Differential D56269 Diff 176755 resolvectl.in

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resolvectl.in

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				#!/bin/sh
				# Copyright (c) 2025 Roy Marples
				# All rights reserved

				# resolvectl subscriber for resolvconf

				# 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.

				[ -f "@SYSCONFDIR@"/resolvconf.conf ] \|\| exit 0
				. "@SYSCONFDIR@/resolvconf.conf" \|\| exit 1

				case "${resolvectl:-NO}" in
				[Yy][Ee][Ss]\|[Tt][Rr][Uu][Ee]\|[Oo][Nn]\|1) ;;
				*) exit 0;;
				esac

				# If we don't have resolvectl or systemd-resolved isn't running then
				# we can't do much.
				# We can't persist our data in /run/systemd/resolve/netif/$ifindex
				# because systemd-resolved keeps it somehow, ie we can't change it
				# once we have inserted it
				if ! [ -d /sys/class/net ] \|\| \
				! type resolvectl >/dev/null 2>&1 \|\| \
				! pidof systemd-resolved >/dev/null
				then
				exit 1
				fi

				# resolvectl only accepts resolv.conf setup per physical interface
				# although resolvconf has always hinted that the named configuration
				# should be $interface.$protocol, this has never been a fixed requirement.
				# Because resolvectl only accepts one configuration per interface we need
				# to try and merge the resolv.conf's together.
				# Luckily resolvconf makes this easy for us.

				# Returns a list of resolvconf entries for a real interface
				get_resolvconf_interfaces() {
				IFACE="$1"
				[ -d /sys/class/net/"$IFACE" ] \|\| return 1

				IFACES=
				for IFACE_PROTO in $(@SBINDIR@/resolvconf -Li "$IFACE" "$IFACE.*" 2>/dev/null); do
				# ens5 will work with ens5.dhcp and ens5.ra,
				# but not ens5.5 or ens5.5.dhcp
				if [ "$IFACE_PROTO" != "$IFACE" ]; then
				# Ensure that ens5.5.dhcp doesn't work for ens5
				if [ "${IFACE_PROTO%.*}" != "$IFACE" ]; then
				continue
				fi
				# Ensure that ens5.dhcp isn't a real interface
				# as ens5.5 likely is and the .5 matches the .dhcp
				if [ -d /sys/class/net/"$IFACE_PROTO" ]; then
				continue
				fi
				fi
				IFACES="$IFACES${IFACES:+ }$IFACE_PROTO"
				done
				echo "$IFACES"
				}

				# For the given interface, apply a list of resolvconf entries
				apply_resolvconf() {
				IFACE="$1"
				shift

				if [ -z "$1" ]; then
				resolvectl revert "$IFACE"
				return
				fi

				# Set the default-route property first to avoid leakage.
				# If any entry is private, the whole interface has to be private.
				# If a more granular approach is needed, consider using the
				# systemd-resolved subscriber instead which supports DNS delegates.
				if [ -n "$(@SBINDIR@/resolvconf -p $@)" ]; then
				resolvectl default-route "$IFACE" false
				else
				resolvectl default-route "$IFACE" true
				fi

				# Now set domain and dns
				DOMAIN=$(@SBINDIR@/resolvconf -L $@ 2>/dev/null \| sed -n -e "s/domain //p" -e "s/search //p")
				NS=$(@SBINDIR@/resolvconf -L $@ 2>/dev/null \| sed -n -e "s/nameserver //p")
				if [ -n "$DOMAIN" ]; then
				# If any entry is marked as not searchable, we mark all the
				# domains as non searchable.
				# If a more granular approach is needed, consider using the
				# systemd-resolved subscriber instead which supports DNS delegates.
				if [ -n "$(@SBINDIR@/resolvconf -pp $@)" ]; then
				ND=
				for d in $DOMAIN; do
				ND="$ND${ND:+ }~$d"
				done
				DOMAIN="$ND"
				fi
				resolvectl domain "$IFACE" $DOMAIN
				else
				resolvectl domain "$IFACE" ""
				fi
				if [ -n "$NS" ]; then
				resolvectl dns "$IFACE" $NS
				else
				resolvectl dns "$IFACE" ""
				fi
				}

				# To get the full features of resolvconf, we need to work out each interface
				# for every resolvconf addition and deletion
				# This is because resolvconf.conf might have changed OR an exclusive
				# interface deleted which makes other interfaces visible.
				cd /sys/class/net
				for IFACE in *; do
				if [ "$IFACE" = lo ]; then
				# systemd-resolved doesn't work with lo
				continue
				fi

				IFACES=$(get_resolvconf_interfaces "$IFACE")
				apply_resolvconf "$IFACE" $IFACES
				done

				# warn about resolv.conf with no matching interface
				FAILED=
				for IFACE_PROTO in $(@SBINDIR@/resolvconf -Li); do
				IFACE="${IFACE_PROTO%.*}"
				if [ "$IFACE" = lo ]; then
				# Don't warn about loopback interface as that is typically
				# used to configure libc for a nameserver on it and the libc
				# subscriber will process that just fine.
				continue
				fi

				if ! [ -d "/sys/class/net/$IFACE" ]; then
				FAILED="$FAILED${FAILED:+ }$IFACE_PROTO"
				fi
				done
				if [ -n "$FAILED" ]; then
				echo "Could not apply resolv.conf to resolvectl: $FAILED" >&2
				fi