xref: /freebsd/lib/libc/net/gethostnamadr.c (revision daf1cffce2e07931f27c6c6998652e90df6ba87e)
1 /*-
2  * Copyright (c) 1994, Garrett Wollman
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS ``AS IS'' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  */
25 
26 #if defined(LIBC_SCCS) && !defined(lint)
27 static char sccsid[] = "@(#)$FreeBSD$";
28 static char rcsid[] = "$FreeBSD$";
29 #endif /* LIBC_SCCS and not lint */
30 
31 #include <sys/param.h>
32 #include <sys/socket.h>
33 #include <netinet/in.h>
34 #include <arpa/inet.h>
35 #include <netdb.h>
36 #include <stdio.h>
37 #include <ctype.h>
38 #include <errno.h>
39 #include <string.h>
40 #include <arpa/nameser.h>		/* XXX hack for _res */
41 #include <resolv.h>			/* XXX hack for _res */
42 
43 #define _PATH_HOSTCONF	"/etc/host.conf"
44 
45 enum service_type {
46   SERVICE_NONE = 0,
47   SERVICE_BIND,
48   SERVICE_HOSTS,
49   SERVICE_NIS };
50 #define SERVICE_MAX	SERVICE_NIS
51 
52 static struct {
53   const char *name;
54   enum service_type type;
55 } service_names[] = {
56   { "hosts", SERVICE_HOSTS },
57   { "/etc/hosts", SERVICE_HOSTS },
58   { "hosttable", SERVICE_HOSTS },
59   { "htable", SERVICE_HOSTS },
60   { "bind", SERVICE_BIND },
61   { "dns", SERVICE_BIND },
62   { "domain", SERVICE_BIND },
63   { "yp", SERVICE_NIS },
64   { "yellowpages", SERVICE_NIS },
65   { "nis", SERVICE_NIS },
66   { 0, SERVICE_NONE }
67 };
68 
69 static enum service_type service_order[SERVICE_MAX + 1];
70 static int service_done = 0;
71 
72 static enum service_type
73 get_service_name(const char *name) {
74 	int i;
75 	for(i = 0; service_names[i].type != SERVICE_NONE; i++) {
76 		if(!strcasecmp(name, service_names[i].name)) {
77 			return service_names[i].type;
78 		}
79 	}
80 	return SERVICE_NONE;
81 }
82 
83 static void
84 init_services()
85 {
86 	char *cp, *p, buf[BUFSIZ];
87 	register int cc = 0;
88 	FILE *fd;
89 
90 	if ((fd = (FILE *)fopen(_PATH_HOSTCONF, "r")) == NULL) {
91 				/* make some assumptions */
92 		service_order[0] = SERVICE_BIND;
93 		service_order[1] = SERVICE_HOSTS;
94 		service_order[2] = SERVICE_NONE;
95 	} else {
96 		while (fgets(buf, BUFSIZ, fd) != NULL && cc < SERVICE_MAX) {
97 			if(buf[0] == '#')
98 				continue;
99 
100 			p = buf;
101 			while ((cp = strsep(&p, "\n \t,:;")) != NULL && *cp == '\0')
102 				;
103 			if (cp == NULL)
104 				continue;
105 			do {
106 				if (isalpha((unsigned char)cp[0])) {
107 					service_order[cc] = get_service_name(cp);
108 					if(service_order[cc] != SERVICE_NONE)
109 						cc++;
110 				}
111 				while ((cp = strsep(&p, "\n \t,:;")) != NULL && *cp == '\0')
112 					;
113 			} while(cp != NULL && cc < SERVICE_MAX);
114 		}
115 		service_order[cc] = SERVICE_NONE;
116 		fclose(fd);
117 	}
118 	service_done = 1;
119 }
120 
121 struct hostent *
122 gethostbyname(const char *name)
123 {
124 	struct hostent *hp;
125 
126 	if (_res.options & RES_USE_INET6) {		/* XXX */
127 		hp = gethostbyname2(name, AF_INET6);	/* XXX */
128 		if (hp)					/* XXX */
129 			return (hp);			/* XXX */
130 	}						/* XXX */
131 	return (gethostbyname2(name, AF_INET));
132 }
133 
134 struct hostent *
135 gethostbyname2(const char *name, int type)
136 {
137 	struct hostent *hp = 0;
138 	int nserv = 0;
139 
140 	if (!service_done)
141 		init_services();
142 
143 	while (!hp) {
144 		switch (service_order[nserv]) {
145 		      case SERVICE_NONE:
146 			return NULL;
147 		      case SERVICE_HOSTS:
148 			hp = _gethostbyhtname(name, type);
149 			break;
150 		      case SERVICE_BIND:
151 			hp = _gethostbydnsname(name, type);
152 			break;
153 		      case SERVICE_NIS:
154 			hp = _gethostbynisname(name, type);
155 			break;
156 		}
157 		nserv++;
158 	}
159 	return hp;
160 }
161 
162 struct hostent *
163 gethostbyaddr(const char *addr, int len, int type)
164 {
165 	struct hostent *hp = 0;
166 	int nserv = 0;
167 
168 	if (!service_done)
169 		init_services();
170 
171 	while (!hp) {
172 		switch (service_order[nserv]) {
173 		      case SERVICE_NONE:
174 			return 0;
175 		      case SERVICE_HOSTS:
176 			hp = _gethostbyhtaddr(addr, len, type);
177 			break;
178 		      case SERVICE_BIND:
179 			hp = _gethostbydnsaddr(addr, len, type);
180 			break;
181 		      case SERVICE_NIS:
182 			hp = _gethostbynisaddr(addr, len, type);
183 			break;
184 		}
185 		nserv++;
186 	}
187 	return hp;
188 }
189 
190 #ifdef _THREAD_SAFE
191 struct hostent_data;
192 
193 /*
194  * Temporary function (not thread safe)
195  */
196 int gethostbyaddr_r(const char *addr, int len, int type,
197 	struct hostent *result, struct hostent_data *buffer)
198 {
199 	struct hostent *hp;
200 	int ret;
201 	if ((hp = gethostbyaddr(addr, len, type)) == NULL) {
202 		ret = -1;
203 	} else {
204 		memcpy(result, hp, sizeof(struct hostent));
205 		ret = 0;
206 	}
207 	return(ret);
208 }
209 #endif
210 
211 void
212 sethostent(stayopen)
213 	int stayopen;
214 {
215 	_sethosthtent(stayopen);
216 	_sethostdnsent(stayopen);
217 }
218 
219 void
220 endhostent()
221 {
222 	_endhosthtent();
223 	_endhostdnsent();
224 }
225