Announcing CVSup 16.0
---------------------
Release 16.0 of CVSup, the CVS-aware network file distribution
system, is now available.
What Has Changed Since the Previous Release?
--------------------------------------------
Changes marked with "(*)" were also included in release 15.5, a
Linux portability release that saw only limited distribution.
Implemented strong authentication to control access to the server
when desired. It uses a challenge-response protocol which is immune
to packet sniffing and replay attacks. No passwords are sent over
the network in either direction. Both the client and the server
can independently verify the identities of each other. A new
"-a" option on the client allows it to force the server to prove
its identity. There is a new "cvpasswd" utility which is used
for creating scrambled passwords for the server's authentication
database.
Added a new "-s" client option to greatly reduce the client's
disk
load, at significant cost in safety. The option suppresses the
usual stat(2) calls that check the status of each file against what
is recorded in the list (checkouts) file. It makes updates run
quite a bit faster, but it is not safe if there is any possibility
that the client's files might be modified locally in between CVSup
updates. See the caveats in cvsup(1) for more details. (*)
Extended the update algorithm for RCS files to handle arbitrary
"newphrases" attached to deltas. (See rcsfile(5) if you don't
know what "newphrases" means.) Newer versions of CVS use them
when the "PreservePermissions" feature is turned on. This caused
previous versions of CVSup to get checksum mismatches and perform
time-consuming fixups. Note, checkout mode doesn't actually honor
these newphrases yet; but CVS mode mirrors them properly now.
Added a "umask=nnn" option in cvsupfiles to specify the umask to
use when updating a collection. It can be different for each
collection if desired.
Made CVSup preserve file permissions more strictly. It used to
ignore the mode bits masked off by the umask. That was wrong. Now
it enforces (client mode) == ((server mode) & ~(client umask))
exactly. As a result, you may see a few zillion "SetAttrs" messages
the first time you update using this version of CVSup. This is
nothing to be alarmed about. Note: if "preserve" is in your
cvsupfile, the effective umask is forced to 0. That causes the
client's file permissions to be set exactly equal to those on the
server.
Added a new "-D" client option to skip all updates except file
deletions. This is useful if the client's disk space is very
limited. You can make one run with "-D" to free up as much space
as possible. Then make another run without "-D" to update the
remaining files. If files or directories have been renamed on
the server, this ensures that all of the old versions are deleted
before any of the new ones are created. NOTE: This option is not
implemented yet for checkout mode. (*)
Fixed a signal race in the server. Under extremely rare conditions,
the race caused the master server to hang in an infinite loop. (*)
Fixed the client so that it no longer dies if it fails to delete a
directory. The usual cause is that the user has put an extraneous
file in the directory, making it non-empty even though CVSup thinks
it should be empty. Now the client issues a warning but continues
on. (*)
Fixed a bug that caused the client to loop if a collection contained
a top-level directory with a one-character name.
Fixed a bug that could cause the client to die if its version of an
RCS file was in fact completely unrelated to the one on the server
even though they had the same name. Now that situation is detected,
and CVSup simply replaces the file wholesale rather than attempting
to edit it.
Fixed the client to clean up better if it is killed by a signal.
Added Joseph Koshy's "cvsupchk" script, which finds extra
unwanted
files that may be littering your source tree. Look for it in the
new "contrib" subdirectory of the release.
Added Wolfram Schneider's "cvsup2httplog" script. It converts a
cvsupd log file to standard httpd log file format, so that it can
be analyzed by tools such as webalizer. You'll find it in the new
"contrib" subdirectory.
Added a "cvsupwho" script, inspired by Garrett Wollman, to list the
currently active clients of a CVSup server. Look for it in the new
"contrib" subdirectory.
Changed the default connection mode to multiplexed, since it can
handle all situations that the other modes can handle. Deprecated
active mode, passive mode, and SOCKS mode.
Added a setsockopt(... SO_REUSEADDR ...) call in the server just
before the point where it tries to bind the listen socket on
start-up. This allows the server to be re-started immediately after
you have killed it, even if some of the old connections are still
lingering. Formerly, a "Port in use" error would be reported, and
you would have no choice but to wait until the old connections timed
out.
Added network I/O statistics to the server's final log message
for each client. Also added logging of I/O statistics on a
per-collection basis. The per-collection messages are at "info"
priority, while the others are at "notice" level.
Made some portability fixes for Linux and Digital Unix. The
software now builds and runs whether using SRC Modula-3 or the newer
PM3 release.
Added pre-formatted manual pages to the source distribution. They
are named "*.cat".
Where to Get CVSup
------------------
CVSup is free software. It is available from:
ftp://ftp.FreeBSD.org/pub/FreeBSD/development/CVSup/
and from all of the many FreeBSD FTP mirrors. You can find a complete
list of them in the FreeBSD Handbook at:
http://www.freebsd.org/handbook/mirrors.html
CVSup is also available from the author's FTP server:
ftp://ftp.polstra.com/pub/FreeBSD/CVSup/
Please avoid this server if possible. It has a wimpy link to the
Internet.
Full sources as well as FreeBSD binaries are available:
cvsup-bin-16.0.tar.gz FreeBSD static binaries for the client
(includes GUI)
cvsup.nogui-bin-16.0.tar.gz FreeBSD static binaries for the client
(no GUI)
cvsupd-bin-16.0.tar.gz FreeBSD static binaries for the server
cvsup-16.0.tar.gz Sources **
The MD5 file signatures for these files are:
MD5 (cvsup-bin-16.0.tar.gz) = 57c25981d3c1d82a79b9ae18aaea715b
MD5 (cvsup.nogui-bin-16.0.tar.gz) = 02497824fb097c6fe01424106b073f89
MD5 (cvsupd-bin-16.0.tar.gz) = c03347b4c0dbfc2a911cc1b5a045c3bb
MD5 (cvsup-16.0.tar.gz) = bad884ccbd4ed129d360487c87c089a4
Binaries for other platforms are also available. See the CVSup FAQ
for their locations:
http://www.polstra.com/projects/freeware/CVSup/
An updated port will appear soon in the "net" category of the FreeBSD
ports and packages collection:
http://www.freebsd.org/ports/
If you want SOCKS support, you must also install the "modula-3-socks"
port or package. You'll find it in the "lang" category of the
FreeBSD
ports and packages collection at the URL above. SOCKS is supported
only under FreeBSD, and only with dynamically linked executables. The
static binary distributions do not support SOCKS.
** If you wish to build CVSup from the sources, be sure to read the
discussion further on in this announcement.
Compatibility with Previous Releases
------------------------------------
This version is believed to interoperate properly with all earlier
public releases of CVSup.
What Is CVSup?
--------------
CVSup is a software package for distributing and updating collections
of files across a network. It can efficiently and accurately
mirror all types of Unix files, including sources, binaries, hard
links, symbolic links, and even device nodes. CVSup's streaming
communication protocol and multithreaded architecture make it most
likely the fastest mirroring tool in existence today.
In addition to being a great general-purpose mirroring tool, CVSup
includes special features and optimizations specifically tailored to
CVS repositories. By taking advantage of the special properties of
the files contained in CVS repositories, CVSup is able to perform
updates much faster than traditional systems. CVSup parses and
understands the RCS files making up a CVS repository. When updates
occur, CVSup extracts new deltas directly from the RCS files on the
server and edits them into the client's RCS files. Likewise, CVSup
notes the addition of new symbolic tags to the files on the server and
sends only the new tags to the client.
CVSup is able to merge new deltas and tags from the server with deltas
and tags added locally on the client machine. This makes it possible
for the client to check local modifications into his repository
without their being obliterated by subsequent updates from the server.
In addition to distributing the RCS files themselves, CVSup is able to
distribute specific checked-out versions. The client can specify a
symbolic tag, a date, or both and CVSup will extract the appropriate
versions from the server's CVS repository. Checked-out versions do
not need to be stored on the server, since CVSup can extract any
version directly from the CVS repository. If the client has an
existing checked-out tree, CVSup will apply the appropriate edits to
update the tree or transform it into the requested version. Only the
differences between the existing version and the desired version are
sent across the network.
To update non-RCS files, CVSup uses the highly efficient rsync
algorithm, developed by Andrew Tridgell and Paul Mackerras.
CVSup uses lightweight processes (threads) to implement a streaming
protocol across the network. This completely eliminates the delays
associated with the lock-step, request-reply form of communication
used by many existing protocols, such as sup and NNTP. Information
is transferred at the full available speed of the network in both
directions at once. Network latency and server response delays
are rendered practically irrelevant.
CVSup uses the "zlib" compression package to optionally compress all
communications. This provides an additional 65-75% compression, on
top of the diff-based compression already built into CVSup.
For efficiency, all processing is built into the CVSup package
itself. Neither the client nor the server execute any other
programs.
For further information about how CVSup works, see the (somewhat out
of date) "Blurb" document in the CVSup distribution.
Using CVSup to Maintain FreeBSD Sources
---------------------------------------
CVSup servers for the FreeBSD sources are currently running at about
35 mirror sites around the world. For an up-to-date list of them,
see:
http://www.freebsd.org/handbook/mirrors-cvsup.html
Using CVSup, you can easily receive or update any of the standard
FreeBSD source releases, namely, "cvs", "current", and
"stable".
The manual page for cvsup(1) describes how to do that. For more detailed
instructions, see the section on CVSup in the FreeBSD Handbook:
http://www.FreeBSD.org/handbook/cvsup.html
Building CVSup from the Sources
-------------------------------
CVSup is written in Modula-3, a modern, compiled, object-oriented
language. Modula-3 integrates threads, exceptions, and garbage
collection, providing an ideal vehicle for this sort of application.
Without Modula-3, CVSup would almost certainly not exist today.
If you wish to build CVSup from the sources, you will first need
to install the free Modula-3 compiler and runtime libraries. This
release of CVSup has been tested using both SRC Modula-3 release 3.6
and the PM3-1.1.9 release. They are available from the following
locations:
SRC: http://www.research.digital.com/SRC/modula-3/html/srcm3.html
PM3: http://m3.polymtl.ca/m3/
The PM3 release is more actively maintained, and it includes fixes for
a number of bugs that are present in SRC Modula-3. Patches to fix the
bugs are available from the SRC web site, but they must be applied
manually. The PM3 release is available as Linux RPMs as well as in
source form.
A FreeBSD port of SRC Modula-3 (including the necessary patches)
is available in the FreeBSD ports collection, in "lang/modula-3".
The corresponding package is, of course, available in the packages
collection.
You will also need version 1.0.4 or later of the "zlib" library.
In FreeBSD-2.1.6 and later releases, this library has been incorporated
into the system sources, in "src/lib/libz". Prior to that, a
FreeBSD port was available in "devel/libz" of the FreeBSD ports
collection. For other sources of this library, see the "Install"
file. Do not try to use versions earlier than 1.0.4.
To build the entire system from source under FreeBSD, simply type
"make" in the top-level directory. (That's the directory that has
sub-directories named "client" and "server", among others.)
To force
the executables to be statically linked, add
M3FLAGS=-DSTATIC
to the command line. To build the client without the GUI (e.g., if
you don't have the X Window System installed on your machine), add
M3FLAGS=-DNOGUI
To do both of these things, use quotes like this:
M3FLAGS="-DSTATIC -DNOGUI"
The Makefiles should work on any reasonable Unix system. If you
have trouble with them, it is easy to build the components manually.
Simply chdir into each of the following subdirectories in the given
order and type "m3build":
suptcp
suplib
client
server
cvpasswd
To build statically linked executables, add "-DSTATIC" to each
"m3build" command. To build the client without the GUI, add
"-DNOGUI".
Notes for Specific Platforms
----------------------------
The following hints have been found to work. They don't exclude other
possibilities, of course.
FreeBSD:
Use the SRC compiler from the FreeBSD ports collection.
Linux:
Use the PM3 RPMs (version 1.1.9 or later).
Solaris:
Use the SRC compiler (the "SOLgnu" target). Be sure to apply these
patches first:
http://www.research.digital.com/SRC/modula-3/html/patches36.html#sol2exec
http://www.research.digital.com/SRC/modula-3/html/patches36.html#libaio
Digital Unix:
Use the SRC compiler (the "ALPHA_OSF" target). Be sure to apply
this patch first:
http://www.research.digital.com/SRC/modula-3/html/patches36.html#randomReal64
When you run cvsup or cvsupd, you must add the argument
"@M3nopreemption" to the command line.
NetBSD, OpenBSD, BSD/OS:
Use the FreeBSD static binaries. When you run cvsup or cvsupd,
you must add the argument "@M3novm" to the command line.
Portability Issues
------------------
I intend for CVSup to be portable to most POSIX systems. Earlier
releases have been run on a number of different platforms, including
FreeBSD, Linux, HP-UX, SunOS, Solaris, and DEC OSF/1 ALPHA. In the
current release I have attempted to increase rather than decrease
portability.
Anybody who succeeds in porting CVSup to other systems is encouraged
to send his changes to <cvsup-bugs@polstra.com>. As long as the
changes are reasonably palatable, they will be incorporated into
future CVSup releases.
CVSup uses several POSIX-specific functions which may make it more
of an effort to port the package to non-POSIX systems such as Win32.
These functions include mmap, fork, syslog, stat, and chmod, among
others.
Status of this Release
----------------------
CVSup was first released publicly in August of 1996. Since then
it has seen heavy use, and it has been quite stable. Like all
software, though, it is not perfect. Please be prepared to find
bugs -- without a doubt, there are some.
Problems?
---------
Please report bugs to <cvsup-bugs@polstra.com>.
For More Information
--------------------
http://www.polstra.com/projects/freeware/CVSup/
John Polstra, <jdp@polstra.com>
Copyright 1996, 1997, 1998, 1999 John D. Polstra
$Id: Announce,v 1.46 1999/02/10 01:15:56 jdp Exp $
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