usr/src/lib/libmail/common/getdomain.c

   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 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #include "libmail.h"
  33 #include <sys/types.h>
  34 #include <ctype.h>
  35 #ifdef SVR4
  36 #include <sys/utsname.h>
  37 #include <sys/systeminfo.h>
  38 #endif
  39
  40 #define NMLN 512
  41 #ifdef SVR4
  42 #if SYS_NMLN > NMLN
  43 #undef NMLN
  44 #define NMLN SYS_NMLN
  45 #endif
  46 #endif
  47
  48 static char *look4domain(char *, char *, int);
  49 static char *readdomain(char *, int);
  50
  51 /*
  52  *  NAME
  53  *      maildomain() - retrieve the domain name
  54  *
  55  *  SYNOPSIS
  56  *      char *maildomain()
  57  *
  58  *  DESCRIPTION
  59  *      Retrieve the domain name from xgetenv("DOMAIN").
  60  *      If that is not set, look in /etc/resolv.conf, /etc/inet/named.boot
  61  *      and /etc/named.boot for "^domain[ ]+<domain>".
  62  *      If that is not set, use sysinfo(SI_SRPC_DOMAIN) from
  63  *      -lnsl. Otherwise, return an empty string.
  64  */
  65
  66 /* read a file for the domain */
  67 static char *look4domain(char *file, char *buf, int size)
  68 {
  69         char *ret = 0;
  70         FILE *fp = fopen(file, "r");
  71
  72         if (!fp)
  73                 return (0);
  74
  75         while (fgets(buf, size, fp))
  76                 if (strncmp(buf, "domain", 6) == 0)
  77         if (isspace(buf[6])) {
  78                 char *x = skipspace(buf + 6);
  79                 if (isgraph(*x)) {
  80                         trimnl(x);
  81                         strmove(buf, x);
  82                         ret = buf;
  83                         break;
  84                 }
  85         }
  86
  87         (void) fclose(fp);
  88         return (ret);
  89 }
  90
  91 /* read the domain from the xenvironment or one of the files */
  92 static char *readdomain(char *buf, int size)
  93 {
  94         char *ret;
  95
  96         if ((ret = xgetenv("DOMAIN")) != 0) {
  97                 (void) strncpy(buf, ret, size);
  98                 return (buf);
  99         }
 100
 101         if (((ret = look4domain("/etc/resolv.conf", buf, size)) != 0) ||
 102             ((ret = look4domain("/etc/inet/named.boot", buf, size)) != 0) ||
 103             ((ret = look4domain("/etc/named.boot", buf, size)) != 0))
 104                 return (ret);
 105
 106 #ifdef SVR4
 107         if (sysinfo(SI_SRPC_DOMAIN, buf, size) >= 0)
 108                 return (buf);
 109 #endif
 110
 111         return (0);
 112 }
 113
 114 char *
 115 maildomain(void)
 116 {
 117         static char *domain = 0;
 118         static char dombuf[NMLN+1] = ".";
 119
 120         /* if we've already been here, return the info */
 121         if (domain != 0)
 122                 return (domain);
 123
 124         domain = readdomain(dombuf+1, NMLN);
 125
 126         /* Make certain that the domain begins with a single dot */
 127         /* and does not have one at the end. */
 128         if (domain) {
 129                 size_t len;
 130                 domain = dombuf;
 131                 while (*domain && *domain == '.')
 132                         domain++;
 133                 domain--;
 134                 len = strlen(domain);
 135                 while ((len > 0) && (domain[len-1] == '.'))
 136                         domain[--len] = '\0';
 137         }
 138         /* no domain information */
 139         else
 140                 domain = "";
 141
 142         return (domain);
 143 }