#!/bin/sh # Copyright (c) 2007-2016 Roy Marples # All rights reserved # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions # are met: # * Redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer. # * Redistributions in binary form must reproduce the above # copyright notice, this list of conditions and the following # disclaimer in the documentation and/or other materials provided # with the distribution. # # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. RESOLVCONF="$0" SYSCONFDIR=@SYSCONFDIR@ LIBEXECDIR=@LIBEXECDIR@ VARDIR=@VARDIR@ # Disregard dhcpcd setting unset interface_order state_dir # If you change this, change the test in VFLAG and libc.in as well local_nameservers="127.* 0.0.0.0 255.255.255.255 ::1" dynamic_order="tap[0-9]* tun[0-9]* vpn vpn[0-9]* ppp[0-9]* ippp[0-9]*" interface_order="lo lo[0-9]*" name_server_blacklist="0.0.0.0" # Support original resolvconf configuration layout # as well as the openresolv config file if [ -f "$SYSCONFDIR"/resolvconf.conf ]; then . "$SYSCONFDIR"/resolvconf.conf [ -n "$state_dir" ] && VARDIR="$state_dir" elif [ -d "$SYSCONFDIR/resolvconf" ]; then SYSCONFDIR="$SYSCONFDIR/resolvconf" if [ -f "$SYSCONFDIR"/interface-order ]; then interface_order="$(cat "$SYSCONFDIR"/interface-order)" fi fi IFACEDIR="$VARDIR/interfaces" METRICDIR="$VARDIR/metrics" PRIVATEDIR="$VARDIR/private" EXCLUSIVEDIR="$VARDIR/exclusive" LOCKDIR="$VARDIR/lock" _PWD="$PWD" warn() { echo "$*" >&2 } error_exit() { echo "$*" >&2 exit 1 } usage() { cat <<-EOF Usage: ${RESOLVCONF##*/} [options] Inform the system about any DNS updates. Options: -a \$INTERFACE Add DNS information to the specified interface (DNS supplied via stdin in resolv.conf format) -m metric Give the added DNS information a metric -p Mark the interface as private -x Mark the interface as exclusive -d \$INTERFACE Delete DNS information from the specified interface -f Ignore non existant interfaces -I Init the state dir -u Run updates from our current DNS information -l [\$PATTERN] Show DNS information, optionally from interfaces that match the specified pattern -i [\$PATTERN] Show interfaces that have supplied DNS information optionally from interfaces that match the specified pattern -v [\$PATTERN] echo NEWDOMAIN, NEWSEARCH and NEWNS variables to the console -h Show this help cruft EOF [ -z "$1" ] && exit 0 echo error_exit "$*" } echo_resolv() { local line= OIFS="$IFS" [ -n "$1" -a -f "$IFACEDIR/$1" ] || return 1 echo "# resolv.conf from $1" # Our variable maker works of the fact each resolv.conf per interface # is separated by blank lines. # So we remove them when echoing them. while read -r line; do IFS="$OIFS" if [ -n "$line" ]; then # We need to set IFS here to preserve any whitespace IFS='' printf "%s\n" "$line" fi done < "$IFACEDIR/$1" echo IFS="$OIFS" } # Strip any trailing dot from each name as a FQDN does not belong # in resolv.conf(5) # If you think otherwise, capture a DNS trace and you'll see libc # will strip it regardless. # This also solves setting up duplicate zones in our subscribers. strip_trailing_dots() { local n= d= for n; do printf "$d%s" "${n%.}" d=" " done printf "\n" } # Parse resolv.conf's and make variables # for domain name servers, search name servers and global nameservers parse_resolv() { local line= ns= ds= search= d= n= newns= local new=true iface= private=false p= domain= l= islocal= newns= while read -r line; do case "$line" in "# resolv.conf from "*) if ${new}; then iface="${line#\# resolv.conf from *}" new=false if [ -e "$PRIVATEDIR/$iface" ]; then private=true else # Allow expansion cd "$IFACEDIR" private=false for p in $private_interfaces; do case "$iface" in "$p"|"$p":*) private=true; break;; esac done fi fi ;; "nameserver "*) islocal=false for l in $local_nameservers; do case "${line#* }" in $l) islocal=true echo "LOCALNAMESERVERS=\"\$LOCALNAMESERVERS ${line#* }\"" break ;; esac done $islocal || ns="$ns${line#* } " ;; "domain "*) search="$(strip_trailing_dots ${line#* })" if [ -z "$domain" ]; then domain="$search" echo "DOMAIN=\"$domain\"" fi ;; "search "*) search="$(strip_trailing_dots ${line#* })" ;; *) [ -n "$line" ] && continue if [ -n "$ns" -a -n "$search" ]; then newns= for n in $ns; do newns="$newns${newns:+,}$n" done ds= for d in $search; do ds="$ds${ds:+ }$d:$newns" done echo "DOMAINS=\"\$DOMAINS $ds\"" fi echo "SEARCH=\"\$SEARCH $search\"" if ! $private; then echo "NAMESERVERS=\"\$NAMESERVERS $ns\"" fi ns= search= new=true ;; esac done } uniqify() { local result= while [ -n "$1" ]; do case " $result " in *" $1 "*);; *) result="$result $1";; esac shift done echo "${result# *}" } dirname() { local dir= OIFS="$IFS" local IFS=/ set -- $@ IFS="$OIFS" if [ -n "$1" ]; then printf %s . else shift fi while [ -n "$2" ]; do printf "/%s" "$1" shift done printf "\n" } config_mkdirs() { local e=0 f d for f; do [ -n "$f" ] || continue d="$(dirname "$f")" if [ ! -d "$d" ]; then if type install >/dev/null 2>&1; then install -d "$d" || e=$? else mkdir "$d" || e=$? fi fi done return $e } list_resolv() { [ -d "$IFACEDIR" ] || return 0 local report=false list= retval=0 cmd="$1" excl= shift case "$IF_EXCLUSIVE" in [Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1) if [ -d "$EXCLUSIVEDIR" ]; then cd "$EXCLUSIVEDIR" for i in *; do if [ -f "$i" ]; then list="${i#* }" break fi done fi excl=true ;; *) excl=false ;; esac # If we have an interface ordering list, then use that. # It works by just using pathname expansion in the interface directory. if [ -n "$1" ]; then list="$*" $force || report=true elif ! $excl; then cd "$IFACEDIR" for i in $interface_order; do [ -f "$i" ] && list="$list $i" for ii in "$i":* "$i".*; do [ -f "$ii" ] && list="$list $ii" done done for i in $dynamic_order; do if [ -e "$i" -a ! -e "$METRICDIR/"*" $i" ]; then list="$list $i" fi for ii in "$i":* "$i".*; do if [ -f "$ii" -a ! -e "$METRICDIR/"*" $ii" ]; then list="$list $ii" fi done done if [ -d "$METRICDIR" ]; then cd "$METRICDIR" for i in *; do [ -f "$i" ] && list="$list ${i#* }" done fi list="$list *" fi cd "$IFACEDIR" retval=1 for i in $(uniqify $list); do # Only list interfaces which we really have if ! [ -f "$i" ]; then if $report; then echo "No resolv.conf for interface $i" >&2 retval=2 fi continue fi if [ "$cmd" = i -o "$cmd" = "-i" ]; then printf %s "$i " else echo_resolv "$i" fi [ $? = 0 -a "$retval" = 1 ] && retval=0 done [ "$cmd" = i -o "$cmd" = "-i" ] && echo return $retval } list_remove() { local list= e= l= result= found= retval=0 [ -z "$2" ] && return 0 eval list=\"\$$1\" shift set -f for e; do found=false for l in $list; do case "$e" in $l) found=true;; esac $found && break done if $found; then retval=$(($retval + 1)) else result="$result $e" fi done set +f echo "${result# *}" return $retval } echo_prepend() { echo "# Generated by resolvconf" if [ -n "$search_domains" ]; then echo "search $search_domains" fi for n in $name_servers; do echo "nameserver $n" done echo } echo_append() { echo "# Generated by resolvconf" if [ -n "$search_domains_append" ]; then echo "search $search_domains_append" fi for n in $name_servers_append; do echo "nameserver $n" done echo } replace() { local r= k= f= v= val= sub= while read -r keyword value; do for r in $replace; do k="${r%%/*}" r="${r#*/}" f="${r%%/*}" r="${r#*/}" v="${r%%/*}" case "$keyword" in $k) case "$value" in $f) value="$v";; esac ;; esac done val= for sub in $value; do for r in $replace_sub; do k="${r%%/*}" r="${r#*/}" f="${r%%/*}" r="${r#*/}" v="${r%%/*}" case "$keyword" in $k) case "$sub" in $f) sub="$v";; esac ;; esac done val="$val${val:+ }$sub" done printf "%s %s\n" "$keyword" "$val" done } make_vars() { local newdomains= d= dn= newns= ns= # Clear variables DOMAIN= DOMAINS= SEARCH= NAMESERVERS= LOCALNAMESERVERS= if [ -n "$name_servers" -o -n "$search_domains" ]; then eval "$(echo_prepend | parse_resolv)" fi if [ -z "$VFLAG" ]; then IF_EXCLUSIVE=1 list_resolv -i "$@" >/dev/null || IF_EXCLUSIVE=0 eval "$(list_resolv -l "$@" | replace | parse_resolv)" fi if [ -n "$name_servers_append" -o -n "$search_domains_append" ]; then eval "$(echo_append | parse_resolv)" fi # Ensure that we only list each domain once for d in $DOMAINS; do dn="${d%%:*}" list_remove domain_blacklist "$dn" >/dev/null || continue case " $newdomains" in *" ${dn}:"*) continue;; esac newns= for nd in $DOMAINS; do if [ "$dn" = "${nd%%:*}" ]; then ns="${nd#*:}" while [ -n "$ns" ]; do case ",$newns," in *,${ns%%,*},*) ;; *) list_remove name_server_blacklist \ "${ns%%,*}" >/dev/null \ && newns="$newns${newns:+,}${ns%%,*}";; esac [ "$ns" = "${ns#*,}" ] && break ns="${ns#*,}" done fi done if [ -n "$newns" ]; then newdomains="$newdomains${newdomains:+ }$dn:$newns" fi done DOMAIN="$(list_remove domain_blacklist $DOMAIN)" SEARCH="$(uniqify $SEARCH)" SEARCH="$(list_remove domain_blacklist $SEARCH)" NAMESERVERS="$(uniqify $NAMESERVERS)" NAMESERVERS="$(list_remove name_server_blacklist $NAMESERVERS)" LOCALNAMESERVERS="$(uniqify $LOCALNAMESERVERS)" LOCALNAMESERVERS="$(list_remove name_server_blacklist $LOCALNAMESERVERS)" echo "DOMAIN='$DOMAIN'" echo "SEARCH='$SEARCH'" echo "NAMESERVERS='$NAMESERVERS'" echo "LOCALNAMESERVERS='$LOCALNAMESERVERS'" echo "DOMAINS='$newdomains'" } force=false VFLAG= while getopts a:Dd:fhIilm:puvVx OPT; do case "$OPT" in f) force=true;; h) usage;; m) IF_METRIC="$OPTARG";; p) IF_PRIVATE=1;; V) VFLAG=1 if [ "$local_nameservers" = \ "127.* 0.0.0.0 255.255.255.255 ::1" ] then local_nameservers= fi ;; x) IF_EXCLUSIVE=1;; '?') ;; *) cmd="$OPT"; iface="$OPTARG";; esac done shift $(($OPTIND - 1)) args="$iface${iface:+ }$*" # -I inits the state dir if [ "$cmd" = I ]; then if [ -d "$VARDIR" ]; then rm -rf "$VARDIR"/* fi exit $? fi # -D ensures that the listed config file base dirs exist if [ "$cmd" = D ]; then config_mkdirs "$@" exit $? fi # -l lists our resolv files, optionally for a specific interface if [ "$cmd" = l -o "$cmd" = i ]; then list_resolv "$cmd" "$args" exit $? fi # Not normally needed, but subscribers should be able to run independently if [ "$cmd" = v -o -n "$VFLAG" ]; then make_vars "$iface" exit $? fi # Test that we have valid options if [ "$cmd" = a -o "$cmd" = d ]; then if [ -z "$iface" ]; then usage "Interface not specified" fi elif [ "$cmd" != u ]; then [ -n "$cmd" -a "$cmd" != h ] && usage "Unknown option $cmd" usage fi if [ "$cmd" = a ]; then for x in '/' \\ ' ' '*'; do case "$iface" in *[$x]*) error_exit "$x not allowed in interface name";; esac done for x in '.' '-' '~'; do case "$iface" in [$x]*) error_exit \ "$x not allowed at start of interface name";; esac done [ "$cmd" = a -a -t 0 ] && error_exit "No file given via stdin" fi if [ ! -d "$VARDIR" ]; then if [ -L "$VARDIR" ]; then dir="$(readlink "$VARDIR")" # link maybe relative cd "${VARDIR%/*}" if ! mkdir -m 0755 -p "$dir"; then error_exit "Failed to create needed" \ "directory $dir" fi else if ! mkdir -m 0755 -p "$VARDIR"; then error_exit "Failed to create needed" \ "directory $VARDIR" fi fi fi if [ ! -d "$IFACEDIR" ]; then mkdir -m 0755 -p "$IFACEDIR" || \ error_exit "Failed to create needed directory $IFACEDIR" if [ "$cmd" = d ]; then # Provide the same error messages as below if ! ${force}; then cd "$IFACEDIR" for i in $args; do warn "No resolv.conf for interface $i" done fi ${force} exit $? fi fi # An interface was added, changed, deleted or a general update was called. # Due to exclusivity we need to ensure that this is an atomic operation. # Our subscribers *may* need this as well if the init system is sub par. # As such we spinlock at this point as best we can. # We don't use flock(1) because it's not widely available and normally resides # in /usr which we do our very best to operate without. [ -w "$VARDIR" ] || error_exit "Cannot write to $LOCKDIR" : ${lock_timeout:=10} while true; do if mkdir "$LOCKDIR" 2>/dev/null; then trap 'rm -rf "$LOCKDIR";' EXIT trap 'rm -rf "$LOCKDIR"; exit 1' INT QUIT ABRT SEGV ALRM TERM echo $$ >"$LOCKDIR/pid" break fi pid=$(cat "$LOCKDIR/pid") if ! kill -0 "$pid"; then warn "clearing stale lock pid $pid" rm -rf "$LOCKDIR" continue fi lock_timeout=$(($lock_timeout - 1)) if [ "$lock_timeout" -le 0 ]; then error_exit "timed out waiting for lock from pid $pid" fi sleep 1 done case "$cmd" in a) # Read resolv.conf from stdin resolv="$(cat)" changed=false changedfile=false # If what we are given matches what we have, then do nothing if [ -e "$IFACEDIR/$iface" ]; then if [ "$(echo "$resolv")" != \ "$(cat "$IFACEDIR/$iface")" ] then changed=true changedfile=true fi else changed=true changedfile=true fi # Set metric and private before creating the interface resolv.conf file # to ensure that it will have the correct flags [ ! -d "$METRICDIR" ] && mkdir "$METRICDIR" oldmetric="$METRICDIR/"*" $iface" newmetric= if [ -n "$IF_METRIC" ]; then # Pad metric to 6 characters, so 5 is less than 10 while [ ${#IF_METRIC} -le 6 ]; do IF_METRIC="0$IF_METRIC" done newmetric="$METRICDIR/$IF_METRIC $iface" fi rm -f "$METRICDIR/"*" $iface" [ "$oldmetric" != "$newmetric" -a \ "$oldmetric" != "$METRICDIR/* $iface" ] && changed=true [ -n "$newmetric" ] && echo " " >"$newmetric" case "$IF_PRIVATE" in [Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1) if [ ! -d "$PRIVATEDIR" ]; then [ -e "$PRIVATEDIR" ] && rm "$PRIVATEDIR" mkdir "$PRIVATEDIR" fi [ -e "$PRIVATEDIR/$iface" ] || changed=true [ -d "$PRIVATEDIR" ] && echo " " >"$PRIVATEDIR/$iface" ;; *) if [ -e "$PRIVATEDIR/$iface" ]; then rm -f "$PRIVATEDIR/$iface" changed=true fi ;; esac oldexcl= for x in "$EXCLUSIVEDIR/"*" $iface"; do if [ -f "$x" ]; then oldexcl="$x" break fi done case "$IF_EXCLUSIVE" in [Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1) if [ ! -d "$EXCLUSIVEDIR" ]; then [ -e "$EXCLUSIVEDIR" ] && rm "$EXCLUSIVEDIR" mkdir "$EXCLUSIVEDIR" fi cd "$EXCLUSIVEDIR" for x in *; do [ -f "$x" ] && break done if [ "${x#* }" != "$iface" ]; then if [ "$x" = "${x% *}" ]; then x=10000000 else x="${x% *}" fi if [ "$x" = "0000000" ]; then warn "exclusive underflow" else x=$(($x - 1)) fi if [ -d "$EXCLUSIVEDIR" ]; then echo " " >"$EXCLUSIVEDIR/$x $iface" fi changed=true fi ;; *) if [ -f "$oldexcl" ]; then rm -f "$oldexcl" changed=true fi ;; esac if $changedfile; then printf "%s\n" "$resolv" >"$IFACEDIR/$iface" || exit $? elif ! $changed; then exit 0 fi unset changed changedfile oldmetric newmetric x oldexcl ;; d) # Delete any existing information about the interface cd "$IFACEDIR" changed=false for i in $args; do if [ -e "$i" ]; then changed=true elif ! ${force}; then warn "No resolv.conf for interface $i" fi rm -f "$i" "$METRICDIR/"*" $i" \ "$PRIVATEDIR/$i" \ "$EXCLUSIVEDIR/"*" $i" || exit $? done if ! ${changed}; then # Set the return code based on the forced flag ${force} exit $? fi unset changed i ;; esac case "${resolvconf:-YES}" in [Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1) ;; *) exit 0;; esac eval "$(make_vars)" export RESOLVCONF DOMAINS SEARCH NAMESERVERS LOCALNAMESERVERS : ${list_resolv:=list_resolv -l} retval=0 # Run scripts in the same directory resolvconf is run from # in case any scripts accidently dump files in the wrong place. cd "$_PWD" for script in "$LIBEXECDIR"/*; do if [ -f "$script" ]; then eval script_enabled="\$${script##*/}" case "${script_enabled:-YES}" in [Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1) ;; *) continue;; esac if [ -x "$script" ]; then "$script" "$cmd" "$iface" else (set -- "$cmd" "$iface"; . "$script") fi retval=$(($retval + $?)) fi done exit $retval