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

   1 #!/bin/sh
   2 # Copyright 2007-2008 Roy Marples
   3 # All rights reserved
   4
   5 # dnsmasq 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 # This is very important!
  30 # We assume that we are a local dns cache - after all, why would a server
  31 # use resolvconf?
  32 # Now that we have assumed this, we also assume that generic DHCP clients
  33 # will enter their domains and search domains ONLY in the "search" field
  34 # in their resolv.confs and VPN clients will put the domain they are for
  35 # into the domain field only.
  36 # This allows dnsmasq to forward domains for a specific VPN domain to the
  37 # VPN nameserver and everything else to the standard name servers.
  38
  39 # A sample dnsmasq config that works as above is like so.
  40 # NOTE: The loopback interface on some systems maybe lo0.
  41 #domain-needed
  42 #interface=lo
  43 #resolv-file=@PREFIX@/etc/dnsmasq-resolv.conf
  44 #conf-file=@PREFIX@/etc/dnsmasq-resolvconf.conf
  45
  46 # The last step is to configure dns configuration for /etc/resolv.conf
  47 # for the lo interface. You can do this in resolvconf as well by adding
  48 #nameserver 127.0.0.1
  49 # to resolv.conf.d/base
  50
  51 # Load our variables from resolvconf
  52 eval "$(resolvconf -v)"
  53
  54 PREFIX=@PREFIX@
  55 DNSMASQRESOLV="${PREFIX}/etc/dnsmasq-resolv.conf"
  56 DNSMASQCONF="${PREFIX}/etc/dnsmasq-resolvconf.conf"
  57 DNSMASQPID=/var/run/dnsmasq.pid
  58
  59 NEWCONF="# Generated by resolvconf\n"
  60 NEWRESOLV="${NEWCONF}"
  61
  62 # Using DBUS means that we never have to restart the daemon
  63 # This is important as it means we should not drop DNS queries
  64 # whilst changing DNS options around. However, DBUS support is optional
  65 # so we need to validate a few things first.
  66 # Check for DBus support in the binary
  67
  68 DBUS=no
  69 DBUSPID=/var/run/dbus/dbus.pid
  70 [ -s "${DBUSPID}" ] || DBUSPID=/var/run/dbus.pid
  71 [ -s "${DBUSPID}" ] || DBUSPID=/var/run/dbus/pid
  72 if [ -s "${DBUSPID}" -a -s ${DNSMASQPID} ]; then
  73         if dnsmasq --version 2>/dev/null | \
  74                 grep -q "^Compile time options.*[[:space:]]DBus[[:space:]]" \
  75                 ; then
  76                 # Sanity - check that dnsmasq and dbus are running
  77                 if kill -0 $(cat "${DBUSPID}") 2>/dev/null \
  78                         && kill -0 $(cat ${DNSMASQPID}) 2>/dev/null; then
  79                         DBUS=yes
  80                         NEWCONF="${NEWCONF}\n# Domain specific servers will be sent over dbus\nenable-dbus\n"
  81                 fi
  82         fi
  83 fi
  84
  85 for N in ${NAMESERVERS}; do
  86         case "\n${NEWRESOLV}\n" in
  87                 *"\nnameserver ${N}\n");;
  88                 *) NEWRESOLV="${NEWRESOLV}nameserver ${N}\n";;
  89         esac
  90 done
  91
  92 DBUSDEST=
  93 for D in ${DOMAINS}; do
  94         DN="${D%%:*}"
  95         NS="${D#*:}"
  96         while [ -n "${NS}" ]; do
  97                 if [ "${DBUS}" = "yes" ]; then
  98                         SIFS=${IFS-y} OIFS=$IFS
  99                         IFS=.
 100                         set -- ${NS%%,*}
 101                         NUM="0x$(printf "%02x" $1 $2 $3 $4)"
 102                         if [ "${SIFS}" = "y" ]; then
 103                                 unset IFS
 104                         else
 105                                 IFS=$OIFS
 106                         fi
 107                         DBUSDEST="${DBUSDEST} uint32:$(printf "%u" ${NUM}) string:${DN}"
 108                 else
 109                         NEWCONF="${NEWCONF}server=/${DN}/${NS%%,*}\n"
 110                 fi
 111                 [ "${NS}" = "${NS#*,}" ] && break
 112                 NS="${NS#*,}"
 113         done
 114 done
 115
 116 RELOAD="no"
 117 if [ -e "${DNSMASQCONF}" ]; then
 118         if [ "$(cat "${DNSMASQCONF}")" != "$(printf "${NEWCONF}")" ]; then
 119                 RELOAD="yes"
 120                 printf "${NEWCONF}" > "${DNSMASQCONF}"
 121         fi
 122 else
 123         RELOAD="yes"
 124         printf "${NEWCONF}" > "${DNSMASQCONF}"
 125 fi
 126 if [ -e "${DNSMASQRESOLV}" ]; then
 127         if [ "$(cat "${DNSMASQRESOLV}")" != "$(printf "${NEWRESOLV}")" ]; then
 128                 RELOAD="yes"
 129                 printf "${NEWRESOLV}" > "${DNSMASQRESOLV}"
 130         fi
 131 else
 132         # dnsmasq polls this file so no need to set RELOAD="yes"
 133         printf "${NEWRESOLV}" > "${DNSMASQRESOLV}"
 134 fi
 135
 136 [ "${RELOAD}" = "yes" ] && resolvconf -s dnsmasq restart
 137 if [ "${DBUS}" = "yes" ]; then
 138         [ "${RELOAD}" != "yes" ] && kill -HUP $(cat ${DNSMASQPID})
 139         # Send even if empty so old servers are cleared
 140         dbus-send --system --dest=uk.org.thekelleys.dnsmasq \
 141                 /uk/org/thekelleys/dnsmasq uk.org.thekelleys.SetServers \
 142                 ${DBUSDEST}
 143 fi