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

   1 #!/bin/sh
   2 # Copyright 2006 Gentoo Foundation
   3 # Copyright 2007 Roy Marples
   4 # Distributed under the terms of the GNU General Public License v2
   5
   6 # libc resolv.conf updater
   7
   8 # Written by Roy Marples (uberlord@gentoo.org)
   9 # Heavily based on Debian resolvconf by Thomas Hood
  10
  11 PREFIX=
  12 RESOLVCONF="${PREFIX}"/etc/resolvconf
  13 RESOLVCONFS="$(resolvconf -l)"
  14 BASE="${RESOLVCONF}/resolv.conf.d/base"
  15
  16 uniqify() {
  17     local result=
  18     while [ -n "$1" ]; do
  19                 case " ${result} " in
  20                         *" $1 "*) ;;
  21                         *) result="${result} $1" ;;
  22                 esac
  23                 shift
  24         done
  25     echo "${result# *}"
  26 }
  27
  28 OUR_NS=
  29 if [ -e "${BASE}" ]; then
  30         OUR_NS="$(sed -n -e 's/^[[:space:]]*nameserver[[:space:]]*//p' "${BASE}")"
  31 fi
  32 OUR_NS="$(uniqify \
  33         ${OUR_NS} \
  34         $(echo "${RESOLVCONFS}" \
  35         | sed -n -e 's/^[[:space:]]*nameserver[[:space:]]*//p') \
  36 )"
  37
  38 # libc only allows for 3 nameservers
  39 # truncate after 127 as well
  40 i=0
  41 NS=
  42 LOCALH=false
  43 for N in ${OUR_NS}; do
  44         i=$((${i} + 1))
  45         NS="${NS} ${N}"
  46         [ "${i}" = "3" ] && break
  47         case "${N}" in
  48                 127.*) LOCALH=true; break ;;
  49         esac
  50 done
  51
  52 # This is nasty!
  53 # If we have a local nameserver then assume they are intelligent enough
  54 # to be forwarding domain requests to the correct nameserver and not search
  55 # ones. This means we prefer search then domain, otherwise, we use them in
  56 # the order given to us.
  57 OUR_SEARCH=
  58 if ${LOCALH} ; then
  59         if [ -e "${BASE}" ]; then
  60                 OUR_SEARCH="$(sed -n -e 's/^[[:space:]]*search[[:space:]]*//p' "${BASE}")"
  61         fi
  62         OUR_SEARCH="${OUR_SEARCH} $(echo "${RESOLVCONFS}" \
  63                 | sed -n 's/^[[:space:]]*search[[:space:]]*//p')"
  64         if [ -e "${BASE}" ]; then
  65                 OUR_SEARCH="${OUR_SEARCH} $(sed -n -e 's/^[[:space:]]*domain[[:space:]]*//p' "${BASE}")"
  66         fi
  67         OUR_SEARCH="${OUR_SEARCH} $( echo "${RESOLVCONFS}" \
  68                 | sed -n -e 's/^[[:space:]]*domain[[:space:]]*//p')"
  69 else
  70         if [ -e "${BASE}" ]; then
  71                 OUR_SEARCH="$(sed -n -e 's/^[[:space:]]*search[[:space:]]*//p' \
  72                         -e 's/^[[:space:]]*domain[[:space:]]*//p' "${BASE}")"
  73         fi
  74         OUR_SEARCH="${OUR_SEARCH} $(echo "${RESOLVCONFS}" \
  75                 | sed -n -e 's/^[[:space:]]*search[[:space:]]*//p' \
  76                         -e 's/^[[:space:]]*domain[[:space:]]*//p')"
  77 fi
  78
  79 # libc only allows for 6 search domains
  80 i=0
  81 SEARCH=
  82 for S in $(uniqify ${OUR_SEARCH}); do
  83         i=$((${i} + 1))
  84         SEARCH="${SEARCH} ${S}"
  85         [ "${i}" = "6" ] && break
  86 done
  87 [ -n "${SEARCH}" ] && SEARCH="search${SEARCH}"
  88
  89 # Hold our new resolv.conf in a variable to save on temporary files
  90 NEWCONF="# Generated by resolvconf\n"
  91 [ -e "${RESOLVCONF}"/resolv.conf.d/head ] \
  92         && NEWCONF="${NEWCONF}$(cat "${RESOLVCONF}"/resolv.conf.d/head)\n"
  93 [ -n "${SEARCH}" ] && NEWCONF="${NEWCONF}${SEARCH}\n"
  94 for N in ${NS}; do
  95         NEWCONF="${NEWCONF}nameserver ${N}\n"
  96 done
  97
  98 # Now dump everything else from our resolvs
  99 if [ -e "${BASE}" ]; then
 100         NEWCONF="${NEWCONF}$(sed -e '/^[[:space:]]*$/d' \
 101                 -e '/^[[:space:]]*nameserver[[:space:]]*.*/d' \
 102                 -e '/^[[:space:]]*search[[:space:]]*.*/d' \
 103                 -e '/^[[:space:]]*domain[[:space:]]*.*/d' \
 104                 "${BASE}")"
 105 fi
 106
 107 # We don't know we're using GNU sed, so we do it like this
 108 NEWCONF="${NEWCONF}$(echo "${RESOLVCONFS}" | sed -e '/^[[:space:]]*$/d' \
 109         -e '/^[[:space:]]*#/d' \
 110         -e '/^[[:space:]]*nameserver[[:space:]]*.*/d' \
 111         -e '/^[[:space:]]*search[[:space:]]*.*/d' \
 112         -e '/^[[:space:]]*domain[[:space:]]*.*/d' \
 113         )"
 114 [ -e "${RESOLVCONF}"/resolv.conf.d/tail ] \
 115         && NEWCONF="${NEWCONF}$(cat "${RESOLVCONF}"/resolv.conf.d/tail)"
 116
 117 # Check if the file has actually changed or not
 118 if [ -e "${RESOLVCONF}"/run/resolv.conf ]; then
 119         [ "$(cat "${RESOLVCONF}"/run/resolv.conf)" = "$(printf "${NEWCONF}")" ] && exit 0
 120 fi
 121
 122 # Create our resolv.conf now
 123 printf "${NEWCONF}" > "${RESOLVCONF}"/run/resolv.conf
 124
 125 # Restart nscd if it's running
 126 if [ -x /etc/init.d/nscd ]; then
 127         /etc/init.d/nscd --nodeps --quiet conditionalrestart
 128 fi
 129 if [ -x /etc/rc.d/nscd ]; then
 130         /etc/rc.d/nscd restart
 131 fi
 132
 133 # Notify users of the resolver
 134 for x in "${REVOLVCONF}"/update-libc.d/*; do
 135         [ -e "${x}" ] && "${x}" "$@"
 136 done
 137
 138 # vim: ts=4 :