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### Description

We are running Kamailio in a Microsoft Azure VM. Azure started adding EDNS0 support - in the form of OPT pseudo-records at the end of replies - a few weeks ago and since then we see a lot of ERROR entries in Kamailio log. These do however have no function impact.

From what I can see they are simply not handled in core/resolv.c (EDNS0 is type 41).

Version in use is latest 5.2 package from Kamailio repo on Debian 9 (Stretch).

Log entries provided below

### Troubleshooting

None, as this has no functional impact aside from filling the logs.

#### Reproduction

I can provide pcap of DNS traffic that contains EDNS0 OPT pseudo-entries on request.

#### Debugging Data

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gdb /path/to/kamailio /path/to/corefile bt full info locals list

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``` (paste your debugging data here) ```

#### Log Messages

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``` Oct 1 14:02:01 kamailio /usr/sbin/kamailio[78878]: ERROR: <core> [core/resolve.c:941]: get_record(): unknown type 41 ``` These lines are seen repeatedly only differing in timestamp and PID of kamailio process. In total about 40% of log entries are like the one above.

#### 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). -->

not related to SIP, but to DNS

### Possible Solutions

Add EDNS0 type 41 in core/resolv.c and don't fire an ERROR in the logs.

### Additional Information

* **Kamailio Version** - output of `kamailio -v`

``` version: kamailio 5.2.4 (x86_64/linux) flags: STATS: Off, USE_TCP, USE_TLS, USE_SCTP, TLS_HOOKS, USE_RAW_SOCKS, DISABLE_NAGLE, USE_MCAST, DNS_IP_HACK, SHM_MEM, SHM_MMAP, PKG_MALLOC, Q_MALLOC, F_MALLOC, TLSF_MALLOC, DBG_SR_MEMORY, USE_FUTEX, FAST_LOCK-ADAPTIVE_WAIT, USE_DNS_CACHE, USE_DNS_FAILOVER, USE_NAPTR, USE_DST_BLACKLIST, HAVE_RESOLV_RES ADAPTIVE_WAIT_LOOPS=1024, MAX_RECV_BUFFER_SIZE 262144 MAX_URI_SIZE 1024, BUF_SIZE 65535, DEFAULT PKG_SIZE 8MB poll method support: poll, epoll_lt, epoll_et, sigio_rt, select. id: unknown compiled with gcc 6.3.0 ```

* **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 `uname -a`) -->

``` Debian 9.11 Linux kamailio 4.19.0-0.bpo.5-cloud-amd64 #1 SMP Debian 4.19.37-3~bpo9+1 (2019-05-18) x86_64 GNU/Linux ```