add JoinDefaultPort for servers' configuration

5 files changed, 25 insertions, 15 deletions

diff --git a/finger/serve.go b/finger/serve.go
index 5675dcf..1bc69b8 100644
--- a/finger/serve.go
+++ b/finger/serve.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 	"io"
 	"net"
-	"strings"
 
 	sr "tildegit.org/tjp/sliderule"
 	"tildegit.org/tjp/sliderule/internal"
@@ -30,9 +29,8 @@ func NewServer(
 ) (sr.Server, error) {
 	fs := &fingerServer{handler: handler}
 
-	if strings.IndexByte(hostname, ':') < 0 {
-		hostname = net.JoinHostPort(hostname, "79")
-	}
+	hostname = internal.JoinDefaultPort(hostname, "79")
+	address = internal.JoinDefaultPort(address, "79")
 
 	var err error
 	fs.Server, err = internal.NewServer(ctx, hostname, network, address, errLog, fs.handleConn)
diff --git a/gemini/serve.go b/gemini/serve.go
index 01e186f..a439ce0 100644
--- a/gemini/serve.go
+++ b/gemini/serve.go
@@ -38,9 +38,8 @@ func NewServer(
 ) (sr.Server, error) {
 	s := &server{handler: handler}
 
-	if strings.IndexByte(hostname, ':') < 0 {
-		hostname = net.JoinHostPort(hostname, "1965")
-	}
+	hostname = internal.JoinDefaultPort(hostname, "1965")
+	address = internal.JoinDefaultPort(address, "1965")
 
 	internalServer, err := internal.NewServer(ctx, hostname, network, address, errorLog, s.handleConn)
 	if err != nil {
diff --git a/gopher/serve.go b/gopher/serve.go
index bad7935..7b32f2f 100644
--- a/gopher/serve.go
+++ b/gopher/serve.go
@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"io"
 	"net"
-	"strings"
 
 	sr "tildegit.org/tjp/sliderule"
 	"tildegit.org/tjp/sliderule/internal"
@@ -31,9 +30,8 @@ func NewServer(
 ) (sr.Server, error) {
 	gs := &gopherServer{handler: handler}
 
-	if strings.IndexByte(hostname, ':') < 0 {
-		hostname = net.JoinHostPort(hostname, "70")
-	}
+	hostname = internal.JoinDefaultPort(hostname, "70")
+	address = internal.JoinDefaultPort(address, "70")
 
 	var err error
 	gs.Server, err = internal.NewServer(ctx, hostname, network, address, errLog, gs.handleConn)
diff --git a/internal/server.go b/internal/server.go
index 3efdf6e..e3fbfb2 100644
--- a/internal/server.go
+++ b/internal/server.go
@@ -3,6 +3,7 @@ package internal
 import (
 	"context"
 	"net"
+	"strings"
 	"sync"
 )
 
@@ -126,3 +127,19 @@ func (s *Server) propagateClose() {
 		_ = s.Listener.Close()
 	}()
 }
+
+// JoinDefaultPort appends ":<port>" iff the address does not already contain a port.
+func JoinDefaultPort(address string, port string) string {
+	if address[0] == '[' {
+		hend := strings.LastIndexByte(address, ']')
+		if len(address) > hend+1 && address[hend+1] == ':' {
+			return address
+		}
+		return net.JoinHostPort(address[1:hend], port)
+	}
+
+	if strings.Contains(address, ":") {
+		return address
+	}
+	return net.JoinHostPort(address, port)
+}
diff --git a/spartan/serve.go b/spartan/serve.go
index 61199b1..a477a45 100644
--- a/spartan/serve.go
+++ b/spartan/serve.go
@@ -7,7 +7,6 @@ import (
 	"fmt"
 	"io"
 	"net"
-	"strings"
 
 	sr "tildegit.org/tjp/sliderule"
 	"tildegit.org/tjp/sliderule/internal"
@@ -32,9 +31,8 @@ func NewServer(
 ) (sr.Server, error) {
 	ss := &spartanServer{handler: handler}
 
-	if strings.IndexByte(hostname, ':') < 0 {
-		hostname = net.JoinHostPort(hostname, "300")
-	}
+	hostname = internal.JoinDefaultPort(hostname, "300")
+	address = internal.JoinDefaultPort(address, "300")
 
 	var err error
 	ss.Server, err = internal.NewServer(ctx, hostname, network, address, errLog, ss.handleConn)