roy.marples.name Git - openresolv/blob - libc.in

   1 #!/bin/sh
   2 # Copyright 2007-2008 Roy Marples
   3 # All rights reserved
   4
   5 # libc subscriber for resolvconf
   6 # You could symlink /etc/resolv.conf to resolvconf/run/resolv.conf
   7 # for a read only etc, if resolvconf/run is linked to /var/run/resolvconf.
   8
   9 # Redistribution and use in source and binary forms, with or without
  10 # modification, are permitted provided that the following conditions
  11 # are met:
  12 #     * Redistributions of source code must retain the above copyright
  13 #       notice, this list of conditions and the following disclaimer.
  14 #     * Redistributions in binary form must reproduce the above
  15 #       copyright notice, this list of conditions and the following
  16 #       disclaimer in the documentation and/or other materials provided
  17 #       with the distribution.
  18 #
  19 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  20 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  21 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  22 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  23 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  24 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  25 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  26 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  27 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  28 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  29 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  30
  31 RESOLVCONF=/etc/resolv.conf
  32 PREFIX=@PREFIX@
  33 SYSCONFDIR=@SYSCONFDIR@
  34 RESOLVCONFS="$(resolvconf -l)"
  35 BASE="${SYSCONFDIR}/resolv.conf.d/base"
  36
  37 uniqify() {
  38     local result=
  39     while [ -n "$1" ]; do
  40                 case " ${result} " in
  41                         *" $1 "*);;
  42                         *) result="${result} $1";;
  43                 esac
  44                 shift
  45         done
  46     echo "${result# *}"
  47 }
  48
  49 OUR_NS=
  50 if [ -e "${BASE}" ]; then
  51         OUR_NS="$(sed -n -e 's/^[[:space:]]*nameserver[[:space:]]*//p' "${BASE}")"
  52 fi
  53 OUR_NS="$(uniqify \
  54         ${OUR_NS} \
  55         $(echo "${RESOLVCONFS}" \
  56         | sed -n -e 's/^[[:space:]]*nameserver[[:space:]]*//p') \
  57 )"
  58
  59 # libc only allows for 3 nameservers
  60 # truncate after 127 as well
  61 i=0
  62 NS=
  63 LOCALH=false
  64 for N in ${OUR_NS}; do
  65         i=$((${i} + 1))
  66         NS="${NS} ${N}"
  67         [ "${i}" = "3" ] && break
  68         case "${N}" in
  69                 127.*) LOCALH=true; break;;
  70         esac
  71 done
  72
  73 # This is nasty!
  74 # If we have a local nameserver then assume they are intelligent enough
  75 # to be forwarding domain requests to the correct nameserver and not search
  76 # ones. This means we prefer search then domain, otherwise, we use them in
  77 # the order given to us.
  78 OUR_SEARCH=
  79 if ${LOCALH}; then
  80         if [ -e "${BASE}" ]; then
  81                 OUR_SEARCH="$(sed -n -e 's/^[[:space:]]*search[[:space:]]*//p' "${BASE}")"
  82         fi
  83         OUR_SEARCH="${OUR_SEARCH} $(echo "${RESOLVCONFS}" \
  84                 | sed -n 's/^[[:space:]]*search[[:space:]]*//p')"
  85         if [ -e "${BASE}" ]; then
  86                 OUR_SEARCH="${OUR_SEARCH} $(sed -n -e 's/^[[:space:]]*domain[[:space:]]*//p' "${BASE}")"
  87         fi
  88         OUR_SEARCH="${OUR_SEARCH} $( echo "${RESOLVCONFS}" \
  89                 | sed -n -e 's/^[[:space:]]*domain[[:space:]]*//p')"
  90 else
  91         if [ -e "${BASE}" ]; then
  92                 OUR_SEARCH="$(sed -n -e 's/^[[:space:]]*search[[:space:]]*//p' \
  93                         -e 's/^[[:space:]]*domain[[:space:]]*//p' "${BASE}")"
  94         fi
  95         OUR_SEARCH="${OUR_SEARCH} $(echo "${RESOLVCONFS}" \
  96                 | sed -n -e 's/^[[:space:]]*search[[:space:]]*//p' \
  97                         -e 's/^[[:space:]]*domain[[:space:]]*//p')"
  98 fi
  99
 100 # libc only allows for 6 search domains
 101 i=0
 102 SEARCH=
 103 for S in $(uniqify ${OUR_SEARCH}); do
 104         i=$((${i} + 1))
 105         SEARCH="${SEARCH} ${S}"
 106         [ "${i}" = "6" ] && break
 107 done
 108 [ -n "${SEARCH}" ] && SEARCH="search${SEARCH}"
 109
 110 # Hold our new resolv.conf in a variable to save on temporary files
 111 NEWCONF="# Generated by resolvconf\n"
 112 [ -e "${SYSCONFDIR}"/resolv.conf.d/head ] \
 113         && NEWCONF="${NEWCONF}$(cat "${SYSCONFDIR}"/resolv.conf.d/head)\n"
 114 [ -n "${SEARCH}" ] && NEWCONF="${NEWCONF}${SEARCH}\n"
 115 for N in ${NS}; do
 116         NEWCONF="${NEWCONF}nameserver ${N}\n"
 117 done
 118
 119 # Now dump everything else from our resolvs
 120 if [ -e "${BASE}" ]; then
 121         NEWCONF="${NEWCONF}$(sed -e '/^[[:space:]]*$/d' \
 122                 -e '/^[[:space:]]*nameserver[[:space:]]*.*/d' \
 123                 -e '/^[[:space:]]*search[[:space:]]*.*/d' \
 124                 -e '/^[[:space:]]*domain[[:space:]]*.*/d' \
 125                 "${BASE}")\n"
 126 fi
 127
 128 # We don't know we're using GNU sed, so we do it like this
 129 NEWCONF="${NEWCONF}$(echo "${RESOLVCONFS}" | sed -e '/^[[:space:]]*$/d' \
 130         -e '/^[[:space:]]*#/d' \
 131         -e '/^[[:space:]]*nameserver[[:space:]]*.*/d' \
 132         -e '/^[[:space:]]*search[[:space:]]*.*/d' \
 133         -e '/^[[:space:]]*domain[[:space:]]*.*/d' \
 134         )"
 135 [ -e "${SYSCONFDIR}"/resolv.conf.d/tail ] \
 136         && NEWCONF="${NEWCONF}$(cat "${SYSCONFDIR}"/resolv.conf.d/tail)\n"
 137
 138 # Check if the file has actually changed or not
 139 if [ -e "${RESOLVCONF}" ]; then
 140         [ "$(cat "${RESOLVCONF}")" = "$(printf "${NEWCONF}")" ] && exit 0
 141 fi
 142
 143 # Create our resolv.conf now
 144 (umask 022; printf "${NEWCONF}" > "${RESOLVCONF}")
 145
 146 resolvconf -s nscd restart
 147 retval=$?
 148
 149 # Notify users of the resolver
 150 for x in "${SYSCONFDIR}"/update-libc.d/*; do
 151         if [ -e "${x}" ]; then
 152                 "${x}" "$@"
 153                 retval=$((${retval} + $?))
 154         fi
 155 done
 156 exit ${retval}