discover

Documentation

Overview

Package discover is used to look up information about XMPP-based services.

Index

• Variables
• func LookupBOSH(ctx context.Context, resolver *net.Resolver, client *http.Client, ...) (urls []string, err error)
• func LookupPort(network, service string) (uint16, error)
• func LookupService(ctx context.Context, resolver *net.Resolver, service, network string, ...) (addrs []*net.SRV, err error)
• func LookupWebsocket(ctx context.Context, resolver *net.Resolver, client *http.Client, ...) (urls []string, err error)
• type Link
• type XRD

Variables

var (
	ErrNoServiceAtAddress = errors.New("This address does not offer the requested service")
)

Errors related to address and service lookups.

Functions

func LookupBOSH

func LookupBOSH(ctx context.Context, resolver *net.Resolver, client *http.Client, addr *jid.JID) (urls []string, err error)

LookupBOSH discovers BOSH endpoints that are valid for the given address using DNS TXT records and Web Host Metadata as described in XEP-0156. If client is nil, only DNS is queried.

func LookupPort

func LookupPort(network, service string) (uint16, error)

LookupPort returns the default port for the provided network and service using net.LookupPort. If the provided service is one of xmpp-client, xmpp-server, or xmpp-bosh and it is not found by net.LookupPort, a default value is returned.

func LookupService

func LookupService(ctx context.Context, resolver *net.Resolver, service, network string, addr net.Addr) (addrs []*net.SRV, err error)

LookupService looks for an XMPP service hosted by the given address. It returns addresses from SRV records or the default domain (as a fake SRV record) if no real records exist. Service should be one of "xmpp-client" or "xmpp-server".

func LookupWebsocket

func LookupWebsocket(ctx context.Context, resolver *net.Resolver, client *http.Client, addr *jid.JID) (urls []string, err error)

LookupWebsocket discovers websocket endpoints that are valid for the given address using DNS TXT records and Web Host Metadata as described in XEP-0156. If client is nil, only DNS is queried.

Types

type Link

type Link struct {
	Rel  string `xml:"rel,attr"`
	Href string `xml:"href,attr"`
}

Link is an individual hyperlink in an XRD document.

type XRD

type XRD struct {
	XMLName xml.Name `xml:"http://docs.oasis-open.org/ns/xri/xrd-1.0 XRD"`
	Links   []Link   `xml:"Link"`
}

XRD represents an Extensible Resource Descriptor document of the form:

<?xml version='1.0' encoding=utf-9'?>
<XRD xmlns='http://docs.oasis-open.org/ns/xri/xrd-1.0'>
  …
  <Link rel="urn:xmpp:alt-connections:xbosh"
        href="https://web.example.com:5280/bosh" />
  <Link rel="urn:xmpp:alt-connections:websocket"
        href="wss://web.example.com:443/ws" />
  …
</XRD>

as defined by RFC 6415 and OASIS.XRD-1.0.