Using Login Commands

An AFP client uses the following commands to get information about a file server and to open and close a session with it:

• FPGetSrvrInfo

• FPGetAuthMethods (deprecated)

• FPLogin and FPLoginExt

• FPLoginCont

• FPGetSrvrParms

• FPGetSessionToken

• FPDisconnectOldSession

• FPLogout

• FPMapID

• FPMapName

• FPChangePassword

• FPGetUserInfo

The AFP client sends the FPGetSrvrInfo command to obtain server information. The FPGetSrvrInfo command returns server information including the following server parameters: server name, machine type, AFP version strings, UAM strings, volume icon and mask, a bitmap of flags, and optionally, a list of available Open Directory names. For descriptions of server parameters, see FPGetSrvrInfo in the Reference section.

From the lists of AFP versions and UAMs that the server supports, the AFP client selects the highest AFP version and the most secure UAM that the AFP client supports. To establish a session with the file server, the AFP client includes the strings for the selected AFP version and UAM in an FPLogin or FPLoginExt command.

When calling FPLoginExt, the AFP client must specify the user name in UTF-8 encoding and specify the Open Directory domain in which the user can be found. (A user name specified in UTF-8 encoding is the same as a AFPName file name, except that there is no text encoding hint.)

In response to the FPLogin or FPLoginExt command, the server performs user authentication. Depending on the selected UAM, the entire user authentication process can involve one or more FPLoginCont commands to complete the authentication process with the server. A session is established between the file server and the AFP client when the authentication process completes successfully.

After a session is established, the AFP client must obtain a list of the server’s volumes. To obtain the list, the AFP client makes an FPGetSrvrParms command, which returns the number of volumes shared by the server, the names of the volumes, and whether they are password-protected.

The FPGetSessionToken command gets a reconnect token that the AFP client may later use if the session is disconnected unintentionally. In the case of an unintentional disconnection, the AFP client logs in again using the same user and authentication information that it used to log in previously, re-establishes the state of the connection, and sends an FPDisconnectOldSession command that passes the reconnect token to the server to tell it to release resources associated with the disconnected session.

When the AFP client user no longer needs to communicate with the server, the AFP client issues an FPLogout command to terminate the session.

The FPMapID and FPMapName commands are used for directory access control. The FPMapID command obtains the user or group name corresponding to a given User or Group ID. The FPMapName command converts a user or group name to the corresponding User or Group ID.

The FPChangePassword command changes a user’s password.

The FPGetUserInfo command retrieves information about a user.

The FPGetSrvrMsg command retrieves log in and server messages from the server.