rlm_sql_log(5) FreeRADIUS Module rlm_sql_log(5)NAMErlm_sql_log - FreeRADIUS Module
DESCRIPTION
The rlm_sql_log module appends the SQL queries in a log file which is
read later by the scripts/radsqlrelay Perl program.
The purpose of this module is to de-couple the storage of long-term
accounting data in SQL from "live" information needed by the RADIUS
server as it's running. If you are not using SQL for simultaneous
login restrictions (i.e. "sql" is not listed in the "session" section
of "radiusd.conf"), then this module allows you to log SQL queries to a
file, and then process them at your leisure.
The benefit of this approach is that for a busy server, the overhead of
performing SQL qeuries may be significant. Also, if the SQL databases
are large (as is typical for ones storing months of data), the INSERTs
and UPDATEs may take a relatively long time. Rather than slowing down
the RADIUS server by having it interact with a database, you can just
log the queries to a file, and then run those queries on another
machine, or at a time when the RADIUS server is typically lightly
loaded.
If the "sql" module is listed in the "session" section of
"radiusd.conf", then a similar system can still be used. In that case,
one database would be used to maintain "live" session information.
That database would be small, fast, and information would be deleted
from it when a user logs out. A second database would store long-term
accounting information, as described above.
LIMITATIONS
This module only performs the dynamic expansion of the variables found
in the SQL statements. No operation is executed on the database server.
(this would be done later by an external program) That means the module
is useful only with non-"SELECT" statements.
CONFIGURATION
The main configuration items to be aware of are the path of the log
file and the different SQL queries.
path An entry named "path" sets the full path of the file where the
SQL queries are recorded. (this variable is run through dynamic
string expansion, and can include FreeRADIUS variables to create
a dynamic filename)
Accounting queries
When a accounting record is processed, the module searches a
config entry keyed by the Acct-Status-Type attribute present in
the packet. For example, the SQL to be run on an accounting
start must be named "Start" in the configuration for the module.
Other usual values for Acct-Status-Type are "Stop", "Alive",
"Accounting-On", etc. See the VALUEs for Acct-Status-Type in
the dictionary.rfc2866 file.
Post-Auth query
An entry named "Post-Auth" sets the query to run during the
post-authentication stage. This query is mainly used to log
sessions where there may not be a later accounting packet.
modules {
...
sql_log {
path = "${radacctdir}/sql-relay"
acct_table = "radacct"
postauth_table = "radpostauth"
sql_user_name = "%{%{User-Name}:-DEFAULT}"
Start = "INSERT INTO ${acct_table} ..."
Stop = "UPDATE ${acct_table} SET ..."
Alive = "UPDATE ${acct_table} SET ..."
Post-Auth = "INSERT INTO ${postauth_table} ..."
}
...
}
accounting {
...
sql_log
...
}
post-auth {
...
sql_log
...
}
SECTIONS
accounting, post-auth
FILES
/etc/raddb/radiusd.conf
SEE ALSOradsqlrelay(8), radiusd(8), radiusd.conf(5)AUTHOR
Nicolas Baradakis <nicolas.baradakis@cegetel.net>
28 May 2005 rlm_sql_log(5)
