Improve client port handling and fix IPv6 client port testing

Using [golines](https://github.com/segmentio/golines):
`golines -w .`

README.md

@@ -7,7 +7,7 @@
   - [Usage](#usage)
   - [Examples](#examples)
     - [Run a default TCP server](#run-a-default-tcp-server)
-    - [Run a TLS server only](#run-a-tls-server-only)
+    - [Run a TLS (HTTP/2) server only](#run-a-tls-http2-server-only)
     - [Run a default TCP server with a custom template and trust a custom header set by an upstream proxy](#run-a-default-tcp-server-with-a-custom-template-and-trust-a-custom-header-set-by-an-upstream-proxy)
   - [Download](#download)
   - [Docker](#docker)
@@ -30,7 +30,7 @@ curl -6 ifconfig.es
 
 ## Features
 
-- TLS is avaliable.
+- TLS and HTTP/2.
 - Can run behind a proxy by trusting a custom header (usually `X-Real-IP`) to figure out the source IP address.
 - IPv4 and IPv6.
 - Geolocation info including ASN. This feature is possible thanks to [maxmind](https://dev.maxmind.com/geoip/geolite2-free-geolocation-data?lang=en) GeoLite2 databases. In order to use these databases, a license key is needed. Please visit Maxmind site for further instructions and get a free license.
@@ -96,7 +96,7 @@ Usage of ./whatismyip:
 ./whatismyip -geoip2-city ./test/GeoIP2-City-Test.mmdb -geoip2-asn ./test/GeoLite2-ASN-Test.mmdb
 ```
 
-### Run a TLS server only
+### Run a TLS (HTTP/2) server only
 
 ```bash
 ./whatismyip -geoip2-city ./test/GeoIP2-City-Test.mmdb -geoip2-asn ./test/GeoLite2-ASN-Test.mmdb -bind "" -tls-bind :8081 -tls-crt ./test/server.pem -tls-key ./test/server.key

cmd/whatismyip.go

@@ -112,7 +112,8 @@ func runTLSServer() {
 
 	go func() {
 		log.Printf("Starting TLS server listening on %s", setting.App.TLSAddress)
-		if err := tlsServer.ListenAndServeTLS(setting.App.TLSCrtPath, setting.App.TLSKeyPath); err != nil && !errors.Is(err, http.ErrServerClosed) {
+		if err := tlsServer.ListenAndServeTLS(setting.App.TLSCrtPath, setting.App.TLSKeyPath); err != nil &&
+			!errors.Is(err, http.ErrServerClosed) {
 			log.Fatal(err)
 		}
 		log.Printf("Stopping TLS server...")

internal/setting/app.go

@@ -36,11 +36,23 @@ func Setup() {
 	city := flag.String("geoip2-city", "", "Path to GeoIP2 city database")
 	asn := flag.String("geoip2-asn", "", "Path to GeoIP2 ASN database")
 	template := flag.String("template", "", "Path to template file")
-	address := flag.String("bind", defaultAddress, "Listening address (see https://pkg.go.dev/net?#Listen)")
+	address := flag.String(
-	addressTLS := flag.String("tls-bind", "", "Listening address for TLS (see https://pkg.go.dev/net?#Listen)")
+		"bind",
+		defaultAddress,
+		"Listening address (see https://pkg.go.dev/net?#Listen)",
+	)
+	addressTLS := flag.String(
+		"tls-bind",
+		"",
+		"Listening address for TLS (see https://pkg.go.dev/net?#Listen)",
+	)
 	tlsCrtPath := flag.String("tls-crt", "", "When using TLS, path to certificate file")
 	tlsKeyPath := flag.String("tls-key", "", "When using TLS, path to private key file")
-	trustedHeader := flag.String("trusted-header", "", "Trusted request header for remote IP (e.g. X-Real-IP)")
+	trustedHeader := flag.String(
+		"trusted-header",
+		"",
+		"Trusted request header for remote IP (e.g. X-Real-IP)",
+	)
 	ver := flag.Bool("version", false, "Output version information and exit")
 
 	flag.Parse()

router/generic.go

@@ -5,7 +5,6 @@ import (
 	"net/http"
 	"path/filepath"
 	"regexp"
-	"strings"
 
 	"github.com/dcarrillo/whatismyip/internal/httputils"
 	"github.com/dcarrillo/whatismyip/internal/setting"
@@ -46,12 +45,14 @@ func getRoot(ctx *gin.Context) {
 }
 
 func getClientPortAsString(ctx *gin.Context) {
-	ctx.String(http.StatusOK, strings.Split(ctx.Request.RemoteAddr, ":")[1]+"\n")
+	_, port, _ := net.SplitHostPort(ctx.Request.RemoteAddr)
+	ctx.String(http.StatusOK, port+"\n")
 }
 
 func getAllAsString(ctx *gin.Context) {
 	output := "IP: " + ctx.ClientIP() + "\n"
-	output += "Client Port: " + strings.Split(ctx.Request.RemoteAddr, ":")[1] + "\n"
+	_, port, _ := net.SplitHostPort(ctx.Request.RemoteAddr)
+	output += "Client Port: " + port + "\n"
 
 	r := service.Geo{IP: net.ParseIP(ctx.ClientIP())}
 	if record := r.LookUpCity(); record != nil {
@@ -82,10 +83,11 @@ func jsonOutput(ctx *gin.Context) JSONResponse {
 		version = 6
 	}
 
+	_, port, _ := net.SplitHostPort(ctx.Request.RemoteAddr)
 	return JSONResponse{
 		IP:              ctx.ClientIP(),
 		IPVersion:       version,
-		ClientPort:      strings.Split(ctx.Request.RemoteAddr, ":")[1],
+		ClientPort:      port,
 		Country:         cityRecord.Country.Names["en"],
 		CountryCode:     cityRecord.Country.ISOCode,
 		City:            cityRecord.City.Names["en"],

router/generic_test.go

@@ -1,6 +1,7 @@
 package router
 
 import (
+	"net"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -9,7 +10,18 @@ import (
 )
 
 func TestIP4RootFromCli(t *testing.T) {
-	uas := []string{"", "curl", "wget", "libwww-perl", "python", "ansible-httpget", "HTTPie", "WindowsPowerShell", "http_request", "Go-http-client"}
+	uas := []string{
+		"",
+		"curl",
+		"wget",
+		"libwww-perl",
+		"python",
+		"ansible-httpget",
+		"HTTPie",
+		"WindowsPowerShell",
+		"http_request",
+		"Go-http-client",
+	}
 
 	req, _ := http.NewRequest("GET", "/", nil)
 	req.Header.Set("X-Real-IP", testIP.ipv4)
@@ -37,7 +49,7 @@ func TestHost(t *testing.T) {
 
 func TestClientPort(t *testing.T) {
 	req, _ := http.NewRequest("GET", "/client-port", nil)
-	req.RemoteAddr = testIP.ipv4 + ":" + "1000"
+	req.RemoteAddr = net.JoinHostPort(testIP.ipv4 , "1000")
 	req.Header.Set("X-Real-IP", testIP.ipv4)
 
 	w := httptest.NewRecorder()
@@ -60,10 +72,10 @@ func TestNotFound(t *testing.T) {
 
 func TestJSON(t *testing.T) {
 	expectedIPv4 := `{"client_port":"1000","ip":"81.2.69.192","ip_version":4,"country":"United Kingdom","country_code":"GB","city":"London","latitude":51.5142,"longitude":-0.0931,"postal_code":"","time_zone":"Europe/London","asn":0,"asn_organization":"","host":"test","headers":{"X-Real-Ip":["81.2.69.192"]}}`
-	expectedIPv6 := `{"asn":3352, "asn_organization":"TELEFONICA DE ESPANA", "city":"", "client_port":"9000", "country":"", "country_code":"", "headers":{"X-Real-Ip":["2a02:9000::1"]}, "host":"test", "ip":"2a02:9000::1", "ip_version":6, "latitude":0, "longitude":0, "postal_code":"", "time_zone":""}`
+	expectedIPv6 := `{"asn":3352, "asn_organization":"TELEFONICA DE ESPANA", "city":"", "client_port":"1000", "country":"", "country_code":"", "headers":{"X-Real-Ip":["2a02:9000::1"]}, "host":"test", "ip":"2a02:9000::1", "ip_version":6, "latitude":0, "longitude":0, "postal_code":"", "time_zone":""}`
 
 	req, _ := http.NewRequest("GET", "/json", nil)
-	req.RemoteAddr = testIP.ipv4 + ":" + "1000"
+	req.RemoteAddr = net.JoinHostPort(testIP.ipv4, "1000")
 	req.Host = "test"
 	req.Header.Set("X-Real-IP", testIP.ipv4)
 
@@ -74,7 +86,7 @@ func TestJSON(t *testing.T) {
 	assert.Equal(t, contentType.json, w.Header().Get("Content-Type"))
 	assert.JSONEq(t, expectedIPv4, w.Body.String())
 
-	req.RemoteAddr = testIP.ipv6 + ":" + "1000"
+	req.RemoteAddr = net.JoinHostPort(testIP.ipv6, "1000")
 	req.Host = "test"
 	req.Header.Set("X-Real-IP", testIP.ipv6)
 
@@ -106,7 +118,7 @@ X-Real-Ip: 81.2.69.192
 `
 
 	req, _ := http.NewRequest("GET", "/all", nil)
-	req.RemoteAddr = testIP.ipv4 + ":" + "1000"
+	req.RemoteAddr = net.JoinHostPort(testIP.ipv4 , "1000")
 	req.Host = "test"
 	req.Header.Set("X-Real-IP", testIP.ipv4)
 	req.Header.Set("Header1", "one")