openconnect: allow specify --protocol from config

openconnect v8.10 supports 4 VPN protocols

  --protocol=anyconnect  Compatible with Cisco AnyConnect SSL VPN, as well as ocserv (default)
  --protocol=nc          Compatible with Juniper Network Connect
  --protocol=gp          Compatible with Palo Alto Networks (PAN) GlobalProtect SSL VPN
  --protocol=pulse       Compatible with Pulse Connect Secure SSL VPN

This patch allows user to specify protocol use the new "vpn_protocol"
option and deprecate the old option "juniper" which seems to be missing in
the current openconnect client.

Signed-off-by: Mengyang Li <mayli.he@gmail.com>

net/openconnect/files/openconnect.sh

@@ -15,6 +15,7 @@ proto_openconnect_init_config() {
 	proto_config_add_int "port"
 	proto_config_add_int "mtu"
 	proto_config_add_int "juniper"
+	proto_config_add_string "vpn_protocol"
 	proto_config_add_boolean "no_dtls"
 	proto_config_add_string "interface"
 	proto_config_add_string "username"
@@ -46,6 +47,7 @@ proto_openconnect_setup() {
 		form_entry \
 		interface \
 		juniper \
+		vpn_protocol \
 		mtu \
 		no_dtls \
 		os \
@@ -93,6 +95,10 @@ proto_openconnect_setup() {
 		append_args --juniper
 	fi
 
+	[ -n "$vpn_protocol" ] && {
+		append_args --protocol "$vpn_protocol"
+	}
+
 	[ -n "$serverhash" ] && {
 		append_args "--servercert=$serverhash"
 		append_args --no-system-trust