| [9] | 1 | .\" Copyright (c) 1985 Regents of the University of California.
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| 2 | .\" All rights reserved. The Berkeley software License Agreement
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| 3 | .\" specifies the terms and conditions for redistribution.
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| 4 | .\"
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| 5 | .\" @(#)ftpd.8c 6.4 (Berkeley) 5/28/86
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| 6 | .\"
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| 7 | .TH FTPD 8
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| 8 | .SH NAME
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| 9 | ftpd, in.ftpd, setup.anonftp \- DARPA Internet File Transfer Protocol server
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| 10 | .SH SYNOPSIS
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| 11 | .B "ftp stream tcp nowait root /usr/sbin/in.ftpd in.ftpd"
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| 12 | .br
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| 13 | .B "tcpd ftp /usr/sbin/in.ftpd"
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| 14 | .SH DESCRIPTION
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| 15 | .B Ftpd
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| 16 | is the DARPA Internet File Transfer Prototocol
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| 17 | server process. The server uses the TCP protocol
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| 18 | and listens at the port specified in the ``ftp''
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| 19 | service specification; see
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| 20 | .BR services (5).
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| 21 | .PP
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| 22 | The ftp server currently supports the following ftp
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| 23 | requests; case is not distinguished.
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| 24 | .PP
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| 25 | .nf
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| 26 | .ta \w'Request 'u
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| 27 | \fBRequest Description\fP
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| 28 | ABOR abort previous command
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| 29 | ACCT specify account (ignored)
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| 30 | ALLO allocate storage (vacuously)
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| 31 | APPE append to a file
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| 32 | CDUP change to parent of current working directory
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| 33 | CWD change working directory
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| 34 | DELE delete a file
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| 35 | HELP give help information
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| 36 | LIST give list files in a directory (``ls -lA'')
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| 37 | MKD make a directory
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| 38 | MODE specify data transfer \fImode\fP
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| 39 | NLST give name list of files in directory (``ls'')
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| 40 | NOOP do nothing
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| 41 | PASS specify password
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| 42 | PASV prepare for server-to-server transfer
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| 43 | PORT specify data connection port
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| 44 | PWD print the current working directory
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| 45 | QUIT terminate session
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| 46 | RETR retrieve a file
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| 47 | RMD remove a directory
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| 48 | RNFR specify rename-from file name
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| 49 | RNTO specify rename-to file name
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| 50 | STOR store a file
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| 51 | STOU store a file with a unique name
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| 52 | STRU specify data transfer \fIstructure\fP
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| 53 | TYPE specify data transfer \fItype\fP
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| 54 | USER specify user name
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| 55 | XCUP change to parent of current working directory
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| 56 | XCWD change working directory
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| 57 | XMKD make a directory
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| 58 | XPWD print the current working directory
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| 59 | XRMD remove a directory
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| 60 | .fi
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| 61 | .PP
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| 62 | The remaining ftp requests specified in Internet RFC 959 are
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| 63 | recognized, but not implemented.
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| 64 | .PP
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| 65 | The ftp server will abort an active file transfer only when the
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| 66 | ABOR command is preceded by a Telnet "Interrupt Process" (IP)
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| 67 | signal and a Telnet "Synch" signal in the command Telnet stream,
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| 68 | as described in Internet RFC 959.
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| 69 | .PP
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| 70 | .B Ftpd
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| 71 | interprets file names according to the ``globbing''
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| 72 | conventions used by
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| 73 | .BR csh (1).
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| 74 | This allows users to utilize the metacharacters ``*?[]{}~''.
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| 75 | .PP
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| 76 | .B Ftpd
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| 77 | authenticates users according to three rules.
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| 78 | .IP 1)
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| 79 | The user name must be in the password data base,
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| 80 | .BR /etc/passwd ,
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| 81 | and not have a null password. In this case a password
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| 82 | must be provided by the client before any file operations
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| 83 | may be performed.
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| 84 | .IP 2)
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| 85 | The user name must not appear in the file
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| 86 | .BR /etc/ftpusers .
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| 87 | .IP 3)
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| 88 | If the user name is ``anonymous'' or ``ftp'', an
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| 89 | anonymous ftp account must be present in the password
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| 90 | file (user ``ftp''). In this case the user is allowed
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| 91 | to log in by specifying any password (by convention this
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| 92 | is given as the client host's name).
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| 93 | .PP
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| 94 | In the last case,
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| 95 | .B ftpd
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| 96 | takes special measures to restrict the client's access privileges.
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| 97 | The server performs a
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| 98 | .BR chroot (2)
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| 99 | command to the home directory of the ``ftp'' user.
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| 100 | In order that system security is not breached, it is recommended
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| 101 | that the ``ftp'' subtree be constructed with care; the following
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| 102 | rules are recommended.
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| 103 | .IP ~ftp)
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| 104 | Make the home directory owned by ``ftp'' and unwritable by anyone.
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| 105 | .IP ~ftp/bin)
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| 106 | Make this directory owned by the super-user and unwritable by
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| 107 | anyone. The program
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| 108 | .BR ls (1)
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| 109 | must be present to support the list commands. This
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| 110 | program should have mode 111.
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| 111 | .IP ~ftp/etc)
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| 112 | This directory could be created, and could have
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| 113 | .BR passwd (5)
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| 114 | and
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| 115 | .BR group (5)
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| 116 | databases in it so that
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| 117 | .B ls
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| 118 | can show file ownership, but outsiders will grab your password file and
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| 119 | misuse it to spam you. So don't bother.
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| 120 | .IP ~ftp/pub)
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| 121 | Make this directory mode 755 and owned by the super-user. Create
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| 122 | directories in it owned by users if those users want to manage an
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| 123 | anonymous ftp directory.
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| 124 | .IP ~ftp/pub/incoming)
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| 125 | Optionally create this directory for anonymous uploads. Make it mode
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| 126 | 777. The FTP daemon will create files with mode 266, so remote users
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| 127 | can write a file, but only local users can do something with it.
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| 128 | .PP
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| 129 | The script
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| 130 | .B setup.anonftp
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| 131 | can be used to create or check an anonymous FTP tree.
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| 132 | .SH "SEE ALSO"
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| 133 | .BR ftp (1).
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| 134 | .SH BUGS
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| 135 | The anonymous account is inherently dangerous and should
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| 136 | avoided when possible.
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| 137 | .ig \" MINIX 3 doesn't have privileged port numbers (yet?)
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| 138 | .PP
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| 139 | The server must run as the super-user
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| 140 | to create sockets with privileged port numbers. It maintains
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| 141 | an effective user id of the logged in user, reverting to
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| 142 | the super-user only when binding addresses to sockets. The
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| 143 | possible security holes have been extensively
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| 144 | scrutinized, but are possibly incomplete.
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| 145 | ..
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