FTPD(8c,C) AIX TCP/IP User's Guide FTPD(8c,C)
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ftpd
PURPOSE
Provides the server function for the FTP protocol.
SYNTAX
+----------------+
/etc/ftpd ---| +------------+ |---|
+-| -d |-+
^| -l ||
|| -ttimeout ||
|| -v ||
|+------------+|
+--------------+
DESCRIPTION
The ftpd command is the DARPA Internet File Transfer Protocol server process.
The server uses the TCP protocol and listens at the port specified in the FTP
service specification (see "services"). The ftpd command is usually started by
inetd, a daemon, which listens on the ftp port for requests.
FLAGS
The ftpd command options are:
-d Writes debugging information to the syslog.
-l Logs each FTP session in the syslog.
-t Sets the inactivity timeout period to timeout, which is given in
seconds. There must be no whitespace between -t and timeout.
-v Equivalent to -d.
The FTP server timeouts an inactive session after 15 minutes. If the -t option
is specified, the inactivity timeout period is set to timeout.
The FTP server currently supports the following FTP requests. Case is not
distinguished.
Request Description
ABOR Abort previous command
ACCT Specify account (ignored)
ALLO Allocate storage (vacuously)
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APPE Append to a file
CDUP Change to parent of current working directory
CWD Change working directory
DELE Delete a file
HELP Give help information
LIST Give list files in a directory (ls -lg)
MKD Make a directory
MODE Specify data transfer mode
NLST Give name list of files in directory (ls)
NOOP Do nothing
PASS Specify password
PASV Prepare for server-to-server transfer
PORT Specify data connection port
PWD Print the current working directory
QUIT Terminate session
RETR Retrieve a file
RMD Remove a directory
RNFR Specify rename-from file name
RNTO Specify rename-to file name
STOR Store a file
STOU Store a file with a unique name
STRU Specify data transfer structure
TYPE Specify data transfer type
USER Specify user name
XCUP Change to parent of current working directory
XCWD Change working directory
XMKD Make a directory
XPWD Print the current working directory
XRMD Remove a directory
The FTP server stops an active file transfer only when the abor command is
preceded by a TELNET Interrupt Process (IP) signal and a TELNET SYNCH signal in
the command TELNET stream, as described in J. Postel and J. Reynolds etal File
Transfer Protocol.
This command interprets file names according to the globbing conventions used
by the C shell. This allows users to utilize the metacharacters * ? [ { } ].
The ftpd command verification users according to the following rules:
1. The user name must be in the password data base, /etc/passwd, and not have
a null password. In this case, a password must be provided by the client
before any file operations may be performed.
2. The user name must not appear in the file /etc/ftpusers.
Note: This file must be created by the system administrator.
3. The user must have a standard shell.
4. If the user name is anonymous or FTP, an anonymous FTP account must be
present in the password file (user FTP). In this case, the user is allowed
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to log in by specifying any password (by convention this is given as the
client host's name).
In the last case, ftpd takes special measures to restrict the client's access
privileges. The server performs a chroot system call, see AIX Operating System
Technical Reference for additional information, to the home directory of the
FTP user. In order that system security is not breached, it is recommended
that the FTP subtree be constructed with care. The following rules are
recommended.
ftp Make the home directory owned by FTP and unwritable by anyone.
ftp/bin Make this directory owned by the superuser and unwritable by anyone.
The program ls, refer to AIX Operating System Command Reference, must
be present to support the list commands. This program should have mode
111.
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ftp/etc Make this directory owned by the superuser and unwritable by anyone.
The files passwd and group (see AIX Operating System Technical
Reference) must be present for the ls command to work properly. These
files should be mode 444.
ftp/pub Make this directory mode 777 and owned by FTP. Users should then place
files, which are to be accessible via the anonymous account, in this
directory.
RELATED INFORMATION
In this book: "ftp"
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