go/r3-netstatus/r3xmppbot/ping.go

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