Look up SRV records for xmpp- and xmpps-client

connect.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"fmt"
+	"net"
+	"strings"
+
+	"github.com/mattn/go-xmpp" // BSD-3-Clause
+)
+
+func connect(options xmpp.Options, directTLS bool) (*xmpp.Client, error) {
+
+	// Lookup SRV records if server is not specified manually
+	if options.Host == "" {
+		server := options.User[strings.LastIndex(options.User, "@")+1:]
+		// Lookup xmpp-client SRV records if direct TLS is not required
+		if !directTLS {
+			// TODO: Fallback to 5222 if no xmpp-client SRV records exist
+			if _, addrs, err := net.LookupSRV("xmpp-client", "tcp", server); err == nil {
+				if len(addrs) > 0 {
+					for _, adr := range addrs {
+						options.Host = fmt.Sprintf("%s:%d", adr.Target, adr.Port)
+						// Connect to server
+						client, err := options.NewClient()
+						if err == nil {
+							return client, err
+						}
+					}
+				}
+			}
+			// TODO: Quit with error if NoTLS is set
+			// Unset STartTLS as we try direct TLS now
+			options.NoTLS = false
+			options.StartTLS = false
+		}
+		// Lookup xmpps-client SRV records
+		// TODO: Fallback to 5223 and 443 if no xmpps-client SRV records exist
+		if _, addrs, err := net.LookupSRV("xmpps-client", "tcp", server); err == nil {
+			if len(addrs) > 0 {
+				for _, adr := range addrs {
+					options.Host = fmt.Sprintf("%s:%d", adr.Target, adr.Port)
+					// Connect to server
+					client, err := options.NewClient()
+					if err == nil {
+						return client, err
+					}
+				}
+			}
+		}
+	}
+	client, err := options.NewClient()
+	return client, err
+}

go-sendxmpp.go

@@ -8,10 +8,8 @@ import (
 	"bufio"
 	"crypto/tls"
 	"errors"
-	"fmt"
 	"io"
 	"log"
-	"net"
 	"os"
 	"os/exec"
 	"os/user"
@@ -291,30 +289,6 @@ func main() {
 		server = *flagServer
 	}
 
-	// Determine server part if no server is specified.
-	if server == "" {
-		server = strings.Split(user, "@")[1]
-
-		// Lookup SRV record for xmpps-client if direct TLS is requested
-		if *flagTLS {
-			if _, addrs, err := net.LookupSRV("xmpps-client", "tcp", server); err == nil {
-
-				if len(addrs) > 0 {
-					// Default to first record
-					server = fmt.Sprintf("%s:%d", addrs[0].Target, addrs[0].Port)
-					defP := addrs[0].Priority
-					for _, adr := range addrs {
-						if adr.Priority < defP {
-							server = fmt.Sprintf("%s:%d", adr.Target, adr.Port)
-							defP = adr.Priority
-						}
-					}
-				}
-			}
-		}
-
-	}
-
 	// Overwrite password if specified via command line flag.
 	if *flagPassword != "" {
 		password = *flagPassword
@@ -333,20 +307,23 @@ func main() {
 
 	// Use ALPN
 	var tlsConfig tls.Config
-	tlsConfig.ServerName = strings.Split(user, "@")[1]
+	tlsConfig.ServerName = user[strings.LastIndex(user, "@")+1:]
 	tlsConfig.NextProtos = append(tlsConfig.NextProtos, "xmpp-client")
 	tlsConfig.InsecureSkipVerify = *flagSkipVerify
 
 	// Set XMPP connection options.
 	options := xmpp.Options{
-		Host:      server,
-		User:      user,
-		Resource:  *flagResource,
-		Password:  password,
-		NoTLS:     !*flagTLS,
-		StartTLS:  !*flagTLS,
-		Debug:     *flagDebug,
-		TLSConfig: &tlsConfig,
+		Host:        server,
+		User:        user,
+		// TODO: Check whether the timeout is reasonable or maybe make
+		// it configurable
+		DialTimeout: 1 * time.Second,
+		Resource:    *flagResource,
+		Password:    password,
+		NoTLS:       !*flagTLS,
+		StartTLS:    !*flagTLS,
+		Debug:       *flagDebug,
+		TLSConfig:   &tlsConfig,
 	}
 
 	// Read message from file.
@@ -358,7 +335,7 @@ func main() {
 	}
 
 	// Connect to server.
-	client, err := options.NewClient()
+	client, err := connect(options, *flagTLS)
 	if err != nil {
 		log.Fatal(err)
 	}