File nss-mdns-config of Package nss-mdns
#!/bin/sh
# vim: set ts=2 sw=2 et:
#
# Copyright (C) 2025 SUSE LLC
# 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.
# * Neither the name of the <ORGANIZATION> nor the names of its contributors
# may be used to endorse or promote products derived from this software
# without specific prior written permission.
#
# 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.
#
#
# (Licensed under the simplified BSD license)
#
# Authors: Vincent Untz <vuntz@opensuse.org>
# Stefan Schubert <schubi@suse.com>
#
ETC_NSSWITCH=/etc/nsswitch.conf
usage() {
echo "nss-mdns-config [--enable|--disable] [-4|-6] [--no-backup]"
}
ENABLE=0
DISABLE=0
IPv4=0
IPv6=0
IPvALL=0
BACKUP=1
while test $# -gt 0; do
case "$1" in
--enable) ENABLE=1; shift;;
--disable) DISABLE=1; shift;;
-4) IPv4=1; shift;;
-6) IPv6=1; shift;;
--no-backup) BACKUP=0; shift;;
*) usage; exit 1;;
esac
done
if test "$ENABLE" -eq 1 -a "$DISABLE" -eq 1; then
usage
exit 1
fi
if test "$IPv4" -eq 1 -a "$IPv6" -eq 1; then
# Supporting -4 and -6 at the same time would make --enable more complex,
# since we'd like it to add both mdns4_minimal and mdns6_minimal. So just
# don't do it for now.
usage
exit 1
fi
if test "$IPv4" -ne 1 -a "$IPv6" -ne 1; then
IPv4=1
IPv6=1
IPvALL=1
fi
NSSWITCH_CONFIG_EXE="/bin/nsswitch-config"
NSS_MDNS_ETC_FILE="/etc/nsswitch.conf.d/25-nss-mdns.conf"
NSS_MDNS_ETC_FILE_IPV4="/etc/nsswitch.conf.d/25-nss-mdns-ipv4.conf"
NSS_MDNS_ETC_FILE_IPV6="/etc/nsswitch.conf.d/25-nss-mdns-ipv6.conf"
$NSSWITCH_CONFIG_EXE --is_generated >/dev/null 2>&1
if [ "$?" -eq 0 ] ; then
if test "$ENABLE" -ne 1 -a "$DISABLE" -ne 1; then
# displaying status
if ! test -f $ETC_NSSWITCH; then
echo "No $ETC_NSSWITCH has been found for information"
fi
if test -f "$NSS_MDNS_ETC_FILE"; then
echo "Full support for nss-mdns is enabled."
elif test -f "$NSS_MDNS_ETC_FILE_IPV4"; then
echo "Support for nss-mdns is enabled for IPv4."
elif test -f "$NSS_MDNS_ETC_FILE_IPV6"; then
echo "Support for nss-mdns is enabled for IPv6."
else
echo "Support for nss-mdns is disabled."
fi
exit 0
elif test "$DISABLE" -eq 1; then
# disabling
rm /etc/nsswitch.conf.d/25-nss-mdns* >/dev/null 2>&1
elif test "$ENABLE" -eq 1; then
# enabling
mkdir -p /etc/nsswitch.conf.d
rm /etc/nsswitch.conf.d/25-nss-mdns* >/dev/null 2>&1
if test "$IPvALL" -eq 1; then
echo "# mdns_minimal has been generated by nss-mdns" >$NSS_MDNS_ETC_FILE
echo "hosts: mdns_minimal [NOTFOUND=return]" >>$NSS_MDNS_ETC_FILE
elif test "$IPv4" -eq 1; then
echo "# mdns4_minimal has been generated by nss-mdns" >$NSS_MDNS_ETC_FILE_IPV4
echo "hosts: mdns4_minimal [NOTFOUND=return]" >>$NSS_MDNS_ETC_FILE_IPV4
elif test "$IPv6" -eq 1; then
echo "# mdns6_minimal has been generated by nss-mdns" >$NSS_MDNS_ETC_FILE_IPV6
echo "hosts: mdns6_minimal [NOTFOUND=return]" >>$NSS_MDNS_ETC_FILE_IPV6
else
echo "Internal error when enabling."
exit 1
fi
fi
echo "Using $NSSWITCH_CONFIG_EXE for generating $ETC_NSSWITCH"
exit $($NSSWITCH_CONFIG_EXE)
fi
# Go on with this use case:
# Updating /etc/nsswitch.conf which has been created manually or
# by older releases.
# ...
# ..
# .
HOSTS=$(grep -m1 "^\s*hosts:" "$ETC_NSSWITCH")
if test $? -ne 0; then
echo "No hosts configuration in $ETC_NSSWITCH."
exit 0
fi
VALUE=$(echo $HOSTS | sed "s/^\s*hosts:\s*//g")
if test "$ENABLE" -ne 1 -a "$DISABLE" -ne 1; then
IPv4_ENABLED=0
IPv6_ENABLED=0
ENABLED=0
echo "Checking user changed $ETC_NSSWITCH."
for ITEM in $VALUE; do
if [ "$ITEM" = "mdns4_minimal" -o "$ITEM" = "mdns4" ]; then
IPv4_ENABLED=1
elif [ "$ITEM" = "mdns6_minimal" -o "$ITEM" = "mdns6" ]; then
IPv6_ENABLED=1
elif [ "$ITEM" = "mdns_minimal" -o "$ITEM" = "mdns" ]; then
ENABLED=1
fi
done
if test "$ENABLED" -eq 1; then
echo "Full support for nss-mdns is enabled."
elif test "$IPv4_ENABLED" -eq 1 -a "$IPv6_ENABLED" -eq 1; then
echo "Support for nss-mdns is enabled for IPv4 and IPv6."
elif test "$IPv4_ENABLED" -eq 1; then
echo "Support for nss-mdns is enabled for IPv4."
elif test "$IPv6_ENABLED" -eq 1; then
echo "Support for nss-mdns is enabled for IPv6."
else
echo "Support for nss-mdns is disabled."
fi
elif test "$DISABLE" -eq 1; then
NEWVALUE=""
DROPACTION=0
for ITEM in $VALUE; do
if [ "$ITEM" = "mdns4_minimal" -o "$ITEM" = "mdns4" ] && [ "$IPv4" -eq 1 ]; then
DROPACTION=1
elif [ "$ITEM" = "mdns6_minimal" -o "$ITEM" = "mdns6" ] && [ "$IPv6" -eq 1 ]; then
DROPACTION=1
elif [ "$ITEM" = "mdns_minimal" -o "$ITEM" = "mdns" ]; then
if test "$IPvALL" -eq 1; then
DROPACTION=1
elif test "$IPv4" -eq 1; then
NEWVALUE="$NEWVALUE `echo $ITEM | sed 's:mdns:mdns6:'`"
DROPACTION=0
elif test "$IPv6" -eq 1; then
NEWVALUE="$NEWVALUE `echo $ITEM | sed 's:mdns:mdns4:'`"
DROPACTION=0
else
echo "Internal error when disabling $ITEM."
exit 1
fi
elif [ "${ITEM#[}" != "$ITEM" -a "$DROPACTION" -eq 1 ]; then
DROPACTION=0
else
NEWVALUE="$NEWVALUE $ITEM"
DROPACTION=0
fi
done
NEWVALUE=$(echo $NEWVALUE | sed "s/^\s*//;s/^\s*$//")
echo "Patching already existing $ETC_NSSWITCH."
sed -i "s/\(^\s*hosts:\s*\).*/\1$NEWVALUE/" "$ETC_NSSWITCH"
elif test "$ENABLE" -eq 1; then
NEWVALUE=""
FOUND=0
FOUND_DNS=0
DROPACTION=0
for ITEM in $VALUE; do
if [ "$ITEM" = "mdns_minimal" -o "$ITEM" = "mdns4_minimal" -o "$ITEM" = "mdns6_minimal" ]; then
if test "$FOUND_DNS" -eq 1; then
# don't keep *_minimal after dns; it's not desired there
DROPACTION=1
else
if [ "$IPvALL" -eq 1 ] && [ "$ITEM" = "mdns4_minimal" -o "$ITEM" = "mdns6_minimal" ]; then
# no need to keep mdns[46]_minimal since we'll add mdns_minimal
DROPACTION=1
else
if [ "$ITEM" = "mdns_minimal" ]; then
FOUND=1
elif [ "$ITEM" = "mdns4_minimal" -a "$IPv4" -eq 1 ]; then
FOUND=1
elif [ "$ITEM" = "mdns6_minimal" -a "$IPv6" -eq 1 ]; then
FOUND=1
fi
# force the use of [NOTFOUND=return] after *_minimal
NEWVALUE="$NEWVALUE $ITEM [NOTFOUND=return]"
DROPACTION=1
fi
fi
elif [ "$ITEM" = "mdns" -o "$ITEM" = "mdns4" -o "$ITEM" = "mdns6" ]; then
# we simply don't use the non-minimal version in our setup, so drop it
DROPACTION=1
elif [ "$ITEM" = "dns" ]; then
FOUND_DNS=1
DROPACTION=0
if test "$FOUND" -ne 1; then
FOUND=1
if test "$IPvALL" -eq 1; then
NEWVALUE="$NEWVALUE mdns_minimal [NOTFOUND=return] $ITEM"
elif test "$IPv4" -eq 1; then
NEWVALUE="$NEWVALUE mdns4_minimal [NOTFOUND=return] $ITEM"
elif test "$IPv6" -eq 1; then
NEWVALUE="$NEWVALUE mdns6_minimal [NOTFOUND=return] $ITEM"
else
echo "Internal error when enabling."
exit 1
fi
else
NEWVALUE="$NEWVALUE $ITEM"
fi
elif [ "${ITEM#[}" != "$ITEM" -a "$DROPACTION" -eq 1 ]; then
DROPACTION=0
else
NEWVALUE="$NEWVALUE $ITEM"
DROPACTION=0
fi
done
if test "$FOUND_DNS" -ne 1; then
echo "No dns service for hosts configuration in $ETC_NSSWITCH."
exit 0
fi
NEWVALUE=$(echo $NEWVALUE | sed "s/^\s*//;s/^\s*$//")
if test "$BACKUP" -eq 1; then
cp -a "$ETC_NSSWITCH" "${ETC_NSSWITCH}bak"
fi
echo "Patching already existing $ETC_NSSWITCH."
sed -i "s/\(^\s*hosts:\s*\).*/\1$NEWVALUE/" "$ETC_NSSWITCH"
fi
