Internet Software Consortium DHCP Distribution
Release Candidate 12
Version 3 of the ISC DHCP Distribution includes the following features
that are new since version 2.0:
- DHCP Failover Protocol support
- OMAPI, an API for accessing and modifying the DHCP server and
- Conditional behaviour
- Storing arbitrary information on leases
- Address pools with access control
- Client classing
- Address allocation restriction by class
- Relay agent information option support
- Dynamic DNS updates
- Many bug fixes, performance enhancements, and minor new DHCP
This is a release candidate for a minor bug fix release to follow ISC
DHCP 3.0. The main bug fixed here is a bug in the subclass allocation
code that could result in a memory smash. Any users of the ISC DHCP server
who are using subclasses should seriously consider upgrading to 3.0.1
either now or when the final 3.0.1 release comes out.
If you are running 3.0 beta 1 and are doing dynamic DNS updates, the
lease file is no longer forward-compatible to 3.0 final. A script
has been provided to convert 3.0b1 lease files. This is in
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.
The Dynamic DNS Update support is a descendent of an implementation
done by Lans Carstensen and Brian Dols at Rose-Hulman Institute of
Technology, Jim Watt at Applied Biosystems, Irina Goble at Integrated
Measurement Systems, Igor Sharfmesser at Kazakh Telecom, and Brian
Murrell at BC Tel Advanced Communications. I'd like to express my
thanks to all of these good people here, both for working on the code
and for prodding me into improving it.
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.
- Delcaring 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
- 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
- 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
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
- Applied the remainder of the dhcpctl memory leak patch provided by Bill
Squier at ReefEdge, Inc. (email@example.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
- A few memory leaks were repaired thanks to patches from Bill Squier at
ReefEdge, Inc. (firstname.lastname@example.org).
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
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
- 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
- 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
- Add the missing 3.0 Beta 1 lease conversion script.
- Read dhcp client script hooks if they exist, rather than only if
Changes since 3.0 Release Candidate 1
- Fix a memory smash that happens when fixed-address leases are used.
ANY SITE AT WHICH FIXED-ADDRESS STATEMENTS ARE BEING USED SHOULD
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
- 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
- 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.
- 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/
DHCPREQUEST/DHCPACK/DHCPREQUEST/DHCPNAK sequence. This was the
result of a deceptively silly bug in supersede_lease.
- Fix client script exit status check, according to a fix supplied by
- 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
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
- When we get a bogus state lease binding state transition, don't do
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
- 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
- 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
- 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
- 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
Changes since 3.0 Beta 2 Patchlevel 10
- Fix a bug introduced during debugging (!) and accidentally committed
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
- 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
- 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
- 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
- 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
- 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 overried, 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
- Fix a place dhcprequest() where static leases could leak.
- Include memory.h in omapip_p.h so that we don't get warnings about
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.