ProxyServer(3)

NAME

       DBI::ProxyServer - a server for the DBD::Proxy driver

SYNOPSIS

           use DBI::ProxyServer;
           DBI::ProxyServer::main(@ARGV);

DESCRIPTION

       DBI::Proxy Server is a module for implementing a proxy for the DBI
       proxy driver, DBD::Proxy. It allows access to databases over the net-
       work if the DBMS does not offer networked operations. But the proxy
       server might be usefull for you, even if you have a DBMS with inte-
       grated network functionality: It can be used as a DBI proxy in a fire-
       walled environment.

       DBI::ProxyServer runs as a daemon on the machine with the DBMS or on
       the firewall. The client connects to the agent using the DBI driver
       DBD::Proxy, thus in the exactly same way than using DBD::mysql,
       DBD::mSQL or any other DBI driver.

       The agent is implemented as a RPC::PlServer application. Thus you have
       access to all the possibilities of this module, in particular encryp-
       tion and a similar configuration file. DBI::ProxyServer adds the possi-
       bility of query restrictions: You can define a set of queries that a
       client may execute and restrict access to those. (Requires a DBI driver
       that supports parameter binding.) See "CONFIGURATION FILE".

       The provided driver script, dbiproxy(1), may either be used as it is or
       used as the basis for a local version modified to meet your needs.

OPTIONS

       When calling the DBI::ProxyServer::main() function, you supply an array
       of options. (@ARGV, the array of command line options is used, if you
       don't.) These options are parsed by the Getopt::Long module.  The Prox-
       yServer inherits all of RPC::PlServer's and hence Net::Daemon's options
       and option handling, in particular the ability to read options from
       either the command line or a config file. See RPC::PlServer(3). See
       Net::Daemon(3). Available options include

       chroot (--chroot=dir)
           (UNIX only)  After doing a bind(), change root directory to the
           given directory by doing a chroot(). This is usefull for security,
           but it restricts the environment a lot. For example, you need to
           load DBI drivers in the config file or you have to create hard
           links to Unix sockets, if your drivers are using them. For example,
           with MySQL, a config file might contain the following lines:

               my $rootdir = '/var/dbiproxy';
               my $unixsockdir = '/tmp';
               my $unixsockfile = 'mysql.sock';
               foreach $dir ($rootdir, "$rootdir$unixsockdir") {
                   mkdir 0755, $dir;
               }
               link("$unixsockdir/$unixsockfile",
                    "$rootdir$unixsockdir/$unixsockfile");
               require DBD::mysql;

               {
                   'chroot' => $rootdir,
                   ...
               }

           If you don't know chroot(), think of an FTP server where you can
           see a certain directory tree only after logging in. See also the
           --group and --user options.

       clients
           An array ref with a list of clients. Clients are hash refs, the
           attributes accept (0 for denying access and 1 for permitting) and
           mask, a Perl regular expression for the clients IP number or its
           host name. See "Access control" below.

       configfile (--configfile=file)
           Config files are assumed to return a single hash ref that overrides
           the arguments of the new method. However, command line arguments in
           turn take precedence over the config file. See the "CONFIGURATION
           FILE" section below for details on the config file.

       debug (--debug)
           Turn debugging mode on. Mainly this asserts that logging messages
           of level "debug" are created.

       facility (--facility=mode)
           (UNIX only) Facility to use for "Sys::Syslog (3)". The default is
           daemon.

       group (--group=gid)
           After doing a bind(), change the real and effective GID to the
           given.  This is usefull, if you want your server to bind to a priv-
           ileged port (<1024), but don't want the server to execute as root.
           See also the --user option.

           GID's can be passed as group names or numeric values.

       localaddr (--localaddr=ip)
           By default a daemon is listening to any IP number that a machine
           has. This attribute allows to restrict the server to the given IP
           number.

       localport (--localport=port)
           This attribute sets the port on which the daemon is listening. It
           must be given somehow, as there's no default.

       logfile (--logfile=file)
           Be default logging messages will be written to the syslog (Unix) or
           to the event log (Windows NT). On other operating systems you need
           to specify a log file. The special value "STDERR" forces logging to
           stderr. See Net::Daemon::Log(3) for details.

       mode (--mode=modename)
           The server can run in three different modes, depending on the envi-
           ronment.

           If you are running Perl 5.005 and did compile it for threads, then
           the server will create a new thread for each connection. The thread
           will execute the server's Run() method and then terminate. This
           mode is the default, you can force it with "--mode=threads".

           If threads are not available, but you have a working fork(), then
           the server will behave similar by creating a new process for each
           connection.  This mode will be used automatically in the absence of
           threads or if you use the "--mode=fork" option.

           Finally there's a single-connection mode: If the server has
           accepted a connection, he will enter the Run() method. No other
           connections are accepted until the Run() method returns (if the
           client disconnects).  This operation mode is usefull if you have
           neither threads nor fork(), for example on the Macintosh. For
           debugging purposes you can force this mode with "--mode=single".

       pidfile (--pidfile=file)
           (UNIX only) If this option is present, a PID file will be created
           at the given location.

       user (--user=uid)
           After doing a bind(), change the real and effective UID to the
           given.  This is usefull, if you want your server to bind to a priv-
           ileged port (<1024), but don't want the server to execute as root.
           See also the --group and the --chroot options.

           UID's can be passed as group names or numeric values.

       version (--version)
           Supresses startup of the server; instead the version string will be
           printed and the program exits immediately.

CONFIGURATION FILE

       The configuration file is just that of RPC::PlServer or Net::Daemon
       with some additional attributes in the client list.

       The config file is a Perl script. At the top of the file you may
       include arbitraty Perl source, for example load drivers at the start
       (usefull to enhance performance), prepare a chroot environment and so
       on.

       The important thing is that you finally return a hash ref of option
       name/value pairs. The possible options are listed above.

       All possibilities of Net::Daemon and RPC::PlServer apply, in particular

       Host and/or User dependent access control
       Host and/or User dependent encryption
       Changing UID and/or GID after binding to the port
       Running in a chroot() environment

       Additionally the server offers you query restrictions. Suggest the fol-
       lowing client list:

           'clients' => [
               { 'mask' => '^admin\.company\.com$',
                 'accept' => 1,
                 'users' => [ 'root', 'wwwrun' ],
               },
               {
                 'mask' => '^admin\.company\.com$',
                 'accept' => 1,
                 'users' => [ 'root', 'wwwrun' ],
                 'sql' => {
                      'select' => 'SELECT * FROM foo',
                      'insert' => 'INSERT INTO foo VALUES (?, ?, ?)'
                      }
               }

       then only the users root and wwwrun may connect from admin.company.com,
       executing arbitrary queries, but only wwwrun may connect from other
       hosts and is restricted to

           $sth->prepare("select");

       or

           $sth->prepare("insert");

       which in fact are "SELECT * FROM foo" or "INSERT INTO foo VALUES (?, ?,
       ?)".

AUTHOR

           Copyright (c) 1997    Jochen Wiedmann
                                 Am Eisteich 9
                                 72555 Metzingen
                                 Germany

                                 Email: joe@ispsoft.de
                                 Phone: +49 7123 14881

       The DBI::ProxyServer module is free software; you can redistribute it
       and/or modify it under the same terms as Perl itself. In particular
       permission is granted to Tim Bunce for distributing this as a part of
       the DBI.

ProxyServer(3)

NAME

SYNOPSIS

DESCRIPTION

OPTIONS

CONFIGURATION FILE

AUTHOR

SEE ALSO