[SR-Users] Re: from TCP to UDP and Kamailio doing it wrong

If you just strip the incoming ;transport=tcp attribute, I think all should be well when t_relay() consumes the modified RURI. > On 7 Mar 2024, at 12:48, Alberto Diez via sr-users <sr-users(a)lists.kamailio.org> wrote: > > Hi Sergiu, > yes I am pretty sure something is going wrong. > I do have kamailio listening udp sockets and also the dispatcher is on UDP doing SIP OPTIONS over UDP all the time without any problem. > I have not tried forcing the socket I tried to find out why kamailio is trying to use TCP with the targets even when I use t_relay_to_udp and that's how I ended up finding that function which claims not to do something if next_hop is 0 but doing it nevertheless (which I guess is something going wrong in general in Kamailio not in particular in my setup). > I will try forcing the socket, but that crazy tm module function rewrites the socket was already given as a destination (yes I already checked that in the C code before!) > Best regards > alberto > El 07/03/2024 a las 17:43, Sergiu Pojoga escribió: >> You must be doing something essentially wrong if it came down to checking C functions for something as trivial as transport conversion.. >> >> Are you sure you have a UDP listening socket? >> kamcmd corex.list_sockets >> >> Result of: >> kamcmd dispatcher.list >> >> Have you tried forcing the send socket? >> https://www.kamailio.org/wiki/cookbooks/devel/pseudovariables#fs_-_forced_s… >> >> Cheers >> >> On Thu, Mar 7, 2024 at 11:27 AM Alberto Diez via sr-users <sr-users(a)lists.kamailio.org> wrote: >> Hi kamailio community, >> >> I have an issue with a Kamailio 5.7. It's listening both in TCP and >> UDP. In my scenario requests arrive from devices on TCP, but I want to >> forward to the next hops on UDP. I am avoiding using any type of DNS >> resolution; since I am always forwarding to predefined next hops I am >> using the dispatcher module (defined with the IP addresses and >> transport=udp) or I wrote config files using t_relay_to_udp or >> t_relay_to with a udp: followed by IP address. I never set up FQDNS >> only IP addresses and in all of them I explicitly mention UDP. >> >> In all of these scenarios I have tried Kamailio insists in trying to use >> TCP with the next hop and failing because the next_hop is only UDP. I >> guess because the message arrived using TCP Kamilio does that but I find >> the behavior very confusing. >> >> I nailed down that in my situation its the tm module function >> prepare_new_uac (in file src/modules/tm/t_fwd.c line 119) being the one >> that missbehaves. The documentation of the function says literraly : >> >> "* t->uac[branch].request.dst will be filled if next_hop !=0 with the result >> * of the DNS resolution (next_hop, fproto and fsocket). >> * If next_hop is 0 all the dst members except the send_flags are read-only >> * (send_flags it's updated) and are supposed to be pre-filled." >> >> I found out that even when next_hop is 0 the function changes the >> t->uac[branch].request.dst proto, socket etc. its there that the >> kamailio takes the wrong decision, until that function is called within >> add_auc, the destination proto or the fproto etc is always 1 (UDP) >> which is what I am trying to force from the config file or the >> dispatcher definition (I tried both ways). But after calling that >> function then it comes as a 2 (TCP) >> >> The problematic function is a monster of 500 lines and I would like to >> avoid having to understand it. Since I think the scenario is not so >> unusual I just want to ask if maybe I am missing something that I should >> do to avoid the Kamailio to select TCP and in order to have the tm >> module respecting my preference for UDP (either with dispatcher module >> and the transport param or with t_relay_to or t_relay_to_udp I don't >> care the way). >> >> Any hints are welcome. >> >> Best regards >> >> alberto >> >> __________________________________________________________ >> Kamailio - Users Mailing List - Non Commercial Discussions >> To unsubscribe send an email to sr-users-leave(a)lists.kamailio.org >> Important: keep the mailing list in the recipients, do not reply only to the sender! >> Edit mailing list options or unsubscribe: > __________________________________________________________ > Kamailio - Users Mailing List - Non Commercial Discussions > To unsubscribe send an email to sr-users-leave(a)lists.kamailio.org > Important: keep the mailing list in the recipients, do not reply only to the sender! > Edit mailing list options or unsubscribe: