libreswan: fix default subnet matching

Match only explicit default-route subnet tokens when normalizing leftsubnets and rightsubnets.

The previous regex treated dots as wildcards.

Values such as 10.250.0.0/16 and 10.0.0.0/8 were rewritten to 0.0.0.0/0.

Fixes: openwrt/openwrt#23795
Signed-off-by: Dharmik Parmar <dharmikparmar2004@yahoo.com>

Author: dhrm1k

net/libreswan/Makefile

@@ -8,7 +8,7 @@ include $(TOPDIR)/rules.mk
 
 PKG_NAME:=libreswan
 PKG_VERSION:=4.12
-PKG_RELEASE:=4
+PKG_RELEASE:=5
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://download.libreswan.org/

net/libreswan/files/etc/init.d/ipsec

@@ -78,6 +78,20 @@ expand_phase2alg() {
 	phase2alg_proposal="${encryption_algorithm:+${encryption_algorithm// /+}${hash_algorithm:+-${hash_algorithm// /+}${dh_group:+-${dh_group// /+}}}}"
 }
 
+has_default_subnet() {
+	local subnet
+
+	for subnet in $1; do
+		case "$subnet" in
+		0.0.0.0|0.0.0.0/0)
+			return 0
+			;;
+		esac
+	done
+
+	return 1
+}
+
 generate_tunnel_config() {
 	local id=$1
 	local config_file="$IPSEC_CONF_DIR/$id.conf"
@@ -118,12 +132,12 @@ generate_tunnel_config() {
 	config_get psk "$id" psk
 
 	if [ -n "$leftsubnets" ]; then
-		[[ "$leftsubnets" =~ 0.0.0.0* ]] && leftsubnets="0.0.0.0/0"
+		has_default_subnet "$leftsubnets" && leftsubnets="0.0.0.0/0"
 		leftsubnets="{${leftsubnets// /,}}"
 	fi
 
 	if [ -n "$rightsubnets" ]; then
-		[[ "$rightsubnets" =~ 0.0.0.0* ]] && rightsubnets="0.0.0.0/0"
+		has_default_subnet "$rightsubnets" && rightsubnets="0.0.0.0/0"
 		rightsubnets="{${rightsubnets// /,}}"
 	fi