CSUP(1)

NAME
csup - network distribution package for CVS repositories

SYNOPSIS
csup [-146aksvzZ] [-A addr] [-b base] [-c collDir] [-d delLimit] [-h host] [-i pattern] [-l lockfile] [-L verbosity] [-p port] [-r maxRetries] supfile

DESCRIPTION
csup is a software package for updating collections of files across a network. It is a rewrite of the CVSup software in C. This manual page describes the usage of the csup client program.

Unlike more traditional network distribution packages, such as rdist and sup, csup has specific optimizations for distributing CVS repositories. csup takes advantage of the properties of CVS repositories and the files they contain (in particular, RCS files), enabling it to perform updates much faster than traditional systems.

csup is a general-purpose network file updating package. It is extremely fast, even for collections of files which have nothing to do with CVS or RCS.

OPTIONS
The client program csup requires at least a single argument, supfile. It names a file describing one or more collections of files to be transferred and/or updated from the server. The supfile has a format similar to the corresponding file used by sup. In most cases, csup can use existing sup supfiles.

The following options are supported by csup:

-1  Disables automatic retries when transient failures occur. Without this option, a transient failure such as a dropped network connection causes csup to retry repeatedly, using randomized exponential backoff to space the retries. This option is equivalent to -r 0.

-4  Forces csup to use IPv4 addresses only.

-6  Forces csup to use IPv6 addresses only.

-a  Requires the server to authenticate itself (prove its identity) to the client. If authentication of the server fails, the update is canceled. See AUTHENTICATION, below.

-A addr
    Specifies a local address to bind to when connecting to the server. The local address might be a hostname or a numeric host address string consisting of a dotted decimal IPv4 address or an IPv6 address. This may be useful on hosts which have multiple IP addresses.

-b base
    Specifies the base directory under which csup will maintain its bookkeeping files, overriding any base specifications in the supfile.

-c collDir
    Specifies the subdirectory of base where the information about the collections is maintained. The default is sup.

-d delLimit
    Specifies the maximum number of files that may be deleted in a single update run. Any attempt to exceed the limit results in a fatal error. This can provide some protection against temporary configuration mistakes on the server. The default limit is infinity.

-h host
    Specifies the server host to contact, overriding any host specifications in the supfile.

-i pattern
    Causes csup to include only files and directories matching pattern in the update. If a directory matches the pattern, then the entire subtree rooted at the directory is included. If this option is specified multiple times, the patterns are combined using the ‘or’ operation. If no -i options are given, the default is to update all files in each collection.

    The pattern is a standard file name pattern. It is interpreted relative to the collection's prefix directory. Slash characters are matched only by explicit slashes in the pattern. Leading periods in file name are not treated specially.

-k  Causes csup to keep the temporary copies of any incorrectly edited files, in the event of checksum mismatches. This option is for debugging, to help determine why the files were edited incorrectly. Regardless of whether this option is specified, the permanent versions of faulty files are replaced with correct versions obtained by transferring the files in their entirety. Such transfers are called fixups.

-l lockfile
    Creates and locks the lockfile while the update is in progress. If lockfile is already locked, csup fails without performing automatic retries. This option is useful when csup is executed periodically from cron. It prevents a job from interfering with an earlier job that is perhaps taking extra long because of network problems.

    The process-ID is written to the lock file in text form when the lock is successfully acquired. Upon termination of the update, the lock file is removed.

-L verbosity
    Sets the verbosity level for output. A level of 0 causes csup to be completely silent unless errors occur. A level of 1 (the default) causes each updated file to be listed. A level of 2 provides more detailed information about the updates performed on each file. All messages are directed to the standard output.

-p port
    Sets the TCP port to which csup attempts to connect on the server host. The default port is 5999.

-r maxRetries
    Limits the number of automatic retries that will be attempted when transient errors such as lost network connections are encountered. By default, csup will retry indefinitely until an update is successfully completed. The retries are spaced using randomized exponential backoff. Note that -r 0 is equivalent to the -1 option.

-s  Suppresses the check of each client file's status against what is recorded in the list file. Instead, the list file is assumed to be accurate. This option greatly reduces the amount of disk activity and results in faster updates with less load on the client host. However it should only be used if client's files are never modified locally in any way. Mirror sites may find this option beneficial to reduce the disk load on their systems. For safety, even mirror sites should run csup occasionally (perhaps once a day) without the -s option.

    Without the -s option, csup performs a stat(2) call on each file and verifies that its attributes match those recorded in the list file. This ensures that any file changes made outside of csup are detected and corrected.

    If the -s option is used when one or more files have been modified locally, the results are undefined. Local file damage may remain uncorrected, updates may be missed, or csup may abort prematurely.

-v  Prints the version number and exits, without contacting the server.

-z  Enables compression for all collections, as if the compress keyword were added to every collection in the supfile.

-Z  Disables compression for all collections, as if the compress keyword were removed from every collection in the supfile.

The supfile is a text file which specifies the file collections to be updated. Comments begin with ‘#’ and extend to the end of the line. Lines that are empty except for comments and white space are ignored. Each remaining line begins with the name of a server-defined collection of files. Following the collection name on the line are zero or more keywords or keyword=value pairs.

Default settings may be specified in lines whose collection name is *default. Such defaults will apply to subsequent lines in the supfile. Multiple *default lines may be present. New values augment or override any defaults specified earlier in the supfile. Values specified explicitly for a collection override any default values.

The most commonly used keywords are:

release=releaseName
    This specifies the release of the files within a collection. Like collection names, release names are defined by the server configuration files. Usually there is only one release in each collection, but there may be any number. Collections which come from a CVS repository often use release=cvs by convention. Non-CVS collections conventionally use release=current.

base=base
    This specifies a directory under which csup will maintain its bookkeeping files, describing the state of each collection on the client machine. The base directory must already exist; csup will not create it. The default base directory is /usr/local/etc/cvsup.

prefix=prefix
    This is the directory under which updated files will be placed. By default, it is the same as base. If it is not an absolute pathname, it is interpreted relative to base. The prefix directory must already exist; csup will not create it.

    As a special case, if prefix is a symbolic link pointing to a nonexistent file named ‘SKIP’, then csup will skip the collection. The parameters associated with the collection are still checked for validity, but none of its files will be updated. This feature allows a site to use a standard supfile on several machines, yet control which collections get updated on a per-machine basis.

host=hostname
    This specifies the server machine from which all files will be taken. csup requires that all collections in a single run come from the same host. If you wish to update collections from several different hosts, you must run csup several times.

delete
    The presence of this keyword gives csup permission to delete files. If it is missing, no files will be deleted.

    The presence of the delete keyword puts csup into so-called exact mode. In exact mode, csup does its best to make the client's files correspond to those on the server. This includes deleting individual deltas and symbolic tags from RCS files, as well as deleting entire files. In exact mode, csup verifies every edited file with a checksum, to ensure that the edits have produced a file identical to the master copy on the server. If the checksum test fails for a file, then csup falls back upon transferring the entire file.

    In general, csup deletes only files which are known to the server. Extra files present in the client's tree are left alone, even in exact mode. More precisely, csup is willing to delete two classes of files:
    •   Files that were previously created or updated by csup itself.
    •   Checked-out versions of files which are marked as dead on the server.

use-rel-suffix
    Causes csup to append a suffix constructed from the release and tag to the name of each list file that it maintains. See THE LIST FILE for details.

compress
    This enables compression of all data sent across the network. Compression is quite effective, normally eliminating 65% to 75% of the bytes that would otherwise need to be transferred. However, it is costly in terms of CPU time on both the client and the server. On local area networks, compression is generally counter-productive; it actually slows down file updates. On links with speeds of 56K bits/second or less, compression is almost always beneficial. For network links with speeds between these two extremes, let experimentation be your guide.

    The -z command line option enables the compress keyword for all collections, regardless of what is specified in the supfile. Likewise, the -Z command line option disables the compress option for all collections. csup uses a looser checksum for RCS files, which ignores harmless differences in white space. Different versions of CVS and RCS produce a variety of differences in white space for the same RCS files. Thus the strict checksum can report spurious mismatches for files which are logically identical. This can lead to numerous unneeded “fixups”, and thus to slow updates.

umask=n
    Causes csup to use a umask value of n (an octal number) when updating the files in the collection. This option is ignored if preserve is specified.

Some additional, more specialized keywords are described below. Unrecognized keywords are silently ignored for backward compatibility with sup.

CVS MODE
CVSup supports two primary modes of operation. They are called CVS mode and checkout mode.

In CVS mode, the client receives copies of the actual RCS files making up the master CVS repository. CVS mode is the default mode of operation. It is appropriate when the user wishes to maintain a full copy of the CVS repository on the client machine.

CVS mode is also appropriate for file collections which are not based upon a CVS repository. The files are simply transferred verbatim, without interpretation.

CHECKOUT MODE
In checkout mode, the client receives specific revisions of files, checked out directly from the server's CVS repository. Checkout mode allows the client to receive any version from the repository, without requiring any extra disk space on the server for storing multiple versions in checked-out form. Checkout mode provides much flexibility beyond that basic functionality, however. The client can specify any CVS symbolic tag, or any date, or both, and csup will provide the corresponding checked-out versions of the files in the repository.

Checkout mode is selected on a per-collection basis, by the presence of one or both of the following keywords in the supfile:

tag=tagname
    This specifies a symbolic tag that should be used to select the revisions that are checked out from the CVS repository. The tag may refer to either a branch or a specific revision. It must be symbolic; numeric revision numbers are not supported.

    For the FreeBSD source repository, the most commonly used tags will be:

    RELENG_6
        The ‘stable’ branch.

    .   The main branch (the ‘current’ release). This is the default, if only the date keyword is given.

date=
    [cc] yy.mm.dd.hh.mm.ss This specifies a date that should be used to select the revisions that are checked out from the CVS repository. The client will receive the revisions that were in effect at the specified date and time.

    At present, the date format is inflexible. All 17 or 19 characters must be specified, exactly as shown. For the years 2000 and beyond, specify the century cc. For earlier years, specify only the last two digits yy. Dates and times are considered to be GMT. The default date is ‘’., which means “as late as possible”.

To enable checkout mode, you must specify at least one of these keywords. If both are missing, csup defaults to CVS mode.

If both a branch tag and a date are specified, then the revisions on the given branch, as of the given date, will be checked out. It is permitted, but not particularly useful, to specify a date with a specific release tag.

In checkout mode, the tag and/or date may be changed between updates. For example, suppose that a collection has been transferred using the specification ‘tag=.’. The user could later change the specification to ‘tag=RELENG_3’. This would cause csup to edit the checked-out files in such a way as to transform them from the ‘current’ versions to the ‘stable’ versions. In general, csup is willing to transform any tag/date combination into any other tag/date combination, by applying the intervening RCS deltas to the existing files.

When transforming a collection of checked-out files from one tag to another, it is important to specify the list keyword in the supfile, to ensure that the same list file is used both before and after the transformation. The list file is described in THE LIST FILE, below.

THE LIST FILE
For efficiency, csup maintains a bookkeeping file for each collection, called the list file. The list file contains information about which files and revisions the client currently possesses. It also contains information used for verifying that the list file is consistent with the actual files in the client's tree.

The list file is not strictly necessary. If it is deleted, or becomes inconsistent with the actual client files, csup falls back upon a less efficient method of identifying the client's files and performing its updates. Depending on csup's mode of operation, the fallback method employs time stamps, checksums, or analysis of RCS files.

Because the list file is not essential, csup is able to “adopt” an existing file tree acquired by FTP or from a CD-ROM. csup identifies the client's versions of the files, updates them as necessary, and creates a list file for future use. Adopting a foreign file tree is not as fast as performing a normal update. It also produces a heavier load on the server.

The list file is stored in a collection-specific directory; see FILES for details. Its name always begins with ‘checkouts’. If the keyword use-rel-suffix is specified in the supfile, a suffix, formed from the release and tag, is appended to the name. The default suffix can be overridden by specifying an explicit suffix in the supfile:

list=suffix
    This specifies a suffix for the name of the list file. A leading dot is provided automatically. For example, ‘list=stable’ would produce a list file named checkouts.stable, regardless of the release, tag, or use-rel-suffix keyword.

REFUSE FILES
The user can specify sets of files that he does not wish to receive. The files are specified as file name patterns in so-called refuse files. The patterns are separated by whitespace, and multiple patterns are permitted on each line. Files and directories matching the patterns are neither updated nor deleted; they are simply ignored.

There is currently no provision for comments in refuse files.

The patterns are similar to those of sh(1), except that there is no special treatment for slashes or for filenames that begin with a period. For example, the pattern ‘*.c’ will match any file name ending with ‘.c’ including those in subdirectories, such as ‘foo/bar/lam.c’. All patterns are interpreted relative to the collection's prefix directory.

If the files are coming from a CVS repository, as is usually the case, then they will be RCS files. These have a ‘,v’ suffix which must be taken into account in the patterns. For example, the FreeBSD documentation files are in a sub-directory of base called ‘doc’. If ‘Makefile’ from that directory is not required then the line

doc/Makefile

will not work because the file on the server is called ‘Makefile,v’. A better solution would be

doc/Makefile*

which will match whether ‘Makefile’ is an RCS file or not.

As another example, to receive the FreeBSD documentation files without the Japanese, Russian, and Chinese translations, create a refuse file containing the following lines:

doc/ja*
doc/ru*
doc/zh*

As many as three refuse files are examined for each supfile line. There can be a global refuse file named base/collDir/refuse which applies to all collections and releases. There can be a per-collection refuse file named base/collDir/collection /refuse which applies to a specific collection. Finally, there can be a per-release and tag refuse file which applies only to a given release/tag combination within a collection. The name of the latter is formed by suffixing the name of the per-collection refuse file in the same manner as described above for the list file. None of the refuse files are required to exist.

csup has a built-in default value of /usr/local/etc/cvsup for base and sup for collDir but it is possible to override both of these. The value of base can be changed using the -b option or a base=pathname entry in the supfile. (If both are used the -b option will override the supfile entry.) The value of collDir can only be changed with the -c option; there is no supfile command to change it.

As an example, suppose that the base and collDir both have their default values, and that the collection and release are ‘src-all’ and ‘cvs’, respectively. Assume further that checkout mode is being used with ‘tag=RELENG_3’. The three possible refuse files would then be named:

/usr/local/etc/cvsup/sup/refuse
/usr/local/etc/cvsup/sup/src-all/refuse
/usr/local/etc/cvsup/sup/src-all/refuse.cvs:RELENG_3

If the supfile includes the command base=/foo the refuse files would be:

/foo/sup/refuse
/foo/sup/src-all/refuse
/foo/sup/src-all/refuse.cvs:RELENG_3

If -b /bar is used (even with base=/foo in the supfile):

/bar/sup/refuse
/bar/sup/src-all/refuse
/bar/sup/src-all/refuse.cvs:RELENG_3

and with -c stool as well:

/bar/stool/refuse
/bar/stool/src-all/refuse
/bar/stool/src-all/refuse.cvs:RELENG_3

AUTHENTICATION
csup implements an optional authentication mechanism which can be used by the client and server to verify each other's identities. Public CVSup servers normally do not enable authentication. csup users may ignore this section unless they have been informed that authentication is required by the administrator of their server.

The authentication subsystem 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.

The file $HOME/.csup/auth holds the information used for authentication. This file contains a record for each server that the client is allowed to access. Each record occupies one line in the file. Lines beginning with ‘#’ are ignored, as are lines containing only white space. White space is significant everywhere else in the file. Fields are separated by ‘’: characters.

Each record of the file has the following form:

    serverName:clientName:
    password:comment

All fields must be present even if some of them are empty. ServerName is the name of the server to which the record applies. By convention, it is the canonical fully-qualified domain name of the server, e.g., ‘CVSup177.FreeBSD.ORG’. This must agree with the server's own idea of its name. The name is case-insensitive.

ClientName is the name the client uses to gain access to the server. By convention, e-mail addresses are used for all client names, e.g., ‘BillyJoe@FreeBSD.org’. Client names are case-insensitive.

Password is a secret string of characters that the client uses to prove its identity. It may not contain any ‘’: or newline characters.

Comment may contain any additional information to identify the record. It is not interpreted by the program.

To set up authentication for a given server, one must perform the following steps:

1.  Obtain the official serverName from the administrator of the server or from some other source.

2.  Choose an appropriate clientName. It should be in the form of a valid e-mail address, to make it easy for the server administrator to contact the user if necessary.

3.  Choose an arbitrary secret password.

4.  Run the cpasswd utility, and type in the password when prompted for it. The utility will print out a line to send to the server administrator, and instruct you how to modify your $HOME/.csup/auth file. You should use a secure channel to send the line to the server administrator.

Since $HOME/.csup/auth contains passwords, you should ensure that it is not readable by anyone except yourself.

Authentication works independently in both directions. The server administrator controls whether you must prove your identity. You control whether to check the server's identity, by means of the -a command line option.

csup AND FIREWALLS
In its default mode, csup will work through any firewall which permits outbound connections to port 5999 of the server host.

USING csup WITH SOCKS
csup can be used through a SOCKS proxy server with the tsocks command. The csup executable needs to be dynamically-linked with the system libraries for tsocks to work properly.

USING ssh PORT FORWARDING
As an alternative to SOCKS, a user behind a firewall can penetrate it with the TCP port forwarding provided by the Secure Shell package ssh. The user must have a login account on the CVSup server host in order to do this. The procedure is as follows:

1.  Establish a connection to the server host with ssh, like this:

        ssh -f -x -L 5999:localhost:5999 serverhost sleep 60

    Replace serverhost with the hostname of the CVSup server, but type ‘localhost’ literally. This sets up the required port forwarding. You must start csup before the 60-second sleep finishes. Once the update has begun, ssh will keep the forwarded channels open as long as they are needed.

2.  Run csup on the local host, including the arguments ‘-h localhost’ on the command line.

FILES
/usr/local/etc/cvsup
    Default base directory.
sup Default collDir subdirectory.
base/collDir/collection
    /checkouts* List files.

SEE ALSO
cpasswd(1), cvs(1), rcsintro(1), ssh(1).

AUTHORS
-nosplit Maxime Henrion <mux@FreeBSD.org> is the author of csup, the rewrite of CVSup in C. John Polstra <jdp@polstra.com> is the author of CVSup.

LEGALITIES
CVSup is a registered trademark of John D. Polstra.

csup is released under a 2-clauses BSD license.

BUGS
An RCS file is not recognized as such unless its name ends with ‘,v’.

Any directory named ‘Attic’ is assumed to be a CVS Attic, and is treated specially.