cp = strpbrk(p, " \t\n");
1404	if (cp != NULL) {
1405		if (*cp == '\n')
1406			more = 1;
1407		*cp++ = '\0';
1408	}
1409	if (!hp->h_name)
1410		hp->h_name = p;
1411	else if (strcmp(hp->h_name, p) == 0)
1412		;
1413	else
1414		addalias(q, p, aliases, maxaliases);
1415	p = cp;
1416	if (more)
1417		goto nextline;
1418
1419	while (cp && *cp) {
1420		if (*cp == ' ' || *cp == '\t') {
1421			cp++;
1422			continue;
1423		}
1424		if (*cp == '\n') {
1425			cp++;
1426			goto nextline;
1427		}
1428		addalias(q, cp, aliases, maxaliases);
1429		cp = strpbrk(cp, " \t");
1430		if (cp != NULL)
1431			*cp++ = '\0';
1432	}
1433
1434done:
1435	if (hp->h_name == NULL) {
1436		free(aliases);
1437		return NULL;
1438	}
1439
1440	ptr = info->buf;
1441	len = info->buflen;
1442
1443	anum = (size_t)(q - aliases);
1444	HENT_ARRAY(hp->h_addr_list, naddrs, ptr, len);
1445	HENT_ARRAY(hp->h_aliases, anum, ptr, len);
1446
1447	for (i = 0; i < naddrs; i++)
1448		HENT_COPY(hp->h_addr_list[i], &host_addrs[i], hp->h_length,
1449		    ptr, len);
1450	hp->h_addr_list[naddrs] = NULL;
1451
1452	HENT_SCOPY(hp->h_name, hp->h_name, ptr, len);
1453
1454	for (i = 0; i < anum; i++)
1455		HENT_SCOPY(hp->h_aliases[i], aliases[i], ptr, len);
1456	hp->h_aliases[anum] = NULL;
1457	free(aliases);
1458
1459	return hp;
1460nospc:
1461	free(aliases);
1462	*info->he = NETDB_INTERNAL;
1463	errno = ENOSPC;
1464	return NULL;
1465}
1466
1467/*ARGSUSED*/
1468int
1469_yp_gethtbyaddr(void *rv, void *cb_data, va_list ap)
1470{
1471	struct hostent *hp = NULL;
1472	char *ypcurrent;
1473	int ypcurrentlen, r;
1474	char name[INET6_ADDRSTRLEN];	/* XXX enough? */
1475	const unsigned char *uaddr;
1476	int af;
1477	const char *map;
1478	struct getnamaddr *info = rv;
1479
1480	_DIAGASSERT(rv != NULL);
1481
1482	uaddr = va_arg(ap, unsigned char *);
1483	/* NOSTRICT skip len */(void)va_arg(ap, int);
1484	af = va_arg(ap, int);
1485
1486	if (!__ypdomain) {
1487		if (_yp_check(&__ypdomain) == 0)
1488			return NS_UNAVAIL;
1489	}
1490	/*
1491	 * XXX unfortunately, we cannot support IPv6 extended scoped address
1492	 * notation here.  gethostbyaddr() is not scope-aware.  too bad.
1493	 */
1494	if (inet_ntop(af, uaddr, name, (socklen_t)sizeof(name)) == NULL)
1495		return NS_UNAVAIL;
1496	switch (af) {
1497	case AF_INET:
1498		map = "hosts.byaddr";
1499		break;
1500	default:
1501		map = "ipnodes.byaddr";
1502		break;
1503	}
1504	ypcurrent = NULL;
1505	r = yp_match(__ypdomain, map, name,
1506		(int)strlen(name), &ypcurrent, &ypcurrentlen);
1507	if (r == 0)
1508		hp = _yp_hostent(ypcurrent, af, info);
1509	else
1510		hp = NULL;
1511	free(ypcurrent);
1512	if (hp == NULL) {
1513		*info->he = HOST_NOT_FOUND;
1514		return NS_NOTFOUND;
1515	}
1516	return NS_SUCCESS;
1517}
1518
1519/*ARGSUSED*/
1520int
1521_yp_gethtbyname(void *rv, void *cb_data, va_list ap)
1522{
1523	struct hostent *hp;
1524	char *ypcurrent;
1525	int ypcurrentlen, r;
1526	const char *name;
1527	int af;
1528	const char *map;
1529	struct getnamaddr *info = rv;
1530
1531	_DIAGASSERT(rv != NULL);
1532
1533	name = va_arg(ap, char *);
1534	/* NOSTRICT skip string len */(void)va_arg(ap, int);
1535	af = va_arg(ap, int);
1536
1537	if (!__ypdomain) {
1538		if (_yp_check(&__ypdomain) == 0)
1539			return NS_UNAVAIL;
1540	}
1541	switch (af) {
1542	case AF_INET:
1543		map = "hosts.byname";
1544		break;
1545	default:
1546		map = "ipnodes.byname";
1547		break;
1548	}
1549	ypcurrent = NULL;
1550	r = yp_match(__ypdomain, map, name,
1551		(int)strlen(name), &ypcurrent, &ypcurrentlen);
1552	if (r == 0)
1553		hp = _yp_hostent(ypcurrent, af, info);
1554	else
1555		hp = NULL;
1556	free(ypcurrent);
1557	if (hp == NULL) {
1558		*info->he = HOST_NOT_FOUND;
1559		return NS_NOTFOUND;
1560	}
1561	return NS_SUCCESS;
1562}
1563#endif
1564
1565/*
1566 * Non-reentrant versions.
1567 */
1568
1569struct hostent *
1570gethostbyname(const char *name)
1571{
1572	struct hostent *result = NULL;
1573	res_static rs = __res_get_static(); /* Use res_static to provide thread-safety. */
1574
1575	gethostbyname_r(name, &rs->host, rs->hostbuf, sizeof(rs->hostbuf), &result, &h_errno);
1576	return result;
1577}
1578
1579struct hostent *
1580gethostbyname2(const char *name, int af)
1581{
1582	struct hostent *result = NULL;
1583	res_static rs = __res_get_static(); /* Use res_static to provide thread-safety. */
1584
1585	gethostbyname2_r(name, af, &rs->host, rs->hostbuf, sizeof(rs->hostbuf), &result, &h_errno);
1586	return result;
1587}
1588
1589struct hostent *
1590android_gethostbynamefornet(const char *name, int af, unsigned netid, unsigned mark)
1591{
1592	struct hostent *hp;
1593	res_state res = __res_get_state();
1594	if (res == NULL)
1595		return NULL;
1596	res_static rs = __res_get_static(); /* Use res_static to provide thread-safety. */
1597	hp = gethostbyname_internal(name, af, res, &rs->host, rs->hostbuf, sizeof(rs->hostbuf),
1598	                            &h_errno, netid, mark);
1599	__res_put_state(res);
1600	return hp;
1601}
1602
1603struct hostent *
1604gethostbyaddr(const void *addr, socklen_t len, int af)
1605{
1606	return android_gethostbyaddrfornet_proxy(addr, len, af, NETID_UNSET, MARK_UNSET);
1607}
1608
1609struct hostent *
1610android_gethostbyaddrfornet(const void *addr, socklen_t len, int af, unsigned netid, unsigned mark)
1611{
1612	return android_gethostbyaddrfornet_proxy(addr, len, af, netid, mark);
1613}
1614
1615__LIBC_HIDDEN__ struct hostent*
1616android_gethostbyaddrfornet_proxy(const void* addr, socklen_t len, int af,
1617                                  unsigned netid, unsigned mark)
1618{
1619	res_static rs = __res_get_static(); /* Use res_static to provide thread-safety. */
1620	return android_gethostbyaddrfornet_proxy_internal(addr, len, af, &rs->host, rs->hostbuf,
1621                                                    sizeof(rs->hostbuf), &h_errno, netid, mark);
1622}
1623
1624struct hostent *
1625gethostent(void)
1626{
1627  res_static  rs = __res_get_static();
1628	if (!rs->hostf) {
1629	  sethostent_r(&rs->hostf);
1630	  if (!rs->hostf) {
1631	    h_errno = NETDB_INTERNAL;
1632	    return NULL;
1633	  }
1634	}
1635	memset(&rs->host, 0, sizeof(rs->host));
1636	return netbsd_gethostent_r(rs->hostf, &rs->host, rs->hostbuf, sizeof(rs->hostbuf), &h_errno);
1637}
1638