[Click] Click-1.2.4 released

[Eddie Kohler]

Hi all,

We are pleased to announce the release of Click version 1.2.4, which
includes several bugfixes and enhancements. The relevant portion of the
NEWS file is below. There were a couple important source code changes in
this release; if you write your own elements, please read the NEWS.

Download Click and browse related documentation at

http://www.pdos.lcs.mit.edu/click/

Thanks!
Eddie


Version 1.2.4   21.May.2002

* Drivers

** FreeBSD module updates from Luigi Rizzo.

** The Linux kernel module can support its own /proc-like file system,
   "clickfs". This file system is faster and takes less memory than the
   default /proc/click filesystem, and it is not subject to arbitrary
   limits on the number of files. Generally you will mount it under /click.
   (Click-install takes care of file system mounting and unmounting.) Give
   ./configure the --enable-clickfs option to enable clickfs (and disable
   /proc/click). Currently, clickfs only works under Linux 2.2. In the next
   release, it will also work under Linux 2.4, and --enable-clickfs will be
   the default.

** Fix several race conditions in the Linux kernel module.

** The user-level driver works on Solaris. Thanks to David Scott Page
   <page at cs.utexas.edu> for patches and suggestions.

* Elements

** Add notifier support. The NotifierQueue element acts like a Queue, but
   can reschedule downstream Tasks when packets arrive on a previously
   empty Queue. This can greatly reduce CPU usage. Several other elements
   listen for notification, including DelayUnqueue, Discard, and ToDevice.

** Rename FromLinux, ToLinux, and ToLinuxSniffers to FromHost, ToHost, and
   ToHostSniffers. The old names are still available.

** Classifier optimization algorithm changed. The new algorithm, based on
   dominators, is much faster for medium-to-large Classifiers.

** Add FromDAGDump element in the analysis package. This element reads DAG
   dumps (see http://dag.cs.waikato.ac.nz/).

** Add LinearIPLookup element, a version of StaticIPLookup that supports
   dynamically adding and removing routes.

** Add SortedIPLookup element, a version of LinearIPLookup that sorts its
   routes.

** Bug fixes and enhancements in AddressInfo, CheckIPHeader, DelayUnqueue,
   DriverManager, Linux FromDevice, FromDump, FromIPSummaryDump,
   FrontDropQueue, Grid elements, ICMPPingResponder, ICMPSendPings,
   IPAddrRewriter, IPFragmenter, IPPrint, IPReassembler, IPRewriter,
   IPRouteTable, RadixIPLookup, TCPRewriter, TimeFilter, ToIPSummaryDump,
   etc.

** Add RandomSwitch element.

** Add preliminary elements that support regression testing, in
   elements/test.

* Tools

** Add click-pretty tool, which pretty-prints Click configuration files as
   HTML.

** Click-install works for the FreeBSD kernel module.

** Click-install exits with nonzero exit status if the configuration could
   not be initialized.

* Internals

** The signatures for the `Element::configure()' and
   `Element::live_reconfigure()' methods have changed. Formerly, these
   methods took a `const Vector<String> &conf'. Now, they take a
   `Vector<String> &conf', and the methods may alter the `conf' argument
   however they'd like. The old signatures still work for backward
   compatibility, but they are deprecated, and will be removed in a future
   release.

** Deprecated `Element::uninitialize()' in favor of a new method,
   `Element::cleanup(CleanupStage stage)'. The `stage' argument, an
   enumerated value, says how far the element was initialized: not at all
   (CLEANUP_NO_ROUTER), configure() failed (CLEANUP_CONFIGURE_FAILED),
   configure() succeeded but initialize() was not called
   (CLEANUP_CONFIGURED), initialize() failed (CLEANUP_INITIALIZE_FAILED),
   initialize() succeeded but the router as a whole failed
   (CLEANUP_INITIALIZED), and the router initialized successfully,
   including this element (CLEANUP_ROUTER_INITIALIZED). So `uninitialize()'
   corresponded to `stage >= CLEANUP_INITIALIZED'.
   `Element::uninitialize()' works for now, but it will be removed in a
   future release.

** The signature for the `Element::configuration()' method has also changed.
   It no longer takes a `bool *' argument.

** Add cp_va_parse_remove_keywords() function, which removes keywords from
   an argument list.

** Moved network-header-structure #include files to include/clicknet. For
   instance, `#include <click/click_ip.h>' should now be written `#include
   <clicknet/ip.h>'. The old names still work, but will be removed in a
   future release.

** Renamed `IPAddress::mask_more_specific()' method to
   `IPAddress::mask_as_specific()', to emphasize that it allows equality.

** Changed click_ip6 header structure.

** Tools substantially rewritten. The tool library is now much easier to
   deal with, so tools should be easier to write, debug, and understand.

** Better handling of out-of-memory events.

** Improved `Packet::uniqueify()' implementation: it now copies only the
   packet data, not both header and data.

** Click identifiers can no longer end with a slash.

* Acknowledgements

** Thanks to the usual suspects (AUTHORS), and to David Scott Page
   <page at cs.utexas.edu>, Luigi Rizzo <rizzo at aciri.org>, Eric Freudenthal
   <eric.freudenthal at nyu.edu> and Tao Zhao <taozhao at cs.nyu.edu>, and Jose
   Vasconcellos <jvasco at bellatlantic.net>.