contrib/openresolv/libc.in

   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
  29 SYSCONFDIR=@SYSCONFDIR@
  30 LIBEXECDIR=@LIBEXECDIR@
  31 VARDIR=@VARDIR@
  32 IFACEDIR="$VARDIR/interfaces"
  33 NL="
  34 "
  35
  36 # sed may not be available, and this is faster on small files
  37 key_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
  59 keys_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
  73 local_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
  77 if [ -f "$SYSCONFDIR"/resolvconf.conf ]; then
  78         . "$SYSCONFDIR"/resolvconf.conf
  79 elif [ -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
  95 fi
  96 : ${resolv_conf:=/etc/resolv.conf}
  97 : ${libc_service:=nscd}
  98 : ${list_resolv:=@SBINDIR@/resolvconf -l}
  99 if [ "${resolv_conf_head-x}" = x ] && [ -f "$SYSCONFDIR"/resolv.conf.head ]
 100 then
 101         resolv_conf_head="$(cat "${SYSCONFDIR}"/resolv.conf.head)"
 102 fi
 103 if [ "${resolv_conf_tail-x}" = x ] && [ -f "$SYSCONFDIR"/resolv.conf.tail ]
 104 then
 105         resolv_conf_tail="$(cat "$SYSCONFDIR"/resolv.conf.tail)"
 106 fi
 107
 108 backup=true
 109 signature="# Generated by resolvconf"
 110
 111 uniqify()
 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
 124 case "${resolv_conf_passthrough:-NO}" in
 125 [Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1)
 126         backup=false
 127         newest=
 128         for conf in "$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 "$(@SBINDIR@/resolvconf -v)"
 147         ;;
 148 esac
 149 case "${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         ;;
 206 esac
 207
 208 # Check if the file has actually changed or not
 209 if [ -e "$resolv_conf" ]; then
 210         [ "$(cat "$resolv_conf")" = "$(printf %s "$newconf")" ] && exit 0
 211 fi
 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.
 216 if $backup; then
 217         if [ "$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
 227 fi
 228
 229 # Create our resolv.conf now
 230 (umask 022; printf %s "$newconf" >"$resolv_conf")
 231 if [ -n "$libc_restart" ]; then
 232         eval $libc_restart
 233 elif [ -n "$RESTARTCMD" ]; then
 234         set -- ${libc_service}
 235         eval "$RESTARTCMD"
 236 else
 237         @SBINDIR@/resolvconf -r ${libc_service}
 238 fi
 239
 240 retval=0
 241 # Notify users of the resolver
 242 for script in "$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
 251 done
 252 exit $retval