feat(pia): port forwarding options VPN_PORT_FORWARDING_USERNAME and VPN_PORT_FORWARDING_PASSWORD

- Retro-compatible with `OPENVPN_USER` + `OPENVPN_PASSWORD`
- No more reading for the OpenVPN auth file
- Allow to use PIA port forwarding with Wireguard

internal/vpn/portforward.go

@@ -30,6 +30,8 @@ func (l *Loop) startPortForwarding(data tunnelUpData) (err error) {
 			Interface:      data.vpnIntf,
 			ServerName:     data.serverName,
 			CanPortForward: data.canPortForward,
+			Username:       data.username,
+			Password:       data.password,
 		},
 	}
 	return l.portForward.UpdateWith(partialUpdate)

internal/vpn/run.go

@@ -50,6 +50,8 @@ func (l *Loop) Run(ctx context.Context, done chan<- struct{}) {
 			canPortForward: canPortForward,
 			portForwarder:  portForwarder,
 			vpnIntf:        vpnInterface,
+			username:       settings.Provider.PortForwarding.Username,
+			password:       settings.Provider.PortForwarding.Password,
 		}
 
 		openvpnCtx, openvpnCancel := context.WithCancel(context.Background())

internal/vpn/tunnelup.go

@@ -12,6 +12,8 @@ type tunnelUpData struct {
 	vpnIntf        string
 	serverName     string // used for PIA
 	canPortForward bool   // used for PIA
+	username       string // used for PIA
+	password       string // used for PIA
 	portForwarder  PortForwarder
 }