From 6f923dac5a3dbdb4d88119b766b16fa2d1490bb8 Mon Sep 17 00:00:00 2001
From: Michael Tremer <michael.tremer@ipfire.org>
Date: Sat, 30 Jun 2012 13:12:57 +0000
Subject: [PATCH] DNS: Add RDNSS functionality.

The radv daemon is now able to announce DNS servers.
There have also been bugfixes for minor problems.
---
 functions.dns   | 13 ++++++-
 functions.radvd | 93 ++++++++++++++++++++++++++++---------------------
 network         | 13 ++++---
 3 files changed, 75 insertions(+), 44 deletions(-)

diff --git a/functions.dns b/functions.dns
index 39ddfad7..7d153cd0 100644
--- a/functions.dns
+++ b/functions.dns
@@ -28,6 +28,10 @@ NETWORK_CONFIG_FILE_PARAMS="${NETWORK_CONFIG_FILE_PARAMS} DNS_USE_LOCAL_RESOLVER
 DNS_RANDOMIZE=false
 NETWORK_CONFIG_FILE_PARAMS="${NETWORK_CONFIG_FILE_PARAMS} DNS_RANDOMIZE"
 
+# Set this option to true if the DNS servers should be advertised by
+# radvd.
+DNS_ADVERTISE_SERVERS="true"
+
 DNS_SERVER_CONFIG_FILE="${NETWORK_CONFIG_DIR}/dns-servers"
 
 # Path to the configuration file of the DNS resolver.
@@ -52,7 +56,7 @@ function __dns_server_println() {
 }
 
 function __dns_server_sort() {
-	sort -k2 -u -g
+	sort -k2 -g | uniq
 }
 
 function dns_server_list() {
@@ -66,6 +70,13 @@ function dns_server_list() {
 	done < ${DNS_SERVER_CONFIG_FILE} | __dns_server_sort
 }
 
+function dns_server_list_no_priority() {
+	local server priority
+	dns_server_list | while read server priority; do
+		echo "${server}"
+	done
+}
+
 function dns_server_add() {
 	local server=${1}
 	assert isset server
diff --git a/functions.radvd b/functions.radvd
index 81e7aba9..0126a67a 100644
--- a/functions.radvd
+++ b/functions.radvd
@@ -30,46 +30,23 @@ function radvd_update() {
 }
 
 function radvd_write_config() {
-	# Clear the config file.
-	__radvd_clear
-
-	# Write header to the file.
-	__radvd_write "#"
-	__radvd_write "# This is the radvd daemon configuration file."
-	__radvd_write "# THIS FILE IS AUTOMATICALLY GENERATED AND WILL OVERWRITE"
-	__radvd_write "# ANY CUSTOM CHANGES!"
-	__radvd_write "#"
-	__radvd_write "# $(date -u)"
-	__radvd_write "#\n"
+	config_header "radv daemon configuration file" > ${RADVD_CONFIGFILE}
 
 	# Write the configuration for all zones.
 	local zone
 	for zone in $(zones_get_local); do
 		__radvd_config_interface ${zone}
-	done
-}
-
-function radvd_clear() {
-	__radvd_clear
-}
-
-function __radvd_clear() {
-	log DEBUG "Clearing radvd config file."
 
-	: > ${RADVD_CONFIGFILE}
-}
+	done >> ${RADVD_CONFIGFILE}
 
-function __radvd_write() {
-	echo -e "$@" >> ${RADVD_CONFIGFILE}
+	return ${EXIT_OK}
 }
 
 function __radvd_config_interface() {
 	local zone=${1}
-	shift
-
 	assert isset zone
 
-	log DEBUG "Writing radvd configuration for ${zone}"
+	log DEBUG "Writing radvd configuration for ${zone}."
 
 	# If the interface does not provide any routing information,
 	# we can skip this whole stuff.
@@ -87,16 +64,54 @@ function __radvd_config_interface() {
 		return ${EXIT_OK}
 	fi
 
-	__radvd_write "interface ${zone} {"
-	__radvd_write "	AdvSendAdvert on;"
-	__radvd_write "	MinRtrAdvInterval 3;"
-	__radvd_write "	MaxRtrAdvInterval 10;"
-	__radvd_write "	IgnoreIfMissing on;"
-	__radvd_write ""
-	__radvd_write "	prefix ${prefix} {"
-	__radvd_write "		AdvOnLink on;"
-	__radvd_write "		AdvAutonomous on;"
-	__radvd_write "		AdvRouterAddr on;"
-	__radvd_write "	};"
-	__radvd_write "};\n"
+	print "interface ${zone} {"
+	print "	AdvSendAdvert on;"
+	print "	MinRtrAdvInterval 3;"
+	print "	MaxRtrAdvInterval 10;"
+	print "	IgnoreIfMissing on;"
+	print
+	print "	prefix ${prefix} {"
+	print "		AdvOnLink on;"
+	print "		AdvAutonomous on;"
+	print "		AdvRouterAddr on;"
+	print "	};"
+	print
+
+	# Add the DNS configuration.
+	__radvd_config_dns ${zone}
+
+	print "};"
+	print
+}
+
+function __radvd_config_dns() {
+	local zone=${1}
+
+	# Do nothing, when this option is not enabled.
+	enabled DNS_ADVERTISE_SERVERS || return ${EXIT_OK}
+
+	# XXX it is kind of difficult to announce our local
+	# resolver.
+
+	local server servers
+	for server in $(dns_server_list_no_priority); do
+		# Filter out non IPv6 addresses.
+		ipv6_is_valid ${server} || continue
+
+		servers="${servers} ${server}"
+	done
+
+	# Remove whitespaces.
+	servers=$(echo ${servers})
+
+	# If there are no servers to announce, we stop right here.
+	if ! isset servers; then
+		log DEBUG "No servers to announce."
+		return ${EXIT_OK}
+	fi
+
+	print "	RDNSS ${servers} {"
+	print "		# Use the defaults here."
+	print "	};"
+	print
 }
diff --git a/network b/network
index 9dee7472..808d2cd6 100755
--- a/network
+++ b/network
@@ -544,6 +544,10 @@ function cli_dns() {
 		exit ${EXIT_ERROR}
 	fi
 
+	# Get the new server to process (if any).
+	local server=${1}
+	local priority=${2}
+
 	case "${cmd}" in
 		list)
 			__dns_server_println "SERVER" "PRIORITY"
@@ -551,12 +555,12 @@ function cli_dns() {
 			exit ${EXIT_OK}
 			;;
 		add)
-			log INFO "Adding new DNS server: ${server}..."
-			dns_server_add $@
+			log INFO "Adding new DNS server: ${server}"
+			dns_server_add ${server} ${priority}
 			;;
 		remove)
-			log INFO "Removing DNS server: ${server}..."
-			dns_server_remove $@
+			log INFO "Removing DNS server: ${server}"
+			dns_server_remove ${server} ${priority}
 			;;
 		update)
 			# Just run the update afterwards.
@@ -568,6 +572,7 @@ function cli_dns() {
 
 	# Update the local DNS configuration after changes have been made.
 	dns_generate_resolvconf
+	radvd_update
 
 	exit ${EXIT_OK}
 }
-- 
2.47.3