getdomain.c revision 1219:f89f56c2d9ac 
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/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
24/*	  All Rights Reserved  	*/
25
26/*
27 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
28 * Use is subject to license terms.
29 */
30
31#pragma ident	"%Z%%M%	%I%	%E% SMI"
32/*LINTLIBRARY*/
33
34#include "c_synonyms.h"
35#include "libmail.h"
36#include <sys/types.h>
37#include <ctype.h>
38#ifdef SVR4
39#include <sys/utsname.h>
40#include <sys/systeminfo.h>
41#endif
42
43#define	NMLN 512
44#ifdef SVR4
45#if SYS_NMLN > NMLN
46#undef NMLN
47#define	NMLN SYS_NMLN
48#endif
49#endif
50
51static char *look4domain(char *, char *, int);
52static char *readdomain(char *, int);
53
54/*
55 *  NAME
56 *	maildomain() - retrieve the domain name
57 *
58 *  SYNOPSIS
59 *	char *maildomain()
60 *
61 *  DESCRIPTION
62 *	Retrieve the domain name from xgetenv("DOMAIN").
63 *	If that is not set, look in /etc/resolv.conf, /etc/inet/named.boot
64 *	and /etc/named.boot for "^domain[ ]+<domain>".
65 *	If that is not set, use sysinfo(SI_SRPC_DOMAIN) from
66 *	-lnsl. Otherwise, return an empty string.
67 */
68
69/* read a file for the domain */
70static char *look4domain(char *file, char *buf, int size)
71{
72	char *ret = 0;
73	FILE *fp = fopen(file, "r");
74
75	if (!fp)
76		return (0);
77
78	while (fgets(buf, size, fp))
79		if (strncmp(buf, "domain", 6) == 0)
80	if (isspace(buf[6])) {
81		char *x = skipspace(buf + 6);
82		if (isgraph(*x)) {
83			trimnl(x);
84			strmove(buf, x);
85			ret = buf;
86			break;
87		}
88	}
89
90	(void) fclose(fp);
91	return (ret);
92}
93
94/* read the domain from the xenvironment or one of the files */
95static char *readdomain(char *buf, int size)
96{
97	char *ret;
98
99	if ((ret = xgetenv("DOMAIN")) != 0) {
100		(void) strncpy(buf, ret, size);
101		return (buf);
102	}
103
104	if (((ret = look4domain("/etc/resolv.conf", buf, size)) != 0) ||
105	    ((ret = look4domain("/etc/inet/named.boot", buf, size)) != 0) ||
106	    ((ret = look4domain("/etc/named.boot", buf, size)) != 0))
107		return (ret);
108
109#ifdef SVR4
110	if (sysinfo(SI_SRPC_DOMAIN, buf, size) >= 0)
111		return (buf);
112#endif
113
114	return (0);
115}
116
117char *
118maildomain(void)
119{
120	static char *domain = 0;
121	static char dombuf[NMLN+1] = ".";
122
123	/* if we've already been here, return the info */
124	if (domain != 0)
125	    return (domain);
126
127	domain = readdomain(dombuf+1, NMLN);
128
129	/* Make certain that the domain begins with a single dot */
130	/* and does not have one at the end. */
131	if (domain) {
132		size_t len;
133		domain = dombuf;
134		while (*domain && *domain == '.')
135			domain++;
136		domain--;
137		len = strlen(domain);
138		while ((len > 0) && (domain[len-1] == '.'))
139			domain[--len] = '\0';
140	}
141	/* no domain information */
142	else
143		domain = "";
144
145	return (domain);
146}
147