It should be done by NAS. For example PPPoE and PPTP have lcp packets, If no response for some time from client to NAS then NAS decides that session is down and sends acct-stop packet to radius server. Radius server sets the corresponding record to SQL session table.
Or there is another method: depending on NAS type radiusd can connect to NAS and check activity of user session directly on NAS - this is more reliable source of information. See radcheck.pl. On Tue, 1 Jun 2010 16:24:54 +0700 Spacelee <fjct...@gmail.com> wrote: > > i want to limit user's behavior, such as a username can login only once at > the same time... > > 1、modifiy default and inner-tunnel in > > # Session database, used for checking Simultaneous-Use. Either the radutmp > # or rlm_sql module can handle this. > # The rlm_sql module is *much* faster > session { > #radutmp > > # See "Simultaneous Use Checking Querie" in sql.conf > sql > > } > 2、modify dialup.conf in etc/raddb/sql/mysql > > # Uncomment simul_count_query to enable simultaneous use checking > > simul_count_query = "SELECT COUNT(*) \ > FROM ${acct_table1} \ > WHERE username = '%{SQL-User-Name}' \ > AND acctstoptime IS NULL" > > 3、add a entry to the table radgorucheck > INSERT INTO `radgroupcheck` ( `id` , `GroupName` , `Attribute` , `op` , > `Value` ) > VALUES ( > NULL , ’user’, ’Simultaneous-Use’, ’:=’, ’1’ > ); > > 4. update the user "test" to the group "user" > > > i finally tried successfully, but if , i say if the radius server was down > suddenly or the user logout > improperly(such as he poweroff the computer directly). then the record will > still be record in the table as > he was still online ...so we need to modify the record, but how to ? can > freeradius judge it by itself, or > how to judge the user if offline ? > > -- > Spacelee > > > > -- > Spacelee -- Anton [WARM-RIPE] Stack ltd division head tel. 8 (3822) 555-797 - List info/subscribe/unsubscribe? See http://www.freeradius.org/list/users.html