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

   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 # Written by Roy Marples (roy@marples.name)
   7 # Based on Debian resolvconf by Thomas Hood
   8
   9 argv0="$0"
  10
  11 PREFIX=
  12 RESOLVCONF="${PREFIX}"/etc/resolvconf
  13 UPDATED="${RESOLVCONF}"/update.d
  14 VARDIR="${RESOLVCONF}"/run
  15 IFACEDIR="${VARDIR}/interfaces"
  16
  17 error_exit() {
  18         echo "$*" >&2
  19         exit 1
  20 }
  21
  22 usage() {
  23         cat <<-EOF
  24         Usage: ${argv0##*/} [options]
  25
  26         Inform the system about any DNS updates.
  27
  28         Options:
  29           -a \$INTERFACE    Add DNS information to the specified interface
  30                            (DNS supplied via stdin in resolv.conf format)
  31           -d \$INTERFACE    Delete DNS information from the specified interface
  32           -u               Run updates from our current DNS information
  33           -l [\$PATTERN]    Show DNS information, optionally from interfaces
  34                            that match the specified pattern
  35           -i [\$PATTERN]    Show interfaces that have supplied DNS information
  36                    optionally from interfaces that match the specified
  37                    pattern
  38           -v [\$PATTERN]    echo NEWDOMAIN, NEWSEARCH and NEWNS variables to
  39                            the console
  40           -h               Show this help cruft
  41         EOF
  42         [ -z "$@" ] && exit 0
  43         echo
  44         error_exit "$*"
  45 }
  46
  47 echo_resolv() {
  48         [ -n "$1" -a -e "${IFACEDIR}/$1" ] || return 1
  49         echo "# resolv.conf for interface $1"
  50         grep "." "${IFACEDIR}/$1"
  51         echo
  52 }
  53
  54 uniqify() {
  55     local result=
  56     while [ -n "$1" ]; do
  57                 case " ${result} " in
  58                         *" $1 "*) ;;
  59                         *) result="${result} $1" ;;
  60                 esac
  61                 shift
  62         done
  63     echo "${result# *}"
  64 }
  65
  66 if [ -n "$1" ]; then
  67         CMD="$1"
  68         shift
  69 fi
  70 if [ -n "$1" ]; then
  71         IFACE="$1"
  72         shift
  73 fi
  74
  75 # -l is a Gentoo option that lists our resolv files
  76 # optionally for a specific interface
  77 if [ "x${CMD}" = "x-l" -o "x${CMD}" = "x-i" ]; then
  78         [ -d "${IFACEDIR}" ] || exit 0
  79
  80         # If we have an interface ordering list, then use that.
  81         # It works by just using pathname expansion in the interface directory.
  82         if [ -n "${IFACE}" ]; then
  83                 LIST="${IFACE} $@"
  84         elif [ -r "${RESOLVCONF}"/interface-order ]; then
  85                 LIST="$(cat "${RESOLVCONF}"/interface-order)"
  86         fi
  87
  88         # If we don't have a list then prefer lo, tunnels, ppp
  89         # and then anything else.
  90         if [ -z "${LIST}" ]; then
  91                 LIST="lo lo[0-9]* tap[0-9]* tun[0-9]* vpn vpn[0-9]* ppp[0-9]* ippp[0-9]* *"
  92         fi
  93
  94         cd "${IFACEDIR}"
  95         for IFACE in $(uniqify ${LIST}); do
  96                 # Only list interfaces which we really have
  97                 [ -e "${IFACE}" ] || continue
  98
  99                 if [ "x${CMD}" = "x-i" ]; then
 100                         printf "${IFACE} "
 101                 else
 102                         echo_resolv "${IFACE}"
 103                 fi
 104         done
 105         [ "x${CMD}" = "x-i" ] && echo
 106         exit 0
 107 fi
 108
 109 if [ "x${CMD}" = "x-v" ]; then
 110         NS=
 111         DOMAIN=
 112         SEARCH=
 113         NEWSEARCH=
 114         NEWNS=
 115         NEWDOMAIN=
 116         LINES="$("${argv0}" -l "${IFACE}" | sed -e "s/'/'\\\\''/g" -e "s/^/'/g" -e "s/$/'/g")"
 117         eval set -- ${LINES}
 118         for LINE in "$@"; do
 119                 case "${LINE}" in
 120                         "nameserver "*)
 121                                 case "${LINE#* }" in
 122                                         127.*) continue ;;
 123                                 esac
 124                                 NS="${NS}${LINE#* } "
 125                                 ;;
 126                         "domain "*)
 127                                 [ -z "${SEARCH}" ] && DOMAIN="${LINE#* }"
 128                                 ;;
 129                         "search "*)
 130                                 SEARCH="${LINE#* }"
 131                                 DOMAIN=
 132                                 ;;
 133                         *)
 134                                 if [ -z "${LINE}" ]; then
 135                                         for N in ${NS}; do
 136                                                 if [ -n "${DOMAIN}" ]; then
 137                                                         NEWDOMAIN="${NEWDOMAIN} ${DOMAIN},${N}"
 138                                                 elif [ -n "${SEARCH}" ]; then
 139                                                         for S in ${SEARCH}; do
 140                                                                 NEWSEARCH="${NEWSEARCH} ${S},${N}"
 141                                                         done
 142                                                 else
 143                                                         NEWNS="${NEWNS} ${N}"
 144                                                 fi
 145                                         done
 146                                         NS=
 147                                         DOMAIN=
 148                                         SEARCH=
 149                                 fi
 150                                 ;;
 151                 esac
 152         done
 153
 154         # Prefer DOMAIN nameservers over SEARCH nameservers
 155         # if we are supplied both.
 156         NEWDOMAIN="$(uniqify ${NEWDOMAIN})"
 157         NEWSEARCH="$(uniqify ${NEWSEARCH})"
 158         NEWNS="$(uniqify ${NEWNS})"
 159         for S in ${NEWSEARCH}; do
 160                 for DN in ${NEWDOMAIN}; do
 161                         if [ "${S%,*}" = "${DN%,*}" ]; then
 162                                 NEWSEARCH="$(echo "${NEWSEARCH}" | sed -e "s/${S}/${DN}/g")"
 163                                 NEWDOMAIN="$(echo "${NEWDOMAIN}" | sed -e "s/${DN}//g")"
 164                                 break
 165                         fi
 166                 done
 167         done
 168
 169         echo "NEWDOMAIN='${NEWDOMAIN}'"
 170         echo "NEWSEARCH='${NEWSEARCH}'"
 171         echo "NEWNS='${NEWNS}'"
 172         exit 0
 173 fi
 174
 175 # Test that we have valid options
 176 if [ "x${CMD}" = "x-a" -o "x${CMD}" = "x-d" ]; then
 177         if [ -z "${IFACE}" ]; then
 178                 usage "Interface not specified"
 179         fi
 180 elif [ "x${CMD}" != "x-u" ]; then
 181         [ -n "x${CMD}" -a "x${CMD}" != "x-h" ] && usage "Unknown option ${CMD}"
 182         usage
 183 fi
 184 if [ "x${CMD}" = "x-a" ]; then
 185         for x in '/' \\ ' ' '*'; do
 186                 case "${IFACE}" in
 187                         *[${x}]*) error_exit "${x} not allowed in interface name" ;;
 188                 esac
 189         done
 190         for x in '.' '-' '~'; do
 191                 case "${IFACE}" in
 192                         [${x}]*) error_exit "${x} not allowed at start of interface name" ;;
 193                 esac
 194         done
 195         [ "x${CMD}" = "x-a" -a -t 0 ] && error_exit "No file given via stdin"
 196         IFACERESOLV="${IFACEDIR}/${IFACE}"
 197 fi
 198
 199 # Ensure that libdir exists
 200 if [ ! -d "${IFACEDIR}" ]; then
 201         if [ ! -d "${VARDIR}" ]; then
 202                 if [ -L "${VARDIR}" ]; then
 203                         DIR="$(readlink "${VARDIR}")"
 204                         # Change to /etc as link maybe relative
 205                         cd "${VARDIR%/*}"
 206                         if ! mkdir -m 0755 -p "${DIR}"; then
 207                                 error_exit "Failed to create needed directory ${DIR}"
 208                         fi
 209                 else
 210                         if ! mkdir -m 0755 -p "${VARDIR}"; then
 211                                 error_exit "Failed to create needed directory ${VARDIR}"
 212                         fi
 213                 fi
 214         fi
 215         mkdir -m 0755 -p "${IFACEDIR}" || \
 216                 error_exit "Failed to create needed directory ${IFACEDIR}"
 217 else
 218         # Delete any existing information about the interface
 219         if [ "x${CMD}" = "x-a" -o "x${CMD}" = "x-d" ]; then
 220                 cd "${IFACEDIR}"
 221                 for iface in ${IFACE}; do
 222                         rm -f "${iface}"
 223                 done
 224         fi
 225 fi
 226
 227 if [ "x${CMD}" = "x-a" ]; then
 228         # Create our resolv.conf file
 229         cat >"${IFACEDIR}"/"${IFACE}"
 230 fi
 231
 232 for x in "${UPDATED}"/*; do
 233         [ -e "${x}" ] && "${x}" "${CMD}" "${IFACE}"
 234 done
 235
 236 # vim: set ts=4 :