go-sendxmpp/connect.go

// Copyright Martin Dosch.
// Use of this source code is governed by the BSD-2-clause
// license that can be found in the LICENSE file.

package main

import (
	"errors"
	"fmt"
	"net"
	"strings"

	"github.com/mattn/go-xmpp"        // BSD-3-Clause
	"salsa.debian.org/mdosch/xmppsrv" // BSD-2-Clause
)

func connect(options xmpp.Options, directTLS bool) (*xmpp.Client, error) {
	// Look up SRV records if server is not specified manually.
	if options.Host == "" {
		server := options.User[strings.Index(options.User, "@")+1:]
		// Look up xmpp-client SRV records.
		srvMixed, err := xmppsrv.LookupClient(server)
		if len(srvMixed) > 0 && err == nil {
			for _, adr := range srvMixed {
				if !directTLS && adr.Type != "xmpps-client" {
					// Use StartTLS
					options.NoTLS = true
					options.StartTLS = true
				} else if adr.Type == "xmpps-client" {
					// Use direct TLS
					options.NoTLS = false
					options.StartTLS = false
				}
				options.Host = net.JoinHostPort(adr.Target, fmt.Sprint(adr.Port))
				// Connect to server
				client, err := options.NewClient()
				if errors.Unwrap(err) == nil {
					return client, nil
				}
			}
		}
		// Try port 5223 if directTLS is set and no xmpp-client SRV records are provided.
		if directTLS {
			options.NoTLS = false
			options.StartTLS = false
			options.Host = net.JoinHostPort(server, "5223")
		} else {
			// Try port 5222 if no xmpp-client SRV records are provided and directTLS is not set.
			options.NoTLS = true
			options.StartTLS = true
			options.Host = net.JoinHostPort(server, "5222")
		}
	}
	// Connect to server
	client, err := options.NewClient()
	if errors.Unwrap(err) == nil {
		return client, nil
	}
	return client, fmt.Errorf("failed to connect to server: %w", err)
}