xref: /illumos-gate/usr/src/lib/libnsl/nss/gethostent.c (revision cb5caa98)
17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*cb5caa98Sdjl  * Common Development and Distribution License (the "License").
6*cb5caa98Sdjl  * You may not use this file except in compliance with the License.
77c478bd9Sstevel@tonic-gate  *
87c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
97c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
107c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
117c478bd9Sstevel@tonic-gate  * and limitations under the License.
127c478bd9Sstevel@tonic-gate  *
137c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
147c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
157c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
167c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
177c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
187c478bd9Sstevel@tonic-gate  *
197c478bd9Sstevel@tonic-gate  * CDDL HEADER END
207c478bd9Sstevel@tonic-gate  */
2161961e0fSrobinson 
227c478bd9Sstevel@tonic-gate /*
23e8031f0aSraf  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
247c478bd9Sstevel@tonic-gate  * Use is subject to license terms.
25e8031f0aSraf  */
26e8031f0aSraf 
27e8031f0aSraf /*
287c478bd9Sstevel@tonic-gate  * Ye olde non-reentrant interface (MT-unsafe, caveat utor)
297c478bd9Sstevel@tonic-gate  */
307c478bd9Sstevel@tonic-gate 
317c478bd9Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
327c478bd9Sstevel@tonic-gate 
33e8031f0aSraf #include "mt.h"
347c478bd9Sstevel@tonic-gate #include <stdlib.h>
357c478bd9Sstevel@tonic-gate #include <ctype.h>
367c478bd9Sstevel@tonic-gate #include <string.h>
377c478bd9Sstevel@tonic-gate #include <strings.h>
387c478bd9Sstevel@tonic-gate #include <netdb.h>
397c478bd9Sstevel@tonic-gate #include <stdio.h>
407c478bd9Sstevel@tonic-gate #include <arpa/inet.h>
417c478bd9Sstevel@tonic-gate #include <nss_dbdefs.h>
427c478bd9Sstevel@tonic-gate #include <netinet/in.h>
437c478bd9Sstevel@tonic-gate #include <sys/socket.h>
447c478bd9Sstevel@tonic-gate 
457c478bd9Sstevel@tonic-gate /*
467c478bd9Sstevel@tonic-gate  * Still just a global.  If you want per-thread h_errno,
477c478bd9Sstevel@tonic-gate  * use the reentrant interfaces (gethostbyname_r et al)
487c478bd9Sstevel@tonic-gate  */
497c478bd9Sstevel@tonic-gate int h_errno;
507c478bd9Sstevel@tonic-gate 
517c478bd9Sstevel@tonic-gate #ifdef	NSS_INCLUDE_UNSAFE
527c478bd9Sstevel@tonic-gate 
537c478bd9Sstevel@tonic-gate /*
547c478bd9Sstevel@tonic-gate  * Don't free this, even on an endhostent(), because bitter experience shows
557c478bd9Sstevel@tonic-gate  * that there's production code that does getXXXbyYYY(), then endXXXent(),
567c478bd9Sstevel@tonic-gate  * and then continues to use the pointer it got back.
577c478bd9Sstevel@tonic-gate  */
587c478bd9Sstevel@tonic-gate static nss_XbyY_buf_t *buffer;
597c478bd9Sstevel@tonic-gate #define	GETBUF()	\
607c478bd9Sstevel@tonic-gate 	NSS_XbyY_ALLOC(&buffer, sizeof (struct hostent), NSS_BUFLEN_HOSTS)
617c478bd9Sstevel@tonic-gate 	/* === ?? set ENOMEM on failure?  */
627c478bd9Sstevel@tonic-gate 
637c478bd9Sstevel@tonic-gate struct hostent *
gethostbyname(const char * nam)647c478bd9Sstevel@tonic-gate gethostbyname(const char *nam)
657c478bd9Sstevel@tonic-gate {
667c478bd9Sstevel@tonic-gate 	nss_XbyY_buf_t  *b;
677c478bd9Sstevel@tonic-gate 
6861961e0fSrobinson 	if ((b = GETBUF()) == 0)
6961961e0fSrobinson 		return (NULL);
7061961e0fSrobinson 	return (gethostbyname_r(nam, b->result, b->buffer, b->buflen,
7161961e0fSrobinson 		    &h_errno));
727c478bd9Sstevel@tonic-gate }
737c478bd9Sstevel@tonic-gate 
747c478bd9Sstevel@tonic-gate struct hostent *
gethostbyaddr(const void * addr,socklen_t len,int type)757c478bd9Sstevel@tonic-gate gethostbyaddr(const void *addr, socklen_t len, int type)
767c478bd9Sstevel@tonic-gate {
777c478bd9Sstevel@tonic-gate 	nss_XbyY_buf_t	*b;
787c478bd9Sstevel@tonic-gate 
797c478bd9Sstevel@tonic-gate 	h_errno = 0;
807c478bd9Sstevel@tonic-gate 	if (type == AF_INET6)
817c478bd9Sstevel@tonic-gate 		return (getipnodebyaddr(addr, len, type, &h_errno));
827c478bd9Sstevel@tonic-gate 
8361961e0fSrobinson 	if ((b = GETBUF()) == 0)
8461961e0fSrobinson 		return (NULL);
8561961e0fSrobinson 	return (gethostbyaddr_r(addr, len, type,
8661961e0fSrobinson 		    b->result, b->buffer, b->buflen, &h_errno));
877c478bd9Sstevel@tonic-gate }
887c478bd9Sstevel@tonic-gate 
897c478bd9Sstevel@tonic-gate struct hostent *
gethostent(void)907c478bd9Sstevel@tonic-gate gethostent(void)
917c478bd9Sstevel@tonic-gate {
927c478bd9Sstevel@tonic-gate 	nss_XbyY_buf_t	*b;
937c478bd9Sstevel@tonic-gate 
9461961e0fSrobinson 	if ((b = GETBUF()) == 0)
9561961e0fSrobinson 		return (NULL);
9661961e0fSrobinson 	return (gethostent_r(b->result, b->buffer, b->buflen, &h_errno));
977c478bd9Sstevel@tonic-gate }
987c478bd9Sstevel@tonic-gate 
997c478bd9Sstevel@tonic-gate /*
1007c478bd9Sstevel@tonic-gate  * Return values: 0 = success, 1 = parse error, 2 = erange ...
1017c478bd9Sstevel@tonic-gate  * The structure pointer passed in is a structure in the caller's space
1027c478bd9Sstevel@tonic-gate  * wherein the field pointers would be set to areas in the buffer if
1037c478bd9Sstevel@tonic-gate  * need be. instring and buffer should be separate areas.
1047c478bd9Sstevel@tonic-gate  */
1057c478bd9Sstevel@tonic-gate int
__str2hostent(int af,const char * instr,int lenstr,void * ent,char * buffer,int buflen)1067c478bd9Sstevel@tonic-gate __str2hostent(int af, const char *instr, int lenstr, void *ent, char *buffer,
1077c478bd9Sstevel@tonic-gate     int buflen)
1087c478bd9Sstevel@tonic-gate {
1097c478bd9Sstevel@tonic-gate 	struct hostent	*host	= (struct hostent *)ent;
1107c478bd9Sstevel@tonic-gate 	const char	*p, *addrstart, *limit;
1117c478bd9Sstevel@tonic-gate 	int		naddr, i, aliases_erange = 0;
1127c478bd9Sstevel@tonic-gate 	int		addrlen, res;
1137c478bd9Sstevel@tonic-gate 	char		addrbuf[100];  /* Why 100? */
1147c478bd9Sstevel@tonic-gate 	struct in_addr	*addrp;
1157c478bd9Sstevel@tonic-gate 	struct in6_addr	*addrp6;
1167c478bd9Sstevel@tonic-gate 	char		**addrvec;
1177c478bd9Sstevel@tonic-gate 
1187c478bd9Sstevel@tonic-gate 	if ((instr >= buffer && (buffer + buflen) > instr) ||
11961961e0fSrobinson 	    (buffer >= instr && (instr + lenstr) > buffer))
1207c478bd9Sstevel@tonic-gate 		return (NSS_STR_PARSE_PARSE);
1217c478bd9Sstevel@tonic-gate 	if (af != AF_INET && af != AF_INET6) {
1227c478bd9Sstevel@tonic-gate 		/*
1237c478bd9Sstevel@tonic-gate 		 * XXX - Returning ERANGE here is completely bogus.
1247c478bd9Sstevel@tonic-gate 		 * Unfortunately, there's no error code identifying
1257c478bd9Sstevel@tonic-gate 		 * bogus calls from the backend (and nothing the user
1267c478bd9Sstevel@tonic-gate 		 * can do about our bugs anyway).
1277c478bd9Sstevel@tonic-gate 		 */
1287c478bd9Sstevel@tonic-gate 		return (NSS_STR_PARSE_ERANGE);
1297c478bd9Sstevel@tonic-gate 	}
1307c478bd9Sstevel@tonic-gate 
1317c478bd9Sstevel@tonic-gate 	/*
1327c478bd9Sstevel@tonic-gate 	 * The DNS-via-YP code returns multiple lines for a key.
1337c478bd9Sstevel@tonic-gate 	 * Normal YP return values do not contain newlines (nor do
1347c478bd9Sstevel@tonic-gate 	 * lines from /etc/hosts or other sources)
1357c478bd9Sstevel@tonic-gate 	 * We count the number of newlines; this should give us
1367c478bd9Sstevel@tonic-gate 	 * the number of IP addresses specified.
1377c478bd9Sstevel@tonic-gate 	 * We'll also call the aliases code and instruct it to
1387c478bd9Sstevel@tonic-gate 	 * stop at the first newline as the remaining lines will
1397c478bd9Sstevel@tonic-gate 	 * all contain the same hostname/aliases (no aliases, unfortunately).
1407c478bd9Sstevel@tonic-gate 	 *
1417c478bd9Sstevel@tonic-gate 	 * When confronted with a string with embedded newlines,
1427c478bd9Sstevel@tonic-gate 	 * this code will take the hostname/aliases on the first line
1437c478bd9Sstevel@tonic-gate 	 * and each of the IP addresses at the start of all lines.
1447c478bd9Sstevel@tonic-gate 	 * Because the NIS protocol limits return values to 1024 bytes,
1457c478bd9Sstevel@tonic-gate 	 * we still do not get all addresses.  If you want to fix
1467c478bd9Sstevel@tonic-gate 	 * that problem, do not look here.
1477c478bd9Sstevel@tonic-gate 	 */
1487c478bd9Sstevel@tonic-gate 
1497c478bd9Sstevel@tonic-gate 	p = instr;
1507c478bd9Sstevel@tonic-gate 
1517c478bd9Sstevel@tonic-gate 	/* Strip trailing newlines */
1527c478bd9Sstevel@tonic-gate 	while (lenstr > 0 && p[lenstr - 1] == '\n')
1537c478bd9Sstevel@tonic-gate 		lenstr--;
1547c478bd9Sstevel@tonic-gate 
1557c478bd9Sstevel@tonic-gate 	naddr = 1;
1567c478bd9Sstevel@tonic-gate 	limit = p + lenstr;
1577c478bd9Sstevel@tonic-gate 
1587c478bd9Sstevel@tonic-gate 	for (; p < limit && (p = memchr(p, '\n', limit - p)); p++)
1597c478bd9Sstevel@tonic-gate 		naddr++;
1607c478bd9Sstevel@tonic-gate 
1617c478bd9Sstevel@tonic-gate 	/* Allocate space for naddr addresses and h_addr_list */
1627c478bd9Sstevel@tonic-gate 
1637c478bd9Sstevel@tonic-gate 	if (af == AF_INET6) {
1647c478bd9Sstevel@tonic-gate 		addrp6 = (struct in6_addr *)ROUND_DOWN(buffer + buflen,
1657c478bd9Sstevel@tonic-gate 		    sizeof (*addrp6));
1667c478bd9Sstevel@tonic-gate 		addrp6 -= naddr;
1677c478bd9Sstevel@tonic-gate 		addrvec = (char **)ROUND_DOWN(addrp6, sizeof (*addrvec));
1687c478bd9Sstevel@tonic-gate 		addrvec -= naddr + 1;
1697c478bd9Sstevel@tonic-gate 	} else {
1707c478bd9Sstevel@tonic-gate 		addrp = (struct in_addr *)ROUND_DOWN(buffer + buflen,
1717c478bd9Sstevel@tonic-gate 		    sizeof (*addrp));
1727c478bd9Sstevel@tonic-gate 		addrp -= naddr;
1737c478bd9Sstevel@tonic-gate 		addrvec = (char **)ROUND_DOWN(addrp, sizeof (*addrvec));
1747c478bd9Sstevel@tonic-gate 		addrvec -= naddr + 1;
1757c478bd9Sstevel@tonic-gate 	}
1767c478bd9Sstevel@tonic-gate 
17761961e0fSrobinson 	if ((char *)addrvec < buffer)
1787c478bd9Sstevel@tonic-gate 		return (NSS_STR_PARSE_ERANGE);
1797c478bd9Sstevel@tonic-gate 
1807c478bd9Sstevel@tonic-gate 	/* For each addr, parse and get it */
1817c478bd9Sstevel@tonic-gate 
1827c478bd9Sstevel@tonic-gate 	p = instr;
1837c478bd9Sstevel@tonic-gate 
1847c478bd9Sstevel@tonic-gate 	for (i = 0; i < naddr; i ++) {
1857c478bd9Sstevel@tonic-gate 
1867c478bd9Sstevel@tonic-gate 		limit = memchr(p, '\n', lenstr - (p - instr));
1877c478bd9Sstevel@tonic-gate 		if (limit == NULL)
1887c478bd9Sstevel@tonic-gate 			limit = instr + lenstr;
1897c478bd9Sstevel@tonic-gate 
19061961e0fSrobinson 		while (p < limit && isspace(*p))
1917c478bd9Sstevel@tonic-gate 			p++;
1927c478bd9Sstevel@tonic-gate 		addrstart = p;
19361961e0fSrobinson 		while (p < limit && !isspace(*p))
1947c478bd9Sstevel@tonic-gate 			p++;
19561961e0fSrobinson 		if (p >= limit)
1967c478bd9Sstevel@tonic-gate 		    /* Syntax error - no hostname present or truncated line */
1977c478bd9Sstevel@tonic-gate 		    return (NSS_STR_PARSE_PARSE);
1987c478bd9Sstevel@tonic-gate 		addrlen = p - addrstart;
19961961e0fSrobinson 		if (addrlen >= sizeof (addrbuf))
2007c478bd9Sstevel@tonic-gate 			/* Syntax error -- supposed IP address is too long */
2017c478bd9Sstevel@tonic-gate 			return (NSS_STR_PARSE_PARSE);
20261961e0fSrobinson 		(void) memcpy(addrbuf, addrstart, addrlen);
2037c478bd9Sstevel@tonic-gate 		addrbuf[addrlen] = '\0';
2047c478bd9Sstevel@tonic-gate 
2057c478bd9Sstevel@tonic-gate 		if (addrlen > ((af == AF_INET6) ? INET6_ADDRSTRLEN
20661961e0fSrobinson 							: INET_ADDRSTRLEN))
2077c478bd9Sstevel@tonic-gate 			/* Syntax error -- supposed IP address is too long */
2087c478bd9Sstevel@tonic-gate 			return (NSS_STR_PARSE_PARSE);
2097c478bd9Sstevel@tonic-gate 		if (af == AF_INET) {
2107c478bd9Sstevel@tonic-gate 			/*
2117c478bd9Sstevel@tonic-gate 			 * inet_pton() doesn't handle d.d.d, d.d, or d formats,
2127c478bd9Sstevel@tonic-gate 			 * so we must use inet_addr() for IPv4 addresses.
2137c478bd9Sstevel@tonic-gate 			 */
2147c478bd9Sstevel@tonic-gate 			addrvec[i] = (char *)&addrp[i];
21561961e0fSrobinson 			if ((addrp[i].s_addr = inet_addr(addrbuf)) ==
21661961e0fSrobinson 								0xffffffffU)
2177c478bd9Sstevel@tonic-gate 				/* Syntax error -- bogus IPv4 address */
2187c478bd9Sstevel@tonic-gate 				return (NSS_STR_PARSE_PARSE);
2197c478bd9Sstevel@tonic-gate 		} else {
2207c478bd9Sstevel@tonic-gate 			/*
2217c478bd9Sstevel@tonic-gate 			 * In the case of AF_INET6, we can have both v4 and v6
2227c478bd9Sstevel@tonic-gate 			 * addresses, so we convert v4's to v4 mapped addresses
2237c478bd9Sstevel@tonic-gate 			 * and return them as such.
2247c478bd9Sstevel@tonic-gate 			 */
2257c478bd9Sstevel@tonic-gate 			addrvec[i] = (char *)&addrp6[i];
2267c478bd9Sstevel@tonic-gate 			if (strchr(addrbuf, ':') != 0) {
22761961e0fSrobinson 				if (inet_pton(af, addrbuf, &addrp6[i]) != 1)
2287c478bd9Sstevel@tonic-gate 					return (NSS_STR_PARSE_PARSE);
2297c478bd9Sstevel@tonic-gate 			} else {
2307c478bd9Sstevel@tonic-gate 				struct in_addr in4;
23161961e0fSrobinson 				if ((in4.s_addr = inet_addr(addrbuf)) ==
23261961e0fSrobinson 								0xffffffffU)
2337c478bd9Sstevel@tonic-gate 					return (NSS_STR_PARSE_PARSE);
2347c478bd9Sstevel@tonic-gate 				IN6_INADDR_TO_V4MAPPED(&in4, &addrp6[i]);
2357c478bd9Sstevel@tonic-gate 			}
2367c478bd9Sstevel@tonic-gate 		}
2377c478bd9Sstevel@tonic-gate 
2387c478bd9Sstevel@tonic-gate 		/* First address, this is where we get the hostname + aliases */
2397c478bd9Sstevel@tonic-gate 		if (i == 0) {
2407c478bd9Sstevel@tonic-gate 			while (p < limit && isspace(*p)) {
2417c478bd9Sstevel@tonic-gate 				p++;
2427c478bd9Sstevel@tonic-gate 			}
2437c478bd9Sstevel@tonic-gate 			host->h_aliases = _nss_netdb_aliases(p, limit - p,
2447c478bd9Sstevel@tonic-gate 				buffer, ((char *)addrvec) - buffer);
2457c478bd9Sstevel@tonic-gate 			if (host->h_aliases == NULL)
2467c478bd9Sstevel@tonic-gate 				aliases_erange = 1; /* too big for buffer */
2477c478bd9Sstevel@tonic-gate 		}
2487c478bd9Sstevel@tonic-gate 		if (limit >= instr + lenstr)
2497c478bd9Sstevel@tonic-gate 			break;
2507c478bd9Sstevel@tonic-gate 		else
2517c478bd9Sstevel@tonic-gate 			p = limit + 1;		/* skip NL */
2527c478bd9Sstevel@tonic-gate 	}
2537c478bd9Sstevel@tonic-gate 
2547c478bd9Sstevel@tonic-gate 	if (host->h_aliases == 0) {
2557c478bd9Sstevel@tonic-gate 		if (aliases_erange)
2567c478bd9Sstevel@tonic-gate 			res = NSS_STR_PARSE_ERANGE;
2577c478bd9Sstevel@tonic-gate 		else
2587c478bd9Sstevel@tonic-gate 			res = NSS_STR_PARSE_PARSE;
2597c478bd9Sstevel@tonic-gate 	} else {
2607c478bd9Sstevel@tonic-gate 		/* Success */
2617c478bd9Sstevel@tonic-gate 		host->h_name = host->h_aliases[0];
2627c478bd9Sstevel@tonic-gate 		host->h_aliases++;
2637c478bd9Sstevel@tonic-gate 		res = NSS_STR_PARSE_SUCCESS;
2647c478bd9Sstevel@tonic-gate 	}
2657c478bd9Sstevel@tonic-gate 	/*
2667c478bd9Sstevel@tonic-gate 	 * If i < naddr, we quit the loop early and addrvec[i+1] needs NULL
2677c478bd9Sstevel@tonic-gate 	 * otherwise, we ran naddr iterations and addrvec[naddr] needs NULL
2687c478bd9Sstevel@tonic-gate 	 */
2697c478bd9Sstevel@tonic-gate 	addrvec[i >= naddr ? naddr : i + 1] = 0;
2707c478bd9Sstevel@tonic-gate 	if (af == AF_INET6) {
2717c478bd9Sstevel@tonic-gate 		host->h_length    = sizeof (struct in6_addr);
2727c478bd9Sstevel@tonic-gate 	} else {
2737c478bd9Sstevel@tonic-gate 		host->h_length    = sizeof (struct in_addr);
2747c478bd9Sstevel@tonic-gate 	}
2757c478bd9Sstevel@tonic-gate 	host->h_addrtype  = af;
2767c478bd9Sstevel@tonic-gate 	host->h_addr_list = addrvec;
2777c478bd9Sstevel@tonic-gate 
2787c478bd9Sstevel@tonic-gate 	return (res);
2797c478bd9Sstevel@tonic-gate }
2807c478bd9Sstevel@tonic-gate #endif	/* NSS_INCLUDE_UNSAFE */
281