>From 12a53657696ecb768ac23bb7b0ce8a2cda4f64f7 Mon Sep 17 00:00:00 2001
From: Eygene Ryabinkin <rea-fbsd@codelabs.ru>
Date: Thu, 24 Apr 2008 13:56:48 +0400
Subject: [PATCH] Some modifications to the new rc.d/resolv code.

Following comments by Jeremie Le Hen in the freebsd-current list,
  http://lists.freebsd.org/pipermail/freebsd-current/2008-April/085077.html
I had made the following changes:

- the existing forwarders file is never chowned/chmodded, only the
  new one does;
- add_new_bind_forwarders() now accepts empty arguments to create
  empty forwarders list; it also checks for the empty server names
  in the list and omits them;
- now there is a single place for the creation of the forwarders
  and resolv files -- at the end of the script; the actual contents
  of the files are governed by the variables that are set in the
  respective places;
- prepended underscores for the script-global variables to avoid
  interfering with other global variables; not a strict measure,
  since there is no policy on variable names.

Signed-off-by: Eygene Ryabinkin <rea-fbsd@codelabs.ru>
---
 etc/rc.d/resolv |   68 ++++++++++++++++++++++++++++++-------------------------
 1 files changed, 37 insertions(+), 31 deletions(-)

diff --git a/etc/rc.d/resolv b/etc/rc.d/resolv
index e5f9f32..0d42278 100644
--- a/etc/rc.d/resolv
+++ b/etc/rc.d/resolv
@@ -98,7 +98,7 @@ install_new_file() {
 		rm -f "$1"
 		return 1
 	else
-		cp -f "$1" "$2"
+		cat "$1" > "$2"
 	fi
 
 	rm -f "$1"
@@ -111,68 +111,74 @@ install_new_file() {
 # Arguments.
 #   $1 - the list of forwarders, separated by ',' or ' '.
 add_new_bind_forwarders() {
-	local tmpf
+	local tmpf existed
 
 	tmpf="$resolv_named_forwarders_file".new.$$
 
-	[ -z "$1" ] && return
 	checkyesno resolv_build_named_forwarders || return
 
+	existed=no
+	if [ -e "$resolv_named_forwarders_file" ]; then
+		existed=yes
+	fi
+
 	echo 'forwarders {' > "$tmpf"
 	set -- "$1"
 	for nameserver in `IFS=', '; echo $*`; do
-		echo "$nameserver;"
+		[ -n "$nameserver" ] && echo "$nameserver;"
 	done >> "$tmpf"
 	echo '};' >> "$tmpf"
 
 	# New contents?  Try to reload named.
 	if install_new_file "$tmpf" "$resolv_named_forwarders_file"; then
-		chown -RL root:wheel "$resolv_named_forwarders_file"
-		chmod -RL 644 "$resolv_named_forwarders_file"
+		if [ "$existed" = no ]; then
+			chown -RL root:wheel "$resolv_named_forwarders_file"
+			chmod -RL 644 "$resolv_named_forwarders_file"
+		fi
 
 		named_condreload
 	fi
 }
 
-tmp_resolv=/etc/resolv.conf.new.$$
-rm -f "$tmp_resolv"
+_tmp_resolv=/etc/resolv.conf.new.$$
+rm -f "${_tmp_resolv}"
+_nslist=""
+_defdomain=""
+_mkresolv=no
 # If user specified static resolv parameters, use them.
 if [ -n "${resolv_domain}" -o -n "${resolv_nameservers}" ]; then
-	build_resolv \
-	    "${resolv_domain}" "${resolv_nameservers}" \
-	    > "$tmp_resolv"
-	add_new_bind_forwarders "${resolv_nameservers}"
+	_nslist="${resolv_nameservers}"
+	_defdomain="${resolv_domain}"
+	_mkresolv=yes
 # dhclient-script calls us using kenv's dhclient.* parameters
 elif [ -n "`/bin/kenv dhclient.domain-name-servers 2> /dev/null`" -o \
     -n "`/bin/kenv dhclient.domain-name 2> /dev/null`" ]; then
-	build_resolv \
-	    "`/bin/kenv dhclient.domain-name 2> /dev/null`" \
-	    "`/bin/kenv dhclient.domain-name-servers`" \
-	    > "$tmp_resolv"
-	add_new_bind_forwarders "`/bin/kenv dhclient.domain-name-servers`"
+	_nslist="`/bin/kenv dhclient.domain-name-servers`"
+	_defdomain="`/bin/kenv dhclient.domain-name 2> /dev/null`"
+	_mkresolv=yes
 # If the info is available via dhcp/kenv (from the boot time)
 # build the resolv.conf, but only if it is not already exists.
 # This is the old historical behaviour of /etc/rc.d/resolv.
 elif [ ! -e /etc/resolv.conf -a \
     -n "`/bin/kenv dhcp.domain-name-servers 2> /dev/null`" ]; then
-	build_resolv \
-	    "`/bin/kenv dhcp.domain-name 2> /dev/null`" \
-	    "`/bin/kenv dhcp.domain-name-servers`" > "$tmp_resolv"
-	add_new_bind_forwarders "`/bin/kenv dhcp.domain-name-servers`"
+	_nslist="`/bin/kenv dhcp.domain-name-servers`"
+	_defdomain="`/bin/kenv dhcp.domain-name 2> /dev/null`"
+	_mkresolv=yes
 else
-	# Create forwarders file without forwarding servers.
+	# Create forwarders file without forwarding servers to clear
+	# the server list possibly left from the previous invocations.
+	# Eventually, this creates the file if its creation was requested,
+	# but no file currently exists.
+	#
 	# We can not just make it empty, because in the case
 	# of the 'forward only;' directives, named will throw
 	# error about non-existent 'forwarders' clause.
-	if checkyesno resolv_build_named_forwarders; then
-		if [ -e "$resolv_named_forwarders_file" ]; then
-			cat << "EOF" > "$resolv_named_forwarders_file"
-forwarders {};
-EOF
-			named_condreload
-		fi
-	fi
+	_nslist=""
 fi
 
-install_new_file "$tmp_resolv" /etc/resolv.conf
+add_new_bind_forwarders "${_nslist}"
 
+if [ "${_mkresolv}" = yes ]; then
+	build_resolv "${_defdomain}" "${_nslist}" > "${_tmp_resolv}"
+	install_new_file "${_tmp_resolv}" /etc/resolv.conf
+fi
-- 
1.5.3.8