DHCP 4.3.5b1 Release Notes


                Internet Systems Consortium DHCP Distribution

                            Version 4.3.5b1

                            7 September 2016

                             Release Notes

                              NEW FEATURES

The major "theme" for ISC DHCP 4.3.x was to update the support for

DHCPv6 to include several of the features that have been available

for DHCPv4.  These include:

- Support the use of classes

- Support for on_commit, on_expiry and on_release statements

- Better logging of address assignments

- Support for using DHCPv6 relay options in expressions

This release also adds support for the standard DDNS as described in the

current RFCs as well as enhancing support for dynamically adding and removing

subclasses via OMAPI.

There are a number of DHCPv6 limitations and features missing in this

release, which will be addressed in the future:

- Only Solaris, Linux, FreeBSD, NetBSD, and OpenBSD are supported.

- DHCPv6 includes human-readable text in status code messages, in

  English.  A method to reconfigure or support other languages would

  be preferable.

- The "host-identifier" option is limited to a simple token.

- The client and server can only operate DHCPv4 or DHCPv6 at a time,

  not both.  To use both protocols simultaneously, two instances of the

  relevant daemon are required, one with the '-6' command line option.

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 (eay@cryptsoft.com).

                        Changes since 4.3.4

- Fixed util/bindvar.sh error handling.

  [ISC-Bugs #41973]

- Correct error message in relay to use remote id length instead

  of circuit id length.

  [ISC-Bugs #42556]

- Add support for including an encapsulated option in a response

  from the DHCPv6 server.  This allows the v6 FQDN option to be

  returned in responses.

  [ISC-Bugs #29246]

- 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 ignored 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/dhcp-lease-list.pl to make it more friendly.

  They 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/dhcp-lease-list.pl 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 adelaide.edu.au), 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, dhcp-lease-list.pl, 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, configure.ac 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 configure.ac

  [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 Gibbons.  [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, brad@bendily.com.

  [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 configure.ac 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 <roy@marples.name>.

- 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 ("foo.bar.ba.example.com").

- 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 ip6.arpa. rather than default to in-addr.arpa 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

  to a REQUEST.

- 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 updated to be more helpful.

  Manpage information for this value has also been updated.

- Abandoned or dissociated (err condition) leases now remove any related

  dynamic dns bindings.  Thanks to a patch from Patrick Schoo.

- Attempting to write a new lease file to replace a corrupt (due to

  encountering non-retryable errors during writing) lease file should

  no longer result in an infinite recursion.

- Host declaration hardware addresses and client identifiers may only be

  configured once.  dhcpd will now fail to load config files that specify

  multiple identifiers (previous versions would silently over-ride the

  value with the later configured value).

- Several option codes that have been allocated since our last release

  have been named and documented.

- Option names of the form "unknown-123" have been removed from the in-

  memory hash tables.  In order to support options of these names that

  may appear in dhclient.leases or similar in previous versions, the

  parser will now find the new option code definition, or mock up a

  generic option code definition.  This should result in a smooth

  transition from one name to the other, as the new name is used to

  write new output.

                        Changes since 3.0.4rc1

- The dhcp-options.5 manpage was updated to correct indentation errors

  thanks to a patch from Jean Delvare.

                        Changes since 3.0.4b3

- Some manual pages were clarified pursuant to discussion on the dhcp-server

  mailing list.

                        Changes since 3.0.4b2

- Null-termination sensing for certain clients that unfortunately require

  it in DHCPINFORM processing was repaired.

- The host-name option and a few others were moved from "X" format to "t"

  format to be compatible with new NULL handling functions.

- DHCPINFORM processing is a little more careful about return addressing

  its responses, or if responding via a relay.  The INFORM related

  messages also log the 'effective client ip address' rather than the

  client's supplied ciaddr (since some clients produce null ciaddrs).

- The server was inappropriately sending leases to the RESET state in the

  event that multiple active leases were found to match a singly-identified

  client.  This was changed to RELEASED (by accepting a different, ACTIVE

  binding, the client is implicitly releasing its lease).  This repairs a

  bug wherein secondary servers in failover pairs detecting this condition

  move leases to RESET, and primaries refuse to accept that state

  transition (properly).

- The memset-after-dmalloc() changes made in 3.0.4b1 have been backed out.

                        Changes since 3.0.4b1

- Command line parsing in omshell was repaired - it no longer closes

  STDIN after reading one line.

- The resolver library no longer closes the /etc/resolv.conf file

  descriptor it opened twice.

- Changes to trailing NULL removal in 't' option-atoms has been rethought,

  it now includes 'd' (domain name) types, and tries hard not to rewind an

  option beyond the start of the text field it is un-terminating.

                        Changes since 3.0.3

- A DDNS update handling function was misusing the DNS error codes, rather

  than the internal generic result enumeration.  The result is a confusing

  syslog line, logging the wrong condition.

- The DHCP Server was not checking pool balance in the case where it brought

  a non-ACTIVE lease out of storage for a client that was returning to use

  a lease it once had long ago, and had since expired.

- Failover peers no longer bother to look for free leases to allocate when

  they already found the client's ACTIVE lease.  DISCOVERs are load balanced

  whether freely-allocated or not, unless the server doubts the peer has

  leases to allocate.

- Fixed a bug in dhcrelay agent addition code that suppressed trailing

  PAD options - it was suppressing only one trailing PAD option, rather

  than the entire block of them.

! Fixed some unlikely overlapping-region memcpy() bugs in dhcrelay agent

  option addition and stripping code.  Added a few sanity checks.  Although

  highly improbable, due to requiring the reception of a DHCP datagram well

  in excess of all known to be used physical MTU limitations, it is possible

  this may have been used in a stack overflow security vulnerability.  Thanks

  to a patch from infamous42md.

! Added some sanity checks to OMAPI connection/authentication code.

  Although highly improbable, due to having to deliver in excess of 2^32

  bytes of data via the OMAPI channel, not to mention requiring dhcpd to

  be able to malloc() a memory region 2^32 bytes in size, it was possible

  this might have resulted in a heap overflow security vulnerability.

  Thanks to a patch from infamous42md.

- dmalloc() memset()'s the non-debug (data) portion of the allocated

  memory to zero.  Code that memset()'s the result returned by dmalloc() to

  zero is redundant.  These redundancies were removed.

- Some type declaration corrections to u_int16_t were made in common/tr.c

  (Token Ring support) thanks to a patch from Jason Vas Dias at Red Hat.

- A failover bug that was allowing leases that EXPIRED or were RELEASED

  where tsfp and tstp are identical timestamps to languish in these

  transitional states has been repaired.  As a side effect, lease

  databases should be kept more consistent overall, not just for these

  transitional states.

- If the lease db is deleted out from under the daemon, and it moves to rewrite

  the db, it will go ahead with the operation and move the new db into place

  once it detects the old db does not exist.

- dhclient now ignores IRDA, SIT, and IEEE1394 network interfaces, as it

  is either nonsensical or (in the case of IEEE1394) is not known to support

  these interfaces.  Thanks to Marius Gedminas and Andrew Pollock of Debian.

- Some previously undocumented reasons for dhclient-script invoking has

  been documented in the dhclient-script.8 manpage.

- Failover potential expiry calculations (TSTP) have been corrected.  Results

  should be substantially more consistent, and proper given the constraints.

- Adjusted lease state validation checks in potential-conflict, to

  account for possible clock skew similarly to normal state, and several

  previously illegal transitions were made legal (ex: active->released).

- An impossible sanity check was removed from omapi/buffer.c, thanks to a

  patch from 'infamous42md'.

- An OMAPI host/network byte order problem in lease time values has been


- Several minor bugs, largely relating to treating 8-byte time values as

  4-byte entities, have been repaired after careful review of the FreeBSD

  ports collection's patch set.  Thanks to the nameless entities who have

  contributed to the FreeBSD ports.

- When writing a trace file, the file is now created with permissions 0600,

  to help administrators avoid accidentally publicising sensitive config


- The calculation of the maximum size of DHCP packets no longer includes

  Ethernet framing overhead.  The result is that the 'Maximum Message

  Size' option advertised by clients, or the default value 576, is no

  longer reduced by 14 bytes, and instead directly reflects the IP level

  MTU (and the default, minimum allowed IP MTU of 576).

- The special status of RELEASED/EXPIRED/RESET leases when a server

  is operating in partner-down was fixed.  It no longer requires a

  lease be twice the MCLT beyond STOS to 'reallocate', and the expiry

  event to turn these into FREE leases without peer acknowledgement

  (after STOS+MCLT) has been repaired.

- Compilation on older Solaris systems (lacking /usr/include/sys/int_types.h)

  has been repaired.

- "append"ing a string onto the end of a "t" type option (such as the

  domain-name field) that had been improperly NULL-terminated by the

  DHCP server will no longer result in a truncated string containing

  only the option from the server, and not the expected appended value.

  Thanks to a patch from Jason Vas Dias at Red Hat.

- File handlers on configuration state (config files and lease dbs) should

  be treated consistently, regardless of whether TRACING is defined or not.

- The Linux build environment has had some minor improvements - better

  sensing of 64-bit pointer sizes (only used for establishing an icmp_id),

  and corrections to #if operators regarding LINUX_MAJOR should it ever

  move to 3.[01].x.

- The server now tries harder to survive the condition where it is unable

  to open a new lease file to rewrite the lease state database.

                        Changes since 3.0.3b3

- dhclient.conf documentation for interface {} was updated to reflect recent

  discussion on the dhcp-hackers mailing list.

- In response to reports that the software does not compile on GCC 4.0.0,

  -Werror was removed from Makefile.conf for all platforms that used it.

  We will address the true problem in a future release; this is a temporary


                        Changes since 3.0.3b2

- An error in code changes introduced in 3.0.3b2 was corrected, which caused

  static BOOTP clients to receive random addresses.

                        Changes since 3.0.3b1

- A bug was fixed in BOOTPREQUEST handling code wherein stale references to

  host records would be left behind on leases that were not allocated to the

  client currently booting (eg in the case where the host was denied booting).

- The dhcpd.conf.5 manpage was updated to be more clear in regards to

  multiple host declarations (thanks to Vincent McIntyre).  'Interim' style

  dynamic updates were also retouched.

                        Changes since 3.0.2

- A bug was fixed where a server might load balance a DHCP REQUEST to its

  peer after already choosing not to load balance the preceding DISCOVER.

  The peer cannot allocate the originating server's lease.

- In the case where a secondary server lost its stable storage while the

  primary was still in communications-interrupted, and came back online,

  the lease databases would not be fully transferred to the secondary.

  This was due to the secondary errantly sending an extra UPDREQ message

  when the primary made its state transition to PARTNER-DOWN known.

- The package will now compile cleanly in gcc 3.3 and 3.4.  As a side effect,

  lease structures will be 9 bytes smaller on all platforms.  Thanks to

  Jason Vas Dias at Red Hat.

- Interface discovery code in DISCOVER_UNCONFIGURED mode is now

  properly restricted to only detecting broadcast interfaces.  Thanks

  to a patch from Jason Vas Dias at Red Hat.

- decode_udp_ip_header was changed so that the IP address was copied out

  to a variable, rather than referenced by a pointer.  This enforces 4-byte

  alignment of the 32-bit IP address value.  Thanks to a patch from Dr.

  Peter Poeml.

- An incorrect log message was corrected thanks to a patch from

  Dr. Peter Poeml.

- A bug in DDNS was repaired, where if the server's first DDNS action was

  a DDNS removal rather than a DDNS update, the resolver library's

  retransmit timer and retry timer was set to the default, implying a

  15 second timeout interval.  Which is a little excessive in a synchronous,

  single-threaded system.  In all cases, ISC DHCP should now hold fast to

  a 1-second timeout, trying only once.

- The siaddr field was being improperly set to the server-identifier when

  responding to DHCP messages.  RFC2131 clarified the siaddr field as

  meaning the 'next server in the bootstrap process', eg a tftp server.

  The siaddr field is now left zeroed unless next-server is configured.

- mockup_lease() could have returned in an error condition (or in the

  condition where no fixed-address was found matching the shared

  network) with stale references to a host record.  This is probably not

  a memory leak since host records generally never die anyway.

- A bug was repaired where failover servers would let stale client identifiers

  persist on leases that were reallocated to new clients not sending an id.

- Binding scopes ("set var = value;") are now removed from leases allocated

  by failover peers if the lease had expired.  This should help reduce the

  number of stale binding scopes on leases.

- A small memory leak was closed involving client identifiers larger than

  7 bytes, and failover.

- Configuring a subnet in dhcpd.conf with a subnet mask of 32 bits might

  cause an internal function to overflow heap.  Thanks to Jason Vas Dias

  at Red Hat.

- Some inconsistencies in treating numbers that the lexer parsed as 'NUMBER'

  or 'NUMBER_OR_NAME' was repaired.  Hexadecimal parsing is affected, and

  should work better.

- In several cases, parse warnings were being issued before the lexical

  token had been advanced to the token whose value was causing an error...

  causing parse warnings to claim the problem is on the wrong token.

- Host declarations matching on client identifier for dynamic leases will

  no longer match fixed-address host declarations (this is now identical

  to behaviour for host records matching on hardware address).

                        Changes since 3.0.2rc3

- A previously undocumented configuration directive, 'local-address',

  was documented in the dhcpd.conf manpage.

                        Changes since 3.0.2rc2

- Two variables introduced in 3.0.2b1 were used without being initialized

  in the case where neither the FILE nor SNAME fields were available for

  overloading.  This was repaired.

- A heretofore believed to be impossible corner case of the option

  overloading implementation turned out to be possible ("Unable to sort

  overloaded options after 10 tries.").  The implementation was reworked

  to consider the case of an option so large it would require more than

  three chunks to fit.

- Many other instances of variables being used without being initialized

  were repaired.

- An uninitialized variable in omapi_io_destroy() led to the discovery

  that this function may result in orphaned pointers (and hence, a memory


                        Changes since 3.0.2rc1

- allocate_lease() was rewritten to repair a bug in which the server would

  try to allocate an ABANDONED lease when FREE leases were available.

                        Changes since 3.0.2b1

- Some dhcp-eval.5 manpage formatting was repaired.

                        Changes since 3.0.1

- A bug was fixed in the server's 'option overloading' implementation,

  where options loaded into the 'file' and 'sname' packet fields were

  not aligned precisely as rfc2131 dictates.

- The FreeBSD client script was changed to support the case where a domain

  name was not provided by the server.

- A memory leak in 'omshell' per each command line parsed was

  repaired, thanks to a patch from Jarkko Torppa.

- Log functions writing to stderr were adjusted to use the STDERR_FILENO

  system definition rather than '2'.  This is a no-op for 90% of platforms.

- One call to trace_write_packet_iov() counted the number of io vectors

  incorrectly, causing inconsistent tracefiles.  This was fixed.

- Some expression parse failure memory leaks were closed.

- A host byte order problem in tracefiles was repaired.

- Pools configured in DHCPD for failover possessing permission lists that

  previously were assumed to not include dynamic bootp clients are now

  a little more pessimistic.  The result is, dhcpd will nag you about just

  about most pools that possess a 'allow' statement with no 'deny' that

  would definitely match a dynamic bootp client.

- The 'ddns-update-style' configuration warning bit now insists that

  the configuration be globally scoped.

- Two memory leaks in dhclient were closed thanks to a patch from Felix


- Some minor but excellently pedantic documentation errors were fixed

  thanks to a patch from Thomas Klausner.

- Bugs in operator precedence in executable statements have been repaired

  once again.  More legal syntaxes should be parsed legally.

- Failing to initialize a tracefile for any reason if a tracefile was

  specified is now a fatal error.  Thanks to a patch from Albert Herranz.

- Corrected a bug in which the number of leases transferred as calculated

  by the failover primary and sent to peers in POOLRESP responses may be

  incorrect.  This value is not believed to be used by other failover

  implementations, excepting perhaps as logged information.

- Corrected a bug in which 'dhcp_failover_send_poolresp()' was in fact

  sending POOLREQ messages instead of POOLRESP mesasges.  This message

  was essentially ignored since failover secondaries effectively do not

  respond to POOLREQ messages.

- Type definitions for various bitwidths of integers in the sunos5-5

  build of ISC DHCP have been fixed.  It should compile and run more

  easily when built in 64-bit for this platform.

- "allow known-clients;" is now a legal syntax, to avoid confusion.

- If one dhcp server chooses to 'load balance' a request to its failover

  peer, it first checks to see if it believes said peer has a free

  lease to allocate before ignoring the DISCOVER.

- log() was logging a work buffer, rather than the value returned by

  executing the statements configured by the user.  In some cases,

  the work buffer and the intended results were the same.  In some other

  cases, they were not.  This was fixed thanks to a patch from Gunnar

  Fjone and directconnect.no.

- Compiler warnings for some string type conversions was fixed, thanks

  to Andreas Gustafsson.

- The netbsd build environments were simplified to one, in which

  -Wconversion is not used, thanks to Andreas Gustafsson.

- How randomness in the backoff-cutoff dhclient configuration variable

  is implemented was better documented in the manpage, and the behaviour

  of dhclient in REQUEST timeout handling was changed to match that of

  DISCOVER timeout handling.

- Omapi was hardened against clients that pass in null values, thanks

  to a patch from Mark Jason Dominus.

- A bug was fixed in dhclient that kept it from doing client-side

  ddns updates.  Thanks to a patch from Andreas Gustafsson, which

  underwent some modification after review by Jason Vas Dias.

- Failover implementations disconnected due to the network between

  them (rather than one of the two shutting down) will now try to

  re-establish the failover connection every 5 seconds, rather than

  to simply try once and give up until one of them is restarted.

  Thanks to a patch from Ulf Ekberg from Infoblox, and field testing

  by Greger V. Teigre which led to an enhancement to it.

- A problem that kept DHCP Failover secondaries from tearing down

  ddns records was repaired.  Thanks to a patch from Ulf Ekberg from


- 64bit pointer sizes are detected properly on FreeBSD now.

- A bug was repaired where the DHCP server would leave stale references

  to host records on leases it once thought about offering to certain

  clients.  The result would be to apply host and 'known' scopes to the

  wrong clients (possibly denying booting).  NOTE:  The 'mis-host' patch

  that was being circulated as a workaround is not the way this bug was

  fixed.  If you were a victim of this bug in 3.0.1, you are cautioned

  to proceed carefully and see if it fixes your problem.

- A bug was repaired in the server's DHCPINFORM handling, where it

  tried to divine the client's address from the source packet and

  would get it wrong.  Thanks to Anshuman Singh Rawat.

- A log message was introduced to help illuminate the case where the

  server was unable to find a lease to assign to any BOOTP client.

  Thanks to Daniel Baker.

- A minor dhcpd.conf.5 manpage error was fixed.

                        Changes since 3.0.1rc14

- The global variable 'cur_time' was centralized and is now uniformly of a

  type #defined in system-dependent headers.  It had previously been defined

  in one of many places as a 32-bit value, and this causes mayhem on 64-bit

  big endian systems.  It probably wasn't too healthy on little endian

  systems either.

- A printf format string error introduced in rc14 was repaired.

- AIX system-dependent header file was altered to only define NO_SNPRINTF

  if the condition used to #ifdef in vsnprintf in AIX' header files

  is false.

- The Alpha/OSF system-dependent header file was altered to define

  NO_SNPRINTF on OS revisions older than 4.0G.

- omapip/test.c had string.h added to its includes.

                        Changes since 3.0.1rc13

! CAN-2004-0460 - CERT VU#317350: Five stack overflow exploits were closed

  in logging messages with excessively long hostnames provided by the

  clients.  It is highly probable that these could have been used by

  attackers to gain arbitrary root access on systems using ISC DHCP 3.0.1

  release candidates 12 or 13.  Special thanks to Gregory Duchemin for

  both finding and solving the problem.

! CAN-2004-0461 - CERT VU#654390: Once the above was closed, an opening

  in log_*() functions was evidenced, on some specific platforms where

  vsnprintf() was not believed to be available and calls were wrapped to

  sprintf() instead.  Again, credit goes to Gregory Duchemin for finding

  the problem.  Calls to snprintf() are now linked to a distribution-local

  snprintf implementation, only in those cases where the architecture is

  not known to provide one (see includes/cf/[arch].h).  If you experience

  linking problems with snprintf/vsnprintf or 'isc_print_' functions, this

  is where to look.  This vulnerability did not exist in any previously

  published version of ISC DHCP.

- Compilation on hpux 11.11 was repaired.

- 'The cross-compile bug fix' was backed out.

                        Changes since 3.0.1rc12

- Fixed a bug in omapi lease lookup function, to form the hardware

  address for the hash lookup correctly, thanks to a patch from

  Richard Hirst.

- Fixed a bug where dhcrelay was sending relayed responses back to the

  broadcast address, but with the source's unicast mac address.  Should

  now conform to rfc2131 section 4.1.

- Cross-compile bug fix; use $(AR) instead of ar.  Thanks to Morten Brorup.

- Fixed a crash bug in dhclient where dhcpd servers that do not provide

  renewal times results in an FPE.  As a side effect, dhclient can now

  properly handle 0xFFFFFFFF (-1) expiry times supplied by servers.  Thanks

  to a patch from Burt Silverman.

- The 'ping timeout' debugs from rc12 were removed to -DDEBUG only,

  and reformatted to correct a compilation error on Solaris platforms.

- A patch was applied which fixes a case where leases read from the

  leases database do not properly over-ride previously read leases.

- dhcpctl.3 manpage was tweaked.

                        Changes since 3.0.1rc11

- A patch from Steve Campbell was applied with minor modifications to

  permit reverse dns PTR record updates with values containing spaces.

- A patch from Florian Lohoff was applied with some modifications to

  dhcrelay.  It now discards packets whose hop count exceeds 10 by default,

  and a command-line option (-c) can be used to set this threshold.

- A failover bug relating to identifying peers by name length instead of

  by name was fixed.

- Declaring failover configs within shared-network statements should no

  longer result in error.

- The -nw command line option to dhclient now works.

- Thanks to a patch from Michael Richardson:

        - Some problems with long option processing have been fixed.

        - Some fixes to minires so that updates of KEY records will work.

- contrib/ms2isc was updated by Shu-Min Chang of the Intel Corporation.

  see contrib/ms2isc/readme.txt for revision notes.

- Dhclient no longer uses shell commands to kill another instance of

  itself, it sends the signal directly.  Thanks to a patch from Martin


- The FreeBSD dhclient-script was changed so that a failure to write to

  /etc/resolv.conf does not prematurely end the script.  This keeps dhclient

  from looping infinitely when this is the case.  Thanks to a patch from

  Martin Blapp.

- A patch from Bill Stephens was applied which resolves a problem with lease

  expiry times in failover configurations.

- A memory leak in configuration parsing was closed thanks to a patch from

  Steve G.

- The function which discovers interfaces will now skip non-broadcast or

  point-to-point interfaces, thanks to a patch from David Brownlee.

- Options not yet known by the dhcpd or dhclient have had their names

  changed such that they do not contain # symbols, in case they should ever

  appear in a lease file.  An option that might have been named "#144" is

  now "unknown-144".

- Another patch from Bill Stephens which allows the ping-check timeout to

  be configured as 'ping-timeout'.  Defaults to 1.

                        Changes since 3.0.1rc10

- Potential buffer overflows in minires repaired.

- A change to the linux client script to use /bin/bash, since /bin/sh may

  not be bash.

- Some missing va_end cleanups thanks to a patch from Thomas Klausner.

- A correction of boolean parsing syntax validation - some illegal syntaxes

  that worked before are now detected and produce errs, some legal syntaxes

  that errored before will now work properly.

- Some search-and-replace errors that caused some options to change their

  names was repaired.

- Shu-min Chang of the Intel corporation has contributed a perl script and

  module that converts the MS NT4 DHCP configuration to a ISC DHCP3

  configuration file.

- Applied the remainder of the dhcpctl memory leak patch provided by Bill

  Squier at ReefEdge, Inc.  (groo@reefedge.com).

- Missing non-optional failover peer configurations will now result in a soft

  error rather than a null dereference.

                        Changes since 3.0.1rc9

- A format string was corrected to fix compiler warnings.

- A number of spelling corrections were made in the man pages.

- The dhclient.conf.5 man page was changed to refer to do-forward-updates

  rather than a configuration option that doesn't exist.

- A FreeBSD-specific bug in the interface removal handling was fixed.

- A Linux-specific Token Ring detection problem was fixed.

- Hashes removed from as-yet-unknown agent options, having those options

  appear in reality before we know about them will no longer produce

  self-corrupting lease databases.

- dhclient will use the proper port numbers now when using the -g option.

- A order-of-operations bug with 2 match clauses in 1 class statement is

  fixed thanks to a patch from Andrew Matheson.

- Compilation problems on Solaris were fixed.

- Compilation problems when built with DEBUG or DEBUG_PACKET were repaired.

- A fix to the dhcp ack process which makes certain group options will be

  included in the first DHCPOFFER message was made thanks to a patch from

  Ling Gou.

- A few memory leaks were repaired thanks to patches from Bill Squier at

  ReefEdge, Inc.  (groo@reefedge.com).

- A fix for shared-networks that sometimes give clients options for the

  wrong subnets (in particular, 'option routers') was applied, thanks to

  Ted Lemon for the patch.

- Omshell's handling of dotted octets as values was changed such that dots

  one after the other produce zero values in the integer string.

                        Changes since 3.0.1rc8

- Fix a format string vulnerability in the server that could lead to a

  remote root compromise (discovered by NGSEC Research Team, www.ngsec.com).

- Add additional support for NetBSD/sparc64.

- Fix a bug in the command-line parsing of the client.  Also, resolve

  a memory leak.

- Add better support for shells other than bash in the Linux client


- Various build fixes for modern versions of FreeBSD and Linux.

- Fix a bad bounds check when printing binding state names.

- Clarify documentation about fixed-address and multiple addresses.

- Fix a typo in the authoritative error message.

- Make a log entry when we can't write a billing class.

- Use conversion targets that are the right size on all architectures.

- Increment the hop count when relaying.

- Log a message when lease state is changed through OMAPI.

- Don't rerun the shared_network when evaluating the pool.

- Fix a reversed test in the parser.

- Change the type of rbuf_max.

- Make FTS_LAST a manifest constant to quiet warnings.

                        Changes since 3.0.1rc7

- Fix two compiler warnings that are generated when compiling on Solaris

  with gcc.   These stop the build, even though they weren't actually

  errors, because we prefer that our builds generate no warnings.

                        Changes since 3.0.1rc6

- Don't allow a lease that's in the EXPIRED, RELEASED or RESET state

  to be renewed.

- Implement lease stealing for cases where the primary has fewer leases

  than the secondary, as called for by the standard.

- Add a fudge factor to the lease expiry acceptance code, (suggested

  by Kevin Miller of CMU).

- Fix a bug in permit_list_match that made it much too willing to say

  that two permit lists matched.

- Unless DEBUG_DNS_UPDATES is defined, print more user-friendly (and

  also more compact) messages about DNS updates.

- Fix a bug in generating wire-format domain names for the FQDN option.

- Fix a bug where the FQDN option would not be returned if the client

  requested it, contrary to the standard.

- On Darwin, use the FreeBSD DHCP client script.

- On NetBSD/sparc, don't check for casting warnings.

- Add a flag in the DHCP client to disable updating the client's A

  record when sending an FQDN option indicating that the client is

  going to update its A record.

- In the client, don't attempt a DNS update until one second after

  configuring the new IP address, and if the update times out, keep

  trying until a response, positive or negative, is received from the

  DNS server.

- Fix an uninitialized memory bug in the DHCP client.

- Apply some FreeBSD-specific bug fixes suggested by Murray Stokely.

- Fix a bug in ns_parserr(), where it was returning the wrong sort

  of result code in some cases (suggested by Ben Harris of the

  NetBSD project).

- Fix a bug in is_identifier(), where it was checking against EOF

  instead of the END_OF_FILE token (also suggested by Ben Harris).

- Fix a bug where if an option universe contained no options, the

  DHCP server could dump core (Walter Steiner).

- Fix a bug in the handling of encapsulated options.

- Fix a bug that prevented NWIP suboptions from being processed.

- Delete the FTS_BOOTP and FTS_RESERVED states and implement them

  as modifier flags to the FTS_ACTIVE state, as called for in the

  failover protocol standard.

- Fix bugs in the pool merging code that resulted in references and

  dereferences of null pointers.   This bug had no impact unless the

  POINTER_DEBUG flag was defined.

- In the server, added a do-forward-updates flag that can be used to

  disable forward updates in all cases, so that sites that want the

  clients to take sole responsibility for updating their A record can

  do so.

- Make it possible to disable optimization of PTR record updates.

                        Changes since 3.0.1rc5

- Include some new documentation and changes provided by Karl Auer.

- Add a workaround for some Lexmark printers that send a double-NUL-

  terminated host-name option, which would break DNS updates.

- Fix an off-by-one error in the MAC-address checking code for

  DHCPRELEASE that was added in 3.0.1rc5.

- Fix a bug where client-specific information was not being discarded

  from the lease when it expired or was released, resulting in

  problems if the lease was reallocated to a different client.

- If more than one allocation pool is specified that has the same set

  of constraints as another allocation pool on the same shared

  network, merge the two pools.

- Don't print an error in fallback_discard, since this just causes

  confusion and does not appear to be helping to encourage anyone to

  fix this bug.

                        Changes since 3.0.1rc4

- Fix a bug that would cause the DHCP server to spin if asked to parse

  a certain kind of incorrect statement.

- Fix a related bug that would prevent an error from being reported in

  the same case.

- Additional documentation.

- Make sure that the hardware address matches the lease when

  processing a DHCPRELEASE message.

                        Changes since 3.0.1rc3

- A minor bug fix in the arguments to a logging function call.

- Documentation update for dhcpd.conf.

                        Changes since 3.0.1rc2

- Allow the primary to send a POOLREQ message.   This isn't what the current

  failover draft says to do, so we may have to back it out if I can't get the

  authors to relent, but the scheme for balancing that's specified in the

  current draft seems needlessly hairy, so I'm floating a trial balloon.

  The rc1 code did not implement the method described in the draft either.

                        Changes since 3.0.1rc1

- Treat NXDOMAIN and NXRRSET as success when we are trying to delete a

  domain or RRSET.   This allows the DHCP server to forget about a name

  it added to the DNS once it's been removed, even if the DHCP server

  wasn't the one that removed it.

- Install defaults for failover maximum outstanding updates and maximum

  silent time.   This prevents problems that might occur if these values

  were not configured.

- Don't do DDNS deletes if ddns-update-style is none.

- Return relay agent information options in DHCPNAK.   This prevents DHCPNAK

  messages from being dropped when the relay agent information option contains

  routing information.

- Fix a problem where coming up in recover wouldn't result in an update

  request being sent.

- Add some more chatty messages when we start a recovery update and when it's


- Fix a possible problem where some state might have been left around

  after the peer lost contact and regained contact about how many updates

  were pending.

- Don't nix a lease update because of a lease conflict.   This test has

  never (as far as I know) prevented a mistake, and it appears to cause

  problems with failover.

- Add support in rc history code for keeping a selective history, rather

  than a history of all references and dereferences.   This code is only used

  when extensive additional debugging is enabled.

                           Changes since 3.0

- Make allocators for hash tables.   As a side effect, this fixes a memory

  smash in the subclass allocation code.

- Fix a small bug in omshell where if you try to close an object when

  no object is open, it dumps core.

- Fix an obscure coredump that could occur on shutdown.

- Fix a bug in the recording of host declaration rubouts in the lease file.

- Fix two potential spins in the host deletion code.

- Fix a core dump that would happen if an application tried to update

  a host object attribute with a null value.

                Changes since 3.0 Release Candidate 12

- Fix a memory leak in the evaluation code.

- Fix an obscure core dump.

- Print a couple of new warnings when parsing the configuration file

  when crucial information is left out.

- Log "no free leases" as an error.

- Documentation updates.

                Changes since 3.0 Release Candidate 11

- Always return a subnet selection option if one is sent.

- Fix a warning that was being printed because an automatic data

  structure wasn't zeroed.

- Fix some failover state transitions that were being handled


- When supersede_lease is called on a lease whose end time has already

  expired, but for which a state transition has not yet been done, do

  a state transition.   This fixes the case where if the secondary

  allocated a lease to a client and the lease "expired" while the

  secondary was in partner-down, no expiry event would actually

  happen, so the lease would remain active until the primary was


                Changes since 3.0 Release Candidate 10

- Fix a bug that was preventing released leases from changing state

  in failover-enabled pools.

- Fix a core dump in the client identifier finder code (for host


- Finish fixing a bug where bogus data would sometimes get logged to

  the dhclient.leases file because it was opened as descriptor 2.

- Fix the Linux dhclient-script according to suggestions made by

  several people on the dhcp-client mailing list.

- Log successful DNS updates at LOG_INFO, not LOG_ERROR.

- Print an error message and refuse to run if a failover peer is

  defined but not referenced by any pools.

- Correct a confusing error message in failover.

                Changes since 3.0 Release Candidate 9

- Fix a bug in lease allocation for Dynamic BOOTP clients.

          Changes since 3.0 Release Candidate 8 Patchlevel 2

- Fix a bug that prevented update-static-leases from working.

- Document failover-state OMAPI object.

- Fix a compilation error on SunOS 4.

          Changes since 3.0 Release Candidate 8 Patchlevel 1

- Fix a parsing bug that broke dns updates (both interim and ad-hoc).

  This was introduced in rc8pl1 as an unintended result of the memory

  leakage fixes that were in pl1.

- Fix a long-standing bug where the server would record that an update

  had been done for a client with no name, even though no update had

  been done, and then when the client's lease expired the deletion of

  that nonexistant record would time out because the name was the null


- Clean up the omshell, dhcpctl and omapi man pages a bit.

                Changes since 3.0 Release Candidate 8

- Fix a bug that could cause the DHCP server to spin if

  one-lease-per-client was enabled.

- Fix a bug that was causing core dumps on BSD/os in the presence of

  malformed packets.

- In partner-down state, don't restrict lease lengths to MCLT.

- On the failover secondary, record the MCLT received from the primary

  so that if we come up without a connection to the primary we don't

  wind up giving out zero-length leases.

- Fix some compilation problems on BSD/os.

- Fix a bunch of memory leaks.

- Fix a couple of bugs in the option printer.

- Fix an obscure error reporting bug in the dns update code, and also

  make the message clearer when a key algorithm isn't supported.

- Fix a bug in the tracing code that prevented trace runs that used

  tcp connections from being played back.

- Add some additional debugging capability for catching memory leaks

  on exit.

- Make the client release the lease correctly on shutdown.

- Add some configurability to the build system.

- Install omshell manual page in man1, not man8.

- Craig Gwydir sent in a patch that fixes a long-standing bug in the

  DHCP client that could cause core dumps, but that for some reason

  hadn't been noticed until now.

                Changes since 3.0 Release Candidate 7

- Fix a bug in failover where we weren't sending updates after a

  transition from communications-interrupted to normal.

- Handle expired/released/reset -> free transition according to the

  protocol specification (this works - the other way not only wasn't

  conformant, but also didn't work).

- Add a control object in both client and server that allows either

  daemon to be shut down cleanly.

- When writing a lease, if we run out of disk space, shut down the

  output file and insist on writing a new one before proceeding.

- In the server, if the OMAPI listener port is occupied, keep trying

  to get it, rather than simply giving up and exiting.

- Support fetching variables from leases and also updating and adding

  variables to leases via OMAPI.

- If two failover peers have wildly different clocks, refuse to start

  doing failover.

- Fix a bug in the DNS update code that could cause core dumps when

  running on alpha processors.

- Fixed a bug in ddns updates for static lease entries, thanks to a

  patch from Andrey M Linkevitch.

- Add support for Darwin/MacOS X

- Install omshell (including new documentation).

- Support DNS updates in the client (this is a very obscure feature

  that most DHCP client users probably will not be able to use).

- Somewhat cleaner status logging in the client.

- Make OMAPI key naming syntax compatible with the way keys are

  actually named (key names are domain names).

- Fix a bug in the lease file writer.

- Install DHCP ISC headers in a different place than BIND 9 ISC

  headers, to avoid causing trouble in BIND 9 builds.

- Don't send updates for attributes on an object when the attributes

  haven't changed.   Support deleting attributes on remote objects.

- Fix a number of bugs in omshell, and add the unset and refresh


- Handle disconnects in OMAPI a little bit more intelligently (so that

  the caller gets ECONNRESET instead of EINVAL).

- Fix a bunch of bugs in the handling of clients that have existing

  leases when the try to renew their leases while failover is


                Changes since 3.0 Release Candidate 6

- Fix a core dump that could happen when processing a DHCPREQUEST from

  a client that had a host declaration that contained both a

  fixed-address declaration and a dhcp-client-identifier option

  declaration, if the client identifier was longer than nine bytes.

- Fix a memory leak that could happen in certain obscure cases when

  using omapi to manipulate leases.

- Fix some bugs and omissions in omshell.

                Changes since 3.0 Release Candidate 5

- Fix a bug in omapi_object_dereference that prevented objects in

  chains from having their reference counts decreased on dereference.

- Fix a bug in omapi_object_dereference that would prevent object

  chains from being freed upon removal of the last reference external

  to the chain.

- Fix a number of other memory leaks in the OMAPI protocol subsystem.

- Add code in the OMAPI protocol handler to trace memory leakage.

- Clean up the memory allocation/reference history printer.

- Support input of dotted quads and colon-separated hex lists as

  attribute values in omshell.

- Fix a typo in the Linux interface discovery code.

- Conditionalize a piece of trace code that wasn't conditional.

                Changes since 3.0 Release Candidate 4

- Fix a bug that would prevent leases from being abandoned properly on


- Fix failover peer OMAPI support.

- In failover, correctly handle expiration of leases.   Previously,

  leases would never be reclaimed because they couldn't make the

  transition from EXPIRED to FREE.

- Fix some broken failover state transitions.

- Documentation fixes.

- Take out an unnecessary check in DHCP relay agent information option

  stashing code that was preventing REBINDING clients from rebinding.

- Prevent failover peers from allocating leases in DHCPREQUEST

  processing if the lease belongs to the other server.

- Record server version in lease file introductory comment.

- Correctly report connection errors in OMAPI and failover.

- Make authentication signature algorithm name comparisons in OMAPI


- Fix compile problem on SunOS 4.x

- If a signature algorithm is not terminated with '.', terminate it so

  that comparisons between fully-qualified names will work


- Different SIOCGIFCONF probe code, may "fix" problem on some Linux

  systems with the probe not working correctly.

- Don't allow user to type omapi key on command line of omshell.

                Changes since 3.0 Release Candidate 3

- Do lease billing on startup in a way that I *think* will finally do

  the billing correctly - the previous method could overbill as a

  result of duplicate leases.

- Document OMAPI server objects.

          Changes since 3.0 Release Candidate 2 Patchlevel 1

- Fix some problems in the DDNS update code.   Thanks to Albert

  Herranz for figuring out the main problem.

- Fix some reference counting errors on host entries that were causing

  core dumps.

- Fix a byte-swap bug in the token ring code, thanks to Jochen


- Fix a bug in lease billing, thanks to Jonas Bulow.

                Changes since 3.0 Release Candidate 2

- Change the conditions under which a DHCPRELEASE is actually

  committed to be consistent with lease binding states rather than

  using the lease end time.   This may fix some problems with the

  billing class code.

- Fix a bug where lease updates would fail on Digital Unix (and maybe

  others) because malloc was called with a size of zero.

- Fix a core dump that happens when the DHCP server can't create its

  trace file.

          Changes since 3.0 Release Candidate 1 Patchlevel 1

- Fix the dhcp_failover_put_message to not attempt to allocate a

  zero-length buffer.   Some versions of malloc() fail if you try to

  allocate a zero-length buffer, and this was causing problems on,

  e.g., Digital Unix.

- Fix a case where the failover code was printing an error message

  when no error had occurred.

- Fix a problem where when a server went down and back up again, the

  peer would not see a state transition and so would stay in the

  non-communicating state.

- Be smart about going into recover_wait.

- Fix a problem in the failover implementation where peers would fail

  to come into sync if interrupted in the RECOVER state.   This could

  have been the cause of some problems people have reported recently.

- Fix a problem with billing classes where they would not be unbilled

  when the client lease expired.

- If select fails, figure out which descriptor is bad, and cut it out

  of the I/O loop.   This prevents a potentially nasty spin.  I

  haven't heard any report it in a while, but it came up consistently

  in testing.

- Fix a bug in the relay agent where if you specified interfaces on

  the command line, it would fail.

- Fix a couple of small bugs in the omapi connection object (no known

  user impact).

- Add the missing 3.0 Beta 1 lease conversion script.

- Read dhcp client script hooks if they exist, rather than only if

  they're executable.

                Changes since 3.0 Release Candidate 1

- Fix a memory smash that happens when fixed-address leases are used.


  UPGRADE IMMEDIATELY.   This has been a long-standing bug - thanks to

  Alvise Nobile for discovering it and helping me to find it!

- Fix a small bug in binary-to-ascii, thanks to H. Peter Anvin of


- There is a known problem with the DHCP server doing failover on

  Compaq Alpha systems.   This patchlevel is not a release candidate

  because of this bug.   The bug should be straightforward to fix, so

  a new release candidate is expected shortly.

- There is a known problem in the DDNS update code that is probably a

  bug, and is not, as far as we know, fixed in this patchlevel.

                Changes since 3.0 Beta 2 Patchlevel 24

- Went over problematic failover state transitions and made them all

  work, so that failover should now much less fragile.

- Add some dhcpctl and omapi documentation

- Fix compile errors when compiling with unusual predefines.

- Make Token Ring work on Linux 2.4

- Fix the Digital Unix BPF_WORDALIGN bug.

- Fix some dhcp client documentation errors.

- Update some parts of the README file.

- Support GCC on SCO.

                Changes since 3.0 Beta 2 Patchlevel 23

- Fix a bug in the DNS update code where a status code was not being

  checked.   This may have been causing core dumps.

- When parsing the lease file, if a lease declaration includes a

  billing class statement, and the lease already has a billing class,

  unbill the old class.

- When processing failover transactions, where acks will be deferred,

  process the state transition immediately.

-  Don't try to use the new SIOCGIFCONF buffer size detection code on

   Linux 2.0, which doesn't provide this functionality.

- Apply a patch suggested by Tuan Uong for a problem in dlpi.c.

- Fix a problem in using the which command in the configure script.

- Fix a parse error in the client when setting up an omapi listener.

- Document the -n and -g flags to the client.

- Make sure there is always a stdin and stdout on startup.   This

  prevents shell scripts from accidentally writing error messages into

  configuration files that happen to be opened as stderr.

- If an interface is removed, the client will now notice that it is

  gone rather than spinning.   This has only been tested on NetBSD.

- The client will attempt to get an address even if it can't create a

  lease file.

- Don't overwrite tracefiles.

- Fix some memory allocation bugs in failover.

                Changes since 3.0 Beta 2 Patchlevel 22

- Apply some patches suggested by Cyrille Lefevre, who is maintaining

  the FreeBSD ISC DHCP Distribution port.

- Fix a core dump in DHCPRELEASE.

                Changes since 3.0 Beta 2 Patchlevel 21

- This time for sure: fix the spin described in the changes for pl20.

                Changes since 3.0 Beta 2 Patchlevel 20

- Fix a problem with Linux detecting large numbers of interfaces (Ben)

- Fix a memory smash in the quotify code, which was introduced in


- Actually fix the spin described in the changes for pl20.   The

  previous fix only partially fixed the problem - enough to get it

  past the regression test.

                Changes since 3.0 Beta 2 Patchlevel 19

- Fix a bug that could cause the server to abort if compiled with

  POINTER_DEBUG enabled.

- Fix a bug that could cause the server to spin when responding to a


- Apply Joost Mulders' suggested patches for DLPI on x86.

- Support NUL characters in quoted strings.

- Install unformatted man pages on SunOS.

                Changes since 3.0 Beta 2 Patchlevel 18

- Allow the server to be placed in partner-down state using OMAPI.

  (Damien Neil)

- Implement omshell, which can be used to do arbitrary things to the

  server (in theory). (Damien Neil)

- Fix a case where if a client had two different leases the server could

  actually dereference the second one when it hadn't been referenced,

  leading to memory corruption and a core dump. (James Brister)

- Fix a case where a client could request the address of another client's

  lease, but find_lease wouldn't detect that the other client had it, and

  would attempt to allocate it to the client, resulting in a lease conflict


- Fix a case where a client with more than one client identifier could be

  given a lease where the hardware address was correct but the client

  identifier was not, resulting in a lease conflict message.

- Fix a problem where the server could write out a colon-separated

  hex list as a value for a variable, which would then not parse.

  The fix is to always write strings as quoted strings, with any

  non-printable characters quoted as octal escape sequences.   So

  a file written the old way still won't work, but new files written

  this way will work.

- Fix documentation for sending non-standard options.

- Use unparsable names for unknown options.    WARNING: this will

  break any configuration files that use the option-nnn convention.

  If you want to continue to use this convention for some options,

  please be sure to write a definition, like this:

  option option-nnn code nnn = string;

  You can use a descriptive name instead of option-nnn if you like.

- Fix a problem where we would see a DHCPDISCOVER/DHCPOFFER/


  result of a deceptively silly bug in supersede_lease.

- Fix client script exit status check, according to a fix supplied by

  Hermann Lauer.

- Fix an endianness bug in the tracefile support, regarding ICMP


- Fix a bug in the client where the medium would not work correctly if

  it contained quoted strings.

                       ** there was no pl17 **

                Changes since 3.0 Beta 2 Patchlevel 16

- Add support for transaction tracing.   This allows the state of the

  DHCP server on startup, and all the subsequent transactions, to be

  recorded in a file which can then be played back to reproduce the

  behaviour of the DHCP server.   This can be used to quickly

  reproduce bugs that cause core dumps or corruption, and also for

  tracking down memory leaks.

- Incorporate some bug fixes provided by Joost Mulders for the DLPI

  package which should clear up problems people have been seeing on


- Fix bugs in the handling of options stored as linked lists (agent

  options, fqdn options and nwip options) that could cause memory

  corruption and core dumps.

- Fix a bug in DHCPREQUEST handling that resulted in DHCPNAK messages

  not being send in some cases when they were needed.

- Make the lease structure somewhat more compact.

- Make initial failover startup *much* faster.   This was researched

  and implemented by Damien Neil.

- Add a --version flag to all executables, which prints the program

  name and version to standard output.

- Don't rewrite the lease file every thousand leases.

- A bug in nit.c for older SunOS machines was fixed by a patch sent in

  by Takeshi Hagiwara.

- Fix a memory corruption bug in the DHCP client.

- Lots of documentation updates.

- Add a feature allowing environment variables to be passed to the

  DHCP client script on the DHCP client command line.

- Fix client medium support, which had been broken for some time.

- Fix a bug in the DHCP client initial startup backoff interval, which

  would cause two DHCPDISCOVERS to be sent back-to-back on startup.

                Changes since 3.0 Beta 2 Patchlevel 15

- Some documentation tweaks.

- Maybe fix a problem in the DLPI code.

- Fix some error code space inconsistencies in ddns update code.

- Support relay agents that intercept unicast DHCP messages to stuff

  agent options into them.

- Fix a small memory leak in the relay agent option support code.

- Fix a core dump that would occur if a packet was sent with no


                Changes since 3.0 Beta 2 Patchlevel 14

- Finish fixing a long-standing bug in the agent options code.   This

  was causing core dumps and failing to operate correctly - in

  particular, agent option stashing wasn't working.   Agent option

  stashing should now be working, meaning that agent options can be

  used in class statements to control address allocation.

- Fix up documentation.

- Fix a couple of small memory leaks that would have added up

  significantly in a high-demand situation.

- Add a log-facility configuration parameter.

- Fix a compile error on some older operating systems.

- Add the ability in the client to execute certain statements before

  transmitting packets to the server.   Handy for debugging; not much

  practical use otherwise.

- Don't send faked-out giaddr when renewing or bound - again, useful

  for debugging.

                Changes since 3.0 Beta 2 Patchlevel 13

- Fixed a problem where the fqdn decoder would sometimes try to store

  an option with an (unsigned) negative length, resulting in a core

  dump on some systems.

- Work around the Win98 DHCP client, which NUL-terminates the FQDN


- Work around Win98 and Win2k clients that will claim they want to do

  the update even when they don't have any way to do it.

- Fix some log messages that can be printed when failover is operating

  that were not printing enough information.

- It was possible for a DHCPDISCOVER to get an allocation even when

  the state machine said the server shouldn't be responding.

- Don't load balance DHCPREQUESTs from clients in RENEWING and

  REBINDING, since in RENEWING, if we heard it, it's for us, and in

  REBINDING, the client wouldn't have got to REBINDING if its primary

  were answering.

- When we get a bogus state lease binding state transition, don't do

  the transition.

                Changes since 3.0 Beta 2 Patchlevel 12

- Fixed a couple of silly compile errors.

                Changes since 3.0 Beta 2 Patchlevel 11

- Albert Herranz tracked down and fixed a subtle bug in the base64

  decoder that would prevent any key with an 'x' in its base64

  representation from working correctly.

- Thanks to Chris Cheney and Michael Sanders, we have a fix for the

  hang that they both spotted in the DHCP server - when

  one-lease-per-client was set, the code to release the "other" lease

  could spin.

- Fix a problem with alignment of the input buffer in bpf in cases

  where two packets arrive in the same bpf read.

- Fix a problem where the relay agent would crash if you specified an

  interface name on the command line.

- Add the ability to conditionalize client behaviour based on the

  client state.

- Add support for the FQDN option, and added support for a new way of

  doing ddns updates (ddns update style interim) that allows more than

  one DHCP server to update the DNS for the same network(s).   This

  was implemented by Damien Neil with some additional functionality

  added by Ted Lemon.

- Damien added a "log" statement, so that the configuration file can

  be made to log debugging information and other information.

- Fixed a bug that caused option buffers not to be terminated with an

  end option.

- Fixed a long-standing bug in the support for option spaces where the

  options are stored as an ordered list rather than in a hash table,

  which could theoretically result in memory pool corruption.

- Prevent hardware declarations with no actual hardware address from

  being written as something unparsable, and behave correctly in the

  face of a null hardware address on input.

- Allow key names to be FQDNs, and qualify the algorithm name if it is

  specified unqualified.

- Modify the DDNS update code so that it never prints the "resolver

  failed" message, but instead says *why* the resolver failed.

- Officially support the subnet selection option, which now has an


- Fix a build bug on MacOS X.

- Allow administrator to disable ping checking.

- Clean up dhcpd.conf documentation and add more information about how

  it works.

                Changes since 3.0 Beta 2 Patchlevel 10

- Fix a bug introduced during debugging (!) and accidentally committed

  to CVS.

                Changes since 3.0 Beta 2 Patchlevel 9

- Fix DHCP client handling of vendor encapsulated options.

- Fix a bug in the handling of relay agent information options introduced

  in patchlevel 9.

- Stash agent options on client leases by default, and use the stashed

  options at renewal time.

- Add the ability to test the client's binding state in the client

  configuration language.

- Fix a core dump in the DNS update code.

- Fix some expression evaluation bugs that were causing updates to be

  done when no client hostname was received.

- Fix expression evaluation debugging printfs.

- Teach pretty_print_option to print options in option spaces other than

  the DHCP option space.

- Add a warning message if the RHS of a not is not boolean.

- Never select for more than a day, because some implementations of

  select will just fail if the timeout is too long (!).

- Fix a case where a DHCPDISCOVER from an unknown network would be

  silently dropped.

- Fix a bug where if a client requested an IP address for which a different

  client had the lease, the DHCP server would reallocate it anyway.

- Fix the DNS update code so that if the client changes its name, the DNS

  will be correctly updated.

                Changes since 3.0 Beta 2 Patchlevel 8

- Oops, there was another subtle math error in the header-length


                Changes since 3.0 Beta 2 Patchlevel 7

- Oops, forgot to byte-swap udp header length before bounds-checking it.

                Changes since 3.0 Beta 2 Patchlevel 6

- Fix a possible DoS attack where a client could cause the checksummer

  to dump core.   This was a read, not a write, so it shouldn't be

  possible to exploit it any further than that.

- Implement client- and server-side support for using the Client FQDN


- Support for other option spaces in the client has been added.   This

  means that it is now possible to define a vendor option space on the

  client, request options in that space from the server (which must

  define the same option space), and then use those options in the

  client.   This also allows NWIP and Client FQDN options to be used


- Add object initializer support.   This means that objects can now be

  initialized to something other than all-zeros when allocated, which

  makes, e.g., the interface object support code a little more robust.

- Fix an off-by-one bug in the host stuffer.   This was causing host

  deletes not the work, and may also have been causing OMAPI

  connections to get dropped.   Thanks to James Brister for tracking

  this one down!

- Fixed a core dump in the interface discovery code that is triggered

  when there is no subnet declaration for an interface, but the server

  decides to continue running.   Thanks to Shane Kerr for tracking

  down and fixing this problem.

                Changes since 3.0 Beta 2 Patchlevel 5

- Fix a bug in the recent enhancement to the interface discovery code

  to support arbitrary-length interface lists.

- Support NUL-terminated DHCP options when initializing client-script


- Fix suffix operator.

- Fix NetWare/IP option parsing.

- Better error/status checking in dhcpctl initialization and omapi

  connection code.

- Fix a potential memory smash in dhcpctl code.

- Fix SunOS4 and (maybe) Ultrix builds.

- Fix a bug where a certain sort of incoming packet could cause a core

  dump on Solaris (and probably elsewhere).

- Add some more safety checks in error logging code.

- Add support for ISC_R_INCOMPLETE in OMAPI protocol connection code.

- Fix relay agent so that if an interface is specified on the command

  line, the relay agent does not dump core.

- Fix class matching so that match if can be combined with match or

  spawn with.

- Do not allow spurious leases in the lease database to introduce

  potentially bogus leases into the in-memory database.

- Fix a byte-order problem in the client hardware address type code

  for OMAPI.

- Be slightly less picky about what sort of hardware addresses OMAPI

  can install in host declarations.

                Changes since 3.0 Beta 2 Patchlevel 4

- Incorporated Peter Marschall's proposed change to array/record

  parsing, which allows things like the slp-agent option to be encoded

  correctly.   Thanks very much to Peter for taking the initiative to

  do this, and for doing such a careful job of it (e.g., updating the


- Added an encoding for the slp-agent option.   :')

- Fixed SunOS 4 build.  Thanks to Robert Elz for responding to my

  request for help on this with patches!

- Incorporated a change that should fix a problem reported by Philippe

  Jumelle where when the network connection between two servers is

  lost, they never reconnect.

- Fix client script files other than that for NetBSD to actually use

  make_resolv_conf as documented in the manual page.

- Fix a bug in the packet handling code that could result in a core


- Fix a bug in the bootp code where responses on the local net would

  be sent to the wrong MAC address.   Thanks to Jerry Schave for

  catching this one.

                Changes since 3.0 Beta 2 Patchlevel 3

- In the DHCP client, execute client statements prior to using the values

  of options, so that the client configuration can overridden, e.g., the

  lease renewal time.

- Fix a reference counting error that would result in very reproducible

  failures in updates, as well as occasional core dumps, if a zone was

  declared without a key.

- Fix some Linux 2.0 compilation problems.

- Fix a bug in scope evaluation during execution of "on" statements that

  caused values not to be recorded on leases.

- If the dhcp-max-message-size option is specified in scope, and the

  client didn't send this option, use the one specified in scope to

  determine the maximum size of the response.

                Changes since 3.0 Beta 2 Patchlevel 2

- Fix a case where spawning subclasses were being allocated

  incorrectly, resulting in a core dump.

- Fix a case where the DHCP server might inappropriately NAK a

  RENEWING client.

- Fix a place dhcprequest() where static leases could leak.

- Include memory.h in omapip_p.h so that we don't get warnings about

  using memcmp().

                Changes since 3.0 Beta 2 Patchlevel 1

- Notice when SIOCFIGCONF returns more data than fit in the buffer -

  allocate a larger buffer, and retry.   Thanks to Greg Fausak for

  pointing this out.

- In the server, if no interfaces were configured, report an error and


- Don't ever record a state of 'startup'.

- Don't try to evaluate the local failover binding address if none was

  specified.   Thanks to Joseph Breu for finding this.