Writing exit programs for anonymous File Transfer Protocol

To use anonymous File Transfer Protocol (FTP) on the IBM® i operating system, you need to write two exit programs: FTP Server Logon exit program and FTP Server Request Validation exit program.

The FTP Server Logon exit program enables the ANONYMOUS user ID and forces the ANONYMOUS user to the public library or directory. The FTP Server Request Validation exit program restricts the commands, files, and directories or libraries that the ANONYMOUS user can use.

Exit points and exit point formats

The FTP server communicates with each exit program through a specific exit point. Parameters are passed between the server and the exit program. The format of the exchanged information is specified by an exit point format.

Program	Exit Point	Format
Server logon	QIBM_QTMF_SVR_LOGON	TCPL0100, TCPL0200, or TCPL0300. ¹
Request validation	QIBM_QTMF_SERVER_REQ	VLRQ0100
¹ An exit point might have more than one format, but an exit program can only be registered for one of the exit point formats. Examine each of these formats, then choose the one most appropriate for your system.

Example programs

Example programs are available to help you set up anonymous FTP on your system. You can use these examples as a starting point to build your own programs. By copying portions of the code from the examples, you can add them to programs that you write yourself. It is suggested that you run the example programs on a system other than your production system.

Note: These examples are for illustration purposes only. They do not contain enough features to run on a production machine as is. Feel free to use them as a starting point, or to use sections of code as you write your own programs.