wip

.github/workflows/ci.yml

@@ -66,6 +66,33 @@ jobs:
       - name: Build final image
         run: docker build -t final-image .
 
+      - name: Run Wireguard
+        if: |
+          github.repository == 'qdm12/gluetun' &&
+          (
+            github.event_name == 'push' ||
+            (github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name == github.repository)
+          )
+        run: |
+          docker run -it --rm --cap-add=NET_ADMIN -e VPNSP=mullvad -e VPN_TYPE=wireguard \
+          -e WIREGUARD_PRIVATE_KEY=${{ secrets.WIREGUARD_PRIVATE_KEY }} \
+          -e WIREGUARD_ADDRESS=${{ secrets.WIREGUARD_ADDRESS }} \
+          final-image \
+          exit-once-connected
+
+      - name: Run OpenVPN
+        if: |
+          github.repository == 'qdm12/gluetun' &&
+          (
+            github.event_name == 'push' ||
+            (github.event_name == 'pull_request' && github.event.pull_request.head.repo.full_name == github.repository)
+          )
+        run: |
+          docker run -it --rm --cap-add=NET_ADMIN -e VPNSP=mullvad -e VPN_TYPE=openvpn \
+          -e OPENVPN_PASSWORD=${{ secrets.OPENVPN_PASSWORD }} \
+          final-image \
+          exit-once-connected
+
   codeql:
     runs-on: ubuntu-latest
     permissions:

Dockerfile

@@ -85,7 +85,7 @@ ENV VPN_SERVICE_PROVIDER=pia \
     OPENVPN_PASSWORD= \
     OPENVPN_USER_SECRETFILE=/run/secrets/openvpn_user \
     OPENVPN_PASSWORD_SECRETFILE=/run/secrets/openvpn_password \
-    OPENVPN_VERSION=2.4 \
+    OPENVPN_VERSION=2.6 \
     OPENVPN_VERBOSITY=1 \
     OPENVPN_FLAGS= \
     OPENVPN_CIPHERS= \
@@ -224,9 +224,6 @@ EXPOSE 8000/tcp 8888/tcp 8388/tcp 8388/udp
 HEALTHCHECK --interval=5s --timeout=5s --start-period=10s --retries=3 CMD /gluetun-entrypoint healthcheck
 ARG TARGETPLATFORM
 RUN apk add --no-cache --update -l wget && \
-    apk add --no-cache --update -X "https://dl-cdn.alpinelinux.org/alpine/v3.12/main" openvpn\~2.4 && \
-    apk add --no-cache --update -X "https://dl-cdn.alpinelinux.org/alpine/v3.16/main" openssl\~1.1 && \
-    mv /usr/sbin/openvpn /usr/sbin/openvpn2.4 && \
     apk add --no-cache --update -X "https://dl-cdn.alpinelinux.org/alpine/v3.17/main" openvpn\~2.5 && \
     mv /usr/sbin/openvpn /usr/sbin/openvpn2.5 && \
     apk del openvpn && \

cmd/gluetun/main.go

@@ -145,6 +145,7 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 	tun Tun, netLinker netLinker, cmder RunStarter,
 	cli clier,
 ) error {
+	var exitOnceConnected bool
 	if len(args) > 1 { // cli operation
 		switch args[1] {
 		case "healthcheck":
@@ -159,6 +160,8 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 			return cli.FormatServers(args[2:])
 		case "genkey":
 			return cli.GenKey(args[2:])
+		case "exit-once-connected":
+			exitOnceConnected = true
 		default:
 			return fmt.Errorf("%w: %s", errCommandUnknown, args[1])
 		}
@@ -270,7 +273,6 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 
 	err = printVersions(ctx, logger, []printVersionElement{
 		{name: "Alpine", getVersion: alpineConf.Version},
-		{name: "OpenVPN 2.4", getVersion: ovpnConf.Version24},
 		{name: "OpenVPN 2.5", getVersion: ovpnConf.Version25},
 		{name: "OpenVPN 2.6", getVersion: ovpnConf.Version26},
 		{name: "IPtables", getVersion: firewallConf.Version},
@@ -478,7 +480,8 @@ func _main(ctx context.Context, buildInfo models.BuildInformation,
 	controlGroupHandler.Add(httpServerHandler)
 
 	healthLogger := logger.New(log.SetComponent("healthcheck"))
-	healthcheckServer := healthcheck.NewServer(allSettings.Health, healthLogger, vpnLooper)
+	healthcheckServer := healthcheck.NewServer(allSettings.Health, healthLogger, vpnLooper,
+		exitOnceConnected)
 	healthServerHandler, healthServerCtx, healthServerDone := goshutdown.NewGoRoutineHandler(
 		"HTTP health server", goroutine.OptionTimeout(defaultShutdownTimeout))
 	go healthcheckServer.Run(healthServerCtx, healthServerDone)

go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/golang/mock v1.6.0
 	github.com/klauspost/compress v1.17.11
 	github.com/klauspost/pgzip v1.2.6
-	github.com/pelletier/go-toml/v2 v2.2.2
+	github.com/pelletier/go-toml/v2 v2.2.3
 	github.com/qdm12/dns/v2 v2.0.0-rc8
 	github.com/qdm12/gosettings v0.4.3
 	github.com/qdm12/goshutdown v0.3.0
@@ -22,7 +22,7 @@ require (
 	github.com/youmark/pkcs8 v0.0.0-20201027041543-1326539a0a0a
 	golang.org/x/exp v0.0.0-20241009180824-f66d83c29e7c
 	golang.org/x/net v0.30.0
-	golang.org/x/sys v0.26.0
+	golang.org/x/sys v0.27.0
 	golang.org/x/text v0.19.0
 	golang.zx2c4.com/wireguard v0.0.0-20231211153847-12269c276173
 	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20230429144221-925a1e7659e6

go.sum

@@ -4,7 +4,6 @@ github.com/breml/rootcerts v0.2.18 h1:KjZaNT7AX/akUjzpStuwTMQs42YHlPyc6NmdwShVba
 github.com/breml/rootcerts v0.2.18/go.mod h1:S/PKh+4d1HUn4HQovEB8hPJZO6pUZYrIhmXBhsegfXw=
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
 github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/fatih/color v1.18.0 h1:S8gINlzdQ840/4pfAwic/ZE0djQEH3wM94VfqLTZcOM=
@@ -42,8 +41,8 @@ github.com/mikioh/ipaddr v0.0.0-20190404000644-d465c8ab6721 h1:RlZweED6sbSArvlE9
 github.com/mikioh/ipaddr v0.0.0-20190404000644-d465c8ab6721/go.mod h1:Ickgr2WtCLZ2MDGd4Gr0geeCH5HybhRJbonOgQpvSxc=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822/go.mod h1:+n7T8mK8HuQTcFwEeznm/DIxMOiR9yIdICNftLE1DvQ=
-github.com/pelletier/go-toml/v2 v2.2.2 h1:aYUidT7k73Pcl9nb2gScu7NSrKCSHIDE89b3+6Wq+LM=
-github.com/pelletier/go-toml/v2 v2.2.2/go.mod h1:1t835xjRzz80PqgE6HHgN2JOsmgYu/h4qDAS4n929Rs=
+github.com/pelletier/go-toml/v2 v2.2.3 h1:YmeHyLY8mFWbdkNWwpr+qIL2bEqT0o95WSdkNHvL12M=
+github.com/pelletier/go-toml/v2 v2.2.3/go.mod h1:MfCQTFTvCcUyyvvwm1+G6H/jORL20Xlb6rzQu9GuUkc=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_golang v1.20.5 h1:cxppBPuYhUnsO6yo/aoRol4L7q7UFfdm+bR9r+8l63Y=
@@ -74,13 +73,6 @@ github.com/riobard/go-bloom v0.0.0-20200614022211-cdc8013cb5b3 h1:f/FNXud6gA3MNr
 github.com/riobard/go-bloom v0.0.0-20200614022211-cdc8013cb5b3/go.mod h1:HgjTstvQsPGkxUsCd2KWxErBblirPizecHcpD3ffK+s=
 github.com/rogpeppe/go-internal v1.13.1 h1:KvO1DLK/DRN07sQ1LQKScxyZJuNnedQ5/wKSR38lUII=
 github.com/rogpeppe/go-internal v1.13.1/go.mod h1:uMEvuHeurkdAXX61udpOXGD/AzZDWNMNyH2VO9fmH0o=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSSt89Yw=
-github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
-github.com/stretchr/objx v0.5.2/go.mod h1:FRsXN1f5AsAjCGJKqEizvkpNtU+EGNCLh3NxZ/8L+MA=
-github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
-github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
-github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
 github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/ulikunitz/xz v0.5.11 h1:kpFauv27b6ynzBNT/Xy+1k+fK4WswhN/6PN5WhFAGw8=
@@ -120,8 +112,8 @@ golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.10.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.26.0 h1:KHjCJyddX0LoSTb3J+vWpupP9p0oznkqVk/IfjymZbo=
-golang.org/x/sys v0.26.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.27.0 h1:wBqf8DvsY9Y/2P8gAfPDEYNuS30J4lPHJxXSb/nJZ+s=
+golang.org/x/sys v0.27.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
@@ -150,7 +142,6 @@ gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntN
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/ini.v1 v1.67.0 h1:Dgnx+6+nfE+IfzjUEISNeydPJh9AXNNsWbGP9KzCsOA=
 gopkg.in/ini.v1 v1.67.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gvisor.dev/gvisor v0.0.0-20230927004350-cbd86285d259 h1:TbRPT0HtzFP3Cno1zZo7yPzEEnfu8EjLfl6IU9VfqkQ=

internal/configuration/settings/openvpn.go

@@ -19,7 +19,7 @@ import (
 // OpenVPN contains settings to configure the OpenVPN client.
 type OpenVPN struct {
 	// Version is the OpenVPN version to run.
-	// It can only be "2.4".
+	// It can only be "2.5" or "2.6".
 	Version string `json:"version"`
 	// User is the OpenVPN authentication username.
 	// It cannot be nil in the internal state if OpenVPN is used.
@@ -90,7 +90,7 @@ var ivpnAccountID = regexp.MustCompile(`^(i|ivpn)\-[a-zA-Z0-9]{4}\-[a-zA-Z0-9]{4
 
 func (o OpenVPN) validate(vpnProvider string) (err error) {
 	// Validate version
-	validVersions := []string{openvpn.Openvpn24}
+	validVersions := []string{openvpn.Openvpn25, openvpn.Openvpn26}
 	if err = validate.IsOneOf(o.Version, validVersions...); err != nil {
 		return fmt.Errorf("%w: %w", ErrOpenVPNVersionIsNotValid, err)
 	}
@@ -289,7 +289,7 @@ func (o *OpenVPN) overrideWith(other OpenVPN) {
 }
 
 func (o *OpenVPN) setDefaults(vpnProvider string) {
-	o.Version = gosettings.DefaultComparable(o.Version, openvpn.Openvpn24)
+	o.Version = gosettings.DefaultComparable(o.Version, openvpn.Openvpn26)
 	o.User = gosettings.DefaultPointer(o.User, "")
 	if vpnProvider == providers.Mullvad {
 		o.Password = gosettings.DefaultPointer(o.Password, "m")

internal/configuration/settings/settings.go

@@ -4,7 +4,9 @@ import (
 	"fmt"
 	"net/netip"
 
+	"github.com/qdm12/gluetun/internal/configuration/settings/helpers"
 	"github.com/qdm12/gluetun/internal/constants/providers"
+	"github.com/qdm12/gluetun/internal/constants/vpn"
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/pprof"
 	"github.com/qdm12/gosettings/reader"
@@ -160,6 +162,18 @@ func (s Settings) Warnings() (warnings []string) {
 			" so this will likely not work anymore. See https://github.com/qdm12/gluetun/issues/1498.")
 	}
 
+	if helpers.IsOneOf(s.VPN.Provider.Name, providers.SlickVPN) &&
+		s.VPN.Type == vpn.OpenVPN {
+		warnings = append(warnings, "OpenVPN 2.5 and 2.6 use OpenSSL 3 "+
+			"which prohibits the usage of weak security in today's standards. "+
+			s.VPN.Provider.Name+" uses weak security which is out "+
+			"of Gluetun's control so the only workaround is to allow such weaknesses "+
+			`using the OpenVPN option tls-cipher "DEFAULT:@SECLEVEL=0". `+
+			"You might want to reach to your provider so they upgrade their certificates. "+
+			"Once this is done, you will have to let the Gluetun maintainers know "+
+			"by creating an issue, attaching the new certificate and we will update Gluetun.")
+	}
+
 	// TODO remove in v4
 	if s.DNS.ServerAddress.Unmap().Compare(netip.AddrFrom4([4]byte{127, 0, 0, 1})) != 0 {
 		warnings = append(warnings, "DNS address is set to "+s.DNS.ServerAddress.String()+

internal/configuration/settings/settings_test.go

@@ -30,7 +30,7 @@ func Test_Settings_String(t *testing.T) {
 |   |           ├── Protocol: UDP
 |   |           └── Private Internet Access encryption preset: strong
 |   └── OpenVPN settings:
-|       ├── OpenVPN version: 2.4
+|       ├── OpenVPN version: 2.6
 |       ├── User: [not set]
 |       ├── Password: [not set]
 |       ├── Private Internet Access encryption preset: strong

internal/constants/openvpn/versions.go

@@ -1,5 +1,6 @@
 package openvpn
 
 const (
-	Openvpn24 = "2.4"
+	Openvpn25 = "2.5"
+	Openvpn26 = "2.6"
 )

internal/healthcheck/server.go

@@ -9,15 +9,16 @@ import (
 )
 
 type Server struct {
-	logger  Logger
-	handler *handler
-	dialer  *net.Dialer
-	config  settings.Health
-	vpn     vpnHealth
+	logger            Logger
+	handler           *handler
+	dialer            *net.Dialer
+	config            settings.Health
+	vpn               vpnHealth
+	exitOnceConnected bool
 }
 
 func NewServer(config settings.Health,
-	logger Logger, vpnLoop StatusApplier,
+	logger Logger, vpnLoop StatusApplier, exitOnceConnected bool,
 ) *Server {
 	return &Server{
 		logger:  logger,

internal/netlink/ipv6_test.go

@@ -0,0 +1,13 @@
+package netlink
+
+import (
+	"testing"
+
+	"github.com/qdm12/log"
+)
+
+func Test_IsIPv6Supported(t *testing.T) {
+	n := New(log.New(log.SetLevel(log.LevelDebug)))
+	supported, err := n.IsIPv6Supported()
+	t.Log(supported, err)
+}

internal/openvpn/start.go

@@ -13,7 +13,8 @@ import (
 var ErrVersionUnknown = errors.New("OpenVPN version is unknown")
 
 const (
-	binOpenvpn24 = "openvpn2.4"
+	binOpenvpn25 = "openvpn2.5"
+	binOpenvpn26 = "openvpn2.6"
 )
 
 func start(ctx context.Context, starter CmdStarter, version string, flags []string) (
@@ -21,8 +22,10 @@ func start(ctx context.Context, starter CmdStarter, version string, flags []stri
 ) {
 	var bin string
 	switch version {
-	case openvpn.Openvpn24:
-		bin = binOpenvpn24
+	case openvpn.Openvpn25:
+		bin = binOpenvpn25
+	case openvpn.Openvpn26:
+		bin = binOpenvpn26
 	default:
 		return nil, nil, nil, fmt.Errorf("%w: %s", ErrVersionUnknown, version)
 	}

internal/openvpn/version.go

@@ -8,8 +8,12 @@ import (
 	"strings"
 )
 
-func (c *Configurator) Version24(ctx context.Context) (version string, err error) {
-	return c.version(ctx, binOpenvpn24)
+func (c *Configurator) Version25(ctx context.Context) (version string, err error) {
+	return c.version(ctx, binOpenvpn25)
+}
+
+func (c *Configurator) Version26(ctx context.Context) (version string, err error) {
+	return c.version(ctx, binOpenvpn26)
 }
 
 var ErrVersionTooShort = errors.New("version output is too short")

internal/provider/airvpn/openvpnconf.go

@@ -28,8 +28,6 @@ func (p *Provider) OpenVPNConfig(connection models.Connection,
 	}
 
 	switch settings.Version {
-	case openvpn.Openvpn24:
-		providerSettings.Ciphers = []string{openvpn.AES256cbc}
 	case openvpn.Openvpn25, openvpn.Openvpn26:
 		providerSettings.Ciphers = []string{
 			openvpn.AES256gcm, openvpn.AES256cbc, openvpn.AES192gcm,

internal/provider/custom/openvpnconf_test.go

@@ -64,8 +64,8 @@ func Test_modifyConfig(t *testing.T) {
 				"suppress-timestamps",
 				"auth-user-pass /etc/openvpn/auth.conf",
 				"verb 0",
-				"cipher cipher", //nolint:dupword
-				"ncp-ciphers cipher",
+				"data-ciphers-fallback cipher",
+				"data-ciphers cipher",
 				"auth sha512",
 				"mssfix 1000",
 				"pull-filter ignore \"route-ipv6\"",

internal/provider/slickvpn/openvpnconf.go

@@ -31,5 +31,11 @@ func (p *Provider) OpenVPNConfig(connection models.Connection,
 		},
 	}
 
+	// SlickVPN's certificate is sha1WithRSAEncryption and sha1 is now
+	// rejected by openssl 3.x.x which is used by OpenVPN >= 2.5.
+	// We lower the security level to 3 to allow this algorithm,
+	// see https://www.openssl.org/docs/man1.1.1/man3/SSL_CTX_set_security_level.html
+	providerSettings.TLSCipher = "DEFAULT:@SECLEVEL=0"
+
 	return utils.OpenVPNConfig(providerSettings, connection, settings, ipv6Supported)
 }

internal/provider/utils/cipher.go

@@ -10,7 +10,7 @@ func CipherLines(ciphers []string) (lines []string) {
 	}
 
 	return []string{
-		"cipher " + ciphers[0],
-		"ncp-ciphers " + strings.Join(ciphers, ":"),
+		"data-ciphers-fallback " + ciphers[0],
+		"data-ciphers " + strings.Join(ciphers, ":"),
 	}
 }

internal/provider/utils/cipher_test.go

@@ -16,16 +16,16 @@ func Test_CipherLines(t *testing.T) {
 		"empty version": {
 			ciphers: []string{"AES"},
 			lines: []string{
-				"cipher AES",
-				"ncp-ciphers AES",
+				"data-ciphers-fallback AES",
+				"data-ciphers AES",
 			},
 		},
-		"2.4": {
+		"2.5": {
 			ciphers: []string{"AES", "CBC"},
-			version: "2.4",
+			version: "2.5",
 			lines: []string{
-				"cipher AES",
-				"ncp-ciphers AES:CBC",
+				"data-ciphers-fallback AES",
+				"data-ciphers AES:CBC",
 			},
 		},
 	}

internal/publicip/api/api.go

@@ -3,7 +3,11 @@ package api
 import (
 	"errors"
 	"fmt"
+	"maps"
 	"net/http"
+	"net/url"
+	"regexp"
+	"slices"
 	"strings"
 )
 
@@ -16,6 +20,8 @@ const (
 	IP2Location Provider = "ip2location"
 )
 
+const echoipPrefix = "echoip#"
+
 type NameToken struct {
 	Name  string
 	Token string
@@ -30,15 +36,19 @@ func New(nameTokenPairs []NameToken, client *http.Client) (
 		if err != nil {
 			return nil, fmt.Errorf("parsing API name: %w", err)
 		}
-		switch provider {
-		case Cloudflare:
+		switch {
+		case provider == Cloudflare:
 			fetchers[i] = newCloudflare(client)
-		case IfConfigCo:
-			fetchers[i] = newIfConfigCo(client)
-		case IPInfo:
+		case provider == IfConfigCo:
+			const ifConfigCoURL = "https://ifconfig.co"
+			fetchers[i] = newEchoip(client, ifConfigCoURL)
+		case provider == IPInfo:
 			fetchers[i] = newIPInfo(client, nameTokenPair.Token)
-		case IP2Location:
+		case provider == IP2Location:
 			fetchers[i] = newIP2Location(client, nameTokenPair.Token)
+		case strings.HasPrefix(string(provider), echoipPrefix):
+			url := strings.TrimPrefix(string(provider), echoipPrefix)
+			fetchers[i] = newEchoip(client, url)
 		default:
 			panic("provider not valid: " + provider)
 		}
@@ -46,20 +56,88 @@ func New(nameTokenPairs []NameToken, client *http.Client) (
 	return fetchers, nil
 }
 
+var regexEchoipURL = regexp.MustCompile(`^http(s|):\/\/.+$`)
+
 var ErrProviderNotValid = errors.New("API name is not valid")
 
 func ParseProvider(s string) (provider Provider, err error) {
-	switch strings.ToLower(s) {
-	case "cloudflare":
-		return Cloudflare, nil
-	case string(IfConfigCo):
-		return IfConfigCo, nil
-	case "ipinfo":
-		return IPInfo, nil
-	case "ip2location":
-		return IP2Location, nil
-	default:
-		return "", fmt.Errorf(`%w: %q can only be "cloudflare", "ifconfigco", "ip2location" or "ipinfo"`,
-			ErrProviderNotValid, s)
+	possibleProviders := []Provider{
+		Cloudflare,
+		IfConfigCo,
+		IP2Location,
+		IPInfo,
 	}
+	stringToProvider := make(map[string]Provider, len(possibleProviders))
+	for _, provider := range possibleProviders {
+		stringToProvider[string(provider)] = provider
+	}
+	provider, ok := stringToProvider[strings.ToLower(s)]
+	if ok {
+		return provider, nil
+	}
+
+	customPrefixToURLRegex := map[string]*regexp.Regexp{
+		echoipPrefix: regexEchoipURL,
+	}
+	for prefix, urlRegex := range customPrefixToURLRegex {
+		match, err := checkCustomURL(s, prefix, urlRegex)
+		if !match {
+			continue
+		} else if err != nil {
+			return "", err
+		}
+		return Provider(s), nil
+	}
+
+	providerStrings := make([]string, 0, len(stringToProvider)+len(customPrefixToURLRegex))
+	for _, providerString := range slices.Sorted(maps.Keys(stringToProvider)) {
+		providerStrings = append(providerStrings, `"`+providerString+`"`)
+	}
+	for _, prefix := range slices.Sorted(maps.Keys(customPrefixToURLRegex)) {
+		providerStrings = append(providerStrings, "a custom "+prefix+" url")
+	}
+
+	return "", fmt.Errorf(`%w: %q can only be %s`,
+		ErrProviderNotValid, s, orStrings(providerStrings))
+}
+
+var ErrCustomURLNotValid = errors.New("custom URL is not valid")
+
+func checkCustomURL(s, prefix string, regex *regexp.Regexp) (match bool, err error) {
+	if !strings.HasPrefix(s, prefix) {
+		return false, nil
+	}
+	s = strings.TrimPrefix(s, prefix)
+	_, err = url.Parse(s)
+	if err != nil {
+		return true, fmt.Errorf("%s %w: %w", prefix, ErrCustomURLNotValid, err)
+	}
+
+	if regex.MatchString(s) {
+		return true, nil
+	}
+
+	return true, fmt.Errorf("%s %w: %q does not match regular expression: %s",
+		prefix, ErrCustomURLNotValid, s, regex)
+}
+
+func orStrings(strings []string) (result string) {
+	return joinStrings(strings, "or")
+}
+
+func joinStrings(strings []string, lastJoin string) (result string) {
+	if len(strings) == 0 {
+		return ""
+	}
+
+	result = strings[0]
+	for i := 1; i < len(strings); i++ {
+		if i < len(strings)-1 {
+			result += ", " + strings[i]
+		} else {
+			result += " " + lastJoin + " " + strings[i]
+		}
+	}
+
+	return result
 }

internal/publicip/api/api_test.go

@@ -0,0 +1,68 @@
+package api
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_ParseProvider(t *testing.T) {
+	t.Parallel()
+
+	testCases := map[string]struct {
+		s          string
+		provider   Provider
+		errWrapped error
+		errMessage string
+	}{
+		"empty": {
+			errWrapped: ErrProviderNotValid,
+			errMessage: `API name is not valid: "" can only be ` +
+				`"cloudflare", "ifconfigco", "ip2location", "ipinfo" or a custom echoip# url`,
+		},
+		"invalid": {
+			s:          "xyz",
+			errWrapped: ErrProviderNotValid,
+			errMessage: `API name is not valid: "xyz" can only be ` +
+				`"cloudflare", "ifconfigco", "ip2location", "ipinfo" or a custom echoip# url`,
+		},
+		"ipinfo": {
+			s:        "ipinfo",
+			provider: IPInfo,
+		},
+		"IpInfo": {
+			s:        "IpInfo",
+			provider: IPInfo,
+		},
+		"echoip_url_empty": {
+			s:          "echoip#",
+			errWrapped: ErrCustomURLNotValid,
+			errMessage: `echoip# custom URL is not valid: "" ` +
+				`does not match regular expression: ^http(s|):\/\/.+$`,
+		},
+		"echoip_url_invalid": {
+			s:          "echoip#postgres://localhost:3451",
+			errWrapped: ErrCustomURLNotValid,
+			errMessage: `echoip# custom URL is not valid: "postgres://localhost:3451" ` +
+				`does not match regular expression: ^http(s|):\/\/.+$`,
+		},
+		"echoip_url_valid": {
+			s:        "echoip#http://localhost:3451",
+			provider: Provider("echoip#http://localhost:3451"),
+		},
+	}
+
+	for name, testCase := range testCases {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			provider, err := ParseProvider(testCase.s)
+
+			assert.Equal(t, testCase.provider, provider)
+			assert.ErrorIs(t, err, testCase.errWrapped)
+			if testCase.errWrapped != nil {
+				assert.EqualError(t, err, testCase.errMessage)
+			}
+		})
+	}
+}

internal/publicip/api/echoip.go

@@ -6,39 +6,45 @@ import (
 	"fmt"
 	"net/http"
 	"net/netip"
+	"strings"
 
 	"github.com/qdm12/gluetun/internal/models"
 )
 
-type ifConfigCo struct {
+type echoip struct {
 	client *http.Client
+	url    string
 }
 
-func newIfConfigCo(client *http.Client) *ifConfigCo {
-	return &ifConfigCo{
+func newEchoip(client *http.Client, url string) *echoip {
+	return &echoip{
 		client: client,
+		url:    url,
 	}
 }
 
-func (i *ifConfigCo) String() string {
-	return string(IfConfigCo)
+func (e *echoip) String() string {
+	s := e.url
+	s = strings.TrimPrefix(s, "http://")
+	s = strings.TrimPrefix(s, "https://")
+	return s
 }
 
-func (i *ifConfigCo) CanFetchAnyIP() bool {
+func (e *echoip) CanFetchAnyIP() bool {
 	return true
 }
 
-func (i *ifConfigCo) Token() string {
+func (e *echoip) Token() string {
 	return ""
 }
 
 // FetchInfo obtains information on the ip address provided
-// using the ifconfig.co/json API. If the ip is the zero value,
+// using the echoip API at the url given. If the ip is the zero value,
 // the public IP address of the machine is used as the IP.
-func (i *ifConfigCo) FetchInfo(ctx context.Context, ip netip.Addr) (
+func (e *echoip) FetchInfo(ctx context.Context, ip netip.Addr) (
 	result models.PublicIP, err error,
 ) {
-	url := "https://ifconfig.co/json"
+	url := e.url + "/json"
 	if ip.IsValid() {
 		url += "?ip=" + ip.String()
 	}
@@ -48,7 +54,7 @@ func (i *ifConfigCo) FetchInfo(ctx context.Context, ip netip.Addr) (
 		return result, err
 	}
 
-	response, err := i.client.Do(request)
+	response, err := e.client.Do(request)
 	if err != nil {
 		return result, err
 	}