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

   1 #!/bin/sh
   2 # Copyright 2006 Gentoo Foundation
   3 # Copyright 2007 Roy Marples
   4 # All rights reserved
   5
   6 # libc subscriber for resolvconf
   7
   8 # Redistribution and use in source and binary forms, with or without
   9 # modification, are permitted provided that the following conditions
  10 # are met:
  11 #     * Redistributions of source code must retain the above copyright
  12 #       notice, this list of conditions and the following disclaimer.
  13 #     * Redistributions in binary form must reproduce the above
  14 #       copyright notice, this list of conditions and the following
  15 #       disclaimer in the documentation and/or other materials provided
  16 #       with the distribution.
  17 #
  18 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29
  30 PREFIX=
  31 RESOLVCONF="${PREFIX}"/etc/resolvconf
  32 RESOLVCONFS="$(resolvconf -l)"
  33 BASE="${RESOLVCONF}/resolv.conf.d/base"
  34
  35 uniqify() {
  36     local result=
  37     while [ -n "$1" ]; do
  38                 case " ${result} " in
  39                         *" $1 "*) ;;
  40                         *) result="${result} $1" ;;
  41                 esac
  42                 shift
  43         done
  44     echo "${result# *}"
  45 }
  46
  47 OUR_NS=
  48 if [ -e "${BASE}" ]; then
  49         OUR_NS="$(sed -n -e 's/^[[:space:]]*nameserver[[:space:]]*//p' "${BASE}")"
  50 fi
  51 OUR_NS="$(uniqify \
  52         ${OUR_NS} \
  53         $(echo "${RESOLVCONFS}" \
  54         | sed -n -e 's/^[[:space:]]*nameserver[[:space:]]*//p') \
  55 )"
  56
  57 # libc only allows for 3 nameservers
  58 # truncate after 127 as well
  59 i=0
  60 NS=
  61 LOCALH=false
  62 for N in ${OUR_NS}; do
  63         i=$((${i} + 1))
  64         NS="${NS} ${N}"
  65         [ "${i}" = "3" ] && break
  66         case "${N}" in
  67                 127.*) LOCALH=true; break ;;
  68         esac
  69 done
  70
  71 # This is nasty!
  72 # If we have a local nameserver then assume they are intelligent enough
  73 # to be forwarding domain requests to the correct nameserver and not search
  74 # ones. This means we prefer search then domain, otherwise, we use them in
  75 # the order given to us.
  76 OUR_SEARCH=
  77 if ${LOCALH} ; then
  78         if [ -e "${BASE}" ]; then
  79                 OUR_SEARCH="$(sed -n -e 's/^[[:space:]]*search[[:space:]]*//p' "${BASE}")"
  80         fi
  81         OUR_SEARCH="${OUR_SEARCH} $(echo "${RESOLVCONFS}" \
  82                 | sed -n 's/^[[:space:]]*search[[:space:]]*//p')"
  83         if [ -e "${BASE}" ]; then
  84                 OUR_SEARCH="${OUR_SEARCH} $(sed -n -e 's/^[[:space:]]*domain[[:space:]]*//p' "${BASE}")"
  85         fi
  86         OUR_SEARCH="${OUR_SEARCH} $( echo "${RESOLVCONFS}" \
  87                 | sed -n -e 's/^[[:space:]]*domain[[:space:]]*//p')"
  88 else
  89         if [ -e "${BASE}" ]; then
  90                 OUR_SEARCH="$(sed -n -e 's/^[[:space:]]*search[[:space:]]*//p' \
  91                         -e 's/^[[:space:]]*domain[[:space:]]*//p' "${BASE}")"
  92         fi
  93         OUR_SEARCH="${OUR_SEARCH} $(echo "${RESOLVCONFS}" \
  94                 | sed -n -e 's/^[[:space:]]*search[[:space:]]*//p' \
  95                         -e 's/^[[:space:]]*domain[[:space:]]*//p')"
  96 fi
  97
  98 # libc only allows for 6 search domains
  99 i=0
 100 SEARCH=
 101 for S in $(uniqify ${OUR_SEARCH}); do
 102         i=$((${i} + 1))
 103         SEARCH="${SEARCH} ${S}"
 104         [ "${i}" = "6" ] && break
 105 done
 106 [ -n "${SEARCH}" ] && SEARCH="search${SEARCH}"
 107
 108 # Hold our new resolv.conf in a variable to save on temporary files
 109 NEWCONF="# Generated by resolvconf\n"
 110 [ -e "${RESOLVCONF}"/resolv.conf.d/head ] \
 111         && NEWCONF="${NEWCONF}$(cat "${RESOLVCONF}"/resolv.conf.d/head)\n"
 112 [ -n "${SEARCH}" ] && NEWCONF="${NEWCONF}${SEARCH}\n"
 113 for N in ${NS}; do
 114         NEWCONF="${NEWCONF}nameserver ${N}\n"
 115 done
 116
 117 # Now dump everything else from our resolvs
 118 if [ -e "${BASE}" ]; then
 119         NEWCONF="${NEWCONF}$(sed -e '/^[[:space:]]*$/d' \
 120                 -e '/^[[:space:]]*nameserver[[:space:]]*.*/d' \
 121                 -e '/^[[:space:]]*search[[:space:]]*.*/d' \
 122                 -e '/^[[:space:]]*domain[[:space:]]*.*/d' \
 123                 "${BASE}")"
 124 fi
 125
 126 # We don't know we're using GNU sed, so we do it like this
 127 NEWCONF="${NEWCONF}$(echo "${RESOLVCONFS}" | sed -e '/^[[:space:]]*$/d' \
 128         -e '/^[[:space:]]*#/d' \
 129         -e '/^[[:space:]]*nameserver[[:space:]]*.*/d' \
 130         -e '/^[[:space:]]*search[[:space:]]*.*/d' \
 131         -e '/^[[:space:]]*domain[[:space:]]*.*/d' \
 132         )"
 133 [ -e "${RESOLVCONF}"/resolv.conf.d/tail ] \
 134         && NEWCONF="${NEWCONF}$(cat "${RESOLVCONF}"/resolv.conf.d/tail)"
 135
 136 # Check if the file has actually changed or not
 137 if [ -e "${RESOLVCONF}"/run/resolv.conf ]; then
 138         [ "$(cat "${RESOLVCONF}"/run/resolv.conf)" = "$(printf "${NEWCONF}")" ] && exit 0
 139 fi
 140
 141 # Create our resolv.conf now
 142 printf "${NEWCONF}" > "${RESOLVCONF}"/run/resolv.conf
 143
 144 # Restart nscd if it's running
 145 if [ -x /etc/init.d/nscd ]; then
 146         /etc/init.d/nscd --nodeps --quiet conditionalrestart
 147 fi
 148 if [ -x /etc/rc.d/nscd ]; then
 149         /etc/rc.d/nscd restart
 150 fi
 151
 152 # Notify users of the resolver
 153 for x in "${REVOLVCONF}"/update-libc.d/*; do
 154         [ -e "${x}" ] && "${x}" "$@"
 155 done
 156
 157 # vim: ts=4 :