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

   1 #!/bin/sh
   2 # Copyright 2007 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 PREFIX=
  30 RESOLVCONF="${PREFIX}"/etc/resolvconf
  31 RESOLVCONFS="$(resolvconf -l)"
  32 BASE="${RESOLVCONF}/resolv.conf.d/base"
  33
  34 uniqify() {
  35     local result=
  36     while [ -n "$1" ]; do
  37                 case " ${result} " in
  38                         *" $1 "*);;
  39                         *) result="${result} $1";;
  40                 esac
  41                 shift
  42         done
  43     echo "${result# *}"
  44 }
  45
  46 OUR_NS=
  47 if [ -e "${BASE}" ]; then
  48         OUR_NS="$(sed -n -e 's/^[[:space:]]*nameserver[[:space:]]*//p' "${BASE}")"
  49 fi
  50 OUR_NS="$(uniqify \
  51         ${OUR_NS} \
  52         $(echo "${RESOLVCONFS}" \
  53         | sed -n -e 's/^[[:space:]]*nameserver[[:space:]]*//p') \
  54 )"
  55
  56 # libc only allows for 3 nameservers
  57 # truncate after 127 as well
  58 i=0
  59 NS=
  60 LOCALH=false
  61 for N in ${OUR_NS}; do
  62         i=$((${i} + 1))
  63         NS="${NS} ${N}"
  64         [ "${i}" = "3" ] && break
  65         case "${N}" in
  66                 127.*) LOCALH=true; break;;
  67         esac
  68 done
  69
  70 # This is nasty!
  71 # If we have a local nameserver then assume they are intelligent enough
  72 # to be forwarding domain requests to the correct nameserver and not search
  73 # ones. This means we prefer search then domain, otherwise, we use them in
  74 # the order given to us.
  75 OUR_SEARCH=
  76 if ${LOCALH}; then
  77         if [ -e "${BASE}" ]; then
  78                 OUR_SEARCH="$(sed -n -e 's/^[[:space:]]*search[[:space:]]*//p' "${BASE}")"
  79         fi
  80         OUR_SEARCH="${OUR_SEARCH} $(echo "${RESOLVCONFS}" \
  81                 | sed -n 's/^[[:space:]]*search[[:space:]]*//p')"
  82         if [ -e "${BASE}" ]; then
  83                 OUR_SEARCH="${OUR_SEARCH} $(sed -n -e 's/^[[:space:]]*domain[[:space:]]*//p' "${BASE}")"
  84         fi
  85         OUR_SEARCH="${OUR_SEARCH} $( echo "${RESOLVCONFS}" \
  86                 | sed -n -e 's/^[[:space:]]*domain[[:space:]]*//p')"
  87 else
  88         if [ -e "${BASE}" ]; then
  89                 OUR_SEARCH="$(sed -n -e 's/^[[:space:]]*search[[:space:]]*//p' \
  90                         -e 's/^[[:space:]]*domain[[:space:]]*//p' "${BASE}")"
  91         fi
  92         OUR_SEARCH="${OUR_SEARCH} $(echo "${RESOLVCONFS}" \
  93                 | sed -n -e 's/^[[:space:]]*search[[:space:]]*//p' \
  94                         -e 's/^[[:space:]]*domain[[:space:]]*//p')"
  95 fi
  96
  97 # libc only allows for 6 search domains
  98 i=0
  99 SEARCH=
 100 for S in $(uniqify ${OUR_SEARCH}); do
 101         i=$((${i} + 1))
 102         SEARCH="${SEARCH} ${S}"
 103         [ "${i}" = "6" ] && break
 104 done
 105 [ -n "${SEARCH}" ] && SEARCH="search${SEARCH}"
 106
 107 # Hold our new resolv.conf in a variable to save on temporary files
 108 NEWCONF="# Generated by resolvconf\n"
 109 [ -e "${RESOLVCONF}"/resolv.conf.d/head ] \
 110         && NEWCONF="${NEWCONF}$(cat "${RESOLVCONF}"/resolv.conf.d/head)\n"
 111 [ -n "${SEARCH}" ] && NEWCONF="${NEWCONF}${SEARCH}\n"
 112 for N in ${NS}; do
 113         NEWCONF="${NEWCONF}nameserver ${N}\n"
 114 done
 115
 116 # Now dump everything else from our resolvs
 117 if [ -e "${BASE}" ]; then
 118         NEWCONF="${NEWCONF}$(sed -e '/^[[:space:]]*$/d' \
 119                 -e '/^[[:space:]]*nameserver[[:space:]]*.*/d' \
 120                 -e '/^[[:space:]]*search[[:space:]]*.*/d' \
 121                 -e '/^[[:space:]]*domain[[:space:]]*.*/d' \
 122                 "${BASE}")"
 123 fi
 124
 125 # We don't know we're using GNU sed, so we do it like this
 126 NEWCONF="${NEWCONF}$(echo "${RESOLVCONFS}" | sed -e '/^[[:space:]]*$/d' \
 127         -e '/^[[:space:]]*#/d' \
 128         -e '/^[[:space:]]*nameserver[[:space:]]*.*/d' \
 129         -e '/^[[:space:]]*search[[:space:]]*.*/d' \
 130         -e '/^[[:space:]]*domain[[:space:]]*.*/d' \
 131         )"
 132 [ -e "${RESOLVCONF}"/resolv.conf.d/tail ] \
 133         && NEWCONF="${NEWCONF}$(cat "${RESOLVCONF}"/resolv.conf.d/tail)"
 134
 135 # Check if the file has actually changed or not
 136 if [ -e "${RESOLVCONF}"/run/resolv.conf ]; then
 137         [ "$(cat "${RESOLVCONF}"/run/resolv.conf)" = "$(printf "${NEWCONF}")" ] && exit 0
 138 fi
 139
 140 # Create our resolv.conf now
 141 (umask 022; printf "${NEWCONF}" > "${RESOLVCONF}"/run/resolv.conf)
 142
 143 resolvconf -s nscd restart
 144
 145 # Notify users of the resolver
 146 for x in "${REVOLVCONF}"/update-libc.d/*; do
 147         [ -e "${x}" ] && "${x}" "$@"
 148 done
 149
 150 # vim: ts=4 :