Software Update: Unbound 1.13.0

When you perform a dns lookup, a recursor initially starts by asking the lookup query to a dns root server. This can then redirect to other servers, from where it can redirect to other servers and so on, until finally a server is reached that knows the answer or knows that the look-up is not possible. The latter can be the case if the name does not exist or the servers do not respond. The process of going through different authoritative servers is called recursion. Unbound is a dns recursor with support for modern standards such as Query Name Minimization† Aggressive Use of DNSsec-Validated Cache and authority zones† The developers released version 1.13.0 a few days ago and made the following changes and improvements:

New features

• Pass the comm_reply information to the inplace_cb_reply* functions during the mesh state and update the documentation on that.
• fix #330† [Feature request] Add unencrypted DNS over HTTPS support. This adds the option http-notls-downstream: yesno to change that, and the dohclient test code has the -n option.
• Merge PR #228 : infra-keep-probing option to probe hosts that are down. Add infra-keep-probing: yes option. Hosts that are down are probed more frequently. With the option turned on, it probes about every 120 seconds, eventually after exponential backoff, and that keeps that way. If traffic keeps up for the domain. It probes with one at a time, eg. one query is allowed to probe, other queries within that 120 second interval are turned away.
• Merge PR #313 from Ralph Dolmans: Replace edns-client-tag with edns-client-string option.
• Merge PR #283 : Stream reuse. This implements upstream stream reuse for performing several queries over the same TCP or TLS channel.
• Fix to connect() to UDP destinations, default turned on, this lowers vulnerability to ICMP side channels. Option to toggle udp-connect, default is enabled.

Bug Fixes

• fix #319: potential memory leak on config failure, in rpz config.
• Fix dnstap socket and the chroot not applied properly to the dnstap socket path.
• Fix warning in libnss compile, nss_buf2dsa is not used without DSA.
• fix #323: unbound testsuite fails on mock build in systemd-nspawn if systemd support is build.
• Fix for python reply callback to see mesh state reply_list member, it only removes it briefly for the commpoint call so that it does not drop it and attempt to modify the reply list during reply.
• Fix that if there are on reply callbacks, those are called per reply and a new message created if that was modified by the call.
• Free up auth zone parse region after use for lookup of host
• Merge PR #326 from netblue30: DoH: implement content-length header field.
• DoH content length, simplify code, remove declaration after statement and fix cast warning.
• Fix that if there are reply callbacks for the given rcode, those are called per reply and a new message created if that was modified by the call.
• Fix that the out of order TCP processing does not limit the number of outstanding queries over a connection.
• Fix python documentation warning on functions.rst inplace_cb_reply.
• Log ip address when http session recv fails, eg. due to tls fail.
• Fix to set the tcp handler event toggle flag back to default when the handler structure is reused.
• Clean the fix for out of order TCP processing limits on number of queries. It was tested to work.
• Fix that http settings have colon in set_option, for http-endpoint, http-max-streams, http-query-buffer-size, http-response-buffer-size, and http-nodelay.
• Fix memory leak of https port string when reading config.
• local-zone regional allocations outside of chunk
• Merge PR #324 from James Renken: Add modern X.509v3 extensions to unbound-control TLS certificates.
• Fix for PR #324 to attach the x509v3 extensions to the client certificate.
• fix #327: net/if.h check fails on some darwin versions; contribution by Joshua Root.
• fix #320: potential memory corruption due to size miscomputation upton custom region alloc init.
• fix #333: Unbound Segmentation Fault w/ log_info Functions From Python Mod.
• Fix that minimal-responses does not remove addresses from a priming query response.
• In man page note that tls-cert-bundle is read before permission drop and chroot.
• fix #341: fixing a possible memory leak.
• Fix memory leak after fix for possible memory leak failure.
• fix #343: Fail to build –with-libnghttp2 with error: ‘SSIZE_MAX’ undeclared.
• fix for #303 CVE-2020-28935 : Fix that symlink does not interfere with chown of pidfile.
• fix #347: IP_DONTFRAG broken on Apple xcode 12.2.
• fix #350: with the AF_NETLINK permission, to fix 1.12.0 error: failed to list interfaces: getifaddrs: Address family not supported by protocol.
• merge #351 from dvzrv: Add AF_NETLINK to set of allowed socket address families.
• iana port list updated.
• Fix crash when TLS connection is closed prematurely, when reuse tree comparison is not properly identical to insertion.
• Fix padding of struct regional for 32bit systems.
• with udp-connect ignore connection refused with UDP timeouts.
• Fix udp-connect on FreeBSD, do send calls on connected UDP socket.
• Better fix for reuse tree comparison for is-tls sockets. Where the tree key identity is preserved after cleanup of the TLS state.
• Fix memory leak for edns client tag opcode config element.
• Attempt fix for libevent state in tcp reuse cases after a packet is written.
• Fix readagain and writeagain callback functions for comm point cleanup.
• Fix to omit UDP receive errors from log, if verbosity low. These happen because of udp-connect.
• for #352: contrib/metrics.awk for Prometheus style metrics output.
• Fix that after failed read, the readagain cannot activate.
• Clear readagain upon decommission of pending tcp structure.
• Fix compile warning for type cast in http2_submit_dns_response.
• Fix when use free buffer to initialize rbtree for stream reuse.
• Fix compile warnings for windows.
• Fix compile warnings in rpz initialization.
• Fix contrib/metrics.awk for FreeBSD awk compatibility.
• Fix assertion failure on double callback when iterator loses interest in query at head of line that then has the tcp stream not kept for reuse.
• Fix stream reuse and tcp fast open.