fix 'WARNING: Message has 41 extra bytes at end'

[dukeartem]

Without this fix we have WARNING: Message has 41 extra bytes at end in

dig -b _non_local_address_ @127.0.0.1 non-existent-domain.com
; <<>> DiG 9.16.1-Ubuntu <<>> -b _non_local_address_ @127.0.0.1  non-existent-domain.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 14481
;; flags: qr rd ad; QUERY: 0, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
;; WARNING: recursion requested but not available
;; WARNING: Message has 28 extra bytes at end

;; Query time: 1 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Monday Dec 04 17:51:26 UTC 2023
;; MSG SIZE  rcvd: 40

configuration:

server:
        root-hints: "named.root"
        directory: "/"
        pidfile: "/unbound.pid"
        chroot: ""
        port: 5353
        interface-automatic: "yes"
        interface: ::1
        interface: 127.0.0.1
        ip-freebind: "yes"
        do-daemonize: "no"
        num-threads: 1
        num-queries-per-thread: 10
        prefer-ip6: "yes"
        access-control: 0.0.0.0/0 refuse_non_local
        access-control: ::0/0 refuse_non_local
        module-config: "iterator"

version:

/unbound/unbound -V
Version 1.19.0-trunk
Configure line: --disable-static --prefix=/var/empty/unbound-1.19.0 --bindir=/var/empty/tmp/out/bin --sbindir=/var/empty/tmp/out/sbin --includedir=/var/empty/tmp/out/include --oldincludedir=/var/empty/tmp/out/include --mandir=/var/empty/tmp/out/share/man --infodir=/var/empty/tmp/out/share/info --docdir=/var/empty/tmp/out/share/doc/unbound --libdir=/var/empty/tmp/out/lib --libexecdir=/var/empty/tmp/out/libexec --localedir=/var/empty/tmp/out/share/locale --disable-rpath --enable-dnstap --enable-dnscrypt --enable-subnet --enable-systemd --libdir=/usr/lib --prefix= --with-libevent=/var/empty/libevent-2.1.12-dev --with-pidfile=/run/unbound.pid --with-rootkey-file=/var/lib/unbound/root.key --with-ssl=/var/empty/openssl-1.1.1o-dev --with-username= --with-libnghttp2=/var/empty/nghttp2-1.47.0-dev
Linked libs: libevent 2.1.12-stable (it uses epoll), OpenSSL 1.1.1t  7 Feb 2023
Linked modules: dns64 subnetcache respip validator iterator
DNSCrypt feature available

[wcawijngaards]

This looks like a good change. That removes unneeded bytes from the end of the message for the REFUSED response.

[wcawijngaards]

Thanks for the fix! It is added to the code repository, and should help remove unneeded bytes from the end of the refused reply, in that condition, no EDE attached.