Dear Postgres Team, For my thesis about secure access control for database systems I need to implement a new decision algorithm for deciding if commands can be executed. For that algorithm to work I need to keep a stack that holds all the commands that are currently running, like a stacktrace. Each stack entry should contain the following: - Session user - User that runs the command (differs if we have security definer on triggers) - Command - Oid of trigger (if it is one) Now my problem consists of two steps: - First I need to decide if the algorithm supports the trigger type (only of LANGUAGE PLPGSQL). - Second I need to get the SQL command that the function will execute. What I tried was the following: In the file trigger.c I have found the location where the function is called. There I have access to the FunctionCallInfoData struct. I have seen on http://www.postgresql.org/docs/9.4/static/functions-info.html that there is a function which should return the functions definition as a Datum from the function oid. Now this is a bit weird since in the source code the function expects a pointer to a FunctionCallInfoData struct, which is no problem since I have access to both there. But when I pass the the pointer to the FunctionCallInfoData I always get an error stating that the cache lookup failed. I really don't know why, since when I investigate the struct fcinfo in gdb it has valid entries and also the oid of the function is accessible. I would be glad for some help here. Also another problem that I have at the moment is the following: My advisor wanted to have a uniform interface for access control, thus I have refactored the code of postgres and moved the relevant access control parts to a new module (src/backend/access_control). Now I have put the header files in src/include/access_control. What I don't quite get is how to get make a Makefile that delivers the object files as postgres needs them to link them to the main binary. Is it enough to make a Makefile that just creates the object files and leaves them in the correct folder for the root Makefile to pick them up or do I need to modify the root Makefile too? Thank you very much for your help in advance, for both problems I have tried many variations and researched quite much, but did not find a solution. Kind regards, Mohammed Ajil -- -------------------------------------------- Mohammed Ajil Bsc CS D-INFK ajilm@xxxxxxxxxxxxxxx -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
