diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:49:46 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:49:46 +0000 |
commit | 50b37d4a27d3295a29afca2286f1a5a086142cec (patch) | |
tree | 9212f763934ee090ef72d823f559f52ce387f268 /raddb/mods-config/sql/ippool/mssql/procedure.sql | |
parent | Initial commit. (diff) | |
download | freeradius-upstream.tar.xz freeradius-upstream.zip |
Adding upstream version 3.2.1+dfsg.upstream/3.2.1+dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'raddb/mods-config/sql/ippool/mssql/procedure.sql')
-rw-r--r-- | raddb/mods-config/sql/ippool/mssql/procedure.sql | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/raddb/mods-config/sql/ippool/mssql/procedure.sql b/raddb/mods-config/sql/ippool/mssql/procedure.sql new file mode 100644 index 0000000..5c621fb --- /dev/null +++ b/raddb/mods-config/sql/ippool/mssql/procedure.sql @@ -0,0 +1,137 @@ +-- +-- A stored procedure to reallocate a user's previous address, otherwise +-- provide a free address. +-- +-- Using this SP reduces the usual set dialogue of queries to a single +-- query: +-- +-- BEGIN TRAN; "SELECT FOR UPDATE"; UPDATE; COMMIT TRAN; -> EXEC sp +-- +-- The stored procedure is executed on an database instance within a single +-- round trip which often leads to reduced deadlocking and significant +-- performance improvements especially on multi-master clusters, perhaps even +-- by an order of magnitude or more. +-- +-- To use this stored procedure the corresponding queries.conf statements must +-- be configured as follows: +-- +-- allocate_begin = "" +-- allocate_find = "\ +-- EXEC fr_allocate_previous_or_new_framedipaddress \ +-- @v_pool_name = '%{control:${pool_name}}', \ +-- @v_username = '%{User-Name}', \ +-- @v_callingstationid = '%{Calling-Station-Id}', \ +-- @v_nasipaddress = '%{NAS-IP-Address}', \ +-- @v_pool_key = '${pool_key}', \ +-- @v_lease_duration = ${lease_duration} \ +-- " +-- allocate_update = "" +-- allocate_commit = "" +-- + +CREATE INDEX UserName_CallingStationId ON radippool(pool_name,UserName,CallingStationId) +GO + +CREATE OR ALTER PROCEDURE fr_allocate_previous_or_new_framedipaddress + @v_pool_name VARCHAR(64), + @v_username VARCHAR(64), + @v_callingstationid VARCHAR(64), + @v_nasipaddress VARCHAR(15), + @v_pool_key VARCHAR(64), + @v_lease_duration INT +AS + BEGIN + + -- MS SQL lacks a "SELECT FOR UPDATE" statement, and its table + -- hints do not provide a direct means to implement the row-level + -- read lock needed to guarentee that concurrent queries do not + -- select the same Framed-IP-Address for allocation to distinct + -- users. + -- + -- The "WITH cte AS ( SELECT ... ) UPDATE cte ... OUTPUT INTO" + -- patterns in this procedure body compensate by wrapping + -- the SELECT in a synthetic UPDATE which locks the row. + + DECLARE @r_address_tab TABLE(id VARCHAR(15)); + DECLARE @r_address VARCHAR(15); + + BEGIN TRAN; + + -- Reissue an existing IP address lease when re-authenticating a session + -- + WITH cte AS ( + SELECT TOP(1) FramedIPAddress + FROM radippool WITH (xlock rowlock readpast) + WHERE pool_name = @v_pool_name + AND expiry_time > CURRENT_TIMESTAMP + AND NASIPAddress = @v_nasipaddress AND pool_key = @v_pool_key + ) + UPDATE cte + SET FramedIPAddress = FramedIPAddress + OUTPUT INSERTED.FramedIPAddress INTO @r_address_tab; + SELECT @r_address = id FROM @r_address_tab; + + -- Reissue an user's previous IP address, provided that the lease is + -- available (i.e. enable sticky IPs) + -- + -- When using this SELECT you should delete the one above. You must also + -- set allocate_clear = "" in queries.conf to persist the associations + -- for expired leases. + -- + -- WITH cte AS ( + -- SELECT TOP(1) FramedIPAddress + -- FROM radippool WITH (xlock rowlock readpast) + -- WHERE pool_name = @v_pool_name + -- AND NASIPAddress = @v_nasipaddress AND pool_key = @v_pool_key + -- ) + -- UPDATE cte + -- SET FramedIPAddress = FramedIPAddress + -- OUTPUT INSERTED.FramedIPAddress INTO @r_address_tab; + -- SELECT @r_address = id FROM @r_address_tab; + + -- If we didn't reallocate a previous address then pick the least + -- recently used address from the pool which maximises the likelihood + -- of re-assigning the other addresses to their recent user + -- + IF @r_address IS NULL + BEGIN + WITH cte AS ( + SELECT TOP(1) FramedIPAddress + FROM radippool WITH (xlock rowlock readpast) + WHERE pool_name = @v_pool_name + AND expiry_time < CURRENT_TIMESTAMP + ORDER BY + expiry_time + ) + UPDATE cte + SET FramedIPAddress = FramedIPAddress + OUTPUT INSERTED.FramedIPAddress INTO @r_address_tab; + SELECT @r_address = id FROM @r_address_tab; + END + + -- Return nothing if we failed to allocated an address + -- + IF @r_address IS NULL + BEGIN + COMMIT TRAN; + RETURN; + END + + -- Update the pool having allocated an IP address + -- + UPDATE radippool + SET + NASIPAddress = @v_nasipaddress, + pool_key = @v_pool_key, + CallingStationId = @v_callingstationid, + UserName = @v_username, + expiry_time = DATEADD(SECOND,@v_lease_duration,CURRENT_TIMESTAMP) + WHERE framedipaddress = @r_address; + + COMMIT TRAN; + + -- Return the address that we allocated + SELECT @r_address; + + END +GO |