VPN Unlimited support (#499)

- Fixes #420 
- Revert to docker/build-push-action@v2.4.0

internal/provider/vpnunlimited/connection.go

@@ -0,0 +1,44 @@
+package vpnunlimited
+
+import (
+	"errors"
+
+	"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"
+)
+
+var ErrProtocolUnsupported = errors.New("network protocol is not supported")
+
+func (p *Provider) GetOpenVPNConnection(selection configuration.ServerSelection) (
+	connection models.OpenVPNConnection, err error) {
+	const port = 1194
+	const protocol = constants.UDP
+	if selection.TCP {
+		return connection, ErrProtocolUnsupported
+	}
+
+	servers, err := p.filterServers(selection)
+	if err != nil {
+		return connection, err
+	}
+
+	var connections []models.OpenVPNConnection
+	for _, server := range servers {
+		for _, IP := range server.IPs {
+			connection := models.OpenVPNConnection{
+				IP:       IP,
+				Port:     port,
+				Protocol: protocol,
+			}
+			connections = append(connections, connection)
+		}
+	}
+
+	if selection.TargetIP != nil {
+		return utils.GetTargetIPConnection(connections, selection.TargetIP)
+	}
+
+	return utils.PickRandomConnection(connections, p.randSource), nil
+}

internal/provider/vpnunlimited/filter.go

@@ -0,0 +1,31 @@
+package vpnunlimited
+
+import (
+	"github.com/qdm12/gluetun/internal/configuration"
+	"github.com/qdm12/gluetun/internal/models"
+	"github.com/qdm12/gluetun/internal/provider/utils"
+)
+
+func (p *Provider) filterServers(selection configuration.ServerSelection) (
+	servers []models.VPNUnlimitedServer, err error) {
+	for _, server := range p.servers {
+		switch {
+		case
+			utils.FilterByPossibilities(server.Country, selection.Countries),
+			utils.FilterByPossibilities(server.City, selection.Cities),
+			utils.FilterByPossibilities(server.Hostname, selection.Hostnames),
+			selection.FreeOnly && !server.Free,
+			selection.StreamOnly && !server.Stream,
+			selection.TCP && !server.TCP,
+			!selection.TCP && !server.UDP:
+		default:
+			servers = append(servers, server)
+		}
+	}
+
+	if len(servers) == 0 {
+		return nil, utils.NoServerFoundError(selection)
+	}
+
+	return servers, nil
+}

internal/provider/vpnunlimited/openvpnconf.go

@@ -0,0 +1,69 @@
+package vpnunlimited
+
+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 (p *Provider) BuildConf(connection models.OpenVPNConnection,
+	username string, settings configuration.OpenVPN) (lines []string) {
+	lines = []string{
+		"client",
+		"dev tun",
+		"nobind",
+		"persist-key",
+		"tls-exit",
+		"remote-cert-tls server",
+
+		// VPNUnlimited specific
+		"reneg-sec 0",
+		"ping 5",
+		"ping-exit 30",
+		"comp-lzo no",
+		"route-metric 1",
+
+		// 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(),
+	}
+
+	if settings.Cipher != "" {
+		lines = append(lines, utils.CipherLines(settings.Cipher, settings.Version)...)
+	}
+
+	if settings.Auth != "" {
+		lines = append(lines, "auth "+settings.Auth)
+	}
+
+	if settings.MSSFix > 0 {
+		lines = append(lines, "mssfix "+strconv.Itoa(int(settings.MSSFix)))
+	}
+
+	if !settings.Root {
+		lines = append(lines, "user "+username)
+	}
+
+	lines = append(lines, utils.WrapOpenvpnCA(
+		constants.VPNUnlimitedCertificateAuthority)...)
+	lines = append(lines, utils.WrapOpenvpnCert(
+		settings.Provider.ExtraConfigOptions.ClientCertificate)...)
+	lines = append(lines, utils.WrapOpenvpnKey(
+		settings.Provider.ExtraConfigOptions.ClientKey)...)
+
+	lines = append(lines, "")
+
+	return lines
+}

internal/provider/vpnunlimited/portforward.go

@@ -0,0 +1,17 @@
+package vpnunlimited
+
+import (
+	"context"
+	"net"
+	"net/http"
+
+	"github.com/qdm12/gluetun/internal/firewall"
+	"github.com/qdm12/golibs/logging"
+	"github.com/qdm12/golibs/os"
+)
+
+func (p *Provider) PortForward(ctx context.Context, client *http.Client,
+	openFile os.OpenFileFunc, pfLogger logging.Logger, gateway net.IP,
+	fw firewall.Configurator, syncState func(port uint16) (pfFilepath string)) {
+	panic("port forwarding is not supported for VPN Unlimited")
+}

internal/provider/vpnunlimited/provider.go

@@ -0,0 +1,19 @@
+package vpnunlimited
+
+import (
+	"math/rand"
+
+	"github.com/qdm12/gluetun/internal/models"
+)
+
+type Provider struct {
+	servers    []models.VPNUnlimitedServer
+	randSource rand.Source
+}
+
+func New(servers []models.VPNUnlimitedServer, randSource rand.Source) *Provider {
+	return &Provider{
+		servers:    servers,
+		randSource: randSource,
+	}
+}