ppp: don't start ppp with IPv6 support if ipv6 is not supported

Signed-off-by: Rosy Song <rosysong@rosinson.com>
Signed-off-by: Hans Dedecker <dedeckeh@gmail.com>

package/network/services/ppp/Makefile

@@ -10,7 +10,7 @@ include $(INCLUDE_DIR)/kernel.mk
 
 PKG_NAME:=ppp
 PKG_VERSION:=2.4.7
-PKG_RELEASE:=13
+PKG_RELEASE:=14
 
 PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
 PKG_SOURCE_URL:=https://download.samba.org/pub/ppp/

package/network/services/ppp/files/ppp.sh

@@ -74,7 +74,7 @@ ppp_generic_init_config() {
 	proto_config_add_string pppd_options
 	proto_config_add_string 'connect:file'
 	proto_config_add_string 'disconnect:file'
-	proto_config_add_string ipv6
+	[ -e /proc/sys/net/ipv6 ] && proto_config_add_string ipv6
 	proto_config_add_boolean authfail
 	proto_config_add_int mtu
 	proto_config_add_string pppname
@@ -88,7 +88,10 @@ ppp_generic_setup() {
 	local config="$1"; shift
 	local localip
 
-	json_get_vars ipv6 ip6table demand keepalive keepalive_adaptive username password pppd_options pppname unnumbered persist maxfail holdoff peerdns
+	json_get_vars ip6table demand keepalive keepalive_adaptive username password pppd_options pppname unnumbered persist maxfail holdoff peerdns
+
+	[ ! -e /proc/sys/net/ipv6 ] && ipv6=0 || json_get_var ipv6 ipv6
+
 	if [ "$ipv6" = 0 ]; then
 		ipv6=""
 	elif [ -z "$ipv6" -o "$ipv6" = auto ]; then
@@ -148,9 +151,9 @@ ppp_generic_setup() {
 		${connect:+connect "$connect"} \
 		${disconnect:+disconnect "$disconnect"} \
 		ip-up-script /lib/netifd/ppp-up \
-		ipv6-up-script /lib/netifd/ppp6-up \
+		${ipv6:+ipv6-up-script /lib/netifd/ppp6-up} \
 		ip-down-script /lib/netifd/ppp-down \
-		ipv6-down-script /lib/netifd/ppp-down \
+		${ipv6:+ipv6-down-script /lib/netifd/ppp-down} \
 		${mtu:+mtu $mtu mru $mtu} \
 		"$@" $pppd_options
 }