go/r3-netstatus/r3xmppbot/ping.go

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