Max length of SQl return string?

Arran Cudbard-Bell a.cudbardb at
Thu Nov 28 16:24:18 CET 2013

On 28 Nov 2013, at 14:54, Phil Mayers <p.mayers at> wrote:

> On 28/11/13 14:41, Alexander Silveröhrt wrote:
>> Hello,
>> We are doing a query which are supposed to comeback with a bunch of
>> subscriber accounts.
>>  update request {
>>                 Subscriber-Accounts := "%{sql-cisco-bng:SELECT
>> GROUP_CONCAT(username SEPARATOR ';') FROM radcheck WHERE username LIKE
>> '%{User-Name}%%'}"
>>  }
>> But it seems that there is a limit on how long the return string can be?
> Well, it's a radius attribute, so it's probably 253 bytes.
> Not sure if this limit is changed/removed in later versions of the server (e.g. for attributes which are internal, since they never go on the wire there's no protocol reason to limit their length)

It's... better. But there are many places static buffers are still used. The VP themselves now have a char pointer in the union, which points to a chunk of talloced memory in the VP context.

However, the xlat functions still need to be updated to do dynamic allocation, the limit is probably around 1000bytes. break on rlm_sql.c:144, p freespace and see :)

Arran Cudbard-Bell <a.cudbardb at>
FreeRADIUS Development Team

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