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CHANGELOG
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version 2.86
Handle DHCPREBIND requests in the DHCPv6 server code.
Thanks to Aichun Li for spotting this omission, and the initial
patch.
Fix bug which caused dnsmasq to lose track of processes forked
to handle TCP DNS connections under heavy load. The code
checked that at least one free process table slot was
available before listening on TCP sockets, but didn't take
into account that more than one TCP connection could
arrive, so that check was not sufficient to ensure that
there would be slots for all new processes. It compounded
this error by silently failing to store the process when
it did run out of slots. Even when this bug is triggered,
all the right things happen, and answers are still returned.
Only under very exceptional circumstances, does the bug
manifest itself: see
https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2021q2/014976.html
Thanks to Tijs Van Buggenhout for finding the conditions under
which the bug manifests itself, and then working out
exactly what was going on.
Major rewrite of the DNS server and domain handling code.
This should be largely transparent, but it drastically
improves performance and reduces memory foot-print when
configuring large numbers domains of the form
local=/adserver.com/
or
local=/adserver.com/#
Lookup times now grow as log-to-base-2 of the number of domains,
rather than greater than linearly, as before.
The change makes multiple addresses associated with a domain work
address=/example.com/1.2.3.4
address=/example.com/5.6.7.8
It also handles multiple upstream servers for a domain better; using
the same try/retry algorithms as non domain-specific servers. This
also applies to DNSSEC-generated queries.
Finally, some of the oldest and gnarliest code in dnsmasq has had
a significant clean-up. It's far from perfect, but it _is_ better.
Revise resource handling for number of concurrent DNS queries. This
used to have a global limit, but that has a problem when using
different servers for different upstream domains. Queries which are
routed by domain to an upstream server which is not responding will
build up and trigger the limit, which breaks DNS service for
all other domains which could be handled by other servers. The
change is to make the limit per server-group, where a server group
is the set of servers configured for a particular domain. In the
common case, where only default servers are declared, there is
no effective change.
Improve efficiency of DNSSEC. The sharing point for DNSSEC RR data
used to be when it entered the cache, having been validated. After
that queries requiring the KEY or DS records would share the cached
values. There is a common case in dual-stack hosts that queries for
A and AAAA records for the same domain are made simultaneously.
If required keys were not in the cache, this would result in two
requests being sent upstream for the same key data (and all the
subsequent chain-of-trust queries.) Now we combine these requests
and elide the duplicates, resulting in fewer queries upstream
and better performance. To keep a better handle on what's
going on, the "extra" logging mode has been modified to associate
queries and answers for DNSSEC queries in the same way as ordinary
queries. The requesting address and port have been removed from
DNSSEC logging lines, since this is no longer strictly defined.
Connection track mark based DNS query filtering. Thanks to
Etan Kissling for implementing this It extends query filtering
support beyond what is currently possible
with the `--ipset` configuration option, by adding support for:
1) Specifying allowlists on a per-client basis, based on their
associated Linux connection track mark.
2) Dynamic configuration of allowlists via Ubus.
3) Reporting when a DNS query resolves or is rejected via Ubus.
4) DNS name patterns containing wildcards.
Disallowed queries are not forwarded; they are rejected
with a REFUSED error code.
Allow smaller than 64 prefix lengths in synth-domain, with caveats.
--synth-domain=1234:4567::/56,example.com is now valid.
Make domains generated by --synth-domain appear in replies
when in authoritative mode.
Ensure CAP_NET_ADMIN capability is available when
conntrack is configured. Thanks to Yick Xie for spotting
the lack of this.
When --dhcp-hostsfile --dhcp-optsfile and --addn-hosts are
given a directory as argument, define the order in which
files within that directory are read (alphabetical order
of filename). Thanks to Ed Wildgoose for the initial patch
and motivation for this.
version 2.85
Fix problem with DNS retries in 2.83/2.84.
The new logic in 2.83/2.84 which merges distinct requests
for the same domain causes problems with clients which do
retries as distinct requests (differing IDs and/or source ports.)
The retries just get piggy-backed on the first, failed, request.
The logic is now changed so that distinct requests for repeated
queries still get merged into a single ID/source port, but
they now always trigger a re-try upstream.
Thanks to Nicholas Mu for his analysis.
Tweak sort order of tags in get-version. v2.84 sorts
before v2.83, but v2.83 sorts before v2.83rc1 and 2.83rc1
sorts before v2.83test1. This fixes the problem which lead
to 2.84 announcing itself as 2.84rc2.
Avoid treating a --dhcp-host which has an IPv6 address
as eligible for use with DHCPv4 on the grounds that it has
no address, and vice-versa. Thanks to Viktor Papp for
spotting the problem. (This bug was fixed was back in 2.67, and
then regressed in 2.81).
Add --dynamic-host option: A and AAAA records which take their
network part from the network of a local interface. Useful
for routers with dynamically prefixes. Thanks
to Fred F for the suggestion.
Teach --bogus-nxdomain and --ignore-address to take an IPv4 subnet.
Use random source ports where possible if source
addresses/interfaces in use.
CVE-2021-3448 applies. Thanks to Petr Menšík for spotting this.
It's possible to specify the source address or interface to be
used when contacting upstream name servers: server=8.8.8.8@1.2.3.4
or server=8.8.8.8@1.2.3.4#66 or server=8.8.8.8@eth0, and all of
these have, until now, used a single socket, bound to a fixed
port. This was originally done to allow an error (non-existent
interface, or non-local address) to be detected at start-up. This
means that any upstream servers specified in such a way don't use
random source ports, and are more susceptible to cache-poisoning
attacks.
We now use random ports where possible, even when the
source is specified, so server=8.8.8.8@1.2.3.4 or
server=8.8.8.8@eth0 will use random source
ports. server=8.8.8.8@1.2.3.4#66 or any use of --query-port will
use the explicitly configured port, and should only be done with
understanding of the security implications.
Note that this change changes non-existing interface, or non-local
source address errors from fatal to run-time. The error will be
logged and communication with the server not possible.
Change the method of allocation of random source ports for DNS.
Previously, without min-port or max-port configured, dnsmasq would
default to the compiled in defaults for those, which are 1024 and
65535. Now, when neither are configured, it defaults instead to
the kernel's ephemeral port range, which is typically
32768 to 60999 on Linux systems. This change eliminates the
possibility that dnsmasq may be using a registered port > 1024
when a long-running daemon starts up and wishes to claim it.
This change does likely slightly reduce the number of random ports
and therefore the protection from reply spoofing. The older
behaviour can be restored using the min-port and max-port config
switches should that be a concern.
Scale the size of the DNS random-port pool based on the
value of the --dns-forward-max configuration.
Tweak TFTP code to check sender of all received packets, as
specified in RFC 1350 para 4.
Support some wildcard matching of input tags to --tag-if.
Thanks to Geoff Back for the idea and the patch.
version 2.84
Fix a problem, introduced in 2.83, which could see DNS replies
being sent via the wrong socket. On machines running both
IPv4 and IPv6 this could result in sporadic messages of
the form "failed to send packet: Network is unreachable" and
the lost of the query. Since the error is sporadic and of
low probability, the client retry would normally succeed.
Change HAVE_NETTLEHASH compile-time to HAVE_CRYPTOHASH.
version 2.83
Use the values of --min-port and --max-port in outgoing
TCP connections to upstream DNS servers.
Fix a remote buffer overflow problem in the DNSSEC code. Any
dnsmasq with DNSSEC compiled in and enabled is vulnerable to this,
referenced by CVE-2020-25681, CVE-2020-25682, CVE-2020-25683
CVE-2020-25687.
Be sure to only accept UDP DNS query replies at the address
from which the query was originated. This keeps as much entropy
in the {query-ID, random-port} tuple as possible, to help defeat
cache poisoning attacks. Refer: CVE-2020-25684.
Use the SHA-256 hash function to verify that DNS answers
received are for the questions originally asked. This replaces
the slightly insecure SHA-1 (when compiled with DNSSEC) or
the very insecure CRC32 (otherwise). Refer: CVE-2020-25685.
Handle multiple identical near simultaneous DNS queries better.
Previously, such queries would all be forwarded
independently. This is, in theory, inefficient but in practise
not a problem, _except_ that is means that an answer for any
of the forwarded queries will be accepted and cached.
An attacker can send a query multiple times, and for each repeat,
another {port, ID} becomes capable of accepting the answer he is
sending in the blind, to random IDs and ports. The chance of a
successful attack is therefore multiplied by the number of repeats
of the query. The new behaviour detects repeated queries and
merely stores the clients sending repeats so that when the
first query completes, the answer can be sent to all the
clients who asked. Refer: CVE-2020-25686.
version 2.82
Improve behaviour in the face of network interfaces which come
and go and change index. Thanks to Petr Mensik for the patch.
Convert hard startup failure on NETLINK_NO_ENOBUFS under qemu-user
to a warning.
Allow IPv6 addresses ofthe form [::ffff:1.2.3.4] in --dhcp-option.
Fix crash under heavy TCP connection load introduced in 2.81.
Thanks to Frank for good work chasing this down.
Change default lease time for DHCPv6 to one day.
Alter calculation of preferred and valid times in router
advertisements, so that these do not have a floor applied
of the lease time in the dhcp-range if this is not explicitly
specified and is merely the default.
Thanks to Martin-Éric Racine for suggestions on this.
version 2.81
Improve cache behaviour for TCP connections. For ease of
implementation, dnsmasq has always forked a new process to handle
each incoming TCP connection. A side-effect of this is that
any DNS queries answered from TCP connections are not cached:
when TCP connections were rare, this was not a problem.
With the coming of DNSSEC, it is now the case that some
DNSSEC queries have answers which spill to TCP, and if,
for instance, this applies to the keys for the root, then
those never get cached, and performance is very bad.
This fix passes cache entries back from the TCP child process to
the main server process, and fixes the problem.
Remove the NO_FORK compile-time option, and support for uclinux.
In an era where everything has an MMU, this looks like
an anachronism, and it adds to (Ok, multiplies!) the
combinatorial explosion of compile-time options. Thanks to
Kevin Darbyshire-Bryant for the patch.
Fix line-counting when reading /etc/hosts and friends; for
correct error messages. Thanks to Christian Rosentreter
for reporting this.
Fix bug in DNS non-terminal code, added in 2.80, which could
sometimes cause a NODATA rather than an NXDOMAIN reply.
Thanks to Norman Rasmussen, Sven Mueller and Maciej Żenczykowski
for spotting and diagnosing the bug and providing patches.
Support TCP-fastopen (RFC-7413) on both incoming and
outgoing TCP connections, if supported and enabled in the OS.
Improve kernel-capability manipulation code under Linux. Dnsmasq
now fails early if a required capability is not available, and
tries not to request capabilities not required by its
configuration.
Add --shared-network config. This enables allocation of addresses
by the DHCP server in subnets where the server (or relay) does not
have an interface on the network in that subnet. Many thanks to
kamp.de for sponsoring this feature.
Fix broken contrib/lease_tools/dhcp_lease_time.c. A packet
validation check got borked in commit 2b38e382 and release 2.80.
Thanks to Tomasz Szajner for spotting this.
Fix compilation against nettle version 3.5 and later.
Fix spurious DNSSEC validation failures when the auth section
of a reply contains unsigned RRs from a signed zone,
with the exception that NSEC and NSEC3 RRs must always be signed.
Thanks to Tore Anderson for spotting and diagnosing the bug.
Add --dhcp-ignore-clid. This disables reading of DHCP client
identifier option (option 61), so clients are only identified by
MAC addresses.
Fix a bug which stopped --dhcp-name-match from working when a hostname
is supplied in --dhcp-host. Thanks to James Feeney for spotting this.
Fix bug which caused very rarely caused zero-length DHCPv6 packets.
Thanks to Dereck Higgins for spotting this.
Add --tftp-single-port option.
Enhance --conf-dir to load files in a deterministic order. Thanks to
Evgenii Seliavka for the suggestion and initial patch.
In the router advert code, handle case where we have two
different interfaces on the same IPv6 net, and we are doing
RA/DHCP service on only one of them. Thanks to NIIBE Yutaka
for spotting this case and making the initial patch.
Support prefixed ranges of ipv6 addresses in dhcp-host.
This eases problems chain-netbooting, where each link in the
chain requests an address using a different UID. With a single
address, only one gets the "static" address, but with this
fix, enough addresses can be reserved for all the stages of the
boot. Many thanks to Harald Jensås for his work on this idea and
earlier patches.
Add filtering by tag of --dhcp-host directives. Based on a patch
by Harald Jensås.
Allow empty server spec in --rev-server, to match --server.
Remove DSA signature verification from DNSSEC, as specified in
RFC 8624. Thanks to Loganaden Velvindron for the original patch.
Add --script-on-renewal option.
version 2.80
Add support for RFC 4039 DHCP rapid commit. Thanks to Ashram Method
for the initial patch and motivation.
Alter the default for dnssec-check-unsigned. Versions of
dnsmasq prior to 2.80 defaulted to not checking unsigned
replies, and used --dnssec-check-unsigned to switch
this on. Such configurations will continue to work as before,
but those which used the default of no checking will need to be
altered to explicitly select no checking. The new default is
because switching off checking for unsigned replies is
inherently dangerous. Not only does it open the possiblity of forged
replies, but it allows everything to appear to be working even
when the upstream namesevers do not support DNSSEC, and in this
case no DNSSEC validation at all is occuring.
Fix DHCP broken-ness when --no-ping AND --dhcp-sequential-ip
are set. Thanks to Daniel Miess for help with this.
Add a facilty to store DNS packets sent/recieved in a
pcap-format file for later debugging. The file location
is given by the --dumpfile option, and a bitmap controlling
which packets should be dumped is given by the --dumpmask
option.
Handle the case of both standard and constructed dhcp-ranges on the
same interface better. We don't now contruct a dhcp-range if there's
already one specified. This allows the specified interface to
have different parameters and avoids advertising the same
prefix twice. Thanks to Luis Marsano for spotting this case.
Allow zone transfer in authoritative mode if auth-peer is specified,
even if auth-sec-servers is not. Thanks to Raphaël Halimi for
the suggestion.
Fix bug which sometimes caused dnsmasq to wrongly return answers
without DNSSEC RRs to queries with the do-bit set, but only when
DNSSEC validation was not enabled.
Thanks to Petr Menšík for spotting this.
Fix missing fatal errors with some malformed options
(server, local, address, rebind-domain-ok, ipset, alias).
Thanks to Eugene Lozovoy for spotting the problem.
Fix crash on startup with a --synth-domain which has no prefix.
Introduced in 2.79. Thanks to Andreas Engel for the bug report.
Fix missing EDNS0 section in some replies generated by local
DNS configuration which confused systemd-resolvd. Thanks to
Steve Dodd for characterising the problem.
Add --dhcp-name-match config option.
Add --caa-record config option.
Implement --address=/example.com/# as (more efficient) syntactic
sugar for --address=/example.com/0.0.0.0 and
--address=/example.com/::
Returning null addresses is a useful technique for ad-blocking.
Thanks to Peter Russell for the suggestion.
Change anti cache-snooping behaviour with queries with the
recursion-desired bit unset. Instead to returning SERVFAIL, we
now always forward, and never answer from the cache. This
allows "dig +trace" command to work.
Include in the example config file a formulation which
stops DHCP clients from claiming the DNS name "wpad".
This is a fix for the CERT Vulnerability VU#598349.
version 2.79
Fix parsing of CNAME arguments, which are confused by extra spaces.
Thanks to Diego Aguirre for spotting the bug.
Where available, use IP_UNICAST_IF or IPV6_UNICAST_IF to bind
upstream servers to an interface, rather than SO_BINDTODEVICE.
Thanks to Beniamino Galvani for the patch.
Always return a SERVFAIL answer to DNS queries without the
recursion desired bit set, UNLESS acting as an authoritative
DNS server. This avoids a potential route to cache snooping.
Add support for Ed25519 signatures in DNSSEC validation.
No longer support RSA/MD5 signatures in DNSSEC validation,
since these are not secure. This behaviour is mandated in
RFC-6944.
Fix incorrect error exit code from dhcp_release6 utility.
Thanks Gaudenz Steinlin for the bug report.
Use SIGINT (instead of overloading SIGHUP) to turn on DNSSEC
time validation when --dnssec-no-timecheck is in use.
Note that this is an incompatible change from earlier releases.
Allow more than one --bridge-interface option to refer to an
interface, so that we can use
--bridge-interface=int1,alias1
--bridge-interface=int1,alias2
as an alternative to
--bridge-interface=int1,alias1,alias2
Thanks to Neil Jerram for work on this.
Fix for DNSSEC with wildcard-derived NSEC records.
It's OK for NSEC records to be expanded from wildcards,
but in that case, the proof of non-existence is only valid
starting at the wildcard name, *.<domain> NOT the name expanded
from the wildcard. Without this check it's possible for an
attacker to craft an NSEC which wrongly proves non-existence.
Thanks to Ralph Dolmans for finding this, and co-ordinating
the vulnerability tracking and fix release.
CVE-2017-15107 applies.
Remove special handling of A-for-A DNS queries. These
are no longer a significant problem in the global DNS.
http://cs.northwestern.edu/~ychen/Papers/DNS_ToN15.pdf
Thanks to Mattias Hellström for the initial patch.
Fix failure to delete dynamically created dhcp options
from files in -dhcp-optsdir directories. Thanks to
Lindgren Fredrik for the bug report.
Add to --synth-domain the ability to create names using
sequential numbers, as well as encodings of IP addresses.
For instance,
--synth-domain=thekelleys.org.uk,192.168.0.50,192.168.0.70,internal-*
creates 21 domain names of the form
internal-4.thekelleys.org.uk over the address range given, with
internal-0.thekelleys.org.uk being 192.168.0.50 and
internal-20.thekelleys.org.uk being 192.168.0.70
Thanks to Andy Hawkins for the suggestion.
Tidy up Crypto code, removing workarounds for ancient
versions of libnettle. We now require libnettle 3.
version 2.78
Fix logic of appending ".<layer>" to PXE basename. Thanks to Chris
Novakovic for the patch.
Revert ping-check of address in DHCPDISCOVER if there
already exists a lease for the address. Under some
circumstances, and netbooted windows installation can reply
to pings before if has a DHCP lease and block allocation
of the address it already used during netboot. Thanks to
Jan Psota for spotting this.
Fix DHCP relaying, broken in 2.76 and 2.77 by commit
ff325644c7afae2588583f935f4ea9b9694eb52e. Thanks to
John Fitzgibbon for the diagnosis and patch.
Try other servers if first returns REFUSED when
--strict-order active. Thanks to Hans Dedecker
for the patch
Fix regression in 2.77, ironically added as a security
improvement, which resulted in a crash when a DNS
query exceeded 512 bytes (or the EDNS0 packet size,
if different.) Thanks to Christian Kujau, Arne Woerner
Juan Manuel Fernandez and Kevin Darbyshire-Bryant for
chasing this one down. CVE-2017-13704 applies.
Fix heap overflow in DNS code. This is a potentially serious
security hole. It allows an attacker who can make DNS
requests to dnsmasq, and who controls the contents of
a domain, which is thereby queried, to overflow
(by 2 bytes) a heap buffer and either crash, or
even take control of, dnsmasq.
CVE-2017-14491 applies.
Credit to Felix Wilhelm, Fermin J. Serna, Gabriel Campana
Kevin Hamacher and Ron Bowes of the Google Security Team for
finding this.
Fix heap overflow in IPv6 router advertisement code.
This is a potentially serious security hole, as a
crafted RA request can overflow a buffer and crash or
control dnsmasq. Attacker must be on the local network.
CVE-2017-14492 applies.
Credit to Felix Wilhelm, Fermin J. Serna, Gabriel Campana
and Kevin Hamacher of the Google Security Team for
finding this.
Fix stack overflow in DHCPv6 code. An attacker who can send
a DHCPv6 request to dnsmasq can overflow the stack frame and
crash or control dnsmasq.
CVE-2017-14493 applies.
Credit to Felix Wilhelm, Fermin J. Serna, Gabriel Campana
Kevin Hamacher and Ron Bowes of the Google Security Team for
finding this.
Fix information leak in DHCPv6. A crafted DHCPv6 packet can
cause dnsmasq to forward memory from outside the packet
buffer to a DHCPv6 server when acting as a relay.
CVE-2017-14494 applies.
Credit to Felix Wilhelm, Fermin J. Serna, Gabriel Campana
Kevin Hamacher and Ron Bowes of the Google Security Team for
finding this.
Fix DoS in DNS. Invalid boundary checks in the
add_pseudoheader function allows a memcpy call with negative
size An attacker which can send malicious DNS queries
to dnsmasq can trigger a DoS remotely.
dnsmasq is vulnerable only if one of the following option is
specified: --add-mac, --add-cpe-id or --add-subnet.
CVE-2017-14496 applies.
Credit to Felix Wilhelm, Fermin J. Serna, Gabriel Campana
Kevin Hamacher and Ron Bowes of the Google Security Team for
finding this.
Fix out-of-memory Dos vulnerability. An attacker which can
send malicious DNS queries to dnsmasq can trigger memory
allocations in the add_pseudoheader function
The allocated memory is never freed which leads to a DoS
through memory exhaustion. dnsmasq is vulnerable only
if one of the following option is specified:
--add-mac, --add-cpe-id or --add-subnet.
CVE-2017-14495 applies.
Credit to Felix Wilhelm, Fermin J. Serna, Gabriel Campana
Kevin Hamacher and Ron Bowes of the Google Security Team for
finding this.
version 2.77
Generate an error when configured with a CNAME loop,
rather than a crash. Thanks to George Metz for
spotting this problem.
Calculate the length of TFTP error reply packet
correctly. This fixes a problem when the error
message in a TFTP packet exceeds the arbitrary
limit of 500 characters. The message was correctly
truncated, but not the packet length, so
extra data was appended. This is a possible
security risk, since the extra data comes from
a buffer which is also used for DNS, so that
previous DNS queries or replies may be leaked.
Thanks to Mozilla for funding the security audit
which spotted this bug.
Fix logic error in Linux netlink code. This could
cause dnsmasq to enter a tight loop on systems
with a very large number of network interfaces.
Thanks to Ivan Kokshaysky for the diagnosis and
patch.
Fix problem with --dnssec-timestamp whereby receipt
of SIGHUP would erroneously engage timestamp checking.
Thanks to Kevin Darbyshire-Bryant for this work.
Bump zone serial on reloading /etc/hosts and friends
when providing authoritative DNS. Thanks to Harrald
Dunkel for spotting this.
Handle v4-mapped IPv6 addresses sanely in --synth-domain.
These have standard representation like ::ffff:1.2.3.4
and are now converted to names like
<prefix>--ffff-1-2-3-4.<domain>
Handle binding upstream servers to an interface
(--server=1.2.3.4@eth0) when the named interface
is destroyed and recreated in the kernel. Thanks to
Beniamino Galvani for the patch.
Allow wildcard CNAME records in authoritative zones.
For example --cname=*.example.com,default.example.com
Thanks to Pro Backup for sponsoring this development.
Bump the allowed backlog of TCP connections from 5 to 32,
and make this a compile-time configurable option. Thanks
to Donatas Abraitis for diagnosing this as a potential
problem.
Add DNSMASQ_REQUESTED_OPTIONS environment variable to the
lease-change script. Thanks to ZHAO Yu for the patch.
Fix foobar in rrfilter code, that could cause malformed
replies, especially when DNSSEC validation on, and
the upstream server returns answer with the RRs in a
particular order. The only DNS server known to tickle
this is Nominum's. Thanks to Dave Täht for spotting the
bug and assisting in the fix.
Fix the manpage which lied that only the primary address
of an interface is used by --interface-name.
Make --localise-queries apply to names from --interface-name.
Thanks to Kevin Darbyshire-Bryant and Eric Luehrsen
for pushing this.
Improve connection handling when talking to TCP upstream
servers. Specifically, be prepared to open a new TCP
connection when we want to make multiple queries
but the upstream server accepts fewer queries per connection.
Improve logging of upstream servers when there are a lot
of "local addresses only" entries. Thanks to Hannu Nyman for
the patch.
Make --bogus-priv apply to IPv6, for the prefixes specified
in RFC6303. Thanks to Kevin Darbyshire-Bryant for work on this.
Allow use of MAC addresses with --tftp-unique-root. Thanks
to Floris Bos for the patch.
Add --dhcp-reply-delay option. Thanks to Floris Bos
for the patch.
Add mtu setting facility to --ra-param. Thanks to David
Flamand for the patch.
Capture STDOUT and STDERR output from dhcp-script and log
it as part of the dnsmasq log stream. Makes life easier
for diagnosing unexpected problems in scripts.
Thanks to Petr Mensik for the patch.
Generate fatal errors when failing to parse the output
of the dhcp-script in "init" mode. Avoids strange errors
when the script accidentally emits error messages.
Thanks to Petr Mensik for the patch.
Make --rev-server for an RFC1918 subnet work even in the
presence of the --bogus-priv flag. Thanks to
Vladislav Grishenko for the patch.
Extend --ra-param mtu: field to allow an interface name.
This allows the MTU of a WAN interface to be advertised on
the internal interfaces of a router. Thanks to
Vladislav Grishenko for the patch.
Do ICMP-ping check for address-in-use for DHCPv4 when
the client specifies an address in DHCPDISCOVER, and when
an address in configured locally. Thanks to Alin Năstac
for spotting the problem.
Add new DHCP tag "known-othernet" which is set when only a
dhcp-host exists for another subnet. Can be used to ensure
that privileged hosts are not given "guest" addresses by
accident. Thanks to Todd Sanket for the suggestion.
Remove historic automatic inclusion of IDN support when
building internationalisation support. This doesn't
fit now there is a choice of IDN libraries. Be sure
to include either -DHAVE_IDN or -DHAVE_LIBIDN2 for
IDN support.
version 2.76
Include 0.0.0.0/8 in DNS rebind checks. This range
translates to hosts on the local network, or, at
least, 0.0.0.0 accesses the local host, so could
be targets for DNS rebinding. See RFC 5735 section 3
for details. Thanks to Stephen Röttger for the bug report.
Enhance --add-subnet to allow arbitrary subnet addresses.
Thanks to Ed Barsley for the patch.
Respect the --no-resolv flag in inotify code. Fixes bug
which caused dnsmasq to fail to start if a resolv-file
was a dangling symbolic link, even of --no-resolv set.
Thanks to Alexander Kurtz for spotting the problem.
Fix crash when an A or AAAA record is defined locally,
in a hosts file, and an upstream server sends a reply
that the same name is empty. Thanks to Edwin Török for
the patch.
Fix failure to correctly calculate cache-size when
reading a hosts-file fails. Thanks to André Glüpker
for the patch.
Fix wrong answer to simple name query when --domain-needed
set, but no upstream servers configured. Dnsmasq returned
REFUSED, in this case, when it should be the same as when
upstream servers are configured - NOERROR. Thanks to
Allain Legacy for spotting the problem.
Return REFUSED when running out of forwarding table slots,
not SERVFAIL.
Add --max-port configuration. Thanks to Hans Dedecker for
the patch.
Add --script-arp and two new functions for the dhcp-script.
These are "arp" and "arp-old" which announce the arrival and
removal of entries in the ARP or neighbour tables.
Extend --add-mac to allow a new encoding of the MAC address
as base64, by configuring --add-mac=base64
Add --add-cpe-id option.
Don't crash with divide-by-zero if an IPv6 dhcp-range
is declared as a whole /64.
(ie xx::0 to xx::ffff:ffff:ffff:ffff)
Thanks to Laurent Bendel for spotting this problem.
Add support for a TTL parameter in --host-record and
--cname.
Add --dhcp-ttl option.
Add --tftp-mtu option. Thanks to Patrick McLean for the
initial patch.
Check return-code of inet_pton() when parsing dhcp-option.
Bad addresses could fail to generate errors and result in
garbage dhcp-options being sent. Thanks to Marc Branchaud
for spotting this.
Fix wrong value for EDNS UDP packet size when using
--servers-file to define upstream DNS servers. Thanks to
Scott Bonar for the bug report.
Move the dhcp_release and dhcp_lease_time tools from
contrib/wrt to contrib/lease-tools.
Add dhcp_release6 to contrib/lease-tools. Many thanks
to Sergey Nechaev for this code.
To avoid filling logs in configurations which define
many upstream nameservers, don't log more that 30 servers.
The number to be logged can be changed as SERVERS_LOGGED
in src/config.h.
Swap the values if BC_EFI and x86-64_EFI in --pxe-service.
These were previously wrong due to an error in RFC 4578.
If you're using BC_EFI to boot 64-bit EFI machines, you
will need to update your config.
Add ARM32_EFI and ARM64_EFI as valid architectures in
--pxe-service.
Fix PXE booting for UEFI architectures. Modify PXE boot
sequence in this case to force the client to talk to dnsmasq
over port 4011. This makes PXE and especially proxy-DHCP PXE
work with these architectures.
Workaround problems with UEFI PXE clients. There exist
in the wild PXE clients which have problems with PXE
boot menus. To work around this, when there's a single
--pxe-service which applies to client, then that target
will be booted directly, rather then sending a
single-item boot menu.
Many thanks to Jarek Polok, Michael Kuron and Dreamcat4
for their work on the long-standing UEFI PXE problem.
Subtle change in the semantics of "basename" in
--pxe-service. The historical behaviour has always been
that the actual filename downloaded from the TFTP server
is <basename>.<layer> where <layer> is an integer which
corresponds to the layer parameter supplied by the client.
It's not clear what the function of the "layer"
actually is in the PXE protocol, and in practise layer
is always zero, so the filename is <basename>.0
The new behaviour is the same as the old, except when
<basename> includes a file suffix, in which case
the layer suffix is no longer added. This allows
sensible suffices to be used, rather then the
meaningless ".0". Only in the unlikely event that you
have a config with a basename which already has a
suffix, is this an incompatible change, since the file
downloaded will change from name.suffix.0 to just
name.suffix
version 2.75
Fix reversion on 2.74 which caused 100% CPU use when a
dhcp-script is configured. Thanks to Adrian Davey for
reporting the bug and testing the fix.
version 2.74
Fix reversion in 2.73 where --conf-file would attempt to
read the default file, rather than no file.
Fix inotify code to handle dangling symlinks better and
not SEGV in some circumstances.
DNSSEC fix. In the case of a signed CNAME generated by a
wildcard which pointed to an unsigned domain, the wrong
status would be logged, and some necessary checks omitted.
version 2.73
Fix crash at startup when an empty suffix is supplied to
--conf-dir, also trivial memory leak. Thanks to
Tomas Hozza for spotting this.
Remove floor of 4096 on advertised EDNS0 packet size when
DNSSEC in use, the original rationale for this has long gone.
Thanks to Anders Kaseorg for spotting this.
Use inotify for checking on updates to /etc/resolv.conf and
friends under Linux. This fixes race conditions when the files are
updated rapidly and saves CPU by noy polling. To build
a binary that runs on old Linux kernels without inotify,
use make COPTS=-DNO_INOTIFY
Fix breakage of --domain=<domain>,<subnet>,local - only reverse
queries were intercepted. THis appears to have been broken
since 2.69. Thanks to Josh Stone for finding the bug.
Eliminate IPv6 privacy addresses and deprecated addresses from
the answers given by --interface-name. Note that reverse queries
(ie looking for names, given addresses) are not affected.
Thanks to Michael Gorbach for the suggestion.
Fix crash in DNSSEC code with long RRs. Thanks to Marco Davids
for the bug report.
Add --ignore-address option. Ignore replies to A-record
queries which include the specified address. No error is
generated, dnsmasq simply continues to listen for another
reply. This is useful to defeat blocking strategies which
rely on quickly supplying a forged answer to a DNS
request for certain domains, before the correct answer can
arrive. Thanks to Glen Huang for the patch.
Revisit the part of DNSSEC validation which determines if an
unsigned answer is legit, or is in some part of the DNS
tree which should be signed. Dnsmasq now works from the
DNS root downward looking for the limit of signed
delegations, rather than working bottom up. This is
both more correct, and less likely to trip over broken
nameservers in the unsigned parts of the DNS tree
which don't respond well to DNSSEC queries.
Add --log-queries=extra option, which makes logs easier
to search automatically.
Add --min-cache-ttl option. I've resisted this for a long
time, on the grounds that disbelieving TTLs is never a
good idea, but I've been persuaded that there are
sometimes reasons to do it. (Step forward, GFW).
To avoid misuse, there's a hard limit on the TTL
floor of one hour. Thanks to RinSatsuki for the patch.
Cope with multiple interfaces with the same link-local
address. (IPv6 addresses are scoped, so this is allowed.)
Thanks to Cory Benfield for help with this.
Add --dhcp-hostsdir. This allows addition of new host
configurations to a running dnsmasq instance much more
cheaply than having dnsmasq re-read all its existing
configuration each time.
Don't reply to DHCPv6 SOLICIT messages if we're not
configured to do stateful DHCPv6. Thanks to Win King Wan
for the patch.
Fix broken DNSSEC validation of ECDSA signatures.
Add --dnssec-timestamp option, which provides an automatic
way to detect when the system time becomes valid after
boot on systems without an RTC, whilst allowing DNS
queries before the clock is valid so that NTP can run.
Thanks to Kevin Darbyshire-Bryant for developing this idea.
Add --tftp-no-fail option. Thanks to Stefan Tomanek for
the patch.
Fix crash caused by looking up servers.bind, CHAOS text
record, when more than about five --servers= lines are
in the dnsmasq config. This causes memory corruption
which causes a crash later. Thanks to Matt Coddington for
sterling work chasing this down.
Fix crash on receipt of certain malformed DNS requests.
Thanks to Nick Sampanis for spotting the problem.
Note that this is could allow the dnsmasq process's
memory to be read by an attacker under certain
circumstances, so it has a CVE, CVE-2015-3294
Fix crash in authoritative DNS code, if a .arpa zone
is declared as authoritative, and then a PTR query which
is not to be treated as authoritative arrived. Normally,
directly declaring .arpa zone as authoritative is not
done, so this crash wouldn't be seen. Instead the
relevant .arpa zone should be specified as a subnet
in the auth-zone declaration. Thanks to Johnny S. Lee
for the bugreport and initial patch.
Fix authoritative DNS code to correctly reply to NS
and SOA queries for .arpa zones for which we are
declared authoritative by means of a subnet in auth-zone.
Previously we provided correct answers to PTR queries
in such zones (including NS and SOA) but not direct
NS and SOA queries. Thanks to Johnny S. Lee for
pointing out the problem.
Fix logging of DHCPREPLY which should be suppressed
by quiet-dhcp6. Thanks to J. Pablo Abonia for
spotting the problem.
Try and handle net connections with broken fragmentation
that lose large UDP packets. If a server times out,
reduce the maximum UDP packet size field in the EDNS0
header to 1280 bytes. If it then answers, make that
change permanent.
Check IPv4-mapped IPv6 addresses when --stop-rebind
is active. Thanks to Jordan Milne for spotting this.
Allow DHCPv4 options T1 and T2 to be set using --dhcp-option.
Thanks to Kevin Benton for patches and work on this.
Fix code for DHCPCONFIRM DHCPv6 messages to confirm addresses
in the correct subnet, even of not in dynamic address
allocation range. Thanks to Steve Hirsch for spotting
the problem.
Add AddDhcpLease and DeleteDhcpLease DBus methods. Thanks
to Nicolas Cavallari for the patch.
Allow configuration of router advertisements without the
"on-link" bit set. Thanks to Neil Jerram for the patch.
Extend --bridge-interface to DHCPv6 and router
advertisements. Thanks to Neil Jerram for the patch.
version 2.72
Add ra-advrouter mode, for RFC-3775 mobile IPv6 support.
Add support for "ipsets" in *BSD, using pf. Thanks to
Sven Falempin for the patch.
Fix race condition which could lock up dnsmasq when an
interface goes down and up rapidly. Thanks to Conrad
Kostecki for helping to chase this down.
Add DBus methods SetFilterWin2KOption and SetBogusPrivOption
Thanks to the Smoothwall project for the patch.
Fix failure to build against Nettle-3.0. Thanks to Steven
Barth for spotting this and finding the fix.
When assigning existing DHCP leases to interfaces by comparing
networks, handle the case that two or more interfaces have the
same network part, but different prefix lengths (favour the
longer prefix length.) Thanks to Lung-Pin Chang for the
patch.
Add a mode which detects and removes DNS forwarding loops, ie
a query sent to an upstream server returns as a new query to
dnsmasq, and would therefore be forwarded again, resulting in
a query which loops many times before being dropped. Upstream
servers which loop back are disabled and this event is logged.
Thanks to Smoothwall for their sponsorship of this feature.
Extend --conf-dir to allow filtering of files. So
--conf-dir=/etc/dnsmasq.d,\*.conf
will load all the files in /etc/dnsmasq.d which end in .conf
Fix bug when resulted in NXDOMAIN answers instead of NODATA in
some circumstances.
Fix bug which caused dnsmasq to become unresponsive if it
failed to send packets due to a network interface disappearing.
Thanks to Niels Peen for spotting this.
Fix problem with --local-service option on big-endian platforms
Thanks to Richard Genoud for the patch.
version 2.71
Subtle change to error handling to help DNSSEC validation
when servers fail to provide NODATA answers for
non-existent DS records.
Tweak code which removes DNSSEC records from answers when
not required. Fixes broken answers when additional section