1#!/bin/sh
2# Copyright (c) 2007-2009 Roy Marples
3# All rights reserved
4
5# libc subscriber for resolvconf
6
7# Redistribution and use in source and binary forms, with or without
8# modification, are permitted provided that the following conditions
9# are met:
10#     * Redistributions of source code must retain the above copyright
11#       notice, this list of conditions and the following disclaimer.
12#     * Redistributions in binary form must reproduce the above
13#       copyright notice, this list of conditions and the following
14#       disclaimer in the documentation and/or other materials provided
15#       with the distribution.
16#
17# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
21# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
23# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
27# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28
29SYSCONFDIR=@SYSCONFDIR@
30LIBEXECDIR=@LIBEXECDIR@
31VARDIR=@VARDIR@
32IFACEDIR="$VARDIR/interfaces"
33NL="
34"
35
36# sed may not be available, and this is faster on small files
37key_get_value()
38{
39	local key="$1" value= x= line=
40
41	shift
42	if [ $# -eq 0 ]; then
43		while read line; do
44			case "$line" in
45			"$key"*) echo "${line##$key}";;
46			esac
47		done
48	else
49		for x; do
50			while read line; do
51				case "$line" in
52				"$key"*) echo "${line##$key}";;
53				esac
54			done < "$x"
55		done
56	fi
57}
58
59# Support original resolvconf configuration layout
60# as well as the openresolv config file
61if [ -f "$SYSCONFDIR"/resolvconf.conf ]; then
62	. "$SYSCONFDIR"/resolvconf.conf
63elif [ -d "$SYSCONFDIR"/resolvconf ]; then
64	SYSCONFDIR="$SYSCONFDIR/resolvconf/resolv.conf.d"
65	base="$SYSCONFDIR/resolv.conf.d/base"
66	if [ -f "$base" ]; then
67		name_servers="$(key_get_value "nameserver " "$base")"
68		search_domains="$(key_get_value "search " "$base")"
69		if [ -z "$search_domains" ]; then
70			search_domains="$(key_get_value "domain " "$base")"
71		fi
72		resolv_conf_options="$(key_get_value "options " "$base")"
73	fi
74	if [ -f "$SYSCONFDIR"/resolv.conf.d/head ]; then
75		resolv_conf_head="$(cat "${SYSCONFDIR}"/resolv.conf.d/head)"
76	fi
77	if [ -f "$SYSCONFDIR"/resolv.conf.d/tail ]; then
78		resolv_conf_tail="$(cat "$SYSCONFDIR"/resolv.conf.d/tail)"
79	fi
80fi
81: ${resolv_conf:=/etc/resolv.conf}
82: ${libc_service:=nscd}
83: ${libc_restart:=@RESTARTCMD ${libc_service}@}
84: ${list_resolv:=@PREFIX@/sbin/resolvconf -l}
85if [ "${resolv_conf_head-x}" = x -a -f "$SYSCONFDIR"/resolv.conf.head ]; then
86	resolv_conf_head="$(cat "${SYSCONFDIR}"/resolv.conf.head)"
87fi
88if [ "${resolv_conf_tail-x}" = x -a -f "$SYSCONFDIR"/resolv.conf.tail ]; then
89	resolv_conf_tail="$(cat "$SYSCONFDIR"/resolv.conf.tail)"
90fi
91
92uniqify()
93{
94	local result=
95	while [ -n "$1" ]; do
96		case " $result " in
97		*" $1 "*);;
98		*) result="$result $1";;
99		esac
100		shift
101	done
102	echo "${result# *}"
103}
104
105case "${resolv_conf_passthrough:-NO}" in
106[Yy][Ee][Ss]|[Tt][Rr][Uu][Ee]|[Oo][Nn]|1)
107	newest=
108	for conf in "$IFACEDIR"/*; do
109		if [ -z "$newest" -o "$conf" -nt "$newest" ]; then
110			newest="$conf"
111		fi
112	done
113	[ -z "$newest" ] && exit 0
114	newconf="$(cat "$newest")$NL"
115	;;
116*)
117	[ -z "$RESOLVCONF" ] && eval "$(@PREFIX@/sbin/resolvconf -v)"
118	newsearch="$(uniqify $search_domains $SEARCH $search_domains_append)"
119	NS="$LOCALNAMESERVERS $NAMESERVERS"
120	newns="$(uniqify $name_servers $NS $name_servers_append)"
121
122	# Hold our new resolv.conf in a variable to save on temporary files
123	newconf="# Generated by resolvconf$NL"
124	if [ -n "$resolv_conf_head" ]; then
125		newconf="$newconf$resolv_conf_head$NL"
126	fi
127	[ -n "$newsearch" ] && newconf="${newconf}search $newsearch$NL"
128	for n in $newns; do
129		newconf="${newconf}nameserver $n$NL"
130	done
131
132	# Now get any configured options
133	opts="$resolv_conf_options${resolv_conf_options:+ }"
134	opts="$opts$($list_resolv | key_get_value "options ")"
135	if [ -n "$opts" ]; then
136		newconf="${newconf}options"
137		for opt in $(uniqify $opts); do
138			newconf="${newconf} $opt"
139		done
140		newconf="$newconf$NL"
141	fi
142
143	if [ -n "$resolv_conf_tail" ]; then
144		newconf="$newconf$resolv_conf_tail$NL"
145	fi
146	;;
147esac
148
149# Check if the file has actually changed or not
150if [ -e "$resolv_conf" ]; then
151	[ "$(cat "$resolv_conf")" = "$(printf %s "$newconf")" ] && exit 0
152fi
153
154# Create our resolv.conf now
155(umask 022; echo "$newconf" >"$resolv_conf")
156eval $libc_restart
157
158retval=0
159# Notify users of the resolver
160for script in "$LIBEXECDIR"/libc.d/*; do
161	if [ -f "$script" ]; then
162		if [ -x "$script" ]; then
163			"$script" "$@"
164		else
165			(. "$script" "$@")
166		fi
167		retval=$(($retval + $?))
168	fi
169done
170exit $retval
171