%b build date of the ftp-proxy(8) program


 %d current system date in the form YYYY/MM/DD


 %h host name from gethostname(2) 


 %n network name from getdomainname(2) 


 %t current system time in the form HH:MM:SS


 %v version of the ftp-proxy(8) program


 %% a single percent sign

ActiveMaxDataPort

Both user and global context.  Defines the maximum local port
number used when connecting to the client's data port.  The
latter is either the same as the client's control port or the
one given in the most recent
PORT command.  If either minimum
or maximum value is not given, the program defaults to using
port 20, the
ftp-data port as per
RFC 959, for the local end of the socket if the proxy is running as root
(user ID 0) or to use a random port. See also
ActiveMinDataPort and
User options.

ActiveMinDataPort

Both user and global context.  Defines the minimum local port
number used when connecting to the client's data port.
See also
ActiveMaxDataPort and
User options.

AllowMagicUser

Global context only.  Defines a flag that when set to
yes, true, or
on allows the USER name to be optionally interpreted as
user[@host[:port]] where host overrides the
DestinationAddress and port the
DestinationPort directive below. It should only be activated with "trusted"
users, like in an outgoing FTP proxy scenario. See also the
UserMagicChar and
ForceMagicUser options.

AllowTransProxy

Global context only.  Defines a flag that when set to
yes, true, or
on allows to use the proxy as transparent proxy for outgoing ftp.
To get it working you also have to redirect client requests on
a gateway or firewall host (i.e. via ipchains) to the ftp-proxy.
It should only be activated with "trusted" users, like in an
outgoing FTP proxy scenario. You can combine this with the
AllowMagicUser option.

DenyMessage

Global context only.  Defines the name of a file which prevents
any successful login if it exists, even if it is empty.  The
file contents will be sent to the client, each line prefixed
with
'421-' and with variable substitution applied.  The whole file is
followed by a line starting with
'421 ' followed by the
DenyString below.  After sending the connection is closed.  If no such file
exists, the deny mechanism is not triggered altogether.  See also
DenyString option.

DenyString

Global context only.  Defines a string that will be displayed to
clients, prefixed with
'421 ' and variable substitution applied, if and only if a
DenyMessage file exists.  The default is
'Service not available'. See also
DenyMessage option.

DestinationAddress

Both user and global context.  Defines where to redirect incoming
FTP traffic.  Can be given as either dotted decimal IP address or
as DNS host name.  Please note that the global section must always
contain this option as a basic sanity check.

DestinationMaxPort

Both user and global context.  Defines the maximum local port
number to be used when opening a connection to the FTP server.
Valid both for control and for data connections.  Defaults to
not binding prior to connecting and listening, so that the system
selects an arbitrary ephemeral port.  See also
DestinationMinPort option.

DestinationMinPort

Both user and global context.  Defines the minimum local port
number to be used when opening a connection to the FTP server.
See also
DestinationMaxPort option.

DestinationPort

Both user and global context.  Defines the FTP server's control
port where the proxy itself will connect.  This option can either
be given as a numeric value or as the service name retrieved by
getservbyname(3) and defaults to port 21, the
ftp port as per
RFC 959.

DestinationTransferMode

Both user and global context.  Defines the FTP transfer mode to
be used from the proxy to the server.  Legal values are
active, passive, or
client. The latter means to follow the mode the client is using.  The
default value is
client.

FailResetsPasv

Global context only.  Defines the action that is taken when a
data transfer command is failed on the server side.
If the option is set to
yes, true, or
on the client data transfer socket will be closed and the transfer
mode set to the default (active-ftp).


If this flag is set to
no, false, or
off (which is also the default) the socket can be reused for the
next data transfer command in passive mode. This options is
a workaround for Netscape (4.x) clients, that sends a second
data transfer command if the first is failed, while the user
clicks on a symbolic link pointing to a directory.


Note, that this behavior may break the RFC definitions.

ForceMagicUser

Global context only. Same as AllowMagicUser, but makes the
host and port portion mandatory.

ForkLimit

Global context only. Limits the number of incoming client
connections per minute in daemon mode - it defaults to 40
connections per minute.

Group

Global context only.  Defines the UNIX style group ID which is
set by the process before it serves clients.  Default is to
keep the current real group ID.

LDAPAuthDN

Global context only.  Defines a different base distinguished
name that is used when accessing an LDAP directory for user
authentication purposes. It defaults to the value of
LDAPBaseDN. See also
LDAPAuthPWAttr, LDAPAuthPWType, LDAPAuthOKFlag, UserAuthType, LDAPBindDN options.

LDAPAuthOKFlag

Global context only.  Defines an attribute and its value as
attr=value string, i.e. userEnabled=yes, that will be checked while user
authentication in the directory tree specified using
LDAPAuthDN or
LDAPBaseDN. Defaults to an empty string - no flag check used.

LDAPAuthPWAttr

Global context only.  Defines the LDAP password attribute name
used for user authentication.


A common used attribute name is
userPassword. Defaults to an empty string - password authentication disabled.
See also
LDAPAuthPWType option.

LDAPAuthPWType

Global context only.  Defines the LDAP password type / format
and a minimal allowed password length expected as value for
attribute name specified using
LDAPAuthPWAttr.

Valid values are
plain, crypt, {crypt} followed by one number
0-9, i.e.
{crypt}7, plain9 or
plain.

If no minimum length specified the default minimum length of 5
characters is used.


A password type {crypt} means, the password value in the LDAP
directory is prefixed by the {crypt} scheme specification. Other
password schemes, i.e. MD5, are not supported at the moment.


Crypted passwords are only avaliable, if the proxy is compiled
with crypt support - see also
--with-crypt compile time option in configure script.


If the password (without scheme prefix) stored in LDAP directory
is
* or
! the account is disabled and the authentication fails.


Defaults to
plain (equivalent to plain5). See also the
LDAPAuthOKFlag.

LDAPBaseDN

Global context only.  Defines the base distinguished name that
is used when accessing an
LDAP directory, i.e. the root of the tree containing the FTP-Proxy
entries. Defaults to an empty string. If
UserAuthMagic is used, the authuser is used as user name for authentication
and user profiles, otherwise the normal ftp-user name.
See also
LDAPIdentifier, LDAPObjectClass, LDAPServer, UserAuthMagic options.

LDAPBindDN

Defines the distinguished name that is used to (simple) bind
the directory service. Defaults to an empty string (anonymous
bind). It is allowed to include one %s in this string, that
will be replaced with the FTP username or authuser if
UserAuthMagic is used.
See also
UserAuthMagic, LDAPAuthDN, LDAPBindPW options.

LDAPBindPW

Defines the credential (password) that is used to (simple) bind
the directory service using distinguished name given in the
LDAPBindDN option. Defaults to an empty string (anonymous bind).

LDAPIdentifier

Global context only.  Defines the identification attribute for
the access to the
LDAP directory.  This can be thought of as the primary key and
defaults to the string
CN which is short for "Common Name."  See also
LDAPBaseDN, LDAPObjectClass, LDAPServer options.

LDAPObjectClass

Global context only.  Defines the
LDAP object class which holds the entries for the FTP-Proxy access
control.  It is assumed that the possible user specific config
options exist as attributes within a record of this type.  There
is no default, but a value of
FTPProxyUser is recommended.  See also
LDAPBaseDN, LDAPIdentifier, LDAPServer options.

LDAPServer

Global context only.  This is the main option for using an
LDAP directory for retrieving user specific values.  If given, it
denotes the server (and possible port separated by a colon)
where FTP-Proxy will ask for the attributes.  The program will
bind as the anonymous user and try to retrieve the values from
the tree rooted at
LDAPBaseDN, having an object class of
LDAPObjectClass and identified by the
LDAPIdentifier. If the server cannot be reached, the program aborts.  If the
user cannot be found, the program falls back to the configuration
file, but will query only the global values and not the user
specific ones.  See also
LDAPBaseDN, LDAPBindDN, LDAPIdentifier, LDAPObjectClass options.

LDAPVersion

Global context only. Use this option to set the LDAP API version,
the proxy should set: 2 or 3. Use 0 to skip explicit version
setting and use library defaults.
Defaults is version 3 if supported by the library or 2 if not.


Note: OpenLDAP 2.x library defaults to version 2 bind, but the
OpenLDAP server refuses LDAPv2 bind by default.

Listen

Global context only.  Defines the address where the proxy itself
opens the listening port.  The default is
0.0.0.0 which instructs the server to bind to any address.  See also
Port option.

LogDestination

Global context only.  Defines the destination of the logging
information the program wishes to emit.  If the value starts
with a slash (/) it will be interpreted as an absolute path.
This file will be created and kept open during the lifetime
of the process.  The signal
SIGUSR1 can be sent to the (daemon) process in order to rotate this
log file.


A second way to provide logging is via a pipe and is employed
when the first character of the option is a pipe symbol (|).
In this case the rest of the value is interpreted as the name
of a UNIX command which is invoked and receives logging
information on its standard input.


The third way is to use the
syslog(3) service which is assumed for all other values.  The option value
is interpreted as the syslog facility while the severity is
defined by the various messages themselves.

LogLevel

Global context only. Defines the maximal level of logged messages.
The levels are, in order of decreasing importance:
FLT, ERR, WRN, INF, DBG

The default level is
INF. A
LogLevel set to
WRN causes, that only messages with levels
FLT, ERR, WRN will be logged.

MaxClients

Global context only.  Defines the maximum number of clients
the proxy will allow concurrently.  The valid range for this
option is 1 to 512, with a default of 64.  See also
MaxClientsMessage, MaxClientsString options.

MaxClientsMessage

Global context only.  Defines the name of a file that is displayed
to clients if their maximum number defined with
MaxClients has been exceeded. If no such file exists only the
MaxClientsString is displayed, else both the file and the string are transmitted.
After transmission the connection is terminated in any case.
When sending the file, each line is prefixed with
'421-' and variable substitution is applied to it.  See also
MaxClients, MaxClientsString options.

MaxClientsString

Global context only.  Defines a string that will be displayed to
clients, prefixed with
'421 ' and variable substitution applied, if the maximum client number
has been exceeded.  The default is
'Service not available'. See also
MaxClients, MaxClientsMessage options.

MaxRecvBufSize

Global context only. Defines the maximum number of bytes read from
socket at once while data transfers. Default is to read all data as
reported by the kernel.


It may be useful to set a limit (i.e. to 8192), if your proxy
machine uses two interfaces of different speed, i.e. the clients
are accessing the proxy via a high-speed interface (i.e. Fast-Ethernet)
and the proxy is accessing servers using a slower one (i.e. modem,
ISDN link) and your ftp-clients aborts the data transfers because
of a timeout.

PassiveMaxDataPort

Both user and global context.  Defines the maximum local port
number used when listening for the client's data connection.
This is the port number transmitted to the client in a
227 response to the
PASV command.
If either minimum or maximum value is not given, the program
defaults to let the system choose an arbitrary ephemeral
port.  See also
PassiveMinDataPort option.

PassiveMinDataPort

Both user and global context.  Defines the minimum local port
number used when listening for the client's data connection.
See also
PassiveMaxDataPort option.

PidFile

Global context only.  Defines the name of a process ID file where
FTP-Proxy will store its process ID if running as daemon.  The
file contents will be an ASCII string with a trailing newline.
On many operating systems such PID files will be located in the
/var/run directory.

Port

Global context only.  Defines the listening port where the
FTP-Proxy offers its service.  The port can be given as a
number or as a string suitable for retrieval by the
getservbyname(3) function.  It defaults to port 21, the
ftp port as per
RFC 959. See also
Listen option.

PortResetsPasv

Global context only.  Defines the action that is taken when a
PORT command is received while a passive port is open for listening.
If the option is set to
yes, true, or
on, (which is also the default) the socket will be closed and the
passive mode will be terminated (set to active-ftp). Setting
the option to
no, false, or
off does not cancel the listen.  This flag seems necessary because
the RFC is not really clear enough about the correct handling.

SameAddress

Both user and global context.  Defines a boolean value which
determines if the proxy is allowed to be included in so-called
third party server to server transfers.  In this situation
the client first sends a
PASV command to one server, then a
PORT command with the response code to the second server, and then
initiates the transfer with mutual transfer commands on the
two servers.  Specifying this option as
no, false, or
off allows FTP-Proxy to take part in such a transfer, while saying
yes, true, or
on (the default) will enforce that transfers can only take place
to/from the client itself.

ServerRoot

Defines the directory into which the FTP-Proxy performs a
chroot(2) in order to increase its security level. See also the
User and
Group options.


Note, that you have to copy needed libraries, configuration files,
etc into this directory first!

ServerType

Global context only.  Defines the mode in which the FTP-Proxy
is running if no command line switch
(-d/-i) has been provided.  The option value can either be
inetd in which case the proxy expects the client to be available at
standard input and output, or it can be
standalone which means the process will become a daemon, open the listening
port and fork child processes for all future connections.  The
child processes themselves will behave exactly as if they were
started from inetd.

SockBindRand

Global context only.  Defines a flag that when set to
yes, true, or
on , causes the proxy to use a random port in the specified range
via DestinationMinPort/MaxPort, ActiveMinPort/MaxDataPort,
PassiveMinDataPort/MaxDataPort instead of increment the port
number inside of this range. See also
DestinationMinPort, DestinationMaxPort, PassiveMinDataPort, PassiveMaxDataPort, ActiveMinPort, ActiveMaxPort options.

TCPWrapper

Global context only.  Defines a boolean value which is evaluated
by the FTP-Proxy running as a standalone daemon only.  Saying
yes, true, or
on activate the
TCP Wrapper library, whereas
no, false, or
off (the default) disable the function. See also
TCPWrapperName option.

TCPWrapperName

Global context only.  Use given
name for TCP-Wrapper checks instead of the program name (argv[0]).
See also
TCPWrapper option.

TimeOut

Both user and global context.  Defines the time in seconds after
which a client is assumed to be disconnected.  If no activity
is detected from the client after this time, the connection is
closed and the process terminates.  Default value is 900 seconds.

TranslatedAddress

Global context only.  Defines an IP address the server will use
in
227 replies to
PASV commands instead of its own address.  Usually the address where
the client connected to is taken, but this may not be appropriate
in situations where an NAT (Network Address Translation) device
is located in the way from the client to the proxy.  In this
situation the response can be changed to include the input address
of the NAT device.


The value for this option can be given as a DNS host name, as a
dotted decimal IP address, or as a file name.  The latter is
assumed when the name starts with a slash.  The file is opened
and scanned for the desired address.  Blank lines or lines starting
with '#' are ignored.  Reading the address from a file may be useful
for environments with masquerading and dynamic PPP connections.

User

Global context only.  Defines the UNIX style user ID which is
given to the process before it serves clients.  Default is to
keep the current real user ID.


If the proxy does not run as a privileged user (root, user ID 0),
it has no permission to bind a socket to port < 1024 or to preform
a
chroot(2) call.
See also
ActiveMinDataPort, ActiveMaxDataPort, ServerRoot options.

UserMagicChar or UseMagicChar

Global context only. Defines the character to use as separator
between user and host[:port] in the target setting of
AllowMagicUser Default is the '@' character. This allows you to use E-Mail
addresses as usernames for login to the ftp server
(i.e. me@mydomain%ftp.server:21 if you set it to %).

UserAuthMagic

Global context only. This is an authentication extension like
AllowMagicUser, allowing encoding of additional username and
password in the USER and PASS commands for authentication.
Valid values are
@auth for ftpuser@authuser[@host:port] and ftppass@authpass or
auth@ for authuser@[ftpuser@host:port] and authpass@ftppass. See also
LDAPBindDN, LDAPAuthType and
AllowMagicUser.

UserAuthType

Global context only. Defines the authentication mechanism
the proxy should use. Currently "ldap" is implemented to
support simple LDAP authentication using FTP username and
password from USER and PASS commands or the special
authuser and authpass encoded using
UserAuthMagic. See also
LDAPBindDN, LDAPAuthDN,  LDAPAuthPWAttr, LDAPAuthPWType, LDAPAuthOKFlag and
UserAuthMagic options.

UserNameRule

Global context only. Defines a regular expression rule for
validation of the user name (used for profile-setup and
authentication purposes). Defaults to:


^[[:alnum:]]+([%20@/\\\\._-][[:alnum:]]+)*$

It checks, if the first character is alphanumeric, optionally
followed by @/_-. or alphanumeric characters and ending with
an alphanumeric one.


This matches the usual cases inclusive E-Mail adresses and
"domain/user" names.


If regex support is not avaliable, above default rule is still
used and the option ignored. See also
ValidCommands option for regex encoding description.

ValidCommands

Both user and global context.  Defines the list of allowed
FTP commands for the client.  If this option is not installed,
there will be no restriction on the allowed commands.  But if
it is given, then all commands not on this list will be denied.
The list is space separated and may consist of the following
commands:
USER, PASS, ACCT, CWD,  CDUP, SMNT, QUIT, REIN, PORT, PASV, TYPE, STRU, MODE, RETR, STOR, STOU, APPE, ALLO, REST, RNFR, RNTO, ABOR, DELE, RMD,  MKD,  PWD,  LIST, NLST, SITE, SYST, STAT, HELP, NOOP, SIZE, MDTM, MLFL, MAIL, MSND, MSOM, MSAM, MRSQ, MRCP, XCWD, XMKD, XRMD, XPWD, XCUP, AUTH, APSV, EPRT, and
EPSV.

Each command can be followed by an optional equals sign and
POSIX 1003.2 Extended Regular Expression (RE) that describes the valid argument(s) for the command.  If the
whole string is to be matched, the pattern has to start with a
caret (^) and end with a dollar ($).  If no pattern follows a
command, its arguments are not checked.  An example for a name
would be the pattern
'^[a-zA-Z0-9]{1,512}$' for an argument that is mandatory and may consist of up to
512 letters or digits only.  A command that does not allow any
arguments can also easily be represented:
"'QUIT=^$'".

Please note that the regular expression is "pre-processed".
This means that a pattern in the form %xx will be interpreted
as a hexadecimal constant and will be replaced by the value
of that constant.  This looks a bit like HTML and helps to
include characters that might not be handled as expected, like
%20 for space or %5c (equivalent to %5C) for backslash.  The
space is especially important because it is the separator for
the commands within the list itself.


Please note also that regular expression support must have been
enabled with the
--with-regex switch during the
configure compilation step of the whole package.

WelcomeMessage

Global context only.  Defines the name of a file that will be
displayed to all clients as the first action when they open the
control connection.  Each line is prefixed with
'220-' and variable substitution is applied to it.  If no such file
exists it is silently ignored.  See also
WelcomeString option.

WelcomeString

Global context only.  Defines the string that is sent to the
client in order to start login negotiation.  The string is
prefixed with
'220 ' and variable substitution is applied to it.  If this option is
not given it defaults to the following string:


'%h FTP server (%v - %b) ready'.

See also
WelcomeMessage option.