From: Roy Marples <roy@marples.name>
Date: Thu, 14 Aug 2008 10:38:15 +0000 (+0000)
Subject: If resolvconf is not present, try and emulate it's functionality just for dhcpcd... 
X-Git-Tag: v4.0.2~37
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b78ebc2f4c93e0a0b93a839e65d70c331d8134b7;p=thirdparty%2Fdhcpcd.git

If resolvconf is not present, try and emulate it's functionality just for dhcpcd so we can sanely handle >1 instance running.
---

diff --git a/dhcpcd-hooks/20-resolv.conf b/dhcpcd-hooks/20-resolv.conf
index b86d5837..5b02f62b 100644
--- a/dhcpcd-hooks/20-resolv.conf
+++ b/dhcpcd-hooks/20-resolv.conf
@@ -1,5 +1,75 @@
 # Generate /etc/resolv.conf
 # Support resolvconf(8) if available
+# We can merge other dhcpcd resolv.conf files into one like resolvconf,
+# but resolvconf is preferred as other applications like VPN clients
+# can readily hook into it.
+# Also, resolvconf can configure local nameservers such as bind
+# or dnsmasq. This is important as the libc resolver isn't that powerful.
+
+# We store our resolvconfs in /var/run so they are cleaned at boot.
+resolvconf_dir=/var/run/dhcpcd/resolv.conf
+
+uniqify()
+{
+	local result=
+
+	while [ -n "$1" ]; do
+		case " ${result} " in
+		*" $1 "*);;
+		*) result="${result}${result:+ }$1";;
+		esac
+		shift
+	done
+	echo "${result}"
+}
+
+build_resolv_conf()
+{
+	local cf="/etc/resolv.conf.${interface}"
+	local header="${signature_base}"
+	local interfaces= search= srvs= servers= x=
+
+	# Build a list of interfaces
+	for x in "${resolvconf_dir}"/*; do
+		[ -n "${interfaces}" ] && header="${header}, "
+		header="${header}${x##*/}"
+		interfaces="${interfaces}${interfaces:+ }${x##*/}"
+	done
+
+	# Build a search list
+	for x in ${interfaces}; do
+		x="${resolvconf_dir}/${x}"
+		search="${search}${search:+ }$(sed -n 's/^search //p' "${x}")"
+	done
+	[ -n "${search}" ] && search="search $(uniqify "${search}")\n"
+
+	# Build a nameserver list
+	for x in ${interfaces}; do
+		x="${resolvconf_dir}/${x}"
+		srvs="${srvs}${srvs:+ }$(sed -n 's/^nameserver //p' "${x}")"
+	done
+	if [ -n "${srvs}" ]; then
+		for x in $(uniqify "${srvs}"); do
+			servers="${servers}nameserver ${x}\n"
+		done
+	fi
+
+	# Build our final resolv.conf
+	[ -f "${cf}" ] && rm -f "${cf}"
+	echo "${header}" > "${cf}"
+	if [ -f /etc/resolv.conf.head ]; then
+		cat /etc/resolv.conf.head >> "${cf}"
+	else
+		echo "# /etc/resolv.conf.head can replace this line" >> "${cf}"
+	fi
+	printf "${search}${servers}" >> "${cf}"
+	if [ -f /etc/resolv.conf.tail ]; then
+		cat /etc/resolv.conf.tail >> "${cf}"
+	else
+		echo "# /etc/resolv.conf.tail can replace this line" >> "${cf}"
+	fi
+	mv -f "${cf}" /etc/resolv.conf
+}
 
 make_resolv_conf()
 {
@@ -8,7 +78,7 @@ make_resolv_conf()
 		-z "${new_domain_search}" ]; then
 		return 0
 	fi
-	local x= conf="${signature}\n" cf="/etc/resolv.conf.${interface}"
+	local x= conf="${signature}\n"
 	if [ -n "${new_domain_search}" ]; then
 		conf="${conf}search ${new_domain_search}\n"
 	elif [ -n "${new_domain_name}" ]; then
@@ -19,18 +89,17 @@ make_resolv_conf()
 	done
 	if type resolvconf >/dev/null 2>&1; then
 		printf "${conf}" | resolvconf -a "${interface}"
-	else
-		rm -f "${cf}"
-		if [ -f /etc/resolv.conf.head ]; then
-			cat /etc/resolv.conf.head > "${cf}"
-		fi
-		printf "${conf}" >> "${cf}"
-		if [ -f /etc/resolv.conf.tail ]; then
-			cat /etc/resolv.conf.tail >> "${cf}"
-		fi
-		save_conf /etc/resolv.conf
-		mv -f "${cf}" /etc/resolv.conf
+		return $?
 	fi
+
+	if [ ! -d "${resolvconf_dir}" ]; then
+		mkdir -p "${resolvconf_dir}"
+	fi
+	if [ -e "${resolvconf_dir}/${interface}" ]; then
+		rm -f "${resolvconf_dir}/${interface}"
+	fi
+	printf "${conf}" > "${resolvconf_dir}/${interface}"
+	build_resolv_conf
 }
 
 restore_resolv_conf()
@@ -38,11 +107,14 @@ restore_resolv_conf()
 	if type resolvconf >/dev/null 2>&1; then
 		resolvconf -d "${interface}" -f
 	else
-		restore_conf /etc/resolv.conf || return 0
+		if [ -e "${resolvconf_dir}/${interface}" ]; then
+			rm -f "${resolvconf_dir}/${interface}"
+		fi
+		build_resolv_conf
 	fi
 }
 
 case "${reason}" in
 BOUND|INFORM|REBIND|REBOOT|RENEW|TIMEOUT)	make_resolv_conf;;
-EXPIRE|FAIL|IPV4LL|RELEASE|STOP)		restore_resolv_conf;;
+PREINIT|EXPIRE|FAIL|IPV4LL|RELEASE|STOP)	restore_resolv_conf;;
 esac