transport/http : Loosen hostname validation to allow ports to be specified

transport/http/host.go

@@ -2,15 +2,34 @@ package http
 
 import (
 	"fmt"
+	"net"
+	"strconv"
 	"strings"
 )
 
 // ValidateEndpointHost validates that the host string passed in is a valid RFC
 // 3986 host. Returns error if the host is not valid.
 func ValidateEndpointHost(host string) error {
 	var errors strings.Builder
-	labels := strings.Split(host, ".")
+	var hostname string
+	var port string
+	var err error
 
+	if strings.Contains(host, ":") {
+		hostname, port, err = net.SplitHostPort(host)
+		if err != nil {
+			errors.WriteString(fmt.Sprintf("\n endpoint %v, failed to parse, got ", host))
+			errors.WriteString(err.Error())
+		}
+
+		if !ValidPortNumber(port) {
+			errors.WriteString(fmt.Sprintf("port number should be in range [0-65535], got %v", port))
+		}
+	} else {
+		hostname = host
+	}
+
+	labels := strings.Split(hostname, ".")
 	for i, label := range labels {
 		if i == len(labels)-1 && len(label) == 0 {
 			// Allow trailing dot for FQDN hosts.
@@ -23,8 +42,12 @@ func ValidateEndpointHost(host string) error {
 		}
 	}
 
-	if len(host) > 255 {
-		errors.WriteString(fmt.Sprintf("\nendpoint host must be less than 255 characters, but was %d", len(host)))
+	if len(hostname) == 0 && len(port) != 0 {
+		errors.WriteString("\nendpoint host with port must not be empty")
+	}
+
+	if len(hostname) > 255 {
+		errors.WriteString(fmt.Sprintf("\nendpoint host must be less than 255 characters, but was %d", len(hostname)))
 	}
 
 	if len(errors.String()) > 0 {
@@ -33,6 +56,19 @@ func ValidateEndpointHost(host string) error {
 	return nil
 }
 
+// ValidPortNumber return if the port is valid RFC 3986 port
+func ValidPortNumber(port string) bool {
+	i, err := strconv.Atoi(port)
+	if err != nil {
+		return false
+	}
+
+	if i < 0 || i > 65535 {
+		return false
+	}
+	return true
+}
+
 // ValidHostLabel returns if the label is a valid RFC 3986 host label.
 func ValidHostLabel(label string) bool {
 	if l := len(label); l == 0 || l > 63 {

transport/http/host_test.go

@@ -5,6 +5,28 @@ import (
 	"testing"
 )
 
+func TestValidPortNumber(t *testing.T) {
+	cases := []struct {
+		Input string
+		Valid bool
+	}{
+		{Input: "123", Valid: true},
+		{Input: "123.0", Valid: false},
+		{Input: "-123", Valid: false},
+		{Input: "65536", Valid: false},
+		{Input: "0", Valid: true},
+	}
+	for i, c := range cases {
+		t.Run(strconv.Itoa(i), func(t *testing.T) {
+			valid := ValidPortNumber(c.Input)
+			if e, a := c.Valid, valid; e != a {
+				t.Errorf("expect valid %v, got %v", e, a)
+			}
+		})
+	}
+
+}
+
 func TestValidHostLabel(t *testing.T) {
 	cases := []struct {
 		Input string
@@ -48,6 +70,10 @@ func TestValidateEndpointHostHandler(t *testing.T) {
 			Input: "123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456789.123456",
 			Valid: false,
 		},
+		"valid host with port number":         {Input: "abd.123:1234", Valid: true},
+		"valid host with invalid port number": {Input: "abc.123:99999", Valid: false},
+		"empty host with port number":         {Input: ":1234", Valid: false},
+		"valid host with empty port number":   {Input: "abc.123:", Valid: false},
 	}
 
 	for name, c := range cases {