Can I get the headers of received CANCEL?

[calvet27]

Hi,

Can I get the headsers of received CANCEL?
From SRF, We can listen the emitted event for canceled inbound request.

req.on('cancel', () => {
  // TODO something.
});

But we cannot get the headers of CANCEL from that way.
It is required to get some causes of firing CANCEL such as Reason header.

CANCEL sip:68050961695239@...:5060 SIP/2.0
From: "Jess Portugal"sip:*1139@...;tag=2aca825f-14fb3c5-1f1d3e-b89f53e0-45090a0a-13c4-759
To: sip:68050961695239@...
Call-ID: 2dca6bc8-127d3ab1-1f1d3e-afd33848-45090a0a-13c4-759
CSeq: 1 CANCEL
Via: SIP/2.0/UDP ...:5060;rport;branch=z9hG4bK-28d9f76a-1f1d3e-798a3bae-bb733988
Max-Forwards: 70
Supported: 100rel,timer,replaces
Reason: SIP ;cause=200 ;text="Call completed elsewhere
User-Agent: ...
Content-Length: 0

Please let me know how to get the headers.

[JSimoni42]

It looks like this is where the CANCEL event is emitted:

drachtio-srf/lib/drachtio-agent.js

Line 593 in 97d8317

obj.pendingNetworkInvites.get(callId).req.emit('cancel', sipMsg) ;

. You can get the headers from the SipMessage passed to the event listener

[calvet27]

@JSimoni42 ,

Thank you for your answer.
But I already tried to do that,

req.on('cancel', async (cancelReq) => {
...
});

But I think cancelReq.headers is not define.
Actually, I double checked that cancelReq is undefined in that case.
Is it a req object from CANCEL?

[davehorton]

@xquanluu can you comment? I think we just dealt with this requirement recently

[xquanluu]

Take a look at this example:

expectCancel(uri) {
    this.srf.invite((req, res) => {
      req.on('cancel', (cancelReq) => {
        const headers = cancelReq.headers;
        console.log(headers);
      })
      this.srf.createB2BUA(req, res, uri)
        .then(({uas, uac}) => {
          throw new Error('unexpected dialog success - expected CANCEL from uac');
        })
        .catch((err) => {
          debug(`expectCancel: expected a final 487, got ${err}`);
          if (err.status === 487) return;
          throw err;
        });
    });
  }

Output:

{
via: 'SIP/2.0/UDP 172.29.0.2:5060;branch=z9hG4bK-1-1-0;rport=5060',
from: 'sipp sip:sipp@172.29.0.2:5060;tag=1SIPpTag001',
to: 'service sip:service@172.29.0.10:5060',
'call-id': '1-1@172.29.0.2-4',
cseq: '1 CANCEL',
reason: 'SIP;cause=200;text="Call completed elsewhere"',
'content-length': '0'
}

[xquanluu]

Not sure is what you are looking for? @calvet27

[xquanluu]

You may want to play with this testcase:
https://github.com/drachtio/drachtio-srf/blob/main/test/scripts/b2b.js#L24

[calvet27]

@xquanluu

Can you give me version information about supporting cancelReq?

[xquanluu]

Can you use drachtio-srf: 4.5.28
drachtio-server: latest

[calvet27]

@xquanluu

I use 4.4.18. After updating to 4.5.28, I will let you know the results.

[calvet27]

@xquanluu

Can I get you tag information of the latest drachtio?
Is it same with 0.8.22?

[xquanluu]

Yes it's correct.

[calvet27]

@xquanluu
But it looks different.
0.8.22 does not give me cancel object but latest give me.
I updated drachtio-srf to 4.5.26.
Any advice?

[xquanluu]

Can you tell me how you build and deployed drachtio? via docker?

[calvet27]

@xquanluu
Yes. I installed Drachtio SIP Server via Docker. The image is from Docker hub.
Drachtio

I had some tests to compare 0.8.22 and latest and then I noticed that the only the latest one worked properly.
cancelReq is undefined with 0.8.22 and Drachtio SRF 4.5.26 was used for both cases.

[xquanluu]

hmm. Strange but yes please use latest tag.,

0.8.2 was released 2 months ago, from that time up to now there is no official release yet.

[calvet27]

@xquanluu

I'm sorry to make you confused. Now 0.8.22 works properly.
Close this issue! Thank you for your support!

[xquanluu]

Closing this issue.