[OpenSIPS-Users] del_uri_param failure

[Ben Newlin]

Hi,

I am very glad to have the new del_uri_param function. This was a common problem of mine and it is great not to have to use regex to do this. However, while implementing this I have run into some strange behavior by the function when the URI param being deleted does not exist.

In my case I am using the dialog module and attempting to remove a URI param just after the dialog creation. When the function does not find the URI param, it causes the dialog to immediately be destroyed and all message processing stops, including exiting the script.

Feb 21 22:47:42 [371] DBG:uri:del_uri_param: requested key not found in RURI
Feb 21 22:47:42 [371] DBG:dialog:next_state_dlg: unref dlg 0x7f460780a8c8 with 1 -> 2 in entry 0x7f46077fbfa8
Feb 21 22:47:42 [371] DBG:core:evi_param_set: adding string param
Feb 21 22:47:42 [371] DBG:core:evi_param_set: adding string param
Feb 21 22:47:42 [371] DBG:core:evi_param_set: adding int param
Feb 21 22:47:42 [371] DBG:core:evi_param_set: adding int param
Feb 21 22:47:42 [371] DBG:core:destroy_avp_list: destroying list (nil)
Feb 21 22:47:42 [371] DBG:dialog:next_state_dlg: dialog 0x7f460780a8c8 changed from state 1 to state 5, due event 1
Feb 21 22:47:42 [371] DBG:dialog:dlg_onreply: dialog 0x7f460780a8c8 failed (negative reply)
Feb 21 22:47:42 [371] DBG:dialog:unref_dlg: unref dlg 0x7f460780a8c8 with 1 -> 1 in entry 0x7f46077fbfa8
Feb 21 22:47:42 [371] DBG:dialog:unref_dlg: unref dlg 0x7f460780a8c8 with 1 -> 0 in entry 0x7f46077fbfa8
Feb 21 22:47:42 [371] DBG:dialog:unref_dlg: ref <=0 for dialog 0x7f460780a8c8
Feb 21 22:47:42 [371] DBG:dialog:destroy_dlg: destroying dialog 0x7f460780a8c8
Feb 21 22:47:42 [371] DBG:dialog:destroy_dlg: dlg expired or not in list - dlg 0x7f460780a8c8 [3710:1818203549] with clid '2-185 at 127.0.0.1' and tags '185SIPpTag002' 'NULL'
Feb 21 22:47:42 [371] DBG:core:destroy_avp_list: destroying list 0x7f460780c048
Feb 21 22:47:42 [371] DBG:core:receive_msg: cleaning up

The logs indicate that a DLG_EVENT_TDEL is being raised which, when the dialog is still in UNCONFIRMED state, causes the dialog to be destroyed. It’s not clear to me how or why the del_uri_param function could be doing this, especially as a transaction hasn’t even been created for the message yet in this case. I’m not sure what effect this would have if the dialog is in other states or at other times during the call.

It took me a while to realize it was the del_uri_param function causing this, as it seems so strange. But I have verified that when I remove the function, or when I verify the URI param exists before calling the function, everything is fine. That workaround works perfectly well, but it seemed such strange and catastrophic error behavior to drop the entire message that I wanted to report it anyway to see if anything needed to be addressed.

Call traces can be found here: https://pastebin.com/9FnmJCD9

You will see the same INVITE is offered multiple times as OpenSIPS is not responding after dropping the previous requests and dialog.

Thanks,
Ben Newlin

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.opensips.org/pipermail/users/attachments/20180221/3abc376a/attachment-0001.html>