xref: /illumos-gate/usr/src/lib/libnsl/nss/gethostbyname_r.c (revision 9b9d39d2a32ff806d2431dbcc50968ef1e6d46b2)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*
28  * gethostbyname_r() is defined in this file.  It is implemented on top of
29  *   _get_hostserv_inetnetdir_byname() which is also used to implement
30  *   netdir_getbyname() for inet family transports.  In turn the common code
31  *   uses the name service switch policy for "hosts" and "services" unless
32  *   the administrator chooses to bypass the name service switch by
33  *   specifying third-party supplied nametoaddr libs for inet transports
34  *   in /etc/netconfig.
35  *
36  * gethostbyaddr_r() is similarly related to _get_hostserv_inetnetdir_byaddr()
37  *   and netdir_getbyaddr();
38  *
39  * The common code lives in netdir_inet.c.
40  *
41  * gethostent_r(), sethostent() and endhostent() are *not* implemented on top
42  *   of the common interface;  they go straight to the switch and are
43  *   defined in gethostent_r.c.
44  *
45  * There is absolutely no data sharing, not even the stayopen flag or
46  *   enumeration state, between gethostbyYY_r() and gethostent_r();
47  */
48 
49 #include "mt.h"
50 #include <netdb.h>
51 #include <netdir.h>
52 #include <sys/types.h>
53 #include <nss_netdir.h>
54 #include <string.h>
55 
56 extern struct netconfig *__rpc_getconfip();
57 
58 /*
59  * h_errno POLICY: The frontends expect the name service
60  * backends to modify the h_errno in "arg"; _switch_gethostbyYY_r()
61  * will copy that over onto user's h_errnop pointer. This h_errno is
62  * never used for "switching" -- status from nss_search serves
63  * the purpose. There is no explicit zeroing in the case of success.
64  */
65 
66 extern struct hostent *
67 _switch_gethostbyname_r(const char *nam, struct hostent *result, char *buffer,
68 	int buflen, int *h_errnop);
69 
70 extern struct hostent *
71 _switch_gethostbyaddr_r(const char *addr, int length, int type,
72 	struct hostent *result, char *buffer, int buflen, int *h_errnop);
73 
74 #ifdef PIC
75 struct hostent *
76 _uncached_gethostbyname_r(const char *nam, struct hostent *result,
77 	char *buffer, int buflen, int *h_errnop)
78 {
79 	return (_switch_gethostbyname_r(nam, result,
80 	buffer, buflen, h_errnop));
81 }
82 
83 struct hostent *
84 _uncached_gethostbyaddr_r(const char *addr, int length, int type,
85 	struct hostent *result, char *buffer, int buflen, int *h_errnop)
86 {
87 	return (_switch_gethostbyaddr_r(addr, length, type,
88 					result, buffer, buflen, h_errnop));
89 }
90 
91 #endif
92 
93 extern struct hostent *
94 gethostbyname_r(const char *nam, struct hostent *result, char *buffer,
95 	int buflen, int *h_errnop);
96 
97 extern struct hostent *
98 gethostbyaddr_r(const char *addr, int length, int type,
99 	struct hostent *result, char *buffer, int buflen, int *h_errnop);
100 
101 struct hostent *
102 gethostbyname_r(const char *nam, struct hostent *result, char *buffer,
103 	int buflen, int *h_errnop)
104 {
105 	struct netconfig *nconf;
106 	struct	nss_netdirbyname_in nssin;
107 	union	nss_netdirbyname_out nssout;
108 	int neterr, dummy;
109 
110 	if (h_errnop == NULL)
111 		h_errnop = &dummy;
112 
113 	if (strlen(nam) == 0) {
114 		*h_errnop = HOST_NOT_FOUND;
115 		return (NULL);
116 	}
117 
118 	if ((nconf = __rpc_getconfip("udp")) == NULL &&
119 	    (nconf = __rpc_getconfip("tcp")) == NULL) {
120 		*h_errnop = NO_RECOVERY;
121 		return (NULL);
122 	}
123 
124 	nssin.op_t = NSS_HOST;
125 	nssin.arg.nss.host.name = nam;
126 	nssin.arg.nss.host.buf = buffer;
127 	nssin.arg.nss.host.buflen = buflen;
128 
129 	nssout.nss.host.hent = result;
130 	nssout.nss.host.herrno_p = h_errnop;
131 
132 	/*
133 	 * We pass in nconf and let the implementation of the long-named func
134 	 * decide whether to use the switch based on nc_nlookups.
135 	 */
136 	neterr = _get_hostserv_inetnetdir_byname(nconf, &nssin, &nssout);
137 
138 	(void) freenetconfigent(nconf);
139 	if (neterr != ND_OK)
140 		return (NULL);
141 	return (nssout.nss.host.hent);
142 }
143 
144 struct hostent *
145 gethostbyaddr_r(const char *addr, int length, int type,
146 	struct hostent *result, char *buffer, int buflen, int *h_errnop)
147 {
148 	struct netconfig *nconf;
149 	struct	nss_netdirbyaddr_in nssin;
150 	union	nss_netdirbyaddr_out nssout;
151 	int neterr, dummy;
152 
153 	if (h_errnop == NULL)
154 		h_errnop = &dummy;
155 
156 	if (type != AF_INET) {
157 		*h_errnop = HOST_NOT_FOUND;
158 		return (NULL);
159 	}
160 
161 	if ((nconf = __rpc_getconfip("udp")) == NULL &&
162 	    (nconf = __rpc_getconfip("tcp")) == NULL) {
163 		*h_errnop = NO_RECOVERY;
164 		return (NULL);
165 	}
166 
167 	nssin.op_t = NSS_HOST;
168 	nssin.arg.nss.host.addr = addr;
169 	nssin.arg.nss.host.len = length;
170 	nssin.arg.nss.host.type = type;
171 	nssin.arg.nss.host.buf = buffer;
172 	nssin.arg.nss.host.buflen = buflen;
173 
174 	nssout.nss.host.hent = result;
175 	nssout.nss.host.herrno_p = h_errnop;
176 
177 	/*
178 	 * We pass in nconf and let the implementation of this long-named func
179 	 * decide whether to use the switch based on nc_nlookups.
180 	 */
181 	neterr = _get_hostserv_inetnetdir_byaddr(nconf, &nssin, &nssout);
182 
183 	(void) freenetconfigent(nconf);
184 	if (neterr != ND_OK)
185 		return (NULL);
186 	return (nssout.nss.host.hent);
187 }
188