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// Copyright 2013 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package xmpp implements the XMPP IM protocol, as specified in RFC 6120 and
// 6121.
package xmpp
import (
"errors"
"net"
"strconv"
"strings"
"golang.org/x/net/proxy"
ourNet "github.com/twstrike/coyim/net"
)
var (
// ErrServiceNotAvailable means that the service is decidedly not available at this domain
ErrServiceNotAvailable = errors.New("service not available")
)
// Resolve performs a DNS SRV lookup for the XMPP server that serves the given
// domain.
func Resolve(domain string) (hostport []string, err error) {
return massage(net.LookupSRV("xmpp-client", "tcp", domain))
}
// ResolveSRVWithProxy performs a DNS SRV lookup for the xmpp server that serves the given domain over the given proxy
func ResolveSRVWithProxy(proxy proxy.Dialer, domain string) (hostport []string, err error) {
return massage(ourNet.LookupSRV(proxy, "xmpp-client", "tcp", domain))
}
func massage(cname string, addrs []*net.SRV, err error) ([]string, error) {
if err != nil {
return nil, err
}
// https://xmpp.org/rfcs/rfc6120.html#tcp-resolution-prefer
if len(addrs) == 1 && addrs[0].Target == "." {
return nil, ErrServiceNotAvailable
}
ret := make([]string, 0, len(addrs))
for _, addr := range addrs {
hostport := net.JoinHostPort(
strings.TrimSuffix(addr.Target, "."),
strconv.Itoa(int(addr.Port)),
)
ret = append(ret, hostport)
}
return ret, nil
}
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