go/r3-netstatus/r3xmppbot/ping.go

   1 // (c) Bernhard Tittelbach, 2013
   2
   3 package r3xmppbot
   4
   5 import (
   6         "encoding/xml"
   7         "time"
   8
   9         xmpp "code.google.com/p/goexmpp"
  10 )
  11
  12 // XMPP Ping
  13 type XMPPPing struct {
  14         XMLName xml.Name `xml:"urn:xmpp:ping ping"`
  15 }
  16
  17 func HandleServerToClientPing(iq *xmpp.Iq, xmppout chan<- xmpp.Stanza) bool {
  18         ///<iq from='juliet@capulet.lit/balcony' to='capulet.lit' id='s2c1' type='result'/>
  19         if iq.Type != "get" {
  20                 return false
  21         }
  22         for _, ele := range iq.Nested {
  23                 if _, ok := ele.(*XMPPPing); ok {
  24                         xmppout <- &xmpp.Iq{Header: xmpp.Header{To: iq.From, From: iq.To, Id: iq.Id, Type: "result"}}
  25                         return true
  26                 }
  27         }
  28         return false
  29 }
  30
  31 func (botdata *XmppBot) PingServer(timeout_ms time.Duration) (is_up bool) {
  32         ///<iq from='juliet@capulet.lit/balcony' to='capulet.lit' id='c2s1' type='get'>
  33         ///  <ping xmlns='urn:xmpp:ping'/>
  34         ///</iq>
  35         server_jid := new(xmpp.JID)
  36         server_jid.Set(botdata.my_jid_)
  37         iqping := &xmpp.Iq{Header: xmpp.Header{To: server_jid.Domain,
  38                 From:   botdata.my_jid_,
  39                 Id:     <-xmpp.Id,
  40                 Type:   "get",
  41                 Nested: []interface{}{XMPPPing{}}}}
  42         pong := make(chan bool, 1)
  43         defer close(pong)
  44         f := func(v xmpp.Stanza) bool {
  45                 defer recover() //recover from writing to possibly already closed chan
  46                 let_others_handle_stanza := false
  47                 iq, ok := v.(*xmpp.Iq)
  48                 if !ok {
  49                         Syslog_.Printf("response to iq ping wasn't iq: %s", v)
  50                         pong <- false
  51                         return true //let other handlers process reply
  52                 }
  53                 if iq.Type == "error" && iq.Error != nil && iq.Error.Type == "cancel" {
  54                         Debug_.Printf("response to iq ping was cancel, server does not support ping")
  55                         //server does not support ping, but at least we know server is still there
  56                 } else if iq.Type != "result" {
  57                         Syslog_.Printf("response to iq ping was not pong: %s", v)
  58                         let_others_handle_stanza = true //let other handlers process reply
  59                 }
  60                 pong <- true
  61                 return let_others_handle_stanza // return false so that Stanza v will not be appear in xmppclient_.Out()
  62         }
  63         botdata.xmppclient_.HandleStanza(iqping.Id, f)
  64         botdata.xmppclient_.Out <- iqping
  65         go func() {
  66                 defer func() {
  67                         if x := recover(); x == nil {
  68                                 Syslog_.Printf("response to iq ping timed out !!")
  69                         }
  70                 }() //recover from writing to possibly already closed chan. If we did not need to recover, then Handler did not receive reply
  71                 time.Sleep(timeout_ms * time.Millisecond)
  72                 pong <- false //xmpp ping timed out
  73         }()
  74         return <-pong
  75 }