xref: /illumos-gate/usr/src/lib/libnsl/nss/netdir_inet.c (revision 141040e8a310da49386b596573e5dde5580572ec)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 
23 /*
24  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
25  * Use is subject to license terms.
26  */
27 
28 /*
29  * This is where we have chosen to combine every useful bit of code for
30  * all the Solaris frontends to lookup hosts, services, and netdir information
31  * for inet family (udp, tcp) transports. gethostbyYY(), getservbyYY(), and
32  * netdir_getbyYY() are all implemented on top of this code. Similarly,
33  * netdir_options, taddr2uaddr, and uaddr2taddr for inet transports also
34  * find a home here.
35  *
36  * If the netconfig structure supplied has NO nametoaddr libs (i.e. a "-"
37  * in /etc/netconfig), this code calls the name service switch, and
38  * therefore, /etc/nsswitch.conf is effectively the only place that
39  * dictates hosts/serv lookup policy.
40  * If an administrator chooses to bypass the name service switch by
41  * specifying third party supplied nametoaddr libs in /etc/netconfig, this
42  * implementation does NOT call the name service switch, it merely loops
43  * through the nametoaddr libs. In this case, if this code was called
44  * from gethost/servbyYY() we marshal the inet specific struct into
45  * transport independent netbuf or hostserv, and unmarshal the resulting
46  * nd_addrlist or hostservlist back into hostent and servent, as the case
47  * may be.
48  *
49  * Goes without saying that most of the future bugs in gethost/servbyYY
50  * and netdir_getbyYY are lurking somewhere here.
51  */
52 
53 #pragma ident	"%Z%%M%	%I%	%E% SMI"
54 
55 #include "mt.h"
56 #include <ctype.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61 #include <stropts.h>
62 #include <sys/types.h>
63 #include <sys/byteorder.h>
64 #include <sys/ioctl.h>
65 #include <sys/param.h>
66 #include <sys/time.h>
67 #include <errno.h>
68 #include <fcntl.h>
69 #include <thread.h>
70 #include <synch.h>
71 #include <sys/utsname.h>
72 #include <netdb.h>
73 #include <netconfig.h>
74 #include <netdir.h>
75 #include <tiuser.h>
76 #include <sys/socket.h>
77 #include <sys/sockio.h>
78 #include <netinet/in.h>
79 #include <arpa/inet.h>
80 #include <net/if.h>
81 #include <inet/ip.h>
82 #include <inet/ip6_asp.h>
83 #include <sys/dlpi.h>
84 #include <nss_dbdefs.h>
85 #include <nss_netdir.h>
86 #include <syslog.h>
87 #include <nsswitch.h>
88 #include "nss.h"
89 #include "nsl_stdio_prv.h"
90 
91 #define	MAXIFS 32
92 #define	UDPDEV	"/dev/udp"
93 #define	UDP6DEV	"/dev/udp6"
94 
95 #ifdef PIC
96 #define	DOOR_GETHOSTBYNAME_R	_door_gethostbyname_r
97 #define	DOOR_GETHOSTBYADDR_R	_door_gethostbyaddr_r
98 #define	DOOR_GETIPNODEBYNAME_R	_door_getipnodebyname_r
99 #define	DOOR_GETIPNODEBYADDR_R	_door_getipnodebyaddr_r
100 #else
101 #define	DOOR_GETHOSTBYNAME_R	_switch_gethostbyname_r
102 #define	DOOR_GETHOSTBYADDR_R	_switch_gethostbyaddr_r
103 #define	DOOR_GETIPNODEBYNAME_R	_switch_getipnodebyname_r
104 #define	DOOR_GETIPNODEBYADDR_R	_switch_getipnodebyaddr_r
105 #endif /* PIC */
106 
107 #define	DONT_SORT	"SORT_ADDRS=NO"
108 #define	DONT_SORT2	"SORT_ADDRS=FALSE"
109 #define	LINESIZE	100
110 
111 /*
112  * constant values of addresses for HOST_SELF_BIND, HOST_SELF_CONNECT
113  * and localhost.
114  *
115  * The following variables are static to the extent that they should
116  * not be visible outside of this file.
117  */
118 static char *localaddr[] = {"\000\000\000\000", NULL};
119 static char *connectaddr[] = {"\177\000\000\001", NULL};
120 static char *localaddr6[] =
121 {"\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000", NULL};
122 static char *connectaddr6[] =
123 {"\000\000\000\000\000\000\000\000\000\000\000\000\000\000\000\001", NULL};
124 
125 /* IPv4 nd_addrlist */
126 static mutex_t	nd_addr_lock = DEFAULTMUTEX;
127 static struct sockaddr_in sa_con;
128 static struct netbuf nd_conbuf = {sizeof (sa_con),\
129     sizeof (sa_con), (char *)&sa_con};
130 static struct nd_addrlist nd_conaddrlist = {1, &nd_conbuf};
131 
132 /* IPv6 nd_addrlist */
133 static mutex_t	nd6_addr_lock = DEFAULTMUTEX;
134 static struct sockaddr_in6 sa6_con;
135 static struct netbuf nd6_conbuf = {sizeof (sa6_con),\
136 	sizeof (sa6_con), (char *)&sa6_con};
137 static struct nd_addrlist nd6_conaddrlist = {1, &nd6_conbuf};
138 
139 #define	LOCALHOST "localhost"
140 
141 struct servent *_switch_getservbyname_r(const char *, const char *,
142     struct servent *, char *, int);
143 struct servent *_switch_getservbyport_r(int, const char *, struct servent *,
144     char *, int);
145 
146 static int __herrno2netdir(int h_errnop);
147 static struct ifinfo *get_local_info(void);
148 static int getbroadcastnets(struct netconfig *, struct in_addr **);
149 static int hent2ndaddr(int, char **, int *, struct nd_addrlist **);
150 static int ndaddr2hent(int, const char *, struct nd_addrlist *,
151     struct hostent *, char *, int);
152 static int hsents2ndhostservs(struct hostent *, struct servent *, ushort_t,
153     struct nd_hostservlist **);
154 static int ndaddr2srent(const char *, const char *, ushort_t, struct servent *,
155     char *, int);
156 static int ndhostserv2hent(struct netbuf *, struct nd_hostservlist *,
157     struct hostent *, char *, int);
158 static int ndhostserv2srent(int, const char *, struct nd_hostservlist *,
159     struct servent *, char *, int);
160 static int nd2herrno(int nerr);
161 static void order_haddrlist_inet(char **haddrlist, size_t addrcount);
162 static void order_haddrlist_inet6(char **haddrlist, size_t addrcount);
163 static int dstcmp(const void *, const void *);
164 static int nss_strioctl(int af, int cmd, void *ptr, int ilen);
165 static struct in_addr _inet_makeaddr(in_addr_t, in_addr_t);
166 static boolean_t _read_nsw_file(void);
167 
168 /*
169  * Begin: PART I
170  * Top Level Interfaces that gethost/serv/netdir funnel through.
171  */
172 
173 /*
174  * gethost/servbyname always call this function; if they call
175  * with nametoaddr libs in nconf, we call netdir_getbyname
176  * implementation: __classic_netdir_getbyname, otherwise nsswitch.
177  *
178  * netdir_getbyname calls this only if nametoaddr libs are NOT
179  * specified for inet transports; i.e. it's supposed to follow
180  * the name service switch.
181  */
182 int
183 _get_hostserv_inetnetdir_byname(struct netconfig *nconf,
184     struct nss_netdirbyname_in *args, union nss_netdirbyname_out *res)
185 {
186 	int	server_port;
187 	int *servp = &server_port;
188 	char	**haddrlist;
189 	uint32_t dotnameaddr;
190 	char	*dotnamelist[2];
191 	struct in_addr	*inaddrs = NULL;
192 	struct in6_addr	v6nameaddr;
193 	char	**baddrlist = NULL;
194 
195 
196 	if (nconf == NULL) {
197 		_nderror = ND_BADARG;
198 		return (ND_BADARG);
199 	}
200 
201 	/*
202 	 * 1. gethostbyname()/netdir_getbyname() special cases:
203 	 */
204 	switch (args->op_t) {
205 
206 		case NSS_HOST:
207 		/*
208 		 * Worth the performance gain -- assuming a lot of inet apps
209 		 * actively use "localhost".
210 		 */
211 		if (strcmp(args->arg.nss.host.name, LOCALHOST) == 0) {
212 
213 			(void) mutex_lock(&nd_addr_lock);
214 			IN_SET_LOOPBACK_ADDR(&sa_con);
215 			_nderror = ndaddr2hent(AF_INET, args->arg.nss.host.name,
216 			    &nd_conaddrlist, res->nss.host.hent,
217 			    args->arg.nss.host.buf,
218 			    args->arg.nss.host.buflen);
219 			(void) mutex_unlock(&nd_addr_lock);
220 			if (_nderror != ND_OK)
221 				*(res->nss.host.herrno_p) =
222 				    nd2herrno(_nderror);
223 			return (_nderror);
224 		}
225 		/*
226 		 * If the caller passed in a dot separated IP notation to
227 		 * gethostbyname, return that back as the address.
228 		 * The nd_addr_lock mutex was added to be truely re-entrant.
229 		 */
230 		if (inet_aton(args->arg.nss.host.name,
231 		    (struct in_addr *)&dotnameaddr)) {
232 			(void) mutex_lock(&nd_addr_lock);
233 			(void) memset(&sa_con, 0, sizeof (sa_con));
234 			sa_con.sin_family = AF_INET;
235 			sa_con.sin_addr.s_addr = dotnameaddr;
236 			_nderror = ndaddr2hent(AF_INET, args->arg.nss.host.name,
237 			    &nd_conaddrlist, res->nss.host.hent,
238 			    args->arg.nss.host.buf,
239 			    args->arg.nss.host.buflen);
240 			(void) mutex_unlock(&nd_addr_lock);
241 			if (_nderror != ND_OK)
242 				*(res->nss.host.herrno_p) =
243 				    nd2herrno(_nderror);
244 			return (_nderror);
245 		}
246 		break;
247 
248 		case NSS_HOST6:
249 		/*
250 		 * Handle case of literal address string.
251 		 */
252 		if (strchr(args->arg.nss.host6.name, ':') != NULL &&
253 		    (inet_pton(AF_INET6, args->arg.nss.host6.name,
254 		    &v6nameaddr) != 0)) {
255 			int	ret;
256 
257 			(void) mutex_lock(&nd6_addr_lock);
258 			(void) memset(&sa6_con, 0, sizeof (sa6_con));
259 			sa6_con.sin6_family = AF_INET6;
260 			(void) memcpy(&(sa6_con.sin6_addr.s6_addr),
261 			    &v6nameaddr, sizeof (struct in6_addr));
262 			ret = ndaddr2hent(AF_INET6,
263 			    args->arg.nss.host6.name,
264 			    &nd6_conaddrlist, res->nss.host.hent,
265 			    args->arg.nss.host6.buf,
266 			    args->arg.nss.host6.buflen);
267 			(void) mutex_unlock(&nd6_addr_lock);
268 			if (ret != ND_OK)
269 				*(res->nss.host.herrno_p) = nd2herrno(ret);
270 			else
271 				res->nss.host.hent->h_aliases = NULL;
272 			return (ret);
273 		}
274 		break;
275 
276 		case NETDIR_BY:
277 			if (args->arg.nd_hs == 0) {
278 				_nderror = ND_BADARG;
279 				return (ND_BADARG);
280 			}
281 			/*
282 			 * If servname is NULL, return 0 as the port number
283 			 * If servname is rpcbind, return 111 as the port number
284 			 * If servname is a number, return it back as the port
285 			 * number.
286 			 */
287 			if (args->arg.nd_hs->h_serv == 0) {
288 				*servp = htons(0);
289 			} else if (strcmp(args->arg.nd_hs->h_serv, "rpcbind")
290 									== 0) {
291 				*servp = htons(111);
292 			} else if (strspn(args->arg.nd_hs->h_serv, "0123456789")
293 				    == strlen(args->arg.nd_hs->h_serv)) {
294 				*servp = htons(atoi(args->arg.nd_hs->h_serv));
295 			} else {
296 				/* i.e. need to call a name service on this */
297 				servp = NULL;
298 			}
299 
300 			/*
301 			 * If the hostname is HOST_SELF_BIND, we return 0.0.0.0
302 			 * so the  binding can be contacted through all
303 			 * interfaces. If the hostname is HOST_SELF_CONNECT,
304 			 * we return 127.0.0.1 so the address can be connected
305 			 * to locally. If the hostname is HOST_ANY, we return
306 			 * no addresses because IP doesn't know how to specify
307 			 * a service without a host. And finally if we specify
308 			 * HOST_BROADCAST then we ask a tli fd to tell us what
309 			 * the broadcast addresses are for any udp
310 			 * interfaces on this machine.
311 			 */
312 			if (args->arg.nd_hs->h_host == 0) {
313 				_nderror = ND_NOHOST;
314 				return (ND_NOHOST);
315 			} else if ((strcmp(args->arg.nd_hs->h_host,
316 			    HOST_SELF_BIND) == 0)) {
317 				haddrlist = localaddr;
318 			} else if ((strcmp(args->arg.nd_hs->h_host,
319 					    HOST_SELF_CONNECT) == 0)) {
320 				haddrlist = connectaddr;
321 			} else if ((strcmp(args->arg.nd_hs->h_host,
322 					    LOCALHOST) == 0)) {
323 				haddrlist = connectaddr;
324 			} else if ((int)(dotnameaddr =
325 				    inet_addr(args->arg.nd_hs->h_host)) != -1) {
326 				/*
327 				 * If the caller passed in a dot separated IP
328 				 * notation to netdir_getbyname, convert that
329 				 * back into address.
330 				 */
331 
332 				dotnamelist[0] = (char *)&dotnameaddr;
333 				dotnamelist[1] = NULL;
334 				haddrlist = dotnamelist;
335 			} else if ((strcmp(args->arg.nd_hs->h_host,
336 					    HOST_BROADCAST) == 0)) {
337 				/*
338 				 * Now that inaddrs and baddrlist are
339 				 * dynamically allocated, care must be
340 				 * taken in freeing up the
341 				 * memory at each 'return()' point.
342 				 *
343 				 * Early return protection (using
344 				 * FREE_return()) is needed only in NETDIR_BY
345 				 * cases because dynamic allocation is used
346 				 * when args->op_t == NETDIR_BY.
347 				 *
348 				 * Early return protection is not needed in
349 				 * haddrlist==0 conditionals because dynamic
350 				 * allocation guarantees haddrlist!=0.
351 				 *
352 				 * Early return protection is not needed in most
353 				 * servp!=0 conditionals because this is handled
354 				 * (and returned) first.
355 				 */
356 #define	FREE_return(ret) \
357 				{ \
358 				    if (inaddrs) \
359 					    free(inaddrs); \
360 					    if (baddrlist) \
361 						    free(baddrlist); \
362 						    _nderror = ret; \
363 						    return (ret); \
364 				}
365 				int i, bnets;
366 
367 				bnets = getbroadcastnets(nconf, &inaddrs);
368 				if (bnets == 0) {
369 					_nderror = ND_NOHOST;
370 					return (ND_NOHOST);
371 				}
372 				baddrlist = malloc((bnets+1)*sizeof (char *));
373 				if (baddrlist == NULL)
374 					FREE_return(ND_NOMEM);
375 				for (i = 0; i < bnets; i++)
376 					baddrlist[i] = (char *)&inaddrs[i];
377 				baddrlist[i] = NULL;
378 				haddrlist = baddrlist;
379 			} else {
380 				/* i.e. need to call a name service on this */
381 				haddrlist = 0;
382 			}
383 
384 			if (haddrlist && servp) {
385 				int ret;
386 				/*
387 				 * Convert h_addr_list into nd_addrlist.
388 				 * malloc's will be done, freed using
389 				 * netdir_free.
390 				 */
391 				ret = hent2ndaddr(AF_INET, haddrlist, servp,
392 					    res->nd_alist);
393 				FREE_return(ret)
394 				}
395 			break;
396 
397 
398 		case NETDIR_BY6:
399 			if (args->arg.nd_hs == 0) {
400 				_nderror = ND_BADARG;
401 				return (ND_BADARG);
402 			}
403 			/*
404 			 * If servname is NULL, return 0 as the port number.
405 			 * If servname is rpcbind, return 111 as the port number
406 			 * If servname is a number, return it back as the port
407 			 * number.
408 			 */
409 			if (args->arg.nd_hs->h_serv == 0) {
410 				*servp = htons(0);
411 			} else if (strcmp(args->arg.nd_hs->h_serv,
412 				    "rpcbind") == 0) {
413 				*servp = htons(111);
414 			} else if (strspn(args->arg.nd_hs->h_serv, "0123456789")
415 				    == strlen(args->arg.nd_hs->h_serv)) {
416 				*servp = htons(atoi(args->arg.nd_hs->h_serv));
417 			} else {
418 				/* i.e. need to call a name service on this */
419 				servp = NULL;
420 			}
421 
422 			/*
423 			 * If the hostname is HOST_SELF_BIND, we return ipv6
424 			 * localaddress so the binding can be contacted through
425 			 * all interfaces.
426 			 * If the hostname is HOST_SELF_CONNECT, we return
427 			 * ipv6 loopback address so the address can be connected
428 			 * to locally.
429 			 * If the hostname is HOST_ANY, we return no addresses
430 			 * because IP doesn't know how to specify a service
431 			 * without a host.
432 			 * And finally if we specify HOST_BROADCAST then we
433 			 * disallow since IPV6 does not have any
434 			 * broadcast concept.
435 			 */
436 			if (args->arg.nd_hs->h_host == 0) {
437 				return (ND_NOHOST);
438 			} else if ((strcmp(args->arg.nd_hs->h_host,
439 					    HOST_SELF_BIND) == 0)) {
440 				haddrlist = localaddr6;
441 			} else if ((strcmp(args->arg.nd_hs->h_host,
442 					    HOST_SELF_CONNECT) == 0)) {
443 				haddrlist = connectaddr6;
444 			} else if ((strcmp(args->arg.nd_hs->h_host,
445 					    LOCALHOST) == 0)) {
446 				haddrlist = connectaddr6;
447 			} else if (strchr(args->arg.nd_hs->h_host, ':')
448 						    != NULL) {
449 
450 			/*
451 			 * If the caller passed in a dot separated IP notation
452 			 * to netdir_getbyname, convert that back into address.
453 			 */
454 
455 				if ((inet_pton(AF_INET6,
456 					    args->arg.nd_hs->h_host,
457 					    &v6nameaddr)) != 0) {
458 					dotnamelist[0] = (char *)&v6nameaddr;
459 					dotnamelist[1] = NULL;
460 					haddrlist = dotnamelist;
461 				}
462 				else
463 					/* not sure what to return */
464 					return (ND_NOHOST);
465 
466 			} else if ((strcmp(args->arg.nd_hs->h_host,
467 				    HOST_BROADCAST) == 0)) {
468 				/*
469 				 * Don't support broadcast in
470 				 * IPV6
471 				 */
472 				return (ND_NOHOST);
473 			} else {
474 				/* i.e. need to call a name service on this */
475 				haddrlist = 0;
476 			}
477 
478 			if (haddrlist && servp) {
479 				int ret;
480 				/*
481 				 * Convert h_addr_list into nd_addrlist.
482 				 * malloc's will be done, freed
483 				 * using netdir_free.
484 				 */
485 				ret = hent2ndaddr(AF_INET6, haddrlist,
486 				    servp, res->nd_alist);
487 				FREE_return(ret)
488 				}
489 			break;
490 
491 
492 	}
493 
494 	/*
495 	 * 2. Most common scenario. This is the way we ship /etc/netconfig.
496 	 *    Emphasis on improving performance in the "if" part.
497 	 */
498 	if (nconf->nc_nlookups == 0) {
499 		struct hostent	*he = NULL, *tmphe;
500 		struct servent	*se;
501 		int	ret;
502 		nss_XbyY_buf_t	*ndbuf4switch = 0;
503 
504 	switch (args->op_t) {
505 
506 		case NSS_HOST:
507 
508 		he = DOOR_GETHOSTBYNAME_R(args->arg.nss.host.name,
509 		    res->nss.host.hent, args->arg.nss.host.buf,
510 		    args->arg.nss.host.buflen,
511 		    res->nss.host.herrno_p);
512 		if (he == NULL)
513 			return (_nderror = ND_NOHOST);
514 		return (_nderror = ND_OK);
515 
516 		case NSS_HOST6:
517 
518 		he = DOOR_GETIPNODEBYNAME_R(args->arg.nss.host6.name,
519 		    res->nss.host.hent, args->arg.nss.host.buf,
520 		    args->arg.nss.host6.buflen,
521 		    args->arg.nss.host6.af_family,
522 		    args->arg.nss.host6.flags,
523 		    res->nss.host.herrno_p);
524 
525 		if (he == NULL)
526 			return (_nderror = ND_NOHOST);
527 		return (_nderror = ND_OK);
528 
529 		case NSS_SERV:
530 
531 		se = _switch_getservbyname_r(args->arg.nss.serv.name,
532 		    args->arg.nss.serv.proto,
533 		    res->nss.serv, args->arg.nss.serv.buf,
534 		    args->arg.nss.serv.buflen);
535 
536 		_nderror = ND_OK;
537 		if (se == 0)
538 			_nderror = ND_NOSERV;
539 		return (_nderror);
540 
541 		case NETDIR_BY:
542 
543 		if (servp == 0) {
544 			char	*proto =
545 	    (strcmp(nconf->nc_proto, NC_TCP) == 0) ? NC_TCP : NC_UDP;
546 
547 			/*
548 			 * We go through all this for just one port number,
549 			 * which is most often constant. How about linking in
550 			 * an indexed database of well-known ports in the name
551 			 * of performance ?
552 			 */
553 			ndbuf4switch = _nss_XbyY_buf_alloc(
554 				sizeof (struct servent), NSS_BUFLEN_SERVICES);
555 			if (ndbuf4switch == 0)
556 				FREE_return(ND_NOMEM);
557 			se = _switch_getservbyname_r(args->arg.nd_hs->h_serv,
558 				proto, ndbuf4switch->result,
559 				ndbuf4switch->buffer, ndbuf4switch->buflen);
560 			if (!se) {
561 				NSS_XbyY_FREE(&ndbuf4switch);
562 				FREE_return(ND_NOSERV)
563 			}
564 			server_port = se->s_port;
565 			NSS_XbyY_FREE(&ndbuf4switch);
566 		}
567 
568 		if (haddrlist == 0) {
569 			int	h_errnop = 0;
570 
571 			ndbuf4switch = _nss_XbyY_buf_alloc(
572 					sizeof (struct hostent),
573 					NSS_BUFLEN_HOSTS);
574 			if (ndbuf4switch == 0) {
575 				_nderror = ND_NOMEM;
576 				return (ND_NOMEM);
577 			}
578 			/*
579 			 * Search the ipnodes (v6) path first,
580 			 * search will return the v4 addresses
581 			 * as v4mapped addresses.
582 			 */
583 			if ((tmphe = DOOR_GETIPNODEBYNAME_R(
584 			    args->arg.nd_hs->h_host,
585 			    ndbuf4switch->result, ndbuf4switch->buffer,
586 			    ndbuf4switch->buflen, args->arg.nss.host6.af_family,
587 			    args->arg.nss.host6.flags, &h_errnop)) != NULL)
588 				he = __mappedtov4(tmphe, &h_errnop);
589 
590 			if (he == NULL) {
591 				/* Failover case, try hosts db for v4 address */
592 				he = DOOR_GETHOSTBYNAME_R(
593 				args->arg.nd_hs->h_host,
594 				ndbuf4switch->result, ndbuf4switch->buffer,
595 				ndbuf4switch->buflen, &h_errnop);
596 				if (he == NULL) {
597 					NSS_XbyY_FREE(&ndbuf4switch);
598 					_nderror = h_errnop ?
599 					    __herrno2netdir(h_errnop) :
600 					    ND_NOHOST;
601 					return (_nderror);
602 				}
603 				/*
604 				 * Convert h_addr_list into nd_addrlist.
605 				 * malloc's will be done, freed using
606 				 * netdir_free.
607 				 */
608 				ret = hent2ndaddr(AF_INET, he->h_addr_list,
609 					&server_port, res->nd_alist);
610 			} else {
611 				/*
612 				 * Convert h_addr_list into nd_addrlist.
613 				 * malloc's will be done, freed using
614 				 * netdir_free.
615 				 */
616 				ret = hent2ndaddr(AF_INET, he->h_addr_list,
617 					&server_port, res->nd_alist);
618 				freehostent(he);
619 			}
620 
621 			_nderror = ret;
622 			NSS_XbyY_FREE(&ndbuf4switch);
623 			return (ret);
624 		} else {
625 			int ret;
626 			/*
627 			 * Convert h_addr_list into nd_addrlist.
628 			 * malloc's will be done, freed using netdir_free.
629 			 */
630 			ret = hent2ndaddr(AF_INET, haddrlist,
631 				    &server_port, res->nd_alist);
632 			FREE_return(ret)
633 		}
634 
635 
636 		case NETDIR_BY6:
637 
638 			if (servp == 0) {
639 				char	*proto =
640 	(strcmp(nconf->nc_proto, NC_TCP) == 0) ? NC_TCP : NC_UDP;
641 
642 				/*
643 				 * We go through all this for just
644 				 * one port number,
645 				 * which is most often constant.
646 				 * How about linking in
647 				 * an indexed database of well-known
648 				 * ports in the name
649 				 * of performance ?
650 				 */
651 				ndbuf4switch = _nss_XbyY_buf_alloc(
652 					sizeof (struct servent),
653 					NSS_BUFLEN_SERVICES);
654 				if (ndbuf4switch == 0)
655 					FREE_return(ND_NOMEM);
656 				se = _switch_getservbyname_r(
657 					    args->arg.nd_hs->h_serv,
658 				    proto, ndbuf4switch->result,
659 				    ndbuf4switch->buffer, ndbuf4switch->buflen);
660 				if (!se) {
661 					NSS_XbyY_FREE(&ndbuf4switch);
662 					FREE_return(ND_NOSERV)
663 				}
664 				server_port = se->s_port;
665 				NSS_XbyY_FREE(&ndbuf4switch);
666 			}
667 
668 			if (haddrlist == 0) {
669 				int	h_errnop = 0;
670 
671 				ndbuf4switch = _nss_XbyY_buf_alloc(
672 					sizeof (struct hostent),
673 					NSS_BUFLEN_HOSTS);
674 				if (ndbuf4switch == 0) {
675 					_nderror = ND_NOMEM;
676 					return (ND_NOMEM);
677 				}
678 				he = DOOR_GETIPNODEBYNAME_R(
679 				    args->arg.nd_hs->h_host,
680 				    ndbuf4switch->result, ndbuf4switch->buffer,
681 				    ndbuf4switch->buflen,
682 				    args->arg.nss.host6.af_family,
683 				    args->arg.nss.host6.flags, &h_errnop);
684 				if (he == NULL) {
685 					NSS_XbyY_FREE(&ndbuf4switch);
686 					_nderror = h_errnop ?
687 					    __herrno2netdir(h_errnop) :
688 					    ND_NOHOST;
689 					return (_nderror);
690 				}
691 				/*
692 				 * Convert h_addr_list into nd_addrlist.
693 				 * malloc's will be done,
694 				 * freed using netdir_free.
695 				 */
696 				ret = hent2ndaddr(AF_INET6,
697 		    ((struct hostent *)(ndbuf4switch->result))->h_addr_list,
698 				    &server_port, res->nd_alist);
699 				_nderror = ret;
700 				NSS_XbyY_FREE(&ndbuf4switch);
701 				return (ret);
702 			} else {
703 				int ret;
704 				/*
705 				 * Convert h_addr_list into nd_addrlist.
706 				 * malloc's will be done,
707 				 * freed using netdir_free.
708 				 */
709 				ret = hent2ndaddr(AF_INET6, haddrlist,
710 					    &server_port, res->nd_alist);
711 				FREE_return(ret)
712 			}
713 
714 		default:
715 		_nderror = ND_BADARG;
716 		return (ND_BADARG); /* should never happen */
717 	}
718 
719 	} else {
720 		/* haddrlist is no longer used, so clean up */
721 		if (inaddrs)
722 			free(inaddrs);
723 		if (baddrlist)
724 			free(baddrlist);
725 	}
726 
727 	/*
728 	 * 3. We come this far only if nametoaddr libs are specified for
729 	 *    inet transports and we are called by gethost/servbyname only.
730 	 */
731 	switch (args->op_t) {
732 		struct	nd_hostserv service;
733 		struct	nd_addrlist *addrs;
734 		int ret;
735 
736 		case NSS_HOST:
737 
738 		service.h_host = (char *)args->arg.nss.host.name;
739 		service.h_serv = NULL;
740 		if ((_nderror = __classic_netdir_getbyname(nconf,
741 			    &service, &addrs)) != ND_OK) {
742 			*(res->nss.host.herrno_p) = nd2herrno(_nderror);
743 			return (_nderror);
744 		}
745 		/*
746 		 * convert addresses back into sockaddr for gethostbyname.
747 		 */
748 		ret = ndaddr2hent(AF_INET, service.h_host, addrs,
749 		    res->nss.host.hent, args->arg.nss.host.buf,
750 		    args->arg.nss.host.buflen);
751 		if (ret != ND_OK)
752 			*(res->nss.host.herrno_p) = nd2herrno(ret);
753 		netdir_free((char *)addrs, ND_ADDRLIST);
754 		_nderror = ret;
755 		return (ret);
756 
757 		case NSS_SERV:
758 
759 		if (args->arg.nss.serv.proto == NULL) {
760 			/*
761 			 * A similar HACK showed up in Solaris 2.3.
762 			 * The caller wild-carded proto -- i.e. will
763 			 * accept a match using tcp or udp for the port
764 			 * number. Since we have no hope of getting
765 			 * directly to a name service switch backend
766 			 * from here that understands this semantics,
767 			 * we try calling the netdir interfaces first
768 			 * with "tcp" and then "udp".
769 			 */
770 			args->arg.nss.serv.proto = "tcp";
771 			_nderror = _get_hostserv_inetnetdir_byname(nconf, args,
772 			    res);
773 			if (_nderror != ND_OK) {
774 				args->arg.nss.serv.proto = "udp";
775 				_nderror =
776 				    _get_hostserv_inetnetdir_byname(nconf,
777 				    args, res);
778 			}
779 			return (_nderror);
780 		}
781 
782 		/*
783 		 * Third-parties should optimize their nametoaddr
784 		 * libraries for the HOST_SELF case.
785 		 */
786 		service.h_host = HOST_SELF;
787 		service.h_serv = (char *)args->arg.nss.serv.name;
788 		if ((_nderror = __classic_netdir_getbyname(nconf,
789 			    &service, &addrs)) != ND_OK) {
790 			return (_nderror);
791 		}
792 		/*
793 		 * convert addresses back into servent for getservbyname.
794 		 */
795 		_nderror = ndaddr2srent(service.h_serv,
796 		    args->arg.nss.serv.proto,
797 		    /* LINTED pointer cast */
798 		    ((struct sockaddr_in *)addrs->n_addrs->buf)->sin_port,
799 		    res->nss.serv,
800 		    args->arg.nss.serv.buf, args->arg.nss.serv.buflen);
801 		netdir_free((char *)addrs, ND_ADDRLIST);
802 		return (_nderror);
803 
804 		default:
805 		_nderror = ND_BADARG;
806 		return (ND_BADARG); /* should never happen */
807 	}
808 }
809 
810 /*
811  * gethostbyaddr/servbyport always call this function; if they call
812  * with nametoaddr libs in nconf, we call netdir_getbyaddr
813  * implementation __classic_netdir_getbyaddr, otherwise nsswitch.
814  *
815  * netdir_getbyaddr calls this only if nametoaddr libs are NOT
816  * specified for inet transports; i.e. it's supposed to follow
817  * the name service switch.
818  */
819 int
820 _get_hostserv_inetnetdir_byaddr(struct netconfig *nconf,
821     struct nss_netdirbyaddr_in *args, union nss_netdirbyaddr_out *res)
822 {
823 	if (nconf == 0) {
824 		_nderror = ND_BADARG;
825 		return (_nderror);
826 	}
827 
828 	/*
829 	 * 1. gethostbyaddr()/netdir_getbyaddr() special cases:
830 	 */
831 	switch (args->op_t) {
832 
833 		case NSS_HOST:
834 		/*
835 		 * Worth the performance gain: assuming a lot of inet apps
836 		 * actively use "127.0.0.1".
837 		 */
838 		/* LINTED pointer cast */
839 		if (*(uint32_t *)(args->arg.nss.host.addr) ==
840 					htonl(INADDR_LOOPBACK)) {
841 			(void) mutex_lock(&nd_addr_lock);
842 			IN_SET_LOOPBACK_ADDR(&sa_con);
843 			_nderror = ndaddr2hent(AF_INET, LOCALHOST,
844 			    &nd_conaddrlist, res->nss.host.hent,
845 			    args->arg.nss.host.buf,
846 			    args->arg.nss.host.buflen);
847 			(void) mutex_unlock(&nd_addr_lock);
848 			if (_nderror != ND_OK)
849 				*(res->nss.host.herrno_p) =
850 				    nd2herrno(_nderror);
851 			return (_nderror);
852 		}
853 		break;
854 
855 		case NETDIR_BY:
856 		case NETDIR_BY_NOSRV:
857 		{
858 			struct sockaddr_in *sin;
859 
860 			if (args->arg.nd_nbuf == NULL) {
861 				_nderror = ND_BADARG;
862 				return (_nderror);
863 			}
864 
865 			/*
866 			 * Validate the address which was passed
867 			 * as the request.
868 			 */
869 			/* LINTED pointer cast */
870 			sin = (struct sockaddr_in *)args->arg.nd_nbuf->buf;
871 
872 			if ((args->arg.nd_nbuf->len !=
873 				sizeof (struct sockaddr_in)) ||
874 			    (sin->sin_family != AF_INET)) {
875 				_nderror = ND_BADARG;
876 				return (_nderror);
877 			}
878 		}
879 		break;
880 
881 		case NETDIR_BY6:
882 		case NETDIR_BY_NOSRV6:
883 		{
884 			struct sockaddr_in6 *sin6;
885 
886 			if (args->arg.nd_nbuf == NULL) {
887 				_nderror = ND_BADARG;
888 				return (_nderror);
889 			}
890 
891 			/*
892 			 * Validate the address which was passed
893 			 * as the request.
894 			 */
895 			/* LINTED pointer cast */
896 			sin6 = (struct sockaddr_in6 *)args->arg.nd_nbuf->buf;
897 
898 			if ((args->arg.nd_nbuf->len !=
899 				sizeof (struct sockaddr_in6)) ||
900 			    (sin6->sin6_family != AF_INET6)) {
901 				_nderror = ND_BADARG;
902 				return (_nderror);
903 			}
904 		}
905 		break;
906 
907 	}
908 
909 	/*
910 	 * 2. Most common scenario. This is the way we ship /etc/netconfig.
911 	 *    Emphasis on improving performance in the "if" part.
912 	 */
913 	if (nconf->nc_nlookups == 0) {
914 		struct hostent	*he = NULL, *tmphe;
915 		struct servent	*se = NULL;
916 		nss_XbyY_buf_t	*ndbuf4host = 0;
917 		nss_XbyY_buf_t	*ndbuf4serv = 0;
918 		char	*proto =
919 		    (strcmp(nconf->nc_proto, NC_TCP) == 0) ? NC_TCP : NC_UDP;
920 		struct	sockaddr_in *sa;
921 		struct sockaddr_in6 *sin6;
922 		struct in_addr *addr4 = 0;
923 		struct in6_addr v4mapbuf;
924 		int	h_errnop;
925 
926 	switch (args->op_t) {
927 
928 		case NSS_HOST:
929 
930 		he = DOOR_GETHOSTBYADDR_R(args->arg.nss.host.addr,
931 		    args->arg.nss.host.len, args->arg.nss.host.type,
932 		    res->nss.host.hent, args->arg.nss.host.buf,
933 		    args->arg.nss.host.buflen,
934 		    res->nss.host.herrno_p);
935 		if (he == 0)
936 			_nderror = ND_NOHOST;
937 		else
938 			_nderror = ND_OK;
939 		return (_nderror);
940 
941 
942 		case NSS_HOST6:
943 		he = DOOR_GETIPNODEBYADDR_R(args->arg.nss.host.addr,
944 		    args->arg.nss.host.len, args->arg.nss.host.type,
945 		    res->nss.host.hent, args->arg.nss.host.buf,
946 		    args->arg.nss.host.buflen,
947 		    res->nss.host.herrno_p);
948 
949 		if (he == 0)
950 			return (ND_NOHOST);
951 		return (ND_OK);
952 
953 
954 		case NSS_SERV:
955 
956 		se = _switch_getservbyport_r(args->arg.nss.serv.port,
957 		    args->arg.nss.serv.proto,
958 		    res->nss.serv, args->arg.nss.serv.buf,
959 		    args->arg.nss.serv.buflen);
960 
961 		if (se == 0)
962 			_nderror = ND_NOSERV;
963 		else
964 			_nderror = ND_OK;
965 		return (_nderror);
966 
967 		case NETDIR_BY:
968 		case NETDIR_BY_NOSRV:
969 
970 		ndbuf4serv = _nss_XbyY_buf_alloc(sizeof (struct servent),
971 					NSS_BUFLEN_SERVICES);
972 		if (ndbuf4serv == 0) {
973 			_nderror = ND_NOMEM;
974 			return (_nderror);
975 		}
976 		/* LINTED pointer cast */
977 		sa = (struct sockaddr_in *)(args->arg.nd_nbuf->buf);
978 		addr4 = (struct in_addr *)&(sa->sin_addr);
979 
980 		/*
981 		 * if NETDIR_BY_NOSRV or port == 0 skip the service
982 		 * lookup.
983 		 */
984 		if (args->op_t != NETDIR_BY_NOSRV && sa->sin_port != 0) {
985 			se = _switch_getservbyport_r(sa->sin_port, proto,
986 			    ndbuf4serv->result, ndbuf4serv->buffer,
987 				    ndbuf4serv->buflen);
988 			if (!se) {
989 				NSS_XbyY_FREE(&ndbuf4serv);
990 				/*
991 				 * We can live with this - i.e. the address
992 				 * does not
993 				 * belong to a well known service. The caller
994 				 * traditionally accepts a stringified port
995 				 * number
996 				 * as the service name. The state of se is used
997 				 * ahead to indicate the same.
998 				 * However, we do not tolerate this nonsense
999 				 * when we cannot get a host name. See below.
1000 				 */
1001 			}
1002 		}
1003 
1004 		ndbuf4host = _nss_XbyY_buf_alloc(sizeof (struct hostent),
1005 					NSS_BUFLEN_HOSTS);
1006 		if (ndbuf4host == 0) {
1007 			if (ndbuf4serv)
1008 				NSS_XbyY_FREE(&ndbuf4serv);
1009 			_nderror = ND_NOMEM;
1010 			return (_nderror);
1011 		}
1012 
1013 		/*
1014 		 * Since we're going to search the ipnodes (v6) path first,
1015 		 * we need to treat the address as a v4mapped address.
1016 		 */
1017 
1018 		IN6_INADDR_TO_V4MAPPED(addr4, &v4mapbuf);
1019 		if ((tmphe = DOOR_GETIPNODEBYADDR_R((char *)&v4mapbuf,
1020 		    16, AF_INET6, ndbuf4host->result,
1021 			    ndbuf4host->buffer,
1022 			    ndbuf4host->buflen, &h_errnop)) != NULL)
1023 			he = __mappedtov4(tmphe, &h_errnop);
1024 
1025 		if (!he) {
1026 			/* Failover case, try hosts db for v4 address */
1027 			he = DOOR_GETHOSTBYADDR_R((char *)
1028 					&(sa->sin_addr.s_addr), 4,
1029 					sa->sin_family, ndbuf4host->result,
1030 					ndbuf4host->buffer, ndbuf4host->buflen,
1031 					&h_errnop);
1032 			if (!he) {
1033 				NSS_XbyY_FREE(&ndbuf4host);
1034 				if (ndbuf4serv)
1035 					NSS_XbyY_FREE(&ndbuf4serv);
1036 				_nderror = __herrno2netdir(h_errnop);
1037 				return (_nderror);
1038 			}
1039 			/*
1040 			 * Convert host names and service names into hostserv
1041 			 * pairs. malloc's will be done, freed using
1042 			 * netdir_free.
1043 			 */
1044 			h_errnop = hsents2ndhostservs(he, se,
1045 			    sa->sin_port, res->nd_hslist);
1046 		} else {
1047 			/*
1048 			 * Convert host names and service names into hostserv
1049 			 * pairs. malloc's will be done, freed using
1050 			 * netdir_free.
1051 			 */
1052 			h_errnop = hsents2ndhostservs(he, se,
1053 			    sa->sin_port, res->nd_hslist);
1054 			freehostent(he);
1055 		}
1056 
1057 		NSS_XbyY_FREE(&ndbuf4host);
1058 		if (ndbuf4serv)
1059 		    NSS_XbyY_FREE(&ndbuf4serv);
1060 		_nderror = __herrno2netdir(h_errnop);
1061 		return (_nderror);
1062 
1063 		case NETDIR_BY6:
1064 		case NETDIR_BY_NOSRV6:
1065 
1066 		ndbuf4serv = _nss_XbyY_buf_alloc(sizeof (struct servent),
1067 					NSS_BUFLEN_SERVICES);
1068 		if (ndbuf4serv == 0) {
1069 			_nderror = ND_NOMEM;
1070 			return (ND_NOMEM);
1071 		}
1072 		/* LINTED pointer cast */
1073 		sin6 = (struct sockaddr_in6 *)(args->arg.nd_nbuf->buf);
1074 
1075 		/*
1076 		 * if NETDIR_BY_NOSRV6 or port == 0 skip the service
1077 		 * lookup.
1078 		 */
1079 		if (args->op_t != NETDIR_BY_NOSRV6 && sin6->sin6_port == 0) {
1080 			se = _switch_getservbyport_r(sin6->sin6_port, proto,
1081 			    ndbuf4serv->result, ndbuf4serv->buffer,
1082 				    ndbuf4serv->buflen);
1083 			if (!se) {
1084 				NSS_XbyY_FREE(&ndbuf4serv);
1085 				/*
1086 				 * We can live with this - i.e. the address does
1087 				 * not * belong to a well known service. The
1088 				 * caller traditionally accepts a stringified
1089 				 * port number
1090 				 * as the service name. The state of se is used
1091 				 * ahead to indicate the same.
1092 				 * However, we do not tolerate this nonsense
1093 				 * when we cannot get a host name. See below.
1094 				 */
1095 			}
1096 		}
1097 
1098 		ndbuf4host = _nss_XbyY_buf_alloc(sizeof (struct hostent),
1099 					NSS_BUFLEN_HOSTS);
1100 		if (ndbuf4host == 0) {
1101 			if (ndbuf4serv)
1102 				NSS_XbyY_FREE(&ndbuf4serv);
1103 			_nderror = ND_NOMEM;
1104 			return (_nderror);
1105 		}
1106 		he = DOOR_GETIPNODEBYADDR_R((char *)&(sin6->sin6_addr),
1107 		    16, sin6->sin6_family, ndbuf4host->result,
1108 			    ndbuf4host->buffer,
1109 			    ndbuf4host->buflen, &h_errnop);
1110 		if (!he) {
1111 			NSS_XbyY_FREE(&ndbuf4host);
1112 			if (ndbuf4serv)
1113 			    NSS_XbyY_FREE(&ndbuf4serv);
1114 			_nderror = __herrno2netdir(h_errnop);
1115 			return (_nderror);
1116 		}
1117 		/*
1118 		 * Convert host names and service names into hostserv
1119 		 * pairs. malloc's will be done, freed using netdir_free.
1120 		 */
1121 		h_errnop = hsents2ndhostservs(he, se,
1122 		    sin6->sin6_port, res->nd_hslist);
1123 
1124 		NSS_XbyY_FREE(&ndbuf4host);
1125 		if (ndbuf4serv)
1126 		    NSS_XbyY_FREE(&ndbuf4serv);
1127 		_nderror = __herrno2netdir(h_errnop);
1128 		return (_nderror);
1129 
1130 		default:
1131 		_nderror = ND_BADARG;
1132 		return (_nderror); /* should never happen */
1133 	}
1134 
1135 	}
1136 	/*
1137 	 * 3. We come this far only if nametoaddr libs are specified for
1138 	 *    inet transports and we are called by gethost/servbyname only.
1139 	 */
1140 	switch (args->op_t) {
1141 		struct	netbuf nbuf;
1142 		struct	nd_hostservlist *addrs;
1143 		struct	sockaddr_in sa;
1144 
1145 		case NSS_HOST:
1146 
1147 		/* LINTED pointer cast */
1148 		sa.sin_addr.s_addr = *(uint32_t *)args->arg.nss.host.addr;
1149 		sa.sin_family = AF_INET;
1150 		/* Hopefully, third-parties get this optimization */
1151 		sa.sin_port = 0;
1152 		nbuf.buf = (char *)&sa;
1153 		nbuf.len = nbuf.maxlen = sizeof (sa);
1154 		if ((_nderror = __classic_netdir_getbyaddr(nconf,
1155 			    &addrs, &nbuf)) != 0) {
1156 			*(res->nss.host.herrno_p) = nd2herrno(_nderror);
1157 			return (_nderror);
1158 		}
1159 		/*
1160 		 * convert the host-serv pairs into h_aliases and hent.
1161 		 */
1162 		_nderror = ndhostserv2hent(&nbuf, addrs, res->nss.host.hent,
1163 		    args->arg.nss.host.buf, args->arg.nss.host.buflen);
1164 		if (_nderror != ND_OK)
1165 			*(res->nss.host.herrno_p) = nd2herrno(_nderror);
1166 		netdir_free((char *)addrs, ND_HOSTSERVLIST);
1167 		return (_nderror);
1168 
1169 		case NSS_SERV:
1170 
1171 		if (args->arg.nss.serv.proto == NULL) {
1172 			/*
1173 			 * A similar HACK showed up in Solaris 2.3.
1174 			 * The caller wild-carded proto -- i.e. will
1175 			 * accept a match on tcp or udp for the port
1176 			 * number. Since we have no hope of getting
1177 			 * directly to a name service switch backend
1178 			 * from here that understands this semantics,
1179 			 * we try calling the netdir interfaces first
1180 			 * with "tcp" and then "udp".
1181 			 */
1182 			args->arg.nss.serv.proto = "tcp";
1183 			_nderror = _get_hostserv_inetnetdir_byaddr(nconf, args,
1184 			    res);
1185 			if (_nderror != ND_OK) {
1186 				args->arg.nss.serv.proto = "udp";
1187 				_nderror =
1188 				    _get_hostserv_inetnetdir_byaddr(nconf,
1189 					args, res);
1190 			}
1191 			return (_nderror);
1192 		}
1193 
1194 		/*
1195 		 * Third-party nametoaddr_libs should be optimized for
1196 		 * this case. It also gives a special semantics twist to
1197 		 * netdir_getbyaddr. Only for the INADDR_ANY case, it gives
1198 		 * higher priority to service lookups (over host lookups).
1199 		 * If service lookup fails, the backend returns ND_NOSERV to
1200 		 * facilitate lookup in the "next" naming service.
1201 		 * BugId: 1075403.
1202 		 */
1203 		sa.sin_addr.s_addr = INADDR_ANY;
1204 		sa.sin_family = AF_INET;
1205 		sa.sin_port = (ushort_t)args->arg.nss.serv.port;
1206 		sa.sin_zero[0] = '\0';
1207 		nbuf.buf = (char *)&sa;
1208 		nbuf.len = nbuf.maxlen = sizeof (sa);
1209 		if ((_nderror = __classic_netdir_getbyaddr(nconf,
1210 			    &addrs, &nbuf)) != ND_OK) {
1211 			return (_nderror);
1212 		}
1213 		/*
1214 		 * convert the host-serv pairs into s_aliases and servent.
1215 		 */
1216 		_nderror = ndhostserv2srent(args->arg.nss.serv.port,
1217 		    args->arg.nss.serv.proto, addrs, res->nss.serv,
1218 		    args->arg.nss.serv.buf, args->arg.nss.serv.buflen);
1219 		netdir_free((char *)addrs, ND_HOSTSERVLIST);
1220 		return (_nderror);
1221 
1222 		default:
1223 		_nderror = ND_BADARG;
1224 		return (_nderror); /* should never happen */
1225 	}
1226 }
1227 
1228 /*
1229  * Part II: Name Service Switch interfacing routines.
1230  */
1231 
1232 static DEFINE_NSS_DB_ROOT(db_root_hosts);
1233 static DEFINE_NSS_DB_ROOT(db_root_ipnodes);
1234 static DEFINE_NSS_DB_ROOT(db_root_services);
1235 
1236 
1237 /*
1238  * There is a copy of __nss2herrno() in nsswitch/files/gethostent.c.
1239  * It is there because /etc/lib/nss_files.so.1 cannot call
1240  * routines in libnsl.  Care should be taken to keep the two copies
1241  * in sync.
1242  */
1243 int
1244 __nss2herrno(nss_status_t nsstat)
1245 {
1246 	switch (nsstat) {
1247 	case NSS_SUCCESS:
1248 		/* no macro-defined success code for h_errno */
1249 		return (0);
1250 	case NSS_NOTFOUND:
1251 		return (HOST_NOT_FOUND);
1252 	case NSS_TRYAGAIN:
1253 		return (TRY_AGAIN);
1254 	case NSS_UNAVAIL:
1255 		return (NO_RECOVERY);
1256 	}
1257 	/* NOTREACHED */
1258 	return (0);	/* keep gcc happy */
1259 }
1260 
1261 nss_status_t
1262 _herrno2nss(int h_errno)
1263 {
1264 	switch (h_errno) {
1265 	case 0:
1266 		return (NSS_SUCCESS);
1267 	case TRY_AGAIN:
1268 		return (NSS_TRYAGAIN);
1269 	case NO_RECOVERY:
1270 	case NETDB_INTERNAL:
1271 		return (NSS_UNAVAIL);
1272 	case HOST_NOT_FOUND:
1273 	case NO_DATA:
1274 	default:
1275 		return (NSS_NOTFOUND);
1276 	}
1277 }
1278 
1279 static int
1280 __herrno2netdir(int h_errnop)
1281 {
1282 	switch (h_errnop) {
1283 		case 0:
1284 			return (ND_OK);
1285 		case HOST_NOT_FOUND:
1286 			return (ND_NOHOST);
1287 		case TRY_AGAIN:
1288 			return (ND_TRY_AGAIN);
1289 		case NO_RECOVERY:
1290 		case NETDB_INTERNAL:
1291 			return (ND_NO_RECOVERY);
1292 		case NO_DATA:
1293 			return (ND_NO_DATA);
1294 		default:
1295 			return (ND_NOHOST);
1296 	}
1297 }
1298 
1299 /*
1300  * The _switch_getXXbyYY_r() routines should be static.  They used to
1301  * be exported in SunOS 5.3, and in fact publicised as work-around
1302  * interfaces for getting CNAME/aliases, and therefore, we preserve
1303  * their signatures here. Just in case.
1304  */
1305 
1306 struct hostent *
1307 _switch_gethostbyname_r(const char *name, struct hostent *result, char *buffer,
1308     int buflen, int *h_errnop)
1309 {
1310 	nss_XbyY_args_t arg;
1311 	nss_status_t	res;
1312 
1313 	NSS_XbyY_INIT(&arg, result, buffer, buflen, str2hostent);
1314 	arg.key.name	= name;
1315 	arg.stayopen	= 0;
1316 	res = nss_search(&db_root_hosts, _nss_initf_hosts,
1317 	    NSS_DBOP_HOSTS_BYNAME, &arg);
1318 	arg.status = res;
1319 	*h_errnop = arg.h_errno;
1320 	if (arg.returnval != NULL)
1321 		order_haddrlist_af(result->h_addrtype, result->h_addr_list);
1322 	return ((struct hostent *)NSS_XbyY_FINI(&arg));
1323 }
1324 
1325 struct hostent *
1326 _switch_getipnodebyname_r(const char *name, struct hostent *result,
1327     char *buffer, int buflen, int af_family, int flags, int *h_errnop)
1328 {
1329 	nss_XbyY_args_t arg;
1330 	nss_status_t	res;
1331 
1332 	NSS_XbyY_INIT(&arg, result, buffer, buflen, str2hostent6);
1333 	arg.key.ipnode.name	= name;
1334 	arg.key.ipnode.af_family = af_family;
1335 	arg.key.ipnode.flags = flags;
1336 	arg.stayopen	= 0;
1337 	res = nss_search(&db_root_ipnodes, _nss_initf_ipnodes,
1338 	    NSS_DBOP_IPNODES_BYNAME, &arg);
1339 	arg.status = res;
1340 	*h_errnop = arg.h_errno;
1341 	if (arg.returnval != NULL)
1342 		order_haddrlist_af(result->h_addrtype, result->h_addr_list);
1343 	return ((struct hostent *)NSS_XbyY_FINI(&arg));
1344 }
1345 
1346 struct hostent *
1347 _switch_gethostbyaddr_r(const char *addr, int len, int type,
1348     struct hostent *result, char *buffer, int buflen, int *h_errnop)
1349 {
1350 	nss_XbyY_args_t arg;
1351 	nss_status_t	res;
1352 
1353 	NSS_XbyY_INIT(&arg, result, buffer, buflen, str2hostent);
1354 	arg.key.hostaddr.addr	= addr;
1355 	arg.key.hostaddr.len	= len;
1356 	arg.key.hostaddr.type	= type;
1357 	arg.stayopen		= 0;
1358 	res = nss_search(&db_root_hosts, _nss_initf_hosts,
1359 	    NSS_DBOP_HOSTS_BYADDR, &arg);
1360 	arg.status = res;
1361 	*h_errnop = arg.h_errno;
1362 	return (struct hostent *)NSS_XbyY_FINI(&arg);
1363 }
1364 
1365 struct hostent *
1366 _switch_getipnodebyaddr_r(const char *addr, int len, int type,
1367     struct hostent *result, char *buffer, int buflen, int *h_errnop)
1368 {
1369 	nss_XbyY_args_t arg;
1370 	nss_status_t	res;
1371 
1372 	NSS_XbyY_INIT(&arg, result, buffer, buflen, str2hostent6);
1373 	arg.key.hostaddr.addr	= addr;
1374 	arg.key.hostaddr.len	= len;
1375 	arg.key.hostaddr.type	= type;
1376 	arg.stayopen		= 0;
1377 	res = nss_search(&db_root_ipnodes, _nss_initf_ipnodes,
1378 	    NSS_DBOP_IPNODES_BYADDR, &arg);
1379 	arg.status = res;
1380 	*h_errnop = arg.h_errno;
1381 	return (struct hostent *)NSS_XbyY_FINI(&arg);
1382 }
1383 
1384 static void
1385 _nss_initf_services(nss_db_params_t *p)
1386 {
1387 	p->name	= NSS_DBNAM_SERVICES;
1388 	p->default_config = NSS_DEFCONF_SERVICES;
1389 }
1390 
1391 struct servent *
1392 _switch_getservbyname_r(const char *name, const char *proto,
1393     struct servent *result, char *buffer, int buflen)
1394 {
1395 	nss_XbyY_args_t arg;
1396 	nss_status_t	res;
1397 
1398 	NSS_XbyY_INIT(&arg, result, buffer, buflen, str2servent);
1399 	arg.key.serv.serv.name	= name;
1400 	arg.key.serv.proto	= proto;
1401 	arg.stayopen		= 0;
1402 	res = nss_search(&db_root_services, _nss_initf_services,
1403 	    NSS_DBOP_SERVICES_BYNAME, &arg);
1404 	arg.status = res;
1405 	return ((struct servent *)NSS_XbyY_FINI(&arg));
1406 }
1407 
1408 struct servent *
1409 _switch_getservbyport_r(int port, const char *proto, struct servent *result,
1410     char *buffer, int buflen)
1411 {
1412 	nss_XbyY_args_t arg;
1413 	nss_status_t	res;
1414 
1415 	NSS_XbyY_INIT(&arg, result, buffer, buflen, str2servent);
1416 	arg.key.serv.serv.port	= port;
1417 	arg.key.serv.proto	= proto;
1418 	arg.stayopen		= 0;
1419 	res = nss_search(&db_root_services, _nss_initf_services,
1420 	    NSS_DBOP_SERVICES_BYPORT, &arg);
1421 	arg.status = res;
1422 	return ((struct servent *)NSS_XbyY_FINI(&arg));
1423 }
1424 
1425 
1426 /*
1427  * Return values: 0 = success, 1 = parse error, 2 = erange ...
1428  * The structure pointer passed in is a structure in the caller's space
1429  * wherein the field pointers would be set to areas in the buffer if
1430  * need be. instring and buffer should be separate areas.
1431  *
1432  * Defined here because we need it and we (libnsl) cannot have a dependency
1433  * on libsocket (however, libsocket always depends on libnsl).
1434  */
1435 int
1436 str2servent(const char *instr, int lenstr, void *ent, char *buffer, int buflen)
1437 {
1438 	struct servent	*serv	= (struct servent *)ent;
1439 	const char	*p, *fieldstart, *limit, *namestart;
1440 	ssize_t		fieldlen, namelen = 0;
1441 	char		numbuf[12];
1442 	char		*numend;
1443 
1444 	if ((instr >= buffer && (buffer + buflen) > instr) ||
1445 	    (buffer >= instr && (instr + lenstr) > buffer)) {
1446 		return (NSS_STR_PARSE_PARSE);
1447 	}
1448 
1449 	p = instr;
1450 	limit = p + lenstr;
1451 
1452 	while (p < limit && isspace(*p)) {
1453 		p++;
1454 	}
1455 	namestart = p;
1456 	while (p < limit && !isspace(*p)) {
1457 		p++;		/* Skip over the canonical name */
1458 	}
1459 	namelen = p - namestart;
1460 
1461 	if (buflen <= namelen) { /* not enough buffer */
1462 		return (NSS_STR_PARSE_ERANGE);
1463 	}
1464 	(void) memcpy(buffer, namestart, namelen);
1465 	buffer[namelen] = '\0';
1466 	serv->s_name = buffer;
1467 
1468 	while (p < limit && isspace(*p)) {
1469 		p++;
1470 	}
1471 
1472 	fieldstart = p;
1473 	do {
1474 		if (p > limit || isspace(*p)) {
1475 			/* Syntax error -- no port/proto */
1476 			return (NSS_STR_PARSE_PARSE);
1477 		}
1478 	}
1479 	while (*p++ != '/');
1480 	fieldlen = p - fieldstart - 1;
1481 	if (fieldlen == 0 || fieldlen >= sizeof (numbuf)) {
1482 		/* Syntax error -- supposed number is empty or too long */
1483 		return (NSS_STR_PARSE_PARSE);
1484 	}
1485 	(void) memcpy(numbuf, fieldstart, fieldlen);
1486 	numbuf[fieldlen] = '\0';
1487 	serv->s_port = htons((int)strtol(numbuf, &numend, 10));
1488 	if (*numend != '\0') {
1489 		/* Syntax error -- port number isn't a number */
1490 		return (NSS_STR_PARSE_PARSE);
1491 	}
1492 
1493 	fieldstart = p;
1494 	while (p < limit && !isspace(*p)) {
1495 		p++;		/* Scan the protocol name */
1496 	}
1497 	fieldlen = p - fieldstart + 1;		/* Include '\0' this time */
1498 	if (fieldlen > buflen - namelen - 1) {
1499 		return (NSS_STR_PARSE_ERANGE);
1500 	}
1501 	serv->s_proto = buffer + namelen + 1;
1502 	(void) memcpy(serv->s_proto, fieldstart, fieldlen - 1);
1503 	serv->s_proto[fieldlen - 1] = '\0';
1504 
1505 	while (p < limit && isspace(*p)) {
1506 		p++;
1507 	}
1508 	/*
1509 	 * Although nss_files_XY_all calls us with # stripped,
1510 	 * we should be able to deal with it here in order to
1511 	 * be more useful.
1512 	 */
1513 	if (p >= limit || *p == '#') { /* no aliases, no problem */
1514 		char **ptr;
1515 
1516 		ptr = (char **)ROUND_UP(buffer + namelen + 1 + fieldlen,
1517 		    sizeof (char *));
1518 		if ((char *)ptr >= buffer + buflen) {
1519 			/* hope they don't try to peek in */
1520 			serv->s_aliases = 0;
1521 			return (NSS_STR_PARSE_ERANGE);
1522 		} else {
1523 			*ptr = 0;
1524 			serv->s_aliases = ptr;
1525 			return (NSS_STR_PARSE_SUCCESS);
1526 		}
1527 	}
1528 	serv->s_aliases = _nss_netdb_aliases(p, (int)(lenstr - (p - instr)),
1529 	    buffer + namelen + 1 + fieldlen,
1530 	    (int)(buflen - namelen - 1 - fieldlen));
1531 	return (NSS_STR_PARSE_SUCCESS);
1532 }
1533 
1534 /*
1535  * Part III: All `n sundry routines that are useful only in this
1536  * module. In the interest of keeping this source file shorter,
1537  * we would create them a new module only if the linker allowed
1538  * "library-static" functions.
1539  *
1540  * Routines to order addresses based on local interfaces and netmasks,
1541  * to get and check reserved ports, and to get broadcast nets.
1542  */
1543 
1544 union __v4v6addr {
1545 	struct in6_addr	in6;
1546 	struct in_addr	in4;
1547 };
1548 
1549 struct __ifaddr {
1550 	sa_family_t		af;
1551 	union __v4v6addr	addr;
1552 	union __v4v6addr	mask;
1553 };
1554 
1555 struct ifinfo {
1556 	int		count;
1557 	struct __ifaddr	*addresses;
1558 };
1559 
1560 typedef enum {ADDR_ONLINK = 0, ADDR_OFFLINK} addr_class_t;
1561 #define	ADDR_NUMCLASSES	2
1562 
1563 typedef enum {IF_ADDR, IF_MASK}	__ifaddr_type;
1564 static int	__inet_ifassign(sa_family_t, struct __ifaddr *, __ifaddr_type,
1565 				void *);
1566 int		__inet_address_is_local_af(void *, sa_family_t, void *);
1567 
1568 #define	ifaf(index)	(localinfo->addresses[index].af)
1569 #define	ifaddr4(index)	(localinfo->addresses[index].addr.in4)
1570 #define	ifaddr6(index)	(localinfo->addresses[index].addr.in6)
1571 #define	ifmask4(index)	(localinfo->addresses[index].mask.in4)
1572 #define	ifmask6(index)	(localinfo->addresses[index].mask.in6)
1573 #define	ifinfosize(n)	(sizeof (struct ifinfo) + (n)*sizeof (struct __ifaddr))
1574 
1575 #define	lifraddrp(lifr)	((lifr.lifr_addr.ss_family == AF_INET6) ? \
1576 	(void *)&((struct sockaddr_in6 *)&lifr.lifr_addr)->sin6_addr : \
1577 	(void *)&((struct sockaddr_in *)&lifr.lifr_addr)->sin_addr)
1578 
1579 #define	ifassign(lifr, index, type) \
1580 			__inet_ifassign(lifr.lifr_addr.ss_family, \
1581 				&localinfo->addresses[index], type, \
1582 				lifraddrp(lifr))
1583 
1584 /*
1585  * The number of nanoseconds the order_haddrlist_inet() function waits
1586  * to retreive IP interface information.  The default is five minutes.
1587  */
1588 #define	IFINFOTIMEOUT	((hrtime_t)300 * NANOSEC)
1589 
1590 /*
1591  * Sort the addresses in haddrlist.  Since the sorting algorithms are
1592  * address-family specific, the work is done in the address-family
1593  * specific order_haddrlist_<family> functions.
1594  *
1595  * Do not sort addresses if SORT_ADDRS variable is set to NO or FALSE
1596  * in the configuration file /etc/default/nss. This is useful in case
1597  * the order of addresses returned by the nameserver needs to be
1598  * maintained. (DNS round robin feature is one example)
1599  */
1600 void
1601 order_haddrlist_af(sa_family_t af, char **haddrlist)
1602 {
1603 	size_t			addrcount;
1604 	char			**addrptr;
1605 	static boolean_t	checksortcfg = B_TRUE;
1606 	static boolean_t	nosort = B_FALSE;
1607 	static mutex_t		checksortcfg_lock = DEFAULTMUTEX;
1608 
1609 	if (haddrlist == NULL)
1610 		return;
1611 
1612 	/*
1613 	 * Check if SORT_ADDRS is set to NO or FALSE in the configuration
1614 	 * file.  We do not have to sort addresses in that case.
1615 	 */
1616 	(void) mutex_lock(&checksortcfg_lock);
1617 	if (checksortcfg == B_TRUE) {
1618 		checksortcfg = B_FALSE;
1619 		nosort = _read_nsw_file();
1620 	}
1621 	(void) mutex_unlock(&checksortcfg_lock);
1622 
1623 	if (nosort)
1624 		return;
1625 
1626 	/* Count the addresses to sort */
1627 	addrcount = 0;
1628 	for (addrptr = haddrlist; *addrptr != NULL; addrptr++)
1629 		addrcount++;
1630 
1631 	/*
1632 	 * If there's only one address or no addresses to sort, then
1633 	 * there's nothing for us to do.
1634 	 */
1635 	if (addrcount <= 1)
1636 		return;
1637 
1638 	/* Call the address-family specific sorting functions. */
1639 	switch (af) {
1640 	case AF_INET:
1641 		order_haddrlist_inet(haddrlist, addrcount);
1642 		break;
1643 	case AF_INET6:
1644 		order_haddrlist_inet6(haddrlist, addrcount);
1645 		break;
1646 	default:
1647 		break;
1648 	}
1649 }
1650 
1651 /*
1652  * Move any local (on-link) addresses toward the beginning of haddrlist.
1653  * The order within these two classes is preserved.
1654  *
1655  * The interface list is retrieved no more often than every
1656  * IFINFOTIMEOUT nanoseconds. Access to the interface list is
1657  * protected by an RW lock.
1658  *
1659  * If this function encounters an error, haddrlist is unaltered.
1660  */
1661 static void
1662 order_haddrlist_inet(char **haddrlist, size_t addrcount)
1663 {
1664 	static struct	ifinfo *localinfo = NULL;
1665 	static hrtime_t	then = 0; /* the last time localinfo was updated */
1666 	hrtime_t	now;
1667 	static rwlock_t	localinfo_lock = DEFAULTRWLOCK;
1668 	uint8_t		*sortbuf;
1669 	size_t		sortbuf_size;
1670 	struct in_addr	**inaddrlist = (struct in_addr **)haddrlist;
1671 	struct in_addr	**sorted;
1672 	struct in_addr	**classnext[ADDR_NUMCLASSES];
1673 	uint_t		classcount[ADDR_NUMCLASSES];
1674 	addr_class_t	*sortclass;
1675 	int		i;
1676 	int		rc;
1677 
1678 
1679 	/*
1680 	 * The classes in the sortclass array correspond to the class
1681 	 * of the address in the haddrlist list of the same index.
1682 	 * The classes are:
1683 	 *
1684 	 * ADDR_ONLINK	on-link address
1685 	 * ADDR_OFFLINK	off-link address
1686 	 */
1687 	sortbuf_size = addrcount *
1688 	    (sizeof (struct in_addr *) + sizeof (addr_class_t));
1689 	if ((sortbuf = malloc(sortbuf_size)) == NULL)
1690 		return;
1691 	/* LINTED pointer cast */
1692 	sorted = (struct in_addr **)sortbuf;
1693 	/* LINTED pointer cast */
1694 	sortclass = (addr_class_t *)(sortbuf +
1695 	    (addrcount * sizeof (struct in_addr *)));
1696 
1697 	/*
1698 	 * Get a read lock, and check if the interface information
1699 	 * is too old.
1700 	 */
1701 	(void) rw_rdlock(&localinfo_lock);
1702 	now = gethrtime();
1703 	if (localinfo == NULL || ((now - then) > IFINFOTIMEOUT)) {
1704 		/* Need to update I/F info. Upgrade to write lock. */
1705 		(void) rw_unlock(&localinfo_lock);
1706 		(void) rw_wrlock(&localinfo_lock);
1707 		/*
1708 		 * Another thread might have updated "then" between
1709 		 * the rw_unlock() and rw_wrlock() calls above, so
1710 		 * re-check the timeout.
1711 		 */
1712 		if (localinfo == NULL || ((now - then) > IFINFOTIMEOUT)) {
1713 			if (localinfo != NULL)
1714 				free(localinfo);
1715 			if ((localinfo = get_local_info()) == NULL) {
1716 				(void) rw_unlock(&localinfo_lock);
1717 				free(sortbuf);
1718 				return;
1719 			}
1720 			then = now;
1721 		}
1722 		/* Downgrade to read lock */
1723 		(void) rw_unlock(&localinfo_lock);
1724 		(void) rw_rdlock(&localinfo_lock);
1725 		/*
1726 		 * Another thread may have updated the I/F info,
1727 		 * so verify that the 'localinfo' pointer still
1728 		 * is non-NULL.
1729 		 */
1730 		if (localinfo == NULL) {
1731 			(void) rw_unlock(&localinfo_lock);
1732 			free(sortbuf);
1733 			return;
1734 		}
1735 	}
1736 
1737 	/*
1738 	 * Classify the addresses.  We also maintain the classcount
1739 	 * array to keep track of the number of addresses in each
1740 	 * class.
1741 	 */
1742 	(void) memset(classcount, 0, sizeof (classcount));
1743 	for (i = 0; i < addrcount; i++) {
1744 		if (__inet_address_is_local_af(localinfo, AF_INET,
1745 		    inaddrlist[i]))
1746 			sortclass[i] = ADDR_ONLINK;
1747 		else
1748 			sortclass[i] = ADDR_OFFLINK;
1749 		classcount[sortclass[i]]++;
1750 	}
1751 
1752 	/* Don't need the interface list anymore in this call */
1753 	(void) rw_unlock(&localinfo_lock);
1754 
1755 	/*
1756 	 * Each element in the classnext array points to the next
1757 	 * element for that class in the sorted address list. 'rc' is
1758 	 * the running count of elements as we sum the class
1759 	 * sub-totals.
1760 	 */
1761 	for (rc = 0, i = 0; i < ADDR_NUMCLASSES; i++) {
1762 		classnext[i] = &sorted[rc];
1763 		rc += classcount[i];
1764 	}
1765 
1766 	/* Now for the actual rearrangement of the addresses */
1767 	for (i = 0; i < addrcount; i++) {
1768 		*(classnext[sortclass[i]]) = inaddrlist[i];
1769 		classnext[sortclass[i]]++;
1770 	}
1771 
1772 	/* Copy the sorted list to inaddrlist */
1773 	(void) memcpy(inaddrlist, sorted,
1774 	    addrcount * sizeof (struct in_addr *));
1775 	free(sortbuf);
1776 }
1777 
1778 /*
1779  * This function implements the IPv6 Default Address Selection's
1780  * destination address ordering mechanism.  The algorithm is described
1781  * in getaddrinfo(3SOCKET).
1782  */
1783 static void
1784 order_haddrlist_inet6(char **haddrlist, size_t addrcount)
1785 {
1786 	struct dstinforeq *dinfo, *dinfoptr;
1787 	struct in6_addr **in6addrlist = (struct in6_addr **)haddrlist;
1788 	struct in6_addr	**in6addr;
1789 
1790 	if ((dinfo = calloc(addrcount, sizeof (struct dstinforeq))) == NULL)
1791 		return;
1792 
1793 	/* Initialize the dstinfo array we'll use for SIOCGDSTINFO */
1794 	dinfoptr = dinfo;
1795 	for (in6addr = in6addrlist; *in6addr != NULL; in6addr++) {
1796 		dinfoptr->dir_daddr = **in6addr;
1797 		dinfoptr++;
1798 	}
1799 
1800 	if (nss_strioctl(AF_INET6, SIOCGDSTINFO, dinfo,
1801 	    addrcount * sizeof (struct dstinforeq)) < 0) {
1802 		free(dinfo);
1803 		return;
1804 	}
1805 
1806 	/* Sort the dinfo array */
1807 	qsort(dinfo, addrcount, sizeof (struct dstinforeq), dstcmp);
1808 
1809 	/* Copy the addresses back into in6addrlist */
1810 	dinfoptr = dinfo;
1811 	for (in6addr = in6addrlist; *in6addr != NULL; in6addr++) {
1812 		**in6addr = dinfoptr->dir_daddr;
1813 		dinfoptr++;
1814 	}
1815 
1816 	free(dinfo);
1817 }
1818 
1819 /*
1820  * Determine number of leading bits that are common between two addresses.
1821  * Only consider bits which fall within the prefix length plen.
1822  */
1823 static uint_t
1824 ip_addr_commonbits_v6(const in6_addr_t *a1, const in6_addr_t *a2)
1825 {
1826 	uint_t		bits;
1827 	uint_t		i;
1828 	uint32_t	diff;	/* Bits that differ */
1829 
1830 	for (i = 0; i < 4; i++) {
1831 		if (a1->_S6_un._S6_u32[i] != a2->_S6_un._S6_u32[i])
1832 			break;
1833 	}
1834 	bits = i * 32;
1835 
1836 	if (bits == IPV6_ABITS)
1837 		return (IPV6_ABITS);
1838 
1839 	/*
1840 	 * Find number of leading common bits in the word which might
1841 	 * have some common bits by searching for the first one from the left
1842 	 * in the xor of the two addresses.
1843 	 */
1844 	diff = ntohl(a1->_S6_un._S6_u32[i] ^ a2->_S6_un._S6_u32[i]);
1845 	if (diff & 0xffff0000ul)
1846 		diff >>= 16;
1847 	else
1848 		bits += 16;
1849 	if (diff & 0xff00)
1850 		diff >>= 8;
1851 	else
1852 		bits += 8;
1853 	if (diff & 0xf0)
1854 		diff >>= 4;
1855 	else
1856 		bits += 4;
1857 	if (diff & 0xc)
1858 		diff >>= 2;
1859 	else
1860 		bits += 2;
1861 	if (!(diff & 2))
1862 		bits++;
1863 
1864 	/*
1865 	 * We don't need to shift and check for the last bit.  The
1866 	 * check for IPV6_ABITS above would have caught that.
1867 	 */
1868 
1869 	return (bits);
1870 }
1871 
1872 
1873 /*
1874  * The following group of functions named rule_*() are individual
1875  * sorting rules for the AF_INET6 address sorting algorithm.  The
1876  * functions compare two addresses (described by two dstinforeq
1877  * structures), and determines if one is "greater" than the other, or
1878  * if the two are equal according to that rule.
1879  */
1880 typedef	int (*rulef_t)(const struct dstinforeq *, const struct dstinforeq *);
1881 
1882 /*
1883  * These values of these constants are no accident.  Since qsort()
1884  * implements the AF_INET6 address sorting, the comparison function
1885  * must return an integer less than, equal to, or greater than zero to
1886  * indicate if the first address is considered "less than", "equal
1887  * to", or "greater than" the second one.  Since we want the best
1888  * addresses first on the list, "less than" is considered preferrable.
1889  */
1890 #define	RULE_PREFER_DA	-1
1891 #define	RULE_PREFER_DB	1
1892 #define	RULE_EQUAL	0
1893 
1894 /* Prefer the addresses that is reachable. */
1895 static int
1896 rule_reachable(const struct dstinforeq *da, const struct dstinforeq *db)
1897 {
1898 	if (da->dir_dreachable == db->dir_dreachable)
1899 		return (RULE_EQUAL);
1900 	if (da->dir_dreachable)
1901 		return (RULE_PREFER_DA);
1902 	return (RULE_PREFER_DB);
1903 }
1904 
1905 /* Prefer the address whose scope matches that of its source address. */
1906 static int
1907 rule_matchscope(const struct dstinforeq *da, const struct dstinforeq *db)
1908 {
1909 	boolean_t da_scope_match, db_scope_match;
1910 
1911 	da_scope_match = da->dir_dscope == da->dir_sscope;
1912 	db_scope_match = db->dir_dscope == db->dir_sscope;
1913 
1914 	if (da_scope_match == db_scope_match)
1915 		return (RULE_EQUAL);
1916 	if (da_scope_match)
1917 		return (RULE_PREFER_DA);
1918 	return (RULE_PREFER_DB);
1919 }
1920 
1921 /* Avoid the address with the link local source address. */
1922 static int
1923 rule_avoidlinklocal(const struct dstinforeq *da, const struct dstinforeq *db)
1924 {
1925 	if (da->dir_sscope == IP6_SCOPE_LINKLOCAL &&
1926 	    da->dir_dscope != IP6_SCOPE_LINKLOCAL &&
1927 	    db->dir_sscope != IP6_SCOPE_LINKLOCAL)
1928 		return (RULE_PREFER_DB);
1929 	if (db->dir_sscope == IP6_SCOPE_LINKLOCAL &&
1930 	    db->dir_dscope != IP6_SCOPE_LINKLOCAL &&
1931 	    da->dir_sscope != IP6_SCOPE_LINKLOCAL)
1932 		return (RULE_PREFER_DA);
1933 	return (RULE_EQUAL);
1934 }
1935 
1936 /* Prefer the address whose source address isn't deprecated. */
1937 static int
1938 rule_deprecated(const struct dstinforeq *da, const struct dstinforeq *db)
1939 {
1940 	if (da->dir_sdeprecated == db->dir_sdeprecated)
1941 		return (RULE_EQUAL);
1942 	if (db->dir_sdeprecated)
1943 		return (RULE_PREFER_DA);
1944 	return (RULE_PREFER_DB);
1945 }
1946 
1947 /* Prefer the address whose label matches that of its source address. */
1948 static int
1949 rule_label(const struct dstinforeq *da, const struct dstinforeq *db)
1950 {
1951 	if (da->dir_labelmatch == db->dir_labelmatch)
1952 		return (RULE_EQUAL);
1953 	if (da->dir_labelmatch)
1954 		return (RULE_PREFER_DA);
1955 	return (RULE_PREFER_DB);
1956 }
1957 
1958 /* Prefer the address with the higher precedence. */
1959 static int
1960 rule_precedence(const struct dstinforeq *da, const struct dstinforeq *db)
1961 {
1962 	if (da->dir_precedence == db->dir_precedence)
1963 		return (RULE_EQUAL);
1964 	if (da->dir_precedence > db->dir_precedence)
1965 		return (RULE_PREFER_DA);
1966 	return (RULE_PREFER_DB);
1967 }
1968 
1969 /* Prefer the address whose output interface isn't an IP tunnel */
1970 static int
1971 rule_native(const struct dstinforeq *da, const struct dstinforeq *db)
1972 {
1973 	boolean_t isatun, isbtun;
1974 
1975 	/* Get the common case out of the way early */
1976 	if (da->dir_dmactype == db->dir_dmactype)
1977 		return (RULE_EQUAL);
1978 
1979 	isatun = da->dir_dmactype == DL_IPV4 || da->dir_dmactype == DL_IPV6;
1980 	isbtun = db->dir_dmactype == DL_IPV4 || db->dir_dmactype == DL_IPV6;
1981 
1982 	if (isatun == isbtun)
1983 		return (RULE_EQUAL);
1984 	if (isbtun)
1985 		return (RULE_PREFER_DA);
1986 	return (RULE_PREFER_DB);
1987 }
1988 
1989 /* Prefer the address with the smaller scope. */
1990 static int
1991 rule_scope(const struct dstinforeq *da, const struct dstinforeq *db)
1992 {
1993 	if (da->dir_dscope == db->dir_dscope)
1994 		return (RULE_EQUAL);
1995 	if (da->dir_dscope < db->dir_dscope)
1996 		return (RULE_PREFER_DA);
1997 	return (RULE_PREFER_DB);
1998 }
1999 
2000 /*
2001  * Prefer the address that has the most leading bits in common with its
2002  * source address.
2003  */
2004 static int
2005 rule_prefix(const struct dstinforeq *da, const struct dstinforeq *db)
2006 {
2007 	uint_t da_commonbits, db_commonbits;
2008 	boolean_t da_isipv4, db_isipv4;
2009 
2010 	da_isipv4 = IN6_IS_ADDR_V4MAPPED(&da->dir_daddr);
2011 	db_isipv4 = IN6_IS_ADDR_V4MAPPED(&db->dir_daddr);
2012 
2013 	/*
2014 	 * At this point, the order doesn't matter if the two addresses
2015 	 * aren't of the same address family.
2016 	 */
2017 	if (da_isipv4 != db_isipv4)
2018 		return (RULE_EQUAL);
2019 
2020 	da_commonbits = ip_addr_commonbits_v6(&da->dir_daddr, &da->dir_saddr);
2021 	db_commonbits = ip_addr_commonbits_v6(&db->dir_daddr, &db->dir_saddr);
2022 
2023 	if (da_commonbits > db_commonbits)
2024 		return (RULE_PREFER_DA);
2025 	if (da_commonbits < db_commonbits)
2026 		return (RULE_PREFER_DB);
2027 	return (RULE_EQUAL);
2028 }
2029 
2030 /*
2031  * This is the function passed to qsort() that does the AF_INET6
2032  * address comparisons.  It compares two addresses using a list of
2033  * rules.  The rules are applied in order until one prefers one
2034  * address over the other.
2035  */
2036 static int
2037 dstcmp(const void *da, const void *db)
2038 {
2039 	int index, result;
2040 	rulef_t rules[] = {
2041 		rule_reachable,
2042 		rule_matchscope,
2043 		rule_avoidlinklocal,
2044 		rule_deprecated,
2045 		rule_label,
2046 		rule_precedence,
2047 		rule_native,
2048 		rule_scope,
2049 		rule_prefix,
2050 		NULL
2051 	};
2052 
2053 	result = 0;
2054 	for (index = 0; rules[index] != NULL; index++) {
2055 		result = (rules[index])(da, db);
2056 		if (result != RULE_EQUAL)
2057 			break;
2058 	}
2059 
2060 	return (result);
2061 }
2062 
2063 /*
2064  * Given haddrlist and a port number, mallocs and populates a new
2065  * nd_addrlist.  The new nd_addrlist maintains the order of the addresses
2066  * in haddrlist, which have already been sorted by order_haddrlist_inet()
2067  * or order_haddrlist_inet6().  For IPv6 this function filters out
2068  * IPv4-mapped IPv6 addresses.
2069  */
2070 int
2071 hent2ndaddr(int af, char **haddrlist, int *servp, struct nd_addrlist **nd_alist)
2072 {
2073 	struct nd_addrlist	*result;
2074 	int			num;
2075 	struct netbuf		*na;
2076 	struct sockaddr_in	*sinbuf, *sin;
2077 	struct sockaddr_in6	*sin6buf, *sin6;
2078 	struct in_addr		**inaddr, **inaddrlist;
2079 	struct in6_addr		**in6addr, **in6addrlist;
2080 
2081 	/* Address count */
2082 	num = 0;
2083 	if (af == AF_INET6) {
2084 		in6addrlist = (struct in6_addr **)haddrlist;
2085 
2086 		/*
2087 		 * Exclude IPv4-mapped IPv6 addresses from the count, as
2088 		 * these are not included in the nd_addrlist we return.
2089 		 */
2090 		for (in6addr = in6addrlist; *in6addr != NULL; in6addr++)
2091 			if (!IN6_IS_ADDR_V4MAPPED(*in6addr))
2092 				num++;
2093 	} else {
2094 		inaddrlist = (struct in_addr **)haddrlist;
2095 
2096 		for (inaddr = inaddrlist; *inaddr != NULL; inaddr++)
2097 			num++;
2098 	}
2099 	if (num == 0)
2100 		return (ND_NOHOST);
2101 
2102 	result = malloc(sizeof (struct nd_addrlist));
2103 	if (result == 0)
2104 		return (ND_NOMEM);
2105 
2106 	result->n_cnt = num;
2107 	result->n_addrs = calloc(num, sizeof (struct netbuf));
2108 	if (result->n_addrs == 0) {
2109 		free(result);
2110 		return (ND_NOMEM);
2111 	}
2112 
2113 	na = result->n_addrs;
2114 	if (af == AF_INET) {
2115 		sinbuf = calloc(num, sizeof (struct sockaddr_in));
2116 		if (sinbuf == NULL) {
2117 			free(result->n_addrs);
2118 			free(result);
2119 			return (ND_NOMEM);
2120 		}
2121 
2122 		sin = sinbuf;
2123 		for (inaddr = inaddrlist; *inaddr != NULL; inaddr++) {
2124 			na->len = na->maxlen = sizeof (struct sockaddr_in);
2125 			na->buf = (char *)sin;
2126 			sin->sin_family = AF_INET;
2127 			sin->sin_addr = **inaddr;
2128 			sin->sin_port = *servp;
2129 			na++;
2130 			sin++;
2131 		}
2132 	} else if (af == AF_INET6) {
2133 		sin6buf = calloc(num, sizeof (struct sockaddr_in6));
2134 		if (sin6buf == NULL) {
2135 			free(result->n_addrs);
2136 			free(result);
2137 			return (ND_NOMEM);
2138 		}
2139 
2140 		sin6 = sin6buf;
2141 		for (in6addr = in6addrlist; *in6addr != NULL; in6addr++) {
2142 			if (IN6_IS_ADDR_V4MAPPED(*in6addr))
2143 				continue;
2144 
2145 			na->len = na->maxlen = sizeof (struct sockaddr_in6);
2146 			na->buf = (char *)sin6;
2147 			sin6->sin6_family = AF_INET6;
2148 			sin6->sin6_addr = **in6addr;
2149 			sin6->sin6_port = *servp;
2150 			na++;
2151 			sin6++;
2152 		}
2153 	}
2154 	*(nd_alist) = result;
2155 	return (ND_OK);
2156 }
2157 
2158 /*
2159  * Given a hostent and a servent, mallocs and populates
2160  * a new nd_hostservlist with host and service names.
2161  *
2162  * We could be passed in a NULL servent, in which case stringify port.
2163  */
2164 int
2165 hsents2ndhostservs(struct hostent *he, struct servent *se,
2166     ushort_t port, struct nd_hostservlist **hslist)
2167 {
2168 	struct	nd_hostservlist *result;
2169 	struct	nd_hostserv *hs;
2170 	int	hosts, servs, i, j;
2171 	char	**hn, **sn;
2172 
2173 	if ((result = malloc(sizeof (struct nd_hostservlist))) == 0)
2174 		return (ND_NOMEM);
2175 
2176 	/*
2177 	 * We initialize the counters to 1 rather than zero because
2178 	 * we have to count the "official" name as well as the aliases.
2179 	 */
2180 	for (hn = he->h_aliases, hosts = 1; hn && *hn; hn++, hosts++);
2181 	if (se)
2182 		for (sn = se->s_aliases, servs = 1; sn && *sn; sn++, servs++);
2183 	else
2184 		servs = 1;
2185 
2186 	if ((hs = calloc(hosts * servs, sizeof (struct nd_hostserv))) == 0) {
2187 		free(result);
2188 		return (ND_NOMEM);
2189 	}
2190 
2191 	result->h_cnt	= servs * hosts;
2192 	result->h_hostservs = hs;
2193 
2194 	for (i = 0, hn = he->h_aliases; i < hosts; i++) {
2195 		sn = se ? se->s_aliases : NULL;
2196 
2197 		for (j = 0; j < servs; j++) {
2198 			if (i == 0)
2199 				hs->h_host = strdup(he->h_name);
2200 			else
2201 				hs->h_host = strdup(*hn);
2202 			if (j == 0) {
2203 				if (se)
2204 					hs->h_serv = strdup(se->s_name);
2205 				else {
2206 					/* Convert to a number string */
2207 					char stmp[16];
2208 
2209 					(void) sprintf(stmp, "%d", port);
2210 					hs->h_serv = strdup(stmp);
2211 				}
2212 			} else
2213 				hs->h_serv = strdup(*sn++);
2214 
2215 			if ((hs->h_host == 0) || (hs->h_serv == 0)) {
2216 				free(result->h_hostservs);
2217 				free(result);
2218 				return (ND_NOMEM);
2219 			}
2220 			hs++;
2221 		}
2222 		if (i)
2223 			hn++;
2224 	}
2225 	*(hslist) = result;
2226 	return (ND_OK);
2227 }
2228 
2229 /*
2230  * Process results from nd_addrlist ( returned by netdir_getbyname)
2231  * into a hostent using buf.
2232  * *** ASSUMES that nd_addrlist->n_addrs->buf contains IP addresses in
2233  * sockaddr_in's ***
2234  */
2235 int
2236 ndaddr2hent(int af, const char *nam, struct nd_addrlist *addrs,
2237     struct hostent *result, char *buffer, int buflen)
2238 {
2239 	int	i, count;
2240 	struct	in_addr *addrp;
2241 	struct	in6_addr *addr6p;
2242 	char	**addrvec;
2243 	struct	netbuf *na;
2244 	size_t	len;
2245 
2246 	result->h_name		= buffer;
2247 	result->h_addrtype	= af;
2248 	result->h_length	= (af == AF_INET) ? sizeof (*addrp):
2249 						    sizeof (*addr6p);
2250 
2251 	/*
2252 	 * Build addrlist at start of buffer (after name);  store the
2253 	 * addresses themselves at the end of the buffer.
2254 	 */
2255 	len = strlen(nam) + 1;
2256 	addrvec = (char **)ROUND_UP(buffer + len, sizeof (*addrvec));
2257 	result->h_addr_list 	= addrvec;
2258 
2259 	if (af == AF_INET) {
2260 		addrp = (struct in_addr *)ROUND_DOWN(buffer + buflen,
2261 		    sizeof (*addrp));
2262 
2263 		count = addrs->n_cnt;
2264 		if ((char *)(&addrvec[count + 1]) > (char *)(&addrp[-count]))
2265 			return (ND_NOMEM);
2266 
2267 		(void) memcpy(buffer, nam, len);
2268 
2269 		for (na = addrs->n_addrs, i = 0;  i < count;  na++, i++) {
2270 			--addrp;
2271 			(void) memcpy(addrp,
2272 			    /* LINTED pointer cast */
2273 			    &((struct sockaddr_in *)na->buf)->sin_addr,
2274 			    sizeof (*addrp));
2275 			*addrvec++ = (char *)addrp;
2276 		}
2277 	} else {
2278 		addr6p = (struct in6_addr *)ROUND_DOWN(buffer + buflen,
2279 			sizeof (*addr6p));
2280 
2281 		count = addrs->n_cnt;
2282 		if ((char *)(&addrvec[count + 1]) > (char *)(&addr6p[-count]))
2283 			return (ND_NOMEM);
2284 
2285 		(void) memcpy(buffer, nam, len);
2286 
2287 		for (na = addrs->n_addrs, i = 0;  i < count;  na++, i++) {
2288 			--addr6p;
2289 			(void) memcpy(addr6p,
2290 			    /* LINTED pointer cast */
2291 			    &((struct sockaddr_in6 *)na->buf)->sin6_addr,
2292 			    sizeof (*addr6p));
2293 			*addrvec++ = (char *)addr6p;
2294 		}
2295 	}
2296 	*addrvec = 0;
2297 	result->h_aliases = addrvec;
2298 
2299 	return (ND_OK);
2300 }
2301 
2302 /*
2303  * Process results from nd_addrlist ( returned by netdir_getbyname)
2304  * into a servent using buf.
2305  */
2306 int
2307 ndaddr2srent(const char *name, const char *proto, ushort_t port,
2308     struct servent *result, char *buffer, int buflen)
2309 {
2310 	size_t	i;
2311 	char	*bufend = (buffer + buflen);
2312 
2313 	result->s_port = (int)port;
2314 
2315 	result->s_aliases =
2316 	    (char **)ROUND_UP(buffer, sizeof (char *));
2317 	result->s_aliases[0] = NULL;
2318 	buffer = (char *)&result->s_aliases[1];
2319 	result->s_name = buffer;
2320 	i = strlen(name) + 1;
2321 	if ((buffer + i) > bufend)
2322 		return (ND_NOMEM);
2323 	(void) memcpy(buffer, name, i);
2324 	buffer += i;
2325 
2326 	result->s_proto	= buffer;
2327 	i = strlen(proto) + 1;
2328 	if ((buffer + i) > bufend)
2329 		return (ND_NOMEM);
2330 	(void) memcpy(buffer, proto, i);
2331 	buffer += i;
2332 
2333 	return (ND_OK);
2334 }
2335 
2336 /*
2337  * Process results from nd_hostservlist ( returned by netdir_getbyaddr)
2338  * into a hostent using buf.
2339  * *** ASSUMES that nd_buf->buf is a sockaddr_in ***
2340  */
2341 int
2342 ndhostserv2hent(struct netbuf *nbuf, struct nd_hostservlist *addrs,
2343     struct hostent *result, char *buffer, int buflen)
2344 {
2345 	int	i, count;
2346 	char	*aliasp;
2347 	char	**aliasvec;
2348 	struct	sockaddr_in *sa;
2349 	struct	nd_hostserv *hs;
2350 	const	char *la;
2351 	size_t	length;
2352 
2353 	/* First, give the lonely address a specious home in h_addr_list. */
2354 	aliasp   = (char  *)ROUND_UP(buffer, sizeof (sa->sin_addr));
2355 	/* LINTED pointer cast */
2356 	sa = (struct sockaddr_in *)nbuf->buf;
2357 	(void) memcpy(aliasp, &(sa->sin_addr), sizeof (sa->sin_addr));
2358 	aliasvec = (char **)ROUND_UP(aliasp + sizeof (sa->sin_addr),
2359 		sizeof (*aliasvec));
2360 	result->h_addr_list = aliasvec;
2361 	*aliasvec++ = aliasp;
2362 	*aliasvec++ = 0;
2363 
2364 	/*
2365 	 * Build h_aliases at start of buffer (after addr and h_addr_list);
2366 	 * store the alias strings at the end of the buffer (before h_name).
2367 	 */
2368 
2369 	aliasp = buffer + buflen;
2370 
2371 	result->h_aliases	= aliasvec;
2372 
2373 	hs = addrs->h_hostservs;
2374 	if (!hs)
2375 		return (ND_NOHOST);
2376 
2377 	length = strlen(hs->h_host) + 1;
2378 	aliasp -= length;
2379 	if ((char *)(&aliasvec[1]) > aliasp)
2380 		return (ND_NOMEM);
2381 	(void) memcpy(aliasp, hs->h_host, length);
2382 
2383 	result->h_name		= aliasp;
2384 	result->h_addrtype	= AF_INET;
2385 	result->h_length	= sizeof (sa->sin_addr);
2386 
2387 	/*
2388 	 * Assumption: the netdir nametoaddr_libs
2389 	 * sort the vector of (host, serv) pairs in such a way that
2390 	 * all pairs with the same host name are contiguous.
2391 	 */
2392 	la = hs->h_host;
2393 	count = addrs->h_cnt;
2394 	for (i = 0;  i < count;  i++, hs++)
2395 		if (strcmp(la, hs->h_host) != 0) {
2396 			size_t len = strlen(hs->h_host) + 1;
2397 
2398 			aliasp -= len;
2399 			if ((char *)(&aliasvec[2]) > aliasp)
2400 				return (ND_NOMEM);
2401 			(void) memcpy(aliasp, hs->h_host, len);
2402 			*aliasvec++ = aliasp;
2403 			la = hs->h_host;
2404 		}
2405 	*aliasvec = 0;
2406 
2407 	return (ND_OK);
2408 }
2409 
2410 /*
2411  * Process results from nd_hostservlist ( returned by netdir_getbyaddr)
2412  * into a servent using buf.
2413  */
2414 int
2415 ndhostserv2srent(int port, const char *proto, struct nd_hostservlist *addrs,
2416     struct servent *result, char *buffer, int buflen)
2417 {
2418 	int	i, count;
2419 	char	*aliasp;
2420 	char	**aliasvec;
2421 	struct	nd_hostserv *hs;
2422 	const	char *host_cname;
2423 	size_t	leni, lenj;
2424 
2425 	result->s_port = port;
2426 	/*
2427 	 * Build s_aliases at start of buffer;
2428 	 * store proto and aliases at the end of the buffer (before h_name).
2429 	 */
2430 
2431 	aliasp = buffer + buflen;
2432 	aliasvec = (char **)ROUND_UP(buffer, sizeof (char *));
2433 
2434 	result->s_aliases	= aliasvec;
2435 
2436 	hs = addrs->h_hostservs;
2437 	if (!hs)
2438 		return (ND_NOHOST);
2439 	host_cname = hs->h_host;
2440 
2441 	leni = strlen(proto) + 1;
2442 	lenj = strlen(hs->h_serv) + 1;
2443 	if ((char *)(&aliasvec[2]) > (aliasp - leni - lenj))
2444 		return (ND_NOMEM);
2445 
2446 	aliasp -= leni;
2447 	(void) memcpy(aliasp, proto, leni);
2448 	result->s_proto = aliasp;
2449 
2450 	aliasp -= lenj;
2451 	(void) memcpy(aliasp, hs->h_serv, lenj);
2452 	result->s_name = aliasp;
2453 
2454 	/*
2455 	 * Assumption: the netdir nametoaddr_libs
2456 	 * do a host aliases first and serv aliases next
2457 	 * enumeration for creating the list of hostserv
2458 	 * structures.
2459 	 */
2460 	count = addrs->h_cnt;
2461 	for (i = 0;
2462 	    i < count && hs->h_serv && strcmp(hs->h_host, host_cname) == 0;
2463 	    i++, hs++) {
2464 		size_t len = strlen(hs->h_serv) + 1;
2465 
2466 		aliasp -= len;
2467 		if ((char *)(&aliasvec[2]) > aliasp)
2468 			return (ND_NOMEM);
2469 		(void) memcpy(aliasp, hs->h_serv, len);
2470 		*aliasvec++ = aliasp;
2471 	}
2472 	*aliasvec = NULL;
2473 
2474 	return (ND_OK);
2475 }
2476 
2477 
2478 static int
2479 nd2herrno(int nerr)
2480 {
2481 	switch (nerr) {
2482 	case ND_OK:
2483 		return (0);
2484 	case ND_TRY_AGAIN:
2485 		return (TRY_AGAIN);
2486 	case ND_NO_RECOVERY:
2487 	case ND_BADARG:
2488 	case ND_NOMEM:
2489 		return (NO_RECOVERY);
2490 	case ND_NO_DATA:
2491 		return (NO_DATA);
2492 	case ND_NOHOST:
2493 	case ND_NOSERV:
2494 		return (HOST_NOT_FOUND);
2495 	default:
2496 		return (NO_RECOVERY);
2497 	}
2498 }
2499 
2500 /*
2501  * This is a utility function so that various parts of libnsl can
2502  * easily send ioctls down to ip.
2503  *
2504  */
2505 int
2506 nss_ioctl(int af, int cmd, void *arg)
2507 {
2508 	int	fd;
2509 	char	*devpath;
2510 	int	retv;
2511 
2512 	switch (af) {
2513 	case AF_INET6:
2514 		devpath = UDP6DEV;
2515 		break;
2516 	case AF_INET:
2517 	case AF_UNSPEC:
2518 	default:
2519 		devpath = UDPDEV;
2520 	}
2521 	if ((fd = open(devpath, O_RDONLY)) < 0) {
2522 		return (-1);
2523 	}
2524 	while ((retv = ioctl(fd, cmd, arg)) == -1) {
2525 		if (errno != EINTR)
2526 	break;
2527 	}
2528 	(void) close(fd);
2529 	return (retv);
2530 }
2531 
2532 static int
2533 nss_strioctl(int af, int cmd, void *ptr, int ilen)
2534 {
2535 	struct strioctl str;
2536 
2537 	str.ic_cmd = cmd;
2538 	str.ic_timout = 0;
2539 	str.ic_len = ilen;
2540 	str.ic_dp = ptr;
2541 
2542 	return (nss_ioctl(af, I_STR, &str));
2543 }
2544 
2545 static struct ifinfo *
2546 get_local_info(void)
2547 {
2548 	int	numifs;
2549 	int	n;
2550 	char	*buf = NULL;
2551 	size_t	needed;
2552 	struct lifconf	lifc;
2553 	struct lifreq	lifreq, *lifr;
2554 	struct lifnum	lifn;
2555 	struct ifinfo	*localinfo;
2556 
2557 	lifn.lifn_family = AF_UNSPEC;
2558 	lifn.lifn_flags = 0;
2559 
2560 getifnum:
2561 	if (nss_ioctl(AF_UNSPEC, SIOCGLIFNUM, &lifn) == -1) {
2562 		numifs = MAXIFS;
2563 	} else {
2564 		numifs = lifn.lifn_count;
2565 	}
2566 
2567 	/*
2568 	 * Add a small fudge factor in case interfaces get plumbed between
2569 	 * the call to SIOCGLIFNUM and SIOCGLIFCONF.
2570 	 */
2571 	needed = (numifs + 4) * sizeof (lifreq);
2572 	if (buf == NULL)
2573 		buf = malloc(needed);
2574 	else
2575 		buf = realloc(buf, needed);
2576 	if (buf == NULL) {
2577 		(void) syslog(LOG_ERR, "n2a get_local_info: malloc failed: %m");
2578 		_nderror = ND_NOMEM;
2579 		return (NULL);
2580 	}
2581 	lifc.lifc_family = AF_UNSPEC;
2582 	lifc.lifc_flags = 0;
2583 	lifc.lifc_len = needed;
2584 	lifc.lifc_buf = buf;
2585 	if (nss_ioctl(AF_UNSPEC, SIOCGLIFCONF, &lifc) == -1) {
2586 		/*
2587 		 * IP returns EINVAL if the buffer was too small to fit
2588 		 * all of the entries.  If that's the case, go back and
2589 		 * try again.
2590 		 */
2591 		if (errno == EINVAL)
2592 			goto getifnum;
2593 
2594 		(void) syslog(LOG_ERR, "n2a get_local_info: "
2595 		    "ioctl (get interface configuration): %m");
2596 		free(buf);
2597 		_nderror = ND_SYSTEM;
2598 		return (NULL);
2599 	}
2600 	/* LINTED pointer cast */
2601 	lifr = (struct lifreq *)buf;
2602 	numifs = lifc.lifc_len/sizeof (lifreq);
2603 	localinfo = malloc(ifinfosize(numifs));
2604 	if (localinfo == NULL) {
2605 		(void) syslog(LOG_ERR, "n2a get_local_info: malloc failed: %m");
2606 		free(buf);
2607 		_nderror = ND_SYSTEM;
2608 		return (NULL);
2609 	}
2610 
2611 	/* LINTED pointer cast */
2612 	localinfo->addresses = (struct __ifaddr *)
2613 	    ((char *)localinfo + sizeof (struct ifinfo));
2614 
2615 	for (localinfo->count = 0, n = numifs; n > 0; n--, lifr++) {
2616 		int af;
2617 
2618 		lifreq = *lifr;
2619 		af = lifreq.lifr_addr.ss_family;
2620 
2621 		/* Squirrel away the address */
2622 		if (ifassign(lifreq, localinfo->count, IF_ADDR) == 0)
2623 			continue;
2624 
2625 		if (nss_ioctl(af, SIOCGLIFFLAGS, &lifreq) < 0) {
2626 			(void) syslog(LOG_ERR,
2627 			    "n2a get_local_info: "
2628 			    "ioctl (get interface flags): %m");
2629 			continue;
2630 		}
2631 		if (!(lifreq.lifr_flags & IFF_UP))
2632 			continue;
2633 
2634 		if (nss_ioctl(af, SIOCGLIFNETMASK, &lifreq) < 0) {
2635 			(void) syslog(LOG_ERR,
2636 			    "n2a get_local_info: "
2637 			    "ioctl (get interface netmask): %m");
2638 			continue;
2639 		}
2640 
2641 		if (ifassign(lifreq, localinfo->count, IF_MASK) == 0)
2642 			continue;
2643 
2644 		localinfo->count++;
2645 	}
2646 
2647 	free(buf);
2648 	return (localinfo);
2649 }
2650 
2651 static int
2652 __inet_ifassign(sa_family_t af, struct __ifaddr *ifa, __ifaddr_type type,
2653     void *addr) {
2654 	switch (type) {
2655 	case IF_ADDR:
2656 		ifa->af = af;
2657 		if (af == AF_INET6) {
2658 			ifa->addr.in6 = *(struct in6_addr *)addr;
2659 		} else {
2660 			ifa->addr.in4 = *(struct in_addr *)addr;
2661 		}
2662 		break;
2663 	case IF_MASK:
2664 		if (ifa->af == af) {
2665 			if (af == AF_INET6) {
2666 				ifa->mask.in6 = *(struct in6_addr *)addr;
2667 			} else {
2668 				ifa->mask.in4 = *(struct in_addr *)addr;
2669 			}
2670 		} else {
2671 			return (0);
2672 		}
2673 		break;
2674 	default:
2675 		return (0);
2676 	}
2677 
2678 	return (1);
2679 }
2680 
2681 /*
2682  *  Some higher-level routines for determining if an address is
2683  *  on a local network.
2684  *
2685  *      __inet_get_local_interfaces() - get an opaque handle with
2686  *          with a list of local interfaces
2687  *      __inet_address_is_local() - return 1 if an address is
2688  *          on a local network; 0 otherwise
2689  *      __inet_free_local_interfaces() - free handle that was
2690  *          returned by __inet_get_local_interfaces()
2691  *
2692  *  A typical calling sequence is:
2693  *
2694  *      p = __inet_get_local_interfaces();
2695  *      if (__inet_address_is_local(p, inaddr)) {
2696  *          ...
2697  *      }
2698  *      __inet_free_local_interfaces(p);
2699  */
2700 
2701 /*
2702  *  Return an opaque pointer to a list of configured interfaces.
2703  */
2704 void *
2705 __inet_get_local_interfaces(void)
2706 {
2707 	return (get_local_info());
2708 }
2709 
2710 /*
2711  *  Free memory allocated by inet_local_interfaces().
2712  */
2713 void
2714 __inet_free_local_interfaces(void *p)
2715 {
2716 	free(p);
2717 }
2718 
2719 /*
2720  *  Determine if an address is on a local network.
2721  *
2722  *  Might have made sense to use SIOCTONLINK, except that it doesn't
2723  *  handle matching on IPv4 network addresses.
2724  */
2725 int
2726 __inet_address_is_local_af(void *p, sa_family_t af, void *addr) {
2727 
2728 	struct ifinfo	*localinfo = (struct ifinfo *)p;
2729 	int		i, a;
2730 	struct in_addr	v4addr;
2731 
2732 	if (localinfo == 0)
2733 		return (0);
2734 
2735 	if (af == AF_INET6 && IN6_IS_ADDR_V4MAPPED((struct in6_addr *)addr)) {
2736 		IN6_V4MAPPED_TO_INADDR((struct in6_addr *)addr, &v4addr);
2737 		af = AF_INET;
2738 		addr = (void *)&v4addr;
2739 	}
2740 
2741 	for (i = 0; i < localinfo->count; i++) {
2742 		if (ifaf(i) == af) {
2743 			if (af == AF_INET6) {
2744 				struct in6_addr *a6 = (struct in6_addr *)addr;
2745 				for (a = 0; a < sizeof (a6->s6_addr); a++) {
2746 					if ((a6->s6_addr[a] &
2747 						ifmask6(i).s6_addr[a]) !=
2748 						(ifaddr6(i).s6_addr[a] &
2749 						ifmask6(i).s6_addr[a]))
2750 						break;
2751 				}
2752 				if (a >= sizeof (a6->s6_addr))
2753 					return (1);
2754 			} else {
2755 				if ((((struct in_addr *)addr)->s_addr &
2756 						ifmask4(i).s_addr) ==
2757 					(ifaddr4(i).s_addr &
2758 						ifmask4(i).s_addr))
2759 					return (1);
2760 			}
2761 		}
2762 	}
2763 
2764 	return (0);
2765 }
2766 
2767 int
2768 __inet_address_is_local(void *p, struct in_addr addr)
2769 {
2770 	return (__inet_address_is_local_af(p, AF_INET, &addr));
2771 }
2772 
2773 int
2774 __inet_uaddr_is_local(void *p, struct netconfig *nc, char *uaddr)
2775 {
2776 	struct netbuf		*taddr;
2777 	sa_family_t		af;
2778 	int			ret;
2779 
2780 	taddr = uaddr2taddr(nc, uaddr);
2781 	if (taddr == 0)
2782 		return (0);
2783 
2784 	/* LINTED pointer cast */
2785 	af = ((struct sockaddr *)taddr->buf)->sa_family;
2786 
2787 	ret = __inet_address_is_local_af(p, af,
2788 		(af == AF_INET6) ?
2789 		/* LINTED pointer cast */
2790 		(void *)&((struct sockaddr_in6 *)taddr->buf)->sin6_addr :
2791 		/* LINTED pointer cast */
2792 		(void *)&((struct sockaddr_in *)taddr->buf)->sin_addr);
2793 
2794 	netdir_free(taddr, ND_ADDR);
2795 	return (ret);
2796 }
2797 
2798 
2799 int
2800 __inet_address_count(void *p)
2801 {
2802 	struct ifinfo *lp = (struct ifinfo *)p;
2803 
2804 	if (lp != 0) {
2805 		return (lp->count);
2806 	} else {
2807 		return (0);
2808 	}
2809 }
2810 
2811 uint32_t
2812 __inet_get_addr(void *p, int n)
2813 {
2814 	struct ifinfo *localinfo = (struct ifinfo *)p;
2815 
2816 	if (localinfo == 0 || n >= localinfo->count || ifaf(n) != AF_INET)
2817 		return (0);
2818 
2819 	return (ifaddr4(n).s_addr);
2820 }
2821 
2822 uint32_t
2823 __inet_get_network(void *p, int n)
2824 {
2825 	struct ifinfo *localinfo = (struct ifinfo *)p;
2826 
2827 	if (localinfo == 0 || n >= localinfo->count || ifaf(n) != AF_INET)
2828 		return (0);
2829 
2830 	return (ifaddr4(n).s_addr & ifmask4(n).s_addr);
2831 }
2832 
2833 char *
2834 __inet_get_uaddr(void *p, struct netconfig *nc, int n)
2835 {
2836 	struct ifinfo *localinfo = (struct ifinfo *)p;
2837 	char *uaddr;
2838 	struct sockaddr_in sin4;
2839 	struct sockaddr_in6 sin6;
2840 	struct netbuf nb;
2841 
2842 	if (localinfo == 0 || nc == 0 || n >= localinfo->count)
2843 		return (0);
2844 
2845 	if (ifaf(n) == AF_INET6) {
2846 		if (strcmp(NC_INET6, nc->nc_protofmly) != 0)
2847 			return (0);
2848 		(void) memset(&sin6, 0, sizeof (sin6));
2849 		sin6.sin6_family = AF_INET6;
2850 		sin6.sin6_addr = ifaddr6(n);
2851 		nb.buf = (char *)&sin6;
2852 		nb.len = sizeof (sin6);
2853 	} else {
2854 		if (strcmp(NC_INET, nc->nc_protofmly) != 0)
2855 			return (0);
2856 		(void) memset(&sin4, 0, sizeof (sin4));
2857 		sin4.sin_family = AF_INET;
2858 		sin4.sin_addr = ifaddr4(n);
2859 		nb.buf = (char *)&sin4;
2860 		nb.len = sizeof (sin4);
2861 	}
2862 
2863 	nb.maxlen = nb.len;
2864 
2865 	uaddr = taddr2uaddr(nc, &nb);
2866 	return (uaddr);
2867 }
2868 
2869 char *
2870 __inet_get_networka(void *p, int n)
2871 {
2872 	struct ifinfo	*localinfo = (struct ifinfo *)p;
2873 
2874 	if (localinfo == 0 || n >= localinfo->count)
2875 		return (0);
2876 
2877 	if (ifaf(n) == AF_INET6) {
2878 		char		buf[INET6_ADDRSTRLEN];
2879 		struct in6_addr	in6;
2880 		int		i;
2881 
2882 		for (i = 0; i < sizeof (in6.s6_addr); i++) {
2883 			in6.s6_addr[i] = ifaddr6(n).s6_addr[i] &
2884 					ifmask6(n).s6_addr[i];
2885 		}
2886 		return (strdup(inet_ntop(AF_INET6, &in6, buf, sizeof (buf))));
2887 	} else {
2888 		struct in_addr	in4;
2889 
2890 		in4.s_addr = ifaddr4(n).s_addr & ifmask4(n).s_addr;
2891 		return (strdup(inet_ntoa(in4)));
2892 	}
2893 }
2894 
2895 static int
2896 in_list(struct in_addr *addrs, int n, struct in_addr a)
2897 {
2898 	int i;
2899 
2900 	for (i = 0; i < n; i++) {
2901 		if (addrs[i].s_addr == a.s_addr)
2902 			return (1);
2903 	}
2904 	return (0);
2905 }
2906 
2907 static int
2908 getbroadcastnets(struct netconfig *tp, struct in_addr **addrs)
2909 {
2910 	struct ifconf ifc;
2911 	struct ifreq ifreq, *ifr;
2912 	struct sockaddr_in *sin;
2913 	struct in_addr a;
2914 	int fd;
2915 	int n, i, numifs;
2916 	char *buf;
2917 	int	use_loopback = 0;
2918 
2919 	_nderror = ND_SYSTEM;
2920 	fd = open(tp->nc_device, O_RDONLY);
2921 	if (fd < 0) {
2922 		(void) syslog(LOG_ERR,
2923 	    "broadcast: open to get interface configuration: %m");
2924 		return (0);
2925 	}
2926 	if (ioctl(fd, SIOCGIFNUM, (char *)&numifs) < 0)
2927 		numifs = MAXIFS;
2928 	buf = malloc(numifs * sizeof (struct ifreq));
2929 	if (buf == NULL) {
2930 		(void) syslog(LOG_ERR, "broadcast: malloc failed: %m");
2931 		(void) close(fd);
2932 		return (0);
2933 	}
2934 	*addrs = malloc(numifs * sizeof (struct in_addr));
2935 	if (*addrs == NULL) {
2936 		(void) syslog(LOG_ERR, "broadcast: malloc failed: %m");
2937 		free(buf);
2938 		(void) close(fd);
2939 		return (0);
2940 	}
2941 	ifc.ifc_len = numifs * (int)sizeof (struct ifreq);
2942 	ifc.ifc_buf = buf;
2943 	/*
2944 	 * Ideally, this ioctl should also tell me, how many bytes were
2945 	 * finally allocated, but it doesnt.
2946 	 */
2947 	if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0) {
2948 		(void) syslog(LOG_ERR,
2949 	    "broadcast: ioctl (get interface configuration): %m");
2950 		free(buf);
2951 		free(*addrs);
2952 		(void) close(fd);
2953 		return (0);
2954 	}
2955 
2956 retry:
2957 	/* LINTED pointer cast */
2958 	ifr = (struct ifreq *)buf;
2959 	for (i = 0, n = ifc.ifc_len / (int)sizeof (struct ifreq);
2960 		n > 0; n--, ifr++) {
2961 		ifreq = *ifr;
2962 		if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifreq) < 0) {
2963 			(void) syslog(LOG_ERR,
2964 		    "broadcast: ioctl (get interface flags): %m");
2965 			continue;
2966 		}
2967 		if (!(ifreq.ifr_flags & IFF_UP) ||
2968 		    (ifr->ifr_addr.sa_family != AF_INET))
2969 			continue;
2970 		if (ifreq.ifr_flags & IFF_BROADCAST) {
2971 			/* LINTED pointer cast */
2972 			sin = (struct sockaddr_in *)&ifr->ifr_addr;
2973 			if (ioctl(fd, SIOCGIFBRDADDR, (char *)&ifreq) < 0) {
2974 				/* May not work with other implementation */
2975 				a = _inet_makeaddr(
2976 				    inet_netof(sin->sin_addr),
2977 				    INADDR_ANY);
2978 				if (!in_list(*addrs, i, a))
2979 					(*addrs)[i++] = a;
2980 			} else {
2981 				/* LINTED pointer cast */
2982 				a = ((struct sockaddr_in *)
2983 				    &ifreq.ifr_addr)->sin_addr;
2984 				if (!in_list(*addrs, i, a))
2985 					(*addrs)[i++] = a;
2986 			}
2987 			continue;
2988 		}
2989 		if (use_loopback && (ifreq.ifr_flags & IFF_LOOPBACK)) {
2990 			/* LINTED pointer cast */
2991 			sin = (struct sockaddr_in *)&ifr->ifr_addr;
2992 			a = sin->sin_addr;
2993 			if (!in_list(*addrs, i, a))
2994 				(*addrs)[i++] = a;
2995 			continue;
2996 		}
2997 		if (ifreq.ifr_flags & IFF_POINTOPOINT) {
2998 			if (ioctl(fd, SIOCGIFDSTADDR, (char *)&ifreq) < 0)
2999 				continue;
3000 			/* LINTED pointer cast */
3001 			a = ((struct sockaddr_in *)
3002 			    &ifreq.ifr_addr)->sin_addr;
3003 			if (!in_list(*addrs, i, a))
3004 				(*addrs)[i++] = a;
3005 			continue;
3006 		}
3007 	}
3008 	if (i == 0 && !use_loopback) {
3009 		use_loopback = 1;
3010 		goto retry;
3011 	}
3012 	free(buf);
3013 	(void) close(fd);
3014 	if (i)
3015 		_nderror = ND_OK;
3016 	else
3017 		free(*addrs);
3018 	return (i);
3019 }
3020 
3021 /*
3022  * This is lifted straight from libsocket/inet/inet_mkaddr.c.
3023  * Copied here to avoid our dependency on libsocket. More importantly,
3024  * to make sure partially static apps that use libnsl, but not
3025  * libsocket, don't get screwed up.
3026  * If you understand the above paragraph, try to get rid of
3027  * this copy of inet_makeaddr; if you don;t, leave it alone.
3028  *
3029  * Formulate an Internet address from network + host.  Used in
3030  * building addresses stored in the ifnet structure.
3031  */
3032 static struct in_addr
3033 _inet_makeaddr(in_addr_t net, in_addr_t host)
3034 {
3035 	in_addr_t addr;
3036 	struct in_addr inaddr;
3037 
3038 	if (net < 128)
3039 		addr = (net << IN_CLASSA_NSHIFT) | (host & IN_CLASSA_HOST);
3040 	else if (net < 65536)
3041 		addr = (net << IN_CLASSB_NSHIFT) | (host & IN_CLASSB_HOST);
3042 	else if (net < 16777216L)
3043 		addr = (net << IN_CLASSC_NSHIFT) | (host & IN_CLASSC_HOST);
3044 	else
3045 		addr = net | host;
3046 	inaddr.s_addr = htonl(addr);
3047 	return (inaddr);
3048 }
3049 
3050 /*
3051  * Routine to read the default configuration file and check if SORT_ADDRS
3052  * is set to NO or FALSE. This routine is called by order_haddrlist_af()
3053  * to determine if the addresses need to be sorted.
3054  */
3055 static boolean_t
3056 _read_nsw_file(void)
3057 {
3058 	char	defval[LINESIZE];
3059 	__NSL_FILE *defl;
3060 	boolean_t	nosort = B_FALSE;
3061 
3062 
3063 	do {
3064 		defl = __nsl_fopen(__NSW_DEFAULT_FILE, "r");
3065 	} while ((defl == NULL) && (errno == EINTR));
3066 
3067 	if (defl == NULL)
3068 		return (B_FALSE);
3069 
3070 	while (__nsl_fgets(defval, sizeof (defval), defl) != NULL) {
3071 		if ((strncmp(DONT_SORT, defval, sizeof (DONT_SORT) - 1) == 0) ||
3072 		    (strncmp(DONT_SORT2, defval,
3073 			sizeof (DONT_SORT2) - 1) == 0)) {
3074 			nosort = B_TRUE;
3075 			break;
3076 		}
3077 	}
3078 	(void) __nsl_fclose(defl);
3079 	return (nosort);
3080 }
3081