My fork of the ISC DHCP server
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Internet Systems Consortium DHCP Distribution
Version 4.4.2
22 January 2020
Release Notes
Please note that that ISC DHCP is now licensed under the Mozilla Public License,
MPL 2.0. Please see to read the MPL 2.0
license terms.
While release 4.4.2 is primarily a maintenance release that addresses a number
of defects, it does introduce a few new features:
- Keama - Keama is a migration utility that assists in converting ISC DHCP
server configuration files to Kea configuration files. It is found in the
keama subdirectory and includes a file with instructions on how
to build it as well as a manpage on its usage.
- Two new server parameters related to ping checking were added:
1. ping-cltt-secs which allows the user to specify the number of seconds
that must elapse since CLTT before a ping check is conducted.
2. ping-timeout-ms which allows the user to specify the amount of time the
server waits for a ping-check response in milliseconds rather than in
In general, the areas of focus for ISC DHCP 4.4 were:
1. Dynamic DNS additions
2. dhclient improvements
3. Support for dynamic shared libraries
Dynamic DNS Improvements:
- We added three new server configuration parameters which influence DDNS
conflict resolution:
1. ddns-dual-stack-mixed-mode - alters DNS conflict resolution behavior
to mitigate issues with non-compliant clients in dual stack environments.
2. ddns-guard-id-must-match - relaxes the DHCID RR client id matching
requirement of DNS conflict resolution.
3. ddns-other-guard-is-dynamic - alters dual-stack-mixed-mode behavior to
allow unguarded DNS entries to be overwritten in certain cases
- The server now honors update-static-leases parameter for static DHCPv6
dhclient Improvements:
- We've added three command line parameters to dhclient:
1. --prefix-len-hint - directs dhclient to use the given length as
the prefix length hint when requesting prefixes
2. --decline-wait-time - instructs the client to wait the given number
of seconds after declining an IPv4 address before issuing a discover
3. --address-prefix-len - specifies the prefix length passed by dhclient
into the client script (via the environment variable ip6_prefixlen) with
each IPv6 address. We added this parameter because we have changed the
default value from 64 to 128 in order to be compliant with RFC3315bis
draft (-09, page 64) and RFC5942, Section 4, point 1.
**WARNING**: The new default value of 128 may not be backwardly compatible
with your environment. If you are operating without a router, such as
between VMs on a host, you may find they cannot see each other with prefix
length of 128. In such cases, you'll need to either provide routing or use
the command line parameter to set the value to 64. Alternatively you may
change the default at compile time by setting DHCLIENT_DEFAULT_PREFIX_LEN
in includes/site.h.
- dhclient will now generate a DHCPv6 DECLINE message when the client script
indicates a DAD failure
Dynamic shared library support:
Configure script,, which supports libtool is now provided
with the source tar ball. This script can be used to configure ISC DHCP
to build with libtool and thus use dynamic shared libraries.
Other Highlights:
- The server now supports dhcp-cache-threshold for DHCPv6 operations
- The server now supports DHPv6 address allocation based on EUI-64 DUIDs
- Experimental support for alternate relay port in the both the server
and relay for IPv4, IPv6 and 4o6 (see: draft-ietf-dhc-relay-port-10.txt)
For information on how to install, configure and run this software, as
well as how to find documentation and report bugs, please consult the
README file.
ISC DHCP uses standard GNU configure for installation. Please review the
output of "./configure --help" to see what options are available.
The system has only been tested on Linux, FreeBSD, and Solaris, and may not
work on other platforms. Please report any problems and suggested fixes to
ISC DHCP is open source software maintained by Internet Systems
Consortium. This product includes cryptographic software written
by Eric Young (
Changes since 4.4.2b1 (Bug Fixes)
- Added a clarification on DHCPINFORMs and server authority to
[Gitlab #37]
- Only emit lease scrubbing log messages when DEBUG_FAILOVER_MESSAGES
is defined.
[Gitlab #72]
- Added the interface name to socket initialization failure log messages.
Prior to this the log messages stated only the error reason without
stating the target interface.
[Gitlab #75]
- Corrected buffer pointer logic in dhcrelay functions that manipulate
agent relay options. Thanks to Thomas Imbert of MSRC Vulnerabilities
& Mitigations for reporting the issue.
- Corrected unresolved symbol errors building relay_unittests when
configured to build using libtool.
Changes since 4.4.1 (New Features)
- A new configuration parameter, ping-cltt-secs (v4 operation only), has
been added to allow the user to specify the number of seconds that must
elapse since CLTT before a ping check is conducted. Prior to this, the
value was hard coded at 60 seconds. Please see the server man pages for
a more detailed discussion.
[ISC-Bugs #36283]
- A new configuration parameter, ping-timeout-ms (v4 operation only),
has been added that allows the user to specify the amount of time
the server waits for a ping-check response in milliseconds rather
than in seconds (via ping-timeout). When greater than zero, the value
of ping-timeout-ms will override the value of ping-timeout. Thanks
to Jay Doran from Bluecat Networks for suggesting this feature.
[Gitlab #10]
- An experimental tool called, Keama (KEA Migration Assistant), which helps
translate ISC DHCP configurations to Kea configurations, is now included
in the distribution.
[Gitlab #34]
Changes since 4.4.1 (Bug Fixes)
- Corrected a misuse of the BIND9 DDNS API which caused DDNS updates to be
carried out over TCP rather than UDP. The coding error was exposed by
migration to BIND9 9.11. Thanks to Jinmei Tatuya at Infoblox for
reporting the issue.
[ISC-Bugs #47757]
- Bind9 now defaults to requiring python to build. The Makefile for
building Bind9 when bundled with ISC DHCP was modified to turn off
this dependency.
[Gitlab #3]
- Corrected a dual-stack mixed-mode issue that occurs when both
ddns-guard-id-must-match and ddns-other-guard-is-dynamic
are enabled and that caused the server to incorrectly interpret
the presence of a guard record belonging to another client as
a case of no guard record at all. Thanks to Fernando Soto
from BlueCat Networks for reporting this issue.
[Gitlab #1]
- Corrected a compilation issue that occurred when building without DNS
update ability (e.g. by undefining NSUPDATE).
[Gitlab #16]
- Corrected an issue that was causing the server, when running in
DHPCv4 mode, to segfault when class lease limits are reached.
Thanks to Peter Nagy at Porion-Digital for reporting the matter
and submitting a patch.
[Gitlab #13]
- Made minor changes to eliminate warnings when compiled with GCC 9.
Thanks to Brett Neumeier for bringing the matter to our attention.
[Gitlab #15]
- Fixed potential memory leaks in parser error message generation
spotted by Coverity, CIDs: 1448191, 1448193, 1448194, 1448195
[Gitlab #30]
- Updated URL of IEEE oui.txt in contrib/ Thanks
to Tommy Smith for contributing the patch.
[Gitlab #26]
- Fixed define flags when using SO_BINDTODEVICE. Thanks to Joe LeVeque for
reporting the issue.
[GitLab #19]
- Applied a patch from OpenBSD to always set the scope id of outbound
DHPCv6 packets. Note this change only applies when compiling under
OpenBSD. Thanks to Brad Smith at OpenBSD from bringing it to our
[Gitlab #33]
- Modified dhclient to not discard config file leases that are
duplicates of server-provided leases and to retain such leases
after they have been used as the fallback active lease and
DHCP service has been restored. This allows them to be used
more than once during the lifetime of a dhclient instance.
This applies to DHCPv4 operation only.
[Gitlab #9]
- Corrected a number of reference counter and zero-length buffer leaks.
Thanks to Christopher Ertl of MSRC Vulnerabilities & Mitigations for
pointing them out.
[Gitlab #57]
- Closed a small window of time between the installation of graceful
shutdown signal handlers and application context startup, during which
the receipt of shutdown signal would cause a REQUIRE() assertion to
occur. Note this issue is only visible when compiling with
[Gitlab #53]
- Corrected a buffer overflow that can occur when retrieving zone
names that are more than 255 characters in length.
[Gitlab #20]
- The "d" domain name option format was incorrectly handled as text
instead of RFC 1035 wire format. Thanks to Jay Doran at BlueCat Networks
for reporting this issue.
[Gitlab #2]
- Improved the error message issued when a host declaration has both
a uid and a dhcp-client-identifier. Server configuration parsing will
now fail if a host declaration specifies more than one uid.
[Gitlab #7]
- Updated developer's documentation on building and running unit tests.
Removed support for --with-atf=bind as BIND9 no longer bundles in ATF
[Gitlab #35]
- Fixed a syntax error in ldap.c which cropped up under Ubuntu
18.04.1/gcc 7.4.0. Thanks to Charles Hedrick for pointing it out.
[Gitlab #51]
- Added clarification to dhcp-options.5 section on ip-address values
describing the first-use DNS resolution of options with hostnames as
values (e.g. next-server).
[Gitlab #28]
- The option format for the server option omapi-key was changed to a
format type 'k' (key name); while server options ldap-port and
ldap-init-retry were changed to 'L' (unsigned 32-bit integer). These
three options were inadvertantly broken when the 'd' format content
was changed to comply with RFC 1035 wire format (see Gitlab #2).
[Gitlab #68]
Changes since 4.4.0 (New Features)
- none
Changes since 4.4.0 (Bug Fixes)
- A delayed-ack value of 0 (the default), now correctly disables the delayed
feature. A change in 4.4.0 prohibited lease updates marking leases active
from be written to the lease file when delayed-ack is 0. This in turn,
caused servers to lose active lease assignments upon restart.
[ISC-Bugs #47141]
! Option reference count was not correctly decremented in error path
when parsing buffer for options. Reported by Felix Wilhelm, Google
Security Team.
[ISC-Bugs #47140]
CVE: CVE-2018-5733
! Corrected an issue where large sized 'X/x' format options were causing
option handling logic to overwrite memory when expanding them to human
readable form. Reported by Felix Wilhelm, Google Security Team.
[ISC-Bugs #47139]
CVE: CVE-2018-5732
- Added use of new Bind9 compatibility header files, that are now necessary
to supply type definitions for primitive data types, removed from Bind9
proper. Altered util/ to pull from Bind9 repo on gitlab.
[ISC-Bugs #48072]
[ISC-Bugs #48071]
Changes since 4.4.0b1 (New Features)
- Duplicate address detection when binding to a new IPv6 address was added
to the following dhclient scripts: linux,freebsd,netbsd,openbsd, and macos.
The scripts will check for DAD errors after binding to a new IPv6 address
for at most --dad-wait-time seconds. If a DAD error is detected the script
will exit with a value of 3, instructing dhclient to decline the address. If
dad-wait-time is zero (the default), DAD error checking is not peformed.
[ISC-Bugs 46805]
- Support for sending and receiving additional DHCP4 options has been added
to both the dhcpd and dhclient. Specifically: option codes 93,94, and 97
(RFC 4578); code 150 (RFC 5859); and codes 209,219, and 211 (RFC 5071).
Beyond configuring, sending, requesting, and receiving these options neither
server nor client apply any additional logic based on their values.
Thanks to Peter Lewis for requesting this change.
[ISC-Bugs 47062]
Changes since 4.4.0b1 (Bug Fixes)
- Added clarifying text to dhcpd.conf.5 explaining the class match expressions
cannot rely on the results of executable statements.
[ISC-Bugs #45451]
- Fixed a bug which causes dhcpd and dhclient to crash on certain
systems when given relative path names for lease or pid files on
the command line. Affected systems are those on which the C library
function, realpath() does not support a second parameter value of
NULL (see manpages for realpath(3)).
[ISC-Bugs #46957]
- Fixed a build issue when building with embedded BIND9 under OpenBSD that
was causing BIND9 build to not generate dns/enumclass.h and dns/enumtype.h.
[ISC-Bugs #46971]
- Added <dhcp>/m4/README to the distribution tarball. Some versions of
ac_local() treat the absence of the m4 subdirectory as error rather than
warning. This was causing the call to autoreconf, necessary for building
with libtool, to fail.
[ISC-Bugs #47075]
Changes since 4.4.0a1 (New Features)
- Added experimental support for relay port (draft-ietf-dhc-relay-port-10.txt)
feature for DHCPv4, DHCPv6 and DHCPv4-over-DHCPv6. Relay port has to be
enabled at compile time via --enable-relay-port and is fully backward
compatible (i.e. works with previous implementations of servers and relays
using the standard ports). A new --rp <relay-port> command line option
specifies to dhcrelay an alternate source port for upstream (i.e. toward
the server) messages. Thanks to Naiming Shen and Enke Chen of Cisco
systems for submitting these patches.
[ISC-Bugs #44535]
- Added --release-on-roam to dhcpd server. When enabled and the server detects
that a DHCPv6 client (IAID+DUID) has roamed to a new network, it will release
the pre-existing leases on the old network and emit a log statement similar
to the following:
"Client: <id> roamed to new network, releasing lease: <address>"
The server will carry out all of the same steps that would normally occur
when a client explicitly releases a lease. This behavior is disabled by
default and may only be specified globally. Prior to this the server renders
the leases unavailable until they expire or the server is restarted. Clients
that need leases in multiple networks must supply a unique IAID in each IA.
When release-on-roam is disabled (the default) the server maintains the
prior behavior of making such leases unavailable until they expire or the
server is restarted. Clients that need leases in multiple networks must
supply a unique IAID in each IA. This parameter may only be specified at
the global level. Thanks to Fernando Soto from BlueCat Networks for
suggesting this change.
[ISC-Bugs #44576]
[ISC-Bugs #46849]
- Support for delayed-ack is now compiled in by default. Prior to this
it had to be enabled at compile time via --enable-delayed-acks. The
default value for delayed-ack, however, has been changed from 28 to 0
(i.e. disabled). This was done to minimize the impact on users not
currently using the feature. Please note that the delayed-ack feature
is not currently compatible with support for DHPCv4-over-DHCPv6 so
when a 4to6 port command line argument enables this in the server the
delayed-ack value is reset to 0.
[ISC-Bugs #42446]
- The server (-6) now honors the parameter, update-static-leases, for static
(fixed-address6) DHCPv6 leases. It is worth noting that because stateful
data is not retained by the server for static leases, each time a client
requests or renews a static lease, the server will perform DDNS updates for
it. This may have significant performance implications for environments
with many clients that request or renew static leases often. Similarly,
the DNS entries will not be removed by server when a client issues a RELEASE
nor if the lease is deleted from the configuration. In such cases the DNS
entries must be removed manually. This feature is disabled by default.
Thanks to both Bill Shirley and dgutier-at-cern-dot-ch for requesting
this change.
[ISC-Bugs #34097]
[ISC-Bugs #41054]
[ISC-Bugs #41450]
- Added to the server (-6) a new statement, local-address6, which specifies
the source address of packets sent by the server. An additional flag,
bind-local-address6, disabled by default, binds the service socket to
to local-address6. Note that bind-local-address does not work with direct
clients: a relay has to forward packets to the server using the
local-address6 destination.
[ISC-Bugs #46084]
Changes since 4.4.0a1 (Bugs)
- The server now recognizes environment variables PATH_DHCPD_DB and
PATH_DHCPD_PID. These had been incorrectly compiled out of the code
unless DHCPv6 support was disabled. Additionally, the server man
pages were corrected to accurately reflect how the server chooses
file names (see lease-file-name and pid-file-name statements). Thanks
to Fernando Soto at Bluecat Networks for bringing this matter to our
[ISC-Bugs #46859]
- Removed an "Impossible condition" error upon exit in the dhcpd server that
has been shutdown via OMAPI. This condition was only apparent under Solaris
when building with --enable-use-sockets and --enable-ipv4-pktinfo.
[ISC-Bugs #36118]
- Corrected some minor Coverity issues: CID 1426059, 1426058, and 1426057.
[ISC-Bugs #46836]
- Added missing text to dhclient.8 and expanded release note coverage
for --address-prefix-len changes.
Changes since 4.3.6 (New Features)
- Added --enable-bind-install to install embedded bind includes and
libraries. Default is to not install them (it was the previous
behavior). If you'd like to change the includedir and/or libdir
installation directories to something different than for ISC DHCP
you must pass them using the --with-bind-extra-config configuration
[ISC-Bugs #39318]
- Added support of dynamic shared libraries with libtool. A new
--enable-libtool configuration parameter is available but
should not be used directly: *please* read the build configuration
section in the README file for the recommended procedure.
[ISC-Bugs #29402]
- IPv6 operation now supports an EUI-64 based address allocation which will
calculate addresses for clients with EUI-64 DUIDs based on those DUIDs when
enabled by setting use-eui-64 true. The parameter may defined down to the
pool scope. Note this feature must be compiled in by defining EUI_64 in
includes/site.h. This flag is undefined by default.
[ISC-Bugs #43927]
- The directory includes/isc-dhcp and it's only occupant, dst.h, have
been removed from the source tree. They are obsolete for branches
other than v4_1_esv.
[ISC-bugs #45541]
- Replaced ISC licensing with Mozilla Public License, MPL 2.0 licensing
throughout. Please see to read
the MPL 2.0 license terms.
[ISC-Bugs #45541]
- Load balancing for failover peers can now be disabled by setting
"load balance max secs" to 0. Doing so for both peers means both
servers will respond to all DHCPDISCOVERs or DHCPREQUESTs as soon as
they are received.
[ISC-Bugs #39669]
- Added a new dhclient command line parameter, --prefix-len-hint <length>.
When used in conjunction with -P, it directs dhclient to use the given
length as the prefix length hint when requesting prefixes. Thanks to both
Indy, of the FireballISO open source project and H. Peter Anvin for
suggesting this change.
[ISC-Bugs #43792]
[ISC-Bugs #35112]
[ISC-Bugs #32228]
[ISC-Bugs #29470]
- dhclient will now wait for 10 seconds after declining an IPv4 address
before issuing a discover. This is in keeping with RFC 2131, section 3.1.5.
Prior to this dhclient did not wait at all. The amount of time dhclient
waits can be specified via a new command line parameter:
--decline-wait-time <seconds>. A value of zero equates to no wait at all.
Thanks to Pavel Kankovsky for bringing this matter to our attention.
[ISC-Bugs #45457]
- dhclient will now include the lease address when logging DHCPOFFERs,
DHCPOFFERs will be logged before their corresponding DHCPREQUESTs are
sent and logged.
[ISC-Bugs #2729]
- When given the -T command line argument, in addition to reading the
current lease file, the server will write the leases to a temporary
lease file. This can help detect issues in server configuration that
only surface when leases are written to the file. The current lease
file will not be modified and the temporary lease file is removed upon
completion of the test.
[ISC-Bugs #22267]
- dhclient will now generate a DHCPv6 DECLINE message containing all IA_NA
addresses which for which the client script indicates a DAD failure. After
receiving the DECLINE reply, dhclient will restart the solicit process.
Note, the client script must exit with a value of 3 to signify that the
address failed DAD. Thanks to Jiri Popelka of Red Hat for submitting the
patch that was the foundation for this change.
[ISC-Bugs #21237]
[ISC-Bugs #23357]
[ISC-Bugs #36966]
- Replaced compilation option, enable-secs-byteorder, with a run-time, server
configuration parameter, check-secs-byte-order. When enabled, the
server will check for clients that do the byte ordering on the secs field
incorrectly. This field should be in network byte order but some clients
get it wrong. When this parameter is enabled the server will examine the
secs field and if it looks wrong (high byte non zero and low byte zero) swap
the bytes. The default is disabled. This parameter is only useful when
doing load balancing within failover.
[ISC-Bugs #45364]
- The default value for server (-6) parameter, prefix-length-mode, has been
changed from "exact" to "prefer". In "prefer" mode the server will offer
the first available prefix with the same length as that requested by the
client. If none are found then it will offer the first available prefix of
any length. This is more in line with with RFC 8168 and should improve
the out-of-the-box user experience.
[ISC-Bugs #45615]
- Added support for 'dhcp-cache-threshold' to IPv6 operation: If a client
renews before 'dhcp-cache-threshold' percent of its lease has elapsed
(default 25%), the server will reuse the allocated lease (provide a
lease within the currently allocated lease-time) rather than extend or
renew the lease. This allows the server to reply without needlessly
writing leases to disk. The preferred and valid lease lifetimes
sent to the client will be reduced by the age of the lease. The option
may be specified down to the pool level and is supported for all three
pool types: NA, TA, and PD.
[ISC-Bugs #45292]
- Added three new server configuration parameters which influence DDNS:
1. ddns-dual-stack-mixed-mode - alters DNS conflict resolution behavior
to mitigate issues with non-compliant clients in dual stack environments.
2. ddns-guard-id-must-match - relaxes the DHCID RR client id matching
requirement of DNS conflict resolution.
3. ddns-other-guard-is-dynamic - alters dual-stack-mixed-mode behavior to
allow unguarded DNS entries to be overwritten in certain cases
[ISC-Bugs #42620]
[ISC-Bugs #42621]
[ISC-Bugs #44753]
- A "key-algorithm <algorithm>" statement has been added to omshell to
allow the specification of the key algorithm to use during transaction
authentication. Prior to this it was hard-coded to be hmac-md5. It now
supports all of the same algorithms as the dhcpd server: hmac-md5 (the
default), hmac-sha1, hmac-sha224, hmac-sha256, hmac-sha384, and hmac-sha512.
[ISC-Bugs #46771]
- Added a server configuration parameter, persist-eui-64-leases, which
determines whether or not EUI-64 based leases are written to the
leases file. Default is true.
[ISC-Bugs #45046]
- Changed the default value of the prefix length passed by dhclient into the
client script for each IPv6 address from 64 to 128. This was done to comply
with RFC3315bis draft (-09, page 64) and RFC5942, Section 4, point 1.
In addition, dhclient now supports a command line argument,
--address-prefix-len, which may be used to override the default value.
**WARNING**: This change may not be backwardly compatible with your
environment. If you are operating without a router, such as between VMs on
a host, you may find they cannot see each with prefix length of 128. In
such cases, you'll need to either provide routing or use the command line
parameter to set the value to 64. Alternatively you may change the default
at compile time by setting DHCLIENT_DEFAULT_PREFIX_LEN in includes/site.h.
[ISC-Bugs #23252]
[ISC-Bugs #37221]
- Modified dhclient (-6) to bypass sending a confirm (INIT REBOOT) when it has
only expired address associations. Thanks to Jiri Popelka at Red Hat for
raising the issue and submitting the patch.
[ISC-Bugs #22675]
Changes since 4.3.6 (Bugs):
- Corrected an issue where the server would return a client's previously
released prefix lease even when the client provides a prefix length
hint that does not match the prior lease. Now the server will only
return the previous lease if it exactly matches the hint. If not
it will attempt to allocate a new prefix based on the hint and the
prefix-length-mode. Thanks to Tim DeNike - Lightspeed Communications
for pointing out the error of our ways.
[ISC-bugs #45780]
- Added explicit include of BIND9 isc/util.h to adapt to revisions
in BIND9 (see BIND9 ticket #46311). Prior to this the build was failing
with implicit function declarations errors for POST() and INSIST().
[ISC-bugs #46332]
- Added to code ignore empty IPv4 host name option (code 12). While RFC 2132
states the option cannot be empty, some clients are apparently capable of
sending it. Prior to this the server was attempting to use it and store it
in the lease file causing issues with DDNS and so forth.
[ISC-bugs #43786]
- Corrected dhclient command line parsing for --dad-wait-time that causes
even valid values to fail as invalid on some environments.
[ISC-Bugs #46535]
- Replaced iasubopt::heap_index with separate values for active and inactive
heaps: iasubopt::active_index and iasubopt::inactive_index. This was done
to accommodate a change in behavior in BIND9 isc_heap_delete().
[ISC-bugs #46719]
! Plugged a socket descriptor leak in OMAPI, that can occur when there is
data pending to be written to an OMAPI connection, when the connection
is closed by the reader. Thanks to Pavel Zhukov at RedHat for bringing
this issue to our attention and whose patch helped guide us in the right
[ISC-Bugs #46767]
- The ability of the server to send back dhcp6.vendor-opts values has been
restored. A change in 4.3.5 (see #29246) which enabled it to send back the
FQDN option unfortunately broke its ability send back dhcp6.vendor-opts.
Thanks to Sumant Gupta (sumantgupta at gmail dot com) of Landis+Gry for
bringing this issue to our attention.
[ISC-Bugs #46427]
Changes since 4.3.6b1
- None
Changes since 4.3.5
- The server now allows the client identifier (option 61) to own leases
in more than one subnet concurrently. Prior to this the server would
incorrectly release an existing lease in one subnet prior to assigning
a lease in another subnet. Note that the prior behavior can be still
be achieved by enabling one-lease-per-client. Thanks to both David Zych at
the University of Illinois and Norm Proffitt of Infoblox for reporting
the issue; and Norm for suggesting a solution.
[ISC-Bugs #41358]
- When replying to a DHCPINFORM, the server will now include options specified
at the pool scope, provided the ciaddr field of the DHCPINFORM is populated.
Prior to this the server only evaluated options down to the subnet scope.
Thanks to Fernando Soto at BlueCat Networks for reporting the issue.
[ISC-Bugs #43219]
[ISC-Bugs #45051]
- When memory allocation fails in a repeated way the process writes
"Run out of memory." on the standard error and exists with status 1.
[ISC-Bugs #32744]
- The new lmdb (Lightning Memory DataBase) bind9 configure option is
now disabled by default to avoid the presence of this library to be
detected which can lead to a link failure.
[ISC-Bugs #45069]
- The linux interface discovery code has been modified to use getifaddrs()
as is done for BSD and OS-X. Prior to this the code would only recognize
the first address on an interface and thereby omit vlans.
Thanks to Jiri Popelka at Redhat, Marius Tomaschewski at SUSE, and Wei
Kong at Novell, who all submitted patches.
[ISC-Bugs #28761]
[ISC-Bugs #31992]
[ISC-Bugs #25428]
[ISC-Bugs #31940]
[ISC-Bugs #32935]
- Fixed a bug in OMAPI that causes omshell to crash when a name-value
pair with a zero length value is shipped in an object. Thanks to
Fernando Soto at BlueCat Networks for reporting the issue and
supplying the patch.
[ISC-Bugs #29108]
- On 64-bit platforms, dhclient now generates the correct value for the
script environment variable, "expiry", the lease expiry value exceeds
0x7FFFFFFF. Prior to this such values would produce negative values
for expiry in the script environment.
[ISC-Bugs #43326]
- Common timer logic was modified to cap the maximum timeout values at
0x7FFFFFFF - 1. Values larger than that were causing fatal timer out of
range errors on 64-bit platforms. Thanks to Jiri Popelka at Red Hat for
reporting the issue.
[ISC-Bugs #28038]
- DHCP6 FQDN option unpacking code now correctly handles values that contain
spaces, special, or non-printable characters. Prior to this the buffer
size needed was underestimated causing a conversion error message to
be logged and DNS updates to be skipped. Thanks to Fernando Soto at
BlueCat Networks for bringing the matter to our attention.
[ISC-Bugs #43592]
- When running in -6 mode, dhclient can enforce the require option statement
and will discard offered leases that do not contain all the required
options specified in the client configuration. If not enabled the client
will still consider such leases. This must be enabled at compile time
(see ENFORCE_DHCPV6_CLIENT_REQUIRE in includes/site.h). Thanks to
Mritunjaykumar Dubey at Nokia for reporting the issue.
[ISC-Bugs #41473]
- Altered DHCPv4 lease time calculation to avoid roll over errors on 64-bit
OS systems when using -1 or large values for default-lease-time. Rollover
values will be replaced with 0x7FFFFFFF - 1. This alleviates unintentionally
short expiration times being handed out when infinite lease times (-1) in
conjunction with failover. Our thanks to Alessandro Gherardi for bringing
the issue to our attention.
[ISC-Bugs #41976]
- Added new compile time option --with-srv-conf-file which specifies a
default location of the server configuration file.
[ISC-Bugs #44765]
- Added --dad-wait-time parameter to dhclient. It specifies the maximum time,
in seconds, that the client process should wait for the duplicate address
detection to complete before initiating DHCP requests. This value is
propagated to the dhclient script and the script is responsible for waiting
the specified amount of time or until DAD has completed. If the script does
not support it, specifying this parameter has no effect. The default value
is 0 which specifies that the script should not wait for DAD. With this
change the following scripts have been modified to support the new parameter:
freebsd, linux, macos, netbsd, openbsd.
[ISC-Bugs #36169]
- The server nows checks both the address and length of a prefix delegation
when attempting to match it to a prefix pool. This ensures the server
responds properly when pool configurations change such that once valid,
"in-pool" delegations are now treated as being invalid. During lease
file loading at startup, the server will discard any PD leases that
are deemed "out-of-pool" either by address or mis-matched prefix length.
Clients seeking to renew or rebind such leases will get a response of
No Binding in the case of the former, and the prefix delegation with
lifetimes set to zero in the case of the latter. Thanks to Mark Nejedlo
at TDS Telecom for reporting this issue.
[ISC-Bugs #35378]
- Modified DDNS support initialization such that DNS related ports will only be
opened by the server (dhcpd) at startup if ddns-update-style is not "none";
by dhclient only if and when the it first attempts an update; and never by
dhcrelay. Prior to this all three always did the initialization at startup
which causes them to always open on and listen for traffic on two random
ports. Thanks to Rodney Beede for reporting this issue.
[ISC-Bugs #45290]
[ISC-Bugs #33377]
- Added error logging to two memory allocation failure checks. Thanks to Bill
Parker (wp02855 at gmail dot com) for reporting the issue.
[ISC-Bugs #41185]
- Corrected a dhclient -6 issue that caused the client to crash with an
"Impossible condition" error after de-preferencing its only IA binding.
The crash occurred when server configuration changes rendered the existing
binding out-of-range and no other leases were available to offer. Thanks
to Pierre Clerissi for bringing this issue to our attention.
[ISC-Bugs #44373]
- By defining CALL_SCRIPT_ON_ONETRY_FAIL in includes/site.h, dhclient will
now call the script with reason set to FAIL when run with -1 (one try) and
there are no server responses. This applies to IPv4 mode only. Thanks for a
patch by Martin Pitt which got to us via Andrew Pollock.
[ISC-bugs #18183]
- The server now detects failover peers that are not referenced in at least
one pool when run with the command line option for test mode, -T. Prior to
this the check was performed too far down stream to be detected in test mode.
[ISC-Bugs #29892]
- Linux script updated. The script is now based on Debian version. It uses
ip tool from iproute2 package and ifconfig is no longer used. This also
addresses an issue of calling arping with inappropriate parameter.
[ISC-bugs #19430]
[ISC-bugs #18111]
- Changed severity of the log message indicating UDP checksum errors in
the received packets from 'info' to 'debug' to avoid logging excessive
number of false positives when UDP checksum offloading is enabled.
[ISC-bugs #41757]
- The directory minires has been removed from the source tree. It has
long been obsolete for branches other than v4_1_esv. Additionally,
includes/minires.h was renamed includes/ns_name.h.
[ISC-bugs #45471]
- Replaced ifconfig parameters "add" and "delete" with "alias" and "-alias"
for IPv6 mode in the client scripts, netbsd and openbsd. This was
preventing IPv6 addresses from being added or removed from interfaces.
Thanks to Tim Dean for reporting this issue.
[ISC-bugs #31573]
Changes since 4.3.5b1
- Corrected a bug which could cause the server to sporadically crash while
loading lease files with the lease-id-format is set to "hex". Our thanks
to Jay Ford, University of Iowa for reporting the issue.
[ISC-Bugs #43185]
- Eliminated a noisy, but otherwise harmless debug log statment that may
appear during server startup when building with --enable-binary-leases
and configuring multiple pools in a shared network. Thanks to Fernando
Soto from BlueCat Networks for reporting the issue and supplying a patch.
[ISC-Bugs #43262]
Changes since 4.3.4
- Fixed util/ error handling.
[ISC-Bugs #41973]
- Correct error message in relay to use remote id length instead
of circuit id length.
[ISC-Bugs #42556]
- Add logic to test directory Makefiles to avoid copying Attfile(s)
when building within the source tree. This eliminates a noisy but
otherwise harmless error message when running "make check".
[ISC-Bugs #41883]
- Leases are now scrubbed of certain prior use information when pool
re-balancing reassigns them from one FO peer to the other. This
corrects an issue where leases that were offered but not used
by the client retained the client hostname from the original
client. Thanks to Pavel Polacek, Jan Evangelista Purkyne University
for reporting the issue.
[ISC-Bugs #42008]
- In the LDAP code and schema add some missing '6' characters to use
the v6 instead of the v4 versions. Thanks to Denis Taranushin for
reporting this issue and supplying its patch.
[ISC-Bugs #42666]
- Correct how the pick-first-value expression is written to a lease
file. Previously it was written as a concat expression due to
a cut and paste error.
[ISC-Bugs #42253]
- Modify the DDNS code to clean up the PTR record even if there
are issues while cleaning up the A or AAAA records.
[ISC-Bugs #23954]
- Added global configuration parameter, abandon-lease-time, which determines
the amount of time a lease remains abandoned. The default is 84600 seconds.
Additionaly, the server now conducts a ping check (if ping checks are
enabled) prior to offering an abandoned lease to client. Our thanks to
David Zych at University of Illinois for reporting the issue and working
with us to produce a viable solution.
[ISC-Bugs #41815]
- Correct handling of interface names during interface discovery. This
addresses an issue where interface names of 15 characters in length
could lead to crashes or interface recognition errors during startup
of dhcpd, dhclient, and dhcrelay.
[ISC-Bugs #42226]
- Updates to contrib/ to make it more friendly.
The updates are: looking for the lease file in more places and skipping
the "processing complete" output when creating machine readable
output. Thanks to Cameron Paine (cbp at null dot net) for the
[ISC-Bugs #42113]
- When reusing a lease for dhcp-cache-threshold return the hostname
to the original lease. Also if the host pointer, UID or hardware address
change don't allow reuse of the lease.
Thanks to Michael Vincent for reporting this and helping us
verify the problem and fix.
[ISC-Bugs #42849]
- Change dmalloc to use a size_t as the length argument to bring it
in line with the call it will make to malloc().
[ISC-Bugs #40843]
- If the failover socket can't be bound, close it. Otherwise if the
user configures an incorrect address in the failover stanza the
server will continue to open new sockets every 90 seconds until
it runs out.
[ISC-Bugs #42452]
- Add DHCPv4-mode, dhcrelay command line options, "-iu" and "-id", that
allow interfaces to be upstream or downstream respectively. Upstream
interfaces will accept and forward only BOOTP replies, while downstream
interfaces will accept and forward only BOOTP requests.
[ISC-Bugs #41547]
- Clean up some memory references in the vendor-class construct.
[ISC-Bugs #42984]
Changes since 4.3.4b1
- None
Changes since 4.3.3
- Corrected a static analyzer warning in common/execute.c
[ISC-Bugs #40374]
- ISC DHCP now follows the common convention to use the base name a
program is invoked with (aka argv[0], vs. a builtin name) for
logs. This should help differentiate syslog entries for DHCPv4 and
DHCPv6 servers. You can define OLD_LOG_NAME in includes/site.h to
keep the previous behavior.
[ISC-Bugs #38692]
- The Linux packet filter code now correctly treats only the least significant
12 bits in an inbound packet's TCI value as the VLAN id (per IEEE 802.1Q).
Prior to this it was using the entire 16 bit value as the VLAN id and
incorrectly discarding packets. Thanks to Jiri Popelka at Red Hat for
reporting this issue and supplying its patch.
[ISC-Bugs #40591]
- Fixed several static analysis issues such as potential null
references, unchecked strdup returns. Thanks to Bill Parker (wp02855 at
gmail dot com) who identified these issues and supplied patches to
address them.
[ISC-Bugs #40754]
[ISC-Bugs #40823]
- Corrected compilation errors that prohibited building the server
and its ATF unit tests when failover is disabled.
[ISC-Bugs #40372]
- Added the lease address to the end of the debug level log message
emitted when an existing lease is renewed within the dhcp-cache-threshold.
Thanks to Nathan Neulinger at Missouri S&T for suggesting the change.
[ISC-Bugs #40598]
- Added dhcpv6 and delayed-ack to settings listed in the "Features:"
section of the configure script output. Additionally, all of the
features reported on will now always show either a "yes" or "no"
value. Prior to this features left to their default setting would
not show a value.
[ISC-Bugs #40381]
- Added a parameter, authoring-byte-order, to the lease file. This value
is automatically added to the top of new lease files by the server and
indicates the internal byte order (big endian or little endian) of the
server. This permits lease files generated on a server with one form of
byte order to be used on a server with the opposite form. Our thanks to
Timothe Litt for calling this to our attention and for the suggestions
he provided.
[ISC-Bugs #38396]
- Fixed a small memory leak in the DHCPv6 version of the client code.
This is unlikely to cause significant issues in actual use.
[ISC-Bugs #40990]
- Corrected a few minor memory leaks in omapi's dereferencing of
host objects. Thanks to Jiri Popelka at Red Hat for reporting
the issue and supplying the patches.
[ISC-Bugs #33990]
[ISC-Bugs #41325]
- Cleaned up some of the Make infrastructure to make --with-libbind
work better. Though it still only works with an absolute path.
[ISC-Bugs #39210]
- Made the embedded bind libraries able to be cross compiled
(please refer to the bind9 documentation to learn how to cross
compile DHCP and its bind library dependency).
[ISC-Bugs #38836]
- Update the client code to better support getting IA_NAs and IA_PDs
in the same packet, see RFC7550 for some discussion.
[ISC-Bugs #40190]
! Update the bounds checking when receiving a packet.
Thanks to Sebastian Poehn from Sophos for the bug report and a suggested
[ISC-Bugs #41267]
CVE: CVE-2015-8605
- When handling an incorrect command line for dhcpd, dhclient or dhcrelay
print out a specific error message about the first error in addition
to the usage string. This may be disabled by editing includes/site.h.
[ISC-Bugs #40321]
[ISC-Bugs #41454]
- The configure script will now exit with an error message if it cannot find
a GNU-style make tool (needed when building BIND libraries) or pkg-config
(needed to locate ATF used for building unit tests). Prior to this the
script would exit indicating success causing subsequent attempts to build
the software to fail.
[ISC-Bugs #40371]
- Properly terminate strings before passing them to regex and fix
a boundary error when creating certain new data strings.
Thanks to Andrey Jr. Melnikov for the bug report.
[ISC-Bugs #41217]
- Option expressions, such as prepend and append, are now supported when
running dhclient for IPv6. Prior to this such statements in the
client configuration file would be parsed but have no affect. Thanks
to Jiri Popelka at Red Hat for reporting the issue.
[ISC-Bugs #39952]
- A failover primary server will now accept a binding status update from the
secondary which transitions a lease from ACTIVE to ABANDONED. This accounts
for instances in which a client declines a lease and only the secondary
server receives it. Prior to this the primary server would reject such an
update as an "invalid state transition".
[ISC_BUGS #25189]
- Properly allocate memory for a bpf filter.
Thanks to Bill Parker (wp02855 at gmail dot com) who identified this issue.
[ISC-Bugs #41485]
- Updated contrib/ to handle garbage in the oui file better
and to print out the hostnames a bit better.
Thanks to Antoine Beaupré from Debian for the suggested patch.
[ISC-Bugs #41288]
- The DHCPv6 server now handles long valid and preferred lease times better.
Values that would cause the internal end time of the lease to wrap are
modified to work as infinite.
[ISC-Bugs #40773]
- Updated support for cross compiling by allowing the library archiver
to be set at configure time via the environment variable 'AR'.
[ISC-Bugs #41536]
- The server will now match DHCPv6 relayed clients to host declarations
which include the "hardware" statement, if the relay connected to the
client supplies the client's hardware address via client-linklayer-address
option as per RFC 6939.
[ISC-Bugs #40334]
- Allow a filename to be specified instead of /dev/random during
configuration. This is passed to the BIND configuration to allow
for cross compilation.
[ISC-Bugs #33835]
- Add more option definitions.
[ISC-Bugs #40562]
- Correct outputting of long lines in the lease file when writing
a lease that includes long strings in an execute statement.
[ISC-Bugs #40994]
- The server will now correctly treat a lease as reserved when the client
requests an infinite lease time (i.e. OxFFFFFFFF) and "infinite-is-reserved"
is enabled. Prior to this the server would halt. In addition, corrections
were made to the server to allow a lease's flags field to be set via omapi.
Prior to this, the server, depending on the host architecture, would
incorrectly parse the new flags value from the omapi message.
[ISC-Bugs #31179]
- ISC DHCP can now be configured and built from a directory other than
the top level source directory. Note that "make distcheck" uses this
[ISC-Bugs #39262]
- Add support for RFC 3527 to dhcrelay. A new, dhcrelay command line argument,
"-U <interface>" enables the addition of a RFC 3527 compliant link selection
suboption to the agent option added for clients directly connected to the
[ISC-Bugs #34875]
[ISC-Bugs #41708]
- Add a new global DHCPv6 option, dhcpv6-set-tee-times, which when enabled
instructs the server to calculate T1 and T2 as recommended in RFC 3315,
Section 22.4.
[ISC-Bugs #25687]
- Corrected minor Coverity issues.
[ISC-Bugs #35144]
- Add support for RFC 7341 DHCPv4 over DHCPv6 with a new configuration
option "--enable-dhcpv4o6". Note this feature requires DHCPv6 support
and is not compatible with delayed-ack. Both client and server use 2
processes which communicate over UDP on a pair of sockets. The new
"-4o6 <port>" command line argument enables DHCPv4 over DHCPv6 support
and specifies the consecutive ports to use for inter-process communication.
Please look at doc/DHCPv4-over-DHCPv6 for more details.
[ISC-Bugs #35711]
- Correct interface name formation when using DLPI under Solaris 11. As of
Solaris 11, ethernet device files are located in "/dev/net". The configure
script has been modified to detect this situation and adjust the directory
used accordingly. Thanks to Jarkko Torppa for reporting this issue and
submitting a patch
[ISC-Bugs #37954]
[ISC-Bugs #40752]
- Add a dereference call when handling an error condition while
decoding a packet.
[ISC-Bugs #41774]
- Add a new parameter, lease-id-format, to both dhcpd and dhclient. The
parameter controls the format in which certain values are written to lease
files. Formats supported are octal - quoted string containing octal
escapes, and hex - unquoted, colon separated hex digits. Thanks to
Jay Ford, University of Iowa for bringing the issue to our attention.
[ISC-Bugs #26378]
! Add an option in site.h to limit the number of failover and control
connections the server will accept. By default this is 200.
[ISC-Bugs #41845]
CVE: CVE-2016-2774
Changes since 4.3.3b1
- None
Changes since 4.3.2
- The server now does a better check to see if it can allocate the memory
for large blocks of v4 leases and should provide a slightly better error
message. Note well: the server pre-allocates v4 addresses, if you use
a large range, such as a /8, the server will attempt to use a large
amount of memory and may not start if there either isn't enough memory
or the size exceeds what the code supports.
[ISC-Bugs #38637]
- The server will now reject unicast Request, Renew, Decline, and Release
messages from a client unless the server would have sent that client the
dhcp6.unicast option. This behavior is in compliance with paragraph 1 in
each of the sections 18.2,1, 18.2.3, 18.2.6, and 18.2.7 of RFC 3315. Prior
to this, the server would simply accept the messages. Now, in order for
the server to accept such a message, the server configuration must include
the dhcp6.unicast option either globally or within the shared network to
which the requested lease belongs. In other words, the server will map
the first IA_XX address found within the client message to a shared-network
and look for the presence of the unicast option there and then globally.
Thanks to Jiri Popelka at Red Hat for this issue and his patch which
inspired the fix.
[ISC-Bugs #21235]
- The ATF (Automated Testing Framework) tools used for optional unit tests
can now be built from its embedded sources in bind, solving the
atf-run / atf-report issue with recent (>= 0.20) versions of ATF.
The new configuration option is "./configure --with-atf=bind".
[ISC-Bugs #38754, #39300]
- Corrected a compilation error introduced by the fix for ISC-Bugs #22806.
On older linuxes that do not include the tpacket_auxdata structure don't
bother allocating the cmsgbuf as it isn't necessary and we don't have
a proper length for it.
[ISC-Bugs #39209]
- Remove the dst directory. This was replaced in 4.2.0 with the dst
code from the Bind libraries but we continued to include it for
backwards compatibility. As we have now released 4.3.x it seems
reasonable to remove it.
[ISC-Buts #39019]
- Write out the DUID server id on startup in all cases, previously if it
was read in from server-duid option in the config or lease files for
DHCPv4 it would not be written to the new lease file.
[ISC-Bugs #37791]
- When parsing dates for leases convert dates past 2038 to "never".
This avoids problems with integer overflows in the date and time
handling code for people that decide to use very large lease times
or add a lease entry with a date far in the future.
[ISC-Bugs #33056]
- Leave the siaddr field clear when sending a NACK as per RFC 2131
table 3.
[ISC-Bugs #38769]
- In the client don't send expired addresses to the script as part of
the binding process. Thanks to Sven Trenkel at Google for reporting
the issue and suggesting the patch.
[ISC-Bugs #38631]
- While parsing IPv6 addresses treat "add" as part of the address instead
of as a token.
[ISC-Bugs #39529]
- Add support for accessing the v4 lease queues (active, free etc) in a
binary fashion instead of needing to walk through a linear list to
insert, find or remove an entry from the queues. In addition add a
compile time option "--enable-binary-leases" to enable the new code
or to continue using the old code. The old code is the default.
Thanks to Fernando Soto from BlueCat Networks for the patch.
[ISC-Bugs #39078]
- Delayed-ack now works properly with Failover. Prior to this, bind updates
post startup were being queued but never delivered. Among other things, this
was causing leases to not transition from expired or released to free.
[ISC-Bugs #31474]
- Clean up parsing of v6 lease files a bit to avoid infinite loops if the
lease file is corrupt in certain ways.
[ISC-Bugs #39760]
- Corrected a crash in dhclient that occurs during lease renewal if the
client is performing its own DNS updates. Thanks to Jiri Popelka at Red Hat
for the bug report.
[ISC-Bugs #38639]
- Corrected an issue in v6 lease file parsing. Prior to this, when encountering
a lease with an address for which no configured pool exists, the server was
declaring the lease file corrupt and incorrectly skipping over the subsequent
entry in the file. The server will now emit a log message indicating that
no pool was found for the address (or prefix) and correctly resume parsing
with the next entry in the lease file. Our thanks to Michal Žejdl for
reporting the issue.
[ISC-Bugs #39314]
- Be more liberal in finding a subnet group associated with a static
prefix. When we added the class matching code for v6 we also added
a requirement that the static prefix must be within a subnet the
client was in, in order to find the proper statements. We now
look for a subnet based on the prefix, failing that on the static
address for the client and failing that on the shared network
[ISC-Bugs #38329]
- Add a new action expression "parse_vendor_options", which can be used
to parse a vendor-encapsualted-option received by the server based on
the encoding specified by the vendor-option-space statement.
[ISC-Bugs #36449]
- Enhance the PARANOIA patch to include fchown() the lease file to
allow it to be manipulated after the server does a chown().
Thanks to Jiri Popelka at Red Hat for the patch.
[ISC-Bugs #36978]
- Relax the requirement that prefix pools must be within the subnet.
This was added in as part of #32453 in order to avoid configuration
mistakes but is being removed as prefixes aren't required to be
within the same subnet and many people configure them in that fashion.
[ISC-Bugs #40077]
- Fixed a server crash that could occur when the server attempts to remove
the billing class from the last lease billed to a dynamic class after said
class has been deleted. Our thanks to Lasse Pesonen for reporting the
[ISC-Bugs #39978]
- LDAP Patches - Numerous small patches submitted by contributors have
been applied to the contributed code which supplies LDAP support.
In addition, two larger submissions have also been included. The
first adds support for IPv6 configuration and the second provides
GSSAPI authentication. We would like to thank the following for their
contributions (alphabetically):
Alex Novak at SUSE
Bill Parker (wp02855 at gmail dot com)
Jiri Popelka at Red Hat
Marius Tomaschewski at SUSE
(william at, The University of Adelaide
[ISC-Bugs #39056]
[ISC-Bugs #22742]
[ISC-Bugs #24449]
[ISC-Bugs #28545]
[ISC-Bugs #29873]
[ISC-Bugs #30183]
[ISC-Bugs #30402]
[ISC-Bugs #32217]
[ISC-Bugs #32240]
[ISC-Bugs #33176]
[ISC-Bugs #33178]
[ISC-Bugs #36409]
[ISC-Bugs #36774]
[ISC-Bugs #37876]
- Handle an out of memory condition in the client a bit better.
Thanks to Frédéric Perrin from Brocade for finding the issue
and suggesting a patch.
[ISC-Bugs #39279]
Changes since 4.3.2rc2
- None
Changes since 4.3.2rc1
- Corrected a compilation error introduced by the fix for ISC-Bugs #37415.
The error occurs on Linux variants that do not support VLAN tag information
in packet auxiliary data. The configure script now only enables inclusion
of the VLAN tag-based logic if it is supported by the underlying OS.
[ISC-Bugs #38677]
Changes since 4.3.2b1
- Specifying the option, --disable-debug, on the configure script command line
now disables debug features. Prior to this, specifying --disable-debug
incorrectly enabled debug features. Thanks to Gustavo Zacarias for reporting
the issue.
[ISC-Bugs #37780]
- Unit test execution now uses a path augmented during configuration
processing of the --with-atf option to locate ATF runtime tools, atf-run
and atf-report. For most installations of ATF, this should alleviate the
need to manually include them in the PATH, as was formerly required.
If the configure script cannot locate the tools it will emit a warning,
informing the user that the tools must be in the PATH when running unit
Secondly, please note that "make check" will now exit with a failure status
code (non-zero) if one or more unit tests fail. This means that invoking
"make check" from an upper level directory will cause the make process to
STOP after the first test subdirectory with failed test(s). To force all
tests in all subdirectories to run, regardless of individual test outcome,
use the command "make -k check".
[ISC-Bugs #38619]
Changes since 4.3.1
- Corrected parser's right brace matching when a statement contains an error.
[ISC-Bugs #36021]
- TSIG-authenticated dynamic DNS updates now support the use of these
additional algorithms: hmac-sha1, hmac-sha224, hmac-sha256, hmac-sha384,
and hmac-sha512
[ISC-Bugs #36947]
- Added check for invalid failover message type. Thanks to Tobias Stoeckmann
working with the OpenBSD project who spotted the issue and provided the
[ISC-Bugs #36653]
- Corrected rate limiting checks for bad packet logging. Thanks to Tobias
Stoeckmann working with the OpenBSD project who spotted the issue and
provided the patch.
[ISC-Bugs #36897]
- Log statements depicting what files will be used by the server now occur
after the configuration file has been processed.
[ISC-Bugs #36671]
- Addressed Coverity issues reported as of 07-31-2014:
[ISC-Bugs #36712] Corrects Coverity reported "high" impact issues.
[ISC-Bugs #36933] Corrects Coverity reported "medium" impact issues
[ISC-Bugs #37708] Fixes compilation error in dst_api.c seen in older
compilers that was introduced by #36712
- Server now supports a failover split value of 256.
[ISC-Bugs] #36664]
- Remove unneeded error #defines. These defines were included in case
external programs required the older versions of the macro. They
have been #ifdeffed for now and will be removed at a future date.
See site.h for the #define to include them again, but you should
switch to using the DHCP_R_* versions instead of the ISC_R_* versions.
Also ISC_R_MULTIPLE has been removed as it is also defined in bind.
[ISC-Bugs #37128]
- Added checks in range6 and prefix6 statement parsing to ensure addresses
are within the declared subnet. Thanks to Jiri Popelka at Red Hat for the
bug report and patch.
[ISC-Bugs #32453]
[ISC-Bugs #17766]
[ISC-Bugs #18510]
[ISC-Bugs #23698]
[ISC-Bugs #28883]
- Addressed checksum issues:
Added checksum readiness check to Linux packet filtering which eliminates
invalid packet drops due to checksum errors when checksum offloading is
in use. Based on dhcp-4.2.2-xen-checksum.patch made to the Fedora project.
[ISC-Bugs #22806]
[ISC-Bugs #15902]
[ISC-Bugs #17739]
[ISC-Bugs #18010]
[ISC-Bugs #22556]
[ISC-Bugs #29769]
Inbound packets with UDP checksums of 0xffff now validate correctly rather
than being dropped.
[ISC-Bugs #24216]
[ISC-Bugs #25587]
- Added the echo-client-id configuration parameter to the server configuration.
The server now supports RFC 6842 compliant behavior by setting a new
configuration parameter, echo-client-id. When enabled, the server will
include the client identifier option (Option code 61) if received, in its
responses. The server identifier returned in NAKs (if enabled) will now
be the globally defined value (if one) if the server cannot attribute the
inbound request to a known subnet.
[ISC-Bugs #35958]
[ISC-Bugs #32545]
- Added support of the configuration parameter, use-host-decl-names, to
BOOTP request handling.
[ISC-Bugs #36233]
- Added logic to ignore the signal, SIGPIPE, which ensures write failures
will be delivered as errors rather than as SIGPIPE signals on all OSs.
Thanks to Marius Tomaschewski from SUSE who reported the issue and provided
the patch upon which the fix is based.
[ISC-Bugs #32222]
- In the failover code, handle the case of communications being interrupted
when the servers are dealing with POTENTIAL-CONFLICT. This patch allows
the primary to accept the secondary moving from POTENTIAL-CONFLICT to
RESOLUTION-INTERRUPTED as well as handling the bind update process better.
In addition the code to resend update or update all requests has been
modified to send requests more often.
[ISC-Bugs #36810]
[ISC-Bugs #20352]
- By default, the server will now choose the value to use in the forward DNS
name from the following in order of preference:
1. FQDN option if provided by the client
2. Host name option if provided by the client
3. Configured option host-name if defined
As before, this may be overridden by defining ddns-hostname to the desired
value (or expression). In addition, the server logic has been extended to
use the value of the host name declaration if use-host-decl-names is enabled
and no other value is available.
[ISC-Bugs #21323]
- DNS updates were being attempted when dhcp-cache-threshold enabled the use of
the existing lease and the forward DNS name had not changed. This has been
[ISC-Bugs #37368]
[ISC-Bugs #38636]
- Corrected an issue which caused dhclient to incorrectly form the result when
prepending or appending to the IPv4 domain-search option, received from the
server, when either of the values being combined contain compressed
[ISC-Bugs #20558]
- Added the server-id-check parameter to the server configuration.
This parameter allows run-time control over whether or not a server,
participating in failover, verifies the dhcp-server-identifier option in
DHCP REQUESTs against the server's id before processing the request.
Formerly, enabling this behavior was done at compilation time through
the use of the #define, SERVER_ID_CHECK, which has been removed from site.h
The functionality is now only available through the new runtime parameter.
[ISC-Bugs #37551]
- During startup, when the server encounters a lease whose binding state is
FTS_BACKUP but whose pool has no configured failover peer, it will reset the
lease's binding state to FTS_FREE. This allows the leases to be reclaimed
by the server after a pool's configuration has changed from failover to
standalone. Prior to this such leases would remain stuck in the backup state
making them unavailable for assignment. Note this conversion will occur
whether or not the server is compiled for failover.
[ISC-Bugs #36960]
- Fixed a small issue in the treatment of hosts in the inform processing
that could cause the response to an inform to include information from
the wrong scope. The two examples we've heard of are getting subnet
instead of group information associated with a host entry, or getting
global information instead of subnet if the host entry was built via
omapi. Thanks to Julien Soula at University of Lille for finding the
bug and supplying a patch.
[ISC-Bugs #35712]
- Avoid calling pool_timer() recursively from supersede_lease(). This could
result in leases changing state incorrectly or delaying the running of the
leae expiration code.
[ISC-Bugs #38002]
- Move the check for a PID file and process to be before we rewrite the
lease file. This avoids the possibility of starting a second instance
of a server which changes the current lease file confusing the first
instance. This check is only included if the admin hasn't disabled PID
[ISC-Bugs #38078]
[ISC-Bugs #38143]
- In the client code change the way preferred_life and max_life are printed
for environment variables to be unsigned rather than signed.
Thanks to Jiri Popelka at Red Hat for the bug report and patch.
[ISC-Bugs #37084]
- Modified Linux packet handling such that packets received via VLAN are now
seen only by the VLAN interface. Prior to this, such packets were seen by
both the VLAN interface and its parent (physical) interface, causing the
server to respond to both. Note this remains an issue for non-Linux OSs.
Thanks to Jiri Popelka at Red Hat for the patch.
[ISC-Bugs #37415]
[ISC-Bugs #37133]
[ISC-Bugs #36668]
[ISC-Bugs #36652]
- Log content has been changed to more directly suggest that admins should
check for multiple IPv6 clients attempting to use the same DUID when only
abandoned addresses are available. Debug level logging will now emit counts
of the total number of, in-use, and abandoned addresses in a shared subnet
when the server finds no addresses available for a given DUID. Lastly,
threshold logging is now automatically disabled for shared subnets whose
total number of possible addresses exceeds (2^64)-1.
[ISC-Bugs #26376]
[ISC-Bugs #38131]
- Added a global parameter, prefix-length-mode, which may be used to determine
how the server uses a non-zero value for prefix-length supplied by clients
when soliciting DHCPv6 prefixes. The server supports selection modes of:
ignore, prefer, exact, minimum and maximum which are described in detail in
the server man pages. The prior behavior of the server was to only offer a
prefix whose length exactly matched the prefix-length value requested. If
no such prefixes were available, the server returned a status of none
available. Note the default mode, "exact", provides this same behavior.
[ISC-Bugs #36780]
[ISC-Bugs #32228]
- Corrected inconsistencies in dhcrelay's setting the upper interface hop count
limit such that it now sets it to 32 when the upstream address is a multicast
address per RFC 3315 Section 20. Prior to this if the -u argument preceded
the -l argument on the command line or if the same interface was specified
for both; the logic to set the hop limit count for the upper interface was
skipped. This caused the hop count limit to be set to the default value
(typically 1) in the outbound upstream packets.
[ISC-Bugs #37426]
Changes since 4.3.1b1
- Modify the linux and openwrt dhclient scripts to process information
from a stateless request. Thanks to Jiri Popelka at Red Hat for the
bug report and patch.
[ISC-Bugs #36102]
- Remove more unused RCSID tags. These weren't noticed in 4.3 as
the code isn't used anymore but we remove them here to keep the
code consistent across versions.
[ISC-Bugs #36451]
Changes since 4.3.0
- Tidy up several small tickets.
Correct parsing of DUID from config file, previously the LL type
was put in the wrong place in the DUID string.
[ISC-Bugs #20962]
Add code to parse "do-forward-updates" as well as "do-forward-update"
Thanks to Jiri Popelka at Red Hat.
[ISC-Bugs #31328]
Remove log_priority as it isn't currently used.
[ISC-Bugs #33397]
Increase the size of the buffer used for reading interface information.
[ISC-Bugs #34858]
- Remove an extra set of the msg_controllen variable.
[ISC-Bugs #21035]
- Add a more understandable error message if a configuration attempts
to add multiple keys for a single zone. Thanks to a patch from Jiri
Popelka at Red Hat.
[ISC-Bugs #31892]
- Fix some minor issues in the dst code.
[ISC-Bugs #34172]
- Properly #ifdef functions so that the code can compile without NSUPDATE.
[ISC-Bugs #35058]
- Update the partner's stos (start time of state, basically when we last
heard from this partner) field when updating the state in failover.
[ISC-Bugs #35549]
- Modify the overload processing to allow space for the remote agent ID.
[ISC-Bugs #35569]
Handle the ordering of the SUBNET_MASK option even if it is the last
option in the list.
[ISC-Bugs #24580]
- Remove the code that allows a server to follow RFC3315 instead of
the subsequent errata from August 2010 when determining which IAs
to include if no addresses will be assigned.
[ISC-Bugs #28938]
- Remove unused RCSID tags.
[ISC-Bugs #35846]
- Correct the v6 client timing code. When doing the timing backoff
for MRT limit it to MRD.
Thanks to Jiri Popelka at Red Hat for the bug report and fix.
[ISC-Bugs #21238
- Add a log entry when killing a client and remove the PID files
when a server, relay or client are killed.
[ISC-Bugs #16970]
[ISC-Bugs #17258]
- Some minor cleanups in the client code.
In addition to checking for dhcpc check for bootpc in the services list.
[ISC-Bugs #18933]
Correct the client code to only try to get a lease once when the
given the "-1" argument.
Thanks to Jiri Popelka at Red Hat for the bug report and fix.
[ISC-Bugs #26735]
When asked for the version don't send the output to syslog.
[ISC-Bugs #29772]
Add the next server information to the environment variables for
use by the client script. In order to avoid changing the client
lease file the next server information isn't written to it.
Thanks to Tomas Hozza at Red Hat for the suggestion and a prototype fix.
[ISC-Bugs #33098]
- Several updates to the dhcp server code.
When not in quiet mode print out the files being used.
[ISC-Bugs #17551]
As accessing some pid files may require privileges move the dropping
of permission bits due to the paranoia patch to be after the pid code.
Thanks to Jiri Popelka at Red Hat for the bug report and fix.
[ISC-Bugs #25806]
When processing a "--version" request don't output the version information
to syslog.
- Add the "enable-log-pid" build option to the configure script. When enabled
this causes the client, server and relay programs to include the PID
number in syslog messages.
Thanks to Marius Tomaschewski for the suggestion and proto-patch.
[ISC-Bugs #29713]
- Add a #define to specify the prefix length used when a client attempts
to configure an address. This can be modified by editing includes/site.h.
By default it is set to 64. While 128 might be a better choice it would
also be a change for currently running systems, so we have left it at 64.
[ISC-Bugs #DHCP-2]
- Add a run time option to the client "-df" to allow the administrator to
point to a second lease file the client can search for a DUID. This can
be used to allow a v4 and a v6 instance of the client to share a DUID.
The second file will only be searched if there isn't a DUID in the main
lease file and the DUID will be written out to the main lease file.
[ISC-Bugs #34886]
- Have the client fsync the lease file to avoid lease corruption if the
client hibernates or otherwise shuts down.
[ISC-Bugs #35894]
- Add a check for L2VLAN in bpf.c to help support VLAN interfaces
Thanks to Steinar Haug for the suggestion.
[ISC-Bugs #36033]
- Modify the handling of the resolv.conf file to allow the DHCP
process to start up even if the resolv.conf file has problems.
[ISC-Bugs #35989]
- Add threshold logging functionality. Two new options,
log-threshold-low and log-threshold-high, indicate to the
server if and when it should log an error message as addresses
in a pool are used.
[ISC-Bugs #34487]
- Add code to properly dereference a pointer in the dhclient code
on an error condition.
[ISC-Bugs #36194]
- Add code to help clean up soft leases.
[ISC-Bugs #36304]
- Disable the gentle shutdown functionality until we can determine
the best way to present it to remove or reduce the side effects.
[ISC-Bugs #36066]
Changes since 4.3.0rc1
- None
Changes since 4.3.0b1
- Tidy up receive packet processing.
Thanks to Brad Plank of GTA for reporting the issue and suggesting
a possible patch.
[ISC-Bugs #34447]
Changes since 4.3.0a1
- Modify the message displayed when a process hits a fatal error.
The new message is much shorter and simply points to the README
and our website for directions on bug submissions.
[ISC-Bugs #24789]
Changes since 4.2.0 (new features)
- If a client renews before 'dhcp-cache-threshold' percent of its lease
has elapsed (default 25%), the server will reuse the allocated lease
(provide a lease within the currently allocated lease-time) rather
than extend or renew the lease. This absolves the server of needing
to perform an fsync() operation on the lease database before reply,
which improves performance. [ISC-Bugs #22228]
Updated this patch to support asynchronous DDNS. If the server is
attempting to do DDNS on a lease it should be updated and written to
disk even if that wouldn't be necessary due to the thresholding.
[ISC-Bugs #26311]
- The 'no available billing' log line now also logs the name of the last
matching billing class tried before failing to provide a billing.
[ISC-Bugs #21759]
- A problem with missing get_hw_addr function when --enable-use-sockets
was used is now solved on GNU/Linux, BSD and GNU/Hurd systems. Note
that use-sockets feature was not tested on those systems. Client and
server code no longer use MAX_PATH constant that is not defined on
GNU/Hurd systems. [ISC-Bugs #25979]
- Add a perl script in the contrib directory,, which
can parse v4 lease files and output the lease information in a more
human friendly manner. This was written by Christian Hammers with
some updates by vom and ISC. This is contributed code and is not
supported by ISC; however it may be useful to some users.
[ISC-Bugs #20680]
- Add support in v6 for on-commit, on-expire and on-release.
[ISC-Bugs #27912]
- Add support for using classes with v6.
[ISC-Bugs #26510]
- Update the DDNS code to current standards and allow for sharing
of DDNS entries between v4 and v6 clients. The new code is used
if the ddns-update-style is set to "standard", the older code is
still available if ddns-update-style is set to "interim". The
oldest DDNS code "ad-hoc" has been removed. Thanks to Thomas Pegeot
who submitted a patch for this issue. This patch is based on
that work with some modifications.
[ISC-Bugs #21139]
- Add a configuration option to the server to suppress using fsync().
Enabling this option will mean that fsync() is never called. This
may provide better performance but there is also a risk that a lease
will not be properly written to the disk after it has been issued
to a client and before the server stops. Using this option is
not recommended.
[ISC-Bugs #34810]
- Add some logging statements to indicate when the server is ready
to serve. One statement is emitted after the server has finished
reading its files and is about to enter the dispatch loop.
This is "Server starting service.".
The second is emitted when a server determines that both it and
its failover peer are in the normal state.
This is "failover peer <name>: Both servers normal."
[ISC-Bugs #33208]
- Add support for accessing options from v6 relays. The v6relay
statement allows the administrator to choose which relay to
use when searching for an option, see the dhcp-options man page
for a description. The host-identifier option has also been
updated to support the use of relay options, see the dhcpd.conf
man page for a description.
[ISC-Bugs #19598]
- When doing DDNS if there isn't an appropriate zone statement attempt
to find a reasonable nameserver via a DNS resolver. This restores
some functionality that was lost in the transition to asynchronous
DDNS. Due to the lack of security and increase in fragility of the
system when using this feature we strongly recommend the use of
appropriate zone statements rather than using this functionality.
[ISC-Bugs #30461]
- Add support for specifying the address from which to send
DDNS updates on the DHCP server. There are two new options
"ddns-local-address4" and "ddns-local-address6" that each take
one instance of their respective address types.
[ISC-Bugs #34779]
- Add ignore-client-uids option in the server. This option causes
the server to not record a client's uid in its lease. This
violates the specification but may also be useful when a client
can dual boot using different client ids but the same mac address.
Thank you to Brian De Wolf at Cal Poly Pomona for the patch.
[ISC-Bugs #32427]
[ISC-Bugs #35066]
- Extend the DHCPINFORM processing to honor the subnet selection option
and take host declarations into account.
Thanks to Christof Chen for testing and submitting the patch.
[ISC-Bugs #35015]
- Extend the hardware expression to look into the lease structure
for a hardware address if there is no packet. This allows the
server to find the hardware address during on-expiry processing.
[ISC-Bugs #24584]
- Add definitions for some options that have been specified by the IETF.
[ISC-Bugs #29268]
[ISC-Bugs #35198]
Changes since 4.2.0 (bug fixes)
- When using 'ignore client-updates;', the FQDN returned to the client
is no longer truncated to one octet.
- Cleaned up an unused hardware address variable in nak_lease().
- Manpage entries for the ia-pd and ia-prefix options were updated to
reflect support for prefix delegation.
- Cleaned up some compiler warnings
- An optimization described in the failover protocol draft is now included,
which permits a DHCP server operating in communications-interrupted state
to 'rewind' a lease to the state most recently transmitted to its peer,
greatly increasing a server's endurance in communications-interrupted.
This is supported using a new 'rewind state' record on the dhcpd.leases
entry for each lease.
- Fix the trace code which was broken by the changes to the DDNS code.
- Update the fsync code to work with the changes to the DDNS code. It now
uses a timer instead of noticing if there are no more packets to process.
- When constructing the DNS name structure from a text string append
the root to relative names. This satisfies a requirement in the DNS
library that names be absolute instead of relative and prevents DHCP
from crashing. [ISC-Bugs #21054]
- "The LDAP Patch" that has been circulating for some time, written by
Brian Masney and S.Kalyanasundraram and maintained for application to
the DHCP-4 sources by David Cantrell has been included. Please be
advised that these sources were contributed, and do not yet meet the
high standards we place on production sources we include by default.
As a result, the LDAP features are only included by using a compile-time
option which defaults off, and if you enable it you do so under your
own recognizance. We will be improving this software over time.
[ISC-Bugs #17741]
- Prohibit including lease time information in a response to a DHCP INFORM.
[ISC-Bugs #21092]
! Accept a client id of length 0 while hashing. Previously the server would
exit if it attempted to hash a zero length client id, providing attackers
with a simple denial of service attack. [ISC-Bugs #21253]
CERT: VU#541921 - CVE: CVE-2010-2156
- A memory leak in ddns processing was closed. [ISC-Bugs #21377]
- Modify the exception handling for initial context creation. Previously
we would try and clean up before exiting. This could present problems
when the cleanup required part of the context that wasn't available. It
also didn't do much as we exited afterwards anyway. Now we simply log
the error and exit. [ISC-Bugs #21093]
- A bug was fixed that could cause the DHCPv6 server to advertise/assign a
previously allocated (active) lease to a client that has changed subnets,
despite being on different shared networks. Dynamic prefixes specifically
allocated in shared networks also now are not offered if the client has
moved. [ISC-Bugs #21152]
- Add some debugging output for use with the DDNS code. [ISC-Bugs #20916]
- Fix the trace code to handle timing events better and to truncate a file
before using instead of overwriting it. [ISC-Bugs #20969]
- Modify the determination of the default TTL to use for DDNS updates.
The user may still configure the ttl via ddns-ttl. The default for
both v4 and v6 is now 1/2 the (preferred) lease time with a limit. The
previous defaults (1/2 lease time without a limit for v4 and a default
value for v6) may be used by defining USE_OLD_DDNS_TTL in site.h
[ISC-Bugs #21126]
- libisc/libdns is now brought up to version 9.7.1rc1. This corrects
three reported flaws in ISC DHCP;
o DHCP processes (dhcpd, dhclient) fail to start if one of either the
IPv4 or IPv6 address families is not present. [ISC-Bugs #21122]
o Assertion failure when attempting to cancel a previously running DDNS
update. [ISC-Bugs #21133]
o Compilation failure of libisc/libdns due to the use of a flexible
array member. [ISC-Bugs #21316]
- Add declaration for variable in debug code in alloc.c. [ISC-Bugs #21472]
- Documentation cleanup covering multiple tickets
[ISC-Bugs #20265] [ISC-Bugs #20259] minor cleanup
[ISC-Bugs #20263] add text describing some default values
[ISC-Bugs #20193] single quotes at the start of a line indicate a control
line to nroff, escape them if we actually want a quote.
[ISC-Bugs #18916] sync the pointer to web pages amongst the different docs
- 'get-host-names true;' now also works even if 'use-host-decl-names true;'
was also configured. The nature of this repair also fixes another
error; the host-name supplied by a client is no longer overridden by a
reverse lookup of the lease address. Thanks to a patch from Wilco Baan
Hofman supplied to us by the Debian package maintenance team.
[ISC-Bugs #21691] {Debian Bug#509445}
- The .TH tag for the dhcp-options manpage was typo repaired
thanks to a report from jidanni and the Debian package maintenance
team. [ISC-Bugs #21676] {Debian Bug#563613}
- More documentation changes - primarily to put the options in the dhclient
and dhcpd man pages into the standard form. Thanks in part to a patch
from David Cantrell at Red Hat.
[ISC-Bugs #20264] and parts of [ISC-Bugs #17744] dhclient.8 changes
- Add code to clear the pointer to an object in an OMAPI handle when the
object is freed due to a dereference. [ISC-Bugs #21306]
- Fixed a bug that leaks host record references onto lease structures,
causing the server to apply configuration intended for one host to any
other innocent clients that come along later. [ISC-Bugs #22018]
- Minor code fixes
[ISC-Bugs #19566] When trying to find the zone for a name for ddns allow
the name to be at the apex of the zone.
[ISC-Bugs #19617] Restrict length of interface name read from command line
in dhcpd - based on a patch from David Cantrell at Red Hat.
[ISC-Bugs #20039] Correct some error messages in dhcpd.c
[ISC-Bugs #20070] Better range check on values when creating a DHCID.
[ISC-Bugs #20198] Avoid writing past the end of the field when adding
overly long file or server names to a packet and add a log message
if the configuration supplied overly long names for these fields.
Thanks to Martin Pala.
[ISC-Bugs #21497] Add a little more randomness to rng seed in client
thanks to a patch from Jeremiah Jinno.
- Correct error handling in DLPI [ISC-Bugs #20378]
- Remove __sun__ and __hpux__ typedefs in osdep.h as they are now being
checked in configure. [ISC-Bugs #20443]
- Modify how the cmsg header is allocated the v6 send and received routines
to compile on more compilers. [ISC-Bugs #20524]
- When parsing a domain name free the memory for the name after we are
done with it. [ISC-Bugs #20824]
- Add an elapsed time option to the release message and refactor the
code to move most of the common code to a single routine.
[ISC-Bugs #21171].
- Two identical log messages for commit_leases() have been disambiguated.
[ISC-Bugs #18915]
- Parse date strings more properly - the code now handles semi-colons in
date strings correctly. Thanks to a patch from Jiri Popelka at Red Hat.
[ISC-Bugs #21501, #20598]
- Fixes to lease input and output.
[ISC-Bugs #20418] - Some systems don't support the "%s" argument to
strftime, paste together the same string using mktime instead.
[ISC-Bugs #19596] - When parsing iaid values accept printable
[ISC-Bugs #21585] - Always print time values in omshell as hex
instead of ascii if the values happen to be printable characters.
- Minor changes for scripts, and Makefiles
[ISC-Bugs #19147] Use domain-search instead of domain-name in manual and
example conf file. Thanks to a patch from David Cantrell
at Red Hat.
[ISC-Bugs #19761] Restore address when doing a rebind in DHCPv6
[ISC-Bugs #19945] Properly close the quote on some arguments.
[ISC-Bugs #20952] Add 64 bit types to
[ISC-Bugs #21308] Add "PATH=" to CLIENT_PATH environment variable
- Update the code to parse dhcpv6 lease files to accept a semi-colon at
the end of the max-life and preferred-life clauses. In order to be
backwards compatible with older lease files not finding a semi-colon
is also accepted. [ISC-Bugs #22303].
! Handle a relay forward message with an unspecified address in the
link address field. Previously such a message would cause the
server to crash. Thanks to a report from John Gibbins. [ISC-Bugs #21992]
CERT: VU#102047 CVE: CVE-2010-3611
- ./configure on longer searches for -lcrypto to explicitly link against.
This fixes a bug where 'dhclient' would have shared library dependencies
on '/usr/lib'. [ISC-Bugs #21967]
- Handle pipe failures more gracefully. Some OSes pass a SIGPIPE
signal to a process and will kill the process if the signal isn't
caught. This patch adds code to turn off the SIGPIPE signal via
a setsockopt() call. The signal is already being ignored as part
of the ISC library. [ISC-Bugs #22269]
- Restore printing of values in omshell to the style pre 21585. For
21585 we changed the print routines to always display time values
as a hex list. This had a side effect of printing all data strings
as a hex list. We shall investigate other ways of displaying time
values more usefully. [ISC-Bugs #22626]
! Fix the handling of connection requests on the failover port.
Previously a connection request from a source that wasn't
listed as a failover peer would cause the server to become
non-responsive. Thanks to a report from Brad Bendily,
[ISC-Bugs #22679]
CERT: VU#159528 CVE: CVE-2010-3616
- Don't pass the ISC_R_INPROGRESS status to the omapi signal handlers.
Passing it through to the handlers caused the omshell program to fail
to connect to the server. [ISC-Bugs #21839]
- Fix the parenthesis in the code to process configuration statements
beginning with "auth". The previous arrangement caused
"auto-partner-down" to be processed incorrectly. [ISC-Bugs #21854]
- Limit the timeout period allowed in the dispatch code to 2^^32-1 seconds.
Thanks to a report from Jiri Popelka at Red Hat.
[ISC-Bugs #22033], [Red Hat Bug #628258]
- When processing the format flags for a given option consume the
flag indicating an optional value correctly. A symptom of this
bug was an infinite loop when trying to parse the slp-service-scope
option. Thanks to a patch from Marius Tomaschewski.
[ISC-Bugs #22055]
- Disable the use of kqueue in the ISC library. This avoids a problem
between the fork and socket code that caused the dhcpd process to
use all available cpu if the program daemonized itself.
[ISC-Bugs #21911]
! When processing a request in the DHCPv6 server code that specifies
an address that is tagged as abandoned (meaning we received a
decline request for it previously) don't attempt to move it from
the inactive to active pool as doing so can result in the server
crashing on an assert failure. Also retag the lease as active
and reset its timeout value.
[ISC-Bugs #21921]
- Removed the restriction on using IPv6 addresses in IPv4 mode. This
allows IPv4 options which contain IPv6 addresses to be specified. For
example the 6rd option can be specified and used like this:
[ISC-Bugs #23039]
option 6rd code 212 = { integer 8, integer 8,
ip6-address, array of ip-address };
option 6rd 16 10 2001::,;
- Handle some DDNS corner cases better. Maintain the DDNS transaction
information when updating a lease and cancel any existing transactions
when removing the ddns information.
[ISC-Bugs #23103]
- Some fixes for LDAP
[ISC-Bugs #21783] - Include lber library when building ldap
[ISC-Bugs #22888] - Enable the ldap code when buidling common
The above fixes are from Jiri Popelka at Red Hat.
- Modify the dlpi code to accept getmsg() returning a positive value.
[ISC-Bugs #22824]
! In dhclient check the data for some string options for
reasonableness before passing it along to the script that
interfaces with the OS.
[ISC-Bugs #23722]
CVE: CVE-2011-0997
- DHCPv6 server now responds properly if client asks for a prefix that
is already assigned to a different client. [ISC-Bugs #23948]
- Add the option "--no-pid" to the client, relay and server code,
to disable writing a pid file. Add the option "-pf pidfile"
to the relay to allow the user to supply the pidfile name at
runtime. Add the "with-relay6-pid-file" option to configure
to allow the user to supply the pidfile name for the relay
in v6 mode at configure time.
[ISC-Bugs #23351] [ISC-Bugs #17541]
- 'dhclient' no longer waits a random interval after first starting up to
begin in the INIT state. This conforms to RFC 2131, but elects not to
implement a 'SHOULD' direction in section 4.1. The goal of this change
is to start up faster. [ISC-Bugs #19660]
- Added 'initial-delay' parameter that specifies maximum amount of time
before client goes to the INIT state. The default value is 0. In previous
versions of the code client could wait up to 5 seconds. The old behavior
may be restored by using 'initial-delay 5;' in the client config file.
[ISC-Bugs #19660]
- ICMP ping-check should now sit closer to precisely the number of seconds
configured (or default 1), due to making use of the new microsecond
scale timer internally to dhcpd. This corrects a bug where the server
may immediately timeout an ICMP ping-check if it was made late in the
current second. [ISC-Bugs #19660]
- The DHCP client will schedule renewal and rebinding events in
microseconds if the DHCP server provided a lease-time that would result
in sub-1-second timers. This corrects a bug where a 2-second or lower
lease-time would cause the DHCP client to enter an infinite loop by
scheduling renewal at zero seconds. [ISC-Bugs #19660]
- Client lease records are recorded at most once every 15 seconds. This
keeps the client from filling the lease database disk quickly on very small
lease times. [ISC-Bugs #19660]
- To defend against RFC 2131 non-compliant DHCP servers which fail to
advertise a lease-time (either mangled, or zero in value) the DHCP
client now adds the server to the reject list ACL and returns to INIT
state to hopefully find an RFC 2131 compliant server (or retry in INIT
forever). [ISC-Bugs #19660]
- Parameters configured to evaluate from user defined function calls can
now be correctly written to dhcpd.leases (as on 'on events' or dynamic
host records inserted via OMAPI). [ISC-Bugs #22266]
- If a 'next-server' parameter is configured in a dynamic host record via
OMAPI as a domain name, the syntax written to disk is now correctly parsed
upon restart. [ISC-Bugs #22266]
- The DHCP server now responds to DHCPLEASEQUERY messages from agents using
IP addresses not covered by a subnet in configuration. Whether or not to
respond to such an agent is still governed by the 'allow leasequery;'
configuration parameter, in the case of an agent not covered by a configured
subnet the root configuration area is examined. Server now also returns
vendor-class-id option, if client sent it. [ISC-Bugs #21094]
- Documentation fixes
[ISC-Bugs #17959] add text to AIX section describing how to have it send
responses to the all-ones address.
[ISC-Bugs #19615] update the includes in dhcpctl/dhcpctl.3 to be more correct
[ISC-Bugs #20676] update dhcpd.conf.5 to include the RFC numbers for DDNS
- Relay no longer crashes, when DHCP packet is received over interface without
any IPv4 address assigned. Also extended logging message about discarding
packets with invalid hlen with information about relevant interface name.
[ISC-Bugs #22409]
- Relay now properly logs that packet was received over interface without
global IPv6 address [ISC-Bugs #24070]
- Linux Packet Filter interface improvement. sockaddr_pkt structure is used,
rather than sockaddr. Packet ethertype is now forced to ETH_P_IP.
[ISC-Bugs #18975]
- Minor code cleanups - but note port change for #23196
[ISC-Bugs #23470] - Modify when an ignore return macro is defined to
handle unsed error return warnings for more versions of gcc.
[ISC-Bugs #23196] - Modify the reply handling in the server code to
send to a specified port rather than to the source port for the incoming
message. Sending to the source port was test code that should have
been removed. The previous functionality may be restored by defining
REPLY_TO_SOURCE_PORT in the includes/site.h file. We suggest you don't
enable this except for testing purposes.
[ISC-Bugs #22695] - Close a file descriptor in an error path.
[ISC-Bugs #19368] - Tidy up variable types in validate_port.
- Code cleanup: remove obsolete PROTO, KandR, INLINE and ANSI_DECL macros
[ISC-Bugs #13151]
- Compilation problem with gcc4.5 and omshell.c resolved. [ISC-Bugs #23831]
- Client Script fixes
[ISC-Bugs #23045] Typos in client/scripts/openbsd
[ISC-Bugs #23565] In the client scripts add a zone id (interface id) if
the domain search address is link local.
[ISC-Bugs #1277] In some of the client scripts add code to handle the
case of the default router information being changed without the address
being changed.
- Documentation cleanup
[ISC-Bugs #23326] Updated References document, several man page updates
- Server no longer complains about NULL pointer when configured
server-identifier expression fails to evaluate. [ISC-Bugs #24547]
- Convert ISC_R_INPROGRESS status to ISC_R_SUCCESS when called from other
than the dispatch handler. This fixes an issue where omshell, when
run from the same platform as the server, would appear to fail to
connect. This is a companion to #21839. [ISC-Bugs #23592]
- Enlarge the buffer size used by the Omshell code and some of the
print routines to allow for greater than 60 characters or, when
printing as hex strings, 20 characters. [ISC-Bugs #22743]
- In Solaris 11 switch to using sockets instead of DLPI, thanks
to a patch form Oracle. [ISC-Bugs #24634].
- Strict checks for content of domain-name DHCPv4 option can now be
configured during compilation time. Even though RFC2132 does not allow
to store more than one domain in domain-name option, such behavior is
now enabled by default, but this may change some time in the future.
See ACCEPT_LIST_IN_DOMAIN_NAME define in includes/site.h.
[ISC-Bugs #24167]
- DNS Update fix. A misconfigured server could crash during DNS update
processing if the configuration included overlapping pools or
multiple fixed-address entries for a single address. This issue
affected both IPv4 and IPv6. The fix allows a server to detect such
conditions, provides the user with extra information and recommended
steps to fix the problem. If the user enables the appropriate option
in site.h then server will be terminated
[ISC-Bugs #23595]
! Two packets were found that cause a server to halt. The code
has been updated to properly process or reject the packets as
appropriate. Thanks to David Zych at University of Illinois
for reporting this issue. [ISC-Bugs #24960]
One CVE number for each class of packet.
- Fix the code that checks for an existing DDNS transaction to cancel
when removing DDNS information, so that we will continue with the
processing if we have a lease even if it doesn't have an outstanding
transaction. [ISC-Bugs #24682]
- Add AM_MAINTAINER_MODE to to avoid rebuilding
configuration files. [ISC-Bugs #24107]
- Add support for passing DDNS information to a DNS server over
an IPv6 address. [ISC-Bugs #22647]
- Enhanced patch for 23595 to handle IPv4 fixed addresses more
cleanly. [ISC-Bugs #23595]
! Add a check for a null pointer before calling the regexec function.
Without this check we could, under some circumstances, pass
a null pointer to the regexec function causing it to segfault.
Thanks to a report from BlueCat Networks.
[ISC-Bugs #26704].
CVE: CVE-2011-4539
! Modify the DDNS handling code. In a previous patch we added logging
code to the DDNS handling. This code included a bug that caused it
to attempt to dereference a NULL pointer and eventually segfault.
While reviewing the code as we addressed this problem, we determined
that some of the updates to the lease structures would not work as
planned since the structures being updated were in the process of
being freed: these updates were removed. In addition we removed an
incorrect call to the DDNS removal function that could cause a failure
during the removal of DDNS information from the DNS server.
Thanks to Jasper Jongmans for reporting this issue.
[ISC-Bugs #27078]
CVE: CVE-2011-4868
- Fixed the code that checks if an address the server is planning
to hand out is in a reserved range. This would appear as
the server being out of addresses in pools with particular ranges.
[ISC-Bugs #26498]
- In the DDNS code handle error conditions more gracefully and add more
logging code. The major change is to handle unexpected cancel events
from the DNS client code.
[ISC-Bugs #26287]
- Tidy up the receive calls and eliminate the need for found_pkt.
[ISC-Bugs #25066]
- Add support for Infiniband over sockets to the server and
relay code. We've tested this on Solaris and hope to expand
support for Infiniband in the future. This patch also corrects
some issues we found in the socket code.
[ISC-Bugs #24245]
- Add a compile time check for the presence of the noreturn attribute
and use it for log_fatal if it's available. This will help code
checking programs to eliminate false positives.
[ISC-Bugs #27539]
- Fixed many compilation problems ("set, but not used" warnings) for
gcc 4.6 that may affect Ubuntu 11.10 users. [ISC-Bugs #27588]
- Modify the code that determines if an outstanding DDNS request
should be cancelled. This patch results in cancelling the
outstanding request less often. It fixes the problem caused
by a client doing a release where the TXT and PTR records
weren't removed from the DNS.
[ISC-BUGS #27858]
- Use offsetof() instead of sizeof() to get the sizes for dhcpv6_relay_packet
and dhcpv6_packet in several more places. Thanks to a report from
Bruno Verstuyft and Vincent Demaertelaere of Excentis.
[ISC-Bugs #27941]
- Remove outdated note in the description of the bootp keyword about the
option not satisfying the requirement of failover peers for denying
dynamic bootp clients.
[ISC-bugs #28574]
- Multiple items to clean up IPv6 address processing.
When processing an IA that we've seen check to see if the
addresses are usable (not in use by somebody else) before
handing it out.
When reading in leases from the file discard expired addresses.
When picking an address for a client include the IA ID in
addition to the client ID to generally pick different addresses
for different IAs.
[ISC-Bugs #23138] [ISC-Bugs #27945] [ISC-Bugs #25586]
[ISC-Bugs #27684]
- Remove unnecessary checks in the lease query code and clean up
several compiler issues (some dereferences of NULL and treating
an int as a boolean).
[ISC-Bugs #26203]
- Fix the NA and PD allocation code to handle the case where a client
provides a preference and the server doesn't have any addresses or
prefixes available. Previously the server ignored the request with
this patch it replies with a NoAddrsAvail or NoPrefixAvail response.
By default the code performs according to the errata of August 2010
for RFC 3315 section 17.2.2; to enable the previous style see the
section on RFC3315_PRE_ERRATA_2010_08 in includes/site.h. This option
may be removed in the future.
Thanks to Jiri Popelka at Red Hat for the patch.
[ISC-Bugs #22676]
- Fix up some issues found by static analysis.
A potential memory leak and NULL dereference in omapi.
The use of a boolean test instead of a bitwise test in dst.
[ISC-Bugs #28941]
- Rotate the lease file when running in v6 mode.
Thanks to Christoph Moench-Tegeder at Astaro for the
report and the first version of the patch.
[ISC-Bugs #24887]
- Correct code to calculate timing values in client to compare
rebind value to infinity instead of renew value.
Thanks to Chenda Huang from H3C Technologies Co., Limited
for reporting this issue.
[ISC-Bugs #29062]
- Fix some issues in the code for parsing and printing options.
[ISC-Bugs #22625] - properly print options that have several fields
followed by an array of something for example "fIa"
[ISC-Bugs #27289] - properly parse options in declarations that have
several fields followed by an array of something for example "fIa"
[ISC-Bugs #27296] - properly determine if we parsed a 16 or 32 bit
value in evaluate_numeric_expression (extract-int).
[ISC-Bugs #27314] - properly parse a zero length option from
a lease file. Thanks to Marius Tomaschewski from SUSE for the report
and prototype patch for this ticket as well as ticket 27289.
! Previously the server code was relaxed to allow packets with zero
length client ids to be processed. Under some situations use of
zero length client ids can cause the server to go into an infinite
loop. As such ids are not valid according to RFC 2132 section 9.14
the server no longer accepts them. Client ids with a length of 1
are also invalid but the server still accepts them in order to
minimize disruption. The restriction will likely be tightened in
the future to disallow ids with a length of 1.
Thanks to Markus Hietava of Codenomicon CROSS project for the
finding this issue and CERT-FI for vulnerability coordination.
[ISC-Bugs #29851]
CVE: CVE-2012-3571
! When attempting to convert a DUID from a client id option
into a hardware address handle unexpected client ids properly.
Thanks to Markus Hietava of Codenomicon CROSS project for the
finding this issue and CERT-FI for vulnerability coordination.
[ISC-Bugs #29852]
CVE: CVE-2012-3570
! A pair of memory leaks were found and fixed. Thanks to
Glen Eustace of Massey University, New Zealand for finding
this issue.
[ISC-Bugs #30024]
CVE: CVE-2012-3954
- Existing legacy unit-tests have been migrated to Automated Test
Framework (ATF). Several new tests have been developed. To enable
unit-tests, please use --with-atf in configure script. A Developer's
Guide has been added. To generate it, please use make devel in
the doc directory. It is currently in early stages of development,
but is expected to grow in the near future. [ISC-Bugs 25901]
! An issue with the use of lease times was found and fixed. Making
certain changes to the end time of an IPv6 lease could cause the
server to abort. Thanks to Glen Eustace of Massey University,
New Zealand for finding this issue.
[ISC-Bugs #30281]
CVE: CVE-2012-3955
- Update the memory leakage debug code to work with v6.
[ISC-Bugs #30297]
- Relax the requirements for deleting an A or AAAA record.
Previously the DDNS removal code required both the A or AAAA
record and the TXT record to exist. This requirement could
cause problems if something interrupted the removal leaving
the TXT record alone. This relaxation was codified in RFC 4703.
[ISC-Bugs #30734]
- Modify the failover code to handle incorrect peer names
better. Previously the structure holding the name might
have been freed inappropriately in some cases and not
freed in other cases.
[ISC-Bugs #30320]
- Add a configure option, enable-secs-byteorder, to deal with
clients that do the byte ordering on the secs field incorrectly.
This field should be in network byte order but some clients
get it wrong. When this option is enabled the server will examine
the secs field and if it looks wrong (high byte non zero and low
byte zero) swap the bytes. The default is disabled. This option
is only useful when doing load balancing within failover.
[ISC-Bugs #26108]
- Fix a set of issues that were discovered via a code inspection
tool. Thanks to Jiri Popelka and Tomas Hozza Red Hat for the logs
and patches.
[ISC-Bugs #23833]
- Parsing unquoted base64 strings improved. Parser now properly handles
strings that contain reserved names. [ISC-Bugs #23048]
- Modify the nak_lease function to make some attempts to find a
server-identifier option to use for the NAK.
[ISC-Bugs #25689]
- The client now passes information about the options it requested
from the server to the script code via environment variables.
These variables are of the form requested_<option_name>=1 with
the option name being the same as used in the new_* and old_*
[ISC-Bugs #29068]
- Add support for a simple check that the server id in a request message
to a failover peer matches the server id of the server. This support
is enabled by editing the file includes/site.h and uncommenting the
definition for SERVER_ID_CHECK. The option has several restrictions
and issues - please read the comment in the site.h file before
enabling it.
[ISC-Bugs #31463]
- Tidy up some compiler issues in the debug code.
[ISC-Bugs #26460]
- Move the dhcpd.conf example file to dhcpd.conf.example to avoid
overwriting the dhcpd.conf file when installing a new version of
ISC DHCP. The user will now need to manual copy and edit the
dhcpd.conf file as desired.
[ISC-Bugs #19337]
- Check the status value when trying to read from a connection to
see if it may have been closed. If it appears closed don't try
to read from it again. This avoids a potential busy-wait like
loop when the peer names are mismatched.
[ISC-Bugs #31231]
- Remove an unused variable to keep compilers happy.
[ISC-Bugs #31983]
- Modify test makefiles to be more similar to standard makefiles
and comment out a currently unused test.
[ISC-Bugs #32089]
- Address static analysis warnings.
[ISC-Bugs #33510] [ISC-Bugs #33511]
- Silence benign static analysis warnings.
[ISC-Bugs #33428]
- Add check for 64-bit package for atf.
[ISC-Bugs #32206]
- Use newer auto* tool packages and turn on RFC_3542 support on Mac OS.
[ISC-Bugs #26303]
- Remove a variable when it isn't being used due to #ifdefs to avoid
a compiler warning on Solaris using GCC.
[ISC-Bugs #33032]
- Add a check for too much whitespace in a config or lease file.
Thanks to Paolo Pellegrino for finding the issue and a suggestion
for the patch.
[ISC-Bugs #33351]
- Fix several problems with using OMAPI to manipulate class and subclass
[ISC-Bugs #27452]
- Added a sleep call after killing the old client to allow time
for the sockets to be cleaned. This should allow the -r option
to work more consistently.
[ISC-Bugs #18175]
- Missing files for ISC DHCP Developer's Guide are now included in
the release tarballs. To generate this documentation, please use
make devel command in doc directory. [ISC-Bugs #32767]
- Update client script for use with openwrt.
[ISC-Bugs #29843]
- Fix the socket handling for DHCPv6 clients to allow multiple instances
of a client on a single machine to work properly. Previously only
one client would receive the packets. Thanks to Jiri Popelka at Red Hat
for the bug report and a potential patch.
[ISC-Bugs #34784]
- Added support for gentle shutdown after signal is received.
[ISC-Bugs #32692] [ISC-Bugs 34945]
- Enhance the DHCPv6 server logging to include the addresses that are assigned
to the clients.
[ISC-Bugs #26377]
- Fix an operation in the DDNS code to be a bitwise instead of logical or.
[ISC-Bugs #35138]
Changes since 4.1.0 (new features)
- Failover port configuration can now be left to defaults (port 647) as
described in the -12 revision of the Failover draft (and assigned by
IANA). Thanks in part to a patch from David Cantrell at Red Hat.
- If configured, dhclient may now transmit to an anycast MAC address,
rather than using a broadcast address. Thanks to a patch from David
Cantrell at Red Hat.
- Added client support for setting interface MTU and metric, thanks to
Roy "UberLord" Marples <>.
- Added client -D option to specify DUID type to send.
- A new failover configuration parameter has been introduced for those
environments where DHCP servers can be reasonably guaranteed to be
"down" when the failover TCP socket is severed, "auto-partner-down".
This parameter is not generally safe, and by default is disabled, so
please carefully review the documentation of this parameter in the
dhcpd.conf(5) manpage before determining to use it yourself.
- Added a configuration function, 'gethostname()', which calls the system
function of the same name and presents the results as a data expression.
This function can be used to incorporate the system level hostname of
the system the DHCP software is operating on in responses or queries (such
as including a failover partner's hostname in a dhcp message or binding
scope, or having a DHCP client send any system hostname in the host-name or
FQDN options by default).
- The dhcp-renewal-time and dhcp-rebinding-time options may now be configured
for DHCPv4 operation and used independently of the dhcp-lease-time
calculations. Invalid renew and rebinding times (e.g., greater than the
determined lease time) are omitted.
- Processing the DHCP to DNS server transactions in an asynchronous fashion,
the DHCP server or client can now continue with its processing while
awaiting replies from the DNS server.
- The 'hardware [ethernet|etc] ...;' parameter in host records has been
extended to attempt to match DHCPv6 clients by the last octets of a
DUID-LL or DUID-LLT provided by the client.
Changes since 4.1.0 (bug fixes)
- Remove infinite loop in token_print_indent_concat().
- Validate the argument to the -p option.
- The notorious 'option <unknown> ... larger than buffer' log line,
which is seen in some malformed DHCP client packets, was modified.
It now logs the universe name, and does not log the length values
(which are bogus corruption read from the packet anyway). It also
carries a hopefully more useful explanation.
- Suppress spurious warnings from configure about --datarootdir
- A bug was fixed that caused the server not to answer some valid Solicit
and Request packets, if the dynamic range covering any requested addresses
had been deleted from configuration.
- Update the code to deal with GCC 4.3. This included two sets of changes.
The first is to the configuration files to include the use of
AC_USE_SYSTEM_EXTENSIONS. The second is to deal with return values that
were being ignored.
- The db-time-format option was documented in manpages.
- Using reserved leases no longer results in 'lease with binding state
free not on its queue' error messages, thanks to a patch from Frode
- Fix a build error in dhcrelay, using older versions of gcc with
dhcpv6 disabled.
- Two uninitialized stack structures are now memset to zero, thanks to a
patch from David Cantrell at Red Hat.
- Fixed a cosmetic bug where pretty-printing valid domain-search options would
result in an erroneous error log message ('garbage in format string').
- A bug in DLPI packet transmission (Solaris, HP/UX) that caused the server
to stop receiving packets is fixed. The same fix also means that the MAC
address will no longer appear 'bogus' on DLPI-based systems.
- A bug in select handling was discovered where the results of one select()
call were discarded, causing the server to process the next select() call
and use more system calls than required. This has been repaired - the
sockets will be handled after the first return from select(), resulting in
fewer system calls.
- The update-conflict-detection feature would leave an FQDN updated without
a DHCID (still currently implemented as a TXT RR). This would cause later
expiration or release events to fail to remove the domain name. The feature
now also inserts the client's up to date DHCID record, so records may safely
be removed at expiration or release time. Thanks to a patch submitted by
Christof Chen.
- Memory leak in the load_balance_mine() function is fixed. This would
leak ~20-30 octets per DHCPDISCOVER packet while failover was in use
and in normal state.
- Various compilation fixes have been included for the memory related
DEBUG #defines in includes/site.h.
- Fixed Linux client script 'unary operator expected' errors with DHCPv6.
- Fixed setting hostname in Linux hosts that require hostname argument
to be double-quoted. Also allow server-provided hostname to
override hostnames 'localhost' and '(none)'.
- Fixed failover reconnection retry code to continue to retry to reconnect
rather than restarting the listener.
- Compilation on Solaris with USE_SOCKETS defined in includes/site.h has
been repaired. Other USE_ overrides should work better.
- A check for the local flavor of IFNAMSIZ had a broken 'else' condition,
that probably still resulted in the correct behaviour (but wouldn't use
a larger defined value provided by the host OS).
- Fixed a bug where an OMAPI socket disconnection message would not result
in scheduling a failover reconnection, if the link had not negotiated a
failover connect yet (e.g.: connection refused, asynch socket connect()
- A bug was fixed that caused the 'conflict-done' state to fail to be parsed
in failover state records.
! A stack overflow vulnerability was fixed in dhclient that could allow
remote attackers to execute arbitrary commands as root on the system,
or simply terminate the client, by providing an over-long subnet-mask
option. CERT VU#410676 - CVE-2009-0692
- Fixed a bug where relay agent options would never be returned when
processing a DHCPINFORM.
- Versions 3.0.x syntax with multiple name->code option definitions is now
supported. Note that, similarly to 3.0.x, for by-code lookups only the
last option definition is used.
- Fixed a bug where a time difference of greater than 60 seconds between a
failover pair could cause the primary to crash on contact with the
secondary. Thanks to a patch from Steinar Haug.
- Don't look for IPv6 interfaces on Linux when running in DHCPv4 mode.
Thanks to patches from Matthew Newton and David Cantrell.
- Secondary servers in a failover pair will now perform ddns removals if
they had performed ddns updates on a lease that is expiring, or was
released through the primary. As part of the same fix, stale binding scopes
will now be removed if a change in identity of a lease's active client is
detected, rather than simply if a lease is noticed to have expired (which it
may have expired without a failover server noticing in some situations).
- A patch supplied by David Cantrell at RedHat was applied that detects
invalid calling parameters given to the ns_name_ntop() function.
Specifically, it detects if the caller passed a pointer and size pair
that causes the pointer to integer-wrap past zero.
! Fixed a fenceposting bug when a client had two host records configured,
one using 'uid' and the other using 'hardware ethernet'. CVE-2009-1892
- Fixed the check in the dhcp_interface_signal_handler routine to verify
the existence of the linked signal handler before calling it.
- Both host and subnet6 configuration groups are now included whether a
fixed-address6 (DHCPv6) is in use or not. Host scoped configuration takes
precedence. This fixes two bugs, one where host scoped configuration
would not be included from a non-fixed-address6 host record, and the equal
and opposite bug where subnet6 scoped configuration would not be used when
over-riding values were not present in a matching fixed-address6 host
- ./configure now checks to ensure the intX_t and u_intX_t types are defined,
correcting a compilation failure when using Sun's compiler.
- Modified the handling of a connection to avoid releasing the omapi io
object for the connection while it is still in use. One symptom from
this error was a segfault when a failover secondary attempted to connect
to the failover primary if their clocks were not synchronized.
- Clean up to allow compilation with gcc 2.95.4 on FreeBSD. Remove an
extra semi-colon from common/dns.c and moved setting a variable to NULL
in server/dhcpv6.c to allow the compiler to decide that the variable
was always properly set.
Changes since 4.1.0b1
- A missing "else" in dhcrelay.c could have caused an interface not to
be recognized.
Changes since 4.1.0a2
- A cosmetic bug in DHCPDECLINE processing was fixed which caused all
successful DHCPDECLINEs to be logged as "not found" rather than
- Added configuration file examples for DHCPv6.
- Some failover debugging #defines have been better defined and some
high frequency messages moved to a deeper debugging symbol.
- The CLTT parameter in failover is now only updated by client activity,
and not by failover binding updates (taking on the peer's CLTT).
- Failover BNDUPD messages are now discarded if they conflict with an
update that has been transmitted, but not acknowledged.
- A bug cleaning up unknown-xxx temporary option definitions was fixed.
- Delayed-ack is now a compile-time option, compiled out by default.
This feature is simply too experimental for right now, and causes
some problems to some failover installations. We will revisit this
in future releases.
- The !inet_pton() call in res_mkupdrec was adjusted to '<= 0' as
inet_pton returns either 1, 0, or -1.
- A dhclient-script for MacOS X has been included, which enables
'dhclient -6' support.
- DDNS removal routines were updated so that the DHCID is not removed until
the client has been deprived of all A and AAAA records (not only the last
one of either of those). This resolves a bug where dual stack clients
would not be able to regain their names after either expiration event.
Changes since 4.1.0a1
- Corrected list of failover state values in dhcpd man page.
- Fixed a bug that caused some request types to be logged incorrectly.
- Clients that sent a parameter request list containing the
routers option before the subnet mask option were receiving
only the latter. Fixed.
- The server wasn't always sending the FQDN option when it should.
- A partner-down failover server no longer emits 'peer holds all free leases'
if it is able to newly-allocate one of the peer's leases.
- Fixed a coredump when adding a class via OMAPI.
- Check whether files are zero length before trying to parse them.
- Ari Edelkind's PARANOIA patch has been included and may be compiled in
via two ./configure parameters, --enable-paranoia and
- ./configure was extended to cover many optional build features, such
as failover, server tracing, debugging, and the execute() command.
- There is now a default 1/4 of a second scheduled delay between delayed
fsync()'s, it can be configured by the max-ack-delay configuration
- A bug was fixed where the length of a hostname was miscalculated, so that
hosts were given odd-looking domain names ("").
- Shared network selection should be done from the innermost relay
valid link-address field, rather than the outermost.
- Prefix pools are attached to shared network scopes.
- Merged IA_XX related structures.
- Add DHCPv6 files in configure.
- A memory leak when using omapi has been fixed.
- DHCPv6 vendor-class options (VSIO) are now only sent when they appear
on the DHCPv6 ORO. This resolves a bug where VSIO options were placed
in IA_NA encapsulated options fields.
- Integrated client with stateless, temporary address and prefix delegation
- A double-dereference in dhclient transmission of DHCPDECLINEs was
- Fix handling of format code 'Z'.
- Support "-1" argument in DHCPv6.
- Merge DHCPv6-only "dhcrelay6" into general-purpose "dhcrelay" (use
"-6" option to select DHCPv6 mode).
- Fix handling of -A and -a flags in dhcrelay; it was failing to expand
packet size as needed to add relay agent options.
- A bug in subnet6 parsing where options contained in subnet6 clauses would
not be applied to clients addressed within that network was repaired.
- When configuring a "subnet {}" or "subnet6 {}" without an explicit
shared-network enclosing it, the DHCP software would synthesize a
shared-network to contain the subnet. However, all configuration
parameters within the subnet more intuitively belong "to any client
on that interface", or rather the synthesized shared-network. So,
when a shared-network is synthesized, it is used to contain the
configuration present inside the subnet {} clause. This means that
the configuration will be valid for all clients on that network, not
just those addressed out of the stated subnet. If you intended the
opposite, the workaround is to explicitly configure an empty
- A bug was fixed where Information-Request processing was not sourcing
configured option values.
- A warning was added since the DHCPv6 processing software does not yet
support class statements.
- Compilation warnings on GCC 4.3 relating to bootp source address
selection were repaired.
- The v6 BSD socket method was updated to use a single UDP BSD socket
no matter how many interfaces are involved, differentiating the
interfaces the packets were received on by the interface index supplied
by the OS.
- The relay agent no longer listens to the All DHCP Servers Multicast
- A bug was fixed in data_string_sprintfa() where va_start was only called
once for two invocations of vsprintf() variants.
- ERO (RFC 4994) server support.
- Basic and partial DHCPv6 leasequery support.
- Reliable DHCPv6 release (previous behavior, send release and exit, is
still available with dhclient -6 -1 -r).
Changes since 4.0.0 (new features)
- Added DHCPv6 rapid commit support.
- Added explicit parser support for zero-length DHCP options, such as
rapid-commit, via format code 'Z'.
- It's now possible to update the "ends" field of a lease with OMAPI.
This is useful if you want not only to release a lease, but also make
it available for reuse right away. Hat tip to Christof Chen.
- Fixed definition of the iaaddr hash functions to use the correct
functions when referencing and dereferencing memory.
- Some definitions not in phase with the IANA registry were updated.
- Allocated interface IDs are better controlled ('u' bit set to zero,
reserved IDs avoided).
- Unicast options are taken into account only for RENEWs.
- NoAddrsAvail answers to SOLICITs are always ADVERTISEs even when a SOLICIT
carries a rapid-commit option.
- Return in place of raise an impossible condition when one tries to release
an empty active lease.
- Timer granularity is now 1/100s in the DHCPv6 client.
- The dhclient-script was updated to create a host route for the default
gateway if the supplied subnet mask for an IPv4 address was a /32. This
allows the client to work in 'captive' network environments, where the
operator does not want clients to crosstalk directly.
- MINUS tokens should be parsable again.
- Multiple (up to "delayed-ack x;" maximum) DHCPv4 packets are now queued and
released in bursts after single fsync() events when the upper limit is
reached or if the receiving sockets go dry. The practical upshot is
that fsync-coupled server performance is now multiplicitively increased.
The default delayed ack limit is 28. Thanks entirely to a patch from
Christof Chen.
Changes since 4.0.0 (bug fixes)
- DHCP now builds on AIX.
- Exit with warning when DHCPv6-specific statements are used in the
config file but -6 is not specified.
- Fixed "--version" flag in dhcrelay
- The 'min-secs' configuration parameter's log message has been updated to
be more helpful.
- The warning logged when an address range doesn't fit in the subnets
they were declared has been updated to be more helpful and identify the
typo in configuration that created the spanning addresses.
- A bug in failover pool rebalancing that caused POOLREQ message ping-pongs
was repaired.
- A flaw in failover pool rebalancing that could cause POOLREQ messages to
be sent outside of the min-balance/max-balance scheduled intervals has
been repaired.
- A cosmetic bug during potential-conflict recovery that caused the peer's
'conflict-done' state message to be logged as 'unknown-state' has been
repaired. It is now logged correctly.
- A bug was fixed where the 'giaddr' may be used to find the client's subnet
rather than its own 'ciaddr'.
- A log message was introduced to clarify the situation where a failover
'address' parameter (the server's local address) did not resolve to an
IPv4 address.
- The minimum site code value was set to 224 in 3.1.0 to track RFC3942. This
broke a lot of legacy site local configurations. The new code in place will
track site local space minimum option codes and logs a warning to encourage
updates and exploration of site local code migration problems. Option
codes less than 128 in site local spaces remain inaccessible.
- A possible relay agent option bug was repaired where random server
initialization state may have been used to signal the relay agent
information options sub-option code for the 'END' of the option space.
- Fixes to allow code to compile and run on Solaris 9.
- Fixes to allow code to compile on Mac OS X Leopard (10.5).
- When server is configured with options that it overrides, a warning is
issued when the configuration file is read, rather than at the time the
option is overridden. This was important, because the warning was given
every time the option was overridden, which could create a lot of
unnecessary logging.
- Fixed a compilation problems on platforms that define a value for FDDI,
which conflicts with a dhcp configuration syntax token by the same name.
- When a failover server suspects it has encountered a peer running a
version 3.0.x failover server, a warning that the failover wire protocol
is incompatible is printed.
- The failover server no longer issues a floating point error if it encounters
a previously undefined option code.
- Fix startup error messages to report a missing "subnet6 declaration", rather
than a missing "subnet declaration", when running as a DHCPv6 server.
- DHCPv6 client timestamp in DUID was based on the year 1970 rather
than the year 2000.
- Warn when attempting to use a hardware parameter in DHCPv6.
- DHCPv6 released resources are now marked as released by the client.
- 'Soft' bindings have no more side-effects.
Changes since 4.0.0b3
- The reverse dns name for PTR updates on IPv6 addresses has been fixed to
use rather than default to and require user
- dhc6_lease_destroy() and dhc6_ia_destroy() now set lease and IA pointers
to NULL after freeing, to prevent subsequent accesses to freed memory.
- The DHCPv6 server would not send the preference option unless the
client requested it, via the ORO. This has been fixed, so the DHCPv6
server will always send the preference value if it is configured.
- When addresses were passed as hints to the server in an IA, they were
incorrectly handled, sometimes being treated as an error. Now the
server will treat these as hints and ignore them if it cannot supply
a requested address.
- If the client had multiple addresses, and one expired (was not renewed
by the server), the client would continue to attempt to renew the same
old address over and over. Now, the client will omit any expired
addresses from future Confirm, Renew, or Rebind messages.
- dhclient -6 will now select renew/rebind timers based upon the longest
address expiration time rather than the shortest expiration time, in
order to avoid cascading renewals in the event a server elects not to
extend one of multiple IAADDR leases.
- The server now limits clients that request multiple addresses to one
address per IA by default, which can be adjusted through the
"limit-addrs-per-ia" configuration option.
- The DHCPv6 client now issues fresh transaction IDs on Renew and Rebind
message exchanges, rather than using the most recent ID.
- The DHCPv6 server now replies to Information-Request messages.
- A bug was fixed in the dhclient-script for BSDs to correctly carry error
codes through some conditions.
- The parsing of some options in the dhclient lease file, in particular
the success DHCPv6 status-code, was fixed.
- A bug was fixed that caused the DHCPv6 ORO option to be corrupted with
seemingly random values.
- A reference overleak in DHCPv6 shared network processing was repaired.
- ./configure now autodetects local database locations rather than trying
to put dhcpd.leases and dhclient.leases in /usr/local/var/db, which no
one ever has.
- Regression fix for bug where server advertised a IPv6 address in
response to a SOLICIT but would not return the address in response
- A bug was fixed where the DHCPv6 server puts the NoAddrsAvail status
code in the IA_NA was fixed. The status code now appears in the root
Changes since 4.0.0b2
- Clarified error message when lease limit exceeded
- Relative time may now be used as a qualifier for 'allow' and 'deny' access
control lists. These directives may be used to assist in re-addressing
address pools without having to constantly reconfigure the server. Please
see 'man dhcpd.conf' for more information on allow/deny 'after time' syntax.
Thanks to a patch from Christof Chen.
- The server will now include multiple IA_NA's and multiple IAADDRs within
them, if advertised by the client. It still only seeks to allocate one
new address.
Changes since 4.0.0b1
- Use different paths for PID and lease files when running in DHCPv4
or DHCPv6 mode, so that servers for both protocols can be run
simultaneously on a single interface.
- Fixed a buffer overflow error which could have allowed a denial
of service under unusual server configurations
- Eliminated a spurious error message from the client
- A number of bugs with the internal handling of lease state on the
server have been fixed. Some of these could cause server crashes.
- The peer_wants_leases() changes pulled up from 3.1.0 were corrected,
'never used' leases will no longer consistently shift between servers
on every pool rebalance run.
- sendmsg()/recvmsg() control buffers are now declared in such a way to
ensure they are correctly aligned on all (esp. 64-bit) architectures.
- The client leasing subsystem was streamlined and corrected to account
more closely for changes in client link attachment selection.
Changes since 4.0.0a3
- The DHCP server no longer requires a "ddns-update-style" statement,
and now defaults to "none", which means DNS updates are disabled.
- Log messages when failover peer names mismatch have been improved to
point out the problem.
- Bug where server advertised a IPv6 address in response to a SOLICIT
but would not return the address in response to a REQUEST. Thanks to
Dennis Kou for finding the bug.
- Fixed an error causing the server to lock up on lease expiration,
reported independently by Jothilingam Vasu and Dennis Kou.
- Fixed a ./configure bug where compile tests were failing due to
"-Werror" (unused variable) rather than the actual test failure. Lead
to inconsistent and unworkable auto-configurations.
- Compilation with DLPI and -Werror has been repaired.
- Error in decoding IA_NA option if multiple interfaces are present
fixed by Marcus Goller.
- DHCPv6 server Confirm message processing has been enhanced - it no
longer replies only to clients with host {} records, it now replies
as directed in RFC3315 section 18.2.2 - that is, to all clients
regardless of the existence of bindings.
- A core dump during expired lease cleanup has been repaired.
- DDNS updates state information are now stored in 'binding scopes' that
follow the leases through their lifecycles. This enables DDNS teardowns
on leases that are assigned and expired inbetween a server restart (the
state is recovered from dhcpd.leases). Arbitrary user-specified binding
scopes ('set var = "value";') are not yet supported.
- Additional compilation problems on HP/UX have been repaired.
Changes since 4.0.0a2
- Fix for startup where there are no IPv4 addresses on an interface.
Thanks to Marcus Goller for reporting the bug.
- Fixed file descriptor leak on listen failure. Thanks to Tom Clark.
- Bug in server configuration parser caused server to get stuck on
startup for certain bad pool declarations. Thanks to Guillaume
Knispel for the bug report and fix.
- Code cleaned to remove warnings reported by "gcc -Wall".
- DHCPv6 is now the default. You can disable DHCPv6 support using the
"--disable-dhcpv6" flag when you run the configure script.
- An internal database inconsistency bug was repaired where the server
would segfault if a client attempted to renew a lease that had been
loaded from persistent storage.
- 'request' and 'also request' syntaxes have been added to accommodate
the DHCPv6 client configuration. 'send dhcp6.oro' is no longer
- Bug fixed where configuration file parsing did not work with
zero-length options; this made it impossible to set the
rapid-commit option.
- Bogus messages about host records with IPv4 fixed-addresses being of
non-128-bits in length were removed.
Changes since 4.0.0a1
- Bug in octal parsing fixed. Thanks to Bernd Fuhrmann for the report
and fix.
- Autoconf now supplies proper flags for Solaris DHCPv6 builds.
- Fix for parsing error on some IPv6 addresses.
- Invalid CIDR representation for IPv6 subnets or ranges now checked
for when loading configuration.
- Compilation on HP/UX has been repaired. The changes should generally
apply to any architecture that supplies SIOCGLIFCONF but does not
use 'struct lifconf' structures to pass values.
- Two new operators, ~= and ~~, have been integrated to implement
boolean matches by regular expression (such as may be used in
class matching statements). Thanks to a patch by Alexandr S.
Agranovsky, which underwent slight modification.
- Fix for icmp packets on 64-bit systems (bug introduced in 4.0).
- A bug was fixed in interface discovery wherein an error identifying
a server-configured interface with no IPv4 addresses would SEGV.
- Fixed a bug in which write_lease() might report a failure incorrectly
- Added support for DHCPv6 Release messages
- Added -x option to dhclient, which triggers dhclient processes
to exit gracefully without releasing leases first
- All binaries (client, server, relay) now change directories
to / before going into daemon mode, so as not to hold $CWD open
- Fixed a bug parsing DHCPv6 client-id's in host-identifier statements
- Fixed a bug with the 'ddns-updates' boolean server configuration
parameter, which caused the server to fail.
Changes since 4.0.0-20070413
- Old (expired) leases are now cleaned.
- IPv6 subnets now have support for arbitrary allocation ranges via
a new 'range6' configuration directive.
- An obviated option code hash lookup to find D6O_CLIENTID was removed.
- Corrected some situations where variables might be used without being
- Silenced several other compiler warnings.
- Include the more standard sys/uio.h rather than rely upon other
header files to include it (fixes a BSD 4.2 compile failure).
- Duplicate dhclient-script updates for DHCPv6 to all provided scripts.
- DHCPv4 I/O methods that failed to sense hardware address were corrected.
- DHCPv4 is now the default (as documented) rather than DHCPv6. The default
was set to DHCPv6 to facilitate ease early development, and forgotten.
- Corrected a segmentation violation in DHCPv4 socket processing.
- dhclient will now fork() into the background once it binds to an
IPv6 address, or immediately if the -n flag is supplied.
- -q is now the default behaviour on dhclient, with -d or -v enabling
non-quiet (stderr logging) mode.
- Fix documentation of the domain-search atom (quoted, with commas).
- Document DHCPv6 options presently in the default table.
- Replaced ./configure shellscripting with GNU Autoconf.
Changes since 3.1.0 (NEW FEATURES)
- DHCPv6 Client and Server protocol support. Use '-6' to run the daemons
as v6-only. Use '-4' to run the daemons as v4-only (default. There is
no support currently for both.
- Server support for multiple IA_NA options, containing at most one
IAADDR option.
- Client support for one IA_NA option, containing any number of IAADDR
- Server support for the DHCPv6 Information-request message.
- Inappropriate unicast DHCPv6 messages sent to the server are now
discarded, and this has rearchitected the IO system slightly.
- The DHCPv6 server DUID defaults to type 1, is persistently stored in
the leases database, and can be over-ridden (either completely, or by
specifying type 1 or type 2).
- The server only uses Rapid-Commit if it has been configured with the
Rapid-Commit option and the client requests it.
- DDNS support. We now update AAAA records in the same place we would
update A records, if we have an IPv6 address. We also generate IP6.ARPA
style names for PTR records if we're dealing with an IPv6 address. Both
A and AAAA updates are done using the same 'fqdn.' virtual option space
(although the DHCPv4 FQDN and DHCPv6 FQDN options are formatted
differently, they both use the same code here).
- The Linux dhclient-script attempts to set and remove assigned addresses,
and to configure /etc/resolv.conf from nameserver and domain name
configurations. It can be extended to configure other parameters.
- Initial DHCPv6 lease support.
- The IO system now tracks all local IP addresses, so that the DHCP
applications (particularly the dhcrelay) can discern between what frames
were transmitted to it, and what frames are being carried through it which
it should not intercept.
Changes since 3.1.0 (Maintenance)
- A bug was repaired where MAC Address Affinity for virgin leases always
mapped to the primary. Virgin leases now have an interleaved preference
between primary and secondary.
- A bug was repaired where MAC Address Affinity for clients with no client
identifier was sometimes mishashed to the peer. Load balancing during
runtime and pool rebalancing were opposing.
- An assertion in lease counting relating to reserved leases was repaired.
- The subnet-mask option inclusion now conforms with RFC2132 section 3.3;
it will only appear prior to the routers option if it is present on the
Parameter-Request-List. The subnet-mask option will also only be
included by default (if it is not on the PRL) in response to DISCOVER
or REQUEST messages.
- The FQDN option is only supplied if the client supplied an FQDN option or
if the FQDN option was explicitly requested on the PRL.
- Dynamic BOOTP leases are now load balanced in failover.
Changes since 3.1.0rc1
- The parse warning that 'deny dynamic bootp;' must be configured for
failover protected subnets was removed.
Changes since 3.1.0b2
- Failover rebalance events no longer play ping pong with round errors
(moving leases between free and back to backup where there are an
odd number of leases).
- The 'pool' log line has been split into two messages, one before the
rebalance run, and one after.
- Any queued BNDACKs are transmitted before transmitting new BNDUPDs.
This enforces the correct sequence of events for the remote server
processing these messages.
Changes since 3.1.0b1
- Fixed a bug that caused OMAPI clients to freeze when opening lease
- A new server config option "fqdn-reply" specifies whether the server
should send out option 81 (FQDN). Defaults to "on". If set to "off",
the FQDN option is not sent, even if the client requested it. This is
needed because some clients misbehave otherwise. Thanks to Christof Chen
at Allianz.
- Allow trace output files (-tf option) to be overwritten, rather than
crashing dhcpd if the file already exists
- A bug was fixed that caused dhcpd to segfault if a pool was declared
outside the scope of a subnet in dhcpd.conf.
- Some uninitialized values were repaired in dhcpleasequery.c that
caused the server to abort.
- A new server config option, 'do-reverse-updates', has been added
which causes the server to abstain from performing updates on PTR
records. Thanks to a patch from Christof Chen at Allianz.
- A bug was repaired in subencapsulation support, where spaces separated
by empty spaces would not get included.
- A bug in dhclient was repaired which caused it to send parameter request
lists of 55 bytes in length no matter how long the declared PRL was.
- 'dhcp.c(3953): non-null pointer' has been repaired. This fixes a flaw
wherein the DHCPv4 server may ignore a configured server-identifier.
- A flaw in failover startup sequences was repaired that sometimes left
the primary DHCP server's pool rebalance schedules unscheduled.
- Corrected a flaw that broke encapsulated spaces included due to presence
on the parameter request list.
Changes since 3.1.0a3
- Some spelling fixes.
Changes since 3.1.0a2
- A bug was fixed where attempting to permit leasequeries results in a
fatal internal error, "Unable to find server option 49".
- A bug was fixed in dhclient rendering the textual output form of the
domain-search option syntax.
Changes since 3.1.0a1
- A bug in the FQDN universe that added FQDN codes to the NWIP universe's
hash table was repaired.
- The servers now try harder to transmit pending binding updates when
entering normal state.
- UPDREQ/UPDREQALL handling was optimized - it no longer dequeues and
requeues all pending updates. This should reduce the number of spurious
'xid mismatch' log messages.
- An option definition referencing leak was fixed, which resulted in early
termination of dhclient upon the renewal event.
- Some default hash table sizes were tweaked, some upwards, some downwards.
3.1.0a1's tables resulted in a reduction in default server memory use.
The new selected values provide more of a zero sum (increasing the size
of tables likely to be populated, decreasing the size of tables unlikely).
- Lease structures appear in three separate hashes: by IP address, by UID,
and by hardware address. One type of table was used for all three, and
improvements to IP address hashing were applied to all three (so UID and
hardware addresses were treated like 4-byte integers). There are now two
types of tables, and the uid/hw hashes use functions more appropriate
to their needs.
- The max-lease-misbalance percentage no longer causes scheduled rebalance
runs to be skipped: it still governs the schedule, but every scheduled
run will attempt balance.
- A segfault bug in recursive encapsulation support has been corrected.
Changes since 3.0 (New Features)
- A workaround for certain STSN servers that send a mangled domain-name
option was introduced for dhclient. The client will now accept corrupted
server responses, if they contain a valid DHCP_MESSAGE_TYPE (OFFER, ACK,
or NAK). The server will continue to not accept corrupt client packets.
- Support for 'reserved' (pseudo-static) and BOOTP leases via failover
was introduced.
- Support for adding, removing, and managing class and subclass statements
via OMAPI.
- The failover implementation was updated to comply with revision 12 of
the protocol draft.
- 'make install' now creates the initial zero-length dhcpd.leases file if
one does not already exist on the system.
- RFC3942 compliance, site-local option spaces start at 224 now, not 128.
- The Load Balance Algorithm was misimplemented. The current implementation
matches RFC 3074.
- lcase() and ucase() configuration expressions have been added which adjust
their arguments from upper to lower and lower to upper cases respectively.
Thanks to a patch from Albert Herranz.
- The dhclient 'reject ...;' statement, which rejects leases given by named
server-identifiers, now permits address ranges to be specified in CIDR
notation. Thanks to a patch from David Boyce.
- The subnet-mask option is now supplied by default, but at lowest
priority. This helps a small minority of clients that provide parameter
request lists, but do not list the subnet-mask option because they were
designed to interoperate with a server that behaves in this manner.
- The FQDN option is similarly supplied even if it does not appear on the
parameter request list, but not to the exclusion of options that do
appear at the parameter request list. Up until now it had ultimate
priority over the client's parameter request list.
- Varying option space code and length bit widths (8/16/32) are now
supported. This is a milestone in achieving RFC 3925 "VIVSO" and
DHCPv6 support.
- A new common (server or client) option, 'db-time-format local;', has
been added which prints the local time in /var/db/dhcpd.leases rather
than UTC. Thanks to a patch from Ken Lalonde.
- Some patches to improve DHCP Server startup speed from Andrew Matheson
have been incorporated.
- Failover pairs now implement 'MAC Affinity' on leases moving from the
active to free states. Leases that belonged to the failover secondary
are moved to BACKUP state rather than FREE upon exiting EXPIRED state.
If lease rebalancing must move leases, it tries first to move leases
that belong to the peer in need.
- The server no longer sends POOLREQ messages unless the pool is severely
misbalanced in the peer's favor (see 'man dhcpd.conf' for more details).
- Pool rebalance events no longer happen upon successfully allocating a
lease. Instead, they happen on a schedule. See 'man dhcpd.conf' for the
min-balance and max-balance statements for more information.
- The DHCP Relay Agent Information Option / Link Selection Sub-Option
is now supported. (See RFC3527 for details).
- A new DDNS related server option, update-conflict-detection, has been
added. If this option is enabled, dhcpd will perform normal DHCID
conflict resolution (the default). If this option is disabled, it will
instead trust the assigned name implicitly (removing any other bindings
on that name). This option has not been made available in dhclient.
- In those cases where the DHCP software manufactures an IP header (to
transmit via bpf, lpf, etc), the IP TTL the software selects has been
increased from 16 to 128. This is intended to match Microsoft Windows
DHCP Client behaviour, to increase compatibility.
- 'ignore client-updates;' now has behaviour that is different from
'deny client-updates;'. The client's request is not truly ignored,
rather it is encouraged. Should this value be configured, the server
updates DNS as though client-updates were set to 'deny'. That is, it
enters into DNS whatever it is configured to do already, provided it is
configured to. Then it sends a response to the client that lets the
client believe it is performing client updates (which it will), probably
for a different name. In essence, this lets the client do as it will,
ignoring this aspect of their request.
- Support for compressed 'domain name list' style DHCP option contents, and
in particular the domain search option (#119) was added.
- The DHCP LEASEQUERY protocol as defined in RFC4388 is now implemented.
LEASEQUERY lets you query the DHCP server for information about a lease,
using either an IP address, MAC address, or client identifier. Thanks
to a patch from Justin Haddad.
- DHCPD is now RFC2131 section 4.1 compliant (broadcast to all-ones ip and
ethernet mac address) on the SCO platform specifically without any strange
ifconfig hacks. Many thanks go to the Kroger Co. for donating the
hardware and funding the development.
- A new common configuration executable statement, execute(), has been
added. This permits dhcpd or dhclient to execute a named external
program with command line arguments specified from other configuration
language. Thanks to a patch written by Mattias Ronnblom, gotten to us
via Robin Breathe.
- A new dhcp server option 'adaptive-lease-time-threshold' has been added
which causes the server to substantially reduce lease-times if there are
few (configured percentage) remaining leases. Thanks to a patch submitted
from Christof Chen.
- Encapsulated option spaces within encapsulated option spaces is now
formally supported.
Changes since 3.0.6rc1
- supersede_lease() now requeues leases in their respective hardware
address hash bucket. This mirrors client identifier behaviour.
Changes since 3.0.5
- Assorted fixes for broken network devices: Packet length is now
determined from the IP header length field to finally calculate the
UDP payload length, because some NIC drivers return more data than
they actually received.
- UDP packets are now stored in aligned data structures.
- A logic error in omapi interface code was repaired that might result in
incorrectly indicating 'up' state when any flags were set, rather than
specifically the INTERFACE_REQUESTED flag. Thanks to a patch from
Jochen Voss which got to us via Andrew Pollock at Debian.
- A reference leak on binding scopes set by ddns updates was repaired.
- A memory leak in the minires_nsendsigned() function call was repaired.
Effectively, this leaked ~176 bytes per DDNS update.
- In the case where an "L2" DHCP Relay Agent (one that does not set giaddr)
was directly attached to the same broadcast domain as the DHCP server,
the RFC3046 relay agent information option was not being returned to the
relay in the server's replies. This was fixed; the dhcp server no longer
requires the giaddr to reply with relay agent information. Note that
this also improves compatibility with L2 devices that "intercept" DHCP
packets and expect relay agent information even in unicast (renewal)
replies. Thanks to a patch from Pekka Silvonen.
- A bug was fixed where the BOOTP header 'sname' field had a value, the
copy written to persistent storage was actually the contents of the
'file' field.
- A bug was fixed where the nwip virtual option space was referencing
the fqdn option's virtual option space's option cache.
- Timestamp parsing errors that indicated missing "minutes" fields rather
than the actually missing "seconds" fields have been repaired thanks to
a patch from Kevin Steves.
- A grammar error in the dhclient.8 manpage was repaired thanks to a patch
from Chris Wagner.
- Several spelling typos were repaired, and some cross-references to other
relevant documents were included in the manpages, thanks to a patch
by Andrew Pollock which got to us via Tomas Pospisek.
- Some bugs were fixed in the 'emergency relay agent options hologram'
which is used to retain relay agent option contents from when the
client was in INIT or REBIND states. This should solve problems where
relay agent options were not echoed from the server, even when giaddr
was set.
- dhclient now closes its descriptor to dhclient.leases prior to executing
dhclient-script. Thanks to a patch from Tomas Pospisek.
- The server's "by client-id" and "by hardware address" hash table lists
are now sorted according to the preference to re-allocate that lease to
returning clients. This should eliminate pool starvation problems
arising when "INIT" clients were given new leases rather than presently
active ones.
Changes since 3.0.5rc1
- A bug was repaired in fixes to the dhclient, which sought to run the
dhclient-script with the 'EXPIRE' state should it receive a NAK in
response to a REQUEST. The client now iterates the PREINIT state
after the EXPIRE state, so that interfaces that might be configured
'down' can be brought back 'up' and initialized.
- DHCPINFORM handling for clients that properly set ciaddr and come to the
server via a relay aget has been repaired.
Changes since 3.0.4
- A warning that host statements declared within subnet or shared-network
scopes are actually global has been added.
- The default minimum lease time (if min-lease-time was not specified)
was raised from 0 to 300. 0 is not thought to be sensible, and is
known to be damaging.
- Added additional fatal error sanity checks surrounding lease binding
state count calculations (free/active counts used for failover pool
- Some time value size fixes in 3.0.4 brought on from FreeBSD /usr/ports were
misapplied to server values rather than client values. The server no longer
advertises 8-byte lease-time options when on 64-bit platforms.
- A bug where leases not in ACTIVE state would get billed to billed classes
(classes with lease limitations) was fixed. Non-active leases OFFERed
to clients are no longer billed (but billing is checked before offering).
- The dhcpd.conf.5 manpage was updated in regard to the ddns-domainname
configuration option - the default configuration and results should be
more clear now.
- If the dhclient were to receive a DHCPNAK while it was in the RENEW
state (and consequently, had an active, 'bound' address and related
configuration options), it would fail to 'tear down' this information
before proceeding into INIT state. dhclient now iterates the dhclient-
script with the 'EXPIRE' action to cause these teardowns prior to entering
INIT state. Thanks to a patch from Chris Zimmerman.
- The omapi.1 manpage had some formatting errors repaired thanks to a patch
from Yoshihiko Sarumaru.
- A few lines of code that were failover-specific were moved within
#if defined() clauses so that compilation without failover could be
made possible.
- The log message emitted when the 'leased-address' value was not available
in dhcpd.conf "executable statements" has been