functions.dns

   1 #!/bin/bash
   2 ###############################################################################
   3 #                                                                             #
   4 # IPFire.org - A linux based firewall                                         #
   5 # Copyright (C) 2012  IPFire Network Development Team                         #
   6 #                                                                             #
   7 # This program is free software: you can redistribute it and/or modify        #
   8 # it under the terms of the GNU General Public License as published by        #
   9 # the Free Software Foundation, either version 3 of the License, or           #
  10 # (at your option) any later version.                                         #
  11 #                                                                             #
  12 # This program is distributed in the hope that it will be useful,             #
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of              #
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
  15 # GNU General Public License for more details.                                #
  16 #                                                                             #
  17 # You should have received a copy of the GNU General Public License           #
  18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
  19 #                                                                             #
  20 ###############################################################################
  21
  22 # Set this to true if localhost should be added as the first DNS server.
  23 DNS_USE_LOCAL_RESOLVER=true
  24 NETWORK_CONFIG_FILE_PARAMS="${NETWORK_CONFIG_FILE_PARAMS} DNS_USE_LOCAL_RESOLVER"
  25
  26 # Set this option to true if the DNS servers should be queried in a random order.
  27 # This is useful to load balance between multiple servers.
  28 DNS_RANDOMIZE=false
  29 NETWORK_CONFIG_FILE_PARAMS="${NETWORK_CONFIG_FILE_PARAMS} DNS_RANDOMIZE"
  30
  31 # Set this option to true if the DNS servers should be advertised by
  32 # radvd.
  33 DNS_ADVERTISE_SERVERS="true"
  34
  35 DNS_SERVER_CONFIG_FILE="${NETWORK_CONFIG_DIR}/dns-servers"
  36
  37 # Path to the configuration file of the DNS resolver.
  38 RESOLV_CONF="/etc/resolv.conf"
  39
  40 function dns_get_hostname() {
  41         local address=${1}
  42         assert isset address
  43
  44         (
  45                 unset HOSTNAME
  46                 eval $(ipcalc -h ${address} 2>/dev/null)
  47                 echo "${HOSTNAME}"
  48         )
  49 }
  50
  51 function __dns_server_println() {
  52         local server=${1}
  53         local priority=${2}
  54
  55         print "%-20s %s" "${server}" "${priority}"
  56 }
  57
  58 function __dns_server_sort() {
  59         sort -k2 -g | uniq
  60 }
  61
  62 function dns_server_list() {
  63         [ -r "${DNS_SERVER_CONFIG_FILE}" ] || return ${EXIT_OK}
  64
  65         local server priority
  66         while read server priority; do
  67                 if [ -n "${server}" ] && [ -n "${priority}" ]; then
  68                         __dns_server_println "${server}" "${priority}"
  69                 fi
  70         done < ${DNS_SERVER_CONFIG_FILE} | __dns_server_sort
  71 }
  72
  73 function dns_server_list_no_priority() {
  74         local server priority
  75         dns_server_list | while read server priority; do
  76                 echo "${server}"
  77         done
  78 }
  79
  80 function dns_server_add() {
  81         local server=${1}
  82         assert isset server
  83
  84         local priority=${2}
  85         if ! isset priority; then
  86                 priority=20
  87         fi
  88         assert isinteger priority
  89
  90         (
  91                 dns_server_list
  92                 __dns_server_println "${server}" "${priority}"
  93         ) | __dns_server_sort > ${DNS_SERVER_CONFIG_FILE}.new
  94
  95         mv ${DNS_SERVER_CONFIG_FILE}{.new,}
  96 }
  97
  98 function dns_server_remove() {
  99         local server=${1}
 100         assert isset server
 101
 102         local entry priority
 103         local entries=$(dns_server_list)
 104
 105         while read entry priority; do
 106                 [ "${entry}" = "${server}" ] && continue
 107                 __dns_server_println "${server}" "${priority}"
 108         done <<< ${entries} | __dns_server_sort > ${DNS_SERVER_CONFIG_FILE}
 109 }
 110
 111 function dns_server_flush() {
 112         : > ${DNS_SERVER_CONFIG_FILE}
 113 }
 114
 115 # Update resolv.conf(5) when initializing the network.
 116 init_register dns_generate_resolvconf
 117
 118 function dns_generate_resolvconf() {
 119         local file=${RESOLV_CONF}
 120
 121         log INFO "Updating resolver configuration..."
 122
 123         config_header "resolver configutation file" > ${file}
 124
 125         if enabled DNS_RANDOMIZE; then
 126                 print "option rotate\n" >> ${file}
 127         fi
 128
 129         # XXX Add search domain.
 130         local proto
 131         local zone
 132         local domainname
 133         for zone in $(zones_get_all); do
 134                 for proto in ${IP_SUPPORTED_PROTOCOLS}; do
 135                         domainname=$(routing_db_get ${zone} ${proto} domain-name)
 136                         if [ -n "${domainname}" ]; then
 137                                 print "search ${domainname}"
 138                         fi
 139                 done
 140         done >> ${file}
 141
 142         # Add the local resolver as the first DNS server if enabled.
 143         if enabled DNS_USE_LOCAL_RESOLVER; then
 144                 print "nameserver ::1" >> ${file}
 145         fi
 146
 147         # First pull in zone name servers.
 148         local server
 149         for server in $(dns_get_zone_name_servers); do
 150                 print "nameserver ${server}"
 151         done >> ${file}
 152
 153         # Dump all DNS servers (if any).
 154         local priority
 155         dns_server_list | while read server priority; do
 156                 print "nameserver ${server}"
 157         done >> ${file}
 158 }
 159
 160 function dns_get_zone_name_servers() {
 161         local servers
 162         local zone
 163         for zone in $(zones_get_all); do
 164                 local proto
 165                 for proto in ${IP_SUPPORTED_PROTOCOLS}; do
 166                         servers=$(routing_db_get ${zone} ${proto} domain-name-servers)
 167
 168                         local server
 169                         for server in ${servers}; do
 170                                 print "${server}"
 171                         done
 172                 done
 173         done
 174 }