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

   1 #!/bin/sh
   2 # Copyright 2006 Gentoo Foundation
   3 # Copyright 2007 Roy Marples
   4 # All rights reserved
   5
   6 # dnsmasq 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 # This is very important!
  31 # We assume that we are a local dns cache - after all, why would a server
  32 # use resolvconf?
  33 # Now that we have assumed this, we also assume that generic DHCP clients
  34 # will enter their domains and search domains ONLY in the "search" field
  35 # in their resolv.confs and VPN clients will put the domain they are for
  36 # into the domain field only.
  37 # This allows dnsmasq to forward domains for a specific VPN domain to the
  38 # VPN nameserver and everything else to the standard name servers.
  39
  40 # A sample dnsmasq config that works as above is like so
  41 #domain-needed
  42 #interface=lo
  43 #resolv-file=/etc/dnsmasq-resolv.conf
  44 #conf-file=/etc/dnsmasq-resolvconf.conf
  45
  46 # The last step is to configure dns configuration for /etc/resolv.conf
  47 # for the lo interface. In Gentoo we set it up like so in /etc/conf.d/net
  48 #dns_servers_lo="127.0.0.1"
  49
  50 # Load our variables from resolvconf
  51 VARS="$(resolvconf -v)"
  52 eval "${VARS}"
  53
  54 PREFIX=/
  55 DNSMASQRESOLV="${PREFIX}/etc/dnsmasq-resolv.conf"
  56 DNSMASQCONF="${PREFIX}/etc/dnsmasq-resolvconf.conf"
  57
  58 NEWCONF="# Generated by resolvconf\n"
  59 NEWRESOLV="${NEWCONF}"
  60
  61 # Using DBUS means that we never have to restart the daemon
  62 # This is important as it means we should not drop DNS queries
  63 # whilst changing DNS options around. However, DBUS support is optional
  64 # so we need to validate a few things first.
  65 # Check for DBus support in the binary
  66 DBUS=no
  67 if [ -s "${PREFIX}"/var/run/dbus.pid -a -s "${PREFIX}"/var/run/dnsmasq.pid ]; then
  68         if dnsmasq --version 2>/dev/null | \
  69                 grep -q "^Compile time options.*[[:space:]]DBus[[:space:]]" \
  70                 ; then
  71                 # Sanity - check that dnsmasq and dbus are running
  72                 if kill -0 $(cat "${PREFIX}"/var/run/dbus.pid) \
  73                         && kill -0 $(cat "${PREFIX}"/var/run/dnsmasq.pid); then
  74                         DBUS=yes
  75                         NEWCONF="${NEWCONF}\n# Domain specific servers will be sent over dbus\n\nenable-dbus\n"
  76                 fi
  77         fi
  78 fi
  79
  80 uniqify() {
  81     local result=
  82     while [ -n "$1" ]; do
  83                 case " ${result} " in
  84                         *" $1 "*) ;;
  85                         *) result="${result} $1" ;;
  86                 esac
  87                 shift
  88         done
  89     echo "${result# *}"
  90 }
  91
  92 # If we only have domain information then put it in search too
  93 [ -z "${NEWSEARCH}" -a -z "${NEWNS}" ] && NEWSEARCH="${NEWDOMAIN}"
  94
  95 for N in ${NEWSEARCH}; do
  96         case " ${NEWSL} " in
  97                 *" ${N%,*} "*) ;;
  98                 *) NEWSL="${NEWSL} ${N%,*}" ;;
  99         esac
 100         case "\n${NEWRESOLV}\n" in
 101                 *"\nnameserver ${N#*,}\n"*) ;;
 102                 *) NEWRESOLV="${NEWRESOLV}nameserver ${N#*,}\n" ;;
 103         esac
 104 done
 105 for N in ${NEWNS}; do
 106         case "\n${NEWRESOLV}\n" in
 107                 *"\nnameserver ${N}\n") ;;
 108                 *) NEWRESOLV="${NEWRESOLV}nameserver ${N}\n" ;;
 109         esac
 110 done
 111 [ -n "${NEWSL}" ] && NEWRESOLV="${NEWRESOLV}search${NEWSL}\n"
 112
 113 DBUSDEST=
 114 for DN in $(uniqify ${NEWDOMAIN}) ; do
 115         if [ "${DBUS}" = "yes" ]; then
 116                 IP=${DN#*,}
 117                 SIFS=${IFS-y} OIFS=$IFS
 118                 IFS=.
 119                 set -- ${IP}
 120                 NUM="0x$(printf "%02x" $1 $2 $3 $4)"
 121                 if [ "${SIFS}" = "y" ]; then
 122                         IFS=$OIFS
 123                 else
 124                         unset IFS
 125                 fi
 126                 DBUSDEST="${DBUSDEST} uint32:$(printf "%d" ${NUM}) string:${DN%,*}"
 127         else
 128                 NEWCONF="${NEWCONF}server=/${DN%,*}/${DN#*,}\n"
 129         fi
 130 done
 131
 132 RELOAD="no"
 133 if [ -e "${DNSMASQCONF}" ]; then
 134         if [ "$(cat "${DNSMASQCONF}")" != "$(printf "${NEWCONF}")" ]; then
 135                 RELOAD="yes"
 136                 printf "${NEWCONF}" > "${DNSMASQCONF}"
 137         fi
 138 else
 139         RELOAD="yes"
 140         printf "${NEWCONF}" > "${DNSMASQCONF}"
 141 fi
 142 if [ -e "${DNSMASQRESOLV}" ]; then
 143         if [ "$(cat "${DNSMASQRESOLV}")" != "$(printf "${NEWRESOLV}")" ]; then
 144                 RELOAD="yes"
 145                 printf "${NEWRESOLV}" > "${DNSMASQRESOLV}"
 146         fi
 147 else
 148         # dnsmasq polls this file so no need to set RELOAD="yes"
 149         printf "${NEWRESOLV}" > "${DNSMASQRESOLV}"
 150 fi
 151
 152 if [ "${RELOAD}" = "yes" ]; then
 153         if [ -x "${PREFIX}"/etc/init.d/dnsmasq ]; then
 154                 /etc/init.d/dnsmasq --quiet --nodeps conditionalrestart
 155         elif [ -x "${PREFIX}"/etc/rc.d/dnsmasq ]; then
 156                 "${PREFIX}"/etc/rc.d/dnsmasq restart
 157         fi
 158 fi
 159
 160 if [ "${DBUS}" = "yes" ]; then
 161         if [ "${RELOAD}" != "yes" ]; then
 162                 if [ -x "${PREFIX}"/etc/init.d/dnsmasq ]; then
 163                         /etc/init.d/dnsmasq --quiet reload
 164                 elif [ -x "${PREFIX}"/etc/rc.d/dnsmasq ]; then
 165                         "${PREFIX}"/etc/rc.d/dnsmasq reload
 166                 fi
 167         fi
 168         # Send even if emtpy so old servers are cleared
 169         dbus-send --system --dest=uk.org.thekelleys.dnsmasq \
 170                 /uk/org/thekelleys/dnsmasq uk.org.thekelleys.SetServers \
 171                 ${DBUSDEST}
 172 fi
 173
 174 # vim: ts=4 :