Maintenance: split each provider in a package

- Fix VyprVPN port
- Fix missing Auth overrides

internal/provider/mullvad/openvpnconf.go

@@ -0,0 +1,77 @@
+package mullvad
+
+import (
+	"strconv"
+
+	"github.com/qdm12/gluetun/internal/configuration"
+	"github.com/qdm12/gluetun/internal/constants"
+	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/utils"
+)
+
+func (m *Mullvad) BuildConf(connection models.OpenVPNConnection,
+	username string, settings configuration.OpenVPN) (lines []string) {
+	if settings.Cipher == "" {
+		settings.Cipher = constants.AES256cbc
+	}
+
+	lines = []string{
+		"client",
+		"dev tun",
+		"nobind",
+		"persist-key",
+		"remote-cert-tls server",
+		"ping 10",
+		"ping-exit 60",
+		"ping-timer-rem",
+		"tls-exit",
+
+		// Mullvad specific
+		"sndbuf 524288",
+		"rcvbuf 524288",
+		"tls-cipher TLS-DHE-RSA-WITH-AES-256-GCM-SHA384:TLS-DHE-RSA-WITH-AES-256-CBC-SHA",
+		"fast-io",
+		"script-security 2",
+
+		// Added constant values
+		"auth-nocache",
+		"mute-replay-warnings",
+		"pull-filter ignore \"auth-token\"", // prevent auth failed loops
+		"auth-retry nointeract",
+		"suppress-timestamps",
+
+		// Modified variables
+		"verb " + strconv.Itoa(settings.Verbosity),
+		"auth-user-pass " + constants.OpenVPNAuthConf,
+		connection.ProtoLine(),
+		connection.RemoteLine(),
+		"data-ciphers-fallback " + settings.Cipher,
+		"data-ciphers " + settings.Cipher,
+	}
+
+	if settings.Auth != "" {
+		lines = append(lines, "auth "+settings.Auth)
+	}
+
+	if settings.Provider.ExtraConfigOptions.OpenVPNIPv6 {
+		lines = append(lines, "tun-ipv6")
+	} else {
+		lines = append(lines, `pull-filter ignore "route-ipv6"`)
+		lines = append(lines, `pull-filter ignore "ifconfig-ipv6"`)
+	}
+
+	if !settings.Root {
+		lines = append(lines, "user "+username)
+	}
+
+	if settings.MSSFix > 0 {
+		lines = append(lines, "mssfix "+strconv.Itoa(int(settings.MSSFix)))
+	}
+
+	lines = append(lines, utils.WrapOpenvpnCA(
+		constants.MullvadCertificate)...)
+
+	lines = append(lines, "")
+
+	return lines
+}