Log Message:
Update isc-{dhclient4,dhcp4,dhcpd4,dhcrelay4} to 4.2.4.

ISC's Release Signing Key can be obtained at:

    http://www.isc.org/about/openpgp/

                        Changes since 4.2.4rc1

- 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]

                        Changes since 4.2.4b1

- None

                        Changes since 4.2.3

! 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.  Previoulsy 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]