source: trunk/minix/lib/ip/res_init.c@ 15

Last change on this file since 15 was 9, checked in by Mattia Monga, 14 years ago

Minix 3.1.2a
File size: 5.6 KB
Line 
1/*-
2 * Copyright (c) 1985, 1989 Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms are permitted provided
6 * that: (1) source distributions retain this entire copyright notice and
7 * comment, and (2) distributions including binaries display the following
8 * acknowledgement: ``This product includes software developed by the
9 * University of California, Berkeley and its contributors'' in the
10 * documentation or other materials provided with the distribution and in
11 * all advertising materials mentioning features or use of this software.
12 * Neither the name of the University nor the names of its contributors may
13 * be used to endorse or promote products derived from this software without
14 * specific prior written permission.
15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
16 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
17 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
18 */
19
20#if defined(LIBC_SCCS) && !defined(lint)
21static char sccsid[] = "@(#)res_init.c 6.14 (Berkeley) 6/27/90";
22#endif /* LIBC_SCCS and not lint */
23
24#if _MINIX
25#include <sys/types.h>
26#include <stdio.h>
27#include <stdlib.h>
28#include <string.h>
29#include <unistd.h>
30
31#include <net/hton.h>
32#include <net/gen/in.h>
33#include <net/gen/inet.h>
34#include <net/gen/nameser.h>
35#include <net/gen/netdb.h>
36#include <net/gen/resolv.h>
37#include <net/gen/socket.h>
38
39#define index(s,c) strchr(s,c)
40#else
41#include <sys/types.h>
42#include <sys/socket.h>
43#include <netinet/in.h>
44#include <stdio.h>
45#include <arpa/nameser.h>
46#include <resolv.h>
47#endif
48
49/*
50 * Resolver state
51 */
52struct state _res;
53
54/*
55 * Set up default settings. If the configuration file exist, the values
56 * there will have precedence. Otherwise, the server address is set to
57 * 127.0.0.1 (localhost) and the default domain name comes from gethostname().
58 *
59 * The configuration file should only be used if you want to redefine your
60 * domain or run without a server on your machine.
61 *
62 * Return 0 if completes successfully, -1 on error
63 */
64int
65res_init()
66{
67 register FILE *fp;
68 register char *cp, **pp;
69 register int n;
70 char buf[BUFSIZ];
71 int haveenv = 0;
72 int havesearch = 0;
73 struct servent* servent;
74 u16_t nameserver_port;
75
76 /* Resolver state default settings */
77 _res.retrans = RES_TIMEOUT; /* retransmition time interval */
78 _res.retry = 4; /* number of times to retransmit */
79 _res.options = RES_DEFAULT; /* options flags */
80 _res.nscount = 0; /* number of name servers */
81 _res.defdname[0] = 0; /* domain */
82
83 servent= getservbyname("domain", NULL);
84 if (!servent)
85 {
86 h_errno= NO_RECOVERY;
87 return -1;
88 }
89 nameserver_port= servent->s_port;
90
91 /* Allow user to override the local domain definition */
92 if ((cp = getenv("LOCALDOMAIN")) != NULL) {
93 (void)strncpy(_res.defdname, cp, sizeof(_res.defdname));
94 haveenv++;
95 }
96
97 if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
98 /* read the config file */
99 while (fgets(buf, sizeof(buf), fp) != NULL) {
100 /* read default domain name */
101 if (!strncmp(buf, "domain", sizeof("domain") - 1)) {
102 if (haveenv) /* skip if have from environ */
103 continue;
104 cp = buf + sizeof("domain") - 1;
105 while (*cp == ' ' || *cp == '\t')
106 cp++;
107 if ((*cp == '\0') || (*cp == '\n'))
108 continue;
109 (void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
110 if ((cp = index(_res.defdname, '\n')) != NULL)
111 *cp = '\0';
112 havesearch = 0;
113 continue;
114 }
115 /* set search list */
116 if (!strncmp(buf, "search", sizeof("search") - 1)) {
117 if (haveenv) /* skip if have from environ */
118 continue;
119 cp = buf + sizeof("search") - 1;
120 while (*cp == ' ' || *cp == '\t')
121 cp++;
122 if ((*cp == '\0') || (*cp == '\n'))
123 continue;
124 (void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
125 if ((cp = index(_res.defdname, '\n')) != NULL)
126 *cp = '\0';
127 /*
128 * Set search list to be blank-separated strings
129 * on rest of line.
130 */
131 cp = _res.defdname;
132 pp = _res.dnsrch;
133 *pp++ = cp;
134 for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
135 if (*cp == ' ' || *cp == '\t') {
136 *cp = 0;
137 n = 1;
138 } else if (n) {
139 *pp++ = cp;
140 n = 0;
141 }
142 }
143 /* null terminate last domain if there are excess */
144 while (*cp != '\0' && *cp != ' ' && *cp != '\t')
145 cp++;
146 *cp = '\0';
147 *pp++ = 0;
148 havesearch = 1;
149 continue;
150 }
151 /* read nameservers to query */
152 if (!strncmp(buf, "nameserver", sizeof("nameserver") - 1) &&
153 _res.nscount < MAXNS) {
154 cp = buf + sizeof("nameserver") - 1;
155 while (*cp == ' ' || *cp == '\t')
156 cp++;
157 if ((*cp == '\0') || (*cp == '\n'))
158 continue;
159 if (!inet_aton(cp, &_res.nsaddr_list[_res.nscount]))
160 continue;
161 _res.nsport_list[_res.nscount]= nameserver_port;
162 _res.nscount++;
163 continue;
164 }
165 }
166 (void) fclose(fp);
167 }
168 if (_res.nscount == 0) {
169 /* "localhost" is the default nameserver. */
170 _res.nsaddr_list[0]= HTONL(0x7F000001);
171 _res.nsport_list[0]= nameserver_port;
172 _res.nscount= 1;
173 }
174 if (_res.defdname[0] == 0) {
175 if (gethostname(buf, sizeof(_res.defdname)) == 0 &&
176 (cp = index(buf, '.')))
177 (void)strcpy(_res.defdname, cp + 1);
178 }
179
180 /* find components of local domain that might be searched */
181 if (havesearch == 0) {
182 pp = _res.dnsrch;
183 *pp++ = _res.defdname;
184 for (cp = _res.defdname, n = 0; *cp; cp++)
185 if (*cp == '.')
186 n++;
187 cp = _res.defdname;
188 for (; n >= LOCALDOMAINPARTS && pp < _res.dnsrch + MAXDFLSRCH;
189 n--) {
190 cp = index(cp, '.');
191 *pp++ = ++cp;
192 }
193 *pp++ = 0;
194 }
195 _res.options |= RES_INIT;
196 return (0);
197}
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