[sr-dev] [kamailio/kamailio] cscf_get_ue_via does not return UE via (#2864)

### Description I put a dispatcher between PCSCF and UE. When I tried to register, Pcscf's save function saved dispatcher's via IP and via port instead of UE's via IP and via port. When I checked save function of ims_registrar_pcscf module , I saw that cscf_get_ue_via function is used for that. And It gives wrong via value. Instead of giving last via , it gives the first via in the via list. Here is the function: https://github.com/kamailio/kamailio/blob/master/src/lib/ims/ims_getters.c ``` /** * Looks for the UE Via in First Via header if its a request * or in the last if its a response and returns its body * @param msg - the SIP message * @returns the via of the UE */ struct via_body* cscf_get_ue_via(struct sip_msg *msg) { struct via_body *vb=0; if (msg->first_line.type==SIP_REQUEST) vb = cscf_get_first_via(msg,0); else vb = cscf_get_last_via(msg); if (!vb) return 0; if (vb->port == 0) vb->port=5060; return vb; } ``` ### Troubleshooting I corrected the code as below: ``` /** * Looks for the UE Via in Last Via header and returns its body * @param msg - the SIP message * @returns the via of the UE */ struct via_body* cscf_get_ue_via(struct sip_msg *msg) { struct via_body *vb=0; vb = cscf_get_last_via(msg); if (!vb) return 0; if (vb->port == 0) vb->port=5060; return vb; } ``` #### Reproduction Try to put a dispatcher between PCSCF and UE. save function of ims_registrar_pcscf module saves dispatcher's IP and port as UE's IP and port. #### Debugging Data ``` (paste your debugging data here) ``` #### Log Messages ``` (paste your log messages here) ``` #### SIP Traffic <!-- If the issue is exposed by processing specific SIP messages, grab them with ngrep or save in a pcap file, then add them next, or attach to issue, or provide a link to download them (e.g., to a pastebin site). --> ``` (paste your sip traffic here) ``` ### Possible Solutions <!-- If you found a solution or workaround for the issue, describe it. Ideally, provide a pull request with a fix. --> ### Additional Information * **Kamailio Version** - output of `kamailio -v` ``` (paste your output here) ``` * **Operating System**: <!-- Details about the operating system, the type: Linux (e.g.,: Debian 8.4, Ubuntu 16.04, CentOS 7.1, ...), MacOS, xBSD, Solaris, ...; Kernel details (output of `lsb_release -a` and `uname -a`) --> ``` (paste your output here) ``` -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/kamailio/kamailio/issues/2864