added the normal arguments to NewClient to Options and made that a central entrypoint for creating new clients

xmpp.go

@@ -97,54 +97,79 @@ func connect(host, user, passwd string) (net.Conn, error) {
 
 // Options are used to specify additional options for new clients, such as a Resource.
 type Options struct {
+	// Host specifies what host to connect to, as either "hostname" or "hostname:port"
+	// If host is not specified, the  DNS SRV should be used to find the host from the domainpart of the JID.
+	// Default the port to 5222.
+	Host string
+
+	// User specifies what user to authenticate to the remote server.
+	User string
+
+	// Password supplies the password to use for authentication with the remote server.
+	Password string
+
 	// Resource specifies an XMPP client resource, like "bot", instead of accepting one
 	// from the server.  Use "" to let the server generate one for your client.
 	Resource string
+
+	// NoTLS disables TLS and specifies that a plain old unencrypted TCP connection should
+	// be used.
+	NoTLS bool
+}
+
+// NewClient establishes a new Client connection based on a set of Options.
+func (o Options) NewClient() (*Client, error) {
+	host := o.Host
+	c, err := connect(host, o.User, o.Password)
+	if err != nil {
+		return nil, err
+	}
+
+	client := new(Client)
+	if o.NoTLS {
+		client.conn = c
+	} else {
+		tlsconn := tls.Client(c, &DefaultConfig)
+		if err = tlsconn.Handshake(); err != nil {
+			return nil, err
+		}
+		if strings.LastIndex(o.Host, ":") > 0 {
+			host = host[:strings.LastIndex(o.Host, ":")]
+		}
+		if err = tlsconn.VerifyHostname(host); err != nil {
+			return nil, err
+		}
+		client.conn = tlsconn
+	}
+
+	if err := client.init(&o); err != nil {
+		client.Close()
+		return nil, err
+	}
+
+	return client, nil
 }
 
 // NewClient creates a new connection to a host given as "hostname" or "hostname:port".
 // If host is not specified, the  DNS SRV should be used to find the host from the domainpart of the JID.
 // Default the port to 5222.
-func NewClient(host, user, passwd string, opts *Options) (*Client, error) {
+func NewClient(host, user, passwd string) (*Client, error) {
-	c, err := connect(host, user, passwd)
+	opts := Options{
-	if err != nil {
+		Host:     host,
-		return nil, err
+		User:     user,
+		Password: passwd,
 	}
-
+	return opts.NewClient()
-	tlsconn := tls.Client(c, &DefaultConfig)
-	if err = tlsconn.Handshake(); err != nil {
-		return nil, err
-	}
-
-	if strings.LastIndex(host, ":") > 0 {
-		host = host[:strings.LastIndex(host, ":")]
-	}
-	if err = tlsconn.VerifyHostname(host); err != nil {
-		return nil, err
-	}
-
-	client := new(Client)
-	client.conn = tlsconn
-	if err := client.init(user, passwd, opts); err != nil {
-		client.Close()
-		return nil, err
-	}
-	return client, nil
 }
 
-func NewClientNoTLS(host, user, passwd string, opts *Options) (*Client, error) {
+func NewClientNoTLS(host, user, passwd string) (*Client, error) {
-	c, err := connect(host, user, passwd)
+	opts := Options{
-	if err != nil {
+		Host:     host,
-		return nil, err
+		User:     user,
+		Password: passwd,
+		NoTLS:    true,
 	}
-
+	return opts.NewClient()
-	client := new(Client)
-	client.conn = c
-	if err := client.init(user, passwd, opts); err != nil {
-		client.Close()
-		return nil, err
-	}
-	return client, nil
 }
 
 func (c *Client) Close() error {
@@ -184,23 +209,18 @@ func cnonce() string {
 	return fmt.Sprintf("%016x", cn)
 }
 
-func (c *Client) init(user, passwd string, opts *Options) error {
+func (c *Client) init(o *Options) error {
 	// For debugging: the following causes the plaintext of the connection to be duplicated to stdout.
 	//c.p = xml.NewDecoder(tee{c.conn, os.Stdout})
 	c.p = xml.NewDecoder(c.conn)
 
-	a := strings.SplitN(user, "@", 2)
+	a := strings.SplitN(o.User, "@", 2)
 	if len(a) != 2 {
-		return errors.New("xmpp: invalid username (want user@domain): " + user)
+		return errors.New("xmpp: invalid username (want user@domain): " + o.User)
 	}
-	user = a[0]
+	user := a[0]
 	domain := a[1]
 
-	resource := ""
-	if opts != nil {
-		resource = opts.Resource
-	}
-
 	// Declare intent to be a jabber client.
 	fmt.Fprintf(c.conn, "<?xml version='1.0'?>\n"+
 		"<stream:stream to='%s' xmlns='%s'\n"+
@@ -228,7 +248,7 @@ func (c *Client) init(user, passwd string, opts *Options) error {
 		if m == "PLAIN" {
 			mechanism = m
 			// Plain authentication: send base64-encoded \x00 user \x00 password.
-			raw := "\x00" + user + "\x00" + passwd
+			raw := "\x00" + user + "\x00" + o.Password
 			enc := make([]byte, base64.StdEncoding.EncodedLen(len(raw)))
 			base64.StdEncoding.Encode(enc, []byte(raw))
 			fmt.Fprintf(c.conn, "<auth xmlns='%s' mechanism='PLAIN'>%s</auth>\n",
@@ -265,7 +285,7 @@ func (c *Client) init(user, passwd string, opts *Options) error {
 			cnonceStr := cnonce()
 			digestUri := "xmpp/" + domain
 			nonceCount := fmt.Sprintf("%08x", 1)
-			digest := saslDigestResponse(user, realm, passwd, nonce, cnonceStr, "AUTHENTICATE", digestUri, nonceCount)
+			digest := saslDigestResponse(user, realm, o.Password, nonce, cnonceStr, "AUTHENTICATE", digestUri, nonceCount)
 			message := "username=" + user + ", realm=" + realm + ", nonce=" + nonce + ", cnonce=" + cnonceStr + ", nc=" + nonceCount + ", qop=" + qop + ", digest-uri=" + digestUri + ", response=" + digest + ", charset=" + charset
 			fmt.Fprintf(c.conn, "<response xmlns='%s'>%s</response>\n", nsSASL, base64.StdEncoding.EncodeToString([]byte(message)))
 
@@ -317,10 +337,10 @@ func (c *Client) init(user, passwd string, opts *Options) error {
 	}
 
 	// Send IQ message asking to bind to the local user name.
-	if resource == "" {
+	if o.Resource == "" {
 		fmt.Fprintf(c.conn, "<iq type='set' id='x'><bind xmlns='%s'></bind></iq>\n", nsBind)
 	} else {
-		fmt.Fprintf(c.conn, "<iq type='set' id='x'><bind xmlns='%s'><resource>%s</resource></bind></iq>\n", nsBind, resource)
+		fmt.Fprintf(c.conn, "<iq type='set' id='x'><bind xmlns='%s'><resource>%s</resource></bind></iq>\n", nsBind, o.Resource)
 	}
 	var iq clientIQ
 	if err = c.p.DecodeElement(&iq, nil); err != nil {