1#!/bin/sh 2# Copyright (c) 2007-2019 Roy Marples 3# All rights reserved 4 5# libc subscriber for resolvconf 6 7# Redistribution and use in source and binary forms, with or without 8# modification, are permitted provided that the following conditions 9# are met: 10# * Redistributions of source code must retain the above copyright 11# notice, this list of conditions and the following disclaimer. 12# * Redistributions in binary form must reproduce the above 13# copyright notice, this list of conditions and the following 14# disclaimer in the documentation and/or other materials provided 15# with the distribution. 16# 17# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 29SYSCONFDIR=@SYSCONFDIR@ 30LIBEXECDIR=@LIBEXECDIR@ 31VARDIR=@VARDIR@ 32IFACEDIR="$VARDIR/interfaces" 33NL=" 34" 35 36# sed may not be available, and this is faster on small files 37key_get_value() 38{ 39 key="$1" 40 shift 41 42 if [ $# -eq 0 ]; then 43 while read -r line; do 44 case "$line" in 45 "$key"*) echo "${line##$key}";; 46 esac 47 done 48 else 49 for x do 50 while read -r line; do 51 case "$line" in 52 "$key"*) echo "${line##$key}";; 53 esac 54 done < "$x" 55 done 56 fi 57} 58 59keys_remove() 60{ 61 while read -r line; do 62 found=false 63 for key do 64 case "$line" in 65 "$key"*|"#"*|" "*|" "*|"") found=true;; 66 esac 67 $found && break 68 done 69 $found || echo "$line" 70 done 71} 72 73local_nameservers="127.* 0.0.0.0 255.255.255.255 ::1" 74 75# Support original resolvconf configuration layout 76# as well as the openresolv config file 77if [ -f "$SYSCONFDIR"/resolvconf.conf ]; then 78 . "$SYSCONFDIR"/resolvconf.conf 79elif [ -d "$SYSCONFDIR"/resolvconf ]; then 80 SYSCONFDIR="$SYSCONFDIR/resolvconf" 81 base="$SYSCONFDIR/resolv.conf.d/base" 82 if [ -f "$base" ]; then 83 prepend_nameservers="$(key_get_value "nameserver " "$base")" 84 domain="$(key_get_value "domain " "$base")" 85 prepend_search="$(key_get_value "search " "$base")" 86 resolv_conf_options="$(key_get_value "options " "$base")" 87 resolv_conf_sortlist="$(key_get_value "sortlist " "$base")" 88 fi 89 if [ -f "$SYSCONFDIR"/resolv.conf.d/head ]; then 90 resolv_conf_head="$(cat "${SYSCONFDIR}"/resolv.conf.d/head)" 91 fi 92 if [ -f "$SYSCONFDIR"/resolv.conf.d/tail ]; then 93 resolv_conf_tail="$(cat "$SYSCONFDIR"/resolv.conf.d/tail)" 94 fi 95fi 96: ${resolv_conf:=/etc/resolv.conf} 97: ${libc_service:=nscd} 98: ${list_resolv:=@SBINDIR@/resolvconf -l} 99if [ "${resolv_conf_head-x}" = x ] && [ -f "$SYSCONFDIR"/resolv.conf.head ] 100then 101 resolv_conf_head="$(cat "${SYSCONFDIR}"/resolv.conf.head)" 102fi 103if [ "${resolv_conf_tail-x}" = x ] && [ -f "$SYSCONFDIR"/resolv.conf.tail ] 104then 105 resolv_conf_tail="$(cat "$SYSCONFDIR"/resolv.conf.tail)" 106fi 107 108backup=true 109signature="# Generated by resolvconf" 110 111uniqify() 112{ 113 result= 114 while [ -n "$1" ]; do 115 case " $result " in 116 *" $1 "*);; 117 *) result="$result $1";; 118 esac 119 shift 120 done 121 echo "${result# *}" 122} 123 124case "${resolv_conf_passthrough:-NO}" in 125[Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1) 126 backup=false 127 newest= 128 for conf in "$IFACEDIR"/*; do 129 if [ -z "$newest" ] || [ "$conf" -nt "$newest" ]; then 130 newest="$conf" 131 fi 132 done 133 [ -z "$newest" ] && exit 0 134 newconf="$(cat "$newest")$NL" 135 ;; 136/dev/null|[Nn][Uu][Ll][Ll]) 137 : ${resolv_conf_local_only:=NO} 138 if [ "$local_nameservers" = "127.* 0.0.0.0 255.255.255.255 ::1" ]; then 139 local_nameservers= 140 fi 141 # Need to overwrite our variables. 142 eval "$(@SBINDIR@/resolvconf -V)" 143 ;; 144 145*) 146 [ -z "$RESOLVCONF" ] && eval "$(@SBINDIR@/resolvconf -v)" 147 ;; 148esac 149case "${resolv_conf_passthrough:-NO}" in 150[Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1) ;; 151*) 152 : ${domain:=$DOMAIN} 153 newsearch="$(uniqify $prepend_search $SEARCH $append_search)" 154 NS="$LOCALNAMESERVERS $NAMESERVERS" 155 newns= 156 gotlocal=false 157 for n in $(uniqify $prepend_nameservers $NS $append_nameservers); do 158 add=true 159 islocal=false 160 for l in $local_nameservers; do 161 case "$n" in 162 $l) islocal=true; gotlocal=true; break;; 163 esac 164 done 165 if ! $islocal; then 166 case "${resolv_conf_local_only:-YES}" in 167 [Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1) 168 $gotlocal && add=false;; 169 esac 170 fi 171 $add && newns="$newns $n" 172 done 173 174 # Hold our new resolv.conf in a variable to save on temporary files 175 newconf="$signature$NL" 176 if [ -n "$resolv_conf_head" ]; then 177 newconf="$newconf$resolv_conf_head$NL" 178 fi 179 180 [ -n "$domain" ] && newconf="${newconf}domain $domain$NL" 181 if [ -n "$newsearch" ] && [ "$newsearch" != "$domain" ]; then 182 newconf="${newconf}search $newsearch$NL" 183 fi 184 for n in $newns; do 185 newconf="${newconf}nameserver $n$NL" 186 done 187 188 # Now add anything we don't care about such as sortlist and options 189 stuff="$($list_resolv | keys_remove nameserver domain search)" 190 if [ -n "$stuff" ]; then 191 newconf="$newconf$stuff$NL" 192 fi 193 194 # Append any user defined ones 195 if [ -n "$resolv_conf_options" ]; then 196 newconf="${newconf}options $resolv_conf_options$NL" 197 fi 198 if [ -n "$resolv_conf_sortlist" ]; then 199 newconf="${newconf}sortlist $resolv_conf_sortlist$NL" 200 fi 201 202 if [ -n "$resolv_conf_tail" ]; then 203 newconf="$newconf$resolv_conf_tail$NL" 204 fi 205 ;; 206esac 207 208# Check if the file has actually changed or not 209if [ -e "$resolv_conf" ]; then 210 [ "$(cat "$resolv_conf")" = "$(printf %s "$newconf")" ] && exit 0 211fi 212 213# Change is good. 214# If the old file does not have our signature, back it up. 215# If the new file just has our signature, restore the backup. 216if $backup; then 217 if [ "$newconf" = "$signature$NL" ]; then 218 if [ -e "$resolv_conf.bak" ]; then 219 newconf="$(cat "$resolv_conf.bak")$NL" 220 fi 221 elif [ -e "$resolv_conf" ]; then 222 read line <"$resolv_conf" 223 if [ "$line" != "$signature" ]; then 224 cp "$resolv_conf" "$resolv_conf.bak" 225 fi 226 fi 227fi 228 229# Create our resolv.conf now 230(umask 022; echo "$newconf" >"$resolv_conf") 231if [ -n "$libc_restart" ]; then 232 eval $libc_restart 233elif [ -n "$RESTARTCMD" ]; then 234 set -- ${libc_service} 235 eval "$RESTARTCMD" 236else 237 @SBINDIR@/resolvconf -r ${libc_service} 238fi 239 240retval=0 241# Notify users of the resolver 242for script in "$LIBEXECDIR"/libc.d/*; do 243 if [ -f "$script" ]; then 244 if [ -x "$script" ]; then 245 "$script" "$@" 246 else 247 (. "$script") 248 fi 249 retval=$(($retval + $?)) 250 fi 251done 252exit $retval 253